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

Reid, Douglas J.; Bearden, Mark D.; Cabe, James E.

This report explains the development, commissioning, and testing of an engineering scale slagging coal gasifier at PNNL. The initial objective of this project was to commission the gasifier with zero safety incidents. The commissioning work was primarily an empirical study that required an engineering design approach. After bringing the gasifier on-line, tests were conducted to assess the impact of various operating parameters on the synthesis gas (syngas) product composition. The long-term intent of this project is to produce syngas product for use by internal Pacific Northwest National Laboratory (PNNL) researchers in catalyst, materials, and instrumentation development. Future work on themore » project will focus on improving the reliability and performance of the gasifier, with a goal of continuous operation for greater than 4 hours using coal feedstock. In addition, alternate designs that allow for increased flexibility regarding the fuel sources that can be used for syngas production is desired. Continued modifications to the fuel feed system will be pursued to address these goals. Alternative feed mechanisms such as a coal/methanol slurry are being considered.« less

Analysis of the fly ash from the processing of wood chips in a pilot-scale downdraft gasifier: Comparison of inorganic constituents determined by PIXE and ICP-AES

Treesearch

Thomas L Eberhardt; Hui Pan

2013-01-01

Gasification of biomass ultimately generates at least one solid byproduct in which the inorganic constituents of the biomass are concentrated. Given the potential for utilization, or issues with disposal, facile methods are needed for determining the compositions of the fly ashes from recently-available gasifier-based bioenergy systems. Proton induced x-ray emission...

Long-Term Demonstration of Hydrogen Production from Coal at Elevated Temperatures Year 6 - Activity 1.12 - Development of a National Center for Hydrogen Technology

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

Stanislowski, Joshua; Tolbert, Scott; Curran, Tyler

2012-04-30

The Energy & Environmental Research Center (EERC) has continued the work of the National Center for Hydrogen Technology® (NCHT®) Program Year 6 Task 1.12 project to expose hydrogen separation membranes to coal-derived syngas. In this follow-on project, the EERC has exposed two membranes to coal-derived syngas produced in the pilot-scale transport reactor development unit (TRDU). Western Research Institute (WRI), with funding from the State of Wyoming Clean Coal Technology Program and the North Dakota Industrial Commission, contracted with the EERC to conduct testing of WRI’s coal-upgrading/gasification technology for subbituminous and lignite coals in the EERC’s TRDU. This gasifier fires nominallymore » 200–500 lb/hour of fuel and is the pilot-scale version of the full-scale gasifier currently being constructed in Kemper County, Mississippi. A slipstream of the syngas was used to demonstrate warm-gas cleanup and hydrogen separation using membrane technology. Two membranes were exposed to coal-derived syngas, and the impact of coal-derived impurities was evaluated. This report summarizes the performance of WRI’s patent-pending coalupgrading/ gasification technology in the EERC’s TRDU and presents the results of the warm-gas cleanup and hydrogen separation tests. Overall, the WRI coal-upgrading/gasification technology was shown to produce a syngas significantly lower in CO2 content and significantly higher in CO content than syngas produced from the raw fuels. Warm-gas cleanup technologies were shown to be capable of reducing sulfur in the syngas to 1 ppm. Each of the membranes tested was able to produce at least 2 lb/day of hydrogen from coal-derived syngas.« less

Properties and effects of remaining carbon from waste plastics gasifying on iron scale reduction.

PubMed

Zhang, Chongmin; Chen, Shuwen; Miao, Xincheng; Yuan, Hao

2011-06-01

The carbonous activities of three kinds of carbon-bearing materials gasified from plastics were tested with coal coke as reference. The results showed that the carbonous activities of these remaining carbon-bearing materials were higher than that of coal-coke. Besides, the fractal analyses showed that the porosities of remaining carbon-bearing materials were higher than that of coal-coke. It revealed that these kinds of remaining carbon-bearing materials are conducive to improve the kinetics conditions of gas-solid phase reaction in iron scale reduction. Copyright © 2011 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Updraft gasification of salmon processing waste.

PubMed

Rowland, Sarah; Bower, Cynthia K; Patil, Krushna N; DeWitt, Christina A Mireles

2009-10-01

The purpose of this study was 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 degrees C), oxygen deficient environment. Syngas can be combusted to generate power, which recycles energy from waste products. At 66% to 79% moisture, raw salmon waste streams are too wet to undergo pyrolysis and combustion. Ground raw or de-oiled salmon whole fish, heads, viscera, or frames were therefore "dried" by mixing with wood pellets to a final moisture content of 20%. Ground whole salmon with moisture reduced to 12% moisture was gasified without a drying agent. Gasification tests were performed in a small-scale, fixed-bed, updraft gasifer. After an initial start-up period, the gasifier was loaded with 1.5 kg of biomass. Temperature was recorded at 6 points in the gasifier. Syngas was collected during the short steady-state period during each gasifier run and analyzed. Percentages of each type of gas in the syngas were used to calculate syngas heating value. High heating value (HHV) ranged from 1.45 to 1.98 MJ/kg. Bomb calorimetry determined maximum heating value for the salmon by-products. Comparing heating values shows the efficiency of gasification. Cold gas efficiencies of 13.6% to 26% were obtained from the various samples gasified. Though research of gasification as a means of salmon waste disposal and energy production is ongoing, it can be concluded that pre-dried salmon or relatively low moisture content mixtures of waste with wood are gasifiable.

Effect of small-scale biomass gasification at the state of refractory lining the fixed bed reactor

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

Janša, Jan, E-mail: jan.jansa@vsb.cz; Peer, Vaclav, E-mail: vaclav.peer@vsb.cz; Pavloková, Petra, E-mail: petra.pavlokova@vsb.cz

The article deals with the influence of biomass gasification on the condition of the refractory lining of a fixed bed reactor. The refractory lining of the gasifier is one part of the device, which significantly affects the operational reliability and durability. After removing the refractory lining of the gasifier from the experimental reactor, there was done an assessment how gasification of different kinds of biomass reflected on its condition in terms of the main factors affecting its life. Gasification of biomass is reflected on the lining, especially through sticking at the bottom of the reactor. Measures for prolonging the lifemore » of lining consist in the reduction of temperature in the reactor, in this case, in order to avoid ash fusion biomass which it is difficult for this type of gasifier.« less

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

GE pilot plant gasifies all coal types and grades without pretreatment

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

Not Available

1978-03-01

A pilot-scale coal gasification plant at General Electric Company's Research and Development Center, Schenectady, New York, is converting more than three-quarters of a ton of low-grade coal per hour into 100,000 cubic feet of fuel gas suitable for running electric power plants. GE is also going to test new ideas for coal feeding and stirring the reacting mixture to prevent caking. One unique approach will be the use of an extruder to feed coal continuously into the pressurized gasifier through a gas-tight seal, much as toothpaste is squeezed from a tube. The 6-inch-diameter rod of fuel that leaves the extrudermore » is comprised of a mixture of fine coal particles and tar (the latter is a by-product of the gasification process). Once inside, the rod is broken into chunks to form the bed being gasified.« less

Volume I: fluidized-bed code documentation, for the period February 28, 1983-March 18, 1983

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

Piperopoulou, H.; Finson, M.; Bloomfield, D.

1983-03-01

This documentation supersedes the previous documentation of the Fluidized-Bed Gasifier code. Volume I documents a simulation program of a Fluidized-Bed Gasifier (FBG), and Volume II documents a systems model of the FBG. The FBG simulation program is an updated version of the PSI/FLUBED code which is capable of modeling slugging beds and variable bed diameter. In its present form the code is set up to model a Westinghouse commercial scale gasifier. The fluidized bed gasifier model combines the classical bubbling bed description for the transport and mixing processes with PSI-generated models for coal chemistry. At the distributor plate, the bubblemore » composition is that of the inlet gas and the initial bubble size is set by the details of the distributor plate. Bubbles grow by coalescence as they rise. The bubble composition and temperature change with height due to transport to and from the cloud as well as homogeneous reactions within the bubble. The cloud composition also varies with height due to cloud/bubble exchange, cloud/emulsion, exchange, and heterogeneous coal char reactions. The emulsion phase is considered to be well mixed.« less

Bench-scale demonstration of hot-gas desulfurization technology. Quarterly report, April 1 - June 30, 1996

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

NONE

1996-12-31

The US Department of Energy (DOE) Morgantown Energy Technology Center (METC) is sponsoring research in advanced methods for controlling contaminants in hot coal gasifier gas (coal gas) streams of integrated gasification combined-cycle (IGCC) power systems. The programs focus on hot-gas particulate removal and desulfurization technologies that match or nearly match the temperatures and pressures of the gasifier, cleanup system, and power generator. The work seeks to eliminate the need for expensive heat recovery equipment, reduce efficiency losses due to quenching, and minimize wastewater treatment costs. The goal of this project is to continue further development of the zinc titanate desulfurizationmore » and direct sulfur recovery process (DSRP) technologies by (1) scaling up the zinc titanate reactor system; (2) developing an integrated skid-mounted zinc titanate desulfurization-DSRP reactor system; (3) testing the integrated system over an extended period with real coal-as from an operating gasifier to quantify the degradative effect, if any, of the trace contaminants present in cola gas; (4) developing an engineering database suitable for system scaleup; and (5) designing, fabricating and commissioning a larger DSRP reactor system capable of operating on a six-fold greater volume of gas than the DSRP reactor used in the bench-scale field test. The work performed during the April 1 through June 30, 1996 period is described.« less

Method and apparatus for gasifying with a fluidized bed gasifier having integrated pretreating facilities

DOEpatents

Rice, Louis F.

1981-01-01

An integral gasifier including a pretreater section and a gasifier section separated by a distribution grid is defined by a single vessel. The pretreater section pretreats coal or other carbon-containing material to be gasified to prevent caking and agglomeration of the coal in the gasifier. The level of the coal bed of the pretreater section and thus the holding or residence time in said bed is selectively regulated by the amount of pretreated coal which is lifted up a lift pipe into the gasifier section. Thus, the holding time in the pretreater section can be varied according to the amount of pretreat necessary for the particular coal to be gasified.

Gasification of yeast industry treatment plant sludge using downdraft Gasifier.

PubMed

Ayol, Azize; Tezer, Ozgun; Gurgen, Alim

2018-01-01

Sludges produced in biological wastewater treatment plants have rich organic materials in their characteristics. Recent research studies have focused on the energy recovery from sludge due to its high organic content. The gasification process is a thermal conversion technology transforming the chemical energy contained in a solid fuel into thermal energy and electricity. The produced syngas as a mixture of CO, CH 4 , H 2 and other gases can be used to generate electrical energy. The gasification of yeast industry sludge has been experimentally evaluated in a pilot scale downdraft-type gasifier as a route towards the energy recovery. The gasifier has 20 kg biomass/h fuel capacity. During gasification, the temperature achieved was more than 1,000°C in the gasifier, and then the syngas was transferred to the gas engine to yield the electricity. A load was connected to the grid box and approximately 1 kWh electrical power generation for 1 kg dry sludge was determined. The characteristics of residuals - ash, glassy material - were also analyzed. It was found that most of the heavy metals were fixed in the glassy material. Experimental results showed that the yeast industry sludge was an appropriate material for gasification studies and remarkable energy recovery was obtained in terms of power production by using syngas.

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.

Intermittently-fed high-pressure gasifier process

DOEpatents

Bailey, J.M.; Zadoks, A.L.

1993-11-30

An improved gasifier is described which is adapted for gasifying a predetermined charge of non-gaseous fuel into fuel gas. Each charge of non-gaseous fuel, which may have optional conditioning materials added to it, is intermittently fed to a gasifier chamber where each charge is partially burned with high-pressure air supplied thereto. High-pressure and temperature fuel gas is produced which is cleansed prior to passing out of the gasifier chamber. After gasification of the charge of fuel is ended, the gasifier chamber is vented. The residue of the burned charge in the gasifier chamber is removed, along with the contaminated or reacted conditioning materials, and replaced by a fresh charge. The subject invention provides a feasible way of continuously fueling an internal combustion engine with gasified fuel and is compact enough to be practical for even mobile applications. 3 figures.

Intermittently-fed high-pressure gasifier process

DOEpatents

Bailey, John M.; Zadoks, Abraham L.

1993-11-30

An improved gasifier adapted for gasifying a predetermined charge of non-gaseous fuel into fuel gas. Each charge of non-gaseous fuel, which may have optional conditioning materials added to it, is intermittently fed to a gasifier chamber where each charge is partially burned with high-pressure air supplied thereto. High-pressure and temperature fuel gas is produced which is cleansed prior to passing out of the gasifier chamber. After gasification of the charge of fuel is is ended, the gasifier chamber is vented. The residue of the burned charge in the gasifier chamber is removed, along with the contaminated or reacted conditioning materials, and replaced by a fresh charge. The subject invention provides a feasible way of continuously fueling an internal combustion engine with gasified fuel and is compact enough to be practical for even mobile applications.

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.

Development of TDLAS sensor for diagnostics of CO, H2O and soot concentrations in reactor core of pilot-scale gasifier

NASA Astrophysics Data System (ADS)

Sepman, A.; Ögren, Y.; Gullberg, M.; Wiinikka, H.

2016-02-01

This paper reports on the development of the tunable diode laser absorption spectroscopy sensor near 4350 cm-1 (2298 nm) for measurements of CO and H2O mole fractions and soot volume fraction under gasification conditions. Due to careful selection of the molecular transitions [CO ( υ″ = 0 → υ' = 2) R34-R36 and H2O at 4349.337 cm-1], a very weak (negligible) sensitivity of the measured species mole fractions to the temperature distribution inside the high-temperature zone (1000 K < T < 1900 K) of the gasification process is achieved. The selected transitions are covered by the tuning range of single diode laser. The CO and H2O concentrations measured in flat flames generally agree better than 10 % with the results of 1-D flame simulations. Calibration-free absorption measurements of studied species in the reactor core of atmospheric pilot-scale entrained-flow gasifier operated at 0.1 MW power are reported. Soot concentration is determined from the measured broadband transmittance. The estimated uncertainties in the reactor core CO and H2O measurements are 15 and 20 %, respectively. The reactor core average path CO mole fractions are in quantitative agreement with the µGC CO concentrations sampled at the gasifier output.

O absorption measurements in an engineering-scale high-pressure coal gasifier

NASA Astrophysics Data System (ADS)

Sun, Kai; Sur, Ritobrata; Jeffries, Jay B.; Hanson, Ronald K.; Clark, Tommy; Anthony, Justin; Machovec, Scott; Northington, John

2014-10-01

A real-time, in situ water vapor (H2O) sensor using a tunable diode laser near 1,352 nm was developed to continuously monitor water vapor in the synthesis gas of an engineering-scale high-pressure coal gasifier. Wavelength-scanned wavelength-modulation spectroscopy with second harmonic detection (WMS-2 f) was used to determine the absorption magnitude. The 1 f-normalized, WMS-2 f signal (WMS-2 f/1 f) was insensitive to non-absorption transmission losses including beam steering and light scattering by the particulate in the synthesis gas. A fitting strategy was used to simultaneously determine the water vapor mole fraction and the collisional-broadening width of the transition from the scanned 1 f-normalized WMS-2 f waveform at pressures up to 15 atm, which can be used for large absorbance values. This strategy is analogous to the fitting strategy for wavelength-scanned direct absorption measurements. In a test campaign at the US National Carbon Capture Center, the sensor demonstrated a water vapor detection limit of ~800 ppm (25 Hz bandwidth) at conditions with more than 99.99 % non-absorption transmission losses. Successful unattended monitoring was demonstrated over a 435 h period. Strong correlations between the sensor measurements and transient gasifier operation conditions were observed, demonstrating the capability of laser absorption to monitor the gasification process.

Advanced coal gasifier-fuel cell power plant systems design

NASA Technical Reports Server (NTRS)

Heller, M. E.

1983-01-01

Two advanced, high efficiency coal-fired power plants were designed, one utilizing a phosphoric acid fuel cell and one utilizing a molten carbonate fuel cell. Both incorporate a TRW Catalytic Hydrogen Process gasifier and regenerator. Both plants operate without an oxygen plant and without requiring water feed; they, instead, require makeup dolomite. Neither plant requires a shift converter; neither plant has heat exchangers operating above 1250 F. Both plants have attractive efficiencies and costs. While the molten carbonate version has a higher (52%) efficiency than the phosphoric acid version (48%), it also has a higher ($0.078/kWh versus $0.072/kWh) ten-year levelized cost of electricity. The phosphoric acid fuel cell power plant is probably feasible to build in the near term: questions about the TRW process need to be answered experimentally, such as weather it can operate on caking coals, and how effective the catalyzed carbon-dioxide acceptor will be at pilot scale, both in removing carbon dioxide and in removing sulfur from the gasifier.

TDLAS-based sensors for in situ measurement of syngas composition in a pressurized, oxygen-blown, entrained flow coal gasifier

NASA Astrophysics Data System (ADS)

Sur, Ritobrata; Sun, Kai; Jeffries, Jay B.; Hanson, Ronald K.; Pummill, Randy J.; Waind, Travis; Wagner, David R.; Whitty, Kevin J.

2014-07-01

Tunable diode laser absorption spectroscopy based in situ sensors for CO (2.33 μm), CO2 (2.02 μm), CH4 (2.29 μm) and H2O (1.35 μm) were deployed in a pilot-scale (1 ton/day), high-pressure (up to 18 atm), entrained flow, oxygen-blown, slagging coal gasifier at the University of Utah. Measurements of species mole fraction with 3-s time resolution were taken at the pre- and post-filtration stages of the gasifier synthesis gas (called here syngas) output flow. Although particulate scattering makes pre-filter measurements more difficult, this location avoids the time delay of flow through the filtration devices. With the measured species and known N2 concentrations, the H2 content was obtained via balance. The lower heating value and the Wobbe index of the gas mixture were estimated using the measured gas composition. The sensors demonstrated here show promise for monitoring and control of the gasification process.

Behaviors of Char Gasification Based on Two-stage Gasifier of Biomass

NASA Astrophysics Data System (ADS)

Taniguchi, Miki; Sasauchi, Kenichi; Ahn, Chulju; Ito, Yusuke; Hayashi, Toshiaki; Akamatsu, Fumiteru

In order to develop a small-scale gasifier in which biomass can be converted to energy with high efficiency, we planed a gasification process that consists of two parts: pyrolysis part (rotary kiln) and gasification part (downdraft gasifier). We performed fundamental experiments on gasification part and discussed the apropriate conditions such as air supply location, air ratio, air temperature and hearth load. The following results was found: 1) the air supply into the char bed is more effective than that into the gas phase, 2) we can have the maximum cold gas efficiency of 80% on the following conditions: air supply location: char layer, air temperature: 20°C, air ratio: 0.2. 3) As air temperature is higher, the cold gas efficiency is larger. As for the hearth load, the cold gas efficiency becomes higher and reaches the constant level. It is expected from the results that high temperature in the char layer is effective on the char gasification.

Optimization of Biomass Gasification Process for F-T Bio-Diesel Synthesys

NASA Astrophysics Data System (ADS)

Song, Jae Hun; Sung, Yeon Kyung; Yu, Tae U.; Choi, Young Tae; Lee, Uen Do

The characteristics of biomass steam gasification were investigated to make an optimum syngas for Fischer Tropsch (F-T) synthesis of bio-diesel. Korean pine wood chip was used as a fuel and the experiment was conducted in a lab scale bubbling fluidized bed (0.1m LD. x 3.Omheight). Gas composition was evaluated by changing operating parameters such as gasifier temperature, and steam to fuel ratio. Major syngas was monitored by on-line gas analyzer (ND-IR spectroscopy) and gas chromatography (GC). As the temperature of gasifier increases hydrogen in the syngas increases while CO in the product gas decreases. The low concentration of sulfur compound and nitrogen in the product gas shows the potential advantages in the purification process of the syngas for F-T process. Optimum operating condition of the gasifier was found concerning the following gas cleaning and F-T process; H2-CO ratio and total gas yield increase while decreasing methane and CO2 concentrations in the syngas.

Scoping Studies to Evaluate the Benefits of an Advanced Dry Feed System on the Use of Low-Rank Coal

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

Rader, Jeff; Aguilar, Kelly; Aldred, Derek

2012-11-30

This report describes the development of the design of an advanced dry feed system that was carried out under Task 4.0 of Cooperative Agreement DE-FE0007902 with the US DOE, “Scoping Studies to Evaluate the Benefits of an Advanced Dry Feed System on the use of Low- Rank Coal.” The resulting design will be used for the advanced technology IGCC case with 90% carbon capture for sequestration to be developed under Task 5.0 of the same agreement. The scope of work covered coal preparation and feeding up through the gasifier injector. Subcomponents have been broken down into feed preparation (including grindingmore » and drying), low pressure conveyance, pressurization, high pressure conveyance, and injection. Pressurization of the coal feed is done using Posimetric1 Feeders sized for the application. In addition, a secondary feed system is described for preparing and feeding slag additive and recycle fines to the gasifier injector. This report includes information on the basis for the design, requirements for down selection of the key technologies used, the down selection methodology and the final, down selected design for the Posimetric Feed System, or PFS.« less

Numerical investigation of slag formation in an entrained-flow gasifier

NASA Astrophysics Data System (ADS)

Zageris, G.; Geza, V.; Jakovics, A.

2018-05-01

A CFD mathematical model for an entrained-flow gasifier is constructed – the model of an actual gasifier is rendered in 3D and appropriately meshed. Then, the turbulent gas flow in the gasifier is modeled with the realizable k-ε approach, taking devolatilization, combustion and coal gasification in account. Various such simulations are conducted, obtaining results for different air inlet positions and by tracking particles of varying sizes undergoing devolatilization and gasification. The model identifies potential problematic zones where most particles collide with the gasifier walls, indicating risk regions where ash deposits could most likely form. In conclusion, effects on the formation of an ash layer of air inlet positioning and particle size allowed in the main gasifier tank are discussed, and viable solutions such as radial inlet positioning for decreasing the amount of undesirable deposits are proposed. We also conclude that the particular chemical reactions that take place inside the gasifier play a significant role in determining how slagging occurs inside a gasifier.

Agglomeration of SRC residues. Final report

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

Theodore, F.W.; Wasson, G.E.

1982-01-01

EPRI contracted with CCDC to agglomerate Kerr-McGee ash concentrate and determine whether the agglomerates could be used as a fixed-bed gasifier feed. Briquettes were produced from Kerr-McGee ash concentrate which met CCDC's strength criteria for handling as feed to a fixed-bed gasifier. In addition, when shock heated under conditions simulating gasifier conditions, strong coke was produced demonstrating that the briquettes will not disintegrate during the initial temperature shock when charged to the gasifier. The conclusion of this study is that briquettes produced from the Kerr-McGee ash concentrate studied could be considered as feed for a fixed-bed gasifier. The CO/sub 2/-carbonmore » reactivity of the briquettes had values between a typical eastern and western coal. In the case of a dry bottom gasifier where the reactivity is important, it is not clear-cut whether the ash concentrate briquettes would be an economical feed. A closer inspection by a gasifier manufacturer is needed to resolve this issue. Since higher gasification temperatures are used in a slagging gasifier, the reactivity question is eliminated and the briquettes should be considered as a feed. This study does not deal with the exact design of a gasifier since this is a function of the type used. The gasifier manufacturer should be considered in future work for their input on critical design considerations i.e. stirrer design, etc.« less

Dry piston coal feeder

DOEpatents

Hathaway, Thomas J.; Bell, Jr., Harold S.

1979-01-01

This invention provides a solids feeder for feeding dry coal to a pressurized gasifier at elevated temperatures substantially without losing gas from the gasifier by providing a lock having a double-acting piston that feeds the coals into the gasifier, traps the gas from escaping, and expels the trapped gas back into the gasifier.

Physicochemical properties and gasification reactivity of the ultrafine semi-char derived from a bench-scale fluidized bed gasifier

NASA Astrophysics Data System (ADS)

Zhang, Yukui; Zhang, Haixia; Zhu, Zhiping; Na, Yongjie; Lu, Qinggang

2017-08-01

Zhundong coalfield is the largest intact coalfield worldwide and fluidized bed gasification has been considered as a promising way to achieve its clean and efficient utilization. The purpose of this study is to investigate the physicochemical properties and gasification reactivity of the ultrafine semi-char, derived from a bench-scale fluidized bed gasifier, using Zhundong coal as fuel. The results obtained are as follows. In comparison to the raw coal, the carbon and ash content of the semi-char increase after partial gasification, but the ash fusion temperatures of them show no significant difference. Particularly, 76.53% of the sodium in the feed coal has released to the gas phase after fluidized bed gasification. The chemical compositions of the semi-char are closely related to its particle size, attributable to the distinctly different natures of diverse elements. The semi-char exhibits a higher graphitization degree, higher BET surface area, and richer meso- and macropores, which results in superior gasification reactivity than the coal char. The chemical reactivity of the semi-char is significantly improved by an increased gasification temperature, which suggests the necessity of regasification of the semi-char at a higher temperature. Consequently, it will be considered feasible that these carbons in the semi-char from fluidized bed gasifiers are reclaimed and reused for the gasification process.

Design, engineering and evaluation of refractory liners for slagging gasifiers. Final report

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

deTineo, B J; Booth, G; Firestone, R F

1982-08-01

The contract for this program was awarded at the end of September 1978. Work was started on 1 October 1978, on Tasks A, B, and E. Task A, Conceptual Liner Designs, and Task B, Test System Design and Construction, were completed. Task C, Liner Tests, and Task D, Liner Design Evaluation, were to begin upon completion of Task B. Task E, Liner Model Development, is inactive after an initial data compilation and theoretical model development effort. It was to be activated as soon as data were available from Task D. Task F, Liner Design Handbook, was active along with Taskmore » A since the reports of both tasks were to use the same format. At this time, Tasks C, D, and F are not to be completed since funding of this project was phased out by DOE directive. The refractory text facility, which was constructed, was tested and found to perform satisfactorily. It is described in detail, including a hazard analysis which was performed. (LTN)« less

Physical and computational studies of slag behavior in an entrained flow gasifier

NASA Astrophysics Data System (ADS)

Pummill, Randy

This work details an investigation of how to modify slag flow so as to maintain a clear line of sight across the reaction section of an entrained-flow coal gasifier. Physical and computational models were developed to study methods of diverting the molten slag that flows vertically down the walls of the reactor. The physical models employed silicone oil of varying viscosity. The computational models were developed using the Fluent software package. Based on the insight gained from the results of the models, two devices were created and tested in a pilot scale gasifier located at the University of Utah. The first method of slag diversion studied employed a gas jet to impact the slag film and cause it to flow around a sight port in the gasifier wall. By studying the film and jet interactions, it was discovered that the resulting behavior of such a system can be described by a dimensionless ratio of the kinetic energy of the jet and the surface energy of the film. The development of the dimensionless number, called a Lotte number in this work, is presented in detail. Generally, viscous films will be broken by a jet when the Lotte number is greater than 5 and will reclose when the Lotte number falls below a value of 1.5. The second slag diversion method studied used a round alumina tube protruding horizontally into the reaction section to break up the film. As the film impacts the tube, it progresses horizontally along the length of the tube before resuming the downward flow. The models helped to establish how far the tube should protrude into the reactor in order to successfully break up the slag flow. Slag diversion devices were constructed and installed on a pilot scale gasifier. The jet diversion method was found to require an unreasonably large amount of purge gas to be successful and the metal jet suffered from the high temperature of the reactor despite the cooling effect of the gas. The tube diversion method worked very well for a series of experiments. However, erosion of the alumina tube in the reaction section remains an impediment to using such a device in an industrial setting. A design using a water-cooled tube is suggested.

Method and apparatus for enhancing the desulfurization of hot coal gas in a fluid-bed coal gasifier

DOEpatents

Grindley, T.

1988-04-05

A process and apparatus for providing additional desulfurization of the hot gas produced in a fluid-bed coal gasifier, within the gasifier is described. A fluid-bed of iron oxide is located inside the gasifier above the gasification bed in a fluid-bed coal gasifier in which in-bed desulfurization by lime/limestone takes place. The product gases leave the gasification bed typically at 1600 to 1800 F and are partially quenched with water to 1000 to 1200 F before entering the iron oxide bed. The iron oxide bed provides additional desulfurization beyond that provided by the lime /limestone. 1 fig.

Method for enhancing the desulfurization of hot coal gas in a fluid-bed coal gasifier

DOEpatents

Grindley, Thomas

1989-01-01

A process and apparatus for providing additional desulfurization of the hot gas produced in a fluid-bed coal gasifier, within the gasifier. A fluid-bed of iron oxide is located inside the gasifier above the gasification bed in a fluid-bed coal gasifier in which in-bed desulfurization by lime/limestone takes place. The product gases leave the gasification bed typically at 1600.degree. to 1800.degree. F. and are partially quenched with water to 1000.degree. to 1200.degree. F. before entering the iron oxide bed. The iron oxide bed provides additional desulfurization beyond that provided by the lime/limestone.

Down-flow moving-bed gasifier with catalyst recycle

DOEpatents

Halow, John S.

1999-01-01

The gasification of coal and other carbonaceous materials by an endothermic gasification reaction is achieved in the presence of a catalyst in a down-flow, moving-bed gasifier. Catalyst is removed along with ash from the gasifier and is then sufficiently heated in a riser/burner by the combustion of residual carbon in the ash to volatilize the catalyst. This volatilized catalyst is returned to the gasifier where it uniformly contacts and condenses on the carbonaceous material. Also, the hot gaseous combustion products resulting from the combustion of the carbon in the ash along with excess air are introduced into the gasifier for providing heat energy used in the endothermic reaction.

Integrated Fuel Cell/Coal Gasifier

NASA Technical Reports Server (NTRS)

Ferrall, J. F.

1985-01-01

Powerplant design with low-temperature coal gasifier coupled to highly-exothermic fuel cell for efficient production of dc power eliminates need for oxygen in gasifier and achieves high fuel efficiency with recycling of waste heat from fuel cell.

Performance and Characteristics of a Cyclone Gasifier for Gasification of Sawdust

NASA Astrophysics Data System (ADS)

Azman Miskam, Muhamad; Zainal, Z. A.; Idroas, M. Y.

The performance and characteristics of a cyclone gasifier for gasification of sawdust has been studied and evaluated. The system applied a technique to gasify sawdust through the concept of cyclonic motion driven by air injected at atmospheric pressure. This study covers the results obtained for gasification of ground sawdust from local furniture industries with size distribution ranging from 0.25 to 1 mm. It was found that the typical wall temperature for initiating stable gasification process was about 400°C. The heating value of producer gas was about 3.9 MJ m-3 that is sufficient for stable combustion in a dual-fuel engine generator. The highest thermal output from the cyclone gasifier was 57.35 kWT. The highest value of mass conversion efficiency and enthalpy balance were 60 and 98.7%, respectively. The highest efficiency of the cyclone gasifier obtained was 73.4% and this compares well with other researchers. The study has identified the optimum operational condition for gasifying sawdust in a cyclone gasifier and made conclusions as to how the steady gasification process can be achieved.

Apparatus, components and operating methods for circulating fluidized bed transport gasifiers and reactors

DOEpatents

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

2015-02-24

The improvements proposed in this invention provide a reliable apparatus and method to gasify low rank coals in a class of pressurized circulating fluidized bed reactors termed "transport gasifier." The embodiments overcome a number of operability and reliability problems with existing gasifiers. The systems and methods address issues related to distribution of gasification agent without the use of internals, management of heat release to avoid any agglomeration and clinker formation, specific design of bends to withstand the highly erosive environment due to high solid particles circulation rates, design of a standpipe cyclone to withstand high temperature gasification environment, compact design of seal-leg that can handle high mass solids flux, design of nozzles that eliminate plugging, uniform aeration of large diameter Standpipe, oxidant injection at the cyclone exits to effectively modulate gasifier exit temperature and reduction in overall height of the gasifier with a modified non-mechanical valve.

Down-flow moving-bed gasifier with catalyst recycle

DOEpatents

Halow, J.S.

1999-04-20

The gasification of coal and other carbonaceous materials by an endothermic gasification reaction is achieved in the presence of a catalyst in a down-flow, moving-bed gasifier. Catalyst is removed along with ash from the gasifier and is then sufficiently heated in a riser/burner by the combustion of residual carbon in the ash to volatilize the catalyst. This volatilized catalyst is returned to the gasifier where it uniformly contacts and condenses on the carbonaceous material. Also, the hot gaseous combustion products resulting from the combustion of the carbon in the ash along with excess air are introduced into the gasifier for providing heat energy used in the endothermic reaction. 1 fig.

Analysis and control of the METC fluid bed gasifier. Final report (includes technical progress report for October 1994--January 1995), September 1994--September 1996

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

NONE

1996-09-01

This document presents a modeling and control study of the Fluid Bed Gasification (FBG) unit at the Morgantown Energy Technology Center (METC). The work is performed under contract no. DE-FG21-94MC31384. The purpose of this study is to generate a simple FBG model from process data, and then use the model to suggest an improved control scheme which will improve operation of the gasifier. The work first developes a simple linear model of the gasifier, then suggests an improved gasifier pressure and MGCR control configuration, and finally suggests the use of a multivariable control strategy for the gasifier.

Soot blower using fuel gas as blowing medium

DOEpatents

Tanca, Michael C.

1982-01-01

A soot blower assembly (10) for use in combination with a coal gasifier (14). The soot blower assembly is adapted for use in the hot combustible product gas generated in the gasifier as the blowing medium. The soot blower lance (20) and the drive means (30) by which it is moved into and out of the gasifier is housed in a gas tight enclosure (40) which completely surrounds the combination. The interior of the enclosure (40) is pressurized by an inert gas to a pressure level higher than that present in the gasifier so that any combustible product gas leaking from the soot blower lance (20) is forced into the gasifier rather than accumulating within the enclosure.

Experimental Study on Charging Process in the COREX Melter Gasifier

NASA Astrophysics Data System (ADS)

Luo, Zhiguo; You, Yang; Li, Haifeng; Zhou, Heng; Zou, Zongshu

2018-04-01

Burden distribution plays an important role in achieving high stability and energy efficiency in the COREX melter gasifier. In this work, a 1/7.5 scale experimental apparatus is established to investigate the burden distribution under the independent and mixed charging conditions. The effects of GIMBAL distributor angle, rotational speed, DRI-flap angle, and charging pattern on these charging conditions are investigated. The results show that the non-uniform distribution of pellet in circumferential direction is intrinsic to the discharge system due to the shape of the DRI flap. The charging pattern has a significant impact on the ore-to-coal volume ratio and bed voidage. The ore-to-coal volume ratio reaches the peak at 550 to 650 mm, indicating that the reduction burden near the wall is heavier than that in the center. The voidage in the middle region is smaller than that of the center and near-wall region. The results also reveal the size segregation along the radial direction of the burden pile. The smaller particles tend to accumulate in the center while the larger ones segregate more near the wall. The findings obtained from experiments should be helpful for the efficient operation of the COREX melter gasifier.

Fuel Gas Demonstration Plant Program: Small-Scale Industrial Project. Coal procurement activities. Technica report No. 9

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

Not Available

1979-04-14

This report consists of reference material taken from Erie Mining Company project files and includes the following: (1) Investigation of the Main Coal Producing Fields in the United States: This report identifies potential coal fiels for gasifier feedstock and factors influencing coal selection. The report analyzes coal fields located in five separate regions of the United States. Three design coals are discussed and lab reports have been included. Also included are cost considerations for selected coals and preliminary cost data and transportation routing. (2) Analysis of Test Coals Received at Erie Mining Company: Rosebud, Clarion, and Clarion-Brookfield-Kittaning coal samples weremore » received and analyzed at Erie Mining Company. The screen analysis indicated the severe decrepitation of the Rosebud western coal. (3) Criteria for Gasifier Coal: In this study, BCI states that gasifier feed should have the following characteristics: (1) the ratio between the upper and lower size for coal should be 3:1; (2) coal fines should not exceed 10%; (3) coal grading limits which can be handled are maximum range 3'' x 1'', minimum range - 1 1/2'' x 1/2''.« less

Performance potential of combined cycles integrated with low-Btu gasifiers for future electric utility applications

NASA Technical Reports Server (NTRS)

Nainiger, J. J.; Burns, R. K.

1977-01-01

A comparison and an assessment of 10 advanced utility power systems on a consistent basis and to a common level of detail were analyzed. Substantial emphasis was given to a combined cycle systems integrated with low-Btu gasifiers. Performance and cost results from that study were presented for these combined cycle systems, together with a comparative evaluation. The effect of the gasifier type and performance and the interface between the gasifier and the power system were discussed.

Advanced Turbine Technology Applications Project (ATTAP)

NASA Technical Reports Server (NTRS)

1989-01-01

ATTAP activities during the past year were highlighted by an extensive materials assessment, execution of a reference powertrain design, test-bed engine design and development, ceramic component design, materials and component characterization, ceramic component process development and fabrication, component rig design and fabrication, test-bed engine fabrication, and hot gasifier rig and engine testing. Materials assessment activities entailed engine environment evaluation of domestically supplied radial gasifier turbine rotors that were available at the conclusion of the Advanced Gas Turbine (AGT) Technology Development Project as well as an extensive survey of both domestic and foreign ceramic suppliers and Government laboratories performing ceramic materials research applicable to advanced heat engines. A reference powertrain design was executed to reflect the selection of the AGT-5 as the ceramic component test-bed engine for the ATTAP. Test-bed engine development activity focused on upgrading the AGT-5 from a 1038 C (1900 F) metal engine to a durable 1371 C (2500 F) structural ceramic component test-bed engine. Ceramic component design activities included the combustor, gasifier turbine static structure, and gasifier turbine rotor. The materials and component characterization efforts have included the testing and evaluation of several candidate ceramic materials and components being developed for use in the ATTAP. Ceramic component process development and fabrication activities were initiated for the gasifier turbine rotor, gasifier turbine vanes, gasifier turbine scroll, extruded regenerator disks, and thermal insulation. Component rig development activities included combustor, hot gasifier, and regenerator rigs. Test-bed engine fabrication activities consisted of the fabrication of an all-new AGT-5 durability test-bed engine and support of all engine test activities through instrumentation/build/repair. Hot gasifier rig and test-bed engine testing activities were performed.

EVALUATION OF A PROCESS TO CONVERT BIOMASS TO METHANOL FUEL

EPA Science Inventory

The report gives results of a review of the design of a reactor capable of gasifying approximately 50 lb/hr of biomass for a pilot-scale facility to develop, demonstrate, and evaluate the Hynol Process, a high-temperature, high-pressure method for converting biomass into methanol...

EVALUATION OF A PROCESS TO CONVERT BIOMASS TO METHANOL FUEL - PROJECT SUMMARY

EPA Science Inventory

The report gives results of a review of the design of a reactor capable of gasifying approximately 50 lb/hr of biomass for a pilot-scale facility to develop, demonstrate, and evaluate the Hynol Process, a high-temperature, high-pressure method for converting biomass into methanol...

OPTIMIZING SYNTHESIS GAS YIELD FROM THE CROSS DRAFT GASIFICATION OF WOODY BIOMASS

EPA Science Inventory

Biomass can be gasified to yield synthesis gas, tars, and ash. The process is governed by a number of parameters such as the temperature of the gasifying medium (in this case air), and the moisture content of the feedstock. Synthesis gas from gasifying wood pellets was collected ...

The study of integrated coal-gasifier molten carbonate fuel cell systems

NASA Technical Reports Server (NTRS)

1983-01-01

A novel integration concept for a coal-fueled coal gasifier-molten carbonate fuel cell power plant was studied. Effort focused on determining the efficiency potential of the concept, design, and development requirements of the processes in order to achieve the efficiency. The concept incorporates a methane producing catalytic gasifier of the type previously under development by Exxon Research and Development Corp., a reforming molten carbonate fuel cell power section of the type currently under development by United Technologies Corp., and a gasifier-fuel cell recycle loop. The concept utilizes the fuel cell waste heat, in the form of hydrogen and carbon monoxide, to generate additional fuel in the coal gasifier, thereby eliminating the use of both an O2 plant and a stream bottoming cycle from the power plant. The concept has the potential for achieving coal-pile-to-busbar efficiencies of 50-59%, depending on the process configuration and degree of process configuration and degree of process development requirements. This is significantly higher than any previously reported gasifier-molten carbonate fuel cell system.

Integrated control system and method

DOEpatents

Wang, Paul Sai Keat; Baldwin, Darryl; Kim, Myoungjin

2013-10-29

An integrated control system for use with an engine connected to a generator providing electrical power to a switchgear is disclosed. The engine receives gas produced by a gasifier. The control system includes an electronic controller associated with the gasifier, engine, generator, and switchgear. A gas flow sensor monitors a gas flow from the gasifier to the engine through an engine gas control valve and provides a gas flow signal to the electronic controller. A gas oversupply sensor monitors a gas oversupply from the gasifier and provides an oversupply signal indicative of gas not provided to the engine. A power output sensor monitors a power output of the switchgear and provide a power output signal. The electronic controller changes gas production of the gasifier and the power output rating of the switchgear based on the gas flow signal, the oversupply signal, and the power output signal.

Two-stage fixed-bed gasifier with selectable middle gas off-take point

DOEpatents

Strickland, Larry D.; Bissett, Larry A.

1992-01-01

A two-stage fixed bed coal gasifier wherein an annular region is in registry with a gasification zone underlying a devolatilization zone for extracting a side stream of high temperature substantially tar-free gas from the gasifier. A vertically displaceable skirt means is positioned within the gasifier to define the lower portion of the annular region so that vertical displacement of the skirt means positions the inlet into the annular region in a selected location within or in close proximity to the gasification zone for providing a positive control over the composition of the side stream gas.

Shredded Waste Downdraft Gasifier for Overseas Contingency Operations Waste-to-Energy Conversion

DTIC Science & Technology

2015-06-01

results of the proposed experimental test plan and the design of a shredded waste WEC system in Task 5. A. Generators (Left) and Shredded...Shredded Waste 4 8.5 – 27.1 5.1.1.4 Wall Friction Tests In addition to a properly sized outlet, the design of a mass flow vessel must consider...consolidating pressures. 5.1.2.3 Wall Friction Tests In addition to a properly sized outlet, the design of a mass flow vessel must consider the

Apparatus and method for feeding coal into a coal gasifier

DOEpatents

Bissett, Larry A.; Friggens, Gary R.; McGee, James P.

1979-01-01

This invention is directed to a system for feeding coal into a gasifier operating at high pressures. A coal-water slurry is pumped to the desired pressure and then the coal is "dried" prior to feeding the coal into the gasifier by contacting the slurry with superheated steam in an entrained bed dryer for vaporizing the water in the slurry.

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...

Primary zone air proportioner

DOEpatents

Cleary, Edward N. G.

1982-10-12

An air proportioner is provided for a liquid hydrocarbon fueled gas turbine of the type which is convertible to oil gas fuel and to coal gas fuel. The turbine includes a shell for enclosing the turbine, an air duct for venting air in said shell to a gasifier, and a fuel injector for injecting gasified fuel into the turbine. The air proportioner comprises a second air duct for venting air from the air duct for mixing with fuel from the gasifier. The air can be directly injected into the gas combustion basket along with the fuel from the injector or premixed with fuel from the gasifier prior to injection by the fuel injector.

Techno-economic assessment of the Mobil Two-Stage Slurry Fischer-Tropsch/ZSM-5 process

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

El Sawy, A.; Gray, D.; Neuworth, M.

1984-11-01

A techno-economic assessment of the Mobil Two-Stage Slurry Fischer-Tropsch reactor system was carried out. Mobil bench-scale data were evaluated and scaled to a commercial plant design that produced specification high-octane gasoline and high-cetane diesel fuel. Comparisons were made with three reference plants - a SASOL (US) plant using dry ash Lurgi gasifiers and Synthol synthesis units, a modified SASOL plant with a British Gas Corporation slagging Lurgi gasifier (BGC/Synthol) and a BGC/slurry-phase process based on scaled data from the Koelbel Rheinpreussen-Koppers plant. A conceptual commercial version of the Mobil two-stage process shows a higher process efficiency than a SASOL (US)more » and a BGC/Synthol plant. The Mobil plant gave lower gasoline costs than obtained from the SASOL (US) and BGC/Synthol versions. Comparison with published data from a slurry-phase Fischer-Tropsch (Koelbel) unit indicated that product costs from the Mobil process were within 6% of the Koelbel values. A high-wax version of the Mobil process combined with wax hydrocracking could produce gasoline and diesel fuel at comparable cost to the lowest values achieved from prior published slurry-phase results. 27 references, 18 figures, 49 tables.« less

Renewable Energy Institute International (REII): Cooperative Research and Development Final Report, CRADA Number CRD-10-387

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

Carpenter, D.

2014-11-01

NREL will provide the Renewable Energy Institute with detailed on-site biomass gasifier syngas monitoring, using the NREL transportable Molecular Beam Mass Spectrometer. This information will be used to optimize the parameters of the gasifier operation, insuring the quality of the syngas made in the Red Lion Bioenergy gasifier and its compatibility with catalytic conversion to fuels.

Producer gas production of Indonesian biomass in fixed-bed downdraft gasifier as an alternative fuels for internal combustion engines

NASA Astrophysics Data System (ADS)

Simanjuntak, J. P.; Lisyanto; Daryanto, E.; Tambunan, B. H.

2018-03-01

downdraft biomass gasification reactors, coupled with reciprocating internal combustion engines (ICE) are a viable technology for small scale heat and power generation. The direct use of producer gas as fuel subtitution in an ICE could be of great interest since Indonesia has significant land area in different forest types that could be used to produce bioenergy and convert forest materials to bioenergy for use in energy production and the versatility of this engine. This paper will look into the aspect of biomass energie as a contributor to energy mix in Indonesia. This work also contains information gathered from numerous previews study on the downdraft gasifier based on experimental or simulation study on the ability of producer gas as fuels for internal combustion engines aplication. All data will be used to complement the preliminary work on biomass gasification using downdraft to produce producer gas and its application to engines.

Experimental and computational study and development of the bituminous coal entrained-flow air-blown gasifier for IGCC

NASA Astrophysics Data System (ADS)

Abaimov, N. A.; Osipov, P. V.; Ryzhkov, A. F.

2016-10-01

In the paper the development of the advanced bituminous coal entrained-flow air- blown gasifier for the high power integrated gasification combined cycle is considered. The computational fluid dynamics technique is used as the basic development tool. The experiment on the pressurized entrained-flow gasifier was performed by “NPO CKTI” JSC for the thermochemical processes submodel verification. The kinetic constants for Kuznetsk bituminous coal (flame coal), obtained by thermal gravimetric analysis method, are used in the model. The calculation results obtained by the CFD model are in satisfactory agreements with experimental data. On the basis of the verified model the advanced gasifier structure was suggested which permits to increase the hydrogen content in the synthesis gas and consequently to improve the gas turbine efficiency. In order to meet the specified requirements vapor is added on the second stage of MHI type gasifier and heat necessary for air gasification is compensated by supplemental heating of the blasting air.

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.

Low-Chrome/Chrome Free Refractories for Slagging Gasifiers

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

Bennett, J.P.; Kwong, K.-S.; Powell, C.P.

2007-01-01

Gasifiers are containment vessels used to react carbon-containing materials with oxygen and water, producing syngas (CO and H2) that is used in chemical and power production. It is also a potential source of H2 in a future hydrogen economy. Air cooled slagging gasifiers are one type of gasifier, operating at temperatures from 1275-1575º C and at pressures of 400 psi or higher. They typically use coal or petroleum coke as the carbon source, materials which contain ash impurities that liquefy at the gasification temperatures, producing liquid slag in quantities of 100 or more tons/day, depending on the carbon fed ratemore » and the percent ash present in the feedstock. The molten slag is corrosive to refractory linings, causing chemical dissolution and spalling. The refractory lining is composed of chrome oxide, alumina, and zirconia; and is replaced every 3-24 months. Gasifier users would like greater on-line availability and reliability of gasifier liners, something that has impacted gasifier acceptance by industry. Research is underway at NETL to improve refractory service life and to develop a no-chrome or low-chrome oxide alternative refractory liner. Over 250 samples of no- or low-chrome oxide compositions have been evaluated for slag interactions by cup testing; with potential candidates for further studies including those with ZrO2, Al2O3, and MgO materials. The development of improved liner materials is necessary if technologies such as IGCC and DOE’s Near Zero Emissions Advanced Fossil Fuel Power Plant are to be successful and move forward in the marketplace.« less

Landfill gas generation after mechanical biological treatment of municipal solid waste. Estimation of gas generation rate constants.

PubMed

Gioannis, G De; Muntoni, A; Cappai, G; Milia, S

2009-03-01

Mechanical biological treatment (MBT) of residual municipal solid waste (RMSW) was investigated with respect to landfill gas generation. Mechanically treated RMSW was sampled at a full-scale plant and aerobically stabilized for 8 and 15 weeks. Anaerobic tests were performed on the aerobically treated waste (MBTW) in order to estimate the gas generation rate constants (k,y(-1)), the potential gas generation capacity (L(o), Nl/kg) and the amount of gasifiable organic carbon. Experimental results show how MBT allowed for a reduction of the non-methanogenic phase and of the landfill gas generation potential by, respectively, 67% and 83% (8 weeks treatment), 82% and 91% (15 weeks treatment), compared to the raw waste. The amount of gasified organic carbon after 8 weeks and 15 weeks of treatment was equal to 11.01+/-1.25kgC/t(MBTW) and 4.54+/-0.87kgC/t(MBTW), respectively, that is 81% and 93% less than the amount gasified from the raw waste. The values of gas generation rate constants obtained for MBTW anaerobic degradation (0.0347-0.0803y(-1)) resemble those usually reported for the slowly and moderately degradable fractions of raw MSW. Simulations performed using a prediction model support the hypothesis that due to the low production rate, gas production from MBTW landfills is well-suited to a passive management strategy.

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.

INNOVATIVE INSTRUMENTATION AND ANALYSIS OF THE TEMPERATURE MEASUREMENT FOR HIGH TEMPERATURE GASIFICATION

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

Seong W. Lee

During this reporting period, the literature survey including the gasifier temperature measurement literature, the ultrasonic application and its background study in cleaning application, and spray coating process are completed. The gasifier simulator (cold model) testing has been successfully conducted. Four factors (blower voltage, ultrasonic application, injection time intervals, particle weight) were considered as significant factors that affect the temperature measurement. The Analysis of Variance (ANOVA) was applied to analyze the test data. The analysis shows that all four factors are significant to the temperature measurements in the gasifier simulator (cold model). The regression analysis for the case with the normalizedmore » room temperature shows that linear model fits the temperature data with 82% accuracy (18% error). The regression analysis for the case without the normalized room temperature shows 72.5% accuracy (27.5% error). The nonlinear regression analysis indicates a better fit than that of the linear regression. The nonlinear regression model's accuracy is 88.7% (11.3% error) for normalized room temperature case, which is better than the linear regression analysis. The hot model thermocouple sleeve design and fabrication are completed. The gasifier simulator (hot model) design and the fabrication are completed. The system tests of the gasifier simulator (hot model) have been conducted and some modifications have been made. Based on the system tests and results analysis, the gasifier simulator (hot model) has met the proposed design requirement and the ready for system test. The ultrasonic cleaning method is under evaluation and will be further studied for the gasifier simulator (hot model) application. The progress of this project has been on schedule.« less

Development Of An Acoustice Sensor For On-Line Gas Temperature Measurement In Gasifiers

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

Peter Ariessohn; Hans Hornung

2006-10-01

This project was awarded under U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) Program Solicitation DE-PS26-02NT41422 and specifically addresses Technical Topical Area 2 - Gasification Technologies. The project team includes Enertechnix, Inc. as the main contractor and ConocoPhillips Company as a technical partner, who also provides access to the SG Solutions Gasification Facility (formerly Wabash River Energy Limited), host for the field-testing portion of the research. The objective of this project was to adapt acoustic pyrometer technology to make it suitable for measuring gas temperature inside a coal gasifier, to develop a prototype sensor based on this technology,more » and to demonstrate its performance through testing on a commercial gasifier. The project was organized in three phases, each of approximately one year duration. The first phase consisted of researching a variety of sound generation and coupling approaches suitable for use with a high pressure process, evaluation of the impact of gas composition variability on the acoustic temperature measurement approach, evaluation of the impact of suspended particles and gas properties on sound attenuation, evaluation of slagging issues and development of concepts to deal with this issue, development and testing of key prototype components to allow selection of the best approaches, and development of a conceptual design for a field prototype sensor that could be tested on an operating gasifier. The second phase consisted of designing and fabricating a series of prototype sensors, testing them in the laboratory, and developing a conceptual design for a field prototype sensor. The third phase consisted of designing and fabricating the field prototype, and testing it in the lab and in a commercial gasifier to demonstrate the ability to obtain accurate measurements of gas temperature in an operating gasifier. This report describes all of the activities conducted during the project and reports the findings of each activity in detail. The investigation of potential sound generation and coupling methods led to the selection of a reflected shock method which has been developed into a functioning prototype device. The principles of operation of this device and its performance characteristics are described in the report. Modeling of the attenuation of sound by suspended particles and by interaction of the sound pulses with the high temperature syngas inside the gasifier was conducted and the predictions of those models were used to determine the required sound pulse intensity to allow the sound pulses to be detected after passage through the gasifier environment. These modeling results are presented in this report. A study of the likely spatial and temporal variability of gas composition inside the gasifier was performed and the results of that study was used to predict the impact of that variability on the accuracy of the acoustic temperature method. These results are reported here. A design for a port rodding mechanism was developed to deal with potential slagging issues and was incorporated into the prototype sensor. This port rodding mechanism operated flawlessly during the field testing, but because these tests were performed in a region of the gasifier that experiences little slagging, the effectiveness of the rodding mechanism in dealing with highly slagging conditions was not fully demonstrated. This report describes the design and operation of the automated Gasifier Acoustic Pyrometer (autoGAP) which was tested at the Wabash River facility. The results of the tests are reported and analyzed in detail. All of the objectives of the project have been achieved. A field prototype acoustic pyrometer sensor has been successfully tested at the Wabash River gasifier plant. Acoustic signals were propagated through the gases inside the gasifier and were detected by the receiver unit, the times of flight of these sound pulses were measured and these propagation times were converted into temperatures which agreed very well with thermocouple measurements made in the same location as the acoustic measurements. The acoustic pyrometer system was operated under computer control and was shown to be capable of making measurements every 10 minutes (or more frequently) for an extended period. Some minor mechanical issues remain. During testing on the gasifier, one of the pressure seals failed after two days of operation, but this can easily be corrected by the use of a different seal design. Also, the testing performed so far was conducted in a region of the gasifier where conditions are somewhat less harsh than in other parts of the gasifier where thermocouples will not survive. Therefore, additional testing should be performed in those harsher locations to demonstrate the ability of this new measurement technology to provide temperature measurements that cannot be obtained by any other means.« less

Method of generating electricity using an endothermic coal gasifier and MHD generator

DOEpatents

Marchant, David D.; Lytle, John M.

1982-01-01

A system and method of generating electrical power wherein a mixture of carbonaceous material and water is heated to initiate and sustain the endothermic reaction of carbon and water thereby providing a gasified stream containing carbon monoxide, hydrogen and nitrogen and waste streams of hydrogen sulfide and ash. The gasified stream and an ionizing seed material and pressurized air from a preheater go to a burner for producing ionized combustion gases having a temperature of about 5000.degree. to about 6000.degree. F. which are accelerated to a velocity of about 1000 meters per second and passed through an MHD generator to generate DC power and thereafter through a diffuser to reduce the velocity. The gases from the diffuser go to an afterburner and from there in heat exchange relationship with the gasifier to provide heat to sustain the endothermic reaction of carbon and water and with the preheater to preheat the air prior to combustion with the gasified stream. Energy from the afterburner can also be used to energize other parts of the system.

Solids feeder apparatus

DOEpatents

Bell, Jr., Harold S.

1979-01-01

This invention sets forth a double-acting piston, which carries a floating piston, and which is reciprocated in a housing, for feeding coal to a high pressure gasifier system. The housing has a plurality of solids (for instance: coal) in-feeding ports and a single discharge port, the latter port being in communication with a high pressure gasifier system. The double-acting piston sequentially and individually communicates each of the in-feeding ports with the discharge port. The floating piston both seals off the discharge port while each in-feeding port is receiving coal or the like, to prevent undue escape of gas from the gasifier system, and translates in the housing, following a discharge of coal or the like into the discharge port, to return gas which has been admitted into the housing back into the gasifier system.

Analysis and control of the METC fluid-bed gasifier. Quarterly report, October 1994--January 1995

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

Farell, A.E.; Reddy, S.

1995-03-01

This document summarizes work performed for the period 10/1/94 to 2/1/95. The initial phase of the work focuses on developing a simple transfer function model of the Fluidized Bed Gasifier (FBG). This transfer function model will be developed based purely on the gasifier responses to step changes in gasifier inputs (including reactor air, convey air, cone nitrogen, FBG pressure, and coal feedrate). This transfer function model will represent a linear, dynamic model that is valid near the operating point at which the data was taken. In addition, a similar transfer function model will be developed using MGAS in order tomore » assess MGAS for use as a model of the FBG for control systems analysis.« less

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

PREPARATION AND TESTING OF CORROSIONAND SPALLATION-RESISTANT COATINGS

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

Hurley, John

2014-11-01

This Energy & Environmental Research Center (EERC) project is designed to determine if plating APMT®, a specific highly oxidation-resistant oxide dispersion-strengthened FeCrAl alloy made by Kanthal, onto nickel-based superalloy turbine parts is a viable method for substantially improving the lifetimes and maximum use temperatures of the parts. The method for joining the APMT plate to the superalloys is called evaporative metal bonding and involves placing a thin foil of zinc (Zn) between the plate and the superalloy, clamping them together, and heating in an atmosphere-controlled furnace. Upon heating, the Zn melts and dissolves the oxide skins of the alloys atmore » the bond line, allowing the two alloys to diffuse into each other. The Zn then diffuses through the alloys and evaporates from their surfaces. Laboratory testing to determine the diffusion rate of Zn through the alloys has been completed. However, an analytical solution does not exist to model the diffusion of zinc through the alloys. For this reason, a finite difference algorithm using MATLAB was developed. It makes use of the hopscotch algorithm. The model allows the user to specify the dimensions of the metal parts, the Zn concentration at the bondline, the mesh size, time step, and Zn diffusivity. The experimentally measured values of diffusivity for Zn in APMT and Rene 80/CM 247LC are approximately 2.7 × 10-12 and 4 × 10-14 m2/s, respectively. While the qualitative behavior of the model appears correct, a comparison of the diffusion predictions with the experimental results from earlier in the project indicates that the expected Zn concentration is significantly higher than that measured experimentally. The difference depends on the assumed initial concentration, which is difficult to quantify exactly under experimental conditions for t = 0. In addition to the diffusion work, the coefficients of thermal expansions were determined for each of the alloys as a function of temperature. This information has been entered into a finite element model using ANSYS so that appropriate force-applying structures can be designed for use in joining structures composed of APMT and the nickel alloys. Finite element modeling has been performed to finalize the fabrication geometry for the corrosion-testing phase. The addition of another bolt increases stress uniformity away from the region where the clamping is applied. It appears that a bolt spacing of approximately 25 mm in each jig is appropriate. This will allow the fabrication of 50-mm-wide sections of joints for the corrosion-testing task. Gasifier sampling activities continue to determine what types of trace contaminants may occur in cleaned syngas that could lead to corrosion or deposition in turbines firing coal syngas. The EERC has several pilot-scale gasifiers that are continually used in a variety of test configurations as determined by the needs of the projects that are funding the tests. We are sampling both noncombusted and combusted syngas produced during some of the pilot-scale gasifier tests. This year sampling was performed of both syngas and combusted syngas while the entrained-flow gasifier (EFG) was firing subbituminous coal from the Antelope Mine in Wyoming. Results of scanning electron microscope analyses of the syngas before combustion showed no submicron particles, only flakes of iron oxide that had likely formed on steel surfaces inside the combustor. As shown in the 2013 annual report, soot was also collected from the syngas when the much-lower-temperature fluid-bed gasifier (FBG) was fired, indicating that the much higher temperature of the EFG prevented soot formation. However, particles collected from the combusted syngas consist almost entirely of submicron soot, and little to no vaporized metals made it past the warm-gas filters and scrubbers in the high-temperature EFG system which could then deposit in a turbine system burning a higher hydrogen syngas. These results are consistent with the analyses of the particulates collected from combusted syngas when the lowertemperature FBG system is used.« less

Low Cost High-H 2 Syngas Production for Power and Liquid Fuels

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

Zhou, S. James

2015-07-31

This report summarizes the technical progress made of the research project entitled “Low Cost High-H2 Syngas Production for Power and Liquid Fuels,” under DOE Contract No. DE-FE-0011958. The period of performance was October 1, 2013 through July 30, 2015. The overall objectives of this project was to determine the technical and economic feasibility of a systems approach for producing high hydrogen syngas from coal with the potential to reduce significantly the cost of producing power, chemical-grade hydrogen or liquid fuels, with carbon capture to reduce the environmental impact of gasification. The project encompasses several areas of study and the resultsmore » are summarized here. (1) Experimental work to determine the technical feasibility of a novel hybrid polymer/metal H2-membrane to recover pure H2 from a coal-derived syngas was done. This task was not successful. Membranes were synthesized and show impermeability of any gases at required conditions. The cause of this impermeability was most likely due to the densification of the porous polymer membrane support made from polybenzimidazole (PBI) at test temperatures above 250 °C. (2) Bench-scale experimental work was performed to extend GTI's current database on the University of California Sulfur Recovery Process-High Pressure (UCSRP-HP) and recently renamed Sulfur Removal and Recovery (SR2) process for syngas cleanup including removal of sulfur and other trace contaminants, such as, chlorides and ammonia. The SR2 process tests show >90% H2S conversion with outlet H2S concentrations less than 4 ppmv, and 80-90% ammonia and chloride removal with high mass transfer rates. (3) Techno-economic analyses (TEA) were done for the production of electric power, chemical-grade hydrogen and diesel fuels, from a mixture of coal- plus natural gas-derived syngas using the Aerojet Rocketdyne (AR) Advanced Compact coal gasifier and a natural gas partial oxidation reactor (POX) with SR2 technology. Due to the unsuccessful experimental results with the hybrid polymer/metal H2 membrane, a conventional CO2 capture (single-stage Selexol) and hydrogen purification (PSA) technologies were used in the appropriate cases. In all cases, the integrated system of Advanced Compact coal gasifier, non-catalytic natural gas partial oxidation, and SR2 multicontaminant removal with state-of-the-art auxiliary system provided a 5-25% cost advantage over the base line plants using GEE coal gasifier with conventional Selexol/Claus sulfur removal and recovery. These plants also produce 18-30% less CO2 than with the conventional coal gasification plants.« less

Possibility study of gasifier with axial circulating flue gas for reducing Tar

NASA Astrophysics Data System (ADS)

Poowadin, T.; Polsongkram, M.; Khantikomol, P.

2018-01-01

This present research article aims to study the possibility of gasification by axial core flue gas circulating kiln and find the efficiency of syngas production. An axial core flue gas circulating tube was installed in the center of the updraft gasifier in purposing of tar reducing. In the present study, the eucalyptus wood chip 4, 8, and 10 kg with the moisture content 16% were examined. Several type-K thermocouples were employed to measure the temperatures at preheat, combustion, reduction, pyrolysis, drying, and gas outlet zone. The results showed that the temperatures in the combustion and the reduction zone of the kiln with the axial core flue gas recirculating were lower than the kiln without the core owing to installing the core would reduce the combustion zone area in biomass burning. Obviously, the temperature in the pyrolysis and drying zone were nearly the same as both with and without the core. In consideration of syngas components, it was found that CO production from the gasifier with the core was higher than the gasifier without the core about 25%. Other gases, however, were almost same. The syngas production efficiency obtained from the gasifier with the core decreased with increasing the mass of biomass. It showed that the highest efficiency was 30% at 4 kg supplying biomass. In comparison, the efficiencies of both the kilns with and without the core were not different. For liquid product, the amount of liquid decreased about 47.23% comparing with the gasifier without the core.

Advanced Turbine Technology Applications Project (ATTAP)

NASA Technical Reports Server (NTRS)

1992-01-01

ATTAP activities during the past year included test-bed engine design and development, ceramic component design, materials and component characterization, ceramic component process development and fabrication, ceramic component rig testing, and test-bed engine fabrication and testing. Significant technical challenges remain, but all areas exhibited progress. Test-bed engine design and development included engine mechanical design, combustion system design, alternate aerodynamic designs of gasifier scrolls, and engine system integration aimed at upgrading the AGT-5 from a 1038 C (1900 F) metal engine to a durable 1372 C (2500 F) structural ceramic component test-bed engine. ATTAP-defined ceramic and associated ceramic/metal component design activities completed include the ceramic gasifier turbine static structure, the ceramic gasifier turbine rotor, ceramic combustors, the ceramic regenerator disk, the ceramic power turbine rotors, and the ceramic/metal power turbine static structure. The material and component characterization efforts included the testing and evaluation of seven candidate materials and three development components. Ceramic component process development and fabrication proceeded for the gasifier turbine rotor, gasifier turbine scroll, gasifier turbine vanes and vane platform, extruded regenerator disks, and thermal insulation. Component rig activities included the development of both rigs and the necessary test procedures, and conduct of rig testing of the ceramic components and assemblies. Test-bed engine fabrication, testing, and development supported improvements in ceramic component technology that permit the achievement of both program performance and durability goals. Total test time in 1991 amounted to 847 hours, of which 128 hours were engine testing, and 719 were hot rig testing.

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

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

Air gasification of rice husk in bubbling fluidized bed reactor with bed heating by conventional charcoal.

PubMed

Makwana, J P; Joshi, Asim Kumar; Athawale, Gaurav; Singh, Dharminder; Mohanty, Pravakar

2015-02-01

An experimental study of air gasification of rice husk was conducted in a bench-scale fluidized bed gasifier (FBG) having 210 mm diameter and 1600 mm height. Heating of sand bed material was performed using conventional charcoal fuel. Different operating conditions like bed temperature, feeding rate and equivalence ratio (ER) varied in the range of 750-850 °C, 25-31.3 kg/h, and 0.3-0.38, respectively. Flow rate of air was kept constant (37 m(3)/h) during FBG experiments. The carbon conversion efficiencies (CCE), cold gas efficiency, and thermal efficiency were evaluated, where maximum CCE was found as 91%. By increasing ER, the carbon conversion efficiency was decreased. Drastic reduction in electric consumption for initial heating of gasifier bed with charcoal compared to ceramic heater was ∼45%. Hence rice husk is found as a potential candidate to use directly (without any processing) in FBG as an alternative renewable energy source from agricultural field. Copyright © 2014 Elsevier 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.

Co-gasification of pine and oak biochar with sub-bituminous coal in carbon dioxide.

PubMed

Beagle, E; Wang, Y; Bell, D; Belmont, E

2018-03-01

Pine and oak biochars derived as byproducts of demonstration-scale pyrolysis, and blends of these two feedstocks with Powder River Basin coal, were gasified in a carbon dioxide environment using a modified drop tube reactor (MDTR) and a thermogravimetric analyzer (TGA). The impact of gasification temperature on conversion kinetics was evaluated from the temporal evolution of major product gases in the MDTR as measured using a mass spectrometer. Random pore modeling was conducted to simulate gasification in the MDTR with favorable results. The MDTR and TGA were used to conduct gasification for assessment of non-linear additive effects in the blends. Additive analysis of the blends showed deviation from the experimental blend results, indicating inhibiting effects of co-gasifying the biochar and coal. Inhibitory effects are more significant for oak than pine and more pronounced in the TGA at lower gasification temperatures. Results are discussed in the context of feedstock and reactor type. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dynamic Modeling and Plantwide Control of a Hybrid Power and Chemical Plant: An Integrated Gasification Combined Cycle Coupled with a Methanol Plant

NASA Astrophysics Data System (ADS)

Robinson, Patrick J.

Gasification has been used in industry on a relatively limited scale for many years, but it is emerging as the premier unit operation in the energy and chemical industries. The switch from expensive and insecure petroleum to solid hydrocarbon sources (coal and biomass) is occurring due to the vast amount of domestic solid resources, national security and global warming issues. Gasification (or partial oxidation) is a vital component of "clean coal" technology. Sulfur and nitrogen emissions can be reduced, overall energy efficiency is increased and carbon dioxide recovery and sequestration are facilitated. Gasification units in an electric power generation plant produce a fuel gas for driving combustion turbines. Gasification units in a chemical plant generate synthesis gas, which can be used to produce a wide spectrum of chemical products. Future plants are predicted to be hybrid power/chemical plants with gasification as the key unit operation. The coupling of an Integrated Gasification Combined Cycle (IGCC) with a methanol plant can handle swings in power demand by diverting hydrogen gas from a combustion turbine and synthesis gas from the gasifier to a methanol plant for the production of an easily-stored, hydrogen-consuming liquid product. An additional control degree of freedom is provided with this hybrid plant, fundamentally improving the controllability of the process. The idea is to base-load the gasifier and use the more responsive gas-phase units to handle disturbances. During the summer days, power demand can fluctuate up to 50% over a 12-hour period. The winter provides a different problem where spikes of power demand can go up 15% within the hour. The following dissertation develops a hybrid IGCC / methanol plant model, validates the steady-state results with a National Energy Technical Laboratory study, and tests a proposed control structure to handle these significant disturbances. All modeling was performed in the widely used chemical process simulators Aspen Plus and Aspen Dynamics. This dissertation first presents a simple approximate method for achieving the objective of having a gasifier model that can be exported into Aspen Dynamics. Limitations in the software dealing with solids make this a necessary task. The basic idea is to use a high molecular weight hydrocarbon that is present in the Aspen library as a pseudo fuel. For many plantwide dynamic studies, a rigorous high-fidelity dynamic model of the gasifier is not needed because its dynamics are very fast and the gasifier gas volume is a relatively small fraction of the total volume of the entire plant. The proposed approximate model captures the essential macro-scale thermal, flow, composition and pressure dynamics. This paper does not attempt to optimize the design or control of gasifiers, but merely presents an idea of how to dynamically simulate coal gasification in an approximate way. This dissertation also presents models of the downstream units of a typical IGCC. Dynamic simulations of the H2S absorption/stripping unit, Water-gas Shift (WGS) reactors, and CO2 absorption/stripping unit are essential for the development of stable and agile plantwide control structures of this hybrid power/chemical plant. Due to the high pressure of the system, hydrogen sulfide is removed by means of physical absorption. SELEXOLRTM (a mixture of the dimethyl ethers of polyethylene glycol) is used to achieve a gas purity of less than 5 ppm H2S. This desulfurized synthesis gas is sent to two water gas shift reactors that convert a total of 99% of carbon monoxide to hydrogen. Physical absorption of carbon dioxide with Selexol produces a hydrogen rich stream (90 mol% H2) to be fed into combustion turbines or to a methanol plant. Steady-state economic designs and plantwide control structures are developed in this dissertation. A steady-state economic design, control structure, and successful turndown of the methanol plant are shown in this dissertation. The Plantwide control structure and interaction among units are also shown. The methanol plant was sized to handle a reductions of the power generation from an IGCC by 50%, producing a high purity methanol stream of 99.5 mol%. Advanced regulatory control structures were designed and play a significant role for the successful turndown of the methanol plant to 20% capacity. The cooled methanol reactor is controlled by the exit temperature instead of a peak temperature within the reactor. During times of low capacity and minimum vapor rate within the column, tray temperature is controlled by recycling some of the distillate and bottoms flow. The gasifier feed is held constant. The product hydrogen from the IGCC is fed to the combustion turbine as required by electric power demand. Synthesis gas fed into the methanol plant maintains pressure of the hydrogen stream. Make-up hydrogen is also fed to the methanol plant to maintain stoichiometry via a flow ratio. This ratio is adjusted to hold carbon monoxide composition of the recycle gas in the methanol plant. This dissertation also explores various methods on how to turn down distillation columns to very low capacity. Recycling flow back to the column was determined to be the best method. Inserting Langmuir-Hinshelwood-Hougen-Watson kinetics into Aspen was also demonstrated with an example.

Analysis and control of the METC fluid bed gasifier. Quarterly progress report, January--March 1995

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

NONE

1995-03-01

This document summarizes work performed for the period 10/1/94 to 3/31/95. In this work, three components will form the basis for design of a control scheme for the Fluidized Bed Gasifier (FBG) at METC: (1) a control systems analysis based on simple linear models derived from process data, (2) review of the literature on fluid bed gasifier operation and control, and (3) understanding of present FBG operation and real world considerations. Below we summarize work accomplished to data in each of these areas.

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.

Advanced Turbine Technology Applications Project (ATTAP)

NASA Technical Reports Server (NTRS)

1990-01-01

Advanced Turbine Technology Application Project (ATTAP) activities during the past year were highlighted by test-bed engine design and development activities; ceramic component design; materials and component characterization; ceramic component process development and fabrication; component rig testing; and test-bed engine fabrication and testing. Although substantial technical challenges remain, all areas exhibited progress. Test-bed engine design and development activity included engine mechanical design, power turbine flow-path design and mechanical layout, and engine system integration aimed at upgrading the AGT-5 from a 1038 C metal engine to a durable 1371 C structural ceramic component test-bed engine. ATTAP-defined ceramic and associated ceramic/metal component design activities include: the ceramic combustor body, the ceramic gasifier turbine static structure, the ceramic gasifier turbine rotor, the ceramic/metal power turbine static structure, and the ceramic power turbine rotors. The materials and component characterization efforts included the testing and evaluation of several candidate ceramic materials and components being developed for use in the ATTAP. Ceramic component process development and fabrication activities are being conducted for the gasifier turbine rotor, gasifier turbine vanes, gasifier turbine scroll, extruded regenerator disks, and thermal insulation. Component rig testing activities include the development of the necessary test procedures and conduction of rig testing of the ceramic components and assemblies. Four-hundred hours of hot gasifier rig test time were accumulated with turbine inlet temperatures exceeding 1204 C at 100 percent design gasifier speed. A total of 348.6 test hours were achieved on a single ceramic rotor without failure and a second ceramic rotor was retired in engine-ready condition at 364.9 test hours. Test-bed engine fabrication, testing, and development supported improvements in ceramic component technology that will permit the achievement of program performance and durability goals. The designated durability engine accumulated 359.3 hour of test time, 226.9 of which were on the General Motors gas turbine durability schedule.

Method of operating a coal gasifier

DOEpatents

Blaskowski, Henry J.

1979-01-01

A method of operating an entrained flow coal gasifier which comprises the steps of firing coal at two levels in a combustion zone with near stoichiometric air, removing molten ash from the combustion zone, conveying combustion products upwardly from the combustion zone through a reduction zone, injecting additional coal into the combustion products in the reduction zone and gasifying at least a portion of the coal to form low BTU gas, conveying the gas to a point of use, including also reducing gasifier output by modifying the ratio of air to coal supplied to the upper level of the combustion zone so that the ratio becomes increasingly substoichiometric thereby extending the gasification of coal from the reduction zone into the upper level of the combustion zone, and maintaining the lower level of coal in the combustion zone at near stoichiometric conditions so as to provide sufficient heat to maintain effective slagging conditions.

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.

Liquid Fuel Production from Biomass via High Temperature Steam Electrolysis

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

Grant L. Hawkes; Michael G. McKellar

2009-11-01

A process model of syngas production using high temperature electrolysis and biomass gasification is presented. Process heat from the biomass gasifier is used to heat steam for the hydrogen production via the high temperature steam electrolysis process. Hydrogen from electrolysis allows a high utilization of the biomass carbon for syngas production. Oxygen produced form the electrolysis process is used to control the oxidation rate in the oxygen-fed biomass gasifier. Based on the gasifier temperature, 94% to 95% of the carbon in the biomass becomes carbon monoxide in the syngas (carbon monoxide and hydrogen). Assuming the thermal efficiency of the powermore » cycle for electricity generation is 50%, (as expected from GEN IV nuclear reactors), the syngas production efficiency ranges from 70% to 73% as the gasifier temperature decreases from 1900 K to 1500 K. Parametric studies of system pressure, biomass moisture content and low temperature alkaline electrolysis are also presented.« less

Small-Scale Coal-Biomass to Liquids Production Using Highly Selective Fischer-Tropsch Synthesis

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

Gangwal, Santosh K.; McCabe, Kevin

2015-04-30

The research project advanced coal-to-liquids (CTL) and coal-biomass to liquids (CBTL) processes by testing and validating Chevron’s highly selective and active cobalt-zeolite hybrid Fischer-Tropsch (FT) catalyst to convert gasifier syngas predominantly to gasoline, jet fuel and diesel range hydrocarbon liquids, thereby eliminating expensive wax upgrading operations The National Carbon Capture Center (NCCC) operated by Southern Company (SC) at Wilsonville, Alabama served as the host site for the gasifier slip-stream testing/demonstration. Southern Research designed, installed and commissioned a bench scale skid mounted FT reactor system (SR-CBTL test rig) that was fully integrated with a slip stream from SC/NCCC’s transport integrated gasifiermore » (TRIG TM). The test-rig was designed to receive up to 5 lb/h raw syngas augmented with bottled syngas to adjust the H 2/CO molar ratio to 2, clean it to cobalt FT catalyst specifications, and produce liquid FT products at the design capacity of 2 to 4 L/day. It employed a 2-inch diameter boiling water jacketed fixed-bed heat-exchange FT reactor incorporating Chevron’s catalyst in Intramicron’s high thermal conductivity micro-fibrous entrapped catalyst (MFEC) packing to efficiently remove heat produced by the highly exothermic FT reaction.« less

One Step Biomass Gas Reforming-Shift Separation Membrane Reactor

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

Roberts, Michael J.; Souleimanova, Razima

2012-12-28

GTI developed a plan where efforts were concentrated in 4 major areas: membrane material development, membrane module development, membrane process development, and membrane gasifier scale-up. GTI assembled a team of researchers to work in each area. Task 1.1 Ceramic Membrane Synthesis and Testing was conducted by Arizona State University (ASU), Task 1.2 Metallic Membrane Synthesis and Testing was conducted by the U.S. National Energy Technology Laboratory (NETL), Task 1.3 was conducted by SCHOTT, and GTI was to test all membranes that showed potential. The initial focus of the project was concentrated on membrane material development. Metallic and glass-based membranes weremore » identified as hydrogen selective membranes under the conditions of the biomass gasification, temperatures above 700C and pressures up to 30 atmospheres. Membranes were synthesized by arc-rolling for metallic type membranes and incorporating Pd into a glass matrix for glass membranes. Testing for hydrogen permeability properties were completed and the effects of hydrogen sulfide and carbon monoxide were investigated for perspective membranes. The initial candidate membrane of Pd80Cu20 chosen in 2008 was selected for preliminary reactor design and cost estimates. Although the H2A analysis results indicated a $1.96 cost per gge H2 based on a 5A (micron) thick PdCu membrane, there was not long-term operation at the required flux to satisfy the go/no go decision. Since the future PSA case yielded a $2.00/gge H2, DOE decided that there was insufficient savings compared with the already proven PSA technology to further pursue the membrane reactor design. All ceramic membranes synthesized by ASU during the project showed low hydrogen flux as compared with metallic membranes. The best ceramic membrane showed hydrogen permeation flux of 0.03 SCFH/ft2 at the required process conditions while the metallic membrane, Pd80Cu20 showed a flux of 47.2 SCFH/ft2 (3 orders of magnitude difference). Results from NETL showed Pd80Cu20 with the highest flux, therefore it was chosen as the initial and eventually, final candidate membrane. The criteria for choice were high hydrogen flux, long-term stability, and H2S tolerance. Results from SCHOTT using glass membranes showed a maximum of 0.25 SCFH/ft2, that is an order of magnitude better than the ceramic membrane but still two orders of magnitude lower than the metallic membrane. A membrane module was designed to be tested with an actual biomass gasifier. Some parts of the module were ordered but the work was stopped when a no go decision was made by the DOE.« less

Preparation and testing of corrosion and spallation-resistant coatings

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

Hurley, John P.; Cavalli, Matthew N.

2016-06-30

The goal of this project was to take a recently developed method of bonding oxide dispersion-strengthened (ODS) FeCrAl plating to nickel superalloys closer to commercial use in syngas-fired turbines. The project was designed to better understand and develop the bonding process and to determine if plating APMT®, a specific highly oxidation-resistant ODS FeCrAl alloy made by Kanthal, onto nickel-based superalloy turbine parts is a viable method for substantially improving the lifetimes and maximum use temperatures of the parts. The superalloys investigated for protection were CM247LC and Rene® 80, both alumina scale-forming alloys. The method for bonding the APMT plate tomore » the superalloys is called evaporative metal bonding, which involves placing a thin foil of zinc between the plate and the superalloy, clamping them together, and heating in an atmosphere-controlled furnace. Upon heating, the zinc melts and dissolves the oxide skins of the alloys at the bond line, allowing the two alloys to diffuse into each other. The zinc then diffuses through the alloys and evaporates from their surfaces, creating a bond between the APMT and the superalloy that is stronger than the APMT itself. Testing showed that the diffusivity of zinc in both APMT and CM247LC is quite similar at 700°C but 15 times higher in the APMT at 1214°C. Coefficients of thermal expansion were determined for each of the alloys as a function of temperature. This information was entered into a finite-element model using ANSYS, which was used to design a clamping jig for pressing the APMT to the superalloys at the bonding temperature. Scanning electron microscopy analyses of representative joints showed that no zinc remained in the alloys after bonding Unfortunately, the analyses also showed some small pieces of broken aluminum oxide scale near the bond lines, indicating that its scale was not sufficiently removed during prebonding cleaning. Samples from each of the bonded blocks were sent to Siemens for its standard oxidation, spallation, and corrosion testing, which was scheduled for completion in the spring of 2016. However, because of commercial demands, the tests were not completed by the time of this report except some initial spallation tests at 1150°C. In those tests, several of the APMT plates separated from the CM247LC, likely because of the remaining aluminum oxide scale on the surface of the CM247LC. This implies that surface preparation may need to include machining to remove the oxide scale before bonding rather than just sandblasting. In previous tensile testing at 950°C, the breaks in the tensile samples always occurred in the APMT and not at the joints. Gasifier sampling was completed to determine what types of trace contaminants may occur in cleaned and combusted syngas and that could lead to corrosion or deposition in turbines firing coal syngas. The sampling was done from a pressurized fluidized-bed gasifier and a pressurized entrained-flow gasifier. The particles captured on a filter from syngas were typically 0.2 to 0.5 μm in diameter, whereas those captured from the combusted syngas were slightly larger and more spherical. X-ray photoelectron spectroscopy done at Oak Ridge National Laboratory showed that the particles do not contain any metals and have an atomic composition almost identical to that of the polycarbonate filter. This indicates that the particles are primarily soot-based and not formed from volatilization of metals in the gasifiers.« less

Pressure-Letdown Plates for Coal Gasifiers

NASA Technical Reports Server (NTRS)

Collins, E. R., Jr.

1985-01-01

Variation of pseudoporous plates used with coal gasifiers in pressure letdown stage of processing minimize clogging. Rotating plates containing variable gap annuli continually change flow path to enable erosionless reduction of gas pressure. Particles that otherwise clog porous plugs pass through gaps.

Development of an Acoustic Sensor On-Line Gas Temperature Measurement in Gasifiers

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

Peter Ariessohn

2008-06-30

This project was awarded under U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) Program Solicitation DE-PS26-02NT41422 and specifically addresses Technical Topical Area 2 - Gasification Technologies. The project team includes Enertechnix, Inc. as the main contractor and ConocoPhillips Company as a technical partner, who also provides access to the SG Solutions Gasification Facility (formerly Wabash River Energy Limited), host for the field-testing portion of the research. The objective of this project was to adapt acoustic pyrometer technology to make it suitable for measuring gas temperature inside a coal gasifier, to develop a prototype sensor based on this technology,more » and to demonstrate its performance through testing on a commercial gasifier. The project was organized in three phases, each of approximately one year duration. The first phase consisted of researching a variety of sound generation and coupling approaches suitable for use with a high pressure process, evaluation of the impact of gas composition variability on the acoustic temperature measurement approach, evaluation of the impact of suspended particles and gas properties on sound attenuation, evaluation of slagging issues and development of concepts to deal with this issue, development and testing of key prototype components to allow selection of the best approaches, and development of a conceptual design for a field prototype sensor that could be tested on an operating gasifier. The second phase consisted of designing and fabricating a series of prototype sensors, testing them in the laboratory, and developing a conceptual design for a field prototype sensor. The third phase consisted of designing and fabricating the field prototype, and testing it in the lab and in a commercial gasifier to demonstrate the ability to obtain accurate measurements of gas temperature in an operating gasifier. Following the completion of the initial 3 year project, several continuations were awarded by the Department of Energy to allow Enertechnix to conduct extended testing of the sensor at the Wabash River facility. In February, 2008 the sensor was installed on the gasifier in preparation for a long-term test. During the initial testing of the sensor a stainless steel tube on the sensor failed and allowed syngas to escape. The syngas self-ignited and the ensuing small fire damaged some of the components on the sensor. There was no damage to the gasifier or other equipment and no injuries resulted from this incident. Two meetings were held to identify the root causes of the incident-one at Wabash River and one at Enertechnix. A list of recommended improvements that would have addressed the causes of the incident was created and presented to the Department of Energy on May 2, 2008. However, the DOE decided not to pursue these improvements and terminated the project. This report describes all of the activities conducted during the project and reports the findings of each activity in detail. The investigation of potential sound generation and coupling methods led to the selection of a reflected shock method which has been developed into a functioning prototype device. The principles of operation of this device and its performance characteristics are described in the report. Modeling of the attenuation of sound by suspended particles and by interaction of the sound pulses with the high temperature syngas inside the gasifier was conducted and the predictions of those models were used to determine the required sound pulse intensity to allow the sound pulses to be detected after passage through the gasifier environment. These modeling results are presented in this report. A study of the likely spatial and temporal variability of gas composition inside the gasifier was performed and the results of that study was used to predict the impact of that variability on the accuracy of the acoustic temperature method. These results are reported here. A design for a port rodding mechanism was developed to deal with potential slagging issues and was incorporated into the prototype sensor. This port rodding mechanism operated flawlessly during the field testing, but because these tests were performed in a region of the gasifier that experiences little slagging, the effectiveness of the rodding mechanism in dealing with highly slagging conditions was not fully demonstrated. This report describes the design and operation of the automated Gasifier Acoustic Pyrometer (autoGAP) which was tested at the Wabash River facility. The results of the tests are reported and analyzed in detail. All of the objectives of the initial R&D project were achieved and a field prototype acoustic pyrometer sensor was successfully tested at the Wabash River gasifier plant.« less

Carbonate fuel cell system with thermally integrated gasification

DOEpatents

Steinfeld, G.; Meyers, S.J.; Lee, A.

1996-09-10

A fuel cell system is described which employs a gasifier for generating fuel gas for the fuel cell of the fuel cell system and in which heat for the gasifier is derived from the anode exhaust gas of the fuel cell. 2 figs.

Energy Systems Integration Partnerships: NREL + Cogent Energy Systems

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

Berdahl, Sonja E

2017-08-09

NREL is collaborating with Cogent Energy Systems (Cogent) to introduce small-scale waste-to-energy technology in microgrids.The focus of the project is to test and demonstrate the feasibility, reliability, and usefulness of integrating electricity generated using a simulated syngas composition matching the syngas stream to be produced by a HelioStorm-based WTE gasifier to power a microgrid as a means of addressing and complementing the intermittency of other sources of electricity.

Liquid CO 2/Coal Slurry for Feeding Low Rank Coal to Gasifiers

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

Marasigan, Jose; Goldstein, Harvey; Dooher, John

2013-09-30

This study investigates the practicality of using a liquid CO 2/coal slurry preparation and feed system for the E-Gas™ gasifier in an integrated gasification combined cycle (IGCC) electric power generation plant configuration. Liquid CO 2 has several property differences from water that make it attractive for the coal slurries used in coal gasification-based power plants. First, the viscosity of liquid CO 2 is much lower than water. This means it should take less energy to pump liquid CO 2 through a pipe compared to water. This also means that a higher solids concentration can be fed to the gasifier, whichmore » should decrease the heat requirement needed to vaporize the slurry. Second, the heat of vaporization of liquid CO 2 is about 80% lower than water. This means that less heat from the gasification reactions is needed to vaporize the slurry. This should result in less oxygen needed to achieve a given gasifier temperature. And third, the surface tension of liquid CO 2 is about 2 orders of magnitude lower than water, which should result in finer atomization of the liquid CO 2 slurry, faster reaction times between the oxygen and coal particles, and better carbon conversion at the same gasifier temperature. EPRI and others have recognized the potential that liquid CO 2 has in improving the performance of an IGCC plant and have previously conducted systemslevel analyses to evaluate this concept. These past studies have shown that a significant increase in IGCC performance can be achieved with liquid CO 2 over water with certain gasifiers. Although these previous analyses had produced some positive results, they were still based on various assumptions for liquid CO 2/coal slurry properties.« less

Commercial-scale demonstration of the Liquid Phase Methanol process. Technical progress report number 8, April 1--June 30, 1996

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

NONE

1996-12-31

The project involves the construction of an 80,000 gallon per day (260 tons per day (TPD)) methanol unit utilizing coal-derived synthesis gas from Eastman`s integrated coal gasification facility. The new equipment consists of synthesis gas feed preparation and compression facilities, the liquid phase reactor and auxiliaries, product distillation facilities, and utilities. The technology to be demonstrated is the product of a cooperative development effort by Air Products and DOE in a program that started in 1981. Developed to enhance electric power generation using integrated gasification combined cycle (IGCC) technology, the LPMEOH{trademark} process is ideally suited for directly processing gases producedmore » by modern-day coal gasifiers. Originally tested at a small (10 TPD), DOE-owned experimental unit in LaPorte, Texas, the technology provides several improvements essential for the economic coproduction of methanol and electricity directly from gasified coal. This liquid phase process suspends fine catalyst particles in an inert liquid, forming a slurry. The slurry dissipates the heat of the chemical reaction away from the catalyst surface, protecting the catalyst and allowing the methanol synthesis reaction to proceed at higher rates. At the Eastman complex, the technology is being integrated with existing coal-gasifiers. A carefully developed test plan will allow operations at Eastman to simulate electricity demand load-following in coal-based IGCC facilities. The operations will also demonstrate the enhanced stability and heat dissipation of the conversion process, its reliable on/off operation, and its ability to produce methanol as a clean liquid fuel without additional upgrading.« less

Design and implementation of a laser-based absorption spectroscopy sensor for in situ monitoring of biomass gasification

NASA Astrophysics Data System (ADS)

Viveros Salazar, David; Goldenstein, Christopher S.; Jeffries, Jay B.; Seiser, Reinhard; Cattolica, Robert J.; Hanson, Ronald K.

2017-12-01

Research to demonstrate in situ laser-absorption-based sensing of H2O, CH4, CO2, and CO mole fraction is reported for the product gas line of a biomass gasifier. Spectral simulations were used to select candidate sensor wavelengths that optimize sensitive monitoring of the target species while minimizing interference from other species in the gas stream. A prototype sensor was constructed and measurements performed in the laboratory at Stanford to validate performance. Field measurements then were demonstrated in a pilot scale biomass gasifier at West Biofuels in Woodland, CA. The performance of a prototype sensor was compared for two sensor strategies: wavelength-scanned direct absorption (DA) and wavelength-scanned wavelength modulation spectroscopy (WMS). The lasers used had markedly different wavelength tuning response to injection current, and modern distributed feedback lasers (DFB) with nearly linear tuning response to injection current were shown to be superior, leading to guidelines for laser selection for sensor fabrication. Non-absorption loss in the transmitted laser intensity from particulate scattering and window fouling encouraged the use of normalized WMS measurement schemes. The complications of using normalized WMS for relatively large values of absorbance and its mitigation are discussed. A method for reducing adverse sensor performance effects of a time-varying WMS background signal is also presented. The laser absorption sensor provided measurements with the sub-second time resolution needed for gasifier control and more importantly provided precise measurements of H2O in the gasification products, which can be problematic for the typical gas chromatography sensors used by industry.

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

Advanced Gas Turbine (AGT) technology development

NASA Technical Reports Server (NTRS)

1983-01-01

A 74.5 kW (100 hp) automotive gas turbine was evaluated. The engine structure, bearings, oil system, and electronics were demonstrated and no shaft dynamics or other vibration problem were encountered. Areas identified during the five tests are the scroll retention features, and transient thermal deflection of turbine backplates. Modifications were designed. Seroll retention is addressed by modifying the seal arrangement in front of the gasifier turbine assembly, which will increase the pressure load on the scroll in the forward direction and thereby increase the retention forces. the backplate thermal deflection is addressed by geometric changes and thermal insulation to reduce heat input. Combustor rig proof testing of two ceramic combustor assemblies was completed. The combustor was modified to incorporate slots and reduce sharp edges, which should reduce thermal stresses. The development work focused on techniques to sinter these barrier materials onto the ceramic rotors with successes for both material systems. Silicon carbide structural parts, including engine configuration gasifier rotors (ECRs), preliminary gasifier scroll parts, and gasifier and power turbine vanes are fabricated.

Westinghouse to launch coal gasifier with combined cycle unit

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

Stavsky, R.M.; Margaritis, P.J.

1980-03-01

Following an extensive test program with a prototype coal gasifier, Westinghouse Electric Corp. is now offering an integrated gasifier/combined-cycle unit as a feasible alternative for generating power from coal in an efficient, clean manner. The Westinghouse gasification process uses a single-stage pressurized fluidized-bed reactor, followed by heat recovery, gas cleaning, sulfur and amonia removal and recovery, and gas reheat. The system produces a fuel gas free of sulfur and other contaminants from crushed run-of-mine coals of varying reactivities and caking properties. The by-products include ammonia and sulfur and an agglomerated ash residue that serves as an acceptable landfill. Air formore » the gasifier is bled from the gas-turbine air compressor and further pressurized with a booster compressor. The hot exhaust gases from the gas turbine pass through a heat-recovery steam generator that produces sufficient steam to drive a turbine providing about 40% of the total electricity generated in the plant.« less

Method for the desulfurization of hot product gases from coal gasifier

DOEpatents

Grindley, Thomas

1988-01-01

The gasification of sulfur-bearing coal produces a synthesis gas which contains a considerable concentration of sulfur compounds especially hydrogen sulfide that renders the synthesis gas environmentally unacceptable unless the concentration of the sulfur compounds is significantly reduced. To provide for such a reduction in the sulfur compounds a calcium compound is added to the gasifier with the coal to provide some sulfur absorption. The synthesis gas from the gasifier contains sulfur compounds and is passed through an external bed of a regenerable solid absorbent, preferably zinc ferrite, for essentially completed desulfurizing the hot synthesis gas. This absorbent is, in turn, periodically or continuously regenerated by passing a mixture of steam and air or oxygen through the bed for converting absorbed hydrogen sulfide to sulfur dioxide. The resulting tail gas containing sulfur dioxide and steam is injected into the gasifier where the sulfur dioxide is converted by the calcium compound into a stable form of sulfur such as calcium sulfate.

Coking properties of coal under pressure and their influence on moving-bed gasification. Final report

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

Lancet, M.S.; Curran, G.P.; Sim, F.A.

1982-08-01

The coking properties of seven bituminous coals, including three Eastern US coals, one Midwestern US coal, a Western US coal and two from the UK were studied with respect to the possible utilization of these coals in moving bed gasifier systems. Complete physical, chemical and petrographic analyses were obtained for each coal in addition to the highly specialized CCDC simulated gasifier coking test data. The effects of total pressure, hydrogen partial pressure, heating rate and the addition of gob and tar on the fluidity and swelling properties of each coal was studied. Samples of each coal were shock heated undermore » pressure to simulate coking in the top of a Lurgi gasifier. The resultant cokes were tested for various physical properties and the product yields were determined. Gas release patterns during pressurized pyrolysis were obtained in several instances. The data obtained in this work should provide a valuable data base for future gasifier feedstock evaluation programs.« less

Method of operating a two-stage coal gasifier

DOEpatents

Tanca, Michael C.

1982-01-01

A method of operating an entrained flow coal gasifier (10) via a two-stage gasification process. A portion of the coal (18) to be gasified is combusted in a combustion zone (30) with near stoichiometric air to generate combustion products. The combustion products are conveyed from the combustion zone into a reduction zone (32) wherein additional coal is injected into the combustion products to react with the combustion products to form a combustible gas. The additional coal is injected into the reduction zone as a mixture (60) consisting of coal and steam, preferably with a coal-to-steam weight ratio of approximately ten to one.

Commercialization of biomass projects: A case study of the design, development, and application of a biomass gasifier to a large retrofit market

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

Woerner, W.L.

1994-12-31

The steam production potential of older biomass-fired boilers currently in operation may be significantly increased through the application of a commercially available gasifier. A large percentage of boiler systems in lumber mills and similar applications were initially designed to generate steam through convection heat transfer, and have been horse power rated at approximately 7 to 10 square feet of heating surface to the horse power. This paper deals with the before and after performance characteristics of the first gasifier retrofit installation based on an AED designed unit currently commercially available.

Integrated gasification combined cycle using Egyptian Maghara coal-rice straw feedstock.

PubMed

Hegazy, A; Ghallab, A O; Ashour, F H

2017-06-01

Rice straw is an agricultural waste that causes an annoying problem in Egypt if it is not well exploited. This study focuses on using this waste in power generation by co-gasification of Egyptian Maghara coal and rice straw blends using entrained flow gasifier technology. Aspen Plus was used to conduct a parametric study for investigation of the effect of changing the inputs to the gasifier on the produced gas composition. Three different input parameters, influencing the performance of the gasifier, including the percentage of coal to rice straw in the blend, the fraction of added water to the blend, and the mass percentage of oxygen with respect to the mass of the blend fed to the gasifier were analysed. Two alternative power production schemes (with and without carbon capturing) have been investigated. The obtained optimum feed conditions are: 40% coal in the feed blend, 20% water concentration in the feed slurry, and 80% oxygen with respect to the dry feed blend to the gasifier. For (10 0000 kg per hour) of the feed blend, the power generated was 270.1 MW in the case of non-carbon capturing, while in the case of carbon capturing, 263.52 MW was generated. Although it produces less power, applying carbon capturing techniques means handling less flue gas and thus using smaller gas turbines and results in more environmentally friendly emissions.

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.

Power Systems Development Facility Gasification Test Campaing TC18

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

Southern Company Services

2005-08-31

In support of technology development to utilize coal for efficient, affordable, and environmentally clean power generation, the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama, routinely demonstrates gasification technologies using various types of coals. The PSDF is an engineering scale demonstration of key features of advanced coal-fired power systems, including a KBR Transport Gasifier, a hot gas particulate control device (PCD), advanced syngas cleanup systems, and high pressure solids handling systems. This report details Test Campaign TC18 of the PSDF gasification process. Test campaign TC18 began on June 23, 2005, and ended on August 22, 2005, with the gasifiermore » train accumulating 1,342 hours of operation using Powder River Basin (PRB) subbituminous coal. Some of the testing conducted included commissioning of a new recycle syngas compressor for gasifier aeration, evaluation of PCD filter elements and failsafes, testing of gas cleanup technologies, and further evaluation of solids handling equipment. At the conclusion of TC18, the PSDF gasification process had been operated for more than 7,750 hours.« less

Characterization of fly ash from the gasification of wood and assessment for its application as a soil amendment

Treesearch

Hui Pan; Thomas L. Eberhardt

2011-01-01

Fly ash was collected as a byproduct from the processing of southern pine wood chips in a pilot-scale biomass gasifier. General properties of the fly ash were determined to assess its applicability as a soil amendment. Its alkaline pH (9.5) and high concentrations of Ca, K, and Mg suggest that it could be used as both a liming agent and a fertilizer. The...

Coal gasifier cogeneration powerplant project

NASA Technical Reports Server (NTRS)

Shure, L. I.; Bloomfield, H. S.

1980-01-01

Industrial cogeneration and utility pr systems were analyzed and a conceptual design study was conducted to evaluate the economic feasibility of a coal gasifier power plant for NASA Lewis Research Center. Site location, plant size, and electric power demand were considered in criteria developed for screening and selecting candidates that could use a wide variety of coals, including that from Ohio. A fluidized bed gasifier concept was chosen as the baseline design and key components of the powerplant were technically assessed. No barriers to environmental acceptability are foreseen. If funded, the powerplant will not only meet the needs of the research center, but will reduce the commercial risk for utilities and industries by fully verifying and demonstrating the technology, thus accelerating commercialization.

Hydrogen production from coal

NASA Technical Reports Server (NTRS)

1975-01-01

The gasification reactions necessary for the production of hydrogen from montana subbituminous coal are presented. The coal composition is given. The gasifier types mentioned include: suspension (entrained) combustion; fluidized bed; and moving bed. Each gasification process is described. The steam-iron process, raw and product gas compositions, gasifier feed quantities, and process efficiency evaluations are also included.

Gasified rice hull biochar affects nutrition and growth of five horticulture crops in container culture

USDA-ARS?s Scientific Manuscript database

Phosphate fertilizers used in the production of greenhouse crops can be problematic if released into the environment. Furthermore, the price of phosphate is increasing as demand increases and world supplies decrease. The objective of this research was to determine if gasified rice hull biochar (GR...

Low inlet gas velocity high throughput biomass gasifier

DOEpatents

Feldmann, Herman F.; Paisley, Mark A.

1989-01-01

The present invention discloses a novel method of operating a gasifier for production of fuel gas from carbonaceous fuels. The process disclosed enables operating in an entrained mode using inlet gas velocities of less than 7 feet per second, feedstock throughputs exceeding 4000 lbs/ft.sup.2 -hr, and pressures below 100 psia.

Coal derived fuel gases for molten carbonate fuel cells

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

Not Available

1979-11-01

Product streams from state-of-the-art and future coal gasification systems are characterized to guide fuel cell program planners and researchers in establishing performance goals and developing materials for molten carbonate fuel cells that will be compatible with gasifier product gases. Results are presented on: (1) the range of gasifier raw-gas compositions available from the major classes of coal gasifiers; (2) the degree of gas clean-up achievable with state-of-the-art and future gas clean-up systems; and (3) the energy penalties associated with gas clean-up. The study encompasses fixed-bed, fluid-bed, entrained-bed, and molten salt gasifiers operating with Eastern bituminous and Western subbituminous coals. Gasifiersmore » operating with air and oxygen blowing are evaluated, and the coal gasification product streams are characterized with respect to: (1) major gas stream constituents, e.g., CO, H/sub 2/, CO/sub 2/, CH/sub 4/, N/sub 2/, H/sub 2/O; (2) major gas stream contaminants, e.g., H/sub 2/S, COS, particulates, tars, etc.; and (3) trace element contaminants, e.g., Na, K, V, Cl, Hg, etc.« less

Groundnut shell gasification performance in a fluidized bed gasifier with bubbling air as gasification medium.

PubMed

Singh, Dharminder; Yadav, Sanjeev; Rajesh, V M; Mohanty, Pravakar

2018-05-24

This work was focused on finding the groundnut shell (GNS) gasification performance in a fluidized bed gasifier with bubbling air as gasification medium. GNS in powder form (a mixture of different particle size as given in table 8 in the article) was gasified using naturally available river sand as bed material, top of the bed feeding, conventional charcoal as bed heating medium, and two cyclones for proper cleaning and cooling the product gas. Experiments were performed using different operating conditions such as equivalence ratio (ER) between 0.29 and 0.33, bed temperature between 650°C and 800°C, and feedstock feeding rate between 36 and 31.7 kg/h. Different parameters were evaluated to study the gasifier performance such as gas yield, cold gas efficiency, carbon conversion efficiency (CCE), and high heating value. The most suitable ER value was found to be 0.31, giving the most stable bed temperature profile at 714.4°C with 5-10% fluctuation. Cold gas efficiency and CCE at optimal ER of 0.31 was found to be 71.8% and 91%, respectively.

Gasification of rice straw in a fluidized-bed gasifier for syngas application in close-coupled boiler-gasifier systems.

PubMed

Calvo, L F; Gil, M V; Otero, M; Morán, A; García, A I

2012-04-01

The feasibility and operation performance of the gasification of rice straw in an atmospheric fluidized-bed gasifier was studied. The gasification was carried out between 700 and 850 °C. The stoichiometric air-fuel ratio (A/F) for rice straw was 4.28 and air supplied was 7-25% of that necessary for stoichiometric combustion. Mass and power balances, tar concentration, produced gas composition, gas phase ammonia, chloride and potassium concentrations, agglomeration tendencies and gas efficiencies were assessed. Agglomeration was avoided by replacing the normal alumina-silicate bed by a mixture of alumina-silicate sand and MgO. It was shown that it is possible to produce high quality syngas from the gasification of rice straw. Under the experimental conditions used, the higher heating value (HHV) of the produced gas reached 5.1 MJ Nm(-3), the hot gas efficiency 61% and the cold gas efficiency 52%. The obtained results prove that rice straw may be used as fuel for close-coupled boiler-gasifier systems. Copyright © 2012 Elsevier Ltd. All rights reserved.

Advanced Turbine Technology Applications Project (ATTAP)

NASA Technical Reports Server (NTRS)

1993-01-01

The Advanced Turbine Technologies Application Project (ATTAP) is in the fifth year of a multiyear development program to bring the automotive gas turbine engine to a state at which industry can make commercialization decisions. Activities during the past year included reference powertrain design updates, test-bed engine design and development, ceramic component design, materials and component characterization, ceramic component process development and fabrication, ceramic component rig testing, and test-bed engine fabrication and testing. Engine design and development included mechanical design, combustion system development, alternate aerodynamic flow testing, and controls development. Design activities included development of the ceramic gasifier turbine static structure, the ceramic gasifier rotor, and the ceramic power turbine rotor. Material characterization efforts included the testing and evaluation of five candidate high temperature ceramic materials. Ceramic component process development and fabrication, with the objective of approaching automotive volumes and costs, continued for the gasifier turbine rotor, gasifier turbine scroll, extruded regenerator disks, and thermal insulation. Engine and rig fabrication, testing, and development supported improvements in ceramic component technology. Total test time in 1992 amounted to 599 hours, of which 147 hours were engine testing and 452 were hot rig testing.

Mathematical Modeling of Ultra-Superheated Steam Gasification

NASA Astrophysics Data System (ADS)

Xin, Fen

Pure steam gasification has been of interest in hydrogen production, but with the challenge of supplying heat for endothermic reactions. Traditional solutions included either combusting feedstocks at the price of decreasing carbon conversion ratio, or using costly heating apparatus. Therefore, a distributed gasifier with an Ultra-Superheated-Steam (USS) generator was invented, satisfying the heat requirement and avoiding carbon combustion in steam gasification. This project developed the first version of the Ultra-Superheated-Steam-Fluidization-Model (USSFM V1.0) for the USS gasifier. A stand-alone equilibrium combustion model was firstly developed to calculate the USS mixture, which was the input to the USSFM V1.0. Model development of the USSFM V1.0 included assumptions, governing equations, boundary conditions, supporting equations and iterative schemes of guessed values. There were three nested loops in the dense bed and one loop in the freeboard. The USSFM V1.0 included one main routine and twenty-four subroutines. The USSFM V1.0 was validated with experimental data from the Enercon USS gasifier. The calculated USS mixture had a trace of oxygen, validating the initial expectation of creating an oxygen-free environment in the gasifier. Simulations showed that the USS mixture could satisfy the gasification heat requirement without partial carbon combustion. The USSFM V1.0 had good predictions on the H2% in all tests, and on other variables at a level of the lower oxygen feed. Provided with higher oxygen feed, the USSFM V1.0 simulated hotter temperatures, higher CO% and lower CO2%. Errors were explained by assumptions of equilibrium combustion, adiabatic reactors, reaction kinetics, etc. By investigating specific modeling data, gas-particle convective heat transfers were found to be critical in energy balance equations of both emulsion gas and particles, while bubble size controlled both the mass and energy balance equations of bubble gas. Parametric study suggested a lower level of oxygen feed for higher content of hydrogen. However, too little oxygen would impede fluidization in the bed. The reasonability of iterative schemes and the stability of USSFM V1.0 were tested by the sensitivity analysis of two guessed values. Analytical Hierarchy Process analysis indicated that large-scale gasification is advantageous for hydrogen production but with impediments of high capital cost and CO2 emissions. This study manifested the USS gasifier offering the possibility of generating H2-rich and CO2-lean syngas in a much cheaper distributed way. Currently, the FORTRAN-based USSFM V1.0 had a good correlation with experimental data with a small oxygen feed. On the demand of wider applications, suggestions were proposed at last for the model improvement in future.

Comparison of air pollutant emissions and household air quality in rural homes using improved wood and coal stoves

NASA Astrophysics Data System (ADS)

Du, Wei; Shen, Guofeng; Chen, Yuanchen; Zhu, Xi; Zhuo, Shaojie; Zhong, Qirui; Qi, Meng; Xue, Chunyu; Liu, Guangqing; Zeng, Eddy; Xing, Baoshan; Tao, Shu

2017-10-01

Air pollutant emissions, fuel consumption, and household air pollution were investigated in rural Hubei, central China, as a revisited evaluation of an intervention program to replace coal use by wood in gasifier stoves. Measured emission factors were comparable to the results measured two years ago when the program was initiated. Coal combustion produced significantly higher emissions of CO2, CH4, and SO2 compared with wood combustion; however, wood combustion in gasifier stoves had higher emissions of primary PM2.5 (particles with diameter less than 2.5 μm), Elemental Carbon (EC) and Organic Carbon (OC). In terms of potential impacts on climate, although the use of wood in gasifier stoves produced more black carbon (6.37 vs 910 gCO2e per day per capita from coal and wood use) and less SO2 (-684 vs -312), obvious benefits could be obtained owing to greater OC emissions (-15.4 vs -431), fewer CH4 emissions (865 vs 409) and, moreover, a reduction of CO2 emissions. The total GWC100 (Global Warming Potential over a time horizon of 100 years) would decrease by approximately 90% if coal use were replaced with renewable wood burned in gasifier stoves. However, similar levels of ambient particles and higher indoor OC and EC were found at homes using wood gasifier stoves compared to the coal-use homes. This suggests critical investigations on potential health impacts from the carbon-reduction intervention program.

Adoption and use of a semi-gasifier cooking and water heating stove and fuel intervention in the Tibetan Plateau, China

NASA Astrophysics Data System (ADS)

Clark, S.; Carter, E.; Shan, M.; Ni, K.; Niu, H.; Tseng, J. T. W.; Pattanayak, S. K.; Jeuland, M.; Schauer, J. J.; Ezzati, M.; Wiedinmyer, C.; Yang, X.; Baumgartner, J.

2017-07-01

Improved cookstoves and fuels, such as advanced gasifier stoves, carry the promise of improving health outcomes, preserving local environments, and reducing climate-forcing air pollutants. However, low adoption and use of these stoves in many settings has limited their benefits. We aimed to improve the understanding of improved stove use by describing the patterns and predictors of adoption of a semi-gasifier stove and processed biomass fuel intervention in southwestern China. Of 113 intervention homes interviewed, 79% of homes tried the stove, and the majority of these (92%) continued using it 5-10 months later. One to five months after intervention, the average proportion of days that the semi-gasifier stove was in use was modest (40.4% [95% CI 34.3-46.6]), and further declined over 13 months. Homes that received the stove in the first batch used it more frequently (67.2% [95% CI 42.1-92.3] days in use) than homes that received it in the second batch (29.3% [95% CI 13.8-44.5] days in use), likely because of stove quality and user training. Household stove use was positively associated with reported cooking needs and negatively associated with age of the main cook, household socioeconomic status, and the availability of substitute cleaner-burning stoves. Our results show that even a carefully engineered, multi-purpose semi-gasifier stove and fuel intervention contributed modestly to overall household energy use in rural China.

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

Effect of rice husk ash mass on sustainability pyrolysis zone of fixed bed downdraft gasifier with capacity of 10 kg/hour

NASA Astrophysics Data System (ADS)

Surjosatyo, Adi; Haq, Imaduddin; Dafiqurrohman, Hafif; Gibran, Felly Rihlat

2017-03-01

The formation of pyrolysis sustainability (Sustainable Pyrolysis) is the objective of the gasification process. Pyrolysis zone in the gasification process is the result of the endothermic reaction that get heat from oxidation (combustion) of the fuel with oxygen, where cracking biomass rice husk result of such as charcoal, water vapor, steam tar, and gas - gas (CO, H 2, CH 4, CO 2 and N 2) and must be maintained at a pyrolysis temperature to obtain results plentiful gas (producer gas) or syngas (synthetic gas). Obtaining continuously syngas is indicated by flow rate (discharge) producer gas well and the consistency of the flame on the gas burner, it is highly influenced by the gasification process and the operation of the gasifier and the mass balance (mass balance) between the feeding rate of rice husk with the disposal of ash (ash removal). In experiments conducted is using fixed bed gasifier type downdraft capacity of 10 kg/h. Besides setting the mass of rice husks into the gasifier and disposal arrangements rice husk ash may affect the sustainability of the pyrolysis process, but tar produced during the gasification process causes sticky rice husk ash in the plenum gasifier. Modifications disposal system rice husk ash can facilitate the arrangement of ash disposal then could control the temperature pyrolysis with pyrolysis at temperatures between 500-750 ° C. The experimental study was conducted to determine the effect of mass quantities of rice husk ash issued against sustainability pyrolysis temperature which is obtained at each time disposal of rice husk ash to produce 60-90 grams of ash issued. From some experimental phenomena is expected to be seen pyrolysis and its effect on the flow rate of syngas and the stability of the flame on the gas burner so that this research can find a correlation to obtain performance (performance) gasifier optimal.

Agglomerating combustor-gasifier method and apparatus for coal gasification

DOEpatents

Chen, Joseph L. P.; Archer, David H.

1976-09-21

A method and apparatus for gasifying coal wherein the gasification takes place in a spout fluid bed at a pressure of about 10 to 30 atmospheres and a temperature of about 1800.degree. to 2200.degree.F and wherein the configuration of the apparatus and the manner of introduction of gases for combustion and fluidization is such that agglomerated ash can be withdrawn from the bottom of the apparatus and gas containing very low dust loading is produced. The gasification reaction is self-sustaining through the burning of a stoichiometric amount of coal with air in the lower part of the apparatus to form the spout within the fluid bed. The method and apparatus are particularly suitable for gasifying coarse coal particles.

Catalytic conversion wood syngas to synthetic aviation turbine fuels over a multifunctional catalyst

Treesearch

Qiangu Yan; Fei Yu; Jian Liu; Jason Street; Jinsen Gao; Zhiyong Cai; Jilei Zhang

2013-01-01

A continuous process involving gasification, syngas cleaning, and Fischer–Tropsch (FT) synthesis was developed to efficiently produce synthetic aviation turbine fuels (SATFs). Oak-tree wood chips were first gasified to syngas over a commercial pilot plant downdraft gasifier. The raw wood syngas contains about 47% N2, 21% CO, 18% H2...

Combined cycle power plant incorporating coal gasification

DOEpatents

Liljedahl, Gregory N.; Moffat, Bruce K.

1981-01-01

A combined cycle power plant incorporating a coal gasifier as the energy source. The gases leaving the coal gasifier pass through a liquid couplant heat exchanger before being used to drive a gas turbine. The exhaust gases of the gas turbine are used to generate both high pressure and low pressure steam for driving a steam turbine, before being exhausted to the atmosphere.

Catalytic upgrading nitrogen-riched wood syngas to liquid hydrocarbon mixture over Fe-Pd/ZSM-5 catalyst

Treesearch

Qiangu Yan; Fei Yu; Zhiyong Cai; Jilei Zhang

2012-01-01

Biomass like wood chips, switchgrass and other plant residues are first converted to syngas through gasification process using air, oxygen or steam. A downdraft gasifier is performed for syngas production in Mississippi State. The syngas from the gasifier contains up to 49% (vol) N2. High-level nitrogen-containing (nitrogen can be up to 60%)...

Entrained-flow gasifier and fluidized-bed combustor temperature monitoring using arrays of fs-IR written fiber Bragg gratings

NASA Astrophysics Data System (ADS)

Walker, Robert B.; Ding, Huimin; Coulas, David; Grobnic, Dan; Mihailov, Stephen J.; Duchesne, Marc A.; Hughes, Robin W.; McCalden, David J.; Burchat, Ryan

2015-09-01

Femtosecond written fiber Bragg gratings, have shown great potential for sensing in extreme environments. This paper discusses the fabrication and deployment of several fs-IR written FBG arrays, for monitoring main-spool skin temperatures of an entrained-flow gasifier, as well as the internal temperature gradient of a fluidized bed combustor.

Development of a fixed bed gasifier model and optimal operating conditions determination

NASA Astrophysics Data System (ADS)

Dahmani, Manel; Périlhon, Christelle; Marvillet, Christophe; Hajjaji, Noureddine; Houas, Ammar; Khila, Zouhour

2017-02-01

The main objective of this study was to develop a fixed bed gasifier model of palm waste and to identify the optimal operating conditions to produce electricity from synthesis gas. First, the gasifier was simulated using Aspen PlusTM software. Gasification is a thermo-chemical process that has long been used, but it remains a perfectible technology. It means incomplete combustion of biomass solid fuel into synthesis gas through partial oxidation. The operating parameters (temperature and equivalence ratio (ER)) were thereafter varied to investigate their effect on the synthesis gas composition and to provide guidance for future research and development efforts in process design. The equivalence ratio is defined as the ratio of the amount of air actually supplied to the gasifier and the stoichiometric amount of air. Increasing ER decreases the production of CO and H2 and increases the production of CO2 and H2O while an increase in temperature increases the fraction of CO and H2. The results show that the optimum temperature to have a syngas able to be effectively used for power generation is 900°C and the optimum equivalence ratio is 0.1.

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.

Combined goal gasifier and fuel cell system and method

DOEpatents

Gmeindl, Frank D.; Geisbrecht, Rodney A.

1990-01-01

A molten carbonate fuel cell is combined with a catalytic coal or coal char gasifier for providing the reactant gases comprising hydrogen, carbon monoxide and carbon dioxide used in the operation of the fuel cell. These reactant gases are stripped of sulfur compounds and particulate material and are then separated in discrete gas streams for conveyance to appropriate electrodes in the fuel cell. The gasifier is arranged to receive the reaction products generated at the anode of the fuel cell by the electricity-producing electrochemical reaction therein. These reaction products from the anode are formed primarily of high temperature steam and carbon dioxide to provide the steam, the atmosphere and the heat necessary to endothermically pyrolyze the coal or char in the presence of a catalyst. The reaction products generated at the cathode are substantially formed of carbon dioxide which is used to heat air being admixed with the carbon dioxide stream from the gasifier for providing the oxygen required for the reaction in the fuel cell and for driving an expansion device for energy recovery. A portion of this carbon dioxide from the cathode may be recycled into the fuel cell with the air-carbon dioxide mixture.

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.

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.

The NETL MFiX Suite of multiphase flow models: A brief review and recent applications of MFiX-TFM to fossil energy technologies

DOE PAGES

Li, Tingwen; Rogers, William A.; Syamlal, Madhava; ...

2016-07-29

Here, the MFiX suite of multiphase computational fluid dynamics (CFD) codes is being developed at U.S. Department of Energy's National Energy Technology Laboratory (NETL). It includes several different approaches to multiphase simulation: MFiX-TFM, a two-fluid (Eulerian–Eulerian) model; MFiX-DEM, an Eulerian fluid model with a Lagrangian Discrete Element Model for the solids phase; and MFiX-PIC, Eulerian fluid model with Lagrangian particle ‘parcels’ representing particle groups. These models are undergoing continuous development and application, with verification, validation, and uncertainty quantification (VV&UQ) as integrated activities. After a brief summary of recent progress in the verification, validation and uncertainty quantification (VV&UQ), this article highlightsmore » two recent accomplishments in the application of MFiX-TFM to fossil energy technology development. First, recent application of MFiX to the pilot-scale KBR TRIG™ Transport Gasifier located at DOE's National Carbon Capture Center (NCCC) is described. Gasifier performance over a range of operating conditions was modeled and compared to NCCC operational data to validate the ability of the model to predict parametric behavior. Second, comparison of code predictions at a detailed fundamental scale is presented studying solid sorbents for the post-combustion capture of CO 2 from flue gas. Specifically designed NETL experiments are being used to validate hydrodynamics and chemical kinetics for the sorbent-based carbon capture process.« less

Development of an Acoustic Sensor for On-Line Gas Temperature Measurement in Gasifiers

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

Peter Ariessohn; Hans Hornung

2006-01-15

This project was awarded under U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) Program Solicitation DE-PS26-02NT41422 and specifically addresses Technical Topical Area 2-Gasification Technologies. The project team includes Enertechnix, Inc. as the main contractor and ConocoPhillips Company as a technical partner, who also provides access to the SG Solutions Gasification Facility (formerly Wabash River Energy Limited), host for the field-testing portion of the research. Since 1989 the U.S. Department of Energy has supported development of advanced coal gasification technology. The Wabash River and TECO IGCC demonstration projects supported by the DOE have demonstrated the ability of these plantsmore » to achieve high levels of energy efficiency and extremely low emissions of hazardous pollutants. However, a continuing challenge for this technology is the tradeoff between high carbon conversion which requires operation with high internal gas temperatures, and limited refractory life which is exacerbated by those high operating temperatures. Attempts to control internal gas temperature so as to operate these gasifiers at the optimum temperature have been hampered by the lack of a reliable technology for measuring internal gas temperatures. Thermocouples have serious survival problems and provide useful temperature information for only a few days or weeks after startup before burning out. For this reason, the Department of Energy has funded several research projects to develop more robust and reliable temperature measurement approaches for use in coal gasifiers. Enertechnix has developed a line of acoustic gas temperature sensors for use in coal-fired electric utility boilers, kraft recovery boilers, cement kilns and petrochemical process heaters. Acoustic pyrometry provides several significant advantages for gas temperature measurement in hostile process environments. First, it is non-intrusive so survival of the measurement components is not a serious problem. Second, it provides a line-of-sight average temperature rather than a point measurement, so the measured temperature is more representative of the process conditions than those provided by thermocouples. Unlike radiation pyrometers, the measured temperature is a linear average over the full path rather than a complicated function of gas temperature and the exponential Beer's law. For this reason, acoustic pyrometry is well suited to tomography allowing detailed temperature maps to be created through the use of multiple path measurements in a plane. Therefore, acoustic pyrometry is an attractive choice for measuring gas temperature inside a coal gasifier. The objective of this project is to adapt acoustic pyrometer technology to make it suitable for measuring gas temperature inside a coal gasifier, to develop a prototype sensor based on this technology, and to demonstrate its performance through testing on a commercial gasifier. The project is organized in three phases, each of approximately one year duration. The first phase consists of researching a variety of sound generation and coupling approaches suitable for use with a high pressure process, evaluation of the impact of gas composition variability on the acoustic temperature measurement approach, evaluation of the impact of suspended particles on sound attenuation, evaluation of slagging issues and development of concepts to deal with this issue, development and testing of key prototype components to allow selection of the best approaches, and development of a conceptual design for a field prototype sensor that can be tested on an operating gasifier. The second phase consists of designing and fabricating a series of prototype sensors, testing them in the lab and at a gasifier facility, and developing a conceptual design for an engineering prototype sensor. The third phase consists of designing and fabricating the engineering prototype, testing it in the lab and in a commercial gasifier, and conducting extended field trials to demonstrate sensor performance and investigate the ability to improve gasifier performance through the use of the sensor.« less

Combined compressed air storage-low BTU coal gasification power plant

DOEpatents

Kartsounes, George T.; Sather, Norman F.

1979-01-01

An electrical generating power plant includes a Compressed Air Energy Storage System (CAES) fueled with low BTU coal gas generated in a continuously operating high pressure coal gasifier system. This system is used in coordination with a continuously operating main power generating plant to store excess power generated during off-peak hours from the power generating plant, and to return the stored energy as peak power to the power generating plant when needed. The excess coal gas which is produced by the coal gasifier during off-peak hours is stored in a coal gas reservoir. During peak hours the stored coal gas is combined with the output of the coal gasifier to fuel the gas turbines and ultimately supply electrical power to the base power plant.

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.

Video and thermal imaging system for monitoring interiors of high temperature reaction vessels

DOEpatents

Saveliev, Alexei V [Chicago, IL; Zelepouga, Serguei A [Hoffman Estates, IL; Rue, David M [Chicago, IL

2012-01-10

A system and method for real-time monitoring of the interior of a combustor or gasifier wherein light emitted by the interior surface of a refractory wall of the combustor or gasifier is collected using an imaging fiber optic bundle having a light receiving end and a light output end. Color information in the light is captured with primary color (RGB) filters or complimentary color (GMCY) filters placed over individual pixels of color sensors disposed within a digital color camera in a BAYER mosaic layout, producing RGB signal outputs or GMCY signal outputs. The signal outputs are processed using intensity ratios of the primary color filters or the complimentary color filters, producing video images and/or thermal images of the interior of the combustor or gasifier.

OPTIMIZING SYNTHESIS GAS YIELD FROM THE CROSS ...

EPA Pesticide Factsheets

Symposium Paper Biomass can be gasified to yield synthesis gas, tars, and ash. The process is governed by a number of parameters such as the temperature of the gasifying medium (in this case), and the moisture content of the feedstock. Synthesis gas from gasifying wood pellets was collected and analyzed as a function of inlet air temperature and feedstock moisture content. The air was introduced at temperatures ranging from 630 to 730 °C and the moisture content of the feedstock ranged from 8 to 20%. The data collected was used to establish the relationship between the outcome of gasification and these two parameters, and then to determine optimal operating parameters for maximizing the fuel value (maximizing the concentrations of flammable gases in the synthesis gas) while minimizing the production of gasification tars.

Advanced Gas Turbine (AGT) Technology Project

NASA Technical Reports Server (NTRS)

1986-01-01

Engine testing, ceramic component fabrication and evaluation, component performance rig testing, and analytical studies comprised AGT 100 activities during the 1985 year. Ten experimental assemblies (builds) were evaluated using two engines. Accrued operating time was 120 hr of burning and 170 hr total, bringing cumulative total operating time to 395 hr, all devoid of major failures. Tests identified the generator seals as the primary working fluid leakage sources. Power transfer clutch operation was demonstrated. An alpha SiC gasifier rotor engine test resulted in blade tip failures. Recurring case vibration and shaft whip have limited gasifier shaft speeds to 84%. Ceramic components successfully engine tested now include the SiC scroll assembly, Si3N3 turbine rotor, combustor assembly, regenerator disk bulkhead, turbine vanes, piston rings, and couplings. A compressor shroud design change to reduce heat recirculation back to the inlet was executed. Ceramic components activity continues to focus on the development of state-of-the-art material strength characteristics in full-scale engine hardware. Fiber reinforced glass-ceramic composite turbine (inner) backplates were fabricated by Corning Glass Works. The BMAS/III material performed well in engine testing. Backplates of MAS material have not been engine tested.

Treating esophagus-cardiac carcinoma by YAG laser gasifying with irradiating of hemoporphyrin derivative laser: additional analyses of 110 cases

NASA Astrophysics Data System (ADS)

Yang, Chongjiang; Zhou, Hong; Jiang, Cuilin; Xu, Shouquan

1993-03-01

One-hundred-ten cases with esophagus-cardiac carcinoma treated by YAG laser gasifying together with irradiation of hemoporphyrin derivatives is reported. Here complete remission is seen in 28% of the patients, the total effective rate was 87%. The treatment method is simple and convenient, therefore, it is useful for the treatment of esophaguscardiac, carcinoma in a different stage.

Photoconversion of gasified organic materials into biologically-degradable plastics

DOEpatents

Weaver, P.F.; Pinching Maness.

1993-10-05

A process is described for converting organic materials (such as biomass wastes) into a bioplastic suitable for use as a biodegradable plastic. In a preferred embodiment the process involves thermally gasifying the organic material into primarily carbon monoxide and hydrogen, followed by photosynthetic bacterial assimilation of the gases into cell material. The process is ideally suited for waste recycling and for production of useful biodegradable plastic polymer. 3 figures.

Photoconversion of gasified organic materials into biologically-degradable plastics

DOEpatents

Weaver, Paul F.; Maness, Pin-Ching

1993-01-01

A process is described for converting organic materials (such as biomass wastes) into a bioplastic suitable for use as a biodegradable plastic. In a preferred embodiment the process involves thermally gasifying the organic material into primarily carbon monoxide and hydrogen, followed by photosynthetic bacterial assimilation of the gases into cell material. The process is ideally suited for waste recycling and for production of useful biodegradable plastic polymer.

Progress Report: Transportable Gasifier for On-Farm Disposal ...

EPA Pesticide Factsheets

Report A prototype transportable gasifier intended to process a minimum of 25 tons per day of animal mortalities (scalable to 200 tons per day) was built as part of an interagency effort involving the U.S. Environmental Protection Agency, the Department of Homeland Security, the U.S. Department of Agriculture, and the Department of Defense as well as the State of North Carolina. This effort is intended to demonstrate the feasibility of gasification for disposal of contaminated carcasses and to identify technical challenges and improvements that will simplify, improve, and enhance the gasifier system as a mobile response tool. Initial testing of the prototype in 2008 and 2010 demonstrated partial success by meeting the transportability and rapid deployment requirements. However, the throughput of animal carcasses was approximately 1/3 of the intended design capacity. Modifications have been made to the fuel system, burner system, feed system, control system, power distribution, and ash handling system to increase its operating capacity to the rated design throughput. Further testing will be performed to demonstrate the throughput as well as to demonstrate the ability of the unit to operate around the clock for an extended period of time. This report gives a status update on the progress of the project. Purpose is to give an update on the Transportable Animal Carcass Gasifier.

Mitigation of Syngas Cooler Plugging and Fouling

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

Bockelie, Michael J.

This Final Report summarizes research performed to develop a technology to mitigate the plugging and fouling that occurs in the syngas cooler used in many Integrated Gasification Combined Cycle (IGCC) plants. The syngas cooler is a firetube heat exchanger located downstream of the gasifier. It offers high thermal efficiency, but its’ reliability has generally been lower than other process equipment in the gasification island. The buildup of ash deposits that form on the fireside surfaces in the syngas cooler (i.e., fouling) lead to reduced equipment life and increased maintenance costs. Our approach to address this problem is that fouling ofmore » the syngas cooler cannot be eliminated, but it can be better managed. The research program was funded by DOE using two budget periods: Budget Period 1 (BP1) and Budget Period 2 (BP2). The project used a combination of laboratory scale experiments, analysis of syngas cooler deposits, modeling and guidance from industry to develop a better understanding of fouling mechanisms and to develop and evaluate strategies to mitigate syngas cooler fouling and thereby improve syngas cooler performance. The work effort in BP 1 and BP 2 focused on developing a better understanding of the mechanisms that lead to syngas cooler plugging and fouling and investigating promising concepts to mitigate syngas cooler plugging and fouling. The work effort focused on the following: • analysis of syngas cooler deposits and fuels provided by an IGCC plant collaborating with this project; • performing Jet cleaning tests in the University of Utah Laminar Entrained Flow Reactor to determine the bond strength between an ash deposit to a metal plate, as well as implementing planned equipment modifications to the University of Utah Laminar Entrained Flow Reactor and the one ton per day, pressurized Pilot Scale Gasifier; • performing Computational Fluid Dynamic modeling of industrially relevant syngas cooler configurations to develop a better understanding of deposit formation mechanisms; • performing Techno-Economic-Analysis for a representative IGCC plant to investigate the impact on plant economics, in particular the impacts on the Cost of Electricity (COE), due to plant shutdowns caused by syngas cooler plugging and fouling and potential benefits to plant economics of developing strategies to mitigate syngas cooler fouling; and • performing modeling and pilot scale tests to investigate the potential benefits of using a sorbent (fuel additive) to capture the vaporized metals that result in syngas cooler fouling. All project milestones for BP 1 and BP 2 were achieved. DOE was provided a briefing on our accomplishments in BP1 and BP2 and our proposed plans for Budget Period 3 (BP 3). Based on our research the mitigation technology selected to investigate in BP 3 was the use of a sorbent that can be injected into the gasifier with the fuel slurry to capture vaporized metals that lead to the deposit formation in the syngas cooler. The work effort proposed for BP 3 would have focused on addressing concerns raised by gasification industry personnel for the impacts on gasifier performance of sorbent injection, so that at the end of BP 3 the use of sorbent injection would be at “pre-commercial” stage and ready for use in a Field Demonstration that could be funded by industry or DOE. A Budget Continuation Application (BCA) was submitted to obtain funding for BP3 DOE but DOE chose to not fund the proposed BP3 effort.« less

Coal/Biomass-to-Liquids Demonstration Testing for DLA Energy: Report on Project Tests, Evaluations, and Recommendations

DTIC Science & Technology

2015-08-20

elevated temperatures with sub- stoichiometric oxygen to produce primarily hydrogen and carbon monoxide (called syngas). Syngas can be used for the...of the gasifier and flows downward concurrently with nitrogen, pure oxygen , and steam. The EFG operates at very high temperatures (nominal 2,700... temperature slagging gasifiers), these components are cracked and thermally converted to product gas, especially in the presence of steam and oxygen . For

Biomass gasification for liquid fuel production

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

Najser, Jan, E-mail: jan.najser@vsb.cz, E-mail: vaclav.peer@vsb.cz; Peer, Václav, E-mail: jan.najser@vsb.cz, E-mail: vaclav.peer@vsb.cz; Vantuch, Martin

2014-08-06

In our old fix-bed autothermal gasifier we tested wood chips and wood pellets. We make experiments for Czech company producing agro pellets - pellets made from agricultural waste and fastrenewable natural resources. We tested pellets from wheat and rice straw and hay. These materials can be very perspective, because they dońt compete with food production, they were formed in sufficient quantity and in the place of their treatment. New installation is composed of allothermal biomass fixed bed gasifier with conditioning and using produced syngas for Fischer - Tropsch synthesis. As a gasifying agent will be used steam. Gas purification willmore » have two parts - separation of dust particles using a hot filter and dolomite reactor for decomposition of tars. In next steps, gas will be cooled, compressed and removed of sulphur and chlorine compounds and carbon dioxide. This syngas will be used for liquid fuel synthesis.« less

Biomass gasification for liquid fuel production

NASA Astrophysics Data System (ADS)

Najser, Jan; Peer, Václav; Vantuch, Martin

2014-08-01

In our old fix-bed autothermal gasifier we tested wood chips and wood pellets. We make experiments for Czech company producing agro pellets - pellets made from agricultural waste and fastrenewable natural resources. We tested pellets from wheat and rice straw and hay. These materials can be very perspective, because they dońt compete with food production, they were formed in sufficient quantity and in the place of their treatment. New installation is composed of allothermal biomass fixed bed gasifier with conditioning and using produced syngas for Fischer - Tropsch synthesis. As a gasifying agent will be used steam. Gas purification will have two parts - separation of dust particles using a hot filter and dolomite reactor for decomposition of tars. In next steps, gas will be cooled, compressed and removed of sulphur and chlorine compounds and carbon dioxide. This syngas will be used for liquid fuel synthesis.

Dynamic analysis of process reactors

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

Shadle, L.J.; Lawson, L.O.; Noel, S.D.

1995-06-01

The approach and methodology of conducting a dynamic analysis is presented in this poster session in order to describe how this type of analysis can be used to evaluate the operation and control of process reactors. Dynamic analysis of the PyGas{trademark} gasification process is used to illustrate the utility of this approach. PyGas{trademark} is the gasifier being developed for the Gasification Product Improvement Facility (GPIF) by Jacobs-Siffine Engineering and Riley Stoker. In the first step of the analysis, process models are used to calculate the steady-state conditions and associated sensitivities for the process. For the PyGas{trademark} gasifier, the process modelsmore » are non-linear mechanistic models of the jetting fluidized-bed pyrolyzer and the fixed-bed gasifier. These process sensitivities are key input, in the form of gain parameters or transfer functions, to the dynamic engineering models.« less

Development of standardized air-blown coal gasifier/gas turbine concepts for future electric power systems, Volume 4. Appendix C: Design and performance of standardized fixed bed air-blown gasifier IGCC systems for future electric power generation: Final report

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

Not Available

1991-02-01

This appendix is a compilation of work done to predict overall cycle performance from gasifier to generator terminals. A spreadsheet has been generated for each case to show flows within a cycle. The spreadsheet shows gaseous or solid composition of flow, temperature of flow, quantity of flow, and heat heat content of flow. Prediction of steam and gas turbine performance was obtained by the computer program GTPro. Outputs of all runs for each combined cycle reviewed has been added to this appendix. A process schematic displaying all flows predicted through GTPro and the spreadsheet is also added to this appendix.more » The numbered bubbles on the schematic correspond to columns on the top headings of the spreadsheet.« less

Technician's Perspective on an Ever-Changing Research Environment: Catalytic Conversion of Biomass to Fuels

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

Thibodeaux, J.; Hensley, J.

2013-01-01

The biomass thermochemical conversion platform at the National Renewable Energy Laboratory (NREL) develops and demonstrates processes for the conversion of biomass to fuels and chemicals including gasification, pyrolysis, syngas clean-up, and catalytic synthesis of alcohol and hydrocarbon fuels. In this talk, I will discuss the challenges of being a technician in this type of research environment, including handling and working with catalytic materials and hazardous chemicals, building systems without being given all of the necessary specifications, pushing the limits of the systems through ever-changing experiments, and achieving two-way communication with engineers and supervisors. I will do this by way ofmore » two examples from recent research. First, I will describe a unique operate-to-failure experiment in the gasification of chicken litter that resulted in the formation of a solid plug in the gasifier, requiring several technicians to chisel the material out. Second, I will compare and contrast bench scale and pilot scale catalyst research, including instances where both are conducted simultaneously from common upstream equipment. By way of example, I hope to illustrate the importance of researchers 1) understanding the technicians' perspective on tasks, 2) openly communicating among all team members, and 3) knowing when to voice opinions. I believe the examples in this talk will highlight the crucial role of a technical staff: skills attained by years of experience to build and operate research and production systems. The talk will also showcase the responsibilities of NREL technicians and highlight some interesting behind-the-scenes work that makes data generation from NREL's thermochemical process development unit possible.« less

Flame Stabilization on Microscopic Scale of Wet Biogas with Microflame

NASA Astrophysics Data System (ADS)

Ida, Tamio; Fuchihata, Manabu; Mizuno, Satoru

Harvesting, transportation, energy conversion and the high-efficient utilization, cascade method and market formation besides become with the indispensable element in order to utilize the biomass resource. There are two type biogases; it is gasified gas from dried biomass by partially combustion and wet biogas from wet biomass by methane fermentation, especially from the livestock excrement resources. This paper discusses an experimental study for flame stabilization on microscopic scale with wet biogas (mainly 0.6CH4+0.4CO2). In this study, the microflame with the wet biogas fuels are formed by the diffusion flame on the coppered straight pipes of inner diameter 0.02mm ˜ 1.5mm. This study is obtained stability mapping on microscopic scale of formed microflame by wet biogas fuels. The flame stability limit conditions on microscopic scale of wet biogas is drawn with blow off and extinction flame double limit lines. It is suggested that minimum mixing spatial scale change by the each mixing ratio of the wet biogas.

Feasibility study: Liquid hydrogen plant, 30 tons per day

NASA Technical Reports Server (NTRS)

1975-01-01

The design considerations of the plant are discussed in detail along with management planning, objective schedules, and cost estimates. The processing scheme is aimed at ultimate use of coal as the basic raw material. For back-up, and to provide assurance of a dependable and steady supply of hydrogen, a parallel and redundant facility for gasifying heavy residual oil will be installed. Both the coal and residual oil gasifiers will use the partial oxidation process.

Updraft Fixed Bed Gasification Aspen Plus Model

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

2007-09-27

The updraft fixed bed gasification model provides predictive modeling capabilities for updraft fixed bed gasifiers, when devolatilization data is available. The fixed bed model is constructed using Aspen Plus, process modeling software, coupled with a FORTRAN user kinetic subroutine. Current updraft gasification models created in Aspen Plus have limited predictive capabilities and must be "tuned" to reflect a generalized gas composition as specified in literature or by the gasifier manufacturer. This limits the applicability of the process model.

Experiments on torrefied wood pellet: study by gasification and characterization for waste biomass to energy applications.

PubMed

Rollinson, Andrew N; Williams, Orla

2016-05-01

Samples of torrefied wood pellet produced by low-temperature microwave pyrolysis were tested through a series of experiments relevant to present and near future waste to energy conversion technologies. Operational performance was assessed using a modern small-scale downdraft gasifier. Owing to the pellet's shape and surface hardness, excellent flow characteristics were observed. The torrefied pellet had a high energy density, and although a beneficial property, this highlighted the present inflexibility of downdraft gasifiers in respect of feedstock tolerance due to the inability to contain very high temperatures inside the reactor during operation. Analyses indicated that the torrefaction process had not significantly altered inherent kinetic properties to a great extent; however, both activation energy and pre-exponential factor were slightly higher than virgin biomass from which the pellet was derived. Thermogravimetric analysis-derived reaction kinetics (CO2 gasification), bomb calorimetry, proximate and ultimate analyses, and the Bond Work Index grindability test provided a more comprehensive characterization of the torrefied pellet's suitability as a fuel for gasification and also other combustion applications. It exhibited significant improvements in grindability energy demand and particle size control compared to other non-treated and thermally treated biomass pellets, along with a high calorific value, and excellent resistance to water.

Experiments on torrefied wood pellet: study by gasification and characterization for waste biomass to energy applications

PubMed Central

Rollinson, Andrew N.; Williams, Orla

2016-01-01

Samples of torrefied wood pellet produced by low-temperature microwave pyrolysis were tested through a series of experiments relevant to present and near future waste to energy conversion technologies. Operational performance was assessed using a modern small-scale downdraft gasifier. Owing to the pellet's shape and surface hardness, excellent flow characteristics were observed. The torrefied pellet had a high energy density, and although a beneficial property, this highlighted the present inflexibility of downdraft gasifiers in respect of feedstock tolerance due to the inability to contain very high temperatures inside the reactor during operation. Analyses indicated that the torrefaction process had not significantly altered inherent kinetic properties to a great extent; however, both activation energy and pre-exponential factor were slightly higher than virgin biomass from which the pellet was derived. Thermogravimetric analysis-derived reaction kinetics (CO2 gasification), bomb calorimetry, proximate and ultimate analyses, and the Bond Work Index grindability test provided a more comprehensive characterization of the torrefied pellet's suitability as a fuel for gasification and also other combustion applications. It exhibited significant improvements in grindability energy demand and particle size control compared to other non-treated and thermally treated biomass pellets, along with a high calorific value, and excellent resistance to water. PMID:27293776

Inhalation exposure and risk of polycyclic aromatic hydrocarbons (PAHs) among the rural population adopting wood gasifier stoves compared to different fuel-stove users

NASA Astrophysics Data System (ADS)

Lin, Nan; Chen, Yuanchen; Du, Wei; Shen, Guofeng; Zhu, Xi; Huang, Tianbo; Wang, Xilong; Cheng, Hefa; Liu, Junfeng; Xue, Chunyu; Liu, Guangqing; Zeng, Eddy Y.; Xing, Baoshan; Tao, Shu

2016-12-01

Polycyclic aromatica hydrocarbons (PAHs) are a group of compounds with carcinogenic potentials and residential solid fuel combustion is one major source of PAHs in most developing countries. Replacement of traditional stoves with improved ones is believed to be a practical approach to reduce pollutant emissions, however, field assessments on the performance and consequent impacts on air quality and human health after adopting improved stoves are rare. The study is the first time to quantify inhalation exposure to PAHs among the residents who adopted wood gasifier stoves. The results were compared to those still burning coals in the region and compared to exposure levels for different fuel/stove users in literature. The results showed that the PAHs exposure levels for the wood gasifier stove users were significantly lower than the values for those using traditional wood stoves reported in literature, and the daily exposure concentrations of BaPeq (Benzo[a]pyrene equivalent concentration) can be reduced by 48%-91% if traditional wood stoves were replaced by wood gasifier stoves. The corresponding Incremental Lifetime Cancer Risk (ILCR) decreased approximately four times from 1.94 × 10-4 to 5.17 × 10-5. The average concentration of the total 26 PAHs for the wood users was 1091 ± 722 ng/m3, which was comparable to 1060 ± 927 ng/m3 for those using anthracite coals, but the composition profiles were considerably different. The average BaPeq were 116 and 25.8 ng/m3 for the wood and coal users, respectively, and the corresponding ILCR of the anthracite coal users was 1.69 × 10-5, which was nearly one third of those using the wood gasifier stoves. The wood users exposed to not only high levels of high molecular weight PAHs, but relatively high fractions of particulate phase PAHs in small particles compared to the coal users, resulting in high exposure risks.

Coal-Based Fuel-Cell Powerplants

NASA Technical Reports Server (NTRS)

Ferral, J. F.; Pappano, A. W.; Jennings, C. N.

1986-01-01

Report assesses advanced technologyy design alternatives for integrated coal-gasifier/fuel-cell powerplants. Various gasifier, cleanup, and fuelcell options evaluated. Evaluation includes adjustments to assumed performances and costs of proposed technologies where required. Analysis identifies uncertainties remaining in designs and most promising alternatives and research and development required to develop these technologies. Bulk of report summary and detailed analysis of six major conceptual designs and variations of each. All designs for plant that uses Illinois No. 6 coal and produces 675 MW of net power.

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.

Gasification in pulverized coal flames. First annual progress report, July 1975--June 1976

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

Lenzer, R. C.; George, P. E.; Thomas, J. F.

1976-07-01

This project concerns the production of power and synthesis gas from pulverized coal via suspension gasification. Swirling flow in both concentric jet and cyclone gasifiers will separate oxidation and reduction zones. Gasifier performance will be correlated with internally measured temperature and concentration profiles. A literature review of vortex and cyclone reactors is complete. Preliminary reviews of confined jet reactors and pulverized coal reaction models have also been completed. A simple equilibrium model for power gas production is in agreement with literature correlations. Cold gas efficiency is not a suitable performance parameter for combined cycle operation. The coal handling facility, equippedmore » with crusher, pulverizer and sieve shaker, is in working order. Test cell flow and electrical systems have been designed, and most of the equipment has been received. Construction of the cyclone gasifier has begun. A preliminary design for the gas sampling system, which will utilize a UTI Q-30C mass spectrometer, has been developed.« less

Unmixed fuel processors and methods for using the same

DOEpatents

Kulkarni, Parag Prakash; Cui, Zhe

2010-08-24

Disclosed herein are unmixed fuel processors and methods for using the same. In one embodiment, an unmixed fuel processor comprises: an oxidation reactor comprising an oxidation portion and a gasifier, a CO.sub.2 acceptor reactor, and a regeneration reactor. The oxidation portion comprises an air inlet, effluent outlet, and an oxygen transfer material. The gasifier comprises a solid hydrocarbon fuel inlet, a solids outlet, and a syngas outlet. The CO.sub.2 acceptor reactor comprises a water inlet, a hydrogen outlet, and a CO.sub.2 sorbent, and is configured to receive syngas from the gasifier. The regeneration reactor comprises a water inlet and a CO.sub.2 stream outlet. The regeneration reactor is configured to receive spent CO.sub.2 adsorption material from the gasification reactor and to return regenerated CO.sub.2 adsorption material to the gasification reactor, and configured to receive oxidized oxygen transfer material from the oxidation reactor and to return reduced oxygen transfer material to the oxidation reactor.

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.

Basic refractory and slag management for petcoke carbon feedstock in gasifiers

DOEpatents

Kwong, Kyei-Sing; Bennett, James P; Nakano, Jinichiro

2014-04-22

The disclosure provides methods of operating a slagging gasifier using a carbon feedstock having a relatively high V.sub.2O.sub.5 to SiO.sub.2 ratio, such as petcoke. The disclosure generates a combined chemical composition in the feed mixture having less than 25 wt. % SiO.sub.2, greater than 20 wt. % V.sub.2O.sub.5, and greater than 20 wt. % CaO. The method takes advantage of a novel recognition that increased levels of SiO.sub.2 tend to decrease dissolution of the V.sub.2O.sub.3 which forms under the reducing conditions of the gasifier, and utilizes the CaO additive to establish a chemical phase equilibria comprised of lower melting compounds. The method further provides for control based on the presence of Al.sub.2O.sub.3 and FeO, and provides for a total combined chemical composition of greater than about 5 wt. % MgO for use with refractory linings comprised of MgO based refractory brick.

Equilibrium model analysis of waste plastics gasification using CO2 and steam.

PubMed

Kannan, P; Lakshmanan, G; Al Shoaibi, A; Srinivasakannan, C

2017-12-01

Utilization of carbon dioxide (CO 2 ) in thermochemical treatment of waste plastics may significantly help to improve CO 2 recycling, thus simultaneously curtailing dioxins/furans and CO 2 emissions. Although CO 2 is not such an effective gasifying agent as steam, a few investigations have explored the utilization of CO 2 in conjunction with steam to achieve somewhat higher carbon conversion. This work presents a comparative evaluation study of CO 2 and steam gasification of a typical post-consumer waste plastics mixture using an Aspen Plus equilibrium model. The effect of flow rate of gasifying medium (CO 2 and/or steam) and gasification temperature on product gas composition, carbon conversion, and cold gas efficiency has been analyzed. Simulation results demonstrate that CO 2 can serve as a potential gasifying agent for waste plastics gasification. The resulting product gas was rich in CO whereas CO 2 -steam blends yield a wider H 2 /CO ratio, thus extending the applications of the product gas.

Olivine, dolomite and ceramic filters in one vessel to produce clean gas from biomass.

PubMed

Rapagnà, Sergio; Gallucci, Katia; Foscolo, Pier Ugo

2018-01-01

Heavy organic compounds produced during almond shells gasification in a steam and/or air atmosphere, usually called tar, are drastically reduced in the product gas by using simultaneously in one vessel a ceramic filter placed in the freeboard and a mixture of olivine and dolomite particles in the fluidized bed of the gasifier. The content of tar in the product gas during a reference gasification test with air, in presence of fresh olivine particles only, was 8600mg/Nm 3 of dry gas. By gasifying biomass with steam at the same temperature level of 820°C in a bed of olivine and dolomite (20% by weight), and in the presence of a catalytic ceramic filter inserted in the freeboard of the fluidized bed gasifier, the level of tar was brought down to 57mg/Nm 3 of dry producct gas, with a decrease of more than two orders of magnitude. Copyright © 2017 Elsevier Ltd. All rights reserved.

Wiang Haeng coal-water fuel preparation and gasification, Thailand - task 39

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

Anderson, C.M.; Musich, M.A.; Young, B.C.

In response to an inquiry by the Department of Mineral Resources (DMR) in Thailand, the Energy & Environmental Research Center (EERC) prepared a four-task program to assess the responsiveness of Wiang Haeng coal to the temperature and pressure conditions of hot-water drying (HWD). The results indicate that HWD made several improvements in the coal, notably increases (HWD). The results indicate that HWD made several improvements in the coal, notably increases in heating value and carbon content and reductions in equilibrium moisture and oxygen content. The equilibrium moisture content decreased from 37.4 wt% for the raw coal to about 20 wt%more » for the HWD coals. The energy density for a pumpable coal-water fuel indicates an increase from 4450 to 6650 Btu/lb by hydrothermal treatment. Raw and HWD coal were then gasified at various mild gasification conditions of 700{degrees}C and 30 psig. The tests indicated that the coal is probably similar to other low-rank coals, will produce high levels of hydrogen, and be fairly reactive.« 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

Surface modifications of steels to improve corrosion resistance in sulfidizing-oxidizing environments

NASA Astrophysics Data System (ADS)

Behrani, Vikas

Industrial and power generation processes employ units like boilers and gasifiers to burn sulfur containing fuels to produce steam and syn gas (H 2 and CO), which can generate electricity using turbines and fuel cells. These units often operate under environments containing gases such as H 2S, SO2, O2 etc, which can attack the metallic structure and impose serious problems of corrosion. Corrosion control in high temperature sulfur bearing environments is a challenging problem requiring information on local gaseous species at the surface of alloy and mechanisms of degradation in these environments. Coatings have proved to be a better alternative for improving corrosion resistance without compromising the bulk mechanical properties. Changes in process conditions may result in thermal and/or environment cycling between oxidizing and sulfidizing environments at the alloy surface, which can damage the protective scale formed on the alloy surface, leading to increase in corrosion rates. Objective of this study was to understand the effect of fluctuating environments on corrosion kinetics of carbon steels and develop diffusion based coatings to mitigate the high temperatures corrosion under these conditions. More specifically, the focus was: (1) to characterize the local gaseous environments at the surface of alloys in boilers; (2) optimizing diffusion coatings parameters for carbon steel; (3) understand the underlying failure mechanisms in cyclic environments; (4) to improve aluminide coating behavior by co-deposition of reactive elements such as Yttrium and Hafnium; (5) to formulate a plausible mechanism of coating growth and effects of alloying elements on corrosion; and (6) to understand the spallation behavior of scale by measuring stresses in the scales. The understanding of coating mechanism and effects of fluctuating gaseous environments provides information for designing materials with more reliable performance. The study also investigates the mechanism behind the effect of REs on scale adhesion and sulfidation behavior. Thus, the present work will have a broad impact on the field of materials and coatings selection for high temperature industrial environments such as boilers and gasifiers, and provides information on RE-modified aluminized coatings on carbon steel as an alternative for the use of bulk superalloys under high temperature sulfur bearing environments.

Process for electrochemically gasifying coal using electromagnetism

DOEpatents

Botts, Thomas E.; Powell, James R.

1987-01-01

A process for electrochemically gasifying coal by establishing a flowing stream of coal particulate slurry, electrolyte and electrode members through a transverse magnetic field that has sufficient strength to polarize the electrode members, thereby causing them to operate in combination with the electrolyte to electrochemically reduce the coal particulate in the slurry. Such electrochemical reduction of the coal produces hydrogen and carbon dioxide at opposite ends of the polarized electrode members. Gas collection means are operated in conjunction with the process to collect the evolved gases as they rise from the slurry and electrolyte solution.

An environmental friendly animal waste disposal process with ammonia recovery and energy production: Experimental study and economic analysis.

PubMed

Shen, Ye; Tan, Michelle Ting Ting; Chong, Clive; Xiao, Wende; Wang, Chi-Hwa

2017-10-01

Animal manure waste is considered as an environmental challenge especially in farming areas mainly because of gaseous emission and water pollution. Among all the pollutants emitted from manure waste, ammonia is of greatest concern as it could contribute to formation of aerosols in the air and could hardly be controlled by traditional disposal methods like landfill or composting. On the other hand, manure waste is also a renewable source for energy production. In this work, an environmental friendly animal waste disposal process with combined ammonia recovery and energy production was proposed and investigated both experimentally and economically. Lab-scale feasibility study results showed that 70% of ammonia in the manure waste could be converted to struvite as fertilizer, while solid manure waste was successfully gasified in a 10kW downdraft fixed-bed gasifier producing syngas with the higher heating value of 4.9MJ/(Nm 3 ). Based on experimental results, economic study for the system was carried out using a cost-benefit analysis to investigate the financial feasibility based on a Singapore case study. In addition, for comparison, schemes of gasification without ammonia removal and incineration were also studied for manure waste disposal. The results showed that the proposed gasification-based manure waste treatment process integrated with ammonia recovery was most financially viable. Copyright © 2017 Elsevier Ltd. All rights reserved.

Environmental research program for slagging fixed-bed coal gasification. Status report, November 1981

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

Wilzbach, K. E.; Stetter, J. R.; Reilly, Jr., C. A.

1982-02-01

A collaborative environmental research program to provide information needed to assess the health and environmental effects associated with large-scale coal gasification technology is being conducted by Argonne National Laboratory (ANL) and the Grand Forks Energy Technology Center (GFETC). The objectives are to: investigate the toxicology and chemical composition of coal gasification by-products as a function of process variables and coal feed; compare the characteristics of isokinetic side-stream samples with those of process stream samples; identify the types of compounds responsible for toxicity; evaluate the chemical and toxicological effectiveness of various wastewater treatment operations; refine methodology for the collection and measurementmore » of organic vapors and particulates in workplace air; and obtain preliminary data on workplace air quality. So far the toxicities of a set of process stream samples (tar, oil, and gas liquor) and side-stream condensates from the GFETC gasifier have been measured in a battery of cellular screening tests for mutagenicity and cytotoxicity. Preliminary data on the effects of acute and chronic exposures of laboratory animals to process tar have been obtained. The process tar has been chemically fractionated and the distribution of mutagenicity and compound types among the fractions has been determined. Organic vapors and particulates collected at various times and locations in the gasifier building have been characterized.« less

Quality of charcoal produced using micro gasification and how the new cook stove works in rural Kenya

NASA Astrophysics Data System (ADS)

Njenga, Mary; Mahmoud, Yahia; Mendum, Ruth; Iiyama, Muyiki; Jamnadass, Ramni; Roing de Nowina, Kristina; Sundberg, Cecilia

2016-09-01

Wood based energy is the main source of cooking and heating fuel in Sub-Saharan Africa. Its use rises as the population increases. Inefficient cook stoves result in fuel wastage and health issues associated with smoke in the kitchen. As users are poor women, they tend not to be consulted on cook stove development, hence the need for participatory development of efficient woodfuel cooking systems. This paper presents the findings of a study carried out in Embu, Kenya to assess energy use efficiency and concentrations of carbon monoxide and fine particulate matter from charcoal produced using gasifier cook stoves, compared to conventional wood charcoal. Charcoal made from Grevillea robusta prunings, Zea mays cob (maize cob) and Cocos nucifera (coconut shells) had calorific values of 26.5 kJ g-1, 28.7 kJ g-1 and 31.7 kJ g-1 respectively, which are comparable to conventional wood charcoal with calorific values of 33.1 kJ g-1. Cooking with firewood in a gasifier cook stove and use of the resultant charcoal as by-product to cook another meal in a conventional charcoal stove saved 41% of the amount of fuel compared to cooking with firewood in the traditional three stone open fire. Cooking with firewood based on G. robusta prunings in the traditional open fire resulted in a concentration of fine particulate matter of 2600 μg m-3, which is more than 100 times greater than from cooking with charcoal made from G. robusta prunings in a gasifier. Thirty five percent of households used the gasifier for cooking dinner and lunch, and cooks preferred using it for food that took a short time to prepare. Although the gasifier cook stove is energy and emission efficient there is a need for it to be developed further to better suit local cooking preferences. The energy transition in Africa will have to include cleaner and more sustainable wood based cooking systems.

LIQUID BIO-FUEL PRODUCTION FROM NON-FOOD BIOMASS VIA HIGH TEMPERATURE STEAM ELECTROLYSIS

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

G. L. Hawkes; J. E. O'Brien; M. G. McKellar

2011-11-01

Bio-Syntrolysis is a hybrid energy process that enables production of synthetic liquid fuels that are compatible with the existing conventional liquid transportation fuels infrastructure. Using biomass as a renewable carbon source, and supplemental hydrogen from high-temperature steam electrolysis (HTSE), bio-syntrolysis has the potential to provide a significant alternative petroleum source that could reduce US dependence on imported oil. Combining hydrogen from HTSE with CO from an oxygen-blown biomass gasifier yields syngas to be used as a feedstock for synthesis of liquid transportation fuels via a Fischer-Tropsch process. Conversion of syngas to liquid hydrocarbon fuels, using a biomass-based carbon source, expandsmore » the application of renewable energy beyond the grid to include transportation fuels. It can also contribute to grid stability associated with non-dispatchable power generation. The use of supplemental hydrogen from HTSE enables greater than 90% utilization of the biomass carbon content which is about 2.5 times higher than carbon utilization associated with traditional cellulosic ethanol production. If the electrical power source needed for HTSE is based on nuclear or renewable energy, the process is carbon neutral. INL has demonstrated improved biomass processing prior to gasification. Recyclable biomass in the form of crop residue or energy crops would serve as the feedstock for this process. A process model of syngas production using high temperature electrolysis and biomass gasification is presented. Process heat from the biomass gasifier is used to heat steam for the hydrogen production via the high temperature steam electrolysis process. Oxygen produced form the electrolysis process is used to control the oxidation rate in the oxygen-blown biomass gasifier. Based on the gasifier temperature, 94% to 95% of the carbon in the biomass becomes carbon monoxide in the syngas (carbon monoxide and hydrogen). Assuming the thermal efficiency of the power cycle for electricity generation is 50%, (as expected from GEN IV nuclear reactors), the syngas production efficiency ranges from 70% to 73% as the gasifier temperature decreases from 1900 K to 1500 K. Parametric studies of system pressure, biomass moisture content and low temperature alkaline electrolysis are also presented.« less

Instrumental methods of analysis of sulfur compounds in synfuel process streams. Quarterly technical progress report, July-September 1984

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

Jordan, J.; Talbott, J.

1984-01-01

Task 1. Methods development for the speciation of the polysulfides. Work on this task has been completed in December 1983 and reported accordingly in DOE/PC/40783-T13. Task 2. Methods development for the speciation of dithionite and polythionates. Work on Task 2 has been completed in June 1984 and has been reported accordingly in DOE/PC/40783-T15. Task 3. Total accounting of the sulfur balance in representative samples of synfuel process streams. A systematic and critical comparison of results, obtained in the analysis of sulfur moieties in representative samples of coal conversion process streams, revealed the following general trends. (a) In specimens of highmore » pH (9-10) and low redox potential (-0.3 to -0.4 volt versus NHE) sulfidic and polysulfidic sulfur moieties predominate. (b) In process streams of lower pH and more positive redox potential, higher oxidation states of sulfur (notably sulfate) account for most of the total sulfur present. (c) Oxidative wastewater treatment procedures by the PETC stripping process convert lower oxidation states of sulfur into thiosulfate and sulfate. In this context, remarkable similarities were observed between liquefaction and gasification process streams. However, the thiocyanate present in samples from the Grand Forks gasifier were impervious to the PETC stripping process. (d) Total sulfur contaminant levels in coal conversion process stream wastewater samples are primarily determined by the abundance of sulfur in the coal used as starting material than by the nature of the conversion process (liquefaction or gasification). 13 references.« less

Bio-electricity Generation using Jatropha Oil Seed Cake.

PubMed

Raheman, Hifjur; Padhee, Debasish

2016-01-01

The review of patents reveals that Handling of Jatropha seed cake after extraction of oil is essential as it contains toxic materials which create environmental pollution. The goal of this work is complete utilisation of Jatropha seeds. For this purpose, Jatropha oil was used for producing biodiesel and the byproduct Jatropha seed cake was gasified to obtain producer gas. Both biodiesel and producer gas were used to generate electricity. To achieve this, a system comprising gasifier, briquetting machine, diesel engine and generator was developed. Biodiesel was produced successfully using the method patented for biodiesel production and briquettes of Jatropha seed cake were made using a vertical extruding machine. Producer gas was obtained by gasifying these briquettes in a downdraft gasifier. A diesel engine was then run in dual fuel mode with biodiesel and producer gas instead of only diesel. Electricity was generated by coupling it to a generator. The cost of producing kilowatthour of electricity with biodiesel and diesel in dual fuel mode with producer gas was found to be 0.84 $ and 0.75 $, respectively as compared to 0.69 $ and 0.5 $ for the same fuels in single fuel mode resulting in up to 48 % saving of pilot fuel. Compared to singlefuel mode, there was 25-32 % reduction in system and brake thermal efficiency along with significantly lower NOx, higher CO and CO2 emissions when the bio-electricity generating system was operated in dual fuel mode. Overall, the developed system could produce electricity successfully by completely uti- lising Jatropha seeds without leaving any seed cake to cause environmental pollution.

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.

Coal gasification system with a modulated on/off control system

DOEpatents

Fasching, George E.

1984-01-01

A modulated control system is provided for improving regulation of the bed level in a fixed-bed coal gasifier into which coal is fed from a rotary coal feeder. A nuclear bed level gauge using a cobalt source and an ion chamber detector is used to detect the coal bed level in the gasifier. The detector signal is compared to a bed level set point signal in a primary controller which operates in proportional/integral modes to produce an error signal. The error signal is modulated by the injection of a triangular wave signal of a frequency of about 0.0004 Hz and an amplitude of about 80% of the primary deadband. The modulated error signal is fed to a triple-deadband secondary controller which jogs the coal feeder speed up or down by on/off control of a feeder speed change driver such that the gasifier bed level is driven toward the set point while preventing excessive cycling (oscillation) common in on/off mode automatic controllers of this type. Regulation of the bed level is achieved without excessive feeder speed control jogging.

Gasification of torrefied Miscanthus × giganteus in an air-blown bubbling fluidized bed gasifier.

PubMed

Xue, G; Kwapinska, M; Horvat, A; Kwapinski, W; Rabou, L P L M; Dooley, S; Czajka, K M; Leahy, J J

2014-05-01

Torrefaction is suggested to be an effective method to improve the fuel properties of biomass and gasification of torrefied biomass should provide a higher quality product gas than that from unprocessed biomass. In this study, both raw and torrefied Miscanthus × giganteus (M×G) were gasified in an air-blown bubbling fluidized bed (BFB) gasifier using olivine as the bed material. The effects of equivalence ratio (ER) (0.18-0.32) and bed temperature (660-850°C) on the gasification performance were investigated. The results obtained suggest the optimum gasification conditions for the torrefied M × G are ER 0.21 and 800°C. The product gas from these process conditions had a higher heating value (HHV) of 6.70 MJ/m(3), gas yield 2m(3)/kg biomass (H2 8.6%, CO 16.4% and CH4 4.4%) and cold gas efficiency 62.7%. The comparison between raw and torrefied M × G indicates that the torrefied M × G is more suitable BFB gasification. Copyright © 2014 Elsevier Ltd. All rights reserved.

Influence of operating conditions on the air gasification of dry refinery sludge in updraft gasifier

NASA Astrophysics Data System (ADS)

Ahmed, R.; Sinnathambi, C. M.

2013-06-01

In the present work, details of the equilibrium modeling of dry refinery sludge (DRS) are presented using ASPEN PLUS Simulator in updraft gasifier. Due to lack of available information in the open journal on refinery sludge gasification using updraft gasifier, an evaluate for its optimum conditions on gasification is presented in this paper. For this purpose a Taguchi Orthogonal array design, statistical software is applied to find optimum conditions for DRS gasification. The goal is to identify the most significant process variable in DRS gasification conditions. The process variables include; oxidation zone temperature, equivalent ratio, operating pressure will be simulated and examined. Attention was focused on the effect of optimum operating conditions on the gas composition of H2 and CO (desirable) and CO2 (undesirable) in terms of mass fraction. From our results and finding it can be concluded that the syngas (H2 & CO) yield in term of mass fraction favors high oxidation zone temperature and at atmospheric pressure while CO2 acid gas favor at a high level of equivalent ratio as well as air flow rate favoring towards complete combustion.

CRADA opportunities with METC`s gasification and hot gas cleanup facility

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

Galloway, E N; Rockey, J M; Tucker, M S

1995-06-01

Opportunities exist for Cooperative Research and Development Agreements (CRADA) at the Morgantown Energy Technology Center (METC) to support commercialization of IGCC power systems. METC operates an integrated gasifier and hot gas cleanup facility for the development of gasification and hot gas cleanup technologies. The objective of our program is to gather performance data on gasifier operation, particulate removal, desulfurization and regeneration technologies. Additionally, slip streams are provided for developing various technologies such as; alkali monitoring, particulate measuring, chloride removal, and contaminate recovery processes. METC`s 10-inch diameter air blown Fluid Bed Gasifier (FBG) provides 300 lb/hr of coal gas at 1100{degrees}Fmore » and 425 psig. The particulate laden gas is transported to METC`s Modular Gas Cleanup Rig (MGCR). The gas pressure is reduced to 285 psig before being fed into a candle filter vessel. The candle filter vessel houses four candle filters and multiple test coupons. The particulate free gas is then desulfurized in a sorbent reactor. Starting in 1996 the MGCR system will be able to regenerate the sorbent in the same vessel.« less

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

Sensitivity of Fischer-Tropsch Synthesis and Water-Gas Shift Catalystes to Poisons form High-Temperature High-Pressure Entrained-Flow (EF) Oxygen-Blown Gasifier Gasification of Coal/Biomass Mixtures

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

Burton Davis; Gary Jacobs; Wenping Ma

2009-09-30

There has been a recent shift in interest in converting not only natural gas and coal derived syngas to Fischer-Tropsch synthesis products, but also converting biomass-derived syngas, as well as syngas derived from coal and biomass mixtures. As such, conventional catalysts based on iron and cobalt may not be suitable without proper development. This is because, while ash, sulfur compounds, traces of metals, halide compounds, and nitrogen-containing chemicals will likely be lower in concentration in syngas derived from mixtures of coal and biomass (i.e., using entrained-flow oxygen-blown gasifier gasification gasification) than solely from coal, other compounds may actually be increased.more » Of particular concern are compounds containing alkali chemicals like the chlorides of sodium and potassium. In the first year, University of Kentucky Center for Applied Energy Research (UK-CAER) researchers completed a number of tasks aimed at evaluating the sensitivity of cobalt and iron-based Fischer-Tropsch synthesis (FT) catalysts and a commercial iron-chromia high temperature water-gas shift catalyst (WGS) to alkali halides. This included the preparation of large batches of 0.5%Pt-25%Co/Al{sub 2}O{sub 3} and 100Fe: 5.1Si: 3.0K: 2.0Cu (high alpha) catalysts that were split up among the four different entities participating in the overall project; the testing of the catalysts under clean FT and WGS conditions; the testing of the Fe-Cr WGS catalyst under conditions of co-feeding NaCl and KCl; and the construction and start-up of the continuously stirred tank reactors (CSTRs) for poisoning investigations.« less

Process for electrochemically gasifying coal

DOEpatents

Botts, T.E.; Powell, J.R.

1985-10-25

A process is claimed for electrochemically gasifying coal by establishing a flowing stream of coal particulate slurry, electrolyte and electrode members through a transverse magnetic field that has sufficient strength to polarize the electrode members, thereby causing them to operate in combination with the electrolyte to electrochemically reduce the coal particulate in the slurry. Such electrochemical reduction of the coal produces hydrogen and carbon dioxide at opposite ends of the polarized electrode members. Gas collection means are operated in conjunction with the process to collect the evolved gases as they rise from the slurry and electrolyte solution. 7 figs.

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.

Distributed Fiber Optic Sensor for On-Line Monitoring of Coal Gasifier Refractory Health

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

Wang, Anbo; Yu, Zhihao

This report summarizes technical progress on the program “Distributed Fiber Optic Sensor for On-Line Monitoring of Coal Gasifier Refractory Health,” funded by the National Energy Technology Laboratory of the U.S. Department of Energy, and performed by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering at Virginia Tech. The scope of work entails analyses of traveling grating generation technologies in an optical fiber, as well as the interrogation of the gratings to infer a distributed temperature along the fiber, for the purpose of developing a real-time refractory health condition monitoring technology for coal gasifiers. Duringmore » the project period, which is from 2011-2015, three different sensing principles were studied, including four-wave mixing (FWM), coherent optical time-domain reflectometer (C-OTDR) and Brillouin optical time-domain analysis (BOTDA). By comparing the three methods, the BOTDA was selected for further development into a complete bench-top sensing system for the proposed high-temperature sensing application. Based on the input from Eastman Chemical, the industrial collaborator on this project, a cylindrical furnace was designed and constructed to simulate typical gasifier refractory temperature conditions in the laboratory, and verify the sensor’s capability to fully monitor refractory conditions on the back-side at temperatures up to 1000°C. In the later stages of the project, the sensing system was tested in the simulated environment for its sensing performance and high-temperature survivability. Through theoretical analyses and experimental research on the different factors affecting the sensor performance, a sensor field deployment strategy was proposed for possible future sensor field implementations.« less

A user-centered, iterative engineering approach for advanced biomass cookstove design and development

NASA Astrophysics Data System (ADS)

Shan, Ming; Carter, Ellison; Baumgartner, Jill; Deng, Mengsi; Clark, Sierra; Schauer, James J.; Ezzati, Majid; Li, Jiarong; Fu, Yu; Yang, Xudong

2017-09-01

Unclean combustion of solid fuel for cooking and other household energy needs leads to severe household air pollution and adverse health impacts in adults and children. Replacing traditional solid fuel stoves with high efficiency, low-polluting semi-gasifier stoves can potentially contribute to addressing this global problem. The success of semi-gasifier cookstove implementation initiatives depends not only on the technical performance and safety of the stove, but also the compatibility of the stove design with local cooking practices, the needs and preferences of stove users, and community economic structures. Many past stove design initiatives have failed to address one or more of these dimensions during the design process, resulting in failure of stoves to achieve long-term, exclusive use and market penetration. This study presents a user-centered, iterative engineering design approach to developing a semi-gasifier biomass cookstove for rural Chinese homes. Our approach places equal emphasis on stove performance and meeting the preferences of individuals most likely to adopt the clean stove technology. Five stove prototypes were iteratively developed following energy market and policy evaluation, laboratory and field evaluations of stove performance and user experience, and direct interactions with stove users. The most current stove prototype achieved high performance in the field on thermal efficiency (ISO Tier 3) and pollutant emissions (ISO Tier 4), and was received favorably by rural households in the Sichuan province of Southwest China. Among household cooks receiving the final prototype of the intervention stove, 88% reported lighting and using it at least once. At five months post-intervention, the semi-gasifier stoves were used at least once on an average of 68% [95% CI: 43, 93] of days. Our proposed design strategy can be applied to other stove development initiatives in China and other countries.

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

Matyas, Josef; Cooley, Scott K.; Sundaram, S. K.

Slags of low viscosity readily penetrate the refractory lining in slagging gasifiers, causing rapid and severe corrosion called spalling. In addition, a low-viscosity slag that flows down the gasifier wall forms a relatively thin layer of slag on the refractory surface, allowing the corrosive gases in the gasifier to participate in the chemical reactions between the refractory and the slag. In contrast, a slag viscosity of <25 Pa•s at 1400°C is necessary to minimize the possibility of plugging the slag tap. There is a need to predict and optimize slag viscosity so slagging gasifiers can operate continuously at temperatures rangingmore » from 1300 to 1650°C. The approach adopted in this work was to statistically design and prepare simulated slags, measure the viscosity as a function of temperature, and develop a model to predict slag viscosity based on slag composition and temperature. Statistical design software was used to select compositions from a candidate set of all possible vertices that will optimally represent the composition space for 10 main components. A total of 21 slag compositions were generated, including 5 actual coal slag compositions. The Arrhenius equation was applied to measured viscosity versus temperature data of tested slags, and the Arrhenius coefficients (A and B in ln(vis) = A + B/T) were expressed as linear functions of the slag composition. The viscosity model was validated using 1) data splitting approach, and 2) viscosity/temperature data of selected slag compositions from the literature that were formulated and melted at Pacific Northwest National Laboratory. The capability of the model to predict the viscosity of coal slags was compared with the model developed by Browning et al. because this model can predict the viscosity of slags from coal ash better than the most commonly used empirical models found in the literature.« less

Two-stage coal gasification and desulfurization apparatus

DOEpatents

Bissett, Larry A.; Strickland, Larry D.

1991-01-01

The present invention is directed to a system which effectively integrates a two-stage, fixed-bed coal gasification arrangement with hot fuel gas desulfurization of a first stream of fuel gas from a lower stage of the two-stage gasifier and the removal of sulfur from the sulfur sorbent regeneration gas utilized in the fuel-gas desulfurization process by burning a second stream of fuel gas from the upper stage of the gasifier in a combustion device in the presence of calcium-containing material. The second stream of fuel gas is taken from above the fixed bed in the coal gasifier and is laden with ammonia, tar and sulfur values. This second stream of fuel gas is burned in the presence of excess air to provide heat energy sufficient to effect a calcium-sulfur compound forming reaction between the calcium-containing material and sulfur values carried by the regeneration gas and the second stream of fuel gas. Any ammonia values present in the fuel gas are decomposed during the combustion of the fuel gas in the combustion chamber. The substantially sulfur-free products of combustion may then be combined with the desulfurized fuel gas for providing a combustible fluid utilized for driving a prime mover.

A conceptual design of catalytic gasification fuel cell hybrid power plant with oxygen transfer membrane

NASA Astrophysics Data System (ADS)

Shi, Wangying; Han, Minfang

2017-09-01

A hybrid power generation system integrating catalytic gasification, solid oxide fuel cell (SOFC), oxygen transfer membrane (OTM) and gas turbine (GT) is established and system energy analysis is performed. In this work, the catalytic gasifier uses steam, recycled anode off-gas and pure oxygen from OTM system to gasify coal, and heated by hot cathode off-gas at the same time. A zero-dimension SOFC model is applied and verified by fitting experimental data. Thermodynamic analysis is performed to investigate the integrated system performance, and system sensitivities on anode off-gas back flow ratio, SOFC fuel utilization, temperature and pressure are discussed. Main conclusions are as follows: (1) System overall electricity efficiency reaches 60.7%(HHV) while the gasifier operates at 700 °C and SOFC at 850 °C with system pressure at 3.04 bar; (2) oxygen enriched combustion simplify the carbon-dioxide capture process, which derives CO2 of 99.2% purity, but results in a penalty of 6.7% on system electricity efficiency; (3) with SOFC fuel utilization or temperature increasing, the power output of SOFC increases while GT power output decreases, and increasing system pressure can improve both the performance of SOFC and GT.

Air-flow regulation system for a coal gasifier

DOEpatents

Fasching, George E.

1984-01-01

An improved air-flow regulator for a fixed-bed coal gasifier is provided which allows close air-flow regulation from a compressor source even though the pressure variations are too rapid for a single primary control loop to respond. The improved system includes a primary controller to control a valve in the main (large) air supply line to regulate large slow changes in flow. A secondary controller is used to control a smaller, faster acting valve in a secondary (small) air supply line parallel to the main line valve to regulate rapid cyclic deviations in air flow. A low-pass filter with a time constant of from 20 to 50 seconds couples the output of the secondary controller to the input of the primary controller so that the primary controller only responds to slow changes in the air-flow rate, the faster, cyclic deviations in flow rate sensed and corrected by the secondary controller loop do not reach the primary controller due to the high frequency rejection provided by the filter. This control arrangement provides at least a factor of 5 improvement in air-flow regulation for a coal gasifier in which air is supplied by a reciprocating compressor through a surge tank.

Gasification Product Improvement Facility (GPIF). Final report

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

NONE

1995-09-01

The gasifier selected for development under this contract is an innovative and patented hybrid technology which combines the best features of both fixed-bed and fluidized-bed types. PyGas{trademark}, meaning Pyrolysis Gasification, is well suited for integration into advanced power cycles such as IGCC. It is also well matched to hot gas clean-up technologies currently in development. Unlike other gasification technologies, PyGas can be designed into both large and small scale systems. It is expected that partial repowering with PyGas could be done at a cost of electricity of only 2.78 cents/kWh, more economical than natural gas repowering. It is extremely unfortunatemore » that Government funding for such a noble cause is becoming reduced to the point where current contracts must be canceled. The Gasification Product Improvement Facility (GPIF) project was initiated to provide a test facility to support early commercialization of advanced fixed-bed coal gasification technology at a cost approaching $1,000 per kilowatt for electric power generation applications. The project was to include an innovative, advanced, air-blown, pressurized, fixed-bed, dry-bottom gasifier and a follow-on hot metal oxide gas desulfurization sub-system. To help defray the cost of testing materials, the facility was to be located at a nearby utility coal fired generating site. The patented PyGas{trademark} technology was selected via a competitive bidding process as the candidate which best fit overall DOE objectives. The paper describes the accomplishments to date.« less

Uncertainty analysis of integrated gasification combined cycle systems based on Frame 7H versus 7F gas turbines.

PubMed

Zhu, Yunhua; Frey, H Christopher

2006-12-01

Integrated gasification combined cycle (IGCC) technology is a promising alternative for clean generation of power and coproduction of chemicals from coal and other feedstocks. Advanced concepts for IGCC systems that incorporate state-of-the-art gas turbine systems, however, are not commercially demonstrated. Therefore, there is uncertainty regarding the future commercial-scale performance, emissions, and cost of such technologies. The Frame 7F gas turbine represents current state-of-practice, whereas the Frame 7H is the most recently introduced advanced commercial gas turbine. The objective of this study was to evaluate the risks and potential payoffs of IGCC technology based on different gas turbine combined cycle designs. Models of entrained-flow gasifier-based IGCC systems with Frame 7F (IGCC-7F) and 7H gas turbine combined cycles (IGCC-7H) were developed in ASPEN Plus. An uncertainty analysis was conducted. Gasifier carbon conversion and project cost uncertainty are identified as the most important uncertain inputs with respect to system performance and cost. The uncertainties in the difference of the efficiencies and costs for the two systems are characterized. Despite uncertainty, the IGCC-7H system is robustly preferred to the IGCC-7F system. Advances in gas turbine design will improve the performance, emissions, and cost of IGCC systems. The implications of this study for decision-making regarding technology selection, research planning, and plant operation are discussed.

Gasification: An alternative solution for energy recovery and utilization of vegetable market waste.

PubMed

Narnaware, Sunil L; Srivastava, Nsl; Vahora, Samir

2017-03-01

Vegetables waste is generally utilized through a bioconversion process or disposed of at municipal landfills, dumping sites or dumped on open land, emitting a foul odor and causing health hazards. The presents study deals with an alternative way to utilize solid vegetable waste through a thermochemical route such as briquetting and gasification for its energy recovery and subsequent power generation. Briquettes of 50 mm diameter were produced from four different types of vegetable waste. The bulk density of briquettes produced was increased 10 to 15 times higher than the density of the dried vegetable waste in loose form. The lower heating value (LHV) of the briquettes ranged from 10.26 MJ kg -1 to 16.60 MJ kg -1 depending on the type of vegetable waste. The gasification of the briquettes was carried out in an open core downdraft gasifier, which resulted in syngas with a calorific value of 4.71 MJ Nm -3 at the gasification temperature between 889°C and 1011°C. A spark ignition, internal combustion engine was run on syngas and could generate a maximum load up to 10 kW e . The cold gas efficiency and the hot gas efficiency of the gasifier were measured at 74.11% and 79.87%, respectively. Energy recovery from the organic vegetable waste was possible through a thermochemical conversion route such as briquetting and subsequent gasification and recovery of the fuel for small-scale power generation.

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

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.

Effect of atomizer scale and fluid properties on atomization mechanisms and spray characteristics

NASA Astrophysics Data System (ADS)

Waind, Travis

Atomization is chaos. The breakup of liquid structures by a gas encompasses such a wide range of possible configurations that a definitive mechanism describing breakup in any and all situations is an impossibility. However, when focus is applied, trends can be teased out of experimental data that seem to appropriately describe the action undertaken. These studies sought to better understand atomization, specifically coaxial, two-stream, airblast (or air-assist) atomization in which a central liquid jet is broken up by an annular, high-velocity gas stream. The studies enclosed focused on identifying the effect of changing the atomizer's scale on atomization. While most (but not all) atomization studies only focus on the resulting far-field drop diameters, these studies placed the focus largely on the intermediate structures, in the form of the intact liquid jet (ILJ), while also quantifying the resulting drop diameters. The location and shape of the ILJ constantly change, and on its surface, wavelengths were seen to form and grow, which have been correlated to the resulting drop diameters in previous studies. The studies enclosed herein are unique in that they attempt to apply and explain exiting mechanism-based breakup mechanisms to regimes, fluids, and geometry changes not yet evaluated in the literature. Existing correlations were compared to the experimental data for a range of atomizer geometries, and when they were found lacking, Buckingham-(Pi) theorem was used to develop new correlations for predicting behavior. Additionally, the method developed for the calculation of these parameters for other image sets is included, allowing for easy comparison and value verification. A small-scale, coaxial atomization system was used to atomize water and two silicone oils with air. The atomizers used in these studies had the same general geometry type, but had varying sizes, allowing for the effect of both scale and geometry to be evaluated. These studies quantified instability development and growth along with the resulting spray characteristics, allowing for correlations to be made between the two data sets as the more recent mechanism-based atomization models do. Existing mechanism-based models from the literature are compared to the experimental results, as these existing models have not been evaluated significantly with changing atomizer geometry, high-viscosity fluids, and high flow regimes as was done here. Additionally, two experimental campaigns were undertaken with atomizers used to operate the University of Utah's PDU-scale (process development unit) entrained flow gasifier. The first campaign showed the effect of gas velocity, atomizer load (total flow), and gas-liquid impingement angle on the qualitative cold-flow atomizer performance. These trends are then tied to behavior of the entrained flow gasifier, showing the existence of a minimum required degree of atomization to avoid substantial losses in fuel conversion and efficiency in a gasifier. The second campaign showed the effect of gas flow, liquid flow, and fluid on the quantitative cold-flow atomizer performance. While in the literature, changing fluid properties of Newtonian fluids are shown to have a relatively linear response on atomizer performance, the behavior of non-Newtonian fluids was shown to be much more complex and difficult to predict. The correlations developed for the small-scale atomizers are applied to the micro-hole atomizers and found to be erroneous for the change in atomizer geometry. Buckingham-(Pi) theorem is then used to develop correlations to predict the spray Sauter mean diameter for the micro-hole atomizers. Slurry-fed combustion and gasification systems are but one industrial implementation of atomization. Atomization plays important roles in numerous other industries, and despite decades of study, it is not well understood. This document serves to shed some light on a few small, specific subsets of the topic.

Ceramic components for the AGT 100 engine

NASA Technical Reports Server (NTRS)

Helms, H. E.; Heitman, P. W.

1983-01-01

Historically, automotive gas turbines have not been able to meet requirements of the marketplace with respect to cost, performance, and reliability. However, the development of appropriate ceramic materials has overcome problems related to a need for expensive superalloy components and to limitations regarding the operating temperature. An automotive gas turbine utilizing ceramic components has been developed by a U.S. automobile manufacturer. A 100-horsepower, two-shaft, regenerative engine geometry was selected because it is compatible with manual, automatic, and continuously variable transmissions. Attention is given to the ceramic components, the ceramic gasifier turbine rotor development, the ceramic gasifier scroll, ceramic component testing, and the use of advanced nondestructive techniques for the evaluation of the engine components.

Integrated gasifier combined cycle polygeneration system to produce liquid hydrogen

NASA Technical Reports Server (NTRS)

Burns, R. K.; Staiger, P. J.; Donovan, R. M.

1982-01-01

An integrated gasifier combined cycle (IGCC) system which simultaneously produces electricity, process steam, and liquid hydrogen was evaluated and compared to IGCC systems which cogenerate electricity and process steam. A number of IGCC plants, all employing a 15 MWe has turbine and producing from 0 to 20 tons per day of liquid hydrogen and from 0 to 20 MWt of process steam were considered. The annual revenue required to own and operate such plants was estimated to be significantly lower than the potential market value of the products. The results indicate a significant potential economic benefit to configuring IGCC systems to produce a clean fuel in addition to electricity and process steam in relatively small industrial applications.

Fischer-Tropsch Wastewater Utilization

DOEpatents

Shah, Lalit S.

2003-03-18

The present invention is generally directed to handling the wastewater, or condensate, from a hydrocarbon synthesis reactor. More particularly, the present invention provides a process wherein the wastewater of a hydrocarbon synthesis reactor, such as a Fischer-Tropsch reactor, is sent to a gasifier and subsequently reacted with steam and oxygen at high temperatures and pressures so as to produce synthesis gas. The wastewater may also be recycled back to a slurry preparation stage, where solid combustible organic materials are pulverized and mixed with process water and the wastewater to form a slurry, after which the slurry fed to a gasifier where it is reacted with steam and oxygen at high temperatures and pressures so as to produce synthesis gas.

Correlation between the critical viscosity and ash fusion temperatures of coal gasifier ashes

DOE PAGES

Hsieh, Peter Y.; Kwong, Kyei-Sing; Bennett, James

2015-09-27

Coal gasification yields synthesis gas, an important intermediate in chemical manufacturing. It is also vital to the production of liquid fuels through the Fischer-Tropsch process and electricity in Integrated Gasification Combined Cycle power generation. Minerals naturally present in coal become molten in entrained-flow slagging gasifiers. Molten coal ash slag penetrates and dissolves refractory bricks, leading to costly plant shutdowns. The extent of coal ash slag penetration and refractory brick dissolution depends on the slag viscosity, the gasification temperature, and the composition of slag and bricks. We measured the viscosity of several synthetic coal ash slags with a high-temperature rotary viscometermore » and their ash fusion temperatures through optical image analysis. All measurements were made in a carbon monoxide-carbon dioxide reducing atmosphere that approximates coal gasification conditions. Empirical correlation models based on ash fusion temperatures were used to calculate critical viscosity temperatures based on the coal ash compositions. These values were then compared with those obtained from thermodynamic phase-transition models. An understanding of slag viscosity as a function of ash composition is important to reducing refractory wear in slagging coal gasifiers, which would help to reduce the cost and environmental impact of coal for chemical and electricity production.« less

Correlation between the critical viscosity and ash fusion temperatures of coal gasifier ashes

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

Hsieh, Peter Y.; Kwong, Kyei-Sing; Bennett, James

Coal gasification yields synthesis gas, an important intermediate in chemical manufacturing. It is also vital to the production of liquid fuels through the Fischer-Tropsch process and electricity in Integrated Gasification Combined Cycle power generation. Minerals naturally present in coal become molten in entrained-flow slagging gasifiers. Molten coal ash slag penetrates and dissolves refractory bricks, leading to costly plant shutdowns. The extent of coal ash slag penetration and refractory brick dissolution depends on the slag viscosity, the gasification temperature, and the composition of slag and bricks. We measured the viscosity of several synthetic coal ash slags with a high-temperature rotary viscometermore » and their ash fusion temperatures through optical image analysis. All measurements were made in a carbon monoxide-carbon dioxide reducing atmosphere that approximates coal gasification conditions. Empirical correlation models based on ash fusion temperatures were used to calculate critical viscosity temperatures based on the coal ash compositions. These values were then compared with those obtained from thermodynamic phase-transition models. An understanding of slag viscosity as a function of ash composition is important to reducing refractory wear in slagging coal gasifiers, which would help to reduce the cost and environmental impact of coal for chemical and electricity production.« less

Wear compensating seal means for rotary piston coal feeder

DOEpatents

Gencsoy, Hasan T.; Gardner, John F.

1979-01-01

The present invention is directed to a wear compensating seal arrangement for use in a rotary piston feeder utilized for feeding pulverized coal into a gasifier operating at relatively high pressures and elevated temperatures. The rotary piston feeder has a circular casing with a coal loading opening therein diametrically opposed from a coal discharge and contains a rotatable disoidal rotor having a cylinder in which a reciprocatable piston is disposed. The reciprocation of the piston within the cylinder is provided by a stationary conjugate cam whereby pulverized coal from a coal hopper at atmospheric pressure can be introduced into the cylinder and then discharged therefrom into the high pressure gasifier while maintaining minimal losses of producer gas and the expenditure of minimal energy which would detract from the efficiency of the gasification. The seal arrangement of the present invention is disposed between the rotor and the casing about the coal discharge and prevents the high pressure gases from within the gasifier from escaping between these relatively movable parts during operation of the coal feeder. The seal utilizes a primary seal in contact with the rotor and a secondary seal supporting the primary seal. The primary seal is continuously urged towards the rotor by springs and the high pressure producer gas.

The study of solid circulation rate in a compartmented fluidized bed gasifier (CFBG)

NASA Astrophysics Data System (ADS)

Wee, S. K.; Pok, Y. W.; Law, M. C.; Lee, V. C. C.

2016-06-01

Biomass waste has been abundantly available in Malaysia since the booming of palm oil industry. In order to tackle this issue, gasification is seen a promising technology to convert waste into energy. In view of the heat requirement for endothermic gasification reaction as well as the complex design and operation of multiple fluidized beds, compartmented fluidized bed gasifier (CFBG) with the combustor and the gasifier as separate compartments is proposed. As such, solid circulation rate (SCR) is one of the essential parameters for steady gasification and combustion to be realized in their respective compartments. Experimental and numerical studies (CFD) on the effect of static bed height, main bed aeration, riser aeration and v-valve aeration on SCR have been conducted in a cold- flow CFBG model with only river sand as the fluidizing medium. At lower operating range, the numerical simulations under-predict the SCR as compared to that of the experimental results. Also, it predicts slightly different trends over the range. On the other hand, at higher operating range, the numerical simulations are able to capture those trends as observed in the experimental results at the lower operating range. Overall, the numerical results compare reasonably well with that of the experimental works.

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

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.

Programs for calculating the explosion resistance of buildings and structures

NASA Astrophysics Data System (ADS)

Shevchenko, Nikita; Manucharyan, Rachik; Gravit, Marina; Geraskin, Yuriy

2017-10-01

Trends in the development of the oil and gas processing industry and facilities using liquefied hydrocarbon gases in the technological processes lead to an increase in the number of emergency situations and as a result to the increase of the damage and environmental degradation. A gasified housing stock is a special group of explosive objects. The accident in such disasters lead to hundreds of human victims. The main danger of explosive effects on objects can lead to a large-scale destruction connected with an “internal explosion”. It results in the release of combustible substances (gas, oil, etc.) into enclosed or semi-enclosed rooms (modules) with the ignition (in explosion mode of deflagration or detonation) of air gas mixtures (AGM).

Coal-Derived Warm Syngas Purification and CO 2 Capture-Assisted Methane Production

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

Dagle, Robert A.; King, David L.; Li, Xiaohong S.

2014-10-01

Gasifier-derived syngas from coal has many applications in the area of catalytic transformation to fuels and chemicals. Raw syngas must be treated to remove a number of impurities that would otherwise poison the synthesis catalysts. Inorganic impurities include alkali salts, chloride, sulfur compounds, heavy metals, ammonia, and various P, As, Sb, and Se- containing compounds. Systems comprising multiple sorbent and catalytic beds have been developed for the removal of impurities from gasified coal using a warm cleanup approach. This approach has the potential to be more economic than the currently available acid gas removal (AGR) approaches and improves upon currentlymore » available processes that do not provide the level of impurity removal that is required for catalytic synthesis application. Gasification also lends itself much more readily to the capture of CO 2, important in the regulation and control of greenhouse gas emissions. CO 2 capture material was developed and in this study was demonstrated to assist in methane production from the purified syngas. Simultaneous CO 2 sorption enhances the CO methanation reaction through relaxation of thermodynamic constraint, thus providing economic benefit rather than simply consisting of an add-on cost for carbon capture and release. Molten and pre-molten LiNaKCO 3 can promote MgO and MgO-based double salts to capture CO 2 with high cycling capacity. A stable cycling CO 2 capacity up to 13 mmol/g was demonstrated. This capture material was specifically developed in this study to operate in the same temperature range and therefore integrate effectively with warm gas cleanup and methane synthesis. By combining syngas methanation, water-gas-shift, and CO 2 sorption in a single reactor, single pass yield to methane of 99% was demonstrated at 10 bar and 330°C when using a 20 wt% Ni/MgAl 2O 4 catalyst and a molten-phase promoted MgO-based sorbent. Under model feed conditions both the sorbent and catalyst exhibited favorable stability after multiple test cycles. The cleanup for warm gas cleanup of inorganics was broken down into three major steps: chloride removal, sulfur removal, and the removal for a multitude of trace metal contaminants. Na 2CO 3 was found to optimally remove chlorides at an operating temperature of 450ºC. For sulfur removal two regenerable ZnO beds are used for bulk H 2S removal at 450ºC (<5 ppm S) and a non-regenerable ZnO bed for H 2S polishing at 300ºC (<40 ppb S). It was also found that sulfur from COS could be adsorbed (to levels below our detection limit of 40 ppb) in the presence of water that leads to no detectable slip of H 2S. Finally, a sorbent material comprising of Cu and Ni was found to be effective in removing trace metal impurities such as AsH 3 and PH 3 when operating at 300ºC. Proof-of-concept of the integrated cleanup process was demonstrated with gasifier-generated syngas produced at the Western Research Institute using Wyoming Decker Coal. When operating with a ~1 SLPM feed, multiple inorganic contaminant removal sorbents and a tar-reforming bed was able to remove the vast majority of contaminants from the raw syngas. A tar-reforming catalyst was employed due to the production of tars generated from the gasifier used in this particular study. It is envisioned that in a real application a commercial scale gasifier operating at a higher temperature would produce lesser amount of tar. Continuous operation of a poison-sensitive copper-based WGS catalyst located downstream from the cleanup steps resulted in successful demonstration.« less

ASPEN simulation of a fixed-bed integrated gasification combined-cycle power plant

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

Stone, K.R.

1986-03-01

A fixed-bed integrated gasification combined-cycle (IGCC) power plant has been modeled using the Advanced System for Process ENgineering (ASPEN). The ASPEN simulation is based on a conceptual design of a 509-MW IGCC power plant that uses British Gas Corporation (BGC)/Lurgi slagging gasifiers and the Lurgi acid gas removal process. The 39.3-percent thermal efficiency of the plant that was calculated by the simulation compares very favorably with the 39.4 percent that was reported by EPRI. The simulation addresses only thermal performance and does not calculate capital cost or process economics. Portions of the BGC-IGCC simulation flowsheet are based on the SLAGGERmore » fixed-bed gasifier model (Stefano May 1985), and the Kellogg-Rust-Westinghouse (KRW) iGCC, and the Texaco-IGCC simulations (Stone July 1985) that were developed at the Department of Energy (DOE), Morgantown Energy Technology Center (METC). The simulation runs in 32 minutes of Central Processing Unit (CPU) time on the VAX-11/780. The BGC-IGCC simulation was developed to give accurate mass and energy balances and to track coal tars and environmental species such as SO/sub x/ and NO/sub x/ for a fixed-bed, coal-to-electricity system. This simulation is the third in a series of three IGCC simulations that represent fluidized-bed, entrained-flow, and fixed-bed gasification processes. Alternate process configurations can be considered by adding, deleting, or rearranging unit operation blocks. The gasifier model is semipredictive; it can properly respond to a limited range of coal types and gasifier operating conditions. However, some models in the flowsheet are based on correlations that were derived from the EPRI study, and are therefore limited to coal types and operating conditions that are reasonably close to those given in the EPRI design. 4 refs., 7 figs., 2 tabs.« less

Innovative Instrumentation and Analysis of the Temperature Measurement for High Temperature Gasification

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

Seong W. Lee

The project entitled, ''Innovative Instrumentation and Analysis of the Temperature Measurement for High Temperature Gasification'', was successfully completed by the Principal Investigator, Dr. S. Lee and his research team in the Center for Advanced Energy Systems and Environmental Control Technologies at Morgan State University. The major results and outcomes were presented in semi-annual progress reports and annual project review meetings/presentations. Specifically, the literature survey including the gasifier temperature measurement, the ultrasonic application in cleaning application, and spray coating process and the gasifier simulator (cold model) testing has been successfully conducted during the first year. The results show that four factorsmore » (blower voltage, ultrasonic application, injection time intervals, particle weight) were considered as significant factors that affect the temperature measurement. Then the gasifier simulator (hot model) design and the fabrication as well as the systematic tests on hot model were completed to test the significant factors on temperature measurement in the second year. The advanced Industrial analytic methods such as statistics-based experimental design, analysis of variance (ANOVA) and regression methods were applied in the hot model tests. The results show that operational parameters (i.e. air flow rate, water flow rate, fine dust particle amount, ammonia addition) presented significant impact on the temperature measurement inside the gasifier simulator. The experimental design and ANOVA are very efficient way to design and analyze the experiments. The results show that the air flow rate and fine dust particle amount are statistically significant to the temperature measurement. The regression model provided the functional relation between the temperature and these factors with substantial accuracy. In the last year of the project period, the ultrasonic and subsonic cleaning methods and coating materials were tested/applied on the thermocouple cleaning according to the proposed approach. Different frequency, application time and power of the ultrasonic/subsonic output were tested. The results show that the ultrasonic approach is one of the best methods to clean the thermocouple tips during the routine operation of the gasifier. In addition, the real time data acquisition system was also designed and applied in the experiments. This advanced instrumentation provided the efficient and accurate data acquisition for this project. In summary, the accomplishment of the project provided useful information of the ultrasonic cleaning method applied in thermocouple tip cleaning. The temperature measurement could be much improved both in accuracy and duration provided that the proposed approach is widely used in the gasification facilities.« less

Fluid bed gasification – Plasma converter process generating energy from solid waste: Experimental assessment of sulphur species

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

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

2014-01-15

Highlights: • We investigate gaseous sulphur species whilst gasifying sulphur-enriched wood pellets. • Experiments performed using a two stage fluid bed gasifier – plasma converter process. • Notable SO{sub 2} and relatively low COS levels were identified. • Oxygen-rich regions of the bed are believed to facilitate SO{sub 2}, with a delayed release. • Gas phase reducing regions above the bed would facilitate more prompt COS generation. - Abstract: Often perceived as a Cinderella material, there is growing appreciation for solid waste as a renewable content thermal process feed. Nonetheless, research on solid waste gasification and sulphur mechanisms in particularmore » is lacking. This paper presents results from two related experiments on a novel two stage gasification process, at demonstration scale, using a sulphur-enriched wood pellet feed. Notable SO{sub 2} and relatively low COS levels (before gas cleaning) were interesting features of the trials, and not normally expected under reducing gasification conditions. Analysis suggests that localised oxygen rich regions within the fluid bed played a role in SO{sub 2}’s generation. The response of COS to sulphur in the feed was quite prompt, whereas SO{sub 2} was more delayed. It is proposed that the bed material sequestered sulphur from the feed, later aiding SO{sub 2} generation. The more reducing gas phase regions above the bed would have facilitated COS – hence its faster response. These results provide a useful insight, with further analysis on a suite of performed experiments underway, along with thermodynamic modelling.« less

Removal of H2S pollutant from gasifier syngas by a multistage dual-flow sieve plate column wet scrubber.

PubMed

Kurella, Swamy; Bhukya, Pawan Kishan; Meikap, B C

2017-05-12

The objective of this study was to observe the performance of a lab-scale three-stage dual-flow sieve plate column scrubber for hydrogen sulfide (H 2 S) gas removal from a gas stream, in which the H 2 S concentration was similar to that of gasifier syngas. The tap water was used as scrubbing liquid. The gas and liquid were operated at flow rates in the range of 16.59 × 10 -4 -27.65 × 10 -4 Nm 3 /s and 20.649 × 10 -6 -48.183 × 10 -6 m 3 /s, respectively. The effects of gas and liquid flow rates on the percentage removal of H 2 S were studied at 50-300 ppm inlet concentrations of H 2 S. The increase in liquid flow rate, gas flow rate and inlet H 2 S concentration increased the percentage removal of H 2 S. The maximum of 78.88% removal of H 2 S was observed at 27.65 × 10 -4 Nm 3 /s gas flow rate and 48.183 × 10 -6 m 3 /s liquid flow rate for 300 ppm inlet concentration of H 2 S. A model has also been developed to predict the H 2 S gas removal by using the results from the experiments and adding the parameters that affect the scrubber's performance. The deviations between experimental and predicted H 2 S percentage removal values were observed as less than 16%.

Slurry atomizer for a coal-feeder and dryer used to provide coal at gasifier pressure

DOEpatents

Loth, John L.; Smith, William C.; Friggens, Gary R.

1982-01-01

The present invention is directed to a coal-water slurry atomizer for use a high-pressure dryer employed in a pumping system utilized to feed coal into a pressurized coal gasifier. The slurry atomizer is provided with a venturi, constant area slurry injection conduit, and a plurality of tangentially disposed steam injection ports. Superheated steam is injected into the atomizer through these ports to provide a vortical flow of the steam, which, in turn, shears slurry emerging from the slurry injection conduit. The droplets of slurry are rapidly dispersed in the dryer through the venturi where the water is vaporized from the slurry by the steam prior to deleterious heating of the coal.

High pressure rotary piston coal feeder for coal gasification applications

DOEpatents

Gencsoy, Hasan T.

1977-05-24

The subject development is directed to an apparatus for feeding pulverized coal into a coal gasifier operating at relatively high pressures and elevated temperatures. This apparatus is a rotary piston feeder which comprises a circular casing having a coal loading opening therein diametrically opposed from a coal discharge and contains a rotatable discoid rotor having a cylinder in which a reciprocateable piston is disposed. The reciprocation of the piston within the cylinder is provided by a stationary conjugate cam arrangement whereby the pulverized coal from a coal hopper at atmospheric pressure can be introduced into the cylinder cavity and then discharged therefrom into the high-pressure gasifier without the loss of high pressure gases from within the latter.

Gasification in pulverized coal flames. First quarterly progress report, July--September 1975

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

Laurendeau, N. M.

1975-10-01

This project is concerned with the production of power and synthesis gases from pulverized coal via suspension gasification. Specifically, the concentric jet and vortex gasifiers, with separation of oxidation and reduction zones, will be investigated. Gasifier performance will be correlated with internally measured temperature and concentration profiles. A suction pyrometer will be used to simultaneously measure temperature and gas concentrations. Rapid species analysis will be provided by a UTI Q-30C mass spectrometer system. To date, a coal-handling facility has been developed, test cell design has been initiated, and preliminary literature searches have been made. A coal crusher, pulverizer, feeder, andmore » sieve shaker are on order. Preliminary consultations are underway concerning the mass spectrometer system. (auth)« less

Analysis of potential benefits of integrated-gasifier combined cycles for a utility system

NASA Technical Reports Server (NTRS)

Choo, Y. K.

1983-01-01

Potential benefits of integrated gasifier combined cycle (IGCC) units were evaluated for a reference utility system by comparing long range expansion plans using IGCC units and gas turbine peakers with a plan using only state of the art steam turbine units and gas turbine peakers. Also evaluated was the importance of the benefits of individual IGCC unit characteristics, particularly unit efficiency, unit equivalent forced outage rate, and unit size. A range of IGCC units was analyzed, including cases achievable with state of the art gas turbines and cases assuming advanced gas turbine technology. All utility system expansion plans that used IGCC units showed substantial savings compared with the base expansion plan using the steam turbine units.

Closed-loop system for growth of aquatic biomass and gasification thereof

DOEpatents

Oyler, James R.

2017-09-19

Processes, systems, and methods for producing combustible gas from wet biomass are provided. In one aspect, for example, a process for generating a combustible gas from a wet biomass in a closed system is provided. Such a process may include growing a wet biomass in a growth chamber, moving at least a portion of the wet biomass to a reactor, heating the portion of the wet biomass under high pressure in the reactor to gasify the wet biomass into a total gas component, separating the gasified component into a liquid component, a non-combustible gas component, and a combustible gas component, and introducing the liquid component and non-combustible gas component containing carbon dioxide into the growth chamber to stimulate new wet biomass growth.

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

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

Comparing Trash Disposal and Reuse Options for Deep Space Gateway and Mars Missions

NASA Technical Reports Server (NTRS)

Ewert, Michael; Broyan, James; Goodliff, Kandyce; Clowdsley, Martha; Singleterry, Robert

2017-01-01

Taking out the trash at NASA's newly proposed Deep Space Gateway (DSG) will not be a trivial task. While not the most important aspect of planning this cislunar outpost, there are several options that should be carefully considered since they may affect the crew as well as mission mass and volume. This study extends an earlier one, which focused on waste disposal options for a Mars Transit Vehicle. In that study, gasifying and venting trash along the way was found to noticeably reduce propellant needs and launch mass, whereas keeping processed trash on board in the form of radiation shielding tiles would significantly lower the crew's radiation dose during a solar particle event. Another favorable strategy was packing trash in a used logistics module for disposal. Since the DSG does not need much propulsion to maintain its orbit and Orion will be present with its own radiation storm shelter at the Gateway, the driving factors of the waste disposal trade study are different than for the Mars mission. Besides reviewing the propulsion and radiation shielding factors, potential drivers such as mass, power, volume, crew time, and human factors (e.g. smell) were studied. Disposal options for DSG include jettison of a used logistics module containing waste after every human stay, jettison of the same logistics module after several missions once it is full, regular disposal of trash via an airlock, or gasifying waste products for easier disposal or reuse. Conversely, a heat melt compactor device could be used to remove water and stabilize trash into tiles which could be more compactly stored on board and used as radiation shielding. Equivalent system mass analysis is used to tally the benefits and costs (mass, volume, power, crew time) of each case on an equivalent mass basis. Other more subjective factors are also discussed. Recommendations are made for DSG and Mars mission waste disposal.

Preparation and gasification of a Thailand coal-water fuel

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

Ness, R.O. Jr.; Anderson, C.M.; Musich, M.A.

In response to an inquiry by the Department of Mineral Resources (DMR) in Thailand, the Energy and Environmental Research Center (EERC) prepared a four-task program to assess the responsiveness of Wiang Haeng coal to the temperature and pressure conditions of hot-water drying (HWD). The results indicate that HWD made several improvements in the coal, notably increases in heating value and carbon content and reductions in equilibrium moisture and oxygen content. The equilibrium moisture content decreased from 37.4 wt% for the raw coal to about 20 wt% for the HWD coals. The energy density, determined at 500 cP, indicates an increasemore » from 4450 to 6650 Btu/lb by hydrothermal treatment. Raw and HWD coal were then gasified at various mild gasification conditions of 700 C and 30 psig. The tests indicated that the coal is probably similar to other low-rank coals and will produce high levels of hydrogen and be fairly reactive.« less

Steam gasification of a thermally pretreated high lignin corn stover simultaneous saccharification and fermentation digester residue

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

Howe, Daniel T.; Taasevigen, Danny; Garcia-Perez, Manuel

Efficient conversion of all components in lignocellulosic biomass is essential to realizing economic feasibility of biorefineries. However, when utilizing biochemical pathways, lignin cannot be fermented. Furthermore, the high lignin and high ash residue resulting from simultaneous saccharification and fermentation (SSF) reactors is difficult to thermochemically process due to feed line plugging and bed agglomeration. In this study a corn stover SSF digester residue was thermally pretreated at 300°C for 22.5 minutes (min) and then gasified in a bubbling fluidized bed gasifier to study the effect of thermal pretreatment on its processing behavior. Untreated, pelletized SSF residue was gasified at themore » same conditions to establish the baseline processing behavior. Results indicate that the thermal pretreatment process removes a substantial portion of the polar and non-polar extractives, with a resultant increase in the concentration of lignin, cellulose, and ash. Feed line plugging was not observed, although bed agglomeration was occurring at similar rates for both feedstocks, suggesting that overall ash content is the most important factor affecting bed agglomeration. Benzene, phenol, and polyaromatic hydrocarbons in the tar were present at higher concentrations in the treated material, with higher tar loading in the product gas. Total product gas generation is lower for the treated material, although the overall gas composition does not change.« less

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

Support Services for Ceramic Fiber-Ceramic Matrix Composites

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

Hurley, J.P.

2000-06-06

Structural and functional materials used in solid- and liquid-fueled energy systems are subject to gas- and condensed-phase corrosion and erosion by entrained particles. For a given material, its temperature and the composition of the corrodents determine the corrosion rates, while gas flow conditions and particle aerodynamic diameters determine erosion rates. Because there are several mechanisms by which corrodents deposit on a surface, the corrodent composition depends not only on the composition of the fuel, but also on the temperature of the material and the size range of the particles being deposited. In general, it is difficult to simulate under controlledmore » laboratory conditions all of the possible corrosion and erosion mechanisms to which a material may be exposed in an energy system. Therefore, with funding from the Advanced Research Materials Program, the University of North Dakota Energy & Environmental Research Center (EERC) is coordinating with NCC Engineering and the National Energy Technology Laboratory (NETL) to provide researchers with no-cost opportunities to expose materials in pilot-scale systems to conditions of corrosion and erosion similar to those occurring in commercial power systems. The EERC has two pilot-scale solid-fuel systems available for exposure of materials coupons. The slagging furnace system (SFS) was built under the DOE Combustion 2000 Program as a testing facility for advanced heat exchanger subsystems. It is a 2.5-MMBtu/hr (2.6 x 10{sup 6} kJ/hr) solid-fuel combustion system with exit temperatures of 2700 to 2900 F to ensure that the ash in the main combustor is molten and flowing. Sample coupons may be exposed in the system either within the slagging zone or near the convective air heater at 1800 F (980 C). In addition, a pilot-scale entrained-bed gasifier system known as the transport reactor development unit (TRDU) is available. Also operating at approximately 2.5 MMBtu/hr (2.6 x 10{sup 6} kJ/hr), it is a pressurized unit built to simulate the Kellogg entrained-bed gasifier in use at the Southern Company Services Wilsonville facility, but at 1/10 of the firing rate. At the exit of the unit is a large candle filter vessel typically operated at approximately 1000 F (540 C) in which coupons of materials can be inserted to test their resistance to gasifier ash and gas corrosion. The system also has ports for testing of hydrogen separation membranes that are suitably contained in a pressure housing. In addition, NETL is operating the combustion and environmental research facility (CERF). In recent years, the 0.5 MMBtu/hr (0.5 x 10{sup 6} kJ/hr) CERF has served as a host for exposure of over 60 ceramic and alloy samples at ambient pressure as well as at 200 psig (for tubes). Samples have been inserted in five locations covering 1700-2600 F (930-1430 C), with exposures exceeding 1000 hours. In the present program, the higher priority metals are to be tested at 1500-1600 F (820-870 C) in one CERF location and near 1800-2000 F (980-1090 C) at other locations to compare results with those from the EERC tests.« less

Integrated coal cleaning, liquefaction, and gasification process

DOEpatents

Chervenak, Michael C.

1980-01-01

Coal is finely ground and cleaned so as to preferentially remove denser ash-containing particles along with some coal. The resulting cleaned coal portion having reduced ash content is then fed to a coal hydrogenation system for the production of desirable hydrocarbon gases and liquid products. The remaining ash-enriched coal portion is gasified to produce a synthesis gas, the ash is removed from the gasifier usually as slag, and the synthesis gas is shift converted with steam and purified to produce the high purity hydrogen needed in the coal hydrogenation system. This overall process increases the utilization of as-mined coal, reduces the problems associated with ash in the liquefaction-hydrogenation system, and permits a desirable simplification of a liquids-solids separation step otherwise required in the coal hydrogenation system.

Advanced Gas Turbine (AGT) powertrain system development for automotive applications

NASA Technical Reports Server (NTRS)

1981-01-01

Preliminary layouts were made for the exhaust system, air induction system, and battery installation. Points of interference were identified and resolved by altering either the vehicle or engine designs. An engine general arrangement evolved to meet the vehicle engine compartment constraints while minimizing the duct pressure losses and the heat rejection. A power transfer system (between gasifier and power turbines) was developed to maintain nearly constant temperatures throughout the entire range of engine operation. An advanced four speed automatic transmission was selected to be used with the engine. Performance calculations show improvements in component efficiencies and an increase in fuel economy. A single stage centrifugal compressor design was completed and released for procurement. Gasifier turbine, power turbine, combustor, generator, secondary systems, materials, controls, and transmission development are reported.

AGT100 turbomachinery. [for automobiles

NASA Technical Reports Server (NTRS)

Tipton, D. L.; Mckain, T. F.

1982-01-01

High-performance turbomachinery components have been designed and tested for the AGT100 automotive engine. The required wide range of operation coupled with the small component size, compact packaging, and low cost of production provide significant aerodynamic challenges. Aerodynamic design and development testing of the centrifugal compressor and two radial turbines are described. The compressor achieved design flow, pressure ratio, and surge margin on the initial build. Variable inlet guide vanes have proven effective in modulating flow capacity and in improving part-speed efficiency. With optimum use of the variable inlet guide vanes, the initial efficiency goals have been demonstrated in the critical idle-to-70% gasifier speed range. The gasifier turbine exceeded initial performance goals and demonstrated good performance over a wide range. The radial power turbine achieved 'developed' efficiency goals on the first build.

Development of standardized air-blown coal gasifier/gas turbine concepts for future electric power systems, Volume 4

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

Not Available

1991-02-01

This appendix is a compilation of work done to predict overall cycle performance from gasifier to generator terminals. A spreadsheet has been generated for each case to show flows within a cycle. The spreadsheet shows gaseous or solid composition of flow, temperature of flow, quantity of flow, and heat heat content of flow. Prediction of steam and gas turbine performance was obtained by the computer program GTPro. Outputs of all runs for each combined cycle reviewed has been added to this appendix. A process schematic displaying all flows predicted through GTPro and the spreadsheet is also added to this appendix.more » The numbered bubbles on the schematic correspond to columns on the top headings of the spreadsheet.« less

Model Based Optimal Sensor Network Design for Condition Monitoring in an IGCC Plant

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

Kumar, Rajeeva; Kumar, Aditya; Dai, Dan

2012-12-31

This report summarizes the achievements and final results of this program. The objective of this program is to develop a general model-based sensor network design methodology and tools to address key issues in the design of an optimal sensor network configuration: the type, location and number of sensors used in a network, for online condition monitoring. In particular, the focus in this work is to develop software tools for optimal sensor placement (OSP) and use these tools to design optimal sensor network configuration for online condition monitoring of gasifier refractory wear and radiant syngas cooler (RSC) fouling. The methodology developedmore » will be applicable to sensing system design for online condition monitoring for broad range of applications. The overall approach consists of (i) defining condition monitoring requirement in terms of OSP and mapping these requirements in mathematical terms for OSP algorithm, (ii) analyzing trade-off of alternate OSP algorithms, down selecting the most relevant ones and developing them for IGCC applications (iii) enhancing the gasifier and RSC models as required by OSP algorithms, (iv) applying the developed OSP algorithm to design the optimal sensor network required for the condition monitoring of an IGCC gasifier refractory and RSC fouling. Two key requirements for OSP for condition monitoring are desired precision for the monitoring variables (e.g. refractory wear) and reliability of the proposed sensor network in the presence of expected sensor failures. The OSP problem is naturally posed within a Kalman filtering approach as an integer programming problem where the key requirements of precision and reliability are imposed as constraints. The optimization is performed over the overall network cost. Based on extensive literature survey two formulations were identified as being relevant to OSP for condition monitoring; one based on LMI formulation and the other being standard INLP formulation. Various algorithms to solve these two formulations were developed and validated. For a given OSP problem the computation efficiency largely depends on the “size” of the problem. Initially a simplified 1-D gasifier model assuming axial and azimuthal symmetry was used to test out various OSP algorithms. Finally these algorithms were used to design the optimal sensor network for condition monitoring of IGCC gasifier refractory wear and RSC fouling. The sensors type and locations obtained as solution to the OSP problem were validated using model based sensing approach. The OSP algorithm has been developed in a modular form and has been packaged as a software tool for OSP design where a designer can explore various OSP design algorithm is a user friendly way. The OSP software tool is implemented in Matlab/Simulink© in-house. The tool also uses few optimization routines that are freely available on World Wide Web. In addition a modular Extended Kalman Filter (EKF) block has also been developed in Matlab/Simulink© which can be utilized for model based sensing of important process variables that are not directly measured through combining the online sensors with model based estimation once the hardware sensor and their locations has been finalized. The OSP algorithm details and the results of applying these algorithms to obtain optimal sensor location for condition monitoring of gasifier refractory wear and RSC fouling profile are summarized in this final report.« less

Effect of sewage sludge content on gas quality and solid residues produced by cogasification in an updraft gasifier

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

Seggiani, Maurizia, E-mail: m.seggiani@diccism.unipi.it; Puccini, Monica, E-mail: m.puccini@diccism.unipi.it; Raggio, Giovanni, E-mail: g.raggio@tiscali.it

2012-10-15

Highlights: Black-Right-Pointing-Pointer Cogasification of sewage sludge with wood pellets in updraft gasifier was analysed. Black-Right-Pointing-Pointer The effects of sewage sludge content on the gasification process were examined. Black-Right-Pointing-Pointer Sewage sludge addition up to 30 wt.% reduces moderately the process performance. Black-Right-Pointing-Pointer At high sewage sludge content slagging and clinker formation occurred. Black-Right-Pointing-Pointer Solid residues produced resulted acceptable at landfills for non-hazardous waste. - Abstract: In the present work, the gasification with air of dehydrated sewage sludge (SS) with 20 wt.% moisture mixed with conventional woody biomass was investigated using a pilot fixed-bed updraft gasifier. Attention was focused on the effectmore » of the SS content on the gasification performance and on the environmental impact of the process. The results showed that it is possible to co-gasify SS with wood pellets (WPs) in updraft fixed-bed gasification installations. However, at high content of sewage sludge the gasification process can become instable because of the very high ash content and low ash fusion temperatures of SS. At an equivalent ratio of 0.25, compared with wood pellets gasification, the addition of sewage sludge led to a reduction of gas yield in favor of an increase of condensate production with consequent cold gas efficiency decrease. Low concentrations of dioxins/furans and PAHs were measured in the gas produced by SS gasification, well below the limiting values for the exhaust gaseous emissions. NH{sub 3}, HCl and HF contents were very low because most of these compounds were retained in the wet scrubber systems. On the other hand, high H{sub 2}S levels were measured due to high sulfur content of SS. Heavy metals supplied with the feedstocks were mostly retained in gasification solid residues. The leachability tests performed according to European regulations showed that metals leachability was within the limits for landfilling inert residues. On the other hand, sulfate and chloride releases were found to comply with the limits for non-hazardous residues.« less

Design of structure and simulation of the three-zone gasifier of dense layer of the inverted process

NASA Astrophysics Data System (ADS)

Zagrutdinov, R. Sh; Negutorov, V. N.; Maliykhin, D. G.; Nikishanin, M. S.; Senachin, P. K.

2017-11-01

Experts of LLC “New Energy Technologies” have developed gasifiers designs, with the implementation of the three-zone gasification method, which satisfy the following conditions: 1) the generated gas must be free from tar, soot and hydrocarbons, with a given ratio of CO/H2; 2) to use as the fuel source a wide range of low-grade low-value solid fuels, including biomass and various kinds of carbonaceous wastes; 3) have high reliability in operation, do not require qualified operating personnel, be relatively inexpensive to produce and use steam-air blowing instead of expensive steam-oxygen one; 4) the line of standard sizes should be sufficiently wide (with a single unit capacity of fuel from 1 to 50-70 MW). Two models of gas generators of the inverted gasification process with three combustion zones operating under pressure have been adopted for design: 1) gas generator with a remote combustion chamber type GOP-VKS (two-block version) and 2) a gas generator with a common combustion chamber of the GOP-OK type (single-block version), which is an almost ideal model for increasing the unit capacity. There have been worked out various schemes for the preparation of briquettes from practically the entire spectrum of low-grade fuel: high-ash and high-moisture coals, peat and biomass, including all types of waste - solid household waste, crop, livestock, poultry, etc. In the gas generators there are gasified the cylindrical briquettes with a diameter of 20-25 mm and a length of 25-35 mm. There have been developed a mathematical model and computer code for numerical simulation of synthesis gas generation processes in a gasifier of a dense layer of inverted process during a steam-air blast, including: continuity equations for the 8 gas phase components and for the solid phase; the equation of the heat balance for the entire heterogeneous system; the Darcy law equation (for porous media); equation of state for 8 components of the gas phase; equations for the rates of 3 gas-phase and 4 heterogeneous reactions; macro kinetics law of coke combustion; other equations and boundary conditions.

Commercial-scale demonstration of the Liquid Phase Methanol (LPMEOH{trademark}) process. Technical progress report number 6, October 1--December 31, 1995

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

NONE

1996-12-31

The project involves the construction of an 80,000 gallons per day (260 TPD) methanol unit utilizing coal-derived synthesis gas from Eastman`s integrated coal gasification facility. The new equipment consists of synthesis gas feed preparation and compression facilities, the liquid phase reactor and auxiliaries, product distillation facilities, and utilities. The technology to be demonstrated is the product of a cooperative development effort by Air Products and DOE in a program that started in 1981. Developed to enhance electric power generation using integrated gasification combined cycle (IGCC) technology, the LPMEOH{trademark} process is ideally suited for directly processing gases produced by modern-day coalmore » gasifiers. This liquid phase process suspends fine catalyst particles in an inert liquid, forming a slurry. The slurry dissipates the heat of the chemical reaction away from the catalyst surface protecting the catalyst and allowing the methanol synthesis reaction to proceed at higher rates. At the Eastman complex, the technology will be integrated with existing coal-gasifiers. A carefully developed test plan will allow operations at Eastman to simulate electricity demand load-following in coal-based IGCC facilities. The operations will also demonstrate the enhanced stability and heat dissipation of the conversion process, its reliable on/off operation, and its ability to produce methanol as a clean liquid fuel without additional upgrading. An off-site product testing program will be conducted to demonstrate the suitability of the methanol product as a transportation fuel and as a fuel for stationary applications for small modular electric power generators for distributed power.« less

CO-FIRING COAL: FEEDLOT AND LITTER BIOMASS FUELS

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

Dr. Kalyan Annamalai; Dr. John Sweeten; Dr. Sayeed Mukhtar

2000-10-24

The following are proposed activities for quarter 1 (6/15/00-9/14/00): (1) Finalize the allocation of funds within TAMU to co-principal investigators and the final task lists; (2) Acquire 3 D computer code for coal combustion and modify for cofiring Coal:Feedlot biomass and Coal:Litter biomass fuels; (3) Develop a simple one dimensional model for fixed bed gasifier cofired with coal:biomass fuels; and (4) Prepare the boiler burner for reburn tests with feedlot biomass fuels. The following were achieved During Quarter 5 (6/15/00-9/14/00): (1) Funds are being allocated to co-principal investigators; task list from Prof. Mukhtar has been received (Appendix A); (2) Ordermore » has been placed to acquire Pulverized Coal gasification and Combustion 3 D (PCGC-3) computer code for coal combustion and modify for cofiring Coal: Feedlot biomass and Coal: Litter biomass fuels. Reason for selecting this code is the availability of source code for modification to include biomass fuels; (3) A simplified one-dimensional model has been developed; however convergence had not yet been achieved; and (4) The length of the boiler burner has been increased to increase the residence time. A premixed propane burner has been installed to simulate coal combustion gases. First coal, as a reburn fuel will be used to generate base line data followed by methane, feedlot and litter biomass fuels.« less

Gasification in pulverized coal flames. Second annual progress report, July 1976--August 1977. [Pulverized coal

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

George, P. E.; Lenzer, R. C.; Thomas, J. F.

1977-08-01

This project concerns the production of power and synthesis gases from pulverized coal via suspension gasification. Swirling flow in both concentric jet and cyclone gasifiers will separate oxidation and reduction zones. Gasifier performance will be correlated with internally measured temperature and concentration profiles. The test cell flow system and electrical system, which includes a safety interlock design, has been installed. Calibration of the UTI-30C mass spectrometer and construction of the gas sampling system are complete. Both the coal feeder, which has been calibrated, and the boiler are ready for integration into the test cell flow system. Construction and testing ofmore » the cyclone reactor, including methane combustion experiments, is complete. The confined jet reactor has been designed and construction is underway. Investigation of combustion and gasification modeling techniques has begun.« less

Method and apparatus for making uniform pellets for fusion reactors

DOEpatents

Budrick, Ronald G.; King, Frank T.; Martin, Alfred J.; Nolen, Jr., Robert L.; Solomon, David E.

1977-01-01

A method and apparatus for making uniform pellets for laser driven fusion reactors which comprises selection of a quantity of glass frit which has been accurately classified as to size within a few micrometers and contains an occluded material, such as urea, which gasifies and expands when heated. The sized particles are introduced into an apparatus which includes a heated vertical tube with temperatures ranging from 800.degree. C to 1300.degree. C. The particles are heated during the drop through the tube to molten condition wherein the occluded material gasifies to form hollow microspheres which stabilize in shape and plunge into a collecting liquid at the bottom of the tube. The apparatus includes the vertical heat resistant tube, heaters for the various zones of the tube and means for introducing the frit and collecting the formed microspheres.

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.

Fuel Gas Demonstration Plant Program. Volume I. Demonstration plant

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

Not Available

1979-01-01

The objective of this project is for Babcock Contractors Inc. (BCI) to provide process designs, and gasifier retort design for a fuel gas demonstration plant for Erie Mining Company at Hoyt Lake, Minnesota. The fuel gas produced will be used to supplement natural gas and fuel oil for iron ore pellet induration. The fuel gas demonstration plant will consist of five stirred, two-stage fixed-bed gasifier retorts capable of handling caking and non-caking coals, and provisions for the installation of a sixth retort. The process and unit design has been based on operation with caking coals; however, the retorts have beenmore » designed for easy conversion to handle non-caking coals. The demonstration unit has been designed to provide for expansion to a commercial plant (described in Commercial Plant Package) in an economical manner.« less

Comparison of Integrated Gasifier-Combined Cycle and AFB-steam turbine systems for industrial cogeneration

NASA Technical Reports Server (NTRS)

Nainiger, J. J.; Abbott, J. M.; Burns, R. K.

1981-01-01

In the cogeneration technology alternatives study (CTAS) a number of advanced coal fired systems were examined and systems using a integrated coal gasifier IGCC or a fluid bed combustor AFB were found to yield attractive cogeneration results in industrial cogeneration applications. A range of site requirements and cogeneration sizing strategies using ground rules based on CTAS were used in comparing an IGCC and an AFB. The effect of time variations in site requirements and the sensitivity to fuel and electricity price assumptions are examined. The economic alternatives of industrial or utility ownership are also considered. The results indicate that the IGCC system has potentially higher fuel and emission savings and could be an attractive option for utility ownership. The AFB steam turbine system has a potentially higher return on investment and could be attractive assuming industrial ownership.

Solar heated fluidized bed gasification system

NASA Technical Reports Server (NTRS)

Qader, S. A. (Inventor)

1981-01-01

A solar-powered fluidized bed gasification system for gasifying carbonaceous material is presented. The system includes a solar gasifier which is heated by fluidizing gas and steam. Energy to heat the gas and steam is supplied by a high heat capacity refractory honeycomb which surrounds the fluid bed reactor zone. The high heat capacity refractory honeycomb is heated by solar energy focused on the honeycomb by solar concentrator through solar window. The fluid bed reaction zone is also heated directly and uniformly by thermal contact of the high heat capacity ceramic honeycomb with the walls of the fluidized bed reactor. Provisions are also made for recovering and recycling catalysts used in the gasification process. Back-up furnace is provided for start-up procedures and for supplying heat to the fluid bed reaction zone when adequate supplies of solar energy are not available.

Combustion performance of cellulosic biomass in a gasifier-based cookstove

NASA Astrophysics Data System (ADS)

Sulaiman, Shaharin A.; Romli, Raffisyazana

2012-06-01

Depletion in fossil fuel and increase in the world population may change the trend in future kitchens in households. Cooking with LPG fuel may one day become impossible and households would have to consider alternatives such as electric stoves. One other solution to this problem is through the use of biomass cook stoves. However, traditional cook stoves, predominantly used in the households, are not efficient and its utilizations for domestic cooking have been a major contributor to the ill effects related in respiratory and other health problem. Improved cook stoves programs implemented in the developing world attempt to address these problems. Biomass gasification appears to have significant potential in Asia for domestic cooking applications. Gasifier-based cook stoves are fuel efficient in comparison to traditional cook stove. The objective of this paper is to study the performance of various type of cellulosic biomass in a gasifier-based cook stove. The biomass considered in this study are oil palm fronds, dried leaves, wood sticks, coconut shells, bagasse, charcoal, and saw dust. The samples are analyzed in order to study their chemical properties. The thermochemical properties of the biomass were characterized. The performance of the each of the samples is studied by observing the time taken to boil water. It is found that oil palm fronds are the best type of biomass for the gasifer cook stove. It is also concluded that the higher the carbon content and the calorific value in a biomass, the lesser the time taken to boil the water.

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

NOx results from two combustors tested on medium BTU coal gas

NASA Technical Reports Server (NTRS)

Sherlock, T. P.; Carl, D. E.; Vermes, G.; Schwab, J.; Notardonato, J. J.

1982-01-01

The results of tests of two combustor configurations using coal gas from a 25 ton/day fluidized bed coal gasifier are reported. The trials were run with a ceramic-lined, staged rich/lean burner and an integral, all metal multiannular swirl burner (MASB) using a range of temperatures and pressures representative of industrial turbine inlet conditions. A lean mixture was examined at 104, 197, and 254 Btu/Scf, yielding NO(x) emissions of 5, 20, and 70 ppmv, respectively. The MASB was employed only with a gas rated at 220-270 Btu/Scf, producing 80 ppmv NO(x) at rated engine conditions. The results are concluded to be transferrable to current machines. Further tests on the effects of gas composition, the scaling of combustors to utility size, and the development of improved wall cooling techniques and variable geometry are indicated.

75 FR 42237 - Regulation of Fuels and Fuel Additives: 2011 Renewable Fuel Standards

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-20

... chemical manufacturing. Industry 424690 5169 Chemical and allied products merchant wholesalers. Industry...-chemical process to gasify separated MSW and other waste products and then use a catalyst to convert the...

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

Pressure Reducer for Coal Gasifiers

NASA Technical Reports Server (NTRS)

Kendall, James M., Sr.

1983-01-01

Quasi-porous-plug pressure reducer is designed for gases containing abrasive particles. Gas used to generate high pressure steam to drive electric power generators. In giving up heat to steam, gas drops in temperature. Device used for coal gasification plants.

Regeneratively cooled coal combustor/gasifier with integral dry ash removal

DOEpatents

Beaufrere, A.H.

1982-04-30

A coal combustor/gasifier is disclosed which produces a low or medium combustion gas fired furnances or boilers. Two concentric shells define a combustion air flows to provide regenerative cooling of the inner shell for dry ash operation. A fuel flow and a combustion air flow having opposed swirls are mixed and burned in a mixing-combustion portion of the combustion volume and the ash laden combustion products flow with a residual swirl into an ash separation region. The ash is cooled below the fusion temperature and is moved to the wall by centrifugal force where it is entrained in the cool wall boundary layer. The boundary layer is stabilized against ash re-entrainment as it is moved to an ash removal annulus by a flow of air from the plenum through slots in the inner shell, and by suction on an ash removal skimmer slot.

Preconditioned wire array Z-pinches driven by a double pulse current generator

NASA Astrophysics Data System (ADS)

Wu, Jian; Lu, Yihan; Sun, Fengju; Li, Xingwen; Jiang, Xiaofeng; Wang, Zhiguo; Zhang, Daoyuan; Qiu, Aici; Lebedev, Sergey

2018-07-01

Suppression of the core-corona structure and wire ablation in wire array Z-pinches is investigated using a novel double pulse current generator ‘Qin-1’ facility. The ‘Qin-1’ facility allows coupling a ∼10 kA 20 ns prepulse generator with a ∼0.8 MA 160 ns main current generator. The tailored prepulse current preheats wires to a gaseous state and the time interval between the prepulse and the main current pulse allows formation of a more uniform mass distribution for the implosion. The implosion of a gasified two aluminum-wire array showed no ablation phase and allowed all array mass to participate in the implosion. The initial perturbations formed from the inhomogeneous ablation were suppressed, however, the magneto Rayleigh–Taylor (MRT) instability during the implosion was still significant and further researches on the generation and development of the MRT instabilities of this gasified wire array are needed.

Advanced Gas Turbine (AGT) power-train system development

NASA Technical Reports Server (NTRS)

Helms, H. E.; Johnson, R. A.; Gibson, R. K.

1982-01-01

Technical work on the design and component testing of a 74.5 kW (100 hp) advanced automotive gas turbine is described. Selected component ceramic component design, and procurement were tested. Compressor tests of a modified rotor showed high speed performance improvement over previous rotor designs; efficiency improved by 2.5%, corrected flow by 4.6%, and pressure ratio by 11.6% at 100% speed. The aerodynamic design is completed for both the gasifier and power turbines. Ceramic (silicon carbide) gasifier rotors were spin tested to failure. Improving strengths is indicated by burst speeds and the group of five rotors failed at speeds between 104% and 116% of engine rated speed. The emission results from combustor testing showed NOx levels to be nearly one order of magnitude lower than with previous designs. A one piece ceramic exhaust duct/regenerator seal platform is designed with acceptable low stress levels.

Production of Renewable Natural Gas from Waste Biomass

NASA Astrophysics Data System (ADS)

Kumar, Sachin; Suresh, S.; Arisutha, S.

2013-03-01

Biomass energy is expected to make a major contribution to the replacement of fossil fuels. Methane produced from biomass is referred to as bio-methane, green gas, bio-substitute natural gas or renewable natural gas (RNG) when it is used as a transport fuel. Research on upgrading of the cleaned producer gas to RNG is still ongoing. The present study deals with the conversion of woody biomass into fuels, RNG using gasifier. The various effects of parameters like temperature, pressure, and tar formation on conversion were also studied. The complete carbon conversion was observed at 480 °C and tar yield was significantly less. When biomass was gasified with and without catalyst at about 28 s residence time, ~75 % (w/w) and 88 % (w/w) carbon conversion for without and with catalyst was observed. The interest in RNG is growing; several initiatives to demonstrate the thermal-chemical conversion of biomass into methane and/or RNG are under development.

Development of a bi-equilibrium model for biomass gasification in a downdraft bed reactor.

PubMed

Biagini, Enrico; Barontini, Federica; Tognotti, Leonardo

2016-02-01

This work proposes a simple and accurate tool for predicting the main parameters of biomass gasification (syngas composition, heating value, flow rate), suitable for process study and system analysis. A multizonal model based on non-stoichiometric equilibrium models and a repartition factor, simulating the bypass of pyrolysis products through the oxidant zone, was developed. The results of tests with different feedstocks (corn cobs, wood pellets, rice husks and vine pruning) in a demonstrative downdraft gasifier (350kW) were used for validation. The average discrepancy between model and experimental results was up to 8 times less than the one with the simple equilibrium model. The repartition factor was successfully related to the operating conditions and characteristics of the biomass to simulate different conditions of the gasifier (variation in potentiality, densification and mixing of feedstock) and analyze the model sensitivity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Catalytic conversion wood syngas to synthetic aviation turbine fuels over a multifunctional catalyst.

PubMed

Yan, Qiangu; Yu, Fei; Liu, Jian; Street, Jason; Gao, Jinsen; Cai, Zhiyong; Zhang, Jilei

2013-01-01

A continuous process involving gasification, syngas cleaning, and Fischer-Tropsch (FT) synthesis was developed to efficiently produce synthetic aviation turbine fuels (SATFs). Oak-tree wood chips were first gasified to syngas over a commercial pilot plant downdraft gasifier. The raw wood syngas contains about 47% N(2), 21% CO, 18% H(2), 12% CO(2,) 2% CH(4) and trace amounts of impurities. A purification reaction system was designed to remove the impurities in the syngas such as moisture, oxygen, sulfur, ammonia, and tar. The purified syngas meets the requirements for catalytic conversion to liquid fuels. A multi-functional catalyst was developed and tested for the catalytic conversion of wood syngas to SATFs. It was demonstrated that liquid fuels similar to commercial aviation turbine fuels (Jet A) was successfully synthesized from bio-syngas. Copyright © 2012 Elsevier Ltd. All rights reserved.

Utilization of coal as a source of chemicals

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

Demirbas, A.

Coal consists carbon-based substances can be used as a source of specialty aromatic chemicals and aliphatic chemicals. Four widespread processes allow for making chemicals from coals: gasification, liquefaction, direct conversion, and co-production of chemicals and fuels along with electricity. Coal is gasified to produce synthesis gas (syngas) with a gasifier which is then converted to paraffinic liquid fuels and chemicals by Fischer-Tropsch synthesis. Liquid product from coal gasification mainly contains benzene, toluene, xylene (BTX), phenols, alkylphenols, and cresol. Methanol is made using coal or syngas with hydrogen and carbon monoxide in a 2 to 1 ratio. Coal-derived methanol has manymore » preferable properties as it is free of sulfur and other impurities. Syngas from coal can be reformed to hydrogen. Ammonium sulfate from coal tar by pyrolysis can be converted to ammonia. The humus substances can be recovered from brown coal by alkali extraction.« less

Chromia refractory brick with carbon treatment

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

Bennett, James P.; Kwong, Kyei-Sing

The disclosure provides a refractory brick system comprising a chromia refractory brick for operation in the slagging environment of an air-cooled gasifier. The chromia refractory brick comprises a ceramically-bonded porous chromia refractory having a porosity greater than 9% and having carbon deposits residing within the pores. The brick may be further comprised of Al.sub.2O.sub.3. The air-cooled gasifier generates a liquefied slag in contact with the refractory brick and generally operates at temperatures between 1250.degree. C. and 1575.degree. C. and pressures between 300 psi to 1000 psi, with oxygen partial pressures generally between 10.sup.-4 and 10.sup.-10 atm. The refractory brick performsmore » without substantial chromium carbide or chromium metal formation in the low oxygen partial pressure environment. The inclusion of carbon without chromium carbide formation provides for significant mitigation of slag penetration and significantly reduced refractory wear.« less

Bioconversion of waste biomass to useful products

DOEpatents

Grady, J.L.; Chen, G.J.

1998-10-13

A process is provided for converting waste biomass to useful products by gasifying the biomass to produce synthesis gas and converting the synthesis gas substrate to one or more useful products. The present invention is directed to the conversion of biomass wastes including municipal solid waste, sewage sludge, plastic, tires, agricultural residues and the like, as well as coal, to useful products such as hydrogen, ethanol and acetic acid. The overall process includes the steps of gasifying the waste biomass to produce raw synthesis gas, cooling the synthesis gas, converting the synthesis gas to the desired product or products using anaerobic bioconversion, and then recovering the product or products. In accordance with a particular embodiment of the present invention, waste biomass is converted to synthesis gas containing carbon monoxide and, then, the carbon monoxide is converted to hydrogen by an anaerobic microorganism ERIH2, Bacillus smithii ATCC No. 55404. 82 figs.

Bioconversion of waste biomass to useful products

DOEpatents

Grady, James L.; Chen, Guang Jiong

1998-01-01

A process is provided for converting waste biomass to useful products by gasifying the biomass to produce synthesis gas and converting the synthesis gas substrate to one or more useful products. The present invention is directed to the conversion of biomass wastes including municipal solid waste, sewage sludge, plastic, tires, agricultural residues and the like, as well as coal, to useful products such as hydrogen, ethanol and acetic acid. The overall process includes the steps of gasifying the waste biomass to produce raw synthesis gas, cooling the synthesis gas, converting the synthesis gas to the desired product or products using anaerobic bioconversion, and then recovering the product or products. In accordance with a particular embodiment of the present invention, waste biomass is converted to synthesis gas containing carbon monoxide and, then, the carbon monoxide is converted to hydrogen by an anaerobic microorganism ERIH2, bacillus smithii ATCC No. 55404.

Multi-gene genetic programming based predictive models for municipal solid waste gasification in a fluidized bed gasifier.

PubMed

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

2015-03-01

A multi-gene genetic programming technique is proposed as a new method to predict syngas yield production and the lower heating value for municipal solid waste gasification in a fluidized bed gasifier. The study shows that the predicted outputs of the municipal solid waste gasification process are in good agreement with the experimental dataset and also generalise well to validation (untrained) data. Published experimental datasets are used for model training and validation purposes. The results show the effectiveness of the genetic programming technique for solving complex nonlinear regression problems. The multi-gene genetic programming are also compared with a single-gene genetic programming model to show the relative merits and demerits of the technique. This study demonstrates that the genetic programming based data-driven modelling strategy can be a good candidate for developing models for other types of fuels as well. Copyright © 2014 Elsevier Ltd. All rights reserved.

Coal Integrated Gasification Fuel Cell System Study

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

Chellappa Balan; Debashis Dey; Sukru-Alper Eker

2004-01-31

This study analyzes the performance and economics of power generation systems based on Solid Oxide Fuel Cell (SOFC) technology and fueled by gasified coal. System concepts that integrate a coal gasifier with a SOFC, a gas turbine, and a steam turbine were developed and analyzed for plant sizes in excess of 200 MW. Two alternative integration configurations were selected with projected system efficiency of over 53% on a HHV basis, or about 10 percentage points higher than that of the state-of-the-art Integrated Gasification Combined Cycle (IGCC) systems. The initial cost of both selected configurations was found to be comparable withmore » the IGCC system costs at approximately $1700/kW. An absorption-based CO2 isolation scheme was developed, and its penalty on the system performance and cost was estimated to be less approximately 2.7% and $370/kW. Technology gaps and required engineering development efforts were identified and evaluated.« less

Modeling and investigation of the channeling phenomenon in downdraft stratified gasifers.

PubMed

Allesina, Giulio; Pedrazzi, Simone; Tartarini, Paolo

2013-10-01

Downdraft stratified gasifiers seem to be the reactors which are most influenced by loading conditions. Moreover, the larger the reactor is, the higher the possibility to stumble across a channeling phenomenon. This high sensitivity is due to the limited thickness and superficial placement of the flaming pyrolysis layer coupled with the necessity to keep all the zones parallel for a correct running of this kind of gasifier. This study was aimed at modeling and investigating the channeling phenomenon generated by loading condition variations on a 250-kWe nominal power gasification power plant. The experimental campaign showed great variations in most of the plant outputs. These phenomena were modeled on two modified mathematical models obtained from literature. The results of the models confirmed the capability of this approach to predict the channeling phenomena and its dependency on the loading method. Copyright © 2013 Elsevier Ltd. All rights reserved.

Engineering New Catalysts for In-Process Elimination of Tars

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

Felix, Larry G.

2012-09-30

The key objective of this project was to develop a new and more efficient methodology for engineering and economically producing optimized robust catalysts for the reduction or elimination of tars in biomass gasification. Whereas current catalyst technology typically disposes thin layers of catalytically-active material onto rigid supports via wet chemistry-based methods, this project investigated novel thermal methods for directly incorporating catalytically active materials onto robust supports as well as novel approaches for incorporating catalytically active materials on and/or within an otherwise inert refractory support material which is then subsequently formed and processed to create a catalytically-active material on all exposedmore » surfaces. Specifically, the focus of this engineered catalyst development was on materials which were derived from, or otherwise related to, olivine-like minerals, due to the inherent attrition resistance and moderate catalytic properties exhibited by natural olivine when used in a fluidized bed biomass gasifier. Task 1 of this project successfully demonstrated the direct thermal impregnation of catalytically-active materials onto an olivine substrate, with the production of a Ni-olivine catalyst. Nickel and nickel oxide were thermally impregnated onto an olivine substrate and when reduced were shown to demonstrate improved catalytic activity over the baseline olivine material and equal the tar-decomposing performance of Ni-olivine catalysts prepared by conventional wet impregnation. Task 2 involved coordination with our subcontracted project partners to further develop and characterize catalyst formulations and to optimize activity and production methods. Within this task, several significant new materials were developed. NexTech Materials developed a sintered ceramic nickel-magnesium-silicate catalyst that demonstrated superb catalytic activity and high resistance to deactivation by H2S. Alfred University developed both supported and integrated (bulk) catalysts via a glass-ceramic processing route which were shown to exhibit excellent catalytic activity and superior resistance to attrition deactivation. With the discovery of these active, robust, glass-based catalysts, and with the permission of the project officer, the investigation of waste-based materials as originally proposed for Task 3 and pilot-scale testing proposed in Task 5 were deferred indefinitely in favor of further investigation of the glass-ceramic based catalyst materials. This choice was justified in part because during FY 2006 and through FY 2007, funding restrictions imposed by congressional budget choices significantly reduced funding for DOE biomass-related projects. Funding for this project was limited to what had been authorized which slowed the pace of project work at GTI so that our project partners could continue in their work. Thereafter, project work was allowed to resume and with restored funding, the project continued and concentrated on the development and testing of glass-ceramic catalysts in bulk or supported formats. Work concluded with a final development devoted to increasing the surface area of glass-ceramic catalysts in the form of microspheres. Following that development, project reporting was completed and the project was concluded.« less

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

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.

Preparation and Testing of Corrosion-and Spallation-Resistant Coatings

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

Hurley, John

2013-10-31

This Energy & Environmental Research Center (EERC) project is designed to determine if plating APMT®, a specific highly oxidation-resistant oxide dispersion-strengthened FeCrAl alloy made by Kanthal, onto nickel-based superalloy turbine parts is a viable method for substantially improving the lifetimes and maximum use temperatures of the parts. The method for joining the APMT plate to the superalloys is called evaporative metal bonding and involves placing a thin foil of zinc (Zn) between the plate and the superalloy, clamping them together, and heating in an atmosphere-controlled furnace. Upon heating, the Zn melts and dissolves the oxide skins of the alloys atmore » the bond line, allowing the two alloys to diffuse into each other. The Zn then diffuses through the alloys and evaporates from their surfaces. Laboratory testing to determine the diffusion rate of Zn through the alloys has been completed. We have found that we were not able to create joints when temperatures much lower than the original temperature of 1214°C are used. Therefore, we limited our diffusion rate measurements to the two hold temperatures used in the procedure: 700° and 1214°C. The diffusivity of zinc in both APMT and CM247LC is quite similar at 700°C. Diffusivity in the APMT appears to be slightly higher, but the midline composition after 30 minutes at this temperature is quite similar. At 1214°C, the situation is very different. The calculated diffusivity of zinc in APMT is approximately 15 times higher than in CM247LC or Rene® 80 (~120 vs. ~8 μm²/min) at that temperature. In addition to the diffusion work, the coefficients of thermal expansions were determined for each of the alloys as a function of temperature. This information has been entered into a finite element model using ANSYS so that appropriate force-applying structures can be designed for use in joining structures composed of APMT and the nickel alloys. Gasifier sampling activities continue to determine what types of trace contaminants may occur in cleaned syngas that could lead to corrosion or deposition in turbines firing coal syngas. The EERC has several pilot-scale gasifiers that are continually used in a variety of test configurations as determined by the needs of the projects that are funding the tests. We are sampling both noncombusted and combusted syngas produced during some of the pilot-scale gasifier tests. After modifying our sampling procedures to minimize contamination from the oxidizer, we obtained very good filter samples from both syngas and from the combustion products of the syngas blended with natural gas. Scanning electron microscopy analyses showed that the particles captured on the filter from the syngas were typically 0.2 to 0.5 μm in diameter, whereas those captured from the combusted syngas were slightly larger and more spherical. However, the particles were so small that we could not obtain good spectra from them either at the EERC or JEOL America, the maker of the EERC electron microscope systems. Therefore, the EERC applied for and received time on electron microscopes using different signal analyzers at the Oak Ridge National Laboratory (ORNL) ShaRE User Facility, which is sponsored by the U.S. Department of Energy Scientific User Facilities Division of the Office of Basic Energy Sciences. At ORNL, both x-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy were performed on the samples because these are surface analyses that analyze electrons emitted from within a few nanometers of the surfaces of the particles and filters. The XPS data show that the particles do not contain any metals and, in fact, have an atomic composition almost identical to that of the polycarbonate filter. We currently believe that this indicates that the particles are primarily soot-based and not formed from volatilization of metals in the fluid-bed gasifier. The data indicate that the soot-based particles are not well burned in the thermal oxidizer, although they are significantly oxidized, nitrided, and sulfidized in the combustor. Ion etching to remove the surfaces of the particles indicates that the oxidation, nitridation, and sulfidation of the particles are primarily surface phenomena.« less

Coal: the new black

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

Tullo, A.H.; Tremblay, J.-F.

2008-03-15

Long eclipsed by oil and natural gas as a raw material for high-volume chemicals, coal is making a comeback, with oil priced at more than $100 per barrel. It is relatively cheap feedstock for chemicals such as methanol and China is building plants to convert coal to polyolefins on a large scale and interest is spreading worldwide. Over the years several companies in the US and China have made fertilizers via the gasification of coal. Eastman in Tennessee gasifies coal to make methanol which is then converted to acetic acid, acetic anhydride and acetate fiber. The future vision is tomore » convert methanol to olefins. UOP and Lurgi are the major vendors of this technology. These companies are the respective chemical engineering arms of Honeywell and Air Liquide. The article reports developments in China, USA and India on coal-to-chemicals via coal gasification or coal liquefaction. 2 figs., 2 photo.« less

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

SULFUR TOLERANT CATALYSTS FOR BIOMASS TAR REMOVAL - PHASE I

EPA Science Inventory

In this Small Business Innovation Research (SBIR) project, NexTech Materials proposes a catalytic reforming approach to remove waste tar from gasified biomass on nickel-based catalysts. Biomass gasification is a potential renewable route to producing electricity, liquid fue...

Gas Fermentation-A Flexible Platform for Commercial Scale Production of Low-Carbon-Fuels and Chemicals from Waste and Renewable Feedstocks.

PubMed

Liew, FungMin; Martin, Michael E; Tappel, Ryan C; Heijstra, Björn D; Mihalcea, Christophe; Köpke, Michael

2016-01-01

There is an immediate need to drastically reduce the emissions associated with global fossil fuel consumption in order to limit climate change. However, carbon-based materials, chemicals, and transportation fuels are predominantly made from fossil sources and currently there is no alternative source available to adequately displace them. Gas-fermenting microorganisms that fix carbon dioxide (CO2) and carbon monoxide (CO) can break this dependence as they are capable of converting gaseous carbon to fuels and chemicals. As such, the technology can utilize a wide range of feedstocks including gasified organic matter of any sort (e.g., municipal solid waste, industrial waste, biomass, and agricultural waste residues) or industrial off-gases (e.g., from steel mills or processing plants). Gas fermentation has matured to the point that large-scale production of ethanol from gas has been demonstrated by two companies. This review gives an overview of the gas fermentation process, focusing specifically on anaerobic acetogens. Applications of synthetic biology and coupling gas fermentation to additional processes are discussed in detail. Both of these strategies, demonstrated at bench-scale, have abundant potential to rapidly expand the commercial product spectrum of gas fermentation and further improve efficiencies and yields.

Gas Fermentation—A Flexible Platform for Commercial Scale Production of Low-Carbon-Fuels and Chemicals from Waste and Renewable Feedstocks

PubMed Central

Liew, FungMin; Martin, Michael E.; Tappel, Ryan C.; Heijstra, Björn D.; Mihalcea, Christophe; Köpke, Michael

2016-01-01

There is an immediate need to drastically reduce the emissions associated with global fossil fuel consumption in order to limit climate change. However, carbon-based materials, chemicals, and transportation fuels are predominantly made from fossil sources and currently there is no alternative source available to adequately displace them. Gas-fermenting microorganisms that fix carbon dioxide (CO2) and carbon monoxide (CO) can break this dependence as they are capable of converting gaseous carbon to fuels and chemicals. As such, the technology can utilize a wide range of feedstocks including gasified organic matter of any sort (e.g., municipal solid waste, industrial waste, biomass, and agricultural waste residues) or industrial off-gases (e.g., from steel mills or processing plants). Gas fermentation has matured to the point that large-scale production of ethanol from gas has been demonstrated by two companies. This review gives an overview of the gas fermentation process, focusing specifically on anaerobic acetogens. Applications of synthetic biology and coupling gas fermentation to additional processes are discussed in detail. Both of these strategies, demonstrated at bench-scale, have abundant potential to rapidly expand the commercial product spectrum of gas fermentation and further improve efficiencies and yields. PMID:27242719

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

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

Characterization of carbonaceous aerosols emitted from outdoor wood boilers

EPA Science Inventory

This study examines the chemical properties of carbonaceous aerosols emitted from different outdoor wood-fired boiler (OWB) technologies including two cord-wood heaters, a pellet heater, and a multistage gasifier/combustor. The effect of fuel type [red oak wood (Quercus rubra), w...

Biochar Improves Performance of Plants for Mine Soil Revegetation

EPA Science Inventory

Biochar (the solid by-product of pyrolysis of biomass), has the potential to improve plant performance for revegetation of mine soils by improving soil chemistry, fertility, moisture holding capacity and by binding heavy metals. We investigated the effect of gasified conifer sof...

Jesse E. Hensley | NREL

Science.gov Websites

biomass Low temperature hydrodeoxygenation Advanced equipment and laboratory design Membrane separations Production of Premium Fuels and Chemicals from Gasified Biomass Plant materials contain complex chemical conversion facility and the energy costs associated with gasification (studied in detail by our Analysis team

Toxicological and chemical characterization of the process stream materials and gas combustion products of an experimental low-btu coal gasifier.

PubMed

Benson, J M; Hanson, R L; Royer, R E; Clark, C R; Henderson, R F

1984-04-01

The process gas stream of an experimental pressurized McDowell-Wellman stirred-bed low-Btu coal gasifier, and combustion products of the clean gas were characterized as to their mutagenic properties and chemical composition. Samples of aerosol droplets condensed from the gas were obtained at selected positions along the process stream using a condenser train. Mutagenicity was assessed using the Ames Salmonella mammalian microsome mutagenicity assay (TA98, with and without rat liver S9). All materials required metabolic activation to be mutagenic. Droplets condensed from gas had a specific mutagenicity of 6.7 revertants/microgram (50,000 revertants/liter of raw gas). Methylnaphthalene, phenanthrene, chrysene, and nitrogen-containing compounds were positively identified in a highly mutagenic fraction of raw gas condensate. While gas cleanup by the humidifier-tar trap system and Venturi scrubber led to only a small reduction in specific mutagenicity of the cooled process stream material (4.1 revertants/microgram), a significant overall reduction in mutagenicity was achieved (to 2200 revertants/liter) due to a substantial reduction in the concentration of material in the gas. By the end of gas cleanup, gas condensates had no detectable mutagenic activity. Condensates of combustion product gas, which contained several polycyclic aromatic compounds, had a specific mutagenicity of 1.1 revertants/microgram (4.0 revertants/liter). Results indicate that the process stream material is potentially toxic and that care should be taken to limit exposure of workers to the condensed tars during gasifier maintenance and repair and to the aerosolized tars emitted in fugitive emissions. Health risks to the general population resulting from exposure to gas combustion products are expected to be minimal.

Porous filtering media comparison through wet and dry sampling of fixed bed gasification products

NASA Astrophysics Data System (ADS)

Allesina, G.; Pedrazzi, S.; Montermini, L.; Giorgini, L.; Bortolani, G.; Tartarini, P.

2014-11-01

The syngas produced by fixed bed gasifiers contains high quantities of particulate and tars. This issue, together with its high temperature, avoids its direct exploitation without a proper cleaning and cooling process. In fact, when the syngas produced by gasification is used in an Internal Combustion engine (IC), the higher the content of tars and particulate, the higher the risk to damage the engine is. If these compounds are not properly removed, the engine may fail to run. A way to avoid engine fails is to intensify the maintenance schedule, but these stops will reduce the system profitability. From a clean syngas does not only follow higher performance of the generator, but also less pollutants in the atmosphere. When is not possible to work on the gasification reactions, the filter plays the most important role in the engine safeguard process. This work is aimed at developing and comparing different porous filters for biomass gasifiers power plants. A drum filter was developed and tested filling it with different filtering media available on the market. As a starting point, the filter was implemented in a Power Pallet 10 kW gasifier produced by the California-based company "ALL Power Labs". The original filter was replaced with different porous biomasses, such as woodchips and corn cobs. Finally, a synthetic zeolites medium was tested and compared with the biological media previously used. The Tar Sampling Protocol (TSP) and a modified "dry" method using the Silica Gel material were applied to evaluate the tars, particulate and water amount in the syngas after the filtration process. Advantages and disadvantages of every filtering media chosen were reported and discussed.

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.

Commercial low-Btu coal-gasification plant. Feasibility study: General Refractories Company, Florence, Kentucky. Volume I. Project summary. [Wellman-Galusha

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

None

1981-11-01

In response to a 1980 Department of Energy solicitation, the General Refractories Company submitted a Proposal for a feasibility study of a low Btu gasification facility for its Florence, KY plant. The proposed facility would substitute low Btu gas from a fixed bed gasifier for natural gas now used in the manufacture of insulation board. The Proposal from General Refractories was prompted by a concern over the rising costs of natural gas, and the anticipation of a severe increase in fuel costs resulting from deregulation. The proposed feasibility study is defined. The intent is to provide General Refractories with themore » basis upon which to determine the feasibility of incorporating such a facility in Florence. To perform the work, a Grant for which was awarded by the DOE, General Refractories selected Dravo Engineers and Contractors based upon their qualifications in the field of coal conversion, and the fact that Dravo has acquired the rights to the Wellman-Galusha technology. The LBG prices for the five-gasifier case are encouraging. Given the various natural gas forecasts available, there seems to be a reasonable possibility that the five-gasifier LBG prices will break even with natural gas prices somewhere between 1984 and 1989. General Refractories recognizes that there are many uncertainties in developing these natural gas forecasts, and if the present natural gas decontrol plan is not fully implemented some financial risks occur in undertaking the proposed gasification facility. Because of this, General Refractories has decided to wait for more substantiating evidence that natural gas prices will rise as is now being predicted.« less

INNOVATIVE INSTRUMENTATION AND ANALYSIS OF THE TEMPERATURE MEASUREMENT FOR HIGH TEMPERATURE GASIFICATION

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

Seong W. Lee

2004-10-01

The systematic tests of the gasifier simulator on the clean thermocouple were completed in this reporting period. Within the systematic tests on the clean thermocouple, five (5) factors were considered as the experimental parameters including air flow rate, water flow rate, fine dust particle amount, ammonia addition and high/low frequency device (electric motor). The fractional factorial design method was used in the experiment design with sixteen (16) data sets of readings. Analysis of Variances (ANOVA) was applied to the results from systematic tests. The ANOVA results show that the un-balanced motor vibration frequency did not have the significant impact onmore » the temperature changes in the gasifier simulator. For the fine dust particles testing, the amount of fine dust particles has significant impact to the temperature measurements in the gasifier simulator. The effects of the air and water on the temperature measurements show the same results as reported in the previous report. The ammonia concentration was included as an experimental parameter for the reducing environment in this reporting period. The ammonia concentration does not seem to be a significant factor on the temperature changes. The linear regression analysis was applied to the temperature reading with five (5) factors. The accuracy of the linear regression is relatively low, which is less than 10% accuracy. Nonlinear regression was also conducted to the temperature reading with the same factors. Since the experiments were designed in two (2) levels, the nonlinear regression is not very effective with the dataset (16 readings). An extra central point test was conducted. With the data of the center point testing, the accuracy of the nonlinear regression is much better than the linear regression.« less

Enforcing elemental mass and energy balances for reduced order models

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

Ma, J.; Agarwal, K.; Sharma, P.

2012-01-01

Development of economically feasible gasification and carbon capture, utilization and storage (CCUS) technologies requires a variety of software tools to optimize the designs of not only the key devices involved (e., g., gasifier, CO{sub 2} adsorber) but also the entire power generation system. High-fidelity models such as Computational Fluid Dynamics (CFD) models are capable of accurately simulating the detailed flow dynamics, heat transfer, and chemistry inside the key devices. However, the integration of CFD models within steady-state process simulators, and subsequent optimization of the integrated system, still presents significant challenges due to the scale differences in both time and length,more » as well the high computational cost. A reduced order model (ROM) generated from a high-fidelity model can serve as a bridge between the models of different scales. While high-fidelity models are built upon the principles of mass, momentum, and energy conservations, ROMs are usually developed based on regression-type equations and hence their predictions may violate the mass and energy conservation laws. A high-fidelity model may also have the mass and energy balance problem if it is not tightly converged. Conservations of mass and energy are important when a ROM is integrated to a flowsheet for the process simulation of the entire chemical or power generation system, especially when recycle streams are connected to the modeled device. As a part of the Carbon Capture Simulation Initiative (CCSI) project supported by the U.S. Department of Energy, we developed a software framework for generating ROMs from CFD simulations and integrating them with Process Modeling Environments (PMEs) for system-wide optimization. This paper presents a method to correct the results of a high-fidelity model or a ROM such that the elemental mass and energy are conserved perfectly. Correction factors for the flow rates of individual species in the product streams are solved using a minimization algorithm based on Lagrangian multiplier method. Enthalpies of product streams are also modified to enforce the energy balance. The approach is illustrated for two ROMs, one based on a CFD model of an entrained-flow gasifier and the other based on the CFD model of a multiphase CO{sub 2} adsorber.« less

CO-FIRING COAL, FEEDLOT, AND LITTER BIOMASS (CFB AND LFB) FUELS IN PULVERIZED FUEL AND FIXED BED BURNERS

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

Kalyan Annamalai; John Sweeten; Saqib Mukhtar

2002-01-15

Intensive animal feeding operations create large amounts of animal waste that must be safely disposed of in order to avoid environmental degradation. Cattle feedlots and chicken houses are two examples. In feedlots, cattle are confined to small pens and fed a high calorie grain diet in preparation for slaughter. In chicken houses, thousands of chickens are kept in close proximity. In both of these operations, millions of tons of manure are produced every year. In this project a co-firing technology is proposed which would use manure that cannot be used for fertilizer, for power generation. Since the animal manure hasmore » economic uses as both a fertilizer and as a fuel, it is properly referred to as feedlot biomass (FB) for cow manure, or litter biomass (LB) for chicken manure. The biomass will be used a as a fuel by mixing it with coal in a 90:10 blend and firing it in existing coal fired combustion devices. This technique is known as co-firing, and the high temperatures produced by the coal will allow the biomass to be completely combusted. Therefore, it is the goal of the current research to develop an animal biomass cofiring technology. A cofiring technology is being developed by performing: (1) studies on fundamental fuel characteristics, (2) small scale boiler burner experiments, (3) gasifier experiments, (4) computer simulations, and (5) an economic analysis. The fundamental fuel studies reveal that biomass is not as high a quality fuel as coal. The biomass fuels are higher in ash, higher in moisture, higher in nitrogen and sulfur (which can cause air pollution), and lower in heat content than coal. Additionally, experiments indicate that the biomass fuels have higher gas content, release gases more readily than coal, and less homogeneous. Small-scale boiler experiments revealed that the biomass blends can be successfully fired, and NO{sub x} pollutant emissions produced will be similar to or lower than pollutant emissions when firing coal. This is a surprising result as the levels of N are higher in the biomass fuel than in coal. Further experiments showed that biomass is twice or more effective than coal when used in a reburning process to reduce NO{sub x} emissions. Since crushing costs of biomass fuels may be prohibitive, stoker firing may be cost effective; in order simulate such a firing, future work will investigate the performance of a gasifier when fired with larger sized coal and biomass. It will be a fixed bed gasifier, and will evaluate blends, coal, and biomass. Computer simulations were performed using the PCGC-2 code supplied by BYU and modified by A&M with three mixture fractions for handling animal based biomass fuels in order to include an improved moisture model for handling wet fuels and phosphorus oxidation. Finally the results of the economic analysis show that considerable savings can be achieved with the use of biomass. In the case of higher ash and moisture biomass, the fuel cost savings will be reduced, due to increased transportation costs. A spreadsheet program was created to analyze the fuel savings for a variety of different moisture levels, ash levels, and power plant operating parameters.« less

OUTDOOR BIOMASS GASIFIER HYDRONIC HEATER (OBGHH) - PHASE I

EPA Science Inventory

America needs a clean, affordable, reliable and sustainable product or system to obtain heat for residences in cold climates using renewable, carbon-neutral, plentiful, low-cost biomass fuels of diverse types found close to the location of usage. The available biomass could he...

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.

Gaseous fuel production from nonrecyclable paper wastes by using supported metal catalysts in high-temperature liquid water.

PubMed

Yamaguchi, Aritomo; Hiyoshi, Norihito; Sato, Osamu; Bando, Kyoko K; Shirai, Masayuki

2010-06-21

Paper wastes are used for the production of gaseous fuels over supported metal catalysts. The gasification of the nonrecyclable paper wastes, such as shredded documents and paper sludge, is carried out in high-temperature liquid water. The order of the catalytic activity for the gasification is found to be ruthenium>rhodium>platinum>palladium. A charcoal-supported ruthenium catalyst (Ru/C) is the most effective for the gasification of paper and cellulose. Paper wastes are gasified to a limited degree (32.6 carbon %) for 30 min in water at 523 K to produce methane and carbon dioxide, with a small amount of hydrogen. At 573 K, more complete gasification with almost 100 carbon % is achieved within 10 min in water. At 523 K, the gas yield of paper gasification over Ru/C is higher than that of cellulose powder. The gas yields are increased by ball-milling treatment of the recycled paper and cellulose powder. Printed paper wastes are also gasified at 523 K in water.

Method for in situ carbon deposition measurement for solid oxide fuel cells

NASA Astrophysics Data System (ADS)

Kuhn, J.; Kesler, O.

2014-01-01

Previous methods to measure carbon deposition in solid oxide fuel cell (SOFC) anodes do not permit simultaneous electrochemical measurements. Electrochemical measurements supplemented with carbon deposition quantities create the opportunity to further understand how carbon affects SOFC performance and electrochemical impedance spectra (EIS). In this work, a method for measuring carbon in situ, named here as the quantification of gasified carbon (QGC), was developed. TGA experiments showed that carbon with a 100 h residence time in the SOFC was >99.8% gasified. Comparison of carbon mass measurements between the TGA and QGC show good agreement. In situ measurements of carbon deposition in SOFCs at varying molar steam/carbon ratios were performed to further validate the QGC method, and suppression of carbon deposition with increasing steam concentration was observed, in agreement with previous studies. The technique can be used to investigate in situ carbon deposition and gasification behavior simultaneously with electrochemical measurements for a variety of fuels and operating conditions, such as determining conditions under which incipient carbon deposition is reversible.

Regeneratively cooled coal combustor/gasifier with integral dry ash removal

DOEpatents

Beaufrere, Albert H.

1983-10-04

A coal combustor/gasifier is disclosed which produces a low or medium combustion gas for further combustion in modified oil or gas fired furnaces or boilers. Two concentric shells define a combustion volume within the inner shell and a plenum between them through which combustion air flows to provide regenerative cooling of the inner shell for dry ash operation. A fuel flow and a combustion air flow having opposed swirls are mixed and burned in a mixing-combustion portion of the combustion volume and the ash laden combustion products flow with a residual swirl into an ash separation region. The ash is cooled below the fusion temperature and is moved to the wall by centrifugal force where it is entrained in the cool wall boundary layer. The boundary layer is stabilized against ash re-entrainment as it is moved to an ash removal annulus by a flow of air from the plenum through slots in the inner shell, and by suction on an ash removal skimmer slot.

Experimental comparison of MCFC performance using three different biogas types and methane

NASA Astrophysics Data System (ADS)

Bove, Roberto; Lunghi, Piero

Biogas recovery is an environmentally friendly and cost-effective practice that is getting consensus in both the scientific and industrial community, as the growing number of projects demonstrate. The use of fuel cells as energy conversion systems increases the conversion efficiency, as well as the environmental benefits. Molten carbonate fuel cells (MCFC) operate at a temperature of about 650 °C, thus presenting a high fuel flexibility, compared to low temperature fuel cells. Aim of the present study is to compare the performance of an MCFC single cell, fuelled with different biogas types as well as methane. The biogases considered are derived from the following processes: (1) steam gasification in an entrained flow gasifier; (2) steam gasification in a duel interconnect fluidized bed gasifier; (3) biogas from an anaerobic digestion process. The performances are evaluated for different fuel utilization and current densities. The results are an essential starting point for a complete system design and demonstration.

Application of analytic hierarchy process in a waste treatment technology assessment in Mexico.

PubMed

Taboada-González, Paul; Aguilar-Virgen, Quetzalli; Ojeda-Benítez, Sara; Cruz-Sotelo, Samantha

2014-09-01

The high per capita generation of solid waste and the environmental problems in major rural communities of Ensenada, Baja California, have prompted authorities to seek alternatives for waste treatment. In the absence of a selection methodology, three technologies of waste treatment with energy recovery (an anaerobic digester, a downdraft gasifier, and a plasma gasifier) were evaluated, taking the broader social, political, economic, and environmental issues into considerations. Using the scientific literature as a baseline, interviews with experts, decision makers and the community, and waste stream studies were used to construct a hierarchy that was evaluated by the analytic hierarchy process. In terms of the criteria, judgments, and assumptions made in the model, the anaerobic digester was found to have the highest rating and should consequently be selected as the waste treatment technology for this area. The study results showed low sensitivity, so alternative scenarios were not considered. The methodology developed in this study may be useful for other governments who wish to assess technologies to select waste treatment.

Multi-stage circulating fluidized bed syngas cooling

DOEpatents

Liu, Guohai; Vimalchand, Pannalal; Guan, Xiaofeng; Peng, WanWang

2016-10-11

A method and apparatus for cooling hot gas streams in the temperature range 800.degree. C. to 1600.degree. C. using multi-stage circulating fluid bed (CFB) coolers is disclosed. The invention relates to cooling the hot syngas from coal gasifiers in which the hot syngas entrains substances that foul, erode and corrode heat transfer surfaces upon contact in conventional coolers. The hot syngas is cooled by extracting and indirectly transferring heat to heat transfer surfaces with circulating inert solid particles in CFB syngas coolers. The CFB syngas coolers are staged to facilitate generation of steam at multiple conditions and hot boiler feed water that are necessary for power generation in an IGCC process. The multi-stage syngas cooler can include internally circulating fluid bed coolers, externally circulating fluid bed coolers and hybrid coolers that incorporate features of both internally and externally circulating fluid bed coolers. Higher process efficiencies can be realized as the invention can handle hot syngas from various types of gasifiers without the need for a less efficient precooling step.

Demonstration of a 1 MWe biomass power plant at USMC Base Camp Lejeune. Report for July 1994-May 1997

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

Cleland, J.; Purvis, C.R.

1998-06-01

The paper discusses a biomass energy conversion project being sponsored by EPA to demonstrate an enviromentally and economically sound electrical power option for government installations, industrial sites, rural cooperatives, small municipalities, and developing countries. Wood gasification combined with internal combustion engines was chosen because of (1) recent improvements in gas cleaning, (2) simple economical operation for units < 10 MW, and (3) the option of a clean cheap fuel for the many existing facilities generating expensive electricity from petroleum fuels with reciprocating engines. The plant incorporates a downdraft, moving-bed gasifier utilizing hogged waste wood from the Marine Corps Base atmore » Camp Lejeune, NC. A moving-bed bulk wood dryer and both spark ignition and diesel engines are included. Unique process design features are described briefly, relative to the gasifier, wood drying, tar separation, and process control. A test plan for process optimization and demonstration of reliability, economics, and environmental impact is outlined.« less

Isolated thermocouple amplifier system for stirred fixed-bed gasifier

DOEpatents

Fasching, George E.

1992-01-01

A sensing system is provided for determining the bed temperature profile of the bed of a stirred, fixed-bed gasifier including a plurality of temperature sensors for sensing the bed temperature at different levels, a transmitter for transmitting data based on the outputs of the sensors to a remote operator's station, and a battery-based power supply. The system includes an isolation amplifier system comprising a plurality of isolation amplifier circuits for amplifying the outputs of the individual sensors. The isolation amplifier circuits each comprise an isolation operational amplifier connected to a sensor; a first "flying capacitor" circuit for, in operation, controlling the application of power from the power supply to the isolation amplifier; an output sample and hold circuit connected to the transmitter; a second "flying capacitor" circuit for, in operation, controlling the transfer of the output of the isolation amplifier to the sample and hold circuit; and a timing and control circuit for activating the first and second capacitor circuits in a predetermined timed sequence.

Tar removal during the fluidized bed gasification of plastic waste.

PubMed

Arena, Umberto; Zaccariello, Lucio; Mastellone, Maria Laura

2009-02-01

A recycled polyethylene was fed in a pilot plant bubbling fluidized bed gasifier, having an internal diameter of 0.381 m and a maximum feeding capacity of 90 kg/h. The experimental runs were carried out under various operating conditions: the bed temperature was kept at about 850 degrees C, the equivalence ratio varied between 0.2 and 0.35, the amount of bed material was between 131 and 215 kg, the fluidizing velocity was between 0.5 and 0.7 m/s, quartz sand and olivine were used as bed material, and air and steam were used as fluidizing reactants. The results confirm that the tar removal treatments applied inside the gasifier (primary methods) can eliminate or strongly reduce the need for a further downstream cleanup of the syngas. In particular, the utilization of a natural olivine as an in situ tar reduction agent remarkably improves the quality of the product gas, in terms of both high hydrogen volumetric fraction and larger syngas yield.

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.

Carbon Molecular Sieve Membrane as a True One Box Unit for Large Scale Hydrogen Production

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

Liu, Paul

2012-05-01

IGCC coal-fired power plants show promise for environmentally-benign power generation. In these plants coal is gasified to syngas then processed in a water gas-shift (WGS) reactor to maximize the hydrogen/CO{sub 2} content. The gas stream can then be separated into a hydrogen rich stream for power generation and/or further purified for sale as a chemical and a CO{sub 2} rich stream for the purpose of carbon capture and storage (CCS). Today, the separation is accomplished using conventional absorption/desorption processes with post CO{sub 2} compression. However, significant process complexity and energy penalties accrue with this approach, accounting for ~20% of themore » capital cost and ~27% parasitic energy consumption. Ideally, a one-box process is preferred in which the syngas is fed directly to the WGS reactor without gas pre-treatment, converting the CO to hydrogen in the presence of H{sub 2}S and other impurities and delivering a clean hydrogen product for power generation or other uses. The development of such a process is the primary goal of this project. Our proposed "one-box" process includes a catalytic membrane reactor (MR) that makes use of a hydrogen-selective, carbon molecular sieve (CMS) membrane, and a sulfur-tolerant Co/Mo/Al{sub 2}O{sub 3} catalyst. The membrane reactor's behavior has been investigated with a bench top unit for different experimental conditions and compared with the modeling results. The model is used to further investigate the design features of the proposed process. CO conversion >99% and hydrogen recovery >90% are feasible under the operating pressures available from IGCC. More importantly, the CMS membrane has demonstrated excellent selectivity for hydrogen over H{sub 2}S (>100), and shown no flux loss in the presence of a synthetic "tar"-like material, i.e., naphthalene. In summary, the proposed "one-box" process has been successfully demonstrated with the bench-top reactor. In parallel we have successfully designed and fabricated a full-scale CMS membrane and module for the proposed application. This full-scale membrane element is a 3" diameter with 30"L, composed of ~85 single CMS membrane tubes. The membrane tubes and bundles have demonstrated satisfactory thermal, hydrothermal, thermal cycling and chemical stabilities under an environment simulating the temperature, pressure and contaminant levels encountered in our proposed process. More importantly, the membrane module packed with the CMS bundle was tested for over 30 pressure cycles between ambient pressure and >300 -600 psi at 200 to 300°C without mechanical degradation. Finally, internal baffles have been designed and installed to improve flow distribution within the module, which delivered 90% separation efficiency in comparison with the efficiency achieved with single membrane tubes. In summary, the full-scale CMS membrane element and module have been successfully developed and tested satisfactorily for our proposed one-box application; a test quantity of elements/modules have been fabricated for field testing. Multiple field tests have been performed under this project at National Carbon Capture Center (NCCC). The separation efficiency and performance stability of our full-scale membrane elements have been verified in testing conducted for times ranging from 100 to >250 hours of continuous exposure to coal/biomass gasifier off-gas for hydrogen enrichment with no gas pre-treatment for contaminants removal. In particular, "tar-like" contaminants were effectively rejected by the membrane with no evidence of fouling. In addition, testing was conducted using a hybrid membrane system, i.e., the CMS membrane in conjunction with the palladium membrane, to demonstrate that 99+% H{sub 2} purity and a high degree of CO{sub 2} capture could be achieved. In summary, the stability and performance of the full-scale hydrogen selective CMS membrane/module has been verified in multiple field tests in the presence of coal/biomass gasifier off-gas under this project. A promising process scheme has been developed for power generation and/or hydrogen coproduction with CCS based upon our proposed "one-box" process. Our preliminary economic analysis indicates about 10% reduction in the required electricity selling price and ~40% cost reduction in CCS on per ton CO{sub 2} can be achieved in comparison with the base case involving conventional WGS with a two-stage Selexsol® for CCS. Long term field tests (e.g., >1,000 hrs) with the incorporation of the catalyst for the WGS membrane reactor and more in-depth analysis of the process scheme are recommended for the future study.« less

Gasification of blended animal manures to produce synthesis gas and activated charcoal

USDA-ARS?s Scientific Manuscript database

Blended swine solids, chicken litter, and hardwood are renewable and expensive sources to produce combined heat and power (CHP), fuels and related chemicals. The therrmochemical pathway to gasify manure has the added advantage of destroying harmful pathogens and pharmaceutically active compounds dur...

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...

40 CFR 60.51a - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... that produces gases, liquids, or solids through the heating of MSW, and the gases, liquids, or solids... the highest 4-hour arithmetic average flue gas temperature measured at the particulate matter control... setting or equipment that combusts solid, liquid, or gasified MSW including, but not limited to, field...

40 CFR 62.15410 - What definitions must I know?

Code of Federal Regulations, 2012 CFR

2012-07-01

..., liquids, or solids by heating municipal solid waste. The gases, liquids, or solids produced are combusted... gas temperature measured at the inlet of the particulate matter control device during 4 consecutive... combusts solid, liquid, or gasified municipal solid waste including, but not limited to, field-erected...

40 CFR 60.51a - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... that produces gases, liquids, or solids through the heating of MSW, and the gases, liquids, or solids... the highest 4-hour arithmetic average flue gas temperature measured at the particulate matter control... setting or equipment that combusts solid, liquid, or gasified MSW including, but not limited to, field...

40 CFR 60.51a - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... that produces gases, liquids, or solids through the heating of MSW, and the gases, liquids, or solids... the highest 4-hour arithmetic average flue gas temperature measured at the particulate matter control... setting or equipment that combusts solid, liquid, or gasified MSW including, but not limited to, field...

40 CFR 62.15410 - What definitions must I know?

Code of Federal Regulations, 2013 CFR

2013-07-01

..., liquids, or solids by heating municipal solid waste. The gases, liquids, or solids produced are combusted... gas temperature measured at the inlet of the particulate matter control device during 4 consecutive... combusts solid, liquid, or gasified municipal solid waste including, but not limited to, field-erected...

Student Off-Task Electronic Multitasking Predictors: Scale Development and Validation

ERIC Educational Resources Information Center

Qian, Yuxia; Li, Li

2017-01-01

In an attempt to better understand factors contributing to students' off-task electronic multitasking behavior in class, the research included two studies that developed a scale of students' off-task electronic multitasking predictors (the SOTEMP scale), and explored relationships between the scale and various classroom communication processes and…

EVALUATION OF TRADITIONAL CHARCOALS AND GASIFIER BIOCHARS AS SUSTAINABLE LOW-COST ADSORBENTS FOR WATER TREATMENT SERVING DEVELOPING COMMUNITIES

EPA Science Inventory

This research will break new ground in elucidating connections between principal char manufacture variables and the development of enhanced sorption characteristics in the char product. These variables include feedstock identity (biomass precursor) and form (i.e., whole log...

40 CFR 63.9990 - What are the subcategories of EGUs?

Code of Federal Regulations, 2012 CFR

2012-07-01

... coal or gasified solid oil-derived fuel. For purposes of compliance, monitoring, recordkeeping, and...) National Emission Standards for Hazardous Air Pollutants: Coal- and Oil-Fired Electric Utility Steam... equal to 8,300 Btu/lb, and (2) EGUs designed for low rank virgin coal. (b) Oil-fired EGUs are...

40 CFR 63.9990 - What are the subcategories of EGUs?

Code of Federal Regulations, 2013 CFR

2013-07-01

... coal or gasified solid oil-derived fuel. For purposes of compliance, monitoring, recordkeeping, and...) National Emission Standards for Hazardous Air Pollutants: Coal- and Oil-Fired Electric Utility Steam... equal to 8,300 Btu/lb, and (2) EGUs designed for low rank virgin coal. (b) Oil-fired EGUs are...

40 CFR 63.9990 - What are the subcategories of EGUs?

Code of Federal Regulations, 2014 CFR

2014-07-01

... coal or gasified solid oil-derived fuel. For purposes of compliance, monitoring, recordkeeping, and...) National Emission Standards for Hazardous Air Pollutants: Coal- and Oil-Fired Electric Utility Steam... equal to 8,300 Btu/lb, and (2) EGUs designed for low rank virgin coal. (b) Oil-fired EGUs are...

INDEPENDENT POWER PLANT USING WOOD WASTE

EPA Science Inventory

A 1 MWe power plant using waste wood is to be installed at a U.S. Marine Corps base, which will supply all the wood for the plant from a landfill site. The core energy conversion technology is a down-draft gasifier supplying approximately 150 Btu/scf gas to both spark ignition an...

Gasified grass and wood biochars facilitate plant establishment in acid mine soils

EPA Science Inventory

Heavy metals in exposed mine tailings threaten ecosystems that surround thousands of abandoned mines in the U.S. Biochars derived from the pyrolysis or gasification of biomass may serve as a valuable soil amendment to revegetate mine sites. We evaluated the ability of two biochar...

40 CFR 60.1465 - What definitions must I know?

Code of Federal Regulations, 2013 CFR

2013-07-01

... produces gases, liquids, or solids by heating municipal solid waste. The gases, liquids, or solids produced... arithmetic average flue gas temperature measured at the inlet of the particulate matter control device during... solid, liquid, or gasified municipal solid waste including, but not limited to, field-erected combustion...

40 CFR 60.1465 - What definitions must I know?

Code of Federal Regulations, 2012 CFR

2012-07-01

... produces gases, liquids, or solids by heating municipal solid waste. The gases, liquids, or solids produced... arithmetic average flue gas temperature measured at the inlet of the particulate matter control device during... solid, liquid, or gasified municipal solid waste including, but not limited to, field-erected combustion...

40 CFR 60.1465 - What definitions must I know?

Code of Federal Regulations, 2014 CFR

2014-07-01

... produces gases, liquids, or solids by heating municipal solid waste. The gases, liquids, or solids produced... arithmetic average flue gas temperature measured at the inlet of the particulate matter control device during... solid, liquid, or gasified municipal solid waste including, but not limited to, field-erected combustion...

High-EPA Biomass from Nannochloropsis salina Cultivated in a Flat-Panel Photo-Bioreactor on a Process Water-Enriched Growth Medium

PubMed Central

Safafar, Hamed; Hass, Michael Z.; Møller, Per; Holdt, Susan L.; Jacobsen, Charlotte

2016-01-01

Nannochloropsis salina was grown on a mixture of standard growth media and pre-gasified industrial process water representing effluent from a local biogas plant. The study aimed to investigate the effects of enriched growth media and cultivation time on nutritional composition of Nannochloropsis salina biomass, with a focus on eicosapentaenoic acid (EPA). Variations in fatty acid composition, lipids, protein, amino acids, tocopherols and pigments were studied and results compared to algae cultivated on F/2 media as reference. Mixed growth media and process water enhanced the nutritional quality of Nannochloropsis salina in laboratory scale when compared to algae cultivated in standard F/2 medium. Data from laboratory scale translated to the large scale using a 4000 L flat panel photo-bioreactor system. The algae growth rate in winter conditions in Denmark was slow, but results revealed that large-scale cultivation of Nannochloropsis salina at these conditions could improve the nutritional properties such as EPA, tocopherol, protein and carotenoids compared to laboratory-scale cultivated microalgae. EPA reached 44.2% ± 2.30% of total fatty acids, and α-tocopherol reached 431 ± 28 µg/g of biomass dry weight after 21 days of cultivation. Variations in chemical compositions of Nannochloropsis salina were studied during the course of cultivation. Nannochloropsis salina can be presented as a good candidate for winter time cultivation in Denmark. The resulting biomass is a rich source of EPA and also a good source of protein (amino acids), tocopherols and carotenoids for potential use in aquaculture feed industry. PMID:27483291

High-EPA Biomass from Nannochloropsis salina Cultivated in a Flat-Panel Photo-Bioreactor on a Process Water-Enriched Growth Medium.

PubMed

Safafar, Hamed; Hass, Michael Z; Møller, Per; Holdt, Susan L; Jacobsen, Charlotte

2016-07-29

Nannochloropsis salina was grown on a mixture of standard growth media and pre-gasified industrial process water representing effluent from a local biogas plant. The study aimed to investigate the effects of enriched growth media and cultivation time on nutritional composition of Nannochloropsis salina biomass, with a focus on eicosapentaenoic acid (EPA). Variations in fatty acid composition, lipids, protein, amino acids, tocopherols and pigments were studied and results compared to algae cultivated on F/2 media as reference. Mixed growth media and process water enhanced the nutritional quality of Nannochloropsis salina in laboratory scale when compared to algae cultivated in standard F/2 medium. Data from laboratory scale translated to the large scale using a 4000 L flat panel photo-bioreactor system. The algae growth rate in winter conditions in Denmark was slow, but results revealed that large-scale cultivation of Nannochloropsis salina at these conditions could improve the nutritional properties such as EPA, tocopherol, protein and carotenoids compared to laboratory-scale cultivated microalgae. EPA reached 44.2% ± 2.30% of total fatty acids, and α-tocopherol reached 431 ± 28 µg/g of biomass dry weight after 21 days of cultivation. Variations in chemical compositions of Nannochloropsis salina were studied during the course of cultivation. Nannochloropsis salina can be presented as a good candidate for winter time cultivation in Denmark. The resulting biomass is a rich source of EPA and also a good source of protein (amino acids), tocopherols and carotenoids for potential use in aquaculture feed industry.

Parametric study of prospective early commercial MHD power plants (PSPEC). General Electric Company, task 1: Parametric analysis

NASA Technical Reports Server (NTRS)

Marston, C. H.; Alyea, F. N.; Bender, D. J.; Davis, L. K.; Dellinger, T. C.; Hnat, J. G.; Komito, E. H.; Peterson, C. A.; Rogers, D. A.; Roman, A. J.

1980-01-01

The performance and cost of moderate technology coal-fired open cycle MHD/steam power plant designs which can be expected to require a shorter development time and have a lower development cost than previously considered mature OCMHD/steam plants were determined. Three base cases were considered: an indirectly-fired high temperature air heater (HTAH) subsystem delivering air at 2700 F, fired by a state of the art atmospheric pressure gasifier, and the HTAH subsystem was deleted and oxygen enrichment was used to obtain requisite MHD combustion temperature. Coal pile to bus bar efficiencies in ease case 1 ranged from 41.4% to 42.9%, and cost of electricity (COE) was highest of the three base cases. For base case 2 the efficiency range was 42.0% to 45.6%, and COE was lowest. For base case 3 the efficiency range was 42.9% to 44.4%, and COE was intermediate. The best parametric cases in bases cases 2 and 3 are recommended for conceptual design. Eventual choice between these approaches is dependent on further evaluation of the tradeoffs among HTAH development risk, O2 plant integration, and further refinements of comparative costs.

Low cost hydrogen/novel membrane technology for hydrogen separation from synthesis gas. Task 1, Literature survey

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

Not Available

1986-02-01

To make the coal-to-hydrogen route economically attractive, improvements are being sought in each step of the process: coal gasification, water-carbon monoxide shift reaction, and hydrogen separation. This report addresses the use of membranes in the hydrogen separation step. The separation of hydrogen from synthesis gas is a major cost element in the manufacture of hydrogen from coal. Separation by membranes is an attractive, new, and still largely unexplored approach to the problem. Membrane processes are inherently simple and efficient and often have lower capital and operating costs than conventional processes. In this report current ad future trends in hydrogen productionmore » and use are first summarized. Methods of producing hydrogen from coal are then discussed, with particular emphasis on the Texaco entrained flow gasifier and on current methods of separating hydrogen from this gas stream. The potential for membrane separations in the process is then examined. In particular, the use of membranes for H{sub 2}/CO{sub 2}, H{sub 2}/CO, and H{sub 2}/N{sub 2} separations is discussed. 43 refs., 14 figs., 6 tabs.« less

Modeling biomass gasification in circulating fluidized beds

NASA Astrophysics Data System (ADS)

Miao, Qi

In this thesis, the modeling of biomass gasification in circulating fluidized beds was studied. The hydrodynamics of a circulating fluidized bed operating on biomass particles were first investigated, both experimentally and numerically. Then a comprehensive mathematical model was presented to predict the overall performance of a 1.2 MWe biomass gasification and power generation plant. A sensitivity analysis was conducted to test its response to several gasifier operating conditions. The model was validated using the experimental results obtained from the plant and two other circulating fluidized bed biomass gasifiers (CFBBGs). Finally, an ASPEN PLUS simulation model of biomass gasification was presented based on minimization of the Gibbs free energy of the reaction system at chemical equilibrium. Hydrodynamics plays a crucial role in defining the performance of gas-solid circulating fluidized beds (CFBs). A 2-dimensional mathematical model was developed considering the hydrodynamic behavior of CFB gasifiers. In the modeling, the CFB riser was divided into two regions: a dense region at the bottom and a dilute region at the top of the riser. Kunii and Levenspiel (1991)'s model was adopted to express the vertical solids distribution with some other assumptions. Radial distributions of bed voidage were taken into account in the upper zone by using Zhang et al. (1991)'s correlation. For model validation purposes, a cold model CFB was employed, in which sawdust was transported with air as the fluidizing agent. A comprehensive mathematical model was developed to predict the overall performance of a 1.2 MWe biomass gasification and power generation demonstration plant in China. Hydrodynamics as well as chemical reaction kinetics were considered. The fluidized bed riser was divided into two distinct sections: (a) a dense region at the bottom of the bed where biomass undergoes mainly heterogeneous reactions and (b) a dilute region at the top where most of homogeneous reactions occur in gas phase. Each section was divided into a number of small cells, over which mass and energy balances were applied. Due to the high heating rate in circulating fluidized bed, the pyrolysis was considered instantaneous. A number of homogeneous and heterogeneous reactions were considered in the model. Mass transfer resistance was considered negligible since the reactions were under kinetic control due to good gas-solid mixing. The model is capable of predicting the bed temperature distribution along the gasifier, the concentration and distribution of each species in the vertical direction of the bed, the composition and lower heating value (LHV) of produced gas, the gasification efficiency, the overall carbon conversion and the produced gas production rate. A sensitivity analysis was performed to test its response to several gasifier operating conditions. The model sensitivity analysis showed that equivalence ratio (ER), bed temperature, fluidization velocity, biomass feed rate and moisture content had various effects on the gasifier performance. However, the model was more sensitive to variations in ER and bed temperature. The model was validated using the experimental results obtained from the demonstration plant. The reactor was operated on rice husk at various ERs, fluidization velocities and biomass feed rates. The model gave reasonable predictions. The model was also validated by comparing the simulation results with two other different size CFBBGs using different biomass feedstock, and it was concluded that the developed model can be applied to other CFBBGs using various biomass fuels and having comparable reactor geometries. A thermodynamic model was developed under ASPEN PLUS environment. Using the approach of Gibbs free energy minimization, the model was essentially independent of kinetic parameters. A sensitivity analysis was performed on the model to test its response to operating variables, including ER and biomass moisture content. The results showed that the ER has the most effect on the product gas composition and LHV. The simulation results were compared with the experimental data obtained from the demonstration plant. Keywords: Biomass gasification; Mathematical model; Circulating fluidized bed; Hydrodynamics; Kinetics; Sensitivity analysis; Validation; Equivalence ratio; Temperature; Feed rate; Moisture; Syngas composition; Lower heating value; Gasification efficiency; Carbon conversion

Subjective rating scales as a workload

NASA Technical Reports Server (NTRS)

Bird, K. L.

1981-01-01

A multidimensional bipolar-adjective rating scale is employed as a subjective measure of operator workload in the performance of a one-axis tracking task. The rating scale addressed several dimensions of workload, including cognitive, physical, and perceptual task loading as well as fatigue and stress effects. Eight subjects performed a one-axis tracking task (with six levels of difficulty) and rated these tasks on several workload dimensions. Performance measures were tracking error RMS (root-mean square) and the standard deviation of control stick output. Significant relationships were observed between these performance measures and skill required, task complexity, attention level, task difficulty, task demands, and stress level.

Particulate Hot Gas Stream Cleanup Technical Issues: Quarterly report, July 1-September 30, 1996

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

Pontius, D.H.

1996-12-09

This is the eighth in a series of quarterly reports describing the activities performed under Contract No. DE-AC21-94MC31160. Analyses of Hot Gas Stream Cleanup (HGCU) ashes and descriptions of filter performance address aspects of filter operation that are apparently linked to the characteristics of the collected ash or the performance of the ceramic barrier filter elements. Task 1 is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters (APFS) and to relate these ash properties to the operation and performance of these filters. Task 2 concerns testing and failure analysis ofmore » ceramic filter elements. Under Task I during the past quarter, additional analyses were performed on ashes from the Ahlstrom 10 MWt Pressurized Fluidized Circulating Fluid Bed (PCFB) facility located at Karhula, Finland. Work continued on the HGCU data base being constructed in Microsoft Access. A variety of information has been entered into the data base, including numerical values, short or long text entries, and photographs. Detailed design of a bench top device for high temperature measurement of ash permeability has also begun. In addition to these activities, a paper was prepared and a poster was presented summarizing recent work performed under this contract at the 1996 DOE/METC Contractor`s Conference. A presentation was also given corresponding to the manuscript entitled Particle Characteristics and High-Temperature Filtration that was prepared for publication in the Proceedings of the Thirteenth Annual International Pittsburgh Coal Conference held this September in Pittsburgh, PA. Arrangements have been made to be present at the DOE/METC Modular Gas Cleanup Rig (MGCR) at the conclusion of the next run of the DOE/METC air blown Fluid Bed Gasifier (FBG). This visit will include on-site sampling to collect and characterize the filter cakes collected during FGB operation. Task 2 efforts during the past quarter focused on hoop tensile testing of Schumacher FT20 and Refractron 326 candle filter elements removed from the Karhula APF after 540 hours of service.« less

Gasification of agricultural residues in a demonstrative plant: corn cobs.

PubMed

Biagini, Enrico; Barontini, Federica; Tognotti, Leonardo

2014-12-01

Biomass gasification couples the high power efficiency with the possibility of valuably using the byproducts heat and biochar. The use of agricultural wastes instead of woody feedstock extends the seasonal availability of biomasses. The downdraft type is the most used reactor but has narrow ranges of feedstock specifications (above all on moisture and particle size distribution), so tests on a demonstrative scale are conducted to prove the versatility of the gasifier. Measurements on pressure drops, syngas flow rate and composition are studied to assess the feasibility of such operations with corn cobs. Material and energy balances, and performance indexes are compared for the four tests carried out under different biomass loads (66-85 kg/h). A good operability of the plant and interesting results are obtained (gas specific production of 2 m3/kg, gas heating value 5.6-5.8 MJ/m3, cold gas efficiency in the range 66-68%, potential net power efficiency 21.1-21.6%). Copyright © 2014 Elsevier Ltd. All rights reserved.

Coal gasification systems engineering and analysis. Appendix G: Commercial design and technology evaluation

NASA Technical Reports Server (NTRS)

1980-01-01

A technology evaluation of five coal gasifier systems (Koppers-Totzek, Texaco, Babcock and Wilcox, Lurgi and BGC/Lurgi) and procedures and criteria for evaluating competitive commercial coal gasification designs is presented. The technology evaluation is based upon the plant designs and cost estimates developed by the BDM-Mittelhauser team.

On-Site Field-Feeding Waste to Energy Converter

DTIC Science & Technology

2008-12-01

fundamentals The feedstock and part of the air needed for gasifica- tion enter through the open top of the downdraft gasifier. The motive force for the air...combustion air before entering the TQG, where the gas/air mixture is compressed by the turbocharger and distributed to the cylinders. The amount of JP-8

Gasified grass and wood biochars facilitate plant establishment in acid mine soils

USDA-ARS?s Scientific Manuscript database

Thousands of abandoned mines in the Western U.S. threaten ecosystems, due to high heavy metal concentrations in exposed mine spoils and waters flowing from them. Biochars derived from the pyrolysis or gasification of organic biomass may serve as a valuable soil amendment to revegetate mine sites, du...

Systems analysis of electricity production from coal using fuel cells

NASA Technical Reports Server (NTRS)

Fleming, D. K.

1983-01-01

Gasifiers, heat transfer, gas stability, quench, water-gas shift reaction, reforming-methanation, other catalytic reactions, compressors and expanders, acid-gas removal, the fuel cell, and catalytic combustors are described. System pressure drops, efficiency of rotating power equipment, heat exchangers, chemical reactions, steam systems, and the fuel cell subsystems are discussed.

Gas Production Strategy of Underground Coal Gasification Based on Multiple Gas Sources

PubMed Central

Tianhong, Duan; Zuotang, Wang; Limin, Zhou; Dongdong, Li

2014-01-01

To lower stability requirement of gas production in UCG (underground coal gasification), create better space and opportunities of development for UCG, an emerging sunrise industry, in its initial stage, and reduce the emission of blast furnace gas, converter gas, and coke oven gas, this paper, for the first time, puts forward a new mode of utilization of multiple gas sources mainly including ground gasifier gas, UCG gas, blast furnace gas, converter gas, and coke oven gas and the new mode was demonstrated by field tests. According to the field tests, the existing power generation technology can fully adapt to situation of high hydrogen, low calorific value, and gas output fluctuation in the gas production in UCG in multiple-gas-sources power generation; there are large fluctuations and air can serve as a gasifying agent; the gas production of UCG in the mode of both power and methanol based on multiple gas sources has a strict requirement for stability. It was demonstrated by the field tests that the fluctuations in gas production in UCG can be well monitored through a quality control chart method. PMID:25114953

Parametric study of potential early commercial MHD power plants

NASA Technical Reports Server (NTRS)

Hals, F. A.

1979-01-01

Three different reference power plant configurations were considered with parametric variations of the various design parameters for each plant. Two of the reference plant designs were based on the use of high temperature regenerative air preheaters separately fired by a low Btu gas produced from a coal gasifier which was integrated with the power plant. The third reference plant design was based on the use of oxygen enriched combustion air preheated to a more moderate temperature in a tubular type metallic recuperative heat exchanger which is part of the bottoming plant heat recovery system. Comparative information was developed on plant performance and economics. The highest net plant efficiency of about 45 percent was attained by the reference plant design with the use of a high temperature air preheater separately fired with the advanced entrained bed gasifier. The use of oxygen enrichment of the combustion air yielded the lowest cost of generating electricity at a slightly lower plant efficiency. Both of these two reference plant designs are identified as potentially attractive for early MHD power plant applications.

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

PubMed

Martínez-Lera, S; Torrico, J; Pallarés, J; Gil, A

2013-07-01

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. 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/m3 and cold gas efficiencies up to 60%. Copyright © 2013 Elsevier Ltd. All rights reserved.

Co-gasification of tire and biomass for enhancement of tire-char reactivity in CO2 gasification process.

PubMed

Lahijani, Pooya; Zainal, Zainal Alimuddin; Mohamed, Abdul Rahman; Mohammadi, Maedeh

2013-06-01

In this investigation, palm empty fruit bunch (EFB) and almond shell (AS) were implemented as two natural catalysts rich in alkali metals, especially potassium, to enhance the reactivity of tire-char through co-gasification process. Co-gasification experiments were conducted at several blending ratios using isothermal Thermogravimetric analysis (TGA) under CO2. The pronounced effect of inherent alkali content of biomass-chars on promoting the reactivity of tire-char was proven when acid-treated biomass-chars did not exert any catalytic effect on improving the reactivity of tire-char in co-gasification experiments. In kinetic studies of the co-gasified samples in chemically-controlled regime, modified random pore model (M-RPM) was adopted to describe the reactive behavior of the tire-char/biomass-char blends. By virtue of the catalytic effect of biomass, the activation energy for tire-char gasification was lowered from 250 kJ/mol in pure form 203 to 187 kJ/mol for AS-char and EFB-char co-gasified samples, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

Hydrogen sulfide capture by limestone and dolomite at elevated pressure. 2: Sorbent particle conversion modeling

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

Zevenhoven, C.A.P.; Yrjas, K.P.; Hupa, M.M.

1996-03-01

The physical structure of a limestone or dolomite to be used in in-bed sulfur capture in fluidized bed gasifiers has a great impact on the efficiency of sulfur capture and sorbent use. In this study an unreacted shrinking core model with variable effective diffusivity is applied to sulfidation test data from a pressurized thermogravimetric apparatus (P-TGA) for a set of physically and chemically different limestone and dolomite samples. The particle size was 250--300 {micro}m for all sorbents, which were characterized by chemical composition analysis, particle density measurement, mercury porosimetry, and BET internal surface measurement. Tests were done under typical conditionsmore » for a pressurized fluidized-bed gasifier, i.e., 20% CO{sub 2}, 950 C, 20 bar. At these conditions the limestone remains uncalcined, while the dolomite is half-calcined. Additional tests were done at low CO{sub 2} partial pressures, yielding calcined limestone and fully calcined dolomite. The generalized model allows for determination of values for the initial reaction rate and product layer diffusivity.« less

Gas production strategy of underground coal gasification based on multiple gas sources.

PubMed

Tianhong, Duan; Zuotang, Wang; Limin, Zhou; Dongdong, Li

2014-01-01

To lower stability requirement of gas production in UCG (underground coal gasification), create better space and opportunities of development for UCG, an emerging sunrise industry, in its initial stage, and reduce the emission of blast furnace gas, converter gas, and coke oven gas, this paper, for the first time, puts forward a new mode of utilization of multiple gas sources mainly including ground gasifier gas, UCG gas, blast furnace gas, converter gas, and coke oven gas and the new mode was demonstrated by field tests. According to the field tests, the existing power generation technology can fully adapt to situation of high hydrogen, low calorific value, and gas output fluctuation in the gas production in UCG in multiple-gas-sources power generation; there are large fluctuations and air can serve as a gasifying agent; the gas production of UCG in the mode of both power and methanol based on multiple gas sources has a strict requirement for stability. It was demonstrated by the field tests that the fluctuations in gas production in UCG can be well monitored through a quality control chart method.

On a clean power generation system with the co-gasification of biomass and coal in a quadruple fluidized bed gasifier.

PubMed

Yan, Linbo; He, Boshu

2017-07-01

A clean power generation system was built based on the steam co-gasification of biomass and coal in a quadruple fluidized bed gasifier. The chemical looping with oxygen uncoupling technology was used to supply oxygen for the calciner. The solid oxide fuel cell and the steam turbine were combined to generate power. The calcium looping and mineral carbonation were used for CO 2 capture and sequestration. The aim of this work was to study the characteristics of this system. The effects of key operation parameters on the system total energy efficiency (ŋ ten ), total exergy efficiency (ŋ tex ) and carbon sequestration rate (R cs ) were detected. The energy and exergy balance calculations were implemented and the corresponding Sankey and Grassmann diagrams were drawn. It was found that the maximum energy and exergy losses occurred in the steam turbine. The system ŋ ten and ŋ tex could be ∼50% and ∼47%, and R cs could be over unit. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sensitivity of Fischer-Tropsch Synthesis and Water-Gas Shift Catalysts to Poisons from High-Temperature High-Pressure Entrained-Flow (EF) Oxygen-Blown Gasifier Gasification of Coal/Biomass Mixtures

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

Burton Davis; Gary Jacobs; Wenping Ma

2011-09-30

There has been a recent shift in interest in converting not only natural gas and coal derived syngas to Fischer-Tropsch synthesis products, but also converting biomass-derived syngas, as well as syngas derived from coal and biomass mixtures. As such, conventional catalysts based on iron and cobalt may not be suitable without proper development. This is because, while ash, sulfur compounds, traces of metals, halide compounds, and nitrogen-containing chemicals will likely be lower in concentration in syngas derived from mixtures of coal and biomass (i.e., using entrained-flow oxygen-blown gasifier gasification gasification) than solely from coal, other compounds may actually be increased.more » Of particular concern are compounds containing alkali chemicals like the chlorides of sodium and potassium. In the first year, University of Kentucky Center for Applied Energy Research (UK-CAER) researchers completed a number of tasks aimed at evaluating the sensitivity of cobalt and iron-based Fischer-Tropsch synthesis (FT) catalysts and a commercial iron-chromia high temperature water-gas shift catalyst (WGS) to alkali halides. This included the preparation of large batches of 0.5%Pt-25%Co/Al{sub 2}O{sub 3} and 100Fe: 5.1Si: 3.0K: 2.0Cu (high alpha) catalysts that were split up among the four different entities participating in the overall project; the testing of the catalysts under clean FT and WGS conditions; the testing of the Fe-Cr WGS catalyst under conditions of co-feeding NaCl and KCl; and the construction and start-up of the continuously stirred tank reactors (CSTRs) for poisoning investigations. In the second and third years, researchers from the University of Kentucky Center for Applied Energy Research (UK-CAER) continued the project by evaluating the sensitivity of a commercial iron-chromia high temperature water-gas shift catalyst (WGS) to a number of different compounds, including KHCO{sub 3}, NaHCO{sub 3}, HCl, HBr, HF, H{sub 2}S, NH{sub 3}, and a combination of H{sub 2}S and NH{sub 3}. Cobalt and iron-based Fischer-Tropsch synthesis (FT) catalysts were also subjected to a number of the same compounds in order to evaluate their sensitivities at different concentration levels of added contaminant.« less

The suppression of scale-free fMRI brain dynamics across three different sources of effort: aging, task novelty and task difficulty.

PubMed

Churchill, Nathan W; Spring, Robyn; Grady, Cheryl; Cimprich, Bernadine; Askren, Mary K; Reuter-Lorenz, Patricia A; Jung, Mi Sook; Peltier, Scott; Strother, Stephen C; Berman, Marc G

2016-08-08

There is growing evidence that fluctuations in brain activity may exhibit scale-free ("fractal") dynamics. Scale-free signals follow a spectral-power curve of the form P(f ) ∝ f(-β), where spectral power decreases in a power-law fashion with increasing frequency. In this study, we demonstrated that fractal scaling of BOLD fMRI signal is consistently suppressed for different sources of cognitive effort. Decreases in the Hurst exponent (H), which quantifies scale-free signal, was related to three different sources of cognitive effort/task engagement: 1) task difficulty, 2) task novelty, and 3) aging effects. These results were consistently observed across multiple datasets and task paradigms. We also demonstrated that estimates of H are robust across a range of time-window sizes. H was also compared to alternative metrics of BOLD variability (SDBOLD) and global connectivity (Gconn), with effort-related decreases in H producing similar decreases in SDBOLD and Gconn. These results indicate a potential global brain phenomenon that unites research from different fields and indicates that fractal scaling may be a highly sensitive metric for indexing cognitive effort/task engagement.

The suppression of scale-free fMRI brain dynamics across three different sources of effort: aging, task novelty and task difficulty

PubMed Central

Churchill, Nathan W.; Spring, Robyn; Grady, Cheryl; Cimprich, Bernadine; Askren, Mary K.; Reuter-Lorenz, Patricia A.; Jung, Mi Sook; Peltier, Scott; Strother, Stephen C.; Berman, Marc G.

2016-01-01

There is growing evidence that fluctuations in brain activity may exhibit scale-free (“fractal”) dynamics. Scale-free signals follow a spectral-power curve of the form P(f ) ∝ f−β, where spectral power decreases in a power-law fashion with increasing frequency. In this study, we demonstrated that fractal scaling of BOLD fMRI signal is consistently suppressed for different sources of cognitive effort. Decreases in the Hurst exponent (H), which quantifies scale-free signal, was related to three different sources of cognitive effort/task engagement: 1) task difficulty, 2) task novelty, and 3) aging effects. These results were consistently observed across multiple datasets and task paradigms. We also demonstrated that estimates of H are robust across a range of time-window sizes. H was also compared to alternative metrics of BOLD variability (SDBOLD) and global connectivity (Gconn), with effort-related decreases in H producing similar decreases in SDBOLD and Gconn. These results indicate a potential global brain phenomenon that unites research from different fields and indicates that fractal scaling may be a highly sensitive metric for indexing cognitive effort/task engagement. PMID:27498696

The THERMIE energy farm project

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

Lange, H.J. de; Barbucci, P.; Greil, C.

1998-07-01

At a site close to Pisa (Italy), a plant with a net power-output of approximately 12 MWe will be erected; it features an atmospheric, air-blown, circulating fluidized-bed (CFB) gasifier, integrated with a 10.9 MWe, single-shaft, heavy-duty gas-turbine, suited to burn the low-calorific value fuel-gas produced by the gasifier, and a heat-recovery steam-generator (HRSG), which provides steam to a 5 MWe condensing steam-turbine. The plant's net thermal-efficiency amounts to about 32%. Wet wood is shredded to chips, mixed with the agricultural residues and fed to a dryer. Here, flue gases from the HRSG are used to dry the fuel to themore » desired moisture content. The dried fuel is gasified in a CFB reactor to produce a fuel-gas. This fuel-gas is cooled in two stages during which the gasification air is preheated and steam is produced in a gas-cooler (GC). Then, it is washed in a wet-scrubber and compressed in several intercooled stages before it is delivered to the gas turbine model PGT10 B/1. The gas turbine adopts a newly developed, high-efficiency air-compressor and its special, dual-fuel combustion-chamber is now under development. The combined-cycle is completed with a dual pressure-level HRSG. The steam turbine is fed by the steam produced in the HRSG and the GC located in the gasification island. As a consequence of the changed agricultural market, the fuel will consist not only of short rotation forestry (SRF) but also of forestry and agricultural residues. The wood species include poplar, black locust, willow and chestnut, whereas the agricultural residues comprise olive stones and grape-seed flour. The financial viability of the project relies on the incentive provided by the Italian government with a premium price per kWh of electricity produced from renewables and on the financial contribution from the EU.« less

Model-based estimation of adiabatic flame temperature during coal gasification

NASA Astrophysics Data System (ADS)

Sarigul, Ihsan Mert

Coal gasification temperature distribution in the gasifier is one of the important issues. High temperature may increase the risk of corrosion of the gasifier wall or it may cause an increase in the amount of volatile compounds. At the same time, gasification temperature is a dominant factor for high conversion of products and completing the reactions during coal gasification in a short time. In the light of this information it can be said that temperature is one of key parameters of coal gasification to enhance the production of high heating value syngas and maximize refractory longevity. This study aims to predict the adiabatic flame temperatures of Australian bituminous coal and Indonesian roto coal in an entrained flow gasifier using different operating conditions with the ChemCAD simulation and design program. To achieve these objectives, two types of gasification parameters were carried out using simulation of a vertical entrained flow reactor: oxygen-to-coal feed ratio by kg/kg and pressure and steam-to-coal feed ratio by kg/kg and pressure. In the first part of study the adiabatic flame temperatures, coal gasification products and other coal characteristics of two types of coals were determined using ChemCAD software. During all simulations, coal feed rate, coal particle size, initial temperature of coal, water and oxygen were kept constant. The relationships between flame temperature, coal gasification products and operating parameters were fundamentally investigated. The second part of this study addresses the modeling of the flame temperature relation to methane production and other input parameters used previous chapter. The scope of this work was to establish a reasonable model in order to estimate flame temperature without any theoretical calculation. Finally, sensitivity analysis was performed after getting some basic correlations between temperature and input variables. According to the results, oxygen-to-coal feed ratio has the most influential effect on adiabatic flame temperature.

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

Gasification of empty fruit bunch with carbon dioxide in an entrained flow gasifier for syngas production

NASA Astrophysics Data System (ADS)

Rahmat, N. F. H.; Rasid, R. A.

2017-06-01

The main objectives of this work are to study the gasification of EFB in an atmospheric entrained flow gasifier, using carbon dioxide (CO2) as its gasifying agent and to determine the optimum gasification operating conditions, which includes temperature and the oxidant to fuel (OTF) ratio. These were evaluated in terms of important gasification parameters such as the concentration of hydrogen (H2) and carbon monoxide (CO) produced the syngas ratio H2/CO and carbon conversion. The gasification reactions take place in the presence of CO2 at very high reaction rate because of the high operating temperature (700°C - 900°C). The use of CO2 as the oxidant for gasification process can improve the composition of syngas produced as in the Boudouard reaction. Rise of reaction temperature which is 900°C will increase the concentration of both H2 & CO by up to 81 and 30 respectively, though their production were decreased after the OTF ratio of 0.6 for temperature 700°C & 800°C and OTF ratio 0.8 for temperature 750°C. The operating temperature must be higher than 850°C to ensure the Boudouard reaction become the more prominent reaction for the biomass gasification. The syngas ratio obtained was in the range of ≈ 0.6 - 2.4 which is sufficient for liquid fuel synthesis. For the carbon conversion, the highest fuel conversion recorded at temperature 850°C for all OTF ratios. As the OTF ratio increases, it was found that there was an increase in the formation of CO and H2. This suggests that to achieve higher carbon conversion, high operating temperature and OTF ratio are preferable. This study provides information on the optimum operating conditions for the gasification of biomass, especially the EFB, hence may upsurge the utilization of biomass waste as an energy source.

Reducing the language content in ToM tests: A developmental scale.

PubMed

Burnel, Morgane; Perrone-Bertolotti, Marcela; Reboul, Anne; Baciu, Monica; Durrleman, Stephanie

2018-02-01

The goal of the current study was to statistically evaluate the reliable scalability of a set of tasks designed to assess Theory of Mind (ToM) without language as a confounding variable. This tool might be useful to study ToM in populations where language is impaired or to study links between language and ToM. Low verbal versions of the ToM tasks proposed by Wellman and Liu (2004) for their scale were tested in 234 children (2.5 years to 11.9 years). Results showed that 5 of the tasks formed a scale according to both Guttman and Rasch models whereas all 6 tasks could form a scale according to the Rasch model only. The main difference from the original scale was that the Explicit False Belief task could be included whereas the Knowledge Access (KA) task could not. The authors argue that the more verbal version of the KA task administered in previous studies could have measured language understanding rather than ToM. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Rankings, Standards, and Competition: Task vs. Scale Comparisons

ERIC Educational Resources Information Center

Garcia, Stephen M.; Tor, Avishalom

2007-01-01

Research showing how upward social comparison breeds competitive behavior has so far conflated local comparisons in "task" performance (e.g. a test score) with comparisons on a more general "scale" (i.e. an underlying skill). Using a ranking methodology (Garcia, Tor, & Gonzalez, 2006) to separate task and scale comparisons, Studies 1-2 reveal that…

Field Testing of a Wet FGD Additive for Enhanced Mercury Control - Pilot-Scale Test Results

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

Gary M. Blythe

2006-03-01

This Topical Report summarizes progress on Cooperative Agreement DE-FC26-04NT42309, ''Field Testing of a Wet FGD Additive.'' The objective of the project is to demonstrate the use of a flue gas desulfurization (FGD) additive, Degussa Corporation's TMT-15, to prevent the reemissions of elemental mercury (Hg{sup 0}) in flue gas exiting wet FGD systems on coal-fired boilers. Furthermore, the project intends to demonstrate that the additive can be used to precipitate most of the mercury (Hg) removed in the wet FGD system as a fine TMT salt that can be separated from the FGD liquor and bulk solid byproducts for separate disposal.more » The project will conduct pilot and full-scale tests of the TMT-15 additive in wet FGD absorbers. The tests are intended to determine required additive dosage requirements to prevent Hg{sup 0} reemissions and to separate mercury from the normal FGD byproducts for three coal types: Texas lignite/Power River Basin (PRB) coal blend, high-sulfur Eastern bituminous coal, and low-sulfur Eastern bituminous coal. The project team consists of URS Group, Inc., EPRI, TXU Generation Company LP, Southern Company, and Degussa Corporation. TXU Generation has provided the Texas lignite/PRB co-fired test site for pilot FGD tests, Monticello Steam Electric Station Unit 3. Southern Company is providing the low-sulfur Eastern bituminous coal host site for wet scrubbing tests, as well as the pilot and full-scale jet bubbling reactor (JBR) FGD systems to be tested. A third utility, to be named later, will provide the high-sulfur Eastern bituminous coal full-scale FGD test site. Degussa Corporation is providing the TMT-15 additive and technical support to the test program. The project is being conducted in six tasks. Of the six project tasks, Task 1 involves project planning and Task 6 involves management and reporting. The other four tasks involve field testing on FGD systems, either at pilot or full scale. The four tasks include: Task 2 - Pilot Additive Testing in Texas Lignite Flue Gas; Task 3 - Full-scale FGD Additive Testing in High Sulfur Eastern Bituminous Flue Gas; Task 4 - Pilot Wet Scrubber Additive Tests at Yates; and Task 5 - Full-scale Additive Tests at Plant Yates. This topical report presents the results from the Task 2 and Task 4 pilot-scale additive tests. The Task 3 and Task 5 full-scale additive tests will be conducted later in calendar year 2006.« less

Mental workload associated with operating an agricultural sprayer: an empirical approach.

PubMed

Dey, A K; Mann, D D

2011-04-01

Agricultural spraying involves two major tasks: guiding a sprayer in response to a GPS navigation device, and simultaneous monitoring of rear-attached booms under various illumination and terrain difficulty levels. The aim of the present study was to investigate the effect of illumination, task difficulty, and task level on the mental workload of an individual operating an agricultural sprayer in response to a commercial GPS lightbar, and to explore the sensitivity of the NASA-TLX and SSWAT subjective rating scales in discriminating the subjective experienced workload under various task, illumination, and difficulty levels. Mental workload was measured using performance measures (lateral root mean square error and reaction time), physiological measures (0.1 Hz power of HRV, latency of the P300 component of event-related potential, and eye-glance behavior), and two subjective rating scales (NASA-TLX and SSWAT). Sixteen male university students participated in this experiment, and a fixed-base high-fidelity agricultural tractor simulator was used to create a simulated spraying task. All performance measures, the P300 latency, and subjective rating scales showed a common trend that mental workload increased with the change in illumination from day to night, with task difficulty from low to high, and with task type from single to dual. The 0.1 Hz power of HRV contradicted the performance measures. Eye-glance data showed that under night illumination, participants spent more time looking at the lightbar for guidance information. A similar trend was observed with the change in task type from single to dual. Both subjective rating scales showed a common trend of increasing mental workload with the change in illumination, difficulty, and task levels. However, the SSWAT scale was more sensitive than the NASA-TLX scale. With the change in illumination, difficulty, and task levels, participants spent more mental resources to meet the increased task demand; hence, the illumination, task difficulty, and task level affected the mental workload of an agricultural sprayer operator operating a sprayer in response to a GPS lightbar.

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

Alptekin, Gokhan

The overall objective of the proposed research is to develop a low cost, high capacity CO{sub 2} sorbent and demonstrate its technical and economic viability for pre-combustion CO{sub 2} capture. The specific objectives supporting our research plan were to optimize the chemical structure and physical properties of the sorbent, scale-up its production using high throughput manufacturing equipment and bulk raw materials and then evaluate its performance, first in bench-scale experiments and then in slipstream tests using actual coal-derived synthesis gas. One of the objectives of the laboratory-scale evaluations was to demonstrate the life and durability of the sorbent for overmore » 10,000 cycles and to assess the impact of contaminants (such as sulfur) on its performance. In the field tests, our objective was to demonstrate the operation of the sorbent using actual coal-derived synthesis gas streams generated by air-blown and oxygen-blown commercial and pilot-scale coal gasifiers (the CO{sub 2} partial pressure in these gas streams is significantly different, which directly impacts the operating conditions hence the performance of the sorbent). To support the field demonstration work, TDA collaborated with Phillips 66 and Southern Company to carry out two separate field tests using actual coal-derived synthesis gas at the Wabash River IGCC Power Plant in Terre Haute, IN and the National Carbon Capture Center (NCCC) in Wilsonville, AL. In collaboration with the University of California, Irvine (UCI), a detailed engineering and economic analysis for the new CO{sub 2} capture system was also proposed to be carried out using Aspen PlusTM simulation software, and estimate its effect on the plant efficiency.« less

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.

Advanced Gas Turbine (AGT) Technology Project

NASA Technical Reports Server (NTRS)

1984-01-01

Technical work on the design and effort leading to the testing of a 74.5 kW (100 hp) automotive gas turbine engine is reviewed. Development of the engine compressor, gasifier turbine, power turbine, combustor, regenerator, and secondary system is discussed. Ceramic materials development and the application of such materials in the gas turbine engine components is described.

Biomass energy : the new frontier

Treesearch

John I. Zerbe

2006-01-01

We can have the greatest direct impact on petroleum and natural gas fuel usage by burning or gasifying wood for space heat, process energy and power. One alternative source that is available and underused is surplus wood. Certainly wood that is suitable for use in more valuable products should not be diverted to energy use that provides less income; however, other wood...

Two stage sorption of sulfur compounds

DOEpatents

Moore, William E.

1992-01-01

A two stage method for reducing the sulfur content of exhaust gases is disclosed. Alkali- or alkaline-earth-based sorbent is totally or partially vaporized and introduced into a sulfur-containing gas stream. The activated sorbent can be introduced in the reaction zone or the exhaust gases of a combustor or a gasifier. High efficiencies of sulfur removal can be achieved.

Biochars derived from gasified feedstocks increase the growth and improve the nutrient acquisition of Triticum aestivum (L.) grown in agricultural alfisols

USDA-ARS?s Scientific Manuscript database

The utility of biochars produced by biomass gasification for remediation of acidic production soils and plant growth in general is not as well known compared to effects from biochars resulting from pyrolysis. Our recent characterization of biochars produced from gasification of Kentucky bluegrass (P...

Decreased attention to object size information in scale errors performers.

PubMed

Grzyb, Beata J; Cangelosi, Angelo; Cattani, Allegra; Floccia, Caroline

2017-05-01

Young children sometimes make serious attempts to perform impossible actions on miniature objects as if they were full-size objects. The existing explanations of these curious action errors assume (but never explicitly tested) children's decreased attention to object size information. This study investigated the attention to object size information in scale errors performers. Two groups of children aged 18-25 months (N=52) and 48-60 months (N=23) were tested in two consecutive tasks: an action task that replicated the original scale errors elicitation situation, and a looking task that involved watching on a computer screen actions performed with adequate to inadequate size object. Our key finding - that children performing scale errors in the action task subsequently pay less attention to size changes than non-scale errors performers in the looking task - suggests that the origins of scale errors in childhood operate already at the perceptual level, and not at the action level. Copyright © 2017 Elsevier Inc. All rights reserved.

The Work Tasks Motivation Scale for Teachers (WTMST)

ERIC Educational Resources Information Center

Fernet, Claude; Senecal, Caroline; Guay, Frederic; Marsh, Herbert; Dowson, Martin

2008-01-01

The authors developed and validated a measure of teachers' motivation toward specific work tasks: The Work Tasks Motivation Scale for Teachers (WTMST). The WTMST is designed to assess five motivational constructs toward six work tasks (e.g., class preparation, teaching). The authors conducted a preliminary (n = 42) and a main study among…

Decision paths in complex tasks

NASA Technical Reports Server (NTRS)

Galanter, Eugene

1991-01-01

Complex real world action and its prediction and control has escaped analysis by the classical methods of psychological research. The reason is that psychologists have no procedures to parse complex tasks into their constituents. Where such a division can be made, based say on expert judgment, there is no natural scale to measure the positive or negative values of the components. Even if we could assign numbers to task parts, we lack rules i.e., a theory, to combine them into a total task representation. We compare here two plausible theories for the amalgamation of the value of task components. Both of these theories require a numerical representation of motivation, for motivation is the primary variable that guides choice and action in well-learned tasks. We address this problem of motivational quantification and performance prediction by developing psychophysical scales of the desireability or aversiveness of task components based on utility scaling methods (Galanter 1990). We modify methods used originally to scale sensory magnitudes (Stevens and Galanter 1957), and that have been applied recently to the measure of task 'workload' by Gopher and Braune (1984). Our modification uses utility comparison scaling techniques which avoid the unnecessary assumptions made by Gopher and Braune. Formula for the utility of complex tasks based on the theoretical models are used to predict decision and choice of alternate paths to the same goal.

Field Testing of a Wet FGD Additive for Enhanced Mercury Control - Task 3 Full-scale Test Results

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

Gary Blythe

2007-05-01

This Topical Report summarizes progress on Cooperative Agreement DE-FC26-04NT42309, 'Field Testing of a Wet FGD Additive'. The objective of the project is to demonstrate the use of a flue gas desulfurization (FGD) additive, Degussa Corporation's TMT-15, to prevent the reemission of elemental mercury (Hg{sup 0}) in flue gas exiting wet FGD systems on coal-fired boilers. Furthermore, the project intends to demonstrate whether the additive can be used to precipitate most of the mercury (Hg) removed in the wet FGD system as a fine TMT salt that can be separated from the FGD liquor and bulk solid byproducts for separate disposal.more » The project is conducting pilot- and full-scale tests of the TMT-15 additive in wet FGD absorbers. The tests are intended to determine required additive dosages to prevent Hg{sup 0} reemissions and to separate mercury from the normal FGD byproducts for three coal types: Texas lignite/Power River Basin (PRB) coal blend, high-sulfur Eastern bituminous coal, and low-sulfur Eastern bituminous coal. The project team consists of URS Group, Inc., EPRI, TXU Generation Company LP, Southern Company, and Degussa Corporation. TXU Generation has provided the Texas lignite/PRB cofired test site for pilot FGD tests, Monticello Steam Electric Station Unit 3. Southern Company is providing the low-sulfur Eastern bituminous coal host site for wet scrubbing tests, as well as the pilot- and full-scale jet bubbling reactor (JBR) FGD systems to be tested. IPL, an AES company, provided the high-sulfur Eastern bituminous coal full-scale FGD test site and cost sharing. Degussa Corporation is providing the TMT-15 additive and technical support to the test program as cost sharing. The project is being conducted in six tasks. Of the six project tasks, Task 1 involves project planning and Task 6 involves management and reporting. The other four tasks involve field testing on FGD systems, either at pilot or full scale. The four tasks include: Task 2 - Pilot Additive Testing in Texas Lignite Flue Gas; Task 3 - Full-scale FGD Additive Testing in High-sulfur Eastern Bituminous Flue Gas; Task 4 - Pilot Wet Scrubber Additive Tests at Plant Yates; and Task 5 - Full-scale Additive Tests at Plant Yates. The pilot-scale tests were completed in 2005 and have been previously reported. This topical report presents the results from the Task 3 full-scale additive tests, conducted at IPL's Petersburg Station Unit 2. The Task 5 full-scale additive tests will be conducted later in calendar year 2007.« less

Experimental study on temperature profile of fixed - bed gasification of oil-palm fronds

NASA Astrophysics Data System (ADS)

Atnaw, Samson M.; Sulaiman, Shaharin A.; Moni, M. Nazmi Z.

2012-06-01

Currently the world's second largest palm oil producer Malaysia produces large amount of oil palm biomass each year. The abundance of the biomass introduces a challenge to utilize them as main feedstock for heat and energy generation. Although some oil palm parts and derivatives like empty fruit bunch and fibre have been commercialized as fuel, less attention has been given to oil palm fronds (OPF). Initial feasibility and characterization studies of OPF showed that it is highly feasible as fuel for gasification to produce high value gaseous fuel or syngas. This paper discusses the experimental gasification attempt carried out on OPF using a 50 kW lab scale downdraft gasifier and its results. The conducted study focused on the temperature distributions within the reactor and the characteristics of the dynamic temperature profile for each temperature zones during operation. OPF feedstock of one cubic inch in individual size with 15% average moisture content was utilized. An average pyrolysis zone temperature of 324°Cand an average oxidation zone temperature of 796°Cwere obtained over a total gasification period of 74 minutes. A maximum oxidation zone temperature of 952°Cwas obtained at 486 lpm inlet air flow rate and 10 kg/hr feedstock consumption rate. Stable bluish flare was produced for more than 70% of the total gasification time. The recorded temperature profiles produced closely similar patterns with the temperature profiles recorded from the gasification of woody materials. Similar temperature profile was obtained comparing the results from OPF gasification with that of woody biomass. Furthermore, the successful ignition of the syngas produced from OPF gasification ascertained that OPF indeed has a higher potential as gasification feedstock. Hence, more detailed studies need to be done for better understanding in exploiting the biomass as a high prospect alternative energy solution. In addition, a study of the effect of initial moisture content of OPF feedstock on the temperature distribution profile along the gasifier bed showed that initial moisture content of feedstock in the range of 15% gives satisfactory result, while experiment with feedstock having higher moisture content resulted in lower zone temperature values.

Towards Better Computational Models of the Balance Scale Task: A Reply to Shultz and Takane

ERIC Educational Resources Information Center

van der Maas, Han L. J.; Quinlan, Philip T.; Jansen, Brenda R. J.

2007-01-01

In contrast to Shultz and Takane [Shultz, T.R., & Takane, Y. (2007). Rule following and rule use in the balance-scale task. "Cognition", in press, doi:10.1016/j.cognition.2006.12.004.] we do not accept that the traditional Rule Assessment Method (RAM) of scoring responses on the balance scale task has advantages over latent class analysis (LCA):…

Field Testing of a Wet FGD Additive for Enhanced Mercury Control - Task 5 Full-Scale Test Results

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

Gary Blythe; MariJon Owens

2007-12-01

This Topical Report summarizes progress on Cooperative Agreement DE-FC26-04NT42309, 'Field Testing of a Wet FGD Additive'. The objective of the project is to demonstrate the use of two flue gas desulfurization (FGD) additives, Evonik Degussa Corporation's TMT-15 and Nalco Company's Nalco 8034, to prevent the re-emission of elemental mercury (Hg{sup 0}) in flue gas exiting wet FGD systems on coal-fired boilers. Furthermore, the project intends to demonstrate whether the additive can be used to precipitate most of the mercury (Hg) removed in the wet FGD system as a fine salt that can be separated from the FGD liquor and bulkmore » solid byproducts for separate disposal. The project is conducting pilot- and full-scale tests of the additives in wet FGD absorbers. The tests are intended to determine required additive dosages to prevent Hg{sup 0} re-emissions and to separate mercury from the normal FGD byproducts for three coal types: Texas lignite/Powder River Basin (PRB) coal blend, high-sulfur Eastern bituminous coal, and low-sulfur Eastern bituminous coal. The project team consists of URS Group, Inc., EPRI, Luminant Power (was TXU Generation Company LP), Southern Company, IPL (an AES company), Evonik Degussa Corporation and the Nalco Company. Luminant Power has provided the Texas lignite/PRB co-fired test site for pilot FGD tests and cost sharing. Southern Company has provided the low-sulfur Eastern bituminous coal host site for wet scrubbing tests, as well as the pilot- and full-scale jet bubbling reactor (JBR) FGD systems tested. IPL provided the high-sulfur Eastern bituminous coal full-scale FGD test site and cost sharing. Evonik Degussa Corporation is providing the TMT-15 additive, and the Nalco Company is providing the Nalco 8034 additive. Both companies are also supplying technical support to the test program as in-kind cost sharing. The project is being conducted in six tasks. Of the six project tasks, Task 1 involves project planning and Task 6 involves management and reporting. The other four tasks involve field testing on FGD systems, either at pilot or full scale. The four tasks include: Task 2 - Pilot Additive Testing in Texas Lignite Flue Gas; Task 3 - Full-scale FGD Additive Testing in High-sulfur Eastern Bituminous Flue Gas; Task 4 - Pilot Wet Scrubber Additive Tests at Plant Yates; and Task 5 - Full-scale Additive Tests at Plant Yates. The pilot-scale tests and the full-scale test using high-sulfur coal were completed in 2005 and 2006 and have been previously reported. This topical report presents the results from the Task 5 full-scale additive tests, conducted at Southern Company's Plant Yates Unit 1. Both additives were tested there.« less

Coal gasification plant

DOEpatents

Wood, Andrew

1978-01-01

A removable annular hearth member, shaped to fit over the slag outlet of a slagging gasifier, comprises a cast body of high thermal conductivity having integral coolant passageways, said passageways being formed by shaping a metal tube into a coil having an inlet and an outlet, and casting metal to the desired shape around the coil such that the inlet and outlet communicate exteriorly of the cast body.

77 FR 36519 - Amended Notice of Intent Modifying the Scope of the Environmental Impact Statement for the...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-19

... gasify the coal and petcoke to produce synthesis gas (syngas), which would then be purified to produce a... pipeline to the adjacent Elk Hills Oil Field (owned and operated by Occidental of Elk Hills, Inc. (OEHI..., Gas and Geothermal Resources (DOGGR). Pursuant to California law and a grant of primacy from the...

Modular Biopower System Providing Combined Heat and Power for DoD Installations

DTIC Science & Technology

2013-12-01

ISSUES ......................................................................................... 41 8.4 GASIFIER SHELL INTEGRITY...review of DoD installations revealed that 170 of them had access to significant amounts of woody biomass materials within a 25-mile radius and an...DESCRIPTION The technology uses a downdraft gasification process to convert the energy trapped in biomass into a synthesis gas that is cooled, filtered

Feasibility of Biomass Biodrying for Gasification Process

NASA Astrophysics Data System (ADS)

Hamidian, Arash

An important challenge of biomass gasification is the limitation of feedstock quality especially the moisture content, which plays a significant role on the performance of gasification process. Gasification requires low moisture levels (20% and less) and several reports have emphasized on the moisture as a typical problem while gasifying biomass. Moisture affects overall reaction rates in the gasifiers as a result of temperature drop and ultimately increases tar content, decreases gas yield, changes the composition of produced gas and affects the efficiency. Therefore, it is mandatory to pre-treat the biomass before gasification and reduce the moisture content to the suitable and economic level. The well-known solutions are either natural drying (not practical for commercial plants) or conventional drying technologies (have high operating costs). Biodrying is an alternative process, which uses both convective air and heat of biological reactions as a source of energy, to reduce the moisture. In the biodrying reactor heat is generated from exothermic decomposition of organic fraction of biomass and that is why the process is called "self-heating process". Employing such technology for drying biomass at pre-treatment units of gasification process returns several economic and environmental advantages to mills. In Europe, municipal waste treatment (MSW) plants use the biodrying at commercial scale to degrade a part of the biodegradable fraction of waste to generate heat and reduce the moisture content for high quality SRF (Solid Recovered Fuel) production. In Italy, wine industry is seeking to develop biodrying for energy recovery of grape wastes after fermentation and distillation, which returns economic benefits to the industry. In Canada, the development of biodrying technology for pulp and paper industry was started at Ecole polytechnique de Montreal as an option for sludge management solution. Therefore, batch biodrying reactor was successfully developed in 2004 and the pilot-scale continuous system was designed in 2010 to demonstrate the feasibility of mixed sludge biodrying for efficient combustion in biomass boilers. Mixed sludge was biodried in the reactor to 45% moisture level, which was the suitable level for boiler application. Techno-economic analysis also revealed the potential economic benefits for pulp and paper mills. However, considerable uncertainties existed in terms of feasibility of the biodrying technology for other types of biomass that are usually used in the gasification process, mainly because of low nutrient level of typical lignocellulosic biomass used as feedstock. Furthermore, the technology had not been shown to be economically viable in conjunction with gasification process at pulp and paper mills. In this work the feasibility of low-nutrient biomass biodrying was tested by experiments and techno-economic model was developed to identify the performance of biodrying process for commercial-scale application. In the economic analysis, a comprehensive approach for biodrying cost assessment was introduced that is based on the well-known approach widely used in the process industry and few sources of benefits were identified.

Modeling of indirect carbon fuel cell systems with steam and dry gasification

NASA Astrophysics Data System (ADS)

Ong, Katherine M.; Ghoniem, Ahmed F.

2016-05-01

An indirect carbon fuel cell (ICFC) system that couples coal gasification to a solid oxide fuel cell (SOFC) is a promising candidate for high efficiency stationary power. This study couples an equilibrium gasifier model to a detailed 1D MEA model to study the theoretical performance of an ICFC system run on steam or carbon dioxide. Results show that the fuel cell in the ICFC system is capable of power densities greater than 1.0 W cm-2 with H2O recycle, and power densities ranging from 0.2 to 0.4 W cm-2 with CO2 recycle. This result indicates that the ICFC system performs better with steam than with CO2 gasification as a result of the faster electro-oxidation kinetics of H2 relative to CO. The ICFC system is then shown to reach higher current densities and efficiencies than a thermally decoupled gasifier + fuel cell (G + FC) system because it does not include combustion losses associated with autothermal gasification. 55-60% efficiency is predicted for the ICFC system coupled to a bottoming cycle, making this technology competitive with other state-of-the-art stationary power candidates.

Vapor spill pipe monitor

DOEpatents

Bianchini, G.M.; McRae, T.G.

1983-06-23

The invention is a method and apparatus for continually monitoring the composition of liquefied natural gas flowing from a spill pipe during a spill test by continually removing a sample of the LNG by means of a probe, gasifying the LNG in the probe, and sending the vaporized LNG to a remote ir gas detector for analysis. The probe comprises three spaced concentric tubes surrounded by a water jacket which communicates with a flow channel defined between the inner and middle, and middle and outer tubes. The inner tube is connected to a pump for providing suction, and the probe is positioned in the LNG flow below the spill pipe with the tip oriented partly downward so that LNG is continuously drawn into the inner tube through a small orifice. The probe is made of a high thermal conductivity metal. Hot water is flowed through the water jacket and through the flow channel between the three tubes to provide the necessary heat transfer to flash vaporize the LNG passing through the inner channel of the probe. The gasified LNG is transported through a connected hose or tubing extending from the probe to a remote ir sensor which measures the gas composition.

Hydrogen sulfide capture by limestone and dolomite at elevated pressure. 1: Sorbent performance

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

Yrjas, K.P.; Zevenhoven, C.A.P.; Hupa, M.M.

1996-01-01

Sulfur emission control in fossil fuel gasification plants implies the removal of H{sub 2}S from the product gas either inside the furnace or in the gas clean-up system. In a fluidized-bed gasifier, in-bed sulfur capture can be accomplished by adding a calcium-based sorbent such as limestone or dolomite to the bend and removing the sulfur from the system with the bottom ash in the form of CaS. This work describes the H{sub 2}S uptake by a set of physically and chemically different limestones and dolomites under pressurized conditions, typically for those in a pressurized fluidized-bed gasifier (2 MPa, 950 C).more » The tests were done with a pressurized thermobalance at two p{sub CO{sub 2}} levels. Thus, the sulfidation of both calcined and uncalcined sorbents could be analyzed. The effect of p{sub H{sub 2}S} was also investigated for uncalcined limestones and half-calcined dolomites. The results are presented as conversion of CaCO{sub 3} or CaO to CaS vs time plots. The results are also compared with the sulfur capture performance of the same sorbents under pressurized combustion conditions.« less

Energy Conversion Alternatives Study (ECAS)

NASA Technical Reports Server (NTRS)

1977-01-01

ECAS compared various advanced energy conversion systems that can use coal or coal-derived fuels for baseload electric power generation. It was conducted in two phases. Phase 1 consisted of parametric studies. From these results, 11 concepts were selected for further study in Phase 2. For each of the Phase 2 systems and a common set of ground rules, performance, cost, environmental intrusion, and natural resource requirements were estimated. In addition, the contractors defined the state of the associated technology, identified the advances required, prepared preliminary research and development plans, and assessed other factors that would affect the implementation of each type of powerplant. The systems studied in Phase 2 include steam systems with atmospheric- and pressurized-fluidized-bed boilers; combined cycle gas turbine/steam systems with integrated gasifiers or fired by a semiclean, coal derived fuel; a potassium/steam system with a pressurized-fluidized-bed boiler; a closed-cycle gas turbine/organic system with a high-temperature, atmospheric-fluidized-bed furnace; a direct-coal-fired, open- cycle magnetohydrodynamic/steam system; and a molten-carbonate fuel cell/steam system with an integrated gasifier. The sensitivity of the results to changes in the ground rules and the impact of uncertainties in capital cost estimates were also examined.

Low NO sub x heavy fuel combustor concept program phase 1A gas tests

NASA Technical Reports Server (NTRS)

Cutrone, M. B.; Beebe, K. W.; Cutrone, M. B.

1982-01-01

The emissions performance of a rich lean combustor (developed for liquid fuels) for combustion of simulated coal gases ranging in heating value from 167 to 244 Btu/scf were assessed. The 244 Btu/scf gas is typical of the product gas from an oxygen blown gasifier, while the 167 Btu/scf gas is similar to that from an air blown gasifier. Although meeting NOx goals for the 167 Btu/scf gas, NOx performance of the rich lean combustor did not meet program goals with the 244 Btu/scf gas because of high thermal NOx, similar to levels expected from conventional lean burning combustors. The NOx emissions are attributed to inadequate fuel air mixing in the rich stage resulting from the design of the large central fuel nozzle delivering 71% of the total gas flow. NOx generation from NH3 was significant at ammonia concentrations significantly less tha 0.5%. These levels occur depending on fuel gas cleanup system design, However, NOx yield from ammonia injected into the fuel gas decreased rapidly with increasing ammonia level, and is projected to be less than 10% at NH3 levels of 0.5% or higher.

Evaluation of gas-particle partition of dioxins in flue gas I: evaluation of gasification behavior of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in fly ash by thermal treatment.

PubMed

Yokohama, Naoki; Otaka, Hiroaki; Minato, Ichiro; Nakata, Munetaka

2008-05-01

The gasification behavior of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in fly ash by thermal treatment has been investigated to estimate gas-particle partition in flue gas. The results obtained in thermal experiments under various conditions showed that gasification of PCDD/Fs depends on air flow rate and treatment weight of fly ash as well as treatment temperature. On the other hand, the results obtained in the thermal experiments using dioxin-free fly ash revealed that during thermal treatment, the de novo synthesis, gasification, and decomposition of PCDFs proceeded at different rates. This difference in the reaction rates indicates that thermal treatment time is also a factor in determining the gas-particle partition of PCDD/Fs in fly ash. Therefore, reasonable thermal treatment conditions were established and applied to three ash samples. For all samples, PCDD/Fs started to gasify at 350 degrees C treatment, whereas 53-98% of PCDD/F homologs gasified at 400 degrees C treatment, implying that gaseous PCDD/Fs are dominant in flue gas at temperatures in the range 350-400 degrees C regardless of particle concentration.

Ceramic applications in turbine engines

NASA Technical Reports Server (NTRS)

Byrd, J. A.; Janovicz, M. A.; Thrasher, S. R.

1981-01-01

Development testing activities on the 1900 F-configuration ceramic parts were completed, 2070 F-configuration ceramic component rig and engine testing was initiated, and the conceptual design for the 2265 F-configuration engine was identified. Fabrication of the 2070 F-configuration ceramic parts continued, along with burner rig development testing of the 2070 F-configuration metal combustor in preparation for 1132 C (2070 F) qualification test conditions. Shakedown testing of the hot engine simulator (HES) rig was also completed in preparation for testing of a spin rig-qualified ceramic-bladed rotor assembly at 1132 C (2070 F) test conditions. Concurrently, ceramics from new sources and alternate materials continued to be evaluated, and fabrication of 2070 F-configuration ceramic component from these new sources continued. Cold spin testing of the critical 2070 F-configuration blade continued in the spin test rig to qualify a set of ceramic blades at 117% engine speed for the gasifier turbine rotor. Rig testing of the ceramic-bladed gasifier turbine rotor assembly at 108% engine speed was also performed, which resulted in the failure of one blade. The new three-piece hot seal with the nickel oxide/calcium fluoride wearface composition was qualified in the regenerator rig and introduced to engine operation wiwth marginal success.

Development of Kinetics and Mathematical Models for High Pressure Gasification of Lignite-Switchgrass Blends

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

Agrawal, Pradeep K.

The overall objective of the current project was to investigate the high pressure gasification characteristics of a feed containing both coal and biomass. The two feed types differ in their ash contents and ash composition, particularly the alkali content. Gasification of a combined feed of coal and biomass has the potential for considerable synergies that might lead to a dramatic improvement in process economics and flexibility. The proposed study aimed to develop a detailed understanding of the chemistry, kinetics, and transport effects during high pressure gasification of coal-biomass blend feed. Specifically, we studied to develop: (a) an understanding of themore » catalytic effect of alkali and other inorganic species present in the biomass and coal, (b) an understanding of processing conditions under which synergistic effects of the blending of coal and biomass might be observed. This included the role of particle size, residence time, and proximity of the two feed types, (c) kinetics of high pressure gasification of individual feeds as well as the blends, and (d) development of mathematical models that incorporate kinetics and transport models to enable prediction of gasification rate at a given set of operating conditions, and (e) protocols to extend the results to other feed resources. The goal was to provide a fundamental understanding of the gasification process and guide in optimizing the configurations and design of the next generation of gasifiers. The approach undertaken was centered on two basic premises: (1) the gasification for small particles without internal mass transfer limitations can be treated as the sum of two processes in series (pyrolysis and char gasification) , and (2) the reactivity of the char generated during pyrolysis not only depends on the pressure and temperature but is also affected by the heating rates. Thus low heating rates (10-50 °C/min) typical of PTGA fail to produce char that would typically be formed at high heating rates (~10 4 °C/sec), encountered in entrained flow gasifiers. The char morphology, also a function of the heating rate, would influence the transport rates during the char gasification phase. Thus, heating rate plays a critical role through which both, pyrolysis and char gasification, are interconnected. We utilized two complementary gasification experiments: PEFR (pressurized entrained flow gasifier) and PTGA (pressurized thermo-gravimetric analyzer). The PEFR allowed us to study gasification at pressures, temperatures, and heating rates relevant for coal-biomass gasifiers. The PTGA work was useful in understanding the basic chemistry of the evolution of various gaseous species during pyrolysis. These results helped improved our understanding of the chemistry and chemical changes during pyrolysis. The role alkali metals and other inorganics in char gasification using steam and/or CO 2 was investigated. Finally, the mathematical models for char gasification without the transport effects were developed at commercial operating conditions.« less

Integration of the Mini-Sulfide Sulfite Anthraquinone (MSS-AQ) Pulping Process and Black Liquor Gasification in a Pulp Mill

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

Hasan Jameel, North Carolina State University; Adrianna Kirkman, North Carolina State University; Ravi Chandran,Thermochem Recovery International Brian Turk Research Triangle Institute

2010-01-27

As many of the recovery boilers and other pieces of large capital equipment of U.S. pulp mills are nearing the end of their useful life, the pulp and paper industry will soon need to make long-term investments in new technologies. The ability to install integrated, complete systems that are highly efficient will impact the industry’s energy use for decades to come. Developing a process for these new systems is key to the adoption of state-of-the-art technologies in the Forest Products industry. This project defined an integrated process model that combines mini-sulfide sulfite anthraquinone (MSS-AQ) pulping and black liquor gasification withmore » a proprietary desulfurization process developed by the Research Triangle Institute. Black liquor gasification is an emerging technology that enables the use of MSS-AQ pulping, which results in higher yield, lower bleaching cost, lower sulfur emissions, and the elimination of causticization requirements. The recently developed gas cleanup/absorber technology can clean the product gas to a state suitable for use in a gas turbine and also regenerate the pulping chemicals needed to for the MSS-AQ pulping process. The combination of three advanced technologies into an integrated design will enable the pulping industry to achieve a new level of efficiency, environmental performance, and cost savings. Because the three technologies are complimentary, their adoption as a streamlined package will ensure their ability to deliver maximum energy and cost savings benefits. The process models developed by this project will enable the successful integration of new technologies into the next generation of chemical pulping mills. When compared to the Kraft reference pulp, the MSS-AQ procedures produced pulps with a 10-15 % yield benefit and the ISO brightness was 1.5-2 times greater. The pulp refined little easier and had a slightly lower apparent sheet density (In both the cases). At similar levels of tear index the MSS-AQ pulps also produced a comparable tensile and burst index pulps. Product gas composition determined using computer simulations The results demonstrate that RVS-1 can effectively remove > 99.8% of the H2S present in simulated synthesis gas generated from the gasification of black liquor. This level of sulfur removal was consistent over simulated synthesis gas mixtures that contained from 6 to 9.5 vol % H2S.A significant amount of the sulfur in the simulated syngas was recovered as SO2 during regeneration. The average recovery of sulfur as SO2 was about 75%. Because these are first cycle results, this sulfur recovery is expected to improve. Developed WINGems model of the process.The total decrease in variable operating costs for the BLG process compared to the HERB was in excess of $6,200,000 per year for a mill producing 350,000 tons of pulp per year. This represents a decrease in operating cost of about $17.7/ton of oven dry pulp produced. There will be additional savings in labor and maintenance cost that has not been taken into account. The capital cost for the MSSAQ based gasifier system was estimated at $164,000,000, which is comparable to a High Efficiency Recovery Boiler. The return on investment was estimated at 4%. A gasifier replacement cannot be justified on its own, however if the recovery boiler needs to be replaced the MSSAQ gasifier system shows significantly higher savings. Before black liquor based gasifer technology can be commercialized more work is necessary. The recovery of the absorbed sulfur in the absorbent as sulfur dioxide is only 75%. This needs to be greater than 90% for economical operation. It has been suggested that as the number of cycles is increased the sulfur dioxide recovery might improve. Further research is necessary. Even though a significant amount of work has been done on a pilot scale gasifiers using liquors containing sulfur, both at low and high temperatures the lack of a commercial unit is an impediment to the implementation of the MSSAQ technology. The implementation of a commercial unit needs to be facilated before the benefits of the MSSAQ technology with ZnO absorbtion will become acceptable to the paper industry.« less

Optimization of hydrogen and syngas production from PKS gasification by using coal bottom ash.

PubMed

Shahbaz, Muhammad; Yusup, Suzana; Inayat, Abrar; Patrick, David Onoja; Pratama, Angga; Ammar, Muhamamd

2017-10-01

Catalytic steam gasification of palm kernel shell is investigated to optimize operating parameters for hydrogen and syngas production using TGA-MS setup. RSM is used for experimental design and evaluating the effect of temperature, particle size, CaO/biomass ratio, and coal bottom ash wt% on hydrogen and syngas. Hydrogen production appears highly sensitive to all factors, especially temperature and coal bottom ash wt%. In case of syngas, the order of parametric influence is: CaO/biomass>coal bottom ash wt%>temperature>particle size. The significant catalytic effect of coal bottom ash is due to the presence of Fe 2 O 3 , MgO, Al 2 O 3 , and CaO. A temperature of 692°C, coal bottom ash wt% of 0.07, CaO/biomass of 1.42, and particle size of 0.75mm are the optimum conditions for augmented yield of hydrogen and syngas. The production of hydrogen and syngas is 1.5% higher in the pilot scale gasifier as compared to TGA-MS setup. Copyright © 2017 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.

Commercial-scale demonstration of the Liquid Phase Methanol (LPMEOH{trademark}) process. Technical progress report number 9, July 1--September 30, 1996

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

NONE

The Liquid Phase Methanol (LPMEOH{trademark}) Demonstration Project at Kingsport, Tennessee, is a $213.7 million cooperative agreement between the US Department of Energy (DOE) and Air Products Liquid Phase Conversion Company, L.P. (the Partnership). The LPMEOH{trademark} Process Demonstration Unit is being built at a site located at the Eastman Chemical Company (Eastman) complex in Kingsport. The project involves the construction of an 80,000 gallons per day (260 tons per day (TPD)) methanol unit utilizing coal-derived synthesis gas from Eastman`s integrated coal gasification facility. The new equipment consists of synthesis gas feed preparation and compression facilities, the liquid phase reactor and auxiliaries,more » product distillation facilities, and utilities. This liquid phase process suspends fine catalyst particles in an inert liquid, forming a slurry. The slurry dissipates the heat of the chemical reaction away from the catalyst surface, protecting the catalyst and allowing the methanol synthesis reaction to proceed at higher rates. At the Eastman complex, the technology is being integrated with existing coal-gasifiers.« less

Hydrogen-Rich Syngas Production from Gasification and Pyrolysis of Solar Dried Sewage Sludge: Experimental and Modeling Investigations

PubMed Central

Ghrib, Amina; Friaa, Athar; Ouerghi, Aymen; Naoui, Slim; Belayouni, Habib

2017-01-01

Solar dried sewage sludge (SS) conversion by pyrolysis and gasification processes has been performed, separately, using two laboratory-scale reactors, a fixed-bed pyrolyzer and a downdraft gasifier, to produce mainly hydrogen-rich syngas. Prior to SS conversion, solar drying has been conducted in order to reduce moisture content (up to 10%). SS characterization reveals that these biosolids could be appropriate materials for gaseous products production. The released gases from SS pyrolysis and gasification present relatively high heating values (up to 9.96 MJ/kg for pyrolysis and 8.02  9.96 MJ/kg for gasification) due to their high contents of H2 (up to 11 and 7 wt%, resp.) and CH4 (up to 17 and 5 wt%, resp.). The yields of combustible gases (H2 and CH4) show further increase with pyrolysis. Stoichiometric models of both pyrolysis and gasification reactions were determined based on the global biomass formula, CαHβOγNδSε, in order to assist in the products yields optimization. PMID:28856162

Fe-based Fischer Tropsch Synthesis of biomass-derived syngas: Effect of synthesis method

Treesearch

Khiet Mai; Thomas Elder; Les Groom; James J. Spivey

2015-01-01

Two 100Fe/4Cu/4K/6Zn catalysts were prepared using two different methods: coprecipitation or impregnation methods. The effect of the preparation methods on the catalyst structure, catalytic properties, and the conversion of biomass-derived syngas via Fischer–Tropsch synthesis was investigated. Syngas was derived from gasifying Southern pine woodchips and had the...

COMPARISON OF SODIUM AND POTASSIUM CARBONATES AS LITHIUM ZIRCONATE MODIFIERS FOR HIGH-TEMPERATURE CARBON DIOXIDE CAPTURE FROM BIOMASS-DERIVED SYNTHESIS GAS

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

Olstad, J.L.; Phillips, S.D.

2009-01-01

The process of gasifi cation converts biomass into synthesis gas (syngas), which can be used to produce biofuels. Solid-phase sorbents were investigated for the removal of CO2 from a N2/CO2 gas stream using a CO2 concentration similar to that found in a biomass gasifi cation process. During the gasifying process, large amounts of carbon dioxide (CO2) are created along with the syngas. The produced CO2 must be removed before the syngas can be used for fuel synthesis and to avoid the possible formation of unwanted byproducts. A thermogravimetric analyzer was used to test the CO2 absorption rates of sorbents composedmore » of lithium zirconate (Li2ZrO3), as well as mixtures of Li2ZrO3 with potassium carbonate (K2CO3) and sodium carbonate (Na2CO3). The experimental results show that Li2ZrO3 has a low absorption rate, but sorbents containing combinations of Li2ZrO3 and the K2CO3 and Na2CO3 additives have high uptake rates. Using different proportions of K2CO3 and Na2CO3 produces varying uptake rates, so an optimization experiment was performed to obtain an improved sorbent. The CO2 absorption and regeneration stability of the solid-phase sorbents were also examined. A sorbent composed of Li2ZrO3 and 12.1 weight % Na2CO3 was shown to be stable, based on the consistent CO2 uptake rates. Sorbents prepared with Li2ZrO3, 17.6 weight % K2CO3 and 18.1 weight % Na2CO3 showed instability during regeneration cycles in air at 800 °C. Sorbent stability improved during regeneration cycles at 700 °C. Further testing of the Li2ZrO3 sorbent under actual syngas conditions, including higher pressure and composition, should be done. Once the optimum sorbent has been found, a suitable support will be needed to use the sorbent in an actual reactor.« less

Bio-Fuel Production Assisted with High Temperature Steam Electrolysis

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

Grant Hawkes; James O'Brien; Michael McKellar

2012-06-01

Two hybrid energy processes that enable production of synthetic liquid fuels that are compatible with the existing conventional liquid transportation fuels infrastructure are presented. Using biomass as a renewable carbon source, and supplemental hydrogen from high-temperature steam electrolysis (HTSE), these two hybrid energy processes have the potential to provide a significant alternative petroleum source that could reduce dependence on imported oil. The first process discusses a hydropyrolysis unit with hydrogen addition from HTSE. Non-food biomass is pyrolyzed and converted to pyrolysis oil. The pyrolysis oil is upgraded with hydrogen addition from HTSE. This addition of hydrogen deoxygenates the pyrolysis oilmore » and increases the pH to a tolerable level for transportation. The final product is synthetic crude that could then be transported to a refinery and input into the already used transportation fuel infrastructure. The second process discusses a process named Bio-Syntrolysis. The Bio-Syntrolysis process combines hydrogen from HTSE with CO from an oxygen-blown biomass gasifier that yields syngas to be used as a feedstock for synthesis of liquid synthetic crude. Conversion of syngas to liquid synthetic crude, using a biomass-based carbon source, expands the application of renewable energy beyond the grid to include transportation fuels. It can also contribute to grid stability associated with non-dispatchable power generation. The use of supplemental hydrogen from HTSE enables greater than 90% utilization of the biomass carbon content which is about 2.5 times higher than carbon utilization associated with traditional cellulosic ethanol production. If the electrical power source needed for HTSE is based on nuclear or renewable energy, the process is carbon neutral. INL has demonstrated improved biomass processing prior to gasification. Recyclable biomass in the form of crop residue or energy crops would serve as the feedstock for this process. A process model of syngas production using high temperature electrolysis and biomass gasification is presented. Process heat from the biomass gasifier is used to heat steam for the hydrogen production via the high temperature steam electrolysis process. Oxygen produced form the electrolysis process is used to control the oxidation rate in the oxygen-blown biomass gasifier.« less

Unsupervised Transfer Learning via Multi-Scale Convolutional Sparse Coding for Biomedical Applications

PubMed Central

Chang, Hang; Han, Ju; Zhong, Cheng; Snijders, Antoine M.; Mao, Jian-Hua

2017-01-01

The capabilities of (I) learning transferable knowledge across domains; and (II) fine-tuning the pre-learned base knowledge towards tasks with considerably smaller data scale are extremely important. Many of the existing transfer learning techniques are supervised approaches, among which deep learning has the demonstrated power of learning domain transferrable knowledge with large scale network trained on massive amounts of labeled data. However, in many biomedical tasks, both the data and the corresponding label can be very limited, where the unsupervised transfer learning capability is urgently needed. In this paper, we proposed a novel multi-scale convolutional sparse coding (MSCSC) method, that (I) automatically learns filter banks at different scales in a joint fashion with enforced scale-specificity of learned patterns; and (II) provides an unsupervised solution for learning transferable base knowledge and fine-tuning it towards target tasks. Extensive experimental evaluation of MSCSC demonstrates the effectiveness of the proposed MSCSC in both regular and transfer learning tasks in various biomedical domains. PMID:28129148

Dystonia rating scales: critique and recommendations

PubMed Central

Albanese, Alberto; Sorbo, Francesca Del; Comella, Cynthia; Jinnah, H.A.; Mink, Jonathan W.; Post, Bart; Vidailhet, Marie; Volkmann, Jens; Warner, Thomas T.; Leentjens, Albert F.G.; Martinez-Martin, Pablo; Stebbins, Glenn T.; Goetz, Christopher G.; Schrag, Anette

2014-01-01

Background Many rating scales have been applied to the evaluation of dystonia, but only few have been assessed for clinimetric properties. The Movement Disorders Society commissioned this task force to critique existing dystonia rating scales and place them in the clinical and clinimetric context. Methods A systematic literature review was conducted to identify rating scales that have either been validated or used in dystonia. Results Thirty six potential scales were identified. Eight were excluded because they did not meet review criteria, leaving twenty-eight scales that were critiqued and rated by the task force. Seven scales were found to meet criteria to be “recommended”: the Blepharospasm Disability Index is recommended for rating blepharospasm; the Cervical Dystonia Impact Scale and the Toronto Western Spasmodic Torticollis Rating Scale for rating cervical dystonia; the Craniocervical Dystonia Questionnaire for blepharospasm and cervical dystonia; the Voice Handicap Index (VHI) and the Vocal Performance Questionnaire (VPQ) for laryngeal dystonia; and the Fahn-Marsden Dystonia Rating Scale for rating generalized dystonia. Two “recommended” scales (VHI and VPQ) are generic scales validated on few patients with laryngeal dystonia, whereas the others are disease-specific scales. Twelve scales met criteria for “suggested” and seven scales met criteria for “listed”. All the scales are individually reviewed in the online appendix. Conclusion The task force recommends five specific dystonia scales and suggests to further validate in dystonia two recommended generic voice-disorder scales. Existing scales for oromandibular, arm and task-specific dystonia should be refined and fully assessed. Scales should be developed for body regions where no scales are available, such as lower limbs and trunk. PMID:23893443

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.

Spatial Scaling of the Profile of Selective Attention in the Visual Field.

PubMed

Gannon, Matthew A; Knapp, Ashley A; Adams, Thomas G; Long, Stephanie M; Parks, Nathan A

2016-01-01

Neural mechanisms of selective attention must be capable of adapting to variation in the absolute size of an attended stimulus in the ever-changing visual environment. To date, little is known regarding how attentional selection interacts with fluctuations in the spatial expanse of an attended object. Here, we use event-related potentials (ERPs) to investigate the scaling of attentional enhancement and suppression across the visual field. We measured ERPs while participants performed a task at fixation that varied in its attentional demands (attentional load) and visual angle (1.0° or 2.5°). Observers were presented with a stream of task-relevant stimuli while foveal, parafoveal, and peripheral visual locations were probed by irrelevant distractor stimuli. We found two important effects in the N1 component of visual ERPs. First, N1 modulations to task-relevant stimuli indexed attentional selection of stimuli during the load task and further correlated with task performance. Second, with increased task size, attentional modulation of the N1 to distractor stimuli showed a differential pattern that was consistent with a scaling of attentional selection. Together, these results demonstrate that the size of an attended stimulus scales the profile of attentional selection across the visual field and provides insights into the attentional mechanisms associated with such spatial scaling.

Recurrence quantification analysis of electroencephalograph signals during standard tasks of Waterloo-Stanford group scale of hypnotic susceptibility.

PubMed

Yargholi, Elahe'; Nasrabadi, Ali Motie

2015-01-01

The purpose of this study was to apply RQA (recurrence quantification analysis) on hypnotic electroencephalograph (EEG) signals recorded after hypnotic induction while subjects were doing standard tasks of the Waterloo-Stanford Group Scale (WSGS) of hypnotic susceptibility. Then recurrence quantifiers were used to analyse the influence of hypnotic depth on EEGs. By the application of this method, the capability of tasks to distinguish subjects of different hypnotizability levels was determined. Besides, medium hypnotizable subjects showed the highest disposition to be inducted by hypnotizer. Similarities between brain governing dynamics during tasks of the same type were also observed. The present study demonstrated two remarkable innovations; investigating the EEGs of the hypnotized as doing mental tasks of Waterloo-Stanford Group Scale (WSGS) and applying RQA on hypnotic EEGs.

Improvement of workload estimation techniques in piloting tasks

NASA Technical Reports Server (NTRS)

Wierwille, W. W.

1984-01-01

The Modified Cooper-Harper (MCH) scale has been shown to be a sensitive indicator of workload in several different types of aircrew tasks. The MCH scale, which is a 10 point scale, and five newly devised scales were examined in two different aircraft simulator experiments in which pilot loading was treated as an independent variable. The five scales included a 15 point scale, computerized versions of the MCH and 15 point scales, a scale in which the decision tree was removed, and one in which a 15 point left-to-right format was used. The results indicate that while one of the new scales may be more sensitive in a given experiment, task dependency is a problem. The MCH scale on the other hand exhibits consistent sensitivity and remains the scale recommended for general use. The MCH scale results are consistent with earlier experiments also. The results of the rating scale experiments are presented and the questionnaire results which were directed at obtaining a better understanding of the reasons for the relative sensitivity of the MCH scale and its variations are described.

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

Integration and segregation of large-scale brain networks during short-term task automatization

PubMed Central

Mohr, Holger; Wolfensteller, Uta; Betzel, Richard F.; Mišić, Bratislav; Sporns, Olaf; Richiardi, Jonas; Ruge, Hannes

2016-01-01

The human brain is organized into large-scale functional networks that can flexibly reconfigure their connectivity patterns, supporting both rapid adaptive control and long-term learning processes. However, it has remained unclear how short-term network dynamics support the rapid transformation of instructions into fluent behaviour. Comparing fMRI data of a learning sample (N=70) with a control sample (N=67), we find that increasingly efficient task processing during short-term practice is associated with a reorganization of large-scale network interactions. Practice-related efficiency gains are facilitated by enhanced coupling between the cingulo-opercular network and the dorsal attention network. Simultaneously, short-term task automatization is accompanied by decreasing activation of the fronto-parietal network, indicating a release of high-level cognitive control, and a segregation of the default mode network from task-related networks. These findings suggest that short-term task automatization is enabled by the brain's ability to rapidly reconfigure its large-scale network organization involving complementary integration and segregation processes. PMID:27808095

Novel Surface Modification Method for Ultrasupercritical Coal-Fired Boilers

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

Xiao, T. Danny

2013-05-22

US Department of Energy seeks an innovative coating technology for energy production to reduce the emission of SOx, NOx, and CO2 toxic gaseous species. To realize this need, Inframat Corporation (IMC) proposed an SPS thermal spray coating technique to produce ultrafine/nanocoatings that can be deposited onto the surfaces of high temperature boiler tubes, so that higher temperatures of boiler operation becomes possible, leading to significantly reduced emission of toxic gaseous species. It should be noted that the original PI was Dr. Xinqing Ma, who after 1.5 year conducting this project left Inframat in December, 2008. Thus, the PI was transferredmore » to Dr. Danny Xiao, who originally co-authored the proposal with Dr. Ma, in order to carry the project into a completion. Phase II Objectives: The proposed technology has the following attributes, including: (1). Dispersion of a nanoparticle or alloyed particle in a solvent to form a uniform slurry feedstock; (2). Feeding of the slurry feedstock into a thermal spray flame, followed by deposition of the slurry feedstock onto substrates to form tenacious nanocoatings; (3). High coating performance: including high bonding strength, and high temperature service life in the temperature range of 760oC/1400oF. Following the above premises, our past Phase I project has demonstrated the feasibility in small scale coatings on boiler substrates. The objective of this Phase II project was to focus on scale-up the already demonstrated Phase I work for the fabrication of SPS coatings that can satisfy DOE's emission reduction goals for energy production operations. Specifically, they are: (1). Solving engineering problems to scale-up the SPS-HVOF delivery system to a prototype production sub-delivery system; (2). Produce ultrafine/nanocoatings using the scale-up prototype system; (3). Demonstrate the coated components using the scale-up device having superior properties. Proposed Phase II Tasks: In the original Phase II proposal, we have six (6) technical tasks plus one (1) reporting task, as described below: Task 1 Scale-up and optimize the SPS process; Task 2 Coating design and fabrication with desired microstructure; Task 3 Evaluate microstructure and physical properties; Task 4 Test performance of long-term corrosion and erosion; Task 5 Test mechanical property and reliability; Task 6 Coating of a prototype boiler tube for evaluation; Task 7 Reporting task. To date, we have already completed all the technical tasks of 1 through 6. Major Phase II Achievements: In this four (4) year working period, Inframat had spent great effort to complete the proposed tasks. The project had been completed; the goals have been accomplished. Major achievements obtained include: (1). Developed a prototype scale-up slurry feedstock delivery system for thermal spray coatings; (2). Successfully coated high performance coatings using this scale-up slurry delivery system; (3). Commercial applications in energy efficiency and clean energy components have been developed using this newly fabricated slurry feedstock delivery system.« less

The Integration of Gasification Systems with Gas Engine to Produce Electrical Energy from Biomass

NASA Astrophysics Data System (ADS)

Siregar, K.; Alamsyah, R.; Ichwana; Sholihati; Tou, S. B.; Siregar, N. C.

2018-05-01

The need for energy especially biomass-based renewable energy continues to increase in Indonesia. The objective of this research was to design downdraft gasifier machine with high content of combustible gas on gas engine. Downdraft gasifier machine was adjusted with the synthetic gas produced from biomass. Besides that, the net energy ratio, net energy balance, renewable index, economic analysis, and impact assessment also been conducted. Gas engine that was designed in this research had been installed with capacity of 25 kW with diameter and height of reactor were 900 mm and 1000 mm respectively. The method used here were the design the Detailed Engineering Design (DED), assembly, and performance test of gas engine. The result showed that gas engine for biomass can be operated for 8 hours with performance engine of 84% and capacity of 25 kW. Net energy balance, net energy ratio, and renewable index was 30 MJ/kWh-electric; 0.89; 0.76 respectively. The value of GHG emission of Biomass Power Generation is 0.03 kg-CO2eq/MJ. Electrical production cost for Biomass Power Generation is about Rp.1.500,/kWh which is cheaper than Solar Power Generation which is about of Rp. 3.300,-/kWh.

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

Steven Buckley; Reza Gharavi; Marco Leon

The overall goal of this project has been to develop a highly sensitive, multiplexed TDL-based sensor for CO{sub 2}, CO, H{sub 2}O (and temperature), CH{sub 4}, H{sub 2}S, and NH{sub 3}. Such a sensor was designed with so-called 'plug-and-play' characteristics to accommodate additional sensors, and provided in situ path-integrated measurements indicative of average concentrations at speeds suitable for direct gasifier control. The project developed the sensor and culminated in a real-world test of the underlying technology behind the sensor. During the project, new underlying measurements of spectroscopic constants for all of the gases of interest performed, in custom cells builtmore » for the project. The envisioned instrument was built from scratch from component lasers, fiber optics, amplifier blocks, detectors, etc. The sensor was tested for nearly a week in an operational power plant. The products of this research are expected to have a direct impact on gasifier technology and the production of high-quality syngas, with substantial broader application to coal and other energy systems. This report is the final technical report on project DE-FG26-04NT42172. During the project we completed all of the milestones planned in the project, with a modification of milestone (7) required due to lack of funding and personnel.« less

Impact of feedstock properties and operating conditions on sewage sludge gasification in a fixed bed gasifier.

PubMed

Werle, Sebastian

2014-10-01

This work presents results of experimental studies on the gasification process of granulated sewage sludge in a laboratory fixed bed gasifier. Nowadays, there is a large and pressing need for the development of thermal methods for sewage sludge disposal. Gasification is an example of thermal method that has several advantages over the traditional combustion. Gasification leads to a combustible gas, which can be used for the generation of useful forms of final energy. It can also be used in processes, such as the drying of sewage sludge directly in waste treatment plant. In the present work, the operating parameters were varied over a wide range. Parameters, such as air ratio λ = 0.12 to 0.27 and the temperature of air preheating t = 50 °C to 250 °C, were found to influence temperature distribution and syngas properties. The results indicate that the syngas heating value decreases with rising air ratio for all analysed cases: i.e. for both cold and preheated air. The increase in the concentration of the main combustible components was accompanied by a decrease in the concentration of carbon dioxide. Preheating of the gasification agent supports the endothermic gasification and increases hydrogen and carbon monoxide production. © The Author(s) 2014.

Detailed model for practical pulverized coal furnaces and gasifiers

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

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

1989-08-01

This study has been supported by a consortium of nine industrial and governmental sponsors. Work was initiated on May 1, 1985 and completed August 31, 1989. The central objective of this work was to develop, evaluate and apply a practical combustion model for utility boilers, industrial furnaces and gasifiers. Key accomplishments have included: Development of an advanced first-generation, computer model for combustion in three dimensional furnaces; development of a new first generation fouling and slagging submodel; detailed evaluation of an existing NO{sub x} submodel; development and evaluation of an improved radiation submodel; preparation and distribution of a three-volume final report:more » (a) Volume 1: General Technical Report; (b) Volume 2: PCGC-3 User's Manual; (c) Volume 3: Data Book for Evaluation of Three-Dimensional Combustion Models; and organization of a user's workshop on the three-dimensional code. The furnace computer model developed under this study requires further development before it can be applied generally to all applications; however, it can be used now by specialists for many specific applications, including non-combusting systems and combusting geseous systems. A new combustion center was organized and work was initiated to continue the important research effort initiated by this study. 212 refs., 72 figs., 38 tabs.« less

Gasification of black liquor

DOEpatents

Kohl, A.L.

1987-07-28

A concentrated aqueous black liquor containing carbonaceous material and alkali metal sulfur compounds is treated in a gasifier vessel containing a relatively shallow molten salt pool at its bottom to form a combustible gas and a sulfide-rich melt. The gasifier vessel, which is preferably pressurized, has a black liquor drying zone at its upper part, a black liquor solids gasification zone located below the drying zone, and a molten salt sulfur reduction zone which comprises the molten salt pool. A first portion of an oxygen-containing gas is introduced into the gas space in the gasification zone immediately above the molten salt pool. The remainder of the oxygen-containing gas is introduced into the molten salt pool in an amount sufficient to cause gasification of carbonaceous material entering the pool from the gasification zone but not sufficient to create oxidizing conditions in the pool. The total amount of the oxygen-containing gas introduced both above the pool and into the pool constitutes between 25 and 55% of the amount required for complete combustion of the black liquor feed. A combustible gas is withdrawn from an upper portion of the drying zone, and a melt in which the sulfur content is predominantly in the form of alkali metal sulfide is withdrawn from the molten salt sulfur reduction zone. 2 figs.

Gasification of black liquor

DOEpatents

Kohl, Arthur L.

1987-07-28

A concentrated aqueous black liquor containing carbonaceous material and alkali metal sulfur compounds is treated in a gasifier vessel containing a relatively shallow molten salt pool at its bottom to form a combustible gas and a sulfide-rich melt. The gasifier vessel, which is preferably pressurized, has a black liquor drying zone at its upper part, a black liquor solids gasification zone located below the drying zone, and a molten salt sulfur reduction zone which comprises the molten salt pool. A first portion of an oxygen-containing gas is introduced into the gas space in the gasification zone immediatley above the molten salt pool. The remainder of the oxygen-containing gas is introduced into the molten salt pool in an amount sufficient to cause gasification of carbonaceous material entering the pool from the gasification zone but not sufficient to create oxidizing conditions in the pool. The total amount of the oxygen-containing gas introduced both above the pool and into the pool constitutes between 25 and 55% of the amount required for complete combustion of the black liquor feed. A combustible gas is withdrawn from an upper portion of the drying zone, and a melt in which the sulfur content is predominantly in the form of alkali metal sulfide is withdrawn from the molten salt sulfur reduction zone.

Phosphorus leaching from soils amended with thermally gasified piggery waste ash.

PubMed

Kuligowski, Ksawery; Poulsen, Tjalfe Gorm

2009-09-01

In regions with intensive livestock farming, thermal treatment for local energy extraction from the manure and export of the P rich ash as a fertilizer has gained interest. One of the main risks associated with P fertilizers is eutrophication of water bodies. In this study P and K mobility in ash from anaerobically digested, thermally gasified (GA) and incinerated (IA) piggery waste has been tested using water loads ranging from 0.1 to 200 ml g(-1). Leaching of P from soil columns amended with GA was investigated for one P application rate (205 kg P ha(-1) corresponding to 91 mg P kg(-1) soil dry matter) as a function of precipitation rate (9.5 and 2.5 mm h(-1)), soil type (Jyndevad agricultural soil and sand), amount of time elapsed between ash amendment and onset of precipitation (0 and 5 weeks) and compared to leaching from soils amended with a commercial fertilizer (Na(2)HPO(4)). Water soluble P in GA and IA constituted 0.04% and 0.8% of total ash P. Ash amended soil released much less P (0.35% of total P applied in sand) than Na(2)HPO(4) (97% and 12% of total P applied in Jyndevad and sand, respectively).

The effect of single-task and dual-task balance exercise programs on balance performance in adults with osteoporosis: a randomized controlled preliminary trial.

PubMed

Konak, H E; Kibar, S; Ergin, E S

2016-11-01

Osteoporosis is a serious disease characterized by muscle weakness in the lower extremities, shortened length of trunk, and increased dorsal kyphosis leading to poor balance performance. Although balance impairment increases in adults with osteoporosis, falls and fall-related injuries have been shown to occur mainly during the dual-task performance. Several studies have shown that dual-task performance was improved with specific repetitive dual-task exercises. The aims of this study were to compare the effect of single- and dual-task balance exercise programs on static balance, dynamic balance, and activity-specific balance confidence in adults with osteoporosis and to assess the effectiveness of dual-task balance training on gait speed under dual-task conditions. Older adults (N = 42) (age range, 45-88 years) with osteoporosis were randomly assigned into two groups. Single-task balance training group was given single-task balance exercises for 4 weeks, whereas dual-task balance training group received dual-task balance exercises. Participants received 45-min individualized training session, three times a week. Static balance was evaluated by one-leg stance (OLS) and a kinesthetic ability trainer (KAT) device. Dynamic balance was measured by the Berg Balance Scale (BBS), Time Up and Go (TUG) test, and gait speed. Self-confidence was assessed with the Activities-specific Balance Confidence (ABC-6) scale. Assessments were performed at baseline and after the 4-week program. At the end of the treatment periods, KAT score, BBS score, time in OLS and TUG, gait speeds under single- and dual-task conditions, and ABC-6 scale scores improved significantly in all patients (p < 0.05). However, BBS and gait speeds under single- and dual-task conditions showed significantly greater improvement in the dual-task balance training group than in the single-task balance training group (p < 0.05). ABC-6 scale scores improved more in the single-task balance training group than in the dual-task balance training group (p < 0.05). A 4-week single- and dual-task balance exercise programs are effective in improving static balance, dynamic balance, and balance confidence during daily activities in older adults with osteoporosis. However, single- and dual-task gait speeds showed greater improvement following the application of a specific type of dual-task exercise programs. 24102014-2.

The Psychometric Anatomy of Two Unidimensional Workload Scales

DTIC Science & Technology

2004-10-01

for the subjects to complete. In Task I, the subject takes a deck of shuffled flashcards , each card having one of the scale’s descriptors printed on...workload scale. The size of the flashcards is somewhat arbitrary, but 2.5 by 3 inches should accommodate the length of most descriptors. Task I is

Using Mental Transformation Strategies for Spatial Scaling: Evidence from a Discrimination Task

ERIC Educational Resources Information Center

Möhring, Wenke; Newcombe, Nora S.; Frick, Andrea

2016-01-01

Spatial scaling, or an understanding of how distances in different-sized spaces relate to each other, is fundamental for many spatial tasks and relevant for success in numerous professions. Previous research has suggested that adults use mental transformation strategies to mentally scale spatial input, as indicated by linear increases in response…

Chaos-chaos transition of left hemisphere EEGs during standard tasks of Waterloo-Stanford Group Scale of hypnotic susceptibility.

PubMed

Yargholi, Elahe'; Nasrabadi, Ali Motie

2015-01-01

A recent study, recurrence quantification analysis of EEG signals during standard tasks of Waterloo-Stanford Group Scale of hypnotic susceptibility investigated recurrence quantifiers (RQs) of hypnotic electroencephalograph (EEG) signals recorded after hypnotic induction while subjects were doing standard tasks of Waterloo-Stanford Group Scale (WSGS) of hypnotic susceptibility to distinguish subjects of different hypnotizability levels. Following the same analysis, the current study determines the capability of different RQs to distinguish subjects of low, medium and high hypnotizability level and studies the influence of hypnotizability level on underlying dynamic of tasks. Besides, EEG channels were sorted according to the number of their RQs, which differed significantly among subjects of different hypnotizability levels. Another valuable result was determination of major brain regions in observing significant differences in various task types (ideomotors, hallucination, challenge and memory).

The mind behind the message: advancing theory-of-mind scales for typically developing children, and those with deafness, autism, or Asperger syndrome.

PubMed

Peterson, Candida C; Wellman, Henry M; Slaughter, Virginia

2012-01-01

Children aged 3-12 years (n = 184) with typical development, deafness, autism, or Asperger syndrome took a series of theory-of-mind (ToM) tasks to confirm and extend previous developmental scaling evidence. A new sarcasm task, in the format of H. M. Wellman and D. Liu's (2004) 5-step ToM Scale, added a statistically reliable 6th step to the scale for all diagnostic groups. A key previous finding, divergence in task sequencing for children with autism, was confirmed. Comparisons among diagnostic groups, controlling age, and language ability, showed that typical developers mastered the 6 ToM steps ahead of each of the 3 disabled groups, with implications for ToM theories. The final (sarcasm) task challenged even nondisabled 9-year-olds, demonstrating the new scale's sensitivity to post-preschool ToM growth. © 2012 The Authors. Child Development © 2012 Society for Research in Child Development, Inc.

Label reading, numeracy and Food&Nutrition involvement.

PubMed

Mulders, Maria Dgh; Corneille, O; Klein, O

2018-06-07

The purpose of this study was to investigate objective performance on a nutrition label comprehension task, and the influence of numeracy and food-related involvement on this performance level. A pilot study (n = 45) was run to prepare the scales in French. For the main study (n = 101), participants provided demographic information and answered the nutrition label survey, the short numeracy scale and two different food-related involvement scales (i.e. the food involvement scale and the nutrition involvement scale). Both studies were conducted online, and consent was obtained from all participants. Participants answered correctly only two-thirds of the nutrition label task items. Numeracy and food involvement scores were positively correlated with performance on this task. Finally, food involvement interacted with numeracy. Specifically, people scoring low in numeracy performed generally more poorly on the task, but if they had high food involvement scores, their performance increased. This suggests that high food-related motivation may compensate for poor numeracy skills when dealing with nutrition labels. Copyright © 2018. Published by Elsevier Ltd.

Complexity Measures, Task Type, and Analytic Evaluations of Speaking Proficiency in a School-Based Assessment Context

ERIC Educational Resources Information Center

Gan, Zhengdong

2012-01-01

This study, which is part of a large-scale study of using objective measures to validate assessment rating scales and assessment tasks in a high-profile school-based assessment initiative in Hong Kong, examined how grammatical complexity measures relate to task type and analytic evaluations of students' speaking proficiency in a classroom-based…

A Teacher-Report Measure of Children's Task-Avoidant Behavior: A Validation Study of the Behavioral Strategy Rating Scale

ERIC Educational Resources Information Center

Zhang, Xiao; Nurmi, Jari-Erik; Kiuru, Noona; Lerkkanen, Marja-Kristiina; Aunola, Kaisa

2011-01-01

This study aims to validate a teacher-report measure of children's task-avoidant behavior, namely the Behavioral Strategy Rating Scale (BSRS), in a sample of 352 Finnish children. In each of the four waves from Kindergarten to Grade 2, teachers rated children's task-avoidant behavior using the BSRS, children completed reading and mathematics…

Explorative Function in Williams Syndrome Analyzed through a Large-Scale Task with Multiple Rewards

ERIC Educational Resources Information Center

Foti, F.; Petrosini, L.; Cutuli, D.; Menghini, D.; Chiarotti, F.; Vicari, S.; Mandolesi, L.

2011-01-01

This study aimed to evaluate spatial function in subjects with Williams syndrome (WS) by using a large-scale task with multiple rewards and comparing the spatial abilities of WS subjects with those of mental age-matched control children. In the present spatial task, WS participants had to explore an open space to search nine rewards placed in…

Are we under-utilizing the talents of primary care personnel? A job analytic examination

PubMed Central

Hysong, Sylvia J; Best, Richard G; Moore, Frank I

2007-01-01

Background Primary care staffing decisions are often made unsystematically, potentially leading to increased costs, dissatisfaction, turnover, and reduced quality of care. This article aims to (1) catalogue the domain of primary care tasks, (2) explore the complexity associated with these tasks, and (3) examine how tasks performed by different job titles differ in function and complexity, using Functional Job Analysis to develop a new tool for making evidence-based staffing decisions. Methods Seventy-seven primary care personnel from six US Department of Veterans Affairs (VA) Medical Centers, representing six job titles, participated in two-day focus groups to generate 243 unique task statements describing the content of VA primary care. Certified job analysts rated tasks on ten dimensions representing task complexity, skills, autonomy, and error consequence. Two hundred and twenty-four primary care personnel from the same clinics then completed a survey indicating whether they performed each task. Tasks were catalogued using an adaptation of an existing classification scheme; complexity differences were tested via analysis of variance. Results Objective one: Task statements were categorized into four functions: service delivery (65%), administrative duties (15%), logistic support (9%), and workforce management (11%). Objective two: Consistent with expectations, 80% of tasks received ratings at or below the mid-scale value on all ten scales. Objective three: Service delivery and workforce management tasks received higher ratings on eight of ten scales (multiple functional complexity dimensions, autonomy, human error consequence) than administrative and logistic support tasks. Similarly, tasks performed by more highly trained job titles received higher ratings on six of ten scales than tasks performed by lower trained job titles. Contrary to expectations, the distribution of tasks across functions did not significantly vary by job title. Conclusion Primary care personnel are not being utilized to the extent of their training; most personnel perform many tasks that could reasonably be performed by personnel with less training. Primary care clinics should use evidence-based information to optimize job-person fit, adjusting clinic staff mix and allocation of work across staff to enhance efficiency and effectiveness. PMID:17397534

Field Testing of a Wet FGD Additive for Enhanced Mercury Control

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

Gary Blythe; MariJon Owens

2007-12-31

This document is the final report for DOE-NETL Cooperative Agreement DE-FC26-04NT42309, 'Field Testing of a Wet FGD Additive'. The objective of the project has been to demonstrate the use of two flue gas desulfurization (FGD) additives, Evonik Degussa Corporation's TMT-15 and Nalco Company's Nalco 8034, to prevent the re-emission of elemental mercury (Hg{sup 0}) in flue gas exiting wet FGD systems on coal-fired boilers. Furthermore, the project was intended to demonstrate whether such additives can be used to precipitate most of the mercury (Hg) removed in the wet FGD system as a fine salt that can be separated from themore » FGD liquor and bulk solid byproducts for separate disposal. The project involved pilot- and full-scale tests of the additives in wet FGD absorbers. The tests were intended to determine required additive dosages to prevent Hg{sup 0} re-emissions and to separate mercury from the normal FGD byproducts for three coal types: Texas lignite/Powder River Basin (PRB) coal blend, high-sulfur Eastern bituminous coal, and low-sulfur Eastern bituminous coal. The project team consists of URS Group, Inc., EPRI, Luminant Power (was TXU Generation Company LP), Southern Company, IPL (an AES company), Evonik Degussa Corporation and the Nalco Company. Luminant Power provided the Texas lignite/PRB co-fired test site for pilot FGD tests and project cost sharing. Southern Company provided the low-sulfur Eastern bituminous coal host site for wet scrubbing tests, the pilot- and full-scale jet bubbling reactor (JBR) FGD systems tested, and project cost sharing. IPL provided the high-sulfur Eastern bituminous coal full-scale FGD test site and cost sharing. Evonik Degussa Corporation provided the TMT-15 additive, and the Nalco Company provided the Nalco 8034 additive. Both companies also supplied technical support to the test program as in-kind cost sharing. The project was conducted in six tasks. Of the six tasks, Task 1 involved project planning and Task 6 involved management and reporting. The other four tasks involved field testing on FGD systems, either at pilot or full scale. These four tasks included: Task 2 - Pilot Additive Testing in Texas Lignite Flue Gas; Task 3 - Full-scale FGD Additive Testing in High-sulfur Eastern Bituminous Flue Gas; Task 4 - Pilot Wet Scrubber Additive Tests at Plant Yates; and Task 5 - Full-scale Additive Tests at Plant Yates. The pilot-scale tests were completed in 2005 and the full-scale test using high-sulfur coal was completed in 2006; only the TMT-15 additive was tested in these efforts. The Task 5 full-scale additive tests conducted at Southern Company's Plant Yates Unit 1 were completed in 2007, and both the TMT-15 and Nalco 8034 additives were tested.« less

Age-related Multiscale Changes in Brain Signal Variability in Pre-task versus Post-task Resting-state EEG.

PubMed

Wang, Hongye; McIntosh, Anthony R; Kovacevic, Natasa; Karachalios, Maria; Protzner, Andrea B

2016-07-01

Recent empirical work suggests that, during healthy aging, the variability of network dynamics changes during task performance. Such variability appears to reflect the spontaneous formation and dissolution of different functional networks. We sought to extend these observations into resting-state dynamics. We recorded EEG in young, middle-aged, and older adults during a "rest-task-rest" design and investigated if aging modifies the interaction between resting-state activity and external stimulus-induced activity. Using multiscale entropy as our measure of variability, we found that, with increasing age, resting-state dynamics shifts from distributed to more local neural processing, especially at posterior sources. In the young group, resting-state dynamics also changed from pre- to post-task, where fine-scale entropy increased in task-positive regions and coarse-scale entropy increased in the posterior cingulate, a key region associated with the default mode network. Lastly, pre- and post-task resting-state dynamics were linked to performance on the intervening task for all age groups, but this relationship became weaker with increasing age. Our results suggest that age-related changes in resting-state dynamics occur across different spatial and temporal scales and have consequences for information processing capacity.

The mind behind the message: Advancing theory of mind scales for typically developing children, and those with deafness, autism, or Asperger Syndrome

PubMed Central

Peterson, Candida C.; Wellman, Henry M.; Slaughter, Virginia

2013-01-01

Children aged 3 to 12 years (n=184) with typical development, deafness, autism or Asperger Syndrome took a series of theory-of-mind (ToM) tasks to confirm and extend previous developmental scaling evidence. A new sarcasm task, in the format of Wellman and Liu’s (2004) 5-step ToM scale, added a statistically reliable sixth step to the scale for all diagnostic groups. A key previous finding, divergence in task sequencing for children with autism, was confirmed. Comparisons among diagnostic groups, controlling age and language ability, showed that typical developers mastered the six ToM steps ahead of each of the three disabled groups, with implications for ToM theories. The final (sarcasm) task challenged even nondisabled 9-year-olds, demonstrating the new scale’s sensitivity to post-preschool ToM growth. PMID:22304467

Incremental Validity of the Subscales of the Emotional Regulation Related to Testing Scale for Predicting Test Anxiety

ERIC Educational Resources Information Center

Feldt, Ronald; Lindley, Kyla; Louison, Rebecca; Roe, Allison; Timm, Megan; Utinkova, Nikola

2015-01-01

The Emotional Regulation Related to Testing Scale (ERT Scale) assesses strategies students use to regulate emotion related to academic testing. It has four dimensions: Cognitive Appraising Processes (CAP), Emotion-Focusing Processes (EFP), Task-Focusing Processes (TFP), and Regaining Task-Focusing Processes (RTFP). The study examined the factor…

78 FR 11632 - Record of Decision for Land Acquisition and Airspace Establishment To Support Large-Scale Marine...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-19

... Establishment To Support Large-Scale Marine Air Ground Task Force Live- Fire and Maneuver Training at the Marine...), announces its decision to establish a large-scale Marine Air Ground Task Force (MAGTF) training facility at... through the Federal Aviation Administration the establishment and modification of military Special Use...

Self-Relevant Disgust and Self-Harm Urges in Patients with Borderline Personality Disorder and Depression: A Pilot Study with a Newly Designed Psychological Challenge

PubMed Central

Abdul-Hamid, Sawsan; Denman, Chess; Dudas, Robert B.

2014-01-01

Background Borderline personality disorder (BPD) is a common psychiatric condition associated with self-harm. Self-harm is poorly understood and there is currently no treatment for acute presentations with self-harm urges. Objectives By using a new task (Self-relevant Task; SRT), to explore emotions related to one's own person (PERSON task) and body (BODY task), to study the correlations of these emotions, specifically disgust, with self-harm urge level changes, and to test the task's potential to be developed into an experimental model of self-harming for treatment trials. Methods 17 BPD patients, 27 major depressive disorder (MDD) patients, and 25 healthy volunteers performed the SRT. Emotion labels were extracted from task narratives and disgust and self-harm urge level changes measured by visual analogue scales. We used validated rating scales to measure symptom severity. Results The SRT was effective at inducing negative emotions and self-harm urge changes. Self-harm urge changes correlated with borderline symptom severity. Post-task disgust levels on the visual analogue scales were higher in BPD patients than in healthy controls in the PERSON task, and higher than in both control groups in the BODY task. Changes in disgust levels during the task were significantly greater in the patient groups. Post-task disgust levels or changes in disgust were not associated with self-harm urge changes (except the latter in MDD in the PERSON task), but self-harm urge changes and disgust (but no other emotion) narrative labels were on a whole sample level. Conclusion Although associations with the analogue scale measures were not significant, self-disgust reported in the narrative of patients may be associated with a higher probability of self-harm urges. Further research with larger sample sizes is needed to confirm this relationship and to examine whether reducing self-disgust could reduce self-harm urges. The SRT was effective and safe, and could be standardized for experimental studies. PMID:24956153

Interplay between Functional Connectivity and Scale-Free Dynamics in Intrinsic fMRI Networks

PubMed Central

Ciuciu, Philippe; Abry, Patrice; He, Biyu J.

2014-01-01

Studies employing functional connectivity-type analyses have established that spontaneous fluctuations in functional magnetic resonance imaging (fMRI) signals are organized within large-scale brain networks. Meanwhile, fMRI signals have been shown to exhibit 1/f-type power spectra – a hallmark of scale-free dynamics. We studied the interplay between functional connectivity and scale-free dynamics in fMRI signals, utilizing the fractal connectivity framework – a multivariate extension of the univariate fractional Gaussian noise model, which relies on a wavelet formulation for robust parameter estimation. We applied this framework to fMRI data acquired from healthy young adults at rest and performing a visual detection task. First, we found that scale-invariance existed beyond univariate dynamics, being present also in bivariate cross-temporal dynamics. Second, we observed that frequencies within the scale-free range do not contribute evenly to inter-regional connectivity, with a systematically stronger contribution of the lowest frequencies, both at rest and during task. Third, in addition to a decrease of the Hurst exponent and inter-regional correlations, task performance modified cross-temporal dynamics, inducing a larger contribution of the highest frequencies within the scale-free range to global correlation. Lastly, we found that across individuals, a weaker task modulation of the frequency contribution to inter-regional connectivity was associated with better task performance manifesting as shorter and less variable reaction times. These findings bring together two related fields that have hitherto been studied separately – resting-state networks and scale-free dynamics, and show that scale-free dynamics of human brain activity manifest in cross-regional interactions as well. PMID:24675649

Scale invariant rearrangement of resting state networks in the human brain under sustained stimulation.

PubMed

Tommasin, Silvia; Mascali, Daniele; Moraschi, Marta; Gili, Tommaso; Assan, Ibrahim Eid; Fratini, Michela; DiNuzzo, Mauro; Wise, Richard G; Mangia, Silvia; Macaluso, Emiliano; Giove, Federico

2018-06-14

Brain activity at rest is characterized by widely distributed and spatially specific patterns of synchronized low-frequency blood-oxygenation level-dependent (BOLD) fluctuations, which correspond to physiologically relevant brain networks. This network behaviour is known to persist also during task execution, yet the details underlying task-associated modulations of within- and between-network connectivity are largely unknown. In this study we exploited a multi-parametric and multi-scale approach to investigate how low-frequency fluctuations adapt to a sustained n-back working memory task. We found that the transition from the resting state to the task state involves a behaviourally relevant and scale-invariant modulation of synchronization patterns within both task-positive and default mode networks. Specifically, decreases of connectivity within networks are accompanied by increases of connectivity between networks. In spite of large and widespread changes of connectivity strength, the overall topology of brain networks is remarkably preserved. We show that these findings are strongly influenced by connectivity at rest, suggesting that the absolute change of connectivity (i.e., disregarding the baseline) may be not the most suitable metric to study dynamic modulations of functional connectivity. Our results indicate that a task can evoke scale-invariant, distributed changes of BOLD fluctuations, further confirming that low frequency BOLD oscillations show a specialized response and are tightly bound to task-evoked activation. Copyright © 2018. Published by Elsevier Inc.

Gas distributor for fluidized bed coal gasifier

DOEpatents

Worley, Arthur C.; Zboray, James A.

1980-01-01

A gas distributor for distributing high temperature reaction gases to a fluidized bed of coal particles in a coal gasification process. The distributor includes a pipe with a refractory reinforced lining and a plurality of openings in the lining through which gas is fed into the bed. These feed openings have an expanding tapered shape in the downstream or exhaust direction which aids in reducing the velocity of the gas jets as they enter the bed.

Carbon-On-Carbon Manufacturing

NASA Technical Reports Server (NTRS)

Mungas, Gregory S. (Inventor); Buchanan, Larry (Inventor); Banzon, Jr., Jose T. (Inventor)

2017-01-01

The presently disclosed technology relates to carbon-on-carbon (C/C) manufacturing techniques and the resulting C/C products. One aspect of the manufacturing techniques disclosed herein utilizes two distinct curing operations that occur at different times and/or using different temperatures. The resulting C/C products are substantially non-porous, even though the curing operation(s) substantially gasify a liquid carbon-entrained filler material that saturates a carbon fabric that makes up the C/C products.

Production of JP-8-Based Hydrogen and Advanced Tactical Fuels for the U.S. Military

DTIC Science & Technology

2009-09-24

system in pilot plant gasifier. Table 14. Summary of the Gravimetric Analysis of Tar (heavier than benzene) and PM Sampled from Hot and Cold Side...thorough technoeconomic assessment and analysis of available feedstocks prior to a candidate biomass being selected for energy generation or product...application will also require a thorough technoeconomic assessment and analysis of available feedstocks prior to a candidate biomass being selected

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

Not Available

The SPS Concept Development and Evaluation Program includes a comparative assessment. An early first step in the assessment process is the selection and characterization of alternative technologies. This document describes the cost and performance (i.e., technical and environmental) characteristics of six central station energy alternatives: (1) conventional coal-fired powerplant; (2) conventional light water reactor (LWR); (3) combined cycle powerplant with low-Btu gasifiers; (4) liquid metal fast breeder reactor (LMFBR); (5) photovoltaic system without storage; and (6) fusion reactor.

Enabling In-Theater Processes for Indigenous, Recycled, and Reclaimed Material Manufacturing

DTIC Science & Technology

2015-12-01

compression testing was accomplished on this material alone, as well as infused aluminum foam . The LTS-infused aluminum foam showed an interesting...protection against blast threats. 15. SUBJECT TERMS indigenous manufacturing, concrete alternatives, nondestructive evaluation, metallic foam testing...of Blocks on a FOB: CO2 Supply 11 6.7 Metallic Foam Infiltration with LTS Ceramic 12 6.8 LTS Ceramic Made with Gasified Char 21 6.9 Micro Auto

Activity flow over resting-state networks shapes cognitive task activations.

PubMed

Cole, Michael W; Ito, Takuya; Bassett, Danielle S; Schultz, Douglas H

2016-12-01

Resting-state functional connectivity (FC) has helped reveal the intrinsic network organization of the human brain, yet its relevance to cognitive task activations has been unclear. Uncertainty remains despite evidence that resting-state FC patterns are highly similar to cognitive task activation patterns. Identifying the distributed processes that shape localized cognitive task activations may help reveal why resting-state FC is so strongly related to cognitive task activations. We found that estimating task-evoked activity flow (the spread of activation amplitudes) over resting-state FC networks allowed prediction of cognitive task activations in a large-scale neural network model. Applying this insight to empirical functional MRI data, we found that cognitive task activations can be predicted in held-out brain regions (and held-out individuals) via estimated activity flow over resting-state FC networks. This suggests that task-evoked activity flow over intrinsic networks is a large-scale mechanism explaining the relevance of resting-state FC to cognitive task activations.

Activity flow over resting-state networks shapes cognitive task activations

PubMed Central

Cole, Michael W.; Ito, Takuya; Bassett, Danielle S.; Schultz, Douglas H.

2016-01-01

Resting-state functional connectivity (FC) has helped reveal the intrinsic network organization of the human brain, yet its relevance to cognitive task activations has been unclear. Uncertainty remains despite evidence that resting-state FC patterns are highly similar to cognitive task activation patterns. Identifying the distributed processes that shape localized cognitive task activations may help reveal why resting-state FC is so strongly related to cognitive task activations. We found that estimating task-evoked activity flow (the spread of activation amplitudes) over resting-state FC networks allows prediction of cognitive task activations in a large-scale neural network model. Applying this insight to empirical functional MRI data, we found that cognitive task activations can be predicted in held-out brain regions (and held-out individuals) via estimated activity flow over resting-state FC networks. This suggests that task-evoked activity flow over intrinsic networks is a large-scale mechanism explaining the relevance of resting-state FC to cognitive task activations. PMID:27723746

Development and Confirmatory Factory Analysis of the Achievement Task Value Scale for University Students

ERIC Educational Resources Information Center

Lou, Yu-Chiung; Lin, Hsiao-Fang; Lin, Chin-Wen

2013-01-01

The aims of the study were (a) to develop a scale to measure university students' task value and (b) to use confirmatory factor analytic techniques to investigate the construct validity of the scale. The questionnaire items were developed based on theoretical considerations and the final version contained 38 items divided into 4 subscales.…

Task Effects on Linguistic Complexity and Accuracy: A Large-Scale Learner Corpus Analysis Employing Natural Language Processing Techniques

ERIC Educational Resources Information Center

Alexopoulou, Theodora; Michel, Marije; Murakami, Akira; Meurers, Detmar

2017-01-01

Large-scale learner corpora collected from online language learning platforms, such as the EF-Cambridge Open Language Database (EFCAMDAT), provide opportunities to analyze learner data at an unprecedented scale. However, interpreting the learner language in such corpora requires a precise understanding of tasks: How does the prompt and input of a…

Bilateral robotic priming before task-oriented approach in subacute stroke rehabilitation: a pilot randomized controlled trial.

PubMed

Hsieh, Yu-Wei; Wu, Ching-Yi; Wang, Wei-En; Lin, Keh-Chung; Chang, Ku-Chou; Chen, Chih-Chi; Liu, Chien-Ting

2017-02-01

To investigate the treatment effects of bilateral robotic priming combined with the task-oriented approach on motor impairment, disability, daily function, and quality of life in patients with subacute stroke. A randomized controlled trial. Occupational therapy clinics in medical centers. Thirty-one subacute stroke patients were recruited. Participants were randomly assigned to receive bilateral priming combined with the task-oriented approach (i.e., primed group) or to the task-oriented approach alone (i.e., unprimed group) for 90 minutes/day, 5 days/week for 4 weeks. The primed group began with the bilateral priming technique by using a bimanual robot-aided device. Motor impairments were assessed by the Fugal-Meyer Assessment, grip strength, and the Box and Block Test. Disability and daily function were measured by the modified Rankin Scale, the Functional Independence Measure, and actigraphy. Quality of life was examined by the Stroke Impact Scale. The primed and unprimed groups improved significantly on most outcomes over time. The primed group demonstrated significantly better improvement on the Stroke Impact Scale strength subscale ( p = 0.012) and a trend for greater improvement on the modified Rankin Scale ( p = 0.065) than the unprimed group. Bilateral priming combined with the task-oriented approach elicited more improvements in self-reported strength and disability degrees than the task-oriented approach by itself. Further large-scale research with at least 31 participants in each intervention group is suggested to confirm the study findings.

Performance of an attention-demanding task during treadmill walking shifts the noise qualities of step-to-step variation in step width.

PubMed

Grabiner, Mark D; Marone, Jane R; Wyatt, Marilynn; Sessoms, Pinata; Kaufman, Kenton R

2018-06-01

The fractal scaling evident in the step-to-step fluctuations of stepping-related time series reflects, to some degree, neuromotor noise. The primary purpose of this study was to determine the extent to which the fractal scaling of step width, step width and step width variability are affected by performance of an attention-demanding task. We hypothesized that the attention-demanding task would shift the structure of the step width time series toward white, uncorrelated noise. Subjects performed two 10-min treadmill walking trials, a control trial of undisturbed walking and a trial during which they performed a mental arithmetic/texting task. Motion capture data was converted to step width time series, the fractal scaling of which were determined from their power spectra. Fractal scaling decreased by 22% during the texting condition (p < 0.001) supporting the hypothesized shift toward white uncorrelated noise. Step width and step width variability increased 19% and five percent, respectively (p < 0.001). However, a stepwise discriminant analysis to which all three variables were input revealed that the control and dual task conditions were discriminated only by step width fractal scaling. The change of the fractal scaling of step width is consistent with increased cognitive demand and suggests a transition in the characteristics of the signal noise. This may reflect an important advance toward the understanding of the manner in which neuromotor noise contributes to some types of falls. However, further investigation of the repeatability of the results, the sensitivity of the results to progressive increases in cognitive load imposed by attention-demanding tasks, and the extent to which the results can be generalized to the gait of older adults seems warranted. Copyright © 2018 Elsevier B.V. All rights reserved.

Dry syngas purification process for coal gas produced in oxy-fuel type integrated gasification combined cycle power generation with carbon dioxide capturing feature.

PubMed

Kobayashi, Makoto; Akiho, Hiroyuki

2017-12-01

Electricity production from coal fuel with minimizing efficiency penalty for the carbon dioxide abatement will bring us sustainable and compatible energy utilization. One of the promising options is oxy-fuel type Integrated Gasification Combined Cycle (oxy-fuel IGCC) power generation that is estimated to achieve thermal efficiency of 44% at lower heating value (LHV) base and provide compressed carbon dioxide (CO 2 ) with concentration of 93 vol%. The proper operation of the plant is established by introducing dry syngas cleaning processes to control halide and sulfur compounds satisfying tolerate contaminants level of gas turbine. To realize the dry process, the bench scale test facility was planned to demonstrate the first-ever halide and sulfur removal with fixed bed reactor using actual syngas from O 2 -CO 2 blown gasifier for the oxy-fuel IGCC power generation. Design parameter for the test facility was required for the candidate sorbents for halide removal and sulfur removal. Breakthrough test was performed on two kinds of halide sorbents at accelerated condition and on honeycomb desulfurization sorbent at varied space velocity condition. The results for the both sorbents for halide and sulfur exhibited sufficient removal within the satisfactory short depth of sorbent bed, as well as superior bed conversion of the impurity removal reaction. These performance evaluation of the candidate sorbents of halide and sulfur removal provided rational and affordable design parameters for the bench scale test facility to demonstrate the dry syngas cleaning process for oxy-fuel IGCC system as the scaled up step of process development. Copyright © 2017 Elsevier Ltd. All rights reserved.

The organization of verbs of knowing: evidence for cultural commonality and variation in theory of mind.

PubMed

Schwanenflugel, P J; Martin, M; Takahashi, T

1999-09-01

Cross-cultural commonality and variation in folk theories of knowing were studied by examining the organization of verbs of knowing in German and Japanese adults. German and Japanese adults performed one of two tasks: a similarity judgment task and an attribute rating task. Organizational structure was assessed for the similarity judgment task using multidimensional scaling and additive similarity tree analyses. The attribute rating task was used to describe the characteristics that organized the dimensions and clusters emerging from the scaling solutions. The folk theory of mind displayed was an information processing model with constructive components, although the constructive aspects were more salient for the Germans than for the Japanese.

Optimal dynamic voltage scaling for wireless sensor nodes with real-time constraints

NASA Astrophysics Data System (ADS)

Cassandras, Christos G.; Zhuang, Shixin

2005-11-01

Sensors are increasingly embedded in manufacturing systems and wirelessly networked to monitor and manage operations ranging from process and inventory control to tracking equipment and even post-manufacturing product monitoring. In building such sensor networks, a critical issue is the limited and hard to replenish energy in the devices involved. Dynamic voltage scaling is a technique that controls the operating voltage of a processor to provide desired performance while conserving energy and prolonging the overall network's lifetime. We consider such power-limited devices processing time-critical tasks which are non-preemptive, aperiodic and have uncertain arrival times. We treat voltage scaling as a dynamic optimization problem whose objective is to minimize energy consumption subject to hard or soft real-time execution constraints. In the case of hard constraints, we build on prior work (which engages a voltage scaling controller at task completion times) by developing an intra-task controller that acts at all arrival times of incoming tasks. We show that this optimization problem can be decomposed into two simpler ones whose solution leads to an algorithm that does not actually require solving any nonlinear programming problems. In the case of soft constraints, this decomposition must be partly relaxed, but it still leads to a scalable (linear in the number of tasks) algorithm. Simulation results are provided to illustrate performance improvements in systems with intra-task controllers compared to uncontrolled systems or those using inter-task control.

COMMUNITY-SCALE MODELING FOR AIR TOXICS AND HOMELAND SECURITY

EPA Science Inventory

The purpose of this task is to develop and evaluate numerical and physical modeling tools for simulating ambient concentrations of airborne substances in urban settings at spatial scales ranging from <1-10 km. Research under this task will support client needs in human exposure ...

The Scaling of Water Governance Tasks: A Comparative Federal Analysis of the European Union and Australia

NASA Astrophysics Data System (ADS)

Benson, David; Jordan, Andrew

2010-07-01

Conflicts over how to “scale” policy-making tasks have characterized environmental governance since time immemorial. They are particularly evident in the area of water policy and raise important questions over the democratic legitimacy, economic efficiency and effectiveness of allocating (or “scaling”) tasks to some administrative levels as opposed to others. This article adopts a comparative federalism perspective to assess the “optimality” of scaling—either upward or downward—in one issue area, namely coastal recreational water quality. It does so by comparing the scaling of recreational water quality tasks in the European Union (EU) and Australia. It reveals that the two systems have adopted rather different approaches to scaling and that this difference can partly be accounted for in federal theoretical terms. However, a much greater awareness of the inescapably political nature of scaling processes is nonetheless required. Finally, some words of caution are offered with regard to transferring policy lessons between these two jurisdictions.

Quantification of crew workload imposed by communications-related tasks in commercial transport aircraft

NASA Technical Reports Server (NTRS)

Acton, W. H.; Crabtree, M. S.; Simons, J. C.; Gomer, F. E.; Eckel, J. S.

1983-01-01

Information theoretic analysis and subjective paired-comparison and task ranking techniques were employed in order to scale the workload of 20 communications-related tasks frequently performed by the captain and first officer of transport category aircraft. Tasks were drawn from taped conversations between aircraft and air traffic controllers (ATC). Twenty crewmembers performed subjective message comparisons and task rankings on the basis of workload. Information theoretic results indicated a broad range of task difficulty levels, and substantial differences between captain and first officer workload levels. Preliminary subjective data tended to corroborate these results. A hybrid scale reflecting the results of both the analytical and the subjective techniques is currently being developed. The findings will be used to select representative sets of communications for use in high fidelity simulation.

Worldwide Emerging Environmental Issues Affecting the U.S. Military. February 2009

DTIC Science & Technology

2009-02-01

in a polluted environment. Source: Removal of Oil from Water by Inverse Fluidization of Aerogels http://pubs.acs.org/doi/abs/10.1021/ie800022e...consumer rubbish – paper, plastic , food, wood and agricultural materials – a day into usable ―energy pellets‖ that can be gasified and used to run a...the technologies employed in this latest non- polluting vehicle for ideas on future developments. Source: China’s Chery Auto unveils electric car

Economic analysis of a small-sized combined heat and power plant using forest biomass in the Republic of Korea

Treesearch

Yeongwan Seo; Han-Sup Han; Edward M. (Ted) Bilek; Jungkee Choi; Dusong Cha; Jungsoo Lee

2017-01-01

Economic analysis was conducted on the feasibility of operating a small-sized (500kW/hour) gasification power plant producing heat and electricity in a rural town surrounded by forests in the Republic of Korea. Cost factors that were considered over the plant’s 20-year life included wood procurement, a wood grab loader, a chipper, a chip dryer, a gasifier, a generator...

Progress in net shape fabrication of alpha SiC turbine components

NASA Technical Reports Server (NTRS)

Storm, R. S.; Naum, R. G.

1983-01-01

The development status of component technology in an automotive gas turbine Ceramic Applications in Turbine Engines program is discussed, with attention to such materials and processes having a low cost, net shape fabrication potential as sintered alpha-SiC that has been fashioned by means of injection molding, slip casting, and isostatic pressing. The gas turbine elements produced include a gasifier turbine rotor, a turbine wheel, a connecting duct, a combustor baffle, and a transition duct.

Joint Long-Range Energy Study for Greater Fairbanks Military Complex

DTIC Science & Technology

2005-02-01

be viewed as a two - stage processor of a fuel or feedstock. The feedstock is first gasified using high-temperature plasma heating sys- tems at...Coal-Fired Boilers with New Circulating Fluidized- Bed Boilers (CFBs). EAFB anticipates replacing two current boilers with two new boilers. This...definition to support DD Form 1391 budget level cost estimates for new coal-fired CHPPs at FWA and EAFB and for two new coal-fired CFBs at EAFB • update

Power Sources Focus Group - Evaluation of Plasma Gasification for Waste-to-Energy Conversion

DTIC Science & Technology

2012-09-21

including paper , wood, plastic, food and agricultural waste. The system uses a shredder, dryer , and pelletizing preprocessor to fuel an in-house...limited information available, this paper does not attempt to determine the best way to use plasma in a gasifier. Instead, this paper makes general...Gasification Plasma gasification for the purposes of this paper includes any WTE system using plasma as part of the generation of syngas and/or cleanup

Cooled High-Temperature Radial Turbine Program. Phase 2

DTIC Science & Technology

1992-05-01

proposed for advanced engines with high power-to-weight and inproved SFC requirements. The addition of cooling to the blades of a metal radial turbine ...4 secl/2 ) 62.2 Blade - jet Speed Ratio 0.66 Adiabatic Efficiency (T-to-T, %) 87.0 Cooling flows for the gasifier turbine section are set at 5.7%. The...Way Cincinnati, OH 45215-6301 85 COOLED HIGH-TEMPERATURE RADIAL TURBINE PROGRAM DISTRIBUTION LIST Number Qf Copies General Electric Aircraft Engines

Coal gasification power plant and process

DOEpatents

Woodmansee, Donald E.

1979-01-01

In an integrated coal gasification power plant, a humidifier is provided for transferring as vapor, from the aqueous blowdown liquid into relatively dry air, both (I) at least a portion of the water contained in the aqueous liquid and (II) at least a portion of the volatile hydrocarbons therein. The resulting humidified air is advantageously employed as at least a portion of the hot air and water vapor included in the blast gas supplied via a boost compressor to the gasifier.

Combined hydrothermal liquefaction and catalytic hydrothermal gasification system and process for conversion of biomass feedstocks

DOEpatents

Elliott, Douglas C.; Neuenschwander, Gary G.; Hart, Todd R.

2017-09-12

A combined hydrothermal liquefaction (HTL) and catalytic hydrothermal gasification (CHG) system and process are described that convert various biomass-containing sources into separable bio-oils and aqueous effluents that contain residual organics. Bio-oils may be converted to useful bio-based fuels and other chemical feedstocks. Residual organics in HTL aqueous effluents may be gasified and converted into medium-BTU product gases and directly used for process heating or to provide energy.

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.

Ash bed level control system for a fixed-bed coal gasifier

DOEpatents

Fasching, George E.; Rotunda, John R.

1984-01-01

An ash level control system is provided which incorporates an ash level meter to automatically control the ash bed level of a coal gasifier at a selected level. The ash level signal from the ash level meter is updated during each cycle that a bed stirrer travels up and down through the extent of the ash bed level. The ash level signal is derived from temperature measurements made by thermocouples carried by the stirrer as it passes through the ash bed and into the fire zone immediately above the ash bed. The level signal is compared with selected threshold level signal to determine if the ash level is above or below the selected level once each stirrer cycle. A first counter is either incremented or decremented accordingly. The registered count of the first counter is preset in a down counter once each cycle and the preset count is counted down at a selected clock rate. A grate drive is activated to rotate a grate assembly supporting the ash bed for a period equal to the count down period to maintain the selected ash bed level. In order to avoid grate binding, the controller provides a short base operating duration time each stirrer cycle. If the ash bed level drops below a selected low level or exceeds a selected high level, means are provided to notify the operator.

MICRO AUTO GASIFICATION SYSTEM: EMISSIONS ...

EPA Pesticide Factsheets

A compact, CONEX-housed waste to energy unit, Micro Auto Gasification System (MAGS), was characterized for air emissions from burning of military waste types. The MAGS unit is a dual chamber gasifier with a secondary diesel-fired combustor. Eight tests were conducted with multiple waste types in a 7-day period at the Kilauea Military Camp in Hawai’i. The emissions characterized were chosen based on regulatory emissions limits as well as their ability to cause adverse health effects on humans: particulate matter (PM), mercury, heavy metals, volatile organic compounds (VOCs), polyaromatic hydrocarbons (PAHs), and polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Three military waste feedstock compositions reflecting the variety of wastes to be encountered in theatre were investigated: standard waste (SW), standard waste with increased plastic content (HP), standard waste without SW food components but added first strike ration (FSR) food and packaging material (termed FSR). A fourth waste was collected from the Kilauea dumpster that served the dining facility and room lodging (KMC). Limited scrubber water and solid ash residue samples were collected to obtain a preliminary characterization of these effluents/residues.Gasifying SW, HP, and KMC resulted in similar PCDD/PCDF stack concentrations, 0.26-0.27 ng TEQ/m3 at 7% O2, while FSR waste generated a notably higher stack concentration of 0.68 ng TEQ/m3 at 7% O2. The PM emission

Experiment Investigation of the Influencing Factors on Bed Agglomeration During Fluidized-Bed Gasification of Biomass Fuels

NASA Astrophysics Data System (ADS)

Chen, Y. Q.; Chen, H. P.; Yang, H. P.; Wang, X. H.; Zhang, S. H.

With the depleting of fossil fuel and environmental polluting increasing, the utilization of biomass resources caught increasing concern. Biomass gasification in fluidized bed, as one promising technology, developed quickly. However, serious agglomeration was displayed as biomass ash reacted with bed material (silica sand) at higher temperature. It hindered the wide utilization of CFB gasifier. The objective ofthis work is to investigate the agglomeration behavior between biomass ash and silica sand, and catch the inherent mechanism. Firstly, the influence of ash compounds on the agglomeration behavior was analyzed with biomass ash and synthesis ash compounds addition in fixed bed as ash sample mixed with bed material evenly before every trial. The reaction temperature was set 850°C that is the operated temperature for many fluidized bed gasificated biomass fuels. Then the influence of reaction time was analyzed. The characteristics of the agglomerated silica sand particles were analyzed by the XRD. Finally, it was simulated with HSC computer mode based on thermodynamic equilibrium. It was observed that when the ratio of the biomass ash to the silica sand was above 0.2, the agglomeration was observed. With the increase of the reaction time, more silica sand particles agglomerated with the biomass ash. There are two kinds of silicate eutecticum investigated by the XRD. It is of great significance for the running ofCFB biomass gasifier and the development ofbiomass utilization technology.

[Tampa Electric Company IGCC project]. 1996 DOE annual technical report, January--December 1996

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

NONE

1997-12-31

Tampa Electric Company`s Polk Power Station Unit 1 (PPS-1) Integrated Gasification Combined Cycle (IGCC) demonstration project uses a Texaco pressurized, oxygen-blown, entrained-flow coal gasifier to convert approximately 2,000 tons per day of coal to syngas. The gasification plant is coupled with a combined cycle power block to produce a net 250 MW electrical power output. Coal is slurried in water, combined with 95% pure oxygen from an air separation unit, and sent to the gasifier to produce a high temperature, high pressure, medium-Btu syngas with a heat content of about 250 BTUs/cf (HHV). The syngas then flows through a highmore » temperature heat recovery unit which cools the syngas prior to its entering the cleanup systems. Molten coal ash flows from the bottom of the high temperature heat recovery unit into a water-filled quench chamber where it solidifies into a marketable slag by-product. Approximately 10% of the raw, hot syngas at 900 F is designed to pass through an intermittently moving bed of metal-oxide sorbent which removes sulfur-bearing compounds from the syngas. PPS-1 will be the first unit in the world to demonstrate this advanced metal oxide hot gas desulfurization technology on a commercial unit. The emphasis during 1996 centered around start-up activities.« less

Method for treatment of tar-bearing fuel gas

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

Frauen, L.L.; Kasper, S.

1986-01-07

A process is described of producing a fuel gas which contains condensable tar vapor when it leaves a gasifier, the improvement wherein the tar-bearing gases are treated to remove tar therefrom. The process consists of: (a) continuously conducting hot fuel gas from a gasifier to and discharging it into a spray chamber where the hot tar-bearing gas is contacted with a fine spray of water thereby cooling the tar vapor and evaporating the water to produce a fog-like dispersion of tar in an atmosphere of fuel gas with the temperature in the spray chamber maintained above the dew point ofmore » water; (b) continuously transferring the fuel gas and the dispersion of tar and water to an electrostatic precipitator and precipitating therein at least most of the condensed tar as a liquid; (c) removing the liquid tar so precipitated and conducting at least most of it to a tar burner; (d) burning the tar with no more than the stoichiometric supply of oxygen provided by air to produce oxygen-free and tar-free hot combustion gases; (e) conducting the hot combustion gases directly into a mixer into which the fuel gas and water vapor flows from the precipitator, thereby adding to the fuel gas the sensible heat of the combustion gases; and (f) conducting the mixture so produced to a place of use as a hot fuel gas mixture.« 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.

ECAS Phase I fuel cell results. [Energy Conservation Alternatives Study

NASA Technical Reports Server (NTRS)

Warshay, M.

1978-01-01

This paper summarizes and discusses the fuel cell system results of Phase I of the Energy Conversion Alternatives Study (ECAS). Ten advanced electric powerplant systems for central-station baseload generation using coal were studied by NASA in ECAS. Three types of low-temperature fuel cells (solid polymer electrolyte, SPE, aqueous alkaline, and phosphoric acid) and two types of high-temperature fuel cells (molten carbonate, MC, and zirconia solid electrolyte, SE) were studied. The results indicate that (1) overall efficiency increases with fuel cell temperature, and (2) scale-up in powerplant size can produce a significant reduction in cost of electricity (COE) only when it is accompanied by utilization of waste fuel cell heat through a steam bottoming cycle and/or integration with a gasifier. For low-temperature fuel cell systems, the use of hydrogen results in the highest efficiency and lowest COE. In spite of higher efficiencies, because of higher fuel cell replacement costs integrated SE systems have higher projected COEs than do integrated MC systems. Present data indicate that life can be projected to over 30,000 hr for MC fuel cells, but data are not yet sufficient for similarly projecting SE fuel cell life expectancy.

Fabrication of functional nanomaterials using flame assisted spray pyrolysis

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

Purwanto, Agus, E-mail: aguspur@uns.ac.id

2014-02-24

Flame assisted spray pyrolysis (FASP) is a class of synthesis method for nanomaterials fabrication. The ability to control nanomaterials characteristics and easy to be-scaled up are the main features of FASP. The crystallinity and particles size of the prepared nanomaterials can be easily controlled by variation of fuel flow rate. The precursor concentration, carrier gas flow rate, and carrier gas can be also used to control the prepared nanomaterials. Energy related nanomaterials preparation uses as the example case in FASP application. These material are yttrium aluminum garnet (YAG:Ce) and tungsten oxide (WO{sub 3}). It needs strategies to produce these materialsmore » into nano-sized order. YAG:Ce nanoparticles only can be synthesized by FASP using the urea addition. The decomposition of urea under high temperature of flame promotes the breakage of YAG:Ce particles into nanoparticles. In the preparation of WO{sub 3}, the high temperature flame can be used to gasify WO{sub 3} solid material. As a result, WO{sub 3} nanoparticles can be prepared easily. Generally, to produce nanoparticles via FASP method, the boiling point of the material is important to determine the strategy which will be used.« less

Low NO sub x heavy fuel combustor concept program. Phase 1A: Combustion technology generation coal gas fuels

NASA Technical Reports Server (NTRS)

Sherlock, T. P.

1982-01-01

Combustion tests of two scaled burners using actual coal gas from a 25 ton/day fluidized bed coal gasifier are described. The two combustor configurations studied were a ceramic lined, staged rich/lean burner and an integral, all metal multiannual swirl burner (MASB). The tests were conducted over a range of temperature and pressures representative of current industrial combustion turbine inlet conditions. Tests on the rich lean burner were conducted at three levels of product gas heating values: 104, 197 and 254 btu/scf. Corresponding levels of NOx emissions were 5, 20 and 70 ppmv. Nitrogen was added to the fuel in the form of ammonia, and conversion efficiencies of fuel nitrogen to NOx were on the order of 4 percent to 12 percent, which is somewhat lower than the 14 percent to 18 percent conversion efficiency when src-2 liquid fuel was used. The MASB was tested only on medium btu gas (220 to 270 btu/scf), and produced approximately 80 ppmv NOx at rated engine conditions. Both burners operated similarly on actual coal gas and erbs fuel, and all heating values tested can be successfully burned in current machines.

Parents' self-efficacy, outcome expectations, and self-reported task performance when managing atopic dermatitis in children: instrument reliability and validity.

PubMed

Mitchell, Amy E; Fraser, Jennifer A

2011-02-01

Support and education for parents faced with managing a child with atopic dermatitis is crucial to the success of current treatments. Interventions aiming to improve parent management of this condition are promising. Unfortunately, evaluation is hampered by lack of precise research tools to measure change. To develop a suite of valid and reliable research instruments to appraise parents' self-efficacy for performing atopic dermatitis management tasks; outcome expectations of performing management tasks; and self-reported task performance in a community sample of parents of children with atopic dermatitis. The Parents' Eczema Management Scale (PEMS) and the Parents' Outcome Expectations of Eczema Management Scale (POEEMS) were developed from an existing self-efficacy scale, the Parental Self-Efficacy with Eczema Care Index (PASECI). Each scale was presented in a single self-administered questionnaire, to measure self-efficacy, outcome expectations, and self-reported task performance related to managing child atopic dermatitis. Each was tested with a community sample of parents of children with atopic dermatitis, and psychometric evaluation of the scales' reliability and validity was conducted. A community-based convenience sample of 120 parents of children with atopic dermatitis completed the self-administered questionnaire. Participants were recruited through schools across Australia. Satisfactory internal consistency and test-retest reliability was demonstrated for all three scales. Construct validity was satisfactory, with positive relationships between self-efficacy for managing atopic dermatitis and general perceived self-efficacy; self-efficacy for managing atopic dermatitis and self-reported task performance; and self-efficacy for managing atopic dermatitis and outcome expectations. Factor analyses revealed two-factor structures for PEMS and PASECI alike, with both scales containing factors related to performing routine management tasks, and managing the child's symptoms and behaviour. Factor analysis was also applied to POEEMS resulting in a three-factor structure. Factors relating to independent management of atopic dermatitis by the parent, involving healthcare professionals in management, and involving the child in the management of atopic dermatitis were found. Parents' self-efficacy and outcome expectations had a significant influence on self-reported task performance. Findings suggest that PEMS and POEEMS are valid and reliable instruments worthy of further psychometric evaluation. Likewise, validity and reliability of PASECI was confirmed. Copyright © 2010 Elsevier Ltd. All rights reserved.

Tacit knowledge: A refinement and empirical test of the Academic Tacit Knowledge Scale.

PubMed

Insch, Gary S; McIntyre, Nancy; Dawley, David

2008-11-01

Researchers have linked tacit knowledge to improved organizational performance, but research on how to measure tacit knowledge is scarce. In the present study, the authors proposed and empirically tested a model of tacit knowledge and an accompanying measurement scale of academic tacit knowledge. They present 6 hypotheses that support the proposed tacit knowledge model regarding the role of cognitive (self-motivation, self-organization); technical (individual task, institutional task); and social (task-related, general) skills. The authors tested these hypotheses with 542 responses to the Academic Tacit Knowledge Scale, which included the respondents' grade point average-the performance variable. All 6 hypotheses were supported.

Identifying and individuating cognitive systems: a task-based distributed cognition alternative to agent-based extended cognition.

PubMed

Davies, Jim; Michaelian, Kourken

2016-08-01

This article argues for a task-based approach to identifying and individuating cognitive systems. The agent-based extended cognition approach faces a problem of cognitive bloat and has difficulty accommodating both sub-individual cognitive systems ("scaling down") and some supra-individual cognitive systems ("scaling up"). The standard distributed cognition approach can accommodate a wider variety of supra-individual systems but likewise has difficulties with sub-individual systems and faces the problem of cognitive bloat. We develop a task-based variant of distributed cognition designed to scale up and down smoothly while providing a principled means of avoiding cognitive bloat. The advantages of the task-based approach are illustrated by means of two parallel case studies: re-representation in the human visual system and in a biomedical engineering laboratory.

The contribution of coping related variables and cardiac vagal activity on the performance of a dart throwing task under pressure.

PubMed

Mosley, Emma; Laborde, Sylvain; Kavanagh, Emma

2017-10-01

The aims of this study were 1) to assess the predictive role of coping related variables (CRV) on cardiac vagal activity (derived from heart rate variability), and 2) to investigate the influence of CRV (including cardiac vagal activity) on a dart throwing task under low pressure (LP) and high pressure (HP) conditions. Participants (n=51) completed trait CRV questionnaires: Decision Specific Reinvestment Scale, Movement Specific Reinvestment Scale and Trait Emotional Intelligence Questionnaire. They competed in a dart throwing task under LP and HP conditions. Cardiac vagal activity measurements were taken at resting, task and during recovery for 5min. Self-reported ratings of stress were recorded at three time points via a visual analogue scale. Upon completion of the task, self-report measures of motivation, stress appraisal, attention, perceived pressure and dart throwing experience were completed. Results indicated that resting cardiac vagal activity had no predictors. Task cardiac vagal activity was predicted by resting cardiac vagal activity in both pressure conditions with the addition of a trait CRV in HP. Post task cardiac vagal activity was predicted by resting cardiac vagal activity in both conditions with the addition of a trait CRV in HP. Cardiac vagal reactivity (difference from resting to task) was predicted by a trait CRV in HP conditions. Cardiac vagal recovery (difference from task to post task) was predicted by a state CRV only in LP. Dart throwing task performance was predicted by a combination of both CRV and cardiac vagal activity. The current research suggests that coping related variables and cardiac vagal activity influence dart throwing task performance differently dependent on pressure condition. Copyright © 2017 Elsevier Inc. All rights reserved.

Manpower and Personnel Integration (MANPRINT) and Network Integration Evaluation 13.2: Observations on Cognitive Load in Mission Command

DTIC Science & Technology

2014-03-01

using scales like NASA’s Task Load Index ( TLX ) (Hart and Staveland, 1988). At present, there are no comparable measurement scales for cognitive...Staveland, L. E. Development of NASA- TLX (Task Load Index): Results of empirical and theoretical research. In Human Mental Workload; Hancock, P. A...Requests for Information SA situation awareness TLX Task Load Index TOC tactical operations center WSMR White Sands Missile Range XO executive

Go/No-Go task performance predicts differences in compulsivity but not in impulsivity personality traits.

PubMed

Sánchez-Kuhn, Ana; León, José Juan; Gôngora, Karinna; Pérez-Fernández, Cristian; Sánchez-Santed, Fernando; Moreno, Margarita; Flores, Pilar

2017-11-01

Lack of inhibitory control is present in impulsive and compulsive personality traits. The Go/No-Go task is one of the most effective means to assess response inhibition measured by the ability to appropriately withhold responding to No-Go stimuli. The aim of this work was to study whether differences in performance of Go/No-Go task predicts differences in personality traits related to inhibitory control. For this purpose 63 healthy participants divided into two groups based on the median split of false alarms on the Go/No-Go task completed Barratt Impulsiveness Scale (BIS-11) and the Maudsley Obsessional Compulsive Questionnaire (MOCI). Results showed that participants with high false alarms (H-FA) displayed a high-risk strategy of responding, and higher scores in the MOCI Total and MOCI Checking subscale compared to participants with low false alarms (L-FA). The results show for the first time a relation between the execution of the Go/No-Go task and the MOCI scale. Surprisingly, no relation was found between the Go/No-Go task and the BIS-11 scale. Further studies are needed to define the heterogeneous constructs of compulsivity and impulsivity, and to improve the convergence of the clinical scales and the behavioral measures of these two personality traits. Copyright © 2017 Elsevier B.V. All rights reserved.

The validity and scalability of the Theory of Mind Scale with toddlers and preschoolers.

PubMed

Hiller, Rachel M; Weber, Nathan; Young, Robyn L

2014-12-01

Despite the importance of theory of mind (ToM) for typical development, there remain 2 key issues affecting our ability to draw robust conclusions. One is the continued focus on false belief as the sole measure of ToM. The second is the lack of empirically validated measures of ToM as a broad construct. Our key aim was to examine the validity and reliability of the 5-item ToM scale (Peterson, Wellman, & Liu, 2005). In particular, we extended on previous research of this scale by assessing its scalability and validity for use with children from 2 years of age. Sixty-eight typically developing children (aged 24 to 61 months) were assessed on the scale's 5 tasks, along with a sixth Sally-Anne false-belief task. Our data replicated the scalability of the 5 tasks for a Rasch-but not Guttman-scale. Guttman analysis showed that a 4-item scale may be more suitable for this age range. Further, the tasks showed good internal consistency and validity for use with children as young as 2 years of age. Overall, the measure provides a valid and reliable tool for the assessment of ToM, and in particular, the longitudinal assessment of this ability as a construct. (c) 2014 APA, all rights reserved.

EVALUATION OF SCR CATALYSTS FOR COMBINED CONTROL OF NOX AND MERCURY

EPA Science Inventory

The report documents two-task, bench- and pilot-scale research on the effect of selective catalytic reduction (SCR) catalysts on mercury speciation in Illinois and Powder River Basin (PRB) coal combustion flue gases. In task I, a bench-scale reactor was used to study the oxidatio...

Scaling a Single Attribute: A Methodological Study of Conservation

ERIC Educational Resources Information Center

Hofmann, Richard J.; Trepanier, Mary

1975-01-01

This study was designed to assess the acquisition of conservation of number on equal addition tasks through scalogram analysis to determine if this analysis defines a scale or continuum. Ten block tasks administered to 85 kindergarten children validated Piaget's theory that cognitive development is sequential and continuous. (Author/ED)

Gender differences in laterality patterns for speaking and singing.

PubMed

Hough, M S; Daniel, H J; Snow, M A; O'Brien, K F; Hume, W G

1994-09-01

This study examined behaviors reflecting cerebral organization of speaking and singing in normal college students. The investigation focused on whether differences existed in the laterality patterns of two singing tasks and one speaking task in males and females. Performance was measured on a verbal/manual time-sharing paradigm, coupling finger tapping with three vocal tasks (speaking, singing a rote song, singing up and down a diatonic five note scale). Females exhibited less variation than males in mean tapping rates and laterality scores across all three vocal tasks, thus indicating that gender most likely influences lateralization of vocal tasks. Bilateral integration was indicated for both males and females during singing up/down the aforementioned scale. These findings suggest differential involvement of both hemispheres in processing musical functions.

Polycyclic aromatic hydrocarbon and particulate emissions from two-stage combustion of polystyrene: the effect of the primary furnace temperature.

PubMed

Wang, J; Levendis, Y A; Richter, H; Howard, J B; Carlson, J

2001-09-01

A study is presented on laboratory-scale combustion of polystyrene (PS) to identify staged-combustion conditions that minimize emissions. Batch combustion of shredded PS was conducted in fixed beds placed in a bench-scale electrically heated horizontal muffle furnace. In most cases, combustion of the samples occurred by forming gaseous diffusion flames in atmospheric pressure air. The combustion effluent was mixed with additional air, and it was channeled to a second muffle furnace (afterburner) placed in series. Further reactions took place in the secondary furnace at a residence time of 0.7 s. The gas temperature of the primary furnace was varied in the range of 500-1,000 degrees C, while that of the secondary furnace was kept fixed at 1,000 degrees C. Sampling for CO, CO2, O2, soot, and unburned hydrocarbon emissions (volatile and semivolatile, by GC-MS) was performed at the exits of the two furnaces. Results showed that the temperature of the primary furnace, where PS gasifies, is of paramount importance to the formation and subsequent emissions of organic species and soot. Atthe lowesttemperatures explored, mostly styrene oligomers were identified at the outlet of the primary furnace, but they did not survive the treatment in the secondary furnace. The formation and emission of polycyclic aromatic hydrocarbons (PAH) and soot were suppressed. As the temperature in the first furnace was raised, increasing amounts of a wide range of both unsubstituted and substituted PAH containing up to at least seven condensed aromatic rings were detected. A similar trend was observed for total particulate yields. The secondary furnace treatment reduced the yields of total PAH, but it had an ambiguous effect on individual species. While most low molecular mass PAH were reduced in the secondary furnace, concentrations of some larger PAH increased under certain conditions. Thus, care in the selection of operating conditions of both the primary furnace (gasifier/ burner) and the secondary furnace (afterburner) must be exercised to minimize the emission of hazardous pollutants. The emissions of soot were also reduced in the afterburner but not drastically. This indicates that soot is indeed resistant to oxidation; thus, it would be best to avoid its formation in the first place. An oxidative pyrolysis temperature of PS in the vicinity of 600 degrees C appears to accomplish exactly that. An additional afterburner treatment at a sufficiently high temperature (1,000 degrees C) may be a suitable setting for minimization of most pollutants. To obtain deeper understanding of chemical processes, the experimental results were qualitatively compared with preliminary predictions of a detailed kinetic model that describes formation and destruction pathways of chemical species including most PAH observed in the present work. The modeling was performed forthe secondary furnace assuming plug-flow conditions therein. The experimentally determined chemical composition at the outlet of the primary furnace was part of the input parameters of the model calculation.

The Time on Task Effect in Reading and Problem Solving Is Moderated by Task Difficulty and Skill: Insights from a Computer-Based Large-Scale Assessment

ERIC Educational Resources Information Center

Goldhammer, Frank; Naumann, Johannes; Stelter, Annette; Tóth, Krisztina; Rölke, Heiko; Klieme, Eckhard

2014-01-01

Computer-based assessment can provide new insights into behavioral processes of task completion that cannot be uncovered by paper-based instruments. Time presents a major characteristic of the task completion process. Psychologically, time on task has 2 different interpretations, suggesting opposing associations with task outcome: Spending more…

HD-MTL: Hierarchical Deep Multi-Task Learning for Large-Scale Visual Recognition.

PubMed

Fan, Jianping; Zhao, Tianyi; Kuang, Zhenzhong; Zheng, Yu; Zhang, Ji; Yu, Jun; Peng, Jinye

2017-02-09

In this paper, a hierarchical deep multi-task learning (HD-MTL) algorithm is developed to support large-scale visual recognition (e.g., recognizing thousands or even tens of thousands of atomic object classes automatically). First, multiple sets of multi-level deep features are extracted from different layers of deep convolutional neural networks (deep CNNs), and they are used to achieve more effective accomplishment of the coarseto- fine tasks for hierarchical visual recognition. A visual tree is then learned by assigning the visually-similar atomic object classes with similar learning complexities into the same group, which can provide a good environment for determining the interrelated learning tasks automatically. By leveraging the inter-task relatedness (inter-class similarities) to learn more discriminative group-specific deep representations, our deep multi-task learning algorithm can train more discriminative node classifiers for distinguishing the visually-similar atomic object classes effectively. Our hierarchical deep multi-task learning (HD-MTL) algorithm can integrate two discriminative regularization terms to control the inter-level error propagation effectively, and it can provide an end-to-end approach for jointly learning more representative deep CNNs (for image representation) and more discriminative tree classifier (for large-scale visual recognition) and updating them simultaneously. Our incremental deep learning algorithms can effectively adapt both the deep CNNs and the tree classifier to the new training images and the new object classes. Our experimental results have demonstrated that our HD-MTL algorithm can achieve very competitive results on improving the accuracy rates for large-scale visual recognition.

Generation IV Nuclear Energy Systems Construction Cost Reductions through the Use of Virtual Environments - Task 4 Report: Virtual Mockup Maintenance Task Evaluation

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

Timothy Shaw; Anthony Baratta; Vaughn Whisker

2005-02-28

Task 4 report of 3 year DOE NERI-sponsored effort evaluating immersive virtual reality (CAVE) technology for design review, construction planning, and maintenance planning and training for next generation nuclear power plants. Program covers development of full-scale virtual mockups generated from 3D CAD data presented in a CAVE visualization facility. This report focuses on using Full-scale virtual mockups for nuclear power plant training applications.

Solid handling valve

DOEpatents

Williams, William R.

1979-01-01

The present invention is directed to a solids handling valve for use in combination with lock hoppers utilized for conveying pulverized coal to a coal gasifier. The valve comprises a fluid-actuated flow control piston disposed within a housing and provided with a tapered primary seal having a recessed seat on the housing and a radially expandable fluid-actuated secondary seal. The valve seals are highly resistive to corrosion, erosion and abrasion by the solids, liquids, and gases associated with the gasification process so as to minimize valve failure.

Photoconversion of organic materials into single-cell protein

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

Weaver, P.F.

A process is described for converting organic materials (such as biomass wastes) into sterile, high-grade bacterial protein suitable for use an animal feed or human food supplements. In a preferred embodiment the process involves thermally gasifying the organic material into primarily carbon monoxide, hydrogen and nitrogen products, followed by photosynthetic bacterial assimilation of the gases into cell material, which can be high as 65% protein. The process is ideally suited for waste recycling and for food production under zero-gravity or extra-terrestrial conditions.

Visualization and Measurement of the Deflagration of JA2 Bonded to Various Metal Foils

DTIC Science & Technology

2016-01-01

Disclaimers The findings in this report are not to be construed as an official Department of the Army position unless so designated by other... design tools. There are numerous design parameters, including 1) the wires’ thermophysical properties and diameter(s), 2) their quantity, spacing, and...gasified by combustion. This is suggested by Figs. 7 and 8, which present posttest examinations of 2- and 3-mil-thick foils. On the 2-mil-thick Cu foils, a

Characterization of alternative electric generation technologies for the SPS comparative assessment. Volume 1: Summary of central station technologies

NASA Astrophysics Data System (ADS)

1980-08-01

The technologies selected for the detailed characterization were: solar technology; terrestrial photovoltaic (200 MWe); coal technologies; conventional high sulfur coal combustion with advanced fine gas desulfurization (1250 MWe), and open cycle gas turbine combined cycle plant with low Btu gasifier (1250 MWe); and nuclear technologies: conventional light water reactor (1250 MWe), liquid metal fast breeder reactor (1250 MWe), and magnetic fusion reactor (1320 MWe). A brief technical summary of each power plant design is given.

Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 3: Combustors, furnaces and low-BTU gasifiers. [used in coal gasification and coal liquefaction (equipment specifications)

NASA Technical Reports Server (NTRS)

Hamm, J. R.

1976-01-01

Information is presented on the design, performance, operating characteristics, cost, and development status of coal preparation equipment, combustion equipment, furnaces, low-Btu gasification processes, low-temperature carbonization processes, desulfurization processes, and pollution particulate removal equipment. The information was compiled for use by the various cycle concept leaders in determining the performance, capital costs, energy costs, and natural resource requirements of each of their system configurations.

Apparatus for removal of particulate matter from gas streams

DOEpatents

Smith, Peyton L.; Morse, John C.

2000-01-01

An apparatus for the removal of particulate matter from the gaseous product stream of an entrained flow coal gasifier which apparatus includes an initial screen, an intermediate screen which is aligned with the direction of flow of the gaseous product stream and a final screen transversely disposed to the flow of gaseous product and which apparatus is capable of withstanding at least a pressure differential of about 10 psi (68.95 kPa) or greater at the temperatures of the gaseous product stream.

Photoconversion of organic materials into single-cell protein

DOEpatents

Weaver, Paul F.

2001-01-01

A process is described for converting organic materials (such as biomass wastes) into sterile, high-grade bacterial protein suitable for use an animal feed or human food supplements. In a preferred embodiment the process involves thermally gasifying the organic material into primarily carbon monoxide, hydrogen and nitrogen products, followed by photosynthetic bacterial assimilation of the gases into cell material, which can be as high as 65% protein. The process is ideally suited for waste recycling and for food production under zero-gravity or extra-terrestrial conditions.

Estimation of Handgrip Force from SEMG Based on Wavelet Scale Selection.

PubMed

Wang, Kai; Zhang, Xianmin; Ota, Jun; Huang, Yanjiang

2018-02-24

This paper proposes a nonlinear correlation-based wavelet scale selection technology to select the effective wavelet scales for the estimation of handgrip force from surface electromyograms (SEMG). The SEMG signal corresponding to gripping force was collected from extensor and flexor forearm muscles during the force-varying analysis task. We performed a computational sensitivity analysis on the initial nonlinear SEMG-handgrip force model. To explore the nonlinear correlation between ten wavelet scales and handgrip force, a large-scale iteration based on the Monte Carlo simulation was conducted. To choose a suitable combination of scales, we proposed a rule to combine wavelet scales based on the sensitivity of each scale and selected the appropriate combination of wavelet scales based on sequence combination analysis (SCA). The results of SCA indicated that the scale combination VI is suitable for estimating force from the extensors and the combination V is suitable for the flexors. The proposed method was compared to two former methods through prolonged static and force-varying contraction tasks. The experiment results showed that the root mean square errors derived by the proposed method for both static and force-varying contraction tasks were less than 20%. The accuracy and robustness of the handgrip force derived by the proposed method is better than that obtained by the former methods.

Child Proportional Scaling: Is 1/3 = 2/6 = 3/9 = 4/12?

ERIC Educational Resources Information Center

Boyer, Ty W.; Levine, Susan C.

2012-01-01

The current experiments examined the role of scale factor in children's proportional reasoning. Experiment 1 used a choice task and Experiment 2 used a production task to examine the abilities of kindergartners through fourth-graders to match equivalent, visually depicted proportional relations. The findings of both experiments show that accuracy…

Measurement of assertive behavior: construct and predictive validity of self-report, role-playing, and in-vivo measures.

PubMed

Burkhart, B R; Green, S B; Harrison, W H

1979-04-01

Examined the predictive validity and construct equivalence of the three major procedures used to measure assertive behavior: Self-report, behavioral role-playing, and in-vivo assessment. Seventy-five Ss, who spanned the range of assertiveness, completed two self-report measures of assertiveness, the Rathus Assertiveness Scale (RAS) and the College Self-Expression Scale (CSES); two scales from the Endler S-R Inventory of General Trait Anxiousness, the interpersonal and general anxiety scales; eight role-playing situations that involved the expression of positive and negative assertiveness; and a telephone in-vivo task. In general, the study revealed the following: (1) assertiveness measures are task-dependent in that there was more overlap within task than between tasks; (2) there is a moderate degree of correspondence between self-report and role-playing measures, although this was true only for negative assertion; (3) positive and negative assertion do not appear to have the same topography of responding; and (4) there appears to be no consistent relationship between the in-vivo measure and any other type of assertiveness measure.

Decision tree rating scales for workload estimation: Theme and variations

NASA Technical Reports Server (NTRS)

Wierwille, W. W.; Skipper, J. H.; Rieger, C. A.

1984-01-01

The Modified Cooper-Harper (MCH) scale which is a sensitive indicator of workload in several different types of aircrew tasks was examined. The study determined if variations of the scale might provide greater sensitivity and the reasons for the sensitivity of the scale. The MCH scale and five newly devised scales were examined in two different aircraft simulator experiments in which pilot loading was treated as an independent variable. It is indicated that while one of the new scales may be more sensitive in a given experiment, task dependency is a problem. The MCH scale exhibits consistent senstivity and remains the scale recommended for general use. The MCH scale results are consistent with earlier experiments. The rating scale experiments are reported and the questionnaire results which were directed to obtain a better understanding of the reasons for the relative sensitivity of the MCH scale and its variations are described.

Decision Tree Rating Scales for Workload Estimation: Theme and Variations

NASA Technical Reports Server (NTRS)

Wietwille, W. W.; Skipper, J. H.; Rieger, C. A.

1984-01-01

The modified Cooper-Harper (MCH) scale has been shown to be a sensitive indicator of workload in several different types of aircrew tasks. The MCH scale was examined to determine if certain variations of the scale might provide even greater sensitivity and to determine the reasons for the sensitivity of the scale. The MCH scale and five newly devised scales were studied in two different aircraft simulator experiments in which pilot loading was treated as an independent variable. Results indicate that while one of the new scales may be more sensitive in a given experiment, task dependency is a problem. The MCH scale exhibits consistent sensitivity and remains the scale recommended for general use. The results of the rating scale experiments are presented and the questionnaire results which were directed at obtaining a better understanding of the reasons for the relative sensitivity of the MCH scale and its variations are described.

Indirect Liquefaction of Coal-Biomass Mixture for Production of Jet Fuel with High Productivity and Selectivity

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

Gangwal, Santosh K; McCabe, Kevin

Coal to liquids (CTL) and coal-biomass to liquids (CBTL) processes were advanced by testing and demonstrating Southern Research’s sulfur tolerant nickel-based reforming catalyst and Chevron’s highly selective and active cobalt-zeolite hybrid Fischer-Tropsch (FT) catalyst to clean, upgrade and convert syngas predominantly to jet fuel range hydrocarbon liquids, thereby minimizing expensive cleanup and wax upgrading operations. The National Carbon Capture Center (NCCC) operated by Southern Company (SC) at Wilsonville, Alabama served as the host site for the gasifier slip-stream and simulated syngas testing/demonstration. Reformer testing was performed to (1) reform tar and light hydrocarbons, (2) decompose ammonia in the presence H2S,more » and (3) deliver the required H2 to CO ratio for FT synthesis. FT Testing was performed to produce a product primarily containing C5-C20 liquid hydrocarbons and no C21+ waxy hydrocarbons with productivity greater than 0.7 gC5+/g catalyst/h, and at least 70% diesel and jet fuel range (C8-C20) hydrocarbon selectivity in the liquid product. A novel heat-exchange reactor system was employed to enable the use of the highly active FT catalyst and larger diameter reactors that results in cost reduction for commercial systems. Following laboratory development and testing, SR’s laboratory reformer was modified to operate in a Class 1 Div. 2 environment, installed at NCCC, and successfully tested for 125 hours using raw syngas. The catalyst demonstrated near equilibrium reforming (~90%) of methane and complete reforming/decomposition of tar and ammonia in the presence of up to 380 ppm H2S. For FT synthesis, SR modified and utilized a bench scale skid mounted FT reactor system (SR-CBTL test rig) that was fully integrated with a slip stream from SC/NCCC’s transport gasifier (TRIG). The test-rig developed in a previous project (DE-FE0010231) was modified to receive up to 7.5 lb/h raw syngas augmented with bottled syngas to adjust the H2/CO molar ratio to 2, clean it to cobalt FT catalyst specifications, and produce liquid FT products at the design capacity of up to 6 L/day. Promising Chevron catalyst candidates in the size range from 70-200 μm were loaded onto SR’s 2-inch ID and 4-inch ID bench-scale reactors utilizing IntraMicron’s micro-fiber entrapped catalyst (MFEC) heat exchange reactor technology. During 2 test campaigns, the FT reactors were successfully demonstrated at NCCC using syngas for ~420 hours. The catalyst did not experience deactivation during the tests. SR’s thermo-syphon heat removal system maintained reactor operating temperature along the axis to within ±4 °C. The experiments gave a steady catalyst productivity of 0.7-0.8 g/g catalyst/h, liquid hydrocarbon selectivity of ~75%, and diesel and jet fuel range hydrocarbon selectivity in the liquid product as high as 85% depending on process conditions. A preliminary techno-economic evaluation showed that the SR technology-based 50,000 bpd plant had a 10 % lower total plant cost compared to a conventional slurry reactor based plant. Furthermore, because of the modular nature of the SR technology, it was shown that the total plant cost advantage increases to >35 % as the plant is scaled down to 1000 bpd.« less

Factorial validity and internal consistency of the motivational climate in physical education scale.

PubMed

Soini, Markus; Liukkonen, Jarmo; Watt, Anthony; Yli-Piipari, Sami; Jaakkola, Timo

2014-01-01

The aim of the study was to examine the construct validity and internal consistency of the Motivational Climate in Physical Education Scale (MCPES). A key element of the development process of the scale was establishing a theoretical framework that integrated the dimensions of task- and ego involving climates in conjunction with autonomy, and social relatedness supporting climates. These constructs were adopted from the self-determination and achievement goal theories. A sample of Finnish Grade 9 students, comprising 2,594 girls and 1,803 boys, completed the 18-item MCPES during one physical education class. The results of the study demonstrated that participants had highest mean in task-involving climate and the lowest in autonomy climate and ego-involving climate. Additionally, autonomy, social relatedness, and task- involving climates were significantly and strongly correlated with each other, whereas the ego- involving climate had low or negligible correlations with the other climate dimensions.The construct validity of the MCPES was analyzed using confirmatory factor analysis. The statistical fit of the four-factor model consisting of motivational climate factors supporting perceived autonomy, social relatedness, task-involvement, and ego-involvement was satisfactory. The results of the reliability analysis showed acceptable internal consistencies for all four dimensions. The Motivational Climate in Physical Education Scale can be considered as psychometrically valid tool to measure motivational climate in Finnish Grade 9 students. Key PointsThis study developed Motivational Climate in School Physical Education Scale (MCPES). During the development process of the scale, the theoretical framework using dimensions of task- and ego involving as well as autonomy, and social relatedness supporting climates was constructed. These constructs were adopted from the self-determination and achievement goal theories.The statistical fit of the four-factor model of the MCPES consisting of motivational climate factors supporting perceived autonomy, social relatedness, task-involvement, and ego-involvement was satisfactory. Additionally, the results of the reliability analysis showed acceptable internal consistencies for all four dimensions.The results of the study demonstrated that participants had highest mean in task-involving climate and the lowest in autonomy climate.Autonomy, social relatedness, and task climate were significantly and strongly correlated with each other, whereas the ego climate factor had low or negligible correlations with the other three factors.

Factorial Validity and Internal Consistency of the Motivational Climate in Physical Education Scale

PubMed Central

Soini, Markus; Liukkonen, Jarmo; Watt, Anthony; Yli-Piipari, Sami; Jaakkola, Timo

2014-01-01

The aim of the study was to examine the construct validity and internal consistency of the Motivational Climate in Physical Education Scale (MCPES). A key element of the development process of the scale was establishing a theoretical framework that integrated the dimensions of task- and ego involving climates in conjunction with autonomy, and social relatedness supporting climates. These constructs were adopted from the self-determination and achievement goal theories. A sample of Finnish Grade 9 students, comprising 2,594 girls and 1,803 boys, completed the 18-item MCPES during one physical education class. The results of the study demonstrated that participants had highest mean in task-involving climate and the lowest in autonomy climate and ego-involving climate. Additionally, autonomy, social relatedness, and task- involving climates were significantly and strongly correlated with each other, whereas the ego- involving climate had low or negligible correlations with the other climate dimensions.The construct validity of the MCPES was analyzed using confirmatory factor analysis. The statistical fit of the four-factor model consisting of motivational climate factors supporting perceived autonomy, social relatedness, task-involvement, and ego-involvement was satisfactory. The results of the reliability analysis showed acceptable internal consistencies for all four dimensions. The Motivational Climate in Physical Education Scale can be considered as psychometrically valid tool to measure motivational climate in Finnish Grade 9 students. Key Points This study developed Motivational Climate in School Physical Education Scale (MCPES). During the development process of the scale, the theoretical framework using dimensions of task- and ego involving as well as autonomy, and social relatedness supporting climates was constructed. These constructs were adopted from the self-determination and achievement goal theories. The statistical fit of the four-factor model of the MCPES consisting of motivational climate factors supporting perceived autonomy, social relatedness, task-involvement, and ego-involvement was satisfactory. Additionally, the results of the reliability analysis showed acceptable internal consistencies for all four dimensions. The results of the study demonstrated that participants had highest mean in task-involving climate and the lowest in autonomy climate. Autonomy, social relatedness, and task climate were significantly and strongly correlated with each other, whereas the ego climate factor had low or negligible correlations with the other three factors. PMID:24570617

Subjective scaling of mental workload in a multi-task environment

NASA Technical Reports Server (NTRS)

Daryanian, B.

1982-01-01

Those factors in a multi-task environment that contribute to the operators' "sense" of mental workload were identified. The subjective judgment as conscious experience of mental effort was decided to be the appropriate method of measurement. Thurstone's law of comparative judgment was employed in order to construct interval scales of subjective mental workload from paired comparisons data. An experimental paradigm (Simulated Multi-Task Decision-Making Environment) was employed to represent the ideal experimentally controlled environment in which human operators were asked to "attend" to different cases of Tulga's decision making tasks. Through various statistical analyses it was found that, in general, a lower number of tasks-to-be-processed per unit time (a condition associated with longer interarrival times), results in a lower mental workload, a higher consistency of judgments within a subject, a higher degree of agreement among the subjects, and larger distances between the cases on the Thurstone scale of subjective mental workload. The effects of various control variables and their interactions, and the different characteristics of the subjects on the variation of subjective mental workload are demonstrated.

The Mind behind the Message: Advancing Theory-of-Mind Scales for Typically Developing Children, and Those with Deafness, Autism, or Asperger Syndrome

ERIC Educational Resources Information Center

Peterson, Candida C.; Wellman, Henry M.; Slaughter, Virginia

2012-01-01

Children aged 3-2 years (n = 184) with typical development, deafness, autism, or Asperger syndrome took a series of theory-of-mind (ToM) tasks to confirm and extend previous developmental scaling evidence. A new sarcasm task, in the format of H. M. Wellman and D. Liu's (2004) 5-step ToM Scale, added a statistically reliable 6th step to the scale…

Increasing measurement accuracy of age-related BOLD signal change: minimizing vascular contributions by resting-state-fluctuation-of-amplitude scaling.

PubMed

Kannurpatti, Sridhar S; Motes, Michael A; Rypma, Bart; Biswal, Bharat B

2011-07-01

In this report we demonstrate a hemodynamic scaling method with resting-state fluctuation of amplitude (RSFA) in healthy adult younger and older subject groups. We show that RSFA correlated with breath hold (BH) responses throughout the brain in groups of younger and older subjects which RSFA and BH performed comparably in accounting for age-related hemodynamic coupling changes, and yielded more veridical estimates of age-related differences in task-related neural activity. BOLD data from younger and older adults performing motor and cognitive tasks were scaled using RSFA and BH related signal changes. Scaling with RSFA and BH reduced the skew of the BOLD response amplitude distribution in each subject and reduced mean BOLD amplitude and variability in both age groups. Statistically significant differences in intrasubject amplitude variation across regions of activated cortex, and intersubject amplitude variation in regions of activated cortex were observed between younger and older subject groups. Intra- and intersubject variability differences were mitigated after scaling. RSFA, though similar to BH in minimizing skew in the unscaled BOLD amplitude distribution, attenuated the neural activity-related BOLD amplitude significantly less than BH. The amplitude and spatial extent of group activation were lower in the older than in the younger group before and after scaling. After accounting for vascular variability differences through scaling, age-related decreases in activation volume were observed during the motor and cognitive tasks. The results suggest that RSFA-scaled data yield age-related neural activity differences during task performance with negligible effects from non-neural (i.e., vascular) sources. Copyright © 2010 Wiley-Liss, Inc.

Scaled vibratory feedback can bias muscle use in children with dystonia during a redundant, one-dimensional myocontrol task

PubMed Central

Liyanagamage, Shanie A.; Bertucco, Matteo; Bhanpuri, Nasir H.; Sanger, Terence D.

2016-01-01

Vibratory feedback can be a useful tool for rehabilitation. We examined its use in children with dystonia to understand how it affects muscle activity in a population that does not respond well to standard rehabilitation. We predicted scaled vibration (i.e. vibration that was directly or inversely proportional to muscle activity) would increase use of the vibrated muscle because of task-relevant sensory information, while non-scaled vibration would not change muscle use. The study was conducted on 11 subjects with dystonia and 14 controls. Each subject underwent 4 different types of vibration on the more dystonic biceps muscle (or non-dominant arm in controls) in a one-dimensional, bimanual myocontrol task. Our results showed that only scaled vibratory feedback could bias muscle use without changing overall performance in children with dystonia. We believe there may be a role in rehabilitation for scaled vibratory feedback to retrain abnormal muscle patterns. PMID:27798370

Comparison of NASA-TLX scale, Modified Cooper-Harper scale and mean inter-beat interval as measures of pilot mental workload during simulated flight tasks.

PubMed

Mansikka, Heikki; Virtanen, Kai; Harris, Don

2018-04-30

The sensitivity of NASA-TLX scale, modified Cooper-Harper (MCH) scale and the mean inter-beat interval (IBI) of successive heart beats, as measures of pilot mental workload (MWL), were evaluated in a flight training device (FTD). Operational F/A-18C pilots flew instrument approaches with varying task loads. Pilots' performance, subjective MWL ratings and IBI were measured. Based on the pilots' performance, three performance categories were formed; high-, medium- and low-performance. Values of the subjective rating scales and IBI were compared between categories. It was found that all measures were able to differentiate most task conditions and there was a strong, positive correlation between NASA-TLX and MCH scale. An explicit link between IBI, NASA-TLX, MCH and performance was demonstrated. While NASA-TLX, MCH and IBI have all been previously used to measure MWL, this study is the first one to investigate their association in a modern FTD, using a realistic flying mission and operational pilots.

Increasing measurement accuracy of age-related BOLD signal change: Minimizing vascular contributions by resting-state-fluctuation-of-amplitude scaling

PubMed Central

Kannurpatti, Sridhar S.; Motes, Michael A.; Rypma, Bart; Biswal, Bharat B.

2012-01-01

In this report we demonstrate a hemodynamic scaling method with resting-state fluctuation of amplitude (RSFA) in healthy adult younger and older subject groups. We show that RSFA correlated with breath hold (BH) responses throughout the brain in groups of younger and older subjects, that RSFA and BH performed comparably in accounting for age-related hemodynamic coupling changes, and yielded more veridical estimates of age-related differences in task-related neural activity. BOLD data from younger and older adults performing motor and cognitive tasks were scaled using RSFA and BH related signal changes. Scaling with RSFA and BH reduced the skew of the BOLD response amplitude distribution in each subject and reduced mean BOLD amplitude and variability in both age groups. Statistically significant differences in intra-subject amplitude variation across regions of activated cortex, and inter-subject amplitude variation in regions of activated cortex were observed between younger and older subject groups. Intra- and inter-subject variability differences were mitigated after scaling. RSFA, though similar to BH in minimizing skew in the un-scaled BOLD amplitude distribution, attenuated the neural activity related BOLD amplitude significantly less than BH. The amplitude and spatial extent of group activation were lower in the older than in the younger group prior to and after scaling. After accounting for vascular variability differences through scaling, age-related decreases in activation volume were observed during the motor and cognitive tasks. The results suggest that RSFA-scaled data yield age-related neural activity differences during task performance with negligible effects from non-neural (i.e., vascular) sources. PMID:20665721

Between-Trial Forgetting Due to Interference and Time in Motor Adaptation.

PubMed

Kim, Sungshin; Oh, Youngmin; Schweighofer, Nicolas

2015-01-01

Learning a motor task with temporally spaced presentations or with other tasks intermixed between presentations reduces performance during training, but can enhance retention post training. These two effects are known as the spacing and contextual interference effect, respectively. Here, we aimed at testing a unifying hypothesis of the spacing and contextual interference effects in visuomotor adaptation, according to which forgetting between trials due to either spaced presentations or interference by another task will promote between-trial forgetting, which will depress performance during acquisition, but will promote retention. We first performed an experiment with three visuomotor adaptation conditions: a short inter-trial-interval (ITI) condition (SHORT-ITI); a long ITI condition (LONG-ITI); and an alternating condition with two alternated opposite tasks (ALT), with the same single-task ITI as in LONG-ITI. In the SHORT-ITI condition, there was fastest increase in performance during training and largest immediate forgetting in the retention tests. In contrast, in the ALT condition, there was slowest increase in performance during training and little immediate forgetting in the retention tests. Compared to these two conditions, in the LONG-ITI, we found intermediate increase in performance during training and intermediate immediate forgetting. To account for these results, we fitted to the data six possible adaptation models with one or two time scales, and with interference in the fast, or in the slow, or in both time scales. Model comparison confirmed that two time scales and some degree of interferences in either time scale are needed to account for our experimental results. In summary, our results suggest that retention following adaptation is modulated by the degree of between-trial forgetting, which is due to time-based decay in single adaptation task and interferences in multiple adaptation tasks.

Recovery. Oxygen Transport Membrane-Based OxyCombustion for CO 2 Capture from Power Plants

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

Kelly, Sean; Geary, Joan; Chakravrti, Shrikar

2015-12-22

This Final report documents and summarizes all of the work performed for the DOE award DE-FC26-07NT43088 during the period from April 2007 - June 2012. This report outlines accomplishments for the following tasks: Task 1 – Process and Systems Engineering, Task 2 – OTM Performance Improvement, Task 3 – OTM Manufacturing Development, Task 4 - Laboratory Scale Testing and Task 5 – Project Management.

Embedding Task-Based Neural Models into a Connectome-Based Model of the Cerebral Cortex.

PubMed

Ulloa, Antonio; Horwitz, Barry

2016-01-01

A number of recent efforts have used large-scale, biologically realistic, neural models to help understand the neural basis for the patterns of activity observed in both resting state and task-related functional neural imaging data. An example of the former is The Virtual Brain (TVB) software platform, which allows one to apply large-scale neural modeling in a whole brain framework. TVB provides a set of structural connectomes of the human cerebral cortex, a collection of neural processing units for each connectome node, and various forward models that can convert simulated neural activity into a variety of functional brain imaging signals. In this paper, we demonstrate how to embed a previously or newly constructed task-based large-scale neural model into the TVB platform. We tested our method on a previously constructed large-scale neural model (LSNM) of visual object processing that consisted of interconnected neural populations that represent, primary and secondary visual, inferotemporal, and prefrontal cortex. Some neural elements in the original model were "non-task-specific" (NS) neurons that served as noise generators to "task-specific" neurons that processed shapes during a delayed match-to-sample (DMS) task. We replaced the NS neurons with an anatomical TVB connectome model of the cerebral cortex comprising 998 regions of interest interconnected by white matter fiber tract weights. We embedded our LSNM of visual object processing into corresponding nodes within the TVB connectome. Reciprocal connections between TVB nodes and our task-based modules were included in this framework. We ran visual object processing simulations and showed that the TVB simulator successfully replaced the noise generation originally provided by NS neurons; i.e., the DMS tasks performed with the hybrid LSNM/TVB simulator generated equivalent neural and fMRI activity to that of the original task-based models. Additionally, we found partial agreement between the functional connectivities using the hybrid LSNM/TVB model and the original LSNM. Our framework thus presents a way to embed task-based neural models into the TVB platform, enabling a better comparison between empirical and computational data, which in turn can lead to a better understanding of how interacting neural populations give rise to human cognitive behaviors.

Children's Understanding of Large-Scale Mapping Tasks: An Analysis of Talk, Drawings, and Gesture

ERIC Educational Resources Information Center

Kotsopoulos, Donna; Cordy, Michelle; Langemeyer, Melanie

2015-01-01

This research examined how children represent motion in large-scale mapping tasks that we referred to as "motion maps". The underlying mathematical content was transformational geometry. In total, 19 children, 8- to 10-year-old, created motion maps and captured their motion maps with accompanying verbal description digitally. Analysis of…

Rule Following and Rule Use in the Balance-Scale Task

ERIC Educational Resources Information Center

Shultz, Thomas R.; Takane, Yoshio

2007-01-01

Quinlan et al. [Quinlan, p., van der Mass, H., Jansen, B., Booij, O., & Rendell, M. (this issue). Re-thinking stages of cognitive development: An appraisal of connectionist models of the balance scale task. "Cognition", doi:10.1016/j.cognition.2006.02.004] use Latent Class Analysis (LCA) to criticize a connectionist model of development on the…

Thermodynamic effects of calcium and iron oxides on crystal phase formation in synthetic gasifier slags containing from 0 to 27wt.% V 2O 3

DOE PAGES

Nakano, Jinichiro; Duchesne, Marc; Bennett, James; ...

2014-11-15

Thermodynamic phase equilibria in synthetic slags (Al 2O 3–CaO–FeO–SiO 2–V 2O 3) were investigated with 0–27 wt.% vanadium oxide corresponding to industrial coal–petroleum coke (petcoke) feedstock blends in a simulated gasifier environment. Samples encompassing coal–petcoke mixed slag compositions were equilibrated at 1500 °C in a 64 vol.% CO/36 vol.% CO 2 atmosphere (Po 2 ≈ 10 –8 atm at 1500 °C) for 72 h, followed by rapid water quench, then analyzed by inductively coupled plasma optical emission spectrometry, X-ray diffractometry, and scanning electron microscopy with wavelength dispersive spectroscopy. With increasing CaO content, FeO content, or both; the slag homogeneity regionmore » expanded and a composition range exhibiting crystals was reduced. The mullite (Al 6Si 2O 13) crystalline phase was not present in the slags above 9 wt.% FeO while the karelianite (V 2O 3) crystalline phase was always present in compositions studied if a sufficient amount of vanadium existed in the slag. Furthermore, based on the present experimental equilibrium evaluation, a set of isothermal phase diagrams showing effects of CaO and FeO on thermodynamic phase stabilities in the vanadium-bearing slags is proposed. Some uses of the diagrams for potential industrial practice are discussed.« less

Correction of Dynamic Characteristics of SAR Cryogenic GTE on Consumption of Gasified Fuel

NASA Astrophysics Data System (ADS)

Bukin, V. A.; Gimadiev, A. G.; Gangisetty, G.

2018-01-01

When the gas turbine engines (GTE) NK-88 were developed for liquid hydrogen and NK-89 for liquefied natural gas, performance of the systems with a turbo-pump unitary was improved and its proved without direct regulation of the flow of a cryogenic fuel, which was supplied by a centrifugal pump of the turbo-pump unit (TPU) Command from the “kerosene” system. Such type of the automatic control system (SAR) has the property of partial “neutralization” of the delay caused by gasification of the fuel. This does not require any measurements in the cryogenic medium, and the failure of the centrifugal cryogenic pump does not lead to engine failure. On the other hand, the system without direct regulation of the flow of cryogenic fuel has complex internal dynamic connections, their properties are determined by the characteristics of the incoming units and assemblies, and it is difficult to maintain accurate the maximum boundary level and minimum fuel consumption due to the influence of a booster pressure change. Direct regulation of the consumption of cryogenic fuel (prior to its gasification) is the preferred solution, since for using traditional liquid and gaseous fuels this is the main and proven method. The scheme of correction of dynamic characteristics of a single-loop SAR GTE for the consumption of a liquefied cryogenic fuel with a flow rate correction in its gasified state, which ensures the dynamic properties of the system is not worse than for NK-88 and NK-89 engines.

Evaluation of advanced combustion concepts for dry NO sub x suppression with coal-derived, gaseous fuels

NASA Technical Reports Server (NTRS)

Beebe, K. W.; Symonds, R. A.; Notardonato, J. J.

1982-01-01

The emissions performance of a rich lean combustor (developed for liquid fuels) was determined for combustion of simulated coal gases ranging in heating value from 167 to 244 Btu/scf (7.0 to 10.3 MJ/NCM). The 244 Btu/scf gas is typical of the product gas from an oxygen blown gasifier, while the 167 Btu/scf gas is similar to that from an air blown gasifier. NOx performance of the rich lean combustor did not meet program goals with the 244 Btu/scf gas because of high thermal NOx, similar to levels expected from conventional lean burning combustors. The NOx emissions are attributed to inadequate fuel air mixing in the rich stage resulting from the design of the large central fuel nozzle delivering 71% of the total gas flow. NOx yield from ammonia injected into the fuel gas decreased rapidly with increasing ammonia level, and is projected to be less than 10% at NH3 levels of 0.5% or higher. NOx generation from NH3 is significant at ammonia concentrations significantly less than 0.5%. These levels may occur depending on fuel gas cleanup system design. CO emissions, combustion efficiency, smoke and other operational performance parameters were satisfactory. A test was completed with a catalytic combustor concept with petroleum distillate fuel. Reactor stage NOx emissions were low (1.4g NOx/kg fuel). CO emissions and combustion efficiency were satisfactory. Airflow split instabilities occurred which eventually led to test termination.

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

Udengaard, Niels; Knight, Richard; Wendt, Jesper

This final report presents the results of a four-year technology demonstration project carried out by a consortium of companies sponsored in part by a $25 million funding by the Department of Energy (DOE) under the American Recovery and Reinvestment Act (ARRA). The purpose of the project was to demonstrate a new, economical technology for the thermochemical conversion of woody biomass into gasoline and to demonstrate that the gasoline produced in this way is suitable for direct inclusion in the already existing gasoline pool. The process that was demonstrated uses the Andritz-Carbona fluidized-bed steam-oxygen gasification technology and advanced tar reforming catalyticmore » systems to produce a clean syngas from waste wood, integrated conventional gas cleanup steps, and finally utilizes Haldor Topsoe’s (Topsoe) innovative Topsoe Improved Gasoline Synthesis (TIGASTM) syngas-to-gasoline process. Gas Technology Institute (GTI) carried out the bulk of the testing work at their Flex Fuel development facility in Des Plaines, Illinois; UPM in Minnesota supplied and prepared the feedstocks, and characterization of liquid products was conducted in Phillips 66 labs in Oklahoma. The produced gasoline was used for a single-engine emission test at Southwest Research Institute (SwRI®) in San Antonio, TX, as well as in a fleet test at Transportation Research Center, Inc. (TRC Inc.) in East Liberty, Ohio. The project benefited from the use of existing pilot plant equipment at GTI, including a 21.6 bone dry short ton/day gasifier, tar reformer, Morphysorb® acid gas removal, associated syngas cleanup and gasifier feeding and oxygen systems.« less

Thermodynamics Analysis of Refinery Sludge Gasification in Adiabatic Updraft Gasifier

PubMed Central

Ahmed, Reem; Sinnathambi, Chandra M.; Eldmerdash, Usama; Subbarao, Duvvuri

2014-01-01

Limited information is available about the thermodynamic evaluation for biomass gasification process using updraft gasifier. Therefore, to minimize errors, the gasification of dry refinery sludge (DRS) is carried out in adiabatic system at atmospheric pressure under ambient air conditions. The objectives of this paper are to investigate the physical and chemical energy and exergy of product gas at different equivalent ratios (ER). It will also be used to determine whether the cold gas, exergy, and energy efficiencies of gases may be maximized by using secondary air injected to gasification zone under various ratios (0, 0.5, 1, and 1.5) at optimum ER of 0.195. From the results obtained, it is indicated that the chemical energy and exergy of producer gas are magnified by 5 and 10 times higher than their corresponding physical values, respectively. The cold gas, energy, and exergy efficiencies of DRS gasification are in the ranges of 22.9–55.5%, 43.7–72.4%, and 42.5–50.4%, respectively. Initially, all 3 efficiencies increase until they reach a maximum at the optimum ER of 0.195; thereafter, they decline with further increase in ER values. The injection of secondary air to gasification zone is also found to increase the cold gas, energy, and exergy efficiencies. A ratio of secondary air to primary air of 0.5 is found to be the optimum ratio for all 3 efficiencies to reach the maximum values. PMID:24672368