These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Converting poultry litter to activated carbon: optimal carbonization conditions and product sorption for benzene.  

PubMed

To promote utilization of poultry litter as a source material for manufacturing low-cost activated carbon (AC) that can be used in wastewater treatment, this study investigated optimal production conditions and water-borne organic sorption potential of poultry litter-based AC. Pelletized broiler litter was carbonized at different temperatures for varied time periods and activated with steam at a range of flow rate and time. The AC products were examined for quality characteristics using standard methods and for organic sorption potentials using batch benzene sorption techniques. The study shows that the yield and quality of litter AC varied with production conditions. The optimal production conditions for poultry litter-based AC were carbonization at 700 degrees C for 45 min followed by activation with 2.5 ml min(-1) steam for another 45 min. The resulting AC possessed an iodine number of 454 mg g(-1) and a specific surface area of 403 m2 g(-1). It sorbed benzene in water following sigmoidal kinetic and isothermal patterns. The sorption capacity for benzene was 23.70 mg g(-1), lower than that of top-class commercial AC. The results, together with other reported research findings, suggest that poultry litter is a reasonable feedstock for low-cost AC applicable to pre-treat wastewater contaminated by organic pollutants and heavy metals. PMID:22439566

Guo, Mingxin; Song, Weiping

2011-12-01

2

Activated Carbon Production from Date Stones Using Phosphoric Acid  

Microsoft Academic Search

The effects of activation time and activation temperature on the yield and the adsorptive capacity towards iodine were studied. The yield and the quality of the activated carbon prepared by using H3PO4 were compared with that prepared from date stones using the same equipment, and under similar conditions by using ZnCl2 as an oxidizing agent. The iodine number for the

F. Al-Qaessi; L. Abu-Farah

2010-01-01

3

Optimization of microporous palm shell activated carbon production for flue gas desulphurization: experimental and statistical studies.  

PubMed

Optimizing the production of microporous activated carbon from waste palm shell was done by applying experimental design methodology. The product, palm shell activated carbon was tested for removal of SO2 gas from flue gas. The activated carbon production was mathematically described as a function of parameters such as flow rate, activation time and activation temperature of carbonization. These parameters were modeled using response surface methodology. The experiments were carried out as a central composite design consisting of 32 experiments. Quadratic models were developed for surface area, total pore volume, and microporosity in term of micropore fraction. The models were used to obtain the optimum process condition for the production of microporous palm shell activated carbon useful for SO2 removal. The optimized palm shell activated carbon with surface area of 973 m(2)/g, total pore volume of 0.78 cc/g and micropore fraction of 70.5% showed an excellent agreement with the amount predicted by the statistical analysis. Palm shell activated carbon with higher surface area and microporosity fraction showed good adsorption affinity for SO2 removal. PMID:18952414

Sumathi, S; Bhatia, S; Lee, K T; Mohamed, A R

2009-02-01

4

Production of activated carbons from waste tire--process design and economical analysis.  

PubMed

The process design and economic analysis of process plants to produce activated carbons from waste tires and coal have been performed. The potential range of products from each process has been considered, namely for waste tire--pyro-gas, active carbon, carbon black and pyro-oil; for coal--pyro-gas and active carbons. Sensitivity analyses have been carried out on the main process factors; these are product price, production capacity, total production cost, capital investment and the tipping fee. Net present values for the two plants at various discount factors have been determined and the internal rates of return have been determined as 27.4% and 18.9% for the waste tire plant and the coal plant, respectively. PMID:15504665

Ko, Danny C K; Mui, Edward L K; Lau, Ken S T; McKay, Gordon

2004-01-01

5

Production of activated carbons from pyrolysis of waste tires impregnated with potassium hydroxide.  

PubMed

Activated carbons were produced from waste tires using a chemical activation method. The carbon production process consisted of potassium hydroxide (KOH) impregnation followed by pyrolysis in N2 at 600-900 degrees C for 0-2 hr. The activation method can produce carbons with a surface area (SA) and total pore volume as high as 470 m2/g and 0.57 cm3/g, respectively. The influence of different parameters during chemical activation, such as pyrolysis temperature, holding time, and KOH/tire ratio, on the carbon yield and the surface characteristics was explored, and the optimum preparation conditions were recommended. The pore volume of the resulting carbons generally increases with the extent of carbon gasified by KOH and its derivatives, whereas the SA increases with degree of gasification to reach a maximum value, and then decreases upon further gasification. PMID:11111338

Teng, H; Lin, Y C; Hsu, L Y

2000-11-01

6

Activated carbon from pyrolysis of brewer's spent grain: Production and adsorption properties.  

PubMed

Brewer's spent grain is a low cost residue generated by the brewing industry. Its chemical composition (high nitrogen content 4.35 wt.%, fibres, etc.) makes it very useful for the production of added value in situ nitrogenised activated carbon. The composition of brewer's spent grain revealed high amounts of cellulose (20.8 wt.%), hemicellulose (48.78 wt.%) and lignin (11.3 wt.%). The fat, ethanol extractives and ash accounted for 8.17 wt.%, 4.7 wt.% and 3.2 wt.%, respectively. Different activated carbons were produced in a lab-scale pyrolysis/activation reactor by applying several heat and steam activation profiles on brewer's spent grain. Activated carbon yields from 16.1 to 23.6 wt.% with high N-contents (> 2 wt.%) were obtained. The efficiency of the prepared activated carbons for phenol adsorption was studied as a function of different parameters: pH, contact time and carbon dosage relative to two commercial activated carbons. The equilibrium isotherms were described by the non-linear Langmuir and Freundlich models, and the kinetic results were fitted using the pseudo-first-order model and the pseudo-second-order model. The feasibility of an activated carbon production facility (onsite and offsite) that processes brewer's spent grain for different input feeds is evaluated based on a techno-economic model for estimating the net present value. Even though the model assumptions start from a rather pessimistic scenario, encouraging results for a profitable production of activated carbon using brewer's spent grain are obtained. PMID:25012859

Vanreppelen, Kenny; Vanderheyden, Sara; Kuppens, Tom; Schreurs, Sonja; Yperman, Jan; Carleer, Robert

2014-06-20

7

Brazilian natural fiber (jute) as raw material for activated carbon production.  

PubMed

Jute fiber is the second most common natural cellulose fiber worldwide, especially in recent years, due to its excellent physical, chemical and structural properties. The objective of this paper was to investigate: the thermal degradation of in natura jute fiber, and the production and characterization of the generated activated carbon. The production consisted of carbonization of the jute fiber and activation with steam. During the activation step the amorphous carbon produced in the initial carbonization step reacted with oxidizing gas, forming new pores and opening closed pores, which enhanced the adsorptive capacity of the activated carbon. N2 gas adsorption at 77K was used in order to evaluate the effect of the carbonization and activation steps. The results of the adsorption indicate the possibility of producing a porous material with a combination of microporous and mesoporous structure, depending on the parameters used in the processes, with resulting specific surface area around 470 m2.g-1. The thermal analysis indicates that above 600°C there is no significant mass loss. PMID:25590747

Rombaldo, Carla F S; Lisboa, Antonio C L; Mendez, Manoel O A; Coutinho, Aparecido R

2014-12-01

8

PRODUCTION OF GRANULAR ACTIVATED CARBONS FROM PIG MANURE FOR METAL IONS ADSORPTION  

Technology Transfer Automated Retrieval System (TEKTRAN)

The current method of processing pig waste involves diluting it into large lagoons, which carries both environmental and human health risks. Alternatives to pig waste disposal are its reuse into value added products. This study produces activated carbons from swine manure and characterizes them in...

9

Activated carbons from sewage sludge and discarded tyres: production and optimization.  

PubMed

This is a study about making use of two residual materials such as sludges from a sewage treatment plant and discarded tyres to generate activated carbons and later optimize the production process. H2SO4 and ZnCl2 were used as chemical activating agents. Liquid-phase adsorption tests were made using the produced carbons to retain methylene blue and iodine. The best precursor was sludge activated with ZnCl2. After optimization studies, the best production methodology involved a 1:1 ratio of sludge and ZnCl2, a heating rate of 5 degrees C/min up to 650 degrees C and a residence time of 5 min. The resulting materials adsorbed up to 139.4 mg/g of methylene blue and 1358.5 mg/g of iodine. Nevertheless these carbons may leach Zn while using. To avoid this two treatments were carried out: one consisting of a coating with a polymer and another involving an intensive washing, which was seen to be more efficient. PMID:15955625

Rozada, F; Otero, M; Morán, A; García, A I

2005-09-30

10

GRANULAR ACTIVATED CARBON INSTALLATIONS  

EPA Science Inventory

This paper presents a compilation and summary of design criteria, performance, and cost data from 22 operating municipal and industrial granular activated carbon (GAC) installations that treat water and wastewater or process food and beverage products. Guidance for using this inf...

11

A packed bed membrane reactor for production of biodiesel using activated carbon supported catalyst.  

PubMed

In this study, a novel continuous reactor has been developed to produce high quality methyl esters (biodiesel) from palm oil. A microporous TiO2/Al2O3 membrane was packed with potassium hydroxide catalyst supported on palm shell activated carbon. The central composite design (CCD) of response surface methodology (RSM) was employed to investigate the effects of reaction temperature, catalyst amount and cross flow circulation velocity on the production of biodiesel in the packed bed membrane reactor. The highest conversion of palm oil to biodiesel in the reactor was obtained at 70 °C employing 157.04 g catalyst per unit volume of the reactor and 0.21 cm/s cross flow circulation velocity. The physical and chemical properties of the produced biodiesel were determined and compared with the standard specifications. High quality palm oil biodiesel was produced by combination of heterogeneous alkali transesterification and separation processes in the packed bed membrane reactor. PMID:20888219

Baroutian, Saeid; Aroua, Mohamed K; Raman, Abdul Aziz A; Sulaiman, Nik M N

2011-01-01

12

Production of Carbon Dioxide  

NSDL National Science Digital Library

In this chemistry activity, learners use common chemicals to produce carbon dioxide and observe its properties. This resource includes brief questions for learners to answer after the experiment. Use this activity to introduce learners to carbon dioxide and its use as a fire extinguisher. Note: this activity involves an open flame.

House, The S.

2014-01-28

13

Microbial activity and dissolved organic carbon production in drained and rewetted blanket peat  

NASA Astrophysics Data System (ADS)

Heightened levels of degradation in response to environmental change have resulted in an increased loss of dissolved organic carbon (DOC) in the drainage waters of many peatland catchments across Europe and North America. One significant threat to peatland sustainability has been the installation of artificial drainage ditches, and although recent restoration schemes have pursued drain blocking as a possible strategy for reducing degradation and fluvial carbon losses, little is known about how such processes influence the intimate biological systems operating within these soils. This paper investigates how disturbance, in the form of drainage and drain blocking, influences the rate of microbial activity within a peat soil, and the subsequent impact this has on DOC production potential. Peat samples were extracted from three treatment sites (intact peat, drained peat and drain-blocked peat) in an upland blanket peat catchment in the UK. Microbial activity was measured via laboratory experimentation that incorporated the use of an INT-Formazan dehydrogenase enzyme assay to assess the level of electron transport system (ETS) activity occurring within each treatment. Drainage significantly lowered the height of the water table relative to the intact peat, whilst drain blocking successfully rewetted the peat, having raised the height of the water table relative to the drained site. Mean microbial activity rates at the drained site were found to be 33 % greater than the undisturbed intact peat and almost double that of the restored, drain-blocked site. These results correspond well with previously published data observing significantly greater DOC concentrations in the pore waters of the drained site and significantly lower concentrations at the blocked site, relative to the intact peat. Data from the drain-blocked treatment also provides evidence contrary to the commonly quoted hypothesis that an enzyme-latch reaction may be sustained in drained peat, even once it has been rewetted following water table restoration. Data is also presented that demonstrates how earlier research using INT-Formazan to assess microbial activity in peat, which has not incorporated correction for the spectrophotometric interference incurred from coloured DOC compounds, should be treated with caution.

Wallage, Z. E.; Holden, J.; Jones, T.; McDonald, A. T.

2009-04-01

14

Production of energy and activated carbon from agri-residue: sunflower seed example.  

PubMed

In this work, a biomass processing facility is designed and simulated for the annual conversion of 77 ktons of sunflower residue into electricity and activated carbon. The residue is initially pyrolized to produce low hydrocarbon gases (35 wt%), bio-oils (30 wt%), and char (35 wt%). The gases and bio-oils are separated and combusted to generate high pressure steam, electricity, and steam for conversion of char into activated carbon. Assuming 35% of the char's mass is lost during activation, the proposed process produces 15.6 ktons activated carbon and 5.5 ktons ash annually, while generating 10.2 MW of electricity. Economic analysis of the proposed facility yielded capital costs of $31.64 million, annual operating costs of $31.58 million, and a yearly gross revenue of $38.9 million. A discounted payback period of 6.1 years was determined for the current design, extending to 10 years if the facility were operated at 75% capacity. While the proposed process appears to be economically viable, profitability is highly sensitive to the selling price of electricity and activated carbon, highlighting the need for additional research into the pyrolysis reactor design, char/ash separation techniques, and the quality of activated carbon obtained using char from sunflower residue pyrolysis. PMID:21938425

Donaldson, Adam A; Kadakia, Parag; Gupta, Murlidhar; Zhang, Zisheng

2012-09-01

15

Polyhydroxyalkanoates (PHA) production using wastewater as carbon source and activated sludge as microorganisms.  

PubMed

Activated sludge from different full-scale wastewater treatment plants (municipal, pulp and paper industry, starch manufacturing and cheese manufacturing wastewaters) was used as a source of microorganisms to produce biodegradable plastics in shake flask experiments. Acetate, glucose and different wastewaters were used as carbon sources. Pulp and paper wastewater sludge was found to accumulate maximum concentration (43% of dry weight of suspended solids) of polyhydroxy alkanoates (PHA) with acetate as carbon source. Among the different wastewaters tested as a source of carbon, pulp and paper industry and starch industry wastewaters were found to be the best source of carbon while employing pulp and paper activated sludge for maximum accumulation of PHA. High concentration of volatile fatty acids in these wastewaters was the probable reason. PMID:16749455

Yan, S; Tyagi, R D; Surampalli, R Y

2006-01-01

16

Production of activated carbon by waste tire thermochemical degradation with CO2.  

PubMed

The thermochemical degradation of waste tires in a CO(2) atmosphere without previous treatment of devolatilization (pyrolysis) in order to obtain activated carbons with good textural properties such as surface area and porosity was studied. The operating variables studied were CO(2) flow rate (50 and 150 mL/min), temperature (800 and 900 degrees C) and reaction time (1, 1.5, 2, 2.5 and 3h). Results show a considerable effect of the temperature and the reaction time in the porosity development. Kinetic measurements showed that the reactions involved in the thermochemical degradation of waste tire with CO(2), are similar to those developed in the pyrolysis process carried out under N(2) atmosphere and temperatures below 760 degrees C, for particles sizes of 500 microm and heating rate of 5 degrees C/min. For temperatures higher than 760 degrees C the CO(2) starts to oxidize the remaining carbon black. Activated carbon with a 414-m(2)/g surface area at 900 degrees C of temperature, 150 mL/min of CO(2) volumetric flow and 180 min of reaction time was obtained. In this work it is considering the no reactivity of CO(2) for devolatilization of the tires (up to 760 degrees C), and also the partial oxidation of residual char at high temperature for activation (>760 degrees C). It is confirmed that there are two consecutive stages (devolatilization and activation) developed from the same process. PMID:19398156

Betancur, Mariluz; Martínez, Juan Daniel; Murillo, Ramón

2009-09-15

17

CHARACTERIZATION OF CARBON FIBER EMISSIONS FROM CURRENT AND PROJECTED ACTIVITIES FOR THE MANUFACTURE AND DISPOSAL OF CARBON FIBER PRODUCTS  

EPA Science Inventory

Composite materials formed by impregnating a carbon or graphite fiber mat with plastic binders are being used increasingly in military, aerospace, sports and automotive applications. Carbon fibers are formed primarily from synthetic fibers carbonized in the absence of oxygen. Pos...

18

Removal of mercury from aqueous solutions using activated carbon prepared from agricultural by-product/waste.  

PubMed

Removal of mercury from aqueous solutions using activated carbon prepared from Ceiba pentandra hulls, Phaseolus aureus hulls and Cicer arietinum waste was investigated. The influence of various parameters such as effect of pH, contact time, initial metal ion concentration and adsorbent dose for the removal of mercury was studied using a batch process. The experiments demonstrated that the adsorption process corresponds to the pseudo-second-order-kinetic models and the equilibrium adsorption data fit the Freundlich isotherm model well. The prepared adsorbents ACCPH, ACPAH and ACCAW had removal capacities of 25.88 mg/g, 23.66 mg/g and 22.88 mg/g, respectively, at an initial Hg(II) concentration of 40 mg/L. The order of Hg(II) removal capacities of these three adsorbents was ACCPH>ACPAH>ACCAW. The adsorption behavior of the activated carbon is explained on the basis of its chemical nature. The feasibility of regeneration of spent activated carbon adsorbents for recovery of Hg(II) and reuse of the adsorbent was determined using HCl solution. PMID:18313830

Rao, M Madhava; Reddy, D H K Kumar; Venkateswarlu, Padala; Seshaiah, K

2009-01-01

19

Enhancement of nuclease P1 production by Penicillium citrinum YL104 immobilized on activated carbon filter sponge.  

PubMed

The efficiency of current methods for industrial production of the enzyme nuclease P1 is limited. In this study, we sought to improve fermentation methods for the production of nuclease P1. An immobilized fermentation system using an activated carbon filter sponge as a carrier was used for the production of nuclease P1. In an airlift internal loop reactor (ALR), the fermentation performance of three different fermentation modes, including free-cell fermentation, repeated-batch fermentation, and semi-continuous immobilized fermentation, were compared. The fermentation kinetics in the fermentation broth of the three fermentation modes, including dissolved oxygen (DO), pH value, cell concentration, residual sugar concentration, and enzyme activity, were tested. The productivity of semi-continuous immobilized fermentation reached 8.76 U/mL/h, which was 33.3 and 80.2 % higher than that of repeated-batch fermentation and free-cell fermentation, respectively. The sugar consumption of free-cell, repeated-batch, and semi-continuous immobilized fermentations was 41.2, 30.8, and 25.9 g/L, respectively. These results showed that immobilized-cell fermentation by using Penicillium citrinum with activated carbon filter sponge in an ALR was advantageous for nuclease P1 production, especially in the semi-continuous immobilized fermentation mode. In spite of the significant improvement in nuclease P1 production in semi-continuous immobilized fermentation mode, the specific activity of nuclease P1 was almost equal among the three fermentation modes. PMID:25472432

Zhao, Nan; Ren, Hengfei; Li, Zhenjian; Zhao, Ting; Shi, Xinchi; Cheng, Hao; Zhuang, Wei; Chen, Yong; Ying, Hanjie

2015-02-01

20

Carbon Calculator Activity  

NSDL National Science Digital Library

In this learning activity, students use a web-based carbon calculator to determine their carbon footprint on the basis of their personal and household habits and choices. Students identify which personal activities and household choices produce the most CO2 emissions, compare their carbon footprint to the U.S. and global averages, and identify lifestyle changes they can make to reduce their footprint.

Environmental Literacy and Inquiry Working Group at Lehigh University

21

Simultaneous activation/sulfurization method for production of sulfurized activated carbons: characterization and Hg(II) adsorption capacity.  

PubMed

As an inexpensive method for modification of activated carbons (ACs), sulfurization has attracted significant attention. However, the resulting sulfurized activated carbons (SACs) often are less porous than the original ACs. In this work, we propose a new method for concurrent sulfurization/activation that can lead to preparation of SACs with more porosity than the corresponding non-sulfurized ACs. By using scanning electron microscopy, nitrogen adsorption/desorption, and iodine number experiments, the porous structure of the SACs has been compared with that of non-sulfurized ACs. The specific surface areas of SACs are higher than the corresponding ACs, regardless of the type of activation agents used. For instance, the specific surface area of SAC and AC activated with phosphoric acid is 1,637 and 1,338 m(2)/g, respectively. Additionally, sulfur contents and surface charges (pHpzc) of the SACs and non-sulfurized ACs are compared. In fact, the SACs have higher sulfur contents and more acidic surfaces. Furthermore, the Hg(II) adsorption capacity of SACs has been compared with the corresponding non-sulfurized ACs. The Hg(II) adsorption isotherms on a selected SAC is measured at different pH values and temperatures. Hg(II) adsorptions as high as 293 mg/g are observed by using SACs prepared by the method proposed in this study. PMID:24552726

Shamsijazeyi, Hadi; Kaghazchi, Tahereh

2014-01-01

22

Carbon Black Nanoparticles Promote Endothelial Activation and Lipid Accumulation in Macrophages Independently of Intracellular ROS Production  

PubMed Central

Exposure to nanoparticles (NPs) may cause vascular effects including endothelial dysfunction and foam cell formation, with oxidative stress and inflammation as supposed central mechanisms. We investigated oxidative stress, endothelial dysfunction and lipid accumulation caused by nano-sized carbon black (CB) exposure in cultured human umbilical vein endothelial cells (HUVECs), THP-1 (monocytes) and THP-1 derived macrophages (THP-1a). The proliferation of HUVECs or co-cultures of HUVECs and THP-1 cells were unaffected by CB exposure, whereas there was increased cytotoxicity, assessed by the LDH and WST-1 assays, especially in THP-1 and THP-1a cells. The CB exposure decreased the glutathione (GSH) content in THP-1 and THP-1a cells, whereas GSH was increased in HUVECs. The reactive oxygen species (ROS) production was increased in all cell types after CB exposure. A reduction of the intracellular GSH concentration by buthionine sulfoximine (BSO) pre-treatment further increased the CB-induced ROS production in THP-1 cells and HUVECs. The expression of adhesion molecules ICAM-1 and VCAM-1, but not adhesion of THP-1 to HUVECs or culture dishes, was elevated by CB exposure, whereas these effects were unaffected by BSO pre-treatment. qRT-PCR showed increased VCAM1 expression, but no change in GCLM and HMOX1 expression in CB-exposed HUVECs. Pre-exposure to CB induced lipid accumulation in THP-1a cells, which was not affected by the presence of the antioxidant N-acetylcysteine. In addition, the concentrations of CB to induce lipid accumulation were lower than the concentrations to promote intracellular ROS production in THP-1a cells. In conclusion, exposure to nano-sized CB induced endothelial dysfunction and foam cell formation, which was not dependent on intracellular ROS production. PMID:25184212

Cao, Yi; Roursgaard, Martin; Danielsen, Pernille Høgh; Møller, Peter; Loft, Steffen

2014-01-01

23

GRANULAR ACTIVATED CARBONS FROM AGRICULTURAL BY-PRODUCTS: POTENTIAL APPLICATIONS IN DRINKING WATER AND MUNICIPAL WASTEWATER TREATMENTS.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Activated carbons are used routinely in the drinking water and wastewater treatment industries to remove principally organic contaminants. While coconut shell-based carbons are used in these applications, nutshell-based carbons from tree nuts originating from domestic or U.S. sources have not been ...

24

Production of biodiesel fuel from canola oil with dimethyl carbonate using an active sodium methoxide catalyst prepared by crystallization.  

PubMed

In this study, a novel method for the production of biodiesel under mild conditions using fine particles of sodium methoxide formed in dimethyl carbonate (DMC) is proposed. Biodiesel is generally produced from vegetable oils by the transesterification of triglycerides with methanol. However, this reaction produces glycerol as a byproduct, and raw materials are not effectively utilized. Transesterification with DMC has recently been studied because glycerol is not formed in the process. Although solid-state sodium methoxide has been reported to be inactive for this reaction, the catalytic activity dramatically increased with the preparation of fine catalyst powders by crystallization. The transesterification of canola oil with DMC was studied using this catalyst for the preparation of biodiesel. A conversion greater than 96% was obtained at 65°C for 2h with a 3:1M ratio of DMC and oil and 2.0 wt% catalyst. PMID:24813567

Kai, Takami; Mak, Goon Lum; Wada, Shohei; Nakazato, Tsutomu; Takanashi, Hirokazu; Uemura, Yoshimitsu

2014-07-01

25

Thermocatalytic hydrogen production from the methane in a fluidized bed with activated carbon catalyst  

Microsoft Academic Search

A fluidized bed reactor made of quartz with 0.055m i.d. and 0.65m in height was employed for the thermocatalytic decomposition of methane to produce CO2 free hydrogen. The fluidized bed reactor was proposed in order to overcome the reactor plugging problem due to carbon deposition, which was resulted in the shut-down of the fixed bed reactor system. Several kinds of

Kang Kyu Lee; Gui Young Han; Ki June Yoon; Byung Kwon Lee

2004-01-01

26

DISINFECTION BY-PRODUCT FORMATION BY ALTERNATIVE DISINFECTANTS AND REMOVAL BY GRANULAR ACTIVATED CARBON  

EPA Science Inventory

The effects of the use of the alternative disinfectants on the formation of halogenated disinfection by–products (DBPs) including total organic halide, trihalomethanes, haloacetic acids, haloacetonitriles, haloketones, chloral hydrate, and chloropicrin, were examined along ...

27

DISINFECTION BY-PRODUCT FORMATION BY ALTERNATIVE DISINFECTANTS AND REMOVAL BY GRANULAR ACTIVATED CARBON  

EPA Science Inventory

The effects of the use of the alternative disinfectants on the formation of halogenated disinfection by-products (DBPS) including total organic halide, trihalomethanes, haloacetic acids, haloacentonitriles, haloketones, chloral hydrate, and chloropicrin, were examined along with ...

28

Activated carbons from waste biomass: an alternative use for biodiesel production solid residues.  

PubMed

Defective coffee press cake, a residue from coffee oil biodiesel production, was evaluated as raw material for production of an adsorbent for removal of methylene blue (MB) from aqueous solution. Batch adsorption tests were performed at 25 degrees C and the effects of particle size, contact time, adsorbent dosage and pH were investigated. Preliminary adsorption tests indicated that thermal treatment is necessary in order to improve adsorption capacity. Adsorption kinetics was determined by fitting first and second-order kinetic models to the experimental data, with the second-order model providing the best description of MB adsorption onto the prepared adsorbent. The experimental adsorption equilibrium data were fitted to Langmuir, Freundlich and Temkin adsorption models, with the last two providing the best fits. The experimental data obtained in the present study indicated that this type of waste material is a suitable candidate for use in the production of adsorbents for removal of cationic dyes, thus contributing for the implementation of sustainable development in both the coffee and biodiesel production chains. PMID:18996006

Nunes, Anne A; Franca, Adriana S; Oliveira, Leandro S

2009-03-01

29

Reducing carbon dioxide to products  

DOEpatents

A method reducing carbon dioxide to one or more products may include steps (A) to (C). Step (A) may bubble said carbon dioxide into a solution of an electrolyte and a catalyst in a divided electrochemical cell. The divided electrochemical cell may include an anode in a first cell compartment and a cathode in a second cell compartment. The cathode may reduce said carbon dioxide into said products. Step (B) may adjust one or more of (a) a cathode material, (b) a surface morphology of said cathode, (c) said electrolyte, (d) a manner in which said carbon dioxide is bubbled, (e), a pH level of said solution, and (f) an electrical potential of said divided electrochemical cell, to vary at least one of (i) which of said products is produced and (ii) a faradaic yield of said products. Step (C) may separate said products from said solution.

Cole, Emily Barton; Sivasankar, Narayanappa; Parajuli, Rishi; Keets, Kate A

2014-09-30

30

Carbon Dioxide Production at Home  

NSDL National Science Digital Library

In this problem set, learners will consider the "Carbon Footprint" of a family of four in a given context, as well as the US and global averages, and compare that with their own to answer a series of questions. They will use an online Carbon Footprint calculator to determine their own per-capita carbon production. Answer key is provided. This problem is part of Earth Math: A Brief Mathematical Guide to Earth Science and Climate Change.

2012-08-03

31

Labile dissolved organic carbon and water temperature as regulators of heterotrophic bacterial activity and production in the lakes of SubAntarctic Marion Island  

Microsoft Academic Search

The objectives of the 3 year study were to determine the relationship between bacterial numbers and phytoplankton standing crops (chlorophyll a) in sub-antarctic Marion Island lakes (33) and to determine the relative importance of labile dissolved organic carbon and water temperature as regulators of heterotrophic bacterial activity and production. Bacterial activity (the incorporation and respiration rates of 14C-labelled substrates) and

Richard D. Robarts; Lynne M. Sephton; Richard J. Wicks

1991-01-01

32

Growth of carbon nanofibers on activated carbon fiber fabrics  

Microsoft Academic Search

Activated carbon fiber fabrics, an excellent adsorbent, were used as catalyst supports to grow carbon nanofibers. Because of the microporous structure of the activated carbon fibers, the catalysts could be distributed uniformly on the carbon surface. Based on this concept, the carbon nanofibers can be grown directly on the activated carbon fiber fabrics. We demonstrate that carbon nanofibers with a

Shinn-Shyong Tzeng; Kai-Hsuan Hung; Tse-Hao Ko

2006-01-01

33

Silicate production and availability for mineral carbonation.  

PubMed

Atmospheric carbon dioxide sequestered as carbonates through the accelerated weathering of silicate minerals is proposed as a climate change mitigation technology with the potential to capture billions of tonnes of carbon per year. Although these materials can be mined expressly for carbonation, they are also produced by human activities (cement, iron and steel making, coal combustion, etc.). Despite their potential, there is poor global accounting of silicates produced in this way. This paper presents production estimates (by proxy) of various silicate materials including aggregate and mine waste, cement kiln dust, construction and demolition waste, iron and steel slag, and fuel ash. Approximately 7-17 billion tonnes are produced globally each year with an approximate annual sequestration potential of 190-332 million tonnes C. These estimates provide justification for additional research to accurately quantify the contemporary production of silicate minerals and to determine the location and carbon capture potential of historic material accumulations. PMID:21332128

Renforth, P; Washbourne, C-L; Taylder, J; Manning, D A C

2011-03-15

34

FREUNDLICH ADSORPTION ISOTHERMS OF AGRICULTURAL BY-PRODUCT-BASED POWDERED ACTIVATED CARBONS IN A GEOSMIN-WATER SYSTEM  

Technology Transfer Automated Retrieval System (TEKTRAN)

The present study was designed to model the adsorption of geosmin from water under laboratory conditions using the Freundlich isotherm model. This model was used to compare the efficiency of sugarcane bagasse and pecan shell-based granular activated carbon (GAC) to the efficiency of a coal-based co...

35

Activated carbon from municipal waste  

Microsoft Academic Search

A refuse derived fuel (RDF) was carbonized by partial combustion at 623 K and the carbonized RDF (cRDF) was steam-activated at 1123 K. The cRDF was also treated by 3.3 or 5.2 N nitric acid at a boiling temperature for 3 h prior to the steam-activation. Porous properties of the activated carbons prepared were determined by the nitrogen adsorption method.

S Nagano; H Tamon; T Adzumi; K Nakagawa; T Suzuki

2000-01-01

36

Condensation products of 2-amino-3-cyano-4,6-disubstituted pyridine with carbon disulfide, thiourea, urea & formamide and their antibacterial activity.  

PubMed

Some new 5,7-disubstituted pyrido[2,3-d]pyrimidine derivatives have been synthesized by the condensation of 2-amino-3-cyano-4,6-disubstituted pyridine with carbon disulfide, thiourea, urea and formamide. The structure of these products are supported by their IR and 1H-NMR spectra as well as by elemental analysis. The compounds have been tested for their antibacterial activity against E. coli and S. aureus. PMID:1388612

Gupta, A; Shaihla; Mital, R L; Prakash, L

1992-06-01

37

The adjuvant activity of diesel exhaust particles and carbon black on systemic IgE production to ovalbumin in mice after intranasal instillation  

Microsoft Academic Search

The adjuvant activity of diesel exhaust particles (DEP) on systemic IgE production to ovalbumin (OA) was studied in mice after intranasal administration. The main purpose was to elucidate which part of the particles was responsible for the effect, the carbon core and\\/or the adsorbed organic substances. Female Balb\\/cA mice were immunized with OA either alone or in combination with DEP

Asbjørn Nilsen; Randi Hagemann; Ingvar Eide

1997-01-01

38

Unconverted chars obtained during biomass gasification on a pilot-scale gasifier as a source of activated carbon production  

Microsoft Academic Search

Biomass gasification was used to produce activated carbon on a pilot-scale fluidised-bed gasifier. The feedstock included both biomass alone and biomass mixed with coal and coal\\/granulated plastic wastes. This paper reports the results obtained from four different runs undertaken under various conditions of fuel supply, different ratios of steam\\/air for the gasification and temperature. These conditions were selected because they

A Garc??a-Garc??a; A Gregório; C Franco; F Pinto; D Boavida; I Gulyurtlu

2003-01-01

39

The Soil Moisture Active/Passive (SMAP) Freeze/Thaw Product: Providing a Crucial Linkage between Earth's Water and Carbon Cycles  

NASA Astrophysics Data System (ADS)

Landscape transitions between seasonally frozen and thawed conditions occur each year over roughly 50 million square kilometers of Earth’s Northern Hemisphere, affecting surface meteorological conditions, ecological trace gas dynamics, energy exchange and hydrologic activity profoundly. NASA’s Soil Moisture Active-Pasiive (SMAP) mission, currently planned for launch in 2014, will employ a combined radiometer and high-resolution radar to measure surface soil moisture and freeze/thaw state, thus providing new opportunities for scientific advances and societal benefits. Major science objectives of SMAP support the understanding of processes linking terrestrial water, energy and carbon cycles, the quantification of net carbon flux and the extension of capabilities for weather and climate prediction models. The SMAP suite of data products will include global maps of landscape freeze/thaw state derived from L-band radar at 1-3 km spatial resolution with a 2-day refresh rate for the high northern latitudes (i.e. latitudes above 50 degrees north). The algorithm employed in derivation of the freeze/thaw product employs a temporal change detection scheme to delineate freeze/thaw state changes associated with temporal variations in landscape microwave dielectric constant properties. Development of the algorithm follows from application of legacy data sets provided by satellite radars, both scatterometers and Synthetic Aperture Radars (SARs), and radiometers. This presentation reviews algorithm development, product derivation and validation, product applications and associated SMAP science objectives addressed through the derived freeze/thaw data products. We review efforts in which contemporary and legacy active and passive microwave remote sensing data sets have been applied in prototyping the freeze/thaw product and its applications. This work was performed at the Jet Propulsion Laboratory, California Institute of Technology, and at the University of Montana under contract to the National Aeronautics and Space Administration.

McDonald, K. C.; Kimball, J. S.; Kim, Y.

2010-12-01

40

Enhanced coagulation with powdered activated carbon or MIEX(®) secondary treatment: A comparison of disinfection by-product formation and precursor removal.  

PubMed

The removal of both organic and inorganic disinfection by-product (DBP) precursors prior to disinfection is important in mitigating DBP formation, with halide removal being particularly important in salinity-impacted water sources. A matrix of waters of variable alkalinity, halide concentration and dissolved organic carbon (DOC) concentration were treated with enhanced coagulation (EC) followed by anion exchange (MIEX(®) resin) or powdered activated carbon (PAC) and the subsequent disinfection by-product formation potentials (DBP-FPs) assessed and compared to DBP-FPs for untreated samples. Halide and DOC removal were also monitored for both treatment processes. Bromide and iodide adsorption by MIEX(®) treatment ranged from 0 to 53% and 4-78%, respectively. As expected, EC and PAC treatments did not remove halides. DOC removal by EC/PAC was 70  ±  10%, while EC/MIEX(®) enabled a DOC removal of 66  ±  12%. Despite the halide removals achieved by MIEX(®), increases in brominated disinfection by-product (Br-DBP) formation were observed relative to untreated samples, when favourable Br:DOC ratios were created by the treatment. However, the increases in formation were less than what was observed for the EC/PAC treated waters, which caused large increases in Br-DBP formation when high Br-DBP-forming water quality conditions occurred. The formation potential of fully chlorinated DBPs decreased after treatment in all cases. PMID:25462752

Watson, Kalinda; Farré, Maria José; Knight, Nicole

2014-10-22

41

Production Systems. Laboratory Activities.  

ERIC Educational Resources Information Center

This production systems guide provides teachers with learning activities for secondary students. Introductory materials include an instructional planning outline and worksheet, an outline of essential elements, domains and objectives, a course description, and a content outline. The guide contains 30 modules on the following topics: production

Gallaway, Ann, Ed.

42

Benthic respiration measured by total carbonate production  

Microsoft Academic Search

Abstract The suitability of total carbonate production,instead of oxygen consumption,as a measure,of benthic respiration has been investigated. In situ fluxes of total carbonate, oxygen, calcium, total alkalinity, nutrients, and sulfide across the sediment-water interface were measured in diver- operated benthic flux chambers. Two chambers,were run in parallel to test the influence of oxygen and pH levels on total carbonate production.

LEIF G. ANDERSON; PER O. J. HALL; ÅKE IVERFELDT; MICHIEL M. RUTGERS VAN DER LOEFF; BJØRN SUNDBY; STIG F. G. WESTERLUND

1986-01-01

43

Photoconductivity of activated carbon fibers  

NASA Astrophysics Data System (ADS)

The photoconductivity is measured on a high-surface-area disordered carbon material, namely activated carbon fibers, to investigate their electronic properties. Measurements of decay time, recombination kinetics and temperature dependence of the photoconductivity generally reflect the electronic properties of a material. The material studied in this paper is a highly disordered carbon derived from a phenolic precursor, having a huge specific surface area of 1000 to 2000 sq m/g. Our preliminary thermopower measurements suggest that this carbon material is a p-type semiconductor with an amorphous-like microstructure. The intrinsic electrical conductivity, on the order of 20 S/cm at room temperature, increases with increasing temperature in the range 30 to 290 K. In contrast with the intrinsic conductivity, the photoconductivity in vacuum decreases with increasing temperature. The recombination kinetics changes from a monomolecular process at room temperature to a bimolecular process at low temperatures. The observed decay time of the photoconductivity is approximately 0.3 sec. The magnitude of the photoconductive signal was reduced by a factor of ten when the sample was exposed to air. The intrinsic carrier density and the activation energy for conduction are estimated to be approximately 10(exp 21)/cu cm and approximately 20 meV, respectively. The majority of the induced photocarriers and of the intrinsic carriers are trapped, resulting in the long decay time of the photoconductivity and the positive temperature dependence of the conductivity.

Kuriyama, K.; Dresselhaus, M. S.

1990-08-01

44

Solvent-regenerated activated carbon  

SciTech Connect

This report summarizes the results of a University/Industry research project, sponsored by the New York State Energy Research and Development Authority and Fluids Design Corporation. The research project studied the solvent regeneration of activated carbon. Activate carbon was used to remove trace organics from aqueous streams, then regenerated by desorbing the adsorbates with organic solvents. The project included a survey of the potential applications in New York State industries, fundamental research on the adsorption/desorption phenomena, and design of a full-scale process. The economics of the full-scale process were evaluated and compared to alternate available technologies. The result of this work is a versatile process with attractive economics. A wide range of adsorbates and solvents were found to be acceptable for this process. The design methodologies are developed and the techniques for evaluating a new application are delineated. 13 refs., 12 figs., 4 tabs.

McLaughlin, H. (Fluids Design Corp., Troy, NY (USA))

1988-07-01

45

PRODUCTION OF CARBON PRODUCTS USING A COAL EXTRACTION PROCESS  

SciTech Connect

The purpose of this DOE-funded effort is to develop technologies for carbon products from coal-derived feedstocks. Carbon products can include precursor materials such as solvent extracted carbon ore (SECO) and synthetic pitch (Synpitch). In addition, derived products include carbon composites, fibers, foams and others. Key milestones included producing hydrogenated coal in the Hydrotreating Facility for the first time. The facility is now operational, although digital controls have not yet been completely wired. In addition, ultrasound is being used to investigate enhanced dissolution of coal. Experiments have been carried out.

Dady Dadyburjor; Chong Chen; Elliot B. Kennel; Liviu Magean; Peter G. Stansberry; Alfred H. Stiller; John W. Zondlo

2006-02-23

46

Preparation of steam activated carbon from rubberwood sawdust ( Hevea brasiliensis) and its adsorption kinetics  

Microsoft Academic Search

Activated carbon was produced from a biowaste product, rubberwood sawdust (RWSD) using steam in a high temperature fluidized bed reactor. Experiments were carried out to investigate the influence of various process parameters such as activation time, activation temperature, particle size and fluidising velocity on the quality of the activated carbon. The activated carbon was characterized based on its iodine number,

B. G. Prakash Kumar; K. Shivakamy; Lima Rose Miranda; M. Velan

2006-01-01

47

Food security and climate change: on the potential to adapt global crop production by active selection to rising atmospheric carbon dioxide  

PubMed Central

Agricultural production is under increasing pressure by global anthropogenic changes, including rising population, diversion of cereals to biofuels, increased protein demands and climatic extremes. Because of the immediate and dynamic nature of these changes, adaptation measures are urgently needed to ensure both the stability and continued increase of the global food supply. Although potential adaption options often consider regional or sectoral variations of existing risk management (e.g. earlier planting dates, choice of crop), there may be a global-centric strategy for increasing productivity. In spite of the recognition that atmospheric carbon dioxide (CO2) is an essential plant resource that has increased globally by approximately 25 per cent since 1959, efforts to increase the biological conversion of atmospheric CO2 to stimulate seed yield through crop selection is not generally recognized as an effective adaptation measure. In this review, we challenge that viewpoint through an assessment of existing studies on CO2 and intraspecific variability to illustrate the potential biological basis for differential plant response among crop lines and demonstrate that while technical hurdles remain, active selection and breeding for CO2 responsiveness among cereal varieties may provide one of the simplest and direct strategies for increasing global yields and maintaining food security with anthropogenic change. PMID:22874755

Ziska, Lewis H.; Bunce, James A.; Shimono, Hiroyuki; Gealy, David R.; Baker, Jeffrey T.; Newton, Paul C. D.; Reynolds, Matthew P.; Jagadish, Krishna S. V.; Zhu, Chunwu; Howden, Mark; Wilson, Lloyd T.

2012-01-01

48

Activated carbon adsorption of humic substances  

SciTech Connect

Activated carbon pore-size distribution is an important parameter relative to the carbon's capacity for adsorbing humic substances. The effect of coagulation on adsorption should also be examined wherever granular activated carbon is to be used following coagulation. Experimental investigations using a commercial humic acid and a fulvic acid extracted from peat, and a number of commercial activated carbons, several of which were coal-based, are reported.

Lee, M.C.

1981-08-01

49

Co-production of activated carbon, fuel-gas, and oil from the pyrolysis of corncob mixtures with wet and dried sewage sludge.  

PubMed

This study explored the amount and composition of pyrolysis gas and oil derived from wet material or dried material during the preparation of sludge-corncob activated carbon, and evaluated the physicochemical and surface properties of the obtained two types of sludge-corncob-activated carbons. For wet material, owing to the presence of water, the yields of sludge-corncob activated carbon and the oil fraction slightly decreased while the yield of gases increased. The main pyrolysis gas compounds were H2 and CO2, and more H2 was released from wet material than dried material, whereas the opposite holds for CO2. Heterocyclics, nitriles, organic acids, and steroids were the major components of pyrolysis oil. Furthermore, the presence of water in wet material reduced the yield of polycyclic aromatic hydrocarbons from 6.76% to 5.43%. The yield of furfural, one of heterocyclics, increased sharply from 3.51% to 21.4%, which could be explained by the enhanced hydrolysis of corncob. In addition, the surface or chemical properties of the two sludge-corncob activated carbons were almost not affected by the moisture content of the raw material, although their mesopore volume and diameter were different. In addition, the adsorption capacities of the two sludge-corncob activated carbons towards Pb and nitrobenzene were nearly identical. PMID:24951551

Shao, Linlin; Jiang, Wenbo; Feng, Li; Zhang, Liqiu

2014-06-18

50

Fractal analysis of granular activated carbons using isotherm data  

SciTech Connect

Utilization of adsorption on solid surfaces was exercised for the first time in 1785. Practical application of unactivated carbon filters, and powdered carbon were first demonstrated in the American water treatment plant, and a municipal treatment plant in New Jersey, in 1883 and 1930, respectively. The use of activated carbon became widespread in the next few decades. At present, adsorption on carbons has a wide spread application in water treatment and removal of taste, odor, removal of synthetic organic chemicals, color-forming organics, and desinfection by-products and their naturally occurring precursors. This paper presents an analysis of the surface fractal dimension and adsorption capacity of a group of carbons.

Khalili, N.R.; Pan, M. [Illinois Institute of Technology, Chicago, IL (United States). Dept. of Chemical and Environmental Engineering; Sandi, G. [Argonne National Lab., IL (United States)

1997-08-01

51

Dynamic adsorption of radon by activated carbon.  

PubMed

The adsorption of radon on activated carbon has been used in or considered for a number of applications, including in situ decay beds, cyclic decontamination systems, and diffusive samplers. And although there are numerous measurements of the adsorption coefficients of specific activated carbons for radon, each of these applications depends on knowing, in addition to the adsorption coefficient for radon, the mass transfer factors describing its dynamic adsorption. Here we used a standard procedure in gas chromatography and chemical engineering, the spreading of a pulse as it passes through a bed of adsorbent, to determine these mass transfer factors. For this application, this procedure is developed further to correct the radon adsorption data for distortions caused by the decay of radon and by the presence of radon decay products in the detector. The results from eight activated carbons show a wide variation in the mass transfer coefficients for radon, which could affect significantly the suitability of adsorbents, as demonstrated here by the effect that mass transfer has on the performance of in situ decay beds. PMID:15761299

Gaul, Wayne C; Underhill, Dwight W

2005-04-01

52

Terminating pre-ozonation prior to biological activated carbon filtration results in increased formation of nitrogenous disinfection by-products upon subsequent chlorination.  

PubMed

Previous research demonstrated that ozone dosed before biological activated carbon (BAC) filtration reduces the formation of disinfection by-products (DBPs) upon subsequent chlorination. The current work aimed to evaluate the impact of terminating this pre-ozonation on the ability of the BAC to remove the precursors of N-DBPs. More N-DBP precursors passed into the post-BAC water when the pre-ozonation was terminated, resulting in greater formation of N-DBPs when the water was subsequently chlorinated, compared to a parallel BAC filter when the pre-ozonation was run continuously. Moreover, the N-DBP formation potential was significantly increased in the effluent of the BAC filter after terminating pre-ozonation, compared with the influent of the BAC filter (i.e. the effluent from the sand filter). Therefore, while selectively switching pre-ozonation on/off may have cost and other operational benefits for water suppliers, these should be weighed against the increased formation of N-DBPs and potential associated health risks. PMID:25479807

Chu, Wenhai; Li, Changjun; Gao, Naiyun; Templeton, Michael R; Zhang, Yanshen

2015-02-01

53

Adsorbed natural gas storage with activated carbon  

SciTech Connect

Despite technical advances to reduce air pollution emissions, motor vehicles still account for 30 to 70% emissions of all urban air pollutants. The Clean Air Act Amendments of 1990 require 100 cities in the United States to reduce the amount of their smog within 5 to 15 years. Hence, auto emissions, the major cause of smog, must be reduced 30 to 60% by 1998. Natural gas con be combusted with less pollutant emissions. Adsorbed natural gas (ANG) uses adsorbents and operates with a low storage pressure which results in lower capital costs and maintenance. This paper describes the production of an activated carbon adsorbent produced from an Illinois coal for ANG.

Sun, Jian; Brady, T.A.; Rood, M.J. [Univ. of Illinois, Urbana, IL (United States)] [and others

1996-12-31

54

Adsorption of herbicides using activated carbons  

SciTech Connect

This work describes development of a series of novel activated carbon materials and their testing for possible water treatment applications by studying the adsorption of sodium pentachlorphenolate, PCP (a common herbicide/wood preservative). Although the application of activated carbons is an established technology for the treatment of public water supplies, there is a growing need for materials with higher selectivity and adsorptive capacities as well as high abrasion resistance. The materials that will be discussed include extruded wood-derived carbons with novel pore size distributions and high hardness, as well as activated carbon fiber composites. Comparisons will be made with commercial granular water treatment carbons.

Derbyshire, F.; Jagtoyan, M.; Lafferty, C.; Kimber, G. [Univ. of Kentucky, Lexington, KY (United States)

1996-10-01

55

Properties of differently shaped activated carbon fibers  

Microsoft Academic Search

Differently shaped carbon fibers (R-, I-, C-, Y-, and X-type) were prepared from melt-spinning of reformed naphtha cracking\\u000a bottom oil precursors through various shaped spinnerets. These carbon fibers were activated by steam and activation properties\\u000a were compared. The decrease of hydraulic radius resulted in the extending of the external surface area of carbon fibers. Activation\\u000a energy and rate of differently

Sang-Yong Eom; Seung-Kon Ryu

2010-01-01

56

Microbial Enzyme Activity and Carbon Cycling in Grassland Soil Fractions  

NASA Astrophysics Data System (ADS)

Extracellular enzymes are necessary to degrade complex organic compounds present in soils. Using physical fractionation procedures, we tested whether old soil carbon is spatially isolated from degradative enzymes across a prairie restoration chronosequence in Illinois, USA. We found that carbon-degrading enzymes were abundant in all soil fractions, including macroaggregates, microaggregates, and the clay fraction, which contains carbon with a mean residence time of ~200 years. The activities of two cellulose-degrading enzymes and a chitin-degrading enzyme were 2-10 times greater in organic matter fractions than in bulk soil, consistent with the rapid turnover of these fractions. Polyphenol oxidase activity was 3 times greater in the clay fraction than in the bulk soil, despite very slow carbon turnover in this fraction. Changes in enzyme activity across the restoration chronosequence were small once adjusted for increases in soil carbon concentration, although polyphenol oxidase activity per unit carbon declined by 50% in native prairie versus cultivated soil. These results are consistent with a `two-pool' model of enzyme and carbon turnover in grassland soils. In light organic matter fractions, enzyme production and carbon turnover both occur rapidly. However, in mineral-dominated fractions, both enzymes and their carbon substrates are immobilized on mineral surfaces, leading to slow turnover. Soil carbon accumulation in the clay fraction and across the prairie restoration chronosequence probably reflects increasing physical isolation of enzymes and substrates on the molecular scale, rather than the micron to millimeter scale.

Allison, S. D.; Jastrow, J. D.

2004-12-01

57

Production of bio-based phenolic resin and activated carbon from bio-oil and biochar derived from fast pyrolysis of palm kernel shells.  

PubMed

A fraction of palm kernel shells (PKS) was pyrolyzed in a fluidized bed reactor. The experiments were performed in a temperature range of 479-555°C to produce bio-oil, biochar, and gas. All the bio-oils were analyzed quantitatively and qualitatively by GC-FID and GC-MS. The maximum content of phenolic compounds in the bio-oil was 24.8wt.% at ?500°C. The maximum phenol content in the bio-oil, as determined by the external standard method, was 8.1wt.%. A bio-oil derived from the pyrolysis of PKS was used in the synthesis of phenolic resin, showing that the bio-oil could substitute for fossil phenol up to 25wt.%. The biochar was activated using CO2 at a final activation temperature of 900°C with different activation time (1-3h) to produce activated carbon. Activated carbons produced were microporous, and the maximum surface area of the activated carbons produced was 807m(2)/g. PMID:25227587

Choi, Gyung-Goo; Oh, Seung-Jin; Lee, Soon-Jang; Kim, Joo-Sik

2015-02-01

58

PRODUCTION OF CARBON PRODUCTS USING A COAL EXTRACTION PROCESS  

SciTech Connect

This Department of Energy National Energy Technology Laboratory sponsored project developed carbon products, using mildly hydrogenated solvents to extract the organic portion of coal to create synthetic pitches, cokes, carbon foam and carbon fibers. The focus of this effort was on development of lower cost solvents, milder hydrogenation conditions and improved yield in order to enable practical production of these products. This technology is needed because of the long-term decline in production of domestic feedstocks such as petroleum pitch and coal tar pitch. Currently, carbon products represents a market of roughly 5 million tons domestically, and 19 million tons worldwide. Carbon products are mainly derived from feedstocks such as petroleum pitch and coal tar pitch. The domestic supply of petroleum pitch is declining because of the rising price of liquid fuels, which has caused US refineries to maximize liquid fuel production. As a consequence, the long term trend has a decline in production of petroleum pitch over the past 20 years. The production of coal tar pitch, as in the case of petroleum pitch, has likewise declined significantly over the past two decades. Coal tar pitch is a byproduct of metallurgical grade coke (metcoke) production. In this industry, modern metcoke facilities are recycling coal tar as fuel in order to enhance energy efficiency and minimize environmental emissions. Metcoke production itself is dependent upon the production requirements for domestic steel. Hence, several metcoke ovens have been decommissioned over the past two decades and have not been replaced. As a consequence sources of coal tar are being taken off line and are not being replaced. The long-term trend is a reduction in coal tar pitch production. Thus import of feedstocks, mainly from Eastern Europe and China, is on the rise despite the relatively large transportation cost. To reverse this trend, a new process for producing carbon products is needed. The process must be economically competitive with current processes, and yet be environmentally friendly as well. The solvent extraction process developed uses mild hydrogenation of low cost oils to create powerful solvents that can dissolve the organic portion of coal. The insoluble portion, consisting mainly of mineral matter and fixed carbon, is removed via centrifugation or filtration, leaving a liquid solution of coal chemicals and solvent. This solution can be further refined via distillation to meet specifications for products such as synthetic pitches, cokes, carbon foam and fibers. The most economical process recycles 85% of the solvent, which itself is obtained as a low-cost byproduct from industrial processes such as coal tar or petroleum refining. Alternatively, processes have been developed that can recycle 100% of the solvent, avoiding any need for products derived from petroleum or coal tar.

Dady Dadyburjor; Philip R. Biedler; Chong Chen; L. Mitchell Clendenin; Manoj Katakdaunde; Elliot B. Kennel; Nathan D. King; Liviu Magean; Peter G. Stansberry; Alfred H. Stiller; John W. Zondlo

2004-08-31

59

Sorption of petroleum products by carbon sorbents  

SciTech Connect

A comparative study of the adsorption of petroleum products by micro- and macroporous carbon sorbents was performed. For this purpose, four carbon sorbent samples prepared from various raw materials by various processing techniques were used. The following raw materials were used: (1) fuel mill from the Mezinoskoe deposit; (2) wood waste, shaving and sawdust in ratio (%) of 50:50; and (3) low-caking gas coal of the 2G group from the mine im.Kirova in the Kuznetsk Basin. The pore structures and adsorption capacities of these sorbents for petroleum products were studied. It was found that the adsorption of petroleum products on porous and nonporous carbon sorbents occurred in different manners. In this case, macroporous sorbents with a weakly developed structure of sorbing micro- and mesopores exhibited a maximum capacity for petroleum products.

M.A. Perederii; Y.I. Kurakov; I.N. Malikov; S.V. Molchanov [Institute for Fossil Fuels, Moscow (Russian Federation)

2009-07-01

60

Selecting activated carbon for water and wastewater treatability studies  

SciTech Connect

A series of follow-up investigations were performed to produce data for improving the four-indicator carbon selection method that we developed to identify high-potential activated carbons effective for removing specific organic water pollutants. The carbon's pore structure and surface chemistry are dependent on the raw material and the activation process. Coconut carbons have relatively more small pores than large pores; coal and apricot nutshell/walnut shell fruit carbons have the desirable pore structures for removing adsorbates of all sizes. Chemical activation, excessive activation, and/or thermal reactivation enlarge small pores, resulting in reduced phenol number and higher tannic acid number. Activated carbon's phenol, iodine, methylene blue, and tannic acid numbers are convenient indicators of its surface area and pore volume of pore diameters < 10, 10-15, 15-28, and > 28 angstrom, respectively. The phenol number of a carbon is also a good indicator of its surface acidity of oxygen-containing organic functional groups that affect the adsorptive capacity for aromatic and other small polar organics. The tannic acid number is an indicator of carbon's capacity for large, high-molecular-weight natural organic precursors of disinfection by-products in water treatment. The experimental results for removing nitrobenzene, methyl-tert-butyl ether, 4,4-bisphenol, humic acid, and the organic constituents of a biologically treated coking-plant effluent have demonstrated the effectiveness of this capacity-indicator-based method of carbon selection.

Zhang, W.; Chang, Q.G.; Liu, W.D.; Li, B.J.; Jiang, W.X.; Fu, L.J.; Ying, W.C. [East China University of Chemical Technology, Shanghai (China)

2007-10-15

61

Carbon Dioxide Production and Sodium Transport by the Toad Bladder  

Microsoft Academic Search

IN order to investigate further the relationship of cellular metabolism to active ion transport, we have correlated carbon dioxide production with sodium transport by the urinary bladder of the toad, Bufo marinus, in vitro. The toad bladder was mounted so as to separate the two halves of a glass chamber, and each side was bathed with a phosphate Ringer's solution

Roy H. Maffly; Cecil H. Coggins

1965-01-01

62

A distributed approach to accounting for carbon in wood products  

SciTech Connect

With an evolving political environment of commitments to limit emissions of greenhouse gases, and of markets to trade in emissions permits, there is growing scientific, political, and economic need to accurately evaluate carbon (C) stocks and flows especially those related to human activities. One component of the global carbon cycle that has been contentious is the stock of carbon that is physically held in harvested wood products. The carbon stored in wood products has been sometimes overlooked, but the amount of carbon contained in wood products is not trivial, it is increasing with time, and it is significant to some Parties. This paper is concerned with accurate treatment of harvested wood products in inventories of CO2 emissions to the atmosphere. The methodologies outlined demonstrate a flexible way to expand current methods beyond the assumption of a simple, first-order decay to include the use of more accurate and detailed data while retaining the simplicity of simple formulas. The paper demonstrates that a more accurate representation of decay time can have significant economic implications in a system where emissions are taxed or emissions permits are traded. The method can be easily applied using only data on annual production of wood products and two parameters to characterize their expected lifetime. These methods are not specific to wood products but can be applied to long-lived, carbon-containing products from sources other than wood, e.g. long-lived petrochemical products. A single unifying approach that is both simple and flexible has the potential to be both more accurate in its results, more efficient in its implementation, and economically important to some Parties.

Marland, Eric [Appalachian State University; Stellar, Kirk [Appalachian State University; Marland, Gregg [ORNL

2010-01-01

63

Carbon Footprint Analysis for a GRAPE Production Case Study  

NASA Astrophysics Data System (ADS)

Agriculture activities can play a double role in emitting or sequestering carbon from the atmosphere. Mitigation of greenhouse gas (GHG) emissions in agriculture is one of the most urgent research subjects in the framework of enhancing environmental stewardship. However, little is known about the role of the agriculture in the global carbon balance, since most of the studies applied the Eddy Covariance technique in natural or semi-natural ecosystems to investigate their role in mitigate the anthropogenic carbon release. The application of the Eddy Covariance technique in agricultural systems could greatly improve our knowledge about their role on the global carbon budget and help in modeling the related processes. In addition, there is a growing request from producers, trade companies, and customers on the assessment of the environmental impact of a production process related to agricultural high quality products. In recent years, particular attention was put on the estimation of GHG emissions deriving from productive processes. In this context, a useful tool is the Life Cycle Assessment (LCA), which represents a methodology to estimate GHG emissions related to the entire life cycle of a product. The Carbon Footprint (CF) analysis represents a subset of the LCA, which only considers CO2 emissions with an impact on climate change. With respect to the wine industry, most of studies focused on the CF analysis related to the wine making process in the cellar, while a few studies analyzed the GHG emissions related to the grape production. The aim of this work was to quantify the CO2 emissions due to the grape production and emphasize the double role of a vineyard as a carbon sink or source. An Eddy Covariance station was set up in a representative vineyard located in the Mediterranean Basin (Sardinia, Italy) to measure the net carbon exchange between the surface and the atmosphere. The CF analysis was also conducted to compute the carbon balance of the grape production process in terms of CO2-equivalent emissions by following the International Wine Carbon Protocol (IWCP). Additional terms (e.g. emissions due to fossil fuel combustion, fertilizers, soil tillage) were also quantified. Results showed that the vineyard is able to store net amounts of carbon both in biomass and soil. Human added inputs for the vineyard management practices (e.g. soil tillage) are responsible for the release of significant quantities of GHG in the atmosphere. Results also showed that data obtained from the EC measurements could allow for a direct quantification of part of the terms involved in the grape production process, but the assessment of the carbon sequestration capacity in agricultural sites requires to account for GHG emissions from additional anthropogenic inputs.

Sirca, C.; Marras, S.; Masia, S.; Duce, P.; Zara, P.; Spano, D.

2013-12-01

64

Select metal adsorption by activated carbon made from peanut shells.  

PubMed

Agricultural by-products, such as peanut shells, contribute large quantities of lignocellulosic waste to the environment each growing season; but few, if any, value-added uses exist for their disposal. The objective of this study was to convert peanut shells to activated carbons for use in adsorption of select metal ions, namely, cadmium (Cd2+), copper (Cu2+), lead (Pb2+), nickel (Ni2+) and zinc (Zn2+). Milled peanut shells were pyrolyzed in an inert atmosphere of nitrogen gas, and then activated with steam at different activation times. Following pyrolysis and activation, the carbons underwent air oxidation. The prepared carbons were evaluated either for adsorption efficiency or adsorption capacity; and these parameters were compared to the same parameters obtained from three commercial carbons, namely, DARCO 12x20, NORIT C GRAN and MINOTAUR. One of the peanut shell-based carbons had metal ion adsorption efficiencies greater than two of the three commercial carbons but somewhat less than but close to Minotaur. This study demonstrates that peanut shells can serve as a source for activated carbons with metal ion-removing potential and may serve as a replacement for coal-based commercial carbons in applications that warrant their use. PMID:16364633

Wilson, Kermit; Yang, Hong; Seo, Chung W; Marshall, Wayne E

2006-12-01

65

Controlling Porosity to Improve Activated Carbon Applications  

NASA Astrophysics Data System (ADS)

This chapter presents an overview of preparation and characterization of activated carbons (ACs), activated carbon fibres (ACFs) and activated carbon monoliths (ACMs) to be used in different applications. Examples of the performance of these materials in environmental, energy storage and space applications are presented, remarking the importance of carrying out a suitable porous texture characterization of the materials to understand and optimize their performance in each application. Development of narrow microporosity, which is assessed by CO2 adsorption at 273 K, has been demonstrated to be necessary for these applications. This type of porosity has been obtained by chemical alkaline hydroxide activation of carbon precursors with careful control and thorough understanding of the variables affecting the carbon activation process.

Linares-Solano, Angel; Lozano-Castelló, D.; Lillo-Ródenas, M. A.; Cazorla-Amorós, D.

66

Ris-R-Report Emerging product carbon footprint standards and  

E-print Network

carbon footprinting? 7 3 Methodological issues in product carbon footprinting 9 3.1 Life Cycle AnalysisRisø-R-Report Emerging product carbon footprint standards and schemes and their possible trade Bolwig and Peter Gibbon Title: Emerging product carbon footprint standards and schemes and their possible

67

Metal Ion Adsorption by Activated Carbons Made from Pecan Shells: Effect of Oxygen Level During Activation  

Technology Transfer Automated Retrieval System (TEKTRAN)

Agricultural by-products represent a considerable quantity of harvested commodity crops. The use of by-products as precursors for the production of widely used adsorbents, such as activated carbons, may impart a value-added component of the overall biomass harvested. Our objective in this presenta...

68

Copper (II) Adsorption by Activated Carbons from Pecan Shells: Effect of Oxygen Level During Activation  

Technology Transfer Automated Retrieval System (TEKTRAN)

Agricultural by-products represent a considerable quantity of harvested commodity crops. The use of by-products as precursors for the production of widely used adsorbents, such as activated carbons, may impart a value-added component of the overall biomass harvested. Our objective in this paper is...

69

Catalytic Growth of Macroscopic Carbon Nanofibers Bodies with Activated Carbon  

NASA Astrophysics Data System (ADS)

Carbon-carbon composite of activated carbon and carbon nanofibers have been synthesized by growing Carbon nanofiber (CNF) on Palm shell-based Activated carbon (AC) with Ni catalyst. The composites are in an agglomerated shape due to the entanglement of the defective CNF between the AC particles forming a macroscopic body. The macroscopic size will allow the composite to be used as a stabile catalyst support and liquid adsorbent. The preparation of CNT/AC nanocarbon was initiated by pre-treating the activated carbon with nitric acid, followed by impregnation of 1 wt% loading of nickel (II) nitrate solutions in acetone. The catalyst precursor was calcined and reduced at 300° C for an hour in each step. The catalytic growth of nanocarbon in C2H4/H2 was carried out at temperature of 550° C for 2 hrs with different rotating angle in the fluidization system. SEM and N2 isotherms show the level of agglomeration which is a function of growth density and fluidization of the system. The effect of fluidization by rotating the reactor during growth with different speed give a significant impact on the agglomeration of the final CNF/AC composite and thus the amount of CNFs produced. The macrostructure body produced in this work of CNF/AC composite will have advantages in the adsorbent and catalyst support application, due to the mechanical and chemical properties of the material.

Abdullah, N.; Rinaldi, A.; Muhammad, I. S.; Hamid, S. B. Abd.; Su, D. S.; Schlogl, R.

2009-06-01

70

Reduction of bromate by granular activated carbon  

SciTech Connect

Ozonation of waters containing bromide can lead to the formation of bromate, a probable human carcinogen. Since bromate will be regulated at 10 {micro}g/L by the Stage 1 Disinfectants/Disinfection By-Products Rule, there is considerable interest in finding a suitable method of bromate reduction. Granular activated carbon (GAC) can be used to chemically reduce bromate to bromide, but interference from organic matter and anions present in natural water render this process inefficient. In an effort to improve bromate reduction by GAC, several modifications were made to the GAC filtration process. The use of a biologically active carbon (BAC) filter ahead of a fresh GAC filter with and without preozonation, to remove the biodegradable organic matter, did not substantially improve the bromate removal of the GAC filter. The use of the BAC filter for biological bromate reduction proved to be the most encouraging experiment. By lowering the dissolved oxygen in the influent to the BAC from 8.0 mg/L to 2.0 mg/L, the percent bromate removal increased from 42% to 61%.

Kirisits, M.J.; Snoeyink, V.L.; Kruithof, J.C.

1998-07-01

71

Create a Consortium and Develop Premium Carbon Products from Coal  

SciTech Connect

The objective of these projects was to investigate alternative technologies for non-fuel uses of coal. Special emphasis was placed on developing premium carbon products from coal-derived feedstocks. A total of 14 projects, which are the 2003 Research Projects, are reported herein. These projects were categorized into three overall objectives. They are: (1) To explore new applications for the use of anthracite in order to improve its marketability; (2) To effectively minimize environmental damage caused by mercury emissions, CO{sub 2} emissions, and coal impounds; and (3) To continue to increase our understanding of coal properties and establish coal usage in non-fuel industries. Research was completed in laboratories throughout the United States. Most research was performed on a bench-scale level with the intent of scaling up if preliminary tests proved successful. These projects resulted in many potential applications for coal-derived feedstocks. These include: (1) Use of anthracite as a sorbent to capture CO{sub 2} emissions; (2) Use of anthracite-based carbon as a catalyst; (3) Use of processed anthracite in carbon electrodes and carbon black; (4) Use of raw coal refuse for producing activated carbon; (5) Reusable PACs to recycle captured mercury; (6) Use of combustion and gasification chars to capture mercury from coal-fired power plants; (7) Development of a synthetic coal tar enamel; (8) Use of alternative binder pitches in aluminum anodes; (9) Use of Solvent Extracted Carbon Ore (SECO) to fuel a carbon fuel cell; (10) Production of a low cost coal-derived turbostratic carbon powder for structural applications; (11) Production of high-value carbon fibers and foams via the co-processing of a low-cost coal extract pitch with well-dispersed carbon nanotubes; (12) Use of carbon from fly ash as metallurgical carbon; (13) Production of bulk carbon fiber for concrete reinforcement; and (14) Characterizing coal solvent extraction processes. Although some of the projects funded did not meet their original goals, the overall objectives of the CPCPC were completed as many new applications for coal-derived feedstocks have been researched. Future research in many of these areas is necessary before implementation into industry.

Frank Rusinko; John Andresen; Jennifer E. Hill; Harold H. Schobert; Bruce G. Miller

2006-01-01

72

The effect of carbonization temperature of PAN fiber on the properties of activated carbon fiber composites  

Microsoft Academic Search

The PAN (polyacrylonitrile) based carbon fiber composites were prepared from mixtures of chopped carbon fibers and phenolic resin. Two different carbon fibers were obtained by carbonization of stabilized PAN fiber precursors in nitrogen at 1073 and 1273 K, respectively. Samples of activated carbon fiber composites (ACFCs) were prepared from the carbon fiber composites by activation in carbon dioxide at 1123

J. C. Lee; B. H. Lee; B. G. Kim; M. J. Park; D. Y. Lee; I. H. Kuk; H. Chung; H. S. Kang; H. S. Lee; D. H. Ahn

1997-01-01

73

Activated carbon from leather shaving wastes and its application in removal of toxic materials.  

PubMed

In this study, utilization of a solid waste as raw material for activated carbon production was investigated. For this purpose, activated carbons were produced from chromium and vegetable tanned leather shaving wastes by physical and chemical activation methods. A detailed analysis of the surface properties of the activated carbons including acidity, total surface area, extent of microporosity and mesoporosity was presented. The activated carbon produced from vegetable tanned leather shaving waste produced has a higher surface area and micropore volume than the activated carbon produced from chromium tanned leather shaving waste. The potential application of activated carbons obtained from vegetable tanned shavings as adsorbent for removal of water pollutants have been checked for phenol, methylene blue, and Cr(VI). Adsorption capacities of activated carbons were found to be comparable to that of activated carbons derived from biomass. PMID:20382474

Kantarli, Ismail Cem; Yanik, Jale

2010-07-15

74

Integrating Steel Production with Mineral Carbon Sequestration  

SciTech Connect

The objectives of the project were (i) to develop a combination iron oxide production and carbon sequestration plant that will use serpentine ores as the source of iron and the extraction tailings as the storage element for CO2 disposal, (ii) the identification of locations within the US where this process may be implemented and (iii) to create a standardized process to characterize the serpentine deposits in terms of carbon disposal capacity and iron and steel production capacity. The first objective was not accomplished. The research failed to identify a technique to accelerate direct aqueous mineral carbonation, the limiting step in the integration of steel production and carbon sequestration. Objective (ii) was accomplished. It was found that the sequestration potential of the ultramafic resource surfaces in the US and Puerto Rico is approximately 4,647 Gt of CO2 or over 500 years of current US production of CO2. Lastly, a computer model was developed to investigate the impact of various system parameters (recoveries and efficiencies and capacities of different system components) and serpentinite quality as well as incorporation of CO2 from sources outside the steel industry.

Klaus Lackner; Paul Doby; Tuncel Yegulalp; Samuel Krevor; Christopher Graves

2008-05-01

75

The carbon footprints of food crop production  

Microsoft Academic Search

The agriculture sector contributes significantly to global carbon emissions from diverse sources such as product and machinery manufacture, transport of materials and direct and indirect soil greenhouse gas emissions. In this article, we use farm survey data from the east of Scotland combined with published estimates of emissions for individual farm operations to quantify the relative contribution of a range

Jonathan Hillier; Cathy Hawes; Geoff Squire; Alex Hilton; Stuart Wale; Pete Smith

2009-01-01

76

Quality of poultry litter-derived granular activated carbon.  

PubMed

Utilization of poultry litter as a source material for generating activated carbon is a value-added and environmentally beneficial approach to recycling organic waste. In this study, the overall quality of poultry litter-derived granular activated carbon was systematically evaluated based on its various physical and chemical properties. Granular activated carbon generated from pelletized poultry litter following a typical steam-activation procedure possessed numerous micropores in the matrix. The product exhibited a mean particle diameter of 2.59 mm, an apparent density of 0.45 g cm(-3), a ball-pan hardness of 91.0, an iodine number of 454 mg g(-1), and a BET surface area of 403 m(2) g(-1). It contained high ash, nitrogen, phosphorus contents and the trace elements Cu, Zn, and As. Most of the nutrients and toxic elements were solidified and solution-unextractable. In general, poultry litter-based activated carbon demonstrated overall quality comparable to that of low-grade commercial activated carbon derived from coconut shell and bituminous coal. It is promising to use poultry litter as a feedstock to manufacture activated carbon for wastewater treatment. PMID:19703765

Qiu, Guannan; Guo, Mingxin

2010-01-01

77

Chemical activation of carbon mesophase pitches.  

PubMed

This paper studies the chemical activation of mesophase pitches of different origins in order to obtain activated carbons suitable for use as electrodes in supercapacitors. The effect that the activating agent (NaOH, LiOH, and KOH), the alkaline hydroxide/pitch ratio, and the activation temperature had on the characteristics of the resultant activated carbons was studied. LiOH was found to be a noneffective activating agent, while activation with NaOH and KOH yielded activated carbons with high apparent surface areas and pore volumes. The increase of the KOH/pitch ratio caused an increase of the chemical attack on the carbon, producing higher burnoffs and development of porosity. Extremely high apparent surface areas were obtained when the petroleum pitch was activated with 5:1 KOH/carbon ratio. The increase of the activation temperature caused an increase of the burnoff, although the differences were not as significant as those derived from the use of different proportions of activating agent. PMID:16376916

Mora, E; Blanco, C; Pajares, J A; Santamaría, R; Menéndez, R

2006-06-01

78

Visible-light photocatalytic hydrogen production activity of ZnIn2 S4 microspheres using carbon quantum dots and platinum as dual co-catalysts.  

PubMed

ZnIn(2)S(4) microspheres (ZIS MSs) were for the first time decorated with carbon quantum dots (CQDs) and platinum nanoparticles (NPs) as dual co-catalysts of for photocatalytic H(2) production. The ZIS MSs co-loaded with CQDs and Pt exhibited a high photocatalytic H2 production rate of 1032.2??mol?h(-1) ?g(-1) with an apparent quantum efficiency of 2.2?% (420?nm) in triethanolamine aqueous solution under visible-light irradiation, which was much higher than the respective photocatalytic rates of pure ZIS, Pt loaded ZIS, and CQDs-decorated ZIS. Such a great enhancement was attributed to the integrative effect of good crystallization, enhanced light absorption, high electrical conductivity of CQDs, and the vectorial electron transfer from ZIS to CQDs and Pt NPs (ZIS?CQDs?Pt). PMID:24895096

Li, Qin; Cui, Can; Meng, Huan; Yu, Jiaguo

2014-07-01

79

Thermocatalytic process for CO.sub.2-free production of hydrogen and carbon from hydrocarbons  

DOEpatents

A novel process and apparatus are disclosed for sustainable CO.sub.2-free production of hydrogen and carbon by thermocatalytic decomposition (dissociation, pyrolysis, cracking) of hydrocarbon fuels over carbon-based catalysts in the absence of air and/or water. The apparatus and thermocatalytic process improve the activity and stability of carbon catalysts during the thermocatalytic process and produce both high purity hydrogen (at least, 99.0 volume %) and carbon, from any hydrocarbon fuel, including sulfurous fuels. In a preferred embodiment, production of hydrogen and carbon is achieved by both internal and external activation of carbon catalysts. Internal activation of carbon catalyst is accomplished by recycling of hydrogen-depleted gas containing unsaturated and aromatic hydrocarbons back to the reactor. External activation of the catalyst can be achieved via surface gasification with hot combustion gases during catalyst heating. The process and apparatus can be conveniently integrated with any type of fuel cell to generate electricity.

Muradov, Nazim Z. (Melbourne, FL)

2011-08-23

80

Adsorption of herbicides using activated carbons  

SciTech Connect

This paper describes the results of research in which novel activated carbons have been examined for their efficacy in water treatment and, specifically, for the adsorption of a common herbicide and wood preservative, sodium pentachlorophenolate. To place this work in context, the introduction will discuss first some of the considerations of using activated carbons for water treatment, and then certain aspects of the authors research that has led to this particular topic.

Derbyshire, F.; Jagtoyen, M.; Lafferty, C.; Kimber, G. [Univ. of Kentucky, Lexington, KY (United States)

1996-12-31

81

Petroleum contaminated ground-water: Remediation using activated carbon  

Microsoft Academic Search

Ground-water contamination resulting from the leakage of crude oil and refined petroleum products during extraction and processing operations is a serious and a growing environmental problem in Nigeria. Consequently, a study of the use of activated carbon (AC) in the clean up was undertaken with the aim of reducing the water contamination to a more acceptable level. In the experiments

M. J. Ayotamuno; R. B. Kogbara; S. O. T. Ogaji; S. D. Probert

2006-01-01

82

Pesticide removal by combined ozonation and granular activated carbon filtration  

Microsoft Academic Search

Since the seventies, new water treatment processes have been introduced in the production of drinking water from surface water. Their major aim was to adequately cope with the disinfection of this water, and\\/or with the removal of pesticides and other organic micropollutants from it. This research focused on Biological Activated Carbon (BAC) filtration, which is a combination of ozonation and

E. Orlandini

1999-01-01

83

Natural gas storage in activated carbon pellets without a binder  

Microsoft Academic Search

Activated carbon pellets without a binder from cellulose microcrystals as a raw material were investigated. After compression of the raw materials, the thus obtained raw material pellets were slowly carbonized to 1073 K under nitrogen. To activate them, the carbon pellets were heated to 1173 K under carbon dioxide. The activated carbon pellet shape, after heat treatment, was columnar by

K Inomata; K Kanazawa; Y Urabe; H Hosono; T Araki

2002-01-01

84

Surface heterogeneity of modified active carbons  

SciTech Connect

Active carbons were treated by oxidation and reduction conditions to control the number of functional groups on their surface. Influences of pore and surface structure of the active carbons on the energetic properties of the surface were investigated by measurements of nitrogen adsorption, heats of immersion and differential heats of adsorption. Severe oxidation brings about a decrease in specific surface area and pore volume, suggesting a partial destruction of pores. The acidic groups interact with basic molecules by acid-base interactions resulting in the evolution of high heats of adsorption and with water by hydration interaction resulting in high seat of immersion. The fractal analysis by use of molecular adsorption indicates a decrease in surface roughness with oxidation. These results suggest that active carbons become more heterogeneous with regard to surface energy distribution by oxidation, while the carbons become more homogeneous with regard to surface geometry. 30 refs., 8 figs., 5 tabs.

Tsutsumi, K.; Matsushima, Y.; Matsumoto, A. [Toyohashi Univ. of Technology, Toyohashi (Japan)

1993-10-01

85

Organic solvent regeneration of granular activated carbon  

NASA Astrophysics Data System (ADS)

The use of activated carbon for the treatment of industrial waste-streams was shown to be an effective treatment. The high costs associated with the replacement or thermal regeneration of the carbon have prohibited the economic feasibility of this process. The in situ solvent regeneration of activated carbon by means of organic solvent extraction was suggested as an economically alternative to thermal regeneration. The important aspects of the solvent regeneration process include: the physical and chemical characteristics of the adsorbent, the pore size distribution and energy of adsorption associated with the activated carbon; the degree of solubility of the adsorbate in the organic solvent; the miscibility of the organic solvent in water; and the temperature at which the generation is performed.

Cross, W. H.; Suidan, M. T.; Roller, M. A.; Kim, B. R.; Gould, J. P.

1982-09-01

86

Microwave-assisted regeneration of activated carbon.  

PubMed

Microwave heating was used in the regeneration of methylene blue-loaded activated carbons produced from fibers (PFAC), empty fruit bunches (EFBAC) and shell (PSAC) of oil palm. The dye-loaded carbons were treated in a modified conventional microwave oven operated at 2450 MHz and irradiation time of 2, 3 and 5 min. The virgin properties of the origin and regenerated activated carbons were characterized by pore structural analysis and nitrogen adsorption isotherm. The surface chemistry was examined by zeta potential measurement and determination of surface acidity/basicity, while the adsorptive property was quantified using methylene blue (MB). Microwave irradiation preserved the pore structure, original active sites and adsorption capacity of the regenerated activated carbons. The carbon yield and the monolayer adsorption capacities for MB were maintained at 68.35-82.84% and 154.65-195.22 mg/g, even after five adsorption-regeneration cycles. The findings revealed the potential of microwave heating for regeneration of spent activated carbons. PMID:22728787

Foo, K Y; Hameed, B H

2012-09-01

87

Black Carbon in the Soil Carbon Cycle: Is it an Oxidation Resistant End-Product?  

E-print Network

Black Carbon in the Soil Carbon Cycle: Is it an Oxidation Resistant End-Product? Simone;1 Introduction Soils represent a large carbon pool in the global carbon cycle. Estimates suggest that this pool is twice as large as the atmospheric pool. But its role in the global carbon cycle remains unclear

Fischlin, Andreas

88

Activated Carbon from Dates' Stone by ZnCl2 Activation  

Microsoft Academic Search

A study of the effect of preparation conditions on the yield and quality of activated carbon (AC) produced from dates' stones was made using zinc chloride as an activator. The optimum conditions for AC production was evaluated based on the determination of various adsorption parameters of methylene blue (MB) and phenol. Using MB as an adsorbate it was found that

Yahia A. Alhamed

89

Commercial Product Activation Using RFID  

NASA Technical Reports Server (NTRS)

Radio-frequency identification (RFID) would be used for commercial product activation, according to a proposal. What is new here is the concept of combining RFID with activation - more specifically, using RFID for activating commercial products (principally, electronic ones) and for performing such ancillary functions as tracking individual product units on production lines, tracking shipments, and updating inventories. According to the proposal, an RFID chip would be embedded in each product. The information encoded in the chip would include a unique number for identifying the product. An RFID reader at the point of sale would record the number of the product and would write digital information to the RFID chip for either immediate activation of the product or for later interrogation and processing. To be practical, an RFID product-activation system should satisfy a number of key requirements: the system should be designed to be integrable into the inventory-tracking and the data-processing and -communication infrastructures of businesses along the entire supply chain from manufacture to retail; the system should be resistant to sophisticated hacking; activation codes should be made sufficiently complexity to minimize the probability of activating stolen products; RFID activation equipment at points of sale must be capable to two-way RF communication for the purposes of reading information from, and writing information to, embedded RFID chips; the equipment at points of sale should be easily operable by sales clerks with little or no training; the point-of-sale equipment should verify activation and provide visible and/or audible signals indicating verification or lack thereof; and, the system should be able to handle millions of products per year with minimal human intervention, among other requirements.

Jedrey, Thomas

2008-01-01

90

Activated carbon filaments with mainly mesopores  

SciTech Connect

Activated carbon filaments of diameter {approximately} 0.1 {micro}m, mean pore size (BJH) 65 {angstrom}, specific surface area 1,540 m{sup 2}/g and burn-off 64% (yield 36%) were obtained by activating carbon filaments of diameter {approximately} 0.1 {micro}m in CO{sub 2} + N{sub 2} (1:1) at 970 C for100 min. Prior to this activation, the filaments were surface oxidized by exposure to ozone (0.3 vol.% in air) at 150 C for 3 min. Other than being used as adsorbents for purification and chemical processing, activated carbon materials are used as catalytic materials, battery electrode materials and biomedical engineering materials.

Lu, W.; Chung, D.D.L. [State Univ. of New York, Buffalo, NY (United States). Composite Materials Research Lab.

1996-12-31

91

Converting Poultry Litter into Activated Carbon  

Technology Transfer Automated Retrieval System (TEKTRAN)

Disposal of animal manure is one of the biggest problems facing agriculture today. Now new technology has been designed to covert manure into environmentally friendly and highly valued activated carbon. When pelletized and activated under specific conditions, the litter becomes a highly porous mat...

92

Catalysts for Efficient Production of Carbon Nanotubes  

NASA Technical Reports Server (NTRS)

Several metal alloys have shown promise as improved catalysts for catalytic thermal decomposition of hydrocarbon gases to produce carbon nanotubes (CNTs). Heretofore almost every experiment on the production of carbon nanotubes by this method has involved the use of iron, nickel, or cobalt as the catalyst. However, the catalytic-conversion efficiencies of these metals have been observed to be limited. The identification of better catalysts is part of a continuing program to develop means of mass production of high-quality carbon nanotubes at costs lower than those achieved thus far (as much as $100/g for purified multi-wall CNTs or $1,000/g for single-wall CNTs in year 2002). The main effort thus far in this program has been the design and implementation of a process tailored specifically for high-throughput screening of alloys for catalyzing the growth of CNTs. The process includes an integral combination of (1) formulation of libraries of catalysts, (2) synthesis of CNTs from decomposition of ethylene on powders of the alloys in a pyrolytic chemical-vapor-decomposition reactor, and (3) scanning- electron-microscope screening of the CNTs thus synthesized to evaluate the catalytic efficiencies of the alloys. Information gained in this process is put into a database and analyzed to identify promising alloy compositions, which are to be subjected to further evaluation in a subsequent round of testing. Some of these alloys have been found to catalyze the formation of carbon nano tubes from ethylene at temperatures as low as 350 to 400 C. In contrast, the temperatures typically required for prior catalysts range from 550 to 750 C.

Sun, Ted X.; Dong, Yi

2009-01-01

93

DISPLAYING DYNAMIC CARBON FOOTPRINTS OF PRODUCTS ON MOBILE PHONES  

Microsoft Academic Search

Several brand owners are calculating the carbon footprint of sample products and intend to make the information available to their consumers as a label on the product. A physical label on the items or on the retail shelf will not be flexible enough to show the carbon footprint because of the dynamic nature of carbon emissions and the potential difference

Ali Dada; Felix von Reischach; Thorsten Staake

94

Waste management activities and carbon emissions in Africa  

SciTech Connect

This paper summarizes research into waste management activities and carbon emissions from territories in sub-Saharan Africa with the main objective of quantifying emission reductions (ERs) that can be gained through viable improvements to waste management in Africa. It demonstrates that data on waste and carbon emissions is poor and generally inadequate for prediction models. The paper shows that the amount of waste produced and its composition are linked to national Gross Domestic Product (GDP). Waste production per person is around half that in developed countries with a mean around 230 kg/hd/yr. Sub-Saharan territories produce waste with a biogenic carbon content of around 56% (+/-25%), which is approximately 40% greater than developed countries. This waste is disposed in uncontrolled dumps that produce large amounts of methane gas. Greenhouse gas (GHG) emissions from waste will rise with increasing urbanization and can only be controlled through funding mechanisms from developed countries.

Couth, R. [University of KwaZulu-Natal, CRECHE, School of Civil Engineering, Survey and Construction, Durban 4041 (South Africa); Trois, C., E-mail: troisc@ukzn.ac.za [University of KwaZulu-Natal, CRECHE, School of Civil Engineering, Survey and Construction, Durban 4041 (South Africa)

2011-01-15

95

Natural Product Polyamines That Inhibit Human Carbonic Anhydrases  

PubMed Central

Natural product compound collections have proven an effective way to access chemical diversity and recent findings have identified phenolic, coumarin, and polyamine natural products as atypical chemotypes that inhibit carbonic anhydrases (CAs). CA enzymes are implicated as targets of variable drug therapeutic classes and the discovery of selective, drug-like CA inhibitors is essential. Just two natural product polyamines, spermine and spermidine, have until now been investigated as CA inhibitors. In this study, five more complex natural product polyamines 1–5, derived from either marine sponge or fungi, were considered for inhibition of six different human CA isozymes of interest in therapeutic drug development. All compounds share a simple polyamine core fragment, either spermine or spermidine, yet display substantially different structure activity relationships for CA inhibition. Notably, polyamines 1–5 were submicromolar inhibitors of the cancer drug target CA IX, this is more potent than either spermine or spermidine. PMID:25162012

Davis, Rohan A.; Vullo, Daniela; Supuran, Claudiu T.

2014-01-01

96

MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT  

SciTech Connect

The program efforts are focused on technology and system optimization for cost reduction, commercial design development, and prototype system field trials. The program is designed to advance the carbonate fuel cell technology from full-size field test to the commercial design. FuelCell Energy, Inc. (FCE) is in the later stage of the multiyear program for development and verification of carbonate fuel cell based power plants supported by DOE/NETL with additional funding from DOD/DARPA and the FuelCell Energy team. FCE has scaled up the technology to full-size and developed DFC{reg_sign} stack and balance-of-plant (BOP) equipment technology to meet product requirements, and acquired high rate manufacturing capabilities to reduce cost. FCE has designed submegawatt (DFC300A) and megawatt (DFC1500 and DFC3000) class fuel cell products for commercialization of its DFC{reg_sign} technology. A significant progress was made during the reporting period. The reforming unit design was optimized using a three-dimensional stack simulation model. Thermal and flow uniformities of the oxidant-In flow in the stack module were improved using computational fluid dynamics based flow simulation model. The manufacturing capacity was increased. The submegawatt stack module overall cost was reduced by {approx}30% on a per kW basis. An integrated deoxidizer-prereformer design was tested successfully at submegawatt scale using fuels simulating digester gas, coal bed methane gas and peak shave (natural) gas.

H.C. Maru; M. Farooque

2003-03-01

97

Molten Carbonate Fuel Cell Product Design Improvement  

SciTech Connect

This annual report provides results of Energy Research Corporation`s technical approach to performing the program `Molten Carbonate Fuel Cell (MCFC) Product Design Improvement` covered under the DOE-ERC Cooperative Agreement DE-FC21-95MC31184. This work is supported by DOE/METC and DOD/DARPA as well as ERC Team funds. The objective of the DOE-sponsored program is to advance the direct carbonate fuel cell technology to a level suitable for commercial entry for civilian applications. The overall objective of the DOD/DARPA initiative is to adapt the civilian 2 MW-Class fuel cell power plant for dual fuel DOD applications. This program is designed to advance the carbonate fuel cell technology from the power plant demonstration status to the commercial entry early production unit design stage. The specific objectives which will allow attainment of these overall program goals are: (1) Provide environmental information to support DOE evaluation with respect to the National Environmental Policy Act (NEPA), (2) Define market-responsive power plant requirements and specifications, (3) Establish design for multifuel, low-cost, modular, market-responsive power plant, (4) Resolve power plant manufacturing issues and define the design for the commercial manufacturing facility, (5) Acquire capabilities to support developmental testing of 0370 stacks and BOP equipment as required to prepare for commercial design, and (6) Resolve stack and BOP equipment technology issues and design, build, and field test a modular commercial prototype power plant to demonstrate readiness of the power plant for commercial entry.

NONE

1996-03-01

98

Carbon sequestration from boreal wildfires via Pyrogenic Carbon production  

NASA Astrophysics Data System (ADS)

Fire releases important quantities of carbon (C) to the atmosphere. Every year, an average of 460 Million ha burn around the globe, generating C emissions equivalent to a third of the current annual contribution from fossil fuel combustion. Over the longer-term wildfires are widely considered as 'net zero C emission events', because C emissions from fires, excluding those associated with deforestation and peatland fires, are balanced by C uptake by regenerating vegetation. This 'zero C emission' scenario, however, may be flawed, as it does not consider the production of pyrogenic C (PyC). During fire, part of the biomass C burnt is emitted to the atmosphere but part is transformed into PyC (i.e. charcoal). The enhanced resistance of PyC to environmental degradation compared to unburnt biomass gives it the potential to sequester C over the medium/long term. Therefore, after complete regeneration of the vegetation, the PyC generated may represent an additional C pool and, hence, recurring fire-regrowth cycles could represent net sinks of atmospheric C. To estimate the quantitative importance of PyC production, accurate data on PyC generation with respect to the fuel combusted are needed. Unfortunately, detailed quantification of fuel prior to fire is normally only available for prescribed and experimental fires, which are usually of low-intensity and therefore not representative of higher-intensity wildfires. Furthermore, what little data is available is usually based on only a specific fraction of the PyC present following burning rather than the whole range of PyC products and pools (i.e. PyC in soil, ash, downed wood and standing vegetation). To address this research gap, we utilized the globally unique FireSmart experimental forest fires in Northwest Canada. They are aimed to reproduce wildfire conditions typical for boreal forest and, at the same time, allow pre-fire fuel assessment, fire behaviour monitoring and immediate post-fire fuel and PyC inventory. This allowed, for the first time, quantifying the whole range of PyC components found in-situ immediately after a typical boreal forest fire. The fire examined had a fireline intensity of ~8000 kw/m, which is typical of boreal fires in NW Canada and we found that more than 18% of the fuel consumed was converted to PyC. This rate by far exceeds previous estimates (1-3%) and suggests that PyC production has indeed been substantially underestimated. As boreal forests are the world's largest terrestrial biome and contain half of the forest ecosystem C with a third its net primary productivity being consumed by fire every year, our findings could imply that PyC production from wildfires is a potential carbon sequestration mechanism of sufficient magnitude that warrants inclusion in boreal and perhaps global C budget estimations.

Santin, Cristina; Doerr, Stefan; Preston, Caroline

2014-05-01

99

Preparation of activated carbons from cherry stones by activation with potassium hydroxide  

NASA Astrophysics Data System (ADS)

Using cherry stones, the preparation of activated carbon has been undertaken in the present study by chemical activation with potassium hydroxide. A series of KOH-activated products was prepared by varying the carbonisation temperature in the 400 900 °C range. Such products were characterised texturally by gas adsorption (N2, -196 °C), mercury porosimetry, and helium and mercury density measurements. FT-IR spectroscopy was also applied. The carbons prepared as a rule are microporous and macroporous solids. The degree of development of surface area and porosity increases with increasing carbonisation temperature. For the carbon heated at 900 °C the specific surface area (BET) is 1624 m2 g-1, the micropore volume is 0.67 cm3 g-1, the mesopore volume is 0.28 cm3 g-1, and the macropore volume is 1.84 cm3 g-1.

Olivares-Marín, M.; Fernández-González, C.; Macías-García, A.; Gómez-Serrano, V.

2006-06-01

100

Granular Activated Carbon Filter-Adsorber Systems  

Microsoft Academic Search

The design, operation, and performance of granular activated carbon (GAC) filter-adsorbers were documented and potential problems were identified by means of a survey of operating plants and a review of the literature. It was found that GAC as a total or partial replacement for sand is as effective as conventional filtration media for removing turbidity, provided an appropriate medium size

Sandra L. Graese; Vernon L. Snoeyink; Ramon G. Lee

1987-01-01

101

Nanoscaled palladium catalysts on activated carbon support  

Microsoft Academic Search

The application of nanosized palladium catalysts has gained growing importance over the last few years. Palladiumbased catalytic methods for fine organic synthesis permits the replacement of traditional labor-consuming techniques in multi-step organic syntheses and provides an improvement from the standpoint of cost and environmental impact. The use of activated carbon \\

I. Simakova; A. Koskin; I. Deliy; A. Simakov

2005-01-01

102

MODELING MERCURY CONTROL WITH POWDERED ACTIVATED CARBON  

EPA Science Inventory

The paper presents a mathematical model of total mercury removed from the flue gas at coal-fired plants equipped with powdered activated carbon (PAC) injection for Mercury control. The developed algorithms account for mercury removal by both existing equipment and an added PAC in...

103

Preparation of activated carbon from cherry stones by chemical activation with ZnCl 2  

NASA Astrophysics Data System (ADS)

Cherry stones (CS), an industrial product generated abundantly in the Valle del Jerte (Cáceres province, Spain), were used as precursor in the preparation of activated carbon by chemical activation with ZnCl 2. The influence of process variables such as the carbonisation temperature and the ZnCl 2:CS ratio (impregnation ratio) on textural and chemical-surface properties of the products obtained was studied. Such products were characterised texturally by adsorption of N 2 at -196 °C, mercury porosimetry and density measurements. Information on the surface functional groups and structures of the carbons was provided by FT-IR spectroscopy. Activated carbon with a high development of surface area and porosity is prepared. When using the 4:1 impregnation ratio, the specific surface area (BET) of the resultant carbon is as high as 1971 m 2 g -1. The effect of the increase in the impregnation ratio on the porous structure of activated carbon is stronger than that of the rise in the carbonisation temperature, whereas the opposite applies to the effect on the surface functional groups and structures.

Olivares-Marín, M.; Fernández-González, C.; Macías-García, A.; Gómez-Serrano, V.

2006-06-01

104

Production of carbon molecular sieves from Illinois coal  

USGS Publications Warehouse

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

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

1993-01-01

105

Select metal adsorption by activated carbon made from peanut shells  

Microsoft Academic Search

Agricultural by-products, such as peanut shells, contribute large quantities of lignocellulosic waste to the environment each growing season; but few, if any, value-added uses exist for their disposal. The objective of this study was to convert peanut shells to activated carbons for use in adsorption of select metal ions, namely, cadmium (Cd2+), copper (Cu2+), lead (Pb2+), nickel (Ni2+) and zinc

Kermit Wilson; Hong Yang; Chung W. Seo; Wayne E. Marshall

2006-01-01

106

Preparation of functionalized and metal-impregnated activated carbon by a single-step activation method  

NASA Astrophysics Data System (ADS)

A rapid method to prepare functionalized and metal-impregnated activated carbon from coal is described in this paper. A mixture of ferric chloride and a sub-bituminous coal was used to demonstrate simultaneous coal activation, chlorine functionalization, and iron/iron oxides impregnation in the resulting porous carbon products. The FeCl3 concentration in the mixture, the method to prepare the FeCl3-coal mixture (solid mixing or liquid impregnation), and activation atmosphere and temperature impacted the surface area and porosity development, Cl functionalization, and iron species impregnation and dispersion in the carbon products. Samples activated in nitrogen or a simulated flue gas at 600 or 1000 °C for 1-2 min had surface areas up to ?800 m2/g, bulk iron contents up to 18 wt%, and surface chlorine contents up to 27 wt%. Potential catalytic and adsorption application of the carbon materials was explored in catalytic wet air oxidation (CWAO) of phenol and adsorption of ionic mercury from aqueous solutions. Results indicated that impregnated activated carbons outperformed their non-impregnated counterparts in both the CWAO and adsorption tests.

Dastgheib, Seyed A.; Ren, Jianli; Rostam-Abadi, Massoud; Chang, Ramsay

2014-01-01

107

Experimental design to optimize preparation of activated carbons for use in water treatment.  

PubMed

A series of seven activated carbons was obtained for use in drinking water treatments by steam-activation of olive-waste cakes. This raw material is an abundant and cheap waste byproduct of oil production, making these activated carbons economically feasible. The activated carbons, prepared by the one step method, were characterized, and the evolution of their characteristics (yield, adsorption capacities, and porosity) was analyzed as a function of the experimental parameters (activation temperature and activation time), using the Doehlert matrix. The Doehlert matrix allows the response surface to be studied with a good quality parameter estimation of the quadratic model. Each response has been described by a second order model that was adequate to predict responses in all experimental regions. The coefficients of the postulated model were calculated from the experimental responses by means of least squares regression, using the NEMROD software. We determined the region in which the optimum values of both activation temperature and activation time were achieved for the preparation of activated carbons suitable for use in water treatments. The "optimal activated carbon" was experimentally obtained, and its characteristic parameters showed a good agreement with those calculated from the model. The results obtained for activated carbons prepared by the one-step method were compared with those for activated carbons prepared by the two-step method. The characteristics of activated carbons obtained by the one-step and two-step methods showed that "one-step" activated carbons have a highly developed porous texture formed mainly of large macropores and micropores, whereas "two-step" activated carbons have a predominance of mesopores and narrow micropores. These activated carbons from olive-waste cakes showed a high capacity to adsorb herbicides (2,4-dichlorophenoxyacetic acid, 2,4-D; and 2-methyl, 4-chlorophenoxyacetic acid, MCPA) from water, with adsorption capacity values higher than those corresponding to a commercial activated carbon used from drinking water treatments. PMID:12322759

Baçaoui, Abdelaziz; Dahbi, Abderrahman; Yaacoubi, Abdelrani; Bennouna, Chakib; Maldonado-Hódar, Francisco J; Rivera-Utrilla, José; Carrasco-Marín, Francisco; Moreno-Castilla, Carlos

2002-09-01

108

Carbonation of calcium-containing mineral and industrial by-products  

Microsoft Academic Search

The use of carbon dioxide (CO2) and calcium-containing by-products from industrial activities is receiving increasing interest as a route to valuable carbonate\\u000a materials while reducing CO2 emissions and saving natural resources. In this work, wet-chemical experimental data was assessed, which involved the carbonation\\u000a of three types of materials in aqueous solutions, namely, 1) wollastonite, a calcium silicate mineral, 2) steelmaking

Ron Zevenhoven; Anders Wiklund; Johan Fagerlund; Sanni Eloneva; Ben In’t Veen; Hans Geerlings; Gert Van Mossel; Harold Boerrigter

2010-01-01

109

Studying the effectiveness of activated carbon R95 respirators in reducing the inhalation of combustion by-products in Hanoi, Vietnam: a demonstration study  

PubMed Central

Background Urban air pollution is an increasing health problem, particularly in Asia, where the combustion of fossil fuels has increased rapidly as a result of industrialization and socio-economic development. The adverse health impacts of urban air pollution are well established, but less is known about effective intervention strategies. In this demonstration study we set out to establish methods to assess whether wearing an R95 activated carbon respirator could reduce intake of polycyclic aromatic hydrocarbons (PAH) in street workers in Hanoi, Vietnam. Methods In this demonstration study we performed a cross-over study in which non-smoking participants that worked at least 4 hours per day on the street in Hanoi were randomly allocated to specific respirator wearing sequences for a duration of 2 weeks. Urines were collected after each period, i.e. twice per week, at the end of the working day to measure hydroxy PAHs (OH-PAH) using gas chromatography/high resolution mass spectrometry. The primary endpoint was the urinary concentration of 1-hydroxypyrene (1-OHP). Results Forty-four participants (54.5% male, median age 40 years) were enrolled with the majority being motorbike taxi drivers (38.6%) or street vendors (34.1%). The baseline creatinine corrected urinary level for 1-OHP was much higher than other international comparisons: 1020 ng/g creatinine (IQR: 604–1551). Wearing a R95 mask had no significant effect on 1-OHP levels: estimated multiplicative effect 1.0 (95% CI: 0.92-1.09) or other OH-PAHs, except 1-hydroxynaphthalene (1-OHN): 0.86 (95% CI: 0.11-0.96). Conclusions High levels of urine OH-PAHs were found in Hanoi street workers. No effect was seen on urine OH-PAH levels by wearing R95 particulate respirators in an area of high urban air pollution, except for 1-OHN. A lack of effect may be de to gaseous phase PAHs that were not filtered efficiently by the respirator. The high levels of urinary OH-PAHs found, urges for effective interventions. Trial registration ISRCTN74390617 (date of assignation: 04/08/2009). PMID:23013369

2012-01-01

110

Nitrogen-Containing Carbon Nanotube Synthesized from Polymelem and Activated Carbon Derived from Polymer Blend  

NASA Astrophysics Data System (ADS)

Polymelem possesses a polymeric structure of heptazine (C6N 7) rings connected by amine bridges and our study has demonstrated that it is a promising precursor for the synthesis of nitrogen-containing carbon materials. Nitrogen-containing carbon nanotube (NCNT) was produced by pyrolyzing polymelem as a dual source of carbon and nitrogen with Raney nickel in a high pressure stainless steel cell. Activated carbon was produced from poly(ether ether ketone)/poly(ether imide) (PEEK/PEI blend) and incorporated with polymelem to enhance the hydrogen adsorption. Polymelem was successfully synthesized by pyrolyzing melamine at 450--650 °C and its structure was elucidated by 13C solid state NMR, FTIR, and XRD. The molecular weight determined by a novel LDI MS equipped with a LIFT mode illuminated that polymelem has both linear and cyclic connectivity with a degree of polymerization of 2--5 depending on the synthesis temperature. The decomposition products of polymelem were determined to be cyanoamide, dicyanoamide, and tricyanoamine. Tricyanoamine is the smallest carbon nitride molecule and has been experimentally confirmed for the first time in this study. When polymelem was decomposed in the presence of Raney nickel, homogenous NCNT with nitrogen content of ˜ 4--19 atom% was produced. A mechanism based on a detail analysis of the TEM images at different growth stages proposed that the NCNT propagated via a tip-growth mechanism originating at the nano-domains within the Raney nickel, and was accompanied with the aggregation of the nickel catalysts. Such NCNT exhibited a cup-stack wall structure paired with a compartmental feature. The nitrogen content, tube diameter and wall thickness greatly depended on synthesis conditions. The activated carbon derived from PEEK/PEI blend demonstrated a surface area up to ˜3000 m2/g, and average pore size of < 20 A. Such activated carbon exhibited a hydrogen storage capacity of up to 6.47 wt% at 40 bar, 77 K. The activated carbon has was incorporated with polymelem via a liquid penetration and a CVD method to modify its surface chemistry. The hydrogen adsorption energy of the polymelem doped activated carbon demonstrated a dramatic increase from ˜5 kJ/mol to ˜14 kJ/mol due to the higher polarizability of the polymelem.

Qin, Nan

111

Adsorption of chlorophenols on granular activated carbon  

SciTech Connect

Studies were undertaken of the adsorption of chlorinated phenols from aqueous solution on granular activated carbon (Filtrasorb-400, 30 x 40 mesh). Single-component equilibrium adsorption data on the eight compounds in two concentration ranges at pH 7.0 fit the Langmuir equation better than the Freundlich equation. The adsorptive capacities at pH 7.0 increase from pentachlorophenol to trichlorophenols and are fairly constant from trichlorophenols to monochlorophenols. The adsorption process was found to be exothermic for pentachlorophenol and 2,4,6-trichlorophenol, and endothermic for 2,4-dichlorophenol and 4-chlorophenol. Equilibrium measurements were also conducted for 2,4,5-trichlorophenol, 2,4-dichlorophenol, and 4-chlorophenol over a wide pH range. A surface complexation model was proposed to describe the effect of pH on adsorption equilibria of chlorophenols on activated carbon. The simulations of the model are in excellent agreement with the experimental data. Batch kinetics studies were conducted of the adsorption of chlorinated phenols on granular activated carbon. The results show that the surface reaction model best describes both the short-term and long-term kinetics, while the external film diffusion model describes the short-term kinetics data very well and the linear-driving-force approximation improved its performance for the long-term kinetics. Multicomponent adsorption equilibria of chlorophenols on granular activated carbon was investigated in the micromolar equilibrium concentration range. The Langmuir competitive and Ideal Adsorbed Solution (IAS) models were tested for their performance on the three binary systems of pentachlorophenol/2,4,6-trichlorophenol, 2,4,6-trichlorophenol/2,4-dichlorophenol, and 2,4-dichlorophenol/4-chlorophenol, and the tertiary system of 2,4,6-trichlorophenol/2,4-dichlorophenol/4-chlorophenol, and found to fail to predict the two-component adsorption equilibria of the former two binary systems and the tertiary system.

Yang, M.

1993-12-31

112

PRODUCTION OF CARBON 14 BY COSMIC-RAY NEUTRONS  

Microsoft Academic Search

The rate of production of carbon-14 by cosmic neutrons is calculated by ; multigroup diffusion theory as a function of altitude, latitude, and time, and it ; is normalized to absolute cosmic neutron flux measurements. The global average ; production rate over the last ten solar cycles is found to be 2.50 plus or minus ; 0.50 carbon-14 atoms per

R. E. Lingenfelter

1963-01-01

113

Sorption of heavy metal cations on activated carbon  

Microsoft Academic Search

Activated carbon is used to remove trace amounts of organic compounds from waters and wastewaters. An experimental program was conducted to determine the kinetics of sorption of lead, copper, and zinc on the surface of the powdered activated carbon Nuchar SA, and on granular activated carbon Filtrasorb 400. The results of the experimental program showed that sorption of heavy metals

Wilczak

1988-01-01

114

Characteristics of activated carbon produced from biosludge and its use in wastewater post-treatment.  

PubMed

Experimental research into the bench-scale production of activated carbon from waste-activated sludge from water purification, sawdust, peat, and their mixtures, by carbonisation and activation was undertaken. The research work was carried out to determine possible methods of production of cheap activated carbon from local raw materials and to use it in water purification technology. Along with the samples produced, several commercial activated carbons (namely RB-1, F 100, CA (adsorbent from military gas masks), BAY (product of the USSR)) were tested to compare adsorption properties in the adsorption of phenols, xylidines, amines, methylene blue and molasses. It has been found that the activated carbon produced from waste biosludge was of higher quality than that produced from either sawdust or peat, and performed similarly to RB-1 and F100 in adsorption tests. It was also determined that the activated carbon produced from biosludge could possibly be used in the post-treatment of wastewater. Residual sludge from the biological treatment of the wastewater from the purification of oil-shale in the chemical processing industry could cover up to 80% of the need for activated carbon. Some of this activated carbon could be used in the post-treatment of the same water, adsorbing polyalcaline phenols from the initial content of 4 mg l-1 to the demanded level of 1 mg l-1. PMID:11349382

Pikkov, L; Kallas, J; Rüütmann, T; Rikmann, E

2001-02-01

115

Preparation and ozone-surface modification of activated carbon. Thermal stability of oxygen surface groups  

NASA Astrophysics Data System (ADS)

The control of the surface chemistry of activated carbon by ozone and heat treatment is investigated. Using cherry stones, activated carbons were prepared by carbonization at 900 °C and activation in CO 2 or steam at 850 °C. The obtained products were ozone-treated at room temperature. After their thermogravimetric analysis, the samples were heat-treated to 300, 500, 700 or 900 °C. The textural characterization was carried out by N 2 adsorption at 77 K, mercury porosimetry, and density measurements. The surface analysis was performed by the Bohem method and pH of the point of zero charge (pH pzc). It has been found that the treatment of activated carbon with ozone combined with heat treatment enables one to control the acidic-basic character and strength of the carbon surface. Whereas the treatment with ozone yields acidic carbons, carbon dioxide and steam activations of the carbonized product and the heat treatment of the ozone-treated products result in basic carbons; the strength of a base which increases with the increasing heat treatment temperature. pH pzc ranges between 3.6 and 10.3.

Jaramillo, J.; Álvarez, P. M.; Gómez-Serrano, V.

2010-06-01

116

Beneficial Use of Carbon Dioxide in Precast Concrete Production  

SciTech Connect

The feasibility of using carbon dioxide as feedstock in precast concrete production is studied. Carbon dioxide reacts with calcium compounds in concrete, producing solid calcium carbonates in binding matrix. Two typical precast products are examined for their capacity to store carbon dioxide during the production. They are concrete blocks and fiber?cement panels. The two products are currently mass produced and cured by steam. Carbon dioxide can be used to replace steam in curing process to accelerate early strength, improve the long?term durability and reduce energy and emission. For a reaction within a 24?hour process window, the theoretical maximum possible carbon uptake in concrete is found to be 29% based on cement mass in the product. To reach the maximum uptake, a special process is developed to promote the reaction efficiency to 60?80% in 4?hour carbon dioxide curing and improve the resistance to freeze?thaw cycling and sulfate ion attack. The process is also optimized to meet the project target of $10/tCO{sub 2} in carbon utilization. By the use of self?concentrating absorption technology, high purity CO{sub 2} can be produced at a price below $40/t. With low cost CO{sub 2} capture and utilization technologies, it is feasible to establish a network for carbon capture and utilization at the vicinity of carbon sources. If all block produces and panel producers in United States could adopt carbon dioxide process in their production in place of steam, carbon utilization in these two markets alone could consume more than 2 Mt CO{sub 2}/year. This capture and utilization process can be extended to more precast products and will continue for years to come.

Shao, Yixin

2014-03-31

117

Carbon Cycle in the Lab: Carbon Products and the Processes That Link Them  

NSDL National Science Digital Library

This lab teaches students about the nature of carbon, the different types of compounds it exists in (e.g. charcoal, glucose, carbon dioxide), the biochemical reactions it takes part in (photosynthesis and respiration), the range of processes that carbon and carbon compounds are involved in on Earth, and how these link together form the carbon cycle. They will get a feel for how the whole carbon cycle works by turning the laboratory into a model of the carbon cycle and seeing how the different things that are produced in the cycle (the products) fit together with the way those products are made (the processes). The site contains teacher notes, a list of required materials, student instructions and questions, and a diagram of the carbon cycle.

118

Photorespiration and Carbon Limitation Determine Productivity in Temperate Seagrasses  

PubMed Central

The gross primary productivity of two seagrasses, Zostera marina and Ruppia maritima, and one green macroalga, Ulva intestinalis, was assessed in laboratory and field experiments to determine whether the photorespiratory pathway operates at a substantial level in these macrophytes and to what extent it is enhanced by naturally occurring shifts in dissolved inorganic carbon (DIC) and O2 in dense vegetation. To achieve these conditions in laboratory experiments, seawater was incubated with U. intestinalis in light to obtain a range of higher pH and O2 levels and lower DIC levels. Gross photosynthetic O2 evolution was then measured in this pretreated seawater (pH, 7.8–9.8; high to low DIC:O2 ratio) at both natural and low O2 concentrations (adjusted by N2 bubbling). The presence of photorespiration was indicated by a lower gross O2 evolution rate under natural O2 conditions than when O2 was reduced. In all three macrophytes, gross photosynthetic rates were negatively affected by higher pH and lower DIC. However, while both seagrasses exhibited significant photorespiratory activity at increasing pH values, the macroalga U. intestinalis exhibited no such activity. Rates of seagrass photosynthesis were then assessed in seawater collected from the natural habitats (i.e., shallow bays characterized by high macrophyte cover and by low DIC and high pH during daytime) and compared with open baymouth water conditions (where seawater DIC is in equilibrium with air, normal DIC, and pH). The gross photosynthetic rates of both seagrasses were significantly higher when incubated in the baymouth water, indicating that these grasses can be significantly carbon limited in shallow bays. Photorespiration was also detected in both seagrasses under shallow bay water conditions. Our findings indicate that natural carbon limitations caused by high community photosynthesis can enhance photorespiration and cause a significant decline in seagrass primary production in shallow waters. PMID:24376754

Buapet, Pimchanok; Rasmusson, Lina M.; Gullström, Martin; Björk, Mats

2013-01-01

119

PRODUCTION AND SCREENING OF CARBON PRODUCTS PRECURSORS FROM COAL  

SciTech Connect

The authors have examined effects of blending a raw coal extract (EXT) with an extracted coal-tar pitch (ECTP). Previous reports were concerned with the addition of 15 wt% EXT, or less, on the physical characteristics of the blend and on the development of optical texture following carbonization. Two additional blends of ECTP and EXT were prepared at the 30 and 50 wt% EXT content using a procedure already described. The characteristics of the blends are presented. The density for these blended materials is not much different than the density for the blends reported earlier. The softening point temperature for the 30 wt% EXT increased to over 200 C while the softening point temperature for the 50 wt% EXT blend was too high to be determined by the Mettler method. Coke yields approximately follow the law of mixtures. The optical texture of the green cokes for the 30 and 50 wt% EXT blends is shown. Though the optical texture of the green cokes was not significantly affected where the level of EXT is 15 wt% or less, larger proportions of EXT exert a marked reduction in anisotropy. The co-processing of coal with petroleum residues or other heavy hydrocarbons at elevated temperature and pressure has received considerable attention in the research community as a means to upgrade simultaneously coal and byproducts. Heavy hydrocarbons can function as sources of hydrogen, as well as performing as a medium for dissolution and dispersion of coal fragments. However, the focus of much of the prior research has been on developing fuels, distillable liquids, or synthetic crudes. Comparatively little effort has been deliberately directed toward the production of heavier, non-distillable materials which could perform as binder and extender pitches, impregnants, or feedstocks for cokes and other carbons.

Caulton L. Irwin

2001-05-31

120

Entrapment of Carbon Dioxide in the Active Site of Carbonic Anhydrase II*  

E-print Network

Entrapment of Carbon Dioxide in the Active Site of Carbonic Anhydrase II* Received for publication step of CO2 hydration catalyzed by the zinc- metalloenzyme human carbonic anhydrase II, the binding substrates and revealing hydrophobic pockets in proteins. Since their discovery (2), the carbonic anhydrases

Gruner, Sol M.

121

Impact of backwashing on nitrification in the biological activated carbon filters used in drinking water treatment  

Microsoft Academic Search

Nitrification during biological filtration is currently used in drinking water production to remove ammonia, which is the source of several water quality problems during treatment and distribution. We evaluated here the impact of backwashing on nitrification efficiency in filters used for drinking water treatment. Two different granular activated carbon (one open and one closed carbon superstructure) were tested. Ammonia removal

P. Laurent; A. Kihn; A. Andersson; P. Servais

2003-01-01

122

Carbonation of an active serpentinization system  

NASA Astrophysics Data System (ADS)

Carbonation of serpentinite has been invoked to be a promising tool to mitigate large-scale CO2 emissions, however, monitoring the reaction progress during or after CO2-injection and the interpretation of rapidly evolving fluid-rock equilibria remains a critical but challenging task. We report on a hydrothermal experiment where CO2 was injected into an ongoing serpentinization system in order to assess the changes in fluid chemistry and mineralogy during carbonation. In a first step olivine (Fo90) was reacted with a fluid of seawater chlorinity at 300 °C and 350 bars and fluid-to-rock mass ratio of 2. Under these conditions serpentinization of olivine is very rapid and causes the formation of serpentine, brucite and minor amounts of magnetite. Several fluid samples were taken and immediately analyzed for aqueous silica (SiO2,aq), hydrogen (H2,aq) and pH to monitor the reaction progress. As soon as the serpentine-brucite equilibrium was reached we lowered the temperature to 230°C to facilitate the subsequent carbonation of serpentine, brucite and olivine. The lower temperature was used since carbonation reactions appear to be more rapid and equilibrium CO2 levels are lower, facilitating carbonation reactions. Next, we injected about 9 milimoles of CO2 into the flexible-cell hydrothermal apparatus resulting in a dissolved concentration of about 180 mM CO2,aq. The injection of CO2 caused a drastic change in fluid composition. Within six hours the pH decreased from 9 to 6, while the increased levels of SiO2,aq and CO2,aq indicate talc-magnesite saturation. Two days after the injection the concentrations of SiO2,aq and CO2,aq increased to quartz-magnesite saturation. Subsequently SiO2,aq and CO2,aq decreased to values close to the serpentine-talc-magnesite quasi-invariant point and remained virtually fixed until the experiment was opened after 91 days. The solid reaction products were analyzed using a field emission SEM equipped with an Oxford EDS system. In agreement with the fluid chemistry the secondary mineralogy consists of serpentine, talc, magnesite and traces of magnetite; brucite and quartz are absent. Although relict olivine is present at the end of the experiment the fluid chemistry rapidly responded to the dominating secondary mineralogy, as suggested by the lack of quartz. This experiment shows how the fluid chemistry can be used to remotely monitor changes in mineralogy during carbonation of ultramafic rocks, changes that may be difficult to monitor otherwise.

Klein, F.; McCollom, T. M.

2011-12-01

123

The regeneration of polluted activated carbon by radiation techniques  

NASA Astrophysics Data System (ADS)

In this paper, the regeneration of used activated carbon from monosodium glutamate factory was experimented using radiation and acid-alkali chemical cleaning method. Results showed that the activated carbon saturated with pollutants can be wash away easily by flushing with chemical solution prior irradiation. DSC was used to monitor the change of carbon adsorption

Minghong, Wu; Borong, Bao; Ruimin, Zhou; Jinliang, Zhu; Longxin, Hu

1998-10-01

124

Coal precursors for production of carbon and graphite products. Final report  

SciTech Connect

The main goal of this program was to demonstrate the utility of coal extracts from the West Virginia University (WVU) extraction process as suitable base raw materials for the carbon products encompassed by the Carbon Products Consortium (CPC) team. These include binder and impregnation pitches, Coke for graphite electrodes, Cokes for anodes and specialty graphite, matrices for C/C composites and raw material for mesophase pitch fibers. Previous work in this program has shown that the WVU coal extraction process coupled with hydrotreatment, does have the potential for achieving this objective. The current effort involved screening and evaluation of extracts produced by the WVU Group and recommending appropriate materials for scaleup for subsequent evaluation by Consortium Team members. The program involved an initial characterization of small-scale extracts using standard analytical methods and mesophase formation studies. This was followed by feedback to the WVU Group and to the CPC partners with recommendation of material for scaleup. Similar analytical and mesophase studies on some of the scaled-up extracts was performed. The activation of the coal extraction residues for the purpose of producing a useful active carbon was investigated. A further task was to fabricate a small graphite artifact using Coke derived from coal extract as the filler and the coal extract itself as a binder. The results of the studies are summarized in this report.

Lewis, I.C.; Lewis, R.T.; Mayer, H.K. [Ucar Carbon Co., Inc., Parma, OH (United States)

1996-04-08

125

40 CFR 415.450 - Applicability; description of the lithium carbonate production subcategory.  

Code of Federal Regulations, 2014 CFR

...true Applicability; description of the lithium carbonate production subcategory. 415...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Lithium Carbonate Production Subcategory § 415.450 Applicability; description of the lithium carbonate production subcategory....

2014-07-01

126

40 CFR 415.450 - Applicability; description of the lithium carbonate production subcategory.  

Code of Federal Regulations, 2013 CFR

...true Applicability; description of the lithium carbonate production subcategory. 415...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Lithium Carbonate Production Subcategory § 415.450 Applicability; description of the lithium carbonate production subcategory....

2013-07-01

127

40 CFR 415.450 - Applicability; description of the lithium carbonate production subcategory.  

Code of Federal Regulations, 2010 CFR

...true Applicability; description of the lithium carbonate production subcategory. 415...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Lithium Carbonate Production Subcategory § 415.450 Applicability; description of the lithium carbonate production subcategory....

2010-07-01

128

40 CFR 415.450 - Applicability; description of the lithium carbonate production subcategory.  

Code of Federal Regulations, 2012 CFR

...false Applicability; description of the lithium carbonate production subcategory. 415...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Lithium Carbonate Production Subcategory § 415.450 Applicability; description of the lithium carbonate production subcategory....

2012-07-01

129

40 CFR 415.450 - Applicability; description of the lithium carbonate production subcategory.  

Code of Federal Regulations, 2011 CFR

...true Applicability; description of the lithium carbonate production subcategory. 415...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Lithium Carbonate Production Subcategory § 415.450 Applicability; description of the lithium carbonate production subcategory....

2011-07-01

130

40 CFR 415.300 - Applicability; description of the calcium carbonate production subcategory.  

Code of Federal Regulations, 2010 CFR

...true Applicability; description of the calcium carbonate production subcategory. 415...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Calcium Carbonate Production Subcategory § 415.300 Applicability; description of the calcium carbonate production subcategory....

2010-07-01

131

40 CFR 415.300 - Applicability; description of the calcium carbonate production subcategory.  

Code of Federal Regulations, 2011 CFR

...true Applicability; description of the calcium carbonate production subcategory. 415...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Calcium Carbonate Production Subcategory § 415.300 Applicability; description of the calcium carbonate production subcategory....

2011-07-01

132

40 CFR 415.300 - Applicability; description of the calcium carbonate production subcategory.  

Code of Federal Regulations, 2012 CFR

...false Applicability; description of the calcium carbonate production subcategory. 415...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Calcium Carbonate Production Subcategory § 415.300 Applicability; description of the calcium carbonate production subcategory....

2012-07-01

133

40 CFR 415.300 - Applicability; description of the calcium carbonate production subcategory.  

Code of Federal Regulations, 2014 CFR

...true Applicability; description of the calcium carbonate production subcategory. 415...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Calcium Carbonate Production Subcategory § 415.300 Applicability; description of the calcium carbonate production subcategory....

2014-07-01

134

40 CFR 415.300 - Applicability; description of the calcium carbonate production subcategory.  

Code of Federal Regulations, 2013 CFR

...true Applicability; description of the calcium carbonate production subcategory. 415...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Calcium Carbonate Production Subcategory § 415.300 Applicability; description of the calcium carbonate production subcategory....

2013-07-01

135

Kinetic and equilibrium adsorption of methylene blue and remazol dyes onto steam-activated carbons developed from date pits  

Microsoft Academic Search

Steam-activated carbons DS2 and DS5 were prepared by gasifying 600°C-date pits carbonization products with steam at 950°C to burn-off=20 and 50%, respectively. The textural properties of these carbons were determined from the nitrogen adsorption at ?196°C. The chemistry of the carbon surface was determined from the surface pH and from neutralization of the surface carbon–oxygen groups of basic and acidic

Sheikha S. Ashour

2010-01-01

136

Temporal variations in microbial activities and carbon turnover in subtidal sandy sediments  

NASA Astrophysics Data System (ADS)

Temporal dynamics and vertical patterns in bacterial abundances and activities were studied in a shallow subtidal sand flat in the Sylt-Rømø Basin (North Frisian Wadden Sea, Germany.) Extracellular enzymatic activities, bacterial carbon production and community respiration showed strong (factor of 4 5) temporal variations that were mostly related to seasonal temperature change, but also to changes in substrate availability. These temporal patterns in activity were barely reflected in bacterial (200 400 mmol C m-2) and microphytobenthic biomass (800 1500 mmol C m-2) or the sedimentary carbohydrate inventory (1300 2900 mmol C m-2), suggesting that grazing controls the standing stocks of the microphytobenthic and bacterial assemblages. Despite their exposure to strong hydrodynamic forces such as tidal currents and wind-induced wave surge, the subtidal sandy sediments showed persistent vertical gradients in bacterial abundances, bacterial carbon production and extracellular enzymatic activities at all times. The vertical distribution of these parameters was tightly coupled to that of the microphytobenthos, dominated by diatoms. Despite the low organic carbon content typical for surge-exposed sandy sediments, high extracellular enzymatic activities and bacterial carbon production rates indicate a very active heterotrophic bacterial community, with a gross secondary productivity of 30 180 mmol C m-2, and a biomass turnover time of 2 18 days. Our data suggest that this high activity is supported by the rapid flux of carbohydrates from microphytobenthic primary productivity. Accordingly, the potential activities of enzymes hydrolyzing carbohydrates cover most of the total bacterial carbon demand during all seasons.

Böer, S. I.; Arnosti, C.; van Beusekom, J. E. E.; Boetius, A.

2008-11-01

137

Histochemical demonstration of carbonic anhydrase activity  

Microsoft Academic Search

Freeze-dried frozen sections are floated on the surface of the freshly prepared incubation mixture (CoSO4 1.75 × 10-3M, H2SO4 5.3 × 10-2M, NaHCO3 1.57 × 10-2M and KH2PO4 1.17 to 11.7 × 10-3M; demonstration of weak activity requires high phosphate). A compound containing cobalt and phosphorous precipitates at carbonic anhydrase sites and is converted to CoS. Adequate staining requires only

Holger P. J. Hansson

1967-01-01

138

Charcoal and activated carbon at elevated pressure  

SciTech Connect

High quality charcoal has been produced with very high yields of 50% to 60% from macadamia nut and kukui nut shells and of 44% to 47% from Eucalyptus and Leucaena wood in a bench scale unit at elevated pressure on a 2 to 3 hour cycle, compared to commercial practice of 25% to 30% yield on a 7 to 12 day operating cycle. Neither air pollution nor tar is produced by the process. The effects of feedstock pretreatments with metal additives on charcoal yield are evaluated in this paper. Also, the influences of steam and air partial pressure and total pressure on yields of activated carbon from high yield charcoal are presented.

Antal, M.J. Jr.; Dai, Xiangfeng; Norberg, N. [Univ. of Hawaii at Manoa, Honolulu, HI (United States)] [and others

1995-12-01

139

Preparation of activated carbons from bituminous coal pitches  

NASA Astrophysics Data System (ADS)

High-porosity carbons were prepared from bituminous coal pitches by combining chemical and physical activation. The chemical activation process consisted of potassium hydroxide impregnation followed by carbonization in nitrogen atmosphere. The effect of the KOH impregnation ratio on the surface area and pore volumes evolution of the carbons derived from mesophase pitch was studied. The optimum KOH:pitch ratio was fixed to realize a physical activation process in order to increase the textural parameters of the KOH-activated carbons. Physical activation was performed by carbonizing the KOH-activated carbons followed by gasifying with air. The influence of the carbonization temperature and the residence time of the gasification with air were explored to optimize those preparation parameters.

Gañan, J.; González-Garc?´a, C. M.; González, J. F.; Sabio, E.; Mac?´as-Garc?´a, A.; D?´az-D?´ez, M. A.

2004-11-01

140

MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT  

SciTech Connect

The program was designed to advance the carbonate fuel cell technology from full-size proof-of-concept field test to the commercial design. DOE has been funding Direct FuelCell{reg_sign} (DFC{reg_sign}) development at FuelCell Energy, Inc. (FCE, formerly Energy Research Corporation) from an early state of development for stationary power plant applications. The current program efforts were focused on technology and system development, and cost reduction, leading to commercial design development and prototype system field trials. FCE, in Danbury, CT, is a world-recognized leader for the development and commercialization of high efficiency fuel cells that can generate clean electricity at power stations, or at distributed locations near the customers such as hospitals, schools, universities, hotels and other commercial and industrial applications. FCE has designed three different fuel cell power plant models (DFC300A, DFC1500 and DFC3000). FCE's power plants are based on its patented DFC{reg_sign} technology, where a hydrocarbon fuel is directly fed to the fuel cell and hydrogen is generated internally. These power plants offer significant advantages compared to the existing power generation technologies--higher fuel efficiency, significantly lower emissions, quieter operation, flexible siting and permitting requirements, scalability and potentially lower operating costs. Also, the exhaust heat by-product can be used for cogeneration applications such as high-pressure steam, district heating and air conditioning. Several sub-MW power plants based on the DFC design are currently operating in Europe, Japan and the US. Several one-megawatt power plant design was verified by operation on natural gas at FCE. This plant is currently installed at a customer site in King County, WA under another US government program and is currently in operation. Because hydrogen is generated directly within the fuel cell module from readily available fuels such as natural gas and waste water treatment gas, DFC power plants are ready today and do not require the creation of a hydrogen infrastructure. Product improvement progress made during the program period in the areas of technology, manufacturing processes, cost reduction and balance-of-plant equipment designs is discussed in this report.

H.C. Maru; M. Farooque

2005-03-01

141

Carbon nano structures: Production and characterization  

NASA Astrophysics Data System (ADS)

L'objectif de ce memoire est de preparer et de caracteriser des nanostructures de carbone (CNS -- Carbon Nanostructures, en licence a l'Institut de recherche sur l'hydrogene, Quebec, Canada), un carbone avec un plus grand degre de graphitisation et une meilleure porosite. Le Chapitre 1 est une description generale des PEMFCs (PEMFC -- Polymer Electrolyte Membrane Fuel Cell) et plus particulierement des CNS comme support de catalyseurs, leur synthese et purification. Le Chapitre 2 decrit plus en details la methode de synthese et la purification des CNS, la theorie de formation des nanostructures et les differentes techniques de caracterisation que nous avons utilises telles que la diffraction aux rayons-X (XRD -- X-ray diffraction), la microscopie electronique a transmission (TEM -- transmission electron microscope ), la spectroscopie Raman, les isothermes d'adsorption d'azote a 77 K (analyse BET, t-plot, DFT), l'intrusion au mercure, et l'analyse thermogravimetrique (TGA -- thermogravimetric analysis). Le Chapitre 3 presente les resultats obtenus a chaque etape de la synthese des CNS et avec des echantillons produits a l'aide d'un broyeur de type SPEXRTM (SPEX/CertiPrep 8000D) et d'un broyeur de type planetaire (Fritsch Pulverisette 5). La difference essentielle entre ces deux types de broyeur est la facon avec laquelle les materiaux sont broyes. Le broyeur de type SPEX secoue le creuset contenant les materiaux et des billes d'acier selon 3 axes produisant ainsi des impacts de tres grande energie. Le broyeur planetaire quant a lui fait tourner et deplace le creuset contenant les materiaux et des billes d'acier selon 2 axes (plan). Les materiaux sont donc broyes differemment et l'objectif est de voir si les CNS produits ont les memes structures et proprietes. Lors de nos travaux nous avons ete confrontes a un probleme majeur. Nous n'arrivions pas a reproduire les CNS dont la methode de synthese a originellement ete developpee dans les laboratoires de l'Institut de recherche sur l'hydrogene (IRH). Nos echantillons presentaient toujours une grande quantite de carbure de fer au detriment de la formation de nanostructures de carbone. Apres plusieurs mois de recherche nous avons constate que les metaux de base, soit le fer et le cobalt, etaient contamines. Neanmoins, ces recherches nous ont enseigne beaucoup et les resultats sont presentes aux Appendices I a III. Le carbone de depart est du charbon active commercial (CNS201) qui a ete prealablement chauffe a 1,000°C sous vide pendant 90 minutes pour se debarrasser de toute humidite et autres impuretes. En premiere etape, dans un creuset d'acier durci du CNS201 pretraite fut melange a une certaine quantite de Fe et de Co (99.9 % purs). Des proportions typiques sont 50 pd. %, 44 pd. %, et 6 pd. % pour le C, le Fe, et le Co respectivement. Pour les echantillons prepares avec le broyeur SPEX, trois a six billes en acier durci furent utilisees pour le broyage, de masse relative echantillon/poudre de 35 a 1. Pour les echantillons prepares avec le broyeur planetaire, trente-six billes en acier durci furent utilisees pour le broyage, de masse relative echantillon/poudre de 10 a 1. L'hydrogene fut alors introduit dans le creuset pour les deux types de broyeur a une pression de 1.4 MPa, et l'echantillon fut broye pendant 12 h pour le SPEX et 24 h pour le planetaire. Le broyeur SPEX a un rendement de transfert d'energie mecanique plus grand qu'un broyeur planetaire, mais il a le desavantage de contaminer davantage l'echantillon en Fe par attrition. Cependant, ceci peut etre neglige vu que le Fe etait un des catalyseurs metalliques ajoutes au creuset. En deuxieme etape, l'echantillon broye est transfere sous gaz inerte (argon) dans un tube en quartz, qui est alors chauffe a 700°C pendant 90 minutes. Des mesures de patrons de diffraction a rayons-X sur poudre furent faites pour caracteriser les changements structurels des CNS lors des etapes de synthese. Ces mesures furent prises avec un diffractometre Bruker D8 FOCUS utilisant le rayonnement Cu Ka (lambda = 1.54054 A) et une geometrie T

Beig Agha, Rosa

142

DISINFECTION OF BACTERIA ATTACHED TO GRANULAR ACTIVATED CARBON  

EPA Science Inventory

Heterotrophic plate count bacteria, coliform organisms, and pathogenic microorganisms attached to granular activated carbon (GAC) particles were examined for their susceptibility to chlorine disinfection. When these bacteria were grown on carbon particles and then disinfected wit...

143

Is Net Ecosystem Production Equal to Ecosystem Carbon Accumulation?  

E-print Network

COMMENTARY Is Net Ecosystem Production Equal to Ecosystem Carbon Accumulation? Gary M. Lovett,* Jonathan J. Cole, and Michael L. Pace Institute of Ecosystem Studies, Millbrook, New York 12545, USA ABSTRACT Net ecosystem production (NEP), defined as the difference between gross primary production

Pace, Michael L.

144

Effects of globalisation on carbon footprints of products  

Microsoft Academic Search

Outsourcing of production from the industrialised countries to the newly industrialised economies holds the potential to increase wealth in both places, but what are the environmental costs of the globalised manufacturing systems? This paper looks into the changes in carbon footprint of manufactured products when production is moved from United Kingdom or Denmark to China and uses environmental input–output analysis

I. T. Herrmann; M. Z. Hauschild

2009-01-01

145

Qualitative determination of carbon black in food products.  

PubMed

Carbon black (C.I. 77266) is an insoluble pigment produced by the partial combustion of hydrocarbons. The pigment is known by several synonyms, including vegetable carbon, lamp black and carbon ash, that correspond to the raw materials and methods used for its production. Vegetable carbon (E153) is permitted for use in colouring food in the European Union. The US Food and Drug Administration (USFDA) has not approved the use of any type of carbon black for colouring food, although the agency batch certifies the pigment as D&C Black No. 2 for use in colouring certain cosmetics. Since carbon black (as vegetable carbon) may be present in food products offered for import into the United States, the USFDA's district laboratories need a qualitative analytical method for determining its presence. We have developed an extraction method for this purpose. A sample is broken down and dissolved with nitric acid. The resulting solution is filtered and treated with hydrochloric acid to dissolve any black iron oxide also present as a colour additive. A black residue remaining on the filter paper indicates the presence of carbon black in the food. We confirmed the presence of carbon black in residues from several standards and food products using Raman spectroscopy. The limit of detection for this method is 0.0001%. PMID:22035229

Miranda-Bermudez, E; Belai, N; Harp, B Petigara; Yakes, B J; Barrows, J N

2012-01-01

146

Research on forest carbon pool and carbon release by human activity of Tanjiang River Basin  

Microsoft Academic Search

We researched the relation between forest carbon pool and human activity carbon release of Tanjiang river basin, the finding is: (1)Since 1990, Forest of Tanjiang river basin always act as carbon sink, and the forest carbon sink is more and more obvious. Forest absorbed carbon is 1057.90×10 4 t in 1990, and in 2002, the amount is 1280.61×10 4 t,

Chen Zhiliang; Wu Zhifeng; Liu Xulong; Cheng Jiong; Liu Ping; Xia Nianhe

2005-01-01

147

Accounting for forest carbon pool dynamics in product carbon footprints: Challenges and opportunities  

SciTech Connect

Modification and loss of forests due to natural and anthropogenic disturbance contribute an estimated 20% of annual greenhouse gas (GHG) emissions worldwide. Although forest carbon pool modeling rarely suggests a 'carbon neutral' flux profile, the life cycle assessment community and associated product carbon footprint protocols have struggled to account for the GHG emissions associated with forestry, specifically, and land use generally. Principally, this is due to underdeveloped linkages between life cycle inventory (LCI) modeling for wood and forest carbon modeling for a full range of forest types and harvest practices, as well as a lack of transparency in globalized forest supply chains. In this paper, through a comparative study of U.S. and Chinese coated freesheet paper, we develop the initial foundations for a methodology that rescales IPCC methods from the national to the product level, with reference to the approaches in three international product carbon footprint protocols. Due to differences in geographic origin of the wood fiber, the results for two scenarios are highly divergent. This suggests that both wood LCI models and the protocols need further development to capture the range of spatial and temporal dimensions for supply chains (and the associated land use change and modification) for specific product systems. The paper concludes by outlining opportunities to measure and reduce uncertainty in accounting for net emissions of biogenic carbon from forestland, where timber is harvested for consumer products. - Highlights: Black-Right-Pointing-Pointer Typical life cycle assessment practice for consumer products often excludes significant land use change emissions when estimating carbon footprints. Black-Right-Pointing-Pointer The article provides a methodology to rescale IPCC guidelines for product-level carbon footprints. Black-Right-Pointing-Pointer Life cycle inventories and product carbon footprint protocols need more comprehensive land use-related accounting. Black-Right-Pointing-Pointer Interdisciplinary collaboration linking the LCA and forest carbon modeling communities is necessary.

Newell, Joshua P., E-mail: jpnewell@umich.edu [School of Natural Resources and Environment, University of Michigan, Ann Arbor (United States); Vos, Robert O., E-mail: vos@usc.edu [Spatial Sciences Institute, University of Southern California (United States)

2012-11-15

148

Production of phosphorus and carbon ions with MONO 1001  

E-print Network

1 Production of phosphorus and carbon ions with MONO 1001 J-Y. Pacquet, R. Leroy, C. Barué, C.P. 5133, 14070 Caen Cedex 05, France 1- Phosphorus Mission ECR source MONO10011 4 has been tested of phosphorus 1+ and its capacities to ionize carbon from CO2. The objectives are 200µAp of P

Paris-Sud XI, Université de

149

Methane Decomposition: Production of Hydrogen and Carbon Filaments  

E-print Network

Methane Decomposition: Production of Hydrogen and Carbon Filaments BY T.V. CHOUDHARYa AND D. Fuel cells can be broadly classified into two types; high temperature fuel cells such as molten carbonate fuel cells (MCFCs) and solid oxide polymer fuel cells (SOFCs), which operate at temperatures above

Goodman, Wayne

150

Carbonate thermochemical cycle for the production of hydrogen  

DOEpatents

The present invention is directed to a thermochemical method for the production of hydrogen from water. The method includes reacting a multi-valent metal oxide, water and a carbonate to produce an alkali metal-multi-valent metal oxide compound, carbon dioxide, and hydrogen.

Collins, Jack L (Knoxville, TN) [Knoxville, TN; Dole, Leslie R (Knoxville, TN) [Knoxville, TN; Ferrada, Juan J (Knoxville, TN) [Knoxville, TN; Forsberg, Charles W (Oak Ridge, TN) [Oak Ridge, TN; Haire, Marvin J (Oak Ridge, TN) [Oak Ridge, TN; Hunt, Rodney D (Oak Ridge, TN) [Oak Ridge, TN; Lewis Jr., Benjamin E (Knoxville, TN) [Knoxville, TN; Wymer, Raymond G (Oak Ridge, TN) [Oak Ridge, TN

2010-02-23

151

Metal salen catalyzed production of polytrimethylene carbonate  

E-print Network

polycarbonate derived from trimethylene carbonate, (TMC, 1, 3-dioxan-2-one), has been studied extensively for its potential use as a biodegradable polymer in biomedical and pharmaceutical systems. Its important applications include sutures, drug delivery systems...

Ganguly, Poulomi

2009-06-02

152

MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT  

SciTech Connect

The carbonate fuel cell promises highly efficient, cost-effective and environmentally superior power generation from pipeline natural gas, coal gas, biogas, and other gaseous and liquid fuels. FuelCell Energy, Inc. has been engaged in the development of this unique technology, focusing on the development of the Direct Fuel Cell (DFC{reg_sign}). The DFC{reg_sign} design incorporates the unique internal reforming feature which allows utilization of a hydrocarbon fuel directly in the fuel cell without requiring any external reforming reactor and associated heat exchange equipment. This approach upgrades waste heat to chemical energy and thereby contributes to a higher overall conversion efficiency of fuel energy to electricity with low levels of environmental emissions. Among the internal reforming options, FuelCell Energy has selected the Indirect Internal Reforming (IIR)--Direct Internal Reforming (DIR) combination as its baseline design. The IIR-DIR combination allows reforming control (and thus cooling) over the entire cell area. This results in uniform cell temperature. In the IIR-DIR stack, a reforming unit (RU) is placed in between a group of fuel cells. The hydrocarbon fuel is first fed into the RU where it is reformed partially to hydrogen and carbon monoxide fuel using heat produced by the fuel cell electrochemical reactions. The reformed gases are then fed to the DIR chamber, where the residual fuel is reformed simultaneously with the electrochemical fuel cell reactions. FuelCell Energy plans to offer commercial DFC power plants in various sizes, focusing on the subMW as well as the MW-scale units. The plan is to offer standardized, packaged DFC power plants operating on natural gas or other hydrocarbon-containing fuels for commercial sale. The power plant design will include a diesel fuel processing option to allow dual fuel applications. These power plants, which can be shop-fabricated and sited near the user, are ideally suited for distributed power generation, industrial cogeneration, marine applications and uninterrupted power for military bases. FuelCell Energy operated a 1.8 MW plant at a utility site in 1996-97, the largest fuel cell power plant ever operated in North America. This proof-of-concept power plant demonstrated high efficiency, low emissions, reactive power control, and unattended operation capabilities. Drawing on the manufacture, field test, and post-test experience of the full-size power plant; FuelCell Energy launched the Product Design Improvement (PDI) program sponsored by government and the private-sector cost-share. The PDI efforts are focused on technology and system optimization for cost reduction, commercial design development, and prototype system field trials. The program was initiated in December 1994. Year 2000 program accomplishments are discussed in this report.

H.C. Maru; M. Farooque

2002-02-01

153

Preparation of activated carbon from date pits: Effect of the activation agent and liquid phase oxidation  

Microsoft Academic Search

Two series of activated carbons have been prepared from date pits; series C, using carbon dioxide as activating agent, and series S, prepared by activation with steam under the same experimental conditions. The obtained samples were oxidized with nitric acid in order to introduce more oxygen surface groups. The surface area and porosity of the parent and oxidized activated carbons

Meriem Belhachemi; Rachel V. R. A. Rios; Fatima Addoun; Joaquín Silvestre-Albero; Antonio Sepúlveda-Escribano; Francisco Rodríguez-Reinoso

2009-01-01

154

Technological Intervention for Production of High Carbon Billets  

Microsoft Academic Search

Substantial market exists for high carbon grades having 0.50–0.65 wt% C for agricultural, automobile, and wire drawing application. However, attributes of cast product in terms of internal and surface\\/subsurface quality have to be achieved for the required end applications. For production of high carbon grades, the process route followed at Durgapur Steel Plant is through BOF-LTS\\/LF-Billet Caster. In order to control total

K. Patwari; N. Pradhan; N. Banerjee; B. R. Pal; S. R. Sarkar; B. Mukhopadhyay; S. K. Ray; D. S. Basu

2010-01-01

155

LOW COST PRODUCTION OF CARBON FIBERS FROM LIGNIN MATERIALS  

Microsoft Academic Search

The DOE Vehicle Technologies-funded work at ORNL is directed to the development of processes for the low cost production of carbon fibers. The objective of the project is to develop more energy-efficient, cost-effective processes for production of carbon fibers for use in composite materials for vehicles, which would substantially reduce vehicle weight, increase vehicle fuel economy, and result in lower

Nidia C Gallego; Darren A Baker; Frederick S Baker

2009-01-01

156

Characteristic and mercury adsorption of activated carbon produced by CO2 of chicken waste.  

PubMed

Preparation of activated carbon from chicken waste is a promising way to produce a useful adsorbent for Hg removal. A three-stage activation process (drying at 200 degrees C, pyrolysis in N2 atmosphere, followed by CO2 activation) was used for the production of activated samples. The effects of carbonization temperature (400-600 degrees C), activation temperature (700-900 degrees C), and activation time (1-2.5 h) on the physicochemical properties (weight-loss and BET surface) of the prepared carbon were investigated. Adsorptive removal of mercury from real flue gas onto activated carbon has been studied. The activated carbon from chicken waste has the same mercury capacity as commercial activated carbon (Darco LH) (Hg(v): 38.7% vs. 53.5%, Hg(0): 50.5% vs. 68.8%), although its surface area is around 10 times smaller, 89.5 m2/g vs. 862 m2/g. The low cost activated carbon can be produced from chicken waste, and the procedure is suitable. PMID:18595395

Huang, Yaji; Jin, Baosheng; Zhong, Zhaoping; Zhong, Wenqi; Xiao, Rui

2008-01-01

157

Characterization of activated carbons from oil-palm shell by CO2 activation with no holding carbonization temperature.  

PubMed

Activated carbons can be produced from different precursors, including coals of different ranks, and lignocellulosic materials, by physical or chemical activation processes. The objective of this paper is to characterize oil-palm shells, as a biomass byproduct from palm-oil mills which were converted into activated carbons by nitrogen pyrolysis followed by CO2 activation. The effects of no holding peak pyrolysis temperature on the physical characteristics of the activated carbons are studied. The BET surface area of the activated carbon is investigated using N2 adsorption at 77 K with selected temperatures of 500, 600, and 700°C. These pyrolysis conditions for preparing the activated carbons are found to yield higher BET surface area at a pyrolysis temperature of 700°C compared to selected commercial activated carbon. The activated carbons thus result in well-developed porosities and predominantly microporosities. By using this activation method, significant improvement can be obtained in the surface characteristics of the activated carbons. Thus this study shows that the preparation time can be shortened while better results of activated carbon can be produced. PMID:23737721

Herawan, S G; Hadi, M S; Ayob, Md R; Putra, A

2013-01-01

158

Characterization of Activated Carbons from Oil-Palm Shell by CO2 Activation with No Holding Carbonization Temperature  

PubMed Central

Activated carbons can be produced from different precursors, including coals of different ranks, and lignocellulosic materials, by physical or chemical activation processes. The objective of this paper is to characterize oil-palm shells, as a biomass byproduct from palm-oil mills which were converted into activated carbons by nitrogen pyrolysis followed by CO2 activation. The effects of no holding peak pyrolysis temperature on the physical characteristics of the activated carbons are studied. The BET surface area of the activated carbon is investigated using N2 adsorption at 77?K with selected temperatures of 500, 600, and 700°C. These pyrolysis conditions for preparing the activated carbons are found to yield higher BET surface area at a pyrolysis temperature of 700°C compared to selected commercial activated carbon. The activated carbons thus result in well-developed porosities and predominantly microporosities. By using this activation method, significant improvement can be obtained in the surface characteristics of the activated carbons. Thus this study shows that the preparation time can be shortened while better results of activated carbon can be produced. PMID:23737721

Herawan, S. G.; Hadi, M. S.; Ayob, Md. R.; Putra, A.

2013-01-01

159

Carbon Fiber Production from a Kraft Hardwood Lignin  

SciTech Connect

Lignin is a renewable resource material that is being evaluated for the low cost production of carbon fiber for automotive and other applications. Solvent extraction of a commercial hardwood lignin product yielded a purified lignin free of the contaminants typical of lignins derived from the Kraft chemical pulping of wood. The purified lignin was highly melt-spinnable into fibers, from which carbon fiber was subsequently produced. The lignin has been evaluated in terms of its rheological properties, fiber melt spinning ability, and potential for manufacture of low cost carbon fiber without the need for plasticizing agents or chemical modifications.

Baker, Darren A [ORNL; Gallego, Nidia C [ORNL; Baker, Frederick S [ORNL

2008-01-01

160

Production and screening of carbon products precursors from coal. Quarterly progress report, July 1, 1996--September 30, 1996  

SciTech Connect

This quarterly report covers activities during the period from July 1, 1996 through September 30, 1996 on the development of carbon products precursor materials from coal. The first year of the project ended in February, 1996; however, the WVU research effort continued through August 14, 1997 on a no-cost extension of the original contract. PETC chose to exercise the option for continuation of the projects and $100,000 became available on August 9, 1996. The objective for year two is to focus on development of those carbon products from coal-based solvent extract precursors which have the greatest possibility for commercial success.

Zondlo, J.; Stiller, A.

1996-10-25

161

Gamma X: A Full Capture Mode Detector Array for Carbon Activation  

Microsoft Academic Search

A diagnostic was developed to determine the (rhor)^2 of a DT reaction via the production of tertiary neutrons. High energy neutrons, in the range of 20 to 32 MeV, were incident upon a carbon disk which became activated via the 12C(n,2n) reaction. The activated carbon was then quickly transported to the counting station where it was placed in a NaI

Cassarah Brown; Melissa Cummings; Stephen Padalino; Thomas Sangster; Timothy Duffy; Vladimir Glebov

2008-01-01

162

Activated Carbon Composites for Air Separation  

SciTech Connect

Coal-derived synthesis gas is a potential major source of hydrogen for fuel cells. Oxygen-blown coal gasification is an efficient approach to achieving the goal of producing hydrogen from coal, but a cost-effective means of enriching O2 concentration in air is required. A key objective of this project is to assess the utility of a system that exploits porous carbon materials and electrical swing adsorption to produce an O2-enriched air stream for coal gasification. As a complement to O2 and N2 adsorption measurements, CO2 was used as a more sensitive probe molecule for the characterization of molecular sieving effects. To further enhance the potential of activated carbon composite materials for air separation, work was implemented on incorporating a novel twist into the system; namely the addition of a magnetic field to influence O2 adsorption, which is accompanied by a transition between the paramagnetic and diamagnetic states. The preliminary findings in this respect are discussed.

Baker, Frederick S [ORNL; Contescu, Cristian I [ORNL; Tsouris, Costas [ORNL; Burchell, Timothy D [ORNL

2011-09-01

163

Thermal conversion of municipal solid waste via hydrothermal carbonization: Comparison of carbonization products to products from current waste management techniques  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer Hydrothermal carbonization (HTC) is a novel thermal conversion process. Black-Right-Pointing-Pointer HTC converts wastes into value-added resources. Black-Right-Pointing-Pointer Carbonization integrates majority of carbon into solid-phase. Black-Right-Pointing-Pointer Carbonization results in a hydrochar with high energy density. Black-Right-Pointing-Pointer Using hydrochar as an energy source may be beneficial. - Abstract: Hydrothermal carbonization (HTC) is a novel thermal conversion process that may be a viable means for managing solid waste streams while minimizing greenhouse gas production and producing residual material with intrinsic value. HTC is a wet, relatively low temperature (180-350 Degree-Sign C) thermal conversion process that has been shown to convert biomass to a carbonaceous residue referred to as hydrochar. Results from batch experiments indicate HTC of representative waste materials is feasible, and results in the majority of carbon (45-75% of the initially present carbon) remaining within the hydrochar. Gas production during the batch experiments suggests that longer reaction periods may be desirable to maximize the production of energy-favorable products. If using the hydrochar for applications in which the carbon will remain stored, results suggest that the gaseous products from HTC result in fewer g CO{sub 2}-equivalent emissions than the gases associated with landfilling, composting, and incineration. When considering the use of hydrochar as a solid fuel, more energy can be derived from the hydrochar than from the gases resulting from waste degradation during landfilling and anaerobic digestion, and from incineration of food waste. Carbon emissions resulting from the use of the hydrochar as a fuel source are smaller than those associated with incineration, suggesting HTC may serve as an environmentally beneficial alternative to incineration. The type and extent of environmental benefits derived from HTC will be dependent on hydrochar use/the purpose for HTC (e.g., energy generation or carbon storage).

Lu Xiaowei; Jordan, Beth [Department of Civil and Environmental Engineering, University of South Carolina, 300 Main Street, Columbia, SC 29208 (United States); Berge, Nicole D., E-mail: berge@cec.sc.edu [Department of Civil and Environmental Engineering, University of South Carolina, 300 Main Street, Columbia, SC 29208 (United States)

2012-07-15

164

Enhanced Cellular Activation with Single Walled Carbon Nanotube Bundles  

E-print Network

Enhanced Cellular Activation with Single Walled Carbon Nanotube Bundles Presenting Antibody Stimuli the body using single walled carbon nanotube (SWNT) bundles presenting antibody stimuli. Owing to the large of lymphocytes, useful for basic science applications and clinical immunotherapy. Single walled carbon nanotubes

Fahmy, Tarek

165

High-pressure-activated carbon tetrachloride decomposition  

NASA Astrophysics Data System (ADS)

The pressure-induced molecular dissociation as one of the fundamental problems in physical sciences has aroused many theoretical and experimental studies. Here, using a newly developed particle swarm optimization algorithm, we investigate the high-pressure-induced molecular dissociation. The results show that the carbon tetrachloride (CCl4) is unstable and dissociates into C2Cl6 and Cl2 under approximately 120 GPa and more. The dissociation is confirmed by the lattice dynamic calculations and electronic structure of the Pa3 structure with pressure evolution. The dissociation pressure is far larger than that in the case of high temperature, indicating that the temperature effectively reduces the activation barrier of the dissociation reaction of CCl4. This research improves the understanding of the dissociation reactions of CCl4 and other halogen compounds under high pressures.

Chen, Yuan-Zheng; Zhou, Mi; Sun, Mei-Jiao; Li, Zuo-Wei; Sun, Cheng-Lin

2014-02-01

166

Oil Palm Biomass as a Precursor of Activated Carbons-A Review  

Microsoft Academic Search

Commercial activated carbon has been a preferred adsorbent for the removal of various pollutants, its widespread use is restricted due to its relatively high costs which led to the researches on the possible alternative non-conventional and low cost adsorbents. The use of agricultural products and by-products for instance, has been widely investigated as a replacement for the current costly methods

Mohd Rafatullah; Tanweer Ahmad; Arniza Ghazali; Othman Sulaiman; Mohammed Danish; Rokiah Hashim

2012-01-01

167

Production of single-walled carbon nanotube grids  

DOEpatents

A method of forming a nanotube grid includes placing a plurality of catalyst nanoparticles on a grid framework, contacting the catalyst nanoparticles with a gas mixture that includes hydrogen and a carbon source in a reaction chamber, forming an activated gas from the gas mixture, heating the grid framework and activated gas, and controlling a growth time to generate a single-wall carbon nanotube array radially about the grid framework. A filter membrane may be produced by this method.

Hauge, Robert H; Xu, Ya-Qiong; Pheasant, Sean

2013-12-03

168

Record Methane Storage in Monolithic and Powdered Activated Carbons  

NASA Astrophysics Data System (ADS)

The Alliance for Collaborative Research in Alternative Fuel Technology (ALL-CRAFT) has developed activated carbons from corn cob as adsorbent materials for methane gas storage by physisorption at low pressures. KOH activated carbons were compressed into carbon monolith using chemical binders. High pressure methane isotherms up to 250 bar at room temperature on monolithic and powdered activated carbons were measured gravimetrically and volumetrically. Record methane storage capacities of 250 g CH4/kg carbon and 130 g CH4/liter carbon at 35 bar and 293 K have been achieved. BET surface area, porosity, and pore size distributions were measured from sub-critical nitrogen isotherms. Pore entrances were characterized using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). A prototype adsorbed natural gas (ANG) tank, loaded with carbon monoliths, was tested in Kansas City.

Soo, Yuchoong; Nordwald, E.; Hester, B.; Romanos, J.; Isaacson, B.; Stalla, D.; Moore, D.; Kraus, M.; Burress, J.; Dohnke, E.; Pfeifer, P.

2010-03-01

169

Mechanistic Investigation of Catalytic Carbon-Carbon Bond Activation and Formation by Platinum and Palladium Phosphine  

E-print Network

Mechanistic Investigation of Catalytic Carbon-Carbon Bond Activation and Formation by Platinum impede their development. First, the metal- carbon bond resulting from C-C insertion has been calculated often results in thermal decomposition of the metal complex prior to C-C cleavage. To date, most

Jones, William D.

170

78 FR 15376 - Determinations: Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea  

Federal Register 2010, 2011, 2012, 2013, 2014

...618 (Third Review)] Determinations: Corrosion-Resistant Carbon Steel Flat Products...revocation of the countervailing duty order on corrosion-resistant carbon steel flat products...Korea and the antidumping duty orders on corrosion-resistant carbon steel flat...

2013-03-11

171

Carbon Footprint and Sustainability of Agricultural Production Systems in India  

Microsoft Academic Search

The agriculture sector, which accounts for about 52% of the total workforce despite a steady decline of its share in the gross domestic product (GDP), is still the largest economic sector that plays a significant role in the overall socio-economic development of India. Sustainability of agricultural production systems depends on their carbon (C) footprint and the C output-input ratio. Thus,

H. P. Maheswarappa; V. Srinivasan; R. Lal

2011-01-01

172

Towards Carbon-free Metals Production by Molten Oxide Electrolysis  

E-print Network

Towards Carbon-free Metals Production by Molten Oxide Electrolysis Deepak Khetpal, Andrew Ducret by-products problems with electrolytic technologies: Al electrolysis makes CO2 (½ kg C / kg Al) Mg electrolysis makes Cl2 C & F react to make CF4 & C2F6 C & Cl in presence of O dioxins? furans? #12;Sadoway, MIT

Sadoway, Donald Robert

173

Synthesis of fluorescent carbon nanoparticles directly from active carbon via a one-step ultrasonic treatment  

SciTech Connect

Water-soluble fluorescent carbon nanoparticles were synthesized directly from active carbon by a one-step hydrogen peroxide-assisted ultrasonic treatment. The carbon nanoparticles were characterized by transmission electron microscopy, optical fluorescent microscopy, fluorescent spectroscopy, Fourier transform infrared spectroscopy and ultraviolet-visible spectrophotometer. The results showed that the surface of carbon nanoparticles was rich of hydroxyl groups resulting in high hydrophilicity. The carbon nanoparticles could emit bright and colorful photoluminescence covering the entire visible-to-near infrared spectral range. Furthermore, these carbon nanoparticles also had excellent up-conversion fluorescent properties.

Li, Haitao; He, Xiaodie [Institute of Functional Nano and Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123 (China)] [Institute of Functional Nano and Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123 (China); Liu, Yang, E-mail: yangl@suda.edu.cn [Institute of Functional Nano and Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123 (China) [Institute of Functional Nano and Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123 (China); Department of Chemistry, Northeast Normal University, Changchun 130024 (China); Yu, Hang [Institute of Functional Nano and Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123 (China)] [Institute of Functional Nano and Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123 (China); Kang, Zhenhui, E-mail: zhkang@suda.edu.cn [Institute of Functional Nano and Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123 (China) [Institute of Functional Nano and Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123 (China); Department of Chemistry, Northeast Normal University, Changchun 130024 (China); Lee, Shuit-Tong [Center of Super-Diamond and Advanced Films (COSADF), City University of Hong Kong, Hong Kong SAR (China)] [Center of Super-Diamond and Advanced Films (COSADF), City University of Hong Kong, Hong Kong SAR (China)

2011-01-15

174

Biological productivity and carbon cycling in the Arctic Ocean  

Microsoft Academic Search

Primary production, bacterial production, particulate organic carbon fluxes and organic carbon burial rates were quantified\\u000a during the summer period of 1999 in the Arctic Ocean via14C uptake,3H uptake,234Th\\/238U disequilibrium and210Pbex dating, respectively. The integrated primary production in the water column was as high as 197 mmolC\\/(m2 · d) in the Chukchi\\u000a shelf and was 3.8 mmolC\\/(m2 · d) in the

Min Chen; Yipu Huang; Laodong Guo; Pinghe Cai; Weifeng Yang; Guangshan Liu; Yusheng Qiu

2002-01-01

175

Evaluation of NOAA Carbon Tracker Global Carbon Dioxide Products  

NASA Astrophysics Data System (ADS)

Inter-comparison between National Oceanic and Atmospheric Administration Carbon Tracker (NOAACT) CO2 with satellite observations were carried out in this study. The satellite observations used here are mid troposphere CO2 based on Atmosphere Infrared Sounder (AIRS) on board NASA's Aqua and lower troposphere CO2 based on Greenhouse-gas Observing Satellite (GOSAT) of Japanese Aerospace Exploration Agency (JAXA). There exists good agreement between the seasonal cycles as estimated by NOAACT and Satellite observations. The mid troposphere CO2 exhibits distinct annual cycle in the northern hemisphere with positive detrended value during January-June and negative values during July-December. In the southern hemisphere, the annual cycle is less prominent and opposite phase with respect to the northern hemisphere. The lower tropospheric CO2 in both the hemispheres exhibits mixed signature of annual and semi-annual cycle. The amplitudes of the variability are significantly larger in the northern hemisphere than the southern hemisphere. The inter-annual variability of annual growth rates from the NOAACT is comparable with satellite observations however NOAACT could not resolved the spatial patterns of long-term growth rate as observed in the satellite observations.

Nayak, R. K.; Deepthi, E. N.; Dadhwal, V. K.; Rao, K. H.; Dutt, C. B. S.

2014-11-01

176

Carbon footprint of recycled biogenic products: the challenge of modelling CO2 removal credits  

Microsoft Academic Search

Current carbon footprinting (CF) and life cycle assessment (LCA) methods do not treat recycled biogenic carbon adequately, because the calculation rules for recycled products and biogenic carbon stored in products are defined independently from each other. Therefore, an improved and consistent calculation rule for the CF of product systems containing both recycling processes and carbon stored in products is proposed.

Matthias Finkbeiner; Sabrina Neugebauer; Markus Berger

2012-01-01

177

Net carbon flux in organic and conventional olive production systems  

NASA Astrophysics Data System (ADS)

Agricultural systems are considered as one of the most relevant sources of atmospheric carbon. However, agriculture has the potentiality to mitigate carbon dioxide mainly through soil carbon sequestration. Some agricultural practices, particularly fertilization and soil management, can play a dual role in the agricultural systems regarding the carbon cycle contributing to the emissions and to the sequestration process in the soil. Good soil and input managements affect positively Soil Organic Carbon (SOC) changes and consequently the carbon cycle. The present study aimed at comparing the carbon footprint of organic and conventional olive systems and to link it to the efficiency of both systems on carbon sequestration by calculating the net carbon flux. Data were collected at farm level through a specific and detailed questionnaire based on one hectare as a functional unit and a system boundary limited to olive production. Using LCA databases particularly ecoinvent one, IPCC GWP 100a impact assessment method was used to calculate carbon emissions from agricultural practices of both systems. Soil organic carbon has been measured, at 0-30 cm depth, based on soil analyses done at the IAMB laboratory and based on reference value of SOC, the annual change of SOC has been calculated. Substracting sequestrated carbon in the soil from the emitted on resulted in net carbon flux calculation. Results showed higher environmental impact of the organic system on Global Warming Potential (1.07 t CO2 eq. yr-1) comparing to 0.76 t CO2 eq. yr-1 in the conventional system due to the higher GHG emissions caused by manure fertilizers compared to the use of synthetic foliar fertilizers in the conventional system. However, manure was the main reason behind the higher SOC content and sequestration in the organic system. As a resultant, the organic system showed higher net carbon flux (-1.7 t C ha-1 yr-1 than -0.52 t C ha-1 yr-1 in the conventional system reflecting higher efficiency as a sink for atmospheric CO2 (the negative value of Net C flux indicates that a system is a net sink for atmospheric CO2). In conclusion, this study illustrates the importance of including soil carbon sequestration associated with CO2 emissions in the evaluation process between alternatives of agricultural systems. Thus, organic olive system offers an opportunity to increase carbon sequestration compared to the conventional one although it causes higher C emissions from manure fertilization. Keywords: Net carbon flux, GHG, organic, olive, soil organic carbon

Saeid Mohamad, Ramez; Verrastro, Vincenzo; Bitar, Lina Al; Roma, Rocco; Moretti, Michele; Chami, Ziad Al

2014-05-01

178

DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS  

SciTech Connect

The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. These carbon products include materials used in metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to as ''carbon foam'' and carbon fibers. During this reporting period, efforts have focused on the development of continuous processes for hydrogenation as well as continuous production of carbon foam and coke.

Elliot B. Kennel; Stephen P. Carpenter; Dady Dadyburjor; Manoj Katakdaunde; Liviu Magean; Madhavi Nallani-Chakravartula; Peter G. Stansberry; Alfred H. Stiller; John W. Zondlo

2006-03-27

179

DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS  

SciTech Connect

The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. These carbon products include materials used in metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to as ''carbon foam'' and carbon fibers. During this reporting period, efforts have focused on the development of continuous processes for hydrogenation as well as continuous production of carbon foam and coke.

Elliot B. Kennel; Stephen P. Carpenter; Dady Dadyburjor; Manoj Katakdaunde; Liviu Magean; Peter G. Stansberry; Alfred H. Stiller; John W. Zondlo

2005-06-08

180

MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT  

Microsoft Academic Search

The carbonate fuel cell promises highly efficient, cost-effective and environmentally superior power generation from pipeline natural gas, coal gas, biogas, and other gaseous and liquid fuels. FuelCell Energy, Inc. has been engaged in the development of this unique technology, focusing on the development of the Direct Fuel Cell (DFC{reg_sign}). The DFC{reg_sign} design incorporates the unique internal reforming feature which allows

H. C. Maru; M. Farooque

2002-01-01

181

Activated Carbon Modified with Copper for Adsorption of Propanethiol  

PubMed Central

Activated carbons were characterized texturally and chemically before and after treatment, using surface area determination in the BET model, Boehm titration, TPR, DRX and immersion calorimetry. The adsorption capacity and the kinetics of sulphur compound removal were determined by gas chromatography. It was established that the propanethiol retention capacity is dependent on the number of oxygenated groups generated on the activated carbon surface and that activated carbon modified with CuO at 0.25 M shows the highest retention of propanethiol. Additionally is proposed a mechanism of decomposition of propenothiol with carbon-copper system. PMID:20479992

Moreno-Piraján, Juan Carlos; Tirano, Joaquín; Salamanca, Brisa; Giraldo, Liliana

2010-01-01

182

Toxicity of carbon nanotubes to the activated sludge process.  

PubMed

The discharge of carbon nanotubes (CNTs) from industrial waste or disposal of such materials from commercial and/or domestic use will inevitably occur with increasing production and enter into wastewater treatment facilities with unknown consequences. Therefore, a better knowledge of the toxicity of CNTs to biological processes in wastewater treatment will be critical. This study examined the toxicity of multi-walled carbon nanotubes (MWCNTs) on the microbial communities in activated sludge. A comparative study using the activated sludge respiration inhibition test was performed on both unsheared mixed liquor and sheared mixed liquor to demonstrate the potential toxicity posed by MWCNTs and to illustrate the extent of extracellular polymeric substances (EPS) in protecting the microorganisms from the toxicity of CNTs. Respiration inhibition was observed for both unsheared and sheared mixed liquor when MWCNTs were present, however, greater respiration inhibition was observed for the sheared mixed liquor. The toxicity observed by the respiration inhibition test was determined to be dose-dependent; the highest concentration of MWCNTs exhibited the highest respiration inhibition. Scanning Electron Microscopy (SEM) images demonstrated direct physical contact between MWCNTs and activated sludge flocs. PMID:20149532

Luongo, Lauren A; Zhang, Xiaoqi Jackie

2010-06-15

183

Clouds Versus Carbon: Predicting Vegetation Roughness by Maximizing Productivity  

NASA Technical Reports Server (NTRS)

Surface roughness is one of the dominant vegetation properties that affects land surface exchange of energy, water, carbon, and momentum with the overlying atmosphere. We hypothesize that the canopy structure of terrestrial vegetation adapts optimally to climate by maximizing productivity, leading to an optimum surface roughness. An optimum should exist because increasing values of surface roughness cause increased surface exchange, leading to increased supply of carbon dioxide for photosynthesis. At the same time, increased roughness enhances evapotranspiration and cloud cover, thereby reducing the supply of photosynthetically active radiation. We demonstrate the optimum through sensitivity simulations using a coupled dynamic vegetation-climate model for present day conditions, in which we vary the value of surface roughness for vegetated surfaces. We find that the maximum in productivity occurs at a roughness length of 2 meters, a value commonly used to describe the roughness of today's forested surfaces. The sensitivity simulations also illustrate the strong climatic impacts of vegetation roughness on the energy and water balances over land: with increasing vegetation roughness, solar radiation is reduced by up to 20 W/sq m in the global land mean, causing shifts in the energy partitioning and leading to general cooling of the surface by 1.5 K. We conclude that the roughness of vegetated surfaces can be understood as a reflection of optimum adaptation, and it is associated with substantial changes in the surface energy and water balances over land. The role of the cloud feedback in shaping the optimum underlines the importance of an integrated perspective that views vegetation and its adaptive nature as an integrated component of the Earth system.

Olsen, Lola M.

2004-01-01

184

Heterogeneous mercury reaction chemistry on activated carbon.  

PubMed

Experimental and theory-based investigations have been carried out on the oxidation and adsorption mechanism of mercury (Hg) on brominated activated carbon (AC). Air containing parts per billion concentrations of Hg was passed over a packed-bed reactor with varying sorbent materials at 140 and 30 degrees C. Through X-ray photoelectron spectroscopy surface characterization studies it was found that Hg adsorption is primarily associated with bromine (Br) on the surface, but that it may be possible for surface-bound oxygen (O) to play a role in determining the stability of adsorbed Hg. In addition to surface characterization experiments, the interaction of Hg with brominated AC was studied using plane-wave density functional theory. Various configurations of hydrogen, O, Br, and Hg on the zigzag edge sites of graphene were investigated, and although Hg-Br complexes were found to be stable on the surface, the most stable configurations found were those with Hg adjacent to O. The Hg-carbon (C) bond length ranged from 2.26 to 2.34 A and is approximately 0.1 A shorter when O is a nearest-neighbor atom rather than a next-nearest neighbor, resulting in increased stability of the given configuration and overall tighter Hg-C binding. Through a density of states analysis, Hg was found to gain electron density in the six p-states after adsorption and was found to donate electron density from the five s-states, thereby leading to an oxidized surface-bound Hg complex. PMID:21516937

Wilcox, Jennifer; Sasmaz, Erdem; Kirchofer, Abby; Lee, Sang-Sup

2011-04-01

185

Continual production of glycerol from carbon dioxide by Dunaliella tertiolecta.  

PubMed

Microalgae have high photosynthetic efficiencies and produce many valuable compounds from carbon dioxide. The Dunaliella genus accumulates glycerol, yet no commercial process currently exists for glycerol production from this microalga. Here it was found that in addition to intracellular accumulation, Dunaliella tertiolecta also releases glycerol into the external medium continuously, forming a large and stable carbon pool. The process is not affected by nutrient starvation or onset of cell death. Carbon dioxide was fixed at a constant rate, the bulk of it being channelled to extracellular glycerol (82%), resulting in enhanced photosynthetic carbon assimilation of 5 times that used for biomass production. The final extracellular glycerol concentration was 34 times the maximum concentration of intracellular glycerol; the latter declined further during cell death. Findings from this work will assist in the development of a bioconversion process to produce glycerol using D. tertiolecta without the need for cell harvest or disruption. PMID:23567730

Chow, Yvonne Y S; Goh, Serena J M; Su, Ziheng; Ng, Daphne H P; Lim, Chan Yuen; Lim, Natalie Y N; Lin, Huixin; Fang, Lei; Lee, Yuan Kun

2013-05-01

186

[Flue gas desulfurization by a novel biomass activated carbon].  

PubMed

A novel biomass columnar activated carbon was prepared from walnut shell and pyrolusite was added as a catalyst. The activated carbon prepared was used for flue gas desulphurization in a fixed-bed reactor with 16 g of activated carbon. The impact of operating parameters such as SO2 inlet concentration, space velocity, bed temperature, moisture content and O2 concentration on the desulfurization efficiency of activated carbon was investigated. The results showed that both the breakthrough sulfur capacity and breakthrough time of activated carbon decreased with the increase of SO2 inlet concentration within the range of 0.1% -0.3%. The breakthrough sulfur capacity deceased with the increase of space velocity, with optimal space velocity of 600 h(-1). The optimal bed temperature was 80 degrees C, and the desulfurization efficiency can be reduced if the temperature continue to increase. The presence of moisture and oxygen greatly promoted the adsorption of SO2 onto the activated carbon. The best moisture content was 10%. When the oxygen concentrations were between 10% and 13%, the desulfurization performance of activated carbon was the highest. Under the optimal operating conditions, the sulfur capacity of activated carbon was 252 mg x g(-1), and the breakthrough time was up to 26 h when the SO2 inlet concentration was 0.2%. PMID:23798152

Liu, Jie-Ling; Tang, Zheng-Guang; Chen, Jie; Jiang, Wen-Ju; Jiang, Xia

2013-04-01

187

Acoustical Evaluation of Carbonized and Activated Cotton Nonwovens  

Technology Transfer Automated Retrieval System (TEKTRAN)

The process of manufacturing a carbonized and activated nonwoven made by cotton fiber was investigated in this paper. The study was focused on the acoustic application and nonwoven composites with cotton nonwoven as a base layer and glass fiber nonwoven, cotton nonwoven, and carbonized and activated...

188

The effect of carbonization heating rate on charcoal and active carbon yields  

SciTech Connect

The thermal decomposition of white oak chips was investigated by pyrolyzing 1-k samples at atmospheric pressure in an electrically-heated batch reactor using five carbonization heating rates from 0.98 to 9.44{degrees}C/min, and a maximum temperature of 490{degrees}C. The resulting charcoals were then activated with steam in a second batch reactor. Iodine number was used as a measure of the sorptive capacity of the active carbon. Charcoal yields decreased as the carbonization heating rate increased, particularly for rates less than about VC/min. Active carbon yields decreased and iodine numbers increased as the severity of gasification increased. For carbonization heating rates greater than about 4{degrees}C/min, the active carbon yield for a given iodine number was essentially independent of the heating rate.

Martin, C.E.; Purdy, K.R.; Dubayeh, S.A.; Kerr, C.P.; Garr, T.D. [Tennessee Technological Univ., Cookville, TN (United States)

1991-12-31

189

Multiple Discreteness and Product Differentiation: Demand for Carbonated Soft Drinks  

Microsoft Academic Search

For several of the largest supermarket product categories, such as carbonated soft drinks, canned soups, ready-to-eat cereals, and cookies, consumers regularly purchase assortments of products. Within the category, consumers often purchase multiple products and multiple units of each alternative selected on a given trip. This multiple discreteness violates the single-unit purchase assumption of multinomial logit and probit models. The misspecification

Jean-Pierre Dubé

2004-01-01

190

CHANGES IN THE MICROBIOLOGICAL WATER QUALITY ASSOCIATED WITH USING GRANULAR ACTIVATED CARBON IN DRINKING WATER TREATMENT PROCESSES  

Microsoft Academic Search

Granular activated carbon (GAC) is widely used in drinking water treatment for removal of organic compounds, primarily taste, odor, turbidity and the by-products formed during disinfection process. The possibility of replacement the rapid sand filter in the conventional treatment process by activated carbon filter was considered and the effect on microbiological quality of water produced was studied. The study was

Helmy T. El-Zanfaly; A. H. Mostafa; M. H. Mostafa

191

FOREST HARVESTS AND WOOD PRODUCTS: SOURCES AND SINKS OF ATMOSPHERIC CARBON DIOXIDE  

EPA Science Inventory

Changes in the net carbon(c)sink-source balance related to a country's forest harvesting and use of wood products is an important component in making country-level inventories of greenhouse gas emissions,a current activity within many signatory nations to the UN Framework Convent...

192

The use of nutshell carbons in drinking water filters for removal of chlorination by-products  

Microsoft Academic Search

Chlorination of drinking water is a common practice, used by numerous municipalities in the United States (US) to safeguard their water supplies. However, the chlorine used can chemically react with organic components in the drinking water to produce unwanted chlorination by-products. The objective of this investigation was to evaluate the use of granular activated carbon produced from nutshells (almond, English

Mohamed Ahmedna; Wayne E Marshall; Abdo A Husseiny; Ipek Goktepe; Ramu M Rao

2004-01-01

193

Microporous activated carbons prepared from palm shell by thermal activation and their application to sulfur dioxide adsorption.  

PubMed

Textural characterization of activated carbons prepared from palm shell by thermal activation with carbon dioxide (CO(2)) gas is reported in this paper. Palm shell (endocarp) is an abundant agricultural solid waste from palm-oil processing mills in many tropical countries such as Malaysia, Indonesia, and Thailand. The effects of activation temperature on the textural properties of the palm-shell activated carbons, namely specific surface area (BET method), porosity, and microporosity, were investigated. The activated carbons prepared from palm shell possessed well-developed porosity, predominantly microporosity, leading to potential applications in gas-phase adsorption for air pollution control. Static and dynamic adsorption tests for sulfur dioxide (SO(2)), a common gaseous pollutant, were carried out in a thermogravimetric analyzer and a packed column configuration respectively. The effects of adsorption temperature, adsorbate inlet concentration, and adsorbate superficial velocity on the adsorptive performance of the prepared activated carbons were studied. The palm-shell activated carbon was found to have substantial capability for the adsorption of SO(2), comparable to those of some commercial products and an adsorbent derived from another biomass. PMID:16290726

Guo, Jia; Lua, Aik Chong

2002-07-15

194

Characterization of activated carbon, graphitized carbon fibers and synthetic diamond powder using TPD and DRIFTS  

Microsoft Academic Search

A high surface area activated carbon, graphitized carbon fibers and synthetic diamond powder were characterized by X-ray diffraction, temperature-programmed desorption and diffuse reflectance infrared (IR) spectroscopy (DRIFTS). The activated carbon was analyzed as received as well as after either a nitric acid treatment to introduce oxygen functional groups on its surface or a high temperature treatment (HTT) in H2 at

A. Dandekar; R. T. K. Baker; M. A. Vannice

1998-01-01

195

Carbon sink activity and GHG budget of managed European grasslands  

NASA Astrophysics Data System (ADS)

In agriculture, a large proportion (89%) of greenhouse gas (GHG) emission saving potential may be achieved by means of soil C sequestration. Recent demonstrations of carbon sink activities of European ecosystemes, however, often questioned the existence of C storing grasslands, as though a net sink of C was observed, uncertainty surrounding this estimate was larger than the sink itself (Janssens et al., 2003, Schulze et al., 2009. Then again, some of these estimates were based on a small number of measurements, and on models. Not surprising, there is still, a paucity of studies demonstrating the existence of grassland systems, where C sequestration would exceed (in CO2 equivalents) methane emissions from the enteric fermentation of ruminants and nitrous oxide emissions from managed soils. Grasslands are heavily relied upon for food and forage production. A key component of the carbon sink activity in grasslands is thus the impact of changes in management practices or effects of past and recent management, such as intensification as well as climate (and -variation). We analysed data (i.e. flux, ecological, management and soil organic carbon) from a network of European grassland flux observation sites (36). These sites covered different types and intensities of management, and offered the opportunity to understand grassland carbon cycling and trade-offs between C sinks and CH4 and N2O emissions. For some sites, the assessment of carbon sink activities were compared using two methods; repeated soil inventory and determination of the ecosystem C budget by continuous measurement of CO2 exchange in combination with quantification of other C imports and exports (net C storage, NCS). In general grassland, were a potential sink of C with 60±12 g C /m2.yr (median; min -456; max 645). Grazed sites had a higher NCS compared to cut sites (median 99 vs 67 g C /m2.yr), while permanent grassland sites tended to have a lower NCS compared to temporary sown grasslands (median 64 vs 125 g C /m2.yr). Including CH4 and N2O emission in the budget , revealed that for most sites, GHG emissions were compensated by NCS. The role of management impact,soil organic C and fluxes driven by interannual climate variation will be dicussed in the presentation.

Klumpp, Katja; Herfurth, Damien; Soussana, Jean-Francois; Fluxnet Grassland Pi's, European

2013-04-01

196

Production of superconductor/carbon bicomponent fibers  

NASA Technical Reports Server (NTRS)

Certain materials are unable to be drawn or spun into fiber form due to their improper melting characteristics or brittleness. However, fibrous samples of such materials are often necessary for the fabrication of intricate shapes and composites. In response to this problem, a unique process, referred to as the piggyback process, was developed to prepare fibrous samples of a variety of nonspinnable ceramics. In this technique, specially produced C shaped carbon fibers serve as micromolds to hold the desired materials prior to sintering. Depending on the sintering atmosphere used, bicomponent or single component fibers result. While much has been shown worldwide concerning the YBa2Cu3O(7-x) superconductor, fabrication into unique forms has proven quite difficult. However, a variety of intricate shapes are necessary for rapid commercialization of the superconducting materials. The potential for producing fibrous samples of the YBa2Cu3O(7-x) compound by the piggyback process is being studied. Various organic and acrylic materials were studied to determine suspending ability, reactivity with the YBa2Cu3O(7-x) compound during long term storage, and burn out characteristics. While many questions were answered with respect to the interfacial reactions between YBa2Cu3O(7-x) and carbon, much work is still necessary to improve the quality of the sintered material if the fibers produced are to be incorporated into useful composite or cables.

Wise, S. A.; Fain, C. C.; Leigh, H. D.

1991-01-01

197

Biomass Crop Production: Benefits for Soil Quality and Carbon Sequestration  

SciTech Connect

Research at three locations in the southeastern US is quantifying changes in soil quality and soil carbon storage that occur during production of biomass crops compared with row crops. After three growing seasons, soil quality improved and soil carbon storage increased on plots planted to cottonwood, sycamore, sweetgum with a cover crop, switchgrass, and no-till corn. For tree crops, sequestered belowground carbon was found mainly in stumps and large roots. At the TN site, the coarse woody organic matter storage belowground was 1.3 Mg ha{sup {minus}1}yr{sup {minus}1}, of which 79% was stumps and large roots and 21% fine roots. Switchgrass at the AL site also stored considerable carbon belowground as coarse roots. Most of the carbon storage occurred mainly in the upper 30 cw although coarse roots were found to depths of greater than 60 cm. Biomass crops contributed to improvements in soil physical quality as well as increasing belowground carbon sequestration. The distribution and extent of carbon sequestration depends on the growth characteristics and age of the individual biomass crop species. Time and increasing crop maturity will determine the potential of these biomass crops to significantly contribute to the overall national goal of increasing carbon sequestration and reducing greenhouse gas emissions.

Bandaranayake, W.; Bock, B.R.; Houston, A.; Joslin, J.D.; Pettry, D.E.; Schoenholtz, S.; Thornton, F.C.; Tolbert, V.R.; Tyler, D.

1999-08-29

198

CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION  

SciTech Connect

Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids--single-celled, marine algae that are the major global producers of calcium carbonate--to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

V.J. Fabry, Ph.D.

2003-04-15

199

CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION  

SciTech Connect

Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids single-celled, marine algae that are the major global producers of calcium carbonate to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

V.J. Fabry

2004-04-26

200

CALCIUM CARBONATE PRODUCTION BY COCCOLITHAPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION  

SciTech Connect

Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids--single-celled, marine algae that are the major global producers of calcium carbonate--to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

V. J.Fabry

2004-01-30

201

CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION  

SciTech Connect

Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids--single-celled, marine algae that are the major global producers of calcium carbonate--to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

V.J. Fabry, Ph.D.

2002-12-15

202

CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION  

SciTech Connect

Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids--single-celled, marine algae that are the major global producers of calcium carbonate--to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

V.J. Fabry, Ph.D.

2001-12-15

203

CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION  

SciTech Connect

Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids--single-celled, marine algae that are the major global producers of calcium carbonate--to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

V.J. Fabry, Ph.D.

2002-07-09

204

CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION  

SciTech Connect

Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids single-celled, marine algae that are the major global producers of calcium carbonate to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

V.J. Fabry

2001-07-01

205

CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION  

SciTech Connect

Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids--single-celled, marine algae that are the major global producers of calcium carbonate--to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

V.J. Fabry, Ph.D.

2001-09-10

206

CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION  

SciTech Connect

Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids--single-celled, marine algae that are the major global producers of calcium carbonate--to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

V.J. Fabry, Ph.D.

2003-07-15

207

Activation of carbonic anhydrase II by active-site incorporation of histidine analogs  

E-print Network

Activation of carbonic anhydrase II by active-site incorporation of histidine analogs Ileana Elder of CO2 catalyzed by human carbonic anhydrase II (HCA II) is accompanied by proton transfer from the zinc the largest values of kcat=Km observed for a carbonic anhydrase. Ã? 2003 Elsevier Inc. All rights reserved

Viola, Ronald

208

Adsorption uptake of synthetic organic chemicals by carbon nanotubes and activated carbons  

NASA Astrophysics Data System (ADS)

Carbon nanotubes (CNTs) have shown great promise as high performance materials for adsorbing priority pollutants from water and wastewater. This study compared uptake of two contaminants of interest in drinking water treatment (atrazine and trichloroethylene) by nine different types of carbonaceous adsorbents: three different types of single walled carbon nanotubes (SWNTs), three different sized multi-walled nanotubes (MWNTs), two granular activated carbons (GACs) and a powdered activated carbon (PAC). On a mass basis, the activated carbons exhibited the highest uptake, followed by SWNTs and MWNTs. However, metallic impurities in SWNTs and multiple walls in MWNTs contribute to adsorbent mass but do not contribute commensurate adsorption sites. Therefore, when uptake was normalized by purity (carbon content) and surface area (instead of mass), the isotherms collapsed and much of the CNT data was comparable to the activated carbons, indicating that these two characteristics drive much of the observed differences between activated carbons and CNT materials. For the limited data set here, the Raman D:G ratio as a measure of disordered non-nanotube graphitic components was not a good predictor of adsorption from solution. Uptake of atrazine by MWNTs having a range of lengths and diameters was comparable and their Freundlich isotherms were statistically similar, and we found no impact of solution pH on the adsorption of either atrazine or trichloroethylene in the range of naturally occurring surface water (pH = 5.7-8.3). Experiments were performed using a suite of model aromatic compounds having a range of ?-electron energy to investigate the role of ?-? electron donor-acceptor interactions on organic compound uptake by SWNTs. For the compounds studied, hydrophobic interactions were the dominant mechanism in the uptake by both SWNTs and activated carbon. However, comparing the uptake of naphthalene and phenanthrene by activated carbon and SWNTs, size exclusion effects appear to be more pronounced with activated carbon materials, perhaps due to smaller pore sizes or larger adsorption surface areas in small pores.

Brooks, A. J.; Lim, Hyung-nam; Kilduff, James E.

2012-07-01

209

Carbon cost of nitrogenase activity in Frankia–Alnus incana root nodules  

Microsoft Academic Search

The carbon cost of nitrogenase activity was investigated to determine symbiotic efficiency of the actinorhizal root nodule symbiosis between the woody perennial Alnus incana and the soil bacterium Frankia. Respiration (CO2 production) and nitrogenase activity (H2 production) by intact nodulated root systems were continuously recorded in short-term assays in an open-flow gas exchange system. The assays were conducted in N2:O2,

P.-O. Lundquist

2005-01-01

210

Production of superconductor/carbon bicomponent fibers  

NASA Technical Reports Server (NTRS)

Certain materials are unable to be drawn or spun into fiber form due to their improper melting characteristics or brittleness. However, fibrous samples of such materials are often necessary for the fabrication of intricate shapes and composites. In response to this problem, a unique process, referred to as the piggyback process, was developed to prepare fibrous samples of a variety of nonspinnable ceramics. In this technique, specially produced C-shaped carbon fibers serve as micromolds to hold the desired materials prior to sintering. Depending on the sintering atmosphere used, bicomponent or single component fibers result. While much has been demonstrated worldwide concerning the YBa2Cu3O(7-x) superconductor, fabrication into unique forms has proven quite difficult. However, a variety of intricate shapes are necessary for rapid commercialization of the superconducting materials. The potential for producing fibrous samples of the YBa2Cu3O(7-x) compound by the piggyback process is being investigated. Various organic and acrylic materials were investigated to determine suspending ability, reactivity with the YBa2Cu3O(7-x) compound during long term storage, and burn out characteristics. While many questions were answered with respect to the interfacial reactions between YBa2Cu3O(7-x) and carbon, much work is still necessary to improve the quality of the sintered material if the fibers produced are to be incorporated into useful composites or cables. Additional research is necessary to evaluate quality of the barrier layer during long soakings at the peak temperature; adjust the firing schedule to avoid microcracking and improve densification; and increase the solids loading in the superconductive suspension to decrease porosity.

Wise, S. A.; Fain, C. C.; Leigh, H. D.; Sherrill, M.

1990-01-01

211

Morphogenesis and Production of Enzymes by Penicillium echinulatum in Response to Different Carbon Sources  

PubMed Central

The effect of different carbon sources on morphology and cellulase and xylanase production of Penicillium echinulatum was evaluated in this work. Among the six carbon sources studied, cellulose and sugar cane bagasse were the most suitable for the production of filter paper activity, endoglucanases, xylanases, and ?-glucosidases. However, sucrose and glucose showed ?-glucosidase activities similar to those obtained with the insoluble sources. The polyacrylamide gels proved the enzymatic activity, since different standards bands were detected in the media mentioned above. Regarding morphology, it was observed that the mycelium in a dispersed form provided the greatest enzymatic activity, possibly due to greater interaction between the substrate and hyphae. These data are important in understanding the physiology of fungi and could contribute to obtaining enzyme with potential application in the technology of second generation ethanol. PMID:24877074

Schneider, Willian Daniel Hahn; dos Reis, Laísa; Dillon, Aldo José Pinheiro

2014-01-01

212

Thermoascus aurantiacus CBHI/Cel7A Production in Trichoderma reesei on Alternative Carbon Sources  

NASA Astrophysics Data System (ADS)

To develop functional enzymes in cellulose hydrolysis at or above 70°C the cellobiohydrolase (CBHI/Cel7A) of Thermoascus aurantiacus was cloned and expressed in Trichoderma reesei Rut-C30 under the strong cbh1 promoter. Cellulase production of the parental strain and the novel strain (RF6026) was examined in submerged fermentation experiments using various carbon sources, which were lactose, Solka Floc 200 cellulose powder, and steam pretreated corn stover. An industrially feasible production medium was used containing only distiller's spent grain, KH2PO4, and (NH4)2SO4. Enzyme production was followed by measurements of protein concentration, total cellulase enzyme activity (filter paper activity), ?-glucosidase activity, CBHI activity, and endogenase I (EGI) activity. The Thermoascus CBHI/Cel7A activity was taken as an indication of the heterologous gene expression under the cbh1 promoter.

Benk?, Zsuzsa; Drahos, Eszter; Szengyel, Zsolt; Puranen, Terhi; Vehmaanperä, Jari; Réczey, Kati

213

Carbon footprint of dairy production systems  

Technology Transfer Automated Retrieval System (TEKTRAN)

Greenhouse gas (GHG) emissions and their potential impact on global warming has become an important national and international concern. Dairy production systems along with all other types of animal agriculture are recognized as a source of GHG. Although little information exists on the net GHG emiss...

214

Carbon Monoxide Production in Compartment Fires  

Microsoft Academic Search

The development of empirical correlations for major species yields in compartment fires has become an important priority due to the inability to calculate these quantities from first principles. Studies of simplified upper layer environments have shown that major species production rates can be correlated with the equivalence ratio in what is known as the Global Equivalence Ratio concept (GER). Due

Daniel T. Gottuk; Richard J. Roby; Michelle J. Peatross; Craig L. Beyler

1992-01-01

215

A Carbon Arc Apparatus For Production Of Nanotubes In Microgravity  

NASA Technical Reports Server (NTRS)

Although many methods are available for production of single-walled carbon nanotubes (SWNTs), the conventional carbon arc process remains the most popular due to its simplicity and large production rate. However, high temperatures inside the carbon arc generate strong buoyancy driven convection, and it is hypothesized that the non-uniform environment created by this flow will have large effects on the growth and morphology of SWNTs produced by the arc process. Indeed, using normal gravity experiments, Marin et al. have demonstrated that changes in the buoyant convection plume produced by altering the arc electrode orientation can be used to change the diameter distribution of the SWNTs produced; an effect they attribute to changes in the temperature of the local nanotube growth environment. While these experiments present convincing evidence that buoyant convection has a strong effect on nanotube growth, normal gravity experiments are severely limited in scope. The ideal way to study the effect of buoyancy on SWNT production is to remove it completely. Toward this goal, a microgravity carbon arc reactor has been designed for use in the NASA Glenn 2.2 and 5 second drop towers. Although simple in principle, conventional carbon arc machines, which generally employ large reaction chambers and require heavy duty welding power supplies capable of supplying kilowatts of power, are not suitable for microgravity experiments. Here we describe a miniature carbon arc machine for SWNT production that fits into a conventional drop rig for use on the NASA Glenn 2.2 and 5 second drop towers, but that has a performance (production rate) that is better than most large ground-based machines.

Alford, J. M.; Mason, G. R.; Feikema, D. A.

2003-01-01

216

Soil Inorganic Carbon in Deserts: Active Carbon Sink or Inert Reservoir?  

NASA Astrophysics Data System (ADS)

Soil inorganic carbon is the third largest C pool in the active global carbon cycle, containing at least 800 petagrams of carbon. Although carbonate dissolution-precipitation reactions have been understood for over a century, the role of soil inorganic carbon in carbon sequestration, and in particular pedogenic carbonate, is a deceptively complex process because it involves interdependent connections among climate, plants, microorganisms, silicate minerals, soil moisture, pH, and Ca supply via rain, dust, or in situ weathering. An understanding of soil inorganic carbon as a sink or reservoir also requires examination of the system at local to continental scales and at seasonal to millennial time scales. In desert soils studied in North America, carbon isotope ratios and radiocarbon dates were measured in combination with electron microscopy, lab and field experiments with biological calcite formation, and field measurements of carbon dioxide emissions. These investigations reveal that soil inorganic carbon is both an active sink and a inert reservoir depending on the spatial and temporal scale and source of calcium.

Monger, H. C.; Cole, D. R.

2011-12-01

217

Optimization of carbon source and carbon\\/nitrogen ratio for cordycepin production by submerged cultivation of medicinal mushroom Cordyceps militaris  

Microsoft Academic Search

Effects of various carbon sources and carbon\\/nitrogen ratios on production of a useful bioactive metabolite, cordycepin (3?-deoxyadenosine), by submerged cultivation of a Chinese traditional medicinal mushroom Cordyceps militaris were investigated in shake flasks. The carbon sources examined were lactose, sucrose, glucose, fructose, galactose, maltose and xylose, and glucose was found to be most favourable to cordycepin production, whereas cells grew

Xian-Bing Mao; Titiporn Eksriwong; Somchai Chauvatcharin; Jian-Jiang Zhong

2005-01-01

218

Can we afford to waste carbon dioxide? Carbon dioxide as a valuable source of carbon for the production of light olefins.  

PubMed

Concerns about climate change have increased the amount of activity on carbon capture and sequestration (CCS) as one of the solutions to the problem of rising levels of CO(2) in the troposphere, while the reuse of CO(2) (carbon capture and recycling; CCR) has only recently received more attention. CCR is focused on the possibility of using CO(2) as a cheap (or even negative-value) raw material. This Concept paper analyzes this possibility from a different perspective: In a sustainable vision, can we afford to waste CO(2) as a source of carbon in a changing world faced with a fast depletion of natural carbon sources and in need of a low-carbon, resource-efficient economy? One of the points emerging from this discussion concerns the use of CO(2) for the production of olefins (substituting into or integrating with current energy-intensive methodologies that start from oil or syngas from other fossil fuel resources) if H(2) from renewable resources were available at competitive costs. This offers an opportunity to accelerate the introduction of renewable energy into the chemical production chain, and thus to improve resource efficiency in this important manufacturing sector. PMID:21922678

Centi, Gabriele; Iaquaniello, Gaetano; Perathoner, Siglinda

2011-09-19

219

Temporal variations in microbial activities and carbon turnover in subtidal sandy sediments  

NASA Astrophysics Data System (ADS)

Temporal dynamics and vertical patterns in bacterial abundances and activities were studied in a shallow subtidal sand flat in the Sylt-Rømø Basin (North Frisian Wadden Sea, Germany). Extracellular enzymatic activities, bacterial carbon production and community respiration showed strong (factor of 4-5) temporal variations that were mostly related to seasonal temperature change and to changes in substrate availability. These temporal patterns in enzymatic activity were barely reflected in bacterial (200-400 mmol C m-2) and microphytobenthic biomass (800-1500 mmol C m-2) or the sedimentary carbohydrate inventory (1300-2900 mmol C m-2), suggesting that grazing controls the standing stocks of the microphytobenthic and bacterial assemblages. Despite their exposure to strong hydrodynamic forces such as tidal currents and wind-induced wave surge, the subtidal sandy sediments showed persistent vertical gradients in bacterial abundances, carbon production and extracellular enzymatic activities at all times. The vertical distribution of these parameters was tightly coupled to that of the microphytobenthos, dominated by diatoms. Despite the low organic carbon content typical for surge-exposed sandy sediments, high extracellular enzymatic activities and bacterial carbon production rates indicate a very active heterotrophic bacterial community, with a gross secondary productivity of 30-180 mmol C m-2, and a biomass turnover time of 2-18 days. Our data suggest that this high activity is supported by the rapid flux of carbohydrates from microphytobenthic primary productivity. Accordingly, the potential activities of enzymes hydrolyzing carbohydrates cover most of the total bacterial carbon demand during all seasons.

Böer, S. I.; Arnosti, C.; van Beusekom, J. E. E.; Boetius, A.

2009-07-01

220

Method for creating high carbon content products from biomass oil  

DOEpatents

In a method for producing high carbon content products from biomass, a biomass oil is added to a cracking reactor vessel. The biomass oil is heated to a temperature ranging from about 100.degree. C. to about 800.degree. C. at a pressure ranging from about vacuum conditions to about 20,700 kPa for a time sufficient to crack the biomass oil. Tar is separated from the cracked biomass oil. The tar is heated to a temperature ranging from about 200.degree. C. to about 1500.degree. C. at a pressure ranging from about vacuum conditions to about 20,700 kPa for a time sufficient to reduce the tar to a high carbon content product containing at least about 50% carbon by weight.

Parker, Reginald; Seames, Wayne

2012-12-18

221

40 CFR 60.1330 - How do I monitor the injection rate of activated carbon?  

Code of Federal Regulations, 2014 CFR

...monitor the injection rate of activated carbon? 60.1330 Section 60.1330 Protection...monitor the injection rate of activated carbon? If your municipal waste combustion unit uses activated carbon to control dioxins/furans or...

2014-07-01

222

40 CFR 60.1820 - How do I monitor the injection rate of activated carbon?  

Code of Federal Regulations, 2014 CFR

...monitor the injection rate of activated carbon? 60.1820 Section 60.1820 Protection...monitor the injection rate of activated carbon? If your municipal waste combustion unit uses activated carbon to control dioxins/furans or...

2014-07-01

223

Activated carbon fibers and engineered forms from renewable resources  

DOEpatents

A method of producing activated carbon fibers (ACFs) includes the steps of providing a natural carbonaceous precursor fiber material, blending the carbonaceous precursor material with a chemical activation agent to form chemical agent-impregnated precursor fibers, spinning the chemical agent-impregnated precursor material into fibers, and thermally treating the chemical agent-impregnated precursor fibers. The carbonaceous precursor material is both carbonized and activated to form ACFs in a single step. The method produces ACFs exclusive of a step to isolate an intermediate carbon fiber.

Baker, Frederick S

2013-02-19

224

Carbon-Based Ocean Productivity and Phytoplankton Physiology from Space  

Microsoft Academic Search

Ocean biogeochemical and ecosystem processes are linked by net primary production (NPP) in the ocean's surface layer, where inorganic carbon is fixed by photosynthetic processes. Determinations of NPP are necessarily a function of phytoplankton biomass and its physiological status, but the estimation of these two terms from space has remained an elusive target. Here we present new satellite ocean color

Michael J. Behrenfeld; Emmanuel Boss; David A. Siegel; Donald M. Shea

2005-01-01

225

Laser-Induced Production of Large Carbon-Based Toriods  

Technology Transfer Automated Retrieval System (TEKTRAN)

We report on the production of large carbon-based toroids (CBTs) from fullerencs. The process involves two step laser irradiation of a mixed fullcrene target (76% C-60, 22% C-70). Transmission electron microscopy (11M) clearly identifies toroidal-shaped structures as well as Q-shaped constructs. ...

226

CONSERVATION ROTATIONS FOR COTTON PRODUCTION AND CARBON STORAGE  

Technology Transfer Automated Retrieval System (TEKTRAN)

We conducted a 4-yr study on a Compass loamy sand (Plinthic Paleudult) to compare economics and soil organic carbon (SOC) storage of an intensive cropping system to standard cotton production systems in the Southeast. The system uses sunn hemp (Crotalaria juncea L.) and ultra-narrow row (UNR; 8-inc...

227

Carbon dioxide concentration, photosynthesis, and dry matter production  

Microsoft Academic Search

It has been suggested the increase in atmospheric COâ produced by the burning of fossil fuels will be to some extent counteracted by an increase in carbon fixation by photosynthesis. This hypothesis is based on the assumption that the rate of photosynthesis is limited chiefly by COâ concentration. The effects on photosynthesis and dry matter production by increased levels of

Paul J. Kramer

1981-01-01

228

Activated carbon testing for the 200 area effluent treatment facility  

SciTech Connect

This report documents pilot and laboratory scale testing of activated carbon for use in the 200 Area Effluent Treatment Facility peroxide decomposer columns. Recommendations are made concerning column operating conditions and hardware design, the optimum type of carbon for use in the plant, and possible further studies.

Wagner, R.N.

1997-01-17

229

DESIGN AND CONSTRUCTION OF A MOBILE ACTIVATED CARBON REGENERATOR SYSTEM  

EPA Science Inventory

Activated carbon adsorption has become a standard procedure for the cleanup of contaminated water streams. To facilitate such cleanup at hazardous waste and spill sites, mobile carbon adsorption units have been constructed and are now in use. Their primary drawback is the logisti...

230

HARDWOOD-BASED GRANULAR ACTIVATED CARBON FOR METALS REMEDIATION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Granular activated carbon is usually the adsorbent of choice for removing organic pollutants from air and water waste streams. Its ability to remove metal ions from aqueous media is considered secondary to its ability to remove organics. Only recently was a coal-based, commerical carbon (Minotaur,...

231

HARDWOOD-BASED GRANULAR ACTIVATED CARBON FOR METALS REMEDIATION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Granular activated carbon is usually the adsorbent of choice for removing organic pollutants from air and water waste streams. Its ability to remove metal ions from aqueous media is considered secondary to its ability to remove organics. Only recently was a coal-based, commercial carbon (Minotaur) m...

232

HARDWOOD-BASED GRANULAR ACTIVATED CARBON FOR METALS REMEDIATION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Granular activated carbon is usually the adsorbent of choice for removing organic pollutants from air and water waste streams. Its ability to remove metal ions from aqueous media is considered secondary to its ability to remove organics. Only recently was a coal-based, commercial carbon (Minotaur, C...

233

ELEMENTAL MERCURY CAPTURE BY ACTIVATED CARBON IN A FLOW REACTOR  

EPA Science Inventory

The paper gives results of bench-scale experiments in a flow reactor to simulate the entrained-flow capture of elemental mercury (Hgo) using solid sorbents. Adsorption of Hgo by a lignite-based activated carbon (Calgon FGD) was examined at different carbon/mercury (C/Hg) rat...

234

Silver Nanoparticle Impregnated Bio-Based Activated Carbon with Enhanced Antimicrobial Activity  

NASA Astrophysics Data System (ADS)

The present study involves the production of silver nanoparticles using a novel yeast strain Saccharomyces cerevisiae BU-MBT CY-1 isolated from coconut cell sap. The biological reduction of silver nitrate by the isolate was deducted at various time intervals. The yeast cells after biological silver reduction were harvested and subjected to carbonization at 400°C for 1 h and its properties were analyzed using Fourier transform infra-red spectroscopy, X-ray diffraction, scanning electron microscope attached with energy dispersive spectroscopy and transmission electron microscopy. The average size of the silver nanoparticles present on the surface of the carbonized silver containing yeast cells (CSY) was 19 ± 9 nm. The carbonized control yeast cells (CCY) did not contain any particles on its surface. The carbonized silver nanoparticles containing yeast cells (CSY) were made into bioactive emulsion and tested for its efficacy against various pathogenic Gram positive and Gram negative bacteria. The antimicrobial activity studies indicated that CSY bioactive nanoemulsion was effective against Gram negative organisms than Gram positive organism.

Selvakumar, R.; Suriyaraj, S. P.; Jayavignesh, V.; Swaminathan, K.

2013-08-01

235

Immobilization of enzymes on activated carbon: selection and preparation of the carbon support.  

PubMed

Based upon its superior catalytic activity for H2O2 decomposition, a bituminous coal-based activated carbon was selected for investigations of pretreatment and enzyme immobilization methods. Pretreatments considered include acid washing, exposure to strong oxidizing agents, contact with concentrated peroxide solutions, nitration and amination, isothiocyanate derivatization, silanization, and stearic acid coating. Effects of these pretreatments on morphology and trace-metal content of the carbon pellets have been studied using scanning electron microscopy and dispersive analysis of x rays. Immobilization of glucoamylase by adsorption, glutaraldehyde crosslinking, and covalent attachment to carbon activated by water-soluble diimide or diazotization have been examined. These different enzyme-carbon catalysts have been characterized by their enzyme loading, enzyme activity, catalytic activity for H2O2 decomposition, or combinations of these measures of performance. PMID:106909

Cho, Y K; Bailey, J E

1979-03-01

236

IMPROVING THE COMPLETENESS OF PRODUCT CARBON FOOTPRINTS USING A GLOBAL LINK INPUT–OUTPUT MODEL: THE CASE OF JAPAN  

Microsoft Academic Search

This paper is concerned with the main activities of Japan's ‘Disclosure of CO2 emissions’ programme, aimed at illustrating the CO2 emissions associated with consumer products as a ‘carbon footprint’ (CF). Although the current, provisional guidelines for calculating product carbon footprints specify that only the bottom-up approach is to be used for this purpose, this paper presents useful applications of input–output

Keisuke Nansai; Shigemi Kagawa; Yasushi Kondo; Sangwon Suh; Rokuta Inaba; Kenichi Nakajima

2009-01-01

237

THE PRODUCTION OF CARBON DIOXIDE BY NERVE  

PubMed Central

1. A modified Osterhout respiratory apparatus for the detection of CO2 from nerve is described. 2. The lateral-line nerve from the dogfish discharges CO2 at first with a gush for half an hour or so and then steadily at a lower rate for several hours. 3. Simple handling of the nerve does not increase the output of CO2; cutting it revives gush. 4. The CO2 produced by nerve is not escaping simply from a reservoir but is a true nervous metabolite. 5. The rate of discharge of CO2 from a quiescent nerve varied from 0.0071 to 0.0128 mg. per gram of nerve per minute and averaged 0.0095 mg. 6. Stimulated nerve showed an increased rate of CO2 production of 15.8 percent over that of quiescent nerve. 7. The results of these studies indicate that chemical change is a factor in nerve transmission. PMID:19872167

Parker, G. H.

1925-01-01

238

Carbon-Carbon Bond Activation in Pt(0)-Diphenylacetylene Complexes Bearing  

E-print Network

Carbon-Carbon Bond Activation in Pt(0)-Diphenylacetylene Complexes Bearing Chelating P,N- and P complexes bearing chelating P,N- or P,P-ligands and on the cleavage of the C(sp2)-C(sp) bond complexes bearing chelat- ing P,P-ligands. Thus, the reaction of 1 with 1 equiv bis- (diisopropylphosphino

Jones, William D.

239

GRANULAR ACTIVATED CARBON ADSORPTION AND INFRARED REACTIVATION: A CASE STUDY  

EPA Science Inventory

A study evaluated the effectiveness and cost of removing trace organic contaminants and surrogates from drinking water by granular activated carbon (GAC) adsorption. The effect of multiple reactivations of spent GAC was also evaluated. Results indicated that reactivated GAC eff...

240

Characteristics of activated carbons prepared from pistachio-nut shells by physical activation  

Microsoft Academic Search

Activated carbons were prepared from pistachio-nut shells, which are one type of lignocellulosic material, by a two-step physical method. The effects of the preparation variables on the activated carbon pore structure were studied, followed by the optimization of these operating parameters. It was found that the activation temperature and dwell time are the important parameters that affect the characteristics of

Ting Yang; Aik Chong Lua

2003-01-01

241

Preparation and characterization of activated carbon from date stones by physical activation with steam  

Microsoft Academic Search

Activated carbons are produced from wastes of Algerian date stones by pyrolysis and physical activation in the presence of water vapor into a heated fixed-bed reactor. The effect of pyrolysis temperature and activation hold time on textural and chemical surface properties of raw date stones and carbon materials produced are studied. As expected, the percentage yield decreases with increase of

Chafia Bouchelta; Mohamed Salah Medjram; Odile Bertrand; Jean-Pierre Bellat

2008-01-01

242

Pore size distribution analysis of activated carbons: Application of density functional theory using nongraphitized carbon black as a reference system  

Microsoft Academic Search

The application of nonlocal density functional theory (NLDFT) to determine pore size distribution (PSD) of activated carbons using a nongraphitized carbon black, instead of graphitized thermal carbon black, as a reference system is explored. We show that in this case nitrogen and argon adsorption isotherms in activated carbons are precisely correlated by the theory, and such an excellent correlation would

E. A. Ustinov; D. D. Do; V. B. Fenelonov

2006-01-01

243

Mechanisms of Carbon Nanotube Production by Laser Ablation Process  

NASA Technical Reports Server (NTRS)

We will present possible mechanisms for nanotube production by laser oven process. Spectral emission of excited species during laser ablation of a composite graphite target is compared with that of laser irradiated C60 vapor. The similarities in the transient and spectral data suggest that fullerenes are intermediate precursors for nanotube formation. The confinement of the ablation products by means of a 25-mm diameter tube placed upstream of the target seems to improve the production and purity of nanotubes. Repeated laser pulses vaporize the amorphous/graphitic carbon and possibly catalyst particles, and dissociate fullerenes yielding additional feedstock for SWNT growth.

Scott, Carl D.; Arepalli, Sivaram; Nikolaev, Pavel; Smalley, Richard E.; Nocholson, Leonard S. (Technical Monitor)

2000-01-01

244

Hydrogen storage on activated carbon. Final report  

SciTech Connect

The project studied factors that influence the ability of carbon to store hydrogen and developed techniques to enhance that ability in naturally occurring and factory-produced commercial carbon materials. During testing of enhanced materials, levels of hydrogen storage were achieved that compare well with conventional forms of energy storage, including lead-acid batteries, gasoline, and diesel fuel. Using the best materials, an electric car with a modern fuel cell to convert the hydrogen directly to electricity would have a range of over 1,000 miles. This assumes that the total allowable weight of the fuel cell and carbon/hydrogen storage system is no greater than the present weight of batteries in an existing electric vehicle. By comparison, gasoline cars generally are limited to about a 450-mile range, and battery-electric cars to 40 to 60 miles. The project also developed a new class of carbon materials, based on polymers and other organic compounds, in which the best hydrogen-storing factors discovered earlier were {open_quotes}molecularly engineered{close_quotes} into the new materials. It is believed that these new molecularly engineered materials are likely to exceed the performance of the naturally occurring and manufactured carbons seen earlier with respect to hydrogen storage.

Schwarz, J.A. [Syracuse Univ., NY (United States). Dept. of Chemical Engineering and Materials Science

1994-11-01

245

Sustainable Production of Cannabinoids with Supercritical Carbon Dioxide Technologies  

Microsoft Academic Search

This thesis concerns the production of natural compounds from plant material for pharmaceutical and food applications. It describes the production (extraction and isolation) of cannabinoids, the active components present in cannabis. Many cannabinoids have medicinal properties but not all cannabinoids are available in the (large) quantities necessary to develop new medicines, because so far, for large scale production, there are

H. Perrotin-Brunel

2011-01-01

246

Production of biodiesel from carbon sources of macroalgae, Laminaria japonica.  

PubMed

As aquatic biomass which is called "the third generation biomass", Laminaria japonica (also known as Saccharina japonica) consists of mannitol and alginate which are the main polysaccharides of algal carbohydrates. In this study, oleaginous yeast (Cryptococcus curvatus) was used to produce lipid from carbon sources derived from Laminaria japonica. Volatile fatty acids (VFAs) were produced by fermentation of alginate extracted from L. japonica. Thereafter, mannitol was mixed with VFAs to culture the oleaginous yeast. The highest lipid content was 48.30%. The composition of the fatty acids was similar to vegetable oils. This is the first confirmation of the feasibility of using macroalgae as a carbon source for biodiesel production. PMID:25084043

Xu, Xu; Kim, Ji Young; Oh, Yu Ri; Park, Jong Moon

2014-10-01

247

DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS  

SciTech Connect

The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. These carbon products include materials used in metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to as ''carbon foam'' and carbon fibers. During this reporting period, efforts have focused on the facility modifications for continuous hydrotreating, as well as developing improved protocols for producing synthetic pitches.

Elliot B. Kennel; Stephen P. Carpenter; Dady Dadyburjor; Manoj Katakdaunde; Liviu Magean; Peter G. Stansberry; Alfred H. Stiller; John W. Zondlo

2005-08-11

248

Improved Norway spruce somatic embryo development through the use of abscisic acid combined with activated carbon  

Microsoft Academic Search

The combination of abscisic acid (ABA) and activated carbon increased Norway spruce (Picea abies L., Karst.) cotyledonary somatic embryo yields, increased the number of genotypes forming cotyledonary embryos, caused embryos to form that exhibited improved maturation characteristics, and reduced embryo production costs. Somatic embryos increased in size, showed larger apical regions, became more zygotic-like in shape, and showed higher percentages

G. S. Pullman; P. K. Gupta; R. Timmis; C. Carpenter; M. Kreitinger; E. Welty

2005-01-01

249

One carbon metabolism in anaerobic bacteria: Regulation of carbon and electron flow during organic acid production  

SciTech Connect

This reporting period, progress is reported on the following: metabolic pathway of solvent production in B. methylotrophicum; the biochemical mechanism for metabolic regulation of the succinate fermentation; models to understand the physiobiochemical function of formate metabolism in anaerobes and; models for understanding the influence of low pH on one carbon metabolism. (CBS)

Zeikus, J.G.; Jain, M.K.

1992-01-01

250

Activated carbon fiber composite material and method of making  

DOEpatents

An activated carbon fiber composite for separation and purification, or catalytic processing of fluids is described. The activated composite comprises carbon fibers rigidly bonded to form an open, permeable, rigid monolith capable of being formed to near-net-shape. Separation and purification of gases are effected by means of a controlled pore structure that is developed in the carbon fibers contained in the composite. The open, permeable structure allows the free flow of gases through the monolith accompanied by high rates of adsorption. By modification of the pore structure and bulk density the composite can be rendered suitable for applications such as gas storage, catalysis, and liquid phase processing.

Burchell, Timothy D. (Oak Ridge, TN); Weaver, Charles E. (Knoxville, TN); Chilcoat, Bill R. (Knoxville, TN); Derbyshire, Frank (Lexington, KY); Jagtoyen, Marit (Lexington, KY)

2000-01-01

251

Activated carbon fiber composite material and method of making  

DOEpatents

An activated carbon fiber composite for separation and purification, or catalytic processing of fluids is described. The activated composite comprises carbon fibers rigidly bonded to form an open, permeable, rigid monolith capable of being formed to near-net-shape. Separation and purification of gases are effected by means of a controlled pore structure that is developed in the carbon fibers contained in the composite. The open, permeable structure allows the free flow of gases through the monolith accompanied by high rates of adsorption. By modification of the pore structure and bulk density the composite can be rendered suitable for applications such as gas storage, catalysis, and liquid phase processing.

Burchell, Timothy D. (Oak Ridge, TN); Weaver, Charles E. (Knoxville, TN); Chilcoat, Bill R. (Knoxville, TN); Derbyshire, Frank (Lexington, KY); Jagtoyen, Marit (Lexington, KY)

2001-01-01

252

Cleaner pathways of hydrogen, carbon nano-materials and metals production via solar thermal processing  

Microsoft Academic Search

This paper describes various solar thermochemical processes for the production of hydrogen, carbon nano particles, industrial grade carbon black, and metals with substantially reduced CO2 emission footprint. The paper introduces an innovative approach of a three-dimensional volumetric production of carbon nano particles via thermal cracking of methane gained by carbon seeding as an alternative to the existing two dimensional modes.

Nesrin Ozalp; Michael Epstein; Abraham Kogan

2010-01-01

253

Environmental Remediation and Conversion of Carbon Dioxide (CO2) into Useful Green Products by Accelerated Carbonation Technology  

PubMed Central

This paper reviews the application of carbonation technology to the environmental industry as a way of reducing carbon dioxide (CO2), a green house gas, including the presentation of related projects of our research group. An alternative technology to very slow natural carbonation is the co-called ‘accelerated carbonation’, which completes its fast reaction within few hours by using pure CO2. Carbonation technology is widely applied to solidify or stabilize solid combustion residues from municipal solid wastes, paper mill wastes, etc. and contaminated soils, and to manufacture precipitated calcium carbonate (PCC). Carbonated products can be utilized as aggregates in the concrete industry and as alkaline fillers in the paper (or recycled paper) making industry. The quantity of captured CO2 in carbonated products can be evaluated by measuring mass loss of heated samples by thermo-gravimetric (TG) analysis. The industrial carbonation technology could contribute to both reduction of CO2 emissions and environmental remediation. PMID:20195442

Lim, Mihee; Han, Gi-Chun; Ahn, Ji-Whan; You, Kwang-Suk

2010-01-01

254

Carbon-carbon bond cleavage in activation of the prodrug nabumetone.  

PubMed

Carbon-carbon bond cleavage reactions are catalyzed by, among others, lanosterol 14-demethylase (CYP51), cholesterol side-chain cleavage enzyme (CYP11), sterol 17?-lyase (CYP17), and aromatase (CYP19). Because of the high substrate specificities of these enzymes and the complex nature of their substrates, these reactions have been difficult to characterize. A CYP1A2-catalyzed carbon-carbon bond cleavage reaction is required for conversion of the prodrug nabumetone to its active form, 6-methoxy-2-naphthylacetic acid (6-MNA). Despite worldwide use of nabumetone as an anti-inflammatory agent, the mechanism of its carbon-carbon bond cleavage reaction remains obscure. With the help of authentic synthetic standards, we report here that the reaction involves 3-hydroxylation, carbon-carbon cleavage to the aldehyde, and oxidation of the aldehyde to the acid, all catalyzed by CYP1A2 or, less effectively, by other P450 enzymes. The data indicate that the carbon-carbon bond cleavage is mediated by the ferric peroxo anion rather than the ferryl species in the P450 catalytic cycle. CYP1A2 also catalyzes O-demethylation and alcohol to ketone transformations of nabumetone and its analogs. PMID:24584631

Varfaj, Fatbardha; Zulkifli, Siti N A; Park, Hyoung-Goo; Challinor, Victoria L; De Voss, James J; Ortiz de Montellano, Paul R

2014-05-01

255

A sustainable route for the preparation of activated carbon and silica from rice husk ash.  

PubMed

An environmentally friendly and economically effective process to produce silica and activated carbon form rice husk ask simultaneously has been developed in this study. An extraction yield of silica of 72-98% was obtained and the particle size was 40-50 nm. The microstructures of the as-obtained silica powders were characterized by X-ray diffraction (XRD) and infrared spectra (IR). The surface area, iodine number and capacitance value of activated carbon could achieve 570 m(2)/g, 1708 mg/g, 180 F/g, respectively. In the whole synthetic procedure, the wastewater and the carbon dioxide were collected and reutilized. The recovery rate of sodium carbonate was achieved 92.25%. The process is inexpensive, sustainable, environmentally friendly and suitable for large-scale production. PMID:21194835

Liu, Yan; Guo, Yupeng; Zhu, Yanchao; An, Dongmin; Gao, Wei; Wang, Zhuo; Ma, Yuejia; Wang, Zichen

2011-02-28

256

Natural products and anti-inflammatory activity.  

PubMed

The aim of this review paper was to summarise some commonly available natural products and their anti-inflammatory activity. We have collected data from MEDLINE, Current Contents and scientific journals, which included 92 publications. There are numerous natural products detailed in this literature; however we have summarized a few of the most commonly available and potent ones. In this paper, the natural products with anti-inflammatory activity including curcumin, parthenolide, cucurbitacins, 1,8-cineole, pseudopterosins, lyprinol, bromelain, flavonoids, saponins, marine sponge natural products and Boswellia serrata gum resin were reviewed. Natural products play a significant role in human health in relation to the prevention and treatment of inflammatory conditions. Further studies are being conducted to investigate the mechanism of action, metabolism, safety and long term side effect of these natural products, as well as interactions between these natural products with food and drug components. PMID:16672197

Yuan, Gaofeng; Wahlqvist, Mark L; He, Guoqing; Yang, Min; Li, Duo

2006-01-01

257

India's aluminum industry: Productivity, energy efficiency and carbon emissions  

SciTech Connect

Historical estimates of productivity growth in India's aluminum sector vary from indicating an improvement to a decline in the sector's productivity. The variance may be traced to the time period of study, source of data for analysis, and type of indices and econometric specifications used for reporting productivity growth. An analysis shows that in the twenty year period, 1973 to 1993, productivity in the aluminum sector declined slightly by 0.2%. An econometric analysis reveals that technical progress in India's aluminum sector has been biased towards the use of energy, while it has been labor saving. The decline in productivity was mainly driven by a decline in the 1970s when capacity utilization was low and the energy crisis hit India and the world. From the early 1980s on productivity recuperated. The authors examine the current changes in structure and energy efficiency in the sector. Their analysis shows that the Indian aluminum sector has high potential to move towards world-best technology, which will result in fewer carbon emissions and more efficient energy use. Substantial energy savings and carbon reduction options exist.

Schumacher, Katja; Sathaye, Jayant

1999-07-01

258

CREAT A CONSORTIUM AND DEVELOP PREMIUM CARBON PRODUCTS FROM COAL  

SciTech Connect

The Consortium for Premium Carbon Products from Coal, with funding from the U.S. Department of Energy's National Energy Technology Laboratory and matching funds from industry and academic institutions continued to excel in developing innovative technologies to use coal and coal-derived feedstocks to produce premium carbon product. During Budget Period 5, eleven projects were supported and sub-contracted were awarded to seven organizations. The CPCPC held two meetings and one tutorial at various locations during the year. Budget Period 5 was a time of growth for CPCPC in terms of number of proposals and funding requested from members, projects funded and participation during meetings. Although the membership was stable during the first part of Budget Period 5 an increase in new members was registered during the last months of the performance period.

John M. Andresen

2003-08-01

259

Free nitrous acid pretreatment of wasted activated sludge to exploit internal carbon source for enhanced denitrification.  

PubMed

Using internal carbon source contained in waste activated sludge (WAS) is beneficial for nitrogen removal from wastewater with low carbon/nitrogen ratio, but it is usually limited by sludge disintegration. This study presented a novel strategy based on free nitrous acid (FNA) pretreatment to intensify the release of organic matters from WAS for enhanced denitrification. During FNA pretreatment, soluble chemical oxygen demand (SCOD) production kept increasing when FNA increased from 0 to 2.04mg HNO2-N/L. Compared with untreated WAS, the internal carbon source production increased by 50% in a simultaneous fermentation and denitrification reactor fed with WAS pretreated by FNA for 24h at 2.04mg HNO2-N/L. This also increased denitrification efficiency by 76% and sludge reduction by 87.5%. More importantly, greenhouse gas nitrous oxide production in denitrification was alleviated since more electrons could be provided by FNA pretreated WAS. PMID:25514398

Ma, Bin; Peng, Yongzhen; Wei, Yan; Li, Baikun; Bao, Peng; Wang, Yayi

2015-03-01

260

FENTON-DRIVEN REGENERATION OF GRANULAR ACTIVATED CARBON: A TECHNOLOGY OVERVIEW  

EPA Science Inventory

A Fenton-driven mechanism for regenerating spent granular activated carbon (GAC) involves the combined, synergistic use of two reliable and well established treatment technologies - adsorption onto activated carbon and Fenton oxidation. During carbon adsorption treatment, enviro...

261

76 FR 42679 - Certain Hot-Rolled Carbon Steel Flat Products From India: Final Results of Antidumping Duty...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-533-820] Certain Hot-Rolled Carbon Steel Flat Products From...of the antidumping duty order on certain hot- rolled carbon steel flat products from...2\\ See Certain Hot-Rolled Carbon Steel Flat Products...

2011-07-19

262

68 FR 64853 - Certain Hot-Rolled Carbon Steel Flat Products from South Africa: Final Results of Antidumping...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Carbon Steel Flat Products from South Africa: Final Results of Antidumping...carbon steel flat products from South Africa (68 FR 40903). The review covers...Carbon Steel Flat Products from South Africa, 66 FR 48242 (Sept. 19,...

2003-11-17

263

68 FR 40903 - Certain Hot-Rolled Carbon Steel Flat Products From South Africa: Preliminary Results of...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Carbon Steel Flat Products From South Africa: Preliminary Results of Antidumping...carbon steel flat products from South Africa in response to requests by petitioners...carbon steel flat products from South Africa (66 FR 48242). On...

2003-07-09

264

Spring 2012 Denman Forestry Issues Series presents: Role of Forests and Forest Products in Carbon Mitigation  

E-print Network

Spring 2012 Denman Forestry Issues Series presents: Role of Forests and Forest Products in Carbon@u.washington.edu. Agenda Session 1: Forests, Forest Products, and the C Cycle "Can We Have Our Forest Carbon and Use It Too and Concerns "Pursuing Carbon and Forest Sustainability in Forest Biomass Energy Production" Craig Partridge

Borenstein, Elhanan

265

76 FR 15299 - Certain Hot-Rolled Carbon Steel Flat Products From India: Preliminary Rescission of...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [C-533-821] Certain Hot-Rolled Carbon Steel Flat Products From...countervailing duty (CVD) order on certain hot-rolled carbon steel flat products from...products covered under this order are certain hot-rolled flat- rolled carbon steel...

2011-03-21

266

REMOVAL OF ORGANIC POLLUTANTS FROM SUBCRITICAL WATER WITH ACTIVATED CARBON  

SciTech Connect

The Energy & Environmental Research Center (EERC) has demonstrated that controlling the temperature (and to a lesser extent, the pressure) of water can dramatically change its ability to extract organics and inorganics from matrices ranging from soils and sediments to waste sludges and coal. The dielectric constant of water can be changed from about 80 (a very polar solvent) to <5 (similar to a nonpolar organic solvent) by controlling the temperature (from ambient to about 400 C) and pressure (from about 5 to 350 bar). The EERC has shown that hazardous organic pollutants such as pesticides, PACS (polycyclic aromatic hydrocarbons), and PCBs (polychlorinated biphenyls) can be completely removed from soils, sludges, and sediments at temperatures (250 C) and pressures (<50 atm) that are much milder than typically used for supercritical water processes (temperature >374 C, pressure >221 atm). In addition, the process has been demonstrated to be particularly effective for samples containing very high levels of contaminants (e.g., part per thousand). Current projects include demonstrating the subcritical water remediation process at the pilot scale using an 8-liter system constructed under separate funding during 1997. To date, subcritical water has been shown to be an effective extraction fluid for removing a variety of organic pollutants from soils and sludges contaminated with fossil fuel products and waste products, including PACS from soil (e.g., town gas sites), refining catalysts, and petroleum tank bottom sludges; PCBs from soil and sediments; toxic gasoline components (e.g., benzene) from soil and waste sludge; and phenols from petroleum refinery sludges. The obvious need to clean the wastewater from subcritical water processes led to preliminary experiments with activated carbon placed in line after the extractor. Initial experiments were performed before and after cooling the extractant water (e.g., with water at 200 C and with water cooled to 25 C). Surprisingly, the ability of activated carbon to remove organics from the water is better at a high temperature than at room temperature. These initial results are opposite to those expected from chromatographic theory, since the solubility of the organics is about 100,000-fold higher in the hot water than in ambient water. At present, the physicochemical mechanism accounting for these results is unknown; however, it is possible that the lower surface tension and lower viscosity of subcritical water (compared to water at ambient conditions) greatly increases the available area of the carbon by several orders of magnitude. Regardless of the mechanism involved, the optimal use of activated carbon to clean the wastewater generated from subcritical water remediation will depend on obtaining a better understanding of the controlling parameters. While these investigations focused on the cleanup of wastewater generated from subcritical water remediation, the results also apply to cleanup of any wastewater contaminated with nonpolar and moderately polar organics such as wastewaters from coal and petroleum processing.

Steven B. Hawthorne; Arnaud J. Lagadec

1999-08-01

267

Characterisation and applications of activated carbon produced from Moringa oleifera seed husks by single-step steam pyrolysis  

Microsoft Academic Search

The seed husks of the multipurpose tree Moringa oleifera are potentially a waste product that may be available in large quantities, and previous work has demonstrated that a microporous activated carbon can be produced from them by carbonisation under nitrogen followed by activation in steam. This research examines the efficacy of a simpler and cheaper activation process, single-step steam pyrolysis

A. Michael Warhurst; Gordon L. McConnachie; Simon J. T. Pollard

1997-01-01

268

TOXIC SUBSTANCE REMOVAL IN ACTIVATED SLUDGE AND PAC (POWDERED ACTIVATED CARBON) TREATMENT SYSTEMS  

EPA Science Inventory

The effectiveness of adding powdered activated carbon to activated sludge systems was evaluated for enhanced removal of specific toxic organic compounds. Nine organic compounds encompassing a range of solubility, volatility, biodegradability, and adsorptive properties were studie...

269

Modeling carbon stores in Oregon and Washington forest products: 1900–1992  

Microsoft Academic Search

A new model, FORPROD, for estimating the carbon stored in forest products, considers both the manufacture of the raw logs into products and the fate of the products during use and disposal. Data for historical patterns of harvest, manufacturing efficiencies, and product use and disposal were used for estimating the accumulation of carbon in Oregon and Washington forest products from

Mark E. Harmon; Janice M. Harmon; William K. Ferrell; David Brooks

1996-01-01

270

India's cement industry: Productivity, energy efficiency and carbon emissions  

SciTech Connect

Historical estimates of productivity growth in India's cement sector vary from indicating an improvement to a decline in the sector's productivity. The variance may be traced to the time period of study, source of data for analysis, and type of indices and econometric specifications used for reporting productivity growth. Analysis shows that in the twenty year period, 1973 to 1993, productivity in the aluminum sector increased by 0.8% per annum. An econometric analysis reveals that technical progress in India's cement sector has been biased towards the use of energy and capital, while it has been material and labor saving. The increase in productivity was mainly driven by a period of progress between 1983 and 1991 following partial decontrol of the cement sector in 1982. The authors examine the current changes in structure and energy efficiency in the sector. Their analysis shows that the Indian cement sector is moving towards world-best technology, which will result in fewer carbon emissions and more efficient energy use. However, substantial further energy savings and carbon reduction potentials still exist.

Schumacher, Katja; Sathaye, Jayant

1999-07-01

271

Preparation of high surface area activated carbon by chemical activation using waste PET  

Microsoft Academic Search

Poly (ethylene terephthalate) (PET), the most important specie of thermoplastic polyester, have been widely used in humans' life. Waste PET is not easy to degradation and become a burden for the environment; therefore, its recycling is very important. High surface area activated carbon is prepared by chemical activation using waste PET. The experiment condition are as follows: carbonization temperature 500

Jinyang Chen; Feng Liu; Ruyi Ruan; Zhi Li

2011-01-01

272

Removal of Pb and Zn from the aqueous solutions by activated carbon prepared from Dates stone  

Microsoft Academic Search

The low-cost activated carbon prepared from Date stone, an agricultural solid waste by-product, were prepared by chemical activation with sulphuric acid for the removal of lead and zinc from aqueous solutions has been studied as a function of pH, contact time, metal concentrations and adsorbent concentrations. Adsorption equilibrium was reached after an equilibration time of 60 min and adsorption kinetics

Lotfi Mouni; Djoudi Merabet; Abdelkarim Bouzaza; Lazhar Belkhiri

2010-01-01

273

Bacterial production and carbon conversion based on saltmarsh plant debris  

NASA Astrophysics Data System (ADS)

There is a well-defined succession of micro-organisms which colonize powdered leaf debris from Spartina alterniflora and Juncus roemerianus, and aged natural detrital material when these were incubated in estuarine water at temperatures near to those recorded in the habitat at the time of collection. The natural assemblage of free-living bacteria in estuarine water rapidly enters logarithmic growth, subsequently declining with the increase in numbers of bactivorous microflagellates. These are then replaced by a mixed population of ciliates, choanoflagellates, amoeboid forms and attached bacteria which form part of a complex microbial community associated with particulate debris. The rate of increase of bacterial cells (?), in both spring and summer experiments ranged from 0·010-0·108 h -1 whilst estimates of bacterial carbon production ranged from 1·5 to 10·1 ?g C 1 -1 h -1, values which conform well with estimates obtained from natural assemblages of marine bacteria in coastal and estuarine waters elsewhere. Although both the ease of degradation of the detrital substrate and incubation temperature are of importance, enrichment of both powdered Spartina leaf debris and aged natural detritus with inorganic nutrients evidently enhances bacterial production under experimental conditions. In addition, the amount of carbon utilized to sustain bacterial carbon production shows a significant reduction following enrichment with NH 4, NO 3 or combinations of NO 3 + PO 4. The bacterial carbon conversion efficiency (?g C incorporated into bacterial production per ?g C consumed) × 100, based on powdered Spartina leaves, and aged natural detritus, is thus increased from 9-14%, to as much as 38% in nutrient enriched media. Since NH 4, NO 3 and PO 4 values are generally low in the water column, it seems likely that bacteria achieve a carbon conversion of only 9-14% on natural suspended detrital material, with the possibility of an enhanced conversion of up to 38% occurring at the sediment-water interface where ammonia regeration occurs. This suggests that suspended bacteria which characterize estuarine waters of salt marsh areas may be responsible for the oxidation of 86-91% of the carbon which enters water column microheterotroph food chains, and are probably implicated in the large CO 2 fluxes recently recorded from coastal wetland habitats.

Newell, R. C.; Linley, E. A. S.; Lucas, M. I.

1983-10-01

274

Ratio of Pion Kaon Production in Proton Carbon Interactions  

SciTech Connect

The ratio of pion-kaon production by 120 GeV/c protons incident on carbon target is presented. The data was recorded with the Main Injector Particle Production experiment at Fermi National Accelerator Laboratory. Production ratios of K{sup +}/{pi}{sup +}, K{sup -}/{pi}{sup -}, K{sup -}/K{sup +}, and {pi}{sup -}/{pi}{sup +} are measured in 24 bins in longitudinal momentum from 20 to 90 GeV/c and transverse momentum up to 2 GeV/c. The measurement is compared to existing data sets, particle production Monte Carlo results from FLUKA-06, parametrization of proton-beryllium data at 400/450 GeV/c, and ratios measured by the MINOS experiment on the NuMI target.

Lebedev, Andrey V.; /Harvard U.

2007-05-01

275

Characteristics of activated carbons prepared from pistachio-nut shells by potassium hydroxide activation  

Microsoft Academic Search

High-surface-area activated carbons in granular form were prepared by chemical activation of pistachio-nut shells with potassium hydroxide. The effects of the preparation variables on the carbon pore structure were studied in order to optimize these parameters. It was found that the chemical to shell impregnation ratio, the activation temperature and the activation hold time were the important parameters that affect

Ting Yang; Aik Chong Lua

2003-01-01

276

Apparatus for hydrogen and carbon production via carbon aerosol-catalyzed dissociation of hydrocarbons  

NASA Technical Reports Server (NTRS)

A novel process and apparatus is disclosed for sustainable, continuous production of hydrogen and carbon by catalytic dissociation or decomposition of hydrocarbons at elevated temperatures using in-situ generated carbon particles. Carbon particles are produced by decomposition of carbonaceous materials in response to an energy input. The energy input can be provided by at least one of a non-oxidative and oxidative means. The non-oxidative means of the energy input includes a high temperature source, or different types of plasma, such as, thermal, non-thermal, microwave, corona discharge, glow discharge, dielectric barrier discharge, or radiation sources, such as, electron beam, gamma, ultraviolet (UV). The oxidative means of the energy input includes oxygen, air, ozone, nitrous oxide (NO.sub.2) and other oxidizing agents. The method, apparatus and process of the present invention is applicable to any gaseous or liquid hydrocarbon fuel and it produces no or significantly less CO.sub.2 emissions compared to conventional processes.

Muradov, Nazim Z. (Inventor); Smith, Franklyn (Inventor); Tabatabaie-Raissi, Ali (Inventor)

2012-01-01

277

Measured Enthalpies of Adsorption of Boron-Doped Activated Carbons  

NASA Astrophysics Data System (ADS)

There is significant interest in the properties of boron-doped activated carbons for their potential to improve hydrogen storage.ootnotetextMultiply Surface-Functionalized Nanoporous Carbon for Vehicular Hydrogen Storage, P. Pfeifer et al. DOE Hydrogen Program 2011 Annual Progress Report, IV.C.3, 444-449 (2011). Boron-doped activated carbons have been produced using a process involving the pyrolysis of decaborane (B10H14) and subsequent high-temperature annealing. In this talk, we will present a systematic study of the effect of different boron doping processes on the samples' structure, hydrogen sorption, and surface chemistry. Initial room temperature experiments show a 20% increase in the hydrogen excess adsorption per surface area compared to the undoped material. Experimental enthalpies of adsorption will be presented for comparison to theoretical predictions for boron-doped carbon materials. Additionally, results from a modified version of the doping process will be presented.

Beckner, M.; Romanos, J.; Dohnke, E.; Singh, A.; Schaeperkoetter, J.; Stalla, D.; Burress, J.; Jalisatgi, S.; Suppes, G.; Hawthorne, M. F.; Yu, P.; Wexler, C.; Pfeifer, P.

2012-02-01

278

Helical graphitic carbon nitrides with photocatalytic and optical activities.  

PubMed

Graphitic carbon nitride can be imprinted with a twisted hexagonal rod-like morphology by a nanocasting technique using chiral silicon dioxides as templates. The helical nanoarchitectures promote charge separation and mass transfer of carbon nitride semiconductors, enabling it to act as a more efficient photocatalyst for water splitting and CO2 reduction than the pristine carbon nitride polymer. This is to our knowledge a unique example of chiral graphitic carbon nitride that features both left- and right-handed helical nanostructures and exhibits unique optical activity to circularly polarized light at the semiconductor absorption edge as well as photoredox activity for solar-to-chemical conversion. Such helical nanostructured polymeric semiconductors are envisaged to hold great promise for a range of applications that rely on such semiconductor properties as well as chirality for photocatalysis, asymmetric catalysis, chiral recognition, nanotechnology, and chemical sensing. PMID:25220601

Zheng, Yun; Lin, Lihua; Ye, Xiangju; Guo, Fangsong; Wang, Xinchen

2014-10-27

279

Trivalent chromium removal from wastewater using low cost activated carbon derived from agricultural waste material and activated carbon fabric cloth.  

PubMed

An efficient adsorption process is developed for the decontamination of trivalent chromium from tannery effluents. A low cost activated carbon (ATFAC) was prepared from coconut shell fibers (an agricultural waste), characterized and utilized for Cr(III) removal from water/wastewater. A commercially available activated carbon fabric cloth (ACF) was also studied for comparative evaluation. All the equilibrium and kinetic studies were conducted at different temperatures, particle size, pHs, and adsorbent doses in batch mode. The Langmuir and Freundlich isotherm models were applied. The Langmuir model best fit the equilibrium isotherm data. The maximum adsorption capacities of ATFAC and ACF at 25 degrees C are 12.2 and 39.56 mg/g, respectively. Cr(III) adsorption increased with an increase in temperature (10 degrees C: ATFAC--10.97 mg/g, ACF--36.05 mg/g; 40 degrees C: ATFAC--16.10 mg/g, ACF--40.29 mg/g). The kinetic studies were conducted to delineate the effect of temperature, initial adsorbate concentration, particle size of the adsorbent, and solid to liquid ratio. The adsorption of Cr(III) follows the pseudo-second-order rate kinetics. From kinetic studies various rate and thermodynamic parameters such as effective diffusion coefficient, activation energy and entropy of activation were evaluated. The sorption capacity of activated carbon (ATFAC) and activated carbon fabric cloth is comparable to many other adsorbents/carbons/biosorbents utilized for the removal of trivalent chromium from water/wastewater. PMID:16442720

Mohan, Dinesh; Singh, Kunwar P; Singh, Vinod K

2006-07-31

280

Activated Carbon Composites for Air Separation  

SciTech Connect

In continuation of the development of composite materials for air separation based on molecular sieving properties and magnetic fields effects, several molecular sieve materials were tested in a flow system, and the effects of temperature, flow conditions, and magnetic fields were investigated. New carbon materials adsorbents, with and without pre-loaded super-paramagnetic nanoparticles of Fe3O4 were synthesized; all materials were packed in chromatographic type columns which were placed between the poles of a high intensity, water-cooled, magnet (1.5 Tesla). In order to verify the existence of magnetodesorption effect, separation tests were conducted by injecting controlled volumes of air in a flow of inert gas, while the magnetic field was switched on and off. Gas composition downstream the column was analyzed by gas chromatography and by mass spectrometry. Under the conditions employed, the tests confirmed that N2 - O2 separation occurred at various degrees, depending on material's intrinsic properties, temperature and flow rate. The effect of magnetic fields, reported previously for static conditions, was not confirmed in the flow system. The best separation was obtained for zeolite 13X at sub-ambient temperatures. Future directions for the project include evaluation of a combined system, comprising carbon and zeolite molecular sieves, and testing the effect of stronger magnetic fields produced by cryogenic magnets.

Contescu, Cristian I [ORNL; Baker, Frederick S [ORNL; Tsouris, Costas [ORNL; McFarlane, Joanna [ORNL

2008-03-01

281

Binder-free activated carbon\\/carbon nanotube paper electrodes for use in supercapacitors  

Microsoft Academic Search

Novel inexpensive, light, flexible, and even rollup or wearable devices are required for multi-functional portable electronics and developing new versatile and flexible electrode materials as alternatives to the materials used in contemporary batteries and supercapacitors is a key challenge. Here, binder-free activated carbon (AC)\\/carbon nanotube (CNT) paper electrodes for use in advanced supercapacitors have been fabricated based on low-cost, industrial-grade

Guanghui Xu; Chao Zheng; Qiang Zhang; Jiaqi Huang; Mengqiang Zhao; Jingqi Nie; Xianghua Wang; Fei Wei

2011-01-01

282

A General Methodology for Evaluation of Carbon Sequestration Activities and Carbon Credits  

SciTech Connect

A general methodology was developed for evaluation of carbon sequestration technologies. In this document, we provide a method that is quantitative, but is structured to give qualitative comparisons despite changes in detailed method parameters, i.e., it does not matter what ''grade'' a sequestration technology gets but a ''better'' technology should receive a better grade. To meet these objectives, we developed and elaborate on the following concepts: (1) All resources used in a sequestration activity should be reviewed by estimating the amount of greenhouse gas emissions for which they historically are responsible. We have done this by introducing a quantifier we term Full-Cycle Carbon Emissions, which is tied to the resource. (2) The future fate of sequestered carbon should be included in technology evaluations. We have addressed this by introducing a variable called Time-adjusted Value of Carbon Sequestration to weigh potential future releases of carbon, escaping the sequestered form. (3) The Figure of Merit of a sequestration technology should address the entire life-cycle of an activity. The figures of merit we have developed relate the investment made (carbon release during the construction phase) to the life-time sequestration capacity of the activity. To account for carbon flows that occur during different times of an activity we incorporate the Time Value of Carbon Flows. The methodology we have developed can be expanded to include financial, social, and long-term environmental aspects of a sequestration technology implementation. It does not rely on global atmospheric modeling efforts but is consistent with these efforts and could be combined with them.

Klasson, KT

2002-12-23

283

Detoxification of pesticide waste via activated carbon adsorption process.  

PubMed

Concern about environmental protection has increased over the years from a global viewpoint. To date, the percolation of pesticide waste into the groundwater tables and aquifer systems remains an aesthetic issue towards the public health and food chain interference. With the renaissance of activated carbon, there has been a consistent growing interest in this research field. Confirming the assertion, this paper presents a state of art review of pesticide agrochemical practice, its fundamental characteristics, background studies and environmental implications. Moreover, the key advance of activated carbon adsorption, its major challenges together with the future expectation are summarized and discussed. Conclusively, the expanding of activated carbon adsorption represents a plausible and powerful circumstance, leading to the superior improvement of environmental preservation. PMID:19879688

Foo, K Y; Hameed, B H

2010-03-15

284

The environmental applications of activated carbon/zeolite composite materials.  

PubMed

Over the past couple of years, the resurgence of placing an effective and sustainable amendment to combat against the auxiliary industrial entities, remains a highly contested agenda from a global point. With the renaissance of activated carbon, there has been a steadily growing interest in the research field. Recently, the adoption of zeolite composite, a prestigious advanced catalyst which formulates the enhancement of adsorption rate and hydrogen storage capability, has fore fronted to be a new growing branch in the scientific community. Confirming the assertion, this paper presents a state of art review of activated carbon/zeolite composite technology, its fundamental background studies, and environmental implications. Moreover, its major challenges together with the future expectation are summarized and discussed. Conclusively, the expanding of activated carbon/zeolite composite represents a potentially viable and powerful tool, leading to the plausible improvement of environmental preservation. PMID:21035101

Foo, K Y; Hameed, B H

2011-02-17

285

Removal of target odorous molecules on to activated carbon cloths.  

PubMed

Activated carbon materials are adsorbents whose physico-chemical properties are interesting for the treatment of odorous compounds like hydrogen sulfide. Indeed, their structural parameters (pore structure) and surface chemistry (presence of heteroatoms such as oxygen, hydrogen, nitrogen, sulfur, phosphorus) play an important role in H2S removal. The cloth texture of these adsorbents (activated carbon cloths) is particularly adapted for dealing with high flows, often found in the treatment of odor emissions. Thus, this paper first presents the influence of these parameters through adsorption isothermal curves performed on several materials. Secondly, tests in a dynamic system are described. They highlight the low critical thickness of the fabric compared to granular activated carbon. PMID:15484761

Le Leuch, L M; Subrenat, A; Le Cloirec, P

2004-01-01

286

Modified Activated Carbon to be Used in Clinical Applications  

NASA Astrophysics Data System (ADS)

In this study a novel nano composite of hydroxyapatite nano particles impregnated activated carbon (C-HAp), which was synthesized in our own method, was used in iron adsorption studies. The study was conducted in order to investigate the potential of using C-HAp nanocomposite to be used in clinical detoxifications such as acute iron toxicity where the use of Activated carbon (GAC) is not very effective. Adsorption studies were conducted for synthetic solutions of Fe2+, Fe3+ and iron syrup using GAC, C-HAp and neat HAp as adsorbents. According to the results C-HAp nano composite showed improved properties than GAC in adsorbing Fe2+, Fe3+ and also Fe ions in iron syrup solutions. Thus the results of the in-vitro studies of iron adsorption studies indicated the potential of using C-HAp as an alternative to activated carbon in such clinical applications.

Fernando, M. S.; de Silva, W. R. M.; de Silva, K. M. N.

2014-11-01

287

DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS  

SciTech Connect

The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. The largest applications are those which support metals smelting, such as anodes for aluminum smelting and electrodes for arc furnaces. Other carbon products include materials used in creating fuels for the Direct Carbon Fuel Cell, metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to as ''carbon foam'' and carbon fibers. During this reporting period, efforts have focused on the development of carbon electrodes for Direct Carbon Fuel Cells (DCFC), and on carbon foam composites used in ballistic armor, as well as the hydrotreatment of solvents used in the basic solvent extraction process. A major goal is the production of 1500 pounds of binder pitch, corresponding to about 3000 pounds of hydrotreated solvent.

Elliot B. Kennel; Quentin C. Berg; Stephen P. Carpenter; Dady Dadyburjor; Jason C. Hissam; Manoj Katakdaunde; Liviu Magean; Abha Saddawi; Alfred H. Stiller; John W. Zondlo

2006-03-07

288

Benthic Bacterial and Fungal Productivity and Carbon Turnover in a Freshwater Marsh  

PubMed Central

Heterotrophic bacteria and fungi are widely recognized as crucial mediators of carbon, nutrient, and energy flow in ecosystems, yet information on their total annual production in benthic habitats is lacking. To assess the significance of annual microbial production in a structurally complex system, we measured production rates of bacteria and fungi over an annual cycle in four aerobic habitats of a littoral freshwater marsh. Production rates of fungi in plant litter were substantial (0.2 to 2.4 mg C g?1 C) but were clearly outweighed by those of bacteria (2.6 to 18.8 mg C g?1 C) throughout the year. This indicates that bacteria represent the most actively growing microorganisms on marsh plant litter in submerged conditions, a finding that contrasts strikingly with results from both standing dead shoots of marsh plants and submerged plant litter decaying in streams. Concomitant measurements of microbial respiration (1.5 to 15.3 mg C-CO2 g?1 of plant litter C day?1) point to high microbial growth efficiencies on the plant litter, averaging 45.5%. The submerged plant litter layer together with the thin aerobic sediment layer underneath (average depth of 5 mm) contributed the bulk of microbial production per square meter of marsh surface (99%), whereas bacterial production in the marsh water column and epiphytic biofilms was negligible. The magnitude of the combined production in these compartments (?1,490 g C m?2 year?1) highlights the importance of carbon flows through microbial biomass, to the extent that even massive primary productivity of the marsh plants (603 g C m?2 year?1) and subsidiary carbon sources (?330 g C m?2 year?1) were insufficient to meet the microbial carbon demand. These findings suggest that littoral freshwater marshes are genuine hot spots of aerobic microbial carbon transformations, which may act as net organic carbon importers from adjacent systems and, in turn, emit large amounts of CO2 (here, ?870 g C m?2 year?1) into the atmosphere. PMID:16391096

Buesing, Nanna; Gessner, Mark O.

2006-01-01

289

“Papering” Over Space and Place: Product Carbon Footprint Modeling in the Global Paper Industry  

Microsoft Academic Search

We are witnessing an explosion in carbon calculators for estimating the greenhouse gas (GHG) emissions (i.e., carbon footprint) of households, buildings, cities, and processes. Seeking to capitalize on the emergent “green” consumer, corporations are leading the next iteration in carbon footprinting: consumer products. This potentially lucrative low-carbon frontier, however, faces steep challenges due to complexities of scale, largely a function

Joshua P. Newell; Robert O. Vos

2011-01-01

290

Effect of precursor composition on the activation of pitchbased carbon fibers  

Microsoft Academic Search

Pure and silver-containing carbon fibers were prepared from isotropic pitch precursors supplied by Conoco, Inc., and a Korean research team and activated in carbon dioxide to varying degrees of burn-off. The specific activation rates for the carbon fibers were measured as well as the nitrogen adsorption characteristics of the activated carbon fibers. Scanning electron microscopy was used to investigate the

Yulia V Basova; Dan D Edie; Young-Seak Lee; Laura K Reid; Seung-Kon Ryu

2004-01-01

291

Production of carbonate sediments by a unicellular green alga  

USGS Publications Warehouse

This study investigates the ability of the unicellular green alga Natmochloris atoimis to precipitate CaCO3, quantifies mineral precipitation rates, estimates sediment production in a N. atomiis bloom, and discusses the implications of microbial calcification for carbonate sediment deposition. A series of N. atomus cultures, isolated from Lake Reeve, Australia, were incubated at various pH and calcium concentrations to determine environmental parameters for calcification. Rates of calcification were calculated from initial and postincubation alkalinity, pH, and calcium measurements. Replicate experiments and controls consisting of non-calcifying cultures, uninoculated media, and dead cell cultures were performed using environmental culture parameters determined in series cultures. Average calcification rates from replicate experiments were used to predict daily sediment production rates in a small bloom of N. atomus. N. atomus precipitates 0.138 g/L of calcite in approximately 4 h when incubated at pH 8.5, 14.24 mM calcium concentration, 33 ??C, 100 ??E/m2/s light intensity, and a cell population density of 107 cells/mL. Assuming continuous precipitation, this corresponds to a maximum estimated sediment production rate of 1.6 ?? 106 kg of CaCO3, per 12 h day in a single bloom of 3.2 ?? 109 L. Our results suggest that microbial calcification contributes significantly to the carbonate sediment budget.

Yates, K.K.; Robbins, L.L.

1998-01-01

292

Carbon-based Supercapacitors Produced by Activation of Graphene  

SciTech Connect

Supercapacitors, also called ultracapacitors or electrochemical capacitors, store electrical charge on high-surface-area conducting materials. Their widespread use is limited by their low energy storage density and relatively high effective series resistance. Using chemical activation of exfoliated graphite oxide, we synthesized a porous carbon with a Brunauer-Emmett-Teller surface area of up to 3100 square meters per gram, a high electrical conductivity, and a low oxygen and hydrogen content. This sp{sup 2}-bonded carbon has a continuous three-dimensional network of highly curved, atom-thick walls that form primarily 0.6- to 5-nanometer-width pores. Two-electrode supercapacitor cells constructed with this carbon yielded high values of gravimetric capacitance and energy density with organic and ionic liquid electrolytes. The processes used to make this carbon are readily scalable to industrial levels.

Y Zhu; S Murali; M Stoller; K Ganesh; W Cai; P Ferreira; A Pirkle; R Wallace; K Cychosz; et al.

2011-12-31

293

Carbon-Based Supercapacitors Produced by Activation of Graphene  

SciTech Connect

Supercapacitors, also called ultracapacitors or electrochemical capacitors, store electrical charge on high-surface-area conducting materials. Their widespread use is limited by their low energy storage density and relatively high effective series resistance. Using chemical activation of exfoliated graphite oxide, we synthesized a porous carbon with a Brunauer-Emmett-Teller surface area of up to 3100 square meters per gram, a high electrical conductivity, and a low oxygen and hydrogen content. This sp{sup 2}-bonded carbon has a continuous three-dimensional network of highly curved, atom-thick walls that form primarily 0.6- to 5-nanometer-width pores. Two-electrode supercapacitor cells constructed with this carbon yielded high values of gravimetric capacitance and energy density with organic and ionic liquid electrolytes. The processes used to make this carbon are readily scalable to industrial levels.

Zhu, Y.; Su, D.; Murali, S.; Stoller, M.D.; Ganesh, K.J.; Cai, W.; Ferreira, P.J.; Pirkle, A.; Wallace, R.M.; Cychosz, K.A., Thommes, M.; Stach, E.A.; Ruoff, R.S.

2011-06-24

294

Removing lead in drinking water with activated carbon  

SciTech Connect

A point-of-use (POU) granular activated carbon (GAC) fixed bed adsorber (FBA) was evaluated for reduction of soluble and insoluble lead from drinking water. Some of the factors which affect lead removal by GAC were evaluated, such as carbon type, solution pH, and a limited amount of work on competitive interactions. The design criteria for lead reduction by a POU device are also addressed. Minicolumns were used to evaluate the capacity of carbon for lead under a variety of conditions. The importance of surface chemistry of the carbon and the relationship with the pH of the water for lead reduction was demonstrated. Results indicate that a properly designed POU-GAC-FBA can reduce lead in drinking water to below the EPA action level of 15 ppb while being tested under a variety of conditions as specified under the National Sanitation Foundation (NSF) International Standard 53 test protocol. 37 refs., 9 figs., 1 tab.

Taylor, R.M.; Kuennen, R.W. (Amway Corp., Ada, MI (United States))

1994-02-01

295

Implementing a Terrestrial Carbon Flux Model in Preparation for the Soil Moisture Active Passive Mission  

NASA Astrophysics Data System (ADS)

The NASA Soil Moisture Active Passive (SMAP) mission has a projected launch in 2014 and will provide global mapping of surface soil moisture and landscape freeze/thaw (F/T) status using L-band (1.26 GHz) active and passive microwave remote sensing. Primary science objectives for SMAP include reducing uncertainty regarding terrestrial carbon (CO2) uptake and release and the purported missing carbon sink on land. An operational level 4 carbon (L4_C) product is planned under SMAP to quantify surface soil organic carbon (SOC) stocks, soil moisture and temperature controls for heterotrophic respiration and the net ecosystem exchange of CO2 (NEE) using model assimilation based soil moisture, temperature and F/T inputs from SMAP retrievals with ancillary information on global land cover and vegetation productivity (GPP). We conducted an initial global implementation and evaluation of the SMAP L4_C algorithms using MODIS (MOD17) GPP inputs and MERRA reanalysis based daily surface air temperature and soil moisture fields. The resulting model simulations are generally consistent with the distribution and magnitude of SOC stocks available from global soil inventories, while estimated carbon fluxes also correspond (R2 > 0.6; RMSE < 1.5 g C/m2/day) with CO2 flux measurements from the global tower network (FLUXNET). A model uncertainty analysis indicates an anticipated L4_C product accuracy for NEE within 30 g C / m2 / yr or 1.6 g C / m2 / day, and similar to accuracies attained from tower eddy covariance measurements. The resulting NEE calculations are used as a land surface constraint within an atmospheric transport model assimilation framework (CarbonTracker) to quantify terrestrial source-sink activity for atmospheric CO2. Portions of this work were conducted at the University of Montana and at the Jet Propulsion Laboratory, California Institute of Technology under contract to the National Aeronautics and Space Administration.

Kimball, J. S.; Yi, Y.; Jones, L. A.; Nemani, R. R.; Reichle, R. H.; McDonald, K. C.

2010-12-01

296

Carbon-carbon bond activation of cyclobutenones enabled by the addition of chiral organocatalyst to ketone.  

PubMed

The activation of carbon-carbon (C-C) bonds is an effective strategy in building functional molecules. The C-C bond activation is typically accomplished via metal catalysis, with which high levels of enantioselectivity are difficult to achieve due to high reactivity of metal catalysts and the metal-bound intermediates. It remains largely unexplored to use organocatalysis for C-C bond activation. Here we describe an organocatalytic activation of C-C bonds through the addition of an NHC to a ketone moiety that initiates a C-C single bond cleavage as a key step to generate an NHC-bound intermediate for chemo- and stereo-selective reactions. This reaction constitutes an asymmetric functionalization of cyclobutenones using organocatalysts via a C-C bond activation process. Structurally diverse and multicyclic compounds could be obtained with high optical purities via an atom and redox economic process. PMID:25652912

Li, Bao-Sheng; Wang, Yuhuang; Jin, Zhichao; Zheng, Pengcheng; Ganguly, Rakesh; Chi, Yonggui Robin

2015-01-01

297

Carbon Beam Radio-Therapy and Research Activities at HIMAC  

SciTech Connect

Radio-therapy with carbon ion beam has been carried out since 1994 at HIMAC (Heavy Ion Medical Accelerator in Chiba) in NIRS (National Institute of Radiological Sciences). Now, many types of tumors can be treated with carbon beam with excellent local controls of the tumors. Stimulated with good clinical results, requirement of the dedicated compact facility for carbon beam radio-therapy is increased. To realize this requirement, design study of the facility and the R and D's of the key components in this design are promoted by NIRS. According successful results of these activities, the dedicated compact facility will be realized in Gunma University. In this facility, the established irradiation method is expected to use, which is passive irradiation method with wobbler magnets and ridge filter. In this presentation, above R and D's will be presented together with clinical results and basic research activities at HIMAC.

Kanazawa, Mitsutaka [NIRS, Anagawa4-9-1, Inage-ku, Chiba, 263-8335 (Japan)

2007-05-22

298

76 FR 77775 - Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea: Extension of Time...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Trade Administration [C-580-818] Corrosion-Resistant Carbon Steel Flat Products...review of the countervailing duty order on corrosion-resistant carbon steel flat products...2009, through December 31, 2009. See Corrosion-Resistant Carbon Steel Flat...

2011-12-14

299

78 FR 59651 - Certain Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Notice of...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-580-816] Certain Corrosion-Resistant Carbon Steel Flat Products...the antidumping duty order on certain corrosion-resistant carbon steel flat products...2\\ See Certain Corrosion-Resistant Carbon Steel Flat...

2013-09-27

300

78 FR 19210 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Final Results of...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Trade Administration [C-580-818] Corrosion-Resistant Carbon Steel Flat Products...countervailing duty (CVD) order on corrosion-resistant carbon steel flat products...1\\ See Corrosion-Resistant Carbon Steel Flat...

2013-03-29

301

78 FR 59652 - Certain Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Notice of...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-580-816] Certain Corrosion-Resistant Carbon Steel Flat Products...the antidumping duty order on certain corrosion-resistant carbon steel flat products...2\\ See Certain Corrosion-Resistant Carbon Steel Flat...

2013-09-27

302

Preparation and characterization of activated carbon from palm shell by chemical activation with K2CO3.  

PubMed

Palm shell was used to prepare activated carbon using potassium carbonate (K2CO3) as activating agent. The influence of carbonization temperatures (600-1000 degrees C) and impregnation ratios (0.5-2.0) of the prepared activated carbon on the pore development and yield were investigated. Results showed that in all cases, increasing the carbonization temperature and impregnation ratio, the yield decreased, while the adsorption of CO2 increased, progressively. Specific surface area of activated carbon was maximum about 1170 m2/g at 800 degrees C with activation duration of 2 h and at an impregnation ratio of 1.0. PMID:16380249

Adinata, Donni; Wan Daud, Wan Mohd Ashri; Aroua, Mohd Kheireddine

2007-01-01

303

Thermal behaviour of arsenic trioxide adsorbed on activated carbon.  

PubMed

The thermal stability and desorption of arsenic trioxide (As(2)O(3)) adsorbed on activated carbon (AC) was investigated as this phenomenon is expected to influence the arsenic release during low temperature pyrolysis of chromated copper arsenate (CCA) wood waste. Firstly, a thermogravimetric (TG) experiment with arsenolite, an allotropic form of As(2)O(3), was performed. The sample starts to sublime at temperatures lower than 200 degrees C with a sublimation peak temperature of 271 degrees C. Subsequently, TG experiments with samples of As(2)O(3) adsorbed on AC revealed that only very little (max. 6+/-3 wt%) As(2)O(3) was volatilized at temperatures below 280 degrees C, while still 41.6 (+/-5)wt% of the original arsenic concentration was retained at 440 degrees C and 28.5 (+/-3)wt% at 600 degrees C. The major arsenic volatilization occurred between 300 degrees C and 500 degrees C. The kinetic parameters of desorption, activation energy of desorption (E(d)) and pre-exponential factor (A), were determined by fitting an Arrhenius model to the experimental data, resulting in E(d)=69 kJ/mol, A=1.21 x 10(4)s(-1). It can be concluded that the adsorption of As(2)O(3) on AC can contribute to the thermal stabilisation of As(2)O(3). Consequently, during low temperature pyrolysis of CCA wood arsenic release may be prevented by adsorption of As(2)O(3) on the coal-type product formed during the thermal decomposition of the wood. PMID:19136209

Cuypers, Frederic; De Dobbelaere, Christopher; Hardy, An; Van Bael, Marlies K; Helsen, Lieve

2009-07-30

304

Asphalt-derived high surface area activated porous carbons for carbon dioxide capture.  

PubMed

Research activity toward the development of new sorbents for carbon dioxide (CO2) capture have been increasing quickly. Despite the variety of existing materials with high surface areas and high CO2 uptake performances, the cost of the materials remains a dominant factor in slowing their industrial applications. Here we report preparation and CO2 uptake performance of microporous carbon materials synthesized from asphalt, a very inexpensive carbon source. Carbonization of asphalt with potassium hydroxide (KOH) at high temperatures (>600 °C) yields porous carbon materials (A-PC) with high surface areas of up to 2780 m(2) g(-1) and high CO2 uptake performance of 21 mmol g(-1) or 93 wt % at 30 bar and 25 °C. Furthermore, nitrogen doping and reduction with hydrogen yields active N-doped materials (A-NPC and A-rNPC) containing up to 9.3% nitrogen, making them nucleophilic porous carbons with further increase in the Brunauer-Emmett-Teller (BET) surface areas up to 2860 m(2) g(-1) for A-NPC and CO2 uptake to 26 mmol g(-1) or 114 wt % at 30 bar and 25 °C for A-rNPC. This is the highest reported CO2 uptake among the family of the activated porous carbonaceous materials. Thus, the porous carbon materials from asphalt have excellent properties for reversibly capturing CO2 at the well-head during the extraction of natural gas, a naturally occurring high pressure source of CO2. Through a pressure swing sorption process, when the asphalt-derived material is returned to 1 bar, the CO2 is released, thereby rendering a reversible capture medium that is highly efficient yet very inexpensive. PMID:25531980

Jalilov, Almaz S; Ruan, Gedeng; Hwang, Chih-Chau; Schipper, Desmond E; Tour, Josiah J; Li, Yilun; Fei, Huilong; Samuel, Errol L G; Tour, James M

2015-01-21

305

Activated carbon fiber composites for ammonia, methane and hydrogen adsorption  

Microsoft Academic Search

Complex compound material (activated carbon fiber, saturated with salts, or metal hydrides) was developed as an efficient gas (ammonia, methane, hydrogen) adsorbent for new gas storage and transportation system application. To enhance the performance and thermodynamic efficiency of the gas storage vessels a heat pipe thermal control system was suggested. Copyright , Manchester University Press.

L. L. Vasiliev; L. E. Kanonchik; A. G. Kulakov; D. A. Mishkinis; A. M. Safonova; N. K. Luneva

2006-01-01

306

Acoustical Evaluation of Carbonized and Activated Cotton Nonwovens  

Technology Transfer Automated Retrieval System (TEKTRAN)

An activated carbon fiber nonwoven (ACF) was manufactured from cotton nonowoven fabric. For the ACF acoustical application, a nonwoven composite of ACF with cotton nonwoven as a base layer was developed. Also produced were the composites of the cotton nonwoven base layer with a layer of glass fiber ...

307

EVALUATION OF PROCEDURES TO DESORB BACTERIA FROM GRANULAR ACTIVATED CARBON  

EPA Science Inventory

Physical, chemical, and enzymatic means for the desorption of micro-organisms from granular activated carbon (GAC) were assessed. Data indicate that homogenization at 16,000 rpm for 3 min at 4 C with a mixture of peptone (0.01%), Zwittergent 3-12 ( times 10 to the minus 6 power M...

308

Invertebrate community characteristics in biologically active carbon filter  

Microsoft Academic Search

Biologically active carbon (BAC) system was set up in a water plant of South China during January to December 2007, to study the invertebrate community characteristics of BAC filter. Thirty-seven invertebrate species were found, of which 28 belonging to rotifers. Filter operation could lead to an output of invertebrates in high abundances with the filtrate, and the maximum density could

Xiaowei Li; Yufeng Yang; Lijun Liu; Jinsong Zhang; Qing Wang

2010-01-01

309

POULTRY MANURE-BASED ACTIVATED CARBONS AS MERCURY ADSORBENTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Increased emphasis on reduction of mercury emissions from coal fired electric power plans have resulted in environmental regulations that may in the future require application of activated carbons as mercury sorbents. The sorbents could be injected into the flue gas stream where is adsorbs the merc...

310

Decolorization / deodorization of zein via activated carbons and molecular sieves  

Technology Transfer Automated Retrieval System (TEKTRAN)

The objective is to evaluate a series of granular media consisting of activated carbons and molecular sieves in a batch process for the purpose of clarifying and removal of color and odor components from yellow zein dispersed in an aqueous alcohol medium. The major contributors of yellow zein is du...

311

MICROBIOLOGICAL ALTERATIONS IN DISTRIBUTED WATER TREATED WITH GRANULAR ACTIVATED CARBON  

EPA Science Inventory

The goal of this project was to examine the effect of granular activated carbon (GAC) treatment on the microbiological characteristics of potable water in distribution systems. Data was collected from both field and pilot plant studies. Field monitoring studies from two water tre...

312

SUPERCRITICAL FLUID REGENERATION OF ACTIVATED CARBON FOR ADSORPTION OF PESTICIDES  

EPA Science Inventory

The report describes the development of a new process for regenerating activated carbon, using supercritical CO2 as a desorbent. Supercritical CO2 in the range of 30-250 C and at pressures > 80 atm. is a good solvent for organics. A series of pesticides was tested for treatment b...

313

Characterizing o- and p-nitrophenols adsorption onto innovative activated carbon prepared from date pits.  

PubMed

The production and performance of activated carbon prepared from date pits was investigated. Date pits are an abundant local waste product in many countries; converting them to a commercial product would increase the sustainability of this fruit crop. The date pit activated carbon was shown to have similar characteristics of pore size and surface functional groups as other commercial carbons. Batch experiments were conducted with o- and p-nitrophenol to evaluate the performance of this carbon. Results were analyzed according to Langmuir, Freundlich, and Dubinin-Radushkevich adsorption isotherms. The adsorption capacity of o-nitrophenol was 142.9 mg/g while that of p-nitrophenol was 108.7 mg/g. The adsorption process was physical in nature. The position of the -NO(2) group in the benzene ring has a considerable effect on the adsorption capacity and rate of uptake. The kinetic results showed that a pseudo second-order model appropriately describes the experimental data. The analysis of kinetic data revealed that the mechanism of adsorption is complex with both liquid film diffusion and intraparticle diffusion contributing to adsorption of both adsorbates. PMID:24434965

Altaher, Hossam; Dietrich, Andrea M

2014-01-01

314

DEVELOPMENT OF CARBON PRODUCTS FROM LOW-RANK COALS  

SciTech Connect

The goal of this project is to facilitate the production of carbon fibers from low-rank coal (LRC) tars. To this end, the effect of demineralization on the tar yields and composition was investigated using high-sodium and high-calcium lignites commonly mined in North Dakota. These coals were demineralized by ion exchange with ammonium acetate and by cation dissolution with nitric acid. Two types of thermal processing were investigated for obtaining suitable precursors for pitch and fiber production. Initially, tars were produced by simple pyrolysis of the set of samples at 650 C. Since these experiments produced little usable material from any of the samples, the coals were heated at moderate temperatures (380 and 400 C) in tetralin solvent to form and extract the plastic material (metaplast) that forms at these temperatures.

Edwin S. Olson

2001-07-01

315

Climate change, carbon dioxide, and global crop production: Adaptation to uncertainty  

Technology Transfer Automated Retrieval System (TEKTRAN)

Documented and projected changes in atmospheric carbon dioxide are likely to alter agricultural productivity in two ways: directly, by supplying additional carbon for photosynthesis and growth, and indirectly by altering climate, specifically surface temperatures and precipitation. In this overview...

316

Intravascular Neutrophil Activation Due to Carbon Monoxide Poisoning  

Microsoft Academic Search

Rationale: We hypothesized that platelet-neutrophil interactions occur as a result of acute carbon monoxide (CO) poisoning, and subsequent neutrophil activation triggers events that cause neuro- logic sequelae. Objectives: To identify platelet-neutrophil interactions and neutro- phil activation in patients and in animal models, and to establish the association between these intravascular events and changes linked to CO-mediated neurologic sequelae in an

Stephen R. Thom; Veena M. Bhopale; Shih-Tsung Han; James M. Clark; Kevin R. Hardy

317

Removal of volatile organic compound by activated carbon fiber  

Microsoft Academic Search

Experiments were carried out to study adsorption\\/desorption of volatile organic compound (VOC) on the activated carbon fiber (ACF) under dynamic conditions. The primary objective was to experimentally demonstrate the suitability of ACF in effectively adsorbing VOCs from inert gaseous stream under varying operating conditions, and compare its performance vis-à-vis that of the other commercially available adsorbents, such as granular activated

Debasish Das; Vivekanand Gaur; Nishith Verma

2004-01-01

318

CO sub 2 inhibition of leaf carbonic anhydrase activity in certain assay buffers  

SciTech Connect

Apparent carbonic anhydrase activity in some leaf extracts (measured by the conventional procedure following the rate of H{sup +} production as CO{sub 2} is hydrated to give HCO{sub 3}{sup {minus}} + H{sup +}) varied widely in different assay buffers. With this assay system activity is measured at 0{degree}C with a CO{sub 2} concentration of 25 mM. Using Hepes or phosphate buffer, activity in leaf extracts from maize and wheat was only about 5% of that observed with the enzyme from dicotyledonous plants while the erythrocyte enzyme was unaffected by varying the assay buffer. By contrast, when carbonic anhydrase was measured by the mass spectrometric procedure activity of these various enzymes was the same in a variety of assay buffers; this assay is conducted with a very low concentration of inorganic carbonic. The variations in activity observed with the former assay system were shown to be due to inhibition of enzyme by higher CO{sub 2} concentrations. Some buffers apparently modify the structure of certain carbonic anhydrases in such a way as to make them less sensitive or insensitive to the inhibitory effect of CO{sub 2}.

Hatch, M.D. (CSIRO, Canberra (Australia))

1990-05-01

319

Ammonia-Activated Mesoporous Carbon Membranes for Gas Separations  

SciTech Connect

Porous carbon membranes, which generally show improved chemical and thermal stability compared to polymer membranes, have been used in gas separations for many years. In this work, we show that the post-synthesis ammonia treatment of porous carbon at elevated temperature can improve the permeance and selectivity of these membranes for the separation of carbon dioxide and hydrocarbons from permanent gases. Hierarchically structured porous carbon membranes were exposed to ammonia gas at temperatures ranging from 850 C to 950 C for up to 10 min and the N{sub 2}, CO{sub 2}, and C{sub 3}H{sub 6} permeances were measured for these different membranes. Higher treatment temperatures and longer exposure times resulted in higher gas permeance values. In addition, CO{sub 2}/N{sub 2} and C{sub 3}H{sub 6}/N{sub 2} selectivities increased by a factor of 2 as the treatment temperature and time increased up to a temperature and time of 900 C, 10 min. Higher temperatures showed increased permeance but decreased selectivity indicating excess pore activation. Nitrogen adsorption measurements show that the ammonia treatment increased the porosity of the membrane while elemental analysis revealed the presence of nitrogen-containing surface functionalities in the treated carbon membranes. Thus, ammonia treatment at high temperature provides a controlled method to introduce both added microporosity and surface functionality to enhance gas separations performance of porous carbon membranes.

Mahurin, Shannon Mark [ORNL; Lee, Jeseung [ORNL; Wang, Xiqing [ORNL; Dai, Sheng [ORNL

2011-01-01

320

PERFORMANCE OF ACTIVATED SLUDGE-POWDERED ACTIVATED CARBON-WET AIR REGENERATION SYSTEMS  

EPA Science Inventory

The investigation summarized in the report was undertaken to evaluate the performance of powdered activated carbon (PAC) technology used in conjunction with wet air regeneration (WAR) at municipal wastewater treatment plants. Excessive ash concentrations accumulated in the mixed ...

321

PERFORMANCE OF ACTIVATED SLUDGE-POWDERED ACTIVATED CARBON-WET AIR REGENERATION SYSTEMS  

EPA Science Inventory

The investigation summarized in this report was undertaken to evaluate the performance of powdered activated carbon (PAC) technology used in conjuntion with wet air regeneration (WAR) at municipal wastewater treatment plants. xcessive ash concentrations accumulated in the mixed l...

322

Effect of dissolved carbon dioxide on penicillin fermentations: mycelial growth and penicillin production. [Penicillium chrysogenum  

SciTech Connect

The effect of dissolved carbon dioxide on the specific growth rate and the penicillin production rate of Penicillium chrysogenum was examined experimentally. The dissolved carbon dioxide was found to inhibit the specific growth rate and the penicillin production rate when the aerated submerged penicillin fermentation was exposed to influent gases of 12.6 and 20% carbon dioxide, respectively. Upon exposure to influent gases of 3 and 5% carbon dioxide, no pronounced metabolic inhibition was noted.

Ho, C.S.; Smith, M.D.

1986-01-01

323

Investigating the performance of CoxOy/activated carbon catalysts for ethyl acetate catalytic combustion  

NASA Astrophysics Data System (ADS)

The catalytic properties of Co-supported activated carbon (AC) catalysts for ethyl acetate catalytic elimination in air were investigated. Results showed that air atmosphere promoted the generation of high-valence state cobalt oxides, and promote the production of reactive oxygen species (ROS) in the Co3O4/AC catalyst. ROS crucially functioned in improving the catalytic activity of Co3O4/AC catalysts. Therefore, CoACA catalyst prepared in air exhibited higher catalytic activity than CoACN catalyst prepared in nitrogen, and CoACA catalyst led to high ethyl acetate conversion (>93%) and stability at a low reaction temperature (210 °C).

Xie, Hongmei; Zhao, Xiaoping; Zhou, Guilin; He, Xiaoling; Lan, Hai; Jiang, Zongxuan

2015-01-01

324

Influences of pyrolysis condition and acid treatment on properties of durian peel-based activated carbon.  

PubMed

Durian peel was used for the synthesis of activated carbon used for adsorption of Basic Green 4 dye. Activated carbon was synthesised under either nitrogen (N(2)) atmospheric or vacuum pyrolysis, followed by carbon dioxide (CO(2)) activation. The synthesised activated carbon then was treated with hydrochloric acid (HCl) solution. The results showed that activated carbon synthesised under vacuum pyrolysis exhibited better properties and adsorption capacities than that under nitrogen atmospheric pyrolysis. The HCl treatment improved properties and adsorption capacities of activated carbons. Pseudo-second-order kinetics well described the adsorption of Basic Green 4. PMID:19695874

Nuithitikul, Kamchai; Srikhun, Sarawut; Hirunpraditkoon, Samorn

2010-01-01

325

Carbon footprint of Canadian dairy products: calculations and issues.  

PubMed

The Canadian dairy sector is a major industry with about 1 million cows. This industry emits about 20% of the total greenhouse gas (GHG) emissions from the main livestock sectors (beef, dairy, swine, and poultry). In 2006, the Canadian dairy herd produced about 7.7 Mt of raw milk, resulting in about 4.4 Mt of dairy products (notably 64% fluid milk and 12% cheese). An integrated cradle-to-gate model (field to processing plant) has been developed to estimate the carbon footprint (CF) of 11 Canadian dairy products. The on-farm part of the model is the Unified Livestock Industry and Crop Emissions Estimation System (ULICEES). It considers all GHG emissions associated with livestock production but, for this study, it was run for the dairy sector specifically. Off-farm GHG emissions were estimated using the Canadian Food Carbon Footprint calculator, (cafoo)(2)-milk. It considers GHG emissions from the farm gate to the exit gate of the processing plants. The CF of the raw milk has been found lower in western provinces [0.93 kg of CO2 equivalents (CO2e)/L of milk] than in eastern provinces (1.12 kg of CO2e/L of milk) because of differences in climate conditions and dairy herd management. Most of the CF estimates of dairy products ranged between 1 and 3 kg of CO2e/kg of product. Three products were, however, significantly higher: cheese (5.3 kg of CO2e/kg), butter (7.3 kg of CO2e/kg), and milk powder (10.1 kg of CO2e/kg). The CF results depend on the milk volume needed, the co-product allocation process (based on milk solids content), and the amount of energy used to manufacture each product. The GHG emissions per kilogram of protein ranged from 13 to 40 kg of CO2e. Two products had higher values: cream and sour cream, at 83 and 78 kg of CO2e/kg, respectively. Finally, the highest CF value was for butter, at about 730 kg of CO2e/kg. This extremely high value is due to the fact that the intensity indicator per kilogram of product is high and that butter is almost exclusively fat. Protein content is often used to compare the CF of products; however, this study demonstrates that the use of a common food component is not suitable as a comparison unit in some cases. Functionality has to be considered too, but it might be insufficient for food product labeling because different reporting units (adapted to a specific food product) will be used, and the resulting confusion could lead consumers to lose confidence in such labeling. Therefore, simple units might not be ideal and a more comprehensive approach will likely have to be developed. PMID:23831091

Vergé, X P C; Maxime, D; Dyer, J A; Desjardins, R L; Arcand, Y; Vanderzaag, A

2013-09-01

326

Evaluation of a pilot scale dual media biological activated carbon process for drinking water  

Microsoft Academic Search

This study was carried out to optimize a dual media BAC (biological activated carbon) process for DOC removal and DBPs (disinfection\\u000a by-products) control. Pilot scale tests were coducted at the Tukdo water treatment plant in Seoul, Korea. The dual media BAC\\u000a process is highly efficient in the removal of DOC and THMFP, and is more capable of sustaining microorganisms than

Young-Song Ko; Yoon-Jin Lee; Sang-ho Nam

2007-01-01

327

High specific activity carbon-11 labelling of benzodiazepines: Diazepam and flunitrazepam  

Microsoft Academic Search

In order to study “in vivo” the brain specific receptor sites of benzodiazepines, a method for carbon-11 labelling of diazepam\\u000a and flunitrazepam without irradiation risk to personnel is described. 70 mCi (max. 140 mCi) of injectable labelled product,\\u000a chemically and radiochemically pure, are obtained in 45 minutes with a specific activity of 810 Ci\\/m mole.

M. Maziere; J.-M. Godot; G. Berger; Ch. Prenant; D. Comar

1980-01-01

328

Miocene Global Carbon Isotope Shifts and Marine Biological Productivity.  

NASA Astrophysics Data System (ADS)

The Miocene contains two major global carbon isotope shifts: a negative shift during the late Miocene (~8-6 Ma) and a positive shift during the mid-Miocene (16-14 Ma). We aim at deciphering possible changes in marine biological export productivity during these shifts by calculating paleoproductivity in gC/cm*ky from benthic foraminiferal numbers and accumulation rates at a number of sites spanning the world oceans. Our previous work has illustrated that the onset of the late Miocene negative d 13C shift, which has been attributed to enhanced erosion of terrestrial biomass and expansion of C4 plants, is also accompanied by an increase in marine export productivity from lower than present day values up to 2-3 times modern values at six sites (982, 1088, 721, 846, 1146, 1172; Diester-Haass et al, in press; Diester-Haass et al., in preparation). The Mid-Miocene 'Monterey Event', on the other hand, has been attributed to sequestration of organic material in circum-Pacific basins (Vincent and Berger, 1985) or wide spread deposition of brown coal and drowning of carbonate platforms (Föllmi et al., 2005) . For this particular time interval, our initial results from Site 608 (Atlantic Ocean) reveal relatively constant paleoproductivity values similar to modern ones ( about 10 gC/cm*ky) until 16.5 Ma, after which time paleoproductivity begins to increase until the end of our record at 11 Ma. Superimposed on the trend of generally increasing productivity, there are a number of productivity minima spaced roughly 0.5 million years apart. The long term trend in the paleoproductivity finds some similarities in the global composite benthic foraminiferal d 13C record as both proxies show an overall increase until ~14 Ma. Thereafter, however, paleoproductivity continues to increase while d 13C values decrease marking the end of the Monterey excursion. Stable isotope analyses from these same intervals will show to what extend the smaller scale fluctuations in paleoproductivity can be related to changes in the d13C of the oceanic reservoir or regional water masses. Diester-Haass, L., Billups, K., Emeis, K-C., 2005, Paleoceanography, in press. Vincent, E. and Berger, W., 1985, In: The carbon cycle and atmospheric CO2: Natural variations Archaen to present, edited by Sunquist, E.T. and Broecker, W.S., Am.Geophys. Union Monogr. 32,455-468 Föllmi, K.B. et al., 2005, Geol.Soc.Am.Bull., 117/5, 589-619.

Diester-Haass, L.; Billups, K.

2005-12-01

329

Waste polyvinylchloride derived pitch as a precursor to develop carbon fibers and activated carbon fibers.  

PubMed

Polyvinylchloride (PVC) was successfully recycled through the solvent extraction from waste pipe with an extraction yield of ca. 86%. The extracted PVC was pyrolyzed by a two-stage process (260 and 410 degrees C) to obtain free-chlorine PVC based pitch through an effective removal of chlorine from PVC during the heat-treatment. As-prepared pitch (softening point: 220 degrees C) was spun, stabilized, carbonized into carbon fibers (CFs), and further activated into activated carbon fibers (ACFs) in a flow of CO2. As-prepared CFs show comparable mechanical properties to commercial CFs, whose maximum tensile strength and modulus are 862 MPa and 62 GPa, respectively. The resultant ACFs exhibit a high surface area of 1200 m2/g, narrow pore size distribution and a low oxygen content of 3%. The study provides an effective insight to recycle PVC from waste PVC and develop a carbon precursor for high performance carbon materials such as CFs and ACFs. PMID:17157493

Qiao, W M; Yoon, S H; Mochida, I; Yang, J H

2007-01-01

330

Characteristics of activated carbon prepared from pistachio-nut shell by zinc chloride activation under nitrogen and vacuum conditions  

Microsoft Academic Search

Activated carbons with well-developed pore structures were prepared from pistachio-nut shells by chemical activation using zinc chloride under both nitrogen atmosphere and vacuum conditions. The effects of preparation parameters on the carbon pore structure were studied in order to optimize these parameters. It was found that under vacuum conditions, the characteristics of the activated carbons produced are better than those

Aik Chong Lua; Ting Yang

2005-01-01

331

Activated carbons obtained from sewage sludge by chemical activation: gas-phase environmental applications.  

PubMed

The objective of this study was to evaluate the adsorption capacity for toluene and SO2 of low cost activated carbons prepared from sewage sludge by chemical activation at different impregnation ratios. Samples were characterized by proximate and ultimate analyses, thermogravimetry, infrared spectroscopy and N2 adsorption. Because of the low carbon content of the raw material, the development of porosity in the activated carbons was mainly of a mesoporous nature, with surface areas lower than 300 m(2)/g. The study of gas-phase applications for activated carbons from sewage sludge was carried out using both an organic and an inorganic compound in order to screen for possible applications. Toluene adsorption capacity at saturation was around 280 mg/g, which is a good level of performance given the high ash content of the activated carbons. However, dynamic experiments at low toluene concentration presented diffusion problems resulting from low porosity development. SO2 adsorption capacity is associated with average micropore size, which can be controlled by the impregnation ratio used to prepare the activated carbons. PMID:24747937

Boualem, T; Debab, A; Martínez de Yuso, A; Izquierdo, M T

2014-07-01

332

The Effect of Isolated Mixed Microbial Cultures on the Reduction of Carbon Dioxide Into Methane During Biogas Production  

Microsoft Academic Search

This work describes the effect of mixed culture on reduction of carbon dioxide into methane during biogas production. Various mixed cultures, such as IMS, IWT, IRP, and IMW1, were isolated from marshy soil, decaying woody tissue, rice paddy soil, and mixture of activated sludge from municipal waste treatment plant along with a cow dung-based biogas plant (IMW1), respectively, and separately

R. Singh; S. K. Mandal

2011-01-01

333

The Carbon Balance of Bioenergy Production in Wisconsin Keith R. Cronin  

E-print Network

The Carbon Balance of Bioenergy Production in Wisconsin By Keith R. Cronin A thesis submitted-MADISON Abstract The Carbon Balance of Bioenergy Production in Wisconsin Keith R. Cronin Advisor: Associate Professor Tracey Holloway Gaylord Nelson Institute for Environmental Studies Bioenergy production could

Wisconsin at Madison, University of

334

Estimates of carbon stored in harvested wood products from United States Forest  

E-print Network

Estimates of carbon stored in harvested wood products from United States Forest Service Southern of the harvested carbon is stored in wood products, often for many decades. The United States Forest Service (USFS with the Economics and Statistics Research unit of the United States Forest Service, Forest Products Laboratory

335

Estimates of carbon stored in harvested wood products from United States Forest Service  

E-print Network

Estimates of carbon stored in harvested wood products from United States Forest Service Eastern of the harvested carbon is stored in wood products, often for many decades. The United States Forest Service (USFS Forest Service, Forest Products Laboratory, Madison, WI. Sean Healey is a Research Ecologist

336

An alternate carbon source for enhancing production of polysaccharides by Silene vulgaris callus  

Microsoft Academic Search

Pectin termed silenan and acidic arabinogalactan were isolated as cell-wall polysaccharides of Silene vulgaris callus in the presence of various carbon sources as components of the media. The maximum yields, productivity per litre of medium and production per day of acidic arabinogalactan, were achieved using glucose or galactose as the carbon source. Sucrose was found to increase the production of

Elena A Günter; Yury S Ovodov

2002-01-01

337

Issues on the production and electrochemical separation of oxygen from carbon dioxide  

NASA Technical Reports Server (NTRS)

There is considerable interest in in-situ propellant manufacturing on the moon and Mars. One of the concepts of oxygen production that is being actively pursued is the processing of atmospheric carbon dioxide on Mars to produce oxygen by means of thermal decomposition and electrochemical separation. The key component of such a production facility is the electrochemical separation cell that filters out the oxygen from the gas mixture of carbon dioxide, carbon monoxide, and oxygen. Efficient design of the separation cell and the selection of electrolyte and electrode materials of superior performance for the cell would translate to significant reduction in the power requirement and the mass of the production facility. The objective is to develop the technology required to produce the cells in-house and test various electrolyte and electrode materials systematically until the optimal combination is found. An effective technique was developed for the fabrication of disk shaped cells. Zirconia and Ceria cells were made in-house. Complete modules of the electrochemical cell and housings were designed, fabricated, and tested.

Kaloupis, P.; Sridhar, K. R.

1991-01-01

338

Formation of continuous activated carbon fibers for barrier fabrics  

NASA Astrophysics Data System (ADS)

Commercial protective suits made of active carbon granules or nonwoven fabrics are heavy, have low moisture vapor transport rate, and are uncomfortable. Inherent problems due to construction of barrier fabrics lead to severe heat stress when worn for even short time in warm environments. One proposed method to eliminate these problems is to facilitate the construction of a fabric made of continuous activated carbon fibers (CACF). This study is directed toward investigating the possibility of developing CAFC from two precursors: aramid and fibrillated PAN fiber. It was shown in this study that Kevlar-29 fibers could be quickly carbonized and activated to CACF with high adsorptivity and relatively low weight loss. CACF with high surface area (>500 msp2/g) and reasonable tenacity (?1g/denier) were successfully prepared from Kevlar fibers through a three-step process: pretreatment, carbonization, and activation. X-ray diffraction, Fourier Transform Infrared Spectroscopy (FTIR), and thermal analysis were conducted to understand the evolution of physical and chemical properties during pretreatment. The influence of temperature, heating rate, and pyrolysis environment on the thermal behavior was determined by DSC and TGA/DTA and used as an indicator for optimizing the pyrolysis conditions. Surface analysis by nitrogen isotherms indicated that the resultant fibers had micropores and mesopores on the surface of CACF. This was also inferred by studies on the surface morphology through Scanning Electron Microscopy (SEM) and Scanning Tunneling Microscopy (STM). An investigation of the surface chemical structure by X-ray photoelectron spectroscopy (XPS) before and after activation and elemental analysis confirmed that adsorption of Kevlar based CACF mainly arises due to the physisorption instead of chemisorption. A multistep stabilization along with carbonization and activation was used to prepare active carbon fiber from fibrillated PAN fiber. The resultant fiber retained its fibrillar structure and provided a very high surface area, up to 1400 msp2/g, but was brittle. The characterization of the thermal behavior, mechanical properties, and surface structure of the pyrolyzed fiber at each processing step was also carried out by using various techniques, such as DSC and TGA, Instron, and SEM. These studies provide directions for preparation of CACF from novel precursors.

Liang, Ying

1997-08-01

339

Production and screening of carbon products precursors from coal: Carbon Products Consortium. Quarterly technical progress report and key personnel staffing report number 4, October 1, 1995--December 31, 1995  

SciTech Connect

This quarterly report covers activities during the period from October 1, 1995 through December 31, 1995. The principal events concerning administration of the Carbon Products Consortium (CPC) were the December 12, 1995 Fall business meeting of the CPC and the general CPC review meeting on December 13, 1995. It is noteworthy that CONOCO, Inc. joined the CPC and that the CPC Board of Directors approved annual member fees to help support the CPC organization. Discussions have been initiated on licensing and joint venture arrangements to produce pilot-scale quantities of solvent extract coal pitches. The technical emphasis continues to be the supply of coal-based feedstocks to the industrial participants. There have been several iterations of samples and feedback to meet feedstock characteristics for a wide variety of carbon products. Technology transfer and marketing of the CPC is a continual effort. Interest in the program and positive results from the research continue to grow.

NONE

1996-01-01

340

Carbon nanofibers grown on activated carbon fiber fabrics as electrode of supercapacitors  

NASA Astrophysics Data System (ADS)

Carbon nanofibers (CNFs) were grown directly on activated carbon fiber fabric (ACFF), which was then used as the electrode of supercapacitors. Cyclic voltammetry and ac impedance were used to characterize the electrochemical properties of ACFF and CNF/ACFF electrodes in both aqueous and organic electrolytes. ACFF electrodes show higher specific capacitance than CNF/ACFF electrodes due to larger specific surface area. However, the spaces formed between the CNFs in the CNF/ACFF electrodes are more easily accessed than the slit-type pores of ACFF, and much higher electrical-double layer capacitance was obtained for CNF/ACFF electrodes.

Ko, Tse-Hao; Hung, Kai-Hsuan; Tzeng, Shinn-Shyong; Shen, Jin-Wei; Hung, Cheng-Hsin

2007-12-01

341

Irreversible adsorption of phenolic compounds by activated carbons  

SciTech Connect

Studies were undertaken to determine the reasons why phenolic sorbates can be difficult to remove and recover from activated carbons. The chemical properties of the sorbate and the adsorbent surface, and the influences of changes in the adsorption and desorption conditions were investigated. Comparison of isotherms established after different contact times or at different temperatures indicated that phenolic compounds react on carbon surfaces. The reaction rate is a strong function of temperature. Regeneration of carbons by leaching with acetone recovered at least as much phenol as did regeneration with other solvents or with displacers. The physiochemical properties of adsorbents influences irreversible uptakes. Sorbates differed markedly in their tendencies to undergo irreversible adsorption. 64 refs., 47 figs., 32 tabs.

Grant, T.M.; King, C.J.

1988-12-01

342

Timing of Canopy Closure Influences Carbon Translocation and Seed Production of an Understorey Herb, Trillium apetalon (Trilliaceae)  

PubMed Central

Background and Aims The light availability on a temperate, deciduous-forest floor varies greatly, reflecting the seasonal leaf dynamics of the canopy trees. The growth and/or reproductive activity of understorey plants should be influenced by the length of the high-irradiance period from snowmelt to canopy closure. The aim of the present study was to clarify how spring-blooming species regulate the translocation of photosynthetic products to current reproduction and storage organs during a growing season in accordance with the changing light conditions. Methods Growth pattern, net photosynthetic rate, seed production, and shoot and flower production in the next year of Trillium apetalon were compared between natural and experimentally shaded conditions. Furthermore, translocation of current photosynthetic products within plants was assessed by a labelled carbon-chase experiment. Key Results During the high-irradiance period, plants showed high photosynthetic ability, in which current products were initially used for shoot growth, then reserved in the rhizome. Carbon translocation to developing fruit occurred after canopy closure, but this was very small due to low photosynthetic rates under the darker conditions. The shading treatment in the early season advanced the time of carbon translocation to fruit, but reduced seed production in the current year and flower production of the next year. Conclusions Carbon translocation to the storage organ had priority over seed production under high-irradiance conditions. A shortened bright period due to early canopy closure effectively restricts carbon assimilation, which greatly reduces subsequent reproductive output owing to low photosynthetic products for fruit development and small carbon storage for future reproduction. As populations of this species are maintained by seedling recruitment, acceleration of canopy closure timing may influence the maintenance and dynamics of populations. PMID:18056055

Ida, Takashi Y.; Kudo, Gaku

2008-01-01

343

Authigenic carbonates from active methane seeps offshore southwest Africa  

NASA Astrophysics Data System (ADS)

The southwest African continental margin is well known for occurrences of active methane-rich fluid seeps associated with seafloor pockmarks at water depths ranging broadly from the shelf to the deep basins, as well as with high gas flares in the water column, gas hydrate accumulations, diagenetic carbonate crusts and highly diverse benthic faunal communities. During the M76/3a expedition of R/V METEOR in 2008, gravity cores recovered abundant authigenic carbonate concretions from three known pockmark sites—Hydrate Hole, Worm Hole, the Regab pockmark—and two sites newly discovered during that cruise, the so-called Deep Hole and Baboon Cluster. The carbonate concretions were commonly associated with seep-benthic macrofauna and occurred within sediments bearing shallow gas hydrates. This study presents selected results from a comprehensive analysis of the mineralogy and isotope geochemistry of diagenetic carbonates sampled at these five pockmark sites. The oxygen isotope stratigraphy obtained from three cores of 2-5 m length indicates a maximum age of about 60,000-80,000 years for these sediments. The authigenic carbonates comprise mostly magnesian calcite and aragonite, associated occasionally with dolomite. Their very low carbon isotopic compositions (-61.0 < ?13C ‰ V-PDB < -40.1) suggest anaerobic oxidation of methane (AOM) as the main process controlling carbonate precipitation. The oxygen isotopic signatures (+2.4 < ?18O ‰ V-PDB < +6.2) lie within the range in equilibrium under present-day/interglacial to glacial conditions of bottom seawater; alternatively, the most positive ?18O values might reflect the contribution of 18O-rich water from gas hydrate decomposition. The frequent occurrence of diagenetic gypsum crystals suggests that reduced sulphur (hydrogen sulphide, pyrite) from sub-seafloor sediments has been oxidized by oxygenated bottom water. The acidity released during this process can potentially induce the dissolution of carbonate, thereby providing enough Ca2+ ions for pore solutions to reach gypsum saturation; this is thought to be promoted by the bio-irrigation and burrowing activity of benthic fauna. The ?18O-?13C patterns identified in the authigenic carbonates are interpreted to reflect variations in the rate of AOM during the last glacial-interglacial cycle, in turn controlled by variably strong methane fluxes through the pockmarks. These results complement the conclusions of Kasten et al. in this special issue, based on authigenic barite trends at the Hydrate Hole and Worm Hole pockmarks which were interpreted to reflect spatiotemporal variations in AOM related to subsurface gas hydrate formation-decomposition.

Pierre, Catherine; Blanc-Valleron, Marie-Madeleine; Demange, Jérôme; Boudouma, Omar; Foucher, Jean-Paul; Pape, Thomas; Himmler, Tobias; Fekete, Noemi; Spiess, Volkhard

2012-12-01

344

Natural Oil Production from Microorganisms: Bioprocess and Microbe Engineering for Total Carbon Utilization in Biofuel Production  

SciTech Connect

Electrofuels Project: MIT is using carbon dioxide (CO2) and hydrogen generated from electricity to produce natural oils that can be upgraded to hydrocarbon fuels. MIT has designed a 2-stage biofuel production system. In the first stage, hydrogen and CO2 are fed to a microorganism capable of converting these feedstocks to a 2-carbon compound called acetate. In the second stage, acetate is delivered to a different microorganism that can use the acetate to grow and produce oil. The oil can be removed from the reactor tank and chemically converted to various hydrocarbons. The electricity for the process could be supplied from novel means currently in development, or more proven methods such as the combustion of municipal waste, which would also generate the required CO2 and enhance the overall efficiency of MIT’s biofuel-production system.

None

2010-07-15

345

Mutagenic activity of disinfection by-products.  

PubMed Central

Data on raw water quality, disinfection treatment practices, and the resulting mutagenic properties of the treated water were compiled from pilot- and full-scale treatment experiments to evaluate that parameter which might produce variability in the results of a mutagenic study. Analysis of the data and comparison of treatment practices indicated that the measured mutagenic activity is strongly related to the characteristics of the organic matter in the raw water, the methodology used to sample and detect mutagens, the scale of the study both in terms of treatment flow and period of study, and the point at which and the conditions under which oxidants are added during treatment. Conclusions regarding disinfection systems in full-scale water treatment plants include the following: When raw water is pretreated and high concentrations of organics are present in the raw water, both ozonation and chlorination increased mutagenic activity. However, no significant difference in mutagenicity was found between the two oxidants. Both in the case of a nitrified groundwater and a clarified surface water, the mutagenic activity of the water after ozonation was related to its mutagenic activity before ozonation. With ozonation, mutagenic activity decreased after granular activated carbon (GAC) filtration. Thus, when GAC filtration follows ozone disinfection, early addition of oxidants may not be deleterious to the finished water quality. When chlorine or chlorine dioxide is added after GAC filtration, chlorine dioxide was found to produce a less mutagenic water than chlorine. Although these conclusions suggest means of controlling mutagenic activity during treatment, it must be stressed that the measurement of mutagenicity is a presumptive index of contamination level. PMID:3816721

Cognet, L; Courtois, Y; Mallevialle, J

1986-01-01

346

Production Of High Specific Activity Copper-67  

DOEpatents

A process for the selective production and isolation of high specific activity cu.sup.67 from proton-irradiated enriched Zn.sup.70 target comprises target fabrication, target irradiation with low energy (<25 MeV) protons, chemical separation of the Cu.sup.67 product from the target material and radioactive impurities of gallium, cobalt, iron, and stable aluminum via electrochemical methods or ion exchange using both anion and cation organic ion exchangers, chemical recovery of the enriched Zn.sup.70 target material, and fabrication of new targets for re-irradiation is disclosed.

Jamriska, Sr., David J. (Los Alamos, NM); Taylor, Wayne A. (Los Alamos, NM); Ott, Martin A. (Los Alamos, NM); Fowler, Malcolm (Los Alamos, NM); Heaton, Richard C. (Los Alamos, NM)

2002-12-03

347

Production Of High Specific Activity Copper-67  

DOEpatents

A process for the selective production and isolation of high specific activity Cu.sup.67 from proton-irradiated enriched Zn.sup.70 target comprises target fabrication, target irradiation with low energy (<25 MeV) protons, chemical separation of the Cu.sup.67 product from the target material and radioactive impurities of gallium, cobalt, iron, and stable aluminum via electrochemical methods or ion exchange using both anion and cation organic ion exchangers, chemical recovery of the enriched Zn.sup.70 target material, and fabrication of new targets for re-irradiation is disclosed.

Jamriska, Sr., David J. (Los Alamos, NM); Taylor, Wayne A. (Los Alamos, NM); Ott, Martin A. (Los Alamos, NM); Fowler, Malcolm (Los Alamos, NM); Heaton, Richard C. (Los Alamos, NM)

2003-10-28

348

Chromium removal from water by activated carbon developed from waste rubber tires.  

PubMed

Because of the continuous production of large amount of waste tires, the disposal of waste tires represents a major environmental issue throughout the world. This paper reports the utilization of waste tires (hard-to-dispose waste) as a precursor in the production of activated carbons (pollution-cleaning adsorbent). In the preparation of activated carbon (AC), waste rubber tire (WRT) was thermally treated and activated. The tire-derived activated carbon was characterized by means of scanning electron microscope, energy-dispersive X-ray spectroscopy, FTIR spectrophotometer, and X-ray diffraction. In the IR spectrum, a number of bands centred at about 3409, 2350, 1710, 1650, and 1300-1000 cm(-1) prove the present of hydroxyl and carboxyl groups on the surface of AC in addition to C?C double bonds. The developed AC was tested and evaluated as potential adsorbent removal of chromium (III). Experimental parameters, such as contact time, initial concentration, adsorbent dosage and pH were optimized. A rapid uptake of chromium ions was observed and the equilibrium is achieved in 1 h. It was also found that the adsorption process is pH dependent. This work adds to the global discussion of the cost-effective utilization of waste rubber tires for waste water treatment. PMID:22573097

Gupta, Vinod Kumar; Ali, Imran; Saleh, Tawfik A; Siddiqui, M N; Agarwal, Shilpi

2013-03-01

349

RESEARCH ON CARBON PRODUCTS FROM COAL USING AN EXTRACTIVE PROCESS  

SciTech Connect

This report presents the results of a one-year effort directed at the exploration of the use of coal as a feedstock for a variety of industrially-relevant carbon products. The work was basically divided into three focus areas. The first area dealt with the acquisition of laboratory equipment to aid in the analysis and characterization of both the raw coal and the coal-derived feedstocks. Improvements were also made on the coal-extraction pilot plant which will now allow larger quantities of feedstock to be produced. Mass and energy balances were also performed on the pilot plant in an attempt to evaluate the scale-up potential of the process. The second focus area dealt with exploring hydrogenation conditions specifically aimed at testing several less-expensive candidate hydrogen-donor solvents. Through a process of filtration and vacuum distillation, viable pitch products were produced and evaluated. Moreover, a recycle solvent was also isolated so that the overall solvent balance in the system could be maintained. The effect of variables such as gas pressure and gas atmosphere were evaluated. The pitch product was analyzed and showed low ash content, reasonable yield, good coking value and a coke with anisotropic optical texture. A unique plot of coke yield vs. pitch softening point was discovered to be independent of reaction conditions or hydrogen-donor solvent. The third area of research centered on the investigation of alternate extraction solvents and processing conditions for the solvent extraction step. A wide variety of solvents, co-solvents and enhancement additives were tested with varying degrees of success. For the extraction of raw coal, the efficacy of the alternate solvents when compared to the benchmark solvent, N-methyl pyrrolidone, was not good. However when the same coal was partially hydrogenated prior to solvent extraction, all solvents showed excellent results even for extractions performed at room temperature. Standard analyses of the extraction products indicated that they had the requisite properties of viable carbon-product precursors.

Peter G. Stansberry; Alfred H. Stiller; John W. Zondlo; Chong Chen; Brian Bland; David Fenton

2002-03-31

350

Activation and micropore structure determination of activated carbon-fiber composites  

SciTech Connect

Rigid, high surface area activated carbon fiber composites have been produced with high permeabilities for environmental applications in gas and water purification. These novel monolithic adsorbents can be produced in single pieces to a given size and shape. The project involves a collaboration between the Oak Ridge National Laboratory (ORNL) and the Center for Applied Energy Research (CAER), University of Kentucky. The carbon fiber composites are produced at the ORNL and activated at the CAER using different methods, with the aims of producing a uniform degree of activation, and of closely controlling pore structure and adsorptive properties. The main focus of the present work has been to find a satisfactory means to uniformly activate large samples of carbon fiber composites and produce controlled pore structures. Several environmental applications have been explored for the activated carbon fiber composites. One of these was to evaluate the activated composites for the separation of CH{sub 4}-CO{sub 2} mixtures, and an apparatus was constructed specifically for this purpose. The composites were further evaluated in the cyclic recovery of volatile organics. The activated carbon fiber composites have also been tested for possible water treatment applications by studying the adsorption of sodium pentachlorophenolate, PCP.

Jagtoyen, M.; Derbyshire, F.; Kimber, G. [Univ. of Kentucky, Lexington, KY (United States). Center for Applied Energy Research

1997-09-05

351

Porosity development in activated carbons obtained from date pits under chemical activation with phosphoric acid  

Microsoft Academic Search

Date pits, a low-cost agricultural by-product, was tested as a precursor for the production of porous carbons in a chemical scheme using phosphoric acid. The raw material was impregnated with increasing concentrations of H3PO4 (30–70 vol.%) followed by pyrolysis at 300, 500 or 700 °C. Texture characteristics of the products were determined by adsorption of N2 at 77 K, as

Badie S. Girgis; Abdel-Nasser A. El-Hendawy

2002-01-01

352

Granular activated carbons from palm nut shells for gold di-cyanide adsorption  

NASA Astrophysics Data System (ADS)

Granular activated carbons were produced from palm nut shells by physical activation with steam. The proximate analysis of palm nut shells was investigated by thermogravimetric analysis, and the adsorption capacity of the activated carbons, produced as a result of shell pyrolysis at 600°C followed by steam activation at 900°C in varying activation times, was evaluated using nitrogen adsorption at 77 K. Applicability of the activated carbons for gold dicyanide adsorption was also investigated. Increasing the activation hold time with the attendant increase in the degree of carbon burn-off results in a progressive increase in the surface area of the activated carbons, reaching a value of 903.1 m2/g after activation for 6 h. The volumes of total pores, micropores, and mesopores in the activated carbons also increase progressively with the increasing degree of carbon burn-off, resulting from increasing the activation hold time. The gold di-cyanide adsorption of the activated carbons increases with the rise of pore volume of the activated carbons. The gold di-cyanide adsorption of palm nut shell activated carbon obtained after 6-h activation at 900°C is superior to that of a commercial activated carbon used for gold di-cyanide adsorption.

Buah, William K.; Williams, Paul T.

2013-02-01

353

Adsorption of Bacillus subtilis on single-walled carbon nanotube aggregates, activated carbon and NanoCeram™  

Microsoft Academic Search

Adsorption equilibrium and kinetics of Bacillus subtilis spores on single-walled carbon nanotube aggregates were investigated to explore the possibility of using single-walled carbon nanotubes for concentration, detection and removal of pathogens from contaminated water sources. Batch adsorption experiments were conducted to determine adsorption kinetics and adsorption equilibrium of B. subtilis spores on single-walled carbon nanotube aggregates, activated carbon and NanoCeram™.

Venkata K. K. Upadhyayula; Shuguang Deng; Geoffrey B. Smith; Martha C. Mitchell

2009-01-01

354

75 FR 18153 - Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea: Extension of Time...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Corrosion-Resistant Carbon Steel Flat Products from the Republic...corrosion-resistant carbon steel flat products (CORE) from...Duty Determinations: Certain Steel Products from Korea, 58 FR...complex issues regarding several research and development programs....

2010-04-09

355

Efficient lactulose production from cheese whey using sodium carbonate.  

PubMed

An economical method of lactulose production from cheese whey was developed using sodium carbonate (Na2CO3). Three parameters such as temperature, reaction time, and Na2CO3 concentration were identified as experimental factors, and yield was selected as a response parameter. The experimental factors were optimised employing Response Surface Methodology (RSM). Maximum yield of 29.6% was obtained at reaction time of 20.41min, Na2CO3 of 0.51% at 90°C. To overcome this limited lactulose yield, due to the conversion of lactulose to galactose, fed batch system was applied using dried cheese whey as lactose source. By this system, limit was broken, and 15.8g/L of lactulose is produced in hour. PMID:25466139

Seo, Yeong Hwan; Park, Gwon Woo; Han, Jong-In

2015-04-15

356

Improving Jet Reactor Configuration for Production of Carbon Nanotubes  

NASA Technical Reports Server (NTRS)

The jet mixing reactor has been proposed for the industrial production of fullerene carbon nanotubes. Here we study the flowfield of this reactor using the SIMPLER algorithm. Hot peripheral jets are used to enhance heating of the central jet by mixing with the ambiance of reactor. Numerous configurations of peripheral jets with various number of jets, distance between nozzles, angles between the central jet and a peripheral jets, and twisted configuration of nozzles are considered. Unlike the previous studies of jet mixing, the optimal configuration of peripheral jets produces strong non-uniformity of the central jet in a cross-section. The geometrical shape of reactor is designed to obtain a uniform temperature of a catalyst.

Povitsky, Alex

2000-01-01

357

Trypanocidal Activity of Marine Natural Products  

PubMed Central

Marine natural products are a diverse, unique collection of compounds with immense therapeutic potential. This has resulted in these molecules being evaluated for a number of different disease indications including the neglected protozoan diseases, human African trypanosomiasis and Chagas disease, for which very few drugs are currently available. This article will review the marine natural products for which activity against the kinetoplastid parasites; Trypanosoma brucei brucei, T.b. rhodesiense and T. cruzi has been reported. As it is important to know the selectivity of a compound when evaluating its trypanocidal activity, this article will only cover molecules which have simultaneously been tested for cytotoxicity against a mammalian cell line. Compounds have been grouped according to their chemical structure and representative examples from each class were selected for detailed discussion. PMID:24152565

Jones, Amy J.; Grkovic, Tanja; Sykes, Melissa L.; Avery, Vicky M.

2013-01-01

358

Production and characterization of methyl ester sophorolipids with 22-carbon-fatty acids.  

PubMed

In this study, various fatty acids of 18 and 22 carbons were used as substrates to produce sophorolipids in Candida bombicola ATCC 22214. Methyl esterification of erucic acid and C22-enriched rapeseed oil generated mainly acidic sophorolipids with different degrees of saturation in the fatty acid chain, which was demonstrated by structural analysis using HPLC, LC-MS and NMR spectroscopy. Regardless of methyl esterification, the rapeseed oil served as the best substrate for high production of sophorolipids among the tested. Methyl esterification also had no noticeable effect on the interfacial properties of sophorolipids. However, 22 carbons introduced in the fatty acid chain increased the hydrophobicity of sophorolipids, and therefore improved surface-active properties and biodegradability. PMID:20053555

Shin, Jae Dong; Lee, Jeongmi; Kim, Yong Bum; Han, In-Sun; Kim, Eun-Ki

2010-05-01

359

[Adsorption-desorption performance of honeycomb-shaped activated carbon].  

PubMed

Honeycomb-shaped activated carbon is useful to control organic gas pollution of large air-flow and low concentration. Effects of adsorbents, toluene concentration, velocity of empty bed and temperature of desorption on its adsorption-desorption performance were studied by conducting on dynamic experiments. Results shown that adsorption properties of honeycomb-shaped activated carbon were increased with decreasing of the inlet toluene concentration under the condition of certain outlet toluene concentration, and gas velocity of empty bed was recommend as 1.2-1.8 m x s(-1). With increasing of the desorption temperature, the outlet toluene concentration appeared peak-value and fluctuated widely, and the recommended desorption temperature was 90 degrees C. Gas velocity of empty bed affected the peak value of concentration of the toluene, and practical value was 0.2-0.4 m x s(-1). PMID:22468536

Han, Zhong-Juan; Luo, Fu-Kun; Li, Ze-Qing

2011-12-01

360

Predictions of adsorption equilibria of nonpolar hydrocarbons onto activated carbon  

SciTech Connect

This paper presents a new approach to analyze the adsorption equilibria of nonpolar hydrocarbons onto activated carbon. The kinetic theory of gases and the 10-4-3 potential energy were employed to describe the adsorption process inside micropores. On the basis of this theory, a general isotherm model was proposed which possesses the potential capability of predicting the adsorption equilibria of an adsorbent by using the knowledge of its microporous structure and molecular properties of adsorbates. Experimental data of gases and vapors on Ajax activated carbon were employed to examine the model. Adsorption equilibria of binary mixtures were also investigated with the model, and it is shown that the model is capable of simulating the nonideal, or azeotropic, adsorption behaviors resulting from the structural heterogeneity of the adsorbent.

Do, D.D.; Wang, K. [Univ. of Queensland, St. Lucia, Queensland (Australia). Dept. of Chemical Engineering] [Univ. of Queensland, St. Lucia, Queensland (Australia). Dept. of Chemical Engineering

1998-12-08

361

Bacterial carbon-phosphorus lyase: products, rates, and regulation of phosphonic and phosphinic acid metabolism.  

PubMed Central

Carbon-phosphorus bond cleavage activity, found in bacteria that utilize alkyl- and phenylphosphonic acids, has not yet been obtained in a cell-free system. Given this constraint, a systematic examination of in vivo C-P lyase activity has been conducted to develop insight into the C-P cleavage reaction. Six bacterial strains were obtained by enrichment culture, identified, and characterized with respect to their phosphonic acid substrate specificity. One isolate, Agrobacterium radiobacter, was shown to cleave the carbon-phosphorus bond of a wide range of substrates, including fosfomycin, glyphosate, and dialkyl phosphinic acids. Furthermore, this organism processed vinyl-, propenyl-, and propynylphosphonic acids, a previously uninvestigated group, to ethylene, propene, and propyne, respectively. A determination of product stoichiometries revealed that both C-P bonds of dimethylphosphinic acid are cleaved quantitatively to methane and, furthermore, that the extent of C-P bond cleavage correlated linearly with the specific growth rate for a range of substrates. The broad substrate specificity of Agrobacterium C-P lyase and the comprehensive characterization of the in vivo activity make this an attractive system for further biochemical and mechanistic experiments. In addition, the failure to observe the activity in a group of gram-positive bacteria holds open the possibility that a periplasmic component may be required for in vivo expression of C-P lyase activity. PMID:3804975

Wackett, L P; Shames, S L; Venditti, C P; Walsh, C T

1987-01-01

362

Adsorption of nitrophenol onto activated carbon: isotherms and breakthrough curves  

Microsoft Academic Search

The adsorption isotherm of p-nitrophenol onto granular activated carbon in 25°C aqueous solution was experimentally determined by batch tests. Both the Freundlich and the Redlich-Peterson models were found to fit the adsorption isotherm data well. A series of column tests were performed to determine the breakthrough curves with varying bed depths (3–6cm) and water flow rates (21.6–86.4cm3\\/h). Explicit equations for

Jia-Ming Chern; Yi-Wen Chien

2002-01-01

363

Adsorption of selected herbicides from aqueous solutions on activated carbon  

Microsoft Academic Search

The adsorption of MCPA and 2,4-D on the activated carbon Filtrasorb 300 was studied. The adsorption isotherms of herbicides\\u000a from aqueous solutions were measured over a wide range of solute concentrations and at different temperatures. The experimental\\u000a equilibrium data were analyzed by the Langmuir–Freundlich isotherm taking into account the energetic heterogeneity of adsorption\\u000a system. The effect of temperature and herbicide

A. Derylo-Marczewska; M. Blachnio; A. W. Marczewski; A. Swiatkowski; B. Tarasiuk

2010-01-01

364

Ferrous ion oxidation by Thiobacillus ferrooxidans immobilized on activated carbon  

Microsoft Academic Search

The immobilization of Thiobacillus ferrooxidans on the activated carbon particles as support matrix was investigated. Cycling batch operation results in the complete oxidation of ferrous iron in 8 d when the modified 9 K medium is set to flow through the mini-bioreactor at a rate of 0.104 L\\/h at 25 °C. The oxidation rate of ferrous iron with immobilized T.

Ji-kui ZHOU; Wen-qing QIN; Yin-jian NIU; Hua-xia LI

2006-01-01

365

Mapping of Black Carbon Production From Fire in the U.S.  

NASA Astrophysics Data System (ADS)

Fire prevention and the production of biofuels are two strategies envisioned to reduce carbon export to the atmosphere. However, accounting of carbon budgets in the U.S. are far from complete. Further research may demonstrate that the long term storage of carbon as char, or black carbon, may make naturally burning ecosystems a greater sink of carbon than expected. Black carbon recalcitrance and transport need substantial investigation, but first, determining geographic patterns in the natural production of black carbon in fire is a step toward a better understanding of wildfire's role in the carbon cycle. In this work, we use two existing U.S. mapped estimates of carbon consumption in fire to develop national maps of black carbon generated by fire. National totals are comparable and in line with previous estimates at an average of ~5 Tg per year. Interestingly, spatial patterns in the two products differ, relating in large part to variation between fuel models: one, only accounting for surface fuels, and the other, allowing for stand- replacing fire. The national totals confirm that large amounts of black carbon are generated by fire, but the spatial differences reflect the uncertainty in attempts to map its production explicitly. Future refinement in our understanding and mapping of fire regimes should continue to improve estimates of wildfire-generated black carbon.

Waller, E. K.; Moritz, M. A.

2008-12-01

366

Net Primary Productivity of a CO 2 Enriched Deciduous Forest and the Implications for Carbon Storage  

Microsoft Academic Search

A central question concerning the response of terrestrial ecosystems to a changing atmosphere is whether increased uptake of carbon in response to increasing at- mospheric carbon dioxide concentration results in greater plant biomass and carbon storage or, alternatively, faster cycling of C through the ecosystem. Net primary productivity (NPP) of a closed-canopy Liquidambar styraciflua (sweetgum) forest stand was assessed for

Richard J. Norby; Paul J. Hanson; Elizabeth G. O'Neill; Tim J. Tschaplinski; Jake F. Weltzin; Randi A. Hansen; Weixin Cheng; Stan D. Wullschleger; Carla A. Gunderson; Nelson T. Edwards; Dale W. Johnson

2002-01-01

367

Environmental Analysis of the Coal-based Power Production with Amine-based Carbon Capture  

E-print Network

Environmental Analysis of the Coal-based Power Production with Amine-based Carbon Capture J at the beginning. From an electricity generator's perspective the amine based carbon capture offers some advantages routes without CCS, a broader environmental analysis is necessary. Depending on the type of the carbon

368

Carbon dioxide sequestration via olivine carbonation: Examining the formation of reaction products  

NASA Astrophysics Data System (ADS)

Due to its abundance and natural ability to sequester CO2, olivine has been proposed as one mineral that could be used in the control of CO2 emissions into the atmosphere (Metz, 2005). Large scale peridotite deposits found in locations such as the Western Gneiss Region in Norway could provide in-situ sites for sequestration or the raw materials for ex-situ mineral carbonation. Determining the conditions under which magnesite (MgCO3) forms most efficiently is crucial to conduct a cost effective process. Understanding the development of secondary minerals is particularly important for in-situ methods as these phases can form passivating layers and affect the host rock porosity. The final solution of flow-through experiments conducted at alkaline pH have been shown to be supersaturated with respect to talc and chrysotile (Giammer et al., 2005), although these phases were not found to have precipitated the formation of a passivating, amorphous silica layer has been observed on reacted olivine surfaces (Bearat et al., 2006). By studying magnesite and other products produced during the carbonation of olivine within Teflon lined steel autoclaves we have begun to form a more comprehensive understanding of how these reactions would proceed during sequestration processes. We have performed batch experiments using carbonated saline solutions in the presence of air or gaseous CO2 from 80 to 200 Ë? C. X-ray powder diffraction was used to identify magnesite within the reaction products. Crystals of magnesite up to 20 m in diameter can be observed on olivine grain surfaces with scanning electron microscopy. Secondary reaction products formed a platy layer on olivine surfaces in reactions above 160 Ë? C and below pH 12. Energy dispersive X-ray analysis of the platy layer revealed an increase in Fe concentration. The macroscopically observable red colouration of the reaction products and Raman spectroscopy indicate that hematite is present in these layers. For experiments with a duration of 4 weeks, lizardite has also been identified using X-ray powder diffraction. The Mg/Si ratio obtained from energy dispersive X-ray analysis of the secondary phases from shorter period experiments indicates that lizardite may also be present. However, the components of these platy layers are closely associated and too low in concentration to be distinguishable with X-ray diffraction analysis. We have not observed the precipitation of talc or chrysotile phases in any of our experiments. Amorphous silica has also not been identified in any of the reaction rims. Higher temperature experiments and those with an initial solution slightly undersaturated with respect to magnesite produced well formed carbonate crystals. The presence of CO2 above the solution did not affect the final magnesite crystal shape but did increase the rate of precipitation. References: Bearat H., McKelvy M. J., Chizmeshya A. V. G., Gormley D., Nunez R., Carpenter R. W., Squires K. and Wolf G. H. (2006), Environ. Sci. Technol., 40 4802-4808. Giammar D. E., Bruant R. G. and Peters C. A. (2005), Chem. Geol., 217 257-276. Metz B. D. O., de Coninck H., Loos M. and Meyer L. (2005), IPCC Special Report on Carbon Dioxide Capture and Storage, Cambridge University Press.

King, H. E.; Plümper, O.; Putnis, A.

2009-04-01

369

Preparation and textural characterisation of activated carbon from vine shoots ( Vitis vinifera) by H 3PO 4—Chemical activation  

NASA Astrophysics Data System (ADS)

An abundant and low-cost agricultural waste as vine shoots ( Vitis vinifera) (VS), which is generated by the annual pruning of vineyards, has been used as raw material in the preparation of powder activated carbon (AC) by the method of chemical activation with phosphoric acid. After size reduction, VS were impregnated for 2 h with 60 wt.% H 3PO 4 solution at room temperature, 50 and 85 °C. The three impregnated products were carbonised at 400 °C. The product impregnated at 50 °C was heated either first at 150-250 °C and then at 400 °C or simply at 350-550 °C in N 2 atmosphere. The time of isothermal treatment after each dynamic heating was 2 h. The carbons were texturally characterised by gas adsorption (N 2, -196 °C), mercury porosimetry, and density measurements. FT-IR spectroscopy was also applied. Better developments of surface area and microporosity are obtained when the impregnation of VS with the H 3PO 4 solution is effected at 50 °C and for the products heated isothermally at 200 and 450 °C. The mesopore volume is also usually higher for the products impregnated and heated at intermediate temperatures.

Corcho-Corral, B.; Olivares-Marín, M.; Fernández-González, C.; Gómez-Serrano, V.; Macías-García, A.

2006-06-01

370

Black Carbon And Co-Pollutants Emissions And Energy Efficiency From Bricks Production In Guanajuato, Mexico  

NASA Astrophysics Data System (ADS)

In many parts of the world, small-scale traditional brick kilns are a notorious informal sector source of urban air pollution. Many are both inefficient and burn highly polluting fuels that emit significant levels of black carbon and other pollutants into local communities and to the atmosphere, resulting in severe health and environmental impacts. It is estimated that there are nearly 20,000 traditional brick kilns in Mexico, in which bricks are still produced as they have been for centuries. They are made by hand, dried in the sun, and generally fired in small, one chamber kilns that use various types of fuels, including plastic refuse, used tires, manure, wood scrap, and used motor oil. Three brick kilns, two traditional kilns and an improved kiln (MK2), were sampled as part of the SLCFs-Mexico campaign in Guanajuato, Mexico during March of 2013. The concept of the MK-2 involves covering the kiln with a dome and channeling the output of an active kiln through a second, identical loaded kiln for its additional filtration of the effluents. The results of energy efficiency and carbon mass balance calculations are presented for comparing the production efficiency and carbon emissions from the sampled kilns. Measurements included PM2.5 mass with quartz filters and temporally-resolved elemental carbon and organic carbon composition obtained using thermo-optical methods. The carbon emissions obtained with the mass balance method are compared with concurrent, high- time resolution, emissions measurements obtained using the Aerodyne mobile laboratory employing the tracer method (see abstract by Fortner et al.)

Molina, L. T.; Zavala, M.; Maiz, P.; Monsivais, I.; Chow, J.; Munguia, J.

2013-12-01

371

The Carbon Footprint of Bioenergy Sorghum Production in Central Texas: Production Implications on Greenhouse Gas Emissions, Carbon Cycling, and Life Cycle Analysis  

E-print Network

greenhouse gas (GHG) emissions. However, agronomic management practices influence direct and indirect GHG emissions, and both can have a significant impact on biofuel production efficiency. Our overall objective was to determine the carbon (C) footprint...

Storlien, Joseph Orgean

2013-06-13

372

Enhanced activity and selectivity of carbon nanofiber supported Pd catalysts for nitrite reduction.  

PubMed

Pd-based catalyst treatment represents an emerging technology that shows promise to remove nitrate and nitrite from drinking water. In this work we use vapor-grown carbon nanofiber (CNF) supports in order to explore the effects of Pd nanoparticle size and interior versus exterior loading on nitrite reduction activity and selectivity (i.e., dinitrogen over ammonia production). Results show that nitrite reduction activity increases by 3.1-fold and selectivity decreases by 8.0-fold, with decreasing Pd nanoparticle size from 1.4 to 9.6 nm. Both activity and selectivity are not significantly influenced by Pd interior versus exterior CNF loading. Consequently, turnover frequencies (TOFs) among all CNF catalysts are similar, suggesting nitrite reduction is not sensitive to Pd location on CNFs nor Pd structure. CNF-based catalysts compare favorably to conventional Pd catalysts (i.e., Pd on activated carbon or alumina) with respect to nitrite reduction activity and selectivity, and they maintain activity over multiple reduction cycles. Hence, our results suggest new insights that an optimum Pd nanoparticle size on CNFs balances faster kinetics with lower ammonia production, that catalysts can be tailored at the nanoscale to improve catalytic performance for nitrite, and that CNFs hold promise as highly effective catalyst supports in drinking water treatment. PMID:22295991

Shuai, Danmeng; Choe, Jong Kwon; Shapley, John R; Werth, Charles J

2012-03-01

373

40 CFR 60.1855 - What records must I keep for municipal waste combustion units that use activated carbon?  

Code of Federal Regulations, 2014 CFR

...waste combustion units that use activated carbon? 60.1855 Section 60.1855 Protection...waste combustion units that use activated carbon? For municipal waste combustion units that use activated carbon to control dioxins/furans or...

2014-07-01

374

40 CFR 60.1370 - What records must I keep for municipal waste combustion units that use activated carbon?  

Code of Federal Regulations, 2014 CFR

...waste combustion units that use activated carbon? 60.1370 Section 60.1370 Protection...waste combustion units that use activated carbon? For municipal waste combustion units that use activated carbon to control dioxins/furans or...

2014-07-01

375

Dynamic Mass Transfer Process of Activated Carbon Desulfurization on Fixed Bed  

Microsoft Academic Search

Flue gas desulfurization by activated carbon is an environmental-friendly technique used in thermal power plant. The mass transfer process of SO2 about flue gas desulfurization by activated carbon is analyzed, effective mass transfer velocity of SO2 on fixed bed is proposed and mathematics model is established. Internal diffusivity and internal surface availability coefficient of different activated carbons are measured according

Yi Liu; Zidong Cao

2011-01-01

376

Activated carbon adsorbents from waste tires for air quality control  

SciTech Connect

This study evaluates methodologies for utilizing waste tire rubber to produce carbonaceous adsorbents for use in air quality control operations. Such an approach provides a two-fold environmental and economic benefit. A recycling path is developed for waste tire rubber and new adsorbents are produced from a low cost feedstock for use in environmentally-related operations. Bench-scale and pilot-scale quantities of tire-derived activated carbon (TDAC) were produced from waste tire rubber. Raw tire rubber samples and devolatilized tire char were obtained from several US vendors. The raw samples were analyzed using proximate, ultimate, and elemental analyses. Batches of activated carbon samples were prepared using a bench-scale fixed-tubular reactor to prepare {approximately}10 g samples and a fluidized-bed reactor to prepare {approximately}100 g quantities. About 25 kg of activated carbon was also produced at a pilot-scale commercial facility. The resulting TDACs were then characterized by nitrogen adsorption at 77K. The sample surface areas were determined by the BET method, and the pore size distribution (PSD) was evaluated using the BJH model, and a 3-D PSD model. Performance of the TDACs was evaluated in their ability to remove gaseous mercury species from simulated power-plant flue-gas streams, and for the removal of organic compounds (e.g., acetone and 1,1,1-trichloroethane) from flowing gas streams.

Lehmann, C.M.B.; Rostam-Abadi, M.; Rood, M.J.; Hsi, H.C.

1999-07-01

377

EVALUATION OF FULL SCALE ACTIVATED SLUDGE SYSTEMS UTILIZING POWDERED ACTIVATED CARBON ADDITION WITH WET AIR REGENERATION  

EPA Science Inventory

The addition of powdered activated carbon (PAC) to activated sludge systems is a proven method of wastewater treatment. Of eleven POTWs in the U.S. that were designed for PAC use, ten included wet air regeneration (WAR) for the destruction of secondary sludge solids and recovery ...

378

GpdA-promoter-controlled production of glucose oxidase by recombinant Aspergillus niger using nonglucose carbon sources.  

PubMed

The gpdA-promoter-controlled exocellular production of glucose oxidase (GOD) by recombinant Aspergillus niger NRRL-3 (GOD3-18) during growth on glucose and nonglucose carbon sources was investigated. Screening of various carbon substrates in shake-flask cultures revealed that exocellular GOD activities were not only obtained on glucose but also during growth on mannose, fructose, and xylose. The performance of A. niger NRRL-3 (GOD3-18) using glucose, fructose, or xylose as carbon substrate was compared in more detail in bioreactor cultures. These studies revealed that gpdA-promoter-controlled GOD synthesis was strictly coupled to cell growth. The gpdA-promoter was most active during growth on glucose. However, the unfavorable rapid GOD-catalyzed transformation of glucose into gluconic acid, a carbon source not supporting further cell growth and GOD production, resulted in low biomass yields and, therefore, reduced the advantageous properties of glucose. The total (endo- and exocellular) specific GOD activities were lowest when growth occurred on fructose (only a third of the activity that was obtained on glucose), whereas utilization of xylose resulted in total specific GOD activities nearly as high as reached during growth on glucose. Also, the portion of GOD excreted into the culture fluid reached similar high levels (approximately equal to 90%) by using either glucose or xylose as substrate, whereas growth on fructose resulted in a more pelleted morphology with more than half the total GOD activity retained in the fungal biomass. Finally, growth on xylose resulted in the highest biomass yield and, consequently, the highest total volumetric GOD activity. These results show that xylose is the most favorable carbon substrate for gpdA-promoter-controlled production of exocellular GOD. PMID:11257807

el-Enshasy, H; Hellmuth, K; Rinas, U

2001-01-01

379

An active carbon catalyst prevents coke formation from asphaltenes during the hydrocracking of vacuum residue  

SciTech Connect

Active carbons were prepared by the steam activation of a brown coal char. The active carbon with mesopores showed greater adsorption selectivity for asphaltenes. The active carbon was effective at suppressing coke formation, even with the high hydrocracking conversion of vacuum residue. The analysis of the change in the composition of saturates, aromatics, resins, and asphaltenes in the cracked residue with conversion demonstrated the ability of active carbon to restrict the transformation of asphaltenes to coke. The active carbon that was richer in mesopores was presumably more effective at providing adsorption sites for the hydrocarbon free-radicals generated initially during thermal cracking to prevent them from coupling and polycondensing.

Fukuyama, H.; Terai, S. [Toyo Engineering Corp., Chiba (Japan). Technological Research Center

2007-07-01

380

The Carbon Cycle and its Role in Climate Change: Activity 3  

NSDL National Science Digital Library

In this activity, learners explore the human influences on the carbon cycle and examine how fossil fuels release carbon. Learners role play as miners, power plant operators, car drivers, and home owners in a city. Learners will act out how each member of society contributes to the carbon cycle and then create a classroom mural depicting the path of carbon. Learners can reflect on this process as well as brainstorm ways to lower their carbon footprints. This activity is the third in a series of three activities that introduce learners to the carbon cycle (see related sources), although it is not mandatory that all three activities are completed as a set.

US Bureau of Land Management

2009-01-01

381

Role of Zinc in Catalytic Activity of Carbonic Anhydrase IX  

PubMed Central

The carbonic anhydrases (CAs) in the ? class are zinc-dependent metalloenzymes. Previous studies have reported that recombinant forms of carbonic anhydrase IX (CAIX), a membrane-bound form of CA expressed in solid tumors, appear to be activated by low levels of zinc independent of its well-studied role at the catalytic site. In this study, we sought to determine if CAIX is stimulated by zinc in its native environment. MDA-MB-231 breast cancer cells express CAIX in response to hypoxia. We compared CAIX activity associated with membrane ghosts isolated from hypoxic cells with that in intact hypoxic cells. We measured CA activity directly using 18O exchange from 13CO2 into water determined by membrane inlet mass spectrometry. In membrane ghosts, there was little effect of zinc at low concentrations on CAIX activity, although at high concentration zinc was inhibitory. In intact cells, zinc had no significant effect on CAIX activity. This suggests that there is an appreciable decrease in sensitivity to zinc when CAIX is in its natural membrane milieu compared to the purified forms. PMID:22465027

Tu, Chingkuang; Foster, Lauren; Alvarado, Andrea; McKenna, Robert; Silverman, David N.; Frost, Susan C.

2012-01-01

382

Efficient and cost reduced glucoamylase fed-batch production with alternative carbon-sources.  

PubMed

Glucoamylase is an important industrial enzyme. Glucoamylase production by industrial Aspergillus niger strain featured with two major problems: (1) empirical substrate feeding methods deteriorating the fermentation performance; (2) the high raw materials cost limiting the economics of the glucoamylase product with delegated specification. In this study, we firstly proposed a novel three-stage varied-rate substrate feeding strategy for efficient glucoamylase production in a 5 L bioreactor using the standard feeding medium, by comparing the changing patterns of the important physiological parameters such as DO, OUR, RQ, etc., when using different substrate feeding strategies. With this strategy, the glucoamylase activity and productivity reached higher levels of 11,000 U/ml and 84.6 U/ml/h, respectively. The performance enhancement in this case was beneficial from the following results: DO and OUR could be controlled at the higher levels (30%, 43.83 mmol/l/h) while RQ be maintained at a stable/lower level of 0.60 simultaneously throughout the fed-batch phase. Based on this three-stage varied-rate substrate feeding strategy, we further evaluated the economics of using alternative carbon-sources, attempting to reduce the raw materials cost. The results revealed that cornstarch hydrolysate could be considered as the best carbon-source to replace the standard and expensive feeding medium. In this case, production cost of the glucoamylase with delegated specification (5,000 U/ml) could be saved for more than 61% while the product quality be ensured simultaneously. The proposed strategy showed application potential in improving economics of industrial glucoamylase production. PMID:25262682

Luo, Hongzhen; Liu, Han; He, Zhenni; Zhou, Cong; Shi, Zhongping

2014-09-29

383

Spectroscopic characterization of discharge products in Li-Air cells with aprotic carbonate electrolytes  

SciTech Connect

Raman, infrared and X-ray photoelectron spectroscopies were used to characterize the thick coating of reaction products on carbon and MnO2 coated carbon cathodes produced during discharge of Li-air cells. The results show that neither Li2O2 or Li2O are major components of the insoluble discharge products; instead the products are largely composed of fluorine, lithium, and carbon, with surprisingly little oxygen. The complex reaction chemistry also appears to involve the formation of ethers or alkoxide products at the expense of the carbonate solvent molecules (ethylene carbonate and dimethylcarbonate). The irreversible discharge reaction is likely electrochemically promoted with Li-anion species and dissolved oxygen. Exactly how the molecular O2 participates in the reaction is unclear and requires further study. The addition of a conformal coating of MnO2 on the carbon lowers the cell s operating voltage, but does not alter the overall discharge chemistry.

Veith, Gabriel M [ORNL; Nanda, Jagjit [ORNL; Howe, Jane Y [ORNL; Dudney, Nancy J [ORNL

2011-01-01

384

DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS  

SciTech Connect

The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. The largest applications are those which support metals smelting, such as anodes for aluminum smelting and electrodes for arc furnaces. Other carbon products include materials used in creating fuels for the Direct Carbon Fuel Cell, and porous carbon structural material referred to as ''carbon foam'' and carbon fibers. During this reporting period, hydrotreatment of solvent was completed in preparation for pitch fabrication for graphite electrodes. Coal digestion has lagged but is expected to be complete by next quarter. Studies are reported on coal dissolution, pitch production, foam synthesis using physical blowing agents, and alternate coking techniques.

Dady B. Dadyburjor; Mark E. Heavner; Manoj Katakdaunde; Liviu Magean; J. Joshua Maybury; Alfred H. Stiller; Joseph M. Stoffa; John W. Zondlo

2006-08-01

385

Product carbon footprint (PCF) assessment of Dell laptop - Results and recommendations  

Microsoft Academic Search

The product carbon footprint (PCF) of a mainstream Dell laptop, including raw materials consumption, manufacturing, logistics, product use and end-of-life management was assessed in order to determine environmental “hot spots” across the life cycle. Product bill of material (BOM), supply chain logistics, product energy use and end-of-life scenario data were utilized to model the carbon footprint using generic data found

S. O'Connell; M. Stutz

2010-01-01

386

Drought effects on litterfall, wood production and belowground carbon cycling in an Amazon forest  

E-print Network

Drought effects on litterfall, wood production and belowground carbon cycling in an Amazon forest The Amazon Basin experiences severe droughts that may become more common in the future. Little is known of the effects of such droughts on Amazon forest productivity and carbon allocation. We tested the prediction

Saleska, Scott

387

Fabrication of novel micro-nano carbonous composites based on self-made hollow activated carbon fibers  

NASA Astrophysics Data System (ADS)

The hollow activated carbon fibers (HACF) were prepared by using commercial polypropylene hollow fiber (PPHF) as the template, and phenol-formaldehyde resin (PF) as carbon precursors. Final HACF was formed through the thermal decomposition and carbonization of PF at 700 °C under the nitrogen atmosphere, and activation at 800 °C with carbon dioxide as the activating agent, consecutively. Then, carbon nanotubes (CNTs) were grown by chemical vapor deposition (CVD) techniques using the as-grown porous HACF as substrate. The growth process was achieved by pyrolyzing ethanol steam at 700 °C using nickel as catalyst. Finally, CNTs was grown successfully on the substrate, and a novel tree-like micro-nano carbonous structure CNTs/HACF was fabricated. The as-grown HACF and micro-nano CNTs/HACF were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), and thermogravimetric analysis (TG), respectively. Moreover, the formation mechanisms were also discussed.

Kong, Yuxia; Qiu, Tingting; Qiu, Jun

2013-01-01

388

Removal of bromate and assimilable organic carbon from drinking water using granular activated carbon.  

PubMed

This study investigated the feasibility of using granular activated carbon (GAC) to remove bromate ion (BrO3-) and assimilable organic carbon (AOC) from drinking water through a rapid small-scale column test (RSSCT) method and a pilot-scale study. Results from RSSCT indicated that the GAC capacity for BrO3- removal was dependent on the GAC type, empty bed contact time (EBCT), and source water quality. The GAC with a high number of basic groups and higher pHpzc values showed an increased BrO3- removal capacity. BrO3- removal was improved by increasing EBCT. The high EBCT provides a greater opportunity for BrO3- to be adsorbed and reduced to Br- on the GAC surface. On the other hand, the presence of dissolved organic carbon (DOC) and anions, such as chloride, bromide, and sulfate, resulted in poor BrO3- reduction. In the GAC pilot plant, a GAC column preloaded for 12 months achieved a BrO3- and AOC removal range from 79-96% and 41-75%, respectively. The BrO3- amount removed was found to be proportional to the influent BrO3- concentration. However, the BrO3- removal rate apparently decreased with increasing operation time. In contrast, the AOC apparently increased during the long-term operation period. This may be a result of the contribution due to new GAC being gradually transformed into biological activated carbon (BAC), and the bacterial biomass adsorbed on GAC surface hindering BrO3- reduction by GAC either by blocking pores or adsorbing at the activated sites for BrO3- reduction. PMID:15566189

Huang, W J; Peng, H S; Peng, M Y; Chen, L Y

2004-01-01

389

Managing the cost of emissions for durable, carbon-containing products  

SciTech Connect

We recognize that carbon-containing products do not decay and release CO2 to the atmosphere instantaneously, but release that carbon over extended periods of time. For an initial production of a stock of carbon-containing product, we can treat the release as a probability distribution covering the time over which that release occurs. The probability distribution that models the carbon release predicts the amount of carbon that is released as a function of time. The use of a probability distribution in accounting for the release of carbon to the atmosphere realizes a fundamental shift from the idea that all carbon-containing products contribute to a single pool that decays in proportion to the size of the stock. Viewing the release of carbon as a continuous probabilistic process introduces some theoretical opportunities not available in the former paradigm by taking advantage of other fields where the use of probability distributions has been prevalent for many decades. In particular, theories developed in the life insurance industry can guide the development of pricing and payment structures for dealing with the costs associated with the oxidation and release of carbon. These costs can arise from a number of proposed policies (cap and trade, carbon tax, social cost of carbon, etc), but in the end they all result in there being a cost to releasing carbon to the atmosphere. If there is a cost to the emitter for CO2 emissions, payment for that cost will depend on both when the emissions actually occur and how payment is made. Here we outline some of the pricing and payment structures that are possible which result from analogous theories in the life insurance industry. This development not only provides useful constructs for valuing sequestered carbon, but highlights additional motivations for employing a probability distribution approach to unify accounting methodologies for stocks of carbon containing products.

Shirley, Kevin [Appalachian State University; Marland, Eric [Appalachian State University; Cantrell, Jenna [Appalachian State University; Marland, Gregg [ORNL

2011-03-01

390

Effect of different carbon sources on cellulase production by Hypocrea jecorina (Trichoderma reesei) strains  

PubMed Central

The ascomycete Hypocrea jecorina, an industrial (hemi)cellulase producer, can efficiently degrade plant polysaccharides. At present, the biology underlying cellulase hyperproduction of T. reesei, and the conditions for the enzyme induction, are not completely understood. In the current study, three different strains of T. reesei, including QM6a (wild-type), and mutants QM9414 and RUT-C30, were grown on 7 soluble and 7 insoluble carbon sources, with the later group including 4 pure polysaccharides and 3 lignocelluloses. Time course experiments showed that maximum cellulase activity of QM6a and QM9414 strains, for the majority of tested carbon sources, occurred at 120 hrs, while RUT-C30 had the greatest cellulase activity around 72 hrs. Maximum cellulase production was observed to be 0.035, 0.42 and 0.33 µmol glucose equivalents using microcrystalline celluloses for QM6a, QM9414, and RUTC-30, respectively. Increased cellulase production was positively correlated in QM9414 and negatively correlated in RUT-C30 with ability to grow on microcrystalline cellulose. PMID:22003440

Dashtban, Mehdi; Buchkowski, Robert; Qin, Wensheng

2011-01-01

391

Gamma X: A Full Capture Mode Detector Array for Carbon Activation  

NASA Astrophysics Data System (ADS)

A diagnostic was developed to determine the (?r)^2 of a DT reaction via the production of tertiary neutrons. High energy neutrons, in the range of 20 to 32 MeV, were incident upon a carbon disk which became activated via the 12C(n,2n) reaction. The activated carbon was then quickly transported to the counting station where it was placed in a NaI detector system where the C11 decay via positron emission could be detected in the form of back-to-back 511 KeV annihilation gamma rays. The 6 paired detectors in the system were aligned orthogonally on Cartesian axes. In comparison to the previous 2 detector system used at Rochester, the new 6 detector system has improved counting statistics substantially by increasing sample size and collection solid angle. To obtain a better understanding of the effects of non-uniformly activated samples, radioactive copper pellets were distributed within the carbon sample matrix in a variety of volumetric distributions. In doing so the effects of non-isotropic activation on the efficiency of the detector system could be determined.

Brown, Cassarah; Cummings, Melissa; Padalino, Stephen; Sangster, Thomas; Duffy, Timothy; Glebov, Vladimir

2008-11-01

392

Synthesis of sulfonated porous carbon nanospheres solid acid by a facile chemical activation route  

NASA Astrophysics Data System (ADS)

Generally, porous carbon nanospheres materials are usually prepared via a template method, which is a multi-steps and high-cost strategy. Here, we reported a porous carbon nanosphere solid acid with high surface area and superior porosity, as well as uniform nanospheical morphology, which prepared by a facile chemical activation with ZnCl2 using resorcinol-formaldehyde (RF) resins spheres as precursor. The activation of RF resins spheres by ZnCl2 at 400 °C brought high surface area and large volume, and simultaneously retained numerous oxygen-containing and hydrogen-containing groups due to the relatively low processing temperature. The presence of these functional groups is favorable for the modification of -SO3H groups by a followed sulfonation treating with sulphuric acid and organic sulfonic acid. The results of N2 adsorption-desorption and electron microscopy clearly showed the preservation of porous structure and nanospherical morphology. Infrared spectra certified the variation of surface functional groups after activation and the successful modification of -SO3H groups after sulfonation. The acidities of catalysts were estimated by an indirect titration method and the modified amount of -SO3H groups were examined by energy dispersive spectra. The results suggested sulfonated porous carbon nanospheres catalysts possessed high acidities and -SO3H densities, which endowed their significantly catalytic activities for biodiesel production. Furthermore, their excellent stability and recycling property were also demonstrated by five consecutive cycles.

Chang, Binbin; Guo, Yanzhen; Yin, Hang; Zhang, Shouren; Yang, Baocheng

2015-01-01

393

Feasibility of dibromochloropropane (DBCP) and trichloroethylene (TCE) adsorption onto activated carbons made from nut shells of different almond varieties  

Technology Transfer Automated Retrieval System (TEKTRAN)

Steam-activated carbons were made from shells from five different almond varieties (‘Nonpareil,’ ‘Padre,’ Tuono,’ ‘23-122,’ and ‘Y120-74’) and from a mix of almond types. The purpose of the work was to evaluate if the composition of shells had any effect on the performance of the final product. The ...

394

Solar gasification of coal, activated carbon, coke and coal and biomass mixtures  

NASA Astrophysics Data System (ADS)

The gasification of subbituminous coal, activated carbon, coke and a mixture of coal and biomass by direct solar irradiation in a solar furnace is investigated. Sunlight concentrated by a 23-kW solar furnace was focused directly on the fuel being gasified in a gravity-fed gasifier through a window in the reactor, and steam or CO2 was passed through the bed to react with the fuel and form a combustible product gas. Experiments performed with coal and steam resulted in the conversion of more than 40% of the sunlight arriving at the reactor focus into chemical fuel, with production rate increasing with solar power and product gas composition and thus gas heating value remaining constant. A typical moisture-free gas composition obtained consists of 54% H2, 25% CO, 16% CO2, 4% CH4 and 1% higher hydrocarbons. Experiments with activated carbon and a uniform mixture of coal and biomass resulted in similar conversion efficiencies but slightly different product gas compositions, while coke showed a lower efficiency. Advantages of solar gasification over conventional oxygen-blown gasifiers are indicated.

Gregg, D. W.; Taylor, R. W.; Campbell, J. H.; Taylor, J. R.; Cotton, A.

1980-01-01

395

The effect of KOH:C and activation temperature on hydrogen storage capacities of activated carbons  

NASA Astrophysics Data System (ADS)

The Alliance for Collaborative Research in Alternative Fuel Technologies (ALL-CRAFTootnotetextSee http://all-craft.missouri.edu) has been producing high surface area activated carbons. Here we will investigate the effect of the ratio of activating agent to carbon and activation temperature on hydrogen sorption characteristics and sample structure. Results show that a ratio of 3:1 KOH:C and an activation temperature of 790 C are the ideal activation conditions for hydrogen storage applications. Hydrogen sorption measurements are completed using a volumetric instrument that operates at pressures up to 100 bar and at temperatures of 80 K, the sublimation temperature of dry ice (-78.5 C), and room temperature. Specific surface area and pore size distributions are measured using subcritical nitrogen isotherms.

Rash, Tyler; Beckner, Matt; Romanos, Jimmy; Leimkuehler, Eric; Takeei, Ali; Suppes, Galen; Wexler, Carlos; Pfeifer, Peter

2011-03-01

396

A geospatial assessment of the relationship between reef flat community calcium carbonate production and wave energy  

NASA Astrophysics Data System (ADS)

The ability of benthic communities inhabiting coral reefs to produce calcium carbonate underpins the development of reef platforms and associated sedimentary landforms, as well as the fixation of inorganic carbon and buffering of diurnal pH fluctuations in ocean surface waters. Quantification of the relationship between reef flat community calcium carbonate production and wave energy provides an empirical basis for understanding and managing this functionally important process. This study employs geospatial techniques across the reef platform at Lizard Island, Great Barrier Reef, to (1) map the distribution and estimate the total magnitude of reef community carbonate production and (2) empirically ascertain the influence of wave energy on community carbonate production. A World-View-2 satellite image and a field data set of 364 ground referencing points are employed, along with data on physical reef characteristics (e.g. bathymetry, rugosity) to map and validate the spatial distribution of the four major community carbonate producers (live coral, carbonate sand, green calcareous macroalgae and encrusting calcified algae) across the reef platform. Carbonate production is estimated for the complete reef platform from the composition of these community components. A synoptic model of wave energy is developed using the Simulating WAves Nearshore (SWAN) two-dimensional model for the entire reef platform. The relationship between locally derived measures of carbonate production and wave energy is evaluated at both the global scale and local scale along spatial gradients of wave energy traversing the reef platform. A wave energy threshold is identified, below which carbonate production levels appear to increase with wave energy and above which mechanical forcing reduces community production. This implies an optimal set of hydrodynamic conditions characterized by wave energy levels of approximately 300 J m-2, providing an empirical basis for management of potential changes in community carbonate production associated with climate change-driven increases in wave energy.

Hamylton, S. M.; Pescud, A.; Leon, J. X.; Callaghan, D. P.

2013-12-01

397

Optimizing Carbon/Nitrogen Ratio for Biosurfactant Production by a Bacillus subtilis Strain  

NASA Astrophysics Data System (ADS)

A Bacillus subtilis strain isolated from contaminated soil from a refinery has been screened for biosurfactant production in crystal sugar (sucrose) with different nitrogen sources (NaNO3' (NH4)2SO4' urea, and residual brewery yeast). The highest reduction in surface tension was achieved with a 48-h fermentation of crystal sugar and ammonium nitrate. Optimization of carbon/nitrogen ratio (3,9, and 15) and agitation rate (50, 150, and 250 rpm) for biosurfactant production was carried out using complete factorial design and response surface analysis. The condition of C/N 3 and 250 rpm allowed the maximum increase in surface activity of biosurfactant. A suitable model has been developed, having presented great accordance experimental data. Preliminary characterization of the bioproduct suggested it to be a lipopeptide with some isomers differing from those of a commercial surfactin.

Fonseca, R. R.; Silva, A. J. R.; de Franca, F. P.; Cardoso, V. L.; Sérvulo, E. F. C.

398

Effect of activator on the structure and desulphurization efficiency of sludge-activated carbon.  

PubMed

Sludge-activated carbons (SACs) prepared with excess of activated sludge are used to solve the problems of sludge disposal and odour pollution in a sewage treatment plant. For the preparation, ZnCl2, KOH and H2SO4 are used as activators, respectively. The structure of the SACs are characterized by scanning electron microscope, X-ray photoelectron spectrometer, specific surface area and pore structure technologies, and the adsorption performance of H2S is investigated. Results indicate that the desulphurization activity of SACs, whose activators are ZnCl2 and KOH (SACZ and SACK), is better than that of carbon with H2SO4 as the activator (SACH). The breakthrough time of SACZ and SACK is up to 86 min, the sulphur capacity is 7.7 mg/cm3, and the maximal iodine value is 409.95 mg/g. While the breakthrough time of SACH is only 26 min with the sulphur capacity of 2.3 mg/cm3. A large percentage of pore volume with a diameter of 2-5 nm in the total pore volume is conductive to the desulphurization reaction. The large amount of surface acid functional groups is also helpful to the adsorption of H2S. The desulphurization activity of SACZ and SACK is superior over that of commercial-activated carbon. PMID:25145213

Li, Fen; Yan, Bo; Zhang, Yanping; Zhang, Linhuan; Lei, Tao

2014-01-01

399

Combined geochemical and electrochemical methodology to quantify corrosion of carbon steel by bacterial activity.  

PubMed

The availability of respiratory substrates, such as H2 and Fe(II,III) solid corrosion products within nuclear waste repository, will sustain the activities of hydrogen-oxidizing bacteria (HOB) and iron-reducing bacteria (IRB). This may have a direct effect on the rate of carbon steel corrosion. This study investigates the effects of Shewanella oneidensis (an HOB and IRB model organism) on the corrosion rate by looking at carbon steel dissolution in the presence of H2 as the sole electron donor. Bacterial effect is evaluated by means of geochemical and electrochemical techniques. Both showed that the corrosion rate is enhanced by a factor of 2-3 in the presence of bacteria. The geochemical experiments indicated that the composition and crystallinity of the solid corrosion products (magnetite and vivianite) are modified by bacteria. Moreover, the electrochemical experiments evidenced that the bacterial activity can be stimulated when H2 is generated in a small confinement volume. In this case, a higher corrosion rate and mineralization (vivianite) on the carbon steel surface were observed. The results suggest that the mechanism likely to influence the corrosion rate is the bioreduction of Fe(III) from magnetite coupled to the H2 oxidation. PMID:24064199

Schütz, Marta K; Moreira, Rebeca; Bildstein, Olivier; Lartigue, Jean-Eric; Schlegel, Michel L; Tribollet, Bernard; Vivier, Vincent; Libert, Marie

2014-06-01

400

Pitch-based activated carbon fibers: The effect of precursor composition on pore structure  

NASA Astrophysics Data System (ADS)

Although researchers have previously investigated the effect of precursor differences on the final properties of activated carbon fibers (ACFs), those precursors were not well-characterized. In particular, detailed information about their molecular composition and anisotropy was not available. In this study, seven oligomeric fractions, each of well-defined composition and molecular weight (mol wt) distribution, were isolated from a commercially produced isotropic petroleum pitch (i.e., Marathon M-50) and used for the production of ACFs. Four of these precursors of varying oligomeric composition were fully isotropic and three contained different levels of mesophase, so that the effects of molecular composition and molecular order were successfully isolated from each other. After the precursors were melt-spun into fibers and stabilized, they were processed by so-called "direct activation", whereby carbonization and activation occurred simultaneously. Separate carbonization tests were also carried out in order to separate out the effects of carbonization vs. activation. Carbonization weight loss was found to be higher for fibers prepared from lower average mol wt (480--550 Da) precursors. The presence of mesophase per se did not affect weight loss during carbonization. On the other hand, activation weight loss (˜28 percent) was found to be essentially independent of precursor mol wt for all isotropic fibers. (Activation weight loss for mesophase-containing fibers was much lower.) The micropore volume of the ACFs was found to increase with decreasing precursor mol wt. However, the ratio of pores smaller than 7 A (i.e., the desired pore size for hydrogen storage) to the total pore volume (3.9--30 A) was found to be essentially constant for all isotropic precursors, suggesting that a similar activation mechanism occurred for all of these materials, with both new pore formation and pore widening proceeding at similar rates. For mesophase-containing precursors, on the other hand, this pore volume ratio significantly decreased with increasing mesophase content, indicating that pore widening dominates over new pore formation for this morphology. In conclusion, this study showed that the lowest mol wt precursor (i.e., a 99 percent dimer cut with a mol wt of 480 Da) attained the highest narrow micropore (?7 A) volume required for hydrogen storage.

Tekinalp, Halil Levent

401

Control of Carbon and Electron Flow in Clostridium acetobutylicum Fermentations: Utilization of Carbon Monoxide to Inhibit Hydrogen Production and to Enhance Butanol Yields  

PubMed Central

Extracts prepared from non-solvent-producing cells of Clostridium acetobutylicum contained methyl viologen-linked hydrogenase activity (20 U/mg of protein at 37°C) but did not display carbon monoxide dehydrogenase activity. CO addition readily inhibited the hydrogenase activity of cell extracts or of viable metabolizing cells. Increasing the partial pressure of CO (2 to 10%) in unshaken anaerobic culture tube headspaces significantly inhibited (90% inhibition at 10% CO) both growth and hydrogen production by C. acetobutylicum. Growth was not sensitive to low partial pressures of CO (i.e., up to 15%) in pH-controlled fermentors (pH 4.5) that were continuously gassed and mixed. CO addition dramatically altered the glucose fermentation balance of C. acetobutylicum by diverting carbon and electrons away from H2, CO2, acetate, and butyrate production and towards production of ethanol and butanol. The butanol concentration was increased from 65 to 106 mM and the butanol productivity (i.e., the ratio of butanol produced/total acids and solvents produced) was increased by 31% when glucose fermentations maintained at pH 4.5 were continuously gassed with 85% N2-15% CO versus N2 alone. The results are discussed in terms of metabolic regulation of C. acetobutylicum saccharide fermentations to achieve maximal butanol or solvent yield. PMID:16346643

Kim, Byung Hong; Bellows, Para; Datta, Rathin; Zeikus, J. G.

1984-01-01

402

An investigation of the activity of carbon blacks recovered from elastomer composites  

Microsoft Academic Search

The activity of carbon blacks recovered from elastomer systems is determined by use of a temperature jump technique imposed on the carbon blacks in air using a TG unit. The elastomer composites were composed of styrene-butadiene rubber (SRR), fillers, activators, accelerators together with a number of different carbon blacks. The organic content was pyrolyzed away by heating in nitrogen, the

J. Azizi; D. Dollimore; G. R. Heal; W. A. Kneller; P. Manley; C. C. Philip

1996-01-01

403

Production of fumaric acid by Rhizopus oryzae: role of carbon-nitrogen ratio.  

PubMed

Cytosolic fumarase, a key enzyme for the accumulation of fumaric acid in Rhizopus oryzae, catalyzes the dehydration of L-malic acid to fumaric acid. The effects of carbon-nitrogen ratio on the acid production and activity of cytosolic fumarase were investigated. Under nitrogen limitation stress, the cytosolic fumarase could keep high activity. With the urea concentration decreased from 2.0 to 0.1 g l?¹, the cytosolic fumarase activity increased by 300% and the production of fumaric acid increased from 14.4 to 40.3 g l?¹ and L-malic acid decreased from 2.1 to 0.3 g l?¹. Cytosolic fumarase could be inhibited by substrate analog 3-hydroxybutyric acid. With the addition of 3-hydroxybutyric acid (50 mM) in the fermentation culture, fumaric acid production decreased from 40.3 to 14.1 g l?¹ and L-malic acid increased from 0.3 to 5.4 g l?¹. PMID:21416336

Ding, Yueyue; Li, Shuang; Dou, Chang; Yu, Yang; Huang, He

2011-08-01

404

The impact of co-occurring tree and grassland species on carbon sequestration and potential biofuel production  

E-print Network

The impact of co-occurring tree and grassland species on carbon sequestration and potential biofuel for terrestrial carbon sequestration and potential biofuel production. For P. strobus, above- ground plant carbon harvest for biofuel would result in no net carbon sequestration as declines in soil carbon offset plant

Weiblen, George D

405

Conducting polymer transistors making use of activated carbon gate electrodes.  

PubMed

The characteristics of the gate electrode have significant effects on the behavior of organic electrochemical transistors (OECTs), which are intensively investigated for applications in the booming field of organic bioelectronics. In this work, high specific surface area activated carbon (AC) was used as gate electrode material in OECTs based on the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) doped with poly(styrenesulfonate) (PSS). We found that the high specific capacitance of the AC gate electrodes leads to high drain-source current modulation in OECTs, while their intrinsic quasi-reference characteristics make unnecessary the presence of an additional reference electrode to monitor the OECT channel potential. PMID:25510960

Tang, Hao; Kumar, Prajwal; Zhang, Shiming; Yi, Zhihui; Crescenzo, Gregory De; Santato, Clara; Soavi, Francesca; Cicoira, Fabio

2015-01-14

406

DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS  

SciTech Connect

The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. These carbon products include materials used in metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to as ''carbon foam'' and carbon fibers. The Hydrotreatment Facility is being prepared for trials with coal liquids. Raw coal tar distillate trials have been carried out by heating coal tar in the holding tank in the Hydrotreatment Facility. The liquids are centrifuged to warm the system up in preparation for the coal liquids. The coal tar distillate is then recycled to keep the centrifuge hot. In this way, the product has been distilled such that a softening point of approximately 110 C is reached. Then an ash test is conducted.

Elliot B. Kennel; Chong Chen; Dady Dadyburjor; Liviu Magean; Peter G. Stansberry; Alfred H. Stiller; John W. Zondlo

2005-07-13

407

75 FR 25841 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time...  

Federal Register 2010, 2011, 2012, 2013, 2014

...COMMERCE International Trade Administration [A-580-816] Corrosion-Resistant Carbon Steel Flat Products From the Republic of...the administrative review of the antidumping duty order on corrosion-resistant carbon steel flat products from the Republic...

2010-05-10

408

77 FR 16810 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time...  

Federal Register 2010, 2011, 2012, 2013, 2014

...COMMERCE International Trade Administration [C-580-818] Corrosion-Resistant Carbon Steel Flat Products From the Republic of...published in the Federal Register the countervailing duty order on corrosion-resistant carbon steel flat products (CORE) from...

2012-03-22

409

76 FR 21332 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time...  

Federal Register 2010, 2011, 2012, 2013, 2014

...COMMERCE International Trade Administration [A-580-816] Corrosion-Resistant Carbon Steel Flat Products From the Republic of...the administrative review of the antidumping duty order on corrosion-resistant carbon steel flat products from the Republic...

2011-04-15

410

76 FR 20954 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time...  

Federal Register 2010, 2011, 2012, 2013, 2014

...COMMERCE International Trade Administration [C-580-818] Corrosion-Resistant Carbon Steel Flat Products From the Republic of...published in the Federal Register the countervailing duty order on corrosion-resistant carbon steel flat products (CORE) from...

2011-04-14

411

77 FR 25405 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time...  

Federal Register 2010, 2011, 2012, 2013, 2014

...COMMERCE International Trade Administration [A-580-816] Corrosion-Resistant Carbon Steel Flat Products From the Republic of...the administrative review of the antidumping duty order on corrosion-resistant carbon steel flat products from the Republic...

2012-04-30

412

78 FR 42039 - Certain Hot-Rolled Carbon Steel Flat Products From the People's Republic of China: Preliminary...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Trade Administration [A-570-865] Certain Hot-Rolled Carbon Steel Flat Products From the People's...review of the antidumping duty order on certain hot- rolled carbon steel flat products (``hot-rolled steel'') from the People's...

2013-07-15

413

75 FR 1031 - Certain Hot-Rolled Carbon Steel Flat Products from India: Notice of Preliminary Results of...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration (A-533-820) Certain Hot-Rolled Carbon Steel Flat Products from...review of the antidumping order on certain hot-rolled carbon steel flat products from India (``Indian Hot-Rolled'') manufactured by Essar...

2010-01-08

414

76 FR 48143 - Certain Hot-Rolled Carbon Steel Flat Products From the People's Republic of China: Preliminary...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Trade Administration [A-570-865] Certain Hot-Rolled Carbon Steel Flat Products From the People's...review of the antidumping duty order on certain hot- rolled carbon steel flat products (``hot-rolled'') from the People's Republic...

2011-08-08

415

75 FR 27297 - Certain Hot-Rolled Carbon Steel Flat Products from India: Notice of Final Results of Antidumping...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-533-820] Certain Hot-Rolled Carbon Steel Flat Products from...antidumping duty administrative review for certain hot-rolled carbon steel flat products from India (``Indian Hot-Rolled''). See Certain...

2010-05-14

416

78 FR 40428 - Certain Hot-Rolled Carbon Steel Flat Products from India: Rescission of Antidumping Duty...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Trade Administration [A-533-820] Certain Hot-Rolled Carbon Steel Flat Products from India...review of the antidumping duty order on certain hot- rolled carbon steel flat products (hot rolled steel) from India for the period...

2013-07-05

417

77 FR 45576 - Certain Hot-Rolled Carbon Steel Flat Products From the People's Republic of China: Preliminary...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Trade Administration [A-570-865] Certain Hot-Rolled Carbon Steel Flat Products From the People's...review of the antidumping duty order on certain hot- rolled carbon steel flat products (``hot-rolled steel'') from the People's...

2012-08-01

418

76 FR 7546 - Certain Hot-Rolled Carbon Steel Flat Products From Brazil: Rescission of Countervailing Duty...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Trade Administration [C-351-829] Certain Hot-Rolled Carbon Steel Flat Products From Brazil...review of the countervailing duty order on certain hot- rolled carbon steel flat products (hot-rolled steel) from Brazil for the period...

2011-02-10

419

76 FR 66901 - Certain Hot-Rolled Carbon Steel Flat Products From the People's Republic of China: Final...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Trade Administration [A-570-865] Certain Hot-Rolled Carbon Steel Flat Products From the People's...review of the antidumping duty order on certain hot-rolled carbon steel flat products (``hot-rolled'') from the People's Republic...

2011-10-28

420

77 FR 69790 - Certain Hot-Rolled Carbon Steel Flat Products From the People's Republic of China: Final Results...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Trade Administration [A-570-865] Certain Hot-Rolled Carbon Steel Flat Products From the People's...review of the antidumping duty order on certain hot- rolled carbon steel flat products (``hot-rolled steel'') from the People's...

2012-11-21

421

76 FR 2344 - Certain Hot-Rolled Carbon Steel Flat Products From India: Notice of Preliminary Results of...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-533-820] Certain Hot-Rolled Carbon Steel Flat Products From...of the antidumping duty order on certain hot-rolled carbon steel flat products from India (``Indian Hot-Rolled'') manufactured by Essar...

2011-01-13

422

78 FR 64473 - Certain Hot-Rolled Carbon Steel Flat Products From the People's Republic of China: Final No...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Trade Administration [A-570-865] Certain Hot-Rolled Carbon Steel Flat Products From the People's...review of the antidumping duty order on certain hot- rolled carbon steel flat products (``hot-rolled steel'') from the People's...

2013-10-29

423

76 FR 31938 - Certain Hot-Rolled Carbon Steel Flat Products From India: Notice of Preliminary Results of 2009...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Trade Administration [A-533-820] Certain Hot-Rolled Carbon Steel Flat Products From India...review of the antidumping duty order on certain hot-rolled carbon steel flat products from India (``hot-rolled steel'') manufactured by...

2011-06-02

424

76 FR 62039 - Certain Hot-Rolled Carbon Steel Flat Products From India: Final Results of 2009-2010 Antidumping...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Trade Administration [A-533-820] Certain Hot-Rolled Carbon Steel Flat Products From India...review of the antidumping duty order on certain hot-rolled carbon steel flat products from India (``hot-rolled steel'') manufactured by...

2011-10-06

425

75 FR 55742 - Certain Hot-Rolled Carbon Steel Flat Products from India: Extension of Time Limit for Preliminary...  

Federal Register 2010, 2011, 2012, 2013, 2014

...International Trade Administration [A-533-820] Certain Hot-Rolled Carbon Steel Flat Products from India: Extension of...initiation of antidumping duty administrative review of certain hot- rolled carbon steel flat products from India for the...

2010-09-14

426

Dye removal of activated carbons prepared from NaOH-pretreated rice husks by low-temperature solution-processed carbonization and H3PO4 activation.  

PubMed

A coupling of low-temperature sulfuric acid-assisted carbonization and H3PO4 activation was employed to convert NaOH-pretreated rice husks into activated carbons with extremely high surface area (2028 m(2) g(-1)) and integrated characteristics. The influences of the activation temperature and impregnation ratio on the surface area, pore volume of activated carbons were thoroughly investigated. The morphology and surface chemistry of activated carbons were characterized using N2 sorption, FTIR, XPS, SEM, TEM, etc. The adsorption capacity of resulting carbons obtained under optimum preparation conditions was systematically evaluated using methylene blue under various simulated conditions. The adsorption process can be well described by both Langmuir isotherm model and the pseudo-second order kinetics models; and the maximum monolayer capacity of methylene blue was ca. 578 mg g(-1). PMID:23892148

Chen, Yun; Zhai, Shang-Ru; Liu, Na; Song, Yu; An, Qing-Da; Song, Xiao-Wei

2013-09-01

427

JV Task 119 - Effects of Aging on Treated Activated Carbons  

SciTech Connect

For both the United States and Canada, testing has been under way for electric utilities to find viable and economical mercury control strategies to meet pending future mercury emission limits. The technology that holds the most promise for mercury control in low-chlorine lignite to meet the needs of the Clean Air Act in the United States and the Canada-Wide Standards in Canada is injection of treated activated carbon (AC) into the flue gas stream. Most of the treated carbons are reported to be halogenated, often with bromine. Under a previous multiyear project headed by the Energy & Environmental Research Center (EERC), testing was performed on a slipstream unit using actual lignite-derived flue gas to evaluate various sorbent technologies for their effectiveness, performance, and cost. Testing under this project showed that halogenated ACs performed very well, with mercury capture rates often {ge} 90%. However, differences were noted between treated ACs with respect to reactivity and capacity, possibly as a result of storage conditions. Under certain conditions (primarily storage in ambient air), notable performance degradation had occurred in mercury capture efficiency. Therefore, a small exploratory task within this project evaluated possible differences resulting from storage conditions and subsequent effects of aging that might somehow alter their chemical or physical properties. In order to further investigate this potential degradation of treated (halogenated) ACs, the EERC, together with DOE's National Energy Technology Laboratory, the North Dakota Industrial Commission (NDIC), the Electric Power Research Institute (EPRI), SaskPower, and Otter Tail Power Company, assessed the aging effects of brominated ACs for the effect that different storage durations, temperatures, and humidity conditions have on the mercury sorption capacity of treated ACs. No aging effects on initial capture activity were observed for any carbons or conditions in the investigation. As measured by the 50% breakthrough time, no changes in capacity were observed for Norit LH samples stored frozen and likely none for Norit LH samples stored under high humidity conditions. The major aging effects on capacity for the EERC brominated sample were seen as a decrease in capacity during the first week of storage under high humidity conditions. Storage of the Norit LH and the EERC 5% brominated samples under low humidity conditions resulted in slightly improved capacities. Storage of the 15% brominated sample under high humidity conditions also improved the capacity. Surface analysis using x-ray photoelectron spectroscopy (XPS) showed some migration of bromine to and from the surface occurred during storage, although no net loss of bromine was observed. The migration to the surface in the case of the 15% brominated carbon correlates with the increased capacity observed for this sample. The XPS elemental speciation data for the EERC brominated carbons showed a trend toward more bromide being formed at the expense of covalent bromine during storage. This was especially great for the 15% and the 5% stored in low humidity. The Norit LH samples did not show this increase in bromide concentration. This is consistent with the lack of change in capacity for the Norit LH during storage. The carbon speciation data showed generally more oxidization of carbon surfaces with storage, especially formation of carboxylate groups. The least increase in carboxylate groups was seen for the Norit LH stored under low humidity, which correlates with its increased capacity. In conclusion, the observed changes in surface chemistry can be related to the minimal changes in capacity observed, but the factors operate in different directions, so the relationships are complex. High-quality x-ray absorption fine structure spectra were obtained for most of the samples. Significant changes were observed in the x-ray absorption near edge structure and extended x-ray absorption fine structure spectra of the stored carbons, but proved difficult to interpret and correlate with structural

Edwin Olson; Lucinda Hamre; John Pavlish; Blaise Mibeck

2009-03-25

428

Production of carbon molecular sieves from Illinois coal. Technical report, December 1, 1992--February 28, 1993  

SciTech Connect

Carbon molecular sieves (CMS) have become an increasingly important class of adsorbents for use in gas separation and recovery processes. The overall objective of this project is to determine whether Illinois Basin coals are suitable feedstocks for the production of CMS and to evaluate the potential application of these products in commercial gas separation processes. In Phase 1 of this project, gram quantities of char were prepared from Illinois coal in a fixed-bed reactor under a wide range of pyrolysis and activation conditions. Chars having surface areas of 1500--2100 M{sup 2}/g were produced by chemical activation using potassium hydroxide (KOH) as the activant. These high surface area chars had more than twice the adsorption capacity of commercial molecular sieves. The kinetics of adsorption of various gases, e.g., N{sub 2}, O{sub 2}, CO{sub 2}, CH{sub 4}, CO and H{sub 2}, on these chars at 25{degrees}C was determined. Several chars showed good potential for efficient O{sub 2}/N{sub 2}, CO{sub 2}/CH{sub 4}, CO{sub 2}/H{sub 2} and CH{sub 4}/H{sub 2} separation; both a high adsorption capacity and selectivity were achieved. The full potential of these materials in commercial gas separations has yet to be realized. In Phase 2 of this project, currently in progress, larger quantities of char are being prepared from Illinois coal in a batch fluidized-bed reactor (FBR) and in a continuous rotary tube kiln (RTK). The pore structure of the prepared chars will be tailored for a specific gas separation process by activation in CO{sub 2} and H{sub 2}O and/or carbon deposition with CH{sub 4}.

Lizzio, A.A.; Rostam-Abadi, M. [Illinois Dept. of Energy and Natural Resources, Springfield, IL (United States). Geological Survey; Banerjee, D.D. [Illinois Clean Coal Inst., Carterville, IL (United States)

1993-05-01

429

Carbonic anhydrase activity in isolated chloroplasts of chlamydomonas reinhardtii  

SciTech Connect

In a new assay of carbonic anhydrase, NaH{sup 14}CO{sub 3} solution at the bottom of a sealed vessel releases {sup 14}CO{sub 3} which diffuses to the top of the vessel to be assimilated by actively photosynthesizing Chlamydomonas cells. The assay is initiated by illuminating cells and stopped by turning the light off and killing the cells with acid. Enzyme activity was estimated from acid stable radioactivity above the uncatalyzed background level. With bovine carbonic anhydrase, 1.5 Wilbur Anderson Unit (WAU) can be consistantly measured at 5-6 fold above background. Sonicated whole cells of air adapted wild type (+)gave 741.1 {plus minus} 12.4 WAU/mg chl. Intact washed cells of mixotrophically grown wall-less mutant CWD(-) and a high CO2 requiring wall-less double mutant CIA-3/CW15 (-) gave 7.1 {plus minus} 1.9 and 2.8 {plus minus} 7.8 WAU/mg chl respectively. Chloroplasts isolated from CWD and CIA-3/CW15 and subsequently disrupted gave 64.0 {plus minus} 14.7 and 2.8 {plus minus} 3.2 WAU/mg chl respectively. Chloroplast sonicate from another wall-less mutant CW15(-) gave activity comparable to CWD. Thus on a chlorophyll basis, enzyme activity in chloroplasts from mixotrophically grown cells is about 1/10th of the level found in air adapted wild type cells. CIA-3 seems to lack this activity.

Katzman, G.; Togasaki, R.K. (Indiana Univ., Bloomington (USA)); Marcus, Y. (Carnegie Institute, Stanford, CA (USA)); Moroney, J.V. (Louisiana State Univ., Baton Rouge (USA))

1989-04-01

430

Surface heterogeneity effects of activated carbons on the kinetics of paracetamol removal from aqueous solution  

NASA Astrophysics Data System (ADS)

The removal of a compound with therapeutic activity (paracetamol) from aqueous solutions using chemically modified activated carbons has been investigated. The chemical nature of the activated carbon material was modified by wet oxidation, so as to study the effect of the carbon surface chemistry and composition on the removal of paracetamol. The surface heterogeneity of the carbon created upon oxidation was found to be a determinant in the adsorption capability of the modified adsorbents, as well as in the rate of paracetamol removal. The experimental kinetic data were fitted to the pseudo-second order and intraparticle diffusion models. The parameters obtained were linked to the textural and chemical features of the activated carbons. After oxidation the wettability of the carbon is enhanced, which favors the transfer of paracetamol molecules to the carbon pores (smaller boundary layer thickness). At the same time the overall adsorption rate and removal efficiency are reduced in the oxidized carbon due to the competitive effect of water molecules.

Ruiz, B.; Cabrita, I.; Mestre, A. S.; Parra, J. B.; Pires, J.; Carvalho, A. P.; Ania, C. O.

2010-06-01

431

Importance of structural and chemical heterogeneity of activated carbon surfaces for adsorption of dibenzothiophene  

SciTech Connect

The performance of various activated carbons obtained from different carbon precursors (i.e., plastic waste, coal, and wood) as adsorbents for the desulfurization of liquid hydrocarbon fuels was evaluated. To increase surface heterogeneity, the carbon surface was modified by oxidation with ammonium persulfate. The results showed the importance of activated carbon pore sizes and surface chemistry for the adsorption of dibenzothiophene (DBT) from liquid phase. Adsorption of DBT on activated carbons is governed by two types of contributions: physical and chemical interactions. The former include dispersive interactions in the microporous network of the carbons. While the volume of micropores governs the amount physisorbed, mesopores control the kinetics of the process. On the other hand, introduction of surface functional groups enhances the performance of the activated carbons as a result of specific interactions between the acidic centers of the carbon and the basic structure of DBT molecule as well as sulfur-sulfur interactions.

Ania, C.O.; Bandosz, T.J. [CUNY City College, New York, NY (United States). Dept. of Chemistry

2005-08-16

432

The Carbon Cycle and its Role in Climate Change: Activity 2  

NSDL National Science Digital Library

In this activity (on page 7), learners explore the meaning of a "carbon sink." Using simple props, learners and/or an educator demonstrate how plants act as carbon sinks and how greenhouse gases cause global warming. This activity is the second in a series of three activities that introduce learners to the carbon cycle (see related sources), although it is not mandatory that all three activities are completed as a set.

2014-05-29

433

Activated carbon nanotubes: a highly-active metal-free electrocatalyst for hydrogen evolution reaction.  

PubMed

In this communication, for the first time, we report on the development and utilization of activated carbon nanotubes (CNTs) as a highly-active metal-free electrocatalyst for the hydrogen evolution reaction (HER) with good durability in acidic electrolytes. This catalyst shows an onset overpotential and an exchange current density of 100 mV and 16.0 × 10(-3) mA cm(-2), respectively. The possible catalytic mechanism for the HER is also proposed. PMID:25000967

Cui, Wei; Liu, Qian; Cheng, Ningyan; Asiri, Abdullah M; Sun, Xuping

2014-08-25

434

Short and long-term carbon balance of bioenergy electricity production fueled by forest treatments  

PubMed Central

Background Forests store large amounts of carbon in forest biomass, and this carbon can be released to the atmosphere following forest disturbance or management. In the western US, forest fuel reduction treatments designed to reduce the risk of high severity wildfire can change forest carbon balance by removing carbon in the form of biomass, and by altering future potential wildfire behavior in the treated stand. Forest treatment carbon balance is further affected by the fate of this biomass removed from the forest, and the occurrence and intensity of a future wildfire in this stand. In this study we investigate the carbon balance of a forest treatment with varying fates of harvested biomass, including use for bioenergy electricity production, and under varying scenarios of future disturbance and regeneration. Results Bioenergy is a carbon intensive energy source; in our study we find that carbon emissions from bioenergy electricity production are nearly twice that of coal for the same amount of electricity. However, some emissions from bioenergy electricity production are offset by avoided fossil fuel electricity emissions. The carbon benefit achieved by using harvested biomass for bioenergy electricity production may be increased through avoided pyrogenic emissions if the forest treatment can effectively reduce severity. Conclusion Forest treatments with the use of harvested biomass for electricity generation can reduce carbon emissions to the atmosphere by offsetting fossil fuel electricity generation emissions, and potentially by avoided pyrogenic emissions due to reduced intensity and severity of a future wildfire in the treated stand. However, changes in future wildfire and regeneration regimes may affect forest carbon balance and these climate-induced changes may influence forest carbon balance as much, or more, than bioenergy production. PMID:25187788

2014-01-01

435

Post spinning and pyrolysis processes of polyacrylonitrile (PAN)-based carbon fiber and activated carbon fiber: A review  

Microsoft Academic Search

This paper reviews pyrolysis process to convert PAN precursor fiber into PAN-based carbon fiber and activated carbon fiber. The parameters involved during heat treatment of PAN fiber are consistently discussed. Post spinning treatments of PAN fiber are also discussed in this paper as it has a crucial contribution towards the success of pyrolysis processes. Finally, the recent development and future

N. Yusof; A. F. Ismail

436

New Product Development for Green and Low-Carbon Products—A Case Study of Taiwan's TFT-LCD Manufacturer  

NASA Astrophysics Data System (ADS)

Green supply chain has become an important topic these days due to pollution, global warming, extreme climatic events, etc. A green product is manufactured with the goal of reducing the damage to the environment and limiting the use of energy and other resources at any stage of its life, including raw materials, manufacture, use, and disposal. Carbon footprint is a good measure of the impact that a product has on the environment, especially in climate change, in the entire lifetime of the product. Carbon footprint is directly linked to CO2 emission; thus, the reduction of CO2 emission must be considered in the product life cycle. Although more and more researchers are working on the green supply chain management in the past few years, few have incorporated CO2 emission or carbon footprint into the green supply chain system. Therefore, this research aims to propose an integrated model for facilitating the new product development (NPD) for green and low-carbon products. In this research, a systematic model based on quality function deployment (QFD) is constructed for developing green and low-carbon products in a TFT-LCD manufacturer. Literature review and interviews with experts are done first to collect the factors for developing and manufacturing green and low-carbon products. Fuzzy Delphi method (FDM) is applied next to extract the important factors, and fuzzy interpretive structural modeling (FISM) is used subsequently to understand the relationships among factors. A house of quality (HOQ) for product planning is built last. The results shall provide important information for a TFT-LCD firm in designing a new product.

Lin, Chun-Yu; Lee, Amy H. I.

2011-11-01

437

[Adsorption kinetics of reactive dyes on activated carbon fiber].  

PubMed

The adsorption capability of activated carbon fiber (ACF) to four reactive dyes (reactive brilliant red K-2BP, reactive turquoise blue KN-G, reactive golden yellow K-3RP, reactive black KN-B) in aqueous solution was studied, and adsorption mechanism was focused on from kinetics point of view. The results show that the equilibrium adsorbing capacity (q(e)) of each dye increases with the addition of initial concentration or temperature. On the same condition, the order of q(e) is: reactive brilliant red > reactive golden yellow > reactive black > reactive turquoise blue. The adsorption processes follow a pseudo second-order kinetic rate equation, and the steric structure, size and polarity of dyes are important influence factors to initial adsorption rate. The adsorption activation energy of each dye is low (16.42, 3.56, 5.21, 26.38 kJ x mol(-1) respectively), which indicates that it belongs to physics adsorption. PMID:18290496

Li, Ying; Yue, Qin-Yan; Gao, Bao-Yu; Yang, Jing; Zheng, Yan

2007-11-01

438

DOES TERRESTRIAL CARBON SUBSIDIZE PRODUCTION OF ESTUARINE FISH LARVAE?  

EPA Science Inventory

The research presented demonstrates the important role that terrestrial ecosystems can play in coastal food webs. We show that terrestrial carbon subsidizes the tidal freshwater and oligohaline portions of an estuarine food web, but that this exogenous carbon source is not impor...

439

Structure of Carbon Nanotubes as a Product of Processing Parameters  

E-print Network

of structures, the properties of this material vary from sample to sample creating quite a fuss in the research world. While many scientists put the majority of their focus on properties, it is important to take form various arrays of carbon nanotubes. Furnace Build and Sample Growth In order to grow carbon

Collins, Gary S.

440

Distribution of and changes in industrial carbon dioxide production  

Microsoft Academic Search

The burning of fossils fuels is believed to be the major source responsible for an observed increase in the concentration of carbon dioxide in the atmosphere now measured at many locations around the world. This paper revises earlier published data on the annual amounts of carbon released to the atmosphere during the period 1950--1978 and updates the record through 1980.

Ralph M. Rotty

1983-01-01