Physicochemical evolution during rice straw and coal co-pyrolysis and its effect on co-gasification reactivity.

PubMed

Wei, Juntao; Gong, Yan; Guo, Qinghua; Ding, Lu; Wang, Fuchen; Yu, Guangsuo

2017-03-01

Physicochemical evolution (i.e. pore structure variation, carbon structure change and active AAEM transformation) during rice straw (RS) and Shenfu bituminous coal (SF) co-pyrolysis was quantitatively determined in this work. Moreover, the corresponding char gasification was conducted using a thermogravimetric analyzer (TGA) and relative reactivity was proposed to quantify the co-pyrolysis impact on co-gasification reactivity. The results showed that the development of pore structure in co-pyrolyzed chars was first inhibited and then enhanced with the decrease of SF proportion. The promotion effect of co-pyrolysis on order degree of co-pyrolyzed chars gradually weakened with increasing RS proportion. Co-pyrolysis mainly enhanced active K transformation in co-pyrolyzed chars and the promotion effect was alleviated with increasing RS proportion. The inhibition effect of co-pyrolysis on co-gasification reactivity weakened with increasing RS proportion and gasification temperature, which was mainly attributed to the combination of carbon structure evolution and active AAEM transformation in co-pyrolysis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Characteristics of the microwave pyrolysis and microwave CO2-assisted gasification of dewatered sewage sludge.

PubMed

Chun, Young Nam; Jeong, Byeo Ri

2017-07-28

Microwave drying-pyrolysis or drying-gasification characteristics were examined to convert sewage sludge into energy and resources. The gasification was carried out with carbon dioxide as a gasifying agent. The examination results were compared with those of the conventional heating-type electric furnace to compare both product characteristics. Through the pyrolysis or gasification, gas, tar, and char were generated as products. The produced gas was the largest component of each process, followed by the sludge char and the tar. During the pyrolysis process, the main components of the produced gas were hydrogen and carbon monoxide, with a small amount of hydrocarbons such as methane and ethylene. In the gasification process, however, the amount of carbon monoxide was greater than the amount of hydrogen. In microwave gasification, a large amount of heavy tar was produced. The largest amount of benzene in light tar was generated from the pyrolysis or gasification. Ammonia and hydrogen cyanide, which are precursors of NO x , were also generated. In the microwave heating method, the sludge char produced by pyrolysis and gasification had pores in the mesopore range. This could be explained that the gas obtained from the microwave pyrolysis or gasification of the wet sewage sludge can be used as an alternative fuel, but the tar and NO x precursors in the produced gas should be treated. Sludge char can be used as a biomass solid fuel or as a tar removal adsorbent if necessary.

Rapid co-pyrolysis of rice straw and a bituminous coal in a high-frequency furnace and gasification of the residual char.

PubMed

Yuan, Shuai; Dai, Zheng-hua; Zhou, Zhi-jie; Chen, Xue-li; Yu, Guang-suo; Wang, Fu-chen

2012-04-01

Rapid pyrolysis of rice straw (RS) and Shenfu bituminous coal (SB) separately, and rapid co-pyrolysis of RS/SB blends (mass ratio 1:4, 1:4, and 4:1), were carried out in a high-frequency furnace which can ensure both high heating rate and satisfying contact of fuel particles. Synergies between RS and SB during rapid co-pyrolysis were investigated. Intrinsic and morphological structures of residual char from co-pyrolysis, and their effects on gasification characteristics were also studied. Synergies occurred during rapid co-pyrolysis of RS and SB (RS/SB=1:4) resulting in decreasing char yields and increasing volatile yields. Synergies also happened during gasification of the char derived from co-pyrolysis of RS and SB with mass ratio of 1:4. The increased mass ratio of RS to SB did not only weaken synergies during co-pyrolysis, but significantly reduced the gasification rates of the co-pyrolysis char compared to the calculated values. Results can help to optimize co-conversion process of biomass/coal. Copyright © 2012 Elsevier Ltd. All rights reserved.

Combustion of Coal Char Particles under Fluidized Bed Oxyfiring Conditions

NASA Astrophysics Data System (ADS)

Scala, Fabrizio; Chirone, Riccardo

In this work combustion of single coal char particles was studied at 850°C in a lab-scale fluidized bed under simulated oxyfiring conditions. The burning rate of the particles was followed as a function of time by continuously measuring the outlet CO and O2 concentrations. Some preliminary evaluations on the significance of homogeneous CO oxidation in the reactor and of carbon gasification by CO2 in the char were also carried out. Results showed that the carbon burning rate increases with oxygen concentration and char particle size. The particle temperature is approximately equal to the bed one up to an oxygen concentration of 2%, but it is considerably higher for larger oxygen concentrations. Both CO2 gasification of char and homogeneous CO oxidation are not negligible. The gasification reaction rate is slow and it is likely to be controlled by intrinsic kinetics. During purely gasification conditions the extent of carbon loss due to particle attrition by abrasion (estimated from the carbon mass balance) appears to be more important than under combustion conditions.

Pyrolytic characteristics of biomass acid hydrolysis residue rich in lignin.

PubMed

Huang, Yanqin; Wei, Zhiguo; Yin, Xiuli; Wu, Chuangzhi

2012-01-01

Pyrolytic characteristics of acid hydrolysis residue (AHR) of corncob and pinewood (CAHR, WAHR) were investigated using a thermo-gravimetric analyzer (TGA) and a self-designed pyrolysis apparatus. Gasification reactivity of CAHR char was then examined using TGA and X-ray diffractometer. Result of TGA showed that thermal degradation curves of AHR descended smoothly along with temperature increasing from 150 °C to 850 °C, while a "sharp mass loss stage" for original biomass feedstock (OBF) was observed. Char yield from AHR (42.64-30.35 wt.%) was found to be much greater than that from OBF (26.4-19.15 wt.%). In addition, gasification reactivity of CAHR char was lower than that of corncob char, and there was big difference in micro-crystallite structure. It was also found that CAHR char reactivity decreased with pyrolysis temperature, but increased with pyrolysis heating rate and gasification temperature at 850-950 °C. Furthermore, CAHR char reactivity performed better under steam atmosphere than under CO2 atmosphere. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effect of fuel origin on synergy during co-gasification of biomass and coal in CO2.

PubMed

Zhang, Yan; Zheng, Yan; Yang, Mingjun; Song, Yongchen

2016-01-01

The effect of fuel origin on synergy in coal/biomass blends during co-gasification has been assessed using a congruent-mass thermogravimetry analysis (TGA) method. Results revealed that synergy occurs when ash residuals are formed, followed by an almost complete gasification of biomass. Potassium species in biomass ash play a catalytic role in promoting gasification reactivity of coal char, which is a direct consequence of synergy during co-gasification. The SEM-EDS spectra provided conclusive evidence that the transfer of potassium from biomass to the surface of coal char occurs during co-pyrolysis/gasification. Biomass ash rich in silica eliminated synergy in coal/biomass blends but not to the extent of inhibiting the reaction rate of the blended chars to make it slower than that of separated ones. The best result in terms of synergy was concluded to be the combination of low-ash coal and K-rich biomass. Copyright © 2015 Elsevier Ltd. All rights reserved.

Combustion and Gasification Properties of Plastics Particles.

PubMed

Zevenhoven, Ron; Karlsson, Magnus; Hupa, Mikko; Frankenhaeuser, Martin

1997-08-01

The combustion and gasification behavior of the most common plastics is studied and compared with conventional fuels such as coal, peat, and wood. The aim is to give background data for finding the optimum conditions for co-combustion or co-gasification of a conventional fuel with a certain amount of plastic-derived fuel. Atmospheric or pressurized fluidized bed co-combustion of conventional fuels and plastics are considered to be promising future options. The plastics investigated were poly(ethylene) (PE), poly(propylene) (PP), poly(styrene) (PS), and poly(vinyl chloride) (PVC). Some of the samples had a print or color. The reference fuels were Polish bituminous coal, Finnish peat, and Finnish pine wood. PE, PP, and PS were found to burn like oil. The particles shrank to a droplet and burned completely during the pyrolysis stage, leaving no char. Printing and coloring left a small portion of ash. PVC was the only plastic that produced a carbonaceous residue, and its timescales for heating, devolatilization, and char burning were of the same order as those for peat and wood, and much shorter for the other plastics studied. An important result is that char from PVC contains less than 1% chlorine,99% hydrocarbon. The gasification rate of PVC char (at 1 bar and 25 bar) was of the same order as that of char from coal. Peat-char and wood-char were gasified an order of magnitude faster.

Chemical characterization of chars developed from thermochemical treatment of Kentucky bluegrass seed screenings

USDA-ARS?s Scientific Manuscript database

Char produced from the gasification of post-seed harvest Kentucky bluegrass residues could be recycled to a cropping system as a soil amendment if chemical characterization determined that the gasification process had not produced or concentrated deleterious chemical or physical factors that might h...

Gasification of the char derived from distillation of granulated scrap tyres.

PubMed

López, Félix A; Centeno, Teresa A; Alguacil, Francisco José; Lobato, Belén; López-Delgado, Aurora; Fermoso, Javier

2012-04-01

This work reports the effect of pressure on the steam/oxygen gasification at 1000°C of the char derived from low temperature-pressure distillation of granulated scrap tyres (GST). The study was based on the analysis of gas production, carbon conversion, cold gas efficiency and the high heating value (HHV) of the product. For comparison, similar analyses were carried out for the gasification of coals with different rank. In spite of the relatively high ash (≈12 wt.%) and sulphur (≈3 wt.%) contents, the char produced in GST distillation can be regarded as a reasonable solid fuel with a calorific value of 34MJkg(-1). The combustion properties of the char (E(A)≈50 kJ mol(-1)), its temperature of self-heating (≈264°C), ignition temperature (≈459°C) and burn-out temperature (≈676°C) were found to be similar to those of a semi-anthracite. It is observed that the yield, H(2) and CO contents and HHV of the syngas produced from char gasification increase with pressure. At 0.1 MPa, 4.6 Nm(3)kg(char)(-1) of syngas was produced, containing 28%v/v of H(2) and CO and with a HHV around 3.7 MJ Nm(-3). At 1.5 MPa, the syngas yield achieved 4.9N m(3)kg(char)(-1) with 30%v/v of H(2)-CO and HHV of 4.1 MJ Nm(-3). Carbon conversion significantly increased from 87% at 0.1 MPa to 98% at 1.5 MPa. It is shown that the char derived from distillation of granulated scrap tyres can be further gasified to render a gas of considerable heating value, especially when gasification proceeds at high pressure. Copyright © 2011 Elsevier Ltd. All rights reserved.

Hydrogen production from biomass gasification using biochar as a catalyst/support.

PubMed

Yao, Dingding; Hu, Qiang; Wang, Daqian; Yang, Haiping; Wu, Chunfei; Wang, Xianhua; Chen, Hanping

2016-09-01

Biochar is a promising catalyst/support for biomass gasification. Hydrogen production from biomass steam gasification with biochar or Ni-based biochar has been investigated using a two stage fixed bed reactor. Commercial activated carbon was also studied as a comparison. Catalyst was prepared with an impregnation method and characterized by X-ray diffraction, specific surface and porosity analysis, X-ray fluorescence and scanning electron micrograph. The effects of gasification temperature, steam to biomass ratio, Ni loading and bio-char properties on catalyst activity in terms of hydrogen production were explored. The Ni/AC catalyst showed the best performance at gasification temperature of 800°C, S/B=4, Ni loading of 15wt.%. Texture and composition characterization of the catalysts suggested the interaction between volatiles and biochar promoted the reforming of pyrolysis volatiles. Cotton-char supported Ni exhibited the highest activity of H2 production (64.02vol.%, 92.08mgg(-1) biomass) from biomass gasification, while rice-char showed the lowest H2 production. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of torrefaction on the properties of rice straw high temperature pyrolysis char: Pore structure, aromaticity and gasification activity.

PubMed

Chen, Handing; Chen, Xueli; Qin, Yueqiang; Wei, Juntao; Liu, Haifeng

2017-03-01

The influence of torrefaction on the physicochemical characteristics of char during raw and water washed rice straw pyrolysis at 800-1200°C is investigated. Pore structure, aromaticity and gasification activity of pyrolysis chars are compared between raw and torrefied samples. For raw straw, BET specific surface area decreases with the increased torrefaction temperature at the same pyrolysis temperature and it approximately increases linearly with weight loss during pyrolysis. The different pore structure evolutions relate to the different volatile matters and pore structures between raw and torrefied straw. Torrefaction at higher temperature would bring about a lower graphitization degree of char during pyrolysis of raw straw. Pore structure and carbon crystalline structure evolutions of raw and torrefied water washed straw are different from these of raw straw during pyrolysis. For both raw and water washed straw, CO 2 gasification activities of pyrolysis chars are different between raw and torrefied samples. Copyright © 2016 Elsevier Ltd. All rights reserved.

Differences in gasification behaviors and related properties between entrained gasifier fly ash and coal char

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jing Gu; Shiyong Wu; Youqing Wu

2008-11-15

In the study, two fly ash samples from Texaco gasifiers were compared to coal char and the physical and chemical properties and reactivity of samples were investigated by scanning electron microscopy (SEM), SEM-energy-dispersive spectrometry (EDS), X-ray diffraction (XRD), N{sub 2} and CO{sub 2} adsorption method, and isothermal thermogravimetric analysis. The main results were obtained. The carbon content of gasified fly ashes exhibited 31-37%, which was less than the carbon content of 58-59% in the feed coal. The fly ashes exhibited higher Brunauer-Emmett-Teller (BET) surface area, richer meso- and micropores, more disordered carbon crystalline structure, and better CO{sub 2} gasification reactivitymore » than coal char. Ashes in fly ashes occurred to agglomerate into larger spherical grains, while those in coal char do not agglomerate. The minerals in fly ashes, especial alkali and alkaline-earth metals, had a catalytic effect on gasification reactivity of fly ash carbon. In the low-temperature range, the gasification process of fly ashes is mainly in chemical control, while in the high-temperature range, it is mainly in gas diffusion control, which was similar to coal char. In addition, the carbon in fly ashes was partially gasified and activated by water vapor and exhibited higher BET surface area and better gasification activity. Consequently, the fact that these carbons in fly ashes from entrained flow gasifiers are reclaimed and reused will be considered to be feasible. 15 refs., 7 figs., 5 tabs.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calo, J.M.; Suuberg, E.M.; Hradil, G.

This project is concerned with the study of the nature and behavior of ''active sites'' in char gasification. The research strategy involves use of model chars produced from the phenol-formaldehyde family of resins. These materials have been chosen since they have structural features similar to those in coals, but are much ''cleaner'' in that the concentration of potentially catalytic impurities can be maintained at low levels. It should be borne in mind that the objective of this work is to study non-catalytic gasification processes. In the previous quarterly report, we presented evidence that low temperature oxygen chemisorption does not providemore » a site-specific titration of active sites in chars; the uptake of oxygen by a cleaned char surface was unquestionably shown to be a function of temperature and oxygen partial pressure, and the importance of these variables differs from char to char. The fact that ''active surface area'' (ASA) determined by various arbitrary methods does seem to generally correlate with reactivity, seems to suggest that reactivities under various gasification and chemisorption conditions are correlated but that mechanisitic inferences cannot necessarily be drawn from such data. In the present report, we have extended the study of low temperature oxidation of chars, considering mass loss as well as oxygen uptake, since the two processes are essentially inseparable under a wide range of conditions. This work represents more than a simple attempt at trying to learn more about the oxygen chemisorption technique; rather it offers the opportunity to study the mechanism of oxygen attack on char under conditions that allow for better understanding of the fundamental processes. For these reasons, this work was performed in the pyrogasifier reactor (developed for CO/sub 2/ gasification reactivity studies), and complements the ongoing work in the TGA apparatus. 6 refs., 9 figs., 1 tab.« less

Synergistic combination of biomass torrefaction and co-gasification: Reactivity studies.

PubMed

Zhang, Yan; Geng, Ping; Liu, Rui

2017-12-01

Two typical biomass feedstocks obtained from woody wastes and agricultural residues were torrefied or mildly pyrolized in a fixed-bed reactor. Effects of the torrefaction conditions on product distributions, compositional and energetic properties of the solid products, char gasification reactivity, and co-gasification behavior between coal and torrefied solids were systematically investigated. Torrefaction pretreatment produced high quality bio-solids with not only increased energy density, but also concentrated alkali and alkaline earth metals (AAEM). As a consequence of greater retention of catalytic elements in the solid products, the chars derived from torrefied biomass exhibited a faster conversion than those derived from raw biomass during CO 2 gasification. Furthermore, co-gasification of coal/torrefied biomass blends exhibited stronger synergy compared to the coal/raw biomass blends. The results and insights provided by this study filled a gap in understanding synergy during co-gasification of coal and torrefied biomass. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synergistic effect on co-gasification reactivity of biomass-petroleum coke blended char.

PubMed

Wei, Juntao; Guo, Qinghua; Gong, Yan; Ding, Lu; Yu, Guangsuo

2017-06-01

In this work, effects of gasification temperature (900°C-1100°C) and blended ratio (3:1, 1:1, 1:3) on reactivity of petroleum coke and biomass co-gasification were studied in TGA. Quantification analysis of active AAEM transformation and in situ investigation of morphological structure variations in gasification were conducted respectively using inductively coupled plasma optical emission spectrometer and heating stage microscope to explore synergistic effect on co-gasification reactivity. The results indicated that char gasification reactivity was enhanced with increasing biomass proportion and gasification temperature. Synergistic effect on co-gasification reactivity was presented after complete generation of biomass ash, and gradually weakened with increasing temperature from 1000°C to 1100°C after reaching the most significant value at 1000°C. This phenomenon was well related with the appearance of molten biomass ash rich in glassy state potassium and the weakest inhibition effect on active potassium transformation during co-gasification at the temperature higher than 1000°C. Copyright © 2017 Elsevier Ltd. All rights reserved.

Gasification Characteristics of Coal/Biomass Mixed Fuels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mitchell, Reginald

2014-09-01

A research project was undertaken that had the overall objective of developing the models needed to accurately predict conversion rates of coal/biomass mixtures to synthesis gas under conditions relevant to a commercially-available coal gasification system configured to co-produce electric power as well as chemicals and liquid fuels. In our efforts to accomplish this goal, experiments were performed in an entrained flow reactor in order to produce coal and biomass chars at high heating rates and temperatures, typical of the heating rates and temperatures fuel particles experience in real systems. Mixed chars derived from coal/biomass mixtures containing up to 50% biomassmore » and the chars of the pure coal and biomass components were subjected to a matrix of reactivity tests in a pressurized thermogravimetric analyzer (TGA) in order to obtain data on mass loss rates as functions of gas temperature, pressure and composition as well as to obtain information on the variations in mass specific surface area during char conversion under kinetically-limited conditions. The experimental data were used as targets when determining the unknown parameters in the chemical reactivity and specific surface area models developed. These parameters included rate coefficients for the reactions in the reaction mechanism, enthalpies of formation and absolute entropies of adsorbed species formed on the carbonaceous surfaces, and pore structure coefficients in the model used to describe how the mass specific surface area of the char varies with conversion. So that the reactivity models can be used at high temperatures when mass transport processes impact char conversion rates, Thiele modulus – effectiveness factor relations were also derived for the reaction mechanisms developed. In addition, the reactivity model and a mode of conversion model were combined in a char-particle gasification model that includes the effects of chemical reaction and diffusion of reactive gases through particle pores and energy exchange between the particle and its environment. This char-particle gasification model is capable of predicting the average mass loss rates, sizes, apparent densities, specific surface areas, and temperatures of the char particles produced when co-firing coal and biomass to the type environments established in entrained flow gasifiers operating at high temperatures and elevated pressures.« less

Biomass waste gasification - can be the two stage process suitable for tar reduction and power generation?

PubMed

Sulc, Jindřich; Stojdl, Jiří; Richter, Miroslav; Popelka, Jan; Svoboda, Karel; Smetana, Jiří; Vacek, Jiří; Skoblja, Siarhei; Buryan, Petr

2012-04-01

A pilot scale gasification unit with novel co-current, updraft arrangement in the first stage and counter-current downdraft in the second stage was developed and exploited for studying effects of two stage gasification in comparison with one stage gasification of biomass (wood pellets) on fuel gas composition and attainable gas purity. Significant producer gas parameters (gas composition, heating value, content of tar compounds, content of inorganic gas impurities) were compared for the two stage and the one stage method of the gasification arrangement with only the upward moving bed (co-current updraft). The main novel features of the gasifier conception include grate-less reactor, upward moving bed of biomass particles (e.g. pellets) by means of a screw elevator with changeable rotational speed and gradual expanding diameter of the cylindrical reactor in the part above the upper end of the screw. The gasifier concept and arrangement are considered convenient for thermal power range 100-350 kW(th). The second stage of the gasifier served mainly for tar compounds destruction/reforming by increased temperature (around 950°C) and for gasification reaction of the fuel gas with char. The second stage used additional combustion of the fuel gas by preheated secondary air for attaining higher temperature and faster gasification of the remaining char from the first stage. The measurements of gas composition and tar compound contents confirmed superiority of the two stage gasification system, drastic decrease of aromatic compounds with two and higher number of benzene rings by 1-2 orders. On the other hand the two stage gasification (with overall ER=0.71) led to substantial reduction of gas heating value (LHV=3.15 MJ/Nm(3)), elevation of gas volume and increase of nitrogen content in fuel gas. The increased temperature (>950°C) at the entrance to the char bed caused also substantial decrease of ammonia content in fuel gas. The char with higher content of ash leaving the second stage presented only few mass% of the inlet biomass stream. Copyright © 2011 Elsevier Ltd. All rights reserved.

Method and apparatus for removing coarse unentrained char particles from the second stage of a two-stage coal gasifier

DOEpatents

Donath, Ernest E.

1976-01-01

A method and apparatus for removing oversized, unentrained char particles from a two-stage coal gasification process so as to prevent clogging or plugging of the communicating passage between the two gasification stages. In the first stage of the process, recycled process char passes upwardly while reacting with steam and oxygen to yield a first stage synthesis gas containing hydrogen and oxides of carbon. In the second stage, the synthesis gas passes upwardly with coal and steam which react to yield partially gasified char entrained in a second stage product gas containing methane, hydrogen, and oxides of carbon. Agglomerated char particles, which result from caking coal particles in the second stage and are too heavy to be entrained in the second stage product gas, are removed through an outlet in the bottom of the second stage, the particles being separated from smaller char particles by a counter-current of steam injected into the outlet.

Synergetic and inhibition effects in carbon dioxide gasification of blends of coals and biomass fuels of Indian origin.

PubMed

Satyam Naidu, V; Aghalayam, P; Jayanti, S

2016-06-01

The present study investigates the enhancement of CO2 gasification reactivity of coals due to the presence of catalytic elements in biomass such as K2O, CaO, Na2O and MgO. Co-gasification of three Indian coal chars with two biomass chars has been studied using isothermal thermogravimetric analysis (TGA) in CO2 environment at 900, 1000 and 1100°C. The conversion profiles have been used to establish synergetic or inhibitory effect on coal char reactivity by the presence of catalytic elements in biomass char by comparing the 90% conversion time with and without biomass. It is concluded that both biomasses exhibit synergistic behavior when blended with the three coals with casuarina being more synergetic than empty fruit bunch. Some inhibitory effect has been noted for the high ash coal at the highest temperature with higher 90% conversion time for the blend over pure coal, presumably due to diffusional control of the conversion rate. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mechanism of catalytic gasification of coal char. Quarterly technical report No. 5, October 1 to December 31, 1981

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wood, B. J.; Sancier, K. M.; Sheridan, D. R.

1982-02-26

The purpose of this study is to determine the mechanisms involved in the catalytic reactions of coal char and to identify the specific reaction steps and the parameters that control the catalytic process. The mode of action of the catalyst can be viewed in two ways. In one view, the catalyst participates in a reduction/oxidation cycle. The initial reaction between the carbon and the catalyst reduces the KOH to potassium accompanied by the gaseous reactant (H/sub 2/O or CO/sub 2/), producing further gaseous products (CO and H/sub 2/) and regenerating the initial state of the catalyst. In an alternative view,more » the catalyst initially forms an alkali metal addition compound with the carbon network of the char. The carbon-carbon bonds are altered by the formation of the metal-carbon linkage, possibly by electron transfer from the alkali metal atom to the carbon structure. As a result, the carbon structure is more readily attacked by the gaseous reactant (CO or H/sub 2/O) to produce the products of gasification. The following areas were investigated to provide experimental evidence for these catalytic modes of action: chemical kinetic measurements; thermodynamic measurements; free radicals in reacting carbon; electrical conductivity measurements. A detailed discussion on the catalyst-carbon interaction and on the reaction intermediate is provided.« less

Characterization and partitioning of the char ash collected after the processing of pine wood chips in a pilot-scale gasification unit

Treesearch

Thomas L. Eberhardt; Hui Pan; Leslie H. Groom; Chi-Leung So

2011-01-01

Southern yellow pine wood chips were used as the feedstock for a pilot-scale gasification unit coupled with a 25 kW generator. The pulp-grade wood chips were relatively free of bark and low in ash content. Processing this feedstock yielded a black/sooty by-product that upon combustion in a muffle furnace resulted in an ash content of about 48%. The term "char ash...

Gasification of algal biomass (Cladophora glomerata L.) with CO2/H2O/O2 in a circulating fluidized bed.

PubMed

Ebadi, Abdol Ghaffar; Hisoriev, Hikmat

2017-11-28

Gasification is one of the most important thermochemical routes to produce both synthesis gas (syngas) and chars. The quality of produced syngas wieldy depends on the operating conditions (temperature, residence time, heating rate, and gasifying agent), hydrodynamic properties of gasifier (particle size, minimum fluidization velocity, and gasifier size), and type of feedstock (coal, biomass, oil, and municipal solid wastes). In the present study, simulation of syngas production via circulating fluidized bed (CFB) gasification of algal biomass (Cladophora glomerata L.) at different gasifying agents and particle sizes was carried out, using Aspen Plus simulator. The model which has been validated by using experimental data of the technical literature was used to evaluate the influence of operating conditions on gas composition and performance parameters. The results show that biomass gasification using pure oxygen as the gasification agent has great potential to improve the caloric value of produced gas and performance indicators. It was also found that the produced gas caloric value, syngas yield, and performance parameters (CCE and CGE) increase with reaction temperature but are inversely proportional to the biomass particle size.

Biomass waste gasification - Can be the two stage process suitable for tar reduction and power generation?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sulc, Jindrich; Stojdl, Jiri; Richter, Miroslav

2012-04-15

Highlights: Black-Right-Pointing-Pointer Comparison of one stage (co-current) and two stage gasification of wood pellets. Black-Right-Pointing-Pointer Original arrangement with grate-less reactor and upward moving bed of the pellets. Black-Right-Pointing-Pointer Two stage gasification leads to drastic reduction of tar content in gas. Black-Right-Pointing-Pointer One stage gasification produces gas with higher LHV at lower overall ER. Black-Right-Pointing-Pointer Content of ammonia in gas is lower in two stage moving bed gasification. - Abstract: A pilot scale gasification unit with novel co-current, updraft arrangement in the first stage and counter-current downdraft in the second stage was developed and exploited for studying effects of two stagemore » gasification in comparison with one stage gasification of biomass (wood pellets) on fuel gas composition and attainable gas purity. Significant producer gas parameters (gas composition, heating value, content of tar compounds, content of inorganic gas impurities) were compared for the two stage and the one stage method of the gasification arrangement with only the upward moving bed (co-current updraft). The main novel features of the gasifier conception include grate-less reactor, upward moving bed of biomass particles (e.g. pellets) by means of a screw elevator with changeable rotational speed and gradual expanding diameter of the cylindrical reactor in the part above the upper end of the screw. The gasifier concept and arrangement are considered convenient for thermal power range 100-350 kW{sub th}. The second stage of the gasifier served mainly for tar compounds destruction/reforming by increased temperature (around 950 Degree-Sign C) and for gasification reaction of the fuel gas with char. The second stage used additional combustion of the fuel gas by preheated secondary air for attaining higher temperature and faster gasification of the remaining char from the first stage. The measurements of gas composition and tar compound contents confirmed superiority of the two stage gasification system, drastic decrease of aromatic compounds with two and higher number of benzene rings by 1-2 orders. On the other hand the two stage gasification (with overall ER = 0.71) led to substantial reduction of gas heating value (LHV = 3.15 MJ/Nm{sup 3}), elevation of gas volume and increase of nitrogen content in fuel gas. The increased temperature (>950 Degree-Sign C) at the entrance to the char bed caused also substantial decrease of ammonia content in fuel gas. The char with higher content of ash leaving the second stage presented only few mass% of the inlet biomass stream.« less

On the influence of the char gasification reactions on NO formation in flameless coal combustion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stadler, Hannes; Toporov, Dobrin; Foerster, Malte

2009-09-15

Flameless combustion is a well known measure to reduce NO{sub x} emissions in gas combustion but has not yet been fully adapted to pulverised coal combustion. Numerical predictions can provide detailed information on the combustion process thus playing a significant role in understanding the basic mechanisms for pollutant formation. In simulations of conventional pulverised coal combustion the gasification by CO{sub 2} or H{sub 2} O is usually omitted since its overall contribution to char oxidation is negligible compared to the oxidation with O{sub 2}. In flameless combustion, however, due to the strong recirculation of hot combustion products, primarily CO{sub 2}more » and H{sub 2} O, and the thereby reduced concentration of O{sub 2} in the reaction zone the local partial pressures of CO{sub 2} and H{sub 2} O become significantly higher than that for O{sub 2}. Therefore, the char reaction with CO{sub 2} and H{sub 2} O is being reconsidered. This paper presents a numerical study on the importance of these reactions on pollutant formation in flameless combustion. The numerical models used have been validated against experimental data. By varying the wall temperature and the burner excess air ratio, different cases have been investigated and the impact of considering gasification on the prediction of NO formation has been assessed. It was found that within the investigated ranges of these parameters the fraction of char being gasified increases up to 35%. This leads to changes in the local gas composition, primarily CO distribution, which in turn influences NO formation predictions. Considering gasification the prediction of NO emission is up to 40% lower than the predicted emissions without gasification reactions being taken into account. (author)« less

CO2 co-gasification of lower sulphur petroleum coke and sugar cane bagasse via TG-FTIR analysis technique.

PubMed

Edreis, Elbager M A; Luo, Guangqian; Li, Aijun; Chao, Chen; Hu, Hongyun; Zhang, Sen; Gui, Ben; Xiao, Li; Xu, Kai; Zhang, Pingan; Yao, Hong

2013-05-01

This study investigates the non-isothermal mechanism and kinetic behaviour of gasification of a lower sulphur petroleum coke, sugar cane bagasse and blends under carbon dioxide atmosphere conditions using the thermogravimetric analyser (TGA). The gas products were measured online with coupled Fourier transform infrared spectroscopy (FTIR). The achieved results explored that the sugar cane bagasse and blend gasification happened in two steps: at (<500 °C) the volatiles are released, and at (>700 °C) char gasification occurred, whereas the lower sulphur petroleum coke presented only one char gasification stage at (>800 °C). Significant interactions were observed in the whole process. Some solid-state mechanisms were studied by the Coats-Redfern method in order to observe the mechanisms responsible for the gasification of samples. The results show that the chemical first order reaction is the best responsible mechanism for whole process. The main released gases are CO2, CO, CH4, HCOOH, C6H5OH and CH3COOH. Copyright © 2013 Elsevier Ltd. All rights reserved.

Sugarcane vinasse CO2 gasification and release of ash-forming matters in CO2 and N2 atmospheres.

PubMed

Dirbeba, Meheretu Jaleta; Brink, Anders; DeMartini, Nikolai; Lindberg, Daniel; Hupa, Mikko

2016-10-01

Gasification of sugarcane vinasse in CO2 and the release of ash-forming matters in CO2 and N2 atmospheres were investigated using a differential scanning calorimetry and thermogravimetric analyzer (DSC-TGA) at temperatures between 600 and 800°C. The results showed that pyrolysis is the main mechanism for the release of the organics from vinasse. Release of ash-forming matters in the vinasse is the main cause for vinasse char weight losses in the TGA above 700°C. The losses are higher in N2 than in CO2, and increase considerably with temperature. CO2 gasification also consumes the carbon in the vinasse chars while suppressing alkali release. Alkali release was also significant due to volatilization of KCl and reduction of alkali sulfate and carbonate by carbon. The DSC measured thermal events during heating up in N2 atmosphere that correspond to predicted melting temperatures of alkali salts in the char. Copyright © 2016 Elsevier Ltd. All rights reserved.

Analysis of Hydrogen Generation through Thermochemical Gasification of Coconut Shell Using Thermodynamic Equilibrium Model Considering Char and Tar

PubMed Central

Rupesh, Shanmughom; Muraleedharan, Chandrasekharan; Arun, Palatel

2014-01-01

This work investigates the potential of coconut shell for air-steam gasification using thermodynamic equilibrium model. A thermodynamic equilibrium model considering tar and realistic char conversion was developed using MATLAB software to predict the product gas composition. After comparing it with experimental results the prediction capability of the model is enhanced by multiplying equilibrium constants with suitable coefficients. The modified model is used to study the effect of key process parameters like temperature, steam to biomass ratio, and equivalence ratio on product gas yield, composition, and heating value of syngas along with gasification efficiency. For a steam to biomass ratio of unity, the maximum mole fraction of hydrogen in the product gas is found to be 36.14% with a lower heating value of 7.49 MJ/Nm3 at a gasification temperature of 1500 K and equivalence ratio of 0.15. PMID:27433487

Analysis of Hydrogen Generation through Thermochemical Gasification of Coconut Shell Using Thermodynamic Equilibrium Model Considering Char and Tar.

PubMed

Rupesh, Shanmughom; Muraleedharan, Chandrasekharan; Arun, Palatel

2014-01-01

This work investigates the potential of coconut shell for air-steam gasification using thermodynamic equilibrium model. A thermodynamic equilibrium model considering tar and realistic char conversion was developed using MATLAB software to predict the product gas composition. After comparing it with experimental results the prediction capability of the model is enhanced by multiplying equilibrium constants with suitable coefficients. The modified model is used to study the effect of key process parameters like temperature, steam to biomass ratio, and equivalence ratio on product gas yield, composition, and heating value of syngas along with gasification efficiency. For a steam to biomass ratio of unity, the maximum mole fraction of hydrogen in the product gas is found to be 36.14% with a lower heating value of 7.49 MJ/Nm(3) at a gasification temperature of 1500 K and equivalence ratio of 0.15.

A Hydrodynamic Characteristic of a Dual Fluidized Bed Gasification

NASA Astrophysics Data System (ADS)

Sung, Yeon Kyung; Song, Jae Hun; Bang, Byung Ryeul; Yu, Tae U.; Lee, Uen Do

A cold model dual fluidized bed (DFB) reactor, consisting of two parallel interconnected bubbling and fast fluidized beds, was designed for developing an auto-thermal biomass gasifier. The combustor of this system burns the rest char of the gasification process and provides heat to the gasifier by circulating solids inventory. To find an optimal mixing and circulation of heavy solid inventory and light biomass and char materials, we investigate two types of DFB reactors which have different configuration of distributor and way-out location of the solid inventory and char materials in the gasifier. To determine appropriate operating conditions, we measured minimum fluidization velocity, solid circulation rate, axial solid holdup and gas bypassing between the lower loop seal and the gasifier.

Entrained-flow gasification at elevated pressure: Volume 1: Final technical report, March 1, 1985-April 30,1987

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hedman, P.O.; Smoot, L.D.; Smith, P.J.

1987-10-15

The general purpose of this research program was to develop a basic understanding of the physical and chemical processes in entrained coal gasification and to use the results to improve and evaluate an entrained gasification computer model. The first task included the collection and analysis of in-situ gasifier data at elevated pressures with three coal types (North Dakota lignite, Wyoming subbituminous and Illinois bituminous), the design, construction, and testing of new coal/oxygen/steam injectors with a fourth coal type (Utah bituminous), the collection of supporting turbulent fluid dynamic (LDV) data from cold-flow studies, and the investigation of the feasibility of usingmore » laser-based (CARS) daignostic instruments to make measurements in coal flames. The second task included improvements to the two-dimensional gasifier submodels, tabulation and evaluation of new coal devolatilization and char oxidation data for predictions, fundamental studies of turbulent particle dispersion, the development of improved numerical methods, and validation of the comprehensive model through comparison of predictions with experimental results. The third task was to transfer technical advances to industry and to METC through technical seminars, production of a detailed data book, code placement, and publication of results. Research results for these three tasks are summarized briefly here and presented in detail in the body of the report and in supporting references. 202 refs., 73 figs., 23 tabs.« less

Integrated mild gasification processing at the Homer City Electric Power Generating Station site. Final report, July 1989--June 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

Battista, J.J.; Zawadzki, E.A.

1993-07-01

A new process for the production of commercial grade coke, char, and carbon products has been evaluated by Penelec/NYSEG. The process, developed by Coal Technology Corporation, CTC, utilizes a unique screw reactor to produce a devolatilized char from a wide variety of coals for the production of commercial grade coke for use in blast furnaces, foundries, and other processes requiring high quality coke. This process is called the CTC Mild Gasification Process (MGP). The process economics are significantly enhanced by integrating the new technology into an existing power generating complex. Cost savings are realized by the coke producer, the cokemore » user, and the electric utility company. Site specific economic studies involving the Homer City Generating Station site in Western Pennsylvania, confirmed that an integrated MGP at the Homer City site, using coal fines produced at the Homer City Coal Preparation Plant, would reduce capital and operating costs significantly and would enable the HC Owners to eliminate thermal dryers, obtain low cost fuel in the form of combustible gases and liquids, and obtain lower cost replacement coal on the spot market. A previous report, identified as the Interim Report on the Project, details the technical and economic studies.« less

Study on the combined sewage sludge pyrolysis and gasification process: mass and energy balance.

PubMed

Wang, Zhonghui; Chen, Dezhen; Song, Xueding; Zhao, Lei

2012-12-01

A combined pyrolysis and gasification process for sewage sludge was studied in this paper for the purpose of its safe disposal with energy self-balance. Three sewage sludge samples with different dry basis lower heat values (LHV(db)) were used to evaluate the constraints on this combined process. Those samples were pre-dried and then pyrolysed within the temperature range of 400-550 degrees C. Afterwards, the char obtained from pyrolysis was gasified to produce fuel gas. The experimental results showed that the char yield ranged between 37.28 and 53.75 wt% of the dry sludge and it changed with ash content, pyrolysis temperature and LHV(db) of the sewage sludge. The gas from char gasification had a LHV around 5.31-5.65 MJ/Nm3, suggesting it can be utilized to supply energy in the sewage sludge drying and pyrolysis process. It was also found that energy balance in the combined process was affected by the LHV(db) of sewage sludge, moisture content and pyrolysis temperature. Higher LHV(db), lower moisture content and higher pyrolysis temperature benefit energy self-balance. For sewage sludge with a moisture content of 80 wt%, LHV(db) of sewage sludge should be higher than 18 MJ/kg and the pyrolysis temperature should be higher than 450 degrees C to maintain energy self-sufficiency when volatile from the pyrolysis process is the only energy supplier; when the LHV(db) was in the range of 14.65-18 MJ/kg, energy self-balance could be maintained in this combined process with fuel gas from char gasification as a supplementary fuel; auxiliary fuel was always needed if the LHV(db) was lower than 14.65 MJ/kg.

Evaluation of a Combined Cyclone and Gas Filtration System for Particulate Removal in the Gasification Process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rizzo, Jeffrey J.

2010-04-30

The Wabash gasification facility, owned and operated by sgSolutions LLC, is one of the largest single train solid fuel gasification facilities in the world capable of transforming 2,000 tons per day of petroleum coke or 2,600 tons per day of bituminous coal into synthetic gas for electrical power generation. The Wabash plant utilizes Phillips66 proprietary E-Gas (TM) Gasification Process to convert solid fuels such as petroleum coke or coal into synthetic gas that is fed to a combined cycle combustion turbine power generation facility. During plant startup in 1995, reliability issues were realized in the gas filtration portion of themore » gasification process. To address these issues, a slipstream test unit was constructed at the Wabash facility to test various filter designs, materials and process conditions for potential reliability improvement. The char filtration slipstream unit provided a way of testing new materials, maintenance procedures, and process changes without the risk of stopping commercial production in the facility. It also greatly reduced maintenance expenditures associated with full scale testing in the commercial plant. This char filtration slipstream unit was installed with assistance from the United States Department of Energy (built under DOE Contract No. DE-FC26-97FT34158) and began initial testing in November of 1997. It has proven to be extremely beneficial in the advancement of the E-Gas (TM) char removal technology by accurately predicting filter behavior and potential failure mechanisms that would occur in the commercial process. After completing four (4) years of testing various filter types and configurations on numerous gasification feed stocks, a decision was made to investigate the economic and reliability effects of using a particulate removal gas cyclone upstream of the current gas filtration unit. A paper study had indicated that there was a real potential to lower both installed capital and operating costs by implementing a char cyclonefiltration hybrid unit in the E-Gas (TM) gasification process. These reductions would help to keep the E-Gas (TM) technology competitive among other coal-fired power generation technologies. The Wabash combined cyclone and gas filtration slipstream test program was developed to provide design information, equipment specification and process control parameters of a hybrid cyclone and candle filter particulate removal system in the E-Gas (TM) gasification process that would provide the optimum performance and reliability for future commercial use. The test program objectives were as follows: 1. Evaluate the use of various cyclone materials of construction; 2. Establish the optimal cyclone efficiency that provides stable long term gas filter operation; 3. Determine the particle size distribution of the char separated by both the cyclone and candle filters. This will provide insight into cyclone efficiency and potential future plant design; 4. Determine the optimum filter media size requirements for the cyclone-filtration hybrid unit; 5. Determine the appropriate char transfer rates for both the cyclone and filtration portions of the hybrid unit; 6. Develop operating procedures for the cyclone-filtration hybrid unit; and, 7. Compare the installed capital cost of a scaled-up commercial cyclone-filtration hybrid unit to the current gas filtration design without a cyclone unit, such as currently exists at the Wabash facility.« less

Successful implementation of biochar carbon sequestration in European soils requires additional benefits and close collaboration with the bioenergy sector

NASA Astrophysics Data System (ADS)

Hauggaard-Nielsen, Henrik; Müller-Stöver, Dorette; Bruun, Esben W.; Petersen, Carsten T.

2014-05-01

Biochar soil application has been proposed as a measure to mitigate climate change and on the same time improve soil fertility by increased soil carbon sequestration. However, while on tropical soils the beneficial effects of biochar application on crop growth often become immediately apparent, it has been shown to be more difficult to demonstrate these effects on the more fertile soils in temperate regions. Therefore and because of the lack of carbon credits for farmers, it is necessary to link biochar application to additional benefits, both related to agricultural as well as to bioenergy production. Thermal gasification of biomass is an efficient (95% energy efficiency) and flexible way (able to cope with many different and otherwise difficult-to-handle biomass fuels) to generate bioenergy, while producing a valuable by-product - gasification biochar, containing recalcitrant carbon and essential crop nutrients. The use of the residual char product in agricultural soils will add value to the technology as well as result in additional soil benefits such as providing plant nutrients and improving soil water-holding capacity while reducing leaching risks. From a soil column (30 x 130 cm) experiment with gasification straw biochar amendment to coarse sandy subsoil increased root density of barley at critical depths in the soil profile reducing the mechanical resistance was shown, increasing yields, and the soil's capacity to store plant available water. Incorporation of residuals from a bioenergy technology like gasification show great potentials to reduce subsoil constraints increasing yield potentials on poor soils. Another advantage currently not appropriately utilized is recovery of phosphorus (P). In a recent pot experiments char products originating from low-temperature gasification of various biofuels were evaluated for their suitability as P fertilizers. Wheat straw gasification biochar generally had a low P content but a high P plant availability. To improve the fertilizer value while keeping a high carbon content in the char, the gasification of a combination of sewage sludge and wheat straw was implemented, resulting in a char product with a promising performance as a fertilizer and soil amendment. To implement gasification-biochar as a promising soil improver on the marked, independently of potential carbon market developments and CO2 certificates, stakeholder involvement is strongly required. In a newly established project consortium Bregentved Estate (one of Europe's largest agriculture companies) and the DONG Energy company (one of the leading energy groups in Northern Europe) are in a joint effort trying to integrate the economic matrix of i) biomass needed for bioenergy, ii) profit from energy generation and iii) soil advantages gained from biochar application. Experiments are conducted with a 6MW biomass gasification demonstration plant producing straw biochar used in field plots (12 m x 250 m).

Assessment of Advanced Coal Gasification Processes

NASA Technical Reports Server (NTRS)

McCarthy, John; Ferrall, Joseph; Charng, Thomas; Houseman, John

1981-01-01

This report represents a technical assessment of the following advanced coal gasification processes: AVCO High Throughput Gasification (HTG) Process; Bell Single-Stage High Mass Flux (HMF) Process; Cities Service/Rockwell (CS/R) Hydrogasification Process; Exxon Catalytic Coal Gasification (CCG) Process. Each process is evaluated for its potential to produce SNG from a bituminous coal. In addition to identifying the new technology these processes represent, key similarities/differences, strengths/weaknesses, and potential improvements to each process are identified. The AVCO HTG and the Bell HMF gasifiers share similarities with respect to: short residence time (SRT), high throughput rate, slagging and syngas as the initial raw product gas. The CS/R Hydrogasifier is also SRT but is non-slagging and produces a raw gas high in methane content. The Exxon CCG gasifier is a long residence time, catalytic, fluidbed reactor producing all of the raw product methane in the gasifier. The report makes the following assessments: 1) while each process has significant potential as coal gasifiers, the CS/R and Exxon processes are better suited for SNG production; 2) the Exxon process is the closest to a commercial level for near-term SNG production; and 3) the SRT processes require significant development including scale-up and turndown demonstration, char processing and/or utilization demonstration, and reactor control and safety features development.

Two-stage high temperature sludge gasification using the waste heat from hot blast furnace slags.

PubMed

Sun, Yongqi; Zhang, Zuotai; Liu, Lili; Wang, Xidong

2015-12-01

Nowadays, disposal of sewage sludge from wastewater treatment plants and recovery of waste heat from steel industry, become two important environmental issues and to integrate these two problems, a two-stage high temperature sludge gasification approach was investigated using the waste heat in hot slags herein. The whole process was divided into two stages, i.e., the low temperature sludge pyrolysis at ⩽ 900°C in argon agent and the high temperature char gasification at ⩾ 900°C in CO2 agent, during which the heat required was supplied by hot slags in different temperature ranges. Both the thermodynamic and kinetic mechanisms were identified and it was indicated that an Avrami-Erofeev model could best interpret the stage of char gasification. Furthermore, a schematic concept of this strategy was portrayed, based on which the potential CO yield and CO2 emission reduction achieved in China could be ∼1.92∗10(9)m(3) and 1.93∗10(6)t, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

Calcium silicate cement sorbent for H/sub 2/S removal and improved gasification processes. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoo, H.J.; Steinberg, M.

1983-10-01

Based on the studies performed on the agglomerated cement sorbent (ACS) pellet for in-situ desulfurization of gases and for improved gasification, in low and medium Btu fluidized bed coal gasifier (FBG) systems, the following conclusions can be drawn: (1) The pelletization method by a drum pelletizer is a good way of agglomerating large sized (>20 US mesh) ACS pellets having high sorbent performance. (2) The ACS pellets have a sulfur capture capacity of about 60% at 950/sup 0/C, are 100% regenerable, and so not lose reactivity during cyclic use. (3) The rate of sulfidation increases linearly with H/sub 2/S concentrationmore » in the feed gas stream up to 1.0%. (4) The rate of sulfidation first increases with temperature in an Arrhenius fashion in the temperature range of 800/sup 0/C to 1000/sup 0/C and then decreases with further increase in temperatures, giving rise to an optimum sulfidation temperature of about 1000/sup 0/C. (5) The gasification of coal or coal char either with CO/sub 2/ gas or by partial oxidation in a 40 mm ID FBG shows that the gasification efficiency of coal (or coal char) is very much enhanced with the ACS pellets and with Greer limestone over the coal (or coal char) alone. There is, however, not much difference between the ACS pellets and Greer limestone in the degree of enhancement. (6) The gasification of coal by partial oxidation with air to low Btu gas in a 1-inch coal-fired FBG unit shows that in the temperature range of 800/sup 0/ to 900/sup 0/C the efficiency of coal gasification is improved by as much as 40% when ACS pellets are used compared to the use of Greer limestone. At the same time the sulfur removal efficiency is increased from 50 to 65% with Greer limestone to over 95% with the ACS pellets.« less

Thermochemical characterization of pigeon pea stalk for its efficient utilization as an energy source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Katyal, S.K.; Iyer, P.V.R.

2000-05-01

Pigeon pea stalk is a widely available biomass species in India. In this article the potential use of pigeon pea stalk as a fuel source through thermochemical conversion methods such as combustion, gasification, and pyrolysis has been investigated through experimentation using a thermogravimetric analyzer and pilot-plant-scale equipment. It has been proposed that pigeon pea stalks can be effectively utilized in two ways. The first is to pyrolyze the material to produce value-added products such as char, tar, and fuel gas. The second alternative is to partially pyrolyze the material to remove tar-forming volatiles, followed by gasification of reactive char tomore » generate producer gas.« less

Leaching of major and trace elements from paper-plastic gasification chars: an experimental and modelling study.

PubMed

Fuente-Cuesta, A; Lopez-Anton, M A; Diaz-Somoano, M; Zomeren, A van; Cieplik, M; Martínez-Tarazona, M R

2013-01-15

The control of soluble metal species in the sub-product leachate generated in electricity production processes is of great concern from an environmental and health point of view. Unlike fly ash, the leaching behaviour of char materials has received little attention. Yet, these solids are captured together with fly ashes in the particle control devices of power plants and are emitted in the same way as by-products. The present study was carried out using two char samples: (i) a raw char and (ii) the same type of char employed in a previous study so that it could serve as a sorbent for mercury species in gas phase. The char samples were by-products (residues) that had been generated during the gasification of plastic and paper waste. The leachates were analyzed for the following elements: Al, Ca, Si, Mg, Ba, Cu, Ni, Pb, Zn, Mo and Hg. In addition, geochemical modelling of the leaching test results was employed to identify the underlying chemical processes that led to the release of toxic elements. The results showed that at alkaline pH values, sorption on the solid surfaces of the char was negligible due to the inorganic complexation of cations in the solution. When the char was used as mercury sorbent slight changes occurred on the reactive surface resulting in the modification of the binding of some elements. As the pH increased, complexation with dissolved organic matter played a more important role in the case of some elements such as Cu because of the greater concentration of dissolved organic matter in solution. Copyright © 2012 Elsevier B.V. All rights reserved.

Numerical simulation of waste tyres gasification.

PubMed

Janajreh, Isam; Raza, Syed Shabbar

2015-05-01

Gasification is a thermochemical pathway used to convert carbonaceous feedstock into syngas (CO and H2) in a deprived oxygen environment. The process can accommodate conventional feedstock such as coal, discarded waste including plastics, rubber, and mixed waste owing to the high reactor temperature (1000 °C-1600 °C). Pyrolysis is another conversion pathway, yet it is more selective to the feedstock owing to the low process temperature (350 °C-550 °C). Discarded tyres can be subjected to pyrolysis, however, the yield involves the formation of intermediate radicals additional to unconverted char. Gasification, however, owing to the higher temperature and shorter residence time, is more opted to follow quasi-equilibrium and being predictive. In this work, tyre crumbs are subjected to two levels of gasification modelling, i.e. equilibrium zero dimension and reactive multi-dimensional flow. The objective is to investigate the effect of the amount of oxidising agent on the conversion of tyre granules and syngas composition in a small 20 kW cylindrical gasifier. Initially the chemical compositions of several tyre samples are measured following the ASTM procedures for proximate and ultimate analysis as well as the heating value. The measured data are used to carry out equilibrium-based and reactive flow gasification. The result shows that both models are reasonably predictive averaging 50% gasification efficiency, the devolatilisation is less sensitive than the char conversion to the equivalence ratio as devolatilisation is always complete. In view of the high attained efficiency, it is suggested that the investigated tyre gasification system is economically viable. © The Author(s) 2015.

Changes imposed by pyrolysis, thermal gasification and incineration on composition and phosphorus fertilizer quality of municipal sewage sludge.

PubMed

Thomsen, Tobias Pape; Sárossy, Zsuzsa; Ahrenfeldt, Jesper; Henriksen, Ulrik B; Frandsen, Flemming J; Müller-Stöver, Dorette Sophie

2017-08-01

Fertilizer quality of ash and char from incineration, gasification and pyrolysis of a single municipal sewage sludge sample were investigated by comparing composition and phosphorus (P) plant availability. A process for post oxidation of gasification ash and pyrolysis char was developed and the oxidized materials were investigated as well. Sequential extraction with full elemental balances of the extracted pools as well as scanning electron microscopy with energy dispersive X-ray spectroscopy were used to investigate the mechanisms driving the observed differences in composition and P plant availability in a short-term soil incubation study. The compositional changes related mainly to differences in the proximate composition as well as to the release of especially nitrogen, sulfur, cadmium and to some extent, phosphorus (P). The cadmium load per unit of P was reduced with 75-85% in gasification processes and 10-15% in pyrolysis whereas no reduction was observed in incineration processes. The influence on other heavy metals was less pronounced. The plant availability of P in the substrates varied from almost zero to almost 100% of the plant availability of P in the untreated sludge. Post-oxidized slow pyrolysis char was found to be the substrate with the highest P fertilizer value while ash from commercial fluid bed sludge incineration had the lowest P fertilizer quality. The high P fertilizer value in the best substrate is suggested to be a function of several different mechanisms including structural surface changes and improvements in the association of P to especially magnesium, calcium and aluminum. Copyright © 2017 Elsevier Ltd. All rights reserved.

Production of Substitute Natural Gas from Coal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andrew Lucero

2009-01-31

The goal of this research program was to develop and demonstrate a novel gasification technology to produce substitute natural gas (SNG) from coal. The technology relies on a continuous sequential processing method that differs substantially from the historic methanation or hydro-gasification processing technologies. The thermo-chemistry relies on all the same reactions, but the processing sequences are different. The proposed concept is appropriate for western sub-bituminous coals, which tend to be composed of about half fixed carbon and about half volatile matter (dry ash-free basis). In the most general terms the process requires four steps (1) separating the fixed carbon frommore » the volatile matter (pyrolysis); (2) converting the volatile fraction into syngas (reforming); (3) reacting the syngas with heated carbon to make methane-rich fuel gas (methanation and hydro-gasification); and (4) generating process heat by combusting residual char (combustion). A key feature of this technology is that no oxygen plant is needed for char combustion.« less

Characterization of porosity via secondary reactions. Final technical report, 1 September 1991--30 November 1995

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calo, J.M.; Zhang, L.; Hall, P.J.

1997-09-01

A new approach to the study of porosity and porosity development in coal chars during gasification was investigated. This approach involves the establishment of the relationships between the amount and type of surface complexes evolved during post-activation temperature programmed desorption (TPD), and the porosity, as measured by gas adsorption and small angle neutron scattering (SANS) techniques. With this new method, the total surface area and micropore volume can be determined by the interpretation of post-activation TPD spectra. The primary conclusion of this work is that it is possible to predict total surface area and micropore volume from TPD spectra. Frommore » the extended random pore model, additional information about the micropore surface area, the nonmicroporous surface area, and the mean micropore size development as a function of reaction time (or burn-off) can also be predicted. Therefore, combining the TPD technique and the extended random pore model provides a new method for the characterization of char porosity.« less

Nitric Oxide Reduction over Sewage Sludge and Coal Chars at Conditions Relevant to Staged Fluidized Bed Combustion

NASA Astrophysics Data System (ADS)

Salatino, P.; Solimene, R.; Chirone, R.

The de-NOx potential of coal and of dried and pelletized sewage sludge, a waste-derived fuel candidate for cofiring with coal, is assessed. The experimental procedure is based on operation of a bench scale fluidized bed reactor where NO-doped nitrogen is contacted with batches of the fuel. A second type of experiment has been purposely designed to assess the loss of reactivity of chars toward gasification by NOx as char is heat-treated for pre-set times at temperatures typical of fluidized bed combustion. A simple phenomenological model is developed to shed light on the basic features of the interaction between heterogeneous char-NOx reaction and thermal annealing of the char.

Kinetic analysis of the interactions between calcium ferrite and coal char for chemical looping gasification applications: Identifying reduction routes and modes of oxygen transfer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Riley, Jarrett; Siriwardane, Ranjani; Tian, Hanjing

Chemical Looping Gasification (CLG) is an emerging technology that shows promise for efficient coal gasification by eliminating the need for energy intensive gas separations to achieve a non-nitrogen diluted syngas stream. Oxygen from oxygen carriers, such as CaFe 2O 4, are used for coal gasification in place of conventionally produced gaseous oxygen from cryogenic separation of air. These oxygen carriers are unique for their ability to selectively oxidize coal to form syngas and show limited reactivity with syngas components (H 2, CO). To gain a deeper understanding of how these unique oxygen carriers perform and to offer a first attemptmore » at the reaction modeling of solid mediated interactions of this nature, this study was carried out to determine the kinetic parameters associated with the selective oxidation of coal derived char (Wyodak and Illinois #6) with a metal ferrite, CaFe 2O 4. Using thermogravimetric analysis (TGA) coupled with mass spectrometry, the selective oxygen release of metal ferrite in the presence of char by proximal contact was examined. The application of combinatory model fitting approaches was used to describe controlling resistances during oxygen release. A combination of the modified shrinking core model (SCM) with planar oxygen ion diffusion control and reaction order based models was used for kinetic parameter determination. CaFe 2O 4 particle size plays a major role in the prevailing mode of oxygen release. Particle sizes on the order of 40–50 μm tend to favor first order kinetically controlled regimes independent of geometric and diffusion controls. The probability for oxygen ion diffusion controlling regimes increased when the particle size range of the oxygen carrier was increased up to 350 μm. Char type also impacted the prevalence of the controlling regime. Higher ranked chars react in a slower manner, limiting the gradient for oxygen ion release from the oxygen carrier. Activation energies determined for this process range from 120–200kJ/mol and oxygen ion diffusion coefficients are on the order of 10-8 cm 2/s. It is suggested that oxygen ion movement is regulated by lattice diffusion out of partially reduced phases (Ca 2Fe 2O 5) and through reduced outer layers composed of CaO and Fe. The controlled movement of oxygen ions influences the rate of carbon oxidation in the char and therefore the selectivity towards partial oxidation products, which are desirable in CLG applications.« less

Kinetic analysis of the interactions between calcium ferrite and coal char for chemical looping gasification applications: Identifying reduction routes and modes of oxygen transfer

DOE PAGES

Riley, Jarrett; Siriwardane, Ranjani; Tian, Hanjing; ...

2017-05-20

Chemical Looping Gasification (CLG) is an emerging technology that shows promise for efficient coal gasification by eliminating the need for energy intensive gas separations to achieve a non-nitrogen diluted syngas stream. Oxygen from oxygen carriers, such as CaFe 2O 4, are used for coal gasification in place of conventionally produced gaseous oxygen from cryogenic separation of air. These oxygen carriers are unique for their ability to selectively oxidize coal to form syngas and show limited reactivity with syngas components (H 2, CO). To gain a deeper understanding of how these unique oxygen carriers perform and to offer a first attemptmore » at the reaction modeling of solid mediated interactions of this nature, this study was carried out to determine the kinetic parameters associated with the selective oxidation of coal derived char (Wyodak and Illinois #6) with a metal ferrite, CaFe 2O 4. Using thermogravimetric analysis (TGA) coupled with mass spectrometry, the selective oxygen release of metal ferrite in the presence of char by proximal contact was examined. The application of combinatory model fitting approaches was used to describe controlling resistances during oxygen release. A combination of the modified shrinking core model (SCM) with planar oxygen ion diffusion control and reaction order based models was used for kinetic parameter determination. CaFe 2O 4 particle size plays a major role in the prevailing mode of oxygen release. Particle sizes on the order of 40–50 μm tend to favor first order kinetically controlled regimes independent of geometric and diffusion controls. The probability for oxygen ion diffusion controlling regimes increased when the particle size range of the oxygen carrier was increased up to 350 μm. Char type also impacted the prevalence of the controlling regime. Higher ranked chars react in a slower manner, limiting the gradient for oxygen ion release from the oxygen carrier. Activation energies determined for this process range from 120–200kJ/mol and oxygen ion diffusion coefficients are on the order of 10-8 cm 2/s. It is suggested that oxygen ion movement is regulated by lattice diffusion out of partially reduced phases (Ca 2Fe 2O 5) and through reduced outer layers composed of CaO and Fe. The controlled movement of oxygen ions influences the rate of carbon oxidation in the char and therefore the selectivity towards partial oxidation products, which are desirable in CLG applications.« less

Microwave-assisted pyrolysis of Mississippi coal: A comparative study with conventional pyrolysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdelsayed, Victor; Shekhawat, Dushyant; Smith, Mark W.

Pyrolysis conditions greatly affect the structure-reactivity relationship of char during coal gasification. Here, this work investigated the effect of temperature and microwave heating on the structural properties of the chars generated during pyrolysis, as well as gaseous and tar products. Results showed that microwave pyrolysis of Mississippi coal produced more gaseous products and less tars compared to conventional pyrolysis. Higher CO/CO 2 ratio (>1) was observed under microwave pyrolysis compared to conventional pyrolysis (CO/CO2 < 1), which may be explained by a greater extent of gasification between solid carbon and the CO 2 formed during microwave pyrolysis. Additionally, in microwavemore » pyrolysis, the oil tars generated exhibited lower concentrations of polar oxygenates, while the wax tars showed higher concentrations of non-polar alkanes, as observed from the intensity of CH vibrations in FTIR. The product compositions and FTIR analysis of the tars (oils and waxes) suggest that the microwave interacted preferentially with these polar species, which have relatively higher dielectric properties compared to alkanes. The structure–reactivity relationship of the chars produced was also investigated using a variety of characterization tools such as XRD, BET, SEM, EDS, and FTIR. Finally, the char reactivity towards combustion suggested that microwave-produced chars have a higher thermal stability, likely due to lower O/C ratios, and could be utilized in the metallurgical industry.« less

Microwave-assisted pyrolysis of Mississippi coal: A comparative study with conventional pyrolysis

DOE PAGES

Abdelsayed, Victor; Shekhawat, Dushyant; Smith, Mark W.; ...

2018-01-13

Pyrolysis conditions greatly affect the structure-reactivity relationship of char during coal gasification. Here, this work investigated the effect of temperature and microwave heating on the structural properties of the chars generated during pyrolysis, as well as gaseous and tar products. Results showed that microwave pyrolysis of Mississippi coal produced more gaseous products and less tars compared to conventional pyrolysis. Higher CO/CO 2 ratio (>1) was observed under microwave pyrolysis compared to conventional pyrolysis (CO/CO2 < 1), which may be explained by a greater extent of gasification between solid carbon and the CO 2 formed during microwave pyrolysis. Additionally, in microwavemore » pyrolysis, the oil tars generated exhibited lower concentrations of polar oxygenates, while the wax tars showed higher concentrations of non-polar alkanes, as observed from the intensity of CH vibrations in FTIR. The product compositions and FTIR analysis of the tars (oils and waxes) suggest that the microwave interacted preferentially with these polar species, which have relatively higher dielectric properties compared to alkanes. The structure–reactivity relationship of the chars produced was also investigated using a variety of characterization tools such as XRD, BET, SEM, EDS, and FTIR. Finally, the char reactivity towards combustion suggested that microwave-produced chars have a higher thermal stability, likely due to lower O/C ratios, and could be utilized in the metallurgical industry.« less

Expansion of high-temperature; high-pressure data set for coal gasification. Fifth quarterly report, September 28-December 28, 1985

DOE Office of Scientific and Technical Information (OSTI.GOV)

Solomon, P.R.; Serio, M.A.; Hamblen, D.G.

1985-01-01

During the fifth quarter, the gas mixing station for the high pressure reactor (HPR) system was completed. This station allows us to make reproducible binary mixtures of any two gases. It will be used for pyrolysis experiments in helium/nitrogen or oxygen/nitrogen and gasification experiments in helium/nitrogen or oxygen/nitrogen and gasification experiments in carbon dioxide/nitrogen. In addition, work began on modifications of the HPR system for high pressure (600 psig) operation. A limited amount of data was taken with the HPR system due to the modifications for the mixing station. However, the test plan experiments for pyrolysis in mixtures of heliummore » and nitrogen were completed. In general, there is a slightly higher yield of volatiles and lower yield of char as the helium content (heating rate) increases. A new technique for measuring char reactivity resulted from an Army SBIR program and was further developed under our other METC Contract. It has also been used to characterize chars generated under the current program. It was evident that the severity of the thermal treatment had a direct effect on char reactivity. In this regard, rapid heating to a relatively low temperature was most favorable while slow heating to a high temperature was least favorable. With regard to pressure effects on reactivity, our preliminary data indicated that higher pressures produce chars lower initial reactivity. A total of four experiments were done in the heated tube reactor (HTR) at 60 psig, 800/sup 0/C maximum tube temperature. The trends are the same as observed in the atmospheric pressure experiments for the same tube temperature and cold gas velocity. During the past quarter, a particle temperature (PT) model was under development for the high pressure entrained flow reactor (HPR). 5 refs., 5 figs.« less

Characterization of cellulosic wastes and gasification products from chicken farms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joseph, Paul, E-mail: p.joseph@ulster.ac.uk; Tretsiakova-McNally, Svetlana; McKenna, Siobhan

Highlights: Black-Right-Pointing-Pointer The gas chromatography indicated the variable quality of the producer gas. Black-Right-Pointing-Pointer The char had appreciable NPK values, and can be used as a fertiliser. Black-Right-Pointing-Pointer The bio-oil produced was of poor quality, having high moisture content and low pH. Black-Right-Pointing-Pointer Mass and energy balances showed inadequate level energy recovery from the process. Black-Right-Pointing-Pointer Future work includes changing the operating parameters of the gasification unit. - Abstract: The current article focuses on gasification as a primary disposal solution for cellulosic wastes derived from chicken farms, and the possibility to recover energy from this process. Wood shavings and chickenmore » litter were characterized with a view to establishing their thermal parameters, compositional natures and calorific values. The main products obtained from the gasification of chicken litter, namely, producer gas, bio-oil and char, were also analysed in order to establish their potential as energy sources. The experimental protocol included bomb calorimetry, pyrolysis combustion flow calorimetry (PCFC), thermo-gravimetric analyses (TGA), differential scanning calorimetry (DSC), Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy, elemental analyses, X-ray diffraction (XRD), mineral content analyses and gas chromatography. The mass and energy balances of the gasification unit were also estimated. The results obtained confirmed that gasification is a viable method of chicken litter disposal. In addition to this, it is also possible to recover some energy from the process. However, energy content in the gas-phase was relatively low. This might be due to the low energy efficiency (19.6%) of the gasification unit, which could be improved by changing the operation parameters.« less

Characterization of products obtained from pyrolysis and steam gasification of wood waste, RDF, and RPF.

PubMed

Hwang, In-Hee; Kobayashi, Jun; Kawamoto, Katsuya

2014-02-01

Pyrolysis and steam gasification of woody biomass chip (WBC) obtained from construction and demolition wastes, refuse-derived fuel (RDF), and refuse paper and plastic fuel (RPF) were performed at various temperatures using a lab-scale instrument. The gas, liquid, and solid products were examined to determine their generation amounts, properties, and the carbon balance between raw material and products. The amount of product gas and its hydrogen concentration showed a considerable difference depending on pyrolysis and steam gasification at higher temperature. The reaction of steam and solid product, char, contributed to an increase in gas amount and hydrogen concentration. The amount of liquid products generated greatly depended on temperature rather than pyrolysis or steam gasification. The compositions of liquid product varied relying on raw materials used at 500°C but the polycyclic aromatic hydrocarbons became the major compounds at 900°C irrespective of the raw materials used. Almost fixed carbon (FC) of raw materials remained as solid products under pyrolysis condition whereas FC started to decompose at 700°C under steam gasification condition. For WBC, both char utilization by pyrolysis at low temperature (500°C) and syngas recovery by steam gasification at higher temperature (900°C) might be practical options. From the results of carbon balance of RDF and RPF, it was confirmed that the carbon conversion to liquid products conspicuously increased as the amount of plastic increased in the raw material. To recover feedstock from RPF, pyrolysis for oil recovery at low temperature (500°C) might be one of viable options. Steam gasification at 900°C could be an option but the method of tar reforming (e.g. catalyst utilization) should be considered. Copyright © 2013 Elsevier Ltd. All rights reserved.

Chars from gasification of coal and pine activated with K2CO3: acetaminophen and caffeine adsorption from aqueous solutions.

PubMed

Galhetas, Margarida; Mestre, Ana S; Pinto, Moisés L; Gulyurtlu, Ibrahim; Lopes, Helena; Carvalho, Ana P

2014-11-01

The high carbon contents and low toxicity levels of chars from coal and pine gasification provide an incentive to consider their use as precursors of porous carbons obtained by chemical activation with K2CO3. Given the chars characteristics, previous demineralization and thermal treatments were made, but no improvement on the solids properties was observed. The highest porosity development was obtained with the biomass derived char (Pi). This char sample produced porous materials with preparation yields near 50% along with high porosity development (ABET≈1500m(2)g(-1)). For calcinations at 800°C, the control of the experimental conditions allowed the preparation of samples with a micropore system formed almost exclusively by larger micropores. A mesopore network was developed only for samples calcined at 900°C. Kinetic and equilibrium acetaminophen and caffeine adsorption data, showed that the processes obey to a pseudo-second order kinetic equation and to the Langmuir model, respectively. The results of sample Pi/1:3/800/2 outperformed those of the commercial carbons. Acetaminophen adsorption process was ruled by the micropore size distribution of the carbons. The caffeine monolayer capacities suggest a very efficient packing of this molecule in samples presenting monomodal micropore size distribution. The surface chemistry seems to be the determinant factor that controls the affinity of caffeine towards the carbons. Copyright © 2014 Elsevier Inc. All rights reserved.

Non-slag co-gasification of biomass and coal in entrained-bed furnace

NASA Astrophysics Data System (ADS)

Itaya, Yoshinori; Suami, Akira; Kobayashi, Nobusuke

2018-02-01

Gasification is a promising candidate of processes to upgrade biomass and to yield clean gaseous fuel for utilization of renewable energy resources. However, a sufficient amount of biomass is not always available to operate a large scale of the plant. Co-gasification of biomass with coal is proposed as a solution of the problem. Tar emission is another subject during operation in shaft or kiln type of gasifiers employed conventionally for biomass. The present authors proposed co-gasification of biomass and coal in entrained-bed furnace, which is a representative process without tar emission under high temperature, but operated so to collect dust as flyash without molten slag formation. This paper presents the works performed on co-gasification performance of biomass and pulverized coal to apply to entrained-bed type of furnaces. At first, co-gasification of woody powder and pulverized coal examined using the lab-scale test furnace of the down-flow entrained bed showed that the maximum temperatures in the furnace was over 1500 K and the carbon conversion to gas achieved at higher efficiency than 80-90 percent although the residence time in the furnace was as short as a few seconds. Non-slag co-gasification was carried out successfully without slag formation in the furnace if coal containing ash with high fusion temperature was employed. The trend suggesting the effect of reaction rate enhancement of co-gasification was also observed. Secondary, an innovative sewage sludge upgrading system consisting of self-energy recovery processes was proposed to yield bio-dried sludge and to sequentially produce char without adding auxiliary fuel. Carbonization behavior of bio-dried sludge was evaluated through pyrolysis examination in a lab-scale quartz tube reactor. The thermal treatment of pyrolysis of sludge contributed to decomposition and removal of contaminant components such as nitrogen and sulfur. The gasification kinetics of sludge and coal was also determined by a thermogravimetric analysis. It was revealed that co-gasification rate of sludge and coal chars was influenced negatively due to high ash content in sludge.

A new mathematical solution for predicting char activation reactions

USGS Publications Warehouse

Rafsanjani, H.H.; Jamshidi, E.; Rostam-Abadi, M.

2002-01-01

The differential conservation equations that describe typical gas-solid reactions, such as activation of coal chars, yield a set of coupled second-order partial differential equations. The solution of these coupled equations by exact analytical methods is impossible. In addition, an approximate or exact solution only provides predictions for either reaction- or diffusion-controlling cases. A new mathematical solution, the quantize method (QM), was applied to predict the gasification rates of coal char when both chemical reaction and diffusion through the porous char are present. Carbon conversion rates predicted by the QM were in closer agreement with the experimental data than those predicted by the random pore model and the simple particle model. ?? 2002 Elsevier Science Ltd. All rights reserved.

Allothermal steam gasification of biomass in cyclic multi-compartment bubbling fluidized-bed gasifier/combustor - new reactor concept.

PubMed

Iliuta, Ion; Leclerc, Arnaud; Larachi, Faïçal

2010-05-01

A new reactor concept of allothermal cyclic multi-compartment fluidized bed steam biomass gasification is proposed and analyzed numerically. The concept combines space and time delocalization to approach an ideal allothermal gasifier. Thermochemical conversion of biomass in periodic time and space sequences of steam biomass gasification and char/biomass combustion is simulated in which the exothermic combustion compartments provide heat into an array of interspersed endothermic steam gasification compartments. This should enhance unit heat integration and thermal efficiency and procure N(2)-free biosyngas with recourse neither to oxygen addition in steam gasification nor contact between flue and syngas. The dynamic, one-dimensional, multi-component, non-isothermal model developed for this concept accounts for detailed solid and gas flow dynamics whereupon gasification/combustion reaction kinetics, thermal effects and freeboard-zone reactions were tied. Simulations suggest that allothermal operation could be achieved with switch periods in the range of a minute supporting practical feasibility for portable small-scale gasification units. Copyright 2009 Elsevier Ltd. All rights reserved.

Product Chemistry and Process Efficiency of Biomass Torrefaction, Pyrolysis and Gasification Studied by High-Throughput Techniques and Multivariate Analysis

NASA Astrophysics Data System (ADS)

Xiao, Li

Despite the great passion and endless efforts on development of renewable energy from biomass, the commercialization and scale up of biofuel production is still under pressure and facing challenges. New ideas and facilities are being tested around the world targeting at reducing cost and improving product value. Cutting edge technologies involving analytical chemistry, statistics analysis, industrial engineering, computer simulation, and mathematics modeling, etc. keep integrating modern elements into this classic research. One of those challenges of commercializing biofuel production is the complexity from chemical composition of biomass feedstock and the products. Because of this, feedstock selection and process optimization cannot be conducted efficiently. This dissertation attempts to further evaluate biomass thermal decomposition process using both traditional methods and advanced technique (Pyrolysis Molecular Beam Mass Spectrometry). Focus has been made on data base generation of thermal decomposition products from biomass at different temperatures, finding out the relationship between traditional methods and advanced techniques, evaluating process efficiency and optimizing reaction conditions, comparison of typically utilized biomass feedstock and new search on innovative species for economical viable feedstock preparation concepts, etc. Lab scale quartz tube reactors and 80il stainless steel sample cups coupled with auto-sampling system were utilized to simulate the complicated reactions happened in real fluidized or entrained flow reactors. Two main high throughput analytical techniques used are Near Infrared Spectroscopy (NIR) and Pyrolysis Molecular Beam Mass Spectrometry (Py-MBMS). Mass balance, carbon balance, and product distribution are presented in detail. Variations of thermal decomposition temperature range from 200°C to 950°C. Feedstocks used in the study involve typical hardwood and softwood (red oak, white oak, yellow poplar, loblolly pine), fast growing energy crops (switchgrass), and popular forage crop (alfalfa), as well as biochar derived from those materials and their mixtures. It demonstrated that Py-MBMS coupled with MVA could be used as fast analytical tools for the study of not only biomass composition but also its thermal decomposition behaviors. It found that the impact of biomass composition heavily depends on the thermal decomposition temperature because at different temperature, the composition of biomass decomposed and the impact of minerals on the decomposition reaction varies. At low temperature (200-500°C), organic compounds attribute to the majority of variation in thermal decomposition products. At higher temperature, inorganics dramatically changed the pyrolysis pathway of carbohydrates and possibly lignin. In gasification, gasification tar formation is also observed to be impacted by ash content in vapor and char. In real reactor, biochar structure also has interactions with other fractions to make the final pyrolysis and gasification product. Based on the evaluation of process efficiencies during torrefaction, temperature ranging from 275°C to 300°C with short residence time (<10min) are proposed to be optimal torrefaction conditions. 500°C is preferred to 700°C as primary pyrolysis temperature in two stage gasification because higher primary pyrolysis temperature resulted in more tar and less gasification char. Also, in terms of carbon yield, more carbon is lost in tar while less carbon is retained in gas product using 700°C as primary pyrolysis temperature. In addition, pyrolysis char is found to produce less tar and more gas during steam gasification compared with gasification of pyrolysis vapor. Thus it is suggested that torrefaction might be an efficient pretreatment for biomass gasification because it can largely improve the yield of pyrolysis char during the primary pyrolysis step of gasification thus reduce the total tar of the overall gasification products. Future work is suggested in the end.

Study on tar generated from downdraft gasification of oil palm fronds.

PubMed

Atnaw, Samson Mekbib; Kueh, Soo Chuan; Sulaiman, Shaharin Anwar

2014-01-01

One of the most challenging issues concerning the gasification of oil palm fronds (OPF) is the presence of tar and particulates formed during the process considering its high volatile matter content. In this study, a tar sampling train custom built based on standard tar sampling protocols was used to quantify the gravimetric concentration of tar (g/Nm3) in syngas produced from downdraft gasification of OPF. The amount of char, ash, and solid tar produced from the gasification process was measured in order to account for the mass and carbon conversion efficiency. Elemental analysis of the char and solid tar samples was done using ultimate analysis machine, while the relative concentration of the different compounds in the liquid tar was determined making use of a liquid gas chromatography (GC) unit. Average tar concentration of 4.928 g/Nm3 and 1.923 g/Nm3 was obtained for raw gas and cleaned gas samples, respectively. Tar concentration in the raw gas sample was found to be higher compared to results for other biomass materials, which could be attributed to the higher volatile matter percentage of OPF. Average cleaning efficiency of 61% which is comparable to that of sand bed filter and venturi scrubber cleaning systems reported in the literature was obtained for the cleaning system proposed in the current study.

Study on Tar Generated from Downdraft Gasification of Oil Palm Fronds

PubMed Central

Atnaw, Samson Mekbib; Kueh, Soo Chuan; Sulaiman, Shaharin Anwar

2014-01-01

One of the most challenging issues concerning the gasification of oil palm fronds (OPF) is the presence of tar and particulates formed during the process considering its high volatile matter content. In this study, a tar sampling train custom built based on standard tar sampling protocols was used to quantify the gravimetric concentration of tar (g/Nm3) in syngas produced from downdraft gasification of OPF. The amount of char, ash, and solid tar produced from the gasification process was measured in order to account for the mass and carbon conversion efficiency. Elemental analysis of the char and solid tar samples was done using ultimate analysis machine, while the relative concentration of the different compounds in the liquid tar was determined making use of a liquid gas chromatography (GC) unit. Average tar concentration of 4.928 g/Nm3 and 1.923 g/Nm3 was obtained for raw gas and cleaned gas samples, respectively. Tar concentration in the raw gas sample was found to be higher compared to results for other biomass materials, which could be attributed to the higher volatile matter percentage of OPF. Average cleaning efficiency of 61% which is comparable to that of sand bed filter and venturi scrubber cleaning systems reported in the literature was obtained for the cleaning system proposed in the current study. PMID:24526899

Kinetic modeling of the formation and growth of inorganic nano-particles during pulverized coal char combustion in O 2/N 2 and O 2/CO 2 atmospheres

DOE PAGES

Shaddix, Christopher R.; Niu, Yanqing; Hui, Shi'en; ...

2016-08-01

In this formation of nano-particles during coal char combustion, the vaporization of inorganic components in char and the subsequent homogeneous particle nucleation, heterogeneous condensation, coagulation, and coalescence play decisive roles. Furthermore, conventional measurements cannot provide detailed information on the dynamics of nano-particle formation and evolution, In this study, a sophisticated intrinsic char kinetics model that considers ash effects (including ash film formation, ash dilution, and ash vaporization acting in tandem), both oxidation and gasification by CO 2 and H 2O, homogeneous particle nucleation, heterogeneous vapor condensation, coagulation, and and coalescence mechanisms is developed and used to compare the temporal evolutionmore » of the number and size of nano-particles during coal char particle combustion as a function of char particle size, ash content, and oxygen content in O 2/N 2 and O 2/CO 2 atmospheres .« less

Kinetic modeling of the formation and growth of inorganic nano-particles during pulverized coal char combustion in O 2/N 2 and O 2/CO 2 atmospheres

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shaddix, Christopher R.; Niu, Yanqing; Hui, Shi'en

In this formation of nano-particles during coal char combustion, the vaporization of inorganic components in char and the subsequent homogeneous particle nucleation, heterogeneous condensation, coagulation, and coalescence play decisive roles. Furthermore, conventional measurements cannot provide detailed information on the dynamics of nano-particle formation and evolution, In this study, a sophisticated intrinsic char kinetics model that considers ash effects (including ash film formation, ash dilution, and ash vaporization acting in tandem), both oxidation and gasification by CO 2 and H 2O, homogeneous particle nucleation, heterogeneous vapor condensation, coagulation, and and coalescence mechanisms is developed and used to compare the temporal evolutionmore » of the number and size of nano-particles during coal char particle combustion as a function of char particle size, ash content, and oxygen content in O 2/N 2 and O 2/CO 2 atmospheres .« less

Comprehensive Model of Single Particle Pulverized Coal Combustion Extended to Oxy-Coal Conditions

DOE PAGES

Holland, Troy; Fletcher, Thomas H.

2017-02-22

Oxy-fired coal combustion is a promising potential carbon capture technology. Predictive CFD simulations are valuable tools in evaluating and deploying oxy-fuel and other carbon capture technologies either as retrofit technologies or for new construction. But, accurate predictive simulations require physically realistic submodels with low computational requirements. In particular, comprehensive char oxidation and gasification models have been developed that describe multiple reaction and diffusion processes. Our work extends a comprehensive char conversion code (CCK), which treats surface oxidation and gasification reactions as well as processes such as film diffusion, pore diffusion, ash encapsulation, and annealing. In this work several submodels inmore » the CCK code were updated with more realistic physics or otherwise extended to function in oxy-coal conditions. Improved submodels include the annealing model, the swelling model, the mode of burning parameter, and the kinetic model, as well as the addition of the chemical percolation devolatilization (CPD) model. We compare our results of the char combustion model to oxy-coal data, and further compared to parallel data sets near conventional conditions. A potential method to apply the detailed code in CFD work is given.« less

Comprehensive Model of Single Particle Pulverized Coal Combustion Extended to Oxy-Coal Conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holland, Troy; Fletcher, Thomas H.

Oxy-fired coal combustion is a promising potential carbon capture technology. Predictive CFD simulations are valuable tools in evaluating and deploying oxy-fuel and other carbon capture technologies either as retrofit technologies or for new construction. But, accurate predictive simulations require physically realistic submodels with low computational requirements. In particular, comprehensive char oxidation and gasification models have been developed that describe multiple reaction and diffusion processes. Our work extends a comprehensive char conversion code (CCK), which treats surface oxidation and gasification reactions as well as processes such as film diffusion, pore diffusion, ash encapsulation, and annealing. In this work several submodels inmore » the CCK code were updated with more realistic physics or otherwise extended to function in oxy-coal conditions. Improved submodels include the annealing model, the swelling model, the mode of burning parameter, and the kinetic model, as well as the addition of the chemical percolation devolatilization (CPD) model. We compare our results of the char combustion model to oxy-coal data, and further compared to parallel data sets near conventional conditions. A potential method to apply the detailed code in CFD work is given.« less

Second stage gasifier in staged gasification and integrated process

DOEpatents

Liu, Guohai; Vimalchand, Pannalal; Peng, Wan Wang

2015-10-06

A second stage gasification unit in a staged gasification integrated process flow scheme and operating methods are disclosed to gasify a wide range of low reactivity fuels. The inclusion of second stage gasification unit operating at high temperatures closer to ash fusion temperatures in the bed provides sufficient flexibility in unit configurations, operating conditions and methods to achieve an overall carbon conversion of over 95% for low reactivity materials such as bituminous and anthracite coals, petroleum residues and coke. The second stage gasification unit includes a stationary fluidized bed gasifier operating with a sufficiently turbulent bed of predefined inert bed material with lean char carbon content. The second stage gasifier fluidized bed is operated at relatively high temperatures up to 1400.degree. C. Steam and oxidant mixture can be injected to further increase the freeboard region operating temperature in the range of approximately from 50 to 100.degree. C. above the bed temperature.

Performance characteristics of a slagging gasifier for MHD combustor systems

NASA Technical Reports Server (NTRS)

Smith, K. O.

1979-01-01

The performance of a two stage, coal combustor concept for magnetohydrodynamic (MHD) systems was investigated analytically. The two stage MHD combustor is comprised of an entrained flow, slagging gasifier as the first stage, and a gas phase reactor as the second stage. The first stage was modeled by assuming instantaneous coal devolatilization, and volatiles combustion and char gasification by CO2 and H2O in plug flow. The second stage combustor was modeled assuming adiabatic instantaneous gas phase reactions. Of primary interest was the dependence of char gasification efficiency on first stage particle residence time. The influence of first stage stoichiometry, heat loss, coal moisture, coal size distribution, and degree of coal devolatilization on gasifier performance and second stage exhaust temperature was determined. Performance predictions indicate that particle residence times on the order of 500 msec would be required to achieve gasification efficiencies in the range of 90 to 95 percent. The use of a finer coal size distribution significantly reduces the required gasifier residence time for acceptable levels of fuel use efficiency. Residence time requirements are also decreased by increased levels of coal devolatilization. Combustor design efforts should maximize devolatilization by minimizing mixing times associated with coal injection.

Undergraduate research studies program at participating institutions of the HBCU Fossil Energy Consortium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhatia, S.C.; Cardelino, B.H.; Hall, J.H. Jr.

1990-01-31

This report consists of five quarterly progress reports from four participating universities. The titles of the projects are: Competition of NO and SO{sub 2} for OH generated within electrical aerosol analyzers; Dispersed iron catalysts for coal gasification; Catalytic gasification of coal chars by potassium sulfate and ferrous sulfate mixtures; Removal of certain toxic heavy metal ions in coal conversion process wastewaters; and Study of coal liquefaction catalysts. All reports have been indexed separately for inclusion on the data base. (CK)

Expansion of high-temperature; high-pressure data set for coal gasification: Sixth quarterly report, December 28, 1985-March 28, 1986

DOE Office of Scientific and Technical Information (OSTI.GOV)

Solomon, P.R.; Serio, M.A.; Hamblen, D.G.

1986-01-01

During the sixth quarter, work was completed on modifications of the high pressure reactor (HPR) system for higher pressure (600 psig) operation. A series of pyrolysis experiments was completed in the HPR using mixtures of nitrogen and oxygen at various pressures and compositions. The original intention of the O/sub 2//N/sub 2/ experiments was to examine the effects of oxygen on the pyrolysis product distribution and the char reactivity. Unfortunately, at the temperature, residence time and pressure used for most of the experiments in this series (817/sup 0/C, 0.47 s, 26 psig) nearly complete oxidation of the char and volatile productsmore » occurred. Additional CO/sub 2/ gasification experiments were done to provide a database for revising the test plan. These were done at a variety of temperatures, pressures and CO/sub 2/ concentrations. The reactor was then switched back to nitrogen and additional pyrolysis experiments were done at high pressure (300 psig). When it was observed that the material balance was falling off slightly, it was decided to repeat some of the previous pyrolysis experiments at low pressure. There appeared to be a small, but systematic, reduction in char recovery. We continued to do char reactivity and surface area measurements for chars using the new non-isothermal technique described in the Fifth Quarterly report. A comparison was made of the results for char, tar, and gas yields for 1 atm and 5 atm (60 psig) experiments in the HTR. The asymptotic yield of about 10% was similar for both sets of experiments. A comparison was also made of tar yields for the Montana Rosebud coal from experiments in the HPR and HTR. The observed tar yields were in good agreement for similar experimental conditions. A preliminary version of a particle temperature model for the HPR was completed during the past quarter. 9 refs., 2 figs., 3 tabs.« less

Hydrothermal carbonization of animal manures: Processes and energetics

USDA-ARS?s Scientific Manuscript database

Hydrothermal carbonization (HTC) is an emerging technology for thermochemically converting biomass and waste materials into value-added carbonaceous char called hydrochar. HTC is well suited to manage wet feedstocks streams because pre-drying prior to processing is not required as with gasification...

Co-gasification of biosolids with biomass: Thermogravimetric analysis and pilot scale study in a bubbling fluidized bed reactor.

PubMed

Yu, Ming Ming; Masnadi, Mohammad S; Grace, John R; Bi, Xiaotao T; Lim, C Jim; Li, Yonghua

2015-01-01

This work studied the feasibility of co-gasification of biosolids with biomass as a means of disposal with energy recovery. The kinetics study at 800°C showed that biomass, such as switchgrass, could catalyze the reactions because switchgrass ash contained a high proportion of potassium, an excellent catalyst for gasification. However, biosolids could also inhibit gasification due to interaction between biomass alkali/alkaline earth metals and biosolids clay minerals. In the pilot scale experiments, increasing the proportion of biosolids in the feedstock affected gasification performance negatively. Syngas yield and char conversion decreased from 1.38 to 0.47m(3)/kg and 82-36% respectively as the biosolids proportion in the fuel increased from 0% to 100%. Over the same range, the tar content increased from 10.3 to 200g/m(3), while the ammonia concentration increased from 1660 to 19,200ppmv. No more than 25% biosolids in the fuel feed is recommended to maintain a reasonable gasification. Copyright © 2014 Elsevier Ltd. All rights reserved.

Influence of the reactant carbon-hydrogen-oxygen composition on the key products of the direct gasification of dewatered sewage sludge in supercritical water.

PubMed

Gong, Miao; Zhu, Wei; Fan, Yujie; Zhang, Huiwen; Su, Ying

2016-05-01

The supercritical water gasification of ten different types of dewatered sewage sludges was investigated to understand the relationship between sludge properties and gasification products. Experiments were performed in a high-pressure autoclave at 400°C for 60 min. Results showed that gasification of sewage sludge in supercritical water consists mainly of a gasification reaction, a carbonization reaction and a persistent organic pollutants synthesis reaction. Changes in the reactant C/H/O composition have significant effects on the key gasification products. Total gas production increased with increasing C/H2O of the reactant. The char/coke content increased with increasing C/H ratio of the reactant. A decrease in the C/O ratio of the reactant led to a reduction in polycyclic aromatic hydrocarbon formation. This means that we can adjust the reactant C/H/O composition by adding carbon-, hydrogen-, and oxygen-containing substances such as coal, algae and H2O2 to optimize hydrogen production and to inhibit an undesired by-product formation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Potential method for gas production: high temperature co-pyrolysis of lignite and sewage sludge with vacuum reactor and long contact time.

PubMed

Yang, Xiao; Yuan, Chengyong; Xu, Jiao; Zhang, Weijiang

2015-03-01

Lignite and sewage sludge were co-pyrolyzed in a vacuum reactor with high temperature (900°C) and long contact time (more than 2h). Beneficial synergetic effect on gas yield was clearly observed. Gas yield of blend fuel was evidently higher than that of both parent fuels. The gas volume yield, gas lower heating value (LHV), fixed carbon conversion and H2/CO ratio were 1.42 Nm(3)/kg(blend fuel), 10.57 MJ/Nm(3), 96.64% and 0.88% respectively, which indicated this new method a feasible one for gas production. It was possible that sewage sludge acted as gasification agents (CO2 and H2O) and catalyst (alkali and alkaline earth metals) provider during co-pyrolysis, promoting CO2-char and H2O-char gasification which, as a result, invited the improvement of gas volume yield, gas lower heating value and fixed carbon conversion. Copyright © 2014 Elsevier Ltd. All rights reserved.

Stabilization of lead and copper by biochar amendments in arms range soils: Influence of biochar characteristics, soil property, and equilibrium conditions

USDA-ARS?s Scientific Manuscript database

Soil amendment of char products (biochar) from thermochemical processing (slow/fast pyrolysis and gasification) of biomass for biofuel production has received considerable interests for contaminant sorption, soil fertilization, and carbon sequestration. Of potential sites for biochar application, h...

Conversion of microwave pyrolysed ASR's char using high temperature agents.

PubMed

Donaj, Pawel; Blasiak, Wlodzimierz; Yang, Weihong; Forsgren, Christer

2011-01-15

Pyrolysis enables to recover metals and organic feedstock from waste conglomerates such as: automotive shredder residue (ASR). ASR as well as its pyrolysis solid products, is a morphologically and chemically varied mixture, containing mineral materials, including hazardous heavy metals. The aim of the work is to generate fundamental knowledge on the conversion of the organic residues of the solid products after ASR's microwave pyrolysis, treated at various temperatures and with two different types of gasifying agent: pure steam or 3% (v/v) of oxygen. The research is conducted using a lab-scale, plug-flow gasifier, with an integrated scale for analysing mass loss changes over time of experiment, serving as macro TG at 950, 850 and 760 °C. The reaction rate of char decomposition was investigated, based on carbon conversion during gasification and pyrolysis stage. It was found in both fractions that char conversion rate decreases with the rise of external gas temperature, regardless of the gasifying agent. No significant differences between the reaction rates undergoing with steam and oxygen for char decomposition has been observed. This abnormal char behaviour might have been caused by the inhibiting effects of ash, especially alkali metals on char activity or due to deformation of char structure during microwave heating. Copyright © 2010 Elsevier B.V. All rights reserved.

First Experiences with the New Chalmers Gasifier

NASA Astrophysics Data System (ADS)

Thunman, H.; Seemann, M. C.

During summer 2007 a 2-6 MWth indirect gasification section was integrated into the loop of the existing 82➀2 MWth circulating fluidized bed boiler at Chalmers University. With help of a particle distributor the gasification unit is connected to the loop after the cyclone. Hot bed material entrained from the boiler is so transferred to the gasifier providing the heat for the production of a nearly nitrogen free product gas. Non-gasified char is returned together with the bed material into the boiler and converted. Biomass can be fed into both sections; the boiler and the gasifier. The gasification is separated from the boiler via two loop seals and a particle distributer, directing particles either back to the boiler or into the gasification section. For that reason the CFB boiler can be operated even after the retrofit independently, just like before, or in combined combustion/gasification mode. This possibility keeps the risk for a retrofit low. As, furthermore, the investment costs for the integration are considerably lower than standalone gasification units of that size, the retrofit is an easy way to extend the potential of a CFB Boiler towards bi- and tri-generation (heat, power, fuel) and enter new markets.

The effect of chars and their water extractable organic carbon (WEOC) fractions on atrazine adsorption-desorption processes

NASA Astrophysics Data System (ADS)

Cavoski, I.; Jablonowski, N.; Burauel, P.; Miano, T.

2012-04-01

Chars are carbonaceous material produced from different type of biomass by pyrolysis. They are known as highly effective adsorbents for atrazine therefore limiting its degradation and its diffusion into the aqueous phase. The aim of the present work is to study the effects of different chars and char's derived WEOC on atrazine sorption-desorption processes. The five chars been used in this study derived from: 1) fast pyrolysis from hard wood (FP1); 2) flash pyrolysis from soft wood (FP2); 3) slow pyrolysis from deciduous wood (CC); 4) gasification from deciduous wood (GC) and 5) the market, purchased as activated charcoal standard (AC). Short-term batch equilibration tests were conducted to assess the sorption-desorption behavior of 14C-labeled atrazine on the chars, with a special focus on the desorption behavior using successive dilution method with six consecutive desorption step. Chars and their WEOC were physically and chemically characterized. Results demonstrate that biomass and pyrolysis process used to produce chars affect their physical and chemical properties, and atrazine adsorption-desorption behavior. Atrazine desorption resulted from the positive and competitive interactions between WEOC and chars surfaces. WEOC pool play important role in atrazine adsorption-desorption behavior. FP1 and FP2 with higher concentration of WEOC showed higher desorption rates, whereas GC, CC and AC with insignificant WEOC concentration strongly adsorb atrazine with low desorption rates. According to our results, when high WEOC pools chars are concerned, an increase in atrazine desorption can be observed but further studies would help in confirming the present results.

Hydrogen and syngas production by catalytic gasification of algal biomass (Cladophora glomerata L.) using alkali and alkaline-earth metals compounds.

PubMed

Ebadi, Abdol Ghaffar; Hisoriev, Hikmat; Zarnegar, Mohammad; Ahmadi, Hamed

2018-01-02

The steam gasification of algal biomass (Cladophora glomerata L.) in presence of alkali and alkaline-earth metal compounds catalysts was studied to enhance the yield of syngas and reduce its tar content through cracking and reforming of condensable fractions. The commercial catalysts used include NaOH, KHCO 3 , Na 3 PO 4 and MgO. The gasification runs carried out with a research scale, biomass gasification unit, show that the NaOH has a strong potential for production of hydrogen, along with the added advantages of char converting and tar destruction, allowing enhancement of produced syngas caloric value. When the temperature increased from 700°C to 900°C, the tar content in the gas sharply decreased, while the hydrogen yield increased. Increasing steam/biomass ratio significantly increased hydrogen yield and tar destruction; however, the particle size in the range of 0.5-2.5 mm played a minor role in the process.

Low temperature circulating fluidized bed gasification and co-gasification of municipal sewage sludge. Part 2: Evaluation of ash materials as phosphorus fertilizer.

PubMed

Thomsen, Tobias Pape; Hauggaard-Nielsen, Henrik; Gøbel, Benny; Stoholm, Peder; Ahrenfeldt, Jesper; Henriksen, Ulrik B; Müller-Stöver, Dorette Sophie

2017-08-01

The study is part 2 of 2 in an investigation of gasification and co-gasification of municipal sewage sludge in low temperature gasifiers. In this work, solid residuals from thermal gasification and co-gasification of municipal sewage sludge were investigated for their potential use as fertilizer. Ashes from five different low temperature circulating fluidized bed (LT-CFB) gasification campaigns including two mono-sludge campaigns, two sludge/straw mixed fuels campaigns and a straw reference campaign were compared. Experiments were conducted on two different LT-CFBs with thermal capacities of 100kW and 6MW, respectively. The assessment included: (i) Elemental composition and recovery of key elements and heavy metals; (ii) content of total carbon (C) and total nitrogen (N); (iii) pH; (iv) water extractability of phosphorus after incubation in soil; and (v) plant phosphorus response measured in a pot experiment with the most promising ash material. Co-gasification of straw and sludge in LT-CFB gasifiers produced ashes with a high content of recalcitrant C, phosphorus (P) and potassium (K), a low content of heavy metals (especially cadmium) and an improved plant P availability compared to the mono-sludge ashes, thereby showing the best fertilizer qualities among all assessed materials. It was also found that bottom ashes from the char reactor contained even less heavy metals than cyclone ashes. It is concluded that LT-CFB gasification and co-gasification is a highly effective way to purify and sanitize sewage sludge for subsequent use in agricultural systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pyrolysis of coal

DOEpatents

Babu, Suresh P.; Bair, Wilford G.

1992-01-01

A method for mild gasification of crushed coal in a single vertical elongated reaction vessel providing a fluidized bed reaction zone, a freeboard reaction zone, and an entrained reaction zone within the single vessel. Feed coal and gas may be fed separately to each of these reaction zones to provide different reaction temperatures and conditions in each reaction zone. The reactor and process of this invention provides for the complete utilization of a coal supply for gasification including utilization of caking and non-caking or agglomerating feeds in the same reactor. The products may be adjusted to provide significantly greater product economic value, especially with respect to desired production of char having high surface area.

Method for Biochar Passivation Using Low Percent Oxygen

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Kristin; Dupuis, Dan; Wilcox, Esther

2016-06-06

The thermochemical process development unit may be configured for pyrolysis or gasification. The pyrolysis unit operations include: feed transport system; entrained flow reactor; solids removal and collection; and liquid scrubbing, collection, and filtration. Char accumulates in the collection drums at a rate of ~1.5 kg/hr and must be passivated before it is stored or transported.

Assessment of Tree Leaves Flakes Mixed with Crude Glycerol as a Bioenergy Source

PubMed Central

Hilal-AlNaqbi, Ali; Al-Omari, Salah B.; Selim, Mohamed Y. E.

2016-01-01

The gasification and combustion of dry tree leaves and the cogasification of dry tree leaves soaking crude glycerol were studied experimentally. An updraft fixed bed gasification and combustion system was built. The operation was conducted at different air to fuel ratios. Results show more stable combustion and more effective heat transfer to furnace walls for the cases when tree leaves flakes are mixed with 20 percent (on mass basis) of crude glycerol, as compared with the case when only dry tree leaves are used as fuel. TGA analysis was also conducted for the two fuels used under both air and nitrogen environments. For the crude glycerol, four phases of pyrolysis and gasification were noticed under either of the two surrounding gaseous media (air or nitrogen). For the dry tree leaves, the pyrolysis under nitrogen shows only a simple smooth pyrolysis and gasification curve without showing the different distinct phases that were otherwise identified when the pyrolysis is conducted under air environment. Moreover, the air TGA results lead to more gasification due to the char oxidation at high temperatures. DTG results are also presented and discussed. PMID:27413749

Life cycle assessment of pyrolysis, gasification and incineration waste-to-energy technologies: Theoretical analysis and case study of commercial plants.

PubMed

Dong, Jun; Tang, Yuanjun; Nzihou, Ange; Chi, Yong; Weiss-Hortala, Elsa; Ni, Mingjiang

2018-06-01

Municipal solid waste (MSW) pyrolysis and gasification are in development, stimulated by a more sustainable waste-to-energy (WtE) option. Since comprehensive comparisons of the existing WtE technologies are fairly rare, this study aims to conduct a life cycle assessment (LCA) using two sets of data: theoretical analysis, and case studies of large-scale commercial plants. Seven systems involving thermal conversion (pyrolysis, gasification, incineration) and energy utilization (steam cycle, gas turbine/combined cycle, internal combustion engine) are modeled. Theoretical analysis results show that pyrolysis and gasification, in particular coupled with a gas turbine/combined cycle, have the potential to lessen the environmental loadings. The benefits derive from an improved energy efficiency leading to less fossil-based energy consumption, and the reduced process emissions by syngas combustion. Comparison among the four operating plants (incineration, pyrolysis, gasification, gasification-melting) confirms a preferable performance of the gasification plant attributed to syngas cleaning. The modern incineration is superior over pyrolysis and gasification-melting at present, due to the effectiveness of modern flue gas cleaning, use of combined heat and power (CHP) cycle, and ash recycling. The sensitivity analysis highlights a crucial role of the plant efficiency and pyrolysis char land utilization. The study indicates that the heterogeneity of MSW and syngas purification technologies are the most relevant impediments for the current pyrolysis/gasification-based WtE. Potential development should incorporate into all process aspects to boost the energy efficiency, improve incoming waste quality, and achieve efficient residues management. Copyright © 2018 Elsevier B.V. All rights reserved.

TG-MS analysis and kinetic study for thermal decomposition of six representative components of municipal solid waste under steam atmosphere.

PubMed

Zhang, Jinzhi; Chen, Tianju; Wu, Jingli; Wu, Jinhu

2015-09-01

Thermal decomposition of six representative components of municipal solid waste (MSW, including lignin, printing paper, cotton, rubber, polyvinyl chloride (PVC) and cabbage) was investigated by thermogravimetric-mass spectroscopy (TG-MS) under steam atmosphere. Compared with TG and derivative thermogravimetric (DTG) curves under N2 atmosphere, thermal decomposition of MSW components under steam atmosphere was divided into pyrolysis and gasification stages. In the pyrolysis stage, the shapes of TG and DTG curves under steam atmosphere were almost the same with those under N2 atmosphere. In the gasification stage, the presence of steam led to a greater mass loss because of the steam partial oxidation of char residue. The evolution profiles of H2, CH4, CO and CO2 were well consistent with DTG curves in terms of appearance of peaks and relevant stages in the whole temperature range, and the steam partial oxidation of char residue promoted the generation of more gas products in high temperature range. The multi-Gaussian distributed activation energy model (DAEM) was proved plausible to describe thermal decomposition behaviours of MSW components under steam atmosphere. Copyright © 2015 Elsevier Ltd. All rights reserved.

Updraft gasification of poultry litter at farm-scale--A case study.

PubMed

Taupe, N C; Lynch, D; Wnetrzak, R; Kwapinska, M; Kwapinski, W; Leahy, J J

2016-04-01

Farm and animal wastes are increasingly being investigated for thermochemical conversion, such as gasification, due to the urgent necessity of finding new waste treatment options. We report on an investigation of the use of a farm-scale, auto-thermal gasification system for the production of a heating gas using poultry litter (PL) as a feedstock. The gasification process was robust and reliable. The PL's ash melting temperature was 639°C, therefore the reactor temperature was kept around this value. As a result of the low reactor temperature the process performance parameters were low, with a cold gas efficiency (CGE) of 0.26 and a carbon conversion efficiency (CCE) of 0.44. The calorific value of the clean product gas was 3.39 MJ m(-3)N (LHV). The tar was collected as an emulsion containing 87 wt.% water and the extracted organic compounds were identified. The residual char exceeds thresholds for Zn and Cu to obtain European biochar certification; however, has potential to be classified as a pyrogenic carbonaceous material (PCM), which resembles a high nutrient biochar. Copyright © 2016 Elsevier Ltd. All rights reserved.

Steam-air blown bubbling fluidized bed biomass gasification (BFBBG): Multi-scale models and experimental validation

DOE PAGES

Bates, Richard B.; Ghoniem, Ahmed F.; Jablonski, Whitney S.; ...

2017-02-02

During fluidized bed biomass gasification, complex gas-solid mixing patterns and numerous chemical and physical phenomena make identification of optimal operating conditions challenging. In this work, a parametric experimental campaign was carried out alongside the development of a coupled reactor network model which successfully integrates the individually validated sub-models to predict steady-state reactor performance metrics and outputs. The experiments utilized an integrated gasification system consisting of an externally-heated, bench-scale, 4-in., 5 kWth, fluidized bed steam/air blown gasifier fed with woody biomass equipped with a molecular beam mass spectrometer to directly measure tar species. The operating temperature (750-850°C) and air/fuel equivalence ratiomore » (ER = 0-0.157) were independently varied to isolate their effects. Elevating temperature is shown to improve the char gasification rate and reduce tar concentrations. In conclusion, air strongly impacts the composition of tar, accelerating the conversion of lighter polycyclic-aromatic hydrocarbons into soot precursors, while also improving the overall carbon conversion.« less

Characterization of solid fuels at pressurized fluidized bed gasification conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zevenhoven, R.; Hupa, M.

1998-07-01

The gasification of co-gasification of solid fuel (coal, peat, wood) in air-blown fluidized bed gasifiers is receiving continued attention as an alternative to entrained flow gasifiers which in general are oxygen-blown. Fluidized bed gasification of wood and wood-waste at elevated pressures, and the so-called air-blown gasification cycle are examples of processes which are under development in Europe. based on complete or partial gasification of a solid fuel in a pressurized fluidized bed. At the same time, fuel characterization data for the combination of temperature, pressure and fuel particle heating rate that is encountered in fluidized bed gasification are very scarce.more » In this paper, quantitative data on the characterization of fuels for advanced combustion and gasification technologies based on fluidized beds are given, as a result from the authors participation in the JOULE 2 extension project on clean coal technology of the European community. Eleven solid fuels, ranging from coal via peat to wood, have been studied under typical fluidized bed gasification conditions: 800--1,000 C, 1--25 bar, fuel heating rate in the order of 100--1,000 C/s. Carbon dioxide was used as gasifying agent. A pressurized thermogravimetric reactor was used for the experiments. The results show that the solid residue yield after pyrolysis/devolatilization increases with pressure and decreases with temperature. For coal, the gasification reactivity of the char increases by a factor of 3 to 4 when pressurizing from 1 to 25 bar, for the younger fuels such as peat and wood, this effect is negligible. Several empirical engineering equations are given which relate the fuel performance to the process parameters and the proximate and chemical analyses of the fuel. A pressure maximum was found at which a maximum gasification reactivity occurs, for practically all fuels, and depending on temperature. It is shown that this can be explained and modeled using a Langmuir-Hinshelwood model.« less

Characterisation of solid fuels at pressurised fluidised bed gasification conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zebenhoven, R.; Hupa, M.

1998-04-01

The gasification or co-gasification of solid fuels (coal, peat, wood) in air-blown fluidised bed gasifiers is receiving continued attention as an alternative to entrained flow gasifiers which in general are oxygen-blown. Fluidised bed gasification of wood and wood-waste at elevated pressures, and the so-called air-blown gasification cycle are examples of processes which are under development in Europe, based on complete or partial gasification of a solid fuel in a pressurised fluidised bed. At the same time, fuel characterisation data for the combination of temperature, pressure and fuel particle heating rate that is encountered in fluidised bed gasification are very scarce.more » Quantitative data on the characterisation of fuels for advanced combustion and gasification technologies based on fluidised beds are given, as a result from our participation to the JOULE 2 extension project on clean coal technology of the European Community. Eleven solid fuels, ranging from coal via peat to wood, have been studied under typical fluidised bed gasification conditions: 800-1000{degrees}C, 1-25 bar, fuel heating rate in the order of 100-1000{degrees}C/s. Carbon dioxide was used as gasifying agent. A pressurised thermogravimetric reactor was used for the experiments. The results show that the solid residue yield after pyrolysis/devolatilisation. increases with pressure and decreases with temperature. For coal, the gasification reactivity of the char increases by a factor of 3 to 4 when pressurising from 1 to 25 bar, for the `younger` fuels such as peat and wood, this effect is negligible. Several empirical, `engineering` equations are given which relate the fuel performance to the process parameters and the proximate and chemical analyses of the fuel. A pressure maximum was found at which a maximum gasification reactivity occurs, for practically all fuels, and depending on temperature. It is shown that this can be explained and modelled using a Langmuir-Hinshelwood model.« less

The effect of model fidelity on prediction of char burnout for single-particle coal combustion

DOE PAGES

McConnell, Josh; Sutherland, James C.

2016-07-09

In this study, practical simulation of industrial-scale coal combustion relies on the ability to accurately capture the dynamics of coal subprocesses while also ensuring the computational cost remains reasonable. The majority of the residence time occurs post-devolatilization, so it is of great importance that a balance between the computational efficiency and accuracy of char combustion models is carefully considered. In this work, we consider the importance of model fidelity during char combustion by comparing combinations of simple and complex gas and particle-phase chemistry models. Detailed kinetics based on the GRI 3.0 mechanism and infinitely-fast chemistry are considered in the gas-phase.more » The Char Conversion Kinetics model and nth-Order Langmuir–Hinshelwood model are considered for char consumption. For devolatilization, the Chemical Percolation and Devolatilization and Kobayashi-Sarofim models are employed. The relative importance of gasification versus oxidation reactions in air and oxyfuel environments is also examined for various coal types. Results are compared to previously published experimental data collected under laminar, single-particle conditions. Calculated particle temperature histories are strongly dependent on the choice of gas phase and char chemistry models, but only weakly dependent on the chosen devolatilization model. Particle mass calculations were found to be very sensitive to the choice of devolatilization model, but only somewhat sensitive to the choice of gas chemistry and char chemistry models. High-fidelity models for devolatilization generally resulted in particle temperature and mass calculations that were closer to experimentally observed values.« less

The effect of model fidelity on prediction of char burnout for single-particle coal combustion

DOE Office of Scientific and Technical Information (OSTI.GOV)

McConnell, Josh; Sutherland, James C.

In this study, practical simulation of industrial-scale coal combustion relies on the ability to accurately capture the dynamics of coal subprocesses while also ensuring the computational cost remains reasonable. The majority of the residence time occurs post-devolatilization, so it is of great importance that a balance between the computational efficiency and accuracy of char combustion models is carefully considered. In this work, we consider the importance of model fidelity during char combustion by comparing combinations of simple and complex gas and particle-phase chemistry models. Detailed kinetics based on the GRI 3.0 mechanism and infinitely-fast chemistry are considered in the gas-phase.more » The Char Conversion Kinetics model and nth-Order Langmuir–Hinshelwood model are considered for char consumption. For devolatilization, the Chemical Percolation and Devolatilization and Kobayashi-Sarofim models are employed. The relative importance of gasification versus oxidation reactions in air and oxyfuel environments is also examined for various coal types. Results are compared to previously published experimental data collected under laminar, single-particle conditions. Calculated particle temperature histories are strongly dependent on the choice of gas phase and char chemistry models, but only weakly dependent on the chosen devolatilization model. Particle mass calculations were found to be very sensitive to the choice of devolatilization model, but only somewhat sensitive to the choice of gas chemistry and char chemistry models. High-fidelity models for devolatilization generally resulted in particle temperature and mass calculations that were closer to experimentally observed values.« less

Effects of chemical form of sodium on the product characteristics of alkali lignin pyrolysis.

PubMed

Guo, Da-liang; Yuan, Hong-you; Yin, Xiu-li; Wu, Chuang-zhi; Wu, Shu-bin; Zhou, Zhao-qiu

2014-01-01

The effects of Na as organic bound form or as inorganic salts form on the pyrolysis products characteristics of alkali lignin were investigated by using thermogravimetric analyzer coupled with Fourier transform infrared spectrometry (TG-FTIR), tube furnace and thermo-gravimetric analyzer (TGA). Results of TG-FTIR and tube furnace indicated that the two chemical forms Na reduced the releasing peak temperature of CO and phenols leading to the peak temperature of the maximum mass loss rate shifted to low temperature zone. Furthermore, organic bound Na obviously improved the elimination of alkyl substituent leading to the yields of phenol and guaiacol increased, while inorganic Na increased the elimination of phenolic hydroxyl groups promoting the formation of ethers. It was also found the two chemical forms Na had different effects on the gasification reactivity of chars. For inorganic Na, the char conversion decreased with increasing the char forming temperature, while organic bound Na was opposite. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Microwave-induced cracking of pyrolytic tars coupled to microwave pyrolysis for syngas production.

PubMed

Beneroso, D; Bermúdez, J M; Montes-Morán, M A; Arenillas, A; Menéndez, J A

2016-10-01

Herein a new process is proposed to produce a syngas-rich gas fraction (>80vol% H2+CO) from biowaste based on microwave heating within two differentiated steps in order to avoid tars production. The first step consists of the microwave pyrolysis of biowaste induced by a char-based susceptor at 400-800°C; tars, char and syngas-rich gas fractions being produced. The tars are then fed into the second step where a portion of the char from the first step is used as a bed material in a 0.3:1wt% ratio. This bed is heated up by microwaves up to 800°C, allowing thermal cracking of tars and additional syngas (>90vol% H2+CO) being then produced. This new concept arises as an alternative technology to the gasification of biowastes for producing syngas with no need for catalysts or gasifying reagents to minimise tars production. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synergistic Effect of Co-utilization of Coal and Biomass Char: An Overview

NASA Astrophysics Data System (ADS)

Paiman, M. E. S.; Hamzah, N. S.; Idris, S. S.; Rahman, N. A.; Ismail, K.

2018-05-01

Global concerns on impact of greenhouse gases emission, mostly released from coal-fired power plant, and the depletion of fossil fuel particularly coal, has led the production of electricity from alternatives resources such as co-utilization technologies. Previous studies proved that the co-utilization of coal and biomass/biomass chars has significantly reduced the emission of greenhouse gases either during the pyrolysis, combustion or gasification process in laboratories, pilots as well as in the industrial scales. Interestingly, most of the studies reported the presence of synergistic effect during the co-utilization processes particularly between coal and biomass char while some are not. Biomass chars were found to have porous and highly disorder carbon structure and belong to the class of most reactive carbon material, resulting to be more reactive than those hard coal and lignite. Up to date, microwave assisted pyrolysis is one of the best and latest techniques employed to produce better quality of biomass chars and it is also reduce the processing cost. Lot of works has been done regarding on the existence of synergistic effects during its co-utilization. However, the knowledge is limited to thermal and product characteristics so far. Even so, the specific reasons behind its existence are yet to understand well. Therefore, in this paper, the emphasis will be given on the synergistic effects on emission characteristics of co-utilization of coal and biomass chars so that it can be apply in energy-based industries to help in reduction of the greenhouse gases emission.

Investigation of sewage sludge treatment using air plasma assisted gasification.

PubMed

Striūgas, Nerijus; Valinčius, Vitas; Pedišius, Nerijus; Poškas, Robertas; Zakarauskas, Kęstutis

2017-06-01

This study presents an experimental investigation of downdraft gasification process coupled with a secondary thermal plasma reactor in order to perform experimental investigations of sewage sludge gasification, and compare process parameters running the system with and without the secondary thermal plasma reactor. The experimental investigation were performed with non-pelletized mixture of dried sewage sludge and wood pellets. To estimate the process performance, the composition of the producer gas, tars, particle matter, producer gas and char yield were measured at the exit of the gasification and plasma reactor. The research revealed the distribution of selected metals and chlorine in the process products and examined a possible formation of hexachlorobenzene. It determined that the plasma assisted processing of gaseous products changes the composition of the tars and the producer gas, mostly by destruction of hydrocarbon species, such as methane, acetylene, ethane or propane. Plasma processing of the producer gas reduces their calorific value but increases the gas yield and the total produced energy amount. The presented technology demonstrated capability both for applying to reduce the accumulation of the sewage sludge and production of substitute gas for drying of sewage sludge and electrical power. Copyright © 2017 Elsevier Ltd. All rights reserved.

Gasification of high ash, high ash fusion temperature bituminous coals

DOEpatents

Liu, Guohai; Vimalchand, Pannalal; Peng, WanWang

2015-11-13

This invention relates to gasification of high ash bituminous coals that have high ash fusion temperatures. The ash content can be in 15 to 45 weight percent range and ash fusion temperatures can be in 1150.degree. C. to 1500.degree. C. range as well as in excess of 1500.degree. C. In a preferred embodiment, such coals are dealt with a two stage gasification process--a relatively low temperature primary gasification step in a circulating fluidized bed transport gasifier followed by a high temperature partial oxidation step of residual char carbon and small quantities of tar. The system to process such coals further includes an internally circulating fluidized bed to effectively cool the high temperature syngas with the aid of an inert media and without the syngas contacting the heat transfer surfaces. A cyclone downstream of the syngas cooler, operating at relatively low temperatures, effectively reduces loading to a dust filtration unit. Nearly dust- and tar-free syngas for chemicals production or power generation and with over 90%, and preferably over about 98%, overall carbon conversion can be achieved with the preferred process, apparatus and methods outlined in this invention.

Artificial neural network based modelling approach for municipal solid waste gasification in a fluidized bed reactor.

PubMed

Pandey, Daya Shankar; Das, Saptarshi; Pan, Indranil; Leahy, James J; Kwapinski, Witold

2016-12-01

In this paper, multi-layer feed forward neural networks are used to predict the lower heating value of gas (LHV), lower heating value of gasification products including tars and entrained char (LHV p ) and syngas yield during gasification of municipal solid waste (MSW) during gasification in a fluidized bed reactor. These artificial neural networks (ANNs) with different architectures are trained using the Levenberg-Marquardt (LM) back-propagation algorithm and a cross validation is also performed to ensure that the results generalise to other unseen datasets. A rigorous study is carried out on optimally choosing the number of hidden layers, number of neurons in the hidden layer and activation function in a network using multiple Monte Carlo runs. Nine input and three output parameters are used to train and test various neural network architectures in both multiple output and single output prediction paradigms using the available experimental datasets. The model selection procedure is carried out to ascertain the best network architecture in terms of predictive accuracy. The simulation results show that the ANN based methodology is a viable alternative which can be used to predict the performance of a fluidized bed gasifier. Copyright © 2016 Elsevier Ltd. All rights reserved.

Activated carbon derived from carbon residue from biomass gasification and its application for dye adsorption: Kinetics, isotherms and thermodynamic studies.

PubMed

Maneerung, Thawatchai; Liew, Johan; Dai, Yanjun; Kawi, Sibudjing; Chong, Clive; Wang, Chi-Hwa

2016-01-01

In this work, activated carbon (AC) as an effective and low-cost adsorbent was successfully prepared from carbon residue (or char, one of the by-products from woody biomass gasification) via physical activation. The surface area of char was significantly increased from 172.24 to 776.46m(2)/g after steam activation at 900°C. The obtained activated carbons were then employed for the adsorption of dye (Rhodamine B) and it was found that activated carbon obtained from steam activation exhibited the highest adsorption capability, which is mainly attributed to the higher surface area and the abundance of hydroxyl (-OH) and carboxyl (-COOH) groups on the activated carbon surface. Moreover, it was also found that the adsorption capability significantly increased under the basic condition, which can be attributed to the increased electrostatic interaction between the deprotonated (negatively charged) activated carbon and dye molecules. Furthermore, the equilibrium data were fitted into different adsorption isotherms and found to fit well with Langmuir model (indicating that dye molecules form monolayer coverage on activated carbon) with a maximum monolayer adsorption capability of 189.83mg/g, whereas the adsorption kinetics followed the pseudo-second-order kinetics. Copyright © 2015 Elsevier Ltd. All rights reserved.

PULSE COMBUSTOR DESIGN QUALIFICATION TEST AND CLEAN COAL FEEDSTOCK TEST - VOLUME I AND VOLUME II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Unknown

For this Cooperative Agreement, the pulse heater module is the technology envelope for an indirectly heated steam reformer. The field of use of the steam reformer pursuant to this Cooperative Agreement with DOE is for the processing of sub-bituminous coals and lignite. The main focus is the mild gasification of such coals for the generation of both fuel gas and char--for the steel industry is the main focus. An alternate market application for the substitution of metallurgical coke is also presented. This project was devoted to qualification of a 253-tube pulse heater module. This module was designed, fabricated, installed, instrumentedmore » and tested in a fluidized bed test facility. Several test campaigns were conducted. This larger heater is a 3.5 times scale-up of the previous pulse heaters that had 72 tubes each. The smaller heater has been part of previous pilot field testing of the steam reformer at New Bern, North Carolina. The project also included collection and reduction of mild gasification process data from operation of the process development unit (PDU). The operation of the PDU was aimed at conditions required to produce char (and gas) for the Northshore Steel Operations. Northshore Steel supplied the coal for the process unit tests.« less

Steam gasification of waste tyre: Influence of process temperature on yield and product composition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Portofino, Sabrina, E-mail: sabrina.portofino@enea.it; Donatelli, Antonio; Iovane, Pierpaolo

Highlights: ► Steam gasification of waste tyre as matter and energy recovery treatment. ► Process temperature affects products yield and gas composition. ► High temperature promotes hydrogen production. ► Char exploitation as activated carbon or carbon source. - Abstract: An experimental survey of waste tyre gasification with steam as oxidizing agent has been conducted in a continuous bench scale reactor, with the aim of studying the influence of the process temperature on the yield and the composition of the products; the tests have been performed at three different temperatures, in the range of 850–1000 °C, holding all the other operationalmore » parameters (pressure, carrier gas flow, solid residence time). The experimental results show that the process seems promising in view of obtaining a good quality syngas, indicating that a higher temperature results in a higher syngas production (86 wt%) and a lower char yield, due to an enhancement of the solid–gas phase reactions with the temperature. Higher temperatures clearly result in higher hydrogen concentrations: the hydrogen content rapidly increases, attaining values higher than 65% v/v, while methane and ethylene gradually decrease over the range of the temperatures; carbon monoxide and dioxide instead, after an initial increase, show a nearly constant concentration at 1000 °C. Furthermore, in regards to the elemental composition of the synthesis gas, as the temperature increases, the carbon content continuously decreases, while the oxygen content increases; the hydrogen, being the main component of the gas fraction and having a small atomic weight, is responsible for the progressive reduction of the gas density at higher temperature.« less

Pressurized chemical-looping combustion of coal with an iron ore-based oxygen carrier

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiao, Rui; Song, Min; Zhang, Shuai

2010-06-15

Chemical-looping combustion (CLC) is a new combustion technology with inherent separation of CO{sub 2}. Most of the previous investigations on CLC of solid fuels were conducted under atmospheric pressure. A pressurized CLC combined cycle (PCLC-CC) system is proposed as a promising coal combustion technology with potential higher system efficiency, higher fuel conversion, and lower cost for CO{sub 2} sequestration. In this study pressurized CLC of coal with Companhia Valedo Rio Doce (CVRD) iron ore was investigated in a laboratory fixed bed reactor. CVRD iron ore particles were exposed alternately to reduction by 0.4 g of Chinese Xuzhou bituminous coal gasifiedmore » with 87.2% steam/N{sub 2} mixture and oxidation with 5% O{sub 2} in N{sub 2} at 970 C. The operating pressure was varied between 0.1 MPa and 0.6 MPa. First, control experiments of steam coal gasification over quartz sand were performed. H{sub 2} and CO{sub 2} are the major components of the gasification products, and the operating pressure influences the gas composition. Higher concentrations of CO{sub 2} and lower fractions of CO, CH{sub 4}, and H{sub 2} during the reduction process with CVRD iron ore was achieved under higher pressures. The effects of pressure on the coal gasification rate in the presence of the oxygen carrier were different for pyrolysis and char gasification. The pressurized condition suppresses the initial coal pyrolysis process while it also enhances coal char gasification and reduction with iron ore in steam, and thus improves the overall reaction rate of CLC. The oxidation rates and variation of oxygen carrier conversion are higher at elevated pressures reflecting higher reduction level in the previous reduction period. Scanning electron microscope and energy-dispersive X-ray spectroscopy (SEM-EDX) analyses show that particles become porous after experiments but maintain structure and size after several cycles. Agglomeration was not observed in this study. An EDX analysis demonstrates that there is very little coal ash deposited on the oxygen carrier particles but no appreciable crystalline phases change as verified by X-ray diffraction (XRD) analysis. Overall, the limited pressurized CLC experiments carried out in the present work suggest that PCLC of coal is promising and further investigations are necessary. (author)« less

Analysis of carbon-oxygen reactions by use of a square-input response technique and {sup 18}O isotope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miura, Kouichi; Nakagawa, Hiroyuki

1996-12-31

Carbon gasification reaction has been investigated for decades including the pioneering works of Walker and his co-workers, but its mechanism has not been completely elucidated. The concept of the active surface area (ASA) was proposed by them, and its importance has been recognized. However, since ASA was measured by O{sub 2} chemisorption at below 300{degrees}C where carbon loss through gasification is negligible, it does not reflect the actual gasification situation. To overcome this weak point, measurements of ASA in a batch reactor and the so-called transient kinetic (TK) method were proposed. Ahmed and Back successfully measured the chemisorbed oxygen duringmore » the gasification using a batch reactor, and proposed a new mechanistic sequence for carbon-oxygen reaction which stresses the importance of the reaction between the gaseous oxygen and the chemisorbed oxygen. Radovic et al. proposed the concept of the reactive surface area (RSA), and reported excellent proportionality between the CO{sub 2} gasification rate and the RSA estimated by the TK and the TPD methods. Kapteijn et al. showed that the TK method with labeled molecules is more powerful to examine the mechanism. They found the presence of two types of surface oxygen complexes which desorb at different rates. A Square-input response (SIR) method is applied to the carbon-oxygen reaction. This method allows the observation of transient changes on two step changes. This method has been successfully applied to the analysis of a coal char gasification.« less

Removal of H{sub 2}S using molten carbonate at high temperature

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kawase, Makoto, E-mail: kawase@criepi.denken.or.jp; Otaka, Maromu

2013-12-15

Highlights: • The performance of molten carbonate for the removal of H{sub 2}S improves at higher temperatures. • The degree of H{sub 2}S removal is significantly affected by the CO{sub 2} concentration in syngas. • Addition of carbon elements, such as char and tar, decrease the negative effects of CO{sub 2}. • Continuous addition of carbon elements into molten carbonate enables continuous desulfurization. • Desulfurization using molten carbonate is suitable for gasification gas. - Abstract: Gasification is considered to be an effective process for energy conversion from various sources such as coal, biomass, and waste. Cleanup of the hot syngasmore » produced by such a process may improve the thermal efficiency of the overall gasification system. Therefore, the cleanup of hot syngas from biomass gasification using molten carbonate is investigated in bench-scale tests. Molten carbonate acts as an absorbent during desulfurization and dechlorination and as a thermal catalyst for tar cracking. In this study, the performance of molten carbonate for removing H{sub 2}S was evaluated. The temperature of the molten carbonate was set within the range from 800 to 1000 °C. It is found that the removal of H{sub 2}S is significantly affected by the concentration of CO{sub 2} in the syngas. When only a small percentage of CO{sub 2} is present, desulfurization using molten carbonate is inadequate. However, when carbon elements, such as char and tar, are continuously supplied, H{sub 2}S removal can be maintained at a high level. To confirm the performance of the molten carbonate gas-cleaning system, purified biogas was used as a fuel in power generation tests with a molten carbonate fuel cell (MCFC). The fuel cell is a high-performance sensor for detecting gaseous impurities. When purified gas from a gas-cleaning reactor was continuously supplied to the fuel cell, the cell voltage remained stable. Thus, the molten carbonate gas-cleaning reactor was found to afford good gas-cleaning performance.« less

Biochar, Tool for Climate Change Mitigation and Soil Management

NASA Astrophysics Data System (ADS)

Shackley, Simon; Sohi, Saran; Ibarrola, Rodrigo; Hammond, Jim; Mašek, Ondřej; Brownsort, Peter; Cross, Andrew; Prendergast-Miller, Miranda; Haszeldine, Stuart

Biochar is the solid remains of any organic material that has been heated to at least 350oC in a zero-oxygen or oxygen-limited environment, which is intended to be mixed with soils. If the solid remains are not suitable for addition to soils, or will be burned as a fuel or used as an aggregate in construction, it is defined as char not biochar. There is a very wide range of potential biochar feedstocks, e.g., wood waste, timber, agricultural residues and wastes (straws, bagasse, manure, husks, shells, fibers, etc.), leaves, food wastes, paper and sewage sludge, green waste, distiller's grain, and many others. Pyrolysis is usually the technology of choice for producing biochar, though biomass gasification also produces smaller char yields. Syngas and pyrolytic bio-liquids, which have a potential use as energy carriers, are produced alongside biochar.

Using environmental chemistry technologies for the removal of arsenic from drinking water, and fat and oil based phase change materials for thermal energy storage

NASA Astrophysics Data System (ADS)

Sutterlin, William R.

The first four chapters of this dissertation involve the removal of arsenic from drinking water. Various forms of a macroporous char prepared by partial gasification of subbituminous coal were studied for removal of arsenic(V) and arsenic(III) from water. In increasing order of effectiveness for arsenic(V) removal were untreated char < acid-washed char < char impregnated with iron(III) and gasified < char impregnated with FeS < char impregnated with iron(III) hydroxide < char coated with zerovalent iron < char impregnated with iron(III) oxide. A mass of 10 g of iron(III) oxide char removed arsenic(V) and arsenic(III) from 10,000 mL of water containing 500 micrograms/L of arsenic to levels below 10 micrograms/L. The capacity of the solid to remove arsenic was significantly diminished in water containing 4 mg/L of phosphate. An electrical current passed over 4 g of iron(III) oxide char in a column enabled removal of arsenic(III) from 14,000 mL of 500 micrograms/L arsenic(III) to below 10 micrograms/liter and at significantly higher flow rates than could be employed without electrolysis. The fifth chapter in this dissertation focused on the retention of organics onto a char/concrete pellet. A mixture of naphthalene, pentachlorophenol, biphenyl, toluene, tetrachloroethane, and chlorobenzene were impregnated into a loose granular char, a char/concrete pellet and a sand/concrete pellet. The results showed that the char/concrete pellet had significant advantages over the other forms. Chapters 6--9 focus on phase change materials (PCMs). These PCMs are made from fats and oils. PCMs are perhaps the only proven method that can provide near 100% thermal energy storage. In chapter 7 a novel HPLC method was developed that could provide quantification and qualification of the resulting products formed after PCM synthesis. In chapter 8 thermal cycling studies were conducted on the fat and oil based PCMs. These thermal cycle demonstrated that these PCMs were capable of going through a multitude of freeze and melt processes with little to no degradation if the appropriate preservative is used. Finally in chapter 9 the PCM is incorporated into a simulated 100 th scale house. A traditional freon based evaporator is used to freeze the PCM at night during electrical-off-peak hours. During the peak-load of the day the evaporator is turned off and the PCM provides the cooling for the house.

Fluidized bed gasification of industrial solid recovered fuels.

PubMed

Arena, Umberto; Di Gregorio, Fabrizio

2016-04-01

The study evaluates the technical feasibility of the fluidized bed gasification of three solid recovered fuels (SRFs), obtained as co-products of a recycling process. The SRFs were pelletized and fed to a pilot scale bubbling fluidized bed reactor, operated in gasification and co-gasification mode. The tests were carried out under conditions of thermal and chemical steady state, with a bed of olivine particles and at different values of equivalence ratio. The results provide a complete syngas characterization, in terms of its heating value and composition (including tars, particulates, and acid/basic pollutants) and of the chemical and physical characterization of bed material and entrained fines collected at the cyclone outlet. The feasibility of the fluidized bed gasification process of the different SRFs was evaluated with the support of a material and substance flow analysis, and a feedstock energy analysis. The results confirm the flexibility of fluidized bed reactor, which makes it one of the preferable technologies for the gasification of different kind of wastes, even in co-gasification mode. The fluidized bed gasification process of the tested SRFs appears technically feasible, yielding a syngas of valuable quality for energy applications in an appropriate plant configuration. Copyright © 2016 Elsevier Ltd. All rights reserved.

Supercritical water gasification of biomass: Thermodynamic constraints.

PubMed

Castello, Daniele; Fiori, Luca

2011-08-01

In the present work, the supercritical water gasification (SCWG) of biomass is analyzed with a view to outlining the possible thermodynamic constraints that must be taken into account to develop this new process. In particular, issues concerning the formation of solid carbon and the process heat duty are discussed. The analysis is conducted by means of a two-phase non-stoichiometric thermodynamic model, based on Gibbs free energy minimization. Results show that char formation at equilibrium only occurs at high biomass concentrations, with a strong dependence on biomass composition. As regards the process heat duty, SCWG is mostly endothermic when biomass concentration is low, although a very small amount of oxidizing agent is able to make the process exothermic, with only a small loss in the heating value of the syngas produced. Copyright © 2011 Elsevier Ltd. All rights reserved.

Development of Kinetics and Mathematical Models for High-Pressure Gasification of Lignite-Switchgrass Blends: Cooperative Research and Development Final Report, CRADA Number CRD-11-447

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iisa, Kristiina

2016-04-06

NREL will work with Participant as a subtier partner under DE-FOA-0000240 titled "Co-Production of Power, Fuels, and Chemicals via Coal/Biomass Mixtures." The goal of the project is to determine the gasification characteristics of switchgrass and lignite mixtures and develop kinetic models. NREL will utilize a pressurized thermogravimetric analyzer to measure the reactivity of chars generated in a pressurized entrained-flow reactor at Participant's facilities and to determine the evolution of gaseous species during pyrolysis of switchgrass-lignite mixtures. Mass spectrometry and Fourier-transform infrared analysis will be used to identify and quantify the gaseous species. The results of the project will aid inmore » defining key reactive properties of mixed coal biomass fuels.« less

Development of a Model for the Heat Release Rate of Wood. A Status Report.

DTIC Science & Technology

1985-05-01

K) *contraction factor L effective heat of gasification (kJ/kg) (positive) Lv latent heat of vaporization of water (kJ/kg) (positive) m mass (kg) M...designates the slice bounded by the rear surface 0 ambient or original *0 oxygen R radiation rel release S front surface of specimen Vol volatiles ix w water ...calorimeter. Along the other pathway, char is formed with the release of water and other volatiles having low heats of combustion. The effective heat of

Assessment of the SRI Gasification Process for Syngas Generation with HTGR Integration -- White Paper

DOE Office of Scientific and Technical Information (OSTI.GOV)

A.M. Gandrik

2012-04-01

This white paper is intended to compare the technical and economic feasibility of syngas generation using the SRI gasification process coupled to several high-temperature gas-cooled reactors (HTGRs) with more traditional HTGR-integrated syngas generation techniques, including: (1) Gasification with high-temperature steam electrolysis (HTSE); (2) Steam methane reforming (SMR); and (3) Gasification with SMR with and without CO2 sequestration.

Properties and potential environmental applications of carbon adsorbents from waste tire rubber

USGS Publications Warehouse

Lehmann, C.M.B.; Rameriz, D.; Rood, M.J.; Rostam-Abadi, M.

2000-01-01

The properties of tire-derived carbon adsorbents (TDCA) produced from select tire chars were compared with those derived from an Illinois coal and pistachio nut shells. Chemical analyses of the TDCA indicated that these materials contain metallic elements not present in coal-and nut shell-derived carbons. These metals, introduced during the production of tire rubber, potentially catalyze steam gasification reactions of tire char. TDCA carbons contained larger meso-and macopore volumes than their counterparts derived from coal and nut shell (on the moisture-and ash-free-basis). Adsorptive properties of the tire-derived adsorbent carbons for air separation, gas storage, and gas clean up were also evaluated and compared with those of the coal-and nut shell derived carbons as well as a commercial activated carbon. The results revealed that TDCA carbons are suitable adsorbents for removing vapor-phase mercury from combustion flue gases and hazardous organic compounds from industrial gas streams.

Lock hopper values for coal gasification plant service

NASA Technical Reports Server (NTRS)

Schoeneweis, E. F.

1977-01-01

Although the operating principle of the lock hopper system is extremely simple, valve applications involving this service for coal gasification plants are likewise extremely difficult. The difficulties center on the requirement of handling highly erosive pulverized coal or char (either in dry or slurry form) combined with the requirement of providing tight sealing against high-pressure (possibly very hot) gas. Operating pressures and temperatures in these applications typically range up to 1600 psi (110bar) and 600F (316C), with certain process requirements going even higher. In addition, and of primary concern, is the need for reliable operation over long service periods with the provision for practical and economical maintenance. Currently available data indicate the requirement for something in the order of 20,000 to 30,000 open-close cycles per year and a desire to operate at least that long without valve failure.

Integration of coal gasification and waste heat recovery from high temperature steel slags: an emerging strategy to emission reduction

NASA Astrophysics Data System (ADS)

Sun, Yongqi; Sridhar, Seetharaman; Liu, Lili; Wang, Xidong; Zhang, Zuotai

2015-11-01

With the continuous urbanization and industrialization in the world, energy saving and greenhouse gas (GHG) emission reduction have been serious issues to be addressed, for which heat recovery from traditional energy-intensive industries makes up a significant strategy. Here we report a novel approach to extract the waste heat and iron from high temperature steel slags (1450-1650 oC) produced in the steel industry, i.e., integration of coal gasification and steel slag treatment. Both the thermodynamics and kinetics of the pertinent reactions were identified. It was clarified that the kinetic mechanism for gasification varied from A2 model to A4 model (Avrami-Erofeev) in the presence of slags. Most importantly, the steel slags acted not only as good heat carriers but also as effective catalysts where the apparent activation energy for char gasification got remarkably reduced from 95.7 kJ/mol to 12.1 kJ/mol (A2 model). Furthermore, the FeO in the slags was found to be oxidized into Fe3O4, with an extra energy release, which offered a potential for magnetic separation. Moreover, based on the present research results, an emerging concept, composed of multiple industrial sectors, was proposed, which could serve as an important route to deal with the severe environmental problems in modern society.

Integration of coal gasification and waste heat recovery from high temperature steel slags: an emerging strategy to emission reduction

PubMed Central

Sun, Yongqi; Sridhar, Seetharaman; Liu, Lili; Wang, Xidong; Zhang, Zuotai

2015-01-01

With the continuous urbanization and industrialization in the world, energy saving and greenhouse gas (GHG) emission reduction have been serious issues to be addressed, for which heat recovery from traditional energy-intensive industries makes up a significant strategy. Here we report a novel approach to extract the waste heat and iron from high temperature steel slags (1450–1650 oC) produced in the steel industry, i.e., integration of coal gasification and steel slag treatment. Both the thermodynamics and kinetics of the pertinent reactions were identified. It was clarified that the kinetic mechanism for gasification varied from A2 model to A4 model (Avrami-Erofeev) in the presence of slags. Most importantly, the steel slags acted not only as good heat carriers but also as effective catalysts where the apparent activation energy for char gasification got remarkably reduced from 95.7 kJ/mol to 12.1 kJ/mol (A2 model). Furthermore, the FeO in the slags was found to be oxidized into Fe3O4, with an extra energy release, which offered a potential for magnetic separation. Moreover, based on the present research results, an emerging concept, composed of multiple industrial sectors, was proposed, which could serve as an important route to deal with the severe environmental problems in modern society. PMID:26558350

Integration of coal gasification and waste heat recovery from high temperature steel slags: an emerging strategy to emission reduction.

PubMed

Sun, Yongqi; Sridhar, Seetharaman; Liu, Lili; Wang, Xidong; Zhang, Zuotai

2015-11-12

With the continuous urbanization and industrialization in the world, energy saving and greenhouse gas (GHG) emission reduction have been serious issues to be addressed, for which heat recovery from traditional energy-intensive industries makes up a significant strategy. Here we report a novel approach to extract the waste heat and iron from high temperature steel slags (1450-1650 (o)C) produced in the steel industry, i.e., integration of coal gasification and steel slag treatment. Both the thermodynamics and kinetics of the pertinent reactions were identified. It was clarified that the kinetic mechanism for gasification varied from A2 model to A4 model (Avrami-Erofeev) in the presence of slags. Most importantly, the steel slags acted not only as good heat carriers but also as effective catalysts where the apparent activation energy for char gasification got remarkably reduced from 95.7 kJ/mol to 12.1 kJ/mol (A2 model). Furthermore, the FeO in the slags was found to be oxidized into Fe3O4, with an extra energy release, which offered a potential for magnetic separation. Moreover, based on the present research results, an emerging concept, composed of multiple industrial sectors, was proposed, which could serve as an important route to deal with the severe environmental problems in modern society.

Thermodynamic modelling and solar reactor design for syngas production through SCWG of algae

NASA Astrophysics Data System (ADS)

Venkataraman, Mahesh B.; Rahbari, Alireza; Pye, John

2017-06-01

Conversion of algal biomass into value added products, such as liquid fuels, using solar-assisted supercritical water gasification (SCWG) offers a promising approach for clean fuel production. SCWG has significant advantages over conventional gasification in terms of flexibility of feedstock, faster intrinsic kinetics and lower char formation. A relatively unexplored avenue in SCWG is the use of non-renewable source of energy for driving the endothermic gasification. The use of concentrated solar thermal to provide the process heat is attractive, especially in the case of expensive feedstocks such as algae. This study attempts to identify the key parameters and constraints in designing a solar cavity receiver/reactor for on-sun SCWG of algal biomass. A tubular plug-flow reactor, operating at 24 MPa and 400-600 °C with a solar input of 20MWth is modelled. Solar energy is utilized to increase the temperature of the reaction medium (10 wt.% algae solution) from 400 to 605 °C and simultaneously drive the gasification. The model additionally incorporates material constraints based on the allowable stresses for a commercially available Ni-based alloy (Inconel 625), and exergy accounting for the cavity reactor. A parametric evaluation of the steady state performance and quantification of the losses through wall conduction, external radiation and convection, internal convection, frictional pressure drop, mixing and chemical irreversibility, is presented.

Computational fluid dynamics assessment: Volume 1, Computer simulations of the METC (Morgantown Energy Technology Center) entrained-flow gasifier: Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Celik, I.; Chattree, M.

1988-07-01

An assessment of the theoretical and numerical aspects of the computer code, PCGC-2, is made; and the results of the application of this code to the Morgantown Energy Technology Center (METC) advanced gasification facility entrained-flow reactor, ''the gasifier,'' are presented. PCGC-2 is a code suitable for simulating pulverized coal combustion or gasification under axisymmetric (two-dimensional) flow conditions. The governing equations for the gas and particulate phase have been reviewed. The numerical procedure and the related programming difficulties have been elucidated. A single-particle model similar to the one used in PCGC-2 has been developed, programmed, and applied to some simple situationsmore » in order to gain insight to the physics of coal particle heat-up, devolatilization, and char oxidation processes. PCGC-2 was applied to the METC entrained-flow gasifier to study numerically the flash pyrolysis of coal, and gasification of coal with steam or carbon dioxide. The results from the simulations are compared with measurements. The gas and particle residence times, particle temperature, and mass component history were also calculated and the results were analyzed. The results provide useful information for understanding the fundamentals of coal gasification and for assessment of experimental results performed using the reactor considered. 69 refs., 35 figs., 23 tabs.« less

Biochar affected by composting with farmyard manure.

PubMed

Prost, Katharina; Borchard, Nils; Siemens, Jan; Kautz, Timo; Séquaris, Jean-Marie; Möller, Andreas; Amelung, Wulf

2013-01-01

Biochar applications to soils can improve soil fertility by increasing the soil's cation exchange capacity (CEC) and nutrient retention. Because biochar amendment may occur with the applications of organic fertilizers, we tested to which extent composting with farmyard manure increases CEC and nutrient content of charcoal and gasification coke. Both types of biochar absorbed leachate generated during the composting process. As a result, the moisture content of gasification coke increased from 0.02 to 0.94 g g, and that of charcoal increased from 0.03 to 0.52 g g. With the leachate, the chars absorbed organic matter and nutrients, increasing contents of water-extractable organic carbon (gasification coke: from 0.09 to 7.00 g kg; charcoal: from 0.03 to 3.52 g kg), total soluble nitrogen (gasification coke: from not detected to 705.5 mg kg; charcoal: from 3.2 to 377.2 mg kg), plant-available phosphorus (gasification coke: from 351 to 635 mg kg; charcoal: from 44 to 190 mg kg), and plant-available potassium (gasification coke: from 6.0 to 15.3 g kg; charcoal: from 0.6 to 8.5 g kg). The potential CEC increased from 22.4 to 88.6 mmol kg for the gasification coke and from 20.8 to 39.0 mmol kg for the charcoal. There were little if any changes in the contents and patterns of benzene polycarboxylic acids of the biochars, suggesting that degradation of black carbon during the composting process was negligible. The surface area of the biochars declined during the composting process due to the clogging of micropores by sorbed compost-derived materials. Interactions with composting substrate thus enhance the nutrient loads but alter the surface properties of biochars. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Conceptual design study of a coal gasification combined-cycle powerplant for industrial cogeneration

NASA Astrophysics Data System (ADS)

Bloomfield, H. S.; Nelson, S. G.; Straight, H. F.; Subramaniam, T. K.; Winklepleck, R. G.

1981-03-01

A conceptual design study was conducted to assess technical feasibility, environmental characteristics, and economics of coal gasification. The feasibility of a coal gasification combined cycle cogeneration powerplant was examined in response to energy needs and to national policy aimed at decreasing dependence on oil and natural gas. The powerplant provides the steam heating and baseload electrical requirements while serving as a prototype for industrial cogeneration and a modular building block for utility applications. The following topics are discussed: (1) screening of candidate gasification, sulfur removal and power conversion components; (2) definition of a reference system; (3) quantification of plant emissions and waste streams; (4) estimates of capital and operating costs; and (5) a procurement and construction schedule. It is concluded that the proposed powerplant is technically feasible and environmentally superior.

Conceptual design study of a coal gasification combined-cycle powerplant for industrial cogeneration

NASA Technical Reports Server (NTRS)

Bloomfield, H. S.; Nelson, S. G.; Straight, H. F.; Subramaniam, T. K.; Winklepleck, R. G.

1981-01-01

A conceptual design study was conducted to assess technical feasibility, environmental characteristics, and economics of coal gasification. The feasibility of a coal gasification combined cycle cogeneration powerplant was examined in response to energy needs and to national policy aimed at decreasing dependence on oil and natural gas. The powerplant provides the steam heating and baseload electrical requirements while serving as a prototype for industrial cogeneration and a modular building block for utility applications. The following topics are discussed: (1) screening of candidate gasification, sulfur removal and power conversion components; (2) definition of a reference system; (3) quantification of plant emissions and waste streams; (4) estimates of capital and operating costs; and (5) a procurement and construction schedule. It is concluded that the proposed powerplant is technically feasible and environmentally superior.

Method for Hot Real-Time Sampling of Gasification Products

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pomeroy, Marc D

The Thermochemical Process Development Unit (TCPDU) at the National Renewable Energy Laboratory (NREL) is a highly instrumented half-ton/day pilot scale plant capable of demonstrating industrially relevant thermochemical technologies from lignocellulosic biomass conversion, including gasification. Gasification creates primarily Syngas (a mixture of Hydrogen and Carbon Monoxide) that can be utilized with synthesis catalysts to form transportation fuels and other valuable chemicals. Biomass derived gasification products are a very complex mixture of chemical components that typically contain Sulfur and Nitrogen species that can act as catalysis poisons for tar reforming and synthesis catalysts. Real-time hot online sampling techniques, such as Molecular Beammore » Mass Spectrometry (MBMS), and Gas Chromatographs with Sulfur and Nitrogen specific detectors can provide real-time analysis providing operational indicators for performance. Sampling typically requires coated sampling lines to minimize trace sulfur interactions with steel surfaces. Other materials used inline have also shown conversion of sulfur species into new components and must be minimized. Sample line Residence time within the sampling lines must also be kept to a minimum to reduce further reaction chemistries. Solids from ash and char contribute to plugging and must be filtered at temperature. Experience at NREL has shown several key factors to consider when designing and installing an analytical sampling system for biomass gasification products. They include minimizing sampling distance, effective filtering as close to source as possible, proper line sizing, proper line materials or coatings, even heating of all components, minimizing pressure drops, and additional filtering or traps after pressure drops.« less

Design, scale-up, Six Sigma in processing different feedstocks in a fixed bed downdraft biomass gasifier

NASA Astrophysics Data System (ADS)

Boravelli, Sai Chandra Teja

This thesis mainly focuses on design and process development of a downdraft biomass gasification processes. The objective is to develop a gasifier and process of gasification for a continuous steady state process. A lab scale downdraft gasifier was designed to develop the process and obtain optimum operating procedure. Sustainable and dependable sources such as biomass are potential sources of renewable energy and have a reasonable motivation to be used in developing a small scale energy production plant for countries such as Canada where wood stocks are more reliable sources than fossil fuels. This thesis addresses the process of thermal conversion of biomass gasification process in a downdraft reactor. Downdraft biomass gasifiers are relatively cheap and easy to operate because of their design. We constructed a simple biomass gasifier to study the steady state process for different sizes of the reactor. The experimental part of this investigation look at how operating conditions such as feed rate, air flow, the length of the bed, the vibration of the reactor, height and density of syngas flame in combustion flare changes for different sizes of the reactor. These experimental results also compare the trends of tar, char and syngas production for wood pellets in a steady state process. This study also includes biomass gasification process for different wood feedstocks. It compares how shape, size and moisture content of different feedstocks makes a difference in operating conditions for the gasification process. For this, Six Sigma DMAIC techniques were used to analyze and understand how each feedstock makes a significant impact on the process.

Development of an advanced, continuous mild gasification process for the production of co-products. Quarterly report, October 30, 1991--January 2, 1992

DOE Office of Scientific and Technical Information (OSTI.GOV)

O`Neal, G.W.

1991-12-31

During this quarter the work on Task 3, char upgrading, was in two areas; upgrading Penelec char made from Penelec filter cake to blast furnace formed coke, and evaluating various bituminous pitch binders. The formed coke from Penelec filter cake was of good quality with a high crush strength of 3000 pounds. The reactivity was not equal to that of conventional coke but it is felt that it could be made to equal conventional coke with further study, specifically by adding binder coal to the raw material recipe. The work evaluating bituminous pitch binders confirmed earlier thinking that will bemore » valuable to a commercial scale-up. Asphalt binders are compatible with coal tar binders and produce a coke of equal quality. Hence asphalt binders can be used to supply deficiencies of tar production in units employing coals with insufficient volatile matter to supply enough tar for the coking process. Asphalt binders have about a 50% savings from coal tar pitch. During the 4th Quarter of 1991, a total of 15 Continuous Mild Gasification Unit (CMGU) test runs were made. Efforts continued to determine the optimum forward/reverse ratio to maximize coal feed rate. The success of these efforts has been limited with a maximum coal feed rate of 400 lbs/hr obtainable with a caking coal. The handicap of not having screw shaft heaters cannot be overcome by adjustment of the forward/reverse ratio.« less

Development of an advanced, continuous mild gasification process for the production of co-products

DOE Office of Scientific and Technical Information (OSTI.GOV)

O'Neal, G.W.

1991-01-01

During this quarter the work on Task 3, char upgrading, was in two areas; upgrading Penelec char made from Penelec filter cake to blast furnace formed coke, and evaluating various bituminous pitch binders. The formed coke from Penelec filter cake was of good quality with a high crush strength of 3000 pounds. The reactivity was not equal to that of conventional coke but it is felt that it could be made to equal conventional coke with further study, specifically by adding binder coal to the raw material recipe. The work evaluating bituminous pitch binders confirmed earlier thinking that will bemore » valuable to a commercial scale-up. Asphalt binders are compatible with coal tar binders and produce a coke of equal quality. Hence asphalt binders can be used to supply deficiencies of tar production in units employing coals with insufficient volatile matter to supply enough tar for the coking process. Asphalt binders have about a 50% savings from coal tar pitch. During the 4th Quarter of 1991, a total of 15 Continuous Mild Gasification Unit (CMGU) test runs were made. Efforts continued to determine the optimum forward/reverse ratio to maximize coal feed rate. The success of these efforts has been limited with a maximum coal feed rate of 400 lbs/hr obtainable with a caking coal. The handicap of not having screw shaft heaters cannot be overcome by adjustment of the forward/reverse ratio.« less

Integrated carbon dioxide/sludge gasification using waste heat from hot slags: syngas production and sulfur dioxide fixation.

PubMed

Sun, Yongqi; Zhang, Zuotai; Liu, Lili; Wang, Xidong

2015-04-01

The integrated CO2/sludge gasification using the waste heat in hot slags, was explored with the aim of syngas production, waste heat recovery and sewage sludge disposal. The results demonstrated that hot slags presented multiple roles on sludge gasification, i.e., not only a good heat carrier (500-950 °C) but also an effective desulfurizer (800-900 °C). The total gas yields increased from 0.022 kg/kgsludge at 500 °C to 0.422 kg/kgsludge at 900 °C; meanwhile, the SO2 concentration at 900 °C remarkably reduced from 164 ppm to 114 ppm by blast furnace slags (BFS) and 93 ppm by steel slags (SS), respectively. A three-stage reaction was clarified including volatile release, char transformation and fixed carbon using Gaussian fittings and the kinetic model was analyzed. Accordingly, a decline process using the integrated method was designed and the optimum slag/sludge ratio was deduced. These deciphered results appealed potential ways of reasonable disposal of sewage sludge and efficient recovery of waste heat from hot slags. Copyright © 2015 Elsevier Ltd. All rights reserved.

Integrated bioenergy conversion concepts for small scale gasification power systems

NASA Astrophysics Data System (ADS)

Aldas, Rizaldo Elauria

Thermal and biological gasification are promising technologies for addressing the emerging concerns in biomass-based renewable energy, environmental protection and waste management. However, technical barriers such as feedstock quality limitations, tars, and high NOx emissions from biogas fueled engines impact their full utilization and make them suffer at the small scale from the need to purify the raw gas for most downstream processes, including power generation other than direct boiler use. The two separate gasification technologies may be integrated to better address the issues of power generation and waste management and to complement some of each technologies' limitations. This research project investigated the technical feasibility of an integrated thermal and biological gasification concept for parameters critical to appropriately matching an anaerobic digester with a biomass gasifier. Specific studies investigated the thermal gasification characteristics of selected feedstocks in four fixed-bed gasification experiments: (1) updraft gasification of rice hull, (2) indirect-heated gasification of rice hull, (3) updraft gasification of Athel wood, and (4) downdraft gasification of Athel and Eucalyptus woods. The effects of tars and other components of producer gas on anaerobic digestion at mesophilic temperature of 36°C and the biodegradation potentials and soil carbon mineralization of gasification tars during short-term aerobic incubation at 27.5°C were also examined. Experiments brought out the ranges in performance and quality and quantity of gasification products under different operating conditions and showed that within the conditions considered in the study, these gasification products did not adversely impact the overall digester performance. Short-term aerobic incubation demonstrated variable impacts on carbon mineralization depending on tar and soil conditions. Although tars exhibited low biodegradation indices, degradation may be improved if the microorganisms used to deal with tars are selected and pre-conditioned to the tar environment. Overall, the results provided a basis for operational and design strategy for a combined gasification system but further study is recommended such as determination of the impacts in terms of emissions, power, efficiency and costs associated with the use of producer gas-enriched biogas taking advantage of hydrogen enrichment to reduce NOx and other pollutants in reciprocating engines and other energy conversion systems.

Strategy for Passivating Char Efficiently at the Pilot Scale

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dunning, Timothy C

Fast pyrolysis is a promising pathway for the commercialization of liquid transportation fuels from biomass. Fast pyrolysis is performed at moderate heat (450-600 degrees Celcius) in an oxygen-deficient environment. One of the products of fast pyrolysis is biochar, which is often used as a heat source or as a soil amendment. Biochar is a partially reacted solid that is created in the production of bio-oil during fast pyrolysis. Biochar produced at these conditions contains significant quantities of carbon that adsorb oxygen when exposed to air. Biochar adsorption of oxygen is an exothermic process that may generate sufficient heat for combustionmore » in ambient air. Biochar is also a self-insulating material which compounds the effects of heat generated internally. These factors lead to safety concerns and material handling difficulties. The Thermochemical Process Development Unit at the National Renewable Energy Laboratory operates a pilot plant that may be configured for fast pyrolysis, gasification, and will be introducing catalytic fast pyrolysis capabilities in 2018. The TCPDU designed and installed a system to introduce oxygen to collected biochar systematically for a controlled passivation. Biochar is collected and cooled in an oxygen deficient environment during fast pyrolysis. Oxygen is then introduced to the biochar on a mass flow basis. A sparger imbedded within the biochar sample near the bottom of the bed flows air diluted with nitrogen into the char bed, and excess gasses are removed from the top of the collection drum, above the char bed. Pressure within the collection drum is measured indicating adequate flow through filters. Sample weight is recorded before and after passivation. During passivation, temperature is measured at 18 points within the char bed. Oxygen content and temperature are measured leaving the char bed. Maximum temperature parameters were established to ensure operator safety during biochar passivation. Extensive passivation data was collected on pine and blended feedstocks and has been analyzed to characterize the exotherm of char samples. Observations and data collected while passivating char will be discussed.« less

Gasification reactor engineering approach to understanding the formation of biochar properties

PubMed Central

2016-01-01

The correlation between thermochemical provenance and biochar functionality is poorly understood. To this end, operational reactor temperatures (spanning the reduction zone), pressure and product gas composition measurements were obtained from a downdraft gasifier and compared against elemental composition, surface morphology and polyaromatic hydrocarbon content (PAH) of the char produced. Pine feedstock moisture with values of 7% and 17% was the experimental variable. Moderately high steady-state temperatures were observed inside the reactor, with a ca 50°C difference in how the gasifier operated between the two feedstock types. Both chars exhibited surface properties comparable to activated carbon, but the relatively small differences in temperature caused significant variations in biochar surface area and morphology: micropore area 584 against 360 m2 g−1, and micropore volume 0.287 against 0.172 cm3 g−1. Differences in char extractable PAH content were also observed, with higher concentrations (187 µg g−1 ± 18 compared with 89 ± 19 µg g−1 Σ16EPA PAH) when the gasifier was operated with higher moisture content feedstock. It is recommended that greater detail on operational conditions during biochar production should be incorporated to future biochar characterization research as a consequence of these results. PMID:27616911

Beneficial synergetic effect on gas production during co-pyrolysis of sewage sludge and biomass in a vacuum reactor.

PubMed

Zhang, Weijiang; Yuan, Chengyong; Xu, Jiao; Yang, Xiao

2015-05-01

A vacuum fixed bed reactor was used to pyrolyze sewage sludge, biomass (rice husk) and their blend under high temperature (900°C). Pyrolytic products were kept in the vacuum reactor during the whole pyrolysis process, guaranteeing a long contact time (more than 2h) for their interactions. Remarkable synergetic effect on gas production was observed. Gas yield of blend fuel was evidently higher than that of both parent fuels. The syngas (CO and H2) content and gas lower heating value (LHV) were obviously improved as well. It was highly possible that sewage sludge provided more CO2 and H2O during co-pyrolysis, promoting intense CO2-char and H2O-char gasification, which benefited the increase of gas yield and lower heating value. The beneficial synergetic effect, as a result, made this method a feasible one for gas production. Copyright © 2015. Published by Elsevier Ltd.

Undergraduate research studies program at participating institutions of the HBCU Fossil Energy Consortium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bota, K.B.

1991-01-01

The primary objective of this research program is to expose students in the Historically Black Colleges and Universities (HBCU) Fossil Energy Consortium Institutions to energy and fossil fuels research, to stimulate their interest in the sciences and engineering and to encourage them to pursue graduate studies. This report provides the research accomplishment of the various students who participated in the program. Research results are presented on the following topics: Energy Enhancement and Pollutant Reduction in Coal by Cryogenic Diminution; Competition of NO and SO[sub 2] for OH Generated witin Electrical Aerosol Analyzers; Dispersed Iron Catalysts for Coal Gasification; NQR/NMR Studiesmore » of Copper-Cobalt Catalysts for Syngas Concersion; Catalytic gasification of Coal Chars by Potassium Sulfate and Ferrous Sulfate Mixtures; A New Method for Cleaning and Beneficiation of Ultrafine Coal; Characterization Studies of Coal-Derived Liquids; Study of Coal Liquefaction Catalysts and Removal of Certain Toxic Heavy Metal Ions from Coal Conversion Process Wastewaters.« less

Undergraduate research studies program at participating institutions of the HBCU Fossil Energy Consortium. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bota, K.B.

1991-12-31

The primary objective of this research program is to expose students in the Historically Black Colleges and Universities (HBCU) Fossil Energy Consortium Institutions to energy and fossil fuels research, to stimulate their interest in the sciences and engineering and to encourage them to pursue graduate studies. This report provides the research accomplishment of the various students who participated in the program. Research results are presented on the following topics: Energy Enhancement and Pollutant Reduction in Coal by Cryogenic Diminution; Competition of NO and SO{sub 2} for OH Generated witin Electrical Aerosol Analyzers; Dispersed Iron Catalysts for Coal Gasification; NQR/NMR Studiesmore » of Copper-Cobalt Catalysts for Syngas Concersion; Catalytic gasification of Coal Chars by Potassium Sulfate and Ferrous Sulfate Mixtures; A New Method for Cleaning and Beneficiation of Ultrafine Coal; Characterization Studies of Coal-Derived Liquids; Study of Coal Liquefaction Catalysts and Removal of Certain Toxic Heavy Metal Ions from Coal Conversion Process Wastewaters.« less

Catalytic ethanolysis and gasification of kraft lignin into aromatic alcohols and H2-rich gas over Rh supported on La2O3/CeO2-ZrO2.

PubMed

Yang, Jing; Zhao, Liang; Liu, Chunze; Wang, Yuanyuan; Dai, Liyi

2016-10-01

Efficient catalytic ethanolysis and gasification of kraft lignin were conducted over a versatile supported catalyst Rh/La2O3/CeO2-ZrO2 to give high-value aromatic alcohols and H2-rich gas. The removal of phenolic hydroxyl group was the most prevalent reaction, and importantly, almost no phenols, undesired char and saturating the aromatic ring were detected. Meanwhile, the feedstock and solvent both played key roles in H2 generation that contributed to the hydrodeoxygenation of liquid components and made the whole catalytic process out of H2 supply. Reusability tests of catalyst indicated that the crystalline phase transition and agglomeration of support, the loss of noble metal Rh and carbon deposition were the possible reasons for its deactivation in supercritical ethanol. Comparing with water, methanol and isopropanol system, ethanol was the only effective solvent for the depolymerization process. Copyright © 2016 Elsevier Ltd. All rights reserved.

Process for gasifying carbonaceous material from a recycled condensate slurry

DOEpatents

Forney, Albert J.; Haynes, William P.

1981-01-01

Coal or other carbonaceous material is gasified by reaction with steam and oxygen in a manner to minimize the problems of effluent water stream disposal. The condensate water from the product gas is recycled to slurry the coal feed and the amount of additional water or steam added for cooling or heating is minimized and preferably kept to a level of about that required to react with the carbonaceous material in the gasification reaction. The gasification is performed in a pressurized fluidized bed with the coal fed in a water slurry and preheated or vaporized by indirect heat exchange contact with product gas and recycled steam. The carbonaceous material is conveyed in a gas-solid mixture from bottom to top of the pressurized fluidized bed gasifier with the solids removed from the product gas and recycled steam in a supported moving bed filter of the resulting carbonaceous char. Steam is condensed from the product gas and the condensate recycled to form a slurry with the feed coal carbonaceous particles.

A case-study of landfill minimization and material recovery via waste co-gasification in a new waste management scheme.

PubMed

Tanigaki, Nobuhiro; Ishida, Yoshihiro; Osada, Morihiro

2015-03-01

This study evaluates municipal solid waste co-gasification technology and a new solid waste management scheme, which can minimize final landfill amounts and maximize material recycled from waste. This new scheme is considered for a region where bottom ash and incombustibles are landfilled or not allowed to be recycled due to their toxic heavy metal concentration. Waste is processed with incombustible residues and an incineration bottom ash discharged from existent conventional incinerators, using a gasification and melting technology (the Direct Melting System). The inert materials, contained in municipal solid waste, incombustibles and bottom ash, are recycled as slag and metal in this process as well as energy recovery. Based on this new waste management scheme with a co-gasification system, a case study of municipal solid waste co-gasification was evaluated and compared with other technical solutions, such as conventional incineration, incineration with an ash melting facility under certain boundary conditions. From a technical point of view, co-gasification produced high quality slag with few harmful heavy metals, which was recycled completely without requiring any further post-treatment such as aging. As a consequence, the co-gasification system had an economical advantage over other systems because of its material recovery and minimization of the final landfill amount. Sensitivity analyses of landfill cost, power price and inert materials in waste were also conducted. The higher the landfill costs, the greater the advantage of the co-gasification system has. The co-gasification was beneficial for landfill cost in the range of 80 Euro per ton or more. Higher power prices led to lower operation cost in each case. The inert contents in processed waste had a significant influence on the operating cost. These results indicate that co-gasification of bottom ash and incombustibles with municipal solid waste contributes to minimizing the final landfill amount and has great possibilities maximizing material recovery and energy recovery from waste. Copyright © 2014 Elsevier Ltd. All rights reserved.

Pyrolysis and gasification of landfilled plastic wastes with Ni-Mg-La/Al2O3 catalyst.

PubMed

Kaewpengkrow, Prangtip; Atong, Duangduen; Sricharoenchaikul, Viboon

2012-12-01

Pyrolysis and gasification processes were utilized to study the feasibility of producing fuels from landfilled plastic wastes. These wastes were converted in a gasifier at 700-900 degrees C. The equivalence ratio (ER) was varied from 0.4-0.6 with or without addition ofa Ni-Mg-La/Al2O3 catalyst. The pyrolysis and gasification of plastic wastes without catalyst resulted in relatively low H2, CO and other fuel gas products with methane as the major gaseous species. The highest lower heating value (LHV) was obtained at 800 degrees C and for an ER of 0.4, while the maximum cold gas efficiency occurred at 700 degrees C and for an ER of 0.4. The presence of the Ni-Mg-La/Al2O3 catalyst significantly enhanced H2 and CO production as well as increasing the gas energy content to 15.76-19.26 MJ/m3, which is suitable for further usage as quality fuel gas. A higher temperature resulted in more H2 and CO and other product gas yields, while char and liquid (tars) decreased. The maximum gas yield, gas calorific value and cold gas efficiency were achieved when the Ni-Mg-La/Al2O3 catalyst was used at 900 degrees C. In general, addition of prepared catalyst resulted in greater H2, CO and other light hydrocarbon yields from superior conversion of wastes to these gases. Thus, thermochemical treatment of these problematic wastes using pyrolysis and gasification processes is a very attractive alternative for sustainable waste management.

Effect of H2O on the NO emission characteristics of pulverized coal during oxy-fuel combustion.

PubMed

Lei, Ming; Sun, Cen; Zou, Chan; Mi, Hang; Wang, Chunbo

2018-04-01

The NO emission characteristics of Datong bituminous coal and Yangquan anthracite in O 2 /H 2 O/CO 2 atmospheres were investigated by using a fixed-bed reactor system, and the emission characteristics were compared with the experimental results from O 2 /N 2 and O 2 /CO 2 atmospheres, especially at low O 2 concentrations and high temperatures. The results showed that NO emissions of pulverized coal in O 2 /CO 2 environments were less than those in the O 2 /N 2 environments, regardless of the O 2 concentration and the furnace temperature. Adding H 2 O decreased the possibility of reactions between the reductive groups (NH) and the oxygen radical during devolatilization, which led to a decrease in NO emissions at 1000 °C. However, as the furnace temperature increased, "additional" nitrogen precursors (HCN and NH 3 ) generated by enhanced char-H 2 O gasification were quickly oxidized to generate a large amount of NO during char oxidation that exceeded the amount of NO reduced by NH during devolatilization. Thus, the NO emissions in O 2 /CO 2 /H 2 O atmosphere were higher than those in O 2 /CO 2 atmosphere at a low O 2 concentration. However, as the O 2 concentration increased, the NO emissions in O 2 /CO 2 /H 2 O atmosphere became lower than those in O 2 /CO 2 atmosphere because the effect of H 2 O gasification became weaker. The NO emissions of Yangquan anthracite (YQ) were higher than those of DT, but the changing trend of YQ was similar to that of DT.

Effects of thermal pretreatment and catalyst on biomass gasification efficiency and syngas composition

DOE PAGES

Cheah, Singfoong; Jablonski, Whitney S.; Olstad, Jessica L.; ...

2016-09-16

This work explores the combined effects of thermal pretreatment and using a catalyst in situ on gasification carbon conversion efficiency, as well as product gas and tar content and compositions. To compare the effects of thermal pretreatment, pelletized and ground oak with three different levels of thermal pretreatment were gasified in a fluidized bed reactor. The pretreatments applied to the oak were (1) pelletization, (2) drying at 180 °C in air, and (3) torrefaction at 270 °C in nitrogen. The oak dried at 180 °C produced syngas of similar quality and approximately the same amount of char as untreated oak.more » Torrefaction at 270 °C resulted in syngas with a higher hydrogen to CO ratio, lower methane, and less than half of the total tar -- all of which are desirable properties in terms of product gas quality. However, the oak torrefied at 270 °C also produced more than two times the amount of char as the untreated, pelletized oak. To determine the effect of catalyst, a series of experiments were conducted using olivine impregnated with nickel and cerium as the fluidized bed material in the gasifier. These tests showed that modified olivine can improve hydrogen production and reduce methane and tar levels in the syngas. The result was observed for both treated and untreated oak; although the effect was more substantial for untreated oak, for which the use of modified olivine reduced tar concentrations in the product gas by 60%, with a larger reduction in heavier tars than lighter tars. Furthermore, this result is important because reduction in heavier tar plays a more important role in benefitting downstream operations.« less

A case-study of landfill minimization and material recovery via waste co-gasification in a new waste management scheme

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanigaki, Nobuhiro, E-mail: tanigaki.nobuhiro@eng.nssmc.com; Ishida, Yoshihiro; Osada, Morihiro

Highlights: • A new waste management scheme and the effects of co-gasification of MSW were assessed. • A co-gasification system was compared with other conventional systems. • The co-gasification system can produce slag and metal with high-quality. • The co-gasification system showed an economic advantage when bottom ash is landfilled. • The sensitive analyses indicate an economic advantage when the landfill cost is high. - Abstract: This study evaluates municipal solid waste co-gasification technology and a new solid waste management scheme, which can minimize final landfill amounts and maximize material recycled from waste. This new scheme is considered for amore » region where bottom ash and incombustibles are landfilled or not allowed to be recycled due to their toxic heavy metal concentration. Waste is processed with incombustible residues and an incineration bottom ash discharged from existent conventional incinerators, using a gasification and melting technology (the Direct Melting System). The inert materials, contained in municipal solid waste, incombustibles and bottom ash, are recycled as slag and metal in this process as well as energy recovery. Based on this new waste management scheme with a co-gasification system, a case study of municipal solid waste co-gasification was evaluated and compared with other technical solutions, such as conventional incineration, incineration with an ash melting facility under certain boundary conditions. From a technical point of view, co-gasification produced high quality slag with few harmful heavy metals, which was recycled completely without requiring any further post-treatment such as aging. As a consequence, the co-gasification system had an economical advantage over other systems because of its material recovery and minimization of the final landfill amount. Sensitivity analyses of landfill cost, power price and inert materials in waste were also conducted. The higher the landfill costs, the greater the advantage of the co-gasification system has. The co-gasification was beneficial for landfill cost in the range of 80 Euro per ton or more. Higher power prices led to lower operation cost in each case. The inert contents in processed waste had a significant influence on the operating cost. These results indicate that co-gasification of bottom ash and incombustibles with municipal solid waste contributes to minimizing the final landfill amount and has great possibilities maximizing material recovery and energy recovery from waste.« less

Utilisation of biomass gasification by-products for onsite energy production.

PubMed

Vakalis, S; Sotiropoulos, A; Moustakas, K; Malamis, D; Baratieri, M

2016-06-01

Small scale biomass gasification is a sector with growth and increasing applications owing to the environmental goals of the European Union and the incentivised policies of most European countries. This study addresses two aspects, which are at the centre of attention concerning the operation and development of small scale gasifiers; reuse of waste and increase of energy efficiency. Several authors have denoted that the low electrical efficiency of these systems is the main barrier for further commercial development. In addition, gasification has several by-products that have no further use and are discarded as waste. In the framework of this manuscript, a secondary reactor is introduced and modelled. The main operating principle is the utilisation of char and flue gases for further energy production. These by-products are reformed into secondary producer gas by means of a secondary reactor. In addition, a set of heat exchangers capture the waste heat and optimise the process. This case study is modelled in a MATLAB-Cantera environment. The model is non-stoichiometric and applies the Gibbs minimisation principle. The simulations show that some of the thermal energy is depleted during the process owing to the preheating of flue gases. Nonetheless, the addition of a secondary reactor results in an increase of the electrical power production efficiency and the combined heat and power (CHP) efficiency. © The Author(s) 2016.

Dry coal feeder development program at Ingersoll-Rand Research, Incorporated. [for coal gasification systems

NASA Technical Reports Server (NTRS)

Mistry, D. K.; Chen, T. N.

1977-01-01

A dry coal screw feeder for feeding coal into coal gasification reactors operating at pressures up to 1500 psig is described. Results on the feeder under several different modes of operation are presented. In addition, three piston feeder concepts and their technical and economical merits are discussed.

Comparison of pyrolytic products produced from inorganic-rich and demineralized rice straw (Oryza sativa L.) by fluidized bed pyrolyzer for future biorefinery approach.

PubMed

Eom, In-Yong; Kim, Jae-Young; Lee, Soo-Min; Cho, Tae-Su; Yeo, Hwanmyeong; Choi, Joon-Weon

2013-01-01

The objectives of this study were to investigate the effects of inorganic constituents on the fast pyrolysis of the biomass and to determine the yields as well as physicochemical properties of pyrolytic products. The pyrolytic products were obtained from raw and demineralized rice straw using a fluidized bed type pyrolyzer at different temperatures. As pyrolysis temperature increased, total biooil yield gradually decreased from 46.6 to 29.6 wt.% for the raw-straw, and from 55.4 to 35.3 wt.% for the demineralized rice straw. For demineralized rice straw, higher pyrolysis temperatures promoted gasification reactions but reduced char formations. However, char yield for the raw-straw was relatively unaffected by temperature due to an increase in carbonization reactions that were catalyzed by some inorganics. Certain inorganic constituents in the biomass were distinctively distributed in the biooil, and ICP-ES and GC/MS analysis indicated that some inorganics may be chemically bound to cell wall components. Copyright © 2012 Elsevier Ltd. All rights reserved.

Measurement and modeling of advanced coal conversion processes, Volume II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Solomon, P.R.; Serio, M.A.; Hamblen, D.G.

1993-06-01

A two dimensional, steady-state model for describing a variety of reactive and nonreactive flows, including pulverized coal combustion and gasification, is presented. The model, referred to as 93-PCGC-2 is applicable to cylindrical, axi-symmetric systems. Turbulence is accounted for in both the fluid mechanics equations and the combustion scheme. Radiation from gases, walls, and particles is taken into account using a discrete ordinates method. The particle phase is modeled in a lagrangian framework, such that mean paths of particle groups are followed. A new coal-general devolatilization submodel (FG-DVC) with coal swelling and char reactivity submodels has been added.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chu, C.I.C.; Gillespie, B.L.

One of the most perplexing problems facing the coal industry is how to properly dispose of the waste and/or even recovery a small fraction of the Btu value of the waste, while minimizing the environmental concerns. UCC Research considers this monumental environmental problems as an opportunity to recovery useable organic materials and reduce the environmental problems created by coal waste. Mild gasification is the method used by UCC Research to realize these objectives. Coal feedstocks are fed into the mild gasification system yielding liquids, char, and gases for commercial application. The program consists of seven tasks: Task 1, Characterize Managementmore » of Coal Preparation Wastes; Task 2, Review Design Specifications and Prepare Preliminary Test Plan; Task 3, Select and Characterize Test Feedstocks; Task 4, Acquire/Construct Process Elements; Task 5, Prepare Final Test Plan; Task 6, Implement Final Test Plan; Task 7, Analyze Test Results and Assess System Economics. A schedule of the program is given. The program was initiated on September 30, 1984. Tasks 1, 2, 3, 4, 5, and 6 have been completed. Work is continuing on Task 7.« less

Integrated Biomass Gasification with Catalytic Partial Oxidation for Selective Tar Conversion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Lingzhi; Wei, Wei; Manke, Jeff

Biomass gasification is a flexible and efficient way of utilizing widely available domestic renewable resources. Syngas from biomass has the potential for biofuels production, which will enhance energy security and environmental benefits. Additionally, with the successful development of low Btu fuel engines (e.g. GE Jenbacher engines), syngas from biomass can be efficiently used for power/heat co-generation. However, biomass gasification has not been widely commercialized because of a number of technical/economic issues related to gasifier design and syngas cleanup. Biomass gasification, due to its scale limitation, cannot afford to use pure oxygen as the gasification agent that used in coal gasification.more » Because, it uses air instead of oxygen, the biomass gasification temperature is much lower than well-understood coal gasification. The low temperature leads to a lot of tar formation and the tar can gum up the downstream equipment. Thus, the biomass gasification tar removal is a critical technology challenge for all types of biomass gasifiers. This USDA/DOE funded program (award number: DE-FG36-O8GO18085) aims to develop an advanced catalytic tar conversion system that can economically and efficiently convert tar into useful light gases (such as syngas) for downstream fuel synthesis or power generation. This program has been executed by GE Global Research in Irvine, CA, in collaboration with Professor Lanny Schmidt's group at the University of Minnesota (UoMn). Biomass gasification produces a raw syngas stream containing H2, CO, CO2, H2O, CH4 and other hydrocarbons, tars, char, and ash. Tars are defined as organic compounds that are condensable at room temperature and are assumed to be largely aromatic. Downstream units in biomass gasification such as gas engine, turbine or fuel synthesis reactors require stringent control in syngas quality, especially tar content to avoid plugging (gum) of downstream equipment. Tar- and ash-free syngas streams are a critical requirement for commercial deployment of biomass-based power/heat co-generation and biofuels production. There are several commonly used syngas clean-up technologies: (1) Syngas cooling and water scrubbing has been commercially proven but efficiency is low and it is only effective at small scales. This route is accompanied with troublesome wastewater treatment. (2) The tar filtration method requires frequent filter replacement and solid residue treatment, leading to high operation and capital costs. (3) Thermal destruction typically operates at temperatures higher than 1000oC. It has slow kinetics and potential soot formation issues. The system is expensive and materials are not reliable at high temperatures. (4) In-bed cracking catalysts show rapid deactivation, with durability to be demonstrated. (5) External catalytic cracking or steam reforming has low thermal efficiency and is faced with problematic catalyst coking. Under this program, catalytic partial oxidation (CPO) is being evaluated for syngas tar clean-up in biomass gasification. The CPO reaction is exothermic, implying that no external heat is needed and the system is of high thermal efficiency. CPO is capable of processing large gas volume, indicating a very compact catalyst bed and a low reactor cost. Instead of traditional physical removal of tar, the CPO concept converts tar into useful light gases (eg. CO, H2, CH4). This eliminates waste treatment and disposal requirements. All those advantages make the CPO catalytic tar conversion system a viable solution for biomass gasification downstream gas clean-up. This program was conducted from October 1 2008 to February 28 2011 and divided into five major tasks. - Task A: Perform conceptual design and conduct preliminary system and economic analysis (Q1 2009 ~ Q2 2009) - Task B: Biomass gasification tests, product characterization, and CPO tar conversion catalyst preparation. This task will be conducted after completing process design and system economics analysis. Major milestones include identification of syngas cleaning requirements for proposed system design, identification and selection of tar compounds and 2 mixtures for use in CPO tests, and preparation of CPO catalysts for validation. (Q3 2009 ~ Q4 2009) - Task C: Test CPO with biomass gasification product gas. Optimize CPO performance with selected tar compounds. Optimize CPO performance with multi-component mixtures. Milestones include optimizing CPO catalysts design, collecting CPO experimental data for next stage kinetic modeling and understanding the effect of relative reactivities on ultimate tar conversion and syngas yields. (Q1 2010 ~ Q3 2010) - Task D: Develop tar CPO kinetic model with CPO kinetic model and modeling results as deliverables. (Q3 2010 ~ Q2 2011) - Task E: Project management and reporting. Milestone: Quarterly reports and presentations, final report, work presented at national technical conferences (Q1 2009 ~ Q2 2011) At the beginning of the program, IP landscaping was conducted to understand the operation of various types of biomass gasifiers, their unique syngas/tar compositions and potential tar mitigation options using the catalytic partial oxidation technology. A process simulation model was developed to quantify the system performance and economics impact of CPO tar removal technology. Biomass gasification product compositions used for performance evaluation tests were identified after literature review and system modeling. A reaction system for tar conversion tests was designed, constructed, with each individual component shaken-down in 2009. In parallel, University of Minnesota built a lab-scale unit and evaluated the tar removal performance using catalytic reforming. Benzene was used as the surrogate compound. The biomass gasification raw syngas composition was provided by GE through system studies. In 2010, GE selected different tar compounds and evaluated the tar removal effectiveness of the CPO catalyst. The catalytic performance was evaluated under different operating conditions, including catalyst geometry, S/C ratio, O/C ratio, GHSV, and N2 dilution. An understanding of how to optimize catalytic tar removal efficiency by varying operating conditions has been developed. GE collaborated with UoMn in examining inorganic impurities effects. Catalysts were pre-impregnated with inorganic impurities commonly present in biomass gasification syngas, including Si, Ca, Mg, Na, K, P and S. UoMn performed catalyst characterization and has acquired fundamental understandings of impurities effect on catalytic tar removal. Based on experimental data and the proposed reaction pathway, GE constructed a model to predict kinetic performance for biomass gasification tar cleanup process. Experimental data (eg. tar conversion, reactor inlet and outlet temperatures, product distribution) at different operating conditions were used to validate the model. A good fit between model predictions and experimental data was found. This model will be a valuable tool in designing the tar removal reactor and identifying appropriate operating conditions. We attended the 2011 DOE Biomass Program Thermochemical Platform Review held in Denver, CO from February 16 to 18 and received very positive comments from the review panel. Further, syngas utility and biomass to power/fuel companies expressed strong interest in our tar removal technology.« less

A techno-economic approach to plasma gasification

NASA Astrophysics Data System (ADS)

Ramos, Ana; Rouboa, Abel

2018-05-01

Within the most used Waste-to-Energy technologies plasma gasification is recent and therefore not yet widely commercialized. Thus, it is necessary to conduct a viability study to support the thorough understanding and implementation of this thermal treatment. This paper aims to assess some technical, environmental and economic aspects of plasma gasification paving the way for a more sustained waste management system, as well as taking advantage of the commodity assets granted by the technique. Therefore, results from previously published studies were updated and highlighted as a preliminary starting point in order to potentially evolve to a complete and systematic work.

Assessment of advanced coal gasification processes

NASA Technical Reports Server (NTRS)

Mccarthy, J.; Ferrall, J.; Charng, T.; Houseman, J.

1981-01-01

A technical assessment of the following advanced coal gasification processes is presented: high throughput gasification (HTG) process; single stage high mass flux (HMF) processes; (CS/R) hydrogasification process; and the catalytic coal gasification (CCG) process. Each process is evaluated for its potential to produce synthetic natural gas from a bituminous coal. Key similarities, differences, strengths, weaknesses, and potential improvements to each process are identified. The HTG and the HMF gasifiers share similarities with respect to: short residence time (SRT), high throughput rate, slagging, and syngas as the initial raw product gas. The CS/R hydrogasifier is also SRT, but is nonslagging and produces a raw gas high in methane content. The CCG gasifier is a long residence time, catalytic, fluidbed reactor producing all of the raw product methane in the gasifier.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vorres, K S

The overall accomplishments of the HYGAS program to date are that it has demonstrated the key process concepts and integrated unit operations of coal gasification. It has also demonstrated several methods of hydrogen generation, including catalytic steam reforming of natural gas, electrothermal gasification, and also steam-oxygen gasification. A total of 37 tests with lignite, including a total of 5500 tons of lignite processed, demonstrated the technical feasibility of a gasification process using lignite. A total of 17 tests with bituminous coal involved a total of 3100 tons. Some specific objectives of the HYGAS program for fiscal 1977 include tests tomore » be conducted with subbituminous coal. Data will be collected for use in the design of an effluent treatment and water reuse cycles in a commercial plant. New methanation catalysts will be tested. Materials testing will continue.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anastasia M. Gribik; Ronald E. Mizia; Harry Gatley

This project addresses both the technical and economic feasibility of replacing industrial gas in lime kilns with synthesis gas from the gasification of hog fuel. The technical assessment includes a materials evaluation, processing equipment needs, and suitability of the heat content of the synthesis gas as a replacement for industrial gas. The economic assessment includes estimations for capital, construction, operating, maintenance, and management costs for the reference plant. To perform these assessments, detailed models of the gasification and lime kiln processes were developed using Aspen Plus. The material and energy balance outputs from the Aspen Plus model were used asmore » inputs to both the material and economic evaluations.« less

Flow analysis of metals in a municipal solid waste management system.

PubMed

Jung, C H; Matsuto, T; Tanaka, N

2006-01-01

This study aimed to identify the metal flow in a municipal solid waste (MSW) management system. Outputs of a resource recovery facility, refuse derived fuel (RDF) production facility, carbonization facility, plastics liquefaction facility, composting facility, and bio-gasification facility were analyzed for metal content and leaching concentration. In terms of metal content, bulky and incombustible waste had the highest values. Char from a carbonization facility, which treats household waste, had a higher metal content than MSW incinerator bottom ash. A leaching test revealed that Cd and Pb in char and Pb in RDF production residue exceeded the Japanese regulatory criteria for landfilling, so special attention should be paid to final disposal of these substances. By multiplying metal content and the generation rate of outputs, the metal content of input waste to each facility was estimated. For most metals except Cr, the total contribution ratio of paper/textile/plastics, bulky waste, and incombustible waste was over 80%. Approximately 30% of Cr originated from plastic packaging. Finally, several MSW management scenarios showed that most metals are transferred to landfills and the leaching potential of metals to the environment is quite small.

Flow analysis of metals in a municipal solid waste management system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jung, C.H.; Matsuto, T.; Tanaka, N.

2006-07-01

This study aimed to identify the metal flow in a municipal solid waste (MSW) management system. Outputs of a resource recovery facility, refuse derived fuel (RDF) production facility, carbonization facility, plastics liquefaction facility, composting facility, and bio-gasification facility were analyzed for metal content and leaching concentration. In terms of metal content, bulky and incombustible waste had the highest values. Char from a carbonization facility, which treats household waste, had a higher metal content than MSW incinerator bottom ash. A leaching test revealed that Cd and Pb in char and Pb in RDF production residue exceeded the Japanese regulatory criteria formore » landfilling, so special attention should be paid to final disposal of these substances. By multiplying metal content and the generation rate of outputs, the metal content of input waste to each facility was estimated. For most metals except Cr, the total contribution ratio of paper/textile/plastics, bulky waste, and incombustible waste was over 80%. Approximately 30% of Cr originated from plastic packaging. Finally, several MSW management scenarios showed that most metals are transferred to landfills and the leaching potential of metals to the environment is quite small.« less

Reactivity of young chars via energetic distribution measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calo, J.M.; Lilly, W.D.

1991-01-01

The current project is directed at developing related techniques for the characterization and prediction/correlation of the reactivity of young'' chars to steam and oxygen. Of particular interest is mapping of the reactivity behavior of the resultant chars, as revealed by the energetic heterogeneity of the complexes with char preparation conditions; i.e., heating rate and ultimate temperature. In this first quarterly technical progress report we present the background of the project and the research program for the proposed investigations. The following work was accomplished on the experimental apparatus: a new set of electronics for the UTi quadrupole mass spectrometer head wasmore » purchased and delivered. The Temperature Programmed Desorption (TPD) System was moved to another laboratory and interfaced with the mass spectrometer system. A Polycold{trademark} freon refrigeration system was repaired and interfaced with the vacuum system for the TPD apparatus. It will be used to cool the diffusion pump trap. 60 refs.« less

Development of advanced, continuous mild gasification process for the production of co-products

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ness, R.O. Jr.; Aulich, T.R.

1991-05-01

The current objective of the University of North Dakota Energy and Environmental Research Center (EERC) mild gasification project is to optimize reaction char and marketable liquids production on a 100-lb/hr scale using Wyodak subbituminous and Indiana No. 3 bituminous coals. Tests performed using the EERC 100-lb/hr process development unit (PDU) include a refractory-cure (Test P001), a test using petroleum coke (Test P002), and tests using Wyodak and Indiana coals. The reactor system used for the 11 PDU tests conducted to date consists of a spouted, fluid-bed carbonizer equipped with an on-line condensation train that yields three boiling point fractions ofmore » coal liquids ranging in volatility from about (77{degrees}--750{degrees}F) (25{degrees}--400{degrees}C). The September--December 1990 quarterly report described reaction conditions and the bulk of the analytical results for Tests P010 and P011. This report describes further P010 and P011 analytical work, including the generation of simulated distillation curves for liquid samples on the basis of sulfur content, using gas chromatography coupled with atomic emission detection (GC/AED) analysis. 13 figs., 3 tabs.« less

An innovative example of herb residues recycling by gasification in a fluidized bed.

PubMed

Guo, Feiqiang; Dong, Yuping; Dong, Lei; Jing, Yuanzhuo

2013-04-01

A utilization way of herb residues is designed to convert herb residues to gas fuel in industrial-scale by a circulating fluidized bed gasifier in this paper. The product gas is used in the production of Chinese medicine, and the heat of the flue gas from the boiler can be used in herb residues drying to realize the energy recycling and no herb residues discharge. The gasification characteristics of herb residues in the circulating fluidized bed of 300 kg/h were investigated for about 200 h. The results indicated that the gas composition and tar yield were affected by biomass flow rate, equivalence ratio (ER), moisture content and char circulating. The lower heating value of product gas was 4-5 MJ/m(3) using herb residues as feedstock. When mean biomass flow rate was at 5.5 kg m(-2)s(-1) and ER at 0.35, the product gas reached a good condition with lower heating value of 4.89 MJ/m(3) and cold gas efficiency of 62.36%. When the moisture content changed from 12.5% to 18.7%, the concentrations of H2, CO and CO2 changed from 4.66% to 6.92%, 11.23% to 10.15%, and 16.55% to 17.82% respectively, and the tar content in gas decreased from 15.1g/m(3) to 14.4 g/m(3) when the moisture content increased from 12.5% to 15.4%. There are metal oxides in the ash of herb residues, especially CaO, MgO, K2O, Al2O3, and Fe2O3 which have obvious function on tar catalytic decomposition. The ash that attaches to the char particles can decrease the tar yield and improve the quality of gas after returning to the gasifier. Copyright © 2012 Elsevier Ltd. All rights reserved.

A review of technologies and performances of thermal treatment systems for energy recovery from waste.

PubMed

Lombardi, Lidia; Carnevale, Ennio; Corti, Andrea

2015-03-01

The aim of this work is to identify the current level of energy recovery through waste thermal treatment. The state of the art in energy recovery from waste was investigated, highlighting the differences for different types of thermal treatment, considering combustion/incineration, gasification and pyrolysis. Also different types of wastes - Municipal Solid Waste (MSW), Refuse Derived Fuel (RDF) or Solid Refuse Fuels (SRF) and some typologies of Industrial Waste (IW) (sludge, plastic scraps, etc.) - were included in the analysis. The investigation was carried out mainly reviewing papers, published in scientific journals and conferences, but also considering technical reports, to gather more information. In particular the goal of this review work was to synthesize studies in order to compare the values of energy conversion efficiencies measured or calculated for different types of thermal processes and different types of waste. It emerged that the dominant type of thermal treatment is incineration associated to energy recovery in a steam cycle. When waste gasification is applied, the produced syngas is generally combusted in a boiler to generate steam for energy recovery in a steam cycle. For both the possibilities--incineration or gasification--co-generation is the mean to improve energy recovery, especially for small scale plants. In the case of only electricity production, the achievable values are strongly dependent on the plant size: for large plant size, where advanced technical solutions can be applied and sustained from an economic point of view, net electric efficiency may reach values up to 30-31%. In small-medium plants, net electric efficiency is constrained by scale effect and remains at values around 20-24%. Other types of technical solutions--gasification with syngas use in internally fired devices, pyrolysis and plasma gasification--are less common or studied at pilot or demonstrative scale and, in any case, offer at present similar or lower levels of energy efficiency. Copyright © 2014 Elsevier Ltd. All rights reserved.

Coal gasification systems engineering and analysis. Volume 1: Executive summary

NASA Technical Reports Server (NTRS)

1980-01-01

Feasibility analyses and systems engineering studies for a 20,000 tons per day medium Btu (MBG) coal gasification plant to be built by TVA in Northern Alabama were conducted. Major objectives were as follows: (1) provide design and cost data to support the selection of a gasifier technology and other major plant design parameters, (2) provide design and cost data to support alternate product evaluation, (3) prepare a technology development plan to address areas of high technical risk, and (4) develop schedules, PERT charts, and a work breakdown structure to aid in preliminary project planning. Volume one contains a summary of gasification system characterizations. Five gasification technologies were selected for evaluation: Koppers-Totzek, Texaco, Lurgi Dry Ash, Slagging Lurgi, and Babcock and Wilcox. A summary of the trade studies and cost sensitivity analysis is included.

Investigation on by-products of bioenergy systems (anaerobic digestion and gasification) as potential crop nutrient using FTIR, XRD, SEM analysis and phyto-toxicity test.

PubMed

Kataki, Sampriti; Hazarika, Samarendra; Baruah, D C

2017-07-01

Success and acceptability of the bio energy conversion technology to a large extent depend upon management of the inevitable by-products generated during the conversion process. By-products can be considered favourable as organic fertilizer as they retain nutrients with varying composition depending upon input biomass. However, characteristics of these heterogeneous resources with respect to feedstock and processing conditions have to be assessed to state on their agricultural and environmental benefits. Therefore, 3 types of anaerobic digestion by-products (digestate) from surplus biomass viz. cow dung, Ipomoea carnea:cow dung (60:40 dry weight basis) and rice straw:green gram stover:cow dung (30:30:40 dry weight basis) and one gasification by-product (biochar) from rice husk are considered to understand the fertilizer prospects. Considering 3 potential application options, digestate from each feedstock option was further processed as separated solid, separated liquid and ash from solid digestates. Thus, a total of 10 by-products were investigated for understanding their prospects as fertilizer using Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive X ray Spectroscopy (EDX) and phyto-toxicity test to have a broad insight in terms of their organic, mineral, elemental composition, morphological feature and potential phyto-toxicity. In general, irrespective of origin of feedstock, solid digestate, ash digestate and char showed similarity in terms of composition of functional groups with some degree of variation in relative content as reflected by FTIR analysis. Dominance of organic functional groups in separated solid digestates compared to liquid fraction indicated the former as favourable organic amendments. Quartz was the prevalent mineral phase in all separated solid, ash digestate and rice husk char. Digestates in ash phase represent more concentrated plant nutrient source with higher content of K, Ca, P, Na and Mg than their respective solid phase. Application of ash digestates and char is likely to improve adsorptive capacity of soil for water and nutrient due to presence of relatively uniformly distributed porous particles. Liquid fraction of Ipomoea digestates exhibited inhibitory effect on seed germination of greengram (Vigna radiate) with significant reduction of germination index. Inhibitory effects of by-products were found to correlate negatively with their electrical conductivity and ammonia-nitrogen content. Understanding on spectroscopic, morphological and phytotoxic properties of different application options of bioenergy by-products would be useful for assessment of their appropriate use in agriculture. Copyright © 2017 Elsevier Ltd. All rights reserved.

A review of technologies and performances of thermal treatment systems for energy recovery from waste

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lombardi, Lidia, E-mail: lidia.lombardi@unicusano.it; Carnevale, Ennio; Corti, Andrea

2015-03-15

Highlights: • The topic of energy recovery from waste by thermal treatment is reviewed. • Combustion, gasification and pyrolysis were considered. • Data about energy recovery performances were collected and compared. • Main limitations to high values of energy performances were illustrated. • Diffusion of energy recovery from waste in EU, USA and other countries was discussed. - Abstract: The aim of this work is to identify the current level of energy recovery through waste thermal treatment. The state of the art in energy recovery from waste was investigated, highlighting the differences for different types of thermal treatment, considering combustion/incineration,more » gasification and pyrolysis. Also different types of wastes – Municipal Solid Waste (MSW), Refuse Derived Fuel (RDF) or Solid Refuse Fuels (SRF) and some typologies of Industrial Waste (IW) (sludge, plastic scraps, etc.) – were included in the analysis. The investigation was carried out mainly reviewing papers, published in scientific journals and conferences, but also considering technical reports, to gather more information. In particular the goal of this review work was to synthesize studies in order to compare the values of energy conversion efficiencies measured or calculated for different types of thermal processes and different types of waste. It emerged that the dominant type of thermal treatment is incineration associated to energy recovery in a steam cycle. When waste gasification is applied, the produced syngas is generally combusted in a boiler to generate steam for energy recovery in a steam cycle. For both the possibilities – incineration or gasification – cogeneration is the mean to improve energy recovery, especially for small scale plants. In the case of only electricity production, the achievable values are strongly dependent on the plant size: for large plant size, where advanced technical solutions can be applied and sustained from an economic point of view, net electric efficiency may reach values up to 30–31%. In small-medium plants, net electric efficiency is constrained by scale effect and remains at values around 20–24%. Other types of technical solutions – gasification with syngas use in internally fired devices, pyrolysis and plasma gasification – are less common or studied at pilot or demonstrative scale and, in any case, offer at present similar or lower levels of energy efficiency.« less

CFD-Modeling of the Multistage Gasifier Capacity of 30 KW

NASA Astrophysics Data System (ADS)

Levin, A. A.; Kozlov, A. N.; Svishchev, D. A.; Donskoy, I. G.

2017-11-01

Single-stage fuel gasification processes have been developed and widely studied in Russia and abroad throughout the 20th century. They are fundamental to the creation and design of modern gas generator equipment. Many studies have shown that single-stage gasification process, have already reached the limit of perfection, which was a significant improvement in their performance becomes impossible and unprofitable. The most fully meet modern technical requirements of multistage gasification technology. In the first step of the process, is organized allothermic biomass pyrolysis using heat of exhaust gas and generating power plant. At this stage, the yield of volatile products (gas and tar) of fuel. In the second step, the layer of fuel is, the tar is decomposed by the action of hot air and steam, steam-gas mixture is formed further reacts with the charcoal in the third process stage. The paper presents a model developed by the authors of the multi-stage gasifier for wood chips. The model is made with the use of CFD-modeling software package (COMSOL Multiphisics). To describe the kinetics of wood pyrolysis and gasification of charcoal studies were carried out using a set of simultaneous thermal analysis. For this complex developed original methods of interpretation of measurements, including methods of technical analysis of fuels and determine the parameters of the detailed kinetics and mechanism of pyrolysis.

Achieving waste to energy through sewage sludge gasification using hot slags: syngas production

PubMed Central

Sun, Yongqi; Nakano, Jinichiro; Liu, Lili; Wang, Xidong; Zhang, Zuotai

2015-01-01

To relieve the environmental issues of sewage sludge (SS) disposal and greenhouse gas (GHG) emission in China, we proposed an integrated method for the first time to simultaneously deal with these two problems. The hot slags below 920 °C could act as a good heat carrier for sludge gasification and the increasing CO2 concentration in CO2/O2 atmospheres enhanced the production of CO and H2 at 400–800 °C. Three stages of syngas release were clearly identified by Gaussian fittings, i.e., volatile release, char transformation and fixed carbon reaction. Additionally, the effect of sulfur retention of slags and the synergy effect of the stabilization of toxic elements in the solid residuals were discovered in this study. Furthermore, a novel prototype of multiple industrial and urban systems was put forward, in which the produced CO + H2 could be utilized for direct reduced iron (DRI) production and the solid residuals of sludge ash and glassy slags would be applied as cementitious materials. For a steel plant with an annual production of crude steel of 10 million tons in China, the total annual energy saving and GHG emission reduction achieved are 3.31*105 tons of standard coal and 1.74*106 tons of CO2, respectively. PMID:26074060

Achieving waste to energy through sewage sludge gasification using hot slags: syngas production.

PubMed

Sun, Yongqi; Nakano, Jinichiro; Liu, Lili; Wang, Xidong; Zhang, Zuotai

2015-06-15

To relieve the environmental issues of sewage sludge (SS) disposal and greenhouse gas (GHG) emission in China, we proposed an integrated method for the first time to simultaneously deal with these two problems. The hot slags below 920 °C could act as a good heat carrier for sludge gasification and the increasing CO2 concentration in CO2/O2 atmospheres enhanced the production of CO and H2 at 400-800 °C. Three stages of syngas release were clearly identified by Gaussian fittings, i.e., volatile release, char transformation and fixed carbon reaction. Additionally, the effect of sulfur retention of slags and the synergy effect of the stabilization of toxic elements in the solid residuals were discovered in this study. Furthermore, a novel prototype of multiple industrial and urban systems was put forward, in which the produced CO + H2 could be utilized for direct reduced iron (DRI) production and the solid residuals of sludge ash and glassy slags would be applied as cementitious materials. For a steel plant with an annual production of crude steel of 10 million tons in China, the total annual energy saving and GHG emission reduction achieved are 3.31*10(5) tons of standard coal and 1.74*10(6) tons of CO2, respectively.

Hydrogen production from high moisture content biomass in supercritical water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Antal, M.J. Jr.; Xu, X.

1998-08-01

By mixing wood sawdust with a corn starch gel, a viscous paste can be produced that is easily delivered to a supercritical flow reactor by means of a cement pump. Mixtures of about 10 wt% wood sawdust with 3.65 wt% starch are employed in this work, which the authors estimate to cost about $0.043 per lb. Significant reductions in feed cost can be achieved by increasing the wood sawdust loading, but such an increase may require a more complex pump. When this feed is rapidly heated in a tubular flow reactor at pressures above the critical pressure of water (22more » MPa), the sawdust paste vaporizes without the formation of char. A packed bed of carbon catalyst in the reactor operating at about 650 C causes the tarry vapors to react with water, producing hydrogen, carbon dioxide, and some methane with a trace of carbon monoxide. The temperature and history of the reactor`s wall influence the hydrogen-methane product equilibrium by catalyzing the methane steam reforming reaction. The water effluent from the reactor is clean. Other biomass feedstocks, such as the waste product of biodiesel production, behave similarly. Unfortunately, sewage sludge does not evidence favorable gasification characteristics and is not a promising feedstock for supercritical water gasification.« less

Achieving waste to energy through sewage sludge gasification using hot slags: syngas production

NASA Astrophysics Data System (ADS)

Sun, Yongqi; Nakano, Jinichiro; Liu, Lili; Wang, Xidong; Zhang, Zuotai

2015-06-01

To relieve the environmental issues of sewage sludge (SS) disposal and greenhouse gas (GHG) emission in China, we proposed an integrated method for the first time to simultaneously deal with these two problems. The hot slags below 920 °C could act as a good heat carrier for sludge gasification and the increasing CO2 concentration in CO2/O2 atmospheres enhanced the production of CO and H2 at 400-800 °C. Three stages of syngas release were clearly identified by Gaussian fittings, i.e., volatile release, char transformation and fixed carbon reaction. Additionally, the effect of sulfur retention of slags and the synergy effect of the stabilization of toxic elements in the solid residuals were discovered in this study. Furthermore, a novel prototype of multiple industrial and urban systems was put forward, in which the produced CO + H2 could be utilized for direct reduced iron (DRI) production and the solid residuals of sludge ash and glassy slags would be applied as cementitious materials. For a steel plant with an annual production of crude steel of 10 million tons in China, the total annual energy saving and GHG emission reduction achieved are 3.31*105 tons of standard coal and 1.74*106 tons of CO2, respectively.

Feasibility study for underground coal gasification at the Krabi coal mine site, Thailand: Volume 1. Progress report, December 1--31, 1995; Export trade information

DOE Office of Scientific and Technical Information (OSTI.GOV)

Young, B.C.; Schmit, C.R.

The report, conducted by Energy and Environmental Research Center, was funded by the US Trade and Development Agency. The objective of this report was to determine the technical, environmental and economic feasibility of developing, demonstrating, and commercializing underground coal gasification (UCG) at the Krabi coal mine site in Southern Thailand. This is Volume 1, the Progress Report for the period December 1, 1995, through December 31, 1995.

Production of Jet Fuels from Coal Derived Liquids. Volume 1. Market Assessment for Liquid By-Products from the Great Plains Gasification Plant.

DTIC Science & Technology

1987-08-01

synthesis gas from the gasification plant. This scheme was modified by changing the hydrogen generation step. Instead of the cryogenic separation it...Affairs ASD/PA) and is releasable to the National Technical Information Service NTIS). At NTIS, it will be available to the general public, including...58 Modified El Paso By-Products Schem 158 59 Modified El Paso Economics 158 60 Non-Hydrotreating El Paso Scheme 162 61 Non-Hydrotreating El Paso

High efficiency power generation from coal and wastes utilizing high temperature air combustion technology (Part 1: Performance of pebble bed gasifier for coal and wastes)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kosaka, Hitoshi; Iwahashi, Takashi; Yoshida, Nobuhiro

1998-07-01

A new concept of a gasifier for coal and wastes is proposed where entrained bed and fixed pebble bed are combined. Main features of this pebble bed gasifier are high efficiency molten slag capture, high efficiency gasification and compactness. Coal and RFD combustion experiments using the pebble bed gasifier demonstrated high efficiency capture and continuous extraction of molten slag as well as complete char combustion with extra ordinarily short residence time of pulverized coal and crushed RDF at the temperature level of about 1,500 C within the pebble bed. Durability tests using high temperature electric furnace has shown that highmore » density alumna is a good candidate for pebble material.« less

Unconventional Coal in Wyoming: IGCC and Gasification of Direct Coal Liquefaction Residue

NASA Astrophysics Data System (ADS)

Schaffers, William Clemens

Two unconventional uses for Wyoming Powder River Basin coal were investigated in this study. The first was the use of coal fired integrated gasification combined cycle (IGCC) plants to generate electricity. Twenty-eight different scenarios were modeled using AspenPlusRTM software. These included slurry, mechanical and dried fed gasifiers; Wyodak and Green River coals, 0%, 70%, and 90% CO2 capture; and conventional evaporative vs air cooling. All of the models were constructed on a feed basis of 6,900 tons of coal per day on an "as received basis". The AspenPlus RTM results were then used to create economic models using Microsoft RTM Excel for each configuration. These models assumed a 3 year construction period and a 30 year plant life. Results for capital and operating costs, yearly income, and internal rates of return (IRR) were compared. In addition, the scenarios were evaluated to compare electricity sales prices required to obtain a 12% IRR and to determine the effects of a carbon emissions tax on the sales price. The second part of the study investigated the gasification potential of residue remaining from solvent extraction or liquefaction of Powder River Basin Coal. Coal samples from the Decker mine on the Wyoming-Montana border were extracted with tetralin at a temperature of 360°C and pressure of 250 psi. Residue from the extraction was gasified with CO2 or steam at 833°C, 900°C and 975°C at pressures of 0.1 and 0.4 MPa. Product gases were analyzed with a mass spectrometer. Results were used to determine activation energies, reaction order, reaction rates and diffusion effects. Surface area and electron microscopic analyses were also performed on char produced from the solvent extraction residue.

Coal gasification systems engineering and analysis. Appendix F: Critical technology items/issues

NASA Technical Reports Server (NTRS)

1980-01-01

Critical technology items and issues are defined in which there is a need for developmental research in order to assure technical and economic success for the state of the art of coal gasification in the United States. Technology development needs for the main processing units and the supporting units are discussed. While development needs are shown for a large number of systems, the most critical areas are associated with the gasifier itself and those systems which either feed the gasifier or directly receive products form the gasifier.

Technical Report Cellulosic Based Black Liquor Gasification and Fuels Plant Final Technical Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fornetti, Micheal; Freeman, Douglas

2012-10-31

The Cellulosic Based Black Liquor Gasification and Fuels Plant Project was developed to construct a black liquor to Methanol biorefinery in Escanaba, Michigan. The biorefinery was to be co-located at the existing pulp and paper mill, NewPage’s Escanaba Paper Mill and when in full operation would: • Generate renewable energy for Escanaba Paper Mill • Produce Methanol for transportation fuel of further refinement to Dimethyl Ether • Convert black liquor to white liquor for pulping. Black liquor is a byproduct of the pulping process and as such is generated from abundant and renewable lignocellulosic biomass. The biorefinery would serve tomore » validate the thermochemical pathway and economic models for black liquor gasification. It was a project goal to create a compelling new business model for the pulp and paper industry, and support the nation’s goal for increasing renewable fuels production and reducing its dependence on foreign oil. NewPage Corporation planned to replicate this facility at other NewPage Corporation mills after this first demonstration scale plant was operational and had proven technical and economic feasibility. An overview of the process begins with black liquor being generated in a traditional Kraft pulping process. The black liquor would then be gasified to produce synthesis gas, sodium carbonate and hydrogen sulfide. The synthesis gas is then cleaned with hydrogen sulfide and carbon dioxide removed, and fed into a Methanol reactor where the liquid product is made. The hydrogen sulfide is converted into polysulfide for use in the Kraft pulping process. Polysulfide is a known additive to the Kraft process that increases pulp yield. The sodium carbonate salts are converted to caustic soda in a traditional recausticizing process. The caustic soda is then part of the white liquor that is used in the Kraft pulping process. Cellulosic Based Black Liquor Gasification and Fuels Plant project set out to prove that black liquor gasification could produce transportation fuels and produce pulp at the same time. This has the added advantage of reducing or eliminating the need for a recovery boiler. The recovery boiler is an extremely expensive unit operation in the Kraft process and is key to the chemical recovery system that makes the Kraft process successful. Going to a gasification process with potentially higher energy efficiency, improve the pulping process and be more efficient with the use of wood. At the same time a renewable fuel product can be made. Cellulosic Based Black Liquor Gasification and Fuels Plant progressed with the design of the mill as Chemrec continued to work on their pilot plant data gathering. The design information helped to guide the pilot plant and vice versa. In the end, the design details showed that the process was technically feasible. However, at the relatively small size of this plant the specific capital cost was very high and could only be considered if the pulp operation needed to replace the recovery boiler. Some of the reasons for the costs being high are attributed to the many constraints that needed to be addressed in the pulping process. Additionally, the Methanol product did not have a vehicle fuel supply chain to enter into. A different product selection could have eliminated this issue. However, with the selected design, the installation at Escanaba Paper Mill was not economically feasible and the project was not pursued further.« less

Green-House-Gas-Reduced Coal-and-Biomass-to-Liquid-Based Jet Fuel (GHGR-CBTL) Process - Final Technical report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lux, Kenneth; Imam, Thamina; Chevanan, Nehru

This Final Technical Report describes the work and accomplishments of the project entitled, “Green-House-Gas-Reduced Coal-and-Biomass-to-Liquid-Based Jet Fuel (GHGR-CBTL) Process”. The main objective of the project was to raise the Technology Readiness Level (TRL) of the GHGR-CBTL fuel-production technology from TRL 4 to TRL 5 by producing a drop-in synthetic Jet Propellant 8 (JP-8) with a greenhouse-gas footprint less than or equal to petroleum-based JP-8 by utilizing mixtures of coal and biomass as the feedstock. The system utilizes the patented Altex fuel-production technology, which incorporates advanced catalysts developed by Pennsylvania State University. While the system was not fabricated and tested, majormore » efforts were expended to design the 1-TPD and a full-scale plant. The system was designed, a Block-Flow Diagram (BFD), a Process-Flow Diagram (PFD), and Piping-and-Instrumentation Diagrams (P&IDs) were produced, a Bill of Materials (BOM) and associated spec sheets were produced, commercially available components were selected and procured, custom components were designed and fabricated, catalysts were developed and screened for performance, and permitting activities were conducted. Optimization tests for JP-8 production using C2 olefin as the feed were performed over a range of temperatures, pressures and WHSVs. Liquid yields of between 63 to 65% with 65% JP-8 fraction (41-42% JP-8 yield) at 50 psig were achieved. Life-Cycle Analysis (LCA) was performed by Argonne National Laboratory (ANL), and a GHGR-CBTL module was added to the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET®) model. Based upon the experimental results, the plant design was reconfigured for zero natural-gas imports and minimal electricity imports. The LCA analysis of the reconfigured process utilizing the GREET model showed that if the char from the process was utilized to produce combined heat and power (CHP) then a feed containing 23 wt% biomass and 77 wt% lignite would be needed for parity with petroleum-based JP-8. If the char is not utilized for CHP, but sequestered in a land fill, 24 wt% biomass and 76 wt% lignite would be required. A TEA was performed on this configuration following DOE guidelines and using the ANL-developed GREET module that showed that the GHGR-CBTL TOC and ECO are 69% and 58% of those for the DOE FT-Liquids Baseline Case, respectively. This analysis shows that the economics of the GHGR-CBTL process are significantly better than a gasification/FT process. No technical barriers were identified. The lower costs and the detailed design that was performed under this project are being used by Altex to attract funding partners to move the GHGR-CBTL development forward.« less

Method and system including a double rotary kiln pyrolysis or gasification of waste material

DOEpatents

McIntosh, M.J.; Arzoumanidis, G.G.

1997-09-02

A method is described for destructively distilling an organic material in particulate form wherein the particulates are introduced through an inlet into one end of an inner rotating kiln ganged to and coaxial with an outer rotating kiln. The inner and outer kilns define a cylindrical annular space with the inlet being positioned in registry with the axis of rotation of the ganged kilns. During operation, the temperature of the wall of the inner rotary kiln at the inlet is not less than about 500 C to heat the particulate material to a temperature in the range of from about 200 C to about 900 C in a pyrolyzing atmosphere to reduce the particulate material as it moves from the one end toward the other end. The reduced particulates including char are transferred to the annular space between the inner and the outer rotating kilns near the other end of the inner rotating kiln and moved longitudinally in the annular space from near the other end toward the one end in the presence of oxygen to combust the char at an elevated temperature to produce a waste material including ash. Also, heat is provided which is transferred to the inner kiln. The waste material including ash leaves the outer rotating kiln near the one end and the pyrolysis vapor leaves through the particulate material inlet. 5 figs.

Method and system including a double rotary kiln pyrolysis or gasification of waste material

DOEpatents

McIntosh, Michael J.; Arzoumanidis, Gregory G.

1997-01-01

A method of destructively distilling an organic material in particulate form wherein the particulates are introduced through an inlet into one end of an inner rotating kiln ganged to and coaxial with an outer rotating kiln. The inner and outer kilns define a cylindrical annular space with the inlet being positioned in registry with the axis of rotation of the ganged kilns. During operation, the temperature of the wall of the inner rotary kiln at the inlet is not less than about 500.degree. C. to heat the particulate material to a temperature in the range of from about 200.degree. C. to about 900.degree. C. in a pyrolyzing atmosphere to reduce the particulate material as it moves from the one end toward the other end. The reduced particulates including char are transferred to the annular space between the inner and the outer rotating kilns near the other end of the inner rotating kiln and moved longitudinally in the annular space from near the other end toward the one end in the presence of oxygen to combust the char at an elevated temperature to produce a waste material including ash. Also, heat is provided which is transferred to the inner kiln. The waste material including ash leaves the outer rotating kiln near the one end and the pyrolysis vapor leaves through the particulate material inlet.

Australian Defense.

DTIC Science & Technology

1979-12-01

the Joint Intelligence Organization ( JIO ) came into existence. It was only an analysis and information agency and did not collect intelligence. It was...34to provide expert technical analysis and the best kind of judgment on kinds of security problems that might arise." 3 The JIO brought sections of the... JIO char er detailed its function of intelligence assessments "on military, economic, scientific, and technical matters affecting Australia’s defence

Two stage fluid bed-plasma gasification process for solid waste valorisation: Technical review and preliminary thermodynamic modelling of sulphur emissions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morrin, Shane, E-mail: shane.morrin@ucl.ac.uk; Advanced Plasma Power, South Marston Business park, Swindon, SN3 4DE; Lettieri, Paola, E-mail: p.lettieri@ucl.ac.uk

2012-04-15

Highlights: Black-Right-Pointing-Pointer We investigate sulphur during MSW gasification within a fluid bed-plasma process. Black-Right-Pointing-Pointer We review the literature on the feed, sulphur and process principles therein. Black-Right-Pointing-Pointer The need for research in this area was identified. Black-Right-Pointing-Pointer We perform thermodynamic modelling of the fluid bed stage. Black-Right-Pointing-Pointer Initial findings indicate the prominence of solid phase sulphur. - Abstract: Gasification of solid waste for energy has significant potential given an abundant feed supply and strong policy drivers. Nonetheless, significant ambiguities in the knowledge base are apparent. Consequently this study investigates sulphur mechanisms within a novel two stage fluid bed-plasma gasification process.more » This paper includes a detailed review of gasification and plasma fundamentals in relation to the specific process, along with insight on MSW based feedstock properties and sulphur pollutant therein. As a first step to understanding sulphur partitioning and speciation within the process, thermodynamic modelling of the fluid bed stage has been performed. Preliminary findings, supported by plant experience, indicate the prominence of solid phase sulphur species (as opposed to H{sub 2}S) - Na and K based species in particular. Work is underway to further investigate and validate this.« less

Steam gasification of waste tyre: influence of process temperature on yield and product composition.

PubMed

Portofino, Sabrina; Donatelli, Antonio; Iovane, Pierpaolo; Innella, Carolina; Civita, Rocco; Martino, Maria; Matera, Domenico Antonio; Russo, Antonio; Cornacchia, Giacinto; Galvagno, Sergio

2013-03-01

An experimental survey of waste tyre gasification with steam as oxidizing agent has been conducted in a continuous bench scale reactor, with the aim of studying the influence of the process temperature on the yield and the composition of the products; the tests have been performed at three different temperatures, in the range of 850-1000°C, holding all the other operational parameters (pressure, carrier gas flow, solid residence time). The experimental results show that the process seems promising in view of obtaining a good quality syngas, indicating that a higher temperature results in a higher syngas production (86 wt%) and a lower char yield, due to an enhancement of the solid-gas phase reactions with the temperature. Higher temperatures clearly result in higher hydrogen concentrations: the hydrogen content rapidly increases, attaining values higher than 65% v/v, while methane and ethylene gradually decrease over the range of the temperatures; carbon monoxide and dioxide instead, after an initial increase, show a nearly constant concentration at 1000°C. Furthermore, in regards to the elemental composition of the synthesis gas, as the temperature increases, the carbon content continuously decreases, while the oxygen content increases; the hydrogen, being the main component of the gas fraction and having a small atomic weight, is responsible for the progressive reduction of the gas density at higher temperature. Copyright © 2012 Elsevier Ltd. All rights reserved.

ENGINEERING DEVELOPMENT OF COAL-FIRED HIGH-PERFORMANCE POWER SYSTEMS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Unknown

1999-02-01

A High Performance Power System (HIPPS) is being developed. This system is a coal-fired, combined cycle plant with indirect heating of gas turbine air. Foster Wheeler Development Corporation and a team consisting of Foster Wheeler Energy Corporation, Bechtel Corporation, University of Tennessee Space Institute and Westinghouse Electric Corporation are developing this system. In Phase 1 of the project, a conceptual design of a commercial plant was developed. Technical and economic analyses indicated that the plant would meet the goals of the project which include a 47 percent efficiency (HHV) and a 10 percent lower cost of electricity than an equivalentmore » size PC plant. The concept uses a pyrolysis process to convert coal into fuel gas and char. The char is fired in a High Temperature Advanced Furnace (HITAF). The HITAF is a pulverized fuel-fired boiler/air heater where steam is generated and gas turbine air is indirectly heated. The fuel gas generated in the pyrolyzer is then used to heat the gas turbine air further before it enters the gas turbine. The project is currently in Phase 2 which includes engineering analysis, laboratory testing and pilot plant testing. Research and development is being done on the HIPPS systems that are not commercial or being developed on other projects. Pilot plant testing of the pyrolyzer subsystem and the char combustion subsystem are being done separately, and after each experimental program has been completed, a larger scale pyrolyzer will be tested at the Power Systems Development Facility (PSDF) in Wilsonville, AL. The facility is equipped with a gas turbine and a topping combustor, and as such, will provide an opportunity to evaluate integrated pyrolyzer and turbine operation. This report addresses the areas of technical progress for this quarter. A general arrangement drawing of the char transfer system was forwarded to SCS for their review. Structural steel drawings were used to generate a three-dimensional model of the char transfer system including all pressure vessels and major piping components. Experimental testing at the Combustion and Environmental Test Facility continued during this quarter. Performance of the char burner, as benchmarked by flame stability and low NOx, has been exceptional. The burner was operated successfully both without natural gas and supplemental pulverized coal.« less

Mechanism of SO2 removal by carbon

USGS Publications Warehouse

Lizzio, Anthony A.; DeBarr, Joseph A.

1997-01-01

The reaction of SO2 with carbon (C) in the presence of O2 and H2O involves a series of reactions that leads to the formation of sulfuric acid as the final product. The rate-determining step in the overall process is the oxidation of SO2 to SO3. Three SO2 oxidation reactions are possible. Adsorbed SO2 (C−SO2) can react either with gas phase O2 or with adsorbed oxygen (C−O complex) to form sulfur trioxide (SO3), or gas phase SO2 can react directly with the C−O complex. In optimizing the SO2 removal capabilities of carbon, most studies only assume a given mechanism for SO2 adsorption and conversion to H2SO4 to be operable. The appropriate SO2 oxidation step and role of the C−O complex in this mechanism remain to be determined. The ultimate goal of this study was to prepare activated char from Illinois coal with optimal properties for low-temperature (80−150°C) removal of sulfur dioxide from coal combustion flue gas. The SO2 adsorption capacity of activated char was found to be inversely proportional to the amount of oxygen adsorbed on its surface. A temperature-programmed desorption technique was developed to titrate those sites responsible for adsorption of SO2 and conversion to H2SO4. On the basis of these results, a mechanism for SO2 removal by carbon was proposed. The derived rate expression showed SO2 adsorption to be dependent only on the fundamental rate constant and concentration of carbon atoms designated as free sites. Recent studies indicate a similar relationship exists between the rate of carbon gasification (in CO2 or H2O) and the number of reactive sites as determined by transient kinetics experiments. Utilizing the concept of active or free sites, it was possible to produce a char from Illinois coal having an SO2 adsorption capacity surpassing that of a commercial catalytic activated carbon.

Apparatus and method for solid fuel chemical looping combustion

DOEpatents

Siriwardane, Ranjani V; Weber, Justin M

2015-04-14

The disclosure provides an apparatus and method utilizing fuel reactor comprised of a fuel section, an oxygen carrier section, and a porous divider separating the fuel section and the oxygen carrier section. The porous divider allows fluid communication between the fuel section and the oxygen carrier section while preventing the migration of solids of a particular size. Maintaining particle segregation between the oxygen carrier section and the fuel section during solid fuel gasification and combustion processes allows gases generated in either section to participate in necessary reactions while greatly mitigating issues associated with mixture of the oxygen carrier with char or ash products. The apparatus and method may be utilized with an oxygen uncoupling oxygen carrier such as CuO, Mn.sub.3O.sub.4, or Co.sub.3O.sub.4, or utilized with a CO/H.sub.2 reducing oxygen carrier such as Fe.sub.2O.sub.3.

Combustion properties of Kraft Black Liquors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frederick, W.J. Jr.; Hupa, M.

1993-04-01

In a previous study of the phenomena involved in the combustion of black liquor droplets a numerical model was developed. The model required certain black liquor specific combustion information which was then not currently available, and additional data were needed for evaluating the model. The overall objectives of the project reported here was to provide experimental data on key aspects of black liquor combustion, to interpret the data, and to put it into a form which would be useful for computational models for recovery boilers. The specific topics to be investigated were the volatiles and char carbon yields from pyrolysismore » of single black liquor droplets; a criterion for the onset of devolatilization and the accompanying rapid swelling; and the surface temperature of black liquor droplets during pyrolysis, combustion, and gasification. Additional information on the swelling characteristics of black liquor droplets was also obtained as part of the experiments conducted.« less

A Technical Feasibility Study of a Green Area

DTIC Science & Technology

2012-09-01

40 Biomass Gasification Combined Cycle 40 Waste-to-Electricity 22 - 28 Nuclear 33 - 36 Table 21. Power Plants Efficiencies. After [17] 71 VI...10 6. Biomass and Biofuels ........................................................... 11 7. Earthquakes...31 5. Tidal Power ............................................................................. 32 6. Biomass and Biofuels

Technical assessment of discarded tires gasification as alternative technology for electricity generation.

PubMed

Machin, Einara Blanco; Pedroso, Daniel Travieso; de Carvalho, João Andrade

2017-10-01

Concern about contamination associated with the disposal of tires has led to the search for technologies to reuse discarded tires, which include the use of Tire Derived Fuel (TDF) as fuel in advanced thermal-conversion processes, this allows the energy use of these wastes at affordable costs and reduces the environmental impact on scrap tires disposal. A theoretical assessment of the technical viability of TDF gasification for electric and thermal power generation, from the producer gas combustion in an internal combustion engine and in a gas turbine, was performed. The combustion of producer gas derived from the gasification of TDF in an internal combustion engine driving a generator (ICE-G) appears as the more efficient route for electricity generation when compared with the efficiency obtained with the use of gas turbine (GT-G). A higher global efficiency, considering the electric and thermal generation efficiency can be expected with the use of TDF producer gas in GT-G, where is expected an overall efficiency of 77.49%. The assessment shows that is possible produces up to 7.67MJ and 10.62MJ of electric and thermal energy per kilogram of TDF gasified using an ICE-G and up to 6.06MJ and 13.03MJ of electric and thermal energy respectively per kilogram of gasified TDF using a GT-G. Copyright © 2017 Elsevier Ltd. All rights reserved.

Control technology appendices for pollution control technical manuals. Final report, June 1982-February 1983

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1983-04-01

The document is one of six technical handbooks prepared by EPA to help government officials granting permits to build synfuels facilities, synfuels process developers, and other interested parties. They provide technical data on waste streams from synfuels facilities and technologies capable of controlling them. Process technologies covered in the manuals include coal gasification, coal liquefaction by direct and idirect processing, and the extraction of oil from shale. The manuals offer no regulatory guidance, allowing the industry flexibility in deciding how best to comply with environmental regulations.

Biomass thermochemical gasification: Experimental studies and modeling

NASA Astrophysics Data System (ADS)

Kumar, Ajay

The overall goals of this research were to study the biomass thermochemical gasification using experimental and modeling techniques, and to evaluate the cost of industrial gas production and combined heat and power generation. This dissertation includes an extensive review of progresses in biomass thermochemical gasification. Product gases from biomass gasification can be converted to biopower, biofuels and chemicals. However, for its viable commercial applications, the study summarizes the technical challenges in the gasification and downstream processing of product gas. Corn stover and dried distillers grains with solubles (DDGS), a non-fermentable byproduct of ethanol production, were used as the biomass feedstocks. One of the objectives was to determine selected physical and chemical properties of corn stover related to thermochemical conversion. The parameters of the reaction kinetics for weight loss were obtained. The next objective was to investigate the effects of temperature, steam to biomass ratio and equivalence ratio on gas composition and efficiencies. DDGS gasification was performed on a lab-scale fluidized-bed gasifier with steam and air as fluidizing and oxidizing agents. Increasing the temperature resulted in increases in hydrogen and methane contents and efficiencies. A model was developed to simulate the performance of a lab-scale gasifier using Aspen Plus(TM) software. Mass balance, energy balance and minimization of Gibbs free energy were applied for the gasification to determine the product gas composition. The final objective was to optimize the process by maximizing the net energy efficiency, and to estimate the cost of industrial gas, and combined heat and power (CHP) at a biomass feedrate of 2000 kg/h. The selling price of gas was estimated to be 11.49/GJ for corn stover, and 13.08/GJ for DDGS. For CHP generation, the electrical and net efficiencies were 37 and 86%, respectively for corn stover, and 34 and 78%, respectively for DDGS. For corn stover, the selling price of electricity was 0.1351/kWh. For DDGS, the selling price of electricity was 0.1287/kWh.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

The US Department of Energy is funding an underground coal gasification (UCG) project in steeply dipping coal beds (SDB), at North Knobs, about 8 miles west of Rawlins, Carbon County, Wyoming. The project is being conducted to determine the technical, economic and environmental viability of such a technology. The development of SDB is an interesting target for UCG since such beds contain coals not normally mineable economically by ordinary techniques. Although the underground gasification of SDB has not been attempted in the US, Soviet experience and theoretical work indicate that the gasification of SDB in place offers all the advantagesmore » of underground gasification of horizontal coal seams plus some unique characteristics. The steep angle of dip helps to channel the produced gases up dip to offtake holes and permits the ash and rubble to fall away from the reaction zone helping to mitigate the blocking of the reaction zone in swelling coals. The intersection of SDB with the surface makes the seam accessible for drilling and other preparation. The tests at the North Knobs site will consist of three tests, lasting 20, 80 and 80 days, respectively. A total of 9590 tons of coal is expected to be gasified, with surface facilities utilizing 15 acres of the total section of land. The environmental effects of the experiment are expected to be very small. The key environmental impact is potential groundwater contamination by reaction products from coal gasification. There is good evidence that the surrounding coal effectively blocks the migration of these contaminants.« less

Techno-economic assessment of integrating methanol or Fischer-Tropsch synthesis in a South African sugar mill.

PubMed

Petersen, Abdul M; Farzad, Somayeh; Görgens, Johann F

2015-05-01

This study considered an average-sized sugar mill in South Africa that crushes 300 wet tonnes per hour of cane, as a host for integrating methanol and Fischer-Tropsch synthesis, through gasification of a combined flow of sugarcane trash and bagasse. Initially, it was shown that the conversion of biomass to syngas is preferably done by catalytic allothermal gasification instead of catalytic autothermal gasification. Thereafter, conventional and advanced synthesis routes for both Methanol and Fischer-Tropsch products were simulated with Aspen Plus® software and compared by technical and economic feasibility. Advanced FT synthesis satisfied the overall energy demands, but was not economically viable for a private investment. Advanced methanol synthesis is also not viable for private investment since the internal rate of return was 21.1%, because it could not provide the steam that the sugar mill required. The conventional synthesis routes had less viability than the corresponding advanced synthesis routes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Industrial demonstration plant for the gasification of herb residue by fluidized bed two-stage process.

PubMed

Zeng, Xi; Shao, Ruyi; Wang, Fang; Dong, Pengwei; Yu, Jian; Xu, Guangwen

2016-04-01

A fluidized bed two-stage gasification process, consisting of a fluidized-bed (FB) pyrolyzer and a transport fluidized bed (TFB) gasifier, has been proposed to gasify biomass for fuel gas production with low tar content. On the basis of our previous fundamental study, an autothermal two-stage gasifier has been designed and built for gasify a kind of Chinese herb residue with a treating capacity of 600 kg/h. The testing data in the operational stable stage of the industrial demonstration plant showed that when keeping the reaction temperatures of pyrolyzer and gasifier respectively at about 700 °C and 850 °C, the heating value of fuel gas can reach 1200 kcal/Nm(3), and the tar content in the produced fuel gas was about 0.4 g/Nm(3). The results from this pilot industrial demonstration plant fully verified the feasibility and technical features of the proposed FB two-stage gasification process. Copyright © 2016. Published by Elsevier Ltd.

Black liquor gasification integrated in pulp and paper mills: A critical review.

PubMed

Naqvi, M; Yan, J; Dahlquist, E

2010-11-01

Black liquor gasification (BLG) has potential to replace a Tomlinson recovery boiler as an alternative technology to increase safety, flexibility and energy efficiency of pulp and paper mills. This paper presents an extensive literature review of the research and development of various BLG technologies over recent years based on low and high temperature gasification that include SCA-Billerud process, Manufacturing and Technology Conversion International (MTCI) process, direct alkali regeneration system (DARS), BLG with direct causticization, Chemrec BLG system, and catalytic hydrothermal BLG. A few technologies were tested on pilot scale but most of them were abandoned due to technical inferiority and very fewer are now at commercial stage. The drivers for the commercialization of BLG enabling bio-refinery operations at modern pulp mills, co-producing pulp and value added energy products, are discussed. In addition, the potential areas of research and development in BLG required to solve the critical issues and to fill research knowledge gaps are addressed and highlighted. Copyright 2010 Elsevier Ltd. All rights reserved.

Fourth technical contractors' conference on peat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1981-01-01

This conference reported the status of the US Department of Energy Peat Program. The papers presented dealt with peat dewatering, international peat programs, environmental and socio-economic factors, peat gasification, peat harvesting, and the state peat surveys for 14 states. Separate abstracts were prepared for the individual papers. (CKK)

Critical analysis of pyrolysis process with cellulosic based municipal waste as renewable source in energy and technical perspective.

PubMed

Agarwal, Manu; Tardio, James; Venkata Mohan, S

2013-11-01

To understand the potential of cellulosic based municipal waste as a renewable feed-stock, application of pyrolysis by biorefinery approach was comprehensively studied for its practicable application towards technical and environmental viability in Indian context. In India, where the energy requirements are high, the pyrolysis of the cellulosic waste shows numerous advantages for its applicability as a potential waste-to-energy technology. The multiple energy outputs of the process viz., bio-gas, bio-oil and bio-char can serve the two major energy sectors, viz., electricity and transportation. The process suits best for high bio-gas and electrical energy production when energy input is satisfied from bio-char in form of steam (scheme-1). The bio-gas generated through the process shows its direct utility as a transportation fuel while the bio-oil produced can serve as fuel or raw material to chemical synthesis. On a commercial scale the process is a potent technology towards sustainable development. The process is self-sustained when operated on a continuous mode. Copyright © 2013 Elsevier Ltd. All rights reserved.

Thermal analysis and kinetics of coal during oxy-fuel combustion

NASA Astrophysics Data System (ADS)

Kosowska-Golachowska, Monika

2017-08-01

The pyrolysis and oxy-fuel combustion characteristics of Polish bituminous coal were studied using non-isothermal thermogravimetric analysis. Pyrolysis tests showed that the mass loss profiles were almost similar up to 870°C in both N2 and CO2 atmospheres, while further mass loss occurred in CO2 atmosphere at higher temperatures due to char-CO2 gasification. Replacement of N2 in the combustion environment by CO2 delayed the combustion of bituminous coal. At elevated oxygen levels, TG/DTG profiles shifted through lower temperature zone, ignition and burnout temperatures decreased and mass loss rate significantly increased and complete combustion was achieved at lower temperatures and shorter times. Kinetic analysis for the tested coal was performed using Kissinger-Akahira-Sunose (KAS) method. The activation energies of bituminous coal combustion at the similar oxygen content in oxy-fuel with that of air were higher than that in air atmosphere. The results indicated that, with O2 concentration increasing, the activation energies decreased.

A Fe-C-Ca big cycle in modern carbon-intensive industries: toward emission reduction and resource utilization

PubMed Central

Sun, Yongqi; Sridhar, Seetharaman; Seetharaman, Seshadri; Wang, Hao; Liu, Lili; Wang, Xidong; Zhang, Zuotai

2016-01-01

Herein a big Fe-C-Ca cycle, clarifying the basic element flows and energy flows in modern carbon-intensive industries including the metallurgical industry and the cement industry, was proposed for the first time in the contexts of emission reduction and iron ore degradation nowadays. This big cycle was focused on three industrial elements of Fe, C and Ca and thus it mainly comprised three interdependent loops, i.e., a C-cycle, a Fe-cycle and a Ca-path. As exemplified, we started from the integrated disposal of hot steel slags, a man-made iron resource via char gasification and the employment of hematite, a natural iron resource greatly extended the application area of this idea. Accordingly, based on this concept, the theoretical potentials for energy saving, emission reduction and Fe resource recovery achieved in modern industry are estimated up to 7.66 Mt of standard coal, 63.9 Mt of CO2 and 25.2 Mt of pig iron, respectively. PMID:26923104

A Fe-C-Ca big cycle in modern carbon-intensive industries: toward emission reduction and resource utilization

NASA Astrophysics Data System (ADS)

Sun, Yongqi; Sridhar, Seetharaman; Seetharaman, Seshadri; Wang, Hao; Liu, Lili; Wang, Xidong; Zhang, Zuotai

2016-02-01

Herein a big Fe-C-Ca cycle, clarifying the basic element flows and energy flows in modern carbon-intensive industries including the metallurgical industry and the cement industry, was proposed for the first time in the contexts of emission reduction and iron ore degradation nowadays. This big cycle was focused on three industrial elements of Fe, C and Ca and thus it mainly comprised three interdependent loops, i.e., a C-cycle, a Fe-cycle and a Ca-path. As exemplified, we started from the integrated disposal of hot steel slags, a man-made iron resource via char gasification and the employment of hematite, a natural iron resource greatly extended the application area of this idea. Accordingly, based on this concept, the theoretical potentials for energy saving, emission reduction and Fe resource recovery achieved in modern industry are estimated up to 7.66 Mt of standard coal, 63.9 Mt of CO2 and 25.2 Mt of pig iron, respectively.

Process for hydrocracking carbonaceous material in liquid carrier

DOEpatents

Duncan, Dennis A.

1980-01-01

Solid carbonaceous material is hydrocracked to provide aliphatic and aromatic hydrocarbons for use as gaseous and liquid fuels or chemical feed stock. Particulate carbonaceous material such as coal in slurry with recycled product oil is preheated in liquid state to a temperature of 600.degree.-1200.degree. F. in the presence of hydrogen gas. The product oil acts as a sorbing agent for the agglomerating bitumins to minimize caking within the process. In the hydrocracking reactor, the slurry of oil and carbonaceous particles is heated within a tubular passageway to vaporize the oil and form a gas-solid mixture which is further heated to a hydropyrolysis temperature in excess of 1200.degree. F. The gas-solid mixture is quenched by contact with additional oil to condense normally liquid hydrocarbons for separation from the gases. A fraction of the hydrocarbon liquid product is recycled for quenching and slurrying with the carbonaceous feed. Hydrogen is recovered from the gas for recycle and additional hydrogen is produced by gasification of residual char.

Energy and environmental research emphasizing low-rank coal: Task 3.7, Fuel utilization properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zygarlicke, C.J.

Gasification-type entrained ash and deposits were produced in a pressurized test furnace at high temperature. For the subbituminous Black Thunder coal, the effect of fuel-rich conditions was an increase in quartz, calcite, dolomite, and calcium-rich phases in the entrained ash. Lower particle temperatures, as compared to full air conventional combustion, and the oxygen-lean atmosphere may have caused a reduction in the interaction and assimilation of pure quartz and organically bound calcium into calcium aluminosilicate phases. For the Illinois No. 6 entrained fly ash fuel-rich conditions prevented the oxidation of pyrite and pyrrhotite to iron oxide. Lower temperatures within and surroundingmore » char particles during reducing conditions combustion may have prevented the decomposition of pyrrhotite and enhanced the reaction of iron with aluminosilicate phases. The deposits show similar trends, with the Illinois No. 6 deposit grown under pressurized conditions at a lower temperature having Na and (Ca, Mg, Fe, Na, K) aluminosilicates, calcium carbonate, and an iron sulfide, probably pyrrohotite, present. At higher temperature, loss of sulfur occurs with the increased formation of iron aluminosilicate phases. The Illinois No. 6 and Black Thunder coals were tested with kaolin and lime additives under highly reducing conditions to simulate a gasification environment. The deposit collection zone temperature was varied from 750{degree}C to 1OOO{degree}C. Although no clear trends were evident for the interaction of kaolin or lime with the deposits, the deposits did become more porous, with greatly reduced strength shown for both additives.« less

Effect of dry torrefaction on kinetics of catalytic pyrolysis of sugarcane bagasse

NASA Astrophysics Data System (ADS)

Daniyanto, Sutijan, Deendarlianto, Budiman, Arief

2015-12-01

Decreasing world reserve of fossil resources (i.e. petroleum oil, coal and natural gas) encourage discovery of renewable resources as subtitute for fossil resources. Biomass is one of the main natural renewable resources which is promising resource as alternate resources to meet the world's energy needs and raw material to produce chemical platform. Conversion of biomass, as source of energy, fuel and biochemical, is conducted using thermochemical process such as pyrolysis-gasification process. Pyrolysis step is an important step in the mechanism of pyrolysis - gasification of biomass. The objective of this study is to obtain the kinetic reaction of catalytic pyrolysis of dry torrified sugarcane bagasse which used Ca and Mg as catalysts. The model of kinetic reaction is interpreted using model n-order of single reaction equation of biomass. Rate of catalytic pyrolysis reaction depends on the weight of converted biomass into char and volatile matters. Based on TG/DTA analysis, rate of pyrolysis reaction is influenced by the composition of biomass (i.e. hemicellulose, cellulose and lignin) and inorganic component especially alkali and alkaline earth metallic (AAEM). From this study, it has found two equations rate of reaction of catalytic pyrolysis in sugarcane bagasse using catalysts Ca and Mg. First equation is equation of pyrolysis reaction in rapid zone of decomposition and the second equation is slow zone of decomposition. Value of order reaction for rapid decomposition is n > 1 and for slow decomposition is n<1. Constant and order of reactions for catalytic pyrolysis of dry-torrified sugarcane bagasse with presence of Ca tend to higher than that's of presence of Mg.

Evaluating the feasibility of underground coal gasification in Thailand

DOE Office of Scientific and Technical Information (OSTI.GOV)

Young, B.C.; Harju, J.A.; Schmit, C.R.

Underground coal gasification (UCG) is a clean coal technology that converts in situ coal into a low- to medium-grade product gas without the added expense of mining and reclamation. Potential candidates for UCG are those coal resources that are not economically recoverable or that are otherwise unacceptable for conventional coal utilization processes. The Energy and Environmental Research Center (EERC), through the sponsorship of the US Trade and Development Agency and in collaboration with the Electricity Generating Authority of Thailand (EGAT), is undertaking a feasibility study for the application of UCG in the Krabi coal mining area, 620 miles south ofmore » Bangkok in Thailand. The EERC`s objective for this project is to determine the technical, environmental, and economic feasibility of demonstrating and commercializing UCG at a selected site in the Krabi coal mining area. This paper addresses the preliminary developments and ongoing strategy for evaluating the selected UCG site. The technical, environmental, and economic factors for successful UCG operation are discussed, as well as the strategic issues pertaining to future energy expansion in southern Thailand.« less

Fixed bed gasification for production of industrial fuel gas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1977-10-01

This report summarizes the results of technical and economic evaluations of six commercially available, fixed-bed coal gasification processes for the production of industrial fuel gas. The study was performed for DOE and is intended to assist industrial companies in exploring the feasibility of producing gaseous fuels for both retrofit and new industrial plant situations. The report includes a technical analysis of the physical configuration, performance capabilities, and commercial experiments to-date for both air-blown and oxygen-blown fixed bed gasifiers. The product gas from these gasifiers is analyzed economically for three different degrees of cleanliness: (1) hot raw gas, (2) dust-, tar-,more » and oil-free gas, and (3) dust-, tar-, oil-free and desulfurized gas. The evaluations indicate that low-Btu gases produced from fixed bed gasifiers constitute one of the most logical short-term solutions for helping ease the shortage of natural gas for industrial fuel applications because the technology is well-proven and has been utilized on a commercial scale for several decades both in this country and overseas; time from initiation of design to commercial operation is about two years; the technology is not complicated to construct, operate, or maintain; and a reliable supply of product gas can be generated on-site. The advantages and disadvantages of fixed bed gasification technology are listed. The cost of the low Btu gas is estimated at $2 to $4 per MM Btu depending on gas purity, cost of coal ($20 to $50 per ton) and a number of specified assumptions with respect to financing, reliability, etc. (LTN)« less

New Polymeric Precursors of Silicon Carbide

NASA Technical Reports Server (NTRS)

Litt, M.; Kumar, K.

1987-01-01

Silicon carbide made by pyrolizing polymers. Method conceived for preparation of poly(decamethylcyclohexasilanes) as precursors for preparation of silicon carbide at high yield. Technical potential of polysilanes as precursors of SiC ceramics being explored. Potential limited by intractability of some polysilanes; formation of small, cyclic polycarbosilane fragments during pyrolysis; and overall low char yield and large shrinkage in conversion to ceramics.

Estimation of Coal Reserves for UCG in the Upper Silesian Coal Basin, Poland

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bialecka, Barbara

One of the prospective methods of coal utilization, especially in case of coal resources which are not mineable by means of conventional methods, is underground coal gasification (UCG). This technology allows recovery of coal energy 'in situ' and thus avoid the health and safety risks related to people which are inseparable from traditional coal extraction techniques.In Poland most mining areas are characterized by numerous coal beds where extraction was ceased on account of technical and economic reasons or safety issues. This article presents estimates of Polish hard coal resources, broken down into individual mines, that can constitute the basis ofmore » raw materials for the gasification process. Five mines, representing more than 4 thousand tons, appear to be UCG candidates.« less

A PC Program to Calculate the One-Sided Lower Tolerance Limit for Total Ionizing Dose Radiation Data

DTIC Science & Technology

1991-08-01

include <graphics .h> #define VEDIO OxlO #define ESC 27 1* Decelerations * FILE *pfile; FILE *outf; FILE *inf; mnt n; mnt un; float max scale...regs.h.ah=2; regs .h.dh=y; regs .h.dl=x; regs .h.bh=O; int86( VEDIO , ®s, ®s); char attribute(char blink, char back-color,char intensity, char...set lint mode) union REGS regs; regs.h.ah=O; regs h a l-mode; int86( VEDIO , ®s, ®s); void str-color (char x, char y, char *str, char blink, char

Modification of biochar for functionality improvement in soils

NASA Astrophysics Data System (ADS)

Zwart, Kor; Kuikman, Peter; Ross, Anrew; Takaya, Chibi; Singh, Surjit; Kocaturk, Pelin; Visser, Rian

2014-05-01

Application of biochar to soils is generally considered and practiced in order to improve specific soil functions such as CEC, moisture and nutrient retention and providing additional habitat for micro-organisms. Improvement of these soil functions should lead to a higher crop yield. This would be added value to the long term sequestration of carbon in soils and contribution to renewable energy from producing and using biochar. The concept of using biochar for soil amendment is predicated on biochar behaving in a similar manner as soil organic matter (SOM) does. However, if one critically compares the properties of biochar with the properties of SOM, it is evident that biochar is rather different from SOM [Zwart, 2013 ;Zwart & Kuikman, 2013]. We have has produced a range of biochar from different feedstock using pyrolysis, gasification and hydrothermal carbonisation resulting in chars with significantly different properties. The project also investigates and tested several possibilities for improving the functionality of biochar in soils by either(i) selection of feedstock, (ii), selection of processing conditions and (iii) chemical and physical modification of biochar during and after the production process. Post modification includes the chemical treatment of biochars with either H2O2, KOH, H2SO4 and transitional metals such as Fe and investigates their effect on surface functionality, porosity, surface area, CEC and phosphate sorption. The influence of the addition of chemical modifiers and oxidants during pyrolysis and gasification has also been investigated and their effect on surface functionality determined using similar techniques. The influence of the original biomass structure on the morphology of the resultant biochars has been investigated using scanning electron microscopy.

Century scale char and non-char C co-stabilization in soil free C fractions

NASA Astrophysics Data System (ADS)

Vasilyeva, N. A.; Chenu, C.

2012-04-01

Fate of char particles and reasons of char C stabilization in soils is not well understood especially due to difficulties of its quantification. In this study we showed how char C content could be estimated from elemental analysis along with its size redistribution and co-stabilization with non-char C in long-term. We studied C dynamics in the size and density fractons of soil samples from a historical collection of 80 years bare fallow (no plant input plus tillage) experiment in Versailles, France (1929, 1939, 1949, 1962, 1972, 1991, 2008 years). Coarse char particles were observed in the soil substantially contributing to total organic C. Thus, char C study in this soil was carried out as a nessessary step for estimation of non-char C dynamics. Physical fraction allowed us to follow separately the dynamics of mineral-associated and free C. We analyzed bulk soils, fractions and picked out char particles for C, N and 13C contents. Total organic carbon concentrations in fractions pointed to char C input during 1939-1949 years. After that patterns of C and C/N and δ 13C changes in all fractions suggested redistribution of char C from coarse to finer fractions. Evolution of C/N and δ 13C suggested that all free C fractions, although enriched in char, still contained non-char C in the end of the 80 years C depletion chronosequence. Especially high proportion of non-char C was observed in the silt-size free C fraction. Linear combinations of contrasting char and non-char C C/N values allowed estimation of their proportions from the C/N evolution in the fractions. No substantial admixture of char C was observed for mineral-associated C fractions. Stable C pool in 2008 comprised of 4.6 g C kg-1 soil and was composed of mineral-associated C (3.5 g C kg-1 soil) and char-associated C (1.1 g C kg-1 soil). In both cases organic matter could be stabilized through adsorption and/or occlusion with solid particles (mineral or char). Stabilization capacities of different size class minerals reflected in C concentrations of fractions were 1.2 g C kg-1 for silt-size minerals and 19.4 g C kg-1 for clay-size minerals, contrastingly three orders of magnitude more C was associated with char particles or about 1.2 kg non-char C kg-1 sand-size char and about 1.4 to 3.5 kg non-char C kg-1 silt-size char. Such a high capacity of stabilization by char particles could not be explained by adorbtion alone. In conclusion, combination of C/N and δ13C signature allowed estimation of char content in this soil. Total char C content (sum up of redistributed char C in free fractions) remained not significantly different in the C depletion experiment during five decades after char input. Century scale char and non-char C co-stabilization in this soil could be explained by combination of adsorption and physical protection in microaggregates constructed of mineral and char particles.

The prospect of hazardous sludge reduction through gasification process

NASA Astrophysics Data System (ADS)

Hakiki, R.; Wikaningrum, T.; Kurniawan, T.

2018-01-01

Biological sludge generated from centralized industrial WWTP is classified as toxic and hazardous waste based on the Indonesian’s Government Regulation No. 101/2014. The amount of mass and volume of sludge produced have an impact in the cost to manage or to dispose. The main objective of this study is to identify the opportunity of gasification technology which can be applied to reduce hazardous sludge quantity before sending to the final disposal. This preliminary study covers the technical and economic assessment of the application of gasification process, which was a combination of lab-scale experimental results and assumptions based on prior research. The results showed that the process was quite effective in reducing the amount and volume of hazardous sludge which results in reducing the disposal costs without causing negative impact on the environment. The reduced mass are moisture and volatile carbon which are decomposed, while residues are fix carbon and other minerals which are not decomposed by thermal process. The economical simulation showed that the project will achieve payback period in 2.5 years, IRR value of 53 % and BC Ratio of 2.3. The further study in the pilot scale to obtain the more accurate design and calculations is recommended.

Technical challenges and opportunities in cogasification of coal and biomass

Treesearch

Jagpinder Singh Brar; Kaushlendra Singh; John Zondlo

2013-01-01

Biomass gasification manufacturers are beginning to market 5 to 100 kW capacity gasifiers (e.g., Community Power Corporation (CPC), Littleton, CO and gasifier experimenters kit (GEK), AllPower Labs, Berkeley, CA) for producing electricity and synthetic gas (syngas). These gasifiers operate at 900 to 1000 °C, consuming 1.3 kg of biomass per hour for every kW...

Development of turbomachinery trains for the CASHING, NGCASH, and IGCASH cycle applications: Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gaul, G.; Nakhamkin, M.; Swensen, E.

1994-12-01

Turbomachinery trains were conceptually developed for three power plant concepts: Compressed Air Storage with Humidification and Integrated Gasification and Natural Gas Firing (CASHING), Natural Gas fired Compressed Air Storage with Humidification (NGCASH), and Integrated Gasification fired Compressed Air Storage with Humidification (IGCASH). Performance data, arrangement drawings, cost estimates, and other technical information for the three turboexpander trains were developed based on the Westinghouse BB51 steam turbine for the high pressure expander and the expander section of the W501F or W501D5 combustion turbine for the low pressure expander. The study supports previous EPRI projects investigating the performance and cost of CASHING,more » NGCASH, and IGCASH concepts and provides a basis for quotations that can be used in evaluating compressed air energy storage concepts in future projects.« less

Crystallographic Oxide Phase Identification of Char Deposits Obtained from Space Shuttle Columbia Window Debris

NASA Technical Reports Server (NTRS)

Olivas, J. D.; Wright, M. C.; Christoffersen, R.; Cone, D. M.; McDanels, S. J.

2009-01-01

Analyzing the remains of Space Shuttle Columbia has proven technically beneficial years after the vehicle breakup. This investigation focused on charred deposits on fragments of Columbia overhead windowpanes. Results were unexpected relative to the engineering understanding of material performance in a reentry environment. The TEM analysis demonstrated that the oxides of aluminum and titanium mixed with silicon oxides to preserve a history of thermal conditions to which portions of the vehicle were exposed. The presence of Ti during the beginning of the deposition process, along with the thermodynamic phase precipitation upon cool down, indicate that temperatures well above the Ti melt point were experienced. The stratified observations implied that additional exothermic reaction, expectedly metal combustion of a Ti structure, had to be present for oxide formation. Results are significant for aerospace vehicles where thermal protection system (TPS) breaches cause substructures to be in direct path with the reentry plasma. 1

Pyrolysis and oxy-fuel combustion characteristics and kinetics of petrochemical wastewater sludge using thermogravimetric analysis.

PubMed

Chen, Jianbiao; Mu, Lin; Cai, Jingcheng; Yao, Pikai; Song, Xigeng; Yin, Hongchao; Li, Aimin

2015-12-01

The pyrolysis and oxy-fuel combustion characteristics of petrochemical wastewater sludge (PS) were studied in air (O2/N2) and oxy-fuel (O2/CO2) atmospheres using non-isothermal thermogravimetric analysis (TGA). Pyrolysis experiments showed that the weight loss profiles were almost similar up to 1050K in both N2 and CO2 atmospheres, while further weight loss took place in CO2 atmosphere at higher temperatures due to char-CO2 gasification. Compared with 20%O2/80%N2, the drying and devolatilization stage of PS were delayed in 20%O2/80%CO2 due to the differences in properties of the diluting gases. In oxy-fuel combustion experiments, with O2 concentration increasing, characteristic temperatures decreased, while characteristic combustion rates and combustion performance indexes increased. Kinetic analysis of PS decomposition under various atmospheres was performed using Coats-Redfern approach. The results indicated that, with O2 concentration increasing, the activation energies of Step 1 almost kept constant, while the values of subsequent three steps increased. Copyright © 2015 Elsevier Ltd. All rights reserved.

Techno Economic Analysis of Hydrogen Production by gasification of biomass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Francis Lau

Biomass represents a large potential feedstock resource for environmentally clean processes that produce power or chemicals. It lends itself to both biological and thermal conversion processes and both options are currently being explored. Hydrogen can be produced in a variety of ways. The majority of the hydrogen produced in this country is produced through natural gas reforming and is used as chemical feedstock in refinery operations. In this report we will examine the production of hydrogen by gasification of biomass. Biomass is defined as organic matter that is available on a renewable basis through natural processes or as a by-productmore » of processes that use renewable resources. The majority of biomass is used in combustion processes, in mills that use the renewable resources, to produce electricity for end-use product generation. This report will explore the use of hydrogen as a fuel derived from gasification of three candidate biomass feedstocks: bagasse, switchgrass, and a nutshell mix that consists of 40% almond nutshell, 40% almond prunings, and 20% walnut shell. In this report, an assessment of the technical and economic potential of producing hydrogen from biomass gasification is analyzed. The resource base was assessed to determine a process scale from feedstock costs and availability. Solids handling systems were researched. A GTI proprietary gasifier model was used in combination with a Hysys(reg. sign) design and simulation program to determine the amount of hydrogen that can be produced from each candidate biomass feed. Cost estimations were developed and government programs and incentives were analyzed. Finally, the barriers to the production and commercialization of hydrogen from biomass were determined. The end-use of the hydrogen produced from this system is small PEM fuel cells for automobiles. Pyrolysis of biomass was also considered. Pyrolysis is a reaction in which biomass or coal is partially vaporized by heating. Gasification is a more general term, and includes heating as well as the injection of other ''ingredients'' such as oxygen and water. Pyrolysis alone is a useful first step in creating vapors from coal or biomass that can then be processed in subsequent steps to make liquid fuels. Such products are not the objective of this project. Therefore pyrolysis was not included in the process design or in the economic analysis. High-pressure, fluidized bed gasification is best known to GTI through 30 years of experience. Entrained flow, in contrast to fluidized bed, is a gasification technology applied at much larger unit sizes than employed here. Coal gasification and residual oil gasifiers in refineries are the places where such designs have found application, at sizes on the order of 5 to 10 times larger than what has been determined for this study. Atmospheric pressure gasification is also not discussed. Atmospheric gasification has been the choice of all power system pilot plants built for biomass to date, except for the Varnamo plant in Sweden, which used the Ahlstrom (now Foster Wheeler) pressurized gasifier. However, for fuel production, the disadvantage of the large volumetric flows at low pressure leads to the pressurized gasifier being more economical.« less

MM/T Program for Three Color Light Emitting Diode Display Modules.

DTIC Science & Technology

1981-10-01

DAVID, G W LEWIS DARKAS AG -C 0566 UNCLASSIFIED DELET-TR-RO 0566 1 ML 1.0 ______ 220 1.25 _ 1 .r DELET-TR- 80-0566-1 Research and Development Technical...is transmitted, followed by the "Literal" address of the pixel LA I16170 Sit 1034373S U~ T I I TABLE I SHIFTED ASCU CHAR. BINARY DEC. ASCU 3fHARY DEC

Evaluation of current techniques for isolation of chars as natural adsorbents

USGS Publications Warehouse

Chun, Y.; Sheng, G.; Chiou, C.T.

2004-01-01

Chars in soils or sediments may potentially influence the soil/sediment sorption behavior. Current techniques for the isolation of black carbon including chars rely often on acid demineralization, base extraction, and chemical oxidation to remove salts and minerals, humic acid, and refractory kerogen, respectively. Little is known about the potential effects of these chemical processes on the char surface and adsorptive properties. This study examined the effects of acid demineralization, base extraction, and acidic Cr2O72- oxidation on the surface areas, surface acidity, and benzene adsorption characteristics of laboratory-produced pinewood and wheat-residue chars, pure or mixed with soils, and a commercial activated carbon. Demineralization resulted in a small reduction in the char surface area, whereas base extraction showed no obvious effect. Neither demineralization nor base extraction caused an appreciable variation in benzene adsorption and presumably the char surface properties. By contrast, the Cr2O 72- oxidation caused a >31% reduction in char surface area. The Boehm titration, supplemented by FTIR spectra, indicated that the surface acidity of oxidized chars increased by a factor between 2.3 and 12 compared to nonoxidized chars. Benzene adsorption with the oxidized chars was lower than that with the non-oxidized chars by a factor of >8.9; both the decrease in char surface area and the increase in char surface acidity contributed to the reduction in char adsorptive power. Although the Cr 2O72- oxidation effectively removes resistant kerogen, it is not well suited for the isolation of chars as contaminant adsorbents because of its destructive nature. Alternative nondestructive techniques that preserve the char surface properties and effectively remove kerogen must be sought.

Development of efficient, integrated cellulosic biorefineries : LDRD final report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Teh, Kwee-Yan; Hecht, Ethan S.; Shaddix, Christopher R.

2010-09-01

Cellulosic ethanol, generated from lignocellulosic biomass sources such as grasses and trees, is a promising alternative to conventional starch- and sugar-based ethanol production in terms of potential production quantities, CO{sub 2} impact, and economic competitiveness. In addition, cellulosic ethanol can be generated (at least in principle) without competing with food production. However, approximately 1/3 of the lignocellulosic biomass material (including all of the lignin) cannot be converted to ethanol through biochemical means and must be extracted at some point in the biochemical process. In this project we gathered basic information on the prospects for utilizing this lignin residue material inmore » thermochemical conversion processes to improve the overall energy efficiency or liquid fuel production capacity of cellulosic biorefineries. Two existing pretreatment approaches, soaking in aqueous ammonia (SAA) and the Arkenol (strong sulfuric acid) process, were implemented at Sandia and used to generated suitable quantities of residue material from corn stover and eucalyptus feedstocks for subsequent thermochemical research. A third, novel technique, using ionic liquids (IL) was investigated by Sandia researchers at the Joint Bioenergy Institute (JBEI), but was not successful in isolating sufficient lignin residue. Additional residue material for thermochemical research was supplied from the dilute-acid simultaneous saccharification/fermentation (SSF) pilot-scale process at the National Renewable Energy Laboratory (NREL). The high-temperature volatiles yields of the different residues were measured, as were the char combustion reactivities. The residue chars showed slightly lower reactivity than raw biomass char, except for the SSF residue, which had substantially lower reactivity. Exergy analysis was applied to the NREL standard process design model for thermochemical ethanol production and from a prototypical dedicated biochemical process, with process data supplied by a recent report from the National Research Council (NRC). The thermochemical system analysis revealed that most of the system inefficiency is associated with the gasification process and subsequent tar reforming step. For the biochemical process, the steam generation from residue combustion, providing the requisite heating for the conventional pretreatment and alcohol distillation processes, was shown to dominate the exergy loss. An overall energy balance with different potential distillation energy requirements shows that as much as 30% of the biomass energy content may be available in the future as a feedstock for thermochemical production of liquid fuels.« less

Analysis of integrating compressed air energy storage concepts with coal gasification/combined-cycle systems for continuous power production. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakhamkin, M.; Patel, M.; Andersson, L.

1992-12-01

A previous study sponsored by EPRI concluded that integrating a compressed-air energy storage (CAES) plant with a coal-gasification system (CGS) can reduce the required capacity and cost of the expensive gasification system. The results showed that when compared at an equal plant capacity, the capital cost of the CGS portion of the integrated CAES/CGS plant can be reduced by as much as 30% relative to the same portion of an integrated gasification combined cycle (IGCC) plant. Furthermore, the capital cost of the CAES/CGS.plant, configured as a peaking unit, was found to be slightly lower than that of the base-load IGCCmore » plant. However, the overall economics of the CAES/CGS plant were adversely affected by the low capacity factor of the peak-load service, and ultimately, were found to be less attractive than the IGCC plant. The main objective of this study was to develop and analyze integrated CAES/CGS power plant concepts which provide for continuous (around-the-clock) operation of both the CAES reheat turboexpander train and the CGS facility. The developed concepts also provide utility-load management functions by driving the CAES compressor trains with off-peak electricity supplied through the grid. EPRI contracted with Energy Storage & Power Consultants, Inc. (ESPC) to develop conceptual designs, optimized performance characteristics, and preliminary cost data for these CAES/CGS concepts, and to provide a technical and cost comparison to the IGCC plant. The CAES/CGS concepts developed by ESPC for the current study contrast from those of Reference 1.« less

Analysis of integrating compressed air energy storage concepts with coal gasification/combined-cycle systems for continuous power production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakhamkin, M.; Patel, M.; Andersson, L.

1992-12-01

A previous study sponsored by EPRI concluded that integrating a compressed-air energy storage (CAES) plant with a coal-gasification system (CGS) can reduce the required capacity and cost of the expensive gasification system. The results showed that when compared at an equal plant capacity, the capital cost of the CGS portion of the integrated CAES/CGS plant can be reduced by as much as 30% relative to the same portion of an integrated gasification combined cycle (IGCC) plant. Furthermore, the capital cost of the CAES/CGS.plant, configured as a peaking unit, was found to be slightly lower than that of the base-load IGCCmore » plant. However, the overall economics of the CAES/CGS plant were adversely affected by the low capacity factor of the peak-load service, and ultimately, were found to be less attractive than the IGCC plant. The main objective of this study was to develop and analyze integrated CAES/CGS power plant concepts which provide for continuous (around-the-clock) operation of both the CAES reheat turboexpander train and the CGS facility. The developed concepts also provide utility-load management functions by driving the CAES compressor trains with off-peak electricity supplied through the grid. EPRI contracted with Energy Storage Power Consultants, Inc. (ESPC) to develop conceptual designs, optimized performance characteristics, and preliminary cost data for these CAES/CGS concepts, and to provide a technical and cost comparison to the IGCC plant. The CAES/CGS concepts developed by ESPC for the current study contrast from those of Reference 1.« less

Particle behavior and char burnout mechanisms under pressurized combustion conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bauer, C.M.; Spliethoff, H.; Hein, K.R.G.

Combined cycle systems with coal-fired gas turbines promise highest cycle efficiencies for this fuel. Pressurized pulverized coal combustion, in particular, yields high cycle efficiencies due to the high flue gas temperatures possible. The main problem, however, is to ensure a flue gas clean enough to meet the high gas turbine standards with a dirty fuel like coal. On the one hand, a profound knowledge of the basic chemical and physical processes during fuel conversion under elevated pressures is required whereas on the other hand suitable hot gas cleaning systems need to be developed. The objective of this work was tomore » provide experimental data to enable a detailed description of pressurized coal combustion processes. A series of experiments were performed with two German hvb coals, Ensdorf and Goettelborn, and one German brown coal, Garzweiler, using a semi-technical scale pressurized entrained flow reactor. The parameters varied in the experiments were pressure, gas temperature and bulk gas oxygen concentration. A two-color pyrometer was used for in-situ determination of particle surface temperatures and particle sizes. Flue gas composition was measured and solid residue samples taken and subsequently analyzed. The char burnout reaction rates were determinated varying the parameters pressure, gas temperature and initial oxygen concentration. Variation of residence time was achieved by taking the samples at different points along the reaction zone. The most influential parameters on char burnout reaction rates were found to be oxygen partial pressure and fuel volatile content. With increasing pressure the burn-out reactions are accelerated and are mostly controlled by product desorption and pore diffusion being the limiting processes. The char burnout process is enhanced by a higher fuel volatile content.« less

A feasibility study for underground coal gasification at Krabi Mine, Thailand

DOE Office of Scientific and Technical Information (OSTI.GOV)

Solc, J.; Steadman, E.N.; Boysen, J.E.

A study to evaluate the technical, economical, and environmental feasibility of underground coal gasification (UCG) in the Krabi Mine, Thailand, was conducted by the Energy and Environmental Research Center (EERC) in cooperation with B.C. Technologies (BCT) and the Electricity Generating Authority of Thailand (EGAT). The selected coal resource was found suitable to fuel a UCG facility producing 460,000 MJ/h (436 million Btu/h) of 100--125 Btu/scf gas for 20 years. The raw UCG gas could be produced for a selling price of $1.94/MMBtu. The UCG facility would require a total investment of $13.8 million for installed capital equipment, and annual operatingmore » expenses for the facility would be $7.0 million. The UCG gas could be either cofired in a power plant currently under construction or power a 40 MW simple-cycle gas turbine or a 60 MW combined-cycle power plant.« less

Efficiency of a hybrid-type plasma-assisted fuel reformation system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matveev, I.B.; Serbin, S.I.; Lux, S.M.

2008-12-15

The major advantages of a new plasma-assisted fuel reformation system are its cost effectiveness and technical efficiency. Applied Plasma Technologies has proposed its new highly efficient hybrid-type plasma-assisted system for organic fuel combustion and gasification. The system operates as a multimode multipurpose reactor in a wide range of plasma feedstock gases and turndown ratios. This system also has convenient and simultaneous feeding of several reagents in the reaction zone such as liquid fuels, coal, steam, and air. A special methodology has been developed for such a system in terms of heat balance evaluation and optimization. This methodology considers all existingmore » and possible energy streams, which could influence the system's efficiency. The developed hybrid-type plasma system could be suitable for combustion applications, mobile and autonomous small- to mid-size liquid fuel and coal gasification modules, hydrogen-rich gas generators, waste-processing facilities, and plasma chemical reactors.« less

Scale-up of mild gasification to be a process development unit mildgas 24 ton/day PDU design report. Final report, November 1991--July 1996

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

From November 1991 to April 1996, Kerr McGee Coal Corporation (K-M Coal) led a project to develop the Institute of Gas Technology (IGT) Mild Gasification (MILDGAS) process for near-term commercialization. The specific objectives of the program were to: design, construct, and operate a 24-tons/day adiabatic process development unit (PDU) to obtain process performance data suitable for further design scale-up; obtain large batches of coal-derived co-products for industrial evaluation; prepare a detailed design of a demonstration unit; and develop technical and economic plans for commercialization of the MILDGAS process. The project team for the PDU development program consisted of: K-M Coal,more » IGT, Bechtel Corporation, Southern Illinois University at Carbondale (SIUC), General Motors (GM), Pellet Technology Corporation (PTC), LTV Steel, Armco Steel, Reilly Industries, and Auto Research.« less

Preparation of porous bio-char and activated carbon from rice husk by leaching ash and chemical activation.

PubMed

Ahiduzzaman, Md; Sadrul Islam, A K M

2016-01-01

Preparation porous bio-char and activated carbon from rice husk char study has been conducted in this study. Rice husk char contains high amount silica that retards the porousness of bio-char. Porousness of rice husk char could be enhanced by removing the silica from char and applying heat at high temperature. Furthermore, the char is activated by using chemical activation under high temperature. In this study no inert media is used. The study is conducted at low oxygen environment by applying biomass for consuming oxygen inside reactor and double crucible method (one crucible inside another) is applied to prevent intrusion of oxygen into the char. The study results shows that porous carbon is prepared successfully without using any inert media. The adsorption capacity of material increased due to removal of silica and due to the activation with zinc chloride compared to using raw rice husk char. The surface area of porous carbon and activated carbon are found to be 28, 331 and 645 m(2) g(-1) for raw rice husk char, silica removed rice husk char and zinc chloride activated rice husk char, respectively. It is concluded from this study that porous bio-char and activated carbon could be prepared in normal environmental conditions instead of inert media. This study shows a method and possibility of activated carbon from agro-waste, and it could be scaled up for commercial production.

Coal-to-methanol: an engineering evaluation of Texaco gasification and ICI methanol-synthesis route. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buckingham, P.A.; Cobb, D.D.; Leavitt, A.A.

1981-08-01

This report presents the results of a technical and economic evaluation of producing methanol from bituminous coal using Texaco coal gasification and ICI methanol synthesis. The scope of work included the development of an overall configuration for a large plant comprising coal preparation, air separation, coal gasification, shift conversion, COS hydrolysis, acid gas removal, methanol synthesis, methanol refining, and all required utility systems and off-site facilities. Design data were received from both Texaco and ICI while a design and cost estimate were received from Lotepro covering the Rectisol acid gas removal unit. The plant processes 14,448 tons per day (drymore » basis) of Illinois No. 6 bituminous coal and produces 10,927 tons per day of fuel-grade methanol. An overall thermal efficiency of 57.86 percent was calculated on an HHV basis and 52.64 percent based on LHV. Total plant investment at an Illinois plant site was estimated to be $1159 million dollars in terms of 1979 investment. Using EPRI's economic premises, the first-year product costs were calculated to $4.74 per million Btu (HHV) which is equivalent to $30.3 cents per gallon and $5.37 per million Btu (LHV).« less

Mobility and Molecular Ions of Dimethyl Methyl Phosphonate, Methyl Salicylate, and Acetone.

DTIC Science & Technology

1983-06-01

MICRCOP REOUIO.ET1HR NICOCOPY BRESOUIO EST CHAR T AD .-..., CHEMICOL f.. SYSTEMS US Army Armament 11..: LABORATORY Research and Development Command _NTR...ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT PROJECT, TASK Commnde, Cemicl Sstes LaoraoryAREA & WORK U NIT’NUMBERS CommNder DARCemia Systems Laborato...Chemical Systems Laboratory, ATTN: DRDAR-CLJ-IR, Aberdeen Proving Ground, Maryland 21010. However, the Defense Technical Information Center and National

The effect of char structure on burnout during pulverized coal combustion at pressure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, G.; Wu, H.; Benfell, K.E.

An Australian bituminous coal sample was burnt in a drop tube furnace (DTF) at 1 atm and a pressurized drop tube furnace (PDTF) at 15 atm. The char samples were collected at different burnout levels, and a scanning electron microscope was used to examine the structures of chars. A model was developed to predict the burnout of char particles with different structures. The model accounts for combustion of the thin-walled structure of cenospheric char and its fragmentation during burnout. The effect of pressure on reaction rate was also considered in the model. As a result, approximately 40% and 70% cenosphericmore » char particles were observed in the char samples collected after coal pyrolysis in the DTF and PDTF respectively. A large number of fine particles (< 30 mm) were observed in the 1 atm char samples at burnout levels between 30% and 50%, which suggests that significant fragmentation occurred during early combustion. Ash particle size distributions show that a large number of small ash particles formed during burnout at high pressure. The time needed for 70% char burnout at 15 atm is approximately 1.6 times that at 1 atm under the same temperature and gas environment conditions, which is attributed to the different pressures as well as char structures. The overall reaction rate for cenospheric char was predicted to be approximately 2 times that of the dense chars, which is consistent with previous experimental results. The predicted char burnout including char structures agrees reasonably well with the experimental measurements that were obtained at 1 atm and 15 atm pressures.« less

The Effect of Polymer Char on Nitridation Kinetics of Silicon

NASA Technical Reports Server (NTRS)

Chan, Rickmond C.; Bhatt, Ramakrishna T.

1994-01-01

Effects of polymer char on nitridation kinetics of attrition milled silicon powder have been investigated from 1200 to 1350 C. Results indicate that at and above 1250 C, the silicon compacts containing 3.5 wt percent polymer char were fully converted to Si3N4 after 24 hr exposure in nitrogen. In contrast, the silicon compacts without polymer char could not be fully converted to Si3N4 at 1350 C under similar exposure conditions. At 1250 and 1350 C, the silicon compacts with polymer char showed faster nitridation kinetics than those without the polymer char. As the polymer char content is increased, the amount of SiC in the nitrided material is also increased. By adding small amounts (approx. 2.5 wt percent) of NiO, the silicon compacts containing polymer char can be completely nitrided at 1200 C. The probable mechanism for the accelerated nitridation of silicon containing polymer char is discussed.

Role of oxygen-containing functional groups in forest fire-generated and pyrolytic chars for immobilization of copper and nickel.

PubMed

Esfandbod, Maryam; Merritt, Christopher R; Rashti, Mehran Rezaei; Singh, Balwant; Boyd, Sue E; Srivastava, Prashant; Brown, Christopher L; Butler, Orpheus M; Kookana, Rai S; Chen, Chengrong

2017-01-01

Char as a carbon-rich material, can be produced under pyrolytic conditions, wildfires or prescribed burn offs for fire management. The objective of this study was to elucidate mechanistic interactions of copper (Cu 2+ ) and nickel (Ni 2+ ) with different chars produced by pyrolysis (green waste, GW; blue-Mallee, BM) and forest fires (fresh-burnt by prescribed fire, FC; aged char produced by wild fire, AC). The pyrolytic chars were more effective sorbents of Cu 2+ (∼11 times) and Ni 2+ (∼5 times) compared with the forest fire chars. Both cross-polarization (CPMAS-NMR) and Bloch decay (BDMAS-NMR) 13 C NMR spectroscopies showed that forest fire chars have higher woody components (aromatic functional groups) and lower polar groups (e.g. O-alkyl C) compared with the pyrolytic chars. The polarity index was greater in the pyrolytic chars (0.99-1.34) than in the fire-generated chars (0.98-1.15), while aromaticity was lower in the former than in the latter. Fourier transform infrared (FTIR) and Raman spectroscopies indicated the binding of carbonate and phosphate with both Cu 2+ and Ni 2+ in all chars, but with a greater extent in pyrolytic than forest fire-generated chars. These findings have demonstrated the key role of char's oxygen-containing functional groups in determining their sorption capacity for the Cu 2+ and Ni 2+ in contaminated lands. Copyright © 2016 Elsevier Ltd. All rights reserved.

GTI

DOE Office of Scientific and Technical Information (OSTI.GOV)

GTI

Biomass represents a large potential feedstock resource for environmentally clean processes that produce power or chemicals. It lends itself to both biological and thermal conversion processes and both options are currently being explored. Hydrogen can be produced in a variety of ways. The majority of the hydrogen produced in this country is produced through natural gas reforming and is used as chemical feedstock in refinery operations. In this report we will examine the production of hydrogen by gasification of biomass. Biomass is defined as organic matter that is available on a renewable basis through natural processes or as a by-productmore » of processes that use renewable resources. The majority of biomass is used in combustion processes, in mills that use the renewable resources, to produce electricity for end-use product generation. This report will explore the use of hydrogen as a fuel derived from gasification of three candidate biomass feedstocks: bagasse, switchgrass, and a nutshell mix that consists of 40% almond nutshell, 40% almond prunings, and 20% walnut shell. In this report, an assessment of the technical and economic potential of producing hydrogen from biomass gasification is analyzed. The resource base was assessed to determine a process scale from feedstock costs and availability. Solids handling systems were researched. A GTI proprietary gasifier model was used in combination with a Hysys. design and simulation program to determine the amount of hydrogen that can be produced from each candidate biomass feed. Cost estimations were developed and government programs and incentives were analyzed. Finally, the barriers to the production and commercialization of hydrogen from biomass were determined. The end-use of the hydrogen produced from this system is small PEM fuel cells for automobiles. Pyrolysis of biomass was also considered. Pyrolysis is a reaction in which biomass or coal is partially vaporized by heating. Gasification is a more general term, and includes heating as well as the injection of other ''ingredients'' such as oxygen and water. Pyrolysis alone is a useful first step in creating vapors from coal or biomass that can then be processed in subsequent steps to make liquid fuels. Such products are not the objective of this project. Therefore pyrolysis was not included in the process design or in the economic analysis. High-pressure, fluidized bed gasification is best known to GTI through 30 years of experience. Entrained flow, in contrast to fluidized bed, is a gasification technology applied at much larger unit sizes than employed here. Coal gasification and residual oil gasifiers in refineries are the places where such designs have found application, at sizes on the order of 5 to 10 times larger than what has been determined for this study. Atmospheric pressure gasification is also not discussed. Atmospheric gasification has been the choice of all power system pilot plants built for biomass to date, except for the Varnamo plant in Sweden, which used the Ahlstrom (now Foster Wheeler) pressurized gasifier. However, for fuel production, the disadvantage of the large volumetric flows at low pressure leads to the pressurized gasifier being more economical.« less

Development of Acid Functional Groups and Lactones During the Thermal Degradation of Wood and Wood Components

USGS Publications Warehouse

Rutherford, David W.; Wershaw, Robert L.; Reeves, James B.

2008-01-01

Black carbon (pyrogenic materials including chars) in soils has been recognized as a substantial portion of soil organic matter, and has been shown to play a vital role in nutrient cycling; however, little is known concerning the properties of this material. Previous studies have largely been concerned with the creation of high-surface-area materials for use as sorbents. These materials have been manufactured at high temperature and have often been activated. Chars occurring in the environment can be formed over a wide range of temperature. Because it is extremely difficult to isolate black carbon once it has been incorporated in soils, chars produced in the laboratory under controlled conditions can be used to investigate the range of properties possible for natural chars. This report shows that charring conditions (temperature and time) have substantial impact on the acid functional group and lactone content of chars. Low temperatures (250?C) and long charring times (greater than 72 hours) produce chars with the highest acid functional group and lactone content. The charring of cellulose appears to be responsible for the creation of the acid functional group and lactones. The significance of this study is that low-temperature chars can have acid functional group contents comparable to humic materials (as high as 8.8 milliequivalents per gram). Acid functional group and lactone content decreases as charring temperature increases. The variation in formation conditions expected under natural fire conditions will result in a wide range of sorption properties for natural chars which are an important component of soil organic matter. By controlling the temperature and duration of charring, it is possible to tailor the sorption properties of chars, which may be used as soil amendments.

Constitution of Drop-Tube-Generated Coal Chars from Vitrinite- and Inertinite-Rich South African Coals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Louw, Enette B.; Mitchell, Gareth D.; Wang, Juan

The structural transformations of coal and the resultant char morphologies are strongly dependent on the initial structure and degree of thermoplasticity achieved during coal-to-char transition. These are a function of petrographic composition, rank, particle size, and heating rate and strongly affect combustion behavior. This study compares the devolatilization and subsequent combustion behavior of an inertinite-rich (87.7% dmmf) and a vitrinite-rich (91.8% dmmf) South African coal, wet-screened to a narrow particle size distribution of 200 x 400 mesh. Pyrolysis chars were generated under rapid-heating conditions (104-105 °C/s) in a drop-tube reactor to closely resemble chars generated in pulverized combustion conditions. Themore » inertinite-rich coal took ~ 400 ms to devolatilize in the drop-tube, compared to only ~ 240 ms for the vitrinite-rich sample. The chemical and physical structure (the constitution) of the chars were investigated through a range of chemical, physical, and optical characteristics including the maceral differences, and high ash yields. To evaluate the combustion reactivity non-isothermal burn-out profiles were obtained through thermogravimetrical analyses (TGA) in air. The vitrinite-rich char had on average 20% higher reaction rates than the inertinite-rich char under the various combustion conditions. The char samples were de-ashed with HCl and HF acid which resulted in an increase in combustion reactivity. The maximum reaction rate of the high-ash (36% ash yield) inertinite-rich char increased with 80% after de-ashing. While the vitrinite-rich char with an ash yield of 15%, had a 20% increase in reactivity after de-ashing. The ash acted as a barrier, and the removal of ash most likely increased the access to reactive surface area. The chemical and physical structures of the chars were characterized through a range of different analytical techniques to quantify the factors contributing to reactivity differences. The morphologies of the chars were characterized with SEM and optical microscopy, while quantitative information on the ordered nature of chars was obtained through XRD on de-ashed chars. The inertinite-rich coal experienced limited fluidity during heat-treatment, resulting in slower devolatilization, limited growth in crystallite height (11.8 to 12.6Å), only rounding of particle edges, and producing > 40% of mixed-dense type chars. The vitrinite-char showed more significant structural transformations; producing mostly (80%) extensively swollen crassisphere, tenuisphere, and network-type chars, and XRD showed a large increase in crystallite height (4.3 to 11.7Å). Nitrogen adsorption and small-angle X-ray scattering (SAXS) were utilized to compare the nitrogen surface areas and pore size distributions. Both chars were mostly mesoporous but the inertinite-rich char had double the average pore size, which also resulted in a larger nitrogen surface area since nitrogen can only access surface areas in larger pores. The BET surface area was 3.9 and 2.7 m2/g for the inertinite- and vitrinite-rich chars respectively. SAXS data showed that the vitrinite-rich char had 60% higher frequencies of pores in the micropore range. Helium porosimetry indicated that the inertinite-rich coal and resultant char had higher densities than the vitrinite coal and char; 1.6 and 2.0 g/cm3, compared to 1.3 and 1.9 g/cm3 (dry basis). Non-isothermal TGA burnout profiles showed the inertinite-rich char had a burnout temperature of 680°C, slightly higher than the vitrinite-rich char’s 650 °C. This, along with the peak shape and position in the burnout profiles indicate that the vitrinite-rich char has a higher reactivity. The higher reactivity is due to a combination of factors likely including less organization, grater porosity and access to the reactive site, less ash blocking, and char morphology differences.« less

Conversion of municipal solid waste to hydrogen

NASA Astrophysics Data System (ADS)

Richardson, J. H.; Rogers, R. S.; Thorsness, C. B.

1995-04-01

LLNL and Texaco are cooperatively developing a physical and chemical treatment method for the conversion of municipal solid waste (MSW) to hydrogen via the steps of hydrothermal pretreatment, gasification and purification. LLNL's focus has been on hydrothermal pretreatment of MSW in order to prepare a slurry of suitable viscosity and heating value to allow efficient and economical gasification and hydrogen production. The project has evolved along 3 parallel paths: laboratory scale experiments, pilot scale processing, and process modeling. Initial laboratory-scale MSW treatment results (e.g., viscosity, slurry solids content) over a range of temperatures and times with newspaper and plastics will be presented. Viscosity measurements have been correlated with results obtained at MRL. A hydrothermal treatment pilot facility has been rented from Texaco and is being reconfigured at LLNL; the status of that facility and plans for initial runs will be described. Several different operational scenarios have been modeled. Steady state processes have been modeled with ASPEN PLUS; consideration of steam injection in a batch mode was handled using continuous process modules. A transient model derived from a general purpose packed bed model is being developed which can examine the aspects of steam heating inside the hydrothermal reactor vessel. These models have been applied to pilot and commercial scale scenarios as a function of MSW input parameters and have been used to outline initial overall economic trends. Part of the modeling, an overview of the MSW gasification process and the modeling of the MSW as a process material, was completed by a DOE SERS (Science and Engineering Research Semester) student. The ultimate programmatic goal is the technical demonstration of the gasification of MSW to hydrogen at the laboratory and pilot scale and the economic analysis of the commercial feasibility of such a process.

Coal reserves and resources as well as potentials for underground coal gasification in connection with carbon capture and storage (CCS)

NASA Astrophysics Data System (ADS)

Ilse, Jürgen

2010-05-01

Coal is the energy source with the largest geological availability worldwide. Of all non-renewable energies coal and lignite accounting for 55 % of the reserves and some 76 % of the resources represent the largest potential. Reserves are those geological quantities of a mineral which can currently be mined under technically and economically viable conditions. Resources are those quantities which are either proven but currently not economically recoverable or quantities which can still be expected or explored on the basis of geological findings. The global availability of energy source does not only depend on geological and economic factors. The technical availability, e.g. mining and preparation capacities, the sufficient availability of land and sea-borne transportation as well as transloading capacities and also a political availability are required likewise. The latter may be disturbed by domestic-policy disputes like strikes or unrest or by foreign-policy disputes like embargos, trade conflicts or even tensions and wars in the producing regions. In the energy-economic discussion the reach of fossil primary energies plays a central role with the most important questions being: when will which energy source be exhausted, which impact will future developments have on the energy price, what does the situation of the other energies look like and which alternatives are there? The reach of coal can only be estimated because of the large deposits on the one hand and the uncertain future coal use and demand on the other. The stronger growth of population and the economic catching-up process in the developing and threshold countries will result in a shift of the production and demand centres in the global economy. However, also in case of further increases the geological potential will be sufficient to reliably cover the global coal demand for the next 100 years. The conventional mining of seams at great depths or of thin seams reaches its technical and economic limits. However, these otherwise unprofitable coal deposits can be mined economically by means of underground coal gasification, during which coal is converted into a gaseous product in the deposit. The synthesis gas can be used for electricity generation, as chemical base material or for the production of petrol. This increases the usability of coal resources tremendously. At present the CCS technologies (carbon capture and storage) are a much discussed alternative to other CO2 abatement techniques like efficiency impovements. The capture and subsequent storage of CO2 in the deposits created by the actual underground gasification process seem to be technically feasible.

Effects of pressure on morphology and structure of bio-char from pressurized entrained-flow pyrolysis of microalgae.

PubMed

Maliutina, Kristina; Tahmasebi, Arash; Yu, Jianglong

2018-06-01

The present dataset describes the entrained-flow pyrolysis of Microalgae Chlorella vulgaris and the results obtained during bio-char characterization. The dataset includes a brief explanation of the experimental procedure, experimental conditions and the influence of pyrolysis conditions on bio-chars morphology and carbon structure. The data show an increase in sphericity and surface smoothness of bio-chars at higher pressures and temperatures. Data confirmed that the swelling ratio of bio-chars increased with pressure up to 2.0 MPa. Consequently, changes in carbon structure of bio-chars were investigated using Raman spectroscopy. The data showed the increase in carbon order of chars at elevated pressures. Changes in the chemical structure of bio-char as a function of pyrolysis conditions were investigated using FTIR analysis.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

The coal industry, the utilities, and the state government are planning for development of high-energy coal gasification in Illinois to convert its abundant high-sulfur coal supply to a substitute natural gas. Following a summary of the findings, the following topics are discussed briefly: Illinois coal and the push for coal gasification; coal gasification: a look at the process; potential sites for an Illinois coal gasification industry; the impact of coal gasification's water requirements; solid wastes from coal gasification; land losses: the impact on agriculture; potential human health problems with coal gasification; the energy efficiency of coal gasification; potential economic impactsmore » of coal gasification; the corporations behind high-energy coal gasification; state involvement: legalizing the losses of the people; the national energy picture: the impact of western coal developments on Illinois; action: what you can do now. 27 references. (MCW)« less

Method and apparatus for acoustically monitoring the flow of suspended solid particulate matter. [Patent application; monitoring char flow in coal gasifier

DOEpatents

Roach, P.D.; Raptis, A.C.

1980-11-24

A method and apparatus for monitoring char flow in a coal gasifier system includes flow monitor circuits which measure acoustic attenuation caused by the presence of char in a char line and provides a char flow/no flow indication and an indication of relative char density. The flow monitor circuits compute the ratio of signals in two frequency bands, a first frequency band representative of background noise, and a second higher frequency band in which background noise is attenuated by the presence of char. Since the second frequency band contains higher frequencies, the ratio can be used to provide a flow/no flow indication. The second band can also be selected so that attenuation is monotonically related to particle concentration, providing a quantitative measure of char concentration.

Subcellular distribution of trace elements and liver histology of landlocked Arctic char (Salvelinus alpinus) sampled along a mercury contamination gradient.

PubMed

Barst, Benjamin D; Rosabal, Maikel; Campbell, Peter G C; Muir, Derek G C; Wang, Xioawa; Köck, Günter; Drevnick, Paul E

2016-05-01

We sampled landlocked Arctic char (Salvelinus alpinus) from four lakes (Small, 9-Mile, North, Amituk) in the Canadian High Arctic that span a gradient of mercury contamination. Metals (Hg, Se, Tl, and Fe) were measured in char tissues to determine their relationships with health indices (relative condition factor and hepatosomatic index), stable nitrogen isotope ratios, and liver histology. A subcellular partitioning procedure was employed to determine how metals were distributed between potentially sensitive and detoxified compartments of Arctic char livers from a low- and high-mercury lake (Small Lake and Amituk Lake, respectively). Differences in health indices and metal concentrations among char populations were likely related to differences in feeding ecology. Concentrations of Hg, Se, and Tl were highest in the livers of Amituk char, whereas concentrations of Fe were highest in Small and 9-Mile char. At the subcellular level we found that although Amituk char had higher concentrations of Tl in whole liver than Small Lake char, they maintained a greater proportion of this metal in detoxified fractions, suggesting an attempt at detoxification. Mercury was found mainly in potentially sensitive fractions of both Small and Amituk Lake char, indicating that Arctic char are not effectively detoxifying this metal. Histological changes in char livers, mainly in the form of melano-macrophage aggregates and hepatic fibrosis, could be linked to the concentrations and subcellular distributions of essential or non-essential metals. Copyright © 2016 Elsevier Ltd. All rights reserved.

Molecular aspects of aromatic C additions to soils: Implications of char quality for ecosystem functionality

NASA Astrophysics Data System (ADS)

Keiluweit, M.; Nico, P. S.; Johnson, M. G.; Kleber, M.

2009-12-01

Solid residues of incomplete combustion (biochar or char) are continuously being added to soils due to natural vegetation fires in many ecosystems. However, new strategies for carbon sequestration in soils are likely to include the active addition of biochar to soils. Since biochar is a highly aromatic organic material such additions will modify the native molecular structure of soil organic matter and thus alter interactions with the global atmosphere and hydrosphere. Here we present a molecular level assessment of the physical organization and chemical complexity of biomass-derived chars and, specifically, that of aromatic carbon in char structures. Differences among wood and grass charred at temperatures from 100 to 700°C are investigated. BET-N2 surface area, X-ray diffraction (XRD), synchrotron-based Near-edge X-ray Absorption Fine Structure (NEXAFS) and Fourier transform infrared (FT-IR) spectroscopy results demonstrate how the two plant precursor materials undergo analogous, but quantitatively different physical-chemical transitions as charring intensity increases. These changes suggest the existence of four distinct physical and chemical categories of char. We find that each category of char consists of a unique mixture of chemical phases and physical states: (i) in transition chars the crystalline character of the precursor materials is preserved, (ii) in amorphous chars the heat-altered molecules and incipient aromatic polycondensates are randomly mixed, (iii) composite chars consist of poorly ordered graphene stacks embedded in amorphous phases, and (iv) turbostratic chars are dominated by turbostratic (disordered) graphitic crystallites. There is wide variation in both the chemical and the physical nature of aromatic carbon among these char categories. In this presentation we will point out how molecular variations among the aromatic components of the different char categories translate into differences in their ability to: (i) persist in the environment, (ii) function as environmental sorbents, and (iii) to enable the soil to provide environmental services.

Spatial and temporal trends of mercury and other metals in landlocked char from lakes in the Canadian Arctic archipelago.

PubMed

Muir, Derek; Wang, Xiaowa; Bright, Doug; Lockhart, Lyle; Köck, Günter

2005-12-01

Spatial and temporal trends of mercury (Hg) and 22 other elements were examined in landlocked Arctic char (Salvelinus alpinus) from six lakes in the Canadian Arctic (Char, Resolute and North Lakes, and Amituk Lake on Cornwallis Island, Sapphire Lake on Devon Island and Boomerang Lake on Somerset Island). The objectives of the study were to compare recent concentrations of Hg and other metals in char with older data from Amituk, Resolute and Char Lakes, in order to examine temporal trends as well as to investigate factors influencing spatial trends in contaminant levels such as lake characteristics, trophic position, size and age of the fish. Geometric mean Hg concentrations in dorsal muscle ranged from 0.147 microg/g wet weight (ww) in Resolute Lake to 1.52 microg/g ww in Amituk Lake for samples collected over the period 1999-2003. Char from Amituk Lake also had significantly higher selenium (Se). Mercury in char from Resolute Lake was strongly correlated with fish length, weight, and age, as well as with thallium, lead and Se. In 5 of 6 lakes, Hg concentrations were correlated with stable nitrogen isotope ratios (delta15N) and larger char were feeding at a higher trophic level presumably due to feeding on smaller char. Weight adjusted mean Hg concentrations in char from Amituk Lake, and unadjusted geometric means in Char Lake and Resolute Lakes, did not show any statistically significant increase from the early 1990s to 2003. However, small sample sizes from 1999-2003 for fish <1000 g limited the power of this comparison in Char and Amituk Lakes. In Resolute Lake char, manganese, strontium and zinc showed consistent decreases from 1997 or 1999 to 2003 while nickel generally increased over the 6 year period. Differences in char trophic level inferred from delta15N values best explained the higher concentrations of Hg in Amituk Lake compared to the other lakes.

Short- and medium-chain chlorinated paraffins in biota from the European Arctic -- differences in homologue group patterns.

PubMed

Reth, Margot; Ciric, Anita; Christensen, Guttorm N; Heimstad, Eldbjørg S; Oehme, Michael

2006-08-15

Congener and homologue group patterns of chlorinated paraffins (CPs) in biota can be influenced by different processes, but these are not well studied yet. Short- (SCCPs) and medium-chain chlorinated paraffins (MCCPs) were quantified in liver from Arctic char and seabirds (little auk and kittiwake) collected at Bear Island (European Arctic) as well as in cod from Iceland and Norway. CP concentrations were between 5 and 88 ng/g wet weight (ww) for SCCPs and between 5 and 55 ng/g ww for MCCPs with one exception of 370 ng/g measured in a liver sample from little auk. The SCCP homologue group patterns were compared with those of technical mixtures and of SCCPs present in cod liver from the Baltic Sea. The latter showed a more common SCCP homologue distribution (sum of C(11) and C(12)>60%) in contrast to cod liver from the Northwest of Europe, which had a high abundance of C(10) and C(12) congeners. Seabirds from Bear Island contained an equally distributed SCCP homologue group pattern. In Arctic char, the SCCP distribution was closer to technical products, but with a high proportion (average of 18.9%) of C(10) congeners. A comparison of C(10)/C(12) ratios confirmed the higher abundance of C(10) congeners in samples from higher latitudes. For the first time, MCCPs could be detected in Arctic samples. The average proportion of C(14) congeners was 65.8%. The C(14)/C(15) abundance ratio was similar to technical mixtures. High-chlorinated CPs (Cl(>7)) were also detectable. The average chlorine content of the SCCPs was 61.9% (59.0-63.3%), and that of the MCCPs 55.8% (54.5-57.4%).

Coal without carbon: an investment plan for federal action

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pettus, A.; Tatsutani, M.

2009-09-15

This study examines several technologies for CCS that are not currently receiving adequate development support but that could - in the right policy environment - provide the kind of significant cost reductions (and significant improvements in efficiency) that could greatly accelerate broad, economically attractive CCS deployment. Clean Air Task Force selected these technology areas (though not the technologies themselves) and solicited reports from experts in each field to explore how these technologies might fit into a broader CCS deployment strategy. Each expert was asked to develop a research, development, and demonstration (RD&D) 'road map' that could efficiently move each technologymore » from the laboratory into the commercial mainstream. Because the chapter authors are either technical experts or commercial players and are not, for the most part, energy policy experts, subsequent work will translate their RD&D recommendations into actionable policy proposals. The heart of this report consists of four chapters on advanced coal and CCS technologies: underground coal gasification (UCG), written by Julio Friedmann at Lawrence Livermore National Laboratory; Next generation coal gasification (surface-based gasification) led by Eric Redman at Summit Power Group; Advanced technologies for post-combustion capture (PCC) of CO{sub 2}, led by Howard Herzog at Massachusetts Institute of Technology; and RD&D to speed commercialization of geological CO{sub 2} sequestration (GCS), led by Julio Friedmann. 12 refs., 5 figs., 2 tabs.« less

Thermochemical conversion of waste tyres-a review.

PubMed

Labaki, Madona; Jeguirim, Mejdi

2017-04-01

A review of the energy recovery from waste tyres is presented and focuses on the three thermochemical processes used to valorise waste tyres: pyrolysis, gasification, and combustion/incineration. After recalling the chemical composition of tyres, the thermogravimetric behaviours of tyres or their components under different atmospheres are described. Different kinetic studies on the thermochemical processes are treated. Then, the three processes were investigated, with a particular attention given to the gasification, due to the information unavailability on this process. Pyrolysis is a thermochemical conversion to produce a hydrocarbon rich gas mixture, condensable liquids or tars, and a carbon-rich solid residue. Gasification is a form of pyrolysis, carried out at higher temperatures and under given atmosphere (air, steam, oxygen, carbon dioxide, etc.) in order to yield mainly low molecular weight gaseous products. Combustion is a process that needs a fuel and an oxidizer with an ignition system to produce heat and/or steam. The effects of various process parameters such as temperature, heating rate, residence time, catalyst addition, etc. on the energy efficiency and the products yields and characteristics are mainly reviewed. These thermochemical processes are considered to be the more attractive and practicable methods for recovering energy and material from waste tyres. For the future, they are the main promising issue to treat and valorise used tyres. However, efforts should be done in developing more efficient technical systems.

DOE Coal Gasification Multi-Test Facility: fossil fuel processing technical/professional services

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hefferan, J.K.; Lee, G.Y.; Boesch, L.P.

1979-07-13

A conceptual design, including process descriptions, heat and material balances, process flow diagrams, utility requirements, schedule, capital and operating cost estimate, and alternative design considerations, is presented for the DOE Coal Gasification Multi-Test Facility (GMTF). The GMTF, an engineering scale facility, is to provide a complete plant into which different types of gasifiers and conversion/synthesis equipment can be readily integrated for testing in an operational environment at relatively low cost. The design allows for operation of several gasifiers simultaneously at a total coal throughput of 2500 tons/day; individual gasifiers operate at up to 1200 tons/day and 600 psig using airmore » or oxygen. Ten different test gasifiers can be in place at the facility, but only three can be operated at one time. The GMTF can produce a spectrum of saleable products, including low Btu, synthesis and pipeline gases, hydrogen (for fuel cells or hydrogasification), methanol, gasoline, diesel and fuel oils, organic chemicals, and electrical power (potentially). In 1979 dollars, the base facility requires a $288 million capital investment for common-use units, $193 million for four gasification units and four synthesis units, and $305 million for six years of operation. Critical reviews of detailed vendor designs are appended for a methanol synthesis unit, three entrained flow gasifiers, a fluidized bed gasifier, and a hydrogasifier/slag-bath gasifier.« less

Evaluating phenanthrene sorption on various wood chars

USGS Publications Warehouse

James, G.; Sabatini, D.A.; Chiou, C.T.; Rutherford, D.; Scott, A.C.; Karapanagioti, H.K.

2005-01-01

A certain amount of wood char or soot in a soil or sediment sample may cause the sorption of organic compounds to deviate significantly from the linear partitioning commonly observed with soil organic matter (SOM). Laboratory produced and field wood chars have been obtained and analyzed for their sorption isotherms of a model solute (phenanthrene) from water solution. The uptake capacities and nonlinear sorption effects with the laboratory wood chars are similar to those with the field wood chars. For phenanthrene aqueous concentrations of 1 ??gl-1, the organic carbon-normalized sorption coefficients (log Koc) ranging from 5.0 to 6.4 for field chars and 5.4-7.3 for laboratory wood chars, which is consistent with literature values (5.6-7.1). Data with artificial chars suggest that the variation in sorption potential can be attributed to heating temperature and starting material, and both the quantity and heterogeneity of surface-area impacts the sorption capacity. These results thus help to corroborate and explain the range of log Koc values reported in previous research for aquifer materials containing wood chars. ?? 2004 Elsevier Ltd. All rights reserved.

Characteristics of American coals in relation to their conversion into clean energy fuels. Quarterly technical progress report, July-September 1978

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spackman, W.; Davis, A.; Walker, P. L.

1979-05-01

Certain important aspects of the chemical and physical composition of American lignite coals are being characterized. Differential scanning calorimetry and thermogravimetric analysis were used to study the interaction between oxygen and seventeen coal chars (40 x 100 mesh) at 100/sup 0/C. The same techniques were used to investigate briefly the interaction between air and a highly caking coal at selected isothermal temperatures in the range 100 to 275/sup 0/C.

Process for reducing sulfur in coal char

DOEpatents

Gasior, Stanley J.; Forney, Albert J.; Haynes, William P.; Kenny, Richard F.

1976-07-20

Coal is gasified in the presence of a small but effective amount of alkaline earth oxide, hydroxide or carbonate to yield a char fraction depleted in sulfur. Gases produced during the reaction are enriched in sulfur compounds and the alkaline earth compound remains in the char fraction as an alkaline earth oxide. The char is suitable for fuel use, as in a power plant, and during combustion of the char the alkaline earth oxide reacts with at least a portion of the sulfur oxides produced from the residual sulfur contained in the char to further lower the sulfur content of the combustion gases.

Dynamic molecular structure of plant biomass-derived black carbon (biochar)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keiluweit, M.; Nico, P.S.; Johnson, M.G.

2009-11-15

Char black carbon (BC), the solid residue of incomplete combustion, is continuously being added to soils and sediments due to natural vegetation fires, anthropogenic pollution, and new strategies for carbon sequestration ('biochar'). Here we present a molecular-level assessment of the physical organization and chemical complexity of biomass-derived chars and, specifically, that of aromatic carbon in char structures. BET-N{sub 2} surface area, X-ray diffraction (XRD), synchrotron-based Near-edge X-ray Absorption Fine Structure (NEXAFS), and Fourier transform infrared (FT-IR) spectroscopy are used to show how two plant materials (wood and grass) undergo analogous, but quantitatively different physical-chemical transitions as charring temperature increases frommore » 100 to 700 C. These changes suggest the existence of four distinct categories of char consisting of a unique mixture of chemical phases and physical states: (i) in transition chars the crystalline character of the precursor materials is preserved, (ii) in amorphous chars the heat-altered molecules and incipient aromatic polycondensates are randomly mixed, (iii) composite chars consist of poorly ordered graphene stacks embedded in amorphous phases, and (iv) turbostratic chars are dominated by disordered graphitic crystallites. The molecular variations among the different char categories translate into differences in their ability to persist in the environment and function as environmental sorbents.« less

Ferns and fires: Experimental charring of ferns compared to wood and implications for paleobiology, paleoecology, coal petrology, and isotope geochemistry

DOE Office of Scientific and Technical Information (OSTI.GOV)

McParland, L.C.; Collinson, M.E.; Scott, A.C.

We report the effects of charring on the ferns Osmunda, Pteridium, and Matteucia with coniferous wood (Sequoia) for comparison. Like charred wood, charred ferns shrink, become black and brittle with a silky sheen, and retain three-dimensional cellular structure. Ferns yield recognizable charcoal (up to 800{sup o}C) that could potentially survive in the fossil record enabling reconstruction of ancient fire-prone vegetation containing ferns. Charred fossils of herbaceous ferns would indicate surface fires. Like charred wood, cell-wall layers of charred ferns homogenize, and their reflectance values increase with rising temperature. Charcoalified fragments of thick-walled cells from conifer wood or fern tissues aremore » indistinguishable and so cannot be used to infer the nature of source vegetation. Charred conifer wood and charred fern tissues show a relationship between mean random reflectance and temperature of formation and can be used to determine minimum ancient fire temperatures. Charred fern tissues consistently have significantly more depleted {delta}{sup 13}C values ({le} 4 parts per thousand) than charred wood. Therefore, if an analysis of {delta} {sup 13}C through time included fern charcoal among a succession of wood charcoals, any related shifts in {delta} {sup 13}C could be misinterpreted as atmospheric changes or misused as isotope stratigraphic markers. Thus, charcoals of comparable botanical origin and temperatures of formation should be used in order to avoid misinterpretations of shifts in {delta}{sup 13}C values.« less

Global Development of Commercial Underground Coal Gasification

NASA Astrophysics Data System (ADS)

Blinderman, M. S.

2017-07-01

Global development of Underground Coal Gasification (UCG) is considered here in light of latest trends of energy markets and environmental regulations in the countries that have been traditional proponents of UCG. The latest period of UCG development triggered by initial success of the Chinchilla UCG project (1997-2006) has been characterized by preponderance of privately and share-market funded developments. The deceleration of UCG commercialization has been in part caused by recent significant decrease of world oil, gas and coal prices. Another substantial factor was lack of necessary regulations governing extraction and conversion of coal by UCG method in the jurisdictions where the UCG projects were proposed and developed. Along with these objective causes there seem to have been more subjective and technical reasons for a slowdown or cancelation of several significant UCG projects, including low efficiency, poor environmental performance, and inability to demonstrate technology at a sufficient scale and/or at a competitive cost. Latest proposals for UCG projects are briefly reviewed.

Evaluation of gasification and novel thermal processes for the treatment of municipal solid waste

DOE Office of Scientific and Technical Information (OSTI.GOV)

Niessen, W.R.; Marks, C.H.; Sommerlad, R.E.

1996-08-01

This report identifies seven developers whose gasification technologies can be used to treat the organic constituents of municipal solid waste: Energy Products of Idaho; TPS Termiska Processor AB; Proler International Corporation; Thermoselect Inc.; Battelle; Pedco Incorporated; and ThermoChem, Incorporated. Their processes recover heat directly, produce a fuel product, or produce a feedstock for chemical processes. The technologies are on the brink of commercial availability. This report evaluates, for each technology, several kinds of issues. Technical considerations were material balance, energy balance, plant thermal efficiency, and effect of feedstock contaminants. Environmental considerations were the regulatory context, and such things as composition,more » mass rate, and treatability of pollutants. Business issues were related to likelihood of commercialization. Finally, cost and economic issues such as capital and operating costs, and the refuse-derived fuel preparation and energy c onversion costs, were considered. The final section of the report reviews and summarizes the information gathered during the study.« less

Producing fired bricks using coal slag from a gasification plant in indiana

USGS Publications Warehouse

Chen, L.-M.; Chou, I.-Ming; Chou, S.-F.J.; Stucki, J.W.

2009-01-01

Integrated gasification combined cycle (IGCC) is a promising power generation technology which increases the efficiency of coal-to-power conversion and enhances carbon dioxide concentration in exhaust emissions for better greenhouse gas capture. Two major byproducts from IGCC plants are bottom slag and sulfur. The sulfur can be processed into commercially viable products, but high value applications need to be developed for the slag material in order to improve economics of the process. The purpose of this study was to evaluate the technical feasibility of incorporating coal slag generated by the Wabash River IGCC plant in Indiana as a raw material for the production of fired bricks. Full-size bricks containing up to 20 wt% of the coal slag were successfully produced at a bench-scale facility. These bricks have color and texture similar to those of regular fired bricks and their water absorption properties met the ASTM specifications for a severe weathering grade. Other engineering properties tests, including compressive strength tests, are in progress.

Design of a Decentralized Asynchronous Membership Protocol and an Implementation of Its Communications Layer

DTIC Science & Technology

1993-03-01

sstm[MAXFD], stpm [MAXFD]; u-short fport,bport; char sfport[MLAXPORTI, sbport[MAXPORTII; int childpid; char my~name[MAXHOSTNAME+ 1 ], *ip~add&, char my...34, "tpm", stpm , (char*) NULL); printf ("Error executing tpm\

Method and apparatus for acoustically monitoring the flow of suspended solid particulate matter

DOEpatents

Roach, Paul D.; Raptis, Apostolos C.

1982-01-01

A method and apparatus for monitoring char flow in a coal gasifier system cludes flow monitor circuits which measure acoustic attenuation caused by the presence of char in a char line and provide a char flow/no flow indication and an indication of relative char density. The flow monitor circuits compute the ratio of signals in two frequency bands, a first frequency band representative of background noise, and a second higher frequency band in which background noise is attenuated by the presence of char. Since the second frequency band contains higher frequencies, the ratio can be used to provide a flow/no flow indication. The second band can also be selected so that attenuation is monotonically related to particle concentration, providing a quantitative measure of char concentration.

Effect of reactivity loss on apparent reaction order of burning char particles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murphy, Jeffrey J.; Shaddix, Christopher R.

Considerable debate still exists in the char combustion community over the expected and observed reaction orders of carbon reacting with oxygen. In particular, very low values of the reaction order (approaching zero) are commonly observed in char combustion experiments. These observations appear to conflict with porous catalyst theory as first expressed by Thiele, which suggests that the apparent reaction order must be greater than 0.5. In this work, we propose that this conflict may be resolved by considering the decrease in char reactivity with burnout due to ash effects, thermal annealing, or other phenomena. Specifically, the influence of ash dilutionmore » of the available surface area on the apparent reaction order is explored. Equations describing the ash dilution effect are combined with a model for particle burnout based on single-film nth-order Arrhenius char combustion and yield an analytical expression for the effective reaction order. When this expression is applied for experimental conditions reflecting combustion of individual pulverized coal particles in an entrained flow reactor, the apparent reaction order is shown to be lower than the inherent char matrix reaction order, even for negligible extents of char conversion. As char conversion proceeds and approaches completion, the apparent reaction order drops precipitously past zero to negative values. Conversely, the inclusion of the ash dilution model has little effect on the char conversion profile or char particle temperature until significant burnout has occurred. Taken together, these results suggest that the common experimental observation of low apparent reaction orders during char combustion is a consequence of the lack of explicit modeling of the decrease in char reactivity with burnout. (author)« less

Comparison of the combustion reactivity of TGA and drop tube furnace chars from a bituminous coal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Katherine Le Manquais; Colin Snape; Ian McRobbie

This paper compares the reactivity of chars generated in a drop tube furnace (DTF) to those from TGA. The implications of devolatilization temperature, heating rate and residence time are considered. For the smaller particle size ranges of the bituminous coal investigated (ATC), optimized devolatilization procedures were used to generate corresponding TGA burnout rates between the two char types. However, with fractions of >75 {mu}m, the DTF chars showed an increased burnout propensity when moving from combustion regime II to combustion regime III. Scanning electron microscope (SEM) images and internal surface areas indicate that this is because of incompatible char morphologies.more » Thus, while chars produced under the conditions of TGA pyrolysis strongly resemble raw coal and display an undeveloped pore network; the DTF chars are highly porous, extensively swollen and possess considerably larger internal surface areas. Subsequently, char burnout variability was quantified, with the reactivity distribution for the DTF samples found to be up to an order of magnitude more significant than for the TGA chars. This is attributed to a fluctuating devolatilization environment on the DTF. Finally, a TGA study observed a robust particle size based compensation effect for the TGA chars, with the relative reaction rates and activation energies demonstrating the presence of internal diffusion control. However this phenomenon was partly alleviated for the DTF chars, since their higher porosities reduce mass transfer restrictions. Moreover, it should be realized that DTF char fractions of <38 {mu}m, including those required to ensure true intrinsic control under the investigated burnout conditions, cannot be produced directly. This is because of bridging and sloughing in the DTF's screw-feeder. Instead, such samples must be created by grinding larger particles, which destroys the char's existing porosity. 60 refs., 9 figs., 5 tabs.« less

OXIDATION AND DEVOLATILIZATION OF NITROGEN IN COAL CHAR

EPA Science Inventory

The reactions of organically-bound nitrogen in coal char during combustion have been studied in a laboratory furnace using size-graded char particles prepared by the pyrolysis of a Montana lignite. The time-resolved variations of nitrogen-to-carbon ratio during char oxidation hav...

Mechanical properties of acacia and eucalyptus wood chars

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, M.; Verma, B.B.; Gupta, R.C.

1999-10-01

In the present investigation the effects of carbonization conditions (temperature and heating rate) on the mechanical properties (such as crushing and impact strengths and shatter index) of acacia and eucalyptus wood chars have been determined. The crushing and impact strengths of both the acacia and eucalyptus wood chars (made by slow carbonization) decreased with increase of preparation temperature up to 600 C, followed by an increase thereafter. These wood chars showed a continuous increase in shatter index values with carbonization temperature. In contrast to slow carbonization (heating rate 4 C min{sup {minus}1}), rapid carbonization (heating rate 30 C min{sup {minus}1})more » yielded chars of lower crushing strengths. Slowly carbonized eucalyptus wood gave chars of superior crushing and impact strengths than those produced from acacia wood under the same carbonization conditions. The crushing and impact strengths of these wood chars, in general, have shown an increase with increase in their apparent density. The crushing strength of cubic-shaped wood char decreased with increase in size.« less

Overview of the CHarring Ablator Response (CHAR) Code

NASA Technical Reports Server (NTRS)

Amar, Adam J.; Oliver, A. Brandon; Kirk, Benjamin S.; Salazar, Giovanni; Droba, Justin

2016-01-01

An overview of the capabilities of the CHarring Ablator Response (CHAR) code is presented. CHAR is a one-, two-, and three-dimensional unstructured continuous Galerkin finite-element heat conduction and ablation solver with both direct and inverse modes. Additionally, CHAR includes a coupled linear thermoelastic solver for determination of internal stresses induced from the temperature field and surface loading. Background on the development process, governing equations, material models, discretization techniques, and numerical methods is provided. Special focus is put on the available boundary conditions including thermochemical ablation and contact interfaces, and example simulations are included. Finally, a discussion of ongoing development efforts is presented.

Overview of the CHarring Ablator Response (CHAR) Code

NASA Technical Reports Server (NTRS)

Amar, Adam J.; Oliver, A. Brandon; Kirk, Benjamin S.; Salazar, Giovanni; Droba, Justin

2016-01-01

An overview of the capabilities of the CHarring Ablator Response (CHAR) code is presented. CHAR is a one-, two-, and three-dimensional unstructured continuous Galerkin finite-element heat conduction and ablation solver with both direct and inverse modes. Additionally, CHAR includes a coupled linear thermoelastic solver for determination of internal stresses induced from the temperature field and surface loading. Background on the development process, governing equations, material models, discretization techniques, and numerical methods is provided. Special focus is put on the available boundary conditions including thermochemical ablation, surface-to-surface radiation exchange, and flowfield coupling. Finally, a discussion of ongoing development efforts is presented.

Mercury adsorption of modified mulberry twig chars in a simulated flue gas.

PubMed

Shu, Tong; Lu, Ping; He, Nan

2013-05-01

Mulberry twig chars were prepared by pyrolysis, steam activation and impregnation with H2O2, ZnCl2 and NaCl. Textural characteristics and surface functional groups were performed using nitrogen adsorption and FTIR, respectively. Mercury adsorption of different modified MT chars was investigated in a quartz fixed-bed absorber. The results indicated that steam activation and H2O2-impregnation can improve pore structure significantly and H2O2-impregnation and chloride-impregnation promote surface functional groups. However, chloride-impregnation has adverse effect on pore structure. Mercury adsorption capacities of impregnated MT chars with 10% or 30% H2O2 are 2.02 and 1.77 times of steam activated MT char, respectively. Mercury adsorption capacity of ZnCl2-impregnated MT char increase with increasing ZnCl2 content and is better than that of NaCl-impregnated MT char at the same chloride content. The modified MT char (MT873-A-Z5) prepared by steam activation following impregnation with 5% ZnCl2 exhibits a higher mercury adsorption capacity (29.55 μg g(-1)) than any other MT chars. Copyright © 2013 Elsevier Ltd. All rights reserved.

The combustion of large particles of char in bubbling fluidized beds: The dependence of Sherwood number and the rate of burning on particle diameter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dennis, J.S.; Hayhurst, A.N.; Scott, S.A.

Particles of char derived from a variety of fuels (e.g., biomass, sewage sludge, coal, or graphite), with diameters in excess of {approx}1.5mm, burn in fluidized bed combustors containing smaller particles of, e.g., sand, such that the rate is controlled by the diffusion both of O{sub 2} to the burning solid and of the products CO and CO{sub 2} away from it into the particulate phase. It is therefore important to characterize these mass transfer processes accurately. Measurements of the burning rate of char particles made from sewage sludge suggest that the Sherwood number, Sh, increases linearly with the diameter ofmore » the fuel particle, d{sub char} (for d{sub char}>{approx}1.5mm). This linear dependence of Sh on d{sub char} is expected from the basic equation Sh=2{epsilon}{sub mf}(1+d{sub char}/2{delta}{sub diff})/{tau}, provided the thickness of the boundary layer for mass transfer, {delta}{sub diff}, is constant in the region of interest (d{sub char}>{approx}1.5mm). Such a dependence is not seen in the empirical equations currently used and based on the Frossling expression. It is found here that for chars made from sewage sludge (for d{sub char}>{approx}1.5mm), the thickness of the boundary layer for mass transfer in a fluidized bed, {delta}{sub diff}, is less than that predicted by empirical correlations based on the Frossling expression. In fact, {delta}{sub diff} is not more than the diameter of the fluidized sand particles. Finally, the experiments in this study indicate that models based on surface renewal theory should be rejected for a fluidized bed, because they give unrealistically short contact times for packets of fluidized particles at the surface of a burning sphere. The result is the new correlation Sh = 2{epsilon}{sub mf}/{tau} + (A{sub cush}/A{sub char})(d{sub char}/ {delta}{sub diff}) for the dependence of Sh on d{sub char}, the diameter of a burning char particle. This equation is based on there being a gas-cushion of fluidizing gas underneath a burning char particle; the implication of this correlation is that a completely new picture emerges for the combustion of a char particle in a hot fluidized bed. (author)« less

Compositions and sorptive properties of crop residue-derived chars

USGS Publications Warehouse

Chun, Y.; Sheng, G.; Chiou, G.T.; Xing, B.

2004-01-01

Chars originating from the burning or pyrolysis of vegetation may significantly sorb neutral organic contaminants (NOCs). To evaluate the relationship between the char composition and NOC sorption, a series of char samples were generated by pyrolyzing a wheat residue (Triticum aestivum L) for 6 h at temperatures between 300 ??C and 700 ??C and analyzed for their elemental compositions, surface areas, and surface functional groups. The samples were then studied for their abilities to sorb benzene and nitrobenzene from water. A commercial activated carbon was used as a reference carbonaceous sample. The char samples produced at high pyrolytic temperatures (500-700 ??C) were well carbonized and exhibited a relatively high surface area (>300 m2/g), little organic matter (20% oxygen). The char samples exhibited a significant range of surface acidity/basicity because of their different surface polar-group contents, as characterized by the Boehm titration data and the NMR and FTIR spectra. The NOC sorption by high-temperature chars occurred almost exclusively by surface adsorption on carbonized surfaces, whereas the sorption by low-temperature chars resulted from the surface adsorption and the concurrent smaller partition into the residual organic-matter phase. The chars appeared to have a higher surface affinity for a polar solute (nitrobenzene) than for a nonpolar solute (benzene), the difference being related to the surface acidity/basicity of the char samples.

Production of activated char from Illinois coal for flue gas cleanup

USGS Publications Warehouse

Lizzio, A.A.; DeBarr, J.A.; Kruse, C.W.

1997-01-01

Activated chars were produced from Illinois coal and tested in several flue gas cleanup applications. High-activity chars that showed excellent potential for both SO2 and NOx removal were prepared from an Illinois No. 2 bituminous coal. The SO2 (120 ??C) and NOx (25 ??C) removal performance of one char compared favorably with that of a commercial activated carbon (Calgon Centaur). The NOx removal performance of the same char at 120 ??C exceeded that of the Centaur carbon by more than 1 order of magnitude. Novel char preparation methods were developed including oxidation/thermal desorption and hydrogen treatments, which increased and preserved, respectively, the active sites for SO2 and NOx adsorption. The results of combined SO2/NOx removal tests, however, suggest that SO2 and NOx compete for similar adsorption sites and SO2 seems to be more strongly adsorbed than NO. A low-activity, low-cost char was also developed for cleanup of incinerator flue gas. A three-step method involving coal preoxidation, pyrolysis, and CO2 activation was used to produce the char from Illinois coal. Five hundred pounds of the char was tested on a slipstream of flue gas from a commercial incinerator in Germany. The char was effective in removing >97% of the dioxins and furans present in the flue gas; mercury levels were below detectable limits.

Solid-State NMR Investigation of Bio-chars Produced from Biomass Components and Whole Biomasses

DOE PAGES

Ben, Haoxi; Hao, Naijia; Liu, Qian; ...

2017-08-24

Bio-char is a by-product from thermochemical treatment of biomass and has been identified as an energy condensed product with a comparable heating value as commercial coal. However, the combustion of such solid product as an energy resource is only a preliminary application. It is highly possible to convert bio-char, which always has a condensed aromatic and porous structure to various high-value products. The investigations of the structures and formation pathways for the bio-char are very important to any future applications. In this study, six different biomass components, including cellulose, lignin, and tannin, and three whole biomasses—pine wood, pine residue, andmore » pine bark—have been used to produce bio-char at 400, 500, and 600 °C. Solid-state NMR and FT-IR have been employed in this study to characterize the structures for the bio-chars. The results indicated that the bio-chars produced from lignin contained some methoxyl groups, and the bio-chars produced from tannin contained significantly higher amount of phenolic hydroxyl groups. Compared to the bio-chars produced from pine wood and residue, the bio-chars produced from pine bark contained more aromatic C–O bonds, and aliphatic C–O and C–C bonds, which may be due to the significantly higher amount of lignin and tannin in the pine bark. Furthermore, the elevated amounts of aromatic C–O and aliphatic C–O and C–C bonds in the bio-chars from pine bark appeared to be completely decomposed at 600 °C.« less

Solid-State NMR Investigation of Bio-chars Produced from Biomass Components and Whole Biomasses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ben, Haoxi; Hao, Naijia; Liu, Qian

Bio-char is a by-product from thermochemical treatment of biomass and has been identified as an energy condensed product with a comparable heating value as commercial coal. However, the combustion of such solid product as an energy resource is only a preliminary application. It is highly possible to convert bio-char, which always has a condensed aromatic and porous structure to various high-value products. The investigations of the structures and formation pathways for the bio-char are very important to any future applications. In this study, six different biomass components, including cellulose, lignin, and tannin, and three whole biomasses—pine wood, pine residue, andmore » pine bark—have been used to produce bio-char at 400, 500, and 600 °C. Solid-state NMR and FT-IR have been employed in this study to characterize the structures for the bio-chars. The results indicated that the bio-chars produced from lignin contained some methoxyl groups, and the bio-chars produced from tannin contained significantly higher amount of phenolic hydroxyl groups. Compared to the bio-chars produced from pine wood and residue, the bio-chars produced from pine bark contained more aromatic C–O bonds, and aliphatic C–O and C–C bonds, which may be due to the significantly higher amount of lignin and tannin in the pine bark. Furthermore, the elevated amounts of aromatic C–O and aliphatic C–O and C–C bonds in the bio-chars from pine bark appeared to be completely decomposed at 600 °C.« less

Co-gasification of solid waste and lignite - a case study for Western Macedonia.

PubMed

Koukouzas, N; Katsiadakis, A; Karlopoulos, E; Kakaras, E

2008-01-01

Co-gasification of solid waste and coal is a very attractive and efficient way of generating power, but also an alternative way, apart from conventional technologies such as incineration and landfill, of treating waste materials. The technology of co-gasification can result in very clean power plants using a wide range of solid fuels but there are considerable economic and environmental challenges. The aim of this study is to present the available existing co-gasification techniques and projects for coal and solid wastes and to investigate the techno-economic feasibility, concerning the installation and operation of a 30MW(e) co-gasification power plant based on integrated gasification combined cycle (IGCC) technology, using lignite and refuse derived fuel (RDF), in the region of Western Macedonia prefecture (WMP), Greece. The gasification block was based on the British Gas-Lurgi (BGL) gasifier, while the gas clean-up block was based on cold gas purification. The competitive advantages of co-gasification systems can be defined both by the fuel feedstock and production flexibility but also by their environmentally sound operation. It also offers the benefit of commercial application of the process by-products, gasification slag and elemental sulphur. Co-gasification of coal and waste can be performed through parallel or direct gasification. Direct gasification constitutes a viable choice for installations with capacities of more than 350MW(e). Parallel gasification, without extensive treatment of produced gas, is recommended for gasifiers of small to medium size installed in regions where coal-fired power plants operate. The preliminary cost estimation indicated that the establishment of an IGCC RDF/lignite plant in the region of WMP is not profitable, due to high specific capital investment and in spite of the lower fuel supply cost. The technology of co-gasification is not mature enough and therefore high capital requirements are needed in order to set up a direct co-gasification plant. The cost of electricity estimated was not competitive, compared to the prices dominating the Greek electricity market and thus further economic evaluation is required. The project would be acceptable if modular construction of the unit was first adopted near operating power plants, based on parallel co-gasification, and gradually incorporating the remaining process steps (gas purification, power generation) with the aim of eventually establishing a true direct co-gasification plant.

47 CFR 15.122 - Closed caption decoder requirements for digital television receivers and converter boxes.

Code of Federal Regulations, 2011 CFR

2011-10-01

... code 0×2D Lower-left border (⌊), G2 char code 0×7C G0 dash (-), char code 0×2D Horizontal border... (-), char code 0×2D Upper-left border (⌈), G2 char code 0×7F G0 dash (-), char code 0×2D (4) Support for..., if the character to the left of the embedded return is a hyphen, the embedded return should be...

47 CFR 15.122 - Closed caption decoder requirements for digital television receivers and converter boxes.

Code of Federal Regulations, 2010 CFR

2010-10-01

... code 0×2D Lower-left border (⌊), G2 char code 0×7C G0 dash (-), char code 0×2D Horizontal border... (-), char code 0×2D Upper-left border (⌈), G2 char code 0×7F G0 dash (-), char code 0×2D (4) Support for..., if the character to the left of the embedded return is a hyphen, the embedded return should be...

A critical review on sustainable biochar system through gasification: Energy and environmental applications.

PubMed

You, Siming; Ok, Yong Sik; Chen, Season S; Tsang, Daniel C W; Kwon, Eilhann E; Lee, Jechan; Wang, Chi-Hwa

2017-12-01

This review lays great emphasis on production and characteristics of biochar through gasification. Specifically, the physicochemical properties and yield of biochar through the diverse gasification conditions associated with various types of biomass were extensively evaluated. In addition, potential application scenarios of biochar through gasification were explored and their environmental implications were discussed. To qualitatively evaluate biochar sustainability through the gasification process, all gasification products (i.e., syngas and biochar) were evaluated via life cycle assessment (LCA). A concept of balancing syngas and biochar production for an economically and environmentally feasible gasification system was proposed and relevant challenges and solutions were suggested in this review. Copyright © 2017 Elsevier Ltd. All rights reserved.

Quarterly technical progress report, April-June 1982

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1984-04-01

Progress reports are presented for the following tasks: (1) preparation of low-rank coals; application of liquefaction processes to low-rank coals; (2) slagging fixed-bed gasification; (3) atmospheric fluidized-bed combustion of low-rank coal; (4) ash fouling and combustion modification for low-rank coal; (5) combined flue gas cleanup/simultaneous SO/sub x/-NO/sub x/ control; (6) particulate control and hydrocarbons and trace element emissions from low-rank coals; (7) waste characterization and disposal; and (9) exploratory research.

Meeting today's challenges to supply tomorrow's energy. Clean fossil energy technical and policy seminar

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

2005-07-01

Papers discussed the coal policy of China, Russia, Indonesia and Vietnam; clean coal technology (small-scale coal power plants, carbon capture and sequestration, new coking process SCOPE21, coal gasification (HyPr-RING), CO{sub 2} reduction technology, Supercritical coal-fired units and CFB boilers, EAGLE project, coal liquefaction), the coal consumer's view of clean fossil energy policy, and natural gas policy and technology. Some of the papers only consist of the presentation overheads/viewgraphs.

The effect of 150μm expandable graphite on char expansion of intumescent fire retardant coating

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ullah, Sami, E-mail: samichemist1@gmail.com; Shariff, A. M., E-mail: azmish@petronas.com.my, E-mail: azmibustam@petronas.com.my; Bustam, M. A., E-mail: azmish@petronas.com.my, E-mail: azmibustam@petronas.com.my

2014-10-24

Intumescent is defined as the swelling of certain substances to insulate the underlying substrate when they are heated. In this research work the effect of 150μm expandable graphite (EG) was studied on char expansion, char morphology and char composition of intumescent coating formulations (ICFs). To study the expansion and thermal properties of the coating, nine different formulations were prepared. The coatings were tested at 500 °C for one hour and physically were found very stable and well bound with the steel substrate. The morphology was studied by Scanning Electron Microscopy (SEM). The char composition was analysed by X-ray Diffraction (XRD)more » and Fourier transform infrared spectroscopy (FTIR) techniques. EG above than 10.8wt% expands the char abruptly with uniform network structure and affect the outer surface of the char.« less

Hybrid Molten Bed Gasifier for High Hydrogen Syngas Production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rue, David

The techno-economic analyses of the hybrid molten bed gasification technology and laboratory testing of the HMB process were carried out in this project by the Gas Technology Institute and partner Nexant, Inc. under contract with the US Department of Energy’s National Energy Technology Laboratory. This report includes the results of two complete IGCC and Fischer-Tropsch TEA analyses comparing HMB gasification with the Shell slagging gasification process as a base case. Also included are the results of the laboratory simulation tests of the HMB process using Illinois #6 coal fed along with natural gas, two different syngases, and steam. Work inmore » this 18-month project was carried out in three main Tasks. Task 2 was completed first and involved modeling, mass and energy balances, and gasification process design. The results of this work were provided to Nexant as input to the TEA IGCC and FT configurations studied in detail in Task 3. The results of Task 2 were also used to guide the design of the laboratory-scale testing of the HMB concept in the submerged combustion melting test facility in GTI’s industrial combustion laboratory. All project work was completed on time and budget. A project close-out meeting reviewing project results was conducted on April 1, 2015 at GTI in Des Plaines, IL. The hybrid molten bed gasification process techno-economic analyses found that the HMB process is both technically and economically attractive compared with the Shell entrained flow gasification process. In IGCC configuration, HMB gasification provides both efficiency and cost benefits. In Fischer-Tropsch configuration, HMB shows small benefits, primarily because even at current low natural gas prices, natural gas is more expensive than coal on an energy cost basis. HMB gasification was found in the TEA to improve the overall IGCC economics as compared to the coal only Shell gasification process. Operationally, the HMB process proved to be robust and easy to operate. The burner was stable over the full oxygen to fuel firing range (0.8 to 1.05 of fuel gas stoichiometry) and with all fuel gases (natural gas and two syngas compositions), with steam, and without steam. The lower Btu content of the syngases presented no combustion difficulties. The molten bed was stable throughout testing. The molten bed was easily established as a bed of molten glass. As the composition changed from glass cullet to cullet with slag, no instabilities were encountered. The bed temperature and product syngas temperature remained stable throughout testing, demonstrating that the bed serves as a good heat sink for the gasification process. Product syngas temperature measured above the bed was stable at ~1600ºF. Testing found that syngas quality measured as H 2/CO ratio increased with decreasing oxygen to fuel gas stoichiometric ratio, higher steam to inlet carbon ratio, higher temperature, and syngas compared with natural gas. The highest H 2/CO ratios achieved were in the range of 0.70 to 0.78. These values are well below the targets of 1.5 to 2.0 that were expected and were predicted by modeling. The team, however, is encouraged that the HMB process can and will achieve H 2/CO ratios up to 2.0. Changes needed include direct injection of coal into the molten bed of slag to prevent coal particle bypass into the product gas stream, elevation of the molten bed temperature to approximately 2500ºF, and further decrease of the oxygen to fuel gas ratio to well below the 0.85 minimum ratio used in the testing in this project.« less

A volumetric ablation model of EPDM considering complex physicochemical process in porous structure of char layer

NASA Astrophysics Data System (ADS)

Yang, Liu; Xiao-Jing, Yu; Jian-Ming, Ma; Yi-Wen, Guan; Jiang, Li; Qiang, Li; Sa, Yang

2017-06-01

A volumetric ablation model for EPDM (ethylene- propylene-diene monomer) is established in this paper. This model considers the complex physicochemical process in the porous structure of a char layer. An ablation physics model based on a porous structure of a char layer and another model of heterogeneous volumetric ablation char layer physics are then built. In the model, porosity is used to describe the porous structure of a char layer. Gas diffusion and chemical reactions are introduced to the entire porous structure. Through detailed formation analysis, the causes of the compact or loose structure in the char layer and chemical vapor deposition (CVD) reaction between pyrolysis gas and char layer skeleton are introduced. The Arrhenius formula is adopted to determine the methods for calculating carbon deposition rate C which is the consumption rate caused by thermochemical reactions in the char layer, and porosity evolution. The critical porosity value is used as a criterion for char layer porous structure failure under gas flow and particle erosion. This critical porosity value is obtained by fitting experimental parameters and surface porosity of the char layer. Linear ablation and mass ablation rates are confirmed with the critical porosity value. Results of linear ablation and mass ablation rate calculations generally coincide with experimental results, suggesting that the ablation analysis proposed in this paper can accurately reflect practical situations and that the physics and mathematics models built are accurate and reasonable.

Hormesis is induced in the red flour beetle Tribolium castaneum through ingestion of charred toast.

PubMed

Grünwald, Stefanie; Niedermeier, Janine; Wenzel, Uwe

2015-06-01

Charred foods are generally suspected to exert health threats by providing toxicants, such as acrylamide or polycyclic aromatic hydrocarbons. Using the red flour beetle Tribolium castaneum as a model organism, we tested its survival under heat stress in response to feeding charred toast. Survival of beetles was measured at 42 °C after a pre-feeding phase with flour enriched with increasing concentrations of charred toast. In order to assess the influence of key transcription factors for phase-I and phase-II xenobiotic metabolism, gene homologs for ahr and nrf-2, respectively, were knocked down by the use of RNA interference (RNAi). Beetles fed only charred toast died off much earlier than control beetles fed on flour, whereas beetles fed flour enriched with 5% charred toast survived significantly longer than the control. Both, ahr and nrf-2 proved essential in order to enable the increase in survival by the feeding of 5% charred toast. Moreover, functional loss of ahr and nrf-2 made the beetles hypersensitive versus the feeding of 100% charred toast. Finally, at the transcriptional level, it was shown that RNAi for ahr blocked the inducing activities of charred toast on nrf-2. Our studies suggest a hormetic response of the red flour beetle to feeding of charred toast that causes an increased stress resistance through the activation of ahr and nrf-2. Those adaptations, however, are saturable and accordingly the hormetic effects at increasing concentrations of the toxicants become expended.

Uncertainty Quantification Analysis of Both Experimental and CFD Simulation Data of a Bench-scale Fluidized Bed Gasifier

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shahnam, Mehrdad; Gel, Aytekin; Subramaniyan, Arun K.

Adequate assessment of the uncertainties in modeling and simulation is becoming an integral part of the simulation based engineering design. The goal of this study is to demonstrate the application of non-intrusive Bayesian uncertainty quantification (UQ) methodology in multiphase (gas-solid) flows with experimental and simulation data, as part of our research efforts to determine the most suited approach for UQ of a bench scale fluidized bed gasifier. UQ analysis was first performed on the available experimental data. Global sensitivity analysis performed as part of the UQ analysis shows that among the three operating factors, steam to oxygen ratio has themore » most influence on syngas composition in the bench-scale gasifier experiments. An analysis for forward propagation of uncertainties was performed and results show that an increase in steam to oxygen ratio leads to an increase in H2 mole fraction and a decrease in CO mole fraction. These findings are in agreement with the ANOVA analysis performed in the reference experimental study. Another contribution in addition to the UQ analysis is the optimization-based approach to guide to identify next best set of additional experimental samples, should the possibility arise for additional experiments. Hence, the surrogate models constructed as part of the UQ analysis is employed to improve the information gain and make incremental recommendation, should the possibility to add more experiments arise. In the second step, series of simulations were carried out with the open-source computational fluid dynamics software MFiX to reproduce the experimental conditions, where three operating factors, i.e., coal flow rate, coal particle diameter, and steam-to-oxygen ratio, were systematically varied to understand their effect on the syngas composition. Bayesian UQ analysis was performed on the numerical results. As part of Bayesian UQ analysis, a global sensitivity analysis was performed based on the simulation results, which shows that the predicted syngas composition is strongly affected not only by the steam-to-oxygen ratio (which was observed in experiments as well) but also by variation in the coal flow rate and particle diameter (which was not observed in experiments). The carbon monoxide mole fraction is underpredicted at lower steam-to-oxygen ratios and overpredicted at higher steam-to-oxygen ratios. The opposite trend is observed for the carbon dioxide mole fraction. These discrepancies are attributed to either excessive segregation of the phases that leads to the fuel-rich or -lean regions or alternatively the selection of reaction models, where different reaction models and kinetics can lead to different syngas compositions throughout the gasifier. To improve quality of numerical models used, the effect that uncertainties in reaction models for gasification, char oxidation, carbon monoxide oxidation, and water gas shift will have on the syngas composition at different grid resolution, along with bed temperature were investigated. The global sensitivity analysis showed that among various reaction models employed for water gas shift, gasification, char oxidation, the choice of reaction model for water gas shift has the greatest influence on syngas composition, with gasification reaction model being second. Syngas composition also shows a small sensitivity to temperature of the bed. The hydrodynamic behavior of the bed did not change beyond grid spacing of 18 times the particle diameter. However, the syngas concentration continued to be affected by the grid resolution as low as 9 times the particle diameter. This is due to a better resolution of the phasic interface between the gases and solid that leads to stronger heterogeneous reactions. This report is a compilation of three manuscripts published in peer-reviewed journals for the series of studies mentioned above.« less

Degradation of p-Nitrophenol by Lignin and Cellulose Chars: H2O2-Mediated Reaction and Direct Reaction with the Char.

PubMed

Yang, Jing; Pignatello, Joseph J; Pan, Bo; Xing, Baoshan

2017-08-15

Chars and other black carbons are reactive toward certain compounds. Such reactivity has been attributed to reduction of O 2 by persistent free radicals in the solid to H 2 O 2 , which then back-reacts with the solid to generate reactive oxygen species (ROS; especially HO • ). We studied the decomposition of p-nitrophenol (PNP) by pure lignin and cellulose chars aged in moist air or a vacuum at room temperature for up to a month. In air, the chars chemisorbed oxygen, a portion of which was liberated as H 2 O 2 when the char was submerged in water. The evolved H 2 O 2 was simultaneously decomposed by the char. PNP reacted predominantly in the sorbed state and only reduction products (phenol, catechol) were identified. Aging the char in air sharply (within hours) reduced H 2 O 2 -producing capacity and free radical concentration, but more gradually reduced PNP decay rate over the month-long period. PNP decay was only modestly suppressed (12-30%) by H 2 O 2 removal (catalase), and had little effect on the free radical signal (<6 radicals annihilated per 1000 PNP reacted). Contrasting with previous studies, the results show that direct reaction of PNP with char predominates over H 2 O 2 -dependent reactions, and the vast majority of direct-reacting sites are nonradical in character. Nonradical sites are also responsible in part for H 2 O 2 decomposition; in fact, H 2 O 2 pretreatment depleted PNP reactive sites. Lignin char was generally more reactive than cellulose char. The Fe impurity in lignin played no role. The results are relevant to the fate of pollutants in black carbon-rich environments and the use of carbons in remediation.

Integration of behavioral tests and biochemical biomarkers of terrestrial isopod Porcellio scaber (Isopoda, Crustacea) is a promising methodology for testing environmental safety of chars.

PubMed

Madžarić, Suzana; Kos, Monika; Drobne, Damjana; Hočevar, Matej; Jemec Kokalj, Anita

2018-03-01

We investigated how different carbonized materials, or chars (olive mill pomace biochar (BC) and urban greens pruning residues hydrochar (HC)) affect an important member of soil fauna, the terrestrial isopod Porcellio scaber. The selection behavior of isopods towards chars after a 48 h exposure was studied in (i) soil-char amended tests with single and multiple choices, and (ii) tests with chars offered as pure material. Finally, we exposed the isopods to char-amended soils for a period of 14 days to follow the effect on food consumption, body mass and activities of enzymes that are commonly altered upon stressor exposure (acetylcholinesterase, AChE, and glutathione S-transferase, GST). We showed that isopods are able to select between char amended and un-amended soil and different forms of char amendments: a clear preference for BC, and avoidance of HC were evidenced. The preferences remained the same when the chars were sterilized leading to the conclusion that initial microorganism composition was not the reason for selection, but selection was governed by other chars' physico-chemical properties. It remains to be elucidated which of these properties were the dominant reason for the selection. We also showed that isopods intentionally use BC as food at a similar rate to alder leaves. Medium-term exposure to HC resulted in adverse effects on isopods because it led to reduced feeding and growth, in addition to increasing GST activity, although no alterations in AChE activity were found. We suggest that behavioral tests with P. scaber could be used as a fast, reliable and economically feasible screening method for determining the safety of chars for the soil environment. Results represent significant contribution in the field of char toxicity testing, highlighting the importance of tests with isopods as important members of soil meso fauna, with the aim of influencing environmental policies and quality standards. Copyright © 2017 Elsevier Ltd. All rights reserved.

Production of carbon molecular sieves from Illinois coal

USGS Publications Warehouse

Lizzio, A.A.; Rostam-Abadi, M.

1993-01-01

Carbon molecular sieves (CMS) have become an increasingly important class of adsorbents for application in the separation of gas molecules that vary in size and shape. A study is in progress at the Illinois State Geological Survey to determine whether Illinois basin coals are suitable feedstocks for the production of CMS and to evaluate their potential application in gas separation processes of commercial importance. Chars were prepared from Illinois coal in a fixed-bed reactor under a wide range of heat treatment and activation conditions. The effects of various coal/char pretreatments, including coal demineralization, preoxidation, char activation, and carbon deposition, on the molecular sieve properties of the chars were also investigated. Chars with commercially significant BET surface areas of 1500 m2/g were produced by chemical activation using potassium hydroxide as the activant. These high-surface-area (HSA) chars had more than twice the adsorption capacity of commercial carbon and zeolite molecular sieves. The kinetics of adsorption of various gases, e.g., N2, O2, CO2, CH4, CO and H2, on these chars at 25??C was measured. The O2/N2 molecular sieve properties of one char prepared without chemical activation were similar to those of a commercial CMS. On the other hand, the O2/N2 selectivity of the HSA char was comparable to that of a commercial activated carbon, i.e., essentially unity. Carbon deposition, using methane as the cracking gas, increased the O2/N2 selectivity of the HSA char, but significantly decreased its adsorption capacity. Several chars showed good potential for efficient CO2/CH4 separation; both a relatively high CO2 adsorption capacity and CO2/CH4 selectivity were achieved. The micropore size distribution of selected chars was estimated by equilibrium adsorption of carbon dioxide, n-butane and iso-butane at O??C. The extent of adsorption of each gas corresponded to the effective surface area contained in pores with diameters greater than 3.3, 4.3 and 5.0 A??, respectively. Kinetic and equilibrium adsorption data provided complementary information on the molecular sieving capabilities and microstructure of the prepared chars. ?? 1993.

Considerations on coal gasification

NASA Technical Reports Server (NTRS)

Franzen, J. E.

1978-01-01

Commercial processes for the gasification of coal with oxygen are discussed. The Koppers-Totzek process for the gasification of coal dust entrained in a stream of gasifying agents is described in particular detail. The outlook for future applications of coal gasification is presented.

Tunable Diode Laser Sensors to Monitor Temperature and Gas Composition in High-Temperature Coal Gasifiers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hanson, Ronald; Whitty, Kevin

2014-12-01

The integrated gasification combined cycle (IGCC) when combined with carbon capture and storage can be one of the cleanest methods of extracting energy from coal. Control of coal and biomass gasification processes to accommodate the changing character of input-fuel streams is required for practical implementation of integrated gasification combined-cycle (IGCC) technologies. Therefore a fast time-response sensor is needed for real-time monitoring of the composition and ideally the heating value of the synthesis gas (here called syngas) as it exits the gasifier. The goal of this project was the design, construction, and demonstration an in situ laserabsorption sensor to monitor multiplemore » species in the syngas output from practical-scale coal gasifiers. This project investigated the hypothesis of using laser absorption sensing in particulateladen syngas. Absorption transitions were selected with design rules to optimize signal strength while minimizing interference from other species. Successful in situ measurements in the dusty, high-pressure syngas flow were enabled by Stanford’s normalized and scanned wavelength modulation strategy. A prototype sensor for CO, CH4, CO2, and H2O was refined with experiments conducted in the laboratory at Stanford University, a pilot-scale at the University of Utah, and an engineering-scale gasifier at DoE’s National Center for Carbon Capture with the demonstration of a prototype sensor with technical readiness level 6 in the 2014 measurement campaign.« less

Thermal valorization of post-consumer film waste in a bubbling bed gasifier

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martínez-Lera, S., E-mail: susanamartinezlera@gmail.com; Torrico, J.; Pallarés, J.

2013-07-15

Highlights: • Film waste from packaging is a common waste, a fraction of which is not recyclable. • Gasification can make use of the high energy value of the non-recyclable fraction. • This waste and two reference polymers were gasified in a bubbling bed reactor. • This experimental research proves technical feasibility of the process. • It also analyzes impact of composition and ER on the performance of the plant. - Abstract: The use of plastic bags and film packaging is very frequent in manifold sectors and film waste is usually present in different sources of municipal and industrial wastes.more » A significant part of it is not suitable for mechanical recycling but could be safely transformed into a valuable gas by means of thermal valorization. In this research, the gasification of film wastes has been experimentally investigated through experiments in a fluidized bed reactor of two reference polymers, polyethylene and polypropylene, and actual post-consumer film waste. After a complete experimental characterization of the three materials, several gasification experiments have been performed to analyze the influence of the fuel and of equivalence ratio on gas production and composition, on tar generation and on efficiency. The experiments prove that film waste and analogue polymer derived wastes can be successfully gasified in a fluidized bed reactor, yielding a gas with a higher heating value in a range from 3.6 to 5.6 MJ/m{sup 3} and cold gas efficiencies up to 60%.« less

Waste-to-Energy Decision Support Method for Forward Deployed Forces

DTIC Science & Technology

2014-03-27

15 Gasification ...stable electrical source to generate the plasma. Thermal WTE technology includes three subtypes called incineration, gasification , and pyrolysis...unfavorable public perception associated with the emissions produced by the technology. Gasification Gasification is a thermal process in which

Market Assessment of Biomass Gasification and Combustion Technology for Small- and Medium-Scale Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peterson, D.; Haase, S.

2009-07-01

This report provides a market assessment of gasification and direct combustion technologies that use wood and agricultural resources to generate heat, power, or combined heat and power (CHP) for small- to medium-scale applications. It contains a brief overview of wood and agricultural resources in the U.S.; a description and discussion of gasification and combustion conversion technologies that utilize solid biomass to generate heat, power, and CHP; an assessment of the commercial status of gasification and combustion technologies; a summary of gasification and combustion system economics; a discussion of the market potential for small- to medium-scale gasification and combustion systems; andmore » an inventory of direct combustion system suppliers and gasification technology companies. The report indicates that while direct combustion and close-coupled gasification boiler systems used to generate heat, power, or CHP are commercially available from a number of manufacturers, two-stage gasification systems are largely in development, with a number of technologies currently in demonstration. The report also cites the need for a searchable, comprehensive database of operating combustion and gasification systems that generate heat, power, or CHP built in the U.S., as well as a national assessment of the market potential for the systems.« less

Green Power Initiative

DOE Office of Scientific and Technical Information (OSTI.GOV)

Butler, Patrick Barry

2013-01-28

National energy policy supports the gathering of more detailed and authoritative data on the introduction of renewable bio-based fuels into new and existing district energy systems via the application of biomass gasification. The University of Iowa developed a biomass-fueled, university-scale steam generation system based on biomass gasification technologies. The system serves as a state-of-the-art research and educational facility in the emerging application of gasification in steam generation. The facility, which includes a smaller down-draft gasifier and a larger multi-stage biomass boiler, was designed to operate primarily on wood-based fuels, but has provisions for testing other biomass fuel sources produced withinmore » a 100-mile radius, providing enough flexibility to meet the fluctuating local supply of biomass from industry and Midwest agriculture. The equipment was installed in an existing, staffed facility. The down-draft gasifier unit is operated by College of Engineering staff and students, under the direct technical supervision of qualified Utilities plant staff. The Green Power Initiative also includes a substantial, innovative educational component. In addition to an onsite, graduate-level research program in biomass fuels, the investigators have integrated undergraduate and graduate level teaching – through classroom studies and experiential learning – and applied research into a biomass-based, university-scale, functioning power plant. University of Iowa is unique in that it currently has multiple renewable energy technologies deployed, including significant biomass combustion (oat hulls) at its Main Power Plant and a new reciprocating engine based renewable district energy system. This project complements and supports the national energy policy and State of Iowa initiatives in ethanol and biodiesel. Byproducts of ethanol and biodiesel processes (distiller grains) as well as industry residues (oat hulls, wood chips, construction and demolition waste), farm related material (seed corn and soybean seed), and poplar trees for cleaning up ground water are logical feed stocks for gasification.« less

SEM-EDX and isotope characterization of the organic sulfur in macerals and chars in Illinois Basin coals

USGS Publications Warehouse

Demir, I.; Harvey, R.D.; Hackley, Keith C.

1993-01-01

Two samples of the Herrin (Illinois No. 6) Coal and one sample of the Colchester (Illinois No. 2) Coal from the Illinois Basin were studied to evaluate the spatial distribution of organic sulfur within macerals occurring next to pyrite grains, both in the raw coal and their chars. The chars were produced by pyrolysing the coal at 250-550??C in a nitrogen atmosphere. Representative splits of the coals and their chars were mounted in epoxy and polished for optical microscopy and scanning electron microscopy-energy dispersive x-ray spectroscopy (SEM-EDX). Determinations of organic sulfur concentrations were made at 996 locations within macerals, mostly vitrinite, around 115 grains of pyrite and at 50 locations around 5 pores in chars. The pyrite considered here is restricted to the disseminated type within macerals. On the average, the organic sulfur content increased near pyrite grains after the coals were charred at 550??C, indicating that some of the pyritic sulfur released during charring was retained within the organic matrix rather than being emitted to the atmosphere. One of the coal samples and its chars were isotopically characterized by chemically separating the pyritic and organic sulfur fractions, followed by analyzing the isotopes of the sulfur forms with a Nuclide 6-60 ratio mass spectrometer. The sulfur isotope (??34S) data confirmed the movement of pyritic sulfur into the macerals after charring to 550??C. About 18% of the organic sulfur that remained in the 550??C char had originally been pyritic sulfur in the untreated coal. ?? 1993.

Near infrared spectroscopic examination of charred pine wood, bark, cellulose and lignin: Implications for the quantitative determination of charcoal in soils

USGS Publications Warehouse

Reeves, J. B.; McCarty, G.W.; Rutherford, D.W.; Wershaw, R. L.

2007-01-01

The objective of this research was to investigate the effect of charring on near infrared spectra of materials likely to be present in forest fires in order to determine the feasibility of determining charred carbon in soils. Four materials (cellulose, lignin, pine bark and pine wood) and char from these materials created by charring for various durations (1 to 168 h) and at various temperatures (200 to 450??C) were studied. Near infrared spectra and measures of acidity (total acids, carboxylic acids, lactones and phenols as determined by titration) were available for 56 different samples (Not all samples charred at all temperatures/durations). Results showed spectral changes that varied with the material, temperature and duration of charring. Examination of spectra and correlation plots indicated that changes in the constituents of the materials in question, such as loss of OH groups in carbohydrates, rather than direct determination of typical products produced by charring, such as carboxylic acids, lactones and phenols, were the basis for the spectral changes. Finally, while the spectral changes resulting from charring appeared to be relatively unique to each material, PLS calibrations for total acids, carboxylic acids, lactones and phenols were successfully created (with R2 of 0.991, 0.943, 0.931 and 0.944, respectively) indicating that there is a sufficient commonality in the changes to develop calibrations without the need for unique calibrations for each specific set of charring conditions (i.e. material, temperature and time of heating). ?? IM Publications 2007.

Techno-economic requirements for composite aircraft components

NASA Technical Reports Server (NTRS)

Palmer, Ray

1993-01-01

The primary reason for use of composites is to save structural weight. A well designed composite aircraft structure will usually save 25-30 percent of a well designed metal structure. The weight savings then translates into improved performance of the aircraft in measures of greater payload, increased flying range or improved efficiency - less use of fuel. Composite materials offer technical advantages. Key technical advantages that composites offer are high stiffness, tailored strength capability, fatigue resistance, and corrosion resistance. Low thermal expansion properties produce dimensionally stable structures over a wide range of temperature. Specialty resin 'char' forming characteristics in a fire environment offer potential fire barrier application and safer aircraft. The materials and processes of composite fabrication offer the potential for lower cost structures in the near future. The application of composite materials to aircraft are discussed.

Removal of lead (Pb2+) from aqueous medium by using chars from co-pyrolysis.

PubMed

Bernardo, Maria; Mendes, Sandra; Lapa, Nuno; Gonçalves, Margarida; Mendes, Benilde; Pinto, Filomena; Lopes, Helena; Fonseca, Isabel

2013-11-01

The effectiveness of chars from the co-pyrolysis of pine, used tires and plastic wastes for the removal of lead (Pb(2+)) from aqueous medium, was investigated. The chars were predominantly of macroporous nature, but the introduction of tires in the pyrolysis feedstock enhanced their mesoporous content as well as surface area. Pb(2+) sorption with the chars was a slow and unstable process in which sorption-desorption seems to be competing. The highest Pb(2+) removal (88%) was attained by the char resulting from the pyrolysis of a mixture composed by equal mass ratios of used tires and plastics, at 48 h of contact time. This char was also the one with the overall better performance for Pb(2+) sorption, achieving almost 100% of Pb(2+) removal on the study of the effect of adsorbent dose. Mixing the three raw materials for pyrolysis had no advantage for the resulting char concerning the removal efficiency of Pb(2+). The sorption mechanisms varied according to the pyrolysis feedstock: in chars from feedstock with pine, chemisorption involving complexation with oxygenated surface functional groups followed by cation exchange was the presumable mechanism. In tire rubber derived chars, cation exchange with Ca(2+), K(+), and Zn(2+) played the major role on Pb(2+) sorption. Copyright © 2013 Elsevier Inc. All rights reserved.

77 FR 59166 - South Mississippi Electric Cooperative: Plant Ratcliffe, Kemper County Integrated Gasification...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-26

... Ratcliffe, Kemper County Integrated Gasification Combined-Cycle (IGCC) Project AGENCY: Rural Utilities... Plant Ratcliffe, an Integrated Gasification Combined-Cycle Facility located in Kemper County... Company (MPCo), and will demonstrate the feasibility of the Integrated Gasification Combined-Cycle (IGCC...

An evaluation of the efficacy of various coal combustion models for predicting char burnout

DOE Office of Scientific and Technical Information (OSTI.GOV)

McConnell, Josh; Goshayeshi, Babak; Sutherland, James C.

Coal combustion is comprised of several subprocesses including devolatilization and heterogeneous reactions of the coal char with O 2, CO 2, H 2O and potentially several other species. Much effort has been put forth to develop models for these processes which vary widely in both complexity and computational cost. This work investigates the efficacy of models for devolatilization and char reactions at either end of the complexity and cost spectrums for a range of particle sizes and furnace temperatures and across coal types. The overlap of simulated devolatilization and char consumption is also examined. In the gas phase, a detailedmore » kinetics model based on a reduced version of the GRI 3.0 mechanism is used. The Char Conversion Kinetics and an n th-order Langmuir-Hinshelwood models are considered for char oxidation. The Chemical Percolation and Devolatilization and a two-step model are considered for devolatilization. Results indicate that high-fidelity models perform better at representing particle temperature and mass data across a wide range of O 2 concentrations as well as coal types. A significant overlap in devolatilization and char consumption is observed for both char chemistry and devolatilization models.« less

A burnout prediction model based around char morphology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tao Wu; Edward Lester; Michael Cloke

Several combustion models have been developed that can make predictions about coal burnout and burnout potential. Most of these kinetic models require standard parameters such as volatile content and particle size to make a burnout prediction. This article presents a new model called the char burnout (ChB) model, which also uses detailed information about char morphology in its prediction. The input data to the model is based on information derived from two different image analysis techniques. One technique generates characterization data from real char samples, and the other predicts char types based on characterization data from image analysis of coalmore » particles. The pyrolyzed chars in this study were created in a drop tube furnace operating at 1300{sup o}C, 200 ms, and 1% oxygen. Modeling results were compared with a different carbon burnout kinetic model as well as the actual burnout data from refiring the same chars in a drop tube furnace operating at 1300{sup o}C, 5% oxygen, and residence times of 200, 400, and 600 ms. A good agreement between ChB model and experimental data indicates that the inclusion of char morphology in combustion models could well improve model predictions. 38 refs., 5 figs., 6 tabs.« less

An evaluation of the efficacy of various coal combustion models for predicting char burnout

DOE PAGES

McConnell, Josh; Goshayeshi, Babak; Sutherland, James C.

2016-11-22

Coal combustion is comprised of several subprocesses including devolatilization and heterogeneous reactions of the coal char with O 2, CO 2, H 2O and potentially several other species. Much effort has been put forth to develop models for these processes which vary widely in both complexity and computational cost. This work investigates the efficacy of models for devolatilization and char reactions at either end of the complexity and cost spectrums for a range of particle sizes and furnace temperatures and across coal types. The overlap of simulated devolatilization and char consumption is also examined. In the gas phase, a detailedmore » kinetics model based on a reduced version of the GRI 3.0 mechanism is used. The Char Conversion Kinetics and an n th-order Langmuir-Hinshelwood models are considered for char oxidation. The Chemical Percolation and Devolatilization and a two-step model are considered for devolatilization. Results indicate that high-fidelity models perform better at representing particle temperature and mass data across a wide range of O 2 concentrations as well as coal types. A significant overlap in devolatilization and char consumption is observed for both char chemistry and devolatilization models.« less

Comparative Performance of Three Magnesium Compounds on Thermal Degradation Behavior of Red Gum Wood.

PubMed

Wu, Yiqiang; Yao, Chunhua; Hu, Yunchu; Zhu, Xiaodan; Qing, Yan; Wu, Qinglin

2014-01-24

The effect of basic magnesium carbonate (BMC), magnesium hydroxide (MH), and magnesium chloride hydrate (MCH) on thermal degradation of red gum wood was studied using cone calorimetry, Thermogravimetric-differential scanning calorimetry (TG-DSC) analysis, and X-ray diffraction (XRD) characterization. The results showed common fire retardation actions of the three compounds by releasing incombustible gas and/or water vapor to dilute combustible gas in the flaming zone, and by converting to MgO, which had a satisfactory protective wall effect on the wood. Individually, BMC absorbed heat from the wood at the pre-decomposition stage and, thus, slowed down wood pyrolysis process. It slightly increased the char yield by charring in both the charring stage and the char calcination stage. MH lost water at about 270 °C, close to the temperature at which wood thermally degraded. MH rendered wood char quickly, and the compact char layer impeded further carbonization and burning of inner wood. MCH promoted charring with Mg 2+ as a Lewis acid, and increased wood char yield. MCH also released Cl· free radical and HCl at 167 °C, which easily coordinated with combustion reaction radical, and slowed down, even inhibited, the combustion chain reaction.

Comparative Performance of Three Magnesium Compounds on Thermal Degradation Behavior of Red Gum Wood

PubMed Central

Wu, Yiqiang; Yao, Chunhua; Hu, Yunchu; Zhu, Xiaodan; Qing, Yan; Wu, Qinglin

2014-01-01

The effect of basic magnesium carbonate (BMC), magnesium hydroxide (MH), and magnesium chloride hydrate (MCH) on thermal degradation of red gum wood was studied using cone calorimetry, Thermogravimetric-differential scanning calorimetry (TG-DSC) analysis, and X-ray diffraction (XRD) characterization. The results showed common fire retardation actions of the three compounds by releasing incombustible gas and/or water vapor to dilute combustible gas in the flaming zone, and by converting to MgO, which had a satisfactory protective wall effect on the wood. Individually, BMC absorbed heat from the wood at the pre-decomposition stage and, thus, slowed down wood pyrolysis process. It slightly increased the char yield by charring in both the charring stage and the char calcination stage. MH lost water at about 270°C, close to the temperature at which wood thermally degraded. MH rendered wood char quickly, and the compact char layer impeded further carbonization and burning of inner wood. MCH promoted charring with Mg2+ as a Lewis acid, and increased wood char yield. MCH also released Cl· free radical and HCl at 167°C, which easily coordinated with combustion reaction radical, and slowed down, even inhibited, the combustion chain reaction. PMID:28788480

Energy from gasification of solid wastes.

PubMed

Belgiorno, V; De Feo, G; Della Rocca, C; Napoli, R M A

2003-01-01

Gasification technology is by no means new: in the 1850s, most of the city of London was illuminated by "town gas" produced from the gasification of coal. Nowadays, gasification is the main technology for biomass conversion to energy and an attractive alternative for the thermal treatment of solid waste. The number of different uses of gas shows the flexibility of gasification and therefore allows it to be integrated with several industrial processes, as well as power generation systems. The use of a waste-biomass energy production system in a rural community is very interesting too. This paper describes the current state of gasification technology, energy recovery systems, pre-treatments and prospective in syngas use with particular attention to the different process cycles and environmental impacts of solid wastes gasification.

Improved lignin pyrolysis for phenolics production in a bubbling bed reactor--Effect of bed materials.

PubMed

Li, Dongbing; Briens, Cedric; Berruti, Franco

2015-01-01

Lignin pyrolysis was studied in a bubbling fluidized bed reactor equipped with a fractional condensation train, using nitrogen as the fluidization gas. The effect of different bed materials (silica sand, lignin char, activated lignin char, birch bark char, and foamed glass beads) on bio-oil yield and quality was investigated for a pyrolysis temperature of 550 °C. Results how that a bed of activated lignin char is preferable to the commonly used silica sand: pyrolysis of Kraft lignin with a bed of activated lignin char not only provides a pure char product, but also a higher dry bio-oil yield (with a relative increase of 43%), lower pyrolytic water production, and better bio-oil quality. The bio-oil obtained from Kraft lignin pyrolysis with a bed of activated lignin char has a lower average molecular weight, less tar, more phenolics, and less acidity than when sand is used as bed material. Copyright © 2015 Elsevier Ltd. All rights reserved.

Microbial oxidation of pyrrhotites in coal chars

USGS Publications Warehouse

Miller, K.W.; Risatti, J.B.

1988-01-01

The ability of Thiobacillus ferrooxidans to oxidize pyrrhotite minerals occurring in coal chars was investigated, to evaluate the feasibility of microbial char desulphurization. Bio-oxidation of pyrrhotites in chars produced by two different processes was demonstrated conclusively. Microbial removal of sulphur from a char and its parent coal proceeded at the rate of 3.5% and 12% day-1, respectively with a total of 48% and 81% removal after 27 days. The pH of shake flask cultures containing the coal dropped naturally to a final value of 2.2, while the pH of cultures containing the corresponding char rose and had to be lowered artificially with additional acid. Amending char cultures with elemental sulphur to increase acidity upon bio-oxidation and prevent precipitation of ferric iron was successful; however, the extent of pyrrhotite removal, as demonstated by X-ray diffraction analysis, was not improved. As yet, there is no explanation for the failure of microbial removal of pyrrhotitic sulphur to go to completion. ?? 1988.

Optical spectra of coal gasification products in the RF plasmatron

NASA Astrophysics Data System (ADS)

Fedorovich, S. D.; Burakov, I. A.; Dudolin, A. A.; Markov, A. A.; Khtoo Naing, Aung; Ulziy, Batsamboo; Kavyrshin, D. I.

2017-11-01

The use of solid fuel gasification process is relevant to the regions where there is no opportunity to use natural gas as the main fuel. On the territory of the Russian Federation such regions are largely the Urals, Siberia and the Far East. In order to reduce the harmful effects on the environment solid fuel with high sulfur content, ash content and moisture are subjected to gasification process. One of the major problems of this process is to produce syngas with a low calorific value. For conventional types of gasification (gasification), the value of this quantity ranges 8 - 10 MJ / m3. The use of plasma gasification increases the calorific value of 12 - 16 MJ / m3 which allows the most efficient use of the syngas. The reason for the increase of the value lies in the change of temperature in the reaction zone. A significant rise in temperature in the reaction zone leads to an increase in methane formation reactions constant value, which allows to obtain a final product with a large calorific value. The HFI-plasma torch coal temperature reaches 3000 ° C, and the temperature of coal gasification products can reach 8000 ° C. The aim is to develop methods for determining the composition of the plasma gasification products obtained optical spectra. The Kuznetsky coal used as the starting material. Received and decrypted gasification products optical spectra in a wavelength range from 220 to 1000 nm. Recommendations for the use of the developed method for determining the composition of the plasma gasification products. An analysis of the advantages of using plasma gasification as compared with conventional gasification and coal combustion.

Waste-to-Energy Plant Environmental Assessment, Dyess Air Force Base, Texas

DTIC Science & Technology

2011-09-01

pyrolysis can be defined as “ gasification minus oxygen.” Pyrolysis is the technique of heating organic matter ( biomass ) between 480 and 1,470 °F in the...provider using one of four alternative technologies: 1) gasification ; 2) pyrolysis; 3) plasma gasification /pyrolysis and 4) incineration. Under this...the solicitation to build a WTE plant based on one of the following alternative technologies: I) gasification ; 2) pyrolysis; 3) plasma gasification

The thermal and mechanical properties of a low density elastomeric ablation material

NASA Technical Reports Server (NTRS)

Engelke, W. T.; Robertson, R. W.; Bush, A. L.; Pears, C. D.

1973-01-01

Thermal and mechanical properties data were obtained for a low density elastomeric resin based ablation material with phenolic-glass honeycomb reinforcement. Data were obtained for the material in the charred and uncharred state. Ablation material specimens were charred in a laboratory furnace at temperatures in the range from 600 K to 1700 K to obtain char specimens representative of the ablation char layer formed during reentry. These specimens were then used to obtain effective thermal conductivity, heat capacity, porosity, and permeability data at the char formation temperature. This provided a boxing of the data which enables the prediction of the transient response of the material during ablation. Limited comparisons were made between the furnace charred specimens and specimens which had been exposed to simulated reentry conditions.

Influence of carbonization conditions on the pyrolytic carbon deposition in acacia and eucalyptus wood chars

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, M.; Gupta, R.C.

1997-04-01

The amount of deposited pyrolytic carbon (resulting from the cracking of volatile matter) was found to depend on wood species and carbonization conditions, such as temperature and heating rate. Maximum pyrolytic carbon deposition in both the acacia and eucalyptus wood chars has been observed at a carbonization temperature of 800 C. Rapid carbonization (higher heating rate) of wood significantly reduces the amount of deposited pyrolytic carbon in resulting chars. Results also indicate that the amount of deposited pyrolytic carbon in acacia wood char is less than that in eucalyptus wood char.

Life-Cycle Analysis of Greenhouse Gas Emissions and Water Consumption – Effects of Coal and Biomass Conversion to Liquid Fuels as Analyzed with the GREET Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Qianfeng; Cai, Hao; Han, Jeongwoo

The vast reserves of coal in the U.S. provide a significant incentive for the development of processes for coal conversion to liquid fuels (CTL). Also, CTL using domestic coal can help move the U.S. toward greater energy independence and security. However, current conversion technologies are less economically competitive and generate greater greenhouse gas (GHG) emissions than production of petroleum fuels. Altex Technologies Corporation (Altex, hereinafter) and Pennsylvania State University have developed a hybrid technology to produce jet fuel from a feedstock blend of coal and biomass. Collaborating with Altex, Argonne National Laboratory has expanded and used the Greenhouse gases, Regulatedmore » Emissions, and Energy use in Transportation (GREET®) model to assess the life-cycle GHG emissions and water consumption of this hybrid technology. Biomass feedstocks include corn stover, switchgrass, and wheat straw. The option of biomass densification (bales to pellets) is also evaluated in this study. The results show that the densification process generates additional GHG emissions as a result of additional biomass process energy demand. This process coproduces a large amount of char, and this study investigates two scenarios to treat char: landfill disposal (Char-LF) and combustion for combined heat and power (CHP). Since the CHP scenarios export excess heat and electricity as coproducts, two coproduct handling methods are used for well-to-wake (WTWa) analysis: displacement (Char-CHP-Disp) and energy allocation (Char-CHP-EnAllo). When the feedstock contains 15 wt% densified wheat straw and 85 wt% lignite coal, WTWa GHG emissions of the coal-and-biomass-to-liquid pathways are 116, 97, and 137 gCO2e per megajoule (MJ) under the Char-LF, Char-CHP-Disp, and Char-CHP-EnAllo scenarios, respectively, as compared to conventional jet fuel production at 84 gCO2e/MJ. WTWa water consumption values are 0.072, -0.046, and 0.044 gal/MJ for Char-LF, Char-CHP-Disp, and Char-CHP-EnAllo, respectively, as compared to conventional jet fuel production at 0.028 gal/MJ. To reach the break-even point of 84 gCO2e/MJ, under the assumptions of constant product yields and energy demands regardless of the share of biomass and coal feedstocks, 31 wt%, 23 wt%, and 53 wt% of the feedstock blend need to be biomass under the Char-LF, Char-CHP-Disp, and Char-CHP-EnAllo scenarios, respectively.« less

The effects of the conditions of char formation on the physical properties of charred phenolic-nylon

NASA Technical Reports Server (NTRS)

Smyly, E. D.; Pears, C. D.

1972-01-01

A study was made of the effects of the conditions of char formation on the physical properties of charred phenolic nylon of 0.577 gm/cu cm density. It was found that the thermal conductivity and several of the monitors correlate well with degradation conditions. The monitors included electrical resistivity, sonic velocity, porosity, lattice spacing and crystallite size.

Experimental study on air-stream gasification of biomass micron fuel (BMF) in a cyclone gasifier.

PubMed

Guo, X J; Xiao, B; Zhang, X L; Luo, S Y; He, M Y

2009-01-01

Based on biomass micron fuel (BMF) with particle size of less than 250 microm, a cyclone gasifier concept has been considered in our laboratory for biomass gasification. The concept combines and integrates partial oxidation, fast pyrolysis, gasification, and tar cracking, as well as a shift reaction, with the purpose of producing a high quality of gas. In this paper, experiments of BMF air-stream gasification were carried out by the gasifier, with energy for BMF gasification produced by partial combustion of BMF within the gasifier using a hypostoichiometric amount of air. The effects of ER (0.22-0.37) and S/B (0.15-0.59) and biomass particle size on the performances of BMF gasification and the gasification temperature were studied. Under the experimental conditions, the temperature, gas yields, LHV of the gas fuel, carbon conversion efficiency, stream decomposition and gasification efficiency varied in the range of 586-845 degrees C, 1.42-2.21 N m(3)/kg biomass, 3806-4921 kJ/m(3), 54.44%-85.45%, 37.98%-70.72%, and 36.35%-56.55%, respectively. The experimental results showed that the gasification performance was best with ER being 3.7 and S/B being 0.31 and smaller particle, as well as H(2)-content. And the BMF gasification by air and low temperature stream in the cyclone gasifier with the energy self-sufficiency is reliable.

The hierarchical porous structure bio-char assessments produced by co-pyrolysis of municipal sewage sludge and hazelnut shell and Cu(II) adsorption kinetics.

PubMed

Zhao, Bing; Xu, Xinyang; Zeng, Fanqiang; Li, Haibo; Chen, Xi

2018-05-04

The co-pyrolysis technology was applied to municipal sewage sludge (MSS) and hazelnut shell with alkaline activating agent K 2 CO 3 under N 2 atmosphere. The innovative bio-char produced by co-pyrolysis had significant physical and chemical characteristics. The specific surface area reached 1990.23 m 2 /g, and the iodine absorption number was 1068.22 mg/g after co-pyrolysis at 850 °C. Although hazelnut shell was a kind of solid waste, it also had abundant cellulose resource, which could contribute to porous structure of bio-char during co-pyrolysis with MSS and decrease total heavy metals contents of raw material to increase security of bio-chars. Meanwhile, the residual fractions of heavy metals in bio-char were above 92.95% after co-pyrolysis at 900 °C except Cd to prevent heavy metals digestion, and the bio-char presented significant immobilization behavior from co-pyrolysis technology. Moreover, the yield and the iodine absorption number of bio-chars under different process variables were analyzed, and it was confirmed that appropriate process variables could contribute the yield and the iodine absorption number of bio-char and prevent to etch pore structure excessively to collapse. The changes of surface functional groups and crystallographic structure before and after co-pyrolysis were analyzed by FTIR and XRD, respectively. The hierarchical porous structure of bio-char was presented by SEM and N 2 adsorption-desorption isotherm. The Cu(II) adsorption capacity of the bio-char was 42.28 mg/g after 24 h, and surface functional groups acted as active binding sites for Cu(II) adsorption. Langmuir model and pseudo-second-order model can describe process of Cu(II) adsorption well.

How do molecular marker patterns of BC change at increasing age of chars?

NASA Astrophysics Data System (ADS)

Schneider, M. P. W.; Hilf, M.; Schmidt, M. W. I.

2009-04-01

Black carbon (BC) is considered to be a relatively stable form of organic carbon. However, previous results have shown that the physical and chemical properties of BC can vary considerably with formation temperature. Thus, to understand the long-term carbon sink potential of BC there is increasing interest to gain more information about i) the conditions under which BC was formed, and ii) the resulting degradability of BC under natural conditions. In a first step, we synthesised chars from two different sources of biomass (chestnut wood, rice straw) under well-defined conditions as model substances to analyse the changes in their molecular structure at increasing formation temperature. Results are presented obtained from a set of laboratory produced char samples pyrolysed at increasing temperatures with a high resolution between 200 and 1000 °C. The chars were characterized by a molecular marker method for pyrogenic carbon quantification, which additionally provides information about the degree of condensation of chars. At temperatures between 275 and 500°C, which typically are observed during wildfires and thus are relevant for natural char formation, the molecular marker pattern of the chars remains almost constant. In a next step, we analysed changes in the molecular marker patterns of chars from a chronosequence, with BC deposited between 0 and 100 years ago. Based on the data obtained from the laboratory char series, we compare changes in the molecular marker patterns of the chars from the chronosequence over time. These results show if less condensed forms of BC are degraded preferentially and more condensed, aromatic backbone of BC becomes enriched in the soils with time of degradation. Our results provide information about the fate of BC in the environment, which has important implications in the context of carbon sequestration strategies.

CO2 Capture and Storage in Coal Gasification Projects

NASA Astrophysics Data System (ADS)

Rao, Anand B.; Phadke, Pranav C.

2017-07-01

In response to the global climate change problem, the world community today is in search for an effective means of carbon mitigation. India is a major developing economy and the economic growth is driven by ever-increasing consumption of energy. Coal is the only fossil fuel that is available in abundance in India and contributes to the major share of the total primary energy supply (TPES) in the country. Owing to the large unmet demand for affordable energy, primarily driven by the need for infrastructure development and increasing incomes and aspirations of people, as well as the energy security concerns, India is expected to have continued dependence on coal. Coal is not only the backbone of the electric power generation, but many major industries like cement, iron and steel, bricks, fertilizers also consume large quantities of coal. India has very low carbon emissions (˜ 1.5 tCO2 per capita) as compared to the world average (4.7 tCO2 per capita) and the developed world (11.2 tCO2 per capita). Although the aggregate emissions of the country are increasing with the rising population and fossil energy use, India has a very little contribution to the historical GHG accumulation in the atmosphere linked to the climate change problem. However, a large fraction of the Indian society is vulnerable to the impacts of climate change - due to its geographical location, large dependence on monsoon-based agriculture and limited technical, financial and institutional capacity. Today, India holds a large potential to offer cost-effective carbon mitigation to tackle the climate change problem. Carbon Capture and Storage (CCS) is the process of extraction of Carbon Dioxide (CO2) from industrial and energy related sources, transport to storage locations and long-term isolation from the atmosphere. It is a technology that has been developed in recent times and is considered as a bridging technology as we move towards carbon-neutral energy sources in response to the growing concerns about climate change problem. Carbon Capture and Storage (CCS) is being considered as a promising carbon mitigation technology, especially for large point sources such as coal power plants. Gasification of coal helps in better utilization of this resource offering multiple advantages such as pollution prevention, product flexibility (syngas and hydrogen) and higher efficiency (combined cycle). It also enables the capture of CO2 prior to the combustion, from the fuel gas mixture, at relatively lesser cost as compared to the post-combustion CO2 capture. CCS in gasification projects is considered as a promising technology for cost-effective carbon mitigation. Although many projects (power and non-power) have been announced internationally, very few large-scale projects have actually come up. This paper looks at the various aspects of CCS applications in gasification projects, including the technical feasibility and economic viability and discusses an Indian perspective. Impacts of including CCS in gasification projects (e.g. IGCC plants) have been assessed using a simulation tool. Integrated Environmental Control Model (IECM) - a modelling framework to simulate power plants - has been used to estimate the implications of adding CCS units in IGCC plants, on their performance and costs.

[Dynamics of the parasite fauna of various forms of chars, salvelinus alpinus L., of the Lake Azabach'e basin].

PubMed

Butorina, T E

1975-01-01

The paper deals with age changes in the parasite fauna of different intraspecific forms of chars. It is shown that this year brood and yearlings of predatory, benthofagous, stream and anadromous chars up to 10 cm in length have a similar parasite fauna. During the second year of life the chars come to different feeding; correspondingly changes their parasite fauna which differs considerably in the above forms of chars. Two groups of parasites are distinguished the infection with which increases and decreases with the age of fishes. Observations were carried out on the life cycles, developmental and maturation periods of some parasites of chars. Biological peculiarities of some mixosporidia are studied. A shift in the developmental periods of helminths is noted as compared to those from the European part of the USSR.

Evaluation of char combustion models: measurement and analysis of variability in char particle size and density

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maloney, Daniel J; Monazam, Esmail R; Casleton, Kent H

Char samples representing a range of combustion conditions and extents of burnout were obtained from a well-characterized laminar flow combustion experiment. Individual particles from the parent coal and char samples were characterized to determine distributions in particle volume, mass, and density at different extent of burnout. The data were then compared with predictions from a comprehensive char combustion model referred to as the char burnout kinetics model (CBK). The data clearly reflect the particle- to-particle heterogeneity of the parent coal and show a significant broadening in the size and density distributions of the chars resulting from both devolatilization and combustion.more » Data for chars prepared in a lower oxygen content environment (6% oxygen by vol.) are consistent with zone II type combustion behavior where most of the combustion is occurring near the particle surface. At higher oxygen contents (12% by vol.), the data show indications of more burning occurring in the particle interior. The CBK model does a good job of predicting the general nature of the development of size and density distributions during burning but the input distribution of particle size and density is critical to obtaining good predictions. A significant reduction in particle size was observed to occur as a result of devolatilization. For comprehensive combustion models to provide accurate predictions, this size reduction phenomenon needs to be included in devolatilization models so that representative char distributions are carried through the calculations.« less

NMR studies on the chemical alteration of soil organic matter precursors during controlled charring

NASA Astrophysics Data System (ADS)

Knicker, Heike

2010-05-01

Beside the production of volatiles, vegetation fire transforms various amounts of labile organic components into recalcitrant dark colored and highly aromatic structures. They are incorporated into soils and are assumed to represent an important sink within the global carbon cycle. In order to elucidate the real importance of PyOM as a C-sink, a good understanding of its chemistry is crucial. Although several 'Black Carbon' (BC) models are reported, a commonly accepted view of the chemistry involved in its formation is still missing. Its biogeochemical recalcitrance is commonly associated with a highly condensed aromatic structure. However, recent studies indicated that this view may be oversimplified for PyOM derived from vegetation fire. In order to bring some more light on the structural properties of PyOM produced during vegetation fire, charred plant residues and model chars derived from typical plant macromolecules (casein, cellulose, lignin and condensed tannins) were subjected to controlled charring under oxic conditions (350°C and 450°C) and then characterized by nuclear magnetic resonance (NMR) spectroscopy and elemental analysis. Subsequently, the chemical features of the PyOM were related to its chemical recalcitrance as determined by chemical oxidation with acid potassium dichromate. Charring cellulose (350°C, 8 min) yielded in a low C-recovery (11%). Treating casein in the same way resulted in a survival of 62% of its C and 46% of its N. Comparable high C-recoveries are reported for lignin. After charring Lolium perenne, 34% of its N and C were recovered. NMR-spectroscopic studies revealed that for this sample most of the charred N and C occurred in pyrrole-type structures. Our studies further indicate that the aromatic skeleton of char accumulating after a vegetation fire must contain remains of the lignin backbone and considerable contributions of furans and anhydrosugars from thermally altered cellulose. Enhancing the temperature during the charring of casein to 450°C decreased the C and N recovery to 30% and 23%, respectively. Comparably the C, O and H recovery were also reduced in the cellulose char, but to a considerably higher extent. These changes went along with a further augmentation of the relative contribution of aromatic C. Increased C, H and O losses were also observed for charring of lignin at higher temperature, although they were smaller than those observed for casein and cellulose. The higher temperature considerably altered the chemistry of the lignin char. The atomic H/C ratio, however, remained above 0.5 showing that in average at least every second C is protonated. Subjecting the produced chars to chemical oxidation with acid potassium dichromate clearly demonstrated that the resistance of the casein chars against heat is not necessarily related to chemical recalcitrance. For the char produced at 350°C, only 13% of the C and N remained in the oxidation residues, whereas for that produced at 450°C this value increased to 80%. In contrast, both cellulose chars showed high chemical resistance with a C-survival of more than 80%. Comparatively, the C and N recalcitrance in the grass chars increased with temperature, whereas, the burned wood residues (350°C) suffered an almost complete oxidation. The chars from condensed tannins, on the other hand showed a high chemical resistance independently from the production temperature. In summary, this study confirmed that the thermal, chemical and biological recalcitrance of biochars is related to their chemical structures and N-contents, which on the other hand depend on the source and the respective charring conditions. The resulting high chemical variability of biochars is in accordance with the concept of BC as a continuum and explains the high discrepancy among BC quantifications obtained with common approaches assuming BC as a highly condensed polyaromatic network.

Effects of retorting factors on combustion properties of shale char. 3. Distribution of residual organic matters.

PubMed

Han, Xiangxin; Jiang, Xiumin; Cui, Zhigang; Liu, Jianguo; Yan, Junwei

2010-03-15

Shale char, formed in retort furnaces of oil shale, is classified as a dangerous waste containing several toxic compounds. In order to retort oil shale to produce shale oil as well as treat shale char efficiently and in an environmentally friendly way, a novel kind of comprehensive utilization system was developed to use oil shale for shale oil production, electricity generation (shale char fired) and the extensive application of oil shale ash. For exploring the combustion properties of shale char further, in this paper organic matters within shale chars obtained under different retorting conditions were extracted and identified using a gas chromatography-mass spectrometry (GC-MS) method. Subsequently, the effects of retorting factors, including retorting temperature, residence time, particle size and heating rate, were analyzed in detail. As a result, a retorting condition with a retorting temperature of 460-490 degrees C, residence time of <40 min and a middle particle size was recommended for both keeping nitrogenous organic matters and aromatic hydrocarbons in shale char and improving the yield and quality of shale oil. In addition, shale char obtained under such retorting condition can also be treated efficiently using a circulating fluidized bed technology with fractional combustion. (c) 2009 Elsevier B.V. All rights reserved.

Feasibility of mercury removal from simulated flue gas by activated chars made from poultry manures.

PubMed

Klasson, K Thomas; Lima, Isabel M; Boihem, Larry L; Wartelle, Lynda H

2010-12-01

Increased emphasis on reduction of mercury emissions from coal fired electric power plants has resulted in environmental regulations that may in the future require application of activated carbons as mercury sorbents for mercury removal. At the same time, the quantity of poultry manure generated each year is large and technologies that take advantage of the material should be explored. The purpose of the work was to obtain preliminary data to investigate if activated chars made from different poultry manures could adsorb mercury from simulated flue gas. In laboratory experiments, activated chars made from chicken cake and litter removed mercury from the gas as well as a commercial alternative. It was also found that acid-washing these chars after activation may improve pore structure but does not influence the mercury removal efficiency. Activated chars were also made from turkey cake and litter. These raw materials produced activated chars with similar pore structure as those made from chicken manure, but they did not adsorb mercury as well. Acid-washing the turkey manure-based chars improved their performance, but this step would add to the cost of production. Preliminary evaluations suggest that unwashed activated chars may cost as little as $0.95/kg to produce. Published by Elsevier Ltd.

Combustion of char from plastic wastes pyrolysis

NASA Astrophysics Data System (ADS)

Saptoadi, Harwin; Rohmat, Tri Agung; Sutoyo

2016-06-01

A popular method to recycle plastic wastes is pyrolysis, where oil, gas and char can be produced. These products can be utilized as fuels because they are basically hydrocarbons. The research investigates char properties, including their performance as fuel briquettes. There are 13 char samples from PE (Polyethylene) pyrolyzed at temperatures of around 450 °C, with and without a catalyst. Some of the samples were obtained from PE mixed with other types, such as Polystyrene (PS), Polypropylene (PP), Polyethylene Terephthalate (PET), and Others. Char properties, such as moisture, ash, volatile matter, and fixed carbon contents, are revealed from the proximate analysis, whereas calorific values were measured with a bomb calorimeter. Briquettes are made by mixing 4 g of char with 0.5 - 1 g binder. Briquettes are hollow cylinders with an outer and inner diameter of around 1.75 cm and 0.25 cm, respectively. Combustion is carried out in a furnace with wall temperatures of about 230°C and a constant air velocity of 0.7 m/s. Five out of 13 char briquettes are not feasible because they melt during combustion. Briquettes made from 100% PE wastes burn in substantially shorter duration than those from mixed plastic wastes. Char #1 and #5 are excellent due to their highest energy release, whereas #10 show the worst performance.

Performance, cost and environmental assessment of gasification-based electricity in India: A preliminary analysis

NASA Astrophysics Data System (ADS)

Rani, Abha; Singh, Udayan; Jayant; Singh, Ajay K.; Sankar Mahapatra, Siba

2017-07-01

Coal gasification processes are crucial to decarbonisation in the power sector. While underground coal gasification (UCG) and integrated gasification combined cycle (IGCC) are different in terms of the site of gasification, they have considerable similarities in terms of the types of gasifiers used. Of course, UCG offers some additional advantages such as reduction of the fugitive methane emissions accompanying the coal mining process. Nevertheless, simulation of IGCC plants involving surface coal gasification is likely to give reasonable indication of the 3E (efficiency, economics and emissions) prospects of the gasification pathway towards electricity. This paper will aim at Estimating 3E impacts (efficiency, environment, economics) of gasification processes using simulation carried out in the Integrated Environmental Control Model (IECM) software framework. Key plant level controls which will be studied in this paper will be based on Indian financial regulations and operating costs which are specific to the country. Also, impacts of CO2 capture and storage (CCS) in these plants will be studied. The various parameters that can be studied are plant load factor, impact of coal quality and price, type of CO2 capture process, capital costs etc. It is hoped that relevant insights into electricity generation from gasification may be obtained with this paper.

Performance of Ni/dolomite pellet catalyst on gas distribution from cassava rhizome gasification with a modular fixed-bed gasifier.

PubMed

Sricharoenchaikul, V; Atong, D; Sornkade, P; Nisamaneenate, J

2017-05-01

Thermal conversion of cassava rhizome was performed using a modular downdraft gasifier with the addition of Ni-based catalysts as promising tar eliminating and produced gas upgrading techniques. The activities of a synthesized 5% Ni/dolomite pellet catalyst prepared by impregnation method were investigated in a secondary reactor downstream of the gasifier. High reforming activity of the Ni/dolomite pellet catalyst on tar reduction was achieved. The conversion to H 2 and CO was improved via steam reforming of methane and char reaction with CO 2 . Moreover, the formation of CH 4 and C x H y was diminished through the tar or condensable hydrocarbon reformed on the catalyst surface. The carbon and hydrogen conversions of cassava rhizome with prepared catalyst were 83.79% and 61.78%, respectively, at an air flow rate of 1.98 m 3 /hr. At this condition, tar formation was low, while the lower heating value was 4.39 MJ/m 3 and H 2 to CO molar ratio was 1.22. Generally, the addition of a catalyst not only enhanced gas production, but also reduced tar and particulate matter generation; thus, its implementation should help lessen the pollution control requirement and cost of operation, while allowing higher quality fuel gas production.

Characteristics of coking coal burnout

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakamura, M.; Bailey, J.G.

An attempt was made to clarify the characteristics of coking coal burnout by the morphological analysis of char and fly ash samples. Laboratory-scale combustion testing, simulating an ignition process, was carried out for three kinds of coal (two coking coals and one non-coking coal for reference), and sampled chars were analyzed for size, shape and type by image analysis. The full combustion process was examined in industrial-scale combustion testing for the same kinds of coal. Char sampled at the burner outlet and fly ash at the furnace exit were also analyzed. The difference between the char type, swelling properties, agglomeration,more » anisotropy and carbon burnout were compared at laboratory scale and at industrial scale. As a result, it was found that coking coals produced chars with relatively thicker walls, which mainly impeded char burnout, especially for low volatile coals.« less

Adsorption mechanism for xanthene dyes to cellulose granules.

PubMed

Tabara, Aya; Yamane, Chihiro; Seguchi, Masaharu

2012-01-01

The xanthene dyes, erythrosine, phloxine, and rose bengal, were adsorbed to charred cellulose granules. The charred cellulose granules were preliminarily steeped in ionic (NaOH, NaCl, KOH, KCl, and sodium dodecyl sulfate (SDS)), nonionic (glucose, sucrose, and ethanol), and amphipathic sucrose fatty acid ester (SFAE) solutions, and adsorption tests on the dye to the steeped and charred cellulose granules were conducted. Almost none of the dye was adsorbed when the solutions of ionic and amphipathic molecules were used, but were adsorbed in the case of steeping in the nonionic molecule solutions. Thin-layer chromatography (TLC) and the Fourier transform infra-red (FT-IR) profiles of SFAE which was adsorbed to the charred cellulose granules and extracted by ethyl ether suggested the presence of hydrophobic sites on the surface of the charred cellulose granules. We confirmed that the xanthene dyes could bind to the charred cellulose granules by ionic and hydrophobic bonds.

Tyre char preparation from waste tyre rubber for dye removal from effluents.

PubMed

Mui, Edward L K; Cheung, W H; McKay, Gordon

2010-03-15

A number of chars from waste tyre rubber were prepared by carbonisation at 673-1173 K. The effects of holding time, heating rate and particle size on the textural characteristics and elemental composition of the resultant chars were investigated. It was demonstrated that temperatures over 773 K did not have a significant improvement on the total surface area but resulted in lower char yields following increased aromatisation. Modelling of dye adsorption isotherms showed that the Redlich-Peterson expression yields the best-fit between experimental and predicted data. Furthermore, for a larger sized dye like Acid Yellow 117 (MW=848 g/mol), the amount adsorbed by the tyre char is not directly proportional to the total surface area when compared with a commercial carbon, revealing that factors other than total surface area are involved in the adsorption potential of the tyre chars. (c) 2009 Elsevier B.V. All rights reserved.

Low-calorie bread baked with charred cellulose granules and wheat flour to eliminate toxic xanthene food dye in the alimentary canal.

PubMed

Tabara, Aya; Yamane, Chihiro; Seguchi, Masaharu

2012-01-01

We baked low-calorie bread by mixing charred cellulose granules with wheat flour, using the charred cellulose granules to eliminate toxic xanthene food dyes contained in processed foods from the alimentary canal. The size of the charred cellulose granules played an important role in determining good breadmaking properties in respect of the bread height (mm) and specific volume (SV, cm3/g). Charred cellulose granules with a diameter above 270 μm were blended with wheat flour at 10% to obtain bread with a lower caloric content (1020 kcal/gram of bread) than the control bread (1126 kcal) made solely from wheat flour. The charred cellulose granules taken out from the bread adsorbed toxic xanthene food dyes at around pH 6.5, such that toxic food dyes taken into the alimentary canal were excreted in the feces with the non-digestible cellulose granules.

Influence of pressure on pyrolysis of black liquor: 2. Char yields and component release.

PubMed

Whitty, Kevin; Kullberg, Mika; Sorvari, Vesa; Backman, Rainer; Hupa, Mikko

2008-02-01

This is the second in a series of papers concerning the behavior of black liquor during pyrolysis at elevated pressures. Two industrial black liquors were pyrolyzed under pressurized conditions in two laboratory-scale devices, a pressurized single-particle reactor and a pressurized grid heater. Temperatures ranging between 650 and 1100 degrees C and pressures in the range 1-20 bar were studied. Char yields were calculated and based on analysis of some of the chars the fate of carbon, sodium, potassium and sulfur was determined as a function of pyrolysis pressure. At temperatures below 800 degrees C little variation in char yield was observed at different pressures. At higher temperatures char yield increased with pressure due to slower decomposition of sodium carbonate. For the same reason, sodium release decreased with pressure. Sulfur release, however, increased with pressure primarily because there was less opportunity for its capture in the less-swollen chars.

Structural evolution of maize stalk/char particles during pyrolysis.

PubMed

Fu, Peng; Hu, Song; Sun, Lushi; Xiang, Jun; Yang, Tao; Zhang, Anchao; Zhang, Junying

2009-10-01

The structural evolution characteristics of maize stalk/char particles during pyrolysis were investigated. The char was prepared by pyrolyzing at temperatures ranging from 200 to 900 degrees C. Maize stalk and chars were characterized by thermogravimetric analysis, ultimate analysis (TGA), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), helium density measurement and N(2) adsorption/desorption method. The char yield decreased rapidly with increasing temperature until 400 degrees C. As temperature increased, the char became progressively more aromatic and carbonaceous. The hydroxyl, aliphatic C-H, carbonyl and olefinic C=C groups were lost at high temperatures. Below 500 degrees C, the removal of volatile matter made pore opening. High temperatures led to the occurrence of softening, melting, fusing and carbon structural ordering. The aromatization process started at approximately 350 degrees C and continued to higher temperatures. The shrinkage of carbon structure occurred above 500 degrees C, which was concurrent with the aromatization process.

Mid-infrared diffuse reflectance spectroscopic examination of charred pine wood, bark, cellulose, and lignin: Implications for the quantitative determination of charcoal in soils

USGS Publications Warehouse

Reeves, J. B.; McCarty, G.W.; Rutherford, D.W.; Wershaw, R. L.

2008-01-01

Fires in terrestrial ecosystems produce large amounts of charcoal that persist in the environment and represent a substantial pool of sequestered carbon in soil. The objective of this research was to investigate the effect of charring on mid-infrared spectra of materials likely to be present in forest fires in order to determine the feasibility of determining charred organic matter in soils. Four materials (cellulose, lignin, pine bark, and pine wood) and char from these materials, created by charring for various durations (1 to 168 h) and at various temperatures (200 to 450 ??C), were studied. Mid-infrared spectra and measures of acidity (total acids, carboxylic acids, lactones, and phenols as determined by titration) were determined for 56 different samples (not all samples were charred at all temperatures/durations). Results showed spectral changes that varied with the material, temperature, and duration of charring. Despite the wide range of spectral changes seen with the differing materials and length/temperature of charring, partial least squares calibrations for total acids, carboxylic acids, lactones, and phenols were successfully created (coefficient of determination and root mean squared deviation of 0.970 and 0.380; 0.933 and 0.227; 0.976 and 0.120; and 0.982 and 0.101 meq/g, respectively), indicating that there is a sufficient commonality in the changes to develop calibrations without the need for unique calibrations for each specific material or condition of char formation. ?? 2008 Society for Applied Spectroscopy.

Evaluation of solid oxide fuel cell systems for electricity generation

NASA Technical Reports Server (NTRS)

Somers, E. V.; Vidt, E. J.; Grimble, R. E.

1982-01-01

Air blown (low BTU) gasification with atmospheric pressure Solid Electrolyte Fuel Cells (SOFC) and Rankine bottoming cycle, oxygen blown (medium BTU) gasification with atmospheric pressure SOFC and Rankine bottoming cycle, air blown gasification with pressurized SOFC and combined Brayton/Rankine bottoming cycle, oxygen blown gasification with pressurized SOFC and combined Brayton/Rankine bottoming cycle were evaluated.

Pyrolysis of flax straw: Characterization of char, liquid, and gas as fuel

NASA Astrophysics Data System (ADS)

Tushar, Mohammad Shahed Hasan Khan

The demand for energy continues to outstrip its supply and necessitates the development of renewable energy options. Biomass has been recognized as a major renewable energy source to supplement the declining fossil fuel source of energy. It is the most popular form of renewable energy and, currently, biofuel production is becoming more promising. Being carbon neutral, readily available, and low in sulphur content makes biomass a very promising source of renewable energy. In the present research, both the isothermal and non-isothermal pressurized pyrolysis of flax straw is studied for the first time. In case of isothermal pyrolysis, the influence of pyrolysis temperature and reaction time on char yield and morphology was investigated. The applied pyrolysis temperature was varied between 300 and 500°C. The reaction time was varied from 15 to 60 min. The char yield was found to decrease as pyrolysis temperature and reaction time increased. The char structure and surface morphology were thoroughly investigated by means of x-ray diffraction (XRD), temperature-programmed oxidation (TPO), and scanning electron microscopy (SEM). The degree of porosity and graphitization increased as pyrolysis temperature and time increased. In fact, the experiment performed at 500°C for 1h duration did not yield any char; only residual ash could be obtained. The TPO studies on the char samples corroborated the XRD findings and showed the presence of two types of carbon, namely, amorphous filamentous carbon and graphitic carbon. A thermogravimetric analysis (TGA) of the char was performed to gain an understanding of combustion kinetics and reactivity. It implied that the reactivity of the char decreases as temperature increases, and this finding is well supported by the TPO, TGA, SEM, and XRD characterization data. Furthermore, an empirical global model was devised based on the power law to estimate activation energy and other kinetic parameters. For the non-isothermal pressurized pyrolysis of flax straw, the experiments were carried out at different pressures, ranging from 10 to 40 psig. The three types of products thus obtained (gas, liquid, char) were thoroughly quantified and analyzed. The yields of the products were found to be dependent on the experimental conditions. It was observed that 10 psig of pressure gave the maximum yield of bio-oil, while 20 psig pressure lead to maximum char yield. The gaseous products were analyzed using an online GC, while the bio-oils were characterized using an offline GC/MS. SEM studies were performed to study the char morphology and porosity. The main gaseous products observed were CO, H2, CO2, CH 4, and C3. The bio-oils were mainly composed of phenolic compounds, carboxylic acids, and furfural. The pH and density of the bio-oils was found to increase as pyrolysis pressure increased. SEM investigation gave insights into the porosity of chars; as pressure increased, an increase in the porosity of char was noted. XRD studies showed that amorphous hydrocarbon and graphitic carbons are the major constituents of char, which was supported by TPO experiments. A TGA study showed two reaction zones for char oxidation. The kinetic parameters of oxidation were estimated using a power law model, which was also used for isothermal pyrolysis and isothermal char oxidation kinetics. Based on the data generated, the pressure of 10 psig was found to be optimum for bio-oil production, while a pressure of 20 psig was optimum for char production. With the increase in pressure, the production of individual gas components increased within the pressure range studied. Finally, with the increase in reaction pressure, temperature and time, the produced chars became less reactive.

Preparation and characterization of activated carbon from the char produced in the thermolysis of granulated scrap tyres.

PubMed

López, F A; Centeno, T A; Rodríguez, O; Alguacil, E J

2013-05-01

The char produced in the thermolysis of granulated scrap tyres has few market outlets, reducing the economic viability of the thermolytic process. This paper reports the potential of this char as a low-cost precursor of porous carbons. The tyre-derived char was demineralized in either alkaline or acidic media to reduce its ash, zinc, sulfur, and silica contents. The lowest impurity content was achieved with an HNO3/H2O treatment. The resulting demineralized char was then subjected to activation by KOH or CO2. The Brunauer-Emmett-Teller (BET)-specific surface area of the activated carbon produced by the KOH treatment was 242 m2/g, whereas that of the CO2-activated carbon was 720 m2/g. The textural properties of the latter product were similar to those of some commercial activated carbons. The use of tyre-derived char as a precursor of porous carbons could render the thermolytic treatment of scrap tyres more economically attractive. Char produced in thermolysis of granulated scrap tyres has a few market outlets; in this paper an alternative for its use is presented. The char was converted into activated carbon with textural properties similar to those of some commercial activated carbons. This process could render the thermolytic treatment of scrap tyres more economically attractive.

Proximate analyses and predicting HHV of chars obtained from cocracking of petroleum vacuum residue with coal, plastics and biomass.

PubMed

Ahmaruzzaman, M

2008-07-01

Higher heating value (HHV) and analysis of chars obtained from cocracking of petroleum vacuum residue (XVR) with coal (SC), biomass (BG, CL) and plastics (PP, PS, BL) are important which define the energy content and determine the clean and efficient use of these chars. The main aim of the present study is to analyze the char obtained from cocracking in terms of their proximate analysis data and determination of the HHV of the chars. The char obtained from XVR+PP cocracking showed a HHV of 32.84 MJ/kg, whereas that from CL cracking showed a HHV of 18.52 MJ/kg. The experimentally determined heating values of the char samples obtained from cocracking have been correlated with the theoretical equation based on proximate analysis data. There exists a variety of correlations for predicting HHV from proximate analysis of fuels. Based upon proximate analysis data, the models were tested. The best results show coefficient of determination (R2) of 0.965 and average absolute and bias error of 3.07% and 0.41%, respectively. The heating values obtained from the model were in good agreement with that obtained by experiment. Proximate analysis of the chars obtained from the cocracking of XVR with coal, biomass and plastics showed that there exists a definite interaction of the reactive species, when they were cocracked together.

Nitrogen removal from coal gasification wastewater by activated carbon technologies combined with short-cut nitrogen removal process.

PubMed

Zhao, Qian; Han, Hongjun; Hou, Baolin; Zhuang, Haifeng; Jia, Shengyong; Fang, Fang

2014-11-01

A system combining granular activated carbon and powdered activated carbon technologies along with shortcut biological nitrogen removal (GAC-PACT-SBNR) was developed to enhance total nitrogen (TN) removal for anaerobically treated coal gasification wastewater with less need for external carbon resources. The TN removal efficiency in SBNR was significantly improved by introducing the effluent from the GAC process into SBNR during the anoxic stage, with removal percentage increasing from 43.8%-49.6% to 68.8%-75.8%. However, the TN removal rate decreased with the progressive deterioration of GAC adsorption. After adding activated sludge to the GAC compartment, the granular carbon had a longer service-life and the demand for external carbon resources became lower. Eventually, the TN removal rate in SBNR was almost constant at approx. 43.3%, as compared to approx. 20.0% before seeding with sludge. In addition, the production of some alkalinity during the denitrification resulted in a net savings in alkalinity requirements for the nitrification reaction and refractory chemical oxygen demand (COD) degradation by autotrophic bacteria in SBNR under oxic conditions. PACT showed excellent resilience to increasing organic loadings. The microbial community analysis revealed that the PACT had a greater variety of bacterial taxons and the dominant species associated with the three compartments were in good agreement with the removal of typical pollutants. The study demonstrated that pre-adsorption by the GAC-sludge process could be a technically and economically feasible method to enhance TN removal in coal gasification wastewater (CGW). Copyright © 2014. Published by Elsevier B.V.

Modeling and comparative assessment of municipal solid waste gasification for energy production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arafat, Hassan A., E-mail: harafat@masdar.ac.ae; Jijakli, Kenan

Highlights: • Study developed a methodology for the evaluation of gasification for MSW treatment. • Study was conducted comparatively for USA, UAE, and Thailand. • Study applies a thermodynamic model (Gibbs free energy minimization) using the Gasify software. • The energy efficiency of the process and the compatibility with different waste streams was studied. - Abstract: Gasification is the thermochemical conversion of organic feedstocks mainly into combustible syngas (CO and H{sub 2}) along with other constituents. It has been widely used to convert coal into gaseous energy carriers but only has been recently looked at as a process for producingmore » energy from biomass. This study explores the potential of gasification for energy production and treatment of municipal solid waste (MSW). It relies on adapting the theory governing the chemistry and kinetics of the gasification process to the use of MSW as a feedstock to the process. It also relies on an equilibrium kinetics and thermodynamics solver tool (Gasify®) in the process of modeling gasification of MSW. The effect of process temperature variation on gasifying MSW was explored and the results were compared to incineration as an alternative to gasification of MSW. Also, the assessment was performed comparatively for gasification of MSW in the United Arab Emirates, USA, and Thailand, presenting a spectrum of socioeconomic settings with varying MSW compositions in order to explore the effect of MSW composition variance on the products of gasification. All in all, this study provides an insight into the potential of gasification for the treatment of MSW and as a waste to energy alternative to incineration.« less

Environmental Impacts of the Production and Application of Biochar - EuroChar Project

NASA Astrophysics Data System (ADS)

Rack, Mireille; Woods, Jeremy

2014-05-01

One of the potential benefits of biochar is carbon sequestration. To determine the overall net sequestration potential it is important to analyse the full supply chain, assessing both the direct and indirect emissions associated with the production and application of biochar. However, it is essential to also incorporate additional environmental impact categories to ensure the assessment of a more complete environmental impact profile. This paper uses a full life-cycle assessment (LCA) methodology to evaluate the results from the EuroChar, 'biochar for carbon sequestration and large-scale removal of GHG from the atmosphere', project. This EU Seventh Framework Programme project aims to investigate and reduce uncertainties around the impacts of, and opportunities for, biochar, and in particular explore possible pathways for its introduction into modern agricultural systems in Europe. The LCA methodology, according to the ISO standards, is applied to the project-specific supply chains to analyse the environmental impacts of biochar production and application. Two conversion technologies for the production of biochar are assessed, gasification and hydrothermal carbonization (HTC), in order to provide conversion efficiencies and emission factors for the biochar production component of the supply chain. The selected feedstocks include those derived from waste residues and dedicated crops. For the end use stage, various forms and methods for biochar application are considered. In addition to the Global Warming Potential category, other environmental impact categories are also included in the analysis. The resulting 'feedstock * conversion technology' matrix provides nine pathways for the production and application of biochar, which are applied as a representative basis for the scenario modelling. These scenarios have been developed in order to assess the feedstock and land availability in Europe for the production and application of biochar and to give an order of magnitude assessment as to the potential role for biochar as a material climate mitigation option. Preliminary results show net negative supply chain emissions, indicating biochar to be a carbon sink. Overall, the life cycle stage that contributes most significantly to the environmental impact profile is feedstock production. Feedstock selection is therefore expected to play a key role in determining the overall viability of biochar production and its use in land application. Further sensitivity analyses show that the allocation method of the attributional LCA has the greatest impact on the results, followed by the oxidation rate of the carbon in the biochar, and the transportation distances of the feedstock and biochar. Indirect impacts, such as avoided use of fossil fuel, can significantly alter the results. As the EuroChar project comes to a completion at the end of May 2014, the near-final results are presented at the EGU 2014 General Assembly.

Waste-to-Energy Systems

DTIC Science & Technology

2009-04-01

at hospitals, at schools,” or wherever there are people creating masses of trash.5 Pyrolytic Gasification Pyrolytic gasification is not a new...prevalent with both. Gasification is . . . the chemical reaction and molecular breakdown or degradation of materials. The first pyrolytic gasification...dealing with about 2 tons of mixed solid waste per day, will destroy wood, paper card, food, plastics, and sanitary, clinical, and oil waste and

Landform position and charring conditions control decomposition of soil organic matter and pyrogenic carbon

NASA Astrophysics Data System (ADS)

Abney, R.; Jin, L.; Berhe, A. A.

2017-12-01

Wildfire is a significant global control on both ecosystem properties and biogeochemical cycling, and wildfires are projected to increase in both size and severity with continued climate change. Post-fire, charred biomass, or pyrogenic carbon, is left behind as a significant, relatively slow-cycling component of the soil organic matter pool. Pyrogenic carbon has a turnover time on the centennial scale, and previous research has demonstrated that it is highly susceptible to erosion. However, the interaction of the roles of landform position and combustion temperature remains unexplored. We collected live Pinus jeffreyi bark and charred it under combustion conditions at three temperatures (200°C, 350°C, and 500°C). The charred bark was mixed with soil collected from both eroding and depositional landform positions and incubated for six months. Throughout this incubation, microbial respiration was monitored via collection of CO2, and cumulative respiration was fitted using both single- and multi-pool exponential models. Overall, respiration was highest in soil and char mixtures in the depositional landform positions. Pyrogenic carbon concentrations, as determined by the Kurth Mackenzie Deluca method, declined only slightly in the 200°C char mixed with the depositional soil. Scanning electron microscopy images of the chars before and after incubation illustrate some incorporation of soil organic matter into the structures of the char, and some breakdown of the physical structures of the char. Altogether, the lower temperature chars mixed with the soil from the depositional landform position had the highest decomposition rates, which suggests the role that landform position may play on the stability of pyrogenic carbon at the landscape scale. Furthermore, this implies that the post-fire erosional re-distribution of pyrogenic carbon may act as a significant control of its long-term stabilization in soil and landscape-scale soil carbon stocks.

Effect of surface area and chemisorbed oxygen on the SO2 adsorption capacity of activated char

USGS Publications Warehouse

Lizzio, A.A.; DeBarr, J.A.

1996-01-01

The objective of this study was to determine whether activated char produced from Illinois coal could be used effectively to remove sulfur dioxide from coal combustion flue gas. Chars were prepared from a high-volatile Illinois bituminous coal under a wide range of pyrolysis and activation conditions. A novel char preparation technique was developed to prepare chars with SO2 adsorption capacities significantly greater than that of a commercial activated carbon. In general, there was no correlation between SO2 adsorption capacity and surface area. Temperature-programmed desorption (TPD) was used to determine the nature and extent of carbon-oxygen (C-O) complexes formed on the char surface. TPD data revealed that SO2 adsorption was inversely proportional to the amount of C-O complex. The formation of a stable C-O complex during char preparation may have served only to occupy carbon sites that were otherwise reactive towards SO2 adsorption. A fleeting C(O) complex formed during SO2 adsorption is postulated to be the reaction intermediate necessary for conversion of SO2 to H2SO4. Copyright ?? 1996 Elsevier Science Ltd.

Ultrasonically assisted extraction of calcium and ash from char

NASA Astrophysics Data System (ADS)

Mathumba, E. E.; Mbaya, R. K. K.; Kolesnikov, A.

2018-03-01

This study characterized and removed calcium and ash content from char to improve the chemical quality of char as reductant for titanium smelting application. Calcium in char can be classified in two parts: mineral matter and cationic metals associated with organic matrix. Virgin and chemically treated char was characterized by using ISO 1171, wet chemistry methods, ISO 19579, XRF, and B.E.T. methods. In this present work, demineralization of char with mild chemical leachants such as acetic acid, citric acid, gluconic acid and Ethylene Diamine Tetra Acetic acid with three different ultrasonic power input (150 W, 270 W and 300 W) and semi-dual frequency of 40 kHz tank was investigated. Actual power dissipated into the system was calculated from the calorimetric measurement. An optimum set of process parameters are identified and validated. The ultrasound technology was compared with soaking technology to determine the efficiency of ultrasound system for the removal of calcium. The removal of calcium was exponentially higher with ultrasonic treatment than without it. Results revealed that mild chemical reagents do not harm the carbon content of char. It is evident from the results that amongst the leachants used; acetic and citric acid has caused significant removal of mineral phases.

Two-step gasification of cattle manure for hydrogen-rich gas production: Effect of biochar preparation temperature and gasification temperature.

PubMed

Xin, Ya; Cao, Hongliang; Yuan, Qiaoxia; Wang, Dianlong

2017-10-01

Two-step gasification process was proposed to dispose cattle manure for hydrogen rich gas production. The effect of temperature on product distribution and biochar properties were first studied in the pyrolysis-carbonization process. The steam gasification of biochar derived from different pyrolysis-carbonization temperatures was then performed at 750°C and 850°C. The biochar from the pyrolysis-carbonization temperatures of 500°C had high carbon content and low volatiles content. According to the results of gasification stage, the pyrolysis-carbonization temperature of 500°C and the gasification temperature of 850°C were identified as the suitable conditions for hydrogen production. We obtained 1.61m 3 /kg of syngas production, 0.93m 3 /kg of hydrogen yield and 57.58% of hydrogen concentration. This study shows that two-step gasification is an efficient waste-to-hydrogen energy process. Copyright © 2017 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsumura, Yukihiko; Nuessle, F.W.; Antal, M.J. Jr.

Recently, carbonaceous materials including activated carbon were proven to be effective catalysts for hazardous waste gasification in supercritical water. Using coconut shell activated carbon catalyst, complete decomposition of industrial organic wastes including methanol and acetic acid was achieved. During this process, the total mass of the activated carbon catalyst changes by two competing processes: a decrease in weight via gasification of the carbon by supercritical water, or an increase in weight by deposition of carbonaceous materials generated by incomplete gasification of the biomass feedstocks. The deposition of carbonaceous materials does not occur when complete gasification is realized. Gasification of themore » activated carbon in supercritical water is often favored, resulting in changes in the quality and quantity of the catalyst. To thoroughly understand the hazardous waste decomposition process, a more complete understanding of the behavior of activated carbon in pure supercritical water is needed. The gasification rate of carbon by water vapor at subcritical pressures was studied in relation to coal gasification and generating activated carbon.« less

A study of industrial hydrogen and syngas supply systems

NASA Technical Reports Server (NTRS)

Amos, W. J.; Solomon, J.; Eliezer, K. F.

1979-01-01

The potential and incentives required for supplying hydrogen and syngas feedstocks to the U.S. chemical industry from coal gasification systems were evaluated. Future hydrogen and syngas demand for chemical manufacture was estimated by geographic area and projected economics for hydrogen and syngas manufacture was estimated with geographic area of manufacture and plant size as parameters. Natural gas, oil and coal feedstocks were considered. Problem areas presently affecting the commercial feasibility of coal gasification discussed include the impact of potential process improvements, factors involved in financing coal gasification plants, regulatory barriers affecting coal gasification, coal mining/transportation, air quality regulations, and competitive feedstock pricing barriers. The potential for making coal gasification the least costly H2 and syngas supply option. Options to stimulate coal gasification system development are discussed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsumura, Yukihiko; Nuessle, F.W.; Antal, M.J. Jr.

Recently, carbonaceous materials were proved to be effective catalysts for hazardous waste decomposition in supercritical water. Gasification of the carbonaceous catalyst itself is also expected, however, under supercritical conditions. Thus, it is essential to determine the gasification rate of the carbonaceous materials during this process to determine the active lifetime of the catalysts. For this purpose, the gasification characteristics of granular coconut shell activated carbon in supercritical water alone (600-650{degrees}C, 25.5-34.5 MPa) were investigated. The gasification rate at subatmospheric pressure agreed well with the gasification rate at supercritical conditions, indicating the same reaction mechanism. Methane generation under these conditions ismore » via pyrolysis, and thus is not affected by the water pressure. An iodine number increase of 25% was observed as a result of the supercritical water gasification.« less

Characterization of a Neochlamydia-like Bacterium Associated with Epitheliocystis in Cultured Artic Char Salvelinus alpinus

USDA-ARS?s Scientific Manuscript database

Infections of branchial epithelium by intracellular gram-negative bacteria, termed epitheliocystis, have limited culture of Arctic char (Salvelinus alpinus). To characterize a bacterium associated with epitheliocystis in cultured char, gills were sampled for histopathologic examination, conventional...

Evaluation of the energy transfer in the char zone during ablation. Part 2: In-depth response of ablative composites, volume 1. Ph.D. Thesis, 1975. Final Report

NASA Technical Reports Server (NTRS)

Pike, R. W.; Delvalle, E. G.

1974-01-01

The decomposition of ablative composites is described along with the transport phenomena of pyrolysis gases which result from the decomposition of these plastics as they flow through the porous char of char-forming ablators. The pyrolysis products are those formed by the thermal degradation of nylon-phenolic resin and silicone elastomer composites. Emphasis is placed on the nature and extent of chemical reactions of the pyrolysis products and the char, along with the energy absorbed by the combined pyrolysis and char zone. Chemical reactions with thermodynamically consistent kinetic data are determined in order to develop a realistic analysis for predicting the thermal performance of ablative heat shields.

Attrition-free pyrolysis to produce bio-oil and char.

PubMed

Mauviel, Guillain; Guillain, Mauviel; Kies, Fairouz; Fairouz, Kies; René, Mar Sans; Mar, Sans Rene; Ferrer, Monique; Monique, Ferrer; Lédé, Jacques; Jacques, Lédé

2009-12-01

Experiments are performed on a laboratory scale setup where beech wood chips are heated by gas convection and walls radiation. This study shows that it is possible to obtain high bio-oil and char yields with relatively low external heat transfer coefficients. The main advantage of this convection/radiation heat transfer mode compared to solid-solid collisions, applied in fluidized bed or twin screw reactors, is the reduction of solid attrition (char and sand). Thus tricky gas-solid separation through hot cyclones and/or hot filters could be avoided or reduced. It should be possible to recover directly bio-oil with less char particles and char free of sand dust. These qualities would allow easier use of these bio-products in different applications.

High Pressure Biomass Gasification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Agrawal, Pradeep K

2016-07-29

According to the Billion Ton Report, the U.S. has a large supply of biomass available that can supplement fossil fuels for producing chemicals and transportation fuels. Agricultural waste, forest residue, and energy crops offer potential benefits: renewable feedstock, zero to low CO 2 emissions depending on the specific source, and domestic supply availability. Biomass can be converted into chemicals and fuels using one of several approaches: (i) biological platform converts corn into ethanol by using depolymerization of cellulose to form sugars followed by fermentation, (ii) low-temperature pyrolysis to obtain bio-oils which must be treated to reduce oxygen content via HDOmore » hydrodeoxygenation), and (iii) high temperature pyrolysis to produce syngas (CO + H 2). This last approach consists of producing syngas using the thermal platform which can be used to produce a variety of chemicals and fuels. The goal of this project was to develop an improved understanding of the gasification of biomass at high pressure conditions and how various gasification parameters might affect the gasification behavior. Since most downstream applications of synags conversion (e.g., alcohol synthesis, Fischer-Tropsch synthesis etc) involve utilizing high pressure catalytic processes, there is an interest in carrying out the biomass gasification at high pressure which can potentially reduce the gasifier size and subsequent downstream cleaning processes. It is traditionally accepted that high pressure should increase the gasification rates (kinetic effect). There is also precedence from coal gasification literature from the 1970s that high pressure gasification would be a beneficial route to consider. Traditional approach of using thermogravimetric analyzer (TGA) or high-pressure themogravimetric analyzer (PTGA) worked well in understanding the gasification kinetics of coal gasification which was useful in designing high pressure coal gasification processes. However, similar approach for biomass gasification was not very useful and was the impetus for this study. Specifically, we aimed this study at three broad objectives: (i) defining operating conditions at which C 2-C 4 hydrocarbons are formed since these represent loss of carbon efficiency, (ii) understanding the formation of tar species which create downstream processing difficulties in addition of carbon efficiency loss, and (iii) kinetics of biomass gasification where it would be possible to understand the effect of operating conditions and gas phase composition.« less

Waste to Energy at SUNY Cobleskill

DTIC Science & Technology

2011-05-10

Overview on Army Net Zero Concepts • Gasification Intro. • SUNY Cobleskill Center for Environmental Science and Technology. • TURNW2E™ Gasification ...5 GASIFICATION A TECHNOLOGY 2-fer • Waste Reduction • Reduced Logistics for Waste Transportation • Reduced environmental and personnel impact... GASIFICATION Ash ENERGYWaste T ~ 800oC Partial Combustion O/C ~1/3 • Energy Production • Reduced Fuel Usage for transportation • Increased Energy

Structural features of resorcinol-formaldehyde resin chars and interfacial behavior of water co-adsorbed with low-molecular weight organics

NASA Astrophysics Data System (ADS)

Gun'ko, Vladimir M.; Bogatyrov, Viktor M.; Turov, Vladimir V.; Leboda, Roman; Skubiszewska-Zięba, Jadwiga; Urubkov, Iliya V.

2013-10-01

Products of resorcinol-formaldehyde resin carbonization (chars) are characterized by different morphology (particle shape and sizes) and texture (specific surface area, pore volume and pore size distribution) depending on water content during resin polymerization. At a low amount of water (Cw = 37.8 wt.%) during synthesis resulting in strongly cross-linked polymers, carbonization gives nonporous particles. An increase in the water content to 62.7 wt.% results in a nano/mesoporous char, but if Cw = 73.3 wt.%, a char is purely nanoporous. Despite these textural differences, the Raman spectra of all the chars are similar because of the similarity in the structure of their carbon sheets with a significant contribution of sp3 C atoms. However, the difference in the spatial organization of the carbon sheet stacks in the particles results in the significant differences in the textural and morphological characteristics and in the adsorption properties of chars with respect to water, methane, benzene, hydrogen, methylene chloride, and dimethylsulfoxide.

Coal char oxidation kinetics in air medium

NASA Astrophysics Data System (ADS)

Slyusarskiy, K. V.; Jankovskiy, S. A.; Korotkikh, A. G.; Sorokin, I. V.

2017-01-01

Research on oxidation in air medium process of three different coal chars with various carbon content was presented. The anthracite, T-grade bituminous coal and 2B-grade lignite char powders with particle size less than 80 µm were studied. The coal char oxidation was studied by isothermal method using coupled TG-DSC analyzer Netzsch STA 449 Jupiter F3 in the temperature range 1000-1200 °C. Experiments were carried out at ambient pressure. Volumetric flow rate of oxidation medium into analyzer chamber was 250 ml/min and consisted of oxygen and argon with volumetric ratio 24:1. Based on experimental data, the average rate of carbon oxidation reaction values were defined at each temperature. Kinetic constants (frequency factor and activation energy) of reaction were defined as well via 1st order Arrhenius equation. Activation energy values are in good agreement with the data presented in the literature. Activation energy values for anthracite char are 1.6-1.7 times higher than those for bituminous coal and lignite chars, respectively.

Investigation on the fast co-pyrolysis of sewage sludge with biomass and the combustion reactivity of residual char.

PubMed

Deng, Shuanghui; Tan, Houzhang; Wang, Xuebin; Yang, Fuxin; Cao, Ruijie; Wang, Zhao; Ruan, Renhui

2017-09-01

Gaining the valuable fuels from sewage sludge is a promising method. In this work, the fast pyrolysis characteristics of sewage sludge (SS), wheat straw (WS) and their mixtures in different proportions were carried out in a drop-tube reactor. The combustion reactivity of the residual char obtained was investigated in a thermogravimetric analyzer (TGA). Results indicate that SS and WS at different pyrolysis temperatures yielded different characteristic gas compositions and product distributions. The co-pyrolysis of SS with WS showed that there existed a synergistic effect in terms of higher gas and bio-oil yields and lower char yield, especially at the WS adding percentage of 80wt%. The addition of WS to SS increased the carbon content in the SS char and improved char porous structures, resulting in an improvement in the combustion reactivity of the SS char. The research results can be used to promote co-utilization of sewage sludge and biomass. Copyright © 2017. Published by Elsevier Ltd.

Comparative analysis of waste-to-energy alternatives for a low-capacity power plant in Brazil.

PubMed

Ferreira, Elzimar Tadeu de F; Balestieri, José Antonio P

2018-03-01

The Brazilian National Solid Waste Policy has been implemented with some difficulty, especially in convincing the different actors of society about the importance of conscious awareness among every citizen and businesses concerning adequate solid waste disposal and recycling. Technologies for recovering energy from municipal solid waste were considered in National Solid Waste Policy (NSWP), given that their technical and environmental viability is ensured, being the landfill biogas burning in internal combustion engines and solid waste incineration suggested options. In the present work, an analysis of current technologies and a collection of basic data on electricity generation using biogas from waste/liquid effluents is presented, as well as an assessment of the installation of a facility that harnesses biogas from waste or liquid effluents for producing electricity. Two combined cycle concepts were evaluated with capacity in the range 4-11 MW, gas turbine burning landfill biogas and an incinerator that burns solid waste hybrid cycle, and a solid waste gasification system to burn syngas in gas turbines. A comparative analysis of them demonstrated that the cycle with gasification from solid waste has proved to be technically more appealing than the hybrid cycle integrated with incineration because of its greater efficiency and considering the initially defined guidelines for electricity generation. The economic analysis does not reveal significant attractive values; however, this is not a significant penalty to the project given the fact that this is a pilot low-capacity facility, which is intended to be constructed to demonstrate appropriate technologies of energy recovery from solid waste.

Numerical investigation of the staged gasification of wet wood

NASA Astrophysics Data System (ADS)

Donskoi, I. G.; Kozlov, A. N.; Svishchev, D. A.; Shamanskii, V. A.

2017-04-01

Gasification of wooden biomass makes it possible to utilize forestry wastes and agricultural residues for generation of heat and power in isolated small-scale power systems. In spite of the availability of a huge amount of cheap biomass, the implementation of the gasification process is impeded by formation of tar products and poor thermal stability of the process. These factors reduce the competitiveness of gasification as compared with alternative technologies. The use of staged technologies enables certain disadvantages of conventional processes to be avoided. One of the previously proposed staged processes is investigated in this paper. For this purpose, mathematical models were developed for individual stages of the process, such as pyrolysis, pyrolysis gas combustion, and semicoke gasification. The effect of controlling parameters on the efficiency of fuel conversion into combustible gases is studied numerically using these models. For the controlling parameter are selected heat inputted into a pyrolysis reactor, the excess of oxidizer during gas combustion, and the wood moisture content. The process efficiency criterion is the gasification chemical efficiency accounting for the input of external heat (used for fuel drying and pyrolysis). The generated regime diagrams represent the gasification efficiency as a function of controlling parameters. Modeling results demonstrate that an increase in the fraction of heat supplied from an external source can result in an adequate efficiency of the wood gasification through the use of steam generated during drying. There are regions where it is feasible to perform incomplete combustion of the pyrolysis gas prior to the gasification. The calculated chemical efficiency of the staged gasification is as high as 80-85%, which is 10-20% higher that in conventional single-stage processes.

Influence of Torrefaction on the Conversion Efficiency of the Gasification Process of Sugarcane Bagasse

PubMed Central

Anukam, Anthony; Mamphweli, Sampson; Okoh, Omobola; Reddy, Prashant

2017-01-01

Sugarcane bagasse was torrefied to improve its quality in terms of properties prior to gasification. Torrefaction was undertaken at 300 °C in an inert atmosphere of N2 at 10 °C·min−1 heating rate. A residence time of 5 min allowed for rapid reaction of the material during torrefaction. Torrefied and untorrefied bagasse were characterized to compare their suitability as feedstocks for gasification. The results showed that torrefied bagasse had lower O–C and H–C atomic ratios of about 0.5 and 0.84 as compared to that of untorrefied bagasse with 0.82 and 1.55, respectively. A calorific value of about 20.29 MJ·kg−1 was also measured for torrefied bagasse, which is around 13% higher than that for untorrefied bagasse with a value of ca. 17.9 MJ·kg−1. This confirms the former as a much more suitable feedstock for gasification than the latter since efficiency of gasification is a function of feedstock calorific value. SEM results also revealed a fibrous structure and pith in the micrographs of both torrefied and untorrefied bagasse, indicating the carbonaceous nature of both materials, with torrefied bagasse exhibiting a more permeable structure with larger surface area, which are among the features that favour gasification. The gasification process of torrefied bagasse relied on computer simulation to establish the impact of torrefaction on gasification efficiency. Optimum efficiency was achieved with torrefied bagasse because of its slightly modified properties. Conversion efficiency of the gasification process of torrefied bagasse increased from 50% to approximately 60% after computer simulation, whereas that of untorrefied bagasse remained constant at 50%, even as the gasification time increased. PMID:28952501

Supercritical gasification for the treatment of o-cresol wastewater.

PubMed

Wei, Chao-hai; Hu, Cheng-sheng; Wu, Chao-fei; Yan, Bo

2006-01-01

The supercritical water gasification of phenolic wastewater without oxidant was performed to degrade pollutants and produce hydrogen-enriched gases. The simulated o-cresol wastewater was gasified at 440-650 degrees C and 27.6 MPa in a continuous Inconel 625 reactor with the residence time of 0.42-1.25 min. The influence of the reaction temperature, residence time, pressure, catalyst, oxidant and the pollutant concentration on the gasification efficiency was investigated. Higher temperature and longer residence time enhanced the o-cresol gasification. The TOC removal rate and hydrogen gasification rate were 90.6% and 194.6%, respectively, at the temperature of 650 degrees C and the residence time of 0.83 min. The product gas was mainly composed of H2, CO2, CH4 and CO, among which the total molar percentage of H2 and CH4 was higher than 50%. The gasification efficiency decreased with the pollutant concentration increasing. Both the catalyst and oxidant could accelerate the hydrocarbon gasification at a lower reaction temperature, in which the catalyst promoted H2 production and the oxidant enhanced CO2 generation. The intermediates of liquid effluents were analyzed and phenol was found to be the main composition. The results indicate that the supercritical gasification is a promising way for the treatment of hazardous organic wastewater.

Compositional and thermal evaluation of lignocellulosic and poultry litter chars via high and low temperature pyrolysis

USDA-ARS?s Scientific Manuscript database

Inorganic elements in biomass feedstocks can influence thermochemical reactions as well as the resultant chars elemental, compositional, and thermal characteristics. Chars were produced using slow pyrolysis at less than 400 and at higher than 500 degree Celsius from sugarcane bagasse, peanut hulls,...

Multiscale Architectures and Parallel Algorithms for Video Object Tracking

DTIC Science & Technology

2011-10-01

0 4 : if FIFO1 contains nDt frames then 5: Partition data into blocks. 6: Put SPE control block information...char buf 4 = FF; vec to r unsigned char buf 5 = FF; vec to r unsigned char buf 6 = FF; vec to r unsigned char buf 7 = FF; for ( j = 0 ; j < s i z e ; j...Public Release; Distribution Unlimited 8 7 u 6 ill :J (;) 5 E -;::; c 0 4 ~ u Q) X 3 Q) 8 7 6 u Q) Ul 5 :J (;) E :;::; 4 c 0

Study on coal char ignition by radiant heat flux.

NASA Astrophysics Data System (ADS)

Korotkikh, A. G.; Slyusarskiy, K. V.

2017-11-01

The study on coal char ignition by CO2-continuous laser was carried out. The coal char samples of T-grade bituminous coal and 2B-grade lignite were studied via CO2-laser ignition setup. Ignition delay times were determined at ambient condition in heat flux density range 90-200 W/cm2. The average ignition delay time value for lignite samples were 2 times lower while this difference is larger in high heat flux region and lower in low heat flux region. The kinetic constants for overall oxidation reaction were determined using analytic solution of simplified one-dimensional heat transfer equation with radiant heat transfer boundary condition. The activation energy for lignite char was found to be less than it is for bituminous coal char by approximately 20 %.

Anadromous char as an alternate food choice to marine animals: a synthesis of Hg concentrations, population features and other influencing factors.

PubMed

Evans, Marlene S; Muir, Derek C G; Keating, Jonathan; Wang, Xiaowa

2015-03-15

This study was conducted to confirm sporadic measurements made over the late 1970s to the early 1990 s which determined that mercury (Hg) concentrations were low in anadromous char across Arctic and subarctic Canada including northern Québec and Labrador. Over 2004-2013, anadromous char populations across northern Canada were investigated at 20 sites for Hg concentrations and life history characteristics. Hg concentrations were extremely low in anadromous char muscle, typically <0.05 μg/g (wet weight) and, at each location, generally increased with fish length, age and nitrogen isotope (δ(15)N) ratio and decreased with condition factor and %lipid; correlations with carbon isotope (δ(13)C) ratio were inconsistent. Location and year were significant variables influencing Hg concentrations over the study area; longitude and latitude also were significant influencing variables. Char length, weight, age, condition factor and lipid content explained additional variance. A tendency towards higher Hg concentrations with increasing latitude may be partially related to decreasing growth of char towards the north. However, Hg concentrations in char were positively correlated with growth rates suggesting that Hg concentrations in char also were higher in the more productive study areas, including to the west where mainland riverine inputs of terrestrial carbon, nutrients, and Hg were greater. The data base for assessing time trends in char was limited by the small number of years investigated at most locations, variable fish size across years, small sample size, etc. Where temporal trends were detected, they were of increase on the long term (1970s, 1980s or early 1990 s to the present) but of decrease on the short term (early 2000s to present) with Nain (Labrador) showing the converse pattern. Higher Hg concentrations were also related to lower condition factor and cooler springs. Hg concentrations in anadromous char are compared with other terrestrial, aquatic and marine vertebrates in traditional diets. The known information on anadromous char is reviewed including population features, habitat, and harvests. Future Hg trend monitoring should focus on specific locations and harvest areas within these areas to better assess trends and influencing factors. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

Using BPCA and pyrolysis-GC/MS patterns as a measure of charring intensity

NASA Astrophysics Data System (ADS)

Kaal, Joeri; Schneider, Maximilian P. W.; Schmidt, Michael W. I.

2010-05-01

Many questions remain on the molecular properties of Black C (organic fire residues such as charcoal and soot). Here we compare parameters from two methods that have recently shown to be related to the degree of thermal modification ("charring intensity") of charcoal-Black C: i) the proportion of mellitic acid (B6CA) among benzenepolycarboxylic acids in the BPCA method [1,2,3] and ii) the relative proportions and degree of alkylation of pyrolysis products from Black C in pyrolysis-GC/MS [4]. For that purpose we used laboratory chars from rice straw (grass) and chestnut wood (wood) produced at 200-1000 °C under N2 flow. The chars obtained at 450 °C are reference materials of the Black Carbon Ring Trial [5]. Positive correlations between the charring temperature and BPCA and pyrolysis patterns confirm that these methods can be used to study the degree of thermal impact of charred remains. Pyrolysis-GC/MS allowed us to track the thermal degradation of the major biocomponents lignin, polysaccharides, tannin, aliphatic chain lipids, triterpenoids, chlorophyll and proteins, mostly between 250 and 450 °C. The proportions of the pyrolysis products of Black C (benzene, toluene, benzonitrile, PAHs, etc.) and also the ratios that reflect the abundance of aliphatic cross-linkages between aromatic moieties (benzene/toluene, naphthalene/alkylnaphthalenes, benzofuran/alkylbenzofurans), increase with charring intensity. Nonetheless, chars obtained at T > 600 °C (especially for wood) gave low quality pyrograms and poor reproducibility because of high thermal stability. The relative contributions of B6CA, one of the molecular markers used for the BPCA method, are indicative for the degree of condensation of the chars. The BPCA approach showed a clear increase in the relative contribution of B6CA from ca. 5 % at 200 °C to ca. 95 % at 1000 °C, confirming the ability of this parameter to assess charring intensity. The relative contribution of B6CA remains almost constant at ca. 30 % between 250 and 450 °C. Thus, with regard to estimating the charring intensity of Black C, the BPCA method is more suitable for high T chars (> 450 °C) while pyrolysis-GC/MS seems more appropriate in the lower T range (< 500 °C). This is not surprising as larger clusters of polyaromatic domains (high T) can be assessed by the BPCA method but are resistant against pyrolysis. On the other hand, smaller clusters and non-polycondensed portions of Black C (low T) are amenable to pyrolysis-GC/MS but escape the analytical window of the BPCA method. The two methods may therefore be considered complementary, with BPCA giving reliable quantitative data on Black C content and charring degree of high T chars while pyrolysis-GC/MS is quantitatively weak but provides highly detailed information on the molecular properties of especially lower T chars. References [1] Brodowski, S., Rodionov, A., Haumeier L., Glaser, B., Amelung, W. (2005) Org. Geochem. 36, 1299-1310. [2] Glaser, B., Haumeier, L., Guggenberger, G., Zech, W. (1998) Org. Geochem. 29, 811-819. [3] Schneider, M.P.W., Hilf, M., Vogt, U.F., Schmidt, M.W.I., Org. Geochem. (submitted) [4] Kaal, J., Rumpel, C. (2009) Org. Geochem. 40, 1179-1187. [5] Hammes, K., Schmidt, M.W.I., Smernik, R.J. et al. (2007) Global Biogeochemical Cycles 21, 1-18.

Hybrid Technology of Hard Coal Mining from Seams Located at Great Depths

NASA Astrophysics Data System (ADS)

Czaja, Piotr; Kamiński, Paweł; Klich, Jerzy; Tajduś, Antoni

2014-10-01

Learning to control fire changed the life of man considerably. Learning to convert the energy derived from combustion of coal or hydrocarbons into another type of energy, such as steam pressure or electricity, has put him on the path of scientific and technological revolution, stimulating dynamic development. Since the dawn of time, fossil fuels have been serving as the mankind's natural reservoir of energy in an increasingly great capacity. A completely incomprehensible refusal to use fossil fuels causes some local populations, who do not possess a comprehensive knowledge of the subject, to protest and even generate social conflicts as an expression of their dislike for the extraction of minerals. Our times are marked by the search for more efficient ways of utilizing fossil fuels by introducing non-conventional technologies of exploiting conventional energy sources. During apartheid, South Africa demonstrated that cheap coal can easily satisfy total demand for liquid and gaseous fuels. In consideration of current high prices of hydrocarbon media (oil and gas), gasification or liquefaction of coal seems to be the innovative technology convergent with contemporary expectations of both energy producers as well as environmentalists. Known mainly from literature reports, underground coal gasification technologies can be brought down to two basic methods: - shaftless method - drilling, in which the gasified seam is uncovered using boreholes drilled from the surface, - shaft method, in which the existing infrastructure of underground mines is used to uncover the seams. This paper presents a hybrid shaft-drilling approach to the acquisition of primary energy carriers (methane and syngas) from coal seams located at great depths. A major advantage of this method is the fact that the use of conventional coal mining technology requires the seams located at great depths to be placed on the off-balance sheet, while the hybrid method of underground gasification enables them to become a source of additional energy for the economy. It should be noted, however, that the shaft-drilling method cannot be considered as an alternative to conventional methods of coal extraction, but rather as a complementary and cheaper way of utilizing resources located almost beyond the technical capabilities of conventional extraction methods due to the associated natural hazards and high costs of combating them. This article presents a completely different approach to the issue of underground coal gasification. Repurposing of the already fully depreciated mining infrastructure for the gasification process may result in a large value added of synthesis gas production and very positive economic effect.

Technology Assessment Report: Aqueous Sludge Gasification Technologies

EPA Science Inventory

The study reveals that sludge gasification is a potentially suitable alternative to conventional sludge handling and disposal methods. However, very few commercial operations are in existence. The limited pilot, demonstration or commercial application of gasification technology t...

Comparison of the co-gasification of sewage sludge and food wastes and cost-benefit analysis of gasification- and incineration-based waste treatment schemes.

PubMed

You, Siming; Wang, Wei; Dai, Yanjun; Tong, Yen Wah; Wang, Chi-Hwa

2016-10-01

The compositions of food wastes and their co-gasification producer gas were compared with the existing data of sewage sludge. Results showed that food wastes are more favorable than sewage sludge for co-gasification based on residue generation and energy output. Two decentralized gasification-based schemes were proposed to dispose of the sewage sludge and food wastes in Singapore. Monte Carlo simulation-based cost-benefit analysis was conducted to compare the proposed schemes with the existing incineration-based scheme. It was found that the gasification-based schemes are financially superior to the incineration-based scheme based on the data of net present value (NPV), benefit-cost ratio (BCR), and internal rate of return (IRR). Sensitivity analysis was conducted to suggest effective measures to improve the economics of the schemes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Distinct oxidative stabilities of char versus soot black carbon: Implications for quantification and environmental recalcitrance

NASA Astrophysics Data System (ADS)

Elmquist, Marie; Cornelissen, Gerard; Kukulska, Zofia; Gustafsson, Örjan

2006-06-01

Sequestration in sediments of black carbon (BC) from vegetation fires and fuel combustion may constitute a significant sink of otherwise rapidly cycling carbon from the atmosphere-biosphere cycle. It also has the potential to provide a historical record of atmospheric BC loadings. Previous treatments of BC as one homogeneous entity are being replaced with the growing awareness of a BC combustion continuum, a range spanning from slightly charred biomass to soot and graphite. Here the relative recalcitrance of different BC forms is evaluated, and implications for both BC quantification and environmental stability are considered. The stabilities of four BC reference materials against thermal oxidation in air were quite distinct with T50%BC values (i.e., the temperature where 50% BC remained in the residue) of 444°C (diesel soot-BC), 388°C (n-hexane soot-BC), 338°C (wood char-BC), and 266°C (grass char-BC). The implications for BC quantification have been illustrated for a thermal oxidation (the CTO-375) method commonly applied to study BC in sediments. This technique measured BC:TOC ratios of 78.3 ± 1.3% for the diesel soot-BC and 45.3 ± 6.1% for n-hexane soot-BC, whereas no CTO375-BC was detected for the two analyzed char-BC materials. The greater lability of char-BC compared to soot-BC likely reflects higher accessibility to internal microporosity in char-BC, facilitating internal O2 transfer. Decreasing the temperature cutoff below 375°C to also include char-BC is not possible as thermograms of nonpyrogenic reference materials indicated that such material would then be artifactually quantified as BC. The presence of mineral oxides in the sediment matrix may lead to a catalytically mediated lowering of the activation energy for soot-BC oxidation but not for char-BC or nonpyrogenic organic material. Several recent studies combine to challenge the proposition of complete recalcitrance of BC. Particularly, the thermal lability of char-BC from grassland fires deserves further attention in order to improve the understanding of BC in the global carbon cycle.

Lead sorption characteristics of various chicken bone part-derived chars.

PubMed

Park, Jong-Hwan; Wang, Jim J; Kim, Seong-Heon; Kang, Se-Won; Cho, Ju-Sik; Delaune, Ronald D; Ok, Yong Sik; Seo, Dong-Cheol

2018-01-18

Recycling food waste for beneficial use is becoming increasingly important in resource-limited economy. In this study, waste chicken bones of different parts from restaurant industry were pyrolyzed at 600 °C and evaluated for char physicochemical properties and Pb sorption characteristics. Lead adsorption isotherms by different chicken bone chars were carried out with initial Pb concentration range of 1-1000 mg L -1 at pH 5. The Pb adsorption data were better described by the Langmuir model (R 2  = 0.9289-0.9937; ARE = 22.7-29.3%) than the Freundlich model (R 2  = 0.8684-0.9544; ARE = 35.4-72.0%). Among the chars derived from different chicken bone parts, the tibia bone char exhibited the highest maximum Pb adsorption capacity of 263 mg g -1 followed by the pelvis (222 mg g -1 ), ribs (208 mg g -1 ), clavicle (179 mg g -1 ), vertebrae (159 mg g -1 ), and humerus (135 mg g -1 ). The Pb adsorption capacities were significantly and positively correlated with the surface area, phosphate release amount, and total phosphorus content of chicken bone chars (r ≥ 0.9711). On the other hand, approximately 75-88% of the adsorbed Pb on the chicken bone chars was desorbable with 0.1 M HCl, indicating their recyclability for reuse. Results demonstrated that chicken bone char could be used as an effective adsorbent for Pb removal in wastewater.

Potential application of gasification to recycle food waste and rehabilitate acidic soil from secondary forests on degraded land in Southeast Asia.

PubMed

Yang, Zhanyu; Koh, Shun Kai; Ng, Wei Cheng; Lim, Reuben C J; Tan, Hugh T W; Tong, Yen Wah; Dai, Yanjun; Chong, Clive; Wang, Chi-Hwa

2016-05-01

Gasification is recognized as a green technology as it can harness energy from biomass in the form of syngas without causing severe environmental impacts, yet producing valuable solid residues that can be utilized in other applications. In this study, the feasibility of co-gasification of woody biomass and food waste in different proportions was investigated using a fixed-bed downdraft gasifier. Subsequently, the capability of biochar derived from gasification of woody biomass in the rehabilitation of soil from tropical secondary forests on degraded land (adinandra belukar) was also explored through a water spinach cultivation study using soil-biochar mixtures of different ratios. Gasification of a 60:40 wood waste-food waste mixture (w/w) produced syngas with the highest lower heating value (LHV) 5.29 MJ/m(3)-approximately 0.4-4.0% higher than gasification of 70:30 or 80:20 mixtures, or pure wood waste. Meanwhile, water spinach cultivated in a 2:1 soil-biochar mixture exhibited the best growth performance in terms of height (a 4-fold increment), weight (a 10-fold increment) and leaf surface area (a 5-fold increment) after 8 weeks of cultivation, owing to the high porosity, surface area, nutrient content and alkalinity of biochar. It is concluded that gasification may be an alternative technology to food waste disposal through co-gasification with woody biomass, and that gasification derived biochar is suitable for use as an amendment for the nutrient-poor, acidic soil of adinandra belukar. Copyright © 2016 Elsevier Ltd. All rights reserved.

Etude de production et de caracterisation de biocharbons de panic erige (Panicum virgatum L.) obtenus par pyrolyse

NASA Astrophysics Data System (ADS)

Pilon, Guillaume

This research aimed at the production of biomass char under pyrolytic conditions, targeting biochar as soil amendment, while also considering its application as biocoal, either for bioenergy or subsequent upgrading. The production of biomass char was performed using two bench-scale, batch-type, fixed-bed reactors, each with an operating capacity of 1 and 25 gw.b. /batch, respectively. Switchgrass (Panicum virgatum) has been used for the tests. Production conditions studied implied temperatures of 300, 400 and 500 °C with short residence times (2.5 and 5 min). As well, the effect of using CO2 as vector gas has been compared to a common inert environment of N2. The effects of the previously mentioned parameters were correlated with some important physicochemical characteristics of biomass char. Analyses were also performed on complementary pyrolytic products (bio-oil and gas). The biomass char extraction was performed using a Soxhlet and dichloromethane was used as extracting solvent. The extracts were then characterized by GC-MS thus allowing the identification of several compounds. Specific pyrolysis conditions used at 300 °C - N2 with the 1 g/batch reactor, such as high heating rates as well as high convection conditions, presented advantegeous biomass char yields and properties, and, possible torrefaction process productivity improvement (in comparison to reported literature, such as Gilbert et al. [2009]). The char extracts as well as the bio-oils analysis (also performed using GC-MS), all generated from the 25 g/batch reactor, showed major differences among the compounds obtained from the CO2 and N2 environments, respectively. Several compounds observed in the char extracts appeared less concentrated in the CO2 environment vs N2, for the same reaction temperatures. As an example, at 400 °C, furfural was found only in char extracts from N2 environment as compared to the CO2 environment. Among all studied conditions (for both reactors), only naphthalene and naphthalene derivatives constituted the PAHs content, which was only detected for the chars produced at 500 °C. The use of CO2 as pyrolysis vector gas led to a significant difference for every temperature conditions studied for the biomass char as well as for the liquid and gas products. At 300 °C, in CO 2 environment, it is possible to observe a bio-oil production significantly lower than within a N2 environment (18.0 vs 24.6 %; CO2 vs N2 for P<0.002), a result consistent with the biomass char volatile content that was shown to be significantly higher under the same conditions (0.29 vs 0.35 gchar volatiles content/graw biomass; P=0.1). In addition, at 500 °C, the char ash content was observed to be significantly lower in CO 2 than in N2 (P<0.06). Keywords: Pyrolysis, torrefaction, char, biochar, biocoal, CO 2, Soxhlet extractions, characterization.

TEXACO GASIFICATION PROCESS - INNOVATIVE TECHNOLOGY EVALUATION REPORT

EPA Science Inventory

This report summarizes the evaluation of the Texaco Gasification Process (TGP) conducted under the U.S. Environmental Protection Agency (EPA) Superfund Innovative Technology Evaluation (SITE) Program. The Texaco Gasification Process was developed by Texaco Inc. The TGP is a comm...

Removal of hexavalent Cr by coconut coir and derived chars--the effect of surface functionality.

PubMed

Shen, Ying-Shuian; Wang, Shan-Li; Tzou, Yu-Min; Yan, Ya-Yi; Kuan, Wen-Hui

2012-01-01

The Cr(VI) removal by coconut coir (CC) and chars obtained at various pyrolysis temperatures were evaluated. Increasing the pyrolysis temperature resulted in an increased surface area of the chars, while the corresponding content of oxygen-containing functional groups of the chars decreased. The Cr(VI) removal by CC and CC-derived chars was primarily attributed to the reduction of Cr(VI) to Cr(III) by the materials and the extent and rate of the Cr(VI) reduction were determined by the oxygen-containing functional groups in the materials. The contribution of pure Cr(VI) adsorption to the overall Cr(VI) removal became relatively significant for the chars obtained at higher temperatures. Accordingly, to develop a cost-effective method for removing Cr(VI) from water, the original CC is more advantageous than the carbonaceous counterparts because no pyrolysis is required for the application and CC has a higher content of functional groups for reducing Cr(VI) to less toxic Cr(III). Copyright © 2011 Elsevier Ltd. All rights reserved.

Mechanistic understanding of tetracycline sorption on waste tire powder and its chars as affected by Cu(2+) and pH.

PubMed

Lian, Fei; Song, Zhengguo; Liu, Zhongqi; Zhu, Lingyan; Xing, Baoshan

2013-07-01

The sorption characteristics of tetracycline (TC) by waste tire powder and its chars were investigated to explore the potential of using waste tires as effective sorbents for removal of TC from aqueous solution. Naphthalene (NAPH), a typical hydrophobic organic compound, was selected as asorbate for comparison. TC displayed much lower sorption affinity to tire powder than NAPH. However, it exhibited similar adsorption affinity as NAPH on the pyrolyzed tire chars, which was mainly attributed to π-π electron-donor-acceptor interactions of TC with the graphite surface of chars. TC and Cu(2+) could mutually facilitate the sorption of each other on both tire powder and pyrolyzed chars in a wide pH range. This could be explained by the metallic complexation and/or surface-bridging mechanisms (i.e., Cu- or TC-bridging). However, Cu(2+) and NAPH depressed the sorption of each other on tire powder and displayed negligible impact to each other on the highly pyrolyzed chars. Copyright © 2013 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zia-ul-Mustafa, M., E-mail: engr.ziamustafa@gmail.com; Ahmad, Faiz; Megat-Yusoff, Puteri S. M.

In this study, intumescent fire retardant coatings (IFRC) were developed to investigate the synergistic effects of reinforced mica and wollastonite fillers based IFRC towards heat shielding, char expansion, char composition and char morphology. Ammonium poly-phosphate (APP) was used as acid source, expandable graphite (EG) as carbon source, melamine as blowing agent, boric acid as additive and Hardener H-2310 polyamide amine in bisphenol A epoxy resin BE-188(BPA) was used as curing agent. Bunsen burner fire test was used for thermal performance according to UL-94 for 1 h. Field Emission Scanning Electron Microscopy (FESEM) was used to observe char microstructure. X-Ray Diffraction (XRD)more » and Fourier transform infrared spectroscopy (FTIR) were used to analyse char composition. The results showed that addition of clay filler in IFRC enhanced the fire protection performance of intumescent coating. X-Ray Diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) results showed the presence of boron phosphate, silicon phosphate oxide, aluminium borate in the char that improved the thermal performance of intumescent fire retardant coating (IFRC). Resultantly, the presence of these developed compounds enhanced the Integrity of structural steel upto 500°C.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, B.E.; Ahner, P.F.; Singelton, A.H.

In situ gasification of steeply dipping coal beds (UCG-SDB) has significant advantages over the more conventional horizontal UCG. In fact, the UCG-SDB process appears to be both technically and operationally competitive with surface gasifiers. The results of the Rawlins UCG-SDB field test program suggest that the process can compete with more conventional sources of synthesis gas on an economic basis. The SDB process mechanism has several advantages over the horizontal process and performs in a fashion similar to surface packedbed reactors. The oxygen requirements for the process are quite low and the degree of process control observed at Rawlins ismore » very attractive.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, B.E.; Ahner, P.F.

In-situ gasification of steeply dipping coal beds (UCG-SDB) has significant advantages over the more conventional horizontal UCG. In fact, the UCG-SDB process appears to be both technically and operationally competitive with surface gasifiers. The results of the Rawlins UCG-SDB field test program suggest that the process can compete with more conventional sources of synthesis gas on an economic basis. The SDB process mechanism has several advantages over the horizontal process and performs in a fashion similar to surface packed bed reactors. The oxygen requirements for the process are quite low and the degree of process control observed at Rawlins ismore » very attractive.« less

Biomass conversion processes for energy and fuels

NASA Astrophysics Data System (ADS)

Sofer, S. S.; Zaborsky, O. R.

The book treats biomass sources, promising processes for the conversion of biomass into energy and fuels, and the technical and economic considerations in biomass conversion. Sources of biomass examined include crop residues and municipal, animal and industrial wastes, agricultural and forestry residues, aquatic biomass, marine biomass and silvicultural energy farms. Processes for biomass energy and fuel conversion by direct combustion (the Andco-Torrax system), thermochemical conversion (flash pyrolysis, carboxylolysis, pyrolysis, Purox process, gasification and syngas recycling) and biochemical conversion (anaerobic digestion, methanogenesis and ethanol fermentation) are discussed, and mass and energy balances are presented for each system.

Waste-to-Energy and Fuel Cell Technologies Overview

DTIC Science & Technology

2011-01-13

Integration of stationary fuel cells with biomass gasification is a developing technology that is in need of demonstration. Innovation for Our...the PureCell®400 Innovation for Our Energy Future Gasification of wood wastes is another potential source of useful fuel gas. Wood waste... Gasification → Cleanup → Fuel Cell Gasification uses high temperature to convert cellulosic materials to fuel gas • Hydrogen (H2) • Carbon monoxide (CO

Small Scale Gasification Application and Perspectives in Circular Economy

NASA Astrophysics Data System (ADS)

Klavins, Maris; Bisters, Valdis; Burlakovs, Juris

2018-06-01

Gasification is the process converting solid fuels as coal and organic plant matter, or biomass into combustible gas, called syngas. Gasification is a thermal conversion process using carbonaceous fuel, and it differs substantially from other thermal processes such as incineration or pyrolysis. The process can be used with virtually any carbonaceous fuel. It is an endothermic thermal conversion process, with partial oxidation being the dominant feature. Gasification converts various feedstock including waste to a syngas. Instead of producing only heat and electricity, synthesis gas produced by gasification may be transformed into commercial products with higher value as transport fuels, fertilizers, chemicals and even to substitute natural gas. Thermo-chemical conversion of biomass and solid municipal waste is developing as a tool to promote the idea of energy system without fossil fuels to a reality. In municipal solid waste management, gasification does not compete with recycling, moreover it enhances recycling programs. Pre-processing and after-processing must increase the amount of recyclables in the circular economy. Additionally, end of life plastics can serve as an energy feedstock for gasification as otherwise it cannot be sorted out and recycled. There is great potential for application of gasification technology within the biomass waste and solid waste management sector. Industrial self-consumption in the mode of combined heat and power can contribute to sustainable economic development within a circular economy.

Thermogravimetric and model-free kinetic studies on CO2 gasification of low-quality, high-sulphur Indian coals

NASA Astrophysics Data System (ADS)

Das, Tonkeswar; Saikia, Ananya; Mahanta, Banashree; Choudhury, Rahul; Saikia, Binoy K.

2016-10-01

Coal gasification with CO2 has emerged as a cleaner and more efficient way for the production of energy, and it offers the advantages of CO2 mitigation policies through simultaneous CO2 sequestration. In the present investigation, a feasibility study on the gasification of three low-quality, high-sulphur coals from the north-eastern region (NER) of India in a CO2 atmosphere using thermogravimetric analysis (TGA-DTA) has been made in order to have a better understanding of the physical and chemical characteristics in the process of gasification of coal. Model-free kinetics was applied to determine the activation energies (E) and pre-exponential factors (A) of the CO2 gasification process of the coals. Multivariate non-linear regression analyses were performed to find out the formal mechanisms, kinetic model, and the corresponding kinetic triplets. The results revealed that coal gasification with CO2 mainly occurs in the temperature range of 800∘-1400∘C and a maximum of at around 1100∘C. The reaction mechanisms responsible for CO2 gasification of the coals were observed to be of the ` nth order with autocatalysis (CnB)' and ` nth order (Fn) mechanism'. The activation energy of the CO2 gasification was found to be in the range 129.07-146.81 kJ mol-1.

Coal gasification systems engineering and analysis. Appendix B: Medium B+U gas design

NASA Technical Reports Server (NTRS)

1980-01-01

A four module, 20,000 TPD, based on KT coal gasification technology was designed. The plant processes Kentucky No. 9 coal with provisions for up to five percent North Alabama coal. Medium BTU gas with heat content of 305 BTU/SCF and not more than 200 ppm sulfur is the primary plant product. Sulfur is recovered for scale as prilled sulfur. Ash disposal is on site. The plant is designed for zero water discharge. Trade studies provided the basis for not using boiler produced steam to drive prime movers. Thus process derived steam in excess of process requirements in superheated for power use in prime movers. Electricity from the TVA grid is used to supply the balance of the plant prime mover power requirements. A study of the effect of mine mouth coal cleaning showed that coal cleaning is not an economically preferred route. The design procedure involved defining available processes to meet the requirements of each system, technical/economic trade studies to select the preferred processes, and engineering design and flow sheet development for each module. Cost studies assumed a staggered construction schedule for the four modules beginning spring 1981 and a 90% on stream factor.

Modeling and evaluation of chromium remediation from water using low cost bio-char, a green adsorbent.

PubMed

Mohan, Dinesh; Rajput, Shalini; Singh, Vinod K; Steele, Philip H; Pittman, Charles U

2011-04-15

Oak wood and oak bark chars were obtained from fast pyrolysis in an auger reactor at 400-450 °C. These chars were characterized and utilized for Cr(VI) remediation from water. Batch sorption studies were performed at different temperatures, pH values and solid to liquid ratios. Maximum chromium was removed at pH 2.0. A kinetic study yielded an optimum equilibrium time of 48 h with an adsorbent dose of 10 g/L. Sorption studies were conducted over a concentration range of 1-100mg/L. Cr(VI) removal increased with an increase in temperature (Q(Oak wood)(°): 25 °C = 3.03 mg/g; 35 °C = 4.08 mg/g; 45 °C = 4.93 mg/g and Q(Oakbark)(°): 25 °C = 4.62 mg/g; 35 °C = 7.43 mg/g; 45 °C = 7.51 mg/g). More chromium was removed with oak bark than oak wood. The char performances were evaluated using the Freundlich, Langmuir, Redlich-Peterson, Toth, Radke and Sips adsorption isotherm models. The Sips adsorption isotherm model best fits the experimental data [high regression (R(2)) coefficients]. The overall kinetic data was satisfactorily explained by a pseudo second order rate expression. Water penetrated into the char walls exposing Cr(VI) to additional adsorption sites that were not on the surfaces of dry char pores. It is remarkable that oak chars (S(BET): 1-3m(2)g(-1)) can remove similar amounts of Cr(VI) as activated carbon (S(BET): ∼ 1000 m(2)g(-1)). Thus, byproduct chars from bio-oil production might be used as inexpensive adsorbents for water purification. Char samples were successfully used for chromium remediation from contaminated surface water with dissolved interfering ions. Copyright © 2011 Elsevier B.V. All rights reserved.

Influence of post-treatment strategies on the properties of activated chars from broiler manure.

PubMed

Lima, Isabel M; Boykin, Debbie L; Thomas Klasson, K; Uchimiya, Minori

2014-01-01

There are a myriad of carbonaceous precursors that can be used advantageously to produce activated carbons or chars, due to their low cost, availability and intrinsic properties. Because of the nature of the raw material, production of granular activated chars from broiler manure results in a significant ash fraction. This study was conducted to determine the influence of several pre- and post-treatment strategies in various physicochemical and adsorptive properties of the resulting activated chars. Pelletized samples of broiler litter and cake were pyrolyzed at 700 °C for 1h followed by a 45 min steam activation at 800 °C at different water flow rates from 1 to 5 mL min(-1). For each activation strategy, samples were either water-rinsed or acid-washed and rinsed or used as is (no acid wash/rinse). Activated char's physicochemical and adsorptive properties towards copper ions were selectively affected by both pre- and post-treatments. Percent ash reduction after either rinsing or acid washing ranged from 1.1 to 15.1% but washed activated chars were still alkaline with pH ranging from 8.4 to 9.1. Acid washing or water rinsing had no significant effect in the ability of the activated char to adsorb copper ions, however it significantly affected surface area, pH, ash content and carbon content. Instead, manure type (litter versus cake) and the activation water flow rate were determining factors in copper ion adsorption which ranged from 38 mg g(-1) to 104 mg g(-1) of activated char. Moreover, strong positive correlations were found between copper uptake and concentration of certain elements in the activated char such as phosphorous, sulfur, calcium and sodium. Rinsing could suffice as a post treatment strategy for ash reduction since no significant differences in the carbon properties were observed between rinsed and acid wash treatments. Published by Elsevier Ltd.

Controls upon biomass losses and char production from prescribed burning on UK moorland.

PubMed

Worrall, Fred; Clay, Gareth D; May, Richard

2013-05-15

Prescribed burning is a common management technique used across many areas of the UK uplands. However, there are few data sets that assess the loss of biomass during burning and even fewer data on the effect of burning on above-ground carbon stocks and production of char. During fire the production of char occurs which represents a transfer of carbon from the short term bio-atmospheric cycle to the longer term geological cycle. However, biomass is consumed leading to the reduction in litter formation which is the principal mechanism for peat formation. This study aims to solve the problem of whether loss of biomass during a fire is ever outweighed by the production of refractory forms of carbon during the fire. This study combines both a laboratory study of char production with an assessment of biomass loss from a series of field burns from moorland in the Peak District, UK. The laboratory results show that there are significant effects due to ambient temperature but the most important control on dry mass loss is the maximum burn temperature. Burn temperature was also found to be linearly related to the production of char in the burn products. Optimisation of dry mass loss, char production and carbon content shows that the production of char from certain fires could store more carbon in the ecosystem than if there had been no fire. Field results show that approximately 75% of the biomass and carbon were lost through combustion, a figure comparable to other studies of prescribed fire in other settings. Char-C production was approximately 2.6% of the carbon consumed during the fire. This study has shown that there are conditions (fast burns at high temperatures) under which prescribed fire may increase C sequestration through char production and that these conditions are within existing management options available to practitioners. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of fresh and aged chars from pyrolysis and hydrothermal carbonization on nutrient sorption in agricultural soils

NASA Astrophysics Data System (ADS)

Gronwald, M.; Don, A.; Tiemeyer, B.; Helfrich, M.

2015-06-01

Leaching of nutrients from agricultural soils causes major environmental problems that may be reduced with amendments of chars derived from pyrolysis (pyrochars) or hydrothermal carbonization (hydrochars). Chars are characterized by a high adsorption capacity - i.e. they may retain nutrients such as nitrate and ammonium. However, the physicochemical properties of the chars and hence their sorption capacity likely depend on feedstock and the production process. We investigated the nutrient retention capacity of pyrochars and hydrochars from three different feedstocks (digestates, Miscanthus, woodchips) mixed into different soil substrates (sandy loam and silty loam). Moreover, we investigated the influence of char degradation on its nutrient retention capacity using a 7-month in situ field incubation of pyrochar and hydrochar mixed into soils at three different field sites. Pyrochars showed the highest ability to retain nitrate, ammonium and phosphate, with pyrochar from woodchips being particularly efficient in nitrate adsorption. Ammonium adsorption of pyrochars was controlled by the soil type of the soil-char mixture. We found some ammonium retention on sandy soils, but no pyrochar effect or even ammonium leaching from the loamy soil. The phosphate retention capacity of pyrochars strongly depended on the pyrochar feedstock with large phosphate leaching from digestate-derived pyrochar and some adsorption capacity from woodchip-derived pyrochar. Application of hydrochars to agricultural soils caused small, and often not significant, effects on nutrient retention. In contrast, some hydrochars did increase the leaching of nutrients compared to the non-amended control soil. We found a surprisingly rapid loss of the chars' adsorption capacity after field application of the chars. For all sites and for hydrochar and pyrochar, the adsorption capacity was reduced by 60-80 % to less or no nitrate and ammonium adsorption. Thus, our results cast doubt on the efficiency of char applications to temperate zone soils to minimize nutrient losses via leaching.

Benefits of Integration of Aerojet Rocketdyne and RTI Advanced Gasification Technologies for Hydrogen-Rich Syngas Production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gupta, Vijay; Denton, David; SHarma, Pradeep

The key objective for this project was to evaluate the potential to achieve substantial reductions in the production cost of H 2-rich syngas via coal gasification with near-zero emissions due to the cumulative and synergistic benefits realized when multiple advanced technologies are integrated into the overall conversion process. In this project, Aerojet Rocketdyne’s (AR’s) advanced gasification technology (currently being offered as R-GAS™) and RTI International’s (RTI’s) advanced warm syngas cleanup technologies were evaluated via a number of comparative techno-economic case studies. AR’s advanced gasification technology consists of a dry solids pump and a compact gasifier system. Based on the uniquemore » design of this gasifier, it has been shown to reduce the capital cost of the gasification block by between 40 and 50%. At the start of this project, actual experimental work had been demonstrated through pilot plant systems for both the gasifier and dry solids pump. RTI’s advanced warm syngas cleanup technologies consist primarily of RTI’s Warm Gas Desulfurization Process (WDP) technology, which effectively allows decoupling of the sulfur and CO 2 removal allowing for more flexibility in the selection of the CO 2 removal technology, plus associated advanced technologies for direct sulfur recovery and water gas shift (WGS). WDP has been demonstrated at pre-commercial scale using an activated amine carbon dioxide recovery process which would not have been possible if a majority of the sulfur had not been removed from the syngas by WDP. This pre-commercial demonstration of RTI’s advanced warm syngas cleanup system was conducted in parallel to the activities on this project. The technical data and cost information from this pre-commercial demonstration were extensively used in this project during the techno-economic analysis. With this project, both of RTI’s advanced WGS technologies were investigated. Because RT’s advanced fixed-bed WGS (AFWGS) process was successfully implemented in the WDP pre-commercial demonstration test mentioned above, this technology was used as part of RTI’s advanced warm syngas technology package for the techno-economic analyses for this project. RTI’s advanced transport-reactor-based WGS (ATWGS) process was still conceptual at the start of this project, but one of the tasks for this project was to evaluate the technical feasibility of this technology. In each of the three application-based comparison studies conducted as part of this project, the reference case was based on an existing Department of Energy National Energy Technology Laboratory (DOE/NETL) system study. Each of these references cases used existing commercial technology and the system resulted in > 90% carbon capture. In the comparison studies for the use of the hydrogen-rich syngas generated in either an Integrated Gasification Combined Cycle (IGCC) or a Coal-to-Methanol (CTM) plant, the comparison cases consisted of the reference case, a case with the integration of each individual advanced technology (either AR or RTI), and finally a case with the integration of all the advanced technologies (AR and RTI combined). In the Coal-to-Liquids (CTL) comparison study, the comparison study consisted of only three cases, which included a reference case, a case with just RTI’s advanced syngas cleaning technology, and a case with AR’s and RTI’s advanced technologies. The results from these comparison studies showed that the integration of the advanced technologies did result in substantial benefits, and by far the greatest benefits were achieved for cases integrating all the advanced technologies. For the IGCC study, the fully integrated case resulted in a 1.4% net efficiency improvement, an 18% reduction in capital cost per kW of capacity, a 12% reduction in the operating cost per kWh, and a 75–79% reduction in sulfur emissions. For the CTM case, the fully integrated plant resulted in a 22% reduction in capital cost, a 13% reduction in operating costs, a > 99% net reduction in sulfur emissions, and a reduction of 13–15% in CO 2 emissions. Because the capital cost represents over 60% of the methanol Required Selling Price (RSP), the significant reduction in the capital cost for the advanced technology case resulted in an 18% reduction in methanol RSP. For the CTL case, the fully integrated plant resulted in a 16% reduction in capital cost, which represented a 13% reduction in diesel RSP. Finally, the technical feasibility analysis of RTI’s ATWGS process demonstrated that a fluid-bed catalyst with sufficient attrition resistance and WGS activity could be made and that the process achieved about a 24% reduction in capital cost compared to a conventional fixed-bed commercial process.« less

78 FR 52764 - Extension of Public Comment Period Hydrogen Energy California's Integrated Gasification Combined...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-26

... DEPARTMENT OF ENERGY Extension of Public Comment Period Hydrogen Energy California's Integrated Gasification Combined Cycle Project Preliminary Staff Assessment and Draft Environmental Impact Statement... California's Integrated Gasification Combined Cycle Project Preliminary Staff Assessment/Draft Environmental...

Development, Verification and Validation of Enclosure Radiation Capabilities in the CHarring Ablator Response (CHAR) Code

NASA Technical Reports Server (NTRS)

Salazar, Giovanni; Droba, Justin C.; Oliver, Brandon; Amar, Adam J.

2016-01-01

With the recent development of multi-dimensional thermal protection system (TPS) material response codes including the capabilities to account for radiative heating is a requirement. This paper presents the recent efforts to implement such capabilities in the CHarring Ablator Response (CHAR) code developed at NASA's Johnson Space Center. This work also describes the different numerical methods implemented in the code to compute view factors for radiation problems involving multiple surfaces. Furthermore, verification and validation of the code's radiation capabilities are demonstrated by comparing solutions to analytical results, to other codes, and to radiant test data.

Thermochemical tests on resins: Char resistance of selected phenolic cured epoxides

NASA Technical Reports Server (NTRS)

Keck, F. L.

1982-01-01

Curing epoxy resins with novalac phenolic resins is a feasible approach for increasing intact char of the resin system. Char yields above 40% at 700 C were achieved with epoxy novalac (DEN 438)/novalac phenolic (BRWE 5833) resin systems with or without catalyst such as ethyl tri-phenyl phosphonium iodide. These char yields are comparable to commercially used epoxy resin systems like MY-720/DDS/BF3. Stable prepregs are easily made from a solvent solution of the epoxy/phenolic system and this provides a feasible process for fabrication of same into commercial laminates.

Advanced Systems for Preprocessing and Characterizing Coal-Biomass Mixtures as Next-Generation Fuels and Feedstocks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karmis, Michael; Luttrell, Gerald; Ripepi, Nino

The research activities presented in this report are intended to address the most critical technical challenges pertaining to coal-biomass briquette feedstocks. Several detailed investigations were conducted using a variety of coal and biomass feedstocks on the topics of (1) coal-biomass briquette production and characterization, (2) gasification of coal-biomass mixtures and briquettes, (3) combustion of coal-biomass mixtures and briquettes, and (4) conceptual engineering design and economic feasibility of briquette production. The briquette production studies indicate that strong and durable co-firing feedstocks can be produced by co-briquetting coal and biomass resources commonly available in the United States. It is demonstrated that binderlessmore » coal-biomass briquettes produced at optimized conditions exhibit very high strength and durability, which indicates that such briquettes would remain competent in the presence of forces encountered in handling, storage and transportation. The gasification studies conducted demonstrate that coal-biomass mixtures and briquettes are exceptional gasification feedstocks, particularly with regard to the synergistic effects realized during devolatilization of the blended materials. The mixture combustion studies indicate that coal-biomass mixtures are exceptional combustion feedstocks, while the briquette combustion study indicates that the use of blended briquettes reduces NO x, CO 2, and CO emissions, and requires the least amount of changes in the operating conditions of an existing coal-fired power plant. Similar results were obtained for the physical durability of the pilot-scale briquettes compared to the bench-scale tests. Finally, the conceptual engineering and feasibility analysis study for a commercial-scale briquetting production facility provides preliminary flowsheet and cost simulations to evaluate the various feedstocks, equipment selection and operating parameters.« less

FUEL-FLEXIBLE GASIFICATION-COMBUSTION TECHNOLOGY FOR PRODUCTION OF H2 AND SEQUESTRATION-READY CO2

DOE Office of Scientific and Technical Information (OSTI.GOV)

George Rizeq; Janice West; Arnaldo Frydman

It is expected that in the 21st century the Nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It will be necessary to improve both the thermodynamic efficiency and environmental impact performance of fossil fuel utilization. General Electric Energy and Environmental Research Corporation (GE EER) has developed an innovative fuel-flexible Advanced Gasification-Combustion (AGC) concept to produce H{sub 2} and sequestration-ready CO{sub 2} from solid fuels. The AGC module offers potential for reduced cost and increased energy efficiency relative to conventional gasification and combustion systems. GE EER was awarded a Vision-21 program from U.S. DOE NETL tomore » develop the AGC technology. Work on this three-year program started on October 1, 2000. The project team includes GE EER, California Energy Commission, Southern Illinois University at Carbondale, and T. R. Miles, Technical Consultants, Inc. In the AGC technology, coal/opportunity fuels and air are simultaneously converted into separate streams of (1) pure hydrogen that can be utilized in fuel cells, (2) sequestration-ready CO{sub 2}, and (3) high temperature/pressure oxygen-depleted air to produce electricity in a gas turbine. The process produces near-zero emissions and, based on preliminary modeling work in the first quarter of this program, has an estimated process efficiency of approximately 67% based on electrical and H{sub 2} energy outputs relative to the higher heating value of coal. The three-year R&D program will determine the operating conditions that maximize separation of CO{sub 2} and pollutants from the vent gas, while simultaneously maximizing coal conversion efficiency and hydrogen production. The program integrates lab-, bench- and pilot-scale studies to demonstrate the AGC concept. This is the fifth quarterly technical progress report for the Vision-21 AGC program supported by U.S. DOE NETL (Contract: DE-FC26-00FT40974). This report summarizes program accomplishments for the period starting October 1, 2001 and ending December 31, 2001. The report includes an introduction summarizing the AGC concept, main program tasks, and program objectives; it also provides a summary of program activities covering program management and progress in tasks including lab- and bench-scale experimental testing, pilot-scale design, and economic studies.« less

FUEL-FLEXIBLE GASIFICATION-COMBUSTION TECHNOLOGY FOR PRODUCTION OF H2 AND SEQUESTRATION-READY CO2

DOE Office of Scientific and Technical Information (OSTI.GOV)

George Rizeq; Janice West; Arnaldo Frydman

It is expected that in the 21st century the Nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It will be necessary to improve both the thermodynamic efficiency and environmental impact performance of fossil fuel utilization. General Electric Energy and Environmental Research Corporation (GE EER) has developed an innovative fuel-flexible Advanced Gasification-Combustion (AGC) concept to produce H{sub 2} and sequestration-ready CO{sub 2} from solid fuels. The AGC module offers potential for reduced cost and increased energy efficiency relative to conventional gasification and combustion systems. GE EER was awarded a Vision-21 program from U.S. DOE NETL tomore » develop the AGC technology. Work on this three-year program started on October 1, 2000. The project team includes GE EER, California Energy Commission, Southern Illinois University at Carbondale, and T. R. Miles, Technical Consultants, Inc. In the AGC technology, coal/opportunity fuels and air are simultaneously converted into separate streams of (1) pure hydrogen that can be utilized in fuel cells, (2) sequestration-ready CO{sub 2}, and (3) high temperature/pressure oxygen-depleted air to produce electricity in a gas turbine. The process produces near-zero emissions and, based on preliminary modeling work in the first quarter of this program, has an estimated process efficiency of approximately 67% based on electrical and H{sub 2} energy outputs relative to the higher heating value of coal. The three-year R&D program will determine the operating conditions that maximize separation of CO{sub 2} and pollutants from the vent gas, while simultaneously maximizing coal conversion efficiency and hydrogen production. The program integrates lab-, bench- and pilot-scale studies to demonstrate the AGC concept. This is the seventh quarterly technical progress report for the Vision-21 AGC program supported by U.S. DOE NETL (Contract: DE-FC26-00FT40974). This report summarizes program accomplishments for the period starting April 1, 2002 and ending June 30, 2002. The report includes an introduction summarizing the AGC concept, main program tasks, and program objectives; it also provides a summary of program activities covering program management and progress in tasks including lab-/bench-scale experimental testing and pilot-scale design.« less

FUEL-FLEXIBLE GASIFICATION-COMBUSTION TECHNOLOGY FOR PRODUCTION OF H2 AND SEQUESTRATION-READY CO2

DOE Office of Scientific and Technical Information (OSTI.GOV)

George Rizeq; Janice West; Arnaldo Frydman

It is expected that in the 21st century the Nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It will be necessary to improve both the thermodynamic efficiency and environmental impact performance of fossil fuel utilization. GE Energy and Environmental Research Corporation (GE EER) has developed an innovative fuel-flexible Advanced Gasification-Combustion (AGC) concept to produce H{sub 2} and sequestration-ready CO{sub 2} from solid fuels. The AGC module offers potential for reduced cost and increased energy efficiency relative to conventional gasification and combustion systems. GE EER was awarded a Vision 21 program from U.S. DOE NETL tomore » develop the AGC technology. Work on this three-year program started on October 1, 2000. The project team includes GE EER, California Energy Commission, Southern Illinois University at Carbondale, and T. R. Miles, Technical Consultants, Inc. In the AGC technology, coal/opportunity fuels and air are simultaneously converted into separate streams of (1) pure hydrogen that can be utilized in fuel cells, (2) sequestration-ready CO{sub 2}, and (3) high temperature/pressure oxygen-depleted air to produce electricity in a gas turbine. The process produces near-zero emissions and, based on preliminary modeling work, has an estimated process efficiency of approximately 67% based on electrical and H{sub 2} energy outputs relative to the higher heating value of coal. The three-year R&D program will determine the operating conditions that maximize separation of CO{sub 2} and pollutants from the vent gas, while simultaneously maximizing coal conversion efficiency and hydrogen production. The program integrates lab-, bench- and pilot-scale studies to demonstrate the AGC concept. This is the second annual technical progress report for the Vision 21 AGC program supported by U.S. DOE NETL (Contract No. DE-FC26-00FT40974). This report summarizes program accomplishments for the period starting October 1, 2001 and ending September 30, 2002. The report includes an introduction summarizing the AGC concept, main program tasks, and program objectives; it also provides a summary of program activities and accomplishments covering progress in tasks including lab- and bench-scale experimental testing, pilot-scale design and assembly, and program management.« less

FUEL-FLEXIBLE GASIFICATION-COMBUSTION TECHNOLOGY FOR PRODUCTION OF H2 AND SEQUESTRATION-READY CO2

DOE Office of Scientific and Technical Information (OSTI.GOV)

George Rizeq; Janice West; Arnaldo Frydman

It is expected that in the 21st century the Nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It will be necessary to improve both the thermodynamic efficiency and environmental impact performance of fossil fuel utilization. General Electric Energy and Environmental Research Corporation (GE EER) has developed an innovative fuel-flexible Advanced Gasification-Combustion (AGC) concept to produce H{sub 2} and sequestration-ready CO{sub 2} from solid fuels. The AGC module offers potential for reduced cost and increased energy efficiency relative to conventional gasification and combustion systems. GE EER was awarded a Vision-21 program from U.S. DOE NETL tomore » develop the AGC technology. Work on this three-year program started on October 1, 2000. The project team includes GE EER, California Energy Commission, Southern Illinois University at Carbondale, and T. R. Miles, Technical Consultants, Inc. In the AGC technology, coal/opportunity fuels and air are simultaneously converted into separate streams of (1) pure hydrogen that can be utilized in fuel cells, (2) sequestration-ready CO{sub 2}, and (3) high temperature/pressure oxygen-depleted air to produce electricity in a gas turbine. The process produces near-zero emissions and, based on preliminary modeling work in the first quarter of this program, has an estimated process efficiency of approximately 67% based on electrical and H{sub 2} energy outputs relative to the higher heating value of coal. The three-year R&D program will determine the operating conditions that maximize separation of CO{sub 2} and pollutants from the vent gas, while simultaneously maximizing coal conversion efficiency and hydrogen production. The program integrates lab-, bench- and pilot-scale studies to demonstrate the AGC concept. This is the third quarterly technical progress report for the Vision-21 AGC program supported by U.S. DOE NETL (Contract: DE-FC26-00FT40974). This report summarizes program accomplishments for the period starting April 1, 2001 and ending June 30, 2001. The report includes an introduction summarizing the AGC concept, main program tasks, objectives of this program, and provides a summary of program activities covering program management and progress in first year tasks including lab- and bench-scale design, facilities preparation, and engineering studies.« less

Effect of basalt fibres reinforcement and aluminum trihydrate on the thermal properties of intumescent fire retardant coatings

NASA Astrophysics Data System (ADS)

Yasir, Muhammad; Amir, Norlaili Binti; Ahmad, Faiz; Syahirah Rodzhan, N.

2017-08-01

This research is carried out in order to study the synergistic effect of aluminium trihydrate and basalt fibres on the properties of fire resistant intumescent coatings. Intumescent fire retardant coatings were developed using different flame retardants such as ammonium polyphosphate, expandable graphite, melamine and boric acid. These flame retardants were bound together with the help of epoxy binder along with curing agent. Furthermore, individual and combinations of aluminium trihydrate and basalt fibres was incorporated in the formulations to analyse mechanical and chemical properties of the coatings. Char expansion was observed using furnace test, thermogravimetric analysis was used to determine residual weight, X-Ray Diffraction was performed to investigate compounds present in the char, shear test was conducted to determine char strength and scanning electron microscopy analysis was performed to observe morphology of the burnt char. From the microscopic investigation it was concluded that the dense structure of the char increased the char integrity by adding basalt and aluminium trihydrate as fillers. X-Ray Diffraction results shows the presence boron phosphate, and boric acid which enhanced the thermal performance of the coating up to 800°C. From the Thermogravimetric analysis it was concluded that the residual weight of the char was increased up to 34.9 % for IC-B2A4 which enhanced thermal performance of intumescent coating.

Sensing underground coal gasification by ground penetrating radar

NASA Astrophysics Data System (ADS)

Kotyrba, Andrzej; Stańczyk, Krzysztof

2017-12-01

The paper describes the results of research on the applicability of the ground penetrating radar (GPR) method for remote sensing and monitoring of the underground coal gasification (UCG) processes. The gasification of coal in a bed entails various technological problems and poses risks to the environment. Therefore, in parallel with research on coal gasification technologies, it is necessary to develop techniques for remote sensing of the process environment. One such technique may be the radar method, which allows imaging of regions of mass loss (voids, fissures) in coal during and after carrying out a gasification process in the bed. The paper describes two research experiments. The first one was carried out on a large-scale model constructed on the surface. It simulated a coal seam in natural geological conditions. A second experiment was performed in a shallow coal deposit maintained in a disused mine and kept accessible for research purposes. Tests performed in the laboratory and in situ conditions showed that the method provides valuable data for assessing and monitoring gasification surfaces in the UCG processes. The advantage of the GPR method is its high resolution and the possibility of determining the spatial shape of various zones and forms created in the coal by the gasification process.

Apparatus for mixing char-ash into coal stream

DOEpatents

Blaskowski, Henry J.

1982-03-16

Apparatus for obtaining complete mixing of char with coal prior to the introduction of the mixture into the combustor (30) of a coal gasifier (10). The coal is carried in one air stream (22), and the char in another air stream (54), to a riffle plate arrangement (26), where the streams of solid are intimately mixed or blended.

Char syndrome: an additional family with polythelia, a new finding.

PubMed

Zannolli, R; Mostardini, R; Matera, M; Pucci, L; Gelb, B D; Morgese, G

2000-11-27

This report describes a father and daughter with Char syndrome, a rare autosomal dominant disorder. Both affected individuals had typical face, strabismus, and foot anomalies. The girl also had a patent ductus arteriosus. In addition, both patients had polythelia (supernumerary nipples), a finding not described before in the Char syndrome. Copyright 2000 Wiley-Liss, Inc.

Formation of nanocarbon spheres by thermal treatment of woody char from fast pyrolysis process

Treesearch

Qiangu Yan; Hossein Toghiani; Zhiyong Cai; Jilei Zhang

2014-01-01

Influences of thermal treatment conditions of temperature, reaction cycle and time, and purge gas type on nanocarbon formation over bio-chars from fast pyrolysis and effects of thermal reaction cycle and purge gas type on bio-char surface functional groups were investigated by temperature-programmed desorption (TPD) and temperature programmed reduction methods....

Updraft gasification of salmon processing waste

USDA-ARS?s Scientific Manuscript database

The purpose of this research is to judge the feasibility of gasification for the disposal of waste streams generated through salmon harvesting. Gasification is the process of converting carbonaceous materials into combustible “syngas” in a high temperature (above 700 °C), oxygen deficient environmen...

78 FR 54640 - Extension of Public Comment Period Hydrogen Energy California's Integrated Gasification Combined...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-05

... DEPARTMENT OF ENERGY Extension of Public Comment Period Hydrogen Energy California's Integrated Gasification Combined Cycle Project Preliminary Staff Assessment and Draft Environmental Impact Statement... Integrated Gasification Combined Cycle Project Preliminary Staff Assessment and Draft Environmental Impact...

77 FR 58022 - Montana Regulatory Program

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-19

... additions of statutory definitions of approximate original contour, in situ coal gasification, and recovery... intends to promulgate regulations pertaining to in situ coal gasification within one year. The statutory... which do not have Federal counterparts under SMCRA: ``in situ coal gasification'' and ``recovery fluid...

Method for increasing steam decomposition in a coal gasification process

DOEpatents

Wilson, Marvin W.

1988-01-01

The gasification of coal in the presence of steam and oxygen is significantly enhanced by introducing a thermochemical water-splitting agent such as sulfuric acid, into the gasifier for decomposing the steam to provide additional oxygen and hydrogen usable in the gasification process for the combustion of the coal and enrichment of the gaseous gasification products. The addition of the water-splitting agent into the gasifier also allows for the operation of the reactor at a lower temperature.

Method for increasing steam decomposition in a coal gasification process

DOEpatents

Wilson, M.W.

1987-03-23

The gasification of coal in the presence of steam and oxygen is significantly enhanced by introducing a thermochemical water- splitting agent such as sulfuric acid, into the gasifier for decomposing the steam to provide additional oxygen and hydrogen usable in the gasification process for the combustion of the coal and enrichment of the gaseous gasification products. The addition of the water-splitting agent into the gasifier also allows for the operation of the reactor at a lower temperature.

Near-extinction and final burnout in coal combustion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hurt, R.H.; Davis, K.A.

The late stages of char combustion have a special technological significance, as carbon conversions of 99% or greater are typically required for the economic operation of pulverized coal fired boilers. In the present article, two independent optical techniques are used to investigate near-extinction and final burnout phenomenas. Captive particle image sequences, combined with in situ optical measurements on entrained particles, provide dramatic illustration of the asymptotic nature of the char burnout process. Single particle combustion to complete burnout is seen to comprise two distinct stages: (1) a rapid high-temperature combustion stage, consuming about 70% of the char carbon and endingmore » with near-extinction of the heterogeneous reactions due to a loss of global particle reactivity, and (2) a final burnout stage occurring slowly at lower temperatures. For particles containing mineral matter, the second stage can be further subdivided into: (2a) late char combustion, which begins after the near-extinction event, and converts carbon-rich particles to mixed particle types at a lower temperature and a slower rate; and (2b) decarburization of ash -- the removal of residual carbon inclusions from inorganic (ash) frameworks in the very late stages of combustion. This latter process can be extremely slow, requiring over an order of magnitude more time than the primary rapid combustion stage. For particles with very little ash, the loss of global reactivity leading to early near-extinction is clearly related to changes in the carbonaceous char matrix, which evolves over the course of combustion. Current global kinetic models used for the prediction of char combustion rates and carbon burnout in boilers do not predict the asymptotic nature of char combustion. More realistic models accounting for the evolution of char structure are needed to make accurate predictions in the range of industrial interest.« less

Computational investigations of low-emission burner facilities for char gas burning in a power boiler

NASA Astrophysics Data System (ADS)

Roslyakov, P. V.; Morozov, I. V.; Zaychenko, M. N.; Sidorkin, V. T.

2016-04-01

Various variants for the structure of low-emission burner facilities, which are meant for char gas burning in an operating TP-101 boiler of the Estonia power plant, are considered. The planned increase in volumes of shale reprocessing and, correspondingly, a rise in char gas volumes cause the necessity in their cocombustion. In this connection, there was a need to develop a burner facility with a given capacity, which yields effective char gas burning with the fulfillment of reliability and environmental requirements. For this purpose, the burner structure base was based on the staging burning of fuel with the gas recirculation. As a result of the preliminary analysis of possible structure variants, three types of early well-operated burner facilities were chosen: vortex burner with the supply of recirculation gases into the secondary air, vortex burner with the baffle supply of recirculation gases between flows of the primary and secondary air, and burner facility with the vortex pilot burner. Optimum structural characteristics and operation parameters were determined using numerical experiments. These experiments using ANSYS CFX bundled software of computational hydrodynamics were carried out with simulation of mixing, ignition, and burning of char gas. Numerical experiments determined the structural and operation parameters, which gave effective char gas burning and corresponded to required environmental standard on nitrogen oxide emission, for every type of the burner facility. The burner facility for char gas burning with the pilot diffusion burner in the central part was developed and made subject to computation results. Preliminary verification nature tests on the TP-101 boiler showed that the actual content of nitrogen oxides in burner flames of char gas did not exceed a claimed concentration of 150 ppm (200 mg/m3).

The application of carbon isotope discrimination of charred wheat grains to reconstruct Late Holocene climate change and identify water management strategy in northwest China

NASA Astrophysics Data System (ADS)

Wang, W.; An, C.; Duan, F.; Zhao, Y.; Cao, Z.

2017-12-01

The AMS 14C dating and corresponding carbon stable isotope datum of charred wheat grains from archaeological sites in northwest China especially Hexi Corridor and Xinjiang have been collected widely to study its potential roles in reconstructing past climate change and identifying water management strategies through comparison with integrated regional humidity index, carbon isotope data of wheat grown under modern irrigation environment from study area and Mediterranean charred wheat carbon isotope data. The results suggest (1) carbon isotope discrimination values of charred wheat both in Hexi corridor and Xinjiang could respond well to regional moisture change, and there are also good positive correlation relationship between them (2) in contrast to consistent relationship between decreased carbon isotope discrimination values of charred wheat and dry climate condition, increased carbon isotope discrimination values does not represent wetter regional climate completely and may also reveal effects of human irrigation activities. The higher carbon isotope discrimination value of charred wheat which occurred in the Hexi Corridor from 4000 to 3850 a BP, 2100 a BP and 550 a BP and in Tianshan area of Xinjiang from 3730 a BP could be likely to be related with human activities (3) the carbon isotope discrimination value of charred wheat may have a certain limit which is generally not beyond 19‰. And this upper limit could influence its availability in reflecting abrupt change of precipitation/humidity especially rapid wetter trend. We conclude that carbon isotope analysis of charred wheat grains could be a good tool for reconstructing past climate change and identifying ancient irrigation practices.

Experimental performance of an ablative material as an external insulator for a hypersonic research aircraft

NASA Technical Reports Server (NTRS)

Puster, R. L.; Chapman, A. J.

1977-01-01

An ablative material composed of silica-filled elastomeric silicone was tested to evaluate its thermal and structural performance as an external insulator, or heat shield, for a hypersonic research aircraft. The material was also tested to determine whether it would form a durable char layer when initially heated and thereafter function primarily as an insulator with little further pyrolysis or char removal. Aerothermal tests were representative of nominal Mach 6 cruise conditions of the aircraft, and additional tests were representative of Mach 8 cruise and interference heating conditions. Radiant heating tests were used to simulate the complete nominal Mach 6 surface-temperature history. The silica char that formed during aerothermal tests was not durable. The char experienced a general and preferential surface recession, with the primary mechanism for char removal being erosion. Tests revealed that radiant heating is not a valid technique for simulating aerodynamic heating of the material.

Experimental Study of Hydrogasification of Lignite and Subbituminous Coal Chars

PubMed Central

Gil, Stanisław

2015-01-01

The experimental facility for pressure hydrogasification research was adapted to the pressure of 10 MPa and temperature of 1300 K, which ensured repeatability of results and hydrogen heating to the process temperature. A hydrogasification reaction of chars produced from two rank coals was investigated at temperatures up to 1173 K, pressures up to 8 MPa, and the gas flow rates of 0.5–5 dmn 3/min. Reactivity of the “Szczerców” lignite char was found to be slightly higher than that of the subbituminous “Janina” coal char produced under the same conditions. A high value of the char reactivity was observed to a certain carbon conversion degree, above which a sharp drop took place. It was shown that, to achieve proper carbon conversion, the hydrogasification reaction must proceed at a temperature above 1200 K. PMID:26065028

[Dynamics of parasite fauna of different forms of salmon Salvelinus alpinus L. from the basin of the Lake Azabach'e].

PubMed

Butorina, T E

1975-01-01

The paper deals with age changes in the parasite fauna of different intraspecific forms of chars. It is shown that this year brood and yearlings of predatory, benthofagous, stream and anadromous chars up to 10 cm in length have a similar parasite fauna. During the second year of life the chars come to different feeding; correspondingly changes their parasite fauna which differs considerably in the above forms of chars. Two groups of parasites are distinguished the infection with which increases and decreases with the age of fishes. Observations were carried out on the life cycles, developmental and maturation periods of some parasites of chars. Biological peculiarities of some mixosporidia are studied. A shift in the developmental periods of helminths is noted as compared to those from the European part of the USSR.

Hydrothermal Gasification for Waste to Energy

NASA Astrophysics Data System (ADS)

Epps, Brenden; Laser, Mark; Choo, Yeunun

2014-11-01

Hydrothermal gasification is a promising technology for harvesting energy from waste streams. Applications range from straightforward waste-to-energy conversion (e.g. municipal waste processing, industrial waste processing), to water purification (e.g. oil spill cleanup, wastewater treatment), to biofuel energy systems (e.g. using algae as feedstock). Products of the gasification process are electricity, bottled syngas (H2 + CO), sequestered CO2, clean water, and inorganic solids; further chemical reactions can be used to create biofuels such as ethanol and biodiesel. We present a comparison of gasification system architectures, focusing on efficiency and economic performance metrics. Various system architectures are modeled computationally, using a model developed by the coauthors. The physical model tracks the mass of each chemical species, as well as energy conversions and transfers throughout the gasification process. The generic system model includes the feedstock, gasification reactor, heat recovery system, pressure reducing mechanical expanders, and electricity generation system. Sensitivity analysis of system performance to various process parameters is presented. A discussion of the key technological barriers and necessary innovations is also presented.

Temporal measurements and kinetics of selenium release during coal combustion and gasification in a fluidized bed.

PubMed

Shen, Fenghua; Liu, Jing; Zhang, Zhen; Yang, Yingju

2016-06-05

The temporal release of selenium from coal during combustion and gasification in a fluidized bed was measured in situ by an on-line analysis system of trace elements in flue gas. The on-line analysis system is based on an inductively coupled plasma optical emission spectroscopy (ICP-OES), and can measure concentrations of trace elements in flue gas quantitatively and continuously. The results of on-line analysis suggest that the concentration of selenium in flue gas during coal gasification is higher than that during coal combustion. Based on the results of on-line analysis, a second-order kinetic law r(x)=0.94e(-26.58/RT)(-0.56 x(2) -0.51 x+1.05) was determined for selenium release during coal combustion, and r(x)=11.96e(-45.03/RT)(-0.53 x(2) -0.56 x+1.09) for selenium release during coal gasification. These two kinetic laws can predict respectively the temporal release of selenium during coal combustion and gasification with an acceptable accuracy. Thermodynamic calculations were conducted to predict selenium species during coal combustion and gasification. The speciation of selenium in flue gas during coal combustion differs from that during coal gasification, indicating that selenium volatilization is different. The gaseous selenium species can react with CaO during coal combustion, but it is not likely to interact with mineral during coal gasification. Copyright © 2016 Elsevier B.V. All rights reserved.

The influence of wildfire severity on soil char composition and nitrogen dynamics

NASA Astrophysics Data System (ADS)

Rhoades, Charles; Fegel, Timothy; Chow, Alex; Tsai, Kuo-Pei; Norman, John, III; Kelly, Eugene

2017-04-01

Forest fires cause lasting ecological changes and alter the biogeochemical processes that control stream water quality. Decreased plant nutrient uptake is the mechanism often held responsible for lasting post-fire shifts in nutrient supply and demand, though other upland and in-stream factors also likely contribute to elevated stream nutrient losses. Soil heating, for example, creates pyrogenic carbon (C) and char layers that influence C and nitrogen (N) cycling. Char layer composition and persistence vary across burned landscapes and are influenced first by fire behavior through the temperature and duration of combustion and then by post-fire erosion. To evaluate the link between soil char and stream C and N export we studied areas burned by the 2002 Hayman Fire, the largest wildfire in Colorado, USA history. We compared soil C and N pools and processes across ecotones that included 1) unburned forests, 2) areas with moderate and 3) high wildfire severity. We analyzed 1-2 cm thick charred organic layers that remain visible 15 years after the fire, underlying mineral soils, and soluble leachate from both layers. Unburned soils released more dissolved organic C and N (DOC and DON) from organic and mineral soil layers than burned soils. The composition of DOC leachate characterized by UV-fluorescence, emission-excitation matrices (EEMs) and Fluorescence Regional Integration (FRI) found similarity between burned and unburned soils, underscoring a common organic matter source. Humic and fulvic acid-like fractions, contained in regions V and III of the FRI model, comprised the majority of the fluorescing DOM in both unburned and char layers. Similarity between two EEMs indices (Fluorescence and Freshness), further denote that unburned soils and char layers originate from the same source and are consistent with visual evidence char layers contain significant amounts of unaltered OM. However, the EEMs humification index (HIX) and compositional analysis with pyrolysis GCMS both indicate that C contained or leached from severely-burned char layers has higher aromaticity and thus chemical stability compared to C in unburned soils. Mineral soil (0-5 cm depth) beneath char layers in high severity portions of the Hayman Fire had significantly more soil N and C and lower pH. Potential net mineralization - an index of the supply of plant-available nitrogen - differed between the severely-burned areas and both unburned and moderately-burn areas. Negative net mineralization in unburned and moderately burned soils indicates immobilization or retention of inorganic N by soil microbes. In contrast, soils burned at high severity produced inorganic N sources available to plants, leaching and gas losses. Water soluble nitrate comprised a larger proportion of inorganic N leached from the char layer of high severity burns. Mineral soil in those areas had both higher water soluble nitrate and total inorganic N in leachate. Char layers that have persisted for fifteen years influence soil N turnover within the Hayman Fire affected area and may contribute to elevated N losses in streams burned at high severity. The chemical stability of soil char layers perpetuates their importance for C sequestration and N dynamics in burned landscapes.

Studies on the reduction kinetics of hematite iron ore pellets with noncoking coals for sponge iron plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, M.; Mohapatra, P.; Patel, S.K.

2009-07-01

In the present investigation, fired pellets were made by mixing hematite iron ore fines of -100, -16+18, and -8+10 mesh size in different ratios and studies on their reduction kinetics in Lakhanpur, Orient OC-2 and Belpahar coals were carried out at temperatures ranging from 850{sup o}C to 1000{sup o}C with a view toward promoting the massive utilization of fines in ironmaking. The rate of reduction in all the fired iron ore pellets increased markedly with an increase in temperature up to 1000{sup o}C, and it was more intense in the first 30min. The values of activation energy, calculated from integralmore » and differential approaches, for the reduction of fired pellets (prepared from iron ore fines of -100 mesh size) in coals were found to be in the range 131-148 and 130-181 kJ mol{sup -1} (for =0.2 to 0.8), indicating the process is controlled by a carbon gasification reaction. The addition of selected larger size particles in the matrix of -100 mesh size fines up to the extent studied decreased the activation energy and slightly increased the reduction rates of resultant fired pellets. In comparison to coal, the reduction of fired pellets in char was characterized by significantly lower reduction rates and higher activation energy.« less

Regeneration of glass nanofluidic chips through a multiple-step sequential thermochemical decomposition process at high temperatures.

PubMed

Xu, Yan; Wu, Qian; Shimatani, Yuji; Yamaguchi, Koji

2015-10-07

Due to the lack of regeneration methods, the reusability of nanofluidic chips is a significant technical challenge impeding the efficient and economic promotion of both fundamental research and practical applications on nanofluidics. Herein, a simple method for the total regeneration of glass nanofluidic chips was described. The method consists of sequential thermal treatment with six well-designed steps, which correspond to four sequential thermal and thermochemical decomposition processes, namely, dehydration, high-temperature redox chemical reaction, high-temperature gasification, and cooling. The method enabled the total regeneration of typical 'dead' glass nanofluidic chips by eliminating physically clogged nanoparticles in the nanochannels, removing chemically reacted organic matter on the glass surface and regenerating permanent functional surfaces of dissimilar materials localized in the nanochannels. The method provides a technical solution to significantly improve the reusability of glass nanofluidic chips and will be useful for the promotion and acceleration of research and applications on nanofluidics.

Using bark char codes to predict post-fire cambium mortality

Treesearch

Sharon M. Hood; Danny R. Cluck; Sheri L. Smith; Kevin C. Ryan

2008-01-01

Cambium injury is an important factor in post-fire tree survival. Measurements that quantify the degree of bark charring on tree stems after fire are often used as surrogates for direct cambium injury because they are relatively easy to assign and are non-destructive. However, bark char codes based on these measurements have been inadequately tested to determine how...

Magnetic separation of carbon-encapsulated Fe nanoparticles from thermally-treated wood char

Treesearch

Sung Phil Mun; Zhiyong Cai; Jilei Zhang

2013-01-01

Wood char,a by-product from the fast-pyrolysis process of southern yellow pine wood for bio-oil production, was carbonized with Fenano particles (FeNPs) as a catalyst to prepare carbon-encapsulated Fe nanoparticles. A magnetic separation method was tested to isolate carbon-encapsulated Fe nano particles from the carbonized char. X-ray diffraction pattern clearly shows...

Graphite fiber surface treatment to improve char retention and increase fiber clumping

NASA Technical Reports Server (NTRS)

Paul, J. T., Jr.; Weldy, W. E.

1980-01-01

Composites containing carbon and graphite fibers can release fibers into the atmosphere during a fire. This release can potentially cause failure in some types of electrical equipment. Reduced fiber dispersion during and after combustion will reduce risks. Epoxidized char forming systems were synthesized which will react with commercially available surface treated carbon fiber. Fibers modified with these char formers retained adhesion in a specific epoxy matrix resin. Small scale combustion testing indicates that using these char former modified fibers in laminates will help to reduce the dispersement of fibers resulting from exposure to fire without sacrificing resin to fiber adhesion.

Synergistic effects of mica and wollastonite fillers on thermal performance of intumescent fire retardant coating

NASA Astrophysics Data System (ADS)

Zia-ul-Mustafa, M.; Ahmad, Faiz; Megat-Yusoff, Puteri S. M.; Aziz, Hammad

2015-07-01

In this study, intumescent fire retardant coatings (IFRC) were developed to investigate the synergistic effects of reinforced mica and wollastonite fillers based IFRC towards heat shielding, char expansion, char composition and char morphology. Ammonium poly-phosphate (APP) was used as acid source, expandable graphite (EG) as carbon source, melamine as blowing agent, boric acid as additive and Hardener H-2310 polyamide amine in bisphenol A epoxy resin BE-188(BPA) was used as curing agent. Bunsen burner fire test was used for thermal performance according to UL-94 for 1 h. Field Emission Scanning Electron Microscopy (FESEM) was used to observe char microstructure. X-Ray Diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were used to analyse char composition. The results showed that addition of clay filler in IFRC enhanced the fire protection performance of intumescent coating. X-Ray Diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) results showed the presence of boron phosphate, silicon phosphate oxide, aluminium borate in the char that improved the thermal performance of intumescent fire retardant coating (IFRC). Resultantly, the presence of these developed compounds enhanced the Integrity of structural steel upto 500°C.

Evaluation of wood chip gasification to produce reburn fuel for coal-fired boilers

EPA Science Inventory

Gasification/reburn testing with biomass and other wastes is of interest to both the U.S. Environmental Protection Agency (EPA) and the Italian Ministry of the Environment & Territory (IMET). Gasification systems that use wastes as feedstock should provide a clean, efficient sour...

Improved catalysts for carbon and coal gasification

DOEpatents

McKee, D.W.; Spiro, C.L.; Kosky, P.G.

1984-05-25

This invention relates to improved catalysts for carbon and coal gasification and improved processes for catalytic coal gasification for the production of methane. The catalyst is composed of at least two alkali metal salts and a particulate carbonaceous substrate or carrier is used. 10 figures, 2 tables.

BIOMASS REACTIVITY IN GASIFICATION BY THE HYNOL PROCESS

EPA Science Inventory

A thermobalance reactor was used to evaluate the reactivity of poplar wood in gasification under the operating conditions specific for the Hynol process where biomass is gasified at 30 atm and 800E C with a hydrogen-rich gas recycled from methane synthesis. The gasification invol...

Methods for sequestering carbon dioxide into alcohols via gasification fermentation

DOEpatents

Gaddy, James L; Ko, Ching-Whan; Phillips, J. Randy; Slape, M. Sean

2013-11-26

The present invention is directed to improvements in gasification for use with synthesis gas fermentation. Further, the present invention is directed to improvements in gasification for the production of alcohols from a gaseous substrate containing at least one reducing gas containing at least one microorganism.

Low/medium-Btu coal-gasification feasibility study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1980-11-01

This study examines the feasibility of applying the concepts of Coal Gasification and Combined Cycle Technology to the re-powering of existing steam turbine-electric generating facilities. The primary objectives of this study include: (1) the determination of the feasibility of designing a technically sound system embodying this technology; (2) the determination of the potential for displacing foreign oil by the project; (3) the identificaton of any constraints and/or barriers that might impede the accomplishment of such a project; and (4) the evaluation of the potential benefits of such a system. Although the system is designed around the use of commercially available,more » state-of-the-art components and equipment, a completely integrated, electric generating plant, such as is being proposed here, has not yet been demonstrated. However, the designs developed as part of this study combine these components, utilizing well developed and technically sound concepts in such a way as to provide a reasonable degree of confidence in the workability of the total system. This study offers the potential for reducing oil dependency; the possibility of improving cycle efficiency and extending the useful life of existing facilities; the feasibility of re-vitalizing a facility located within a major load center; and presents some attractive possibilities for a co-generation, district heating application in the central portions of Bridgeport. Although the results of the study produce a number of clear conclusions, they also stimulate additional questions, the resolution of which would require further study and more detailed design. The final resolution of these questions that still remain may have a significant effect on the final conclusions concerning the viability of this project, and it is for this reason that further study is required.« less

The potential applications of using compost chars for removing the hydrophobic herbicide atrazine from solution.

PubMed

Tsui, Lo; Roy, William R

2008-09-01

One commercial compost sample was pyrolyzed to produce chars as a sorbent for removing the herbicide atrazine from solution. The sorption behavior of compost-based char was compared with that of an activated carbon derived from corn stillage. When compost was pyrolyzed, the char yield was greater than 45% when heated under air, and 52% when heated under N(2). In contrast, when the corn stillage was pyrolyzed under N(2), the yield was only 22%. The N(2)-BET surface area of corn stillage activated carbon was 439 m(2)/g, which was much greater than the maximum compost char surface area of 72 m(2)/g. However, the sorption affinity of the compost char for dissolved atrazine was comparable to that of the corn stillage activated carbon. This similarity could have resulted from the initial organic waste being subjected to a relatively long period of thermal processes during composting, and thus, the compost was more thermally stable when compared with the raw materials. In addition, microorganisms transformed the organic wastes into amorphous humic substances, and thus, it was likely that the microporisity was enhanced. Although this micropore structure could not be detected by the N(2)-BET method, it was apparent in the atrazine sorption experiment. Overall, the experimental results suggested that the compost sample in current study was a relatively stable material thermally for producing char, and that it has the potential as a feed stock for making high-quality activated carbon.

Pyrolysis conditions and ozone oxidation effects on ammonia adsorption in biomass generated chars.

PubMed

Kastner, James R; Miller, Joby; Das, K C

2009-05-30

Ammonia adsorbents were generated via pyrolysis of biomass (peanut hulls and palm oil shells) over a range of temperatures and compared to a commercially available activated carbon (AC) and solid biomass residuals (wood and poultry litter fly ash). Dynamic ammonia adsorption studies (i.e., breakthrough curves) were performed using these adsorbents at 23 degrees C from 6 to 17 ppmv NH(3). Of the biomass chars, palm oil char generated at 500 degrees C had the highest NH(3) adsorption capacity (0.70 mg/g, 6 ppmv, 10% relative humidity (RH)), was similar to the AC, and contrasted to the other adsorbents (including the AC), the NH(3) adsorption capacity significantly increased if the relative humidity was increased (4 mg/g, 7 ppmv, 73% RH). Room temperature ozone treatment of the chars and activated carbon significantly increased the NH(3) adsorption capacity (10% RH); resultant adsorption capacity, q (mg/g) increased by approximately 2, 6, and 10 times for palm oil char, peanut hull char (pyrolysis only), and activated carbon, respectively. However, water vapor (73% RH at 23 degrees C) significantly reduced NH(3) adsorption capacity in the steam and ozone treated biomass, yet had no effect on the palm shell char generated at 500 degrees C. These results indicate the feasibility of using a low temperature (and thus low energy input) pyrolysis and activation process for the generation of NH(3) adsorbents from biomass residuals.

Evaluation of Biomass Gasification to Produce Reburning Fuel for Coal-Fired Boilers

EPA Science Inventory

Gasification and reburning testing with biomass and other wastes is of interest to both the U.S. EPA and the Italian Ministry of the Environment & Territory. Gasification systems that use biofuels or wastes as feedstock can provide a clean, efficient source of synthesis gas and p...

Evaluation of wood chip gasification to produce reburrn fuel for coal-fired boilers: AWMA

EPA Science Inventory

Gasification or reburn testing with biomass and other wastes is of interest to both the U.S. Environmental Protection Agency (EPA) and the Italian Ministry of the Environment & Territory (IMET). Gasification systems that use wastes as feedstock should provide a clean, efficient s...

Modeling integrated biomass gasification business concepts

Treesearch

Peter J. Ince; Ted Bilek; Mark A. Dietenberger

2011-01-01

Biomass gasification is an approach to producing energy and/or biofuels that could be integrated into existing forest product production facilities, particularly at pulp mills. Existing process heat and power loads tend to favor integration at existing pulp mills. This paper describes a generic modeling system for evaluating integrated biomass gasification business...

Method for in situ gasification of a subterranean coal bed

DOEpatents

Shuck, Lowell Z.

1977-05-31

The method of the present invention relates to providing controlled directional bores in subterranean earth formations, especially coal beds for facilitating in situ gasification operations. Boreholes penetrating the coal beds are interconnected by laser-drilled bores disposed in various arrays at selected angles to the major permeability direction in the coal bed. These laser-drilled bores are enlarged by fracturing prior to the gasification of the coal bed to facilitate the establishing of combustion zones of selected configurations in the coal bed for maximizing the efficiency of the gasification operation.

The role of high-Btu coal gasification technology

NASA Astrophysics Data System (ADS)

German, M. I.

An analysis is given of the role and economic potential of Lurgi-technology gasification of coal to the year 2000, in relation to other gas-supply options, the further development of gasifier designs, and probable environmental impact. It is predicted that coal gasification may reach 10% of total gas supplies by the year 2000, with Eastern U.S. coal use reaching commercially significant use in the 1990's. It is concluded that coal gasification is the cleanest way of using coal, with minimal physical, chemical, biological and socioeconomic impacts.

Recent regulatory experience of low-Btu coal gasification. Volume III. Supporting case studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ackerman, E.; Hart, D.; Lethi, M.

The MITRE Corporation conducted a five-month study for the Office of Resource Applications in the Department of Energy on the regulatory requirements of low-Btu coal gasification. During this study, MITRE interviewed representatives of five current low-Btu coal gasification projects and regulatory agencies in five states. From these interviews, MITRE has sought the experience of current low-Btu coal gasification users in order to recommend actions to improve the regulatory process. This report is the third of three volumes. It contains the results of interviews conducted for each of the case studies. Volume 1 of the report contains the analysis of themore » case studies and recommendations to potential industrial users of low-Btu coal gasification. Volume 2 contains recommendations to regulatory agencies.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Overend, R.P.; Rivard, C.J.

Gasification is being developed to enable a diverse range of biomass resources to meet modern secondary energy uses, especially in the electrical utility sector. Biological or anaerobic gasification in US landfills has resulted in the installation of almost 500 MW(e) of capacity and represents the largest scale application of gasification technology today. The development of integrated gasification combined cycle generation for coal technologies is being paralleled by bagasse and wood thermal gasification systems in Hawaii and Scandinavia, and will lead to significant deployment in the next decade as the current scale-up activities are commercialized. The advantages of highly reactive biomassmore » over coal in the design of process units are being realized as new thermal gasifiers are being scaled up to produce medium-energy-content gas for conversion to synthetic natural gas and transportation fuels and to hydrogen for use in fuel cells. The advent of high solids anaerobic digestion reactors is leading to commercialization of controlled municipal solid waste biological gasification rather than landfill application. In both thermal and biological gasification, high rate process reactors are a necessary development for economic applications that address waste and residue management and the production and use of new crops for energy. The environmental contribution of biomass in reducing greenhouse gas emission will also be improved.« less

Catalytic Depolymerization of Lignin and Woody Biomass in Supercritical Ethanol: Influence of Reaction Temperature and Feedstock.

PubMed

Huang, Xiaoming; Atay, Ceylanpinar; Zhu, Jiadong; Palstra, Sanne W L; Korányi, Tamás I; Boot, Michael D; Hensen, Emiel J M

2017-11-06

The one-step ethanolysis approach to upgrade lignin to monomeric aromatics using a CuMgAl mixed oxide catalyst is studied in detail. The influence of reaction temperature (200-420 °C) on the product distribution is investigated. At low temperature (200-250 °C), recondensation is dominant, while char-forming reactions become significant at high reaction temperature (>380 °C). At preferred intermediate temperatures (300-340 °C), char-forming reactions are effectively suppressed by alkylation and Guerbet and esterification reactions. This shifts the reaction toward depolymerization, explaining high monomeric aromatics yield. Carbon-14 dating analysis of the lignin residue revealed that a substantial amount of the carbon in the lignin residue originates from reactions of lignin with ethanol. Recycling tests show that the activity of the regenerated catalyst was strongly decreased due to a loss of basic sites due to hydrolysis of the MgO function and a loss of surface area due to spinel oxide formation of the Cu and Al components. The utility of this one-step approach for upgrading woody biomass was also demonstrated. An important observation is that conversion of the native lignin contained in the lignocellulosic matrix is much easier than the conversion of technical lignin.

Catalytic Depolymerization of Lignin and Woody Biomass in Supercritical Ethanol: Influence of Reaction Temperature and Feedstock

PubMed Central

2017-01-01

The one-step ethanolysis approach to upgrade lignin to monomeric aromatics using a CuMgAl mixed oxide catalyst is studied in detail. The influence of reaction temperature (200–420 °C) on the product distribution is investigated. At low temperature (200–250 °C), recondensation is dominant, while char-forming reactions become significant at high reaction temperature (>380 °C). At preferred intermediate temperatures (300–340 °C), char-forming reactions are effectively suppressed by alkylation and Guerbet and esterification reactions. This shifts the reaction toward depolymerization, explaining high monomeric aromatics yield. Carbon-14 dating analysis of the lignin residue revealed that a substantial amount of the carbon in the lignin residue originates from reactions of lignin with ethanol. Recycling tests show that the activity of the regenerated catalyst was strongly decreased due to a loss of basic sites due to hydrolysis of the MgO function and a loss of surface area due to spinel oxide formation of the Cu and Al components. The utility of this one-step approach for upgrading woody biomass was also demonstrated. An important observation is that conversion of the native lignin contained in the lignocellulosic matrix is much easier than the conversion of technical lignin. PMID:29142789

Development of a high-performance coal-fired power generating system with pyrolysis gas and char-fired high temperature furnace (HITAF). Quarterly progress report No. 6, April--June 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1993-08-01

A concept for an advanced coal-fired combined-cycle power generating system is currently being developed. The first phase of this three-phase program consists of conducting the necessary research and development to define the system, evaluating the economic and technical feasibility of the concept, and preparing an R&D plan to develop the concept further. The system proposed to meet these goals is a combined-cycle system where air for a gas turbine is indirectly heated to approximately 1800{degree}F in furnaces fired with coal-derived fuels and then directly heated in a natural-gas-fired combustor to about 2400{degree}F. The system is based on a pyrolyzing processmore » that converts the coal into a low-Btu fuel gas and char. The fuel gas is relatively clean, and it is fired to heat tube surfaces that are susceptible to corrosion and problems from ash deposition. In particular, the high-temperature air heater tubes, which will need to be a ceramic material, will be located in a separate furnace or region of a furnace that is exposed to combustion products from the low-Btu fuel gas only.« less

Charring rate of wood exposed to a constant heat flux

Treesearch

R. H. White; H. C. Tran

1996-01-01

A critical factor in the fire endurance of a wood member is its rate of charring. Most available charring rate data have been obtained using the time-temperature curves of the standard fire resistance tests (ASTM E 119 and ISO 834) to define the fire exposure. The increased use of heat release calorimeters using exposures of constant heat flux levels has broadened the...

Effect of bone on the pyrolysis product distribution and composition in a fixed bed reactor

NASA Astrophysics Data System (ADS)

Alhassan, M.; Andresen, J. M.

2012-04-01

Co-pyrolysis of Biomass including Pistachio shell (PS), Pine wood (PW) and Wheat Straw (WS) with Bone matter (BM) have been investigated to determine the effect of bone on the quality of bio-char and bio-oil produced. The aim of this study is to generate stable and nitrogen enriched bio-char that can act as fertilizer while at the same time optimizes the chemical stability of the char to act as a Carbon Capture and Storage system (CCS) and co-produce high quality oils for renewable energy generation. To achieve this, the present study has focused on the influence of bone matter addition from 0wt% to 25wt% to the biomasses in a fixed bed pyrolysis reactor at 3000C. The analysis of the char products shows that the addition of bone to the biomass increased their char yields up to 10wt% addition. Higher addition was found to reduce the overall char yield from the biomass. At 10wt% bone addition, the carbon, hydrogen, and nitrogen content, and the gross calorific value of the chars were increased by 7wt%, 29wt%, 163wt% and 19Mj/kg, for Wheat straw, 62wt%, 46wt%, 135wt%, 110Mj/kg for Pine wood and 7wt%, 76wt%, 42wt% and 33Mj/kg for Pistachio shells. The oxygen content of the Wheat straw, Pistachio shells and pine wood mixed with 10wt% BM decreased by 28wt%, 21wt%, and 93wt%, respectively. The bio-oil yield increased for the bone addition up to 5%wt% for all the samples, its energy value and concentration of its major chemical components was improved for fuel and pharmaceutical use. Port experiment has shown that plant grown on soil amended with the bio-char produced gave higher yield as compared to that from un-amended soil. Comparison between the three biomasses investigated showed similar pattern of change. Hence it can be concluded that at optimum addition of bone to the biomass, bio-chars and oil yield could be optimized for soil amendment, energy production, while retaining carbon for sequestration.

Recovery of solid fuel from municipal solid waste by hydrothermal treatment using subcritical water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hwang, In-Hee, E-mail: hwang@eng.hokudai.ac.jp; Aoyama, Hiroya; Matsuto, Toshihiko

2012-03-15

Highlights: Black-Right-Pointing-Pointer Hydrothermal treatment using subcritical water was studied to recover solid fuel from MSW. Black-Right-Pointing-Pointer More than 75% of carbon in MSW was recovered as char. Black-Right-Pointing-Pointer Heating value of char was comparable to that of brown coal and lignite. Black-Right-Pointing-Pointer Polyvinyl chloride was decomposed at 295 Degree-Sign C and 8 MPa and was removed by washing. - Abstract: Hydrothermal treatments using subcritical water (HTSW) such as that at 234 Degree-Sign C and 3 MPa (LT condition) and 295 Degree-Sign C and 8 MPa (HT condition) were investigated to recover solid fuel from municipal solid waste (MSW). Printing paper,more » dog food (DF), wooden chopsticks, and mixed plastic film and sheets of polyethylene, polypropylene, and polystyrene were prepared as model MSW components, in which polyvinylchloride (PVC) powder and sodium chloride were used to simulate Cl sources. While more than 75% of carbon in paper, DF, and wood was recovered as char under both LT and HT conditions, plastics did not degrade under either LT or HT conditions. The heating value (HV) of obtained char was 13,886-27,544 kJ/kg and was comparable to that of brown coal and lignite. Higher formation of fixed carbon and greater oxygen dissociation during HTSW were thought to improve the HV of char. Cl atoms added as PVC powder and sodium chloride to raw material remained in char after HTSW. However, most Cl originating from PVC was found to converse into soluble Cl compounds during HTSW under the HT condition and could be removed by washing. From these results, the merit of HTSW as a method of recovering solid fuel from MSW is considered to produce char with minimal carbon loss without a drying process prior to HTSW. In addition, Cl originating from PVC decomposes into soluble Cl compound under the HT condition. The combination of HTSW under the HT condition and char washing might improve the quality of char as alternative fuel.« less

Coal Gasification - section in Kirk-Othmer Concise Encyclopedia of Chemical Technology, 5th Edition, 2-vol. set, July 2007, ISBN 978-0-470-04748-4, pp. 580-587

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shadle, L.J.; Berry, D.A.; Syamlal, Madhava

2007-07-01

Coal gasification is the process of reacting coal with oxygen, steam, and carbon dioxide to form a product gas containing hydrogen and carbon monoxide. Gasification is essentially incomplete combustion. The chemical and physical processes are quite similar, the main difference being the nature of the final products. From a processing point of view the main operating difference is that gasification consumes heat evolved during combustion. Under the reducing environment of gasification the sulfur in the coal is released as hydrogen sulfide rather than sulfur dioxide and the coal's nitrogen is converted mostly to ammonia rather than nitrogen oxides. These reducedmore » forms of sulfur and nitrogen are easily isolated, captured, and utilized, and thus gasification is a clean coal technology with better environmental performance than coal combustion. Depending on the type of gasifier and the operating conditions, gasification can be used to produce a fuel gas suitable for any number of applications. A low heating value fuel gas is produced from an air blown gasifier for use as an industrial fuel and for power production. A medium heating value fuel gas is produced from enriched oxygen blown gasification for use as a synthesis gas in the production of chemicals such as ammonia, methanol, and transportation fuels. A high heating value gas can be produced from shifting the medium heating value product gas over catalysts to produce a substitute or synthetic natural gas (SNG).« less

Sewage sludge as a fuel and raw material for phosphorus recovery: Combined process of gasification and P extraction.

PubMed

Gorazda, K; Tarko, B; Werle, S; Wzorek, Z

2018-03-01

Increasing problems associated with sewage sludge disposal are observed nowadays. As the thermal conversion of sewage sludge (combustion, co-combustion, gasification and pyrolysis) appears to be the most promising alternative for its management, the solid residues left after gasification were examined. The present study evaluates the potential of this waste as an alternative phosphorus source in the context of phosphorus recovery. The obtained solid gasification residues were characterised (chemical and phase composition, thermal properties, surface properties and technological parameters used for phosphorus raw materials) and compared to commercial phosphate raw materials. It was revealed that gasification residue is a valuable source of phosphorus and microelements, comparable to sewage sludge ash (SSA) considered nowadays as secondary phosphorus raw materials. Chemical properties as well as technological parameters characteristic for natural phosphate ores are different. Solid gasification residue was leached with mineral acids (phosphoric and nitric) according to the patented method of phosphorus recovery - PolFerAsh, developed by Cracow University of Technology. It was revealed that phosphorus can be selectively leached from solid gasification residue with high efficiency (73-82%); moreover, most of the iron and heavy metals stay in the solid phase due to the low concentration of acids and proper solid to liquid phase ratio. The obtained leachates are valuable products that can be considered for the production of fertilisers. Combining the gasification process with nutrient recovery provides the opportunity for more environmentally efficient technologies driven by sustainable development rules. Copyright © 2017 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fred D. Brent; Lalit Shah; Earl Berry

The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which uses petroleum coke to produce at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals using ChevronTexaco's proprietary gasification technology. The objective of Phase I is to determine the feasibility and define the concept for the EECP located at a specific site; develop a Research, Development, and Testing (RD&T) Plan to mitigate technical risks and barriers; and prepare a Preliminary Project Financing Plan. The objective of Phase IImore » is to implement the work as outlined in the Phase I RD&T Plan to enhance the development and commercial acceptance of coproduction technology. The objective of Phase III is to develop an engineering design package and a financing and testing plan for an EECP located at a specific site. The project's intended result is to provide the necessary technical, economic, and environmental information needed by industry to move the EECP forward to detailed design, construction, and operation. The partners in this project are Texaco Energy Systems LLC or TES (a subsidiary of ChevronTexaco), General Electric (GE), Praxair, and Kellogg Brown & Root (KBR) in addition to the U.S. Department of Energy (DOE). TES is providing gasification technology and Fischer-Tropsch (F-T) technology developed by Rentech, GE is providing combustion turbine technology, Praxair is providing air separation technology, and KBR is providing engineering. Each of the EECP subsystems was assessed for technical risks and barriers. A plan was developed to mitigate the identified risks (Phase II RD&T Plan, October 2000). The potential technical and economic risks to the EECP from Task 2.5 can be mitigated by demonstrating that the end-use products derived from the upgrading of the F-T synthesis total liquid product can meet or exceed current specifications for the manufacture of ethylene and propylene chemicals from F-T naphtha, for the generation of hydrogen from F-T naphtha to power fuel cells, for direct blending of F-T diesels into transportation fuels, for the conversion of F-T heavy product wax to transportation fuels, and the conversion of F-T Heavy product wax to a valuable high melting point food-grade specialty wax product. Product evaluations conducted under Task 2.5 of Phase II successfully mitigated the above technical and economic risks to the EECP with the development of product yields and product qualities for the production of chemicals, transportation fuels, and specialty food-grade waxes from the F-T synthesis products.« less

Development and Verification of Enclosure Radiation Capabilities in the CHarring Ablator Response (CHAR) Code

NASA Technical Reports Server (NTRS)

Salazar, Giovanni; Droba, Justin C.; Oliver, Brandon; Amar, Adam J.

2016-01-01

With the recent development of multi-dimensional thermal protection system (TPS) material response codes, the capability to account for surface-to-surface radiation exchange in complex geometries is critical. This paper presents recent efforts to implement such capabilities in the CHarring Ablator Response (CHAR) code developed at NASA's Johnson Space Center. This work also describes the different numerical methods implemented in the code to compute geometric view factors for radiation problems involving multiple surfaces. Verification of the code's radiation capabilities and results of a code-to-code comparison are presented. Finally, a demonstration case of a two-dimensional ablating cavity with enclosure radiation accounting for a changing geometry is shown.

Charring Rate for Fire Exposed X-Lam

NASA Astrophysics Data System (ADS)

Wong, Bernice VY; Fah Tee, Kong

2017-06-01

Design of timber structures has been outlined in Eurocode 5. Notional charring rate for softwood and hardwood timber is given. For the performance of X-LAM panels in fire, only little information on charring is available and whether the fire behaviour of X-LAM is similar to homogenous timber panels has not yet been systematically analysed. This paper presents an overview of fire performance of X-LAM and evaluation of its resistance to elevated temperature as an element of structure in comparison to homogeneous timber panels. Numerical study has been carried out based on available experimental results. Charring rates for X-LAM panels obtained from experimental results are compared with those obtained from Eurocode 5 and proposed simplified model.

The thermal and mechanical properties of a low-density glass-fiber-reinforced elastomeric ablation material

NASA Technical Reports Server (NTRS)

Engelke, W. T.; Robertson, R. W.; Bush, A. L.; Pears, C. D.

1974-01-01

An evaluation of the thermal and mechanical properties was performed on a molded low-density elastomeric ablation material designated as Material B. Both the virgin and charred states were examined to provide meaningful inputs to the design of a thermal protection system. Chars representative of the flight chars formed during ablation were prepared in a laboratory furnace from 600 K to 1700 K and properties of effective thermal conductivity, heat capacity, porosity and permeability were determined on the furnace chars formed at various temperature levels within the range. This provided a boxing of the data which will enable the prediction of the transient response of the material during flight ablation.

Erosion characteristics of ethylene propylene diene monomer composite insulation by high-temperature dense particles

NASA Astrophysics Data System (ADS)

Li, Jiang; Guo, Meng-fei; Lv, Xiang; Liu, Yang; Xi, Kun; Guan, Yi-wen

2018-04-01

In this study, a dense particles erosion test motor which can simulate the erosion state of a solid rocket motor under high acceleration was developed. Subsequently, erosion experiments were carried out for the ethylene propylene diene monomer composite insulation and the microstructure of the char layer analysed. A turning point effect was found from the influence of the particle impact velocity on the ablation rate, and three erosion modes were determined according to the micro-morphology of the char layer. A reasonable explanation for the different structures of the char layer in the three modes was presented based on the formation mechanism of the compact/loose structure of the char layer.

Vision of the U.S. biofuel future: a case for hydrogen-enriched biomass gasification

Treesearch

Mark A. Dietenberger; Mark Anderson

2007-01-01

Researchers at the Forest Product Laboratory (FPL) and the University of Wisconsin-Madison (UW) envision a future for biofuels based on biomass gasification with hydrogen enrichment. Synergisms between hydrogen production and biomass gasification technologies will be necessary to avoid being marginalized in the biofuel marketplace. Five feasible engineering solutions...

76 FR 5107 - Regulation of Oil-Bearing Hazardous Secondary Materials From the Petroleum Refining Industry...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-28

... Processed in a Gasification System To Produce Synthesis Gas; Tentative Determination To Deny Petition for... Synthesis Gas,'' published in the Federal Register on January 2, 2008. The EPA considered the petition... Refining Industry Processed in a Gasification System to Produce Synthesis Gas'' (Gasification Rule). This...

Experimental Studies of Coal and Biomass Fuel Synthesis and Flame Characterization for Aircraft Engines

DTIC Science & Technology

2012-03-31

there is a need for fundamental scientific and synergistic research in catalytic biomass fast-hydropyrolysis and advanced coal gasification studies...produce appropriate aviation fuels. 15. SUBJECT TERMS Biomass fast hydropyrolysis, hydrodeoxygenation, and coal gasification 16. SECURITY...22 2.0 Investigation of Coal and Biomass Gasification using In-situ

30 CFR 206.264 - In-situ and surface gasification and liquefaction operations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false In-situ and surface gasification and... THE INTERIOR MINERALS REVENUE MANAGEMENT PRODUCT VALUATION Federal Coal § 206.264 In-situ and surface gasification and liquefaction operations. If an ad valorem Federal coal lease is developed by in-situ or...

30 CFR 1206.463 - In-situ and surface gasification and liquefaction operations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false In-situ and surface gasification and..., DEPARTMENT OF THE INTERIOR NATURAL RESOURCES REVENUE PRODUCT VALUATION Indian Coal § 1206.463 In-situ and surface gasification and liquefaction operations. If an ad valorem Federal coal lease is developed by in...

30 CFR 1206.463 - In-situ and surface gasification and liquefaction operations.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false In-situ and surface gasification and..., DEPARTMENT OF THE INTERIOR NATURAL RESOURCES REVENUE PRODUCT VALUATION Indian Coal § 1206.463 In-situ and surface gasification and liquefaction operations. If an ad valorem Federal coal lease is developed by in...

30 CFR 1206.264 - In-situ and surface gasification and liquefaction operations.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false In-situ and surface gasification and..., DEPARTMENT OF THE INTERIOR NATURAL RESOURCES REVENUE PRODUCT VALUATION Federal Coal § 1206.264 In-situ and surface gasification and liquefaction operations. If an ad valorem Federal coal lease is developed by in...

30 CFR 206.463 - In-situ and surface gasification and liquefaction operations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false In-situ and surface gasification and... THE INTERIOR MINERALS REVENUE MANAGEMENT PRODUCT VALUATION Indian Coal § 206.463 In-situ and surface gasification and liquefaction operations. If an ad valorem Federal coal lease is developed by in-situ or...

30 CFR 1206.264 - In-situ and surface gasification and liquefaction operations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false In-situ and surface gasification and... developed by in-situ or surface gasification or liquefaction technology, the lessee shall propose the value... ENFORCEMENT, DEPARTMENT OF THE INTERIOR Natural Resources Revenue PRODUCT VALUATION Federal Coal § 1206.264 In...

30 CFR 1206.264 - In-situ and surface gasification and liquefaction operations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false In-situ and surface gasification and..., DEPARTMENT OF THE INTERIOR NATURAL RESOURCES REVENUE PRODUCT VALUATION Federal Coal § 1206.264 In-situ and surface gasification and liquefaction operations. If an ad valorem Federal coal lease is developed by in...

30 CFR 1206.463 - In-situ and surface gasification and liquefaction operations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false In-situ and surface gasification and..., DEPARTMENT OF THE INTERIOR NATURAL RESOURCES REVENUE PRODUCT VALUATION Indian Coal § 1206.463 In-situ and surface gasification and liquefaction operations. If an ad valorem Federal coal lease is developed by in...

30 CFR 1206.463 - In-situ and surface gasification and liquefaction operations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false In-situ and surface gasification and... developed by in-situ or surface gasification or liquefaction technology, the lessee shall propose the value... ENFORCEMENT, DEPARTMENT OF THE INTERIOR Natural Resources Revenue PRODUCT VALUATION Indian Coal § 1206.463 In...

30 CFR 1206.264 - In-situ and surface gasification and liquefaction operations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false In-situ and surface gasification and..., DEPARTMENT OF THE INTERIOR NATURAL RESOURCES REVENUE PRODUCT VALUATION Federal Coal § 1206.264 In-situ and surface gasification and liquefaction operations. If an ad valorem Federal coal lease is developed by in...

Countercurrent fixed-bed gasification of biomass at laboratory scale

DOE Office of Scientific and Technical Information (OSTI.GOV)

Di Blasi, C.; Signorelli, G.; Portoricco, G.

1999-07-01

A laboratory-scale countercurrent fixed-bed gasification plant has been designed and constructed to produce data for process modeling and to compare the gasification characteristics of several biomasses (beechwood, nutshells, olive husks, and grape residues). The composition of producer gas and spatial temperature profiles have been measured for biomass gasification at different air flow rates. The gas-heating value always attains a maximum as a function of this operating variable, associated with a decrease of the air-to-fuel ratio. Optical gasification conditions of wood and agricultural residues give rise to comparable gas-heating values, comprised in the range 5--5.5 MJ/Nm{sup 3} with 28--30% CO, 5--7%more » CO{sub 2}, 6--8% H{sub 2}, 1--2% CH{sub 4}, and small amounts of C{sub 2}- hydrocarbons (apart from nitrogen). However, gasification of agricultural residues is more difficult because of bed transport, partial ash sintering, nonuniform flow distribution, and the presence of a muddy phase in the effluents, so that proper pretreatments are needed for largescale applications.« less

Gasification of palm empty fruit bunch in a bubbling fluidized bed: a performance and agglomeration study.

PubMed

Lahijani, Pooya; Zainal, Zainal Alimuddin

2011-01-01

Gasification of palm empty fruit bunch (EFB) was investigated in a pilot-scale air-blown fluidized bed. The effect of bed temperature (650-1050 °C) on gasification performance was studied. To explore the potential of EFB, the gasification results were compared to that of sawdust. Results showed that maximum heating values (HHV) of 5.37 and 5.88 (MJ/Nm3), dry gas yield of 2.04 and 2.0 (Nm3/kg), carbon conversion of 93% and 85 % and cold gas efficiency of 72% and 71 % were obtained for EFB and sawdust at the temperature of 1050 °C and ER of 0.25. However, it was realized that agglomeration was the major issue in EFB gasification at high temperatures. To prevent the bed agglomeration, EFB gasification was performed at temperature of 770±20 °C while the ER was varied from 0.17 to 0.32. Maximum HHV of 4.53 was obtained at ER of 0.21 where no agglomeration was observed. Copyright © 2010 Elsevier Ltd. All rights reserved.

Comparison of phosphorus recovery from incineration and gasification sewage sludge ash.

PubMed

Parés Viader, Raimon; Jensen, Pernille Erland; Ottosen, Lisbeth M; Thomsen, Tobias P; Ahrenfeldt, Jesper; Hauggaard-Nielsen, Henrik

2017-03-01

Incineration of sewage sludge is a common practice in many western countries. Gasification is an attractive option because of its high energy efficiency and flexibility in the usage of the produced gas. However, they both unavoidably produce sewage sludge ashes, a material that is rich in phosphorus, but which is commonly landfilled or used in construction materials. With current uncertainty in phosphate rock supply, phosphorus recovery from sewage sludge ashes has become interesting. In the present work, ashes from incineration and gasification of the same sewage sludge were compared in terms of phosphorus extractability using electrodialytic (ED) methods. The results show that comparable recovery rates of phosphorus were achieved with a single ED step for incineration ashes and a sequential combination of two ED steps for gasification ashes, which was due to a higher influence of iron and/or aluminium in phosphorus solubility for the latter. A product with lower level of metallic impurities and comparable to wet process phosphoric acid was eventually obtained from gasification ashes. Thus, gasification becomes an interesting alternative to incineration also in terms of phosphorus separation.

Taguchi approach for co-gasification optimization of torrefied biomass and coal.

PubMed

Chen, Wei-Hsin; Chen, Chih-Jung; Hung, Chen-I

2013-09-01

This study employs the Taguchi method to approach the optimum co-gasification operation of torrefied biomass (eucalyptus) and coal in an entrained flow gasifier. The cold gas efficiency is adopted as the performance index of co-gasification. The influences of six parameters, namely, the biomass blending ratio, oxygen-to-fuel mass ratio (O/F ratio), biomass torrefaction temperature, gasification pressure, steam-to-fuel mass ratio (S/F ratio), and inlet temperature of the carrier gas, on the performance of co-gasification are considered. The analysis of the signal-to-noise ratio suggests that the O/F ratio is the most important factor in determining the performance and the appropriate O/F ratio is 0.7. The performance is also significantly affected by biomass along with torrefaction, where a torrefaction temperature of 300°C is sufficient to upgrade eucalyptus. According to the recommended operating conditions, the values of cold gas efficiency and carbon conversion at the optimum co-gasification are 80.99% and 94.51%, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

Ab initio calculations and kinetic modeling of thermal conversion of methyl chloride: implications for gasification of biomass.

PubMed

Singla, Mallika; Rasmussen, Morten Lund; Hashemi, Hamid; Wu, Hao; Glarborg, Peter; Pelucchi, Matteo; Faravelli, Tiziano; Marshall, Paul

2018-04-25

Limitations in current hot gas cleaning methods for chlorine species from biomass gasification may be a challenge for end use such as gas turbines, engines, and fuel cells, all requiring very low levels of chlorine. During devolatilization of biomass, chlorine is released partly as methyl chloride. In the present work, the thermal conversion of CH3Cl under gasification conditions was investigated. A detailed chemical kinetic model for pyrolysis and oxidation of methyl chloride was developed and validated against selected experimental data from the literature. Key reactions of CH2Cl with O2 and C2H4 for which data are scarce were studied by ab initio methods. The model was used to analyze the fate of methyl chloride in gasification processes. The results indicate that CH3Cl emissions will be negligible for most gasification technologies, but could be a concern for fluidized bed gasifiers, in particular in low-temperature gasification. The present work illustrates how ab initio theory and chemical kinetic modeling can help to resolve emission issues for thermal processes in industrial scale.

Dwarf char, a new form of chars (the genus Salvelinus) in Lake Kronotskoe

USGS Publications Warehouse

Pavlov, S.D.; Pivovarov, E.A.; Ostberg, C.O.

2012-01-01

Lake Kronotskoe is situated in the Kronotskii State Nature Reserve and is a unique natural heritage of Kamchatka. The lake–river system of the reserve includes numerous springs and small streams and three large inflowing rivers, Listvennichnaya, Unana, and Uzon, which form the main bays of Lake Kronotskoe; one river (Kronotskaya) flows from the lake. This river is characterized by several rapids, which are assumed to be unsurmountable barriers for fish migration. The ichthyofauna of the lake has been isolated for a long time, and some endemic fishes appeared, including char of the genus Salvelinus and the residential form of red salmon Oncorhynchus nerka (the local name is kokanee). These species are perfect model objects to study microevolution processes. Char of Lake Kronotskoe are characterized by significant polymorphism and plasticity [1–3]; therefore, they are extremely valuable for studying the processes of speciation and form development. That is why the populations of char in Lake Kronotskoe are unique and attract special attention of researchers. 

Short-term effects of triiodothyronine on the bowfin, Amia calva (Holostei), and the lake char, Salvelinus namaycush (Teleostei).

PubMed

Ballantyne, J S; John, T M; Singer, T D; Oommen, O V

1992-01-01

To assess the role of triiodothyronine (T3) in mediating short-term changes in metabolism, such as those occurring in circadian patterns, we examined the effects of intraperitoneal injection of T3 on the oxidation of substrates by isolated mitochondria from liver of the bowfin, Amia calva, and red muscle and liver of the lake char, Salvelinus namaycush. Selected enzymes were measured in red muscle and liver of the lake char. Three hours after intraperitoneal injection of T3, oxidation of some substrates by mitochondria isolated from the liver of the bowfin was reduced. Similar treatment had no effect on substrate oxidation in liver mitochondria isolated from lake char. Oxidation of substrates by lake char red muscle mitochondria was stimulated by T3 injection. Citrate synthase levels were increased in red muscle suggesting that changes in enzyme activity may be in part responsible for the short-term mitochondrial responses to T3 injection.

Low levels of hybridization between sympatric Arctic char (Salvelinus alpinus) and Dolly Varden char (Salvelinus malma) highlights their genetic distinctiveness and ecological segregation.

PubMed

May-McNally, Shannan L; Quinn, Thomas P; Taylor, Eric B

2015-08-01

Understanding the extent of interspecific hybridization and how ecological segregation may influence hybridization requires comprehensively sampling different habitats over a range of life history stages. Arctic char (Salvelinus alpinus) and Dolly Varden (S. malma) are recently diverged salmonid fishes that come into contact in several areas of the North Pacific where they occasionally hybridize. To better quantify the degree of hybridization and ecological segregation between these taxa, we sampled over 700 fish from multiple lake (littoral and profundal) and stream sites in two large, interconnected southwestern Alaskan lakes. Individuals were genotyped at 12 microsatellite markers, and genetic admixture (Q) values generated through Bayesian-based clustering revealed hybridization levels generally lower than reported in a previous study (<0.6% to 5% of samples classified as late-generation hybrids). Dolly Varden and Arctic char tended to make different use of stream habitats with the latter apparently abandoning streams for lake habitats after 2-3 years of age. Our results support the distinct biological species status of Dolly Varden and Arctic char and suggest that ecological segregation may be an important factor limiting opportunities for hybridization and/or the ecological performance of hybrid char.

Low levels of hybridization between sympatric Arctic char (Salvelinus alpinus) and Dolly Varden char (Salvelinus malma) highlights their genetic distinctiveness and ecological segregation

PubMed Central

May-McNally, Shannan L; Quinn, Thomas P; Taylor, Eric B

2015-01-01

Understanding the extent of interspecific hybridization and how ecological segregation may influence hybridization requires comprehensively sampling different habitats over a range of life history stages. Arctic char (Salvelinus alpinus) and Dolly Varden (S. malma) are recently diverged salmonid fishes that come into contact in several areas of the North Pacific where they occasionally hybridize. To better quantify the degree of hybridization and ecological segregation between these taxa, we sampled over 700 fish from multiple lake (littoral and profundal) and stream sites in two large, interconnected southwestern Alaskan lakes. Individuals were genotyped at 12 microsatellite markers, and genetic admixture (Q) values generated through Bayesian-based clustering revealed hybridization levels generally lower than reported in a previous study (<0.6% to 5% of samples classified as late-generation hybrids). Dolly Varden and Arctic char tended to make different use of stream habitats with the latter apparently abandoning streams for lake habitats after 2–3 years of age. Our results support the distinct biological species status of Dolly Varden and Arctic char and suggest that ecological segregation may be an important factor limiting opportunities for hybridization and/or the ecological performance of hybrid char. PMID:26356310

Basic study of charring detection at the laser catheter-tip using back scattering light measurement during therapeutic laser irradiation in blood.

PubMed

Takahashi, Mei; Ito, Arisa; Kajihara, Takuro; Matsuo, Hiroki; Arai, Tsunenori

2010-01-01

The purpose of this study is to investigate transient process of the charring at the laser catheter-tip in blood during therapeutic laser irradiation by the back scattering light measurement to detect precursor state of the charring. We took account of using photodynamic therapy for arrhythmia in blood through the laser catheter. We observed the influence of the red laser irradiation (λ=663 nm) upon the shape of red blood cells (RBCs). The RBCs aggregation, round formation, and hemolysis were took place sequentially before charring. With a model blood sandwiched between glass plates simulated as a catheter-tip boundary, we measured diffuse-reflected-light power and transmitted-light power simultaneously and continuously by a microscopic optics during the laser irradiation. We found that measured light power changes were originated with RBCs shape change induced by temperature rise due to the laser irradiation. A gentle peak following a slow descending was observed in the diffuse-reflected-light power history. This history might indicate the precursor state of the charring, in which the hemolysis might be considered to advance rapidly. We think that the measurement of diffuse-reflected-light power history might be able to detect precursor state of charring at the catheter-tip in blood.

Temperature influence on the fast pyrolysis of manure samples: char, bio-oil and gases production

NASA Astrophysics Data System (ADS)

Fernandez-Lopez, Maria; Anastasakis, Kostas; De Jong, Wiebren; Valverde, Jose Luis; Sanchez-Silva, Luz

2017-11-01

Fast pyrolysis characterization of three dry manure samples was studied using a pyrolyzer. A heating rate of 600°C/s and a holding time of 10 s were selected to reproduce industrial conditions. The effect of the peak pyrolysis temperature (600, 800 and 1000°C) on the pyrolysis product yield and composition was evaluated. Char and bio-oil were gravimetrically quantified. Scanning electron microscopy (SEM) was used to analyse the char structure. H2, CH4, CO and CO2 were measured by means of gas chromatography (GC). A decrease in the char yield and an increase of the gas yield were observed when temperature increased. From 800°C on, it was observed that the char yield of samples Dig R and SW were constant, which indicated that the primary devolatilization reactions stopped. This fact was also corroborated by GC analysis. The bio-oil yield slightly increased with temperature, showing a maximum of 20.7 and 27.8 wt.% for samples Pre and SW, respectively, whereas sample Dig R showed a maximum yield of 16.5 wt.% at 800°C. CO2 and CO were the main released gases whereas H2 and CH4 production increased with temperature. Finally, an increase of char porosity was observed with temperature.

Gas processing handbook

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1982-04-01

Brief details are given of processes including: BGC-Lurgi slagging gasification, COGAS, Exxon catalytic coal gasification, FW-Stoic 2-stage, GI two stage, HYGAS, Koppers-Totzek, Lurgi pressure gasification, Saarberg-Otto, Shell, Texaco, U-Gas, W-D.IGI, Wellman-Galusha, Westinghouse, and Winkler coal gasification processes; the Rectisol process; the Catacarb and the Benfield processes for removing CO/SUB/2, H/SUB/2s and COS from gases produced by the partial oxidation of coal; the selectamine DD, Selexol solvent, and Sulfinol gas cleaning processes; the sulphur-tolerant shift (SSK) process; and the Super-meth process for the production of high-Btu gas from synthesis gas.

Method and system for controlling a gasification or partial oxidation process

DOEpatents

Rozelle, Peter L; Der, Victor K

2015-02-10

A method and system for controlling a fuel gasification system includes optimizing a conversion of solid components in the fuel to gaseous fuel components, controlling the flux of solids entrained in the product gas through equipment downstream of the gasifier, and maximizing the overall efficiencies of processes utilizing gasification. A combination of models, when utilized together, can be integrated with existing plant control systems and operating procedures and employed to develop new control systems and operating procedures. Such an approach is further applicable to gasification systems that utilize both dry feed and slurry feed.

Integration of stripping of fines slurry in a coking and gasification process

DOEpatents

DeGeorge, Charles W.

1980-01-01

In an integrated fluid coking and gasification process wherein a stream of fluidized solids is passed from a fluidized bed coking zone to a second fluidized bed and wherein entrained solid fines are recovered by a wet scrubbing process and wherein the resulting solids-liquid slurry is stripped to remove acidic gases, the stripped vapors of the stripping zone are sent to the gas cleanup stage of the gasification product gas. The improved stripping integration is particularly useful in the combination coal liquefaction process, fluid coking of bottoms of the coal liquefaction zone and gasification of the product coke.

Fluidized-bed catalytic coal-gasification process. [US patent; pretreatment to minimize agglomeration

DOEpatents

Euker, C.A. Jr.; Wesselhoft, R.D.; Dunkleman, J.J.; Aquino, D.C.; Gouker, T.R.

1981-09-14

Coal or similar carbonaceous solids impregnated with gasification catalyst constituents are oxidized by contact with a gas containing between 2 vol % and 21 vol % oxygen at a temperature between 50 and 250/sup 0/C in an oxidation zone and the resultant oxidized, catalyst impregnated solids are then gasified in a fluidized bed gasification zone at an elevated pressure. The oxidation of the catalyst impregnated solids under these conditions insures that the bed density in the fluidized bed gasification zone will be relatively high even though the solids are gasified at elevated pressure and temperature.

Studying the specific features pertinent to combustion of chars obtained from coals having different degrees of metamorphism and biomass chars

NASA Astrophysics Data System (ADS)

Bestsennyi, I. V.; Shchudlo, T. S.; Dunaevskaya, N. I.; Topal, A. I.

2013-12-01

Better conditions for igniting low-reaction coal (anthracite) can be obtained, higher fuel burnout ratio can be achieved, and the problem of shortage of a certain grade of coal can be solved by firing coal mixtures and by combusting coal jointly with solid biomass in coal-fired boilers. Results from studying the synergetic effect that had been revealed previously during the combustion of coal mixtures in flames are presented. A similar effect was also obtained during joint combustion of coal and wood in a flame. The kinetics pertinent to combustion of char mixtures obtained from coals characterized by different degrees of metamorphism and the kinetics pertinent to combustion of wood chars were studied on the RSK-1D laboratory setup. It was found from the experiments that the combustion rate of char mixtures obtained from coals having close degrees of metamorphism is equal to the value determined as a weighted mean rate with respect to the content of carbon. The combustion rate of char mixtures obtained from coals having essentially different degrees of metamorphism is close to the combustion rate of more reactive coal initially in the process and to the combustion rate of less reactive coal at the end of the process. A dependence of the specific burnout rate of carbon contained in the char of two wood fractions on reciprocal temperature in the range 663—833 K is obtained. The combustion mode of an experimental sample is determined together with the reaction rate constant and activation energy.

The potential applications of using compost chars for removing the hydrophobic herbicide atrazine from solution

USGS Publications Warehouse

Tsui, L.; Roy, W.R.

2008-01-01

One commercial compost sample was pyrolyzed to produce chars as a sorbent for removing the herbicide atrazine from solution. The sorption behavior of compost-based char was compared with that of an activated carbon derived from corn stillage. When compost was pyrolyzed, the char yield was greater than 45% when heated under air, and 52% when heated under N2. In contrast, when the corn stillage was pyrolyzed under N2, the yield was only 22%. The N2-BET surface area of corn stillage activated carbon was 439 m2/g, which was much greater than the maximum compost char surface area of 72 m2/g. However, the sorption affinity of the compost char for dissolved atrazine was comparable to that of the corn stillage activated carbon. This similarity could have resulted from the initial organic waste being subjected to a relatively long period of thermal processes during composting, and thus, the compost was more thermally stable when compared with the raw materials. In addition, microorganisms transformed the organic wastes into amorphous humic substances, and thus, it was likely that the microporisity was enhanced. Although this micropore structure could not be detected by the N2-BET method, it was apparent in the atrazine sorption experiment. Overall, the experimental results suggested that the compost sample in current study was a relatively stable material thermally for producing char, and that it has the potential as a feed stock for making high-quality activated carbon. ?? 2007 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Gulf Research and Development Company is implementing a DOE-sponsored Underground Coal Gasification project in Steeply Dipping Coal Beds (UCG/SDB) in order to assess the economic and technical viability of UCG in SDB. In the Fall 1980 drilling program, 2 vertical and 2 slant process wells; 3 hydrologic and 1 exploratory well and 4 HFEM wells were completed. The Spring, 1981 program will consist of drilling the remaining instrumentation wells necessary to track the progress of the underground reactor in real time. These will consist of: 6 additional High Frequency Electromagnetic wells (HFEM) and 3 extensometer wells (X). These wells willmore » be installed vertically with an expected deviation of two degrees or less.« less

Cow bones char as a green sorbent for fluorides removal from aqueous solutions: batch and fixed-bed studies.

PubMed

Nigri, Elbert M; Cechinel, Maria Alice P; Mayer, Diego A; Mazur, Luciana P; Loureiro, José M; Rocha, Sônia D F; Vilar, Vítor J P

2017-01-01

Cow bone char was investigated as sorbent for the defluoridation of aqueous solutions. The cow bone char was characterized in terms of its morphology, chemical composition, and functional groups present on the bone char surface using different analytical techniques: SEM, EDS, N 2 -BET method, and FTIR. Batch equilibrium studies were performed for the bone chars prepared using different procedures. The highest sorption capacities for fluoride were obtained for the acid washed (q = 6.2 ± 0.5 mg/g) and Al-doped (q = 6.4 ± 0.3 mg/g) bone chars. Langmuir and Freundlich models fitted well the equilibrium sorption data. Fluoride removal rate in batch system is fast in the first 5 h, decreasing after this time until achieving equilibrium due to pore diffusion. The presence of carbonate and bicarbonate ions in the aqueous solution contributes to a decrease of the fluoride sorption capacity of the bone char by 79 and 31 %, respectively. Regeneration of the F-loaded bone char using 0.5 M NaOH solution leads to a sorption capacity for fluoride of 3.1 mg/g in the second loading cycle. Fluoride breakthrough curve obtained in a fixed-bed column presents an asymmetrical S-shaped form, with a slow approach of C/C 0  → 1.0 due to pore diffusion phenomena. Considering the guideline value for drinking water of 1.5 mg F - /L, as recommended by World Health Organization, the service cycle for fluoride removal was of 71.0 h ([F - ] feed  ∼ 9 mg/L; flow rate = 1 mL/min; m sorbent  = 12.6 g). A mass transfer model considering the pore diffusion was able to satisfactorily describe the experimental data obtained in batch and continuous systems.

Investigation of Coal-biomass Catalytic Gasification using Experiments, Reaction Kinetics and Computational Fluid Dynamics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Battaglia, Francine; Agblevor, Foster; Klein, Michael

A collaborative effort involving experiments, kinetic modeling, and computational fluid dynamics (CFD) was used to understand co-gasification of coal-biomass mixtures. The overall goal of the work was to determine the key reactive properties for coal-biomass mixed fuels. Sub-bituminous coal was mixed with biomass feedstocks to determine the fluidization and gasification characteristics of hybrid poplar wood, switchgrass and corn stover. It was found that corn stover and poplar wood were the best feedstocks to use with coal. The novel approach of this project was the use of a red mud catalyst to improve gasification and lower gasification temperatures. An important resultsmore » was the reduction of agglomeration of the biomass using the catalyst. An outcome of this work was the characterization of the chemical kinetics and reaction mechanisms of the co-gasification fuels, and the development of a set of models that can be integrated into other modeling environments. The multiphase flow code, MFIX, was used to simulate and predict the hydrodynamics and co-gasification, and results were validated with the experiments. The reaction kinetics modeling was used to develop a smaller set of reactions for tractable CFD calculations that represented the experiments. Finally, an efficient tool was developed, MCHARS, and coupled with MFIX to efficiently simulate the complex reaction kinetics.« less

Gasification Characteristics and Kinetics of Coke with Chlorine Addition

NASA Astrophysics Data System (ADS)

Wang, Cui; Zhang, Jianliang; Jiao, Kexin; Liu, Zhengjian; Chou, Kuochih

2017-10-01

The gasification process of metallurgical coke with 0, 1.122, 3.190, and 7.132 wt pct chlorine was investigated through thermogravimetric method from ambient temperature to 1593 K (1320 °C) in purified CO2 atmosphere. The variations in the temperature parameters that T i decreases gradually with increasing chlorine, T f and T max first decrease and then increase, but both in a downward trend indicated that the coke gasification process was catalyzed by the chlorine addition. Then the kinetic model of the chlorine-containing coke gasification was obtained through the advanced determination of the average apparent activation energy, the optimal reaction model, and the pre-exponential factor. The average apparent activation energies were 182.962, 118.525, 139.632, and 111.953 kJ/mol, respectively, which were in the same decreasing trend with the temperature parameters analyzed by the thermogravimetric method. It was also demonstrated that the coke gasification process was catalyzed by chlorine. The optimal kinetic model to describe the gasification process of chlorine-containing coke was the Šesták Berggren model using Málek's method, and the pre-exponential factors were 6.688 × 105, 2.786 × 103, 1.782 × 104, and 1.324 × 103 min-1, respectively. The predictions of chlorine-containing coke gasification from the Šesták Berggren model were well fitted with the experimental data.

Gasification: A Cornerstone Technology

ScienceCinema

Gary Stiegel

2017-12-09

NETL is a leader in the science and technology of gasification - a process for the conversion of carbon-based materials such as coal into synthesis gas (syngas) that can be used to produce clean electrical energy, transportation fuels, and chemicals efficiently and cost-effectively using domestic fuel resources. Gasification is a cornerstone technology of 21st century zero emissions powerplants

New projects for CCGTs with coal gasification (Review)

NASA Astrophysics Data System (ADS)

Olkhovskii, G. G.

2016-10-01

Perspectives of using coal in combined-cycle gas turbine units (CCGTs), which are significantly more efficient than steam power plants, have been associated with preliminary coal gasification for a long time. Due to gasification, purification, and burning the resulting synthesis gas at an increased pressure, there is a possibility to intensify the processes occurring in them and reduce the size and mass of equipment. Physical heat evolving from gasification can be used without problems in the steam circuit of a CCGT. The downside of these opportunities is that the unit becomes more complex and expensive, and its competitiveness is affected, which was not achieved for CCGT power plants with coal gasification built in the 1990s. In recent years, based on the experience with these CCGTs, several powerful CCGTs of the next generation, which used higher-output and cost-effective gas-turbine plants (GTPs) and more advanced systems of gasification and purification of synthesis gas, were either built or designed. In a number of cases, the system of gasification includes devices of CO vapor reforming and removal of the emitted CO2 at a high pressure prior to fuel combustion. Gasifiers with air injection instead of oxygen injection, which is common in coal chemistry, also find application. In this case, the specific cost of the power station considerably decreases (by 15% and more). In units with air injection, up to 40% air required for separation is drawn from the intermediate stage of the cycle compressor. The range of gasified coals has broadened. In order to gasify lignites in one of the projects, a transfer reactor was used. The specific cost of a CCGT with coal gasification rose in comparison with the period when such units started being designed, from 3000 up to 5500 dollars/kW.

Imperium/Lanzatech Syngas Fermentation Project - Biomass Gasification and Syngas Conditioning for Fermentation Evaluation: Cooperative Research and Development Final Report, CRADA Number CRD-12-474

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilcox, E.

2014-09-01

LanzaTech and NREL will investigate the integration between biomass gasification and LanzaTech's proprietary gas fermentation process to produce ethanol and 2,3-butanediol. Using three feed materials (woody biomass, agricultural residue and herbaceous grass) NREL will produce syngas via steam indirect gasification and syngas conditioning over a range of process relevant operating conditions. The gasification temperature, steam-to-biomass ratio of the biomass feed into the gasifier, and several levels of syngas conditioning (based on temperature) will be varied to produce multiple syngas streams that will be fed directly to 10 liter seed fermenters operating with the Lanzatech organism. The NREL gasification system willmore » then be integrated with LanzaTech's laboratory pilot unit to produce large-scale samples of ethanol and 2,3-butanediol for conversion to fuels and chemicals.« less

User Interface to an ICAI System That Teaches Discrete Math

DTIC Science & Technology

1990-06-01

lesson; otherwise, returns the user to the lesson. */ if (!frornlsn) menudeino); else exit((); 90 FUNCTION . flashcards CALLED BY: tools CALLS...char opchar[5j; /* OR, AND, IMPLIES or 1FF * char anchar[5J: /* User’s response: Either TRUE or FALSE * char outputch[ 15]; /* Flashcard that is...y values for the user’s screen. */ maxx = getmaxxo ; maxy = getmaxyo ; /* Sets the coordinates for the flashcard . */ left = maxx/6 right = maxx* 5/6

Experimental Studies of Coal and Biomass Fuel Synthesis and Flame Characterization for Aircraft Engines (Year Two)

DTIC Science & Technology

2011-03-31

2.1 Experimental Investigation of Coal and Biomass Gasification using In-situ Diagnostics ................ 31  2.2 References...need for fundamental scientific and synergistic research in catalytic biomass fast-hydropyrolysis, advanced coal gasification and liquid fuel...experimental findings will improve the scientific knowledge of catalytic biomass fast-hydropyrolysis, coal/ biomass gasification and liquid fuel combustion

Report of the DOD-DOE Workshop on Converting Waste to Energy Using Fuel Cells

DTIC Science & Technology

2011-10-01

for both at current costs, when federal and state incentives are available • The integration of stationary fuel cells with biomass gasification is a... gasification plant utilizing biomass feedstock. 25 FuelCell Energy Market Research, January 2011...cell WTE opportunities near U.S. Department of Energy (DOE)-supported coal gasification sites. • Identify biomass -rich DOD installations

Coal conversion processes and analysis methodologies for synthetic fuels production. [technology assessment and economic analysis of reactor design for coal gasification

NASA Technical Reports Server (NTRS)

1979-01-01

Information to identify viable coal gasification and utilization technologies is presented. Analysis capabilities required to support design and implementation of coal based synthetic fuels complexes are identified. The potential market in the Southeast United States for coal based synthetic fuels is investigated. A requirements analysis to identify the types of modeling and analysis capabilities required to conduct and monitor coal gasification project designs is discussed. Models and methodologies to satisfy these requirements are identified and evaluated, and recommendations are developed. Requirements for development of technology and data needed to improve gasification feasibility and economies are examined.

Apparatus for fixed bed coal gasification

DOEpatents

Sadowski, Richard S.

1992-01-01

An apparatus for fixed-bed coal gasification is described in which coal such as caking coal is continuously pyrolyzed with clump formation inhibited, by combining the coal with a combustible gas and an oxidant, and then continually feeding the pyrolyzed coal under pressure and elevated temperature into the gasification region of a pressure vessel. The materials in the pressure vessel are allowed to react with the gasifying agents in order to allow the carbon contents of the pyrolyzed coal to be completely oxidized. The combustion of gas produced from the combination of coal pyrolysis and gasification involves combining a combustible gas coal and an oxidant in a pyrolysis chamber and heating the components to a temperature of at least 1600.degree. F. The products of coal pyrolysis are dispersed from the pyrolyzer directly into the high temperature gasification region of a pressure vessel. Steam and air needed for gasification are introduced in the pressure vessel and the materials exiting the pyrolyzer flow down through the pressure vessel by gravity with sufficient residence time to allow any carbon to form carbon monoxide. Gas produced from these reactions are then released from the pressure vessel and ash is disposed of.

A Slag Management Toolset for Determining Optimal Coal Gasification Temperatures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kwong, Kyei-Sing; Bennett, James P.

Abstract Gasifier operation is an intricate process because of the complex relationship between slag chemistry and temperature, limitations of feedstock materials, and operational preference. High gasification temperatures increase refractory degradation, while low gasification temperatures can lead to slag buildup on the gasifier sidewall or exit, either of which are problematic during operation. Maximizing refractory service life and gasifier performance require finding an optimized operating temperature range which is a function of the coal slag chemistry and viscosity. Gasifier operators typically use a slag’s viscosity-temperature relationship and/or ash-fusion fluid temperature to determine the gasification temperature range. NETL has built a slagmore » management toolset to determine the optimal temperature range for gasification of a carbon feedstock. This toolset is based on a viscosity database containing experimental data, and a number of models used to predict slag viscosity as a function of composition and temperature. Gasifier users typically have no scientific basis for selecting an operational temperature range for gasification, instead using experience to select operational conditions. The use of the toolset presented in this paper provides a basis for estimating or modifying carbon feedstock slags generated from ash impurities in carbon feedstock.« less

Gaseous fuels production from dried sewage sludge via air gasification.

PubMed

Werle, Sebastian; Dudziak, Mariusz

2014-07-01

Gasification is a perspective alternative method of dried sewage sludge thermal treatment. For the purpose of experimental investigations, a laboratory fixed-bed gasifier installation was designed and built. Two sewage sludge (SS) feedstocks, taken from two typical Polish wastewater treatment systems, were analysed: SS1, from a mechanical-biological wastewater treatment system with anaerobic stabilization (fermentation) and high temperature drying; and (SS2) from a mechanical-biological-chemical wastewater treatment system with fermentation and low temperature drying. The gasification results show that greater oxygen content in sewage sludge has a strong influence on the properties of the produced gas. Increasing the air flow caused a decrease in the heating value of the produced gas. Higher hydrogen content in the sewage sludge (from SS1) affected the produced gas composition, which was characterized by high concentrations of combustible components. In the case of the SS1 gasification, ash, charcoal, and tar were produced as byproducts. In the case of SS2 gasification, only ash and tar were produced. SS1 and solid byproducts from its gasification (ash and charcoal) were characterized by lower toxicity in comparison to SS2. However, in all analysed cases, tar samples were toxic. © The Author(s) 2014.

A Slag Management Toolset for Determining Optimal Coal Gasification Temperatures

DOE PAGES

Kwong, Kyei-Sing; Bennett, James P.

2016-11-25

Abstract Gasifier operation is an intricate process because of the complex relationship between slag chemistry and temperature, limitations of feedstock materials, and operational preference. High gasification temperatures increase refractory degradation, while low gasification temperatures can lead to slag buildup on the gasifier sidewall or exit, either of which are problematic during operation. Maximizing refractory service life and gasifier performance require finding an optimized operating temperature range which is a function of the coal slag chemistry and viscosity. Gasifier operators typically use a slag’s viscosity-temperature relationship and/or ash-fusion fluid temperature to determine the gasification temperature range. NETL has built a slagmore » management toolset to determine the optimal temperature range for gasification of a carbon feedstock. This toolset is based on a viscosity database containing experimental data, and a number of models used to predict slag viscosity as a function of composition and temperature. Gasifier users typically have no scientific basis for selecting an operational temperature range for gasification, instead using experience to select operational conditions. The use of the toolset presented in this paper provides a basis for estimating or modifying carbon feedstock slags generated from ash impurities in carbon feedstock.« less

Experimental study of biomass gasification with oxygen-enriched air in fluidized bed gasifier.

PubMed

Liu, Lingqin; Huang, Yaji; Cao, Jianhua; Liu, Changqi; Dong, Lu; Xu, Ligang; Zha, Jianrui

2018-06-01

Considering the universality, renewability and cleanness of biomass, an experimental research is carried out using rice straw in a two-stage fluidized bed. The experimental analysis identified the relevant parameters in the operation of the two-stage fluidized bed to investigate the properties of biomass enriched air gasification. Results show that higher gasification temperature is conducive to enhance the gasification performance. An increasing ER is shown to go against adding gas heat value. When oxygen concentration increases from 21% to 45%, the gas heating value increases from 4.00MJ/kg to 5.24MJ/kg and the gasification efficiency increases from 29.60% to 33.59%, which shows higher oxygen concentration is conducive to higher quality gas and higher gasification efficiency. A secondary oxygen injection leads to reduction of tar concentration from 15.78g/Nm 3 to 10.24g/Nm 3 . The optimal secondary oxygen ratio is about 33.00%. When the secondary oxygen ratio increased to 46.86%, monocyclic aromatics reduced from 28.17% to 19.65% and PAHs increased from 34.97% to 44.05%, leading to the increase aromatization of tar. Copyright © 2018 Elsevier B.V. All rights reserved.

Biochemical stability of sewage sludge chars and their impact on soil organic matter of a Mediterranean Cambisol

NASA Astrophysics Data System (ADS)

Paneque, Marina; María De la Rosa, José; Aragón, Carlos; Kern, Jürgen; Knicker, Heike

2016-04-01

Transformation of sewage sludge (SS) into char achieves sludge hygienisation, which is necessary prior its application into agricultural soils. The pyrolysis of SS increases its stability in a degree which depends on the thermal treatment used. Thus, chars produced by using hydrothermal carbonization are typically more stable than normal soil organic matter (SOM), but less stable than chars from dry pyrolysis (Libra et al., 2011). Addition of highly-recalcitrant SS-chars to soil will likely increase its carbon sequestration potential; however the fertilizing properties of SS may be compromised due to its alteration during the pyrolysis. The main goal of this work was to investigate the biochemical recalcitrance of two 13C-enriched SS-chars once applied in a Mediterranean Cambisol as well as to evaluate their impact on the SOM quality and carbon stability. Thus, we studied the distribution of 13C between plants and soil after the addition of the 13C-enriched chars (2 atm%) to the soil. Therefore, we performed a greenhouse incubation experiment, using a Mediterranean Cambisol as matrix and tested the following treatments: control (soil alone), raw SS, SS-hydrochar, SS-pyrochar. The SS was produced in a pilot-scale waste-water plant and enriched with 13C by the addition of 13C-glucose during the treatment. The amendment was only applied to the upper 2 cm of the soil matrix where it accounted for 5% of its dry weight. Per pot, 25 seeds of Lolium perenne were sowed and incubated under controlled conditions. The biomass production as well as the concentration of 13C in leaves and roots was determined after 1, 2 and 5 months. The partitioning of the 13C between soil and plant and its transformation into bioavailable forms were monitored by stable isotopic mass spectrometry. The 13C-enrichment of the chars allowed the use of solid-state 13C NMR spectroscopy as a means for the detection of chemical alterations of the chars during their aging. Libra J., Ro K., Kammann C., Funke A., Berge N., Neubauer Y., Titirici M., Fuhner C., Bens O., Kern J., Emmerich K. (2011) Hydrothermal carbonization of biomass residuals: a comparative review of the chemistry, processes and applications of wet and dry pyrolysis. Biofuels, 2 (1), 89-124.

Acidification with nitric acid improves chemical characteristics and reduces phytotoxicity of alkaline chars.

PubMed

Fornes, Fernando; Belda, Rosa Maria

2017-04-15

Charred organic matter is recently receiving attention for its potential use as soilless growth medium. However, depending on its origin and on the manufacturing technology, it can result toxic for plants. This fact implies that a detoxifying treatment ought to be devised in order to reclaim char in this way. We have studied three materials which combine these factors: two pyrolyzed biochars, one from forest waste (BCH-FW) and another from olive mill waste (BCH-OMW), and one hydrothermally carbonized hydrochar from forest waste (HYD-FW). These materials are suspicious of phytotoxicity due to their high pH, high salinity, or presence of organic toxics. For these new materials, it is mandatory to select fast and reliable bioassays to predict their potential phytotoxicity. In order to achieve this goal water extracts of the three chars were subjected to bioassays of seed germination and bioassays of seedling growth in hydroponic conditions. The biochar from olive mill waste and the hydrochar, but not the biochar from forest waste, showed considerable phytotoxicity as seed germination and plant growth were negatively affected (e.g. BCH-OMW reduced seed germination by 80% and caused early seedling death). In order to adjust pH and electrical conductivity for plant growth, treatments of acidification and salt leaching with optimal diluted HNO 3 solutions (0.3 N, 0.2 N, and 0.75 N for BCH-OMW, BCH-FW, and HYD-FW, respectively) as calculated from titration curves, were conducted. The acid treatment reduced electrical conductivity in BCH-OMW (from 9.2 to 4.5 dS m -1 ), pH (maximum in BCH-FW from 9.6 to 6.2) and water soluble carbonaceous compounds (maximum in HYD-FW from 5969 to 2145 mg kg -1 ) in the three chars, and increased N content (maximum in BCH-OMW from 50 to 6342 mg kg -1 ) in the three chars. Bioassays on acid-treated chars demonstrated the absence of phytotoxicity and even stimulation of seedling growth over the control (increase of 86% and 56% for BCH-FW and HYD-FW, respectively). We conclude that acidification of chars with diluted HNO 3 is a viable technique to conform chars to standards for plant growth purposes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Understanding how lake populations of arctic char are structured and function with special consideration of the potential effects of climate change: a multi-faceted approach.

PubMed

Budy, Phaedra; Luecke, Chris

2014-09-01

Size dimorphism in fish populations, both its causes and consequences, has been an area of considerable focus; however, uncertainty remains whether size dimorphism is dynamic or stabilizing and about the role of exogenous factors. Here, we explored patterns among empirical vital rates, population structure, abundance and trend, and predicted the effects of climate change on populations of arctic char (Salvelinus alpinus) in two lakes. Both populations cycle dramatically between dominance by small (≤300 mm) and large (>300 mm) char. Apparent survival (Φ) and specific growth rates (SGR) were relatively high (40-96%; SGR range 0.03-1.5%) and comparable to those of conspecifics at lower latitudes. Climate change scenarios mimicked observed patterns of warming and resulted in temperatures closer to optimal for char growth (15.15 °C) and a longer growing season. An increase in consumption rates (28-34%) under climate change scenarios led to much greater growth rates (23-34%). Higher growth rates predicted under climate change resulted in an even greater predicted amplitude of cycles in population structure as well as an increase in reproductive output (Ro) and decrease in generation time (Go). Collectively, these results indicate arctic char populations (not just individuals) are extremely sensitive to small changes in the number of ice-free days. We hypothesize years with a longer growing season, predicted to occur more often under climate change, produce elevated growth rates of small char and act in a manner similar to a "resource pulse," allowing a sub-set of small char to "break through," thus setting the cycle in population structure.

Understanding how lake populations of arctic char are structured and function with special consideration of the potential effects of climate change: A multi-faceted approach.

USGS Publications Warehouse

Budy, Phaedra; Luecke, Chris

2014-01-01

Size dimorphism in fish populations, both its causes and consequences, has been an area of considerable focus; however, uncertainty remains whether size dimorphism is dynamic or stabilizing and about the role of exogenous factors. Here, we explored patterns among empirical vital rates, population structure, abundance and trend, and predicted the effects of climate change on populations of arctic char (Salvelinus alpinus) in two lakes. Both populations cycle dramatically between dominance by small (≤300 mm) and large (>300 mm) char. Apparent survival (Φ) and specific growth rates (SGR) were relatively high (40–96 %; SGR range 0.03–1.5 %) and comparable to those of conspecifics at lower latitudes. Climate change scenarios mimicked observed patterns of warming and resulted in temperatures closer to optimal for char growth (15.15 °C) and a longer growing season. An increase in consumption rates (28–34 %) under climate change scenarios led to much greater growth rates (23–34 %). Higher growth rates predicted under climate change resulted in an even greater predicted amplitude of cycles in population structure as well as an increase in reproductive output (Ro) and decrease in generation time (Go). Collectively, these results indicate arctic char populations (not just individuals) are extremely sensitive to small changes in the number of ice-free days. We hypothesize years with a longer growing season, predicted to occur more often under climate change, produce elevated growth rates of small char and act in a manner similar to a “resource pulse,” allowing a sub-set of small char to “break through,” thus setting the cycle in population structure.

Stronger association of polycyclic aromatic hydrocarbons with soot than with char in soils and sediments

PubMed Central

Han, Y.M.; Bandowe, B.A.M.; Wei, C.; Cao, J.J.; Wilcke, W.; Wang, G.H.; Ni, H.Y.; Jin, Z.D.; An, Z.S.; Yan, B.Z.

2016-01-01

The knowledge of the association of polycyclic aromatic hydrocarbons (PAHs) with organic matter and carbonaceous materials is critical for a better understanding of their environmental transport, fate, and toxicological effects. Extensive studies have been done with regard to the relationship of PAHs with total organic carbon (TOC) and elemental carbon (EC) in different environmental matrices. The relationship between PAHs and the two subtypes of EC, char (combustion residues) and soot (produced via gas-to-particle conversion) also has been tested in field and laboratory experiments using reference materials. However, a direct comparison of associations of PAHs between with char and with soot in real environmental matrices has to our knowledge not yet been reported because of a lack of methodology to differentiate them. In this study, char and soot were measured using the IMPROVE method to test their associations with 12 EPA priority PAHs measured in topsoil samples (N = 22, top 10 cm) collected from the Guanzhong Plain and in surface sediment samples (N = 32, top 5 cm) from the Wei River (central China). In both soils and sediments, Σ12PAHs were more strongly associated with soot than with char, mainly due to the fact that soot and PAHs were produced in the same gas phase during combustion, had a strong affinity for each other, and were transported and deposited together, while char, the combustion residue, was transported differently to PAHs due to its large particle size. Stronger correlations between PAHs and the different carbon fractions (TOC, soot, and char) in sediments than in soils were observed, which is associated with the redistribution of PAHs among the organic matter pools in water because of the processes during soil erosion and sedimentation in the river. PMID:24656973

Preference for cannibalism and ontogenetic constraints in competitive ability of piscivorous top predators.

PubMed

Byström, Pär; Ask, Per; Andersson, Jens; Persson, Lennart

2013-01-01

Occurrence of cannibalism and inferior competitive ability of predators compared to their prey have been suggested to promote coexistence in size-structured intraguild predation (IGP) systems. The intrinsic size-structure of fish provides the necessary prerequisites to test whether the above mechanisms are general features of species interactions in fish communities where IGP is common. We first experimentally tested whether Arctic char (Salvelinus alpinus) were more efficient as a cannibal than as an interspecific predator on the prey fish ninespine stickleback (Pungitius pungitius) and whether ninespine stickleback were a more efficient competitor on the shared zooplankton prey than its predator, Arctic char. Secondly, we performed a literature survey to evaluate if piscivores in general are more efficient as cannibals than as interspecific predators and whether piscivores are inferior competitors on shared resources compared to their prey fish species. Both controlled pool experiments and outdoor pond experiments showed that char imposed a higher mortality on YOY char than on ninespine sticklebacks, suggesting that piscivorous char is a more efficient cannibal than interspecific predator. Estimates of size dependent attack rates on zooplankton further showed a consistently higher attack rate of ninespine sticklebacks compared to similar sized char on zooplankton, suggesting that ninespine stickleback is a more efficient competitor than char on zooplankton resources. The literature survey showed that piscivorous top consumers generally selected conspecifics over interspecific prey, and that prey species are competitively superior compared to juvenile piscivorous species in the zooplankton niche. We suggest that the observed selectivity for cannibal prey over interspecific prey and the competitive advantage of prey species over juvenile piscivores are common features in fish communities and that the observed selectivity for cannibalism over interspecific prey has the potential to mediate coexistence in size structured intraguild predation systems.