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1

Production of activated carbons from Illinois coals  

Microsoft Academic Search

Although the predominant use of coal is for combustion applications, more beneficial, reasonable and profitable uses may be as a resource for the production of chemicals, and materials, including activated carbon. Activated carbons represent a family of carbonaceous substances manufactured by processes that develop the carbon`s adsorptive properties. The primary objective of this study was to demonstrate that an activated

E. J. Hippo; Jian Sun

1996-01-01

2

Production of activated carbons from almond shell  

Microsoft Academic Search

The production of activated carbons from almond shell, using physical activation by CO2 is reported in this work. The used method has produced activated carbons with apparent BET surface areas and micropore volume as high as 1138m2g?1 and 0.49cm3g?1, respectively. The activated carbons produced have essentially primary micropores and only a small volume of wider micropores. By FTIR analysis it

João M. Valente Nabais; Carlos Eduardo C. Laginhas; P. J. M. Carrott; M. M. L. Ribeiro Carrott

2011-01-01

3

JV Task 90 - Activated Carbon Production from North Dakota Lignite  

Microsoft Academic Search

The Energy & Environmental Research Center (EERC) has pursued a research program for producing activated carbon from North Dakota lignite that can be competitive with commercial-grade activated carbon. As part of this effort, small-scale production of activated carbon was produced from Fort Union lignite. A conceptual design of a commercial activated carbon production plant was drawn, and a market assessment

Steven Benson; Charlene Crocker; Rokan Zaman; Mark Musich; Edwin Olson

2008-01-01

4

Reprocessing of used tires into activated carbon and other products  

Microsoft Academic Search

Landfilling used tires which are generated each year in the US is increasingly becoming an unacceptable solution. A better approach, from an environmental and economic standpoint, is to thermally reprocess the tires into valuable products such as activated carbon, other solid carbon forms (carbon black, graphite, and carbon fibers), and liquid fuels. In this study, high surface area activated carbons

Hsisheng Teng; Michael A. Serio; Marek A. Wojtowicz; Rosemary Bassilakis; Peter R. Solomon

1995-01-01

5

Production of active carbons from waste tyres––a review  

Microsoft Academic Search

A review of the production of activated carbons from waste tyres is presented. The effects of various process parameters, particularly, temperature and heating rate, on the pyrolysis stage are reviewed. The influence of activating conditions, physical and chemical, nature of the activation chemicals, on the active carbon properties are discussed. Under certain process conditions several active carbons with BET surface

Edward L. K. Mui; Danny C. K. Ko; Gordon McKay

2004-01-01

6

PRODUCTION OF ACTIVATED CARBON FROM COAL CHARS USING MICROWAVE ENERGY  

Microsoft Academic Search

The microwave induced reaction of carbon with carbon dioxide has been investigated as a method of production of activated carbon using coal char. Factors which control the carbon-carbon dioxide reaction in a microwave environment were also studied.Results indicate that the reaction rate is primarily controlled by the electric field strength. The reaction rate or conversion follows an Arrhenius type relationship

LOREN M. NORMAN; C. Y. CHA

1995-01-01

7

Production of charcoal and activated carbon at elevated pressure  

Microsoft Academic Search

With its wide range of properties, charcoal finds many commercial applications for domestic cooking, refining of metals (steel, copper, bronze, nickel, aluminum and electro-manganese), production of chemicals (carbon disulfide, calcium carbide, silicon carbide, sodium cyanide, carbon black, fireworks, gaseous chemicals, absorbents, soil conditioners and pharmaceuticals), as well as production of activated carbon and synthesis gas. In 1991, the world production

Xiangfeng Dai; N. Norberg; M. J. Jr. Antal

1995-01-01

8

Production of special activated carbon from lignite for environmental purposes  

Microsoft Academic Search

A treatment technique involving three sequential stages (demineralisation, activation and sulphur dispersion) was developed for the production of suitable activated carbons from Greek lignite. Demineralisation included three steps of acid treatment and samples received were characterised by X-ray diffraction (XRD). A two-stage activation procedure (pyrolysis under nitrogen, followed by activation under carbon dioxide atmosphere) was used for the production of

G Skodras; Th Orfanoudaki; E Kakaras; G. P Sakellaropoulos

2002-01-01

9

Production of activated carbon from olive bagasse by physical activation  

Microsoft Academic Search

Activated carbons were produced from olive bagasse and their characteristics were investigated. Olive bagasse was first carbonized at 500°C in N2 atmosphere. Then, the obtained chars were activated with steam. The effects of activation temperature and duration were examined. The resultant activated carbons were characterized by measuring their porosities and pore size distributions. The activated carbons produced had the BET

Hakan Demiral; ?lknur Demiral; Belgin Karabacako?lu; Fatma Tümsek

2011-01-01

10

Production and characterization of granular activated carbon from activated sludge  

Microsoft Academic Search

In this study, activated sludge was used as a precursor to prepare activated carbon using sulfuric acid as a chemical activation agent. The effect of preparation conditions on the produced activated carbon characteristics as an adsorbent was investigated. The results indicate that the produced activated carbon has a highly porous structure and a specific surface area of 580 m 2

Z. Al-Qodah; R. Shawabkah

2009-01-01

11

Production of activated carbon from rubber wood sawdust  

Microsoft Academic Search

The present work comprehensively addresses various experimental methods reported in the literature and substantiates the use of two-stage activation process with semi-carbonization stage up to 200°C as first stage followed by an activation stage at a desired temperature, for production of activated carbon from carbonaceous precursors using phosphoric acid. Efforts are made towards developing a high surface area activated carbon

C. Srinivasakannan; Mohamad Zailani Abu Bakar

2004-01-01

12

DEVELOPMENT OF ACTIVATED CARBONS FROM COAL COMBUSTION BY-PRODUCTS  

SciTech Connect

The increasing role of coal as a source of energy in the 21st century will demand environmental and cost-effective strategies for the use of coal combustion by-products (CCBPs), mainly unburned carbon in fly ash. Unburned carbon is nowadays regarded as a waste product and its fate is mainly disposal, due to the present lack of efficient routes for its utilization. However, unburned carbon is a potential precursor for the production of adsorbent carbons, since it has gone through a devolatilization process while in the combustor, and therefore, only requires to be activated. Accordingly, the principal objective of this work was to characterize and utilize the unburned carbon in fly ash for the production of activated carbons. The unburned carbon samples were collected from different combustion systems, including pulverized utility boilers, a utility cyclone, a stoker, and a fluidized bed combustor. LOI (loss-on-ignition), proximate, ultimate, and petrographic analyses were conducted, and the surface areas of the samples were characterized by N2 adsorption isotherms at 77K. The LOIs of the unburned carbon samples varied between 21.79-84.52%. The proximate analyses showed that all the samples had very low moisture contents (0.17 to 3.39 wt %), while the volatile matter contents varied between 0.45 to 24.82 wt%. The elemental analyses show that all the unburned carbon samples consist mainly of carbon with very little hydrogen, nitrogen, sulfur and oxygen In addition, the potential use of unburned carbon as precursor for activated carbon (AC) was investigated. Activated carbons with specific surface area up to 1075m{sup 2}/g were produced from the unburned carbon. The porosity of the resultant activated carbons was related to the properties of the unburned carbon feedstock and the activation conditions used. It was found that not all the unburned carbon samples are equally suited for activation, and furthermore, their potential as activated carbons precursors could be inferred from their physical and chemical properties. The developed porosity of the activated carbon was a function of the oxygen content, porosity and H/C ratio of the parent unburned carbon feedstock. It was observed that extended activation times and high activation temperatures increased the porosity of the produced activated carbon at the expense of the solid yield. The development of activated carbon from unburned carbon in fly ash has been proven to be a success by this study in terms of the higher surface areas of the resultant activated carbons, which are comparable with commercial activated carbons. However, unburned carbon samples obtained from coal-fired power plants as by-product have high ash content, which is unwanted for the production of activated carbons. Therefore, the separation of unburned carbon from the fly ash is expected to be beneficial for the utilization of unburned carbon to produce activated carbons with low ash content.

Harold H. Schobert; M. Mercedes Maroto-Valer; Zhe Lu

2003-09-30

13

Simulation of the carbonization stage in the production of activated carbons from wood wastes  

Microsoft Academic Search

A mathematical model of the stage of carbonization of the wood batch was developed, and physicochemical constants of the carbonization reaction were determined. The simulation of the carbonization stage was carried out with the use of a computer, and the parameters of carbonization in the tubular element of a small-capacity commercial reactor for production of activated carbon from plant wastes

Samoilov

1994-01-01

14

Reprocessing of used tires into activated carbon and other products  

SciTech Connect

Landfilling used tires which are generated each year in the US is increasingly becoming an unacceptable solution. A better approach, from an environmental and economic standpoint, is to thermally reprocess the tires into valuable products such as activated carbon, other solid carbon forms (carbon black, graphite, and carbon fibers), and liquid fuels. In this study, high surface area activated carbons (> 800 m{sup 2}/g solid product) were produced in relatively high yields by pyrolysis of tires at up to 900 C, followed by activation in CO{sub 2} at the same temperature. The surface areas of these materials are comparable with those of commercial activated carbons. The efficiency of the activation process (gain in specific surface area/loss in mass) was greatest (up to 138 m{sup 2}/g original tire) when large pieces of tire material were used ({approximately} 170 mg). Oxygen pretreatment of tires was found to enhance both the yield and the surface area of the carbon product. High-pressure treatment of tires at low temperatures (< 400 C) is an alternative approach if the recovery of carbon black or fuel oils is the primary objective.

Teng, H.; Serio, M.A.; Wojtowicz, M.A.; Bassilakis, R.; Solomon, P.R. [Advanced Fuel Research, Inc., East Hartford, CT (United States)

1995-09-01

15

DEVELOPMENT OF ACTIVATED CARBONS FROM COAL COMBUSTION BY-PRODUCTS  

SciTech Connect

The increasing role of coal as a source of energy in the 21st century will demand environmental and cost-effective strategies for the use of coal combustion by-products (CCBPs), mainly unburned carbon in fly ash. Unburned carbon is nowadays regarded as a waste product and its fate is mainly disposal, due to the present lack of efficient routes for its utilization. However, unburned carbon is a potential precursor for the production of adsorbent carbons, since it has gone through a devolatilization process while in the combustor, and therefore, only requires to be activated. Accordingly, this report evaluates and compares several routes for the production of activated carbons from unburned carbon in fly ash, including physical and chemical activation methods. During the present reporting period (June 30, 2001-June 29, 2002), additional characterization work was conducted under Task 1 ''Procurement and characterization of CCBPs''. The suite collected includes samples from pulverized utility boilers, a utility cyclone unit equipped with a beneficiation technology, a stoker, and a fluidized bed combustor. Proximate, ultimate, and petrographic analyses of the fly ash samples previously collected were measured. Furthermore, the surface areas of the samples assembled were characterized by N{sub 2} adsorption isotherms at 77 K. The proximate analyses showed that all the samples had very low moisture contents (0.17 to 3.39 wt%), while volatile matter contents of the samples varied between 0.45 to 24.8 wt%. The ultimate analyses of all the fly ash samples showed that they contained primarily carbon, while the hydrogen contents of all the samples were very low. In addition, during the current reporting period, also Task 2 ''Development of activated carbons'' and Task 3 ''Characterization of activated carbons'' were continued.

Prof. Harold H. Schobert; Dr. M. Mercedes Maroto-Valer; Ms. Zhe Lu

2002-09-27

16

Production and characterization of lignocellulosic biomass-derived activated carbon.  

PubMed

The goal of this work is to establish the technical feasibility of producing activated carbon from pulp mill sludges. KOH chemical activation of four lignocellulosic biomass materials, two sludges from pulp mills, one sludge for a linerboard mill, and cow manure, were investigated experimentally, with a focus on the effects of KOH/biomass ratio (1/1, 1.5/1 and 2/1), activation temperature (400-600 °C) and activation time (1 to 2 h) on the development of porosity. The activation products were characterized for their physical and chemical properties using a surface area analyzer, scanning electron microscopy and Fourier transform infrared spectroscopy. Experiments were carried out to establish the effectiveness of the lignocellulosic biomass-derived activated carbon in removing methylene blue (MB), a surrogate of large organic molecules. The results show that the activated carbon are highly porous with specific surface area greater than 500 m²/g. The yield of activated carbon was greater than the percent of fixed carbon in the dry sludge, suggesting that the activation process was able to capture a substantial amount of carbon from the organic matter in the sludge. While 400 °C was too low, 600 °C was high enough to sustain a substantial rate of activation for linerboard sludge. The KOH/biomass ratio, activation temperature and time all play important roles in pore development and yield control, allowing optimization of the activation process. MB adsorption followed a Langmuir isotherm for all four activated carbon, although the adsorption capacity of NK-primary sludge-derived activated carbon was considerably lower than the rest, consistent with its lower specific surface area. PMID:21099052

Namazi, A B; Jia, C Q; Allen, D G

2010-01-01

17

Production of activated carbons from coffee endocarp by CO 2 and steam activation  

Microsoft Academic Search

In this work the use of coffee endocarp as precursor for the production of activated carbons by steam and CO2 was studied. Activation by both methods produces activated carbons with small external areas and microporous structures having very similar mean pore widths. The activation produces mainly primary micropores and only a small volume of larger micropores. The CO2 activation leads

João M. Valente Nabais; Pedro Nunes; Peter J. M. Carrott; M. Manuela L. Ribeiro Carrott; A. Macías García; M. A. Díaz-Díez

2008-01-01

18

DEVELOPMENT OF ACTIVATED CARBONS FROM COAL COMBUSTION BY-PRODUCTS  

SciTech Connect

The implementation of increasingly stringent Clean Air Act Regulations by the coal utility industry has resulted in an increase in the concentration of unburned carbon in coal combustion fly ash. In 1999, around 6 million tons of unburned carbon were disposed in the US, due to the present lack of efficient routes for its utilization. However, unburned carbon is a potential precursor for the production of adsorbent carbons, since it has gone through a devolatilization process while in the combustor, and therefore, only requires to be activated. Accordingly, this report evaluates and compares several routes for the production of activated carbons from unburned carbon, including physical activation with steam or CO{sub 2}, and chemical activation using KOH pretreatment. During the present reporting period (June 30, 2000--June 29, 2001), Task 1 ''Procurement and characterization of CCBPs'' was concluded, including samples from pulverized utility boilers, a utility cyclone unit equipped with a beneficiation technology, a suspension-fired research boiler, and a class C fly ash. The characterization studies showed that the samples collected have significantly different carbon contents, as determined by the ASTM C114 procedure, with the sample from the cyclone unit containing the highest carbon content (LOI of {approx} 80%), since this unit has been retrofitted with a technology to separate the unburned carbon from the fly ash. The porosity of the samples assembled was characterized by N{sub 2} adsorption isotherms at 77K. The surface areas of the class F fly ash samples from pulverized coal combustors are between 30-40 m{sup 2}/g, while the samples from the suspension-fired research boiler had surface area around 115 m{sup 2}/g. As expected, the surface areas of the class C ash is much higher than that of the class F ashes, with values up to 390 m{sup 2}/g. In addition, during the current reporting period, also Task 2 ''Development of activated carbons'' and Task 3 ''Characterization of activated carbons'' were continued.

Prof. Harold H. Schobert; Dr. M. Mercedes Maroto-Valer; Ms. Zhe Lu

2001-09-29

19

Production Scale-Up or Activated Carbons for Ultracapacitors  

SciTech Connect

Transportation use accounts for 67% of the petroleum consumption in the US. Electric and hybrid vehicles are promising technologies for decreasing our dependence on petroleum, and this is the objective of the FreedomCAR & Vehicle Technologies Program. Inexpensive and efficient energy storage devices are needed for electric and hybrid vehicle to be economically viable, and ultracapacitors are a leading energy storage technology being investigated by the FreedomCAR program. The most important parameter in determining the power and energy density of a carbon-based ultracapacitor is the amount of surface area accessible to the electrolyte, which is primarily determined by the pore size distribution. The major problems with current carbons are that their pore size distribution is not optimized for liquid electrolytes and the best carbons are very expensive. TDA Research, Inc. (TDA) has developed methods to prepare porous carbons with tunable pore size distributions from inexpensive carbohydrate based precursors. The use of low-cost feedstocks and processing steps greatly lowers the production costs. During this project with the assistance of Maxwell Technologies, we found that an impurity was limiting the performance of our carbon and the major impurity found was sulfur. A new carbon with low sulfur content was made and found that the performance of the carbon was greatly improved. We also scaled-up the process to pre-production levels and we are currently able to produce 0.25 tons/year of activated carbon. We could easily double this amount by purchasing a second rotary kiln. More importantly, we are working with MeadWestvaco on a Joint Development Agreement to scale-up the process to produce hundreds of tons of high quality, inexpensive carbon per year based on our processes.

Dr. Steven D. Dietz

2007-01-10

20

ACTIVATED CARBON PRODUCTION FROM PYROLYSIS AND STEAM ACTIVATION OF COTTON GIN TRASH  

Microsoft Academic Search

Cotton gin trash (CGT) was used to produce activated carbon via pyrolysis and steam activation. To determine the effect of pyrolysis temperature and time on the properties of activated carbon, optimization of the pyrolysis conditions at temperatures of 600, 700, and 8000C for 30, 45 and 60 minutes were made. Steam activation of the product char was prepared at temperatures

Joan Rollog Hernandez; Sergio C. Capareda; Froilan L. Aquino

21

Production of activated carbon from a new precursor: Molasses  

Microsoft Academic Search

Activated carbon has been prepared from molasses, a natural precursor of vegetable origin resulting from the sugar industry in Morocco. The preparation of the activated carbon from the molasses has been carried out by impregnation of the precursor with sulfuric acid, followed by carbonization. The adsorption capacity, the BET surface area, and the pore volume of the activated carbon were

K. Legrouri; M. Ezzine; S. Ichcho; H. Hannache; R. Denoyel; R. Pailler; R. Naslain

2005-01-01

22

Production of granular activated carbons from loquat stones by chemical activation  

Microsoft Academic Search

This paper describes the production of activated carbons by chemical activation with KOH and NaOH of the chars obtained through carbonization of loquat stones at 600°C. The chars in the 1.0–2.0mm size range were activated at carbonization temperatures ranging from 600°C to 1000°C, heating rate of 10°C\\/min and a char\\/chemical agent mass ratio of 1\\/2 under nitrogen flow. In addition,

Hale Sütcü; Hakan Demiral

2009-01-01

23

Production of Activated Carbon from Athabasca Oilsands Bitumen  

Microsoft Academic Search

The carbonization process of the pentane insoluble (end-cut) fraction from Athabasca oilsands bitumen in the presence NaOH has been investigated. Chemical activation produced carbon with a well-developed mesoporous structure and a much reduced sulfur content. The yield of the activated carbon increased, whereas sulfur content decreased with an increase in the NaOH load. Physical activation with carbon dioxide resulted in

S. Koutcheiko; T. McCracken; J. Kung; L. Kotlyar

2007-01-01

24

DEVELOPMENT OF ACTIVATED CARBONS FROM COAL COMBUSTION BY-PRODUCTS  

Microsoft Academic Search

The increasing role of coal as a source of energy in the 21st century will demand environmental and cost-effective strategies for the use of coal combustion by-products (CCBPs), mainly fly ash containing unburned carbon. However, the carbonaceous residue in fly ash, unburned carbon (UC), is a potential precursor for the production of adsorbent carbons, since it has gone through a

Harold H. Schobert; M. Mercedes Maroto-Valer; Zhe Lu

2000-01-01

25

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

Microsoft Academic Search

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

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

2004-01-01

26

PRODUCTION OF ACTIVATED CARBON FROM BAMBOO USING CHEMICAL AND STEAM ACTIVATIONS  

Microsoft Academic Search

Bamboo is a natural resource in Malaysia as it takes only several months to grow and be ready for harvesting. Primary processing of bamboo for conversion into specified products generates a large amount of residues is generated. This residue could be effectively converted into value-added products such as activated carbon and charcoal. There are two phases in this progress activity

E. Puad Mahanim; J. Rafidah

27

Production of activated carbon from prosopis ( Prosopis juliflora)  

Microsoft Academic Search

Activated carbon was produced from prosopis (Prosopis juliflora), a wild thorny plant grown in wastelands, by chemical activation using zinc chloride. The process variables: activation temperature, level of zinc chloride required and activation duration of 600°C, 50% and 30 min, respectively, yielded 56.9% of activated carbon. The methylene blue adsorbed and zinc chloride recovery were 23 ml and 52.9%, respectively

R Kailappan; L Gothandapani; R Viswanathan

2000-01-01

28

DEVELOPMENT OF ACTIVATED CARBONS FROM COAL COMBUSTION BY-PRODUCTS  

Microsoft Academic Search

The increasing role of coal as a source of energy in the 21st century will demand environmental and cost-effective strategies for the use of coal combustion by-products (CCBPs), mainly unburned carbon in fly ash. Unburned carbon is nowadays regarded as a waste product and its fate is mainly disposal, due to the present lack of efficient routes for its utilization.

Harold H. Schobert; M. Mercedes Maroto-Valer; Zhe Lu

2003-01-01

29

PRODUCTION OF ACTIVATED CARBON FROM SAWDUST USING FLUIDIZED BED REACTOR  

Microsoft Academic Search

ABSTARCT Activated carbon was produced from sawdust by using steam activation in a high temperature muffle furnace. Fast pyrolysis process was carried out prior in fluidized a bed furnace to produce char before activation process. Experiments were conducted to investigate the influence of various process parameters such as particle size, pyrolysis temperature and activation time on the quality of the

MAN KEE LAM; RIDZUAN ZAKARIA

30

The production of active carbon from corn cobs by chemical activation  

Microsoft Academic Search

Corn cobs obtained as waste from the corn industry, were analyzed by a TG-DTA unit in an atmosphere of flowing nitrogen. The\\u000a carbonaceous products so formed were then produced on a preparative scale and activated chemically using potassium hydroxide.\\u000a This resulted in the formation of a carbon with a very high surface area. The active carbon produced was then examined

P. Aggarwal; D. Dollimore

1997-01-01

31

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

32

A novel method for production of activated carbon from waste tea by chemical activation with microwave energy  

Microsoft Academic Search

This study presents the production of activated carbon from waste tea. Activated carbons were prepared by phosphoric acid activation with and without microwave treatment and carbonisation of the waste tea under nitrogen atmosphere at various temperatures and different phosphoric acid\\/precursor impregnation ratios. The surface properties of the activated carbons were investigated by elemental analysis, BET surface area, SEM, FTIR. Prior

Emine Yagmur; Meryem Ozmak; Zeki Aktas

2008-01-01

33

Production of Activated Carbon from Date Stones by Using Zinc Chloride  

Microsoft Academic Search

Production of activated carbon from date stones by chemical activation with zinc chloride (ZnCl2) was experimentally investigated using a laboratory-scale fluidized-bed reactor. The effects of process variables, such as activation time, activation temperature, impregnation ratio, and particle size, on the production and quality of activated carbon were measured in terms of adsorptive capacity by iodine number test. An activation time

F. A. H. Al-Qaessi

2010-01-01

34

Agricultural residues as precursors for activated carbon production—A review  

Microsoft Academic Search

A review of the production of activated carbons from agricultural residues is presented. The effects of various process parameters on the pyrolysis stage are reviewed. Influences of activating conditions, physical and chemical, on the active carbon properties are discussed. Under certain process conditions several active carbons with BET surface areas, ranging between 250 and 2410m2\\/g and pore volumes of 0.022

O. Ioannidou; A. Zabaniotou

2007-01-01

35

Production of activated carbon from coconut shell char in a fluidized bed reactor  

Microsoft Academic Search

Activated carbon is produced from coconut shell char using steam or carbon dioxide as the reacting gas in a 100 mm diameter fluidized bed reactor. The effect of process parameters such as reaction time, fluidizing velocity, particle size, static bed height, temperature of activation, fluidizing medium, and solid raw material on activation is studied. The product is characterized by determination

P. M. Satya Sai; Jaleel Ahmed; K. Krishnaiah

1997-01-01

36

The production of activated carbon using the equipment of thermal power plants and heating plants  

NASA Astrophysics Data System (ADS)

The production technology of activated carbon using the conventional equipment of the thermal power stations and boiler houses is proposed. The obtained product is directed into the systems of chemical water preparation and water drain of enterprises. The production cycle is invariable when producing the activated carbon by the proposed technology. The fuel consumption and heat losses are considerably reduced when implementing this technology compared with the known analogs of the carbon sorbent. The production efficiency increases if small dust particles are preliminary separated and coal is activated in narrow ranges of fraction sizes.

Osintsev, K. V.; Osintsev, V. V.; Dzhundubaev, A. K.; Kim, S. P.; Al'musin, G. T.; Akbaev, T. A.; Bogatkin, V. I.

2013-08-01

37

Production of Activated Carbons from Pyrolysis of Waste Tires Impregnated with Potassium Hydroxide  

Microsoft Academic Search

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 °C for 0-2 hr. The activation method can produce carbons with a surface area (SA) and total pore volume as high as 470 m\\/g and 0.57 cm\\/g, respectively. The influence of

Hsisheng Teng; Yu-Chuan Lin; Li-Yeh Hsu

2000-01-01

38

The Production of Activated Carbons Using Greek Lignites by Physical and Chemical Activation Methods: A Comparative Study  

Microsoft Academic Search

Twenty-six lignite samples, from eleven different basins of Greece, were examined as a precursor material to produce activated carbons. Two different experimental procedures were compared, a physical one, using CO2 as the activation agent after carbonization in N2, and a chemical one where lignites impregnated with KOH were thereafter activated. Raw materials and activated products were characterized using a variety

N. Pasadakis; G. Romanos; V. Perdikatsis; A. E. Foscolos

2011-01-01

39

Production of Activated Carbon from Peat. A Techno-Economic Feasibility Study.  

National Technical Information Service (NTIS)

The production of activated carbon from peat was studied both with laboratory and pilot plant experiments in a fluidized-bed furnace. Peat coke was mainly used as raw material, and it was gasified partially with steam to granular activated carbon. The act...

K. Sipilae D. Asplund E. Ekman

1984-01-01

40

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

41

Production of activated carbon cloth with controlled structure and porosity from a new precursor  

Microsoft Academic Search

The production of micro and mesoporous activated carbon cloth (ACC) from commercial acrylic textile fibres by physical activation\\u000a with carbon dioxide and the addition of boric acid and sodium hydrogen phosphate as impregnants is reported. The use of sodium\\u000a hydrogen phosphate leads to samples with greater mesopore volume whereas other ACC production conditions studied mainly result\\u000a in microporous materials. This

J. M. Valente Nabais; T. Canário; P. J. M. Carrott; M. M. L. Ribeiro Carrott

2007-01-01

42

Production of activated carbon from Luscar char: Experimental and modeling studies  

Microsoft Academic Search

Central composite design (CCD) was applied to study the influence of activation temperature, mass ratio of steam to char and activation time on the steam activation process of Luscar char. Two quadratic models were developed for BET surface area and yield of activated carbon using Design-Expert software. The models were used to calculate the optimum operating conditions for production of

R. Azargohar; A. K. Dalai

2005-01-01

43

DEVELOPMENT OF ACTIVATED CARBONS FROM COAL COMBUSTION BY-PRODUCTS  

Microsoft Academic Search

The implementation of increasingly stringent Clean Air Act Regulations by the coal utility industry has resulted in an increase in the concentration of unburned carbon in coal combustion fly ash. In 1999, around 6 million tons of unburned carbon were disposed in the US, due to the present lack of efficient routes for its utilization. However, unburned carbon is a

Harold H. Schobert; M. Mercedes Maroto-Valer; Zhe Lu

2001-01-01

44

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

45

Production of activated carbon from bamboo scaffolding waste—process design, evaluation and sensitivity analysis  

Microsoft Academic Search

A feasibility study has been carried out on the preliminary process design of the production of activated carbon from the bamboo scaffolding waste based on 30tonnes of bamboo waste per day throughput. A comparison of the process economics of the stand-alone bamboo carbonization plant with a plant that is integrated into another major processing facility has been studied. The preliminary

Keith K. H. Choy; John P. Barford; Gordon McKay

2005-01-01

46

Application of thermal analysis techniques in activated carbon production  

USGS Publications Warehouse

Thermal analysis techniques have been used at the ISGS as an aid in the development and characterization of carbon adsorbents. Promising adsorbents from fly ash, tires, and Illinois coals have been produced for various applications. Process conditions determined in the preparation of gram quantities of carbons were used as guides in the preparation of larger samples. TG techniques developed to characterize the carbon adsorbents included the measurement of the kinetics of SO2 adsorption, the performance of rapid proximate analyses, and the determination of equilibrium methane adsorption capacities. Thermal regeneration of carbons was assessed by TG to predict the life cycle of carbon adsorbents in different applications. TPD was used to determine the nature of surface functional groups and their effect on a carbon's adsorption properties.

Donnals, G. L.; DeBarr, J. A.; Rostam-Abadi, M.; Lizzio, A. A.; Brady, T. A.

1996-01-01

47

Production of activated carbon from a new precursor molasses by activation with sulphuric acid  

Microsoft Academic Search

Activated carbon has been prepared from molasses, a natural precursor of vegetable origin resulting from the sugar industry in Morocco. The preparation of the activated carbon from the molasses has been carried out by impregnation of the precursor with sulphuric acid, followed by carbonisation at varying conditions (temperature and gas coverage) in order to optimize preparation parameters. The influence of

K. Legrouri; E. Khouya; M. Ezzine; H. Hannache; R. Denoyel; R. Pallier; R. Naslain

2005-01-01

48

Means of increasing raw material resources for production of active carbon black  

Microsoft Academic Search

1.The possibility for increasing the output of raw material for the production of active carbon black by means of extraction of catalytically cracked gas oils of expanded fractional composition, obtained from sour and low-sulfur crudes, was shown.2.Testing of experimental extract samples from 195–420°C fractions in a pilot installation at NIIShP with cyclone reactor showed that carbon balck obtained from these

A. S. Andreeva; B. T. Abaeva; N. A. Okinshevich; A. V. Agafonov

1967-01-01

49

Production of activated carbon from coconut shell: Optimization using response surface methodology  

Microsoft Academic Search

The production of activated carbon from coconut shell treated with phosphoric acid (H3PO4) was optimized using the response surface methodology (RSM). Fifteen combinations of the three variables namely; impregnation ratio (1, 1.5, and 2); activation time (10, 20, and 30min); and activation temperature (400, 450, and 500°C) were optimized based on the responses evaluated (yield, bulk density, average pore diameter,

M. K. B. Gratuito; T. Panyathanmaporn; R.-A. Chumnanklang; N. Sirinuntawittaya; A. Dutta

2008-01-01

50

Production of activated carbon fibres by solid-phase (chemical) activation  

Microsoft Academic Search

The possibility and efficiency of manufacturing activated carbon fibres (ACF) by solid-phase (chemical) activation of fibre\\u000a precursors of different nature were demonstrated. Some characteristics of activation of hydrated cellulose fibres using ZnCl2, NH4Cl, or Na2HPO4 additives were investigated.

O. V. Astashkina; N. F. Bogdan; A. A. Lysenko; E. P. Kuvaeva

2008-01-01

51

EFFECTS OF SODIUM AND CALCIUM IN LIGNITE ON THE PERFORMANCE OF ACTIVATED CARBON PRODUCTS  

SciTech Connect

Powdered activated carbon (PAC) has traditionally been used by the water treatment industry for the removal of compounds contributing to taste and odor problems. PAC also has the potential to remove naturally occurring organic matter (NOM) from raw waters prior to disinfection, thus controlling the formation of regulated disinfection by-products (DBPs). Many small water systems are currently using PAC for taste and odor control and have the potential to use PAC for controlling DBPs. The Energy & Environmental Research Center has been working on the development of a PAC product to remove NOM from surface water supplies to prevent the formation of carcinogenic DBPs during chlorination. During previous studies, the sodium and calcium content of the lignites showed a significant effect on the sorption capacity of the activated carbon product. As much as a 130% increase in the humic acid sorption capacity of a PAC produced from a high-sodium-content lignite was observed. During this study, activated carbons were prepared from three coals representing high-sodium, low-sodium--low-calcium, and high-calcium compositions in two steps, an initial char formation followed by mild activation with steam to avoid excessive burnout. This set of carbons was characterized with respect to physical and chemical properties. The BET (Brunauer-Emmett-Teller) nitrogen adsorption isotherms gave relatively low surface areas (ranging from 245 to 370 m{sup 2}/g). The lowest-BET area was obtained for the high-sodium carbon, which can be attributed to enlargement of micropores as a result of sodium-catalyzed gasification reaction of the carbon structure. This hypothesis is consistent with the scanning electron microscopy microprobe analyses, which show that in both the coal and the activated carbon from this coal, the sodium is distributed over both the carbon structure and the mineral particles. Thus it is initially associated with carboxylate groups on the coal and then as sodium oxide or other active form in close proximity to the carbon and is, therefore, readily available for catalysis of gasification. Humate adsorption isotherms for the high-sodium carbon gave superior results as defined by very high intercepts in modified Freundlich plots. Thus the high-sodium carbon will be considerably more effective in reducing the humate concentration for a given carbon dosage. Analysis of adsorption isotherms indicated the results were consistent with the hypothesis that only the larger pores are effective for binding the large humate molecules, and that the larger pores developed during activation of the high-sodium char give the appropriate macropore structure for humate binding. Toluene adsorption isotherms indicated that the high-calcium carbon and the low-calcium, low-sodium carbon were superior to the high-sodium carbon for small molecules in aqueous solution, but not as effective as a Calgon F-400 commercial activated carbon. This is consistent with the low-BET surface areas observed for the lignite-derived carbons, and thus there are a lower number of sites for binding the smaller toluene molecule in these carbons.

Edwin S. Olson; Kurt E. Eylands; Daniel J. Stepan

2001-12-01

52

EFFECTS OF SODIUM AND CALCIUM IN LIGNITE ON THE PERFORMANCE OF ACTIVATED CARBON PRODUCTS  

Microsoft Academic Search

Powdered activated carbon (PAC) has traditionally been used by the water treatment industry for the removal of compounds contributing to taste and odor problems. PAC also has the potential to remove naturally occurring organic matter (NOM) from raw waters prior to disinfection, thus controlling the formation of regulated disinfection by-products (DBPs). Many small water systems are currently using PAC for

Edwin S. Olson; Kurt E. Eylands; Daniel J. Stepan

2001-01-01

53

Production of Activated Carbon from Jojoba Seed Residue by Chemical Activation Residue Using a Static Bed Reactor  

Microsoft Academic Search

The production of chemically activated carbon from Jojoba seed residue was experimentally investigated using a laboratory-scale static bed reactor. The effects of process variables such as activation time, activation temperature, particle size, chemical reagents (KCl, ZnCl2 and H3PO4) and impregnation ratio on adsorption capacity of activated Jojoba seed residue were studied. The highest iodine number and yield were obtained by

Muhammad Tawalbeh; Mamdouh A. Allawzi; Munther I. Kandah

2005-01-01

54

Production of granular activated carbon from waste walnut shell and its adsorption characteristics for Cu 2+ ion  

Microsoft Academic Search

Production of granular activated carbon by chemical activation has been attempted employing walnut shells as the raw material. The thermal characteristics of walnut shell were investigated by TG\\/DTA and the adsorption capacity of the produced activated carbon was evaluated using the titration method. As the activation temperature increased, the iodine value increased. However, a temperature higher than 400°C resulted in

Jin-Wha Kim; Myoung-Hoi Sohn; Dong-Su Kim; Seung-Man Sohn; Young-Shik Kwon

2001-01-01

55

Production of microporous palm shell based activated carbon for methane adsorption: Modeling and optimization using response surface methodology  

Microsoft Academic Search

In this study, the optimization of the palm shell based activated carbon production using combination of chemical and physical activation for methane adsorption is investigated. response surface methodology (RSM) in combination with central composite design (CCD) was used to optimize the operating parameters of the production process. Physical activation temperature, chemical impregnation ratio and physical activation time were chosen as

Arash Arami-Niya; Wan Mohd Ashri Wan Daud; Farouq S. Mjalli; Faisal Abnisa; Mohammad Saleh Shafeeyan

56

Hydrogen production by catalytic decomposition of methane over activated carbons: kinetic study  

Microsoft Academic Search

Several domestic activated carbons were tested as the catalyst for decomposition of methane. All the activated carbons showed similar deactivation pattern. Mass transport effect in the catalyst particles was observed and the pore mouth blocking appeared to occur noticeably especially in large particles. Between different kinds of the activated carbons, no discernible trend was observed between the initial activity and

Myung Hwan Kim; Eun Kyoung Lee; Jin Hyuk Jun; Sang Jun Kong; Gui Young Han; Byung Kwon Lee; Tae-Jin Lee; Ki June Yoon

2004-01-01

57

Production of activated carbon by K2CO3 activation treatment of cornstalk lignin and its performance in removing phenol and subsequent bioregeneration  

Microsoft Academic Search

Activated carbon was produced by fast precarbonization of cornstalk lignin in a fluidized bed followed by K2CO3 activation. The results showed that the product is essentially microporous carbon whose Brunauer–Emmett–Teller surface area and pore volume when the carbon was activated at 800°C were 1410 m\\/g and 0.77 mL\\/g, respectively. The potential usefulness of the resultant carbons for removal of phenol

Yong Sun; Jian Wei; Gang Yang

2010-01-01

58

Production of granular activated carbon from fruit stones and nutshells and evaluation of their physical, chemical and adsorption properties  

Microsoft Academic Search

An investigation of several agricultural wastes (almond shell, hazelnut shell, walnut shell and apricot stone) revealed that their suitability for granular activated carbon production is not determined by material specific (elemental composition) but type-specific features. Granular activated carbons were evaluated for their physical (attrition, bulk density), chemical (elemental composition, % weight loss), surface (surface area, surface chemistry) and adsorption properties

A Aygün; S Yenisoy-Karaka?; I Duman

2003-01-01

59

Production of Activated Carbon from Palm Oil Shell Waste and Its Adsorption Characteristics  

Microsoft Academic Search

The effects of raw material treatment and concentration of phosphoric acid on the characteristics of activated carbon were investigated. Adsorptions of Cu, Pb, Cr and Cd in activated carbon were carried out to evaluate the adsorptive capacity of selected activated carbons. It was found that treated raw material reduces inorganic element and increases Brunet Elmer Teller (BET) surface area of

W. B. Wan Nik; M. M. Rahman; A. M. Yusof; F. N. Ani; C. M Che Adnan

60

EFFECTS OF SODIUM AND CALCIUM IN LIGNITE ON THE PERFORMANCE OF ACTIVATED CARBON PRODUCTS  

SciTech Connect

New federal drinking water regulations have been promulgated to restrict the levels of disinfection by-products (DBPs) in finished public water supplies. DBPs are suspected carcinogens and are formed when organic material is partially oxidized by disinfectants commonly used in the water treatment industry. Additional federal mandates are expected in the near future that will also affect public water suppliers with respect to DBPs. These new federal drinking water regulations may require public water suppliers to adjust treatment practices or incorporate additional treatment operations into their existing treatment trains. Many options have been identified, including membrane processes, granular activated carbon, powered activated carbon (PAC), enhanced coagulation and/or softening, and alternative disinfectants (e.g., chlorine dioxide, ozone, and chloramines). Of the processes being considered, PAC appears to offer an attractive benefit-to-cost advantage for many water treatment plants, particularly small systems (those serving fewer than 10,000 customers). PAC has traditionally been used by the water treatment industry for the removal of compounds contributing to taste and odor problems. PAC also has the potential to remove naturally occurring organic matter (NOM) from raw waters prior to disinfection, thus controlling the formation of regulated DBPs. Many small water systems are currently using PAC for taste and odor control and have the potential to use PAC for controlling DBPs. Activated carbons can be produced from a variety of raw materials, including wood, peat, coconut husks, and numerous types of coal. The Energy & Environmental Research Center (EERC) has been working on the development of a PAC product to remove NOM from surface water supplies to prevent the formation of carcinogenic DBPs during chlorination. During that study, the sodium and calcium content of the lignites showed a significant effect on the sorption capacity of the activated carbon product. As much as a 130% increase in the humic acid sorption capacity of a PAC produced from a high-sodium-content lignite was observed. We hypothesize that the sodium and calcium content of the coal plays a significant role in the development of pore structures and pore-size distribution, ultimately producing activated carbon products that have greater sorption capacity for specific contaminants, depending on molecular size.

Edwin S. Olson; Kurt E. Eylands; Daniel J. Stepan

2001-12-01

61

Recycling of carbon fibre reinforced polymeric waste for the production of activated carbon fibres  

Microsoft Academic Search

Composite waste composed of carbon fibres and polybenzoxazines resin has been pyrolysed in a fixed bed reactor at temperatures of 350, 400, 450, 500 and 700°C. Solid residues of between 70 and 83.6wt%, liquid yields 14 and 24.6wt% and gas yields 0.7 and 3.8wt% were obtained depending on pyrolysis temperature. The derived pyrolysis liquids contained aniline in high concentration together

Mohamad Anas Nahil; Paul T. Williams

2011-01-01

62

Removal of anaerobic soluble microbial products in a biological activated carbon reactor.  

PubMed

The soluble microbial products (SMP) in the biological treatment effluent are generally of great amount and are poorly biodegradable. Focusing on the biodegradation of anaerobic SMP, the biological activated carbon (BAC) was introduced into the anaerobic system. The experiments were conducted in two identical lab-scale up-flow anaerobic sludge blanket (UASB) reactors. The high strength organics were degraded in the first UASB reactor (UASB1) and the second UASB (UASB2, i.e., BAC) functioned as a polishing step to remove SMP produced in UASB1. The results showed that 90% of the SMP could be removed before granular activated carbon was saturated. After the saturation, the SMP removal decreased to 60% on the average. Analysis of granular activated carbon adsorption revealed that the main role of SMP removal in BAC reactor was biodegradation. A strain of SMP-degrading bacteria, which was found highly similar to Klebsiella sp., was isolated, enriched and inoculated back to the BAC reactor. When the influent chemical oxygen demand (COD) was 10,000 mg/L and the organic loading rate achieved 10 kg COD/(m3 x day), the effluent from the BAC reactor could meet the discharge standard without further treatment. Anaerobic BAC reactor inoculated with the isolated Klebsiella was proved to be an effective, cheap and easy technical treatment approach for the removal of SMP in the treatment of easily-degradable wastewater with COD lower than 10,000 mg/L. PMID:24520716

Dong, Xiaojing; Zhou, Weili; He, Shengbing

2013-09-01

63

Production of activated carbon from organic by-products from the alcoholic beverage industry: Surface area and hardness optimization by using the response surface methodology  

Microsoft Academic Search

The ability of activated carbon to remove pollutants from water in packed column systems is dependent on granular material with mechanical strength sufficient to avoid attrition caused by stream flow. Therefore, an appropriate balance between surface area and hardness is essential when using activated carbon in real systems. The purpose of this research is to determine the optimal production conditions

Cesar Nieto-Delgado; Jose Rene Rangel-Mendez

2011-01-01

64

The production of activated carbon from high-ash sub-bituminous and bituminous South African coals  

SciTech Connect

This paper describes a process for the production of activated carbon in a pilot rotary kiln. The first step comprises crushing and/or sieving and beneficiation of the different ROM coal precursors. The coal precursors used in this investigation are part of Sasol's resources and although they show high reactivity towards steam and CO{sub 2} they unfortunately contains high ash contents. Consequently it is necessary to beneficiate the ROM coal in a second step, to be a suitable feedstock for the production of activated carbon. The final step in the process entails devolatilization and activation of the beneficiated precursors in one continuous step in the kiln. The product characterization results demonstrate that the adsorption features of the activated carbons produced by Sasol compare favorably with that of commercial products.

Prinsloo, F.F.; Opperman, D.P.J.; Budeli, C.; Hauman, D.

1999-07-01

65

H2 production with anaerobic sludge using activated-carbon supported packed-bed bioreactors.  

PubMed

Packed-bed bioreactors containing activated carbon as support carrier were used to produce H2 anaerobically from a sucrose-limiting medium while acclimated sewage sludge was used as the H2 producer. The effects of bed porosity (epsilon(b)) and substrate loading rate on H2 fermentation were examined using packed beds with epsilon(b) of 70-90% being operated at hydraulic retention times (HRT) of 0.5-4 h. Higher epsilon(b) and lower HRT favored H2 production. With 20 g COD l(-1) of sucrose in the feed, the optimal H2 production rate (7.4 l h(-1) l(-1)) was obtained when the bed with epsilon(b) = 90% was operated at HRT = 0.5 h. Flocculation of cells enhanced the retention of sludge for stable operations of the bioreactor at low HRTs. The gas products resulting from fermentative H2 production consisted of 30-40% H2 and 60-70% CO2. Butyric acid was the primary soluble product, followed by propionic acid and valeric acid. PMID:12882288

Lee, Kuo-Shing; Lo, Yung-Sheng; Lo, Yung-Chung; Lin, Ping-Jei; Chang, Jo-Shu

2003-01-01

66

Pyrolysis for the production of activated carbon from cellulosic solid wastes  

Microsoft Academic Search

The preparation of activated carbon by pyrolysis and thermal activation of municipal solid waste was investigated. The organic fraction of the solid waste behaves similarly to cellulose. Satisfactory yields and specific surface were obtained by pyrolysis at 700°C and a heating rate of 1°C\\/min, followed by activation at 900°C with steam and COâ. The overall yield based on carbon was

P. V. Roberts; J. O. Leckie; P. H. Brunner

1978-01-01

67

Bio-based phenols and fuel production from catalytic microwave pyrolysis of lignin by activated carbons.  

PubMed

The aim of this study is to explore catalytic microwave pyrolysis of lignin for renewable phenols and fuels using activated carbon (AC) as a catalyst. A central composite experimental design (CCD) was used to optimize the reaction condition. The effects of reaction temperature and weight hourly space velocity (WHSV, h(-1)) on product yields were investigated. GC/MS analysis showed that the main chemical compounds of bio-oils were phenols, guaiacols, hydrocarbons and esters, most of which were ranged from 71% to 87% of the bio-oils depending on different reaction conditions. Bio-oils with high concentrations of phenol (45% in the bio-oil) were obtained. The calorific value analysis revealed that the high heating values (HHV) of the lignin-derived biochars were from 20.4 to 24.5MJ/kg in comparison with raw lignin (19MJ/kg). The reaction mechanism of this process was analyzed. PMID:24747393

Bu, Quan; Lei, Hanwu; Wang, Lu; Wei, Yi; Zhu, Lei; Zhang, Xuesong; Liu, Yupeng; Yadavalli, Gayatri; Tang, Juming

2014-06-01

68

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

69

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...

70

EXPERIMENTAL STUDY OF THE ADSORPTION OF FISSION PRODUCTS ON ACTIVATED CARBON  

Microsoft Academic Search

A study was made of the adsorption of fission produots in solution on ; activated carbon as affected by pH. Galoride solutions of Y⁹¹, Ce¹⁴⁴-; Pr¹⁴⁴, and Cs¹³⁷ were buffered a t various pH levels and activated ; carbon put in. The use of buffers also made it possible to stady foreign-ion ; effects. The results are tabuluted and discussed

E. Spode; E. Weber

1958-01-01

71

Resveratrol induces hepatic mitochondrial biogenesis through the sequential activation of nitric oxide and carbon monoxide production.  

PubMed

Abstract Aims: Nitric oxide (NO) can induce mitochondrial biogenesis in cultured cells, through increased guanosine 3',5'-monophosphate (cGMP), and activation of peroxisome proliferator-activated receptor gamma coactivator-1? (PGC-1?). We sought to determine the role of NO, heme oxygenase-1 (HO-1), and its reaction product (carbon monoxide [CO]) in the induction of mitochondrial biogenesis by the natural antioxidant resveratrol. Results: S-nitroso-N-acetylpenicillamine (SNAP), an NO donor, induced mitochondrial biogenesis in HepG2 hepatoma cells, and in vivo, through stimulation of PGC-1?. NO-induced mitochondrial biogenesis required cGMP, and was mimicked by the cGMP analogue (8-bromoguanosine 3',5'-cyclic monophosphate [8-Br-cGMP]). Activation of mitochondrial biogenesis by SNAP required HO-1, as it could be reversed by genetic interference of HO-1; and by treatment with the HO inhibitor tin-protoporphyrin-IX (SnPP) in vitro and in vivo. Cobalt protoporphyrin (CoPP)-IX, an HO-1 inducing agent, stimulated mitochondrial biogenesis in HepG2 cells, which could be reversed by the CO scavenger hemoglobin. Application of CO, using the CO-releasing molecule-3 (CORM-3), stimulated mitochondrial biogenesis in HepG2 cells, in a cGMP-dependent manner. Both CoPP and CORM-3-induced mitochondrial biogenesis required NF-E2-related factor-2 (Nrf2) activation and phosphorylation of Akt. The natural antioxidant resveratrol induced mitochondrial biogenesis in HepG2 cells, in a manner dependent on NO biosynthesis, cGMP synthesis, Nrf2-dependent HO-1 activation, and endogenous CO production. Furthermore, resveratrol preserved mitochondrial biogenesis during lipopolysaccharides-induced hepatic inflammation in vivo. Innovation and Conclusions: The complex interplay between endogenous NO and CO production may underlie the mechanism by which natural antioxidants induce mitochondrial biogenesis. Strategies aimed at improving mitochondrial biogenesis may be used as therapeutics for the treatment of diseases involving mitochondrial dysfunction. Antioxid. Redox Signal. 20, 2589-2605. PMID:24041027

Kim, Seul-Ki; Joe, Yeonsoo; Zheng, Min; Kim, Hyo Jeong; Yu, Jae-Kyoung; Cho, Gyeong Jae; Chang, Ki Churl; Kim, Hyoung Kyu; Han, Jin; Ryter, Stefan W; Chung, Hun Taeg

2014-06-01

72

Pilot production of activated carbon from cotton stalks using H 3PO 4  

Microsoft Academic Search

Cotton stalks, an agricultural waste, were chemically activated in a batch process using H3PO4 in a locally designed carbonizer at 420°C in the absence of any purging gases. Mechanically cut short sticks were soaked in diluted H3PO4 for a short duration (Batch 1) and an extended period (Batch 2) prior to thermal treatment. The derived carbons contained both coarse and

Badie S. Girgis; Edward Smith; Mamdouh M. Louis; Abdel-Nasser A. El-Hendawy

2009-01-01

73

The production of activated carbon from high-ash sub-bituminous and bituminous South African coals  

Microsoft Academic Search

This paper describes a process for the production of activated carbon in a pilot rotary kiln. The first step comprises crushing and\\/or sieving and beneficiation of the different ROM coal precursors. The coal precursors used in this investigation are part of Sasol's resources and although they show high reactivity towards steam and CO they unfortunately contains high ash contents. Consequently

F. F. Prinsloo; D. P. J. Opperman; C. Budeli; D. Hauman

1999-01-01

74

Solar Fuels and Chemicals System Design Study - Production and Regeneration of Activated Carbon: Final Report: Volume 1, Executive Summary.  

National Technical Information Service (NTIS)

This report describes the conceptual design of a solar thermal central receiver system that both produces activated carbon from coal and regenerates spent activated carbon. The system design uses molten carbonate salt that is heated in the receiver to tra...

1987-01-01

75

Solar Fuels and Chemicals System Design Study - Production and Regeneration of Activated Carbon: Final Report: Volume 3, Appendices.  

National Technical Information Service (NTIS)

This report describes the conceptual design of a solar thermal central receiver system that both produces activated carbon from coal and regenerates spent activated carbon. The system design uses molten carbonate salt that is heated in the receiver to tra...

1987-01-01

76

Solar Fuels and Chemicals System Design Study - Production and Regeneration of Activated Carbon: Final Report: Volume 2, Conceptual Design.  

National Technical Information Service (NTIS)

This report describes the conceptual design of a solar thermal central receiver system that both produces activated carbon from coal and regenerates spent activated carbon. The system design uses molten carbonate salt that is heated in the receiver to tra...

1987-01-01

77

Activated carbon from broiler litter: Process description and cost of production  

Microsoft Academic Search

Animal manure continues to represent a significantly large and problematic portion of the US agricultural waste generated yearly. Granular activated carbons made from pelletized poultry litter have been shown to adsorb various positively charged metal ions from laboratory-prepared solutions. The objective of this study was to develop a conceptual capital and operating cost estimate using the Superpro Designer process simulation

Isabel M. Lima; Andrew McAloon; Akwasi A. Boateng

2008-01-01

78

Process optimization for methyl ester production from waste cooking oil using activated carbon supported potassium fluoride  

Microsoft Academic Search

This paper presents the transesterification of waste cooking palm oil (WCO) using activated carbon supported potassium fluoride catalyst. A central composite rotatable design was used to optimize the effect of molar ratio of methanol to oil, reaction period, catalyst loading and reaction temperature on the transesterification process. The reactor was pressurized up to 10 bar using nitrogen gas. All the variables

B. H. Hameed; C. S. Goh; L. H. Chin

2009-01-01

79

ON-SITE PRODUCTION OF ACTIVATED CARBON FROM KRAFT BLACK LIQUOR  

EPA Science Inventory

A pilot plant was designed and constructed to produce char via the St. Regis hydropyrolysis kraft chemical recovery process and to produce activated carbon from the char. This report includes discussion of laboratory and prepilot work, the pilot plant, and presents operating resu...

80

Microbial production, enzyme activity, and carbon turnover in surface sediments of the Hudson River estuary  

Microsoft Academic Search

The detrital food web is a major nexus of energy flow in nearly all aquatic ecosystems. Energy enters this nexus by microbial assimilation of detrital carbon. To link microbiological variables with ecosystem process, it is necessary to understand the regulatory hierarchy that controls the distribution of microbial biomass and activity. Toward that goal, we investigated variability in microbial abundance and

R. L. Sinsabaugh; S. Findlay

1995-01-01

81

Production of Extracellular and Cell-Associated Glucosyltransferase Activity by Streptococcus mutans During Growth on Various Carbon Sources  

PubMed Central

The production of extracellular and cell-associated glucosyltransferase activity by Streptococcus mutans strain GS-5 was examined during growth on various carbon sources in a chemically defined medium. S. mutans cells produced glucosyltransferase activity only during logarithmic growth when glucose, fructose, mannitol, or sorbitol was the sole carbon source. Cells growing on mannitol or sorbitol produced approximately half as much extracellular glucosyltransferase activity as cells growing on glucose, although the proportions of the glucosyltransferase activity capable of synthesizing insoluble glucans were similar. Cells growing on fructose produced slightly more extracellular glucosyltransferase activity than cells grown on glucose, yet the proportion of the glucosyltransferase activity capable of synthesizing insoluble glucans was again similar to glucose cultures. S. mutans cells growing in the presence of both glucose and mannitol displayed diauxic growth and initial preferential utilization of glucose. Glucosyltransferase enzyme production occurred only during the phases of cell growth in the presence of the two carbon sources. The cell-associated glucosyltransferase activities of glucose-, fructose-, mannitol-, and sorbitol-grown cells were relatively low, yet all the cells were capable of adherence to glass in the presence of sucrose. When glucose-containing cultures of S. mutans were supplemented with sucrose, extracellular glucosyltransferase activity first became cell associated and then appeared to become inactivated, presumably due to the accumulation of insoluble glucans.

Janda, William M.; Kuramitsu, Howard K.

1978-01-01

82

Production of Activated Carbon from Palm-oil Shell by Pyrolysis and Steam Activation in a Fixed Bed Reactor  

Microsoft Academic Search

The research objective was to produce activated carbon from palm-oil shells by one step pyrolysis and steam activation in a fixed bed reactor with the diameter of 100 mm. The studied variables were activation temperature, activation time, palm-oil shell sizes and flow rate of air. The results showed that the optimum condition was 1.18-2.36 mm of palm-oil shells at 750

Tharapong Vitidsant

83

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

84

Utilization of Arachis hypogaea hull, an agricultural waste for the production of activated carbons to remove phenol from aqueous solutions  

Microsoft Academic Search

Arachis hypogaea hulls, an agricultural waste, were used to prepare activated carbon by chemical activation with zinc chloride under four different activation atmospheres. The most important parameter in chemical activation was found to be the chemical ratio (activating agent\\/precursor). Carbonization temperature and time are the other two important variables, which had significant effect on the pore structure of carbon. The

Kaustubha Mohanty; Debabrata Das; Manindra Nath Biswas

2008-01-01

85

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...

86

Production of activated carbon by waste tire thermochemical degradation with CO 2  

Microsoft Academic Search

The thermochemical degradation of waste tires in a CO2 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 CO2 flow rate (50 and 150mL\\/min), temperature (800 and 900°C) and reaction time (1, 1.5, 2, 2.5 and 3h). Results show

Mariluz Betancur; Juan Daniel Martínez; Ramón Murillo

2009-01-01

87

Production of activated carbon and its catalytic application for oxidation of hydrogen sulphide  

Microsoft Academic Search

Hydrogen sulphide is an environmentally hazardous gas which is present in many gas streams associated with oil and gas industry. Oxidation of H 2S to sulphur in air produces no bulky or waste material and requires no further purification. Activated carbon is known as a catalyst for this reaction. In this research, a coal-based precursor (luscar char) and a biomass-based

Ramin Azargohar

2009-01-01

88

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

89

Pyrolysis of wood impregnated with phosphoric acid for the production of activated carbon: Kinetics and porosity development studies  

Microsoft Academic Search

The pyrolysis of impregnated wood for the production of activated carbon is investigated. Laboratory experiments are performed in a TG for heating rates of 10°C\\/min and 20°C\\/min and a mathematical model for the kinetics of the pyrolysis process is developed and validated. The effect of the temperature and of the time duration of the pyrolysis process on the specific surface

Idriss Ahmed Hared; Jean-Louis Dirion; Sylvain Salvador; Marcel Lacroix; Sebastien Rio

2007-01-01

90

Bacterial Standing Stock, Activity, and Carbon Production during Formation and Growth of Sea Ice in the Weddell Sea, Antarctica †  

PubMed Central

Bacterial response to formation and growth of sea ice was investigated during autumn in the northeastern Weddell Sea. Changes in standing stock, activity, and carbon production of bacteria were determined in successive stages of ice development. During initial ice formation, concentrations of bacterial cells, in the order of 1 × 108 to 3 × 108 liter-1, were not enhanced within the ice matrix. This suggests that physical enrichment of bacteria by ice crystals is not effective. Due to low concentrations of phytoplankton in the water column during freezing, incorporation of bacteria into newly formed ice via attachment to algal cells or aggregates was not recorded in this study. As soon as the ice had formed, the general metabolic activity of bacterial populations was strongly suppressed. Furthermore, the ratio of [3H]leucine incorporation into proteins to [3H]thymidine incorporation into DNA changed during ice growth. In thick pack ice, bacterial activity recovered and growth rates up to 0.6 day-1 indicated actively dividing populations. However, biomass-specific utilization of organic compounds remained lower than in open water. Bacterial concentrations of up to 2.8 × 109 cells liter-1 along with considerably enlarged cell volumes accumulated within thick pack ice, suggesting reduced mortality rates of bacteria within the small brine pores. In the course of ice development, bacterial carbon production increased from about 0.01 to 0.4 ?g of C liter-1 h-1. In thick ice, bacterial secondary production exceeded primary production of microalgae.

Grossmann, Sonnke; Dieckmann, Gerhard S.

1994-01-01

91

Supercritical fluid extraction and temperature-programmed desorption of phenol and its oxidative coupling products from activated carbon  

Microsoft Academic Search

Activated carbon remains one of the most economical adsorbents for the removal of contaminants from water. In particular, activated carbon is known to have an extremely high affinity for phenol and its derivatives. This has been shown to be the result of a catalytic process wherein activated carbon catalyzes the oxidative coupling reactions of phenol in aqueous solution when molecular

Raashina Humayun; Gurkan Karakas; Philip R. Dahlstrom; Umit S. Ozkan; David L. Tomasko

1998-01-01

92

Use of vegetable oils and fatty acid methyl esters in the production of spherical activated carbons  

Microsoft Academic Search

The possibility of using vegetable oils, i.e., rapeseed oil, soybean oil, linseed oil, tung oil, castor oil and dehydroxylated castor oil, and the fatty acid methyl esters (FAMEs) obtained from them, for the agglomeration of bituminous coals was investigated. Both vegetable oils and FAMEs were found to be suitable bridging liquids for the production of spherical agglomerates-precursor of spherical activated

S Gryglewicz; K Grabas; G Gryglewicz

2000-01-01

93

Production of activated carbon from bagasse and rice husk by a single-stage chemical activation method at low retention times  

Microsoft Academic Search

The production of activated carbon from bagasse and rice husk by a single-stage chemical activation method in short retention times (30–60min) was examined in this study. The raw materials were subjected to a chemical pretreatment and were fed to the reactor in the form of a paste (75% moisture). Chemicals examined were ZnCl2, NaOH and H3PO4, for temperatures of 600,

Dimitrios Kalderis; Sophia Bethanis; Panagiota Paraskeva; Evan Diamadopoulos

2008-01-01

94

PEGylated single-walled carbon nanotubes activate neutrophils to increase production of hypochlorous acid, the oxidant capable of degrading nanotubes  

SciTech Connect

Perspectives for the use of carbon nanotubes in biomedical applications depend largely on their ability to degrade in the body into products that can be easily cleared out. Carboxylated single-walled carbon nanotubes (c-SWCNTs) were shown to be degraded by oxidants generated by peroxidases in the presence of hydrogen peroxide. In the present study we demonstrated that conjugation of poly(ethylene glycol) (PEG) to c-SWCNTs does not interfere with their degradation by peroxidase/H{sub 2}O{sub 2} system or by hypochlorite. Comparison of different heme-containing proteins for their ability to degrade PEG-SWCNTs has led us to conclude that the myeloperoxidase (MPO) product hypochlorous acid (HOCl) is the major oxidant that may be responsible for biodegradation of PEG-SWCNTs in vivo. MPO is secreted mainly by neutrophils upon activation. We hypothesize that SWCNTs may enhance neutrophil activation and therefore stimulate their own biodegradation due to MPO-generated HOCl. PEG-SWCNTs at concentrations similar to those commonly used in in vivo studies were found to activate isolated human neutrophils to produce HOCl. Both PEG-SWCNTs and c-SWCNTs enhanced HOCl generation from isolated neutrophils upon serum-opsonized zymosan stimulation. Both types of nanotubes were also found to activate neutrophils in whole blood samples. Intraperitoneal injection of a low dose of PEG-SWCNTs into mice induced an increase in percentage of circulating neutrophils and activation of neutrophils and macrophages in the peritoneal cavity, suggesting the evolution of an inflammatory response. Activated neutrophils can produce high local concentrations of HOCl, thereby creating the conditions favorable for degradation of the nanotubes. -- Highlights: ? Myeloperoxidase (MPO) product hypochlorous acid is able to degrade CNTs. ? PEGylated SWCNTs stimulate isolated neutrophils to produce hypochlorous acid. ? SWCNTs are capable of activating neutrophils in blood samples. ? Activation of neutrophils in blood causes an increase in plasma MPO concentration. ? Intraperitoneal injection of PEG-SWCNTs in mice induces an inflammatory response.

Vlasova, Irina I., E-mail: irina.vlasova@yahoo.com [Research Institute for Physico-Chemical Medicine, Federal Medico-Biological Agency, Moscow (Russian Federation); Vakhrusheva, Tatyana V. [Research Institute for Physico-Chemical Medicine, Federal Medico-Biological Agency, Moscow (Russian Federation)] [Research Institute for Physico-Chemical Medicine, Federal Medico-Biological Agency, Moscow (Russian Federation); Sokolov, Alexey V.; Kostevich, Valeria A. [Research Institute for Physico-Chemical Medicine, Federal Medico-Biological Agency, Moscow (Russian Federation) [Research Institute for Physico-Chemical Medicine, Federal Medico-Biological Agency, Moscow (Russian Federation); Research Institute for Experimental Medicine, Russian Academy of Medical Science, Saint Petersburg (Russian Federation); Gusev, Alexandr A.; Gusev, Sergey A. [Research Institute for Physico-Chemical Medicine, Federal Medico-Biological Agency, Moscow (Russian Federation)] [Research Institute for Physico-Chemical Medicine, Federal Medico-Biological Agency, Moscow (Russian Federation); Melnikova, Viktoriya I. [Institute of Developmental Biology, Russian Academy of Science, Moscow (Russian Federation)] [Institute of Developmental Biology, Russian Academy of Science, Moscow (Russian Federation); Lobach, Anatolii S. [Institute of Problems of Chemical Physics, Russian Academy of Science, Chernogolovka (Russian Federation)] [Institute of Problems of Chemical Physics, Russian Academy of Science, Chernogolovka (Russian Federation)

2012-10-01

95

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

96

Optimization of production conditions for activated carbons from Tamarind wood by zinc chloride using response surface methodology  

Microsoft Academic Search

The low-cost activated carbon was prepared from Tamarind wood an agricultural waste material, by chemical activation with zinc chloride. Activated carbon adsorption is an effective means for reducing organic chemicals, chlorine, heavy metals and unpleasant tastes and odours in effluent or colored substances from gas or liquid streams. Central composite design (CCD) was applied to study the influence of activation

J. N. Sahu; Jyotikusum Acharya; B. C. Meikap

2010-01-01

97

Characterising biofilm development on granular activated carbon used for drinking water production.  

PubMed

Under normal operation conditions, granular activated carbon (GAC) employed in drinking water treatment plants (DWTPs) for natural organic matter (NOM) removal can be colonised by microorganisms which can eventually establish active biofilms. The formation of such biofilms can contribute to NOM removal by biodegradation, but also in clogging phenomena that can make necessary more frequent backwashes. Biofilm occurrence and evolution under full-scale-like conditions (i.e. including periodic backwashing) are still uncertain, and GAC filtration is usually operated with a strong empirical component. The aim of the present study was to assess the formation and growth, if any, of biofilm in a periodically backwashed GAC filter. For this purpose, an on-site pilot plant was assembled and operated to closely mimic the GAC filters installed in the DWTP in Sant Joan Despí (Barcelona, Spain). The study comprised a monitoring of both water and GAC cores withdrawn at various depths and times throughout 1 year operation. The biomass parameters assessed were total cell count by confocal laser scanning microscopy (CLSM), DNA and adenosine triphosphate (ATP). Visual examination of GAC particles was also conducted by high-resolution field emission scanning electron microscopy (FESEM). Additionally, water quality and GAC surface properties were monitored. Results provided insight into the extent and spatial distribution of biofilm within the GAC bed. To sum up, it was found that backwashing could physically detach bacteria from the biofilm, which could however build back up to its pre-backwashing concentration before next backwashing cycle. PMID:23245544

Gibert, Oriol; Lefèvre, Benoît; Fernández, Marc; Bernat, Xavier; Paraira, Miquel; Calderer, Montse; Martínez-Lladó, Xavier

2013-03-01

98

Activated carbon aerogels  

SciTech Connect

Activated carbon aerogels were obtained from the CO{sub 2} activation of the carbon aerogels. The adsorption isotherms of nitrogen on activated carbon aerogels at 77 K were measured and analyzed by the high-resolution {alpha}{sub s} plot to evaluate their porosities. The {alpha}{sub s} plot showed an upward deviation from linearity below {alpha}{sub s} = 0.5, suggesting that the presence of micropores becomes more predominant with the extent of the activation. Activation increased noticeably the pore volume and the surface area (the maximum value: 2600 m{sup 2}.g{sup -1}) without change of the basic network structure of primary particles. Activated carbon aerogels had a bimodal pore size distribution of uniform micropores and mesopores. 16 refs., 2 figs., 1 tab.

Hanzawa, Y.; Kaneko, K. [Chiba Univ. (Japan)] [Chiba Univ. (Japan); Pekala, R.W. [Lawrence Livermore National Lab., CA (United States)] [Lawrence Livermore National Lab., CA (United States); Dresselhaus, M.S. [Massachusetts Inst. of Technology, Cambridge, MA (United States)] [Massachusetts Inst. of Technology, Cambridge, MA (United States)

1996-12-25

99

PEGylated single-walled carbon nanotubes activate neutrophils to increase production of hypochlorous acid, the oxidant capable of degrading nanotubes.  

PubMed

Perspectives for the use of carbon nanotubes in biomedical applications depend largely on their ability to degrade in the body into products that can be easily cleared out. Carboxylated single-walled carbon nanotubes (c-SWCNTs) were shown to be degraded by oxidants generated by peroxidases in the presence of hydrogen peroxide. In the present study we demonstrated that conjugation of poly(ethylene glycol) (PEG) to c-SWCNTs does not interfere with their degradation by peroxidase/H(2)O(2) system or by hypochlorite. Comparison of different heme-containing proteins for their ability to degrade PEG-SWCNTs has led us to conclude that the myeloperoxidase (MPO) product hypochlorous acid (HOCl) is the major oxidant that may be responsible for biodegradation of PEG-SWCNTs in vivo. MPO is secreted mainly by neutrophils upon activation. We hypothesize that SWCNTs may enhance neutrophil activation and therefore stimulate their own biodegradation due to MPO-generated HOCl. PEG-SWCNTs at concentrations similar to those commonly used in in vivo studies were found to activate isolated human neutrophils to produce HOCl. Both PEG-SWCNTs and c-SWCNTs enhanced HOCl generation from isolated neutrophils upon serum-opsonized zymosan stimulation. Both types of nanotubes were also found to activate neutrophils in whole blood samples. Intraperitoneal injection of a low dose of PEG-SWCNTs into mice induced an increase in percentage of circulating neutrophils and activation of neutrophils and macrophages in the peritoneal cavity, suggesting the evolution of an inflammatory response. Activated neutrophils can produce high local concentrations of HOCl, thereby creating the conditions favorable for degradation of the nanotubes. PMID:22884993

Vlasova, Irina I; Vakhrusheva, Tatyana V; Sokolov, Alexey V; Kostevich, Valeria A; Gusev, Alexandr A; Gusev, Sergey A; Melnikova, Viktoriya I; Lobach, Anatolii S

2012-10-01

100

Catalytic dehydrogenative coupling of methane on active carbon. Effect of metal supported on active carbon  

Microsoft Academic Search

Ethane, ethene, ethyne and hydrogen are obtained in good yields via dehydrogenative coupling of methane in the presence of active carbon as a catalyst. The product yield is increased by supporting metal on active carbon.

H. Yagita; A. Ogata; A. Obuchi; K. Mizuno; T. Maeda; K. Fujimoto

1996-01-01

101

Activated carbon catalysts for the production of hydrogen via the sulfur–iodine thermochemical water splitting cycle  

Microsoft Academic Search

Seven activated carbon catalysts obtained from a variety of raw material sources and preparation methods were examined for their catalytic activity to decompose hydrogen iodide (HI) to produce hydrogen, a key reaction in the sulfur–iodine (S–I) thermochemical water splitting cycle. Activity was examined under a temperature ramp from 473 to 773K. Within the group of lignocellulosic steam-activated carbon catalysts, activity

Lucia M. Petkovic; Daniel M. Ginosar; Harry W. Rollins; Kyle C. Burch; Cristina Deiana; Hugo S. Silva; Maria F. Sardella; Dolly Granados

2009-01-01

102

Freundlich adsorption isotherms of agricultural by-product-based powdered activated carbons in a geosmin–water system  

Microsoft Academic Search

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 powdered activated carbon to the efficiency of a coal-based commercial activated carbon (Calgon Filtrasorb 400). When data were generated from Freundlich isotherms, Calgon Filtrasorb 400

Chilton Ng; Jack N Losso; Wayne E Marshall; Ramu M Rao

2002-01-01

103

Activated Carbon Catalysts for the Production of Hydrogen for the Sulfur-Iodine Thermochemical Water Splitting Cycle  

SciTech Connect

Seven activated carbon catalysts obtained from a variety of raw material sources and preparation methods were examined for their catalytic activity to decompose hydroiodic acid (HI) to produce hydrogen; a key reaction in the sulfur-iodine (S-I) thermochemical water splitting cycle. Activity was examined under a temperature ramp from 473 to 773 K. Within the group of ligno-cellulosic steam-activated carbon catalysts, activity increased with surface area. However, both a mineral-based steam-activated carbon and a ligno-cellulosic chemically-activated carbon displayed activities lower than expected based on their higher surface areas. In general, ash content was detrimental to catalytic activity while total acid sites, as determined by Bohem’s titrations, seemed to favor higher catalytic activity within the group of steam-activated carbons. These results suggest, one more time, that activated carbon raw materials and preparation methods may have played a significant role in the development of surface characteristics that eventually dictated catalyst activity and stability as well.

Lucia M. Petkovic; Daniel M. Ginosar; Harry W. Rollins; Kyle C Burch; Cristina Deiana; Hugo S. Silva; Maria F. Sardella; Dolly Granados

2009-05-01

104

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 2.0wt% catalyst. PMID:24813567

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

2014-07-01

105

Subtask 5.1-Effects of Sodium and Calcium in Lignite on the Performance of Activated Carbon Products.  

National Technical Information Service (NTIS)

Powdered activated carbon (PAC) has traditionally been used by the water treatment industry for the removal of compounds contributing to taste and odor problems. PAC also has the potential to remove naturally occurring organic matter (NOM) from raw waters...

E. S. Olson K. E. Eylands D. J. Stephen

2001-01-01

106

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 ...

107

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 ...

108

EFFECTS OF SODIUM AND CALCIUM IN LIGNITE ON THE PERFORMANCE OF ACTIVATED CARBON PRODUCTS  

Microsoft Academic Search

New federal drinking water regulations have been promulgated to restrict the levels of disinfection by-products (DBPs) in finished public water supplies. DBPs are suspected carcinogens and are formed when organic material is partially oxidized by disinfectants commonly used in the water treatment industry. Additional federal mandates are expected in the near future that will also affect public water suppliers with

Edwin S. Olson; Kurt E. Eylands; Daniel J. Stepan

2001-01-01

109

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

110

Activated carbons prepared from phosphoric acid activation of grain sorghum  

Microsoft Academic Search

The production of activated carbons from grain sorghum with phosphoric acid activation has been studied by means of two processes, i.e., one-stage and two-stage. The former comprises simultaneous carbonization and activation after impregnation; the latter, the carbonization of the precursor at 300 °C for 15 min, followed by the activation of the resultant char after impregnation with phosphoric acid. The

Yulu Diao; W. P Walawender; L. T Fan

2002-01-01

111

Commercial activated carbon for the catalytic production of hydrogen via the sulfur–Iodine thermochemical water splitting cycle  

Microsoft Academic Search

Eight commercial activated carbon catalysts were examined for their catalytic activity to decompose hydroiodic acid (HI) to produce hydrogen; a key reaction in the sulfur–iodine (S–I) thermochemical water splitting cycle. Activity was examined under a temperature ramp from 473 to 773 K. No statistically significant correlation was found between the measured catalyst sample properties and catalytic activity. Four of the eight

Daniel M. Ginosar; Lucia M. Petkovic; Kyle C. Burch

2011-01-01

112

Activation of carboplatin by carbonate.  

PubMed

Carboplatin, [Pt(NH3)2(CBDCA-O,O')], 1, where CBDCA is cyclobutane-1,1-dicarboxylate, is in wide clinical use for the treatment of ovarian, lung, and other types of cancer. Because carboplatin is relatively unreactive toward nucleophiles, an important question concerning the drug is the mechanism by which it is activated in vivo. Using [1H,15N] heteronuclear single quantum coherance spectroscopy (HSQC) NMR and 15N-labeled carboplatin, we show that carboplatin reacts with carbonate ion in carbonate buffer to produce ring-opened products, the nature of which depends on the pH of the medium. The assignment of HSQC NMR resonances was facilitated by studying the reaction of carboplatin in strong acid, which also produces a ring-opened product. The HSQC NMR spectra and UV-visible difference spectra show that reaction of carboplatin with carbonate at pH > 8.6 produces mainly cis-[Pt(NH3)2(CO3(-2))(CBDCA-O)]-2, 5, which contains the mono-dentate CBDCA ligand and mono-dentate carbonate. At pH 6.7, the primary product is the corresponding bicarbonato complex, which may be in equilibrium with its decarboxylated hydroxo analogue. The UV-visible absorption data indicate that the pKb for the protonation of 5 is approximately 8.6. Thus, the reaction of carboplatin with carbonate produces a mixture of ring-opened species that are anions at physiological pH. HSQC NMR studies on 15N-labeled carboplatin in RPMI culture media containing 10% fetal bovine serum with and without added carbonate suggest that carbonate is the attacking nucleophile in culture media. However, because the rate of reaction of carbonate with carboplatin at physiological pH is small, NMR peaks for ring-opened carboplatin were not detected with HSQC NMR. The rate of disappearance of carboplatin in culture medium containing 9 x 10(8) Jurkat cells is essentially the same as that in carbonate buffer, indicating that the ring-opening reaction is not affected by the presence of cells. This work shows that carbonate at concentrations found in culture media, blood, and the cytosol readily displaces one arm of the CBDCA ligand of carboplatin to give a ring-opened product, which at physiological pH is a mixture of anions. These ring-opened species may be important in the uptake, antitumor properties, and toxicity of carboplatin. PMID:16411667

Di Pasqua, Anthony J; Goodisman, Jerry; Kerwood, Deborah J; Toms, Bonnie B; Dubowy, Ronald L; Dabrowiak, James C

2006-01-01

113

Carbonate Production by Coral Reefs.  

National Technical Information Service (NTIS)

In the paper, the authors first create hypothetical models of coral reefs, based upon carbonate production estimates for individual organisms; then they compare the models with what is known about real reef communities and their geologic histories. The di...

K. E. Chave S. V. Smith K. J. Roy

1971-01-01

114

Gallic acid water ozonation using activated carbon  

Microsoft Academic Search

The ozonation of gallic acid in water in the presence of activated carbon has been studied at pH 5. Hydrogen peroxide, ketomalonic and oxalic acids were identified as by-products. The process involves two main periods of reaction. The first period, up to complete disappearance of gallic acid, during which ozonation rates are slightly improved by the presence of activated carbon.

Fernando J. Beltrán; Juan F. García-Araya; Inés Giráldez

2006-01-01

115

The role of carbon dioxide in light-activated hydrogen production by Chlamydomonas reinhardtii  

Microsoft Academic Search

Light-activated hydrogen and oxygen evolution as a function of CO2 concentration in helium were measured for the unicellular green alga Chlamydomonas reinhardtii. The concentrations were 58, 30, 0.8 and 0 ppm CO2. The objective of these experiments was to study the differential affinity of CO2\\/HCO3- for their respective Photosystem II and Calvin cycle binding sites vis-à-vis photoevolution of molecular oxygen

Roehl M. Cinco; Jean M. MacInnis; Elias Greenbaum

1993-01-01

116

Powdered activated carbon coupled with enhanced coagulation for natural organic matter removal and disinfection by-product control: Application in a Western Australian water treatment plant  

Microsoft Academic Search

The removal of organic precursors of disinfection by-products (DBPs), i.e. natural organic matter (NOM), prior to disinfection and distribution is considered as the most effective approach to minimise the formation of DBPs. This study investigated the impact of the addition of powdered activated carbon (PAC) to an enhanced coagulation treatment process at an existing water treatment plant on the efficiency

Ina Kristiana; Cynthia Joll; Anna Heitz

2011-01-01

117

Undersoekning av Moejligheterna att Tillverka Aktivt Kol ur Inhemska Ravaror (Investigation of the Possibilities to Produce Active Carbon from Domestic Raw Products).  

National Technical Information Service (NTIS)

A literature investigation was carried out to map the domestic raw products which can be used for preparation of active carbon. A large number of carbonaceous material can be used but the most important is wood, peat and coal, which are available within t...

O. Granbom

1984-01-01

118

Sorption Properties of Activated Carbon.  

National Technical Information Service (NTIS)

Equilibrium adsorption isotherms were determined experimentally at several temperatures for GB, GA, and GF on BPL activated carbon and a a super activated coconut carbon. Prediction of these isotherms using experimental DMMP, CC14 and benzene adsorption d...

E. D. Tolles

1968-01-01

119

Solvent-Regenerated Activated Carbon.  

National Technical Information Service (NTIS)

Activated carbon has long been used to remove undesired organic chemicals from aqueous solutions such as wastewaters, public water supplies and contaminated groundwaters. The major problem with the use of activated carbon is the high cost of regenerating ...

H. McLaughlin

1988-01-01

120

Regeneration of spent activated carbon  

Microsoft Academic Search

According to this patent application, spent activated carbon is regenerated by contacting it with formaldehyde in an amount sufficient to restore its activation. Following the treatment the regenerated carbon is rinsed to remove residual formaldehyde and is then ready for use. When the activated carbon has lost its reductive and sorbant properties through use, i.e., when it has become 'spent,'

K. Popper; W. M. Camirand; G. S. Williams; E. P. Mecchi

1976-01-01

121

POWDERED ACTIVATED CARBON FROM NORTH DAKOTA LIGNITE: AN OPTION FOR DISINFECTION BY-PRODUCT CONTROL IN WATER TREATMENT PLANTS  

SciTech Connect

New federal drinking water regulations have been promulgated to restrict the levels of disinfection by-products (DBPs) in finished public water supplies. DBPs are suspected carcinogens and are formed when organic material is partially oxidized by disinfectants commonly used in the water treatment industry. Additional federal mandates are expected in the near future that will further affect public water suppliers with respect to DBPs. Powdered activated carbon (PAC) has traditionally been used by the water treatment industry for the removal of compounds contributing to taste and odor problems. PAC also has the potential to remove naturally occurring organic matter (NOM) from raw waters prior to disinfection, thus controlling the formation of regulated DBPs. Many small water systems are currently using PAC for taste and odor control and have the potential to use PAC for controlling DBPs. This project, a cooperative effort between the Energy & Environmental Research Center (EERC), the Grand Forks Water Treatment Plant, and the University of North Dakota Department of Civil Engineering, consists of several interrelated tasks. The objective of the research was to evaluate a cost-effective PAC produced from North Dakota lignite for removing NOM from water and reducing trihalomethane formation potential. The research approach was to develop a statistically valid testing protocol that can be used to compare dose-response relationships between North Dakota lignite-derived PAC and commercially available PAC products. A statistical analysis was performed to determine whether significant correlations exist between operating conditions, water properties, PAC properties, and dose-response behavior. Pertinent physical and chemical properties were also measured for each of the waters and each of the PACs.

Daniel J. Stepan; Thomas A. Moe; Melanie D. Hetland; Margaret L. Laumb

2001-06-01

122

COMBINED USE OF ION EXCHANGE RESINS AND GRANULAR ACTIVATED CARBON FOR THE CONTROL OF ORGANIC MATTER AND DISINFECTION BY PRODUCTS  

EPA Science Inventory

The use of anion exchange resin as a pretreatment step to granular activated carbon is evaluated. erformance is evaluated by DOC, SAC, TOXFP, and THMFP parameters. hio River water and Palm Beach groundwater are used. he results show that resin pretreatment is significant in exten...

123

Commercial Activated Carbon for the Catalytic Production of Hydrogen via the Sulfur-Iodine Thermochemical Water Splitting Cycle  

SciTech Connect

Eight activated carbon catalysts were examined for their catalytic activity to decompose hydroiodic acid (HI) to produce hydrogen; a key reaction in the sulfur-iodine (S-I) thermochemical water splitting cycle. Activity was examined under a temperature ramp from 473 to 773 K. No statistically significant correlation was found between catalyst sample properties and catalytic activity. Four of the eight samples were examined for one week of continuous operation at 723 K. All samples appeared to be stable over the period of examination.

Daniel M. Ginosar; Lucia M. Petkovic; Kyle C. Burch

2011-07-01

124

Separation of C 60\\/C 70 mixture on activated carbon and activated carbon fibres  

Microsoft Academic Search

The possibilities for preparative separation of fullerene (C60\\/C70) mixture by flash chromatography on activated carbon or activated carbon fibres as a stationary phase are shown. The effect of the nature of the activated carbon and of its specific surface area on the elution time, Chromatographic peak width, amount, and purity of the recovered product (C60 or C70) was studied. Different

Nevena Manolova; Iliya Rashkov; Denis Legras; sandrine Delpeux; Francois Beguin

1995-01-01

125

Dewatering Peat With Activated Carbon  

NASA Technical Reports Server (NTRS)

Proposed process produces enough gas and carbon to sustain itself. In proposed process peat slurry is dewatered to approximately 40 percent moisture content by mixing slurry with activated carbon and filtering with solid/liquid separation techniques.

Rohatgi, N. K.

1984-01-01

126

Making Activated Carbon by Wet Pressurized Pyrolysis  

NASA Technical Reports Server (NTRS)

A wet pressurized pyrolysis (wet carbonization) process has been invented as a means of producing activated carbon from a wide variety of inedible biomass consisting principally of plant wastes. The principal intended use of this activated carbon is room-temperature adsorption of pollutant gases from cooled incinerator exhaust streams. Activated carbon is highly porous and has a large surface area. The surface area depends strongly on the raw material and the production process. Coconut shells and bituminous coal are the primary raw materials that, until now, were converted into activated carbon of commercially acceptable quality by use of traditional production processes that involve activation by use of steam or carbon dioxide. In the wet pressurized pyrolysis process, the plant material is subjected to high pressure and temperature in an aqueous medium in the absence of oxygen for a specified amount of time to break carbon-oxygen bonds in the organic material and modify the structure of the material to obtain large surface area. Plant materials that have been used in demonstrations of the process include inedible parts of wheat, rice, potato, soybean, and tomato plants. The raw plant material is ground and mixed with a specified proportion of water. The mixture is placed in a stirred autoclave, wherein it is pyrolized at a temperature between 450 and 590 F (approximately between 230 and 310 C) and a pressure between 1 and 1.4 kpsi (approximately between 7 and 10 MPa) for a time between 5 minutes and 1 hour. The solid fraction remaining after wet carbonization is dried, then activated at a temperature of 500 F (260 C) in nitrogen gas. The activated carbon thus produced is comparable to commercial activated carbon. It can be used to adsorb oxides of sulfur, oxides of nitrogen, and trace amounts of hydrocarbons, any or all of which can be present in flue gas. Alternatively, the dried solid fraction can be used, even without the activation treatment, to absorb oxides of nitrogen.

Fisher, John W.; Pisharody, Suresh; Wignarajah, K.; Moran, Mark

2006-01-01

127

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 feed-stocks. 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.

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

2005-12-12

128

Activated carbon from agricultural by-products for the removal of Rhodamine-B from aqueous solution.  

PubMed

Bagasse pith (BP) has been utilized for activated carbon preparation using H(3)PO(4) (BPH) or KOH (BPK) as a chemical activating agent followed by carbonization at 500 degrees C. The physicochemical properties of activated carbon were carried out. The effectiveness of carbon prepared in adsorption of Rhodamine B (RhB) has been studied as a function of adsorbent type, pH, particle size, agitation time, temperature, initial dye concentration, and desorption. The results obtained showed that the adsorb ability of (RhB) to the BPH is higher than that of the BPK carbon by approximately 10 folds (198.6 and 21.5 mg g(-1), respectively). Kinetic studies show that the adsorption of RhB proceeds according to the pseudo-second-order. The intra-particle diffusion was identified to be the rate-limiting step in addition to the film diffusion. The adsorption was analyzed using 5 isotherm models (Langmuir, Freundlich, Temkin, Harkins-Jura, and Halsey isotherm equations). The highest values of r(2) were obtained with Langmuir (0.997). The adsorption capacity, q(m,) was 263.85 (mgg(-1)) at initial pH 5.7 for the particle size 0.25 nm and equilibrium time of 240 min at a temperature of 20 degrees C and initial dye concentration range of 100-600 (mg l(-1)). Temperature effect proves that the adsorption is endothermic with DeltaH=4.151 (kJ mol(-1)), DeltaS=65.786 (J mol(-1)K(-1)) and a decrease in Gibbs energy (DeltaG=-7.939 to -26.729 kJ mol(-1)). Desorption studies were carried out using water medium, HCl and NaOH with desorption of 2.7, 5.4 and 7.8%, respectively of adsorbed RhB confirming the chemical adsorption mechanism of the dye. This adsorbent was found to be both effective and economically viable. PMID:19362414

Gad, Hamdi M H; El-Sayed, Ashraf A

2009-09-15

129

Active carbon production from used tire in two-stage procedure: industrial pyrolysis and bench scale activation with H 2O–CO 2 mixture  

Microsoft Academic Search

In the present study active carbons have been prepared from used tires and their characteristics were investigated. A two-stage activation procedure (pyrolysis at 800°C in N2 atmosphere during 45min in an industrial pyrolyser with a capacity of 1t\\/h, followed by CBp activation with steam in the presence of CO2 at 970°C in a bench scale reactor) was used for the

A. Zabaniotou; P. Madau; P. D. Oudenne; C. G. Jung; M.-P. Delplancke; A. Fontana

2004-01-01

130

Activated carbons from sewage sludge  

Microsoft Academic Search

Activated carbons of different characteristics have been prepared from dried sewage sludge using CO2, air and KOH as activating agents. The adsorption capacity of the resulting materials has been checked using 4-chlorophenol as a target compound in aqueous solution. CO2 and air-activation led to carbons of low BET area which increased with the activation temperature but did not reach 100m2\\/g

Victor Manuel Monsalvo; Angel Fernandez Mohedano; Juan Jose Rodriguez

2011-01-01

131

Optimum manufacturing conditions of activated carbon fiber absorbents. II. Effect of carbonization and activation conditions  

Microsoft Academic Search

In this paper, viscose rayon-based knitted fabrics were utilized as the precursor to produce activated carbon fiber absorbents\\u000a (ACFA). The effects of carbonization and activation conditions on characteristics (ACFA) were examined. Experimental results\\u000a revealed that increasing the flow rate of environmental gas N2 and steam activator used in conjunction and decreasing the production rate of ACFA can obtain better pore

Ching-Iuan Su; Ching-Luh Wang

2007-01-01

132

Characterization of carbon fiber emissions from current and projected activities for the manufacture and disposal of carbon fiber products. Final report  

Microsoft Academic Search

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. Possibilities exist for the release of these fibers to ambient air during their formation, handling, weaving or impregnation, or during the

J. A. Gieseke; R. B. Reif; E. W. Schmidt

1984-01-01

133

Activated Carbon Fibers for Artificial Kidney Devices.  

National Technical Information Service (NTIS)

Activated carbon fibers were made by wet-spinning a dispersion of powdered activated carbon in hydroxyethylcellulose solution. The resulting monofilament had 70% (dry basis) of activated carbon encapsulated in a water-swollen cellulosic binder that was qu...

T. A. Davis

1973-01-01

134

THERMAL REGENERATION OF ACTIVATED CARBON  

EPA Science Inventory

Ecologically, petrochemical wastes constitute a major hazard since waste materials contain relatively large amounts of non-biodegradable and toxic materials which may be discharged continuously. A three-part experimental study of activated carbon adsorption and thermal regenerati...

135

ALTIN METALÜRJ?S? ?Ç?N YERL? KAYNAKLARDAN AKT?F KARBON ÜRET?M? PRODUCTION OF ACTIVATED CARBON FROM INDIGENOUS RAW MATERIALS FOR GOLD METALLURGY  

Microsoft Academic Search

This study was undertaken to determine the possibility of using activated carbon obtained from indigenous raw materials in the recovery of gold complexes in cyanide leach slurries. Apricot and peach stones and hazel-nut shells from different parts of Black Sea region were steam activated to produce activated carbon suitable for gold industry.

Mustafa YALÇIN

136

Activated carbon catalytic ozonation of oxamic and oxalic acids  

Microsoft Academic Search

The oxidation of hazardous organic compounds leads to the formation of several by-products, being oxalic acid and oxamic acid final oxidation products refractory to ozonation. The present work aimed to study the ozonation of those carboxylic acids in the presence of activated carbon at different solution pH. For comparative purposes, experiments of adsorption on activated carbon, ozonation, and ozonation in

P. C. C. Faria; J. J. M. Órfão; M. F. R. Pereira

2008-01-01

137

Development of activated carbon pore structure via physical and chemical activation of biomass fibre waste  

Microsoft Academic Search

Biomass waste in the form of biomass flax fibre, produced as a by-product of the textile industry was processed via both physical and chemical activation to produce activated carbons. The surface area of the physically activated carbons were up to 840m2g?1 and the carbons were of mesoporous structure. Chemical activation using zinc chloride produced high surface area activated carbons up

Paul T. Williams; Anton R. Reed

2006-01-01

138

REACTIONS OF CHLORITE WITH ACTIVATED CARBON AND WITH VANILLIC ACID AND INDAN ADSORBED ON ACTIVATED CARBON  

EPA Science Inventory

The reaction between chlorite (CO2(-1)) and vanillic acid, at pH 6.0 in the presence of granular activated carbon (GAC), yielded several reaction products identifiable by GC/MS; no products were found in the absence of GAC. Indan and ClO2 or ClO2(-1) reacted in aqueous solution a...

139

Ozonation of aniline promoted by activated carbon  

Microsoft Academic Search

The removal of aniline from aqueous solutions by simultaneous use of ozone and activated carbon was investigated at different solution pH. For comparative purposes, single ozonation and adsorption on activated carbon were carried out in the same experimental set-up. In order to evaluate the role of the activated carbon surface chemistry during ozonation, a commercial activated carbon, Norit GAC 1240

P. C. C. Faria; J. J. M. Órfão; M. F. R. Pereira

2007-01-01

140

Activated carbon from pecan shell: process description and economic analysis  

Microsoft Academic Search

Granular activated carbons derived from pecan shells have been shown to adsorb a variety of metal and organic species in various processing wastewaters. Their effectiveness is equivalent to or exceeds comparable commercial carbons in this regard. The objectives of this study were to develop process flow diagrams for the large-scale production of pecan shell-based carbons derived from steam or phosphoric

Chilton Ng; Wayne E Marshall; Ramu M Rao; Rishipal R Bansode; Jacques N Losso

2003-01-01

141

Paracrystalline structure of activated carbons  

NASA Astrophysics Data System (ADS)

Structural studies by means of neutron diffraction of activated carbons, prepared from a polymer of phenol formaldehyde resin by carbonization and activation processes, with variable porosity, are presented. The neutron scattering data were recorded over the range of the scattering vector Q from 2.5 to 500 nm-1. The structure of activated carbons has been described in terms of disordered graphite-like layers with very weak interlayer correlations. The model has been generated by computer simulations and its validity has been tested by comparison of the experimental and calculated intensity functions. Modelling studies have shown that the model containing 3-4 layers each about 2 nm in diameter accounts for the experimental data and that graphite layers are randomly translated and rotated, according to the turbostratic structure. Near-neighbour carbon-carbon distances of about 0.139 nm and 0.154 nm have been determined. The Debye-Waller factor exp (-Q2?2/2) with ? = ?0(r)1/2 suggests a paracrystalline structure within a single layer. The value of the interlayer spacing of 0.36 nm has been found from paracrystalline simulations of the layer arrangement in the c-axis direction. The high quality of the experimental data has enabled determination of the coordination numbers, the interatomic distances and their standard deviations using a curve-fitting procedure over the Q-range from 250 nm to 500 nm, providing structural information about short- and intermediate-range ordering.

Szczygielska, A.; Burian, A.; Dore, J. C.

2001-06-01

142

Rerouting Carbon Flux To Enhance Photosynthetic Productivity  

PubMed Central

The bioindustrial production of fuels, chemicals, and therapeutics typically relies upon carbohydrate inputs derived from agricultural plants, resulting in the entanglement of food and chemical commodity markets. We demonstrate the efficient production of sucrose from a cyanobacterial species, Synechococcus elongatus, heterologously expressing a symporter of protons and sucrose (cscB). cscB-expressing cyanobacteria export sucrose irreversibly to concentrations of >10 mM without culture toxicity. Moreover, sucrose-exporting cyanobacteria exhibit increased biomass production rates relative to wild-type strains, accompanied by enhanced photosystem II activity, carbon fixation, and chlorophyll content. The genetic modification of sucrose biosynthesis pathways to minimize competing glucose- or sucrose-consuming reactions can further improve sucrose production, allowing the export of sucrose at rates of up to 36.1 mg liter?1 h illumination?1. This rate of production exceeds that of previous reports of targeted, photobiological production from microbes. Engineered S. elongatus produces sucrose in sufficient quantities (up to ?80% of total biomass) such that it may be a viable alternative to sugar synthesis from terrestrial plants, including sugarcane.

Ducat, Daniel C.; Avelar-Rivas, J. Abraham; Way, Jeffrey C.

2012-01-01

143

Uptake of mercury (II) from wastewater by activated carbon from an unwanted agricultural solid by-product: coirpith  

Microsoft Academic Search

Adsorption studies of mercury (II) from aqueous solutions on coirpith carbon were investigated under the varying conditions of agitation time, metal ion concentration, adsorbent dose and pH. Adsorption equilibrium reached in 10, 25, 30 and 40min for 10, 20, 30 and 40mgl?1 Hg(II) concentration. Adsorption followed both Langmuir and Freundlich isotherms. The adsorption capacity was 154mgg?1. The percent removal increased

C Namasivayam; K Kadirvelu

1999-01-01

144

Ozonation effect on natural organic matter adsorption and biodegradation – Application to a membrane bioreactor containing activated carbon for drinking water production  

Microsoft Academic Search

More stringent legislation on dissolved organic matter (DOM) urges the drinking water industry to improve in DOM removal, especially when applied to water with high dissolved organic carbon (DOC) contents and low turbidity. To improve conventional processes currently used in drinking water treatment plants (DWTPs), the performances of a hybrid membrane bioreactor containing fluidised activated carbon were investigated at the

Ronan Treguer; Romuald Tatin; Annabelle Couvert; Dominique Wolbert; Annie Tazi-Pain

2010-01-01

145

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.

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

146

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

147

Differential Scanning Calorimetry (DSC) for the Analysis of Activated Carbon.  

National Technical Information Service (NTIS)

The technique of Differential Scanning Calorimetry (DSC) has been applied to the characterization and the analysis of several activated carbons. These activated carbons included BPL carbon (a base carbon), ASC carbon (a BPL carbon impregnated with copper,...

L. E. Cameron S. H. Liang

1991-01-01

148

Plant for the production of activated carbon and electric power from the gases originated in gasification processes  

Microsoft Academic Search

The development of the countries involves a high energy demand; however, the energetic resources used by the moment are not renewable. Events like the energetic crisis of 1973, the continuous geopolitic clashes in energetic resource-rich areas, and the global environmental deterioration as a consequence of the industrial activity taking place in last century, make obvious the need of searching new

J. Gañán; J. P. Turegano; G. Calama; S. Roman; A. Al-Kassir

2006-01-01

149

Evaluation of Biological Activated Carbon for Industrial Water Reuse.  

National Technical Information Service (NTIS)

The Biological Activated Carbon (BAC) technology was tested for the production of reusable water, low in organics concentration, from industrial wastewater. Effluent streams from an oil refinery, a pulp mill, a textile dyeing mill, and a fungicide plant w...

M. Schwartz R. G. Rice A. Benedek

1982-01-01

150

Activated carbon fibre materials for VOC removal  

Microsoft Academic Search

Activated carbon material has been used for many years in air cleaning applications. Powder form activated carbon has been gradually replaced by activate carbon fibre, which allows much smaller pores - specific area of such material may reach up to 2000 m2\\/g. An experimental dynamic volatile organic compound (VOC) generation system has been developed in order to test new types

P Navarri; D Marchal; A Ginestet

2001-01-01

151

System and method for coproduction of activated carbon and steam/electricity  

DOEpatents

A system and method for producing activated carbon comprising carbonizing a solid carbonaceous material in a carbonization zone of an activated carbon production apparatus (ACPA) to yield a carbonized product and carbonization product gases, the carbonization zone comprising carbonaceous material inlet, char outlet and carbonization gas outlet; activating the carbonized product via activation with steam in an activation zone of the ACPA to yield activated carbon and activation product gases, the activation zone comprising activated carbon outlet, activation gas outlet, and activation steam inlet; and utilizing process gas comprising at least a portion of the carbonization product gases or a combustion product thereof; at least a portion of the activation product gases or a combustion product thereof; or a combination thereof in a solid fuel boiler system that burns a solid fuel boiler feed with air to produce boiler-produced steam and flue gas, the boiler upstream of an air heater within a steam/electricity generation plant, said boiler comprising a combustion zone, a boiler-produced steam outlet and at least one flue gas outlet.

Srinivasachar, Srivats (Sturbridge, MA); Benson, Steven (Grand Forks, ND); Crocker, Charlene (Newfolden, MN); Mackenzie, Jill (Carmel, IN)

2011-07-19

152

Black Carbon Production in Open Biomass Combustion  

NASA Astrophysics Data System (ADS)

Reduction in the quantity of forest fuel accumulating in regions prone to wildfires by using fuel reduction burns not only reduces damage to natural resources and habitats (when wildfires subsequently occur), but also provides a mean to generate black carbon of various particle sizes. These include sizes capable of entering the soil matrix and/or undergoing erosion and subsequent deposition in sedimentary sinks. Black carbon represents a compact form of carbon capable of offsetting an equivalent quantity of contemporary fossil carbon released as CO2. Black carbon, provided it is not consumed as a fuel, may serve this purpose for a considerable period in relation to that of our consumption of fossil fuels. Little is presently known of the extent of natural black carbon production in such biomass combustion and it is clearly beneficial to acquire such knowledge and, where possible, to adjust land management practices to enhance this production. This contribution presents the outcomes of an exploratory experiment devised to enable, insofar as possible, (i) a material balance to estimate the yield of black carbon from a small-scale burning of typical forest litter, (ii) identify the primary factors controlling yield (iii) and develop an experimental programme to provide data contributing to the objective of improved model estimates of the black carbon component in the global carbon cycle.

Bryant, R.; Doerr, S. H.; Santin, C.

2012-04-01

153

Ozonation effect on natural organic matter adsorption and biodegradation--application to a membrane bioreactor containing activated carbon for drinking water production.  

PubMed

More stringent legislation on dissolved organic matter (DOM) urges the drinking water industry to improve in DOM removal, especially when applied to water with high dissolved organic carbon (DOC) contents and low turbidity. To improve conventional processes currently used in drinking water treatment plants (DWTPs), the performances of a hybrid membrane bioreactor containing fluidized activated carbon were investigated at the DWTP of Rennes. Preliminary results showed that the residual DOC was the major part of the non-biodegradable fraction. In order to increase the global efficiency, an upstream oxidation step was added to the process. Ozone was chosen to break large molecules and increase their biodegradability. The first step consisted of carrying out lab-scale experiments in order to optimise the necessary ozone dose by measuring the process yield, in terms of biodegradable dissolved organic carbon (BDOC). Secondly, activated carbon adsorption of the DOC present in ozonated water was quantified. The whole process was tested in a pilot unit under field conditions at the DWTP of Rennes (France). Lab-scale experiments confirmed that ozonation increases the BDOC fraction, reduces the aromaticity of the DOC and produces small size organic compounds. Adsorption tests led to the conclusion that activated carbon unexpectedly removes BDOC first. Finally, the pilot unit results revealed an additional BDOC removal (from 0.10 to 0.15 mg L(-1)) of dissolved organic carbon from the raw water considered. PMID:19906398

Treguer, Ronan; Tatin, Romuald; Couvert, Annabelle; Wolbert, Dominique; Tazi-Pain, Annie

2010-02-01

154

Carbon Dioxide: Production and Sequestration  

NSDL National Science Digital Library

In this problem set, learners will refer to a satellite image to calculate the rate of carbon sequestration in the areas of bare land and forested lawn shown to answer a series of questions. Answer key is provided. This is part of Earth Math: A Brief Mathematical Guide to Earth Science and Climate Change.

155

Activated Carbon from Peach Stones Using Phosphoric Acid Activation at Medium Temperatures  

Microsoft Academic Search

In the present study, the activation features of phosphoric acid have been investigated using waste peach stones as the raw material in the production of granular activated carbon. Thermogravimetry\\/differential thermal analysis was conducted to characterize the thermal behavior of peach stone and titration method was used to evaluate the adsorption capacity of the produced activated carbon. It was observed that

Dong-Su Kim

2004-01-01

156

Activated, coal-based carbon foam  

SciTech Connect

An ablation resistant, monolithic, activated, carbon foam produced by the activation of a coal-based carbon foam through the action of carbon dioxide, ozone or some similar oxidative agent that pits and/or partially oxidizes the carbon foam skeleton, thereby significantly increasing its overall surface area and concurrently increasing its filtering ability. Such activated carbon foams are suitable for application in virtually all areas where particulate or gel form activated carbon materials have been used. Such an activated carbon foam can be fabricated, i.e. sawed, machined and otherwise shaped to fit virtually any required filtering location by simple insertion and without the need for handling the "dirty" and friable particulate activated carbon foam materials of the prior art.

Rogers, Darren Kenneth [Wheeling, WV; Plucinski, Janusz Wladyslaw [Glen Dale, WV

2009-06-09

157

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

158

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

159

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

160

Identification of degradation products of ionic liquids in an ultrasound assisted zero-valent iron activated carbon micro-electrolysis system and their degradation mechanism.  

PubMed

Ionic liquids (ILs) have potential applications in many areas of chemical industry because of their unique properties. However, it has been shown that the ILs commonly used to date are toxic and not biodegradable in nature, thus development of efficient chemical methods for the degradation of ILs is imperative. In this work, degradation of imidazolium, piperidinium, pyrrolidinium and morpholinium based ILs in an ultrasound and zero-valent iron activated carbon (ZVI/AC) micro-electrolysis system was investigated, and some intermediates generated during the degradation were identified. It was found that more than 90% of 1-alkyl-3-methylimidazolium bromide ([Cnmim]Br, n = 2, 4, 6, 8, 10) could be degraded within 110 min, and three intermediates 1-alkyl-3-methyl-2,4,5-trioxoimidazolidine, 1-alkyl-3-methylurea and N-alkylformamide were detected. On the other hand, 1-butyl-1-methylpiperidinium bromide ([C4mpip]Br), 1-butyl-1-methylpyrrolidinium bromide ([C4mpyr]Br) and N-butyl-N-methylmorpholinium bromide ([C4mmor]Br) were also effectively degraded through the sequential oxidization into hydroxyl, carbonyl and carboxyl groups in different positions of the butyl side chain, and then the N-butyl side chain was broken to form the final products of N-methylpiperidinium, N-methylpyrrolidinium and N-methylmorpholinium, respectively. Based on these intermediate products, degradation pathways of these ILs were suggested. These findings may provide fundamental information on the assessment of the factors related to the environmental fate and environmental behavior of these commonly used ILs. PMID:23623468

Zhou, Haimei; Lv, Ping; Shen, Yuanyuan; Wang, Jianji; Fan, Jing

2013-06-15

161

Preparation and characterization of activated carbon from waste biomass  

Microsoft Academic Search

Lignocellulosic materials are good and cheap precursors for the production of activated carbon. In this study, activated carbons were prepared from the pyrolysis of soybean oil cake at 600 and 800°C by chemical activation with K2CO3 and KOH. The influence of temperature and type of chemical reagents on the porosity development was investigated and discussed. K2CO3 was found more effective

Turgay Tay; Suat Ucar; Selhan Karagöz

2009-01-01

162

Regional Reactivation of Granular Activated Carbon.  

National Technical Information Service (NTIS)

A major portion of the cost of using Granular Activated Carbon (GAC) as a water treatment unit process is associated with spent carbon replacement or reactivation. Regional reactivation or sharing a reactivation furnace among several users, has been propo...

J. Q. Adams R. M. Clark B. W. Lykins D. Kittredge

1986-01-01

163

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

164

PRODUCTS OF ACTIVATED LYMPHOCYTES  

PubMed Central

General methods were developed and applied to the biosynthesis and purification of products of activated lymphocytes available in minute quantities. The activity studied here was the migration inhibitory factor (MIF) produced by purified protein derivative (PPD)- or concanavalin A (Con A)-stimulated lymphocytes obtained from one guinea pig or less. The methods selected yielded results in terms of two chemical parameters characteristic of the molecules involved, namely Kd on Sephadex G-75 and isoionic point, pI, on isoelectric focusing. When supernatants were fractionated on G-75 columns, there were several areas even in control supernatants which produced migration inhibition relative to medium controls. However, in PPD- and Con A-stimulated supernatants, at least one peak of MIF activity was found solely in the stimulated cultures, with a Kd of 0.15. A double-labeling technique was used to characterize the proteins of this peak. Control, unstimulated cultures were labeled with [14C]leucine and stimulated cultures were labeled with [3H]leucine. After mixing the supernatants and G-75 filtration, a major "ratiolabeled" broad peak. i.e. one with increased 3H/14C ratio, was found. When a narrow portion of this peak about Kd 0.15, containing most of the MIF activity, was subjected to analytical isoelectric focusing, all of the label was associated with proteins of lower net charge than albumin. A unique ratiolabeled peak was found in PPD- and Con A-stimulated fractions with a pI of approx. 5.3. A micropreparative isoelectric focusing technique was developed and yielded MIF activity in the same region as the major ratiolabeled peak. Further study will be required to ascertain whether the ratiolabeled protein is MIF. By following the Kd, pI, and 3H/14C labeling ratio, at least 14 products of activated lymphocytes, synthesized either de novo or in increased amounts, could be distinguished.

Sorg, Clemens; Bloom, Barry R.

1973-01-01

165

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

166

Phenobarbital interactions with derivatized activated carbon surfaces.  

PubMed

The interactions between phenobarbital and activated carbon surfaces were studied in detail in this work. This was accomplished by utilizing different reagents to manipulate the surface polar functional group compositions of different activated carbons, and determining how those modifications changed phenobarbital adsorption. Oxidation of an activated carbon surface caused a systematic decrease in the basal carbon surface, resulting in a concurrent systematic decrease in the non-specific adsorption of phenobarbital. Even more interesting, it was shown for the first time that chemical reduction of some of the carbonyl-containing functional groups on the activated carbon surface caused a significant increase in the specific adsorption of phenobarbital without any significant effect on the non-specific adsorption. These results support the notion that the OH groups on activated carbon surfaces are the specific adsorption sites for phenobarbital from aqueous solutions, and that the basal carbon surface is the region where non-specific adsorption takes place. PMID:16150453

Aburub, Aktham; Wurster, Dale Eric

2006-04-01

167

Synthesis of carbon black/carbon nitride intercalation compound composite for efficient hydrogen production.  

PubMed

The photoactivity of g-C3N4 is greatly limited by its high recombination rate of photogenerated carriers. Coupling g-C3N4 with other materials has been demonstrated to be an effective way to facilitate the separation and transport of charge carriers. Herein we report a composite of conductive carbon black and carbon nitride intercalation compound synthesized through facile one-step molten salt method. The as-prepared carbon black/carbon nitride intercalation compound composite was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), UV-vis absorption spectrum and photoluminescence spectroscopy (PL). The carbon black nanoparticles, homogeneously dispersed on the surface of carbon nitride intercalation compound, efficiently enhanced separation and transport of photogenerated carriers, thus improving the visible-light photocatalytic activity. The composite of 0.5 wt% carbon black and carbon nitride intercalation compound exhibited a H2 production rate of 68.9 ?mol h(-1), which is about 3.2 times higher than hydrogen production on pristine carbon nitride intercalation compound. PMID:24975427

Wu, Zhaochun; Gao, Honglin; Yan, Shicheng; Zou, Zhigang

2014-07-15

168

Nanostructural activated carbons for hydrogen storage  

NASA Astrophysics Data System (ADS)

A series of nanostructured activated carbons have been synthesized from poly(ether ether ketone) (PEEK), and its derivatives. These carbons, with surface area exceeding 3000 m2/g and with average pore diameters of ? 20 A, are proven to be superior hydrogen storage materials, with hydrogen storage capacities up to 5.5 wt% at 77 K and 45 atm. The porous texture of these carbons was controlled via optimizing three synthetic steps: thermo-oxidation of PEEK in air, pyrolysis or carbonization of the oxidized PEEK in an inert atmosphere, and activation of the pre-carbonized PEEK with metal hydroxide. Thermo-oxidation of PEEK and carbonization process were thoroughly studied. These processes have been investigated by MDSC, FTIR, TGA and Py-MS. The pyrolysis or carbonization of PEEK involves the degradation of PEEK chains in three stages. Carbon morphology, including crystallinity and porous texture, is readily controlled by adjusting carbonization temperature. Activation of PEEK carbons, using inorganic bases and other activation agents, produces microporous carbons having a very narrow pore size distribution and an average pore diameter of ? 20 A. The activation control parameters including activation agent, activation temperature, time and carbon morphology have been investigated extensively. High surface area activated carbon is obtained by activating a highly amorphous carbon with a high activation agent/carbon ratio at 800°C. Theoretical calculations show that the pores with smaller diameter, especially smaller than 7 A, favor hydrogen adsorption. The experimental results confirm this fact and show that: (1) the hydrogen adsorption capacity per unit surface area at 77 K and 1 bar is larger in the smaller pores, (2) gravimetric hydrogen storage capacity (W(H2)) is directly proportional to the ultramicropore (< 7 A) volume; and (3) the volumetric hydrogen storage capacity is directly proportional to the volume fraction of ultramicropores in carbon. Hydrogen adsorption in activated carbons synthesized from PEEK and poly(ether imide) blends, poly(phenylene oxide), polybenzimidazole and lignin show similar trends. In addition, W( H2) progressively increases as surface area increases for the carbons with similar average pore diameters. Keywords. carbon, activated carbon, poly(ether ether ketone), poly(ether imide), poly(phenylene oxide), polybenzimidazole, lignin, gas adsorption, hydrogen storage

Li, Suoding

169

Preparation and characterization of activated carbon from waste biomass.  

PubMed

Lignocellulosic materials are good and cheap precursors for the production of activated carbon. In this study, activated carbons were prepared from the pyrolysis of soybean oil cake at 600 and 800 degrees C by chemical activation with K(2)CO(3) and KOH. The influence of temperature and type of chemical reagents on the porosity development was investigated and discussed. K(2)CO(3) was found more effective than KOH as a chemical reagent under identical conditions in terms of both porosity development and yields of the activated carbons. The maximum surface area (1352.86 m(2)g(-1)) was obtained at 800 degrees C with K(2)CO(3) activation which lies in the range of commercial activated carbons. Elemental analyses of the activated carbons indicate insignificant sulphur content for all activated carbons. The ash and sulphur contents of the activated carbons obtained with chemical activation by K(2)CO(3) were lower than those by chemical activation with KOH. PMID:19022575

Tay, Turgay; Ucar, Suat; Karagöz, Selhan

2009-06-15

170

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

171

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

Microsoft Academic Search

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

Ismail Cem Kantarli; Jale Yanik

2010-01-01

172

Studies and characterisations of various activated carbons used for carbon/carbon supercapacitors  

NASA Astrophysics Data System (ADS)

Various activated carbons from the PICA Company have been tested in supercapacitor cells in order to compare their performances. The differences measured in terms of specific capacitance and cell resistance are presented. Porosity measurements made on activated carbon powders and electrode allowed a better understanding of the electrochemical behaviour of these activated carbons. In this way, the PICACTIF SC carbon was found to be an interesting active material for supercapacitors, with a specific capacitance as high as 125 F/g.

Gamby, J.; Taberna, P. L.; Simon, P.; Fauvarque, J. F.; Chesneau, M.

173

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

174

Activated carbon from vetiver roots: Gas and liquid adsorption studies  

Microsoft Academic Search

Large quantities of lignocellulosic residues result from the industrial production of essential oil from vetiver grass (Vetiveria zizanioides) roots. These residues could be used for the production of activated carbon. The yield of char obtained after vetiver roots pyrolysis follows an equation recently developed [A. Ouensanga, L. Largitte, M.A. Arsene, The dependence of char yield on the amounts of components

S. Gaspard; S. Altenor; E. A. Dawson; P. A. Barnes; A. Ouensanga

2007-01-01

175

CHARACTERIZATION OF ACTIVATED CARBONS PREPARED FROM SUGARCANE BAGASSE BY ZnCl2 ACTIVATION  

Microsoft Academic Search

Activated carbons were prepared from the agricultural waste of sugarcane bagasse by the chemical activation with zinc chloride (ZnCl2) at the activation temperature of 500°C with soaking time of 0.5 hour. The influence of activation parameters on the final carbon products was examined by varying the impregnation ratio (i.e., mass ratio of added ZnCl2 to bagasse) and bagasse size. The

W. T. Tsai; C. Y. Chang; M. C. Lin; S. F. Chien; H. F. Sun; M. F. Hsieh

2001-01-01

176

Comparison of metal and carbon catalysts for hydrogen production by methane decomposition  

Microsoft Academic Search

The COx-free hydrogen production by decomposition of methane was carried out over metal-free carbons and bulk and supported metal catalysts. Catalysts based on Ni or Fe (oxides, spinels and ex-hydrotalcite mixed oxides) and carbon-catalysts of different types (carbon black, activated carbon, carbon nanotubes and graphite) have been used and the performance of both different kinds of catalyst compared in the

R. Guil-Lopez; J. A. Botas; J. L. G. Fierro; D. P. Serrano

2011-01-01

177

Merging allylic carbon-hydrogen and selective carbon-carbon bond activation  

NASA Astrophysics Data System (ADS)

Since the nineteenth century, many synthetic organic chemists have focused on developing new strategies to regio-, diastereo- and enantioselectively build carbon-carbon and carbon-heteroatom bonds in a predictable and efficient manner. Ideal syntheses should use the least number of synthetic steps, with few or no functional group transformations and by-products, and maximum atom efficiency. One potentially attractive method for the synthesis of molecular skeletons that are difficult to prepare would be through the selective activation of C-H and C-C bonds, instead of the conventional construction of new C-C bonds. Here we present an approach that exploits the multifold reactivity of easily accessible substrates with a single organometallic species to furnish complex molecular scaffolds through the merging of otherwise difficult transformations: allylic C-H and selective C-C bond activations. The resulting bifunctional nucleophilic species, all of which have an all-carbon quaternary stereogenic centre, can then be selectively derivatized by the addition of two different electrophiles to obtain more complex molecular architecture from these easily available starting materials.

Masarwa, Ahmad; Didier, Dorian; Zabrodski, Tamar; Schinkel, Marvin; Ackermann, Lutz; Marek, Ilan

2014-01-01

178

Enhanced mercury adsorption in activated carbons from biomass materials and waste tires  

Microsoft Academic Search

Agricultural residues and waste tires constitute an important source of precursors for activated carbon production. Activated carbons offer a potential tool for mercury emissions control. In this work, pine and oak wood, olive seed and tire wastes have been used for the preparation of activated carbons, in order to be examined for their mercury removal capacity. In the case of

G. Skodras; Ir. Diamantopoulou; A. Zabaniotou; G. Stavropoulos; G. P. Sakellaropoulos

2007-01-01

179

A new mechanism about the process of preparing nanoporous silica with activated carbon mold  

Microsoft Academic Search

Supercritical fluids can be used to proceed nanoscale casting, during which silica precursor dissolved in supercritical CO2 and the supercritical CO2 was in contact with the active carbon templates. After removal of active carbon templates by calcinations, microporous and mesoporous silica samples replicating not only mesostructures, but also macroscopic of active carbon molds were obtained and the product have better

Qun Xu; Kunlun Ding; Liumin He; Jianbo Li; Yiqun Guo; Haijuan Fan

2005-01-01

180

Natural gas storage with activated carbon from a bituminous coal  

USGS Publications Warehouse

Granular activated carbons ( -20 + 100 mesh; 0.149-0.84 mm) were produced by physical activation and chemical activation with KOH from an Illinois bituminous coal (IBC-106) for natural gas storage. The products were characterized by BET surface area, micropore volume, bulk density, and methane adsorption capacities. Volumetric methane adsorption capacities (Vm/Vs) of some of the granular carbons produced by physical activation are about 70 cm3/cm3 which is comparable to that of BPL, a commercial activated carbon. Vm/Vs values above 100 cm3/cm3 are obtainable by grinding the granular products to - 325 mesh (<0.044 mm). The increase in Vm/Vs is due to the increase in bulk density of the carbons. Volumetric methane adsorption capacity increases with increasing pore surface area and micropore volume when normalizing with respect to sample bulk volume. Compared with steam-activated carbons, granular carbons produced by KOH activation have higher micropore volume and higher methane adsorption capacities (g/g). Their volumetric methane adsorption capacities are lower due to their lower bulk densities. Copyright ?? 1996 Elsevier Science Ltd.

Sun, J.; Rood, M. J.; Rostam-Abadi, M.; Lizzio, A. A.

1996-01-01

181

Activated carbon for gas separation and storage  

Microsoft Academic Search

Activated carbons offer a large spectrum of pore structures and surface chemistry for adsorption of gases, which are being used to design practical pressure swing and thermal swing adsorption processes for separation and purification of gas mixtures. The activated carbons are often preferred over the zeolitic adsorbents in a gas separation process because of their relatively moderate strengths of adsorption

S. Sircar; T. C. Golden; M. B. Rao

1996-01-01

182

ACTIVATED CARBON FROM LIGNITE FOR WATER TREATMENT  

Microsoft Academic Search

High concentrations of humate in surface water result in the formation of excess amounts of chlorinated byproducts during disinfection treatment. These precursors can be removed in water treatment prior to disinfection using powdered activated carbon. In the interest of developing a more cost-effective method for removal of humates in surface water, a comparison of the activities of carbons prepared from

Edwin S. Olson; Daniel J. Stepan

2000-01-01

183

Porous properties of activated carbons from waste newspaper prepared by chemical and physical activation.  

PubMed

Activated carbons were prepared from old newspaper and paper prepared from simulated paper sludge by chemical activation using various alkali carbonates and hydroxides as activating reagents and also by physical activation using steam. In the chemical activation, the influence of oxidation, carbonization, and activation on the porous properties of the resulting activated carbons was investigated. The specific surface areas (S(BET)) of the activated carbons prepared by single-step activation (direct activation without oxidation and carbonization) were higher than those resulting from two-step activation (oxidation-activation and carbonization-activation) and three-step activation (oxidation-carbonization-activation) methods. The S(BET) values were strongly dependent on the activating reagents and the activating conditions, being >1000 m(2)/g using K(2)CO(3), Rb(2)CO(3), Cs(2)CO(3), and KOH as activating reagents but <1000 m(2)/g using Li(2)CO(3), Na(2)CO(3), and NaOH. These differences in S(BET) values are suggested to be related to the ionic radii of the alkalis used as activating reagents. The microstructures of the higher S(BET) samples show a complete loss of fiber shape but those of the lower S(BET) samples maintain the shape. In the physical activation, the porous properties of the activated carbons prepared by the single-step method were examined as a function of the production conditions such as activation temperature, activation time, steam concentration, and flow rate of the carrier gas. The maximum S(BET) and total pore volume (V(P)) were 1086 m(2)/g and 1.01 ml/g, obtained by activation at 850 degrees C for 2 h, flowing 20 mol% of steam in nitrogen gas at 0.5 l/min. A correlation was found between S(BET) and the yield of the product, the maximum S(BET) value corresponding to a product yield of about 10%. This result is suggested to result from competition between pore formation and surface erosion. Compared with chemically activated carbons using K(2)CO(3), the porous properties of the physically activated carbons have lower S(BET) and V(P) values because of the smaller size and lower volume of their micropores. On the other hand, they retain the original fiber shape and the paper sheet morphology after activation. PMID:16256594

Okada, Kiyoshi; Yamamoto, Nobuo; Kameshima, Yoshikazu; Yasumori, Atsuo

2003-06-01

184

Iron oxide nanoparticles embedded in activated carbons prepared from hydrothermally treated waste biomass.  

PubMed

Particles of iron oxide (Fe3O4 ; 20–40 nm) were embedded within activated carbons during the activation of hydrothermally carbonized (HTC) biomasses in a flow of CO2. Four different HTC biomass samples (horse manure, grass cuttings, beer production waste, and biosludge) were used as precursors for the activated carbons. Nanoparticles of iron oxide formed from iron catalyst included in the HTC biomasses. After systematic optimization, the activated carbons had specific surface areas of about 800 m2g1. The pore size distributions of the activated carbons depended strongly on the degree of carbonization of the precursors. Activated carbons prepared from highly carbonized precursors had mainly micropores, whereas those prepared from less carbonized precursors contained mainly mesopores. Given the strong magnetism of the activated carbon–nano-Fe3O4 composites, they could be particularly useful for water purification. PMID:24678001

Hao, Wenming; Björkman, Eva; Yun, Yifeng; Lilliestråle, Malte; Hedin, Niklas

2014-03-01

185

Oxygen reduction activity of carbon nitride supported on carbon nanotubes.  

PubMed

Fuel cells offer an alternative to burning fossil fuels, but use platinum as a catalyst which is expensive and scarce. Cheap, alternative catalysts could enable fuel cells to become serious contenders in the green energy sector. One promising class of catalyst for electrochemical oxygen reduction is iron-containing, nanostructured, nitrogen-doped carbon. The catalytic activity of such N-doped carbons has improved vastly over the years bringing industrial applications ever closer. Stoichiometric carbon nitride powder has only been observed in recent years. It has nitrogen content up to 57% and as such is an extremely interesting material to work with. The electrochemical activity of carbon nitride has already been explored, confirming that iron is not a necessary ingredient for 4-electron oxygen reduction. Here, we synthesize carbon nitride on a carbon nanotube support and subject it to high temperature treatment in an effort to increase the surface area and conductivity. The results lend insight into the mechanism of oxygen reduction and show the potential for carbon nanotube-supported carbon nitride to be used as a catalyst to replace platinum in fuel cells. PMID:22905547

Lyth, S M; Nabae, Y; Islam, N M; Kuroki, S; Kakimoto, M; Miyata, S

2012-06-01

186

Visible-Light Photocatalytic Hydrogen Production Activity of ZnIn2 S4 Microspheres Using Carbon Quantum Dots and Platinum as Dual Co-catalysts.  

PubMed

ZnIn2 S4 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 H2 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

187

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

188

Electrochemical Capacitors: Effect of Activated Carbon Pore Characteristics on the Capacitance Performance of Ionic Liquid Electrolytes  

Microsoft Academic Search

3 m 2 . Porous carbons are extremely attractive as electrode materials due to their large specific surface area, high pore accessibility, excellent thermal and chemical stability, as well as being relatively low cost (3). Of the carbons available for production of EC electrodes, activated carbon xerogels (ACXs) combine the advantages of carbon xerogels based on cross-linked resins which have

F. B. Sillars; S. I. Fletcher; M. Mirzaeian; P. J. Hall

189

Catalytic pyrolysis of CHF 3 over activated carbon and activated carbon supported potassium catalyst  

Microsoft Academic Search

The catalytic activity of activated carbon (AC) and activated carbon supported potassium for the decomposition of CHF3 was investigated at temperatures between 873 and 1173K and at a space velocity of 4300h?1. It is found that activated carbon supported potassium shows high and relatively stable activity during the pyrolysis of CHF3 under the conditions studied. Compared with the gas phase

Wenfeng Han; Eric M. Kennedy; Huazhang Liu; Ying Li; Adesoji A. Adesina; John C. Mackie; Bogdan Z. Dlugogorski

2010-01-01

190

Carbon limitation of biomass production in high-rate oxidation ponds  

Microsoft Academic Search

Theoretical considerations confirmed by outdoor experiments indicated carbon limitation of biomass production in high-rate oxidation ponds at certain seasonal and operational conditions. Apparently, free carbon dioxide concentration in the pond is the major determinant of carbon-limiting algal photosynthesis. High concentrations of free COâ are provided through bacterial respiration which is the main contributor to algal photosynthesis. At high photosynthetic activities

Y. Azov; G. Shelef; R. Moraine

1982-01-01

191

Preparation of activated carbons from macadamia nut shell and coconut shell by air activation  

Microsoft Academic Search

A novel, three-step process for the production of high-quality activated carbons from macadamia nut shell and coconut shell charcoals is described. In this process the charcoal is (1) heated to a high temperature (carbonized), (2) oxidized in air following a stepwise heating program from low (ca. 450 K) to high (ca. 660 K) temperatures (oxygenated), and (3) heated again in

Man S. Tam; Michael Jerry Antal

1999-01-01

192

Steam-activated carbons from a bituminous coal in a continuous multistage fluidized bed pilot plant  

Microsoft Academic Search

A vertical three-stage fluidized bed pilot plant, with downcomers, was designed and built in order to study the continuous process of the production of activated carbons from a high-volatile bituminous coal from the Puertollano basin (Spain), by steam activation. The pilot plant can operate with a production of up to 40 kg per day. Very good activated carbons were produced

I. Martín-Gullón; M. Asensio; A. Marcilla

1996-01-01

193

Dimethyl carbonate production for fuel additives  

SciTech Connect

We have taken note of the transesterification reaction as a highly safe process of dimethyl carbonate (DMC) production for fuel additives. The reaction proceeds under the low corrosiveness and in the relatively mild condition. We have aimed to use an inorganic solid catalyst for this process. The inorganic solid catalyst is thermally stable and can be used in the large-scale fixed bed reactors without a catalyst separation unit. Through the transesterification of ethylene carbonate (EG) with methanol, DMC and ethylene glycol (EG) are co-generated as the products. EG is one of the bulk chemicals produced in the large scale plant comparable to one for the fuel additives. The market balance is important in the coproduction process. On the assumption that the amount of the co-production meets the market balance, the coproduction of DMC and EG is commercially viable. If we can control the amount of the EG coproduction in this process, it makes the process more flexible in the commercial production. Accordingly we have proposed a conceptual process scheme to control the amount of the EG coproduction. In this symposium, the inorganic solid catalyst system applying to the transesterification process and the conceptual process scheme how to control the amount of co-product will be discussed.

Okada, Y.; Kondo, T.; Asaoka, S. [Chiyoda Corp., Yokohama (Japan)

1996-12-31

194

A Framework for Assessing Carbon Flow in Indian Wood Products  

Microsoft Academic Search

This paper uses a lifecycle analysis to trace the fate of carbon bound in wood products until most of the carbon is released back into the atmosphere. A sensitivity analysis has been carried out to find the effect of change in terminal use (recycling, land filling and burning of discarded products), half-life of wood products and decay rate of carbon

Haripriya Gundimeda

2001-01-01

195

Sorption of elemental mercury by activated carbons  

Microsoft Academic Search

The paper gives results of a study of the mechanisms and rate of elemental mercury (Hg) capture by activated carbons, using a bench-scale apparatus. Three types of activated carbons, two thermally activated (PC-100 and FGD) and one impregnated with elemental sulfur (S) (HGR), were used to study the effects of surface area (approximately 550-1000 sq m\\/g), sorption temperature (23-140 C),

S. V. Krishnan; Brian K. Gullett; Wojciech Jozewicz

1994-01-01

196

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

197

Activated carbon from Eucalyptus camaldulensis Dehn bark using phosphoric acid activation.  

PubMed

The powdered activated carbon prepared by phosphoric acid activation was significantly affected by the carbonization temperature and the weight ratio between raw material and phosphoric acid. With an activation time of 1h and an impregnation ratio of 1:1, the activated carbons with better adsorption capacity were obtained at 500 degrees C. A reduction in the adsorption capacity of the carbon product at higher acid content than this was observed, possibly due to the collapse of the micropore structure. The properties of the resulting activated carbon were: bulk density 0.251gcm(-3), ash content 4.88%, yield 26.2%, iodine adsorption 1043mgg(-1), methylene blue adsorption number 427mgg(-1), and BET surface area 1239m2g(-1). PMID:18455392

Patnukao, Phussadee; Pavasant, Prasert

2008-11-01

198

Activated carbons and double layer capacitance  

Microsoft Academic Search

The porous structures and electrochemical double layer capacitance of activated carbon microbeads and carbon fibers were investigated using nitrogen gas adsorption and electrochemical constant current cycling (CCC) methods. Porous structural information on pore size distribution (PSD) and surface area were extracted through a gas adsorption analysis program based on density functional theory (DFT). The relation between the porous surface areas

Hang Shi

1996-01-01

199

REGIONAL REACTIVATION OF GRANULAR ACTIVATED CARBON  

EPA Science Inventory

A major portion of the cost of using Granular Activated Carbon (GAC) as a water treatment unit process is associated with spent carbon replacement or reactivation. Regional reactivation or sharing a reactivation furnace among several users, has been proposed as a means of minimiz...

200

Vapor Phase Impregnation of Active Carbons.  

National Technical Information Service (NTIS)

The purpose of the research was to study methods for the vapor deposition of metals and metal salts into the pores of activated carbons, and evaluate properties imparted to the carbons for toxic gas removal by this method of impregnation. A successful met...

D. M. Andrews J. P. Redmond

1969-01-01

201

Activated Carbon Fibers for Artificial Kidney Devices.  

National Technical Information Service (NTIS)

Filaments made by wet-spinning a dispersion of powdered activated carbon in hydroxyethylcellulose solution have 70% (w/w, dry basis) of the absorbent carbon encapsulated in a water-swollen cellulosic binder that is permeable to solutes with molecular weig...

T. A. Davis

1974-01-01

202

78 FR 13894 - Certain Activated Carbon From China  

Federal Register 2010, 2011, 2012, 2013

...731-TA-1103 (Review)] Certain Activated Carbon From China Determination On...antidumping duty order on certain activated carbon from China would be likely to...February 2013), entitled Certain Activated Carbon from China: Investigation...

2013-03-01

203

Fermentative production of ethanol from carbon monoxide.  

PubMed

'Too much Carbon Monoxide for me to bear…' are the opening lyrics of the CAKE song Carbon Monoxide (from their 2004 album Pressure Chief), and while this may be the case for most living organisms, several species of bacteria both thrive on this otherwise toxic gas, and metabolize it for the production of fuels and chemicals. Indeed CO fermentation offers the opportunity to sustainably produce fuels and chemicals without impacting the availability of food resources or even farm land. Mounting commercial interest in the potential of this process has in turn triggered greater scrutiny of the molecular and genetic basis for CO metabolism, as well as the challenges associated with the implementation and operation of gas fermentation at scale. PMID:21353524

Köpke, Michael; Mihalcea, Christophe; Bromley, Jason C; Simpson, Séan D

2011-06-01

204

Gas Adsorption by Activated and Impregnated Carbons.  

National Technical Information Service (NTIS)

An assembly has been constructed for measuring equilibrium absorption isotherms on activated and impregnated carbons. The pumping system, pressure-measuring devices and microbalance assembly have been tested. Construction of the fume hood exhaust and filt...

P. J. Reucroft C. T. Chiou

1975-01-01

205

ACTIVATED CARBON ADSORPTION OF TRACE ORGANIC COMPOUNDS  

EPA Science Inventory

Research was conducted to determine how effectively humic substances and the trace contaminants 2-methylisoborneol (MIB), geosmin, the chlorophenols and polynuclear aromatic hydrocarbons were adsorbed by activated carbon under the competitive adsorption conditions encountered in ...

206

CO2 adsorption by activated templated carbons.  

PubMed

Highly porous carbons have been prepared by the chemical activation of two mesoporous carbons obtained by using hexagonal- (SBA-15) and cubic (KIT-6)-ordered mesostructured silica as hard templates. These materials were investigated as sorbents for CO(2) capture. The activation process was carried out with KOH at different temperatures in the 600-800°C range. Textural characterization of these activated carbons shows that they have a dual porosity made up of mesopores derived from the templated carbons and micropores generated during the chemical activation step. As a result of the activation process, there is an increase in the surface area and pore volume from 1020 m(2)g(-1) and 0.91 cm(3)g(-1) for the CMK-8 carbon to a maximum of 2660 m(2)g(-1) and 1.38 cm(3)g(-1) for a sample activated at 800°C (KOH/CMK-8 mass ratio of 4). Irrespective of the type of templated carbon used as precursor or the operational conditions used for the synthesis, the activated samples exhibit similar CO(2) uptake capacities, of around 3.2 mmol CO(2)g(-1) at 25°C. The CO(2) capture capacity seems to depend on the presence of narrow micropores (<1 nm) rather than on the surface area or pore volume of activated carbons. Furthermore, it was found that these porous carbons exhibit a high CO(2) adsorption rate, a good selectivity for CO(2)-N(2) separation and they can be easily regenerated. PMID:21999954

Sevilla, Marta; Fuertes, Antonio B

2012-01-15

207

Hydrogen production by catalytic decomposition of methane over carbon catalysts in a fluidized bed  

Microsoft Academic Search

A fluidized bed reactor made of quartz tube with an I.D. of 0.055 m and a height of 1.0 m was employed for the thermocatalytic\\u000a decomposition of methane to produce CO2 — free hydrogen. The fluidized bed was used for continuous withdrawal of the carbon products from the reactor. Two kinds\\u000a of carbon catalysts — activated carbon and carbon black

Jae Uk Jung; Wooseok Nam; Ki June Yoon; Gui Young Han

2007-01-01

208

Bromate removal during transition from new granular activated carbon (GAC) to biological activated carbon (BAC)  

Microsoft Academic Search

Bromate removal by activated carbon after ozonation is a subject of concern, since bromate is commonly found in the ozonation of bromide-containing water. Though new GAC (granular activated carbon) shows the capacity to reduce bromate to bromide, in the long-term use of GAC following ozonation, its bromate removal rate apparently decreases during transition from new GAC to BAC (biological activated

Mari Asami; Takako Aizawa; Takayuki Morioka; Wataru Nishijima; Akihisa Tabata; Yasumoto Magara

1999-01-01

209

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

210

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

211

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

212

Bacterial carbon production in Lake Erie is influenced by viruses and solar radiation  

Microsoft Academic Search

Bacterial production is an integral recycling mechanism that facilitates carbon flow through aquatic food webs. Factors influencing bacterial activity therefore impact carbon flow. Although ecologists consider grazing and dis - solved organic carbon flux to be the major regulators of bacterial activity, we explored two other important pressures. Virus-like particle abundance ranged from 3.7 ? 1010 to 37.9 ? 1010·L-1

Steven W. Wilhelm; Ralph E. H. Smith

2000-01-01

213

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

214

Efficient production of H 2 and carbon nanotube from CH 4 over single wall carbon nanohorn  

NASA Astrophysics Data System (ADS)

A new catalyst for efficient production of H 2 from CH 4 without CO 2 emission has been requested. We prepared highly-dispersed Pd nanoparticles on single wall carbon nanohorn (Pd-SWCNH) and on oxidized SWCNH (Pd-oxSWCNH) without an anti-aggregation agent. The Pd nanoparticle size on SWCNH and oxSWCNH determined by electron microscopy are around 2.5 and 2.7 nm, respectively. Each sample provides efficiently H 2 and hollow carbon nanofibers through CH 4 decomposition. The H 2 release over the Pd-dispersed SWCNH samples starts from ca. 820 K and is quite large amount compared with a commercial Pd-activated carbon.

Aoki, Yusuke; Urita, Koki; Noguchi, Daisuke; Itoh, Tsutomu; Kanoh, Hirofumi; Ohba, Tomonori; Yudasaka, Masako; Iijima, Sumio; Kaneko, Katsumi

2009-11-01

215

TWO-STAGE GRANULAR ACTIVATED CARBON TREATMENT  

EPA Science Inventory

Two 6.3 l/sec (0.15 mgd), two-stage, packed-bed, downflow granular activated carbon pilot plants were operated continuously for 33 months using unfiltered and unchlorinated activated sludge plant effluent. The main objective of the study was to compare the performance of granular...

216

Structural and adsorptive properties of activated carbons prepared by carbonization and activation of resins  

Microsoft Academic Search

Four activated carbons (S1–S4) possessing different structural characteristics were prepared by carbonization of commercial resins (used for ion exchange) and subsequent activation. Their textural parameters were determined on the basis of nitrogen adsorption–desorption at 77.4 K, analyzed by applying several local and overall adsorption isotherm equations. The nature of carbon surface functionalities was analyzed by FTIR spectroscopy. The GC and

R. Leboda; J. Skubiszewska-Zi?ba; W. Tomaszewski; V. M. Gun'ko

2003-01-01

217

Comparison of Toluene Adsorption Among Granular Activated Carbon and Different Types of Activated Carbon Fibers (ACFs)  

Microsoft Academic Search

Activated carbon fiber (ACF) has been demonstrated to be a good adsorbent for the removal of organic vapors in air. Some ACF has a comparable or larger surface area and higher adsorption capacity when compared with granular activated carbon (GAC) commonly used in respiratory protection devices. ACF is an attractive alternative adsorbent to GAC because of its ease of handling,

Jo Anne G. Balanay; Shaun A. Crawford; Claudiu T. Lungu

2011-01-01

218

Electrochemical storage of energy in acrylic activated carbon fibres and activated carbons made from industrial residues  

Microsoft Academic Search

In this work the application as electrochemical capacitors of novel materials, never tested before for this propose, were investigated using classic cyclic voltammetry, chrono potentiometry, chrono amperometry and electrochemical impedance spectroscopy. The tested materials were prepared in our laboratory: a) acrylic activated carbon fibres (ACF) (samples F920, F932, F993) produced from a commercial acrylic fiber by carbon dioxide activation at

J. Valente Nabais; J. Teixeira; I. Almeida; P. J. M. Carrott; M. M. L. R. Carrott; Rua Romão Ramalho

219

[Effect of carbon and nitrogen sources on the cellulolytic activity of Trametes trogii].  

PubMed

Trametes trogii was grown in a liquid synthetic medium containing different carbon and nitrogen sources. Enzymatic activities of cellulases (endoglucanase, exoglucanase and beta-glucosidase) were measured in culture supernatants. Organic nitrogen sources were the most favourable for growth and cellulase production. Increasing nitrogen concentrations also increased cellulase production. Among carbon sources, crystalline cellulose, cellobiose and a mixture of carboxymethylcellulose and cellobiose induced maximal endoglucanase production. The optimal concentration of the carbon source was 10 g/l. PMID:7568864

Levin, L; Forchiassin, F

1995-01-01

220

Dye adsorption by sewage sludge-based activated carbons in batch and fixed-bed systems  

Microsoft Academic Search

The present research work deals with the production of activated carbons by chemical activation and pyrolysis of sewage sludges. The adsorbent properties of these sewage sludges based activated carbons were studied by liquid-phase adsorption tests. Dyes removal from colored wastewater being a possible application for sludge based adsorbents, methylene blue and saphranine removing from solution was studied. Pure and binary

F. Rozada; L. F. Calvo; A. I. Garc??a; J. Mart??n-Villacorta; M. Otero

2003-01-01

221

Activated Carbon Open Circuit Potential Shifts in Aqueous Solutions  

Microsoft Academic Search

Interaction of certain organic compounds with activated carbon and its effect on the carbon open circuit potentials were studied. It was shown that shifts in open circuit potentials depended on the filling of the activated carbon surface. Whereas adsorption of the investigated compounds on the carbon led to positive potential shifts, their elimination (desorption) from carbon surface led to shifts

Mikhail M. Goldin; Gary Blanchard; Alexander Volkov; Mogely Khubutiya; Vladimir Kolesnikov; Anatoly Evseev; Mark Goldin

2007-01-01

222

Periclase-carbon parts with a graphite kish (periclase-carbon refractories for steel melting production)  

Microsoft Academic Search

Conclusions A method has been developed for production of periclase-carbon parts from periclase-lime patching powders with the addition of graphite kish. The periclase-carbon parts made using parallel mixing of the components possess higher properties.

L. B. Khoroshavin; V. A. Perepelitsyn; T. I. Boriskova; L. V. Ivashchenko; L. B. Romanovskii; N. F. Kravtsov; A. F. Kravchenkov; K. G. Kurteev; E. G. Krekker

1988-01-01

223

A novel activated carbon for supercapacitors  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer A novel activated carbon was prepared from phenol-melamine-formaldehyde resin. Black-Right-Pointing-Pointer The carbon has large surface area with microporous, and high heteroatom content. Black-Right-Pointing-Pointer Heteroatom-containing functional groups can improve the pseudo-capacitance. Black-Right-Pointing-Pointer Physical and chemical properties lead to the good electrochemical properties. -- Abstract: A novel activated carbon has been prepared by simple carbonization and activation of phenol-melamine-formaldehyde resin which is synthesized by the condensation polymerization method. The morphology, thermal stability, surface area, elemental composition and surface chemical composition of samples have been investigated by scanning electron microscope, thermogravimetry and differential thermal analysis, Brunauer-Emmett-Teller measurement, elemental analysis and X-ray photoelectron spectroscopy, respectively. Electrochemical properties have been studied by cyclic voltammograms, galvanostatic charge/discharge, and electrochemical impedance spectroscopy measurements in 6 mol L{sup -1} potassium hydroxide. The activated carbon shows good capacitive behavior and the specific capacitance is up to 210 F g{sup -1}, which indicates that it may be a promising candidate for supercapacitors.

Shen, Haijie [Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, College of Chemistry, Xiangtan University, Hunan 411105 (China)] [Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, College of Chemistry, Xiangtan University, Hunan 411105 (China); Liu, Enhui, E-mail: liuenhui99@sina.com.cn [Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, College of Chemistry, Xiangtan University, Hunan 411105 (China)] [Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, College of Chemistry, Xiangtan University, Hunan 411105 (China); Xiang, Xiaoxia; Huang, Zhengzheng; Tian, Yingying; Wu, Yuhu; Wu, Zhilian; Xie, Hui [Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, College of Chemistry, Xiangtan University, Hunan 411105 (China)] [Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, College of Chemistry, Xiangtan University, Hunan 411105 (China)

2012-03-15

224

Carbon Dioxide Capture with Amine-Grafted Activated Carbon  

Microsoft Academic Search

There are several possible methods by which amine groups can be grafted on the surface of activated carbon (AC) to improve\\u000a their capacity for CO2 adsorption. Ethylenediamine and diethylenetriamine were selected as amino compounds for anchoring on the surface of an oxidized\\u000a AC. Oxidation of AC was carried out by concentrated nitric acid. For each amino compound, two “in-solvent” and

Amirhossein Houshmand; Wan Mohd Ashri Wan Daud; Min-Gyu Lee; Mohammad Saleh Shafeeyan

225

Catalytic oxidation of TNT by activated carbon  

Microsoft Academic Search

Activated carbon can remove 2,4,6-trinitrotoluene (TNT) and 1,3,5-trinitrobenzene (TNB) from aqueous solution and promote oxidation of TNT. After equilibrating a 0.35 mM TNT solution with activated carbon (0.2–1% w\\/v), HPLC and GC\\/MS analysis confirmed the presence of 2,4,6-trinitrobenzaldehyde (TNBAld) and 2,4,6-trinitrobenzene (TNB), and provided strong evidence supporting 2,4,6-trinitrobenzyl alcohol (TNBAlc) as an intermediate of TNT oxidation. After 6 d, TNT

G. K. Vasilyeva; V. D. Kreslavski; P. J. Shea

2002-01-01

226

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

227

Activated carbon monoliths for methane storage  

NASA Astrophysics Data System (ADS)

The use of adsorbent storage media for natural gas (methane) vehicles allows for the use of non-cylindrical tanks due to the decreased pressure at which the natural gas is stored. The use of carbon powder as a storage material allows for a high mass of methane stored for mass of sample, but at the cost of the tank volume. Densified carbon monoliths, however, allow for the mass of methane for volume of tank to be optimized. In this work, different activated carbon monoliths have been produced using a polymeric binder, with various synthesis parameters. The methane storage was studied using a home-built, dosing-type instrument. A monolith with optimal parameters has been fabricated. The gravimetric excess adsorption for the optimized monolith was found to be 161 g methane for kg carbon.

Chada, Nagaraju; Romanos, Jimmy; Hilton, Ramsey; Suppes, Galen; Burress, Jacob; Pfeifer, Peter

2012-02-01

228

Formation of Carbon Nanostructures in Electrolytic Production of Alkali Metals  

Microsoft Academic Search

Carbon-based solid phase containing open and closed multiwalled carbon nanotubes (up to 5% of the total carbon) was found\\u000a in the waste from industrial production of metallic lithium by electrolysis of lithium chloride melt with graphite electrodes.

N. I. Alekseev; O. V. Arapov; I. M. Belozerov; Yu. G. Osipov; K. N. Semenov; S. V. Polovtsev; N. A. Charykov; S. G. Izotova

2005-01-01

229

Quantitating carbon monoxide production from heme by vascular plant preparations in vitro  

Microsoft Academic Search

Heme in animals is mainly degraded enzymatically, producing a predictable amount of carbon monoxide (CO). Under some conditions, alternative sources of CO production are important, such as lipid peroxidation and photo-oxidation. Less is known about CO production in plants as a reflection of enzymatic activity or coupled oxidation, but a sensitive assay for CO production in plants would be a

Hendrik J. Vreman; Ronald J. Wong; David K. Stevenson

2011-01-01

230

Preparation and characterization of activated carbon from demineralized tyre char  

NASA Astrophysics Data System (ADS)

Activated carbon is the most adsorbing material for industrial waste water treatment. For wider applications, the main consideration is to manufacture activated carbon from low cost precursors, which are easily available and cost effective. One such source is scrap tyres. Recently much effort has been devoted to the thermal degradation of tyres into gaseous and liquid hydrocarbons and solid char residue, all of which have the potential to be processed into valuable products. As for solid residue, char can be used either as low-grade reinforcing filler or as activated carbon. The product recovered by a typical pyrolysis of tyres are usually, 33-38 wt% pyrolytic char, 38-55 wt% oil and 10-30 wt% solid fractions. In the present work activated carbon was prepared from pyrolyzed tyre char (PC). Demineralization involves the dissolution of metal into acids i.e. HCl, HNO3 and H2SO4 and in base i.e. NaOH. Different concentration of acid and base were used. Sodium hydroxide showed maximum amount of metal oxide removal. Further the concentration of sodium hydroxide was varied from 1N to 6N. As the concentration of acid are increased demineralization increases. 6N Sodium hydroxide is found to be more effective demineralising agent of tyre char.

Manocha, S.; Prasad, Guddu R.; Joshi, Parth.; Zala, Ranjitsingh S.; Gokhale, Siddharth S.; Manocha, L. M.

2013-06-01

231

Production of carbon molecular sieves from illinois coals. An assessment  

USGS Publications Warehouse

Chars were produced from an Illinois No. 2 bituminous coal under various pyrolysis and activation conditions and tested for their molecular sieve properties. The amount of N2 compared to the amount of CO2 adsorbed by each char was used as a preliminary indicator of its molecular sieve properties. This relatively simple, but apparently useful test was confirmed by successfully characterizing the well-known molecular sieve properties of a commercial zeolite and molecular sieve carbon. In addition, coal chars having relatively high surface areas (800-1800 m2/g) were produced and tested for their molecular sieving capabilities. These carbon materials, which have high adsorption capacities and relatively narrow pore size distributions, should be ideal candidates for the commercial production of CMS.

Lizzio, Anthony, A.; Rostam-Abadi, Massoud

1991-01-01

232

The Properties of Activated Carbon Made from Waste Newsprint Paper  

Microsoft Academic Search

Activated carbon is a porous material made by activation of carbon materials, such as coal, by steam or carbon dioxide gas to form numerous micropores on the surface which gives the material high adsorption characteristics and it is widely used as a purifier for water and air. In this research, to develop a new use for waste paper, activated carbon

Masahiro Shimada; Hisashi Hamabe; Takahiko Iida; Kensuke Kawarada; Takayuki Okayama

1999-01-01

233

Porous properties of activated carbons from waste newspaper prepared by chemical and physical activation  

Microsoft Academic Search

Activated carbons were prepared from old newspaper and paper prepared from simulated paper sludge by chemical activation using various alkali carbonates and hydroxides as activating reagents and also by physical activation using steam. In the chemical activation, the influence of oxidation, carbonization, and activation on the porous properties of the resulting activated carbons was investigated. The specific surface areas (SBET)

Kiyoshi Okada; Nobuo Yamamoto; Yoshikazu Kameshima; Atsuo Yasumori

2003-01-01

234

Preparation and characterization of activated carbons from oil-palm stones for gas-phase adsorption  

Microsoft Academic Search

Preparation and characterization of activated carbons from oil-palm stones by carbon dioxide activation were studied in this paper. These oil-palm stones are agricultural by-products from palm-oil mills in several tropical countries. Ultimate and proximate analyses, pycnometry, mercury porosimetry, surface area and porosimetry as well as transmission electron microscopy were carried out for evaluating the textural properties of the activated carbons.

Aik Chong Lua; Jia Guo

2001-01-01

235

Atypical ethanol production by carbon catabolite derepressed lactobacilli.  

PubMed

Cost effective use of lignocellulosic biomass for bio-based chemical production requires the discovery of novel strains and processes. Lactobacillus pentosus JH5XP5 is a carbon catabolite repression negative mutant which utilizes glucose and pentoses derived from lignocellulosic biomass in the media simultaneously. With a broad range of carbon substrates, L. pentosus JH5XP5 produced a significant amount of ethanol without acetate formation. The yields of ethanol were 2.0- to 2.5-fold higher than those of lactate when glucose, galactose or maltose was used either as a single carbon source or simultaneously with glucose. L. pentosus JH5XP5 was successfully used in an integrated process of simultaneous saccharification and mixed sugar fermentation of rice straw hydrolysate. During the fermentation, the enzyme activities for the saccharification of cellulose were not diminished. Moreover glucose, xylose, and arabinose sugars derived from rice straw hyrolysate were consumed concurrently as if a single carbon source existed and no sugars or cellulosic fiber remained after the fermentation. PMID:20663662

Kim, Jae-Han; Block, David E; Shoemaker, Sharon P; Mills, David A

2010-11-01

236

Microbial enhancement of oil production from carbonate reservoirs  

SciTech Connect

The goal of this work is to evaluate the potential for Microbial Enhanced Oil Recovery (MEOR) in carbonate reservoirs. Specific objectives include: review of the literature pertinent to MEOR in carbonate reservoirs, a study of the microbial ecology of carbonate reservoirs, isolation of microorganisms and their end-products of metabolism on carbonate pore structure, the recovery of residual oil from carbonates in model core systems, and development of models to examine and predict MEOR processes in carbonate reservoirs. 1 ref., 3 figs., 1 tab.

Tanner, R.S.; Knapp, R.M.; McInerney, M.J.; Udegbunam, E.O.

1991-01-01

237

Adsorption of Tin Using Granular Activated Carbon  

Microsoft Academic Search

Adsorption studies for removal of tin from the aqueous phase using granular activated carbon (GAC) and characterization of GAC were carried out. Particle size, proximate, ash, and ultimate analyses were carried out for the physiochemical characteristics of GAC. Thermogravimetric analysis was also done both in ambient and nitrogen atmospheres to see the effect of temperature on GAC stability. Morphological characteristics

Kailas L. WASEWAR; Shiv KUMAR; B. PRASAD

2009-01-01

238

Drinking Water Treatment: Activated Carbon Filtration  

NSDL National Science Digital Library

This site, presented by the University of Nebraska - Lincoln Extension, discusses the principles, processes and requirements of activated carbon filtration systems for the domestic (household) user. The site addresses contaminants removed, those not removed, water testing, principals of treatment and the equipment used in this treatment.

Divorak, Bruce I.; Skipton, Sharon

2008-10-21

239

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

240

OPTIMIZING GAC (GRANULAR ACTIVATED CARBON) SYSTEMS  

EPA Science Inventory

Granular activated carbon (GAC) is an effective technique for removing synthetic organics from both ground and surface waters. Questions have been raised, however, over the cost of using GAC in this manner. To provide insight into these cost issues, the Drinking Water Research Di...

241

EPA'S RESEARCH PROGRAM IN GRANULAR ACTIVATED CARBON  

EPA Science Inventory

Research into Granular Activated Carbon (GAC) for use in drinking water treatment has a long history in the Drinking Water Research Division and its predecessor organizations. tudies were conducted by the U.S. Public Health Service in the late fifties and early sixties to examine...

242

USING POWDERED ACTIVATED CARBON: A CRITICAL REVIEW  

EPA Science Inventory

Because the performance of powdered activated carbon (PAC) for uses other than taste and odor control is poorly documented, the purpose of this article is to critically review uses that have been reported and to analyze means of employing PAC more efficiently. The extent of adsor...

243

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...

244

ACTIVATED CARBON TREATMENT OF KRAFT BLEACHING EFFLUENTS  

EPA Science Inventory

The removal of color and organic contaminants by adsorption on activated carbon from the effluent of a kraft pulp bleaching plant was investigated in a pilot plant. The caustic bleach effluent, which contains 80% of the color from pulp bleaching, was decolorized successfully when...

245

Rate of Thermal Regeneration of Activated Carbon.  

National Technical Information Service (NTIS)

Activated carbon was reacted with steam at varying gas flow rates, steam concentrations and temperatures. The reaction kinetics va ed with the steam concentration to the 0.58 power and had an activatio ergy of 63.6 kcal/g mole. The reaction rate was found...

H. E. Klei D. W. Sundstrom

1974-01-01

246

USING POWDERED ACTIVATED CARBON: A CRITICAL REVIEW  

EPA Science Inventory

Because the performance of powdered activated carbon (PAC) for uses other than taste and odor control is poorly documented, the purpose of this article is to critically review uses that have been reported (i.e., pesticides and herbicides, synthetic organic chemicals, and trihalom...

247

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).

2012-01-01

248

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

249

Activated carbon from vetiver roots: gas and liquid adsorption studies.  

PubMed

Large quantities of lignocellulosic residues result from the industrial production of essential oil from vetiver grass (Vetiveria zizanioides) roots. These residues could be used for the production of activated carbon. The yield of char obtained after vetiver roots pyrolysis follows an equation recently developed [A. Ouensanga, L. Largitte, M.A. Arsene, The dependence of char yield on the amounts of components in precursors for pyrolysed tropical fruit stones and seeds, Micropor. Mesopor. Mater. 59 (2003) 85-91]. The N(2) adsorption isotherm follows either the Freundlich law K(F)P(alpha) which is the small alpha equation limit of a Weibull shaped isotherm or the classical BET isotherm. The surface area of the activated carbons are determined using the BET method. The K(F) value is proportional to the BET surface area. The alpha value increases slightly when the burn-off increases and also when there is a clear increase in the micropore distribution width. PMID:17092643

Gaspard, S; Altenor, S; Dawson, E A; Barnes, P A; Ouensanga, A

2007-06-01

250

Preparation of activated carbons from macadamia nut shell and coconut shell by air activation  

SciTech Connect

A novel, three-step process for the production of high-quality activated carbons from macadamia nut shell and coconut shell charcoals is described. In this process the charcoal is (1) heated to a high temperature (carbonized), (2) oxidized in air following a stepwise heating program from low (ca. 450 K) to high (ca. 660 K) temperatures (oxygenated), and (3) heated again in an inert environment to a high temperature (activated). By use of this procedure, activated carbons with surface areas greater than 1,000 m{sub 2}/g are manufactured with an overall yield of 15% (based on the dry shell feed). Removal of carbon mass by the development of mesopores and macropores is largely responsible for increases in the surface area of the carbons above 600 m{sub 2}/g. Thus, the surface area per gram of activated carbon can be represented by an inverse function of the yield for burnoffs between 15 and 60%. These findings are supported by mass-transfer calculations and pore-size distribution measurements. A kinetic model for gasification of carbon by oxygen, which provides for an Eley-Rideal type reaction of a surface oxide with oxygen in air, fits the measured gasification rates reasonably well over the temperature range of 550--660 K.

Tam, M.S.; Antal, M.J. Jr.

1999-11-01

251

International patenting activity in the field of carbon nanotubes  

Microsoft Academic Search

Carbon nanotubes (CNT) are unique nanostructures with remarkable electronic and mechanical properties and could be used, for example, in nanometre-sized electronics or to strengthen polymer materials. Today, both SWNT and MWNT are being used as key components in the production of high-strength composites, and advanced sensors, electronic and optical devices, catalysts, batteries and fuel cells.Patenting activity in this sub-field of

R. K Gupta; I. Dwivedy

2005-01-01

252

Pyrolysis of scrap tires and conversion of chars to activated carbon  

Microsoft Academic Search

The primary objective of this work was to demonstrate the conversion of scrap tires to activated carbon. The authors have been successful in this endeavor, producing carbons with surface areas greater than 500 m[sup 2]\\/g and significant micropore volumes. Tire shreddings were pyrolyzed in batch reactors, and the pyrolysis chars activated by reaction with superheated steam. Solid products of pyrolysis

Akbar A. Merchant; Mark A. Petrich

1993-01-01

253

Carbon-based nanostructured materials for enhanced H2 production  

NASA Astrophysics Data System (ADS)

A key fundamental limit of the thermal splitting of bulk water is the fact that the ground state of oxygen is paramagnetic, whereas the ground state of water is diamagnetic. Here, we propose to explore a new paradigm in H2 production: a process in which the system remains on the spin singlet potential surface throughout the reaction, by exploiting the catalytic role of defective carbon substrates. Using first principles modeling techniques, we found evidence that mono-vacancy defects in graphite and carbon nanotubes give rise to a rich chemistry, yielding many possible water dissociation pathways, some of which have activation barriers lower than half the value for the dissociation of bulk water. This reduction is caused by spin selection rules that allow the system to remain on the same spin surface throughout the reaction. These novel reactions enhance the hydrogen yield and the reaction rate. In the presence of water only, this reaction is self-limiting: when all of the defects are oxidized, the reaction is complete, and no further H2 is produced. There are several possibilities to achieve regeneration of the active surface sites, such as photo-excitation, vibrational excitations or further reaction with other molecules. We will discuss this exploration in the context of a complete cycle of energy storage and release through the production of H2.

Kostov, M. K.; Santiso, E. E.; George, A. M.; Gubbins, K. E.; Nardelli, M. B.

2006-03-01

254

Noncovalent immobilization of electrocatalysts on carbon electrodes for fuel production.  

PubMed

We show that molecular catalysts for fuel-forming reactions can be immobilized on graphitic carbon electrode surfaces via noncovalent interactions. A pyrene-appended bipyridine ligand (P) serves as the linker between each complex and the surface. Immobilization of a rhodium proton-reduction catalyst, [Cp*Rh(P)Cl]Cl (1), and a rhenium CO2-reduction catalyst, Re(P)(CO)3Cl (2), afford electrocatalytically active assemblies. X-ray photoelectron spectroscopy and electrochemistry confirm catalyst immobilization. Reduction of 1 in the presence of p-toluenesulfonic acid results in catalytic H2 production, while reduction of 2 in the presence of CO2 results in catalytic CO production. PMID:24245686

Blakemore, James D; Gupta, Ayush; Warren, Jeffrey J; Brunschwig, Bruce S; Gray, Harry B

2013-12-11

255

Regulation of ROS Production and Vascular Function by Carbon Monoxide  

PubMed Central

Carbon monoxide (CO) is a gaseous molecule produced from heme by heme oxygenase (HO). CO interacts with reduced iron of heme-containing proteins, leading to its involvement in various cellular events via its production of mitochondrial reactive oxygen species (ROS). CO-mediated ROS production initiates intracellular signal events, which regulate the expression of adaptive genes implicated in oxidative stress and functions as signaling molecule for promoting vascular functions, including angiogenesis and mitochondrial biogenesis. Therefore, CO generated either by exogenous delivery or by HO activity can be fundamentally involved in regulating mitochondria-mediated redox cascades for adaptive gene expression and improving blood circulation (i.e., O2 delivery) via neovascularization, leading to the regulation of mitochondrial energy metabolism. This paper will highlight the biological effects of CO on ROS generation and cellular redox changes involved in mitochondrial metabolism and angiogenesis. Moreover, cellular mechanisms by which CO is exploited for disease prevention and therapeutic applications will also be discussed.

Choi, Yoon Kyung; Por, Elaine D.; Kwon, Young-Guen; Kim, Young-Myeong

2012-01-01

256

Sustainable production of green feed from carbon dioxide and hydrogen.  

PubMed

Carbon dioxide hydrogenation to form hydrocarbons was conducted on two iron-based catalysts, prepared according to procedures described in the literature, and on a new iron spinel catalyst. The CO2 conversion measured in a packed-bed reactor was limited to about 60% because of excessive amounts of water produced in this process. Switching to a system of three packed-bed reactors in series with interim removal of water and condensed hydrocarbons increased CO2 conversion to as much as 89%. The pure spinel catalyst displayed a significantly higher activity and selectivity than those of the other iron catalysts. This process produces a product called green feed, which is similar in composition to the product of a high-temperature, iron-based Fischer–Tropsch process from syngas. The green feed can be readily converted into renewable fuels by well-established technologies. PMID:24678062

Landau, Miron V; Vidruk, Roxana; Herskowitz, Moti

2014-03-01

257

Production and characterization of carbon structures derived from wood  

NASA Astrophysics Data System (ADS)

The objective of this research was to produce structural carbon materials from wood, a renewable biomaterial, for advanced material application. A broad range of materials were produced for study including carbonized wood, resin infused carbon composites made from carbonized wood, and carbon nanotubes from wood fibers. The effect of slow heating on the properties of carbonized wood was studied and important carbonized wood properties were found to be produced over a range of heating rates and peak temperatures. Slow heating rates promoted the formation and growth of graphene sheets in turbostratic crystallites, which had a significant influence on the electrical resistivity and Young's modulus of the carbonized wood. A reduction in the rate of heating may be beneficial with respect to carbon properties and the prevention of crack production during the manufacture of large monolithic carbon specimens from wood and wood-based materials. Investigation of selected physical and mechanical properties of resin-infused porous carbon composites made from medium density fiberboard demonstrated that the infused material can be used in specific applications, where high mechanical strength is not required but high dimensional stability at elevated-use temperatures, fire safety, or static dissipation and shielding is required. A unique cyclic heating process has been developed to produce carbon nanotubes directly from wood fibers. Study on the oxidative behavior of carbons derived from cellulose and lignin showed that cellulose carbon ablates faster at a lower temperature in air than lignin carbon when they were prepared at temperatures lower than 500°C due to cellulose carbon's lower content of aromatic structures. It is hypothesized that the formation of carbon nanotubes during the cyclic heating process occurred via template synthesis, with the nanochannels formed from the ablation of cellulose fibrils functioning as a template. Evidence of formation of nanochannels has been observed, but the growth mechanism of carbon nanotubes in this specific process must be further explored.

Xie, Xinfeng

258

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.

Buapet, Pimchanok; Rasmusson, Lina M.; Gullstrom, Martin; Bjork, Mats

2013-01-01

259

MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT  

Microsoft Academic Search

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

H. C. Maru; M. Farooque

2003-01-01

260

HEMP-derived activated carbon fibers by chemical activation with phosphoric acid  

Microsoft Academic Search

Activated carbon fibers were prepared by chemical activation of hemp fibers with phosphoric acid at different carbonization temperatures and impregnation ratios. Surface properties of the activated carbons fibers were significantly influenced by the activation temperature and the impregnation ratio. An increase of either of these parameters produced a high development of the porous structure of the fibers. Activated carbon fibers

J. M. Rosas; J. Bedia; J. Rodríguez-Mirasol; T. Cordero

2009-01-01

261

Selective activation of carbon-carbon bonds next to a carbonyl group  

NASA Astrophysics Data System (ADS)

ORGANOMETALLIC complexes are used to effect a wide range of catalytic transformations in organic synthesis, such as the activation of C-H bonds1,2. Carbon-carbon bonds, however, are generally unreactive towards transition metals under homogeneous conditions. C-C bond activation by a process of oxidative addition to soluble transition-metal complexes has been limited mostly to stoichiometric (not catalytic) reactions1,3-7,18, to highly strained substrates such as cyclopropane and cubane1,8-11 or to chelating ketones19. Here we present a synthetically useful process of selective C-C bond activation in which the C-C bond adjacent to a carbonyl group is opened by insertion of a soluble rhodium(I) complex. The resulting organometallic intermediate can be transformed to a variety of products in a way that regenerates the rhodium complex. We anticipate that this catalytic scheme will have considerable utility in organic synthesis.

Murakami, Masahiro; Amii, Hideki; Ito, Yoshihiko

1994-08-01

262

Nitrogen activated-carbon sorption compressor  

NASA Astrophysics Data System (ADS)

Joule-Thomson (JT) sorption cryocooling is the most mature technology for cooling from a normal Room-Temperature (RT) down to temperatures below 100 K in the absence of moving parts. Therefore, high reliability and no vibrations are attainable, in comparison with other cryocoolers. Nitrogen is usually used as the working fluid for cooling to temperatures between 80 and 100 K and activated carbons are the best adsorbent for this purpose. In this paper we present the development of a sorption compressor for nitrogen with a commercial Chemviron pelleted activated carbon. The development consists of sorption measurements that we performed for characterizing the adsorption of nitrogen on the selected adsorbent, and the compressor experimental results are compared with equilibrium condition analysis and numerical heat transfer analysis predictions

Tzabar, Nir; Grossman, Gershon

2012-06-01

263

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

264

APPRAISAL OF POWDERED ACTIVATED CARBON PROCESSES FOR MUNICIPAL WASTEWATER TREATMENT  

EPA Science Inventory

Powdered activated carbon has been the subject of several developmental efforts directed towards producing improved methods for treating municipal wastewaters. Granular activated carbon has proven itself as an effective means of reducing dissolved organic contaminant levels, but ...

265

Phenol degradation by microorganisms adsorbed on activated carbon  

Microsoft Academic Search

The phenol degradation by Candida sp. and Pseudomonas sp. immobilized on activated carbon was investigated. Thanks to its great adsorptive surface, activated carbon is suited as supporting material for microorganisms and also provides a high adsorption capacity for phenol.

H. M. Ehrhardt; H. J. Rehm

1985-01-01

266

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

267

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

268

Tc-99 Adsorption on Selected Activated Carbons - Batch Testing Results  

SciTech Connect

CH2M HILL Plateau Remediation Company (CHPRC) is currently developing a 200-West Area groundwater pump-and-treat system as the remedial action selected under the Comprehensive Environmental Response, Compensation, and Liability Act Record of Decision for Operable Unit (OU) 200-ZP-1. This report documents the results of treatability tests Pacific Northwest National Laboratory researchers conducted to quantify the ability of selected activated carbon products (or carbons) to adsorb technetium-99 (Tc-99) from 200-West Area groundwater. The Tc-99 adsorption performance of seven activated carbons (J177601 Calgon Fitrasorb 400, J177606 Siemens AC1230AWC, J177609 Carbon Resources CR-1240-AW, J177611 General Carbon GC20X50, J177612 Norit GAC830, J177613 Norit GAC830, and J177617 Nucon LW1230) were evaluated using water from well 299-W19-36. Four of the best performing carbons (J177606 Siemens AC1230AWC, J177609 Carbon Resources CR-1240-AW, J177611 General Carbon GC20X50, and J177613 Norit GAC830) were selected for batch isotherm testing. The batch isotherm tests on four of the selected carbons indicated that under lower nitrate concentration conditions (382 mg/L), Kd values ranged from 6,000 to 20,000 mL/g. In comparison. Under higher nitrate (750 mg/L) conditions, there was a measureable decrease in Tc-99 adsorption with Kd values ranging from 3,000 to 7,000 mL/g. The adsorption data fit both the Langmuir and the Freundlich equations. Supplemental tests were conducted using the two carbons that demonstrated the highest adsorption capacity to resolve the issue of the best fit isotherm. These tests indicated that Langmuir isotherms provided the best fit for Tc-99 adsorption under low nitrate concentration conditions. At the design basis concentration of Tc 0.865 µg/L(14,700 pCi/L), the predicted Kd values from using Langmuir isotherm constants were 5,980 mL/g and 6,870 mL/g for for the two carbons. These Kd values did not meet the target Kd value of 9,000 mL/g. Tests conducted to ascertain the effects of changing pH showed that at pH values of 6.5 and 7.5, no significant differences existed in Tc-adsorption performance for three of the carbons, but the fourth carbon performed better at pH 7.5. When the pH was increased to 8.5, a slight decline in performance was observed for all carbons. Tests conducted to ascertain the temperature effect on Tc-99 adsorption indicated that at 21 ºC, 27 ºC, and 32 ºC there were no significant differences in Tc-99 adsorption for three of the carbons. The fourth carbon showed a noticeable decline in Tc-99 adsorption performance with increasing temperature. The presence of volatile organic compounds (VOCs) in the source water did not significantly affect Tc-99 adsorption on either of two carbons tested. Technetium-99 adsorption differed by less than 15% with or without VOCs present in the test water, indicating that Tc-99 adsorption would not be significantly affected if VOCs were removed from the water prior to contact with carbon.

Mattigod, Shas V.; Wellman, Dawn M.; Golovich, Elizabeth C.; Cordova, Elsa A.; Smith, Ronald M.

2010-12-01

269

Hydrothermal carbons from hemicellulose-derived aqueous hydrolysis products as electrode materials for supercapacitors.  

PubMed

Acid pretreatment of lignocellulosic biomass, required for bioethanol production, generates large amounts of by-products, such as lignin and hydrolyzed hemicellulose fractions, which have found so far very limited applications. In this work, we demonstrate how the recovered hemicellulose hydrolysis products can be effectively utilized as a precursor for the synthesis of functional carbon materials through hydrothermal carbonization (HTC). The morphology and chemical structure of the synthesized HTC carbons are thoroughly characterized to highlight their similarities with glucose-derived HTC carbons. Furthermore, two routes for introducing porosity within the HTC carbon structure are presented: i) silica nanoparticle hard-templating, which is shown to be a viable method for the synthesis of carbonaceous hollow spheres; and ii) KOH chemical activation. The synthesized activated carbons (ACs) show an extremely high porosity (pore volume?1.0 cm(3) g(-1)) mostly composed of micropores (90 % of total pore volume). Because of their favorable textural properties, the ACs are further tested as electrodes for supercapacitors, yielding very promising results (300 F g(-1) at 250 mA g(-1)) and confirming the high suitability of KOH-activated HTC carbons derived from spruce and corncob hydrolysis products as materials for electric double layer supercapacitors. PMID:23319452

Falco, Camillo; Sieben, Juan Manuel; Brun, Nicolas; Sevilla, Marta; van der Mauelen, Torbjorn; Morallón, Emilia; Cazorla-Amorós, Diego; Titirici, Maria-Magdalena

2013-02-01

270

Biomorphic activated porous carbons with complex microstructures from lignocellulosic residues  

Microsoft Academic Search

Transformation of coir fibers, coir pith and coconut shell endocarp microstructures is described for the formation of activated carbons. The carbonization\\/activation process was carried out using ZnCl2 as activating agent at 800°C under CO2 atmosphere. The carbonization\\/activation process was evaluated by TGA\\/DTG measurements which evidenced an increase in the initial decomposition temperature along with increase in the carbon amount as

Jeremias S. Macedo; Larissa Otubo; Odair Pastor Ferreira; Iara de Fátima Gimenez; Italo Odone Mazali; Ledjane Silva Barreto

2008-01-01

271

Comparison of physicochemical properties of nitrogen-enriched activated carbons prepared by physical and chemical activation of brown coal  

SciTech Connect

Nitrogen-enriched active carbon has been obtained from Polish brown coal from the 'Konin' colliery. The process of ammoxidation by a mixture of ammonia and air at the ratio of 1:3 has been performed at two temperatures (300 and 350{degree}C) at different stages of the production, that is, at that of precursor, char, and active carbon. It has been shown that the stage at which the process of ammoxidation is conducted has profound effect on the amount of nitrogen introduced into the carbon structure. The carbonization and activation (by steam or KOH) of nitrogen-enriched samples leads to significant reduction of the nitrogen content. The final products were microporous active carbons of well-developed surface area varying from 604 to 3181 m{sup 2}/g and having nitrogen content from 0.4 to 6.5 wt%, showing different acid-base character of the surface. 28 refs., 7 tabs.

Piotr Nowicki; Robert Pietrzak; Helena Wachowska [Adam Mickiewicz University, Poznan (Poland). Laboratory of Coal Chemistry and Technology

2008-11-15

272

Comparison of textile dyeing effluent adsorption on commercial activated carbon and activated carbon prepared from olive stone by ZnCl 2 activation  

Microsoft Academic Search

Adsorption of Remazol Red B on activated carbon prepared from olive stone and commercial activated carbon from aqueous solutions was compared. Different activating agent (ZnCl2) amounts and adsorbent particle size were studied to optimize adsorbent surface area. The adsorptive property of commercial activated carbon and activated carbon prepared from olive stone were investigated in terms of adsorbent dose, temperature, equilibrium

Mehmet U?urlu; Ahmet Gürses; Metin Aç?ky?ld?z

2008-01-01

273

JV Task 15 - Powdered Activated Carbon from North Dakota Lignite: An Option for Disinfection By-Product Control in Water Treatment Plants.  

National Technical Information Service (NTIS)

New federal drinking water regulations have been promulgated to restrict the levels of disinfection by-products (DBPs) in finished public water supplies. DBPs are suspected carcinogens and are formed when organic material is partially oxidized by disinfec...

D. J. Stepan T. A. Moe M. D. Hetland M. L. Laumb

2001-01-01

274

Molten carbonate fuel cell product development test  

NASA Astrophysics Data System (ADS)

Advanced fuel cell active components have been developed and scaled up from laboratory scale to commercial scale. Full width components of both the stabilized nickel cathodes and the low chrome anodes have been successfully cast on M-C Power's production tape caster. An improved design for a fuel cell separator plate has been developed. The improved design meets the goals of lower cost and manufacturing simplicity, and addresses performance issues of the current commercial area plate. The engineering that the Bechtel Corporation has completed for the MCFC power plant includes a site design, a preliminary site layout, a Process Flow Diagram, and specification for the procurement of some of the major equipment items. Raw materials for anode and cathode components were ordered and received during the first half of 1993. Tape casting of anodes was started in late summer and continued through August. In addition to the technical progress mentioned above, an environment assessment was prepared in compliance with the National Environmental Policy Act of 1969 (NEPA). As a result, the PDT has received a categorical exclusion from the Air Pollution Control District permit requirements. The PDT is configured to demonstrate the viability of natural gas-fueled MCFC for the production of electricity and thermal energy in an environmentally benign manner for use in commercial and industrial applications.

1993-12-01

275

76 FR 67142 - Certain Activated Carbon From the People's Republic of China: Final Results and Partial...  

Federal Register 2010, 2011, 2012, 2013

...and anthracite), wood, coconut shells, olive stones, and peat. The thermal and steam treatments remove organic materials and...as cellulose, including wood, sawdust, paper mill waste and peat. To the extent that an imported activated carbon product...

2011-10-31

276

75 FR 70208 - Certain Activated Carbon From the People's Republic of China: Final Results and Partial...  

Federal Register 2010, 2011, 2012, 2013

...and anthracite), wood, coconut shells, olive stones, and peat. The thermal and steam treatments remove organic materials and...as cellulose, including wood, sawdust, paper mill waste and peat. To the extent that an imported activated carbon product...

2010-11-17

277

BREAKPOINT CHLORINATION/ACTIVATED CARBON TREATMENT: EFFECT ON VOLATILE HALOGENATED ORGANICS  

EPA Science Inventory

The production and removal of six volatile halogenated organic compounds during treatment of tertiary clarified and filtered wastewater by breakpoint chlorination and activated carbon was examined in a continuous flow pilot plant. Short contact time breakpoint chlorination of fil...

278

Porosity Characterization of Activated Carbons From Wood Precursors via Small Angle Neutron Scattering  

Microsoft Academic Search

Activated carbon products are used in a wide range of commercial gas and liquid phase applications, ranging from control of gasoline emissions from vehicles to purification of drinking water through \\

J. M. Calo; F. S. Baker; P. J. Hall

279

Granular activated carbons from nutshells for the uptake of metals and organic compounds  

Microsoft Academic Search

Almond and pecan shells were chosen as hard, lignocellulosic precursors for the production of granular activated carbons (GACs) in order to create carbons for the adsorption of both organic compounds and metals. They were activated either chemically, with H3PO4, or physically, with CO2, under a variety of conditions. Following activation, a portion of the GACs were oxidized with air.The acid-activated

C. A. Toles; W. E. Marshall; M. M. Johns

1997-01-01

280

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

281

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

282

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

Code of Federal Regulations, 2010 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....

2009-07-01

283

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

Code of Federal Regulations, 2010 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....

2009-07-01

284

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

285

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

286

Binding of human serum albumin to single-walled carbon nanotubes activated neutrophils to increase production of hypochlorous Acid, the oxidant capable of degrading nanotubes.  

PubMed

Previous studies have shown that carboxylated single-walled carbon nanotubes (SWCNTs) can be catalytically biodegraded by hypochlorite (OCl(-)) and reactive radical intermediates of the human neutrophil enzyme myeloperoxidase (MPO). However, the importance of protein-SWCNT interactions in the biodegradation of SWCNTs was not stressed. Here, we used both experimental and theoretical approaches to investigate the interactions of SWCNTs with human serum albumin (HSA, one of the most abundant proteins in blood circulation) and found that the binding was involved in the electrostatic interactions of positively charged Arg residues of HSA with the carboxyls on the nanotubes, along with the ?-? stacking interactions between SWCNTs and aromatic Tyr residues in HSA. Compared with SWCNTs, the binding of HSA could result in a reduced effect for OCl(-) (or the human MPO system)-induced SWCNTs degradation in vitro. However, the HSA-SWCNT interactions would enhance cellular uptake of nanotubes and stimulate MPO release and OCl(-) generation in neutrophils, thereby creating the conditions favorable for the degradation of the nanotubes. Upon zymosan stimulation, both SWCNTs and HSA-SWCNTs were significantly biodegraded in neutrophils, and the degree of biodegradation was more for HSA-SWCNTs under these relevant in vivo conditions. Our findings suggest that the binding of HSA may be an important determinant for MPO-mediated SWCNT biodegradation in human inflammatory cells and therefore shed light on the biomedical and biotechnological applications of safe carbon nanotubes by comprehensive preconsideration of their interactions with human serum proteins. PMID:24870066

Lu, Naihao; Li, Jiayu; Tian, Rong; Peng, Yi-Yuan

2014-06-16

287

INHIBITORY EFFECT OF SORBITOL ON ACETAMINOPHEN ADSORPTION BY ACTIVATED CARBON  

Microsoft Academic Search

The effective use of activated carbon as oral adsorbent in the primary treatment of acute acetaminophen poisoning was studied. The adsorption characteristics of acetaminophen onto activated carbons in presence of sorbitol were investigated in vitro. Both the equilibrium amount adsorbed and the removal rate of acetaminophen onto activated carbon were decreased with the increase of sorbitol concentration in solutions. The

Takeo Nakamura; Yoshihito Oida; Kazuoki Matsumoto; Naohito Kawasaki; Seiki Tanada

2002-01-01

288

REACTION OF ACTIVATED CARBON WITH AQUEOUS CHLORINE AND CHLORINE DIOXIDE  

EPA Science Inventory

The objective of this research was to determine whether aqueous chlorine and chlorine dioxide react with activated carbon, or with compounds adsorbed on activated carbon, to produce compounds that would not form in the absence of activated carbon. The experimental conditions were...

289

REMOVAL OF DYE BY IMMOBILISED PHOTOCATALYST LOADED ACTIVATED CARBON  

Microsoft Academic Search

The ability of activated carbon to adsorb and titanium dioxide to photodegrade organic impurities from water bodies is well accepted. Combination of the two is expected to enhance the removal efficiency due to the synergistic effect. This has enabled activated carbon to adsorb more and at the same time the lifespan of activated carbon is prolonged as the workload of

Zulkarnain Zainal; Chang Sook Keng; Abdul Halim Abdullah

290

Prediction of equilibrium adsorption of water onto activated carbon  

Microsoft Academic Search

In applications such as VOC removal from humid air streams and steam regeneration of activated carbon, adsorption of water vapor has been encountered. The equilibrium adsorption of water onto activated carbon is a frequently encountered phenomenon in the industrial operation of adsorbers. This situation highlights a need for a method of prediction of equilibrium adsorption of water onto activated carbon

Madhusudhan Huggahalli; James R. Fair

1996-01-01

291

Less-costly activated carbon for sewage treatment  

NASA Technical Reports Server (NTRS)

Lignite-aided sewage treatment is based on absorption of dissolved pollutants by activated carbon. Settling sludge is removed and dried into cakes that are pyrolyzed with lignites to yield activated carbon. Lignite is less expensive than activated carbon previously used to supplement pyrolysis yield.

Ingham, J. D.; Kalvinskas, J. J.; Mueller, W. A.

1977-01-01

292

Desorption by ultrasound: Phenol on activated carbon and polymeric resin  

Microsoft Academic Search

An experimental feasibility study of using ultrasound to accomplish the difficult desorption of phenol from activated carbon and polymeric resin adsorbents is discussed. The desorption rates of activated carbon were found to significantly increase by ultrasound at 40 kHz and 1.44 MHz. Attrition of the activated carbon due to cavitation could be prevented by operating at a higher frequency and

Salil U. Rege; Ralph T. Yang; Charles A. Cain

1998-01-01

293

Molten Carbonate Fuel Cell Product Design Improvement.  

National Technical Information Service (NTIS)

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 ...

H. C. Maru F. Farooque

2003-01-01

294

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

295

Production of Carbon Products Using a Coal Extraction Process. (Semiannual Report, September 11, 2003-March 10, 2004).  

National Technical Information Service (NTIS)

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, der...

D. Dadyburjor

2006-01-01

296

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

Microsoft Academic Search

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

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

2010-01-01

297

Carbon limitation of biomass production in high-rate oxidation ponds  

SciTech Connect

Theoretical considerations confirmed by outdoor experiments indicated carbon limitation of biomass production in high-rate oxidation ponds at certain seasonal and operational conditions. Apparently, free carbon dioxide concentration in the pond is the major determinant of carbon-limiting algal photosynthesis. High concentrations of free CO/sub 2/ are provided through bacterial respiration which is the main contributor to algal photosynthesis. At high photosynthetic activities and low organic loadings, free CO/sub 2/ concentrations are low; its flux into algal cells determines photosynthesis and biomass production rate in the pond.

Azov, Y.; Shelef, G.; Moraine, R.

1982-03-01

298

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

299

Removal of volatile organic compounds from activated carbon by thermal desorption and catalytic combustion  

Microsoft Academic Search

The thermal desorption of saturated activated carbon discharged from an industrial adsorber and catalytic oxidation of desorbed\\u000a products over a Pt\\/Al2O3 catalyst were investigated. The activated carbon is almost completely regenerated by flushing with air at 200?C for 30 min.\\u000a Desorbed products are fully oxidized over the Pt\\/Al2O3 catalyst above 275?C.

D. Rankovic; Z. Arsenijevic; N. Radic; B. Grbic; Ž. Grbav?i?

2007-01-01

300

Carbon Monoxide Dehydrogenase Activity in Bradyrhizobium japonicum  

PubMed Central

Bradyrhizobium japonicum strain 110spc4 was capable of chemolithoautotrophic growth with carbon monoxide (CO) as a sole energy and carbon source under aerobic conditions. The enzyme carbon monoxide dehydrogenase (CODH; EC 1.2.99.2) has been purified 21-fold, with a yield of 16% and a specific activity of 58 nmol of CO oxidized/min/mg of protein, by a procedure that involved differential ultracentrifugation, anion-exchange chromatography, hydrophobic interaction chromatography, and gel filtration. The purified enzyme gave a single protein and activity band on nondenaturing polyacrylamide gel electrophoresis and had a molecular mass of 230,000 Da. The 230-kDa enzyme was composed of large (L; 75-kDa), medium (M; 28.4-kDa), and small (S; 17.2-kDa) subunits occurring in heterohexameric (LMS)2 subunit composition. The 75-kDa polypeptide exhibited immunological cross-reactivity with the large subunit of the CODH of Oligotropha carboxidovorans. The B. japonicum enzyme contained, per mole, 2.29 atoms of Mo, 7.96 atoms of Fe, 7.60 atoms of labile S, and 1.99 mol of flavin. Treatment of the enzyme with iodoacetamide yielded di(carboxamidomethyl)molybdopterin cytosine dinucleotide, identifying molybdopterin cytosine dinucleotide as the organic portion of the B. japonicum CODH molybdenum cofactor. The absorption spectrum of the purified enzyme was characteristic of a molybdenum-containing iron-sulfur flavoprotein.

Lorite, Maria J.; Tachil, Jorg; Sanjuan, Juan; Meyer, Ortwin; Bedmar, Eulogio J.

2000-01-01

301

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

302

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

303

Investigations about the quantitative changes of carbon dioxide production in humans. Report 2: Carbon dioxide production during fever and its relationship with heat production  

NASA Technical Reports Server (NTRS)

Investigations are cited and explained for carbon dioxide production during fever and its relationship with heat production. The general topics of discussion are: (1) carbon dioxide production for alternating fever attacks; (2) heat balance during the perspiration phase; (3) heat balance during the chill phase; (4) the theory of fever; and (5) chill phase for other fever attacks.

Liebermeister, C.

1978-01-01

304

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

305

Electrochemical regeneration of activated carbon cloth exhausted with bentazone.  

PubMed

The electrochemical regeneration of an activated carbon cloth exhausted with a common herbicide (bentazone) was investigated under different operating conditions. The reversibility of the desorption process was confirmed by monitoring the UV spectra of the solution while cathodic polarization is being applied. Neither nanotextural nor chemical changes are produced in the carbon cloth upon polarization in the absence of the adsorbate. Upon cathodic polarization of a carbon cloth working electrode preloaded with bentazone, negative charges appear on the surface. A partial bentazone desorption results from repulsive electrostatic interactions between the negative charges on the carbon cloth and bentazone. When the electrode potential is below the thermodynamic value for cathodic decomposition of water, hydroxyl ions are liberated. Such ions provoke local pH changes that are responsible of the dissociation of bentazone and carbon surface groups to their anionic form. As a consequence of the pH increase, an almost reversible desorption of bentazone is observed. The effects of several operating parameters on the regeneration efficiency were evaluated. Higher regeneration efficiencies were attained under potentiostatic as compared to galvanostatic conditions, as OH- production strongly depends on the applied potential. PMID:18605577

Ania, Conchi O; Béguin, François

2008-06-15

306

Granular and monolithic activated carbons from KOH-activation of olive stones  

Microsoft Academic Search

Different activated carbons were prepared by KOH-activation of carbonized olive stones by varying the KOH\\/carbon weight ratio and the particle size of the precursor. The activated carbon with the best surface characteristics was furthermore steam-activated. Other activated carbon was obtained by using directly olive stones as raw material. In this case the precursor particles were broken by the KOH solution,

Ruth Ubago-Pérez; Francisco Carrasco-Marín; David Fairén-Jiménez; Carlos Moreno-Castilla

2006-01-01

307

Activated carbons from flax shive and cotton gin waste as environmental adsorbents for the chlorinated hydrocarbon trichloroethylene.  

PubMed

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 to show that flax shive and cotton gin waste can serve as a precursor for activated carbon that can be used for adsorption of trichloroethylene (TCE) from both the liquid and gas phases. Testing was conducted on carbon activated with phosphoric acid or steam. The results show that activated carbon made from flax shive performed better than select commercial activated carbons, especially at higher TCE concentrations. The activation method employed had little effect on TCE adsorption in gas or vapor phase studies but liquid phase studies suggested that steam activation is slightly better than phosphoric acid activation. As expected, the capacity for the activated carbons depended on the fluid phase equilibrium concentration. At a fluid concentration of 2 mg of TCE/L of fluid, the capacity of the steam activated carbon made from flax shive was similar at 64 and 80 mg TCE/g of carbon for the vapor and liquid phases, respectively. Preliminary cost estimates suggest that the production costs of such carbons are $1.50 to $8.90 per kg, depending on activation method and precursor material; steam activation was significantly less expensive than phosphoric acid activation. PMID:19540755

Klasson, K Thomas; Wartelle, Lynda H; Lima, Isabel M; Marshall, Wayne E; Akin, Danny E

2009-11-01

308

Preparation of titania\\/silica mesoporous composites with activated carbon template in supercritical carbon dioxide  

Microsoft Academic Search

Titania\\/silica mesoporous composites have been prepared with nanoscale casting process using activated carbon as template in supercritical carbon dioxide (SC CO2). The composite precursor of tetrabutyl titanate and tetraethyl orthosilicate (TEOS) were dissolved in supercritical CO2, and then coated on activated carbon in the desired supercritical condition. After removal of activated carbon template by calcinations in air at 600°C, TiO2\\/SiO2

Qun Xu; Haijuan Fan; Yiqun Guo; Yanxia Cao

2006-01-01

309

Nanoporous ferric oxide prepared with activated carbon template in supercritical carbon dioxide  

Microsoft Academic Search

Nanoporous ferric oxide has been prepared with nanoscale casting process using activated carbon template in supercritical carbon dioxide. The precursors with the cosolvent of acetone were dissolved in supercritical CO2, and then attached to activated carbon in the supercritical condition. After removal of the activated carbon template by calcinations in air at 873K, the nanoporous Fe2O3 was obtained. Four factors

Haijuan Fan; Qun Xu; Yiqun Guo; Qi Peng; Zhenzhong Hou

2006-01-01

310

On the performance of supercapacitors with electrodes based on carbon nanotubes and carbon activated material—A review  

NASA Astrophysics Data System (ADS)

Supercapacitors or electrochemical double-layer capacitors (EDLCs) have capacitance value up to thousands of Farads at the same size as for conventional capacitors. At such capacitance value EDLCs are of interest for electrical energy storage. The specific energy of commercial supercapacitors is limited to 5-6 Wh/kg, whereas for batteries the lower limit is 35-40 Wh/kg. Nonetheless other advantages of supercapacitors make them already useful in conjunction with batteries in power applications. Main results related to supercapacitor performance improvement available in literature are presented. Research efforts have been done to increase the specific capacitance of supercapacitor electrodes based on activated or porous carbon material, already used in commercial products. By using available activated carbon with a specific surface area reaching 3000 m 2/g, specific capacitance values up to 300 F/g have been reported for the investigated experimental supercapacitors. Nonetheless, further optimization of activated carbon properties and its use in supercapacitor electrodes is required for 300 F/g and higher value. By addition of metallic oxides or conductive polymers in the activated carbon used for EDLC electrodes, specific capacitance enhancement takes place. Carbon nanotubes used in experimental supercapacitor electrodes resulted in specific capacitance as high as 180 F/g but higher electrical conductivity and consequently, specific power than in the case of activated carbon was observed. Addition of a small percent of carbon nanotubes in the activated carbon for electrodes results in performance improvement (higher capacitance and conductivity). Nevertheless, high cost of carbon nanotubes prevents their use in commercial products.

Obreja, Vasile V. N.

2008-05-01

311

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

312

Characteristics and humidity control capacity of activated carbon from bamboo  

Microsoft Academic Search

Activated carbons were prepared from bamboo by chemical activation with K2CO3 or physical activation with CO2. The structural and surface chemical characteristics of the activated carbons were determined by N2 adsorption–desorption and Boehm titration, respectively. The water vapor adsorption properties of the activated carbons with various pore structures (preparation conditions) were examined. The relationship between water vapor adsorption capacity and

Toshihide Horikawa; Yoshiyuki Kitakaze; Tomoki Sekida; Jun’ichi Hayashi; Masahiro Katoh

2010-01-01

313

Production of biohydrogen by aqueous phase reforming of polyols over platinum catalysts supported on three-dimensionally bimodal mesoporous carbon.  

PubMed

Now in 3D! Three-dimensionally bimodal carbons (3D-BMC) with mesopores of tunable size (controlled through the polymerization of the carbon precursor) are synthesized. After loading with platinum, the catalysts are used in aqueous phase reforming of polyols, and show superior performance in terms of carbon conversion, hydrogen yield, selectivity, and hydrogen production rate compared to platinum catalysts supported on activated carbon or two-dimensional CMK-3. PMID:22415941

Park, Hyun Ju; Kim, Ho-Dong; Kim, Tae-Wan; Jeong, Kwang-Eun; Chae, Ho-Jeong; Jeong, Soon-Yong; Chung, Young-Min; Park, Young-Kwon; Kim, Chul-Ung

2012-04-01

314

Molten Carbonate Fuel Cell Product Design Improvement.  

National Technical Information Service (NTIS)

The ongoing program is 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(Trade Name) (DFC(Trade Name)) development at FuelCell Energy, Inc. (FCE...

2004-01-01

315

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

316

BACTERIA ASSOCIATED WITH GRANULAR ACTIVATED CARBON PARTICLES IN DRINKING WATER  

EPA Science Inventory

A sampling protocol was developed to examine particles released from granular activated carbon filter beds. A gauze filter/Swinnex procedure was used to collect carbon fines from 201 granular activated carbon-treated drinking water samples over 12 months. Application of a homogen...

317

Role of active sites in the steam activation of high unburned carbon fly ashes  

Microsoft Academic Search

Previous studies on carbon gasification have not included high unburned carbon content fly ashes, and therefore it remains unclear why not all fly ash carbon samples are equally suitable for activation. The concentration of active sites is well known to influence carbon gasification reactions. Therefore, the objective of this work was to investigate the effect of the concentration of active

Zhe Lu; M. Mercedes Maroto-Valer; Harold H. Schobert

2008-01-01

318

ADSORPTION AND DESORPTION OF M-XYLENE FROM SUPERCRITICAL CARBON DIOXIDE ON ACTIVATED CARBON  

Microsoft Academic Search

The equilibrium loadings of m-xylene from supercritical carbon dioxide on activated carbon are reported. The experimental data were obtained by measuring the outlet concentration of m-xylene eluted from a column packed with activated carbon until the effluent reached the input concentration. The Freundlich isotherm expression was found to correlate the experimental data satisfactorily. In a second step, the regeneration by

Jamal Benkhedda; Jean-Noël Jaubert; Danielle Barth; Carsten Zetzl; Gerd Brunner

2001-01-01

319

Unburnt carbon from coal fly ashes as a precursor of activated carbon for nitric oxide removal  

Microsoft Academic Search

The aim of this work is to evaluate the characteristics of an activated carbon obtained from unburnt carbon in coal fly ashes to be used in the removal of NO. Carbon-rich fraction was obtained by mechanical sieving of fly ashes. The mineral matter was removed by conventional HCl and HF demineralization procedure. Activation was carried out with steam at 900°C

Begoña Rubio; M. Teresa Izquierdo; M. Carmen Mayoral; M. Teresa Bona; Jose M. Andres

2007-01-01

320

PAC activity vs by-product precursors in water disinfection  

Microsoft Academic Search

Disinfection by-products (DBP) are among the most significant negative side effects of drinking water treatments. Chlorinated disinfectants and organic precursors found in source waters are involved in their formation. Purpose of this study is to investigate the applicability of powdered activation carbon (PAC) to the adsorptive removal of precursors. Three different PACs provided by manufacturers have been applied to water

P. Sandrucci; G. Merlo; G. Genon; L. Meucci

1995-01-01

321

DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS  

Microsoft Academic Search

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. A process has been developed which results

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

2005-01-01

322

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...

323

Optimization of the Regeneration Procedure for Granular Activated Carbon.  

National Technical Information Service (NTIS)

Laboratory scale experiments were conducted on the regeneration of activated carbons spent in tertiary treatment of wastewater. Wet spent carbon being regenerated thermally undergoes three regeneration stages: drying at about 220F; Pyrolysis of the adsorb...

A. J. Juhola

1970-01-01

324

Disinfection of Bacteria Attached to Granular Activated Carbon.  

National Technical Information Service (NTIS)

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...

M. W. LeChevallier T. S. Hassenauer A. K. Camper G. A. McFeters

1984-01-01

325

REPEATED REDUCTIVE AND OXIDATIVE TREATMENTS ON GRANULAR ACTIVATED CARBON  

EPA Science Inventory

Fenton oxidation and Fenton oxidation preceded by reduction solutions were applied to granular activated carbon (GAC) to chemically regenerate the adsorbent. No adsorbate was present on the GAC so physicochemical effects from chemically aggressive regeneration of the carbon coul...

326

MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT  

Microsoft Academic Search

The ongoing program is 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) for stationary power plant applications. The program efforts are focused on technology and system optimization for cost reduction leading to commercial design development and prototype system

H. C. Maru; M. Farooque

2003-01-01

327

MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT  

Microsoft Academic Search

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

H. C. Maru; M. Farooque

2005-01-01

328

MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT  

Microsoft Academic Search

The ongoing program is 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) for stationary power plant applications. The program efforts are focused on technology and system optimization for cost reduction, leading to commercial design development and prototype system

H. C. Maru; M. Farooque

2004-01-01

329

LOW COST PRODUCTION OF CARBON FIBERS FROM LIGNIN MATERIALS  

SciTech Connect

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 CO2 emissions. Carbon fibers have the potential for substantial weight saving in vehicles because of their remarkable high strength, high modulus, and low density. However, carbon fibers are currently too expensive for large scale automotive use, which necessitates a large reduction in the cost of commercial grade fiber from about $20/lb to $5-7/lb. Lignin, a renewable resource material, has significant potential as a precursor material for low cost carbon fiber production. In this paper we report on progress to demonstrate the melt-spinning of precursor fibers from various lignin sources, the subsequent processing of the lignin precursor fibers into carbon fibers, and carbon fiber properties.

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

2009-01-01

330

Reducing supply chain costs and carbon footprint during product design  

Microsoft Academic Search

Manufacturing companies continue to struggle with simultaneously assessing and reducing supply chain costs and carbon footprint early in the design process as consumers demand more sustainable products. An integrated product design-supply chain design approach is explored and applied to bicycle design. It is shown that the approach can successfully inform decision-makers on the consequences of their choices even when component

Ming-Chuan Chiu; Ahmed J. Alsaffar; Gül E. Okudan; Karl R. Haapala

2010-01-01

331

In situ Diagnostics During Carbon Nanotube Production by Laser Ablation  

NASA Technical Reports Server (NTRS)

The preliminary results of spectral analysis of the reaction zone during the carbon nanotube production by laser ablation method indicate synergetic dependence on dual laser setup. The emission spectra recorded from different regions of the laser ablated plume at different delay times from the laser pulses are used to map the temperatures of C2 and C3. These are compared with Laser Induced Fluorescence (LIF) spectra also obtained during production to model the growth mechanism of carbon nanotubes. Experiments conducted to correlate the spectral features with nanotube yields as a function of different production parameters will be discussed.

Arepalli, Sivaram

1999-01-01

332

Supercritical Carbon Dioxide Regeneration of Activated Carbon Loaded with Contaminants from Rocky Mountain Arsenal Well Water.  

National Technical Information Service (NTIS)

The method of supercritical carbon dioxide (SCF CO2) regeneration of granular activated carbon (GAC) loaded with DIMP (diisopropyl methylphosphonate) from Rocky Mountain Arsenal Well (NO. 23-120) water was investigated. A laboratory-based adsorption/regen...

R. M. O'Brien R. P. de Filippi C. E. Smith D. G. Hager

1982-01-01

333

Selecting activated carbon for water and wastewater treatability studies  

Microsoft Academic Search

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

Wei Zhang; Qi-Gang Chang; Wan-Dong Liu; Bing-Jing Li; Wen-Xin Jiang; Li-Jun Fu; Wei-Chi Ying

2007-01-01

334

Carbon nanotubule membranes for electrochemical energy storage and production  

NASA Astrophysics Data System (ADS)

Ensembles of aligned and monodisperse tubules of graphitic carbon can be prepared by a templating method that involves the chemical-vapour deposition of carbon within the pores of alumina membranes. Tubules with diameters as small as 20nm have been prepared in this way,. The carbon comprising these tubules can be transformed from a disordered material to very highly ordered graphite. Here we show that template-synthesized carbon tubules can be fabricated as free-standing nanoporous carbon membranes, and that narrower, highly ordered graphitic carbon nanotubes can be prepared within the membrane's tubules. Both the outer and the inner tubules are electrochemically active for intercalation of lithium ions, suggesting possible applications in lithium-ion batteries,. The membranes can also be filled with nanoparticles of electrocatalytic metals and alloys. Such catalyst-loaded membranes can be used to electrocatalyse O2 reduction and methanol oxidation, two reactions of importance to fuel-cell technology.

Che, Guangli; Lakshmi, Brinda B.; Fisher, Ellen R.; Martin, Charles R.

1998-05-01

335

The carbon footprint of indoor Cannabis production  

Microsoft Academic Search

The emergent industry of indoor Cannabis production – legal in some jurisdictions and illicit in others – utilizes highly energy intensive processes to control environmental conditions during cultivation. This article estimates the energy consumption for this practice in the United States at 1% of national electricity use, or $6 billion each year. One average kilogram of final product is associated

Evan Mills

2012-01-01

336

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

337

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

338

Production and detection of carbon dioxide on Iapetus  

NASA Astrophysics Data System (ADS)

Cassini VIMS detected carbon dioxide on the surface of Iapetus during its insertion orbit. We evaluated the CO 2 distribution on Iapetus and determined that it is concentrated almost exclusively on Iapetus' dark material. VIMS spectra show a 4.27-?m feature with an absorption depth of 24%, which, if it were in the form of free ice, requires a layer 31 nm thick. Extrapolating for all dark material on Iapetus, the total observable CO 2 would be 2.3 × 10 8 kg. Previous studies note that free CO 2 is unstable at 10 AU over geologic timescales. Carbon dioxide could, however, be stable if trapped or complexed, such as in inclusions or clathrates. While complexed CO 2 has a lower thermal volatility, loss due to photodissociation by UV radiation and gravitational escape would occur at a rate of 2.6 × 10 7 kg year -1. Thus, Iapetus' entire inventory of surface CO 2 could be lost within a few decades. The high loss/destruction rate of CO 2 requires an active source. We conducted experiments that generated CO 2 by UV radiation of simulated icy regolith under Iapetus-like conditions. The simulated regolith was created by flash-freezing degassed water, crushing it into sub-millimeter sized particles, and then mixing it with isotopically labeled amorphous carbon ( 13C) dust. These samples were placed in a vacuum chamber and cooled to temperatures between 50 K and 160 K. The samples were irradiated with UV light, and the products were measured using a mass spectrometer, from which we measured 13CO 2 production at a rate of 2.0 × 10 12 mol s -1. Extrapolating to Iapetus and adjusting for the solar UV intensity and Iapetus' surface area, we calculated that CO 2 production for the entire surface would be 1.1 × 10 7 kg year -1, which is only a factor of two less than the loss rate. As such, UV photochemical generation of CO 2 is a plausible source of the detected CO 2.

Palmer, Eric E.; Brown, Robert H.

2011-04-01

339

Role of activated carbon pellets in carbon dioxide removal  

Microsoft Academic Search

The removal of carbon dioxide from gas\\/air streams is more often becoming necessary in many industries for different purposes. In cryogenic air separation plant, air has to be free from carbon dioxide before its liquefaction otherwise blockage due to freezing of heat exchange equipment would result. Enrichment of methane in biogas to have fuel of higher calorific value can be

S. C Sarkar; A Bose

1997-01-01

340

Comparison of physicochemical properties of nitrogen-enriched activated carbons prepared by physical and chemical activation of brown coal  

Microsoft Academic Search

Nitrogen-enriched active carbon has been obtained from Polish brown coal from the 'Konin' colliery. The process of ammoxidation by a mixture of ammonia and air at the ratio of 1:3 has been performed at two temperatures (300 and 350°C) at different stages of the production, that is, at that of precursor, char, and active carbon. It has been shown that

Piotr Nowicki; Robert Pietrzak; Helena Wachowska

2008-01-01

341

Superhydrophobic activated carbon-coated sponges for separation and absorption.  

PubMed

Highly porous activated carbon with a large surface area and pore volume was synthesized by KOH activation using commercially available activated carbon as a precursor. By modification with polydimethylsiloxane (PDMS), highly porous activated carbon showed superhydrophobicity with a water contact angle of 163.6°. The changes in wettability of PDMS- treated highly porous activated carbon were attributed to the deposition of a low-surface-energy silicon coating onto activated carbon (confirmed by X-ray photoelectron spectroscopy), which had microporous characteristics (confirmed by XRD, SEM, and TEM analyses). Using an easy dip-coating method, superhydrophobic activated carbon-coated sponges were also fabricated; those exhibited excellent absorption selectivity for the removal of a wide range of organics and oils from water, and also recyclability, thus showing great potential as efficient absorbents for the large-scale removal of organic contaminants or oil spills from water. PMID:23650204

Sun, Hanxue; Li, An; Zhu, Zhaoqi; Liang, Weidong; Zhao, Xinhong; La, Peiqing; Deng, Weiqiao

2013-06-01

342

Economic Analysis of Planting Forests on Rice Lands in Texas: Sequestering Carbon and Avoiding Methane Production  

NASA Astrophysics Data System (ADS)

Global climate change is predicted due to increases in greenhouse gasses (i.e. CO2, CH4, CFCs, N2O, O3) in the atmosphere caused by human activities. The atmospheric concentration of methane (CH4), which absorbs and retains heat 21 times more effectively than CO2, has increased. Anaerobic bacterial activity in rice paddies constitutes one of major emission sources of CH4. The rice fields of Texas, for example, accounted for an annual CH4 emission of between 1.1 and 1.6 million tons of CO2 equivalent between 1990 and 2000. Converting marginal rice fields to forests plantations will remove CO2 from the atmosphere, sequester carbon in the forests and prevent the production of CH4. Therefore, carbon credits can be claimed for the carbon sequestered and the avoidance of CH4 production. Analyses were conducted to calculate the amount of carbon sequestered and methane avoided, and the profitability, measured in net present worth (NPW), of managing loblolly pine plantation for 1) timber production only, 2) the dual products of timber products and carbon credits in forests planted on marginal agricultural and unused pastureland and 3) the dual products of timber and carbon storage in forests planted on marginal rice lands. Calculations were performed using three discount rates, three site qualities and five prices for carbon credits. The results indicate that on average quality land, using a discount rate of 8 percent, forests planted on marginal agricultural and unused pastureland earn a NPW of 346 per acre from timber production only; a NPW of 438 per acre from timber and carbon credits (54.4 tons of carbon sequestered), assuming carbon is worth 10 per ton, during one rotation (32 years). The profitability of forest management increases due to the inclusion of carbon credits. The profitability of planting forests on marginal rice fields is even higher, earning a NPW of 566 per acre from timber and carbon credits (54.4 tons of C sequestered and 33.3 tons of C emission avoided).

Kronrad, G. D.; Huang, C.

2005-12-01

343

Feasibility study of production of radioactive carbon black or carbon nanotubes in cyclotron facilities for nanobioscience applications.  

PubMed

A feasibility study regarding the production of radioactive carbon black and nanotubes has been performed by proton beam irradiation. Experimental and theoretical excitation functions of the nuclear reaction (nat)C(p,x)(7)Be in the proton energy range 24-38 MeV are reported, with an acceptable agreement. We have demonstrated that sufficient activities of (7)Be radioisotope can be produced in carbon black and nanotube that would facilitate studies of their possible impact on human and environment. PMID:23274215

Abbas, K; Simonelli, F; Holzwarth, U; Cydzik, I; Bulgheroni, A; Gibson, N; Kozempel, J

2013-03-01

344

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

345

Nitrogen doping of activated carbon loading Fe 2 O 3 and activity in carbon-nitric oxide reaction  

Microsoft Academic Search

Nitrogen doping of activated carbon loading Fe2O3 was performed by annealing in ammonia, and the activity of the modified carbon for NO reduction was studied in the presence\\u000a of oxygen. Results show that Fe2O3 enhances the amount of surface oxygen complexes and facilitates nitrogen incorporation in the carbon, especially in the form\\u000a of pyridinic nitrogen. The modified carbon shows excellent

Xian-kai Wan; Xue-quan Zou; Hui-xiang Shi; Da-hui Wang

2007-01-01

346

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

347

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

348

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.

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

2013-01-01

349

The production, storage, and flow of carbon in Amazonian forests  

NASA Astrophysics Data System (ADS)

The carbon stores and dynamics of tropical forests are the subject of major international scientific and policy attention. Research associated with the Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA) has generated substantial advances in our understanding of the cycling of carbon at selected forest sites in Brazilian Amazonia and generated new insights into how these processes may vary across the wider Amazonian region. Here we report on aspects of this new understanding. We present, in particular, a comprehensive synthesis of carbon cycling in three focal LBA sites (Manaus, Tapajõs, and Caxiuanã), drawing on studies of productivity, litterfall, respiration, physiology, and ecosystem fluxes. These studies are placed in the context of the wider Amazonian region by utilizing the results of the Amazon Forest Inventory Network (RAINFOR) and other forest plots. We discuss the basin-wide distribution of forest biomass derived by combining these plots and a suite of satellite data, and examine the dynamics of carbon cycling in the context of regional carbon stores in the forest. Particular attention is drawn to the strong relationship between forest productivity and turnover, which suggests that higher levels of forest productivity increase forest dynamism rather than forest biomass. We conclude by discussing what the scientific priorities should be for a synthetic region-wide understanding of the carbon dynamics and stores of Amazonian forests.

Malhi, Yadvinder; Saatchi, Sassan; Girardin, Cecile; Aragão, Luiz E. O. C.

350

Use of Unburned Carbon in Fly Ash as Precursor for the Development of Activated Carbons  

Microsoft Academic Search

The increasing role of coal as a source of energy in the 21st century will demand environmental and cost-effective strategies for the use of carbonaceous waste products from coal combustion. The carbonaceous residue in fly ash, unburned carbon (UC), is a potential precursor for the production of adsorbent carbons, since it has gone through a devolatilization process while in the

M. Mercedes Maroto-Valer; Darrell N. Taulbee; Harold H. Schobert; James C. Hower; John M. Andrésen

351

A review of fission product sorption in carbon structures  

NASA Astrophysics Data System (ADS)

This paper presents a review of results in the area of fission product sorption in carbon structures. Emphasis is placed on identifying those parameters of carbon-based materials that likely play a dominant role in fission product sorption and the extent to which these parameters have been studied. In particular, we discuss published studies of the effects of atomic structure, sp2 to sp3 bonding ratio, coke content, defect structures, irradiation level, and percent of amorphous structures and porosity. Furthermore, the evolution of theories and models for carbon sorption are summarized. A review of the literature available to the authors reveals that the mechanics governing fission product sorptivity remain to be fully understood.

Londono-Hurtado, A.; Szlufarska, I.; Bratton, R.; Morgan, D.

2012-07-01

352

Oxidative degradation of trichloroethylene adsorbed on active carbons: Use of microwave energy  

SciTech Connect

Chlorinated hydrocarbon compounds (CHCl), such as chlorinated alkanes/alkenes, benzene and biphenyl etc, represent an important fraction of the industrial hazardous wastes produced. Trichloroethylene (TCE) can be removed from waste streams by adsorption on active carbons. The primary objective of the present work was to study the detoxification in air-stream of TCE adsorbed on different types of active carbons using in situ microwave heating. A secondary objective was to examine the regeneration of used carbons from the effects of repeated cyclic operations (adsorption- detoxification). The experimental study has shown that trichloroethylene adsorbed on active carbon can be oxidatively degradated in presence of microwave radiation. Energy can be transferred efficiently to the reaction sites without losing heat to the surrounding vessel. One of the decomposition product of trichloroethylene is free chlorine which is held very strongly on active carbon. Hydrochloric acid on the other hand seems to be less strongly held and appears in large concentration in the exit gas. Production of free chlorine can be avoided by using chlorohydrocarbon mixed with sufficient internal hydrogen. This is also expected to minimize the problem of carbon regeneration encountered in this study. The results obtained from studies on the oxidative degradation of TCE under microwave radiation are promising in a number of respects: (1) the detoxification of TCE adsorbed on active carbon can be conducted at moderate (<400{degree}C) temperatures, and (2) the used carbon bed can be regenerated. A patent on the process has been issued. 9 refs., 2 figs., 2 tabs.

Varma, R.; Nandi, S.P.

1991-01-01

353

Comparison of Cadmium Ion Adsorption on Various ACTIVATED CARBONS  

Microsoft Academic Search

Studies on the removal of cadmium(II) ions from aqueous solutions by adsorption on various activated carbons [commercial activated carbon (CAC) and chemically prepared activated carbons (CPACs) from raw materials such as straw, saw dust and datesnut] have been carried out with an aim to obtain information on treating effluents containing Cd(II) ions. Factors influencing the adsorption of Cd(II) ions from

Nagarethinam Kannan; Gurusamy Rengasamy

2005-01-01

354

Adsorption of chromium by activated carbon from aqueous solution  

Microsoft Academic Search

Adsorption isotherms of Cr(III) and Cr(VI) ions on two samples of activated carbon fibres and two samples of granulated activated carbons from aqueous solutions in the concentration range 20–1000 mg\\/l have been studied. The adsorption isotherms have been determined after modifying the activated carbon surfaces by oxidation with nitric acid, ammonium persulphate, hydrogen peroxide and oxygen gas at 350°C and

Diksha Aggarwal; Meenakshi Goyal; R. C. Bansal

1999-01-01

355

Nickel adsorption by sodium polyacrylate-grafted activated carbon  

Microsoft Academic Search

A novel sodium polyacrylate grafted activated carbon was produced by using gamma radiation to increase the number of functional groups on the surface. After irradiation the capacity for nickel adsorption was studied and found to have increased from 44.1 to 55.7mgg?1. X-ray absorption spectroscopy showed that the adsorbed nickel on activated carbon and irradiation-grafted activated carbon was coordinated with 6

A. Ewecharoen; P. Thiravetyan; E. Wendel; H. Bertagnolli

2009-01-01

356

Water adsorption with hysteresis effect onto microporous activated carbon fabrics  

Microsoft Academic Search

Understanding the adsorption of water vapor onto activated carbons is important for designing processes to remove dilute contaminants\\u000a from humid gas streams, such as providing protection against chemical warfare agents (CWAs), or against toxic industrial compounds\\u000a (TICs) used in a terrorist chemical attack. Water vapor isotherms for Calgon BPL granular activated carbon (GAC), military\\u000a ASZM-TEDA GAC, electrospun activated carbon nanofibers

Patrick D. Sullivan; Brenton R. Stone; Zaher Hashisho; Mark J. Rood

2007-01-01

357

MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT  

SciTech Connect

The FCE PDI program is designed to advance the carbonate fuel cell technology from the current full-size field test to the commercial design. The specific objectives selected to attain the overall program goal are: Define power plant requirements and specifications; Establish the design for a multifuel, low-cost, modular, market-responsive power plant; Resolve power plant manufacturing issues and define the design for the commercial-scale manufacturing facility; Define the stack and balance-of-plant (BOP) equipment packaging arrangement, and module designs; Acquire capability to support developmental testing of stacks and critical BOP equipment to prepare for commercial design; and Resolve stack and BOP equipment technology issues, and design, build and field test a modular prototype power plant to demonstrate readiness for commercial entry.

Unknown

2000-01-01

358

Operation of Membrane Bioreactor with Powdered Activated Carbon Addition  

Microsoft Academic Search

The effect of powdered activated carbon (PAC) addition to the activated sludge (AS) in a membrane bioreactor (MBR) has been investigated. The long term nature of the tests allowed the PAC to gradually incorporate into the biofloc forming biologically activated carbon (BAC). One series of tests involved 4 bench scale (2 L) MBRs operated at sludge retention times (SRTs) of 30

Choon Aun Ng; Darren Sun; Anthony G. Fane

2006-01-01

359

Preparation of activated carbons from agricultural residues for pesticide adsorption  

Microsoft Academic Search

Activated carbons (ACs) can be used not only for liquid but also for vapour phase applications, such as water treatment, deodorisation, gas purification and air treatment. In the present study, activated carbons produced from agricultural residues (olive kernel, corn cobs, rapeseed stalks and soya stalks) via physical steam activation were tested for the removal of Bromopropylate (BP) from water. For

Ourania A. Ioannidou; Anastasia A. Zabaniotou; George G. Stavropoulos; Triantafyllos A. Albanis

2010-01-01

360

CYANIDE REMOVAL FROM REFINERY WASTEWATER USING POWDERED ACTIVATED CARBON  

EPA Science Inventory

The objective of this project was to evaluate the removal of low level cyanide in petroleum refinery wastewater by the addition of powdered activated carbon and cupric chloride to an activated sludge unit. The activated carbon and cupric chloride act as a catalyst in the oxidatio...

361

N-containing activated carbons for CO2 capture  

Microsoft Academic Search

A series of SK-activated carbons were prepared by carbonising soya beans in the presence of KOH as activation agent. Different activation temperatures were applied to study the influence of preparation conditions on the surface properties of the carbons and their CO2 adsorption capacity. It was found that the CO2 adsorption capacity is directly related to the nature of surface basic

Chao Liu; Wei Xing; Jin Zhou; Shu-ping Zhuo

2012-01-01

362

Influence of carbon–oxygen surface complexes on the surface acidity of tungsten oxide catalysts supported on activated carbons  

Microsoft Academic Search

Tungsten oxide catalysts supported on activated carbons were prepared by using tungsten hexacarbonyl, ammonium tungstate, and tungsten pentaethoxide as precursors. An activated carbon was obtained from olive stone by physical activation. A portion of this activated carbon was oxidized with ammonium peroxydisulfate in order to introduce different oxygen surface complexes. Subsequently, different portions of this oxidized activated carbon were heat

Carlos Moreno-Castilla; Agust??n F. Pérez-Cadenas; Francisco J. Maldonado-Hódar; Francisco Carrasco-Mar??n; José Luis G. Fierro

2003-01-01

363

Adsorption of natural gas and biogas components on activated carbon  

Microsoft Academic Search

Experimental results are presented for the adsorption equilibria of methane, ethane, propane, butane, carbon dioxide, and nitrogen, as well as natural gas odorants tert-butyl mercaptan and tetrahydrothiophene, on an activated carbon with the desirable characteristics for use in a guard bed for adsorbed natural gas storage, but that can also be applied for separation of biogas components, such as carbon

Isabel A. A. C. Esteves; Marta S. S. Lopes; Pedro M. C. Nunes; José P. B. Mota

2008-01-01

364

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

365

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.

2002-04-05

366

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

367

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

368

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.

2002-09-30

369

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

2006-06-30

370

Carbon footprint and ammonia emissions of California beef production systems.  

PubMed

Beef production is a recognized source of greenhouse gas (GHG) and ammonia (NH(3)) emissions; however, little information exists on the net emissions from beef production systems. A partial life cycle assessment (LCA) was conducted using the Integrated Farm System Model (IFSM) to estimate GHG and NH(3) emissions from representative beef production systems in California. The IFSM is a process-level farm model that simulates crop growth, feed production and use, animal growth, and the return of manure nutrients back to the land to predict the environmental impacts and economics of production systems. Ammonia emissions are determined by summing the emissions from animal housing facilities, manure storage, field applied manure, and direct deposits of manure on pasture and rangeland. All important sources and sinks of methane, nitrous oxide, and carbon dioxide are predicted from primary and secondary emission sources. Primary sources include enteric fermentation, manure, cropland used in feed production, and fuel combustion. Secondary emissions occur during the production of resources used on the farm, which include fuel, electricity, machinery, fertilizer, and purchased animals. The carbon footprint is the net exchange of all GHG in carbon dioxide equivalent (CO(2)e) units per kg of HCW produced. Simulated beef production systems included cow-calf, stocker, and feedlot phases for the traditional British beef breeds and calf ranch and feedlot phases for Holstein steers. An evaluation of differing production management strategies resulted in ammonia emissions ranging from 98 ± 13 to 141 ± 27 g/kg HCW and carbon footprints of 10.7 ± 1.4 to 22.6 ± 2.0 kg CO(2)e/kg HCW. Within the British beef production cycle, the cow-calf phase was responsible for 69 to 72% of total GHG emissions with 17 to 27% from feedlot sources. Holstein steers that entered the beef production system as a by-product of dairy production had the lowest carbon footprint because the emissions associated with their mothers were primarily attributed to milk rather than meat production. For the Holstein system, the feedlot phase was responsible for 91% of the total GHG emission, while the calf-ranch phase was responsible for 7% with the remaining 2% from transportation. This simulation study provides baseline emissions data for California beef production systems and indicates where mitigation strategies can be most effective in reducing emissions. PMID:22952361

Stackhouse-Lawson, K R; Rotz, C A; Oltjen, J W; Mitloehner, F M

2012-12-01

371

Effects of Burn-off and Activation Temperature on Preparation of Activated Carbon from Corn Cob Agrowaste by CO 2 and Steam  

Microsoft Academic Search

Previous studies have successfully demonstrated that corn cob is a suitable precursor for production of good activated carbon by chemical activation. However, respond to the need for cleaner production, this study focuses on the physical activation by gasifying agents such as CO2 and steam. The activation temperatures under investigation are 1073 and 1173 K. Within the limit of 50 wt%

Chiung-Fen Chang; Ching-Yuan Chang; Wen-Tien Tsai

2000-01-01

372

Improvements in Production of Single-Walled Carbon Nanotubes  

NASA Technical Reports Server (NTRS)

A continuing program of research and development has been directed toward improvement of a prior batch process in which single-walled carbon nanotubes are formed by catalytic disproportionation of carbon monoxide in a fluidized-bed reactor. The overall effect of the improvements has been to make progress toward converting the process from a batch mode to a continuous mode and to scaling of production to larger quantities. Efforts have also been made to optimize associated purification and dispersion post processes to make them effective at large scales and to investigate means of incorporating the purified products into composite materials. The ultimate purpose of the program is to enable the production of high-quality single-walled carbon nanotubes in quantities large enough and at costs low enough to foster the further development of practical applications. The fluidized bed used in this process contains mixed-metal catalyst particles. The choice of the catalyst and the operating conditions is such that the yield of single-walled carbon nanotubes, relative to all forms of carbon (including carbon fibers, multi-walled carbon nanotubes, and graphite) produced in the disproportionation reaction is more than 90 weight percent. After the reaction, the nanotubes are dispersed in various solvents in preparation for end use, which typically involves blending into a plastic, ceramic, or other matrix to form a composite material. Notwithstanding the batch nature of the unmodified prior fluidized-bed process, the fluidized-bed reactor operates in a continuous mode during the process. The operation is almost entirely automated, utilizing mass flow controllers, a control computer running software specific to the process, and other equipment. Moreover, an important inherent advantage of fluidized- bed reactors in general is that solid particles can be added to and removed from fluidized beds during operation. For these reasons, the process and equipment were amenable to modification for conversion from batch to continuous production.

Balzano, Leandro; Resasco, Daniel E.

2009-01-01

373

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

374

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

375

Carbon limitation of biomass production in high-rate oxidation ponds.  

PubMed

Theoretical considerations confirmed by outdoor experiments indicated carbon limitation of biomass production in high-rate oxidation ponds at certain seasonal and operational conditions. Apparently, free carbon dioxide concentration in the pond is the major determinant of carbonlimiting algal photosynthesis. High concentrations of free CO(2) are provided through bacterial respiration which is the main contributor to algal photosynthesis. At high photosynthetic activities and low organic loadings, free CO(2) concentrations are low; its flux into algal cells determines photosynthesis and biomass production rate in the pond. PMID:18546349

Azov, Y; Shelef, G; Moraine, R

1982-03-01

376

Carbon dioxide sequestration by direct mineral carbonation: process mineralogy of feed and products  

SciTech Connect

Direct mineral carbonation has been investigated as a process to convert gaseous CO2 into a geologically stable final form. The process utilizes a slurry of water, with bicarbonate and salt additions, mixed with a mineral reactant, such as olivine (Mg2SiO4) or serpentine [Mg3Si2O5(OH)4]. Carbon dioxide is dissolved into this slurry, resulting in dissolution of the mineral and precipitation of magnesium carbonate (MgCO3). Optimum results have been achieved using heat pretreated serpentine feed material and high partial pressure of CO2 (PCO2). Specific conditions include: 155?C; PCO2=185 atm; 15% solids. Under these conditions, 78% conversion of the silicate to the carbonate was achieved in 30 minutes. Process mineralogy has been utilized to characterize the feed and process products, and interpret the mineral dissolution and carbonate precipitation reaction paths.

O'Connor, William K.; Dahlin, David C.; Rush, G.E.; Dahlin, Cheryl L.; Collins, W. Keith

2001-01-01

377

Development of Continuous Solvent Extraction Processes for Coal Derived Carbon Products. Quarterly Report.  

National Technical Information Service (NTIS)

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...

2005-01-01

378

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

379

Adsorption kinetics of aromatic compounds on carbon nanotubes and activated carbons.  

PubMed

Adsorption kinetics of two organic compounds on four types of carbonaceous adsorbents (a granular activated carbon [HD4000], an activated carbon fiber [ACF10], a single-walled carbon nanotube [SWNT], and a multiwalled carbon nanotube [MWNT]) was examined in aqueous solutions. The times needed for the adsorption to reach apparent equilibrium on the four carbons followed the order of ACF10?>?HD4000?>?SWNT?>?MWNT. Ultrasonication of the carbon nanotubes (CNTs) accelerated their adsorption kinetics but had no effect on their equilibrium adsorption capacities. The pseudo-second order model (PSOM) provided good fitting for the kinetic data. The fitting of kinetic data with the intraparticle diffusion model indicated that external mass transfer controls the sorption process in the organic compound-CNT systems, whereas intraparticle diffusion dominates in the sorption of organic compounds onto activated carbons. PMID:22021047

Zhang, Shujuan; Shao, Ting; Kose, H Selcen; Karanfil, Tanju

2012-01-01

380

Synthesis procedures for production of carbon nanotube junctions  

NASA Astrophysics Data System (ADS)

A quite wide brunch of the carbon nanotube science, including the utilization of singlewall nanotube for production of nano-electronic devices has being continuously explored even nowadays. Tuning and modifying the synthesis procedures to obtain nanotube junctions of T, Y, H or X shapes lead to inappropriate results concerning the industrial or large scale production. However, the importance and the demand for these junctions are quite large, since these may be the secondary building units of carbon nanotubes based chips or even more complex nanoelectronic devices. Recently, some novel solutions of their preparation have been published. A Taiwanese group described a method to prepare multi-junctioned carbon nanotubes on mechanically pretreated silicon surface applying chemical vapor deposition (CVD) technology using decomposition of methane at 1373 K. The nanotubes were nucleated following the lines prepared by scratching the surface with 600-grit sand paper. Contrary to the physical pretreatment of a substrate surface, chemical reactions can also be used for the preparation of carbon nanotube junctions. P.W. Chu et al. reported interconnecting reactions between functionalized carbon nanotubes . By the described method, the carboxyl groups on the wall of singlewall carbon nanotubes are converted to carbonyl chloride groups by reaction with SOCl2 at room temperature. The formed COCl groups are very reactive on the outer surface and can be reacted easily with various amines, particularly diamines resulting in the formation of amide bonding. When two functionalized carbon nanotubes react with such an amine molecule interconnection of tubes is generated. The resulted carbon nanotube junctions have been investigated by AFM. In this presentation, we report on the results obtained on the preparation of carbon nanotube junctions applying two different procedures. The first method is similar to Chu"s one, which was mentioned above, i.e. we used functionalized multiwall carbon nanotubes and the successful interconnection of them by propylene diamine has been proven by TEM and AFM. The second method demonstrates a novel principle: catalyst material has been deposited on the outer surface of carbon nanotubes and branches of nanotubes were produced at this contact point by catalytic chemical vapor deposition (CCVD) of acetylene. The product has been characterized by TEM.

Kiricsi, Imre; Kónya, Zoltán; Niesz, Krisztián; Koós, Antal A.; Biró, László P.

2003-04-01

381

Physical activation of diatomite-templated carbons and its effect on the adsorption of methylene blue (MB)  

NASA Astrophysics Data System (ADS)

One- and two-step physical activation methods, using CO2 and H2O as activation agents, were performed to enhance the porosity of diatomite-templated carbons. The morphology, pore parameters, and adsorption capacity of diatomite-templated carbons before and after activation were investigated to evaluate the effects of activation. The results showed deconstruction of the macroporous structure occurred after one-step activation, while two-step activation retained the unique tubular and pillared macroporous structure of diatomite-templated carbon, indicating a highly promising activation method. The new-appearing pores after two-step activation were mainly micropores, which formed on the walls of carbon tubes and pillars. Pore parameters, such as the specific surface area and pore volume, as well as the micropore volume, showed a great increase after two-step activation and were 2-3 times larger than those of the original carbon. CO2 was more effective in enhancing the porosity than H2O during two-step activation, and the obtained carbon products had a higher specific surface area and pore volume. Moreover, the carbon products after two-step activation possessed a larger adsorption capacity of methylene blue than the original carbon; the maximum Langmuir adsorption capacity of MB on the CO2-activated carbon was 505.1 mg/g.

Liu, Dong; Yuan, Weiwei; Yuan, Peng; Yu, Wenbin; Tan, Daoyong; Liu, Hongmei; He, Hongping

2013-10-01

382

Molten carbonate fuel cell product design improvement  

SciTech Connect

Drawing on the manufacture, field test, and post-test experience of the sixteen Santa Clara Demonstration Project (SCDP) stacks, ERC is finalizing the next generation commercial entry product design. The second generation cells are 50% larger in area, 40% lighter on equal geometric area basis, and 30% thinner than the earlier design. These improvements have resulted in doubling of the full-height stack power. A low-cost and high-strength matrix has also been developed for improving product ruggedness. The low-cost advanced cell design incorporating these improvements has been refined through six short stack tests. Power production per cell of two times the SCDP maximum power operation, over ten thermal cycles, and overall operating flexibility with respect to load and thermal changes have been demonstrated in these short stack tests. An internally insulated stack enclosure has been designed and fabricated to eliminate the need for an inert gas environment during operation. ERC has acquired the capability for testing 400kW full-height direct fuel ceil (DFC) stack and balance-of-plant equipment. With the readiness of the power plant test facility, the cell package design, and the stack module, full-height stack testing has begun. The first full- height stack incorporating the post-SCDP second generation design was completed. The stack reached a power level of 253 kW, setting a world record for the highest power production from the advanced fuel cell system. Excellent performance uniformity at this power level affirmed manufacturing reproducibility of the components at the factory. This unoptimized small size test has achieved pipeline natural gas to DC electricity conversion efficiency of 47% (based on lower heating value - LHV) including the parasitic power consumed by the BOP equipment; that should translate to more than 50% efficiency in commercial operation, before employing cogeneration. The power plant system also operated smoothly. With the success of this test confirming the full-height stack basic design and with the completion of SCDP stacks post-test feedback, manufacture of the full-height stack representing the commercial prototype design has been completed and system demonstration is planned to start in the first quarter of 1999. These developments as well as manufacturing advances are discussed in this report.

P. Voyentzie; T. Leo; A. Kush; L. Christner; G. Carlson; C. Yuh

1998-12-20

383

Adsorption of aromatic compounds by carbonaceous adsorbents: a comparative study on granular activated carbon, activated carbon fiber, and carbon nanotubes.  

PubMed

Adsorption of three aromatic organic compounds (AOCs) by four types of carbonaceous adsorbents [a granular activated carbon (HD4000), an activated carbon fiber (ACF10), two single-walled carbon nanotubes (SWNT, SWNT-HT), and a multiwalled carbon nanotube (MWNT)] with different structural characteristics but similar surface polarities was examined in aqueous solutions. Isotherm results demonstrated the importance of molecular sieving and micropore effects in the adsorption of AOCs by carbonaceous porous adsorbents. In the absence of the molecular sieving effect, a linear relationship was found between the adsorption capacities of AOCs and the surface areas of adsorbents, independent of the type of adsorbent. On the other hand, the pore volume occupancies of the adsorbents followed the order of ACF10 > HD4000 > SWNT > MWNT, indicating that the availability of adsorption site was related to the pore size distributions of the adsorbents. ACF10 and HD4000 with higher microporous volumes exhibited higher adsorption affinities to low molecular weight AOCs than SWNT and MWNT with higher mesopore and macropore volumes. Due to their larger pore sizes, SWNTs and MWNTs are expected to be more efficient in adsorption of large size molecules. Removal of surface oxygen-containing functional groups from the SWNT enhanced adsorption of AOCs. PMID:20704238

Zhang, Shujuan; Shao, Ting; Kose, H Selcen; Karanfil, Tanju

2010-08-15

384

Lithium Methyl Carbonate as a Reaction Product of Metallic Lithiumand Dimethyl Carbonate  

SciTech Connect

To improve the understanding of passive film formation on metallic lithium in organic electrolyte, we synthesized and characterized lithium methyl carbonate (LiOCO{sub 2}CH{sub 3}), a prototypical component of the film. The chemical structure of this compound was characterized with Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared Spectroscopy (FTIR), and its thermal stability and decomposition pathway was studied by thermo-gravimetric analysis (TGA). The FTIR spectrum of chemically synthesized compound enabled us to resolve multiple products in the passive film on lithium in dimethyl carbonate (DMC). Lithium methyl carbonate is only one of the components, the others being lithium oxalate and lithium methoxide.

Zhuang, Guorong V.; Yang, Hui; Ross Jr., Philip N.; Xu, Kang; Jow, T. Richard

2005-10-16

385

JPL Activated Carbon Treatment System (ACTS) for sewage  

NASA Technical Reports Server (NTRS)

An Activated Carbon Treatment System (ACTS) was developed for sewage treatment and is being applied to a one-million gallon per day sewage treatment pilot plant in Orange County California. Activities reported include pyrolysis and activation of carbon-sewage sludge, and activated carbon treatment of sewage to meet ocean discharge standards. The ACTS Sewage treatment operations include carbon-sewage treatment, primary and secondary clarifiers, gravity (multi-media) filter, filter press dewatering, flash drying of carbon-sewage filter cake, and sludge pyrolysis and activation. Tests were conducted on a laboratory scale, 10,000 gallon per day demonstration plant and pilot test equipment. Preliminary economic studies are favorable to the ACTS process relative to activated sludge treatment for a 175,000,000 gallon per day sewage treatment plant.

1976-01-01

386

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

387

Chemical Analysis of Decomposition Products from Carbon Tetrachloride in Air  

Microsoft Academic Search

An analytical system for the chemical determination of decomposition products from carbon tetrachloride in air has been developed. Total decomposition products are trapped and reduced to chloride in 0.017N sodium hydroxide containing 0.1% arsenious oxide; total chlorides are determined spectrophotometrically by the ferric ammonium sulfate-mercuric thiocyanate method. Phosgene is trapped in 0.25% 4-p-nitrobenzylpyridine and 0.5% N-benzylaniline in diethylphthalate and the

MADBULI H. NOWEIR; EMIL A. PFITZER

1972-01-01

388

Create a Consortium and Develop Premium Carbon Products from Coal  

Microsoft Academic Search

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

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

2006-01-01

389

Carbon-based primary productivity modeling with vertically resolved photoacclimation  

NASA Astrophysics Data System (ADS)

Net primary production (NPP) is commonly modeled as a function of chlorophyll concentration (Chl), even though it has been long recognized that variability in intracellular chlorophyll content from light acclimation and nutrient stress confounds the relationship between Chl and phytoplankton biomass. It was suggested previously that satellite estimates of backscattering can be related to phytoplankton carbon biomass (C) under conditions of a conserved particle size distribution or a relatively stable relationship between C and total particulate organic carbon. Together, C and Chl can be used to describe physiological state (through variations in Chl:C ratios) and NPP. Here, we fully develop the carbon-based productivity model (CbPM) to include information on the subsurface light field and nitracline depths to parameterize photoacclimation and nutrient stress throughout the water column. This depth-resolved approach produces profiles of biological properties (Chl, C, NPP) that are broadly consistent with observations. The CbPM is validated using regional in situ data sets of irradiance-derived products, phytoplankton chlorophyll:carbon ratios, and measured NPP rates. CbPM-based distributions of global NPP are significantly different in both space and time from previous Chl-based estimates because of the distinction between biomass and physiological influences on global Chl fields. The new model yields annual, areally integrated water column production of ˜52 Pg C a-1 for the global oceans.

Westberry, T.; Behrenfeld, M. J.; Siegel, D. A.; Boss, E.

2008-06-01

390

Removal of Toxic Chemicals from Water with Activated Carbon  

Microsoft Academic Search

Activated carbon was effective in removing fish toxicants and anesthetics from water solutions. Its capacity to adsorb 3-trifluoromethyl-4-nitrophenol (TFM), antimycin, Noxfish (5% rotenone), Dibrom, juglone, MS-222, and benzocaine ranged from 0.1 to 64 mg per gram of carbon. The adsorptive capacity (end point considered as a significant discharge) of activated carbon for removal of TFM was determined at column depths

Verdel K. Dawson; Leif L. Marking; Terry D. Bills

1976-01-01

391

TEMPERATURE DEPENDENCE ON ACTIVATED CARBON ADSORPTION OF ATRAZINE  

Microsoft Academic Search

This study examined the effect of temperature on atrazine adsorption in water by activated carbon. Freundlich isotherms for atrazine were determined in batch contactors, using 100-µm activated carbon and atrazine in organic-free laboratory water, as well as treated river water with 2.4 mg\\/L dissolved organic carbon (DOC). Experiments were conducted at four different temperatures (5, 12, 25 and 35oC), with

Gen-Shuh Wang

2003-01-01

392

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

PubMed

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; Camassola, Marli; Dillon, Aldo José Pinheiro

2014-01-01

393

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.

Schneider, Willian Daniel Hahn; dos Reis, Laisa; Dillon, Aldo Jose Pinheiro

2014-01-01

394

Removal of Formaldehyde by Activated Carbons Containing Amino Groups  

Microsoft Academic Search

Formaldehyde has been used for disinfection and antisepsis in hospitals due to its bactericidal action, but it is toxic to humans. Hence, we developed adsorbates for the removal of formaldehyde. The adsorbate was prepared by the amination of an activated carbon surface. The removal efficiency and the adsorption mechanism of formaldehyde onto the aminated activated carbon were studied. The concentrated

Seiki Tanada; Naohito Kawasaki; Takeo Nakamura; Mamiko Araki; Masahiko Isomura

1999-01-01

395

Preparation of nitrogen-enriched activated carbons from brown coal  

SciTech Connect

Nitrogen-enriched activated carbons were prepared from a Polish brown coal. Nitrogen was introduced from urea at 350{sup o}C in an oxidizing atmosphere both to carbonizates obtained at 500-700{sup o}C and to activated carbons prepared from them. The activation was performed at 800{sup o}C with KOH in argon. It has been observed that the carbonization temperature determines the amount of nitrogen that is incorporated (DC5U, 8.4 wt % N{sup daf}; DC6U, 6.3 wt % N{sup daf}; and DC7U, 5.4 wt % N{sup daf}). X-ray photoelectron spectroscopy (XPS) measurements have shown that nitrogen introduced both at the stage of carbonizates and at the stage of activated carbons occurs mainly as -6, -5, and imine, amine and amide groups. On the other hand, the activation of carbons enriched with nitrogen results in the formation of pyridonic nitrogen and N-Q. The introduction of nitrogen at the activated carbon stage leads to a slight decrease in surface area. It has been proven that the most effective way of preparing microporous activated carbons enriched with nitrogen to a considerable extent and having high surface area ({approximately} 3000 m{sup 2}/g) is the following: carbonization - activation - reaction with urea. 40 refs., 1 fig., 6 tabs.

Robert Pietrzak; Helena Wachowska; Piotr Nowicki [Adam Mickiewicz University, Poznan (Poland). Laboratory of Coal Chemistry and Technology, Faculty of Chemistry

2006-05-15

396

[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

397

PRODUCTION OF CARBON PRODUCTS USING A COAL EXTRACTION PROCESS  

SciTech Connect

High melting temperature synthetic pitches (Synpitches) were created using coal derivatives produced from a solvent extraction technique. Solvent extraction is used to separate hydrocarbons from mineral matter as well as other insolubles. Mild hydrogenation can be used to chemically modify resultant material to produce a true pitch. There are three main techniques which can be used to tailor the softening point of the Synpitch. First, the softening point can be controlled by varying the conditions of hydrogenation, chiefly the temperature, pressure and residence time in a hydrogen overpressure. Second, by selectively distilling light hydrocarbons, the softening point of the remaining pitch can be raised. Third, the Synpitch can be blended with another mutually soluble pitch or hydrocarbon liquid. Through such techniques, spinnable isotropic Synpitches have been created from coal feedstocks. Characteristics of Synpitches include high cross-linking reactivity and high molecular weight, resulting in carbon fibers with excellent mechanical properties. To date, mechanical properties have been achieved which are comparable to the state of the art achievable with conventional coal tar pitch or petroleum pitch.

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

2005-12-12

398

Ozone Removal by Filters Containing Activated Carbon: A Pilot Study  

SciTech Connect

This study evaluated the ozone removal performance of moderate-cost particle filters containing activated carbon when installed in a commercial building heating, ventilating, and air conditioning (HVAC) system. Filters containing 300 g of activated carbon per 0.09 m2 of filter face area were installed in two 'experimental' filter banks within an office building located in Sacramento, CA. The ozone removal performance of the filters was assessed through periodic measurements of ozone concentrations in the air upstream and downstream of the filters. Ozone concentrations were also measured upstream and downstream of a 'reference' filter bank containing filters without any activated carbon. The filter banks with prefilters containing activated carbon were removing 60percent to 70percent of the ozone 67 and 81 days after filter installation. In contrast, there was negligible ozone removal by the reference filter bank without activated carbon.

Fisk, William; Spears, Mike; Sullivan, Douglas; Mendell, Mark

2009-09-01

399

Application studies of activated carbon derived from rice husks produced by chemical-thermal process—A review  

Microsoft Academic Search

The production of functional activated carbon materials starting from cheap natural precursors using environmentally friendly processes is a highly attractive subject in material chemistry today. Recently, much attention has been focused on the use of plant biomass to produce functional carbonaceous materials, encompassing economic, environmental and social issues. Besides the classical route to produce activated carbons from fossil materials, rice

Yue Chen; Yanchao Zhu; Zichen Wang; Ying Li; Lili Wang; Lili Ding; Xiaoyan Gao; Yuejia Ma; Yupeng Guo

2011-01-01

400

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

401

Production of ?-Xylosidase Activity by Trichodermaharzianum Strains  

Microsoft Academic Search

.   Nine Trichoderma harzianum strains were screened for ?-xylosidase activity when grown in solid-state cultures on media containing wheat bran as the\\u000a carbon source. All strains produced ?-xylosidase activity, the most active being in extracts of cultures of T. harzianum strain 4. A ?-xylosidase was purified by ammonium sulfate precipitation, ultrafiltration, gel filtration, and ion exchange\\u000a chromatography from solid-state cultures

Fabiano de A. Ximenes; Fabiane Quirino de Paula Silveira; Edivaldo Ximenes F. Filho

1996-01-01

402

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

403

Single carbon surface reactions of 1-octadecene and 2,3,6-trimethylphenol on activated carbon: Implications for methane formation in sediments  

Microsoft Academic Search

The reactions of a terminal alkene (1-octadecene) and a polymethyl phenol (2,3,6-trimethylphenol) on activated carbon have been investigated in closed system pyrolysis experiments in the temperature range 170–340°C. The reaction products of 1-octadecene included methane, isomeric octadecenes, methyl substituted alkanes, alkyl aromatics and an homologous series of n-alkanes with carbon numbers indicative of progressive single carbon depletion of the reactant.

Robert Alexander; Lyndon Berwick; Kieran Pierce

2011-01-01

404

The transport properties of activated carbon fibers  

SciTech Connect

The transport properties of isotropic pitch-based carbon fibers with surface area 1000 m{sup 2}/g have been investigated. We report preliminary results on the electrical conductivity, the magnetoresistance, the thermal conductivity, and the thermopower of these fibers as a function of temperature. Comparisons are made to transport properties of other disordered carbons.

di Vittorio, S.L. (Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (USA)); Dresselhaus, M.S. (Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (USA) Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (USA)); Endo, M. (Department of Electrical Engineering, Faculty of Engineering, Shinshu University, Nagano 380, (Japan)); Issi, J.; Piraux, L.; Bayot, V. (Unite de Physico-Chimie et de Physique des Materiaux, Universite Catholique de Louvain, Louvain-la-Neuve, (Belgium))

1991-04-01

405

Pulsed carbon-plasma source for production processes  

SciTech Connect

This paper describes a pulsed electric-arc accelerator or carbon plasma of the end-window type that produces highstrength diamond-like coatings on cutting tools and parts of process equipment. The average energy of carbon ions, which varies in the range of 40-80 eV according to the operating mode of the source, is measured. The average condensation rate is 15 um/h. The space characteristics of the pulsed plasma beam are measured and the dependence of the stability of the production parameters of the deposition process on the operating reserve of the source is investigated.

Maslov, A.I.; Chistyakov, Y.D.; Dmitriev, G.K.

1985-12-01

406

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

Microsoft Academic Search

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

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

2006-01-01

407

Carbon Nanotube Activities at NASA-Johnson Space Center  

NASA Technical Reports Server (NTRS)

Research activities on carbon nanotubes at NASA-Johnson Space Center include production, purification, characterization and their applications for human space flight. In-situ diagnostics during nanotube production by laser oven process include collection of spatial and temporal data of passive emission and laser induced fluorescence from C2, C3 and Nickel atoms in the plume. Details of the results from the "parametric study" of the pulsed laser ablation process indicate the effect of production parameters including temperature, buffer gas, flow rate, pressure, and laser fluence. Improvement of the purity by a variety of steps in the purification process is monitored by characterization techniques including SEM, TEM, Raman, UV-VIS-NIR and TGA. A recently established NASA-JSC protocol for SWCNT characterization is undergoing revision with feedback from nanotube community. Efforts at JSC over the past five years in composites have centered on structural polymednanotube systems. Recent activities broadened this focus to multifunctional materials, supercapacitors, fuel cells, regenerable CO2 absorbers, electromagnetic shielding, radiation dosimetry and thermal management systems of interest for human space flight. Preliminary tests indicate improvement of performance in most of these applications because of the large surface area as well as high electrical and thermal conductivity exhibited by SWCNTs.

Arepalli, Sivaram

2006-01-01

408

78 FR 35603 - Foreign-Trade Zone 83-Huntsville, Alabama; Application for Production Authority; Toray Carbon...  

Federal Register 2010, 2011, 2012, 2013

...Polyacrylonitrile Fiber/Carbon Fiber Production), Decatur, Alabama...polyacrylonitrile (PAN)-based carbon fiber, and PAN fiber, the primary material input for the company's carbon fiber. The facility will produce...

2013-06-13

409

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

PubMed

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. PMID:22743805

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

2012-07-27

410

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

411

Studies relevant to the catalytic activation of carbon monoxide  

SciTech Connect

Research activity during the 1991--1992 funding period has been concerned with the following topics relevant to carbon monoxide activation. (1) Exploratory studies of water gas shift catalysts heterogenized on polystyrene based polymers. (2) Mechanistic investigation of the nucleophilic activation of CO in metal carbonyl clusters. (3) Application of fast reaction techniques to prepare and to investigate reactive organometallic intermediates relevant to the activation of hydrocarbons toward carbonylation and to the formation of carbon-carbon bonds via the migratory insertion of CO into metal alkyl bonds.

Ford, P.C.

1992-06-04

412

Comparison of catalytic ozonation of phenol by activated carbon and manganese-supported activated carbon prepared from brewing yeast  

Microsoft Academic Search

Activated carbon (AC) was prepared using brewing yeast as precursor by chemical activation and manganese was supported on\\u000a activated carbon (Mn\\/AC) by adsorption-activation method. The characterizations of prepared AC and Mn\\/AC and their performance\\u000a as ozonation catalysts was tested. The results indicated that the crystalline phase of supported manganese was MnO. The total\\u000a BET surface areas of prepared AC and

Guiping Wu; Tae-seop Jeong; Chan-Hee Won; Longzhe Cui

2010-01-01

413

Grain-based activated carbons for natural gas storage.  

PubMed

Natural gas has emerged as a potential alternative to gasoline due to the increase in global energy demand and environmental concerns. An investigation was undertaken to explore the technical feasibility of implementing the adsorbed natural gas (ANG) storage in the fuel tanks of motor vehicles with activated carbons from biomass, e.g., sorghum and wheat. The grain-based activated carbons were prepared by chemical activation; the experimental parameters were varied to identify the optimum conditions. The porosity of the resultant activated carbons was evaluated through nitrogen adsorption; and the storage capacity, through methane adsorption. A comparative study was also carried out with commercial activated carbons from charcoal. The highest storage factor attained was 89 for compacted grain-based activated carbons from grain sorghum with a bulk density of 0.65 g/cm(3), and the highest storage factor attained is 106 for compacted commercial activated carbons (Calgon) with a bulk density of 0.70 g/cm(3). The storage factor was found to increase approximately linearly with increasing bulk density and to be independent of the extent of compaction. This implies that the grain-based activated carbons are the ideal candidates for the ANG storage. PMID:19945864

Zhang, Tengyan; Walawender, Walter P; Fan, L T

2010-03-01

414

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

415

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

416

CCN activation of pure and coated carbon black particles.  

PubMed

The CCN (cloud condensation nucleus) activation of pure and coated carbon black particles was investigated using the University of Vienna cloud condensation nuclei counter (Giebl, H.; Berner, A.; Reischl, G.; Puxbaum, H.; Kasper-Giebl, A.; Hitzenberger, R. J. Aerosol Sci. 2002, 33, 1623-1634). The particles were produced by nebulizing an aqueous suspension of carbon black in a Collison atomizer. The activation of pure carbon black particles was found to require higher supersaturations than predicted by calculations representing the particles as insoluble, wettable spheres with mobility equivalent diameter. To test whether this effect is an artifact due to heating of the light-absorbing carbon black particles in the laser beam, experiments at different laser powers were conducted. No systematic dependence of the activation of pure carbon black particles on laser power was observed. The observations could be modeled using spherical particles and an effective contact angle of 4-6 degrees of water at their surface. The addition of a small amount of NaCl to the carbon black particles (by adding 5% by mass NaCl to the carbon black suspension) greatly enhanced their CCN efficiency. The measured CCN efficiencies were consistent with Kohler theory for particles consisting of insoluble and hygroscopic material. However, coating the carbon black particles with hexadecanol (a typical film-forming compound with one hydrophobic and one hydrophilic end) efficiently suppressed the CCN activation of the carbon black particles. PMID:16572779

Dusek, U; Reischl, G P; Hitzenberger, R

2006-02-15

417

The use of steam and CO 2 as activating agents in the preparation of activated carbons  

Microsoft Academic Search

Four series of activated carbon have been prepared from carbonized olive stones. One of them, series D, was prepared using carbon dioxide as activating agent, and the other three, series AV, W, and H, with water vapor under different experimental conditions. Two of the series, D and H, were prepared in such a way that the gasification rate for both

F. Rodríguez-Reinoso; M. Molina-Sabio; M. T. González

1995-01-01

418

Repeated fed-batch rapid fermentation using yeast cells and activated carbon extraction system  

SciTech Connect

The application of a repeated fed-batch rapid ethanol fermentation employing immobilized yeast cells accompanied by an activated carbon extraction system has been investigated in an attempt to increase product yield. Immobilized and free yeast cells were used to effect ethanol fermentations in a simplified nitrogen-free medium containing only glucose and mineral salts. Repeatedly, fermentation broth with a high ethanol concentration (80 to 100 g/L) was extracted using activated carbon beads (BACM) and the resulting broth of low ethanol content (< 50 g/L) was recycled back for further fermentations. The maximum ethanol productivity achieved in this system was 25 g/L/h. 7 figures, 1 table.

Lee, S.S.; Wang, H.Y.

1982-01-01

419

Changes in surface chemistry of activated carbons by wet oxidation  

Microsoft Academic Search

A series of activated carbons with different degrees of activation were oxidized with H2O2, (NH4)2S2O8 and HNO3 in order to introduce different oxygen surface complexes. Changes in the surface chemistry of the activated carbons after their oxidizing treatments were studied by different techniques including temperature-programmed desorption (TPD), X-ray photoelectron spectroscopy (XPS), Fourier transformed infrared spectroscopy (FTIR), titrations with HCl and

C Moreno-Castilla; M. V López-Ramón; F Carrasco-Mar??n

2000-01-01

420

Pyrolysis of scrap tires and conversion of chars to activated carbon  

SciTech Connect

The primary objective of this work was to demonstrate the conversion of scrap tires to activated carbon. The authors have been successful in this endeavor, producing carbons with surface areas greater than 500 m[sup 2]/g and significant micropore volumes. Tire shreddings were pyrolyzed in batch reactors, and the pyrolysis chars activated by reaction with superheated steam. Solid products of pyrolysis and activation were studied with nitrogen adsorption techniques. They find that the porosity development during steam activation of tire pyrolysis char is similar to that reported for various other chars. A maximum in micropore volume is observed as a function of conversion, but the total surface area increases monotonically with conversion. They suggest that the activation process consists of micropore formation, followed by pore enlargement. The process conditions used in this study are a good starting point from which to optimize a process to convert tires to activated carbon.

Merchant, A.A.; Petrich, M.A. (Northwestern Univ., Evanston, IL (United States). Dept. of Chemical Engineering)

1993-08-01

421

The preparation of activated carbon from macadamia nutshell by chemical activation  

Microsoft Academic Search

Different structured activated carbons were prepared from macadamia nutshell by chemical activation with potassium hydroxide and zinc chloride. The influence of process variables on the carbons' pore structure was studied in order to optimise these parameters. The results were also compared with those previously obtained on the chemical activation of coal. The most important parameter in chemical activation with both

A. Ahmadpour; D. D. Do

1997-01-01

422

Carbon Calculator for Land Use Change from Biofuels Production (CCLUB). Users' Manual and Technical Documentation.  

National Technical Information Service (NTIS)

The Carbon Calculator for Land Use Change from Biofuels Production (CCLUB) calculates carbon emissions from land use change (LUC) for four different ethanol production pathways including corn grain ethanol and cellulosic ethanol from corn stover, miscanth...

J. B. Dunn M. Wang S. Mueller

2011-01-01

423

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

424

Nickel adsorption by sodium polyacrylate-grafted activated carbon.  

PubMed

A novel sodium polyacrylate grafted activated carbon was produced by using gamma radiation to increase the number of functional groups on the surface. After irradiation the capacity for nickel adsorption was studied and found to have increased from 44.1 to 55.7 mg g(-1). X-ray absorption spectroscopy showed that the adsorbed nickel on activated carbon and irradiation-grafted activated carbon was coordinated with 6 oxygen atoms at 2.04-2.06 A. It is proposed that this grafting technique could be applied to other adsorbents to increase the efficiency of metal adsorption. PMID:19576692

Ewecharoen, A; Thiravetyan, P; Wendel, E; Bertagnolli, H

2009-11-15

425

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

426

Carbon-enriched coal fly ash as a precursor of activated carbons for SO 2 removal  

Microsoft Academic Search

Carbon-enriched coal fly ash was evaluated in this work as a low-cost adsorbent for SO2 removal from stack gases. The unburned carbon in coal fly ash was concentrated by mechanical sieving and vegetal oil agglomeration. The carbon concentrates were activated with steam at 900°C in order to develop porosity onto the samples. The performance of these samples in the SO2

M. T. Izquierdo; B. Rubio

2008-01-01

427

Corrosion activity of carbon plastics and protection of metal power structures in contact with carbon plastics  

Microsoft Academic Search

Methods for assessing the corrosion activity of carbon plastics against metal materials and development of complex anticorrosive\\u000a protection of load-bearing units of structures including carbon plastics in contact with metal materials are considered. Data\\u000a on the electrochemically measured corrosion rates in carbon plastic-metal contact pairs and on the efficiency of separating\\u000a layers (sealants, glass fabrics) are presented. Recommendations on corrosion

S. A. Karimova; T. G. Pavlovskaya; D. V. Chesnokov; L. V. Semenova

2011-01-01

428

Structural sorption characteristics of active carbons obtained from wastes  

SciTech Connect

The high cost and shortage of activated carbons have created a search for cheap adsorbents for treatment or final purification of wastewaters. The structural characteristics of solid wastes from pyrolysis of town wastes (AC-1) and activated sludge from treatment plants (AC-2) were investigated. The possibilities of using them for final purification of wastewaters from phosphate ore treatment plants were examined. The test carbons were inferior to commercial samples in micropore volume, but they were at the same level as the commercial samples or better with regard to the volumes of supermicropores and mesopores and the limiting volume of the adsorption space. It was shown that the carbons studied were close to the commercial carbon AG-3 in adsorption activity. These carbons were suitable for use in final purification of biologically purified wastewaters containing oxidation-resistant organic substance.

Petrova, L.A.; Mukhlenov, I.P.; Tubolkin, A.F.; Galutkina, K.A.

1983-04-01

429

78 FR 16654 - Certain Activated Carbon From the People's Republic of China: Continuation of Antidumping Duty Order  

Federal Register 2010, 2011, 2012, 2013

...and anthracite), wood, coconut shells, olive stones, and peat. The thermal and steam treatments remove organic materials and...as cellulose, including wood, sawdust, paper mill waste and peat. To the extent that an imported activated carbon product...

2013-03-18

430

77 FR 33420 - Certain Activated Carbon From the People's Republic of China: Final Results of Expedited Sunset...  

Federal Register 2010, 2011, 2012, 2013

...and anthracite), wood, coconut shells, olive stones, and peat. The thermal and steam treatments remove organic materials and...as cellulose, including wood, sawdust, paper mill waste and peat. To the extent that an imported activated carbon product...

2012-06-06

431

75 FR 981 - Certain Activated Carbon From the People's Republic of China: Notice of Rescission of Changed...  

Federal Register 2010, 2011, 2012, 2013

...and anthracite), wood, coconut shells, olive stones, and peat. The thermal and steam treatments remove organic materials and...as cellulose, including wood, sawdust, paper mill waste and peat. To the extent that an imported activated carbon product...

2010-01-07

432

76 FR 23978 - Certain Activated Carbon From the People's Republic of China: Preliminary Results of the Third...  

Federal Register 2010, 2011, 2012, 2013

...and anthracite), wood, coconut shells, olive stones, and peat. The thermal and steam treatments remove organic materials and...as cellulose, including wood, sawdust, paper mill waste and peat. To the extent that an imported activated carbon product...

2011-04-29

433

Preparation of activated carbon from Canadian coals using a fixed-bed reactor and a spouted bed-kiln system  

Microsoft Academic Search

Several western Canadian coals (Bienfait lignite, Roselyn, Montgomery, Atlas-Century and Egg Lake subbituminous coals, and Coal Valley and Smoky River bituminous coals) were activated with steam to produce granular activated carbons. Activation times and temperatures were 0.5–4.0 h and 650–850°C. The iodine number was used as a primary indicator of product quality. Activated carbons having iodine numbers of ? 500

Ajay K. Dalai; Jasimuz Zaman; Eric L. Tollefson

1996-01-01

434

Mechanism of phenol adsorption onto electro-activated carbon granules.  

PubMed

The main purpose of this paper is to determine the mechanisms which govern the adsorption of the phenol onto electro-activated carbon granules. This new activation technique allowed an increase of the performance of the adsorbent. Two models were utilised to understand the improvement in the performance of electroactivated carbon granules. The first, a simple external resistance model based on film resistance, gave acceptable predictions, with an error of less than 15%, between the theoretical results and experimental data independent of the activation potential and phenol initial concentration. The second linear model, based on diffusion phenomena, was more representative in describing the experiment than the first model. It was observed that the electro-activation method did not change the mechanism which governs phenol adsorption onto granular carbon. Indeed, the same mathematical model based on diffusion phenomena made it possible to predict with a very low error (less than 5%) the experimental data obtained for the favourable activation potential, without activation potential and with an unfavourable activation potential. The electro-activation technique makes it possible to increase the number of active sites that improve the performance of the electro-activated granular carbon compared with conventional granular activated carbon. PMID:14630120

Lounici, H; Aioueche, F; Belhocine, D; Drouiche, M; Pauss, A; Mameri, N

2004-01-01

435

Gas phase atomic hydrogen induced carbon-carbon bond activation in cyclopropane on the Ni(100) surface  

SciTech Connect

Carbon-carbon activation in adsorbed cyclopropane is observed following exposure to gas phase atomic hydrogen on the Ni(100) surface for temperatures as low as 100 K. Exposure to either gas phase atomic hydrogen or deuterium results in formation of adsorbed propyl. In both cases subsequent reaction between adsorbed propyl and coadsorbed hydrogen/deuterium produces propane at 121 K. The activation of a single C-C bond in adsorbed cyclopropane dominates as indicated by the fact that propane is the only product observed. No multiple C-C bond activation which would result in methane or ethane formation was ever observed. These reactions and their mechanisms have been investigated using temperature-programmed reaction and vibrational spectroscopy using high-resolution electron energy loss spectroscopy. The results obtained clearly indicate that C-C bond activation occurs during exposure to gas phase atomic hydrogen. Isotopic labeling studies reveal that the adsorbed propyl intermediate is hydrogenated by labelled surface hydrogen. Carbon-carbon bond activation in adsorbed cyclopropane has never been observed during adsorption on a surface with preadsorbed hydrogen nor during exposure to nascent hydrogen formed by dissociating molecular hydrogen. A detailed potential energy diagram for the reactions of adsorbed cyclopropane on the Ni(100) surface is developed based on results from these experiments and the literature. 68 refs., 11 figs., 1 tab.

Son, K.A.; Gland, J.L. [Univ. of Michigan, Ann Arbor, MI (United States)] [Univ. of Michigan, Ann Arbor, MI (United States)

1996-10-30

436

Noncovalent functionalization of carbon nanotubes with redox active lignin derivatives  

Microsoft Academic Search

Kraft lignin (KL) was adsorbed on multi-wall carbon nanotubes (MWCNTs). After dispersing in dimethylsulfoxide the biopolymer coated MWCNTs formed stable suspensions that could be used to form cast films on glassy carbon electrodes. The composite films after initial oxidation showed redox functions characteristic of quinone moieties. These could be further reacted with thionine (TH) to form a redox active composite

Grzegorz Milczarek

2009-01-01

437

ACTIVATED CARBON PROCESS FOR TREATMENT OF WASTEWATERS CONTAINING HEXAVALENT CHROMIUM  

EPA Science Inventory

The removal of hexavalent chromium, Cr(VI), from dilute aqueous solution by an activated carbon process has been investigated. Two removal mechanisms were observed; hexavalent chromium species were removed by adsorption onto the interior carbon surface and/or through reduction to...

438

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...

439

Production of Carbon Products Using a Coal Extraction Process (Semiannual Report, September 11, 2002-March 10, 2003).  

National Technical Information Service (NTIS)

The purpose of this DOE-funded effort is to develop technologies for carbon products from coal-derived feed-stocks. Carbon products can include precursor materials such as solvent extracted carbon ore (SECO) and synthetic pitch (Synpitch). In addition, de...

D. Dadyburjor

2006-01-01

440

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

Code of Federal Regulations, 2010 CFR

...monitor the injection rate of activated carbon?] 40 PROTECTION OF ENVIRONMENT...monitor the injection rate of activated carbon? If your municipal waste combustion unit uses activated carbon to control...

2009-07-01

441

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

Code of Federal Regulations, 2010 CFR

...monitor the injection rate of activated carbon?] 40 PROTECTION OF ENVIRONMENT...monitor the injection rate of activated carbon? If your municipal waste combustion unit uses activated carbon to control...

2009-07-01

442

40 CFR 62.15275 - How do I monitor the injection rate of activated carbon?  

Code of Federal Regulations, 2013 CFR

...injection rate of activated carbon? 62.15275 Section 62...Before August 30, 1999 Other Monitoring Requirements § 62.15275...injection rate of activated carbon? If your municipal waste combustion unit uses activated carbon to control...

2013-07-01

443

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

Code of Federal Regulations, 2013 CFR

...injection rate of activated carbon? 60.1330 Section 60...After June 6, 2001 Other Monitoring Requirements § 60.1330...injection rate of activated carbon? If your municipal waste combustion unit uses activated carbon to control...

2013-07-01

444

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

Code of Federal Regulations, 2013 CFR

...injection rate of activated carbon? 60.1820 Section 60...1999 Model Rule-Other Monitoring Requirements § 60.1820...injection rate of activated carbon? If your municipal waste combustion unit uses activated carbon to control...

2013-07-01