Sample records for activated carbon production

  1. Production of activated carbons from Illinois coals

    Microsoft Academic Search

    E. J. Hippo; Jian Sun

    1996-01-01

    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

  2. JV Task 90 - Activated Carbon Production from North Dakota Lignite

    Microsoft Academic Search

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

    2008-01-01

    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

  3. DEVELOPMENT OF ACTIVATED CARBONS FROM COAL COMBUSTION BY-PRODUCTS

    SciTech Connect

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

    2003-09-30

    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.

  4. Production and characterization of activated carbons from cereal grains

    Microsoft Academic Search

    A. Venkatraman; W. P. Walawender; L. T. Fan

    1996-01-01

    The term, activated carbon, is a generic name for a family of carbonaceous materials with well-developed porosities and consequently, large adsorptive capacities. Activated carbons are increasingly being consumed worldwide for environmental applications such as separation of volatiles from bulk gases and purification of water and waste-water streams. The global annual production is estimated to be around 300 million kilograms, with

  5. JV Task 90 - Activated Carbon Production from North Dakota Lignite

    SciTech Connect

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

    2008-03-31

    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 was performed to determine likely revenue streams for the produced carbon. Activated carbon was produced from lignite coal in both laboratory-scale fixed-bed reactors and in a small pilot-scale rotary kiln. The EERC was successfully able to upgrade the laboratory-scale activated carbon production system to a pilot-scale rotary kiln system. The activated carbon produced from North Dakota lignite was superior to commercial grade DARCO{reg_sign} FGD and Rheinbraun's HOK activated coke product with respect to iodine number. The iodine number of North Dakota lignite-derived activated carbon was between 600 and 800 mg I{sub 2}/g, whereas the iodine number of DARCO FGD was between 500 and 600 mg I{sub 2}/g, and the iodine number of Rheinbraun's HOK activated coke product was around 275 mg I{sub 2}/g. The EERC performed both bench-scale and pilot-scale mercury capture tests using the activated carbon made under various optimization process conditions. For comparison, the mercury capture capability of commercial DARCO FGD was also tested. The lab-scale apparatus is a thin fixed-bed mercury-screening system, which has been used by the EERC for many mercury capture screen tests. The pilot-scale systems included two combustion units, both equipped with an electrostatic precipitator (ESP). Activated carbons were also tested in a slipstream baghouse at a Texas power plant. The results indicated that the activated carbon produced from North Dakota lignite coal is capable of removing mercury from flue gas. The tests showed that activated carbon with the greatest iodine number was superior to commercial DARCO FGD for mercury capture. The results of the activated carbon market assessment indicate an existing market for water treatment and an emerging application for mercury control. That market will involve both existing and new coal-fired plants. It is expected that 20% of the existing coal-fired plants will implement activated carbon injection by 2015, representing about 200,000 tons of annual demand. The potential annual demand by new plants is even greater. In the mercury control market, two characteristics are going to dominate the customer's buying habit-performance and price. As continued demonstration testing of activated carbon injection at the various coal-fired power plants progresses, the importance of fuel type and plant configuration on the type of activated carbon best suited is being identified.

  6. Production of charcoal and activated carbon at elevated pressure

    SciTech Connect

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

    1995-12-31

    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 of charcoal was 22.8 million cubic meters (3.8 million metric tons) as shown in Table 1. Brazil is the world`s largest charcoal producer --- 5.9 million cubic meters or one million metric tons was produced in 1991, most of which is used in steel and iron industry. African countries produced 45% of the world total amount of charcoal, where 86% of the wood-based energy is for domestic use, most of which is inefficiently used. Charcoal is produced commercially in kilns with a 25% to 30% yield by mass on a 7 to 12 day operating cycle. Until recently, the highest yield of good quality charcoal reported in the literature was 38%. In this paper, and ASME code rated experimental system is presented for producing charcoal and activated carbon from biomass.

  7. ACTIVATED CARBON PRODUCTION FROM COCONUT SHELL WITH (NH4)HCO3 ACTIVATOR AS AN ADSORBENT IN VIRGIN COCONUT OIL PURIFICATION

    Microsoft Academic Search

    Indah Subadra; Bambang Setiaji; Iqmal Tahir

    The activated carbon production from coconut shell with chemical and physical process has been done. This research was investigated the effect of soaking concentration of ammonium bicarbonate as the activator to the characteristics of product. It was also to study the application of activated carbon as an adsorbent in virgin coconut oil purification. Activated carbon was produced by pirolysis of

  8. DEVELOPMENT OF ACTIVATED CARBONS FROM COAL COMBUSTION BY-PRODUCTS

    Microsoft Academic Search

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

    2000-01-01

    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

  9. DEVELOPMENT OF ACTIVATED CARBONS FROM COAL COMBUSTION BY-PRODUCTS

    Microsoft Academic Search

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

    2003-01-01

    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.

  10. DEVELOPMENT OF ACTIVATED CARBONS FROM COAL COMBUSTION BY-PRODUCTS

    Microsoft Academic Search

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

    2002-01-01

    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.

  11. Production and characterization of activated carbons from cereal grains

    SciTech Connect

    Venkatraman, A.; Walawender, S.P.; Fan, L.T. [Kansas State Univ., Manhattan, KS (United States)

    1996-10-01

    The kernels of grain such as corn and hard red winter wheat were subjected to a two-stage pyrolytic process to generate relatively high yields of charcoals. The process involved carbonization of the kernels at low temperatures (250-325{degrees}C) followed by complete devolatilization of the resultant charcoals at around 750{degrees}C. The charcoals were subsequently activated physically with CO{sub 2} at 800{degrees}C to yield activated carbons. The total pore volumes and surface areas of the activated carbons were determined at various degree of activation by physisorption methods. The surface areas from the nitrogen BET method ranged from 500 to 1750 m{sup 2}/g, while the total pore volumes obtained from the volumes at saturation were in the interval from 0.3 to 0.7 cm{sup 3}/g. The fractal nature of the pore interfaces as well as the existence of different types of pores were investigated through small-angle x-ray scattering.

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

    PubMed

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

    2004-01-01

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

  13. DEVELOPMENT OF ACTIVATED CARBONS FROM COAL COMBUSTION BY-PRODUCTS

    Microsoft Academic Search

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

    2001-01-01

    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

  14. Application of thermal analysis techniques in activated carbon production

    USGS Publications Warehouse

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

    1996-01-01

    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.

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

    Microsoft Academic Search

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

    2001-01-01

    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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    Microsoft Academic Search

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

    2001-01-01

    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

  18. On the suitability of agricultural by-products for the manufacture of granular activated carbon

    Microsoft Academic Search

    Wolfgang Heschel; Erhard Klose

    1995-01-01

    An investigation of several agricultural by-products revealed that their suitability for activated carbon production is not determined by general material-specific features (elemental composition) but by type-specific features. A coarse-cellular structure (as in wood), which is indicated by porosities of the raw materials higher than ?35% is disadvantageous. A specific change in the properties of cokes (porosity, density, hardness) is possible

  19. The production of activated silica with carbon dioxide gas

    E-print Network

    Hayes, William Bell

    1956-01-01

    Silicate Feed System. Page III. Main Orifice Mixer and Phase Separator. . . . 22 IV. Exploded View of Main Mixing Orifice. . . , . 26 V. Phase Separator Construction VI. Gel Time of Activated Silica Sols. VII. Sulfur Dioxide Content of Flue Gas versus...- tion of an acldf. c material or other activant. It is usually wrf. t ten as $102 2. Sol, This I. s a general term applied to colloi- dal disperslons as distinguished from true solutions. S. Gel, A silf. ca gel ls a heavf. ly hvdrated, in- terlaced...

  20. The production of activated silica with carbon dioxide gas 

    E-print Network

    Hayes, William Bell

    1956-01-01

    . Descri. ption of Equipment Operation of Equi. pment aly t i cal Procedure Discussion of Results, , 18 , 32 . 35 Conclusions, , 51 He fe rences Appendiw . 54 , 56 LIST OF FIGVRES I. Synthetic Flue Gas Feed Svstem II. Water and Sodium... as a conventional coagulant aid. Activated silica is prepared by the total or par- tial neutralization of the sodium oxide of sodium sili- cate. It is a member of a class of chemicals which must be prepared at the point of use, Prior preparation...

  1. Can iron-making and steelmaking slag products be used to sequester CO2? Passive weathering and active carbonation experiments.

    NASA Astrophysics Data System (ADS)

    Worrall, Fred; Dobrza?ski, Andrew

    2015-04-01

    The high calcium content of iron and steel-making slags has been highlighted as providing a suitable feedstock material and medium with which to sequester CO2 into geologically stable carbonate phases. Optimisation of the natural carbonation process provides the potential for increasing the degree of carbonation above that possible via passive weathering. This study has assessed the baseline passive carbonation potential of several different slag products (graded steel slag aggregate, pellite, GBFS) within the climate of the northern UK. This baseline was then used as a comparison to the carbonation values achieved by the same products when actively reacted in a CO2-rich environment. The active carbonation phase of the project involved a factorial experimental study of materials reacted at 1MPa/10MPa CO2 pressure and 25?C/125?C. This study has shown: 1) That active carbonation of these products can successfully sequester additional CO2. 2) Carbonation potential in general is highly dependent upon grain size within material types, 3) There is a material-dependant cost-benefit issue when using different active carbonation conditions as well as the choice to use active vs. passive carbonation. The median sequestration potential of the slag products in this study is equivalent to the total emissions from 910 people from the UK; the CO2 emissions from 10000 tonnes of cement production; or 340000 tonnes of steel production.

  2. Alkali activation of fly ashes. Part 1: Effect of curing conditions on the carbonation of the reaction products

    Microsoft Academic Search

    M. Criado; A. Palomo; A. Fernández-Jiménez

    2005-01-01

    This paper deals with the alkaline activation of fly ashes for the production of a novel cementitious material and with the effect of curing conditions on the nature of the reaction products. Curing procedures favouring carbonation process negatively affects the development of mechanical strength of this new alkaline cement. Carbonation of the system involves its pH modification and consequently the

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

    Microsoft Academic Search

    A Aygün; S Yenisoy-Karaka?; I Duman

    2003-01-01

    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

  4. Production of activated carbons from a vitrain concentrate from the Stockton coal

    SciTech Connect

    Toles, C.; Rimmer, A.M.; Derbyshire, F.; Jagtoyen, M. [Univ. of Kentucky, Lexington, KY (United States)

    1994-12-31

    Earlier, related studies have shown that porous carbons can be produced by phosphoric acid activation of coal sand hardwood. One of the findings was that the development of surface area appears to be rank-dependant. It is also supposed that maceral composition will affect the response to phosphoric acid activation, although there is no available information on this subject. In this context, a study has been initiated of the phosphoric acid activation of coal macerals. The objectives are to examine the effects of maceral composition and rank on porosity development, and to understand the individual and collective contributions of maceral groups to the activation of coals by phosphoric acid. In this study, a vitrinite concentrate from an hvA bituminous coal (Stockton) was used as starting material for the production of activated carbons by H{sub 3}PO{sub 4} activation. The chemical, morphological, and surface area changes were followed as a function of reaction temperatures and are compared to the results of previous studies.

  5. Environmental scanning electron microscopy of activated carbon production from anthracite by one-step pyrolysis-activation

    Microsoft Academic Search

    Katia Gergova; Semih Eser; Harold H. Schobert; Maria Klimkiewicz; Paul W. Brown

    1995-01-01

    Experiments were carried out to produce activated carbons from anthracite using one-step steam pyrolysis-activation. Environmental scanning electron microscopy (ESEM) was used to observe the porosity development in real time. The anthracite samples were heated in different gas atmospheres before steam activation. The ESEM observations showed that the activation agent had a significant effect on the porosity of activated carbon produced

  6. 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...

  7. Production of fibrous activated carbons from natural cellulose (jute, coconut) fibers for water treatment applications

    Microsoft Academic Search

    Ngoc Hoa Phan; Sebastien Rio; Catherine Faur; Laurence Le Coq; Pierre Le Cloirec; Thanh Hong Nguyen

    2006-01-01

    Different fibrous activated carbons were prepared from natural precursors (jute and coconut fibers) by physical and chemical activation. Physical activation consisted of the thermal treatment of raw fibers at 950°C in an inert atmosphere followed by an activation step with CO2 at the same temperature. In chemical activation, the raw fibers were impregnated in a solution of phosphoric acid and

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

    PubMed

    Kim, J W; Sohn, M H; Kim, D S; Sohn, S M; Kwon, Y S

    2001-08-17

    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 degrees C resulted in a thermal degradation, which was substantiated by scanning electron microscopy (SEM) analysis, and the adsorption capacity decreased. Activation longer than 1h at 375 degrees C resulted in the destruction of the microporous structure of activated carbon. The iodine value increased with the increase in the concentration of ZnCl2 solution. However, excessive ZnCl2 in the solution decreased the iodine value. The extent of activation by ZnCl2 was compared with that by CaCl2 activation. Enhanced activation was achieved when walnut shell was activated by ZnCl2. Applicability of the activated carbon as adsorbent was examined for synthetic copper wastewater. Adsorption of copper ion followed the Freundlich model. Thermodynamic aspects of adsorption have been discussed based on experimental results. The adsorption capacity of the produced activated carbon met the conditions for commercialization and was found to be superior to that made from coconut shell. PMID:11489530

  9. Resveratrol Induces Hepatic Mitochondrial Biogenesis Through the Sequential Activation of Nitric Oxide and Carbon Monoxide Production

    PubMed Central

    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.

    2014-01-01

    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

  10. An innovative treatment concept for future drinking water production: fluidized ion exchange – ultrafiltration – nanofiltration – granular activated carbon filtration

    Microsoft Academic Search

    Sheng Li; S. G. J. Heijman; J. Q. J. C. Verberk; J. C. Van Dijk

    2009-01-01

    A new treatment concept for drinking water production from surface water has been investigated on a pilot scale. The treatment concept consists of fluidized ion exchange (FIEX), ultrafiltration (UF), nanofiltration (NF), and granular activated carbon filtration (GAC). The FIEX process removed calcium and other divalent cations; the UF membrane removed particles and micro-organisms; and the NF membrane and GAC removed

  11. Production of Carbon Dioxide

    NSDL National Science Digital Library

    The Science House

    2014-01-28

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

  12. Application of Thermal Analysis to the Study of Some Waste Agricultural Products for the Preparation of Active Carbons

    Microsoft Academic Search

    T. Lupascu; I. Dranca; V. T. Popa; M. Vass

    2001-01-01

    TG, DTG and DTA methods were used for the investigation of some waste agricultural products, such as grape seeds, walnut shells,\\u000a plum and peach stones, which can serve as raw materials for the production of active carbons. It was demonstrated that thermo\\u000a analytical methods are appropriate to study the thermal characteristics of the above wastes and the data obtained can

  13. 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...

  14. Activated carbon filtration in drinking water production: model prediction and new concepts

    Microsoft Academic Search

    S. G. J. Heijman; R. Hopman

    1999-01-01

    For drinking water companies, it is important to predict the lifetime of granular activated carbon (GAC) for the removal of pesticides. Full-scale experiments in pilot GAC filters are expensive and time-consuming, but fast laboratory experiments do not have the accuracy necessary for a realistic prediciton of the breakthrough curves of pesticides. The problems with these experiments and the models used

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

    Microsoft Academic Search

    R. L. Sinsabaugh; S. Findlay

    1995-01-01

    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

  16. Activated carbons from end-products of tree nut and tree fruit production as sorbents for removing methyl bromide in ventilation effluent following postharvest chamber fumigation.

    PubMed

    Hall, Wiley A; Bellamy, David E; Walse, Spencer S

    2015-04-01

    End-products of tree nuts and tree fruits grown in California, USA were evaluated for the ability to remove methyl bromide (MB) from ventilation effluent following postharvest chamber fumigation. Activated carbon sorbents from walnut and almond shells as well as peach and prune pits were prepared using different methods of pyrolysis, activation, and quenching. Each source and preparation was evaluated for yield from starting material (%, m/m) and performance on tests where MB-containing airstreams were directed through a columnar bed of the activated carbon in an experimental apparatus, termed a parallel adsorbent column tester, which was constructed as a scaled-down model of a chamber ventilation system. We report the number of doses needed to first observe the breakthrough of MB downstream of the bed and the capacity of the activated carbon for MB (%, m/m) based on a fractional percentage of MB mass sorbed at breakthrough relative to mass of the bed prior to testing. Results were based on a novel application of solid-phase microextraction with time-weighted averaging sampling of MB concentration in airstreams, which was quantitative across the range of fumigation-relevant conditions and statistically unaffected by relative humidity. Activated carbons from prune pits, prepared either by steam activation or carbon dioxide activation coupled to water quenching, received the greatest number of doses prior to breakthrough and had the highest capacity, approximately 12-14%, outperforming a commercially marketed activated carbon derived from coconut shells. Experimental evidence is presented that links discrepancy in performance to the relative potential for activated carbons to preferentially sorb water vapor relative to MB. PMID:25758836

  17. Removal of cadmium(II) from wastewater using activated carbon prepared from Agro Industrial by-products.

    PubMed

    Hema, M; Srinivasan, K

    2011-10-01

    Removal of cadmium from wastewater using activated carbons prepared from Cocos nucifera (coconut) and Azadirachta indica (neem) oilcakes-an agricultural solid by-product was investigated. Batch experiments were performed to evaluate the effect of pH, agitation time, initial metal ion concentration and adsorbent dose on the cadmium sorption in coconut oil cake activated carbon (COCAC) and neem oil cake activated carbon (NOCAC). The experiments demonstrated that the adsorption process corresponds to the pseudo-second-order-kinetic model and the equilibrium adsorption data fit well with Temkin isotherm model. The adsorption capacity 'b' calculated from the Langmuir isotherm was 188.68 mg/g for COCAC and 23.7 mg/g for NOCAC. The percent removal of Cd(II) in COCAC increased in pH from 2 to 5, and remained constant up to pH 8, increasing the percent removal with increasing pH for NOCAC. Desorption studies were performed with 0.1M hydrochloric acid. It was found that quantitative recovery of the metal ion is possible. It was also observed that the mechanism of adsorption seems to be ion exchange. Reuse of both carbons were carried out for five cycles at optimum conditions. Adsorption efficiency of carbons was reduced from 99 to 89% in the case of COCAC and 97 to 86% for NOCAC. PMID:23505814

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

    Microsoft Academic Search

    Ramin Azargohar

    2009-01-01

    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

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

    PubMed Central

    Grossmann, Sönnke; Dieckmann, Gerhard S.

    1994-01-01

    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. PMID:16349347

  20. 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...

  1. Detoxification of Eucheuma spinosum Hydrolysates with Activated Carbon for Ethanol Production by the Salt-Tolerant Yeast Candida tropicalis.

    PubMed

    Ra, Chae Hun; Jung, Jang Hyun; Sunwoo, In Young; Kang, Chang Han; Jeong, Gwi-Taek; Kim, Sung-Koo

    2015-06-28

    The objective of this study was to optimize the slurry contents and salt concentrations for ethanol production from hydrolysates of the seaweed Eucheuma spinosum. A monosaccharide concentration of 44.2 g/l as 49.6% conversion of total carbohydrate of 89.1 g/l was obtained from 120 g dw/l seaweed slurry. Monosaccharides from E. spinosum slurry were obtained by thermal acid hydrolysis and enzymatic hydrolysis. Addition of activated carbon at 2.5% (w/v) and the adsorption time of 2 min were used in subsequent adsorption treatments to prevent the inhibitory effect of HMF. The adsorption surface area of the activated carbon powder was 1,400-1,600 m(2)/g and showed selectivity to 5-hydroxymethyl furfural (HMF) from monosaccharides. Candida tropicalis KCTC 7212 was cultured in yeast extract, peptone, glucose, and high-salt medium, and exposed to 80, 90, 100, and 110 practical salinity unit (psu) salt concentrations in the lysates. The 100 psu salt concentration showed maximum cell growth and ethanol production. The ethanol fermentations with activated carbon treatment and use of C. tropicalis acclimated to a high salt concentration of 100 psu produced 17.9 g/l of ethanol with a yield (YEtOH) of 0.40 from E. spinosum seaweed. PMID:25649983

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

    PubMed

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

    2015-02-01

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

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

    SciTech Connect

    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

    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.

  4. Activated carbon and biochar from agricultural by-products in the adorption of Cd, Pb and Zn under laboratory conditions

    NASA Astrophysics Data System (ADS)

    Coscione, Aline; Zini, Barbara

    2015-04-01

    The immobilization of inorganic contaminants by using biochar in soils has played an increasingly important role and it is seen as an attractive alternative for the remediation of heavy metals. Although, the production of activated carbon (CA) from agricultural by-products has received special attention, the activation of the the organic source has been studied in order to increase its porposity, surface area and chemical polarity, resulting in higher adsorption of metals. Therefore, this study aimed to evaluate the effectiveness of BC and CA samples, obtained from a eucalyptus husks and cane sugar bagasse after activation with 20% phosphoric acid and pyrolyzed at 450oC in the retention of Zn, Cd and Pb using contaminated individual solutions. The experiment was performed using samples of activated carbon of eucalyptus husk (CCA), eucalyptus husk biochar (BC), activated carbon of sugar cane bagasse (CBA) and sugar cane bagasse biochar (BB), treated with Zn, Cd (range of tested solution from 0.1 up to 12 mmol L-1) and Pb (from 0.1 up 50 mmol L-1) and the adjustemento of Langmuir adsorption isotherms. Samples obtained from bagasse presented higher adsoprtion of the metals tested then eucalyptus. Also the activation process had not the expected effect on either eucalyptus and bagasse samples The maxmum adsorption capacyty of samples were as follws, in mmol g-1: for Cd - 0.36 for BC; 0.32 for CCA; 0.40 for BB; 0.31 for CBA. For Zn- 0.14 for BC; no adsorbed by CCA; 0.35 5 for BB; 0.06 for CBA. For Pb - 1.24 for BC; 0.40 for CCA; 0,45 for BB; 0,03 for CBA. However, it was also observed that due to the activation with phosphoric acid, the pH of the activated carbon (CCA and CBA) were 2.4 and 2.5 in comparison with the biochars not activated (BC and BB) 9.7 and 7.0 respectively. Thus, it is yet not possible to state if the calculate capacity is due exclusively to the complexation of chemical groups in the surface of samples or to which extent there is a contribution of precipitation caused by the basic pH (non-activated) biochar samples, as shown for Zn and Pb.

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

    Microsoft Academic Search

    S Gryglewicz; K Grabas; G Gryglewicz

    2000-01-01

    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

  6. Carbon starvation increases endoglycosidase activities and production of "unconjugated N-glycans" in Silene alba cell-suspension cultures.

    PubMed Central

    Lhernould, S; Karamanos, Y; Priem, B; Morvan, H

    1994-01-01

    We previously reported the occurrence of oligomannosides and xylomannosides corresponding to unconjugated N-glycans (UNGs) in the medium of a white campion (Silene alba) cell suspension. Attention has been focused on these oligosaccharides since it was shown that they confer biological activities in plants. In an attempt to elucidate the origin of these oligosaccharides, we studied two endoglycosidase activities, putative enzymes involved in their formation. The previously described peptide-N4-(N-acetyl-glucosaminyl) asparagine amidase activity and the endo-N-acetyl-beta-D-glucosaminidase activity described in this paper were both quantified in white campion cells during the culture cycle with variable initial concentrations of sucrose. The lower the sucrose supply, the higher the two activities. Furthermore, endoglycosidase activities were greatly enhanced after the disappearance of sugar from the medium. The production of UNGs in the culture medium rose correlatively. These data strongly suggest that the production of UNGs in our white campion cell-suspension system is due to the increase of these endoglycosidase activities, which reach their highest levels of activity during conditions of carbon starvation. PMID:7991689

  7. Production of granular activated carbon from food-processing wastes (walnut shells and jujube seeds) and its adsorptive properties.

    PubMed

    Bae, Wookeun; Kim, Jongho; Chung, Jinwook

    2014-08-01

    Commercial activated carbon is a highly effective absorbent that can be used to remove micropollutants from water. As a result, the demand for activated carbon is increasing. In this study, we investigated the optimum manufacturing conditions for producing activated carbon from ligneous wastes generated from food processing. Jujube seeds and walnut shells were selected as raw materials. Carbonization and steam activation were performed in a fixed-bed laboratory electric furnace. To obtain the highest iodine number, the optimum conditions for producing activated carbon from jujube seeds and walnut shells were 2 hr and 1.5 hr (carbonization at 700 degrees C) followed by 1 hr and 0.5 hr (activation at 1000 degrees C), respectively. The surface area and iodine number of activated carbon made from jujube seeds and walnut shells were 1,477 and 1,184 m2/g and 1,450 and 1,200 mg/g, respectively. A pore-distribution analysis revealed that most pores had a pore diameter within or around 30-40 angstroms, and adsorption capacity for surfactants was about 2 times larger than the commercial activated carbon, indicating that waste-based activated carbon can be used as alternative. Implications: Wastes discharged from agricultural and food industries results in a serious environmental problem. A method is proposed to convert food-processing wastes such as jujube seeds and walnut shells into high-grade granular activated carbon. Especially, the performance of jujube seeds as activated carbon is worthy of close attention. There is little research about the application ofjujube seeds. Also, when compared to two commercial carbons (Samchully and Calgon samples), the results show that it is possible to produce high-quality carbon, particularly from jujube seed, using a one-stage, 1,000 degrees C, steam pyrolysis. The preparation of activated carbon from food-processing wastes could increase economic return and reduce pollution. PMID:25185390

  8. Biochar as a precursor of activated carbon

    Microsoft Academic Search

    R. Azargohar; A. K. Dalai

    2006-01-01

    Biochar was evaluated as a precursor of activated carbon. This product was produced by chemical activation using potassium\\u000a hydroxide. The effects of operating conditions of activation process, such as temperature, activating agent to biochar mass\\u000a ratio, and nitrogen flow rate, on the textural and chemical properties of the product were investigated. Activated carbon\\u000a produced by this method has internal surface

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  10. Retention efficiency of Cd, Pb and Zn from agricultural by-products activated carbon and biochar under laboratory conditions

    NASA Astrophysics Data System (ADS)

    Coscione, Aline; Ramos, Barbara

    2015-04-01

    The immobilization of inorganic contaminants by using biochar in soils has played an increasingly important role and it is seen as an attractive alternative for the remediation of heavy metals. Although, the production of activated carbon (CA) from agricultural by-products has received special attention, the activation of the the organic source has been studied in order to increase its porposity, surface area and chemical polarity, resulting in higher adsorption of metals. Therefore, this study aimed to evaluate the effectiveness of BC and CA samples, obtained from a eucalyptus husks and cane sugar bagasse after activation with 20% phosphoric acid and pyrolyzed at 450oC in the retention of Zn, Cd and Pb using contaminated individual solutions. The experiment was performed using samples of activated carbon of eucalyptus husk (CCA), eucalyptus husk biochar (BC), activated carbon of sugar cane bagasse (CBA) and sugar cane bagasse biochar (BB) previously treated with Zn, Cd (range of tested solution from 0.1 up to 12 mmol L-1) and Pb (from 0.1 up 50 mmol L-1) which were submitted to stirring with ammonium acetate solution at pH 4.9 for 48 h. The results obtained were adjusted with Langmuir desorptiom isotherms. The pH of the resulting solution, were the meatls were analyse, was measure and remained in the range 4.9 - 5.0. The lower pH found in activated samples (range 2.4-2.5) resulted in larger desorption of metals than the biochar samples (pH of 9.7 for BC and 7.0 for BB). This result is surprising since for the biochar samples it was expected that any precipated metals were dissolved by the desorption solution in addition to metals released by ion exchange. Although the desorption results of activated samoels is still unclear, hich we belive may be explaibed by some adicitonal insterumental analysis, biochar samples showed better potential for application in contaminated soils than the previous.

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

    SciTech Connect

    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

    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.

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

    Microsoft Academic Search

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

    2002-01-01

    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

  13. 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 ...

  14. Dewatering Peat With Activated Carbon

    NASA Technical Reports Server (NTRS)

    Rohatgi, N. K.

    1984-01-01

    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.

  15. Carbon Dioxide Production at Home

    NSDL National Science Digital Library

    2012-08-03

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

  16. Upgrading the rice husk char obtained by flash pyrolysis for the production of amorphous silica and high quality activated carbon.

    PubMed

    Alvarez, Jon; Lopez, Gartzen; Amutio, Maider; Bilbao, Javier; Olazar, Martin

    2014-10-01

    The overall valorization of rice husk char obtained by flash pyrolysis in a conical spouted bed reactor (CSBR) has been studied in a two-step process. Thus, silica has been recovered in a first step and the remaining carbon material has been subjected to steam activation. The char samples used in this study have been obtained by continuous flash pyrolysis in a conical spouted bed reactor at 500°C. Extraction with Na2CO3 allows recovering 88% of the silica contained in the rice husk char. Activation of the silica-free rice husk char has been carried out in a fixed bed reactor at 800°C using steam as activating agent. The porous structure of the activated carbons produced includes a combination of micropores and mesopores, with a BET surface area of up to 1365m(2)g(-1) at the end of 15min. PMID:25127010

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

    SciTech Connect

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

    2011-07-01

    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.

  18. 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...

  19. Helicobacter pylori Urease Suppresses Bactericidal Activity of Peroxynitrite via Carbon Dioxide Production

    PubMed Central

    Kuwahara, Hideo; Miyamoto, Yoichi; Akaike, Takaaki; Kubota, Tatsuo; Sawa, Tomohiro; Okamoto, Shinichiro; Maeda, Hiroshi

    2000-01-01

    Helicobacter pylori can produce a persistent infection in the human stomach, where chronic and active inflammation, including the infiltration of phagocytes such as neutrophils and monocytes, is induced. H. pylori may have a defense system against the antimicrobial actions of phagocytes. We studied the defense mechanism of H. pylori against host-derived peroxynitrite (ONOO?), a bactericidal metabolite of nitric oxide, focusing on the role of H. pylori urease, which produces CO2 and NH3 from urea and is known to be an essential factor for colonization. The viability of H. pylori decreased in a time-dependent manner with continuous exposure to 1 ?M ONOO?, i.e., 0.2% of the initial bacteria remained after a 5-min treatment without urea. The bactericidal action of ONOO? against H. pylori was significantly attenuated by the addition of 10 mM urea, the substrate for urease, whereas ONOO?-induced killing of a urease-deficient mutant of H. pylori or Campylobacter jejuni, another microaerophilic bacterium lacking urease, was not affected by the addition of urea. Such a protective effect of urea was potentiated by supplementation with exogenous urease, and it was almost completely nullified by 10 ?M flurofamide, a specific inhibitor of urease. The bactericidal action of ONOO? was also suppressed by the addition of 20 mM NaHCO3 but not by the addition of 20 mM NH3. In addition, the nitration of l-tyrosine of H. pylori after treatment with ONOO? was significantly reduced by the addition of urea or NaHCO3, as assessed by high-performance liquid chromatography with electrochemical detection. These results suggest that H. pylori-associated urease functions to produce a potent ONOO? scavenger, CO2/HCO3?, that defends the bacteria from ONOO? cytotoxicity. The protective effect of urease may thus facilitate sustained bacterial colonization in the infected gastric mucosa. PMID:10899833

  20. Activated carbon from municipal waste

    Microsoft Academic Search

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

    2000-01-01

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

  1. An insight into the KOH activation mechanism through the production of microporous activated carbon for the removal of Pb 2+ cations

    NASA Astrophysics Data System (ADS)

    El-Hendawy, Abdel-Nasser A.

    2009-01-01

    Chemical activation was used through direct mixing of KOH with maize stalks in the smallest amount of water to provide KOH-to-stalk ratios of 33, 50, 66 and 75% by weight. The KOH-treated stalks were carbonized at 700 °C to produce a series of four activated carbons, besides a non-activated sample that was prepared and carbonized at 550 °C. The porous properties of these carbons were characterized by the Langmuir, BET and Dubinin-Radushkevich linear equations as well as both ?s (alpha- s) and t methods based on nitrogen adsorption isotherms. The chemical reactions involved during the impregnation and the carbonization processes for these hydroxide/lignocellulose mixtures have been proposed. Deep insight has been obtained concerning the possible reactions mechanism. The results showed that the KOH ratio was found to be the basic indicator of micoporosity development. The increase in the concentration of KOH much increased the S? values of the resulting carbons reaching a maximum limit at 66 wt% KOH with S? of 1684 m 2/g and micropore ratio of ˜85% displaying an inverse correlation thereafter. The thermal behaviour and the surface microstructure in addition to the surface functional groups of the maize stalks and their prepared carbons were investigated by TGA, SEM and FTIR. The investigated carbons took up significant amounts of Pb 2+ ions from aqueous solutions, which are ascribed to both the porosity and surface chemical nature of the adsorbents.

  2. Preparation of modified active carbon from brown coal by ammoxidation

    Microsoft Academic Search

    R. Pietrzak; H. Wachowska; P. Nowicki; K. Babe?

    2007-01-01

    The technology of obtaining active carbon enriched in nitrogen from brown coal is described. The effect of ammoxidation by a mixture of ammonia and air at the ratio 1:3 at 300 and 350 °C, at each stage of the active carbon production has been tested. The amount of nitrogen introduced into the active carbon has been proved to depend on the

  3. Microbial activity and carbon, nitrogen, and phosphorus content in a subtropical seagrass estuary (Florida Bay): evidence for limited bacterial use of seagrass production

    Microsoft Academic Search

    Clayton J. Williams; Joseph N. Boyer; Frank J. Jochem

    2009-01-01

    Bacterial abundance, production, and extracellular enzyme activity were determined in the shallow water column, in the epiphytic\\u000a community of Thalassia\\u000a testudinum, and at the sediment surface along with total carbon, nitrogen, and phosphorus in Florida Bay, a subtropical seagrass estuary.\\u000a Data were statistically reduced by principle components analysis (PCA) and multidimensional scaling and related to T. testudinum leaf total phosphorus

  4. ACTIVATED CARBON FROM LIGNITE FOR WATER TREATMENT

    SciTech Connect

    Edwin S. Olson; Daniel J. Stepan

    2000-07-01

    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 North Dakota lignites with those of commercial carbons was conducted. Previous studies indicated that a commercial carbon prepared from Texas lignite (Darco HDB) was superior to those prepared from bituminous coals for water treatment. That the high alkali content of North Dakota lignites would result in favorable adsorptive properties for the very large humate molecules was hypothesized, owing to the formation of larger pores during activation. Since no standard humate test has been previously developed, initial adsorption testing was performed using smaller dye molecules with various types of ionic character. With the cationic dye, methylene blue, a carbon prepared from a high-sodium lignite (HSKRC) adsorbed more dye than the Darco HDB. The carbon from the low-sodium lignite was much inferior. With another cationic dye, malachite green, the Darco HDB was slightly better. With anionic dyes, methyl red and azocarmine-B, the results for the HSKRC and Darco HDB were comparable. A humate test was developed using Aldrich humic acid. The HSKRC and the Darco HDB gave equally high adsorption capacities for the humate (138 mg/g), consistent with the similarities observed in earlier tests. A carbon prepared from a high-sodium lignite from a different mine showed an outstanding improvement (201 mg/g). The carbons prepared from the low-sodium lignites from both mines showed poor adsorption capacities for humate. Adsorption isotherms were performed for the set of activated carbons in the humate system. These exhibited a complex behavior interpreted as resulting from two types of sorption sites. The effect of pH on adsorption was investigated using buffered solutions. The sorption capacity decreased with increasing pH. A study of the effect of activation conditions on the adsorption capacity of the resulting carbon showed that steam activation at 750 C provides the optimum activity with the high-sodium char. An attempt to scale up the carbon production to the 2-kg scale failed to produce the same high activity that was obtained in the 100-g batch unit. Although this research demonstrated that a highly active carbon for water treatment can be produced from high-sodium lignites, much further work is needed to understand what methods and equipment will be needed for large-scale production of this carbon.

  5. Activated carbon to the rescue

    Microsoft Academic Search

    Sen

    1996-01-01

    This article describes the response to pipeline spill of ethylene dichloride (EDC) on the property of an oil company. Activated carbon cleanup proceedure was used. During delivery, changeout, transport, storage, thermal reactivation, and return delivery to the site, the carbon never came into direct contact with operating personnel or the atmosphere. More than 10,000 tones of dredge soil and 50

  6. Carbon Dioxide Production in the Oxidation of Organic

    E-print Network

    Steinbock, Oliver

    Carbon Dioxide Production in the Oxidation of Organic Acids by Cerium(IV) under Aerobic are oxidized to carbon dioxide. Hence, the determination of the stoichiometry between produced CO2 and reduced The study of oxidation of relatively low molecular weight carbonic acids by metal ions has been an active

  7. Carbon dynamics in wood products

    Microsoft Academic Search

    K. Pingoud; A. PUSSINEN

    2001-01-01

    The carbon (C) reservoir of wood products in Finnishconstruction and civil engineering was estimated by three inventoriesincluding the years 1980, 1990 and 1995. The inventory method ismainly based on the statistics of Finnish building stock. The use of differentconstruction materials in different parts of buildings is estimated for eachbuilding type. Information collected through building permits includes thematerials of bearing frames

  8. 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...

  9. Activated carbon catalytic ozonation of oxamic and oxalic acids

    Microsoft Academic Search

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

    2008-01-01

    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

  10. An Evolutionary Approach to Activated Carbon Treatment

    Microsoft Academic Search

    Pierre Schulhof

    1979-01-01

    Activated carbon has been successfully used in France to remove organics and limit the use of chlorine through two processes— simple filtration on activated carbon beds and double filtration on sand and carbon combined with ozonation.

  11. Activated carbon from pecan shell: process description and economic analysis

    Microsoft Academic Search

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

    2003-01-01

    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

  12. Activated carbon to the rescue

    SciTech Connect

    Sen, S. [Calgon Carbon Corp., Pittsburgh, PA (United States)

    1996-03-01

    This article describes the response to pipeline spill of ethylene dichloride (EDC) on the property of an oil company. Activated carbon cleanup proceedure was used. During delivery, changeout, transport, storage, thermal reactivation, and return delivery to the site, the carbon never came into direct contact with operating personnel or the atmosphere. More than 10,000 tones of dredge soil and 50 million gallons of surface water were processed during the emergency response.

  13. Enhanced coagulation with powdered activated carbon or MIEX secondary treatment: a comparison of disinfection by-product formation and precursor removal.

    PubMed

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

    2015-01-01

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

  14. Supporting Information Unexpected Role of Activated Carbon in Promoting

    E-print Network

    Huang, Ching-Hua

    Supporting Information Unexpected Role of Activated Carbon in Promoting Transformation of Secondary. Activated Carbons, Modifications and Characterization. The suite of activated carbon particles and fibers), (ii) coconut shell-based activated carbons: Prominent Systems carbon (PSC) from Prominent Systems Inc

  15. Microporous activated carbons from a bituminous coal

    Microsoft Academic Search

    Francisco Carrasco-Marín; Miguel A. Alvarez-Merino; Carlos Moreno-Castilla

    1996-01-01

    A Spanish bituminous coal was used as raw material to prepare activated carbons both by CO2 and by chemical activation. The activated carbons were characterized by adsorption of N2 at 77 K, CO2 at 273 K and benzene and cyclohexane at 303 K, as well as by mercury porosimetry and helium density. The microporosity of the activated carbons was evaluated

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

    DOEpatents

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

    2011-07-19

    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.

  17. Natural gas storage with activated carbon from a bituminous coal

    Microsoft Academic Search

    Jian Sun; Mark J. Rood; Massoud Rostam-Abadi; Anthony A. Lizzio

    1996-01-01

    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 (VmVs) of some of the granular carbons produced by physical activation

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

    Microsoft Academic Search

    Dong-Su Kim

    2004-01-01

    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

  19. Activated carbon fibre materials for VOC removal

    Microsoft Academic Search

    P Navarri; D Marchal; A Ginestet

    2001-01-01

    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

  20. Perchlorate removal by activated carbon adsorption

    Microsoft Academic Search

    Rovshan Mahmudov; Chin Pao Huang

    2010-01-01

    The adsorption of perchlorate on activated carbon was studied. A total of 10 types of commercial activated carbons were tested for perchlorate adsorption characteristics using pH as the master variable. The activated carbons were made from different base materials such as wood, bituminous coal, and lignite coal and thus expressed different surface characteristics such as specific surface area and surface

  1. Preparation and characterization of activated carbon produced from pomegranate seeds by ZnCl 2 activation

    NASA Astrophysics Data System (ADS)

    Uçar, Suat; Erdem, Murat; Tay, Turgay; Karagöz, Selhan

    2009-08-01

    In this study, pomegranate seeds, a by-product of fruit juice industry, were used as precursor for the preparation of activated carbon by chemical activation with ZnCl 2. The influence of process variables such as the carbonization temperature and the impregnation ratio on textural and chemical-surface properties of the activated carbons was studied. When using the 2.0 impregnation ratio at the carbonization temperature of 600 °C, the specific surface area of the resultant carbon is as high as 978.8 m 2 g -1. The results showed that the surface area and total pore volume of the activated carbons at the lowest impregnation ratio and the carbonization temperature were achieved as high as 709.4 m 2 g -1 and 0.329 cm 3 g -1. The surface area was strongly influenced by the impregnation ratio of activation reagent and the subsequent carbonization temperature.

  2. Activated, coal-based carbon foam

    DOEpatents

    Rogers, Darren Kenneth; Plucinski, Janusz Wladyslaw

    2004-12-21

    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.

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

    Microsoft Academic Search

    C Namasivayam; K Kadirvelu

    1999-01-01

    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

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

    Microsoft Academic Search

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

    2001-01-01

    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

  5. A carbon sink pathway increases carbon productivity in cyanobacteria.

    PubMed

    Oliver, John W K; Atsumi, Shota

    2015-05-01

    The burning of fossil reserves, and subsequent release of carbon into the atmosphere is depleting the supply of carbon-based molecules used for synthetic materials including plastics, oils, medicines, and glues. To provide for future society, innovations are needed for the conversion of waste carbon (CO2) into organic carbon useful for materials. Chemical production directly from photosynthesis is a nascent technology, with great promise for capture of CO2 using sunlight. To improve low yields, it has been proposed that photosynthetic capacity can be increased by a relaxation of bottlenecks inherent to growth. The limits of carbon partitioning away from growth within the cell and the effect of partitioning on carbon fixation are not well known. Here we show that expressing genes in a pathway between carbon fixation and pyruvate increases partitioning to 2,3-butanediol (23BD) and leads to a 1.8-fold increase in total carbon yield in the cyanobacterium Synechococcus elongatus PCC 7942. Specific 2,3-butanediol production increases 2.4-fold. As partitioning increases beyond 30%, it leads to a steep decline in total carbon yield. The data suggests a local maximum for carbon partitioning from the Calvin Benson cycle that is scalable with light intensity. PMID:25777135

  6. Rerouting Carbon Flux To Enhance Photosynthetic Productivity

    PubMed Central

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

    2012-01-01

    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. PMID:22307292

  7. Porosity Development in Activated Carbons Prepared from Walnut Shells by Carbon Dioxide or Steam Activation

    Microsoft Academic Search

    Juan F. Gonza?lez; Silvia Roma?n; Carmen M. Gonzalez-Garcõ ´; J. M. Valente Nabais; Angel L. Ortiz

    2009-01-01

    The influence of carbon dioxide and steam as activating agents on the porosity development of activated carbons produced from walnut shells was investigated. The study was made covering a wide range of burnoff (12-76%) and employing different temperatures and times: in carbon dioxide activation, 850 °C varying the activation time in the range 60-480 min, and in steam activation, 700,

  8. Evaluation of personal care products (PCP) removal efficiency: NF membranes, granular activated carbon (GAC) and ozone process

    Microsoft Academic Search

    Sung yun Lee; Yeomin Yoon

    Advanced water treatment processes, including NF membrane, GAC, and ozone process, were evaluated in terms of removal efficiencies of personal care products (PCP). Four different PCP compounds, DEET, galaxolide, tonalide, and musk ketone, were used to evaluate their removal efficiency by selected advanced water treatment processes. Two different NF membranes, RF and NE40, were studied to investigate PCP removal mechanisms.

  9. Ionised carbon and galaxy activity

    E-print Network

    S. J. Curran

    2009-02-12

    We investigate the possibility that the decrease in the relative luminosity of the 158 micron [CII] line with the far-infrared luminosity in extragalactic sources stems from a stronger contribution from the heated dust emission in the more distant sources. Due to the flux limited nature of these surveys, the luminosity of the detected objects increases with distance. However, the [CII] luminosity does not climb as steeply as that of the far-infrared, giving the decline in the L_[CII]/L_FIR ratio with L_FIR. Investigating this further, we find that the [CII] luminosity exhibits similar drops as measured against the carbon monoxide and radio continuum luminosities. The former may indicate that at higher luminosities a larger fraction of the carbon is locked up in the form of molecules and/or that the CO line radiation also contributes to the cooling, done mainly by the [CII] line at low luminosities. The latter hints at increased activity in these galaxies at greater distances, so we suggest that, in addition to an underlying heating of the dust by a stellar population, there is also heating of the embedded dusty torus by the ultra-violet emission from the active nucleus, resulting in an excess in the far-infrared emission from the more luminous objects.

  10. Phenolic-resin-derived activated carbons

    Microsoft Academic Search

    S. R. Tennison

    1998-01-01

    A novel binderless preparative route is described for the production of phenolic-resin-derived carbons for use as catalyst supports and adsorbents. The carbons can be produced in a wide variety of physical forms ranging from simple granules to large monolithic structures. The fully interconnected macropore structure of the carbons, which derives from the interconnected voids between the primary resin particles, can

  11. Adsorption of indigo carmine by activated carbon

    Microsoft Academic Search

    T. Tamura; T. Miyoshi; K. Boki; S. Tanada

    1988-01-01

    Adsorption of indigo carmine as an acid dye onto activated carbon was studied in order to elucidate its adsorption behavior on the basis of amount adsorbed, pore size distribution, pH and basicity of activated carbon, and pH of filtrate. Activated carbon No.1 and No.4 were the preferable adsorbents for removing indigo carmine in the range of higher and lower equilibrium

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

    PubMed

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

    2015-02-01

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

  13. Microporous activated carbons from ammoxidised anthracite and their capacitance behaviours

    Microsoft Academic Search

    R. Pietrzak; K. Jurewicz; P. Nowicki; K. Babe?; H. Wachowska

    2007-01-01

    The paper presents results of a study on obtaining N-enriched active carbons from anthracite mined in Siberia, and on its use as electrode material in supercapacitors. The anthracite was carbonised, activated with KOH and ammoxidised by a mixture of ammonia and air at the ratio 1:3 at 300 or 350°C, at each stage of the activate production. The products were

  14. Selecting activated carbon for water and wastewater treatability studies

    SciTech Connect

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

    2007-10-15

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

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

    PubMed

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

    2013-06-15

    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

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

    PubMed

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

    2014-03-01

    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

  17. Performance of granular activated carbon for total organic carbon removal

    Microsoft Academic Search

    Paul V. Roberts; R. Scott Summers

    1982-01-01

    The results of papers presented at the second of two conferences concerning the state of the art of the application of oxidation and adsorption techniques (including granular activated carbon) in the treatment of drinking water were analyzed for their application to GAC use in the United States. Total organic carbon was used as the parameter for measuring the removal of

  18. Select metal adsorption by activated carbon made from peanut shells.

    PubMed

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

    2006-12-01

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

  19. Activated carbon for gas separation and storage

    Microsoft Academic Search

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

    1996-01-01

    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

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

    PubMed

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

    2014-08-21

    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

  1. Carbon Dioxide: Production and Sequestration

    NSDL National Science Digital Library

    2012-08-03

    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.

  2. PRODUCTION OF CARBON PRODUCTS USING A COAL EXTRACTION PROCESS

    SciTech Connect

    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

    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.

  3. Preparation and characterization of activated carbon foam from phenolic resin

    Microsoft Academic Search

    Xuefei ZHAO; Shiquan LAI; Hongzha LIU; Lijuan GAO

    2009-01-01

    Activated carbon foam was successfully prepared from phenolic resin synthesized with phenol and formaldehyde under alkali condition. The influence of process variables, such as steam rate, carbonization temperature, carbonization time, activation temperature and activation time on the adsorption capacities of the activated carbon foam was studied. Under the optimum experimental conditions, the activated carbon foam with a specific surface area

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

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

    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.

  5. Sorption of petroleum products by carbon sorbents

    SciTech Connect

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

    2009-07-01

    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.

  6. Regenerate activated carbon using organic solvents

    SciTech Connect

    McLaughlin, H.S.

    1995-07-01

    Adsorption by activated carbon is widely used to remove chemical species from waters and wastewater and volatile organic compounds from vapor streams. In normal applications, the activated carbon gradually accumulates the chemical species removed from the liquid or vapor stream. This causes a progressive reduction in the carbon`s ability to remove additional chemicals from the stream, and eventually the adsorption capacity is consumed and the carbon is spent. At this point, the carbon must either be replaced or be regenerated to restore its adsorptive capacity. Solvent regeneration is one such technology. It uses solvents to dissolve adsorbed material out of the pores of the activated carbon. Then the solvent is removed by steam. This article discusses where solvent regeneration fits into the overall scheme of activated carbon applications and regeneration options. Cost-wise, solvent regeneration of activated carbon is only a few cents per pound more expensive than steam regeneration, and less than one-tenth as expensive as thermal regeneration. Because steam regeneration is appropriate for only certain industrial applications (discussed later), the choice is usually between solvent and thermal regeneration.

  7. A distributed approach to accounting for carbon in wood products

    SciTech Connect

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

    2010-01-01

    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.

  8. Primary radiolysis products of propylene glycol carbonate

    SciTech Connect

    Kucherenko, E.A.; Kartasheva, L.I.; Pikaev, A.K.

    1985-09-01

    The intermediate products of the radiolytic conversions of propylene glycol carbonate were investigated by the methods of microand nanosecond pulse radiolysis. The absorption spectra of these products were measured, and conclusions were drawn about their nature. It was shown that together with reducing intermediate products (radical anions and alcohol-type radicals), oxidative short-lived particles are also formed (possibly CO/sub 3//sup -/). A mechanism of the radiolysis of this system is proposed.

  9. Reduction of bromate by granular activated carbon

    SciTech Connect

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

    1998-07-01

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

  10. Catalytic Growth of Macroscopic Carbon Nanofibers Bodies with Activated Carbon

    SciTech Connect

    Abdullah, N.; Muhammad, I. S.; Hamid, S. B. Abd. [NANOCEN, Block A, Level 3, Institute of Postgraduate Studies, University of Malaya, 50603 Kuala Lumpur (Malaysia); Rinaldi, A. [NANOCEN, Block A, Level 3, Institute of Postgraduate Studies, University of Malaya, 50603 Kuala Lumpur (Malaysia); Inorganic Chemistry Department, Fritz-Haber Institute der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin (Germany); Su, D. S.; Schlogl, R. [Inorganic Chemistry Department, Fritz-Haber Institute der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin (Germany)

    2009-06-01

    Carbon-carbon composite of activated carbon and carbon nanofibers have been synthesized by growing Carbon nanofiber (CNF) on Palm shell-based Activated carbon (AC) with Ni catalyst. The composites are in an agglomerated shape due to the entanglement of the defective CNF between the AC particles forming a macroscopic body. The macroscopic size will allow the composite to be used as a stabile catalyst support and liquid adsorbent. The preparation of CNT/AC nanocarbon was initiated by pre-treating the activated carbon with nitric acid, followed by impregnation of 1 wt% loading of nickel (II) nitrate solutions in acetone. The catalyst precursor was calcined and reduced at 300 deg. C for an hour in each step. The catalytic growth of nanocarbon in C{sub 2}H{sub 4}/H{sub 2} was carried out at temperature of 550 deg. C for 2 hrs with different rotating angle in the fluidization system. SEM and N{sub 2} isotherms show the level of agglomeration which is a function of growth density and fluidization of the system. The effect of fluidization by rotating the reactor during growth with different speed give a significant impact on the agglomeration of the final CNF/AC composite and thus the amount of CNFs produced. The macrostructure body produced in this work of CNF/AC composite will have advantages in the adsorbent and catalyst support application, due to the mechanical and chemical properties of the material.

  11. Sorption of elemental mercury by activated carbons

    Microsoft Academic Search

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

    1994-01-01

    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),

  12. 78 FR 13894 - Certain Activated Carbon From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-01

    ...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...

  13. Flax shive as a source of activated carbon for metals remediaton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flax shive constitutes about 70% of the flax stem and has limited use. Because shive is a lignocellulosic by-product, it can potentially be pyroylzed and activated to produce an activated carbon. The objective of this study was to create an activated carbon from flax shive by chemical activation t...

  14. Carbon dioxide-methane mixture adsorption on activated carbon

    Microsoft Academic Search

    V. Goetz; O. Pupier; A. Guillot

    2006-01-01

    In this work, we report new experimental data of pure and binary adsorption equilibria of carbon dioxide and methane on the\\u000a activated carbon RB2 at 273 and 298 K. The pressure range studied were 0–3.5 MPa for pure gases and 0–0.1 MPa for mixtures.\\u000a The combination of the generalized Dubinin model to describe the pure CO2 and CH4 isotherms with

  15. Create a Consortium and Develop Premium Carbon Products from Coal

    SciTech Connect

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

    2006-01-01

    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.

  16. Activated carbons and double layer capacitance

    Microsoft Academic Search

    Hang Shi

    1996-01-01

    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

  17. The transport properties of activated carbon fibers

    SciTech Connect

    di Vittorio, S.L. (Massachusetts Inst. of Tech., Cambridge, MA (USA). Dept. of Materials Science and Engineering); Dresselhaus, M.S. (Massachusetts Inst. of Tech., Cambridge, MA (USA). Dept. of Electrical Engineering and Computer Science Massachusetts Inst. of Tech., Cambridge, MA (USA). Dept. of Physics); Endo, M. (Shinshu Univ., Nagano (Japan). Dept. of Electrical Engineering); Issi, J-P.; Piraux, L.

    1990-07-01

    The transport properties of activated 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. 19 refs., 4 figs.

  18. New PHA products using unrelated carbon sources

    PubMed Central

    Matias, Fernanda; de Andrade Rodrigues, Maria Filomena

    2011-01-01

    Polyhydroxyalkanoates (PHA) are natural polyesters stored by a wide range of bacteria as carbon source reserve. Due to its chemical characteristics and biodegradability PHA can be used in chemical, medical and pharmaceutical industry for many human purposes. Over the past years, few Burkholderia species have become known for production of PHA. Aside from that, these bacteria seem to be interesting for discovering new PHA compositions which is important to different industrial applications. In this paper, we introduce two new strains which belong either to Burkholderia cepacia complex (Bcc) or genomovar-type, Burkholderia cepacia SA3J and Burkholderia contaminans I29B, both PHA producers from unrelated carbon sources. The classification was based on 16S rDNA and recA partial sequence genes and cell wall fatty acids composition. These two strains were capable to produce different types of PHA monomers or precursors. Unrelated carbon sources were used for growth and PHA accumulation. The amount of carbon source evaluated, or mixtures of them, was increased with every new experiment until it reaches eighteen carbon sources. As first bioprospection experiments staining methods were used with colony fluorescent dye Nile Red and the cell fluorescent dye Nile Blue A. Gas chromatography analysis coupled to mass spectrometry was used to evaluate the PHA composition on each strain cultivated on different carbon sources. The synthesized polymers were composed by short chain length-PHA (scl-PHA), especially polyhydroxybutyrate, and medium chain length-PHA (mcl-PHA) depending on the carbon source used. PMID:24031764

  19. 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 ...

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

    Microsoft Academic Search

    Y. Azov; G. Shelef; R. Moraine

    1982-01-01

    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

  1. Integrating Steel Production with Mineral Carbon Sequestration

    SciTech Connect

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

    2008-05-01

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

  2. Photobiological hydrogen production and carbon dioxide sequestration

    Microsoft Academic Search

    Halil Berberoglu

    2008-01-01

    Photobiological hydrogen production is an alternative to thermochemical and electrolytic technologies with the advantage of carbon dioxide sequestration. However, it suffers from low solar to hydrogen energy conversion efficiency due to limited light transfer, mass transfer, and nutrient medium composition. The present study aims at addressing these limitations and can be divided in three parts: (1) experimental measurements of the

  3. Pesticide removal by combined ozonation and granular activated carbon filtration

    Microsoft Academic Search

    E. Orlandini

    1999-01-01

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

  4. Catalytic Carbon-Carbon and Carbon-Silicon Bond Activation and Functionalization by Nickel Complexes

    E-print Network

    Jones, William D.

    Catalytic Carbon-Carbon and Carbon-Silicon Bond Activation and Functionalization by Nickel of Rochester, Rochester, New York 14627 Received June 11, 1999 The nickel alkyne complexes (dippe)Ni(Me3Si, and nickel phosphine complexes.3 Milstein and co-workers reported the cata- lytic hydrogenolysis

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

    DOEpatents

    Muradov, Nazim Z. (Melbourne, FL)

    2011-08-23

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

  6. Effect of activated carbon on fouling of activated sludge filtration

    Microsoft Academic Search

    Herbert H. P. Fang; Xinlong Shi; Tong Zhang

    2006-01-01

    The effect of adding activated carbon on the fouling of activated sludge filtration was investigated using a complete-mix cell with a flat-sheet cellulosic membrane at a constant pressure gradient of 70 kN\\/m2. Four sludge samples were tested in parallel: a sludge without additive served as control, plus three sludge samples dosed with individual additives, including inert diatomaceous earth, activated carbon

  7. Nanospace engineering of KOH activated carbon

    NASA Astrophysics Data System (ADS)

    Romanos, J.; Beckner, M.; Rash, T.; Firlej, L.; Kuchta, B.; Yu, P.; Suppes, G.; Wexler, C.; Pfeifer, P.

    2012-01-01

    This paper demonstrates that nanospace engineering of KOH activated carbon is possible by controlling the degree of carbon consumption and metallic potassium intercalation into the carbon lattice during the activation process. High specific surface areas, porosities, sub-nanometer (<1 nm) and supra-nanometer (1-5 nm) pore volumes are quantitatively controlled by a combination of KOH concentration and activation temperature. The process typically leads to a bimodal pore size distribution, with a large, approximately constant number of sub-nanometer pores and a variable number of supra-nanometer pores. We show how to control the number of supra-nanometer pores in a manner not achieved previously by chemical activation. The chemical mechanism underlying this control is studied by following the evolution of elemental composition, specific surface area, porosity, and pore size distribution during KOH activation and preceding H3PO4 activation. The oxygen, nitrogen, and hydrogen contents decrease during successive activation steps, creating a nanoporous carbon network with a porosity and surface area controllable for various applications, including gas storage. The formation of tunable sub-nanometer and supra-nanometer pores is validated by sub-critical nitrogen adsorption. Surface functional groups of KOH activated carbon are studied by microscopic infrared spectroscopy.

  8. Carbon-Hydrogen and Carbon-Carbon Bond Activation of Cyclopropane by a Hydridotris(pyrazolyl)borate

    E-print Network

    Jones, William D.

    Carbon-Hydrogen and Carbon-Carbon Bond Activation of Cyclopropane by a Hydridotris and re-forming alkanes via carbon-carbon bond activation using heterogeneous catalysts is an important results in C-H activation of the hydrocarbon. The cyclopropyl hydride complex rearranges in benzene

  9. Organic solvent regeneration of granular activated carbon

    NASA Astrophysics Data System (ADS)

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

    1982-09-01

    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.

  10. Ozone-activated Carbon Mineralization of 17-?-Ethynylestradiol Aqueous Solutions

    Microsoft Academic Search

    F. J. Beltrán; P. Pocostales; P. Alvarez; A. Aguinaco

    2009-01-01

    Ozone and activated carbon (AC) have been used on the removal of 17?-ethynylestradiol (ETOL), a pharmaceutical compound, and its oxidation by-products. Although single ozonation is not able to totally remove the by-products formed from the degradation of the parent compound (about 65% of TOC removal at pH 7 after 2-hour reaction), the ozone\\/AC system led not only to higher TOC

  11. Antimicrobial activity of carbon-based nanoparticles.

    PubMed

    Maleki Dizaj, Solmaz; Mennati, Afsaneh; Jafari, Samira; Khezri, Khadejeh; Adibkia, Khosro

    2015-03-01

    Due to the vast and inappropriate use of the antibiotics, microorganisms have begun to develop resistance to the commonly used antimicrobial agents. So therefore, development of the new and effective antimicrobial agents seems to be necessary. According to some recent reports, carbon-based nanomaterials such as fullerenes, carbon nanotubes (CNTs) (especially single-walled carbon nanotubes (SWCNTs)) and graphene oxide (GO) nanoparticles show potent antimicrobial properties. In present review, we have briefly summarized the antimicrobial activity of carbon-based nanoparticles together with their mechanism of action. Reviewed literature show that the size of carbon nanoparticles plays an important role in the inactivation of the microorganisms. As major mechanism, direct contact of microorganisms with carbon nanostructures seriously affects their cellular membrane integrity, metabolic processes and morphology. The antimicrobial activity of carbon-based nanostructures may interestingly be investigated in the near future owing to their high surface/volume ratio, large inner volume and other unique chemical and physical properties. In addition, application of functionalized carbon nanomaterials as carriers for the ordinary antibiotics possibly will decrease the associated resistance, enhance their bioavailability and provide their targeted delivery. PMID:25789215

  12. Antimicrobial Activity of Carbon-Based Nanoparticles

    PubMed Central

    Maleki Dizaj, Solmaz; Mennati, Afsaneh; Jafari, Samira; Khezri, Khadejeh; Adibkia, Khosro

    2015-01-01

    Due to the vast and inappropriate use of the antibiotics, microorganisms have begun to develop resistance to the commonly used antimicrobial agents. So therefore, development of the new and effective antimicrobial agents seems to be necessary. According to some recent reports, carbon-based nanomaterials such as fullerenes, carbon nanotubes (CNTs) (especially single-walled carbon nanotubes (SWCNTs)) and graphene oxide (GO) nanoparticles show potent antimicrobial properties. In present review, we have briefly summarized the antimicrobial activity of carbon-based nanoparticles together with their mechanism of action. Reviewed literature show that the size of carbon nanoparticles plays an important role in the inactivation of the microorganisms. As major mechanism, direct contact of microorganisms with carbon nanostructures seriously affects their cellular membrane integrity, metabolic processes and morphology. The antimicrobial activity of carbon-based nanostructures may interestingly be investigated in the near future owing to their high surface/volume ratio, large inner volume and other unique chemical and physical properties. In addition, application of functionalized carbon nanomaterials as carriers for the ordinary antibiotics possibly will decrease the associated resistance, enhance their bioavailability and provide their targeted delivery. PMID:25789215

  13. 40 CFR 415.330 - Applicability; description of the carbon monoxide and by-product hydrogen production subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...of the carbon monoxide and by-product hydrogen production subcategory. 415.330...CATEGORY Carbon Monoxide and By-Product Hydrogen Production Subcategory § 415.330...of the carbon monoxide and by-product hydrogen production subcategory. The...

  14. Facile preparation of hierarchically porous carbon using diatomite as both template and catalyst and methylene blue adsorption of carbon products.

    PubMed

    Liu, Dong; Yuan, Peng; Tan, Daoyong; Liu, Hongmei; Wang, Tong; Fan, Mingde; Zhu, Jianxi; He, Hongping

    2012-12-15

    Hierarchically porous carbons were prepared using a facile preparation method in which diatomite was utilized as both template and catalyst. The porous structures of the carbon products and their formation mechanisms were investigated. The macroporosity and microporosity of the diatomite-templated carbons were derived from replication of diatom shell and structure-reconfiguration of the carbon film, respectively. The macroporosity of carbons was strongly dependent on the original morphology of the diatomite template. The macroporous structure composed of carbon plates connected by the pillar- and tube-like macropores resulted from the replication of the central and edge pores of the diatom shells with disk-shaped morphology, respectively. And another macroporous carbon tubes were also replicated from canoe-shaped diatom shells. The acidity of diatomite dramatically affected the porosity of the carbons, more acid sites of diatomite template resulted in higher surface area and pore volume of the carbon products. The diatomite-templated carbons exhibited higher adsorption capacity for methylene blue than the commercial activated carbon (CAC), although the specific surface area was much smaller than that of CAC, due to the hierarchical porosity of diatomite-templated carbons. And the carbons were readily reclaimed and regenerated. PMID:22999465

  15. Preparation of activated carbons from Spanish anthracite

    Microsoft Academic Search

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

    2001-01-01

    In a previous work, the use of a Spanish anthracite for the preparation of activated carbons by chemical activation was analyzed. The results indicated that this raw material is promising for that purpose. In the present paper, that previous work is extended and the effect of different preparation variables on the final porous texture is discussed, such as KOH\\/anthracite ratio,

  16. PYROGENIC ACTIVITY OF CARBON-FILTERED WATERS

    EPA Science Inventory

    The endotoxin content and pyrogenic response of granular activated carbon (GAC) filtered waters were studied. GAC-filtered secondary effluent from an activated sludge pilot plant contained free endotoxins in the range 6-250 micrograms/l yielding positive pyrogenic responses in 18...

  17. Vibration damping with active carbon fiber structures

    Microsoft Academic Search

    Reimund Neugebauer; Holger Kunze; Mathias Riedel; Hans-Jürgen Roscher

    2007-01-01

    This paper presents a mechatronic strategy for active reduction of vibrations on machine tool struts or car shafts. The active structure is built from a carbon fiber composite with embedded piezofiber actuators that are composed of piezopatches based on the Macro Fiber Composite (MFC) technology, licensed by NASA and produced by Smart Material GmbH in Dresden, Germany. The structure of

  18. Properties and degradability of hydrothermal carbonization products.

    PubMed

    Eibisch, Nina; Helfrich, Mirjam; Don, Axel; Mikutta, Robert; Kruse, Andrea; Ellerbrock, Ruth; Flessa, Heinz

    2013-09-01

    Biomass carbonized via hydrothermal carbonization (HTC) yields a liquid and a carbon (C)-rich solid called hydrochar. In soil, hydrochars may act as fertilizers and promote C sequestration. We assumed that the chemical composition of the raw material (woodchips, straw, grass cuttings, or digestate) determines the properties of the liquid and solid HTC products, including their degradability. Additionally, we investigated whether easily mineralizable organic components adsorbed on the hydrochar surface influence the degradability of the hydrochars and could be removed by repetitive washing. Carbon mineralization was measured as CO production over 30 d in aerobic incubation experiments with loamy sand. Chemical analysis revealed that most nutrients were preferably enriched in the liquid phase. The C mineralization of hydrochars from woodchips (2% of total C added), straw (3%), grass (6%), and digestate (14%) were dependent on the raw material carbonized and were significantly lower (by 60-92%; < 0.05) than the mineralization of the corresponding raw materials. Washing of the hydrochars significantly decreased mineralization of digestate-hydrochar (up to 40%) but had no effect on mineralization rates of the other three hydrochars. Variations in C mineralization between different hydrochars could be explained by multiple factors, including differences in the O/C-H/C ratios, C/N ratios, lignin content, amount of oxygen-containing functional groups, and pH. In contrast to the solids, the liquid products were highly degradable, with 61 to 89% of their dissolved organic C being mineralized within 30 d. The liquids may be treated aerobically (e.g., for nutrient recovery). PMID:24216434

  19. Preparation of activated carbons from bituminous coals with COâ activation. 1: Effects of oxygen content in raw coals

    Microsoft Academic Search

    H. Teng; J. A. Ho; Y. F. Hsu; C. T. Hsieh

    1996-01-01

    Activated carbons were prepared from three Australian bituminous coals in this study. The preparation process consisted of carbonization followed by activation in COâ. Experimental results reveal that the oxygen content of the coals has a great influence on the behavior during preparation and on the properties of the products. The coal with a higher O\\/C atomic ratio has a lower

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

    Microsoft Academic Search

    Aik Chong Lua; Jia Guo

    2001-01-01

    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.

  1. Preparation, characterization, and application of activated carbon membrane with carbon whiskers

    Microsoft Academic Search

    S. D. Bae; C. W. Lee; L. S. Kang; A. Sakoda

    2007-01-01

    A novel activated carbon membrane with carbon whiskers (W-ACM) for wastewater and drinking water treatments was designed and prepared. This membrane has carbon whiskers on its surface for preventing the deposition and accumulation of particles and has activated carbon layer below its carbon whiskers for the adsorption of dissolved organics. Adsorption capacity of the membrane was compared with a granular

  2. Modeling the selectivity of activated carbons for efficient separation of hydrogen and carbon dioxide

    E-print Network

    Wu, Jianzhong

    the separation of hydrogen and carbon dioxide via adsorption in activated carbons. In the simulations, both hydrogen and carbon dioxide molecules are modeled as Lennard-Jones spheres, and the activated carbons essentially no preference over the two gases and the selectivity of carbon dioxide relative to hydrogen falls

  3. Hydrogen storage on chemically activated carbons and carbon nanomaterials at high pressures

    Microsoft Academic Search

    M. Jordá-Beneyto; F. Suárez-García; D. Lozano-Castelló; D. Cazorla-Amorós; A. Linares-Solano

    2007-01-01

    Hydrogen adsorption measurements have been carried out at different temperatures (298K and 77K) and high pressure on a series of chemically activated carbons with a wide range of porosities and also on other types of carbon materials, such as activated carbon fibers, carbon nanotubes and carbon nanofibers. This paper provides a useful interpretation of hydrogen adsorption data according to the

  4. A novel activated carbon for supercapacitors

    SciTech Connect

    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

    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.

  5. Preparation and characterization of activated carbon from demineralized tyre char

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

    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.

  6. Waste management activities and carbon emissions in Africa

    SciTech Connect

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

    2011-01-15

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

  7. Treatment of potato processing wastewaters by activated carbon adsorption process

    Microsoft Academic Search

    Yung-Tse Hung

    1984-01-01

    A laboratory study was conducted to determine the effects of degrees of pretreatment, types of activated carbons, dosages\\u000a of activated carbons on the organic removal rates of potato processing wastewaters using the activated carbon adsorption process.\\u000a Primary treated effluents, and secondary treated effluents using activated sludge and powdered activated carbon activated\\u000a sludge processes were used as adsorbate in this study.

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

    SciTech Connect

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

    1999-11-01

    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.

  9. Drinking Water Treatment: Activated Carbon Filtration

    NSDL National Science Digital Library

    Divorak, Bruce I.

    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.

  10. Invertebrate colonization of granular activated carbon filters

    Microsoft Academic Search

    H. Schreiber; D. Schoenen; W. Traunspurger

    1997-01-01

    Results of biological sampling of granular activated carbon (GAC) filtrate taken between May 1994 and August 1995 at three different treatment plants along the river Rhine indicate that GAC filters are colonized by invertebrates. Dominating organism groups were rotifers and nematodes. Depending on operational characteristics, mainly regeneration intervals and backwashing procedures, the filter colonization can lead to an output of

  11. 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...

  12. 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...

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

    PubMed

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

    2007-06-01

    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

  14. Making Activated Carbon for Storing Gas

    NASA Technical Reports Server (NTRS)

    Wojtowicz, Marek A.; Serio, Michael A.; Suuberg, Eric M.

    2005-01-01

    Solid disks of microporous activated carbon, produced by a method that enables optimization of pore structure, have been investigated as means of storing gas (especially hydrogen for use as a fuel) at relatively low pressure through adsorption on pore surfaces. For hydrogen and other gases of practical interest, a narrow distribution of pore sizes <2 nm is preferable. The present method is a variant of a previously patented method of cyclic chemisorption and desorption in which a piece of carbon is alternately (1) heated to the lower of two elevated temperatures in air or other oxidizing gas, causing the formation of stable carbon/oxygen surface complexes; then (2) heated to the higher of the two elevated temperatures in flowing helium or other inert gas, causing the desorption of the surface complexes in the form of carbon monoxide. In the present method, pore structure is optimized partly by heating to a temperature of 1,100 C during carbonization. Another aspect of the method exploits the finding that for each gas-storage pressure, gas-storage capacity can be maximized by burning off a specific proportion (typically between 10 and 20 weight percent) of the carbon during the cyclic chemisorption/desorption process.

  15. Natural Product Polyamines That Inhibit Human Carbonic Anhydrases

    PubMed Central

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

    2014-01-01

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

  16. Active carbons impregnated before activation of olive stones: catalytic activity to remove benzene from gaseous emissions

    Microsoft Academic Search

    M. C. M. Alvim-Ferraz; C. M. T. B. Gaspar

    2004-01-01

    This work analyses the catalytic activity of impregnated active carbons prepared with olive stones to remove benzene from atmospheric emissions through catalytic complete oxidation. When the impregnation step is performed on the raw material or after activation, the influence of carbon texture on the catalyst dispersion and catalytic activity is already well studied. Nevertheless, when the impregnation step is performed

  17. TRANSITION METAL ACTIVATION AND FUNCTIONALIZATION OF CARBON-HYDROGEN BONDS

    E-print Network

    Jones, William D.

    TRANSITION METAL ACTIVATION AND FUNCTIONALIZATION OF CARBON-HYDROGEN BONDS William D. Jones-H and C-C bond functionalization, and (4) carbon-fluorine bond activation. We have made progress in each in our proposal where we have had success. These include: (1) carbon-carbon bond cleavage reactions, (2

  18. Catalytic carbon membranes for hydrogen production

    SciTech Connect

    Damle, A.S.; Gangwal, S.K.

    1992-01-01

    Commercial carbon composite microfiltration membranes may be modified for gas separation applications by providing a gas separation layer with pores in the 1- to 10-nm range. Several organic polymeric precursors and techniques for depositing a suitable layer were investigated in this project. The in situ polymerization technique was found to be the most promising, and pure component permeation tests with membrane samples prepared with this technique indicated Knudsen diffusion behavior. The gas separation factors obtained by mixed-gas permeation tests were found to depend strongly on gas temperature and pressure indicating significant viscous flow at high-pressure conditions. The modified membranes were used to carry out simultaneous water gas shift reaction and product hydrogen separation. These tests indicated increasing CO conversions with increasing hydrogen separation. A simple process model was developed to simulate a catalytic membrane reactor. A number of simulations were carried out to identify operating conditions leading to product hydrogen concentrations over 90 percent. (VC)

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

    Microsoft Academic Search

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

    1997-01-01

    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

  20. MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT

    SciTech Connect

    H.C. Maru; M. Farooque

    2003-03-01

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

  1. Molten Carbonate Fuel Cell Product Design Improvement

    SciTech Connect

    NONE

    1996-03-01

    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.

  2. 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...

  3. Photobiological hydrogen production and carbon dioxide sequestration

    NASA Astrophysics Data System (ADS)

    Berberoglu, Halil

    Photobiological hydrogen production is an alternative to thermochemical and electrolytic technologies with the advantage of carbon dioxide sequestration. However, it suffers from low solar to hydrogen energy conversion efficiency due to limited light transfer, mass transfer, and nutrient medium composition. The present study aims at addressing these limitations and can be divided in three parts: (1) experimental measurements of the radiation characteristics of hydrogen producing and carbon dioxide consuming microorganisms, (2) solar radiation transfer modeling and simulation in photobioreactors, and (3) parametric experiments of photobiological hydrogen production and carbon dioxide sequestration. First, solar radiation transfer in photobioreactors containing microorganisms and bubbles was modeled using the radiative transport equation (RTE) and solved using the modified method of characteristics. The study concluded that Beer-Lambert's law gives inaccurate results and anisotropic scattering must be accounted for to predict the local irradiance inside a photobioreactor. The need for accurate measurement of the complete set of radiation characteristics of microorganisms was established. Then, experimental setup and analysis methods for measuring the complete set of radiation characteristics of microorganisms have been developed and successfully validated experimentally. A database of the radiation characteristics of representative microorganisms have been created including the cyanobacteria Anabaena variabilis, the purple non-sulfur bacteria Rhodobacter sphaeroides and the green algae Chlamydomonas reinhardtii along with its three genetically engineered strains. This enabled, for the first time, quantitative assessment of the effect of genetic engineering on the radiation characteristics of microorganisms. In addition, a parametric experimental study has been performed to model the growth, CO2 consumption, and H 2 production of Anabaena variabilis as functions of irradiance and CO2 concentration. Kinetic models were successfully developed based on the Monod model and on a novel scaling analysis employing the CO2 consumption half-time as the time scale. Finally, the growth and hydrogen production of Anabaena variabilis have been compared in a flat panel photobioreactor using three different nutrient media under otherwise similar conditions. Light to hydrogen energy conversion efficiency for Allen-Arnon medium was superior by a factor of 5.5 to both BG-11 and BG-11o media. This was attributed to the presence of vanadium and larger heterocyst frequency observed in the Allen-Arnon medium.

  4. Production of carbon molecular sieves from Illinois coal

    USGS Publications Warehouse

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

    1993-01-01

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

  5. Suppression of carbon deposition in the iron-catalyzed production of lower olefins from synthesis gas.

    PubMed

    Koeken, Ard C J; Torres Galvis, Hirsa M; Davidian, Thomas; Ruitenbeek, Matthijs; de Jong, Krijn P

    2012-07-16

    Pressure leverage: A tapered-element oscillating microbalance was used to evaluate carbon deposition on a highly selective and active supported iron catalyst for the production of lower olefins. With increasing pressure, the H(2)/CO ratio had a profound effect on the carbon deposition rate and accordingly, conditions leading to minimal carbon deposition, low methane selectivity, and high olefin selectivity were identified. PMID:22693165

  6. REMOVAL OF DYE BY IMMOBILISED PHOTOCATALYST LOADED ACTIVATED CARBON

    Microsoft Academic Search

    Zulkarnain Zainal; Chang Sook Keng; Abdul Halim Abdullah

    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

  7. Textural characterization of active carbons using fractal analysis

    Microsoft Academic Search

    Manuel María Mahamud

    2006-01-01

    This study continues a previous work aiming to explore how fractal analysis may help to understand the textural changes of materials during the manufacture of active carbons. Textural characterization of active carbons is carried out in order to obtain a better understanding of the facts underlying char gasification. The materials selected for study were a series of active carbons obtained

  8. Less-costly activated carbon for sewage treatment

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

    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.

  9. Sorption of heavy metal cations on activated carbon

    Microsoft Academic Search

    Wilczak

    1988-01-01

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

  10. The production of carbon nanotubes from carbon dioxide: challenges and opportunities

    Microsoft Academic Search

    Geoffrey S. Simate; Sunny E. Iyuke; Sehliselo Ndlovu; Clarence S. Yah; Lubinda F. Walubita

    2010-01-01

    Recent advances in the production of carbon nanotubes (CNTs) are reviewed with an emphasis on the use of carbon dioxide (CO2) as a sole source of carbon. Compared to the most widely used carbon precursors such as graphite, methane, acetylene, ethanol, ethylene, and coal-derived hydrocarbons, CO2 is competitively cheaper with relatively high carbon yield content. However, CNT synthesis from CO2

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

    NASA Astrophysics Data System (ADS)

    Qin, Nan

    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.

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

    SciTech Connect

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

    2010-12-01

    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.

  13. Steam and KOH Activated Carbons from Peach Stones

    Microsoft Academic Search

    D. Durano?lu; Ü. Beker

    2012-01-01

    Peach-stone-based activated carbons were prepared by using steam and KOH activation at 800°C. The effects of solid\\/liquid phase KOH and steam activation, alkali and acidic pre-treatment, and also single-step activation on activated carbon properties were investigated comprehensively. The activated carbon produced by solid phase KOH impregnation showed the highest surface area of 835 m\\/g and micropore volume of 0.412 cm\\/g.

  14. Activated carbons from potato peels: The role of activation agent and carbonization temperature of biomass on their use as sorbents for bisphenol A uptake from aqueous solutions

    NASA Astrophysics Data System (ADS)

    Arampatzidou, An; Deliyanni, Eleni A.

    2015-04-01

    Activated carbons prepared from potato peels, a solid waste by product, and activated with different activating chemicals, have been studied for the adsorption of an endocrine disruptor (Bisphenol-A) from aqueous solutions. The potato peels biomass was activated with phosphoric acid, KOH and ZnCl2. The different activating chemicals were tested in order the better activation agent to be found. The carbons were carbonized by pyrolysis, in one step procedure, at three different temperatures in order the role of the temperature of carbonization to be pointed out. The porous texture and the surface chemistry of the prepared activated carbons were characterized by Nitrogen adsorption (BET), Scanning Electron Microscope (SEM), thermal analysis (DTA) and Fourier Transform Infrared Spectroscopy (FTIR). Batch experiments were performed to investigate the effect of pH, the adsorbent dose, the initial bisphenol A concentration and temperature. Equilibrium adsorption data were analyzed by Langmuir and Freundlich isotherms. The thermodynamic parameters such as the change of enthalpy (?H0), entropy (?S0) and Gibb's free energy (?G0) of adsorption systems were also evaluated. The adsorption capacity calculated from the Langmuir isotherm was found to be 450 mg g-1 at an initial pH 3 at 25 °C for the phosphoric acid activated carbon, that make the activated carbon a promising adsorbent material.

  15. Preparation of microfibrous entrapped activated carbon composite

    Microsoft Academic Search

    Huiping Zhang; Lianlian Gao; Xijun Hu

    2009-01-01

    A kind of microfibrous entrapped activated carbon composites were prepared by the wet lay-up paper-making process followed by sintering in N2 at 950°C for 30min. SEM and ASAP 2020 apparatus were used to characterize the structure and test the adsorption isotherm. SEM results indicated that the junctures of the ceramic fiber were completely welded together to cause a sinter-locked three-dimensional

  16. Adsorption of chlorophenols on granular activated carbon

    SciTech Connect

    Yang, M.

    1993-12-31

    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.

  17. Preparation of high surface area activated carbon from corn by chemical activation using potassium hydroxide

    Microsoft Academic Search

    Narges Bagheri; Jalal Abedi

    2009-01-01

    Activated carbons were prepared through chemical activation of corn cob precursor, using potassium hydroxide as the chemical agent. The effect of different parameters, such as particle size, method of mixing, chemical\\/corn ratio, activation time and activation temperature, on weight loss and BET surface area of the produced activated carbons were discussed. The porosity of the activated carbons was evaluated through

  18. Aqueous mercury adsorption by activated carbons.

    PubMed

    Hadi, Pejman; To, Ming-Ho; Hui, Chi-Wai; Lin, Carol Sze Ki; McKay, Gordon

    2015-04-15

    Due to serious public health threats resulting from mercury pollution and its rapid distribution in our food chain through the contamination of water bodies, stringent regulations have been enacted on mercury-laden wastewater discharge. Activated carbons have been widely used in the removal of mercuric ions from aqueous effluents. The surface and textural characteristics of activated carbons are the two decisive factors in their efficiency in mercury removal from wastewater. Herein, the structural properties and binding affinity of mercuric ions from effluents have been presented. Also, specific attention has been directed to the effect of sulfur-containing functional moieties on enhancing the mercury adsorption. It has been demonstrated that surface area, pore size, pore size distribution and surface functional groups should collectively be taken into consideration in designing the optimal mercury removal process. Moreover, the mercury adsorption mechanism has been addressed using equilibrium adsorption isotherm, thermodynamic and kinetic studies. Further recommendations have been proposed with the aim of increasing the mercury removal efficiency using carbon activation processes with lower energy input, while achieving similar or even higher efficiencies. PMID:25644627

  19. Elastic Pore Structure in Activated Carbon

    NASA Astrophysics Data System (ADS)

    Connolly, M. J.; Wexler, Carlos

    2011-11-01

    Adsorbent materials such as activated carbon and Metal-Organic Frameworks (MOFs) have received significant attention as a potential storage material for hydrogen and natural gas. Typically the adsorbent material is assumed to consist of rigid slit- or cylindrical-shaped pores. Recent work, for MOFs in particular, revealed the importance of the mechanical response of the adsorbent in the presence of an adsorbate. In the absence of an adsorbate the pore structure is defined by the size, shape and inter-molecular interactions of the constituent parts of the solid. Here, we demonstrate the flexibility of pore walls in activated carbon and the effect this has on the pore structure of the bulk samples. The interaction is modeled as a competition between Van der Waals interactions between neighboring walls and a resistance to bending due to the rigidity of graphene. Minimal energy configurations were calculated analytically for a simplified potential and numerically for a more realistic potential. The pore structures are discussed in the context of pore measurements on activated carbon samples.

  20. Production of carbon molecular sieves from illinois coals. An assessment

    USGS Publications Warehouse

    Lizzio, Anthony A.; Rostam-Abadi, Massoud

    1991-01-01

    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.

  1. Production of carbon isotopes by laser separation

    NASA Astrophysics Data System (ADS)

    Baranov, Vladimir Y.; Dyad'kin, A. P.; Maluta, D. D.; Kuzmenko, V. A.; Pigulskiy, S. V.; Mezhevov, Vladimir S.; Letokhov, Vladilen S.; Laptev, Vladimir B.; Ryabov, Evgeny A.; Yarovoi, I. V.; Zarin, V. B.; Podoryashy, A. S.

    2000-07-01

    Since the advent of lasers, these unique sources of highly intense and monochromatic radiation have been proposed as excellent tools to induce or catalyze chemical reactions. Due to the great interest to the problem of isotope production, investigation and application, the laser method of isotope separation has received the most attention worldwide and may be the first major commercial application of lasers to chemistry. Laser methods of isotope separation are based on high selectivity and power of laser sources of radiation. One of the most prominent method is based on the effect is isotope-selective multiphoton dissociation of molecules by IR-radiation (MLIS-method). This phenomena was discovered in Russia in 1974 and developed from scientific investigations to industrial scale production of 13C isotopes in collaboration between the Kurchatov Institute of Atomic Energy, TRINITI and Institute of Spectroscopy of RAS. Demonstration facilities for sulfur and carbon isotope separation with average productivity up to 2 g/h have been created as a result of collaboration and these systems are aimed at optimization of MLIS process and evaluation of its cost efficiency. Experiments show that laser produced isotopes are far cheaper as compared to any conventional technique. Results of basic scientific research, existing technological cooperation allow to start building a laser isotope separation plant. Light element isotopes produced there can answer a wide variety of demands in many technologies. These isotopes can be readily used in medicine, agriculture, environmental monitoring, etc.

  2. Nonclassical activation of carbon monoxide by organoactinides

    SciTech Connect

    Marks, T.J. (Northwestern Univ., Evanston, Il); Manriquez, J.M.; Fagan, P.J.; Day, V.W.; Day, C.S.; Vollmer, S.H.

    1980-01-01

    This article reviews recent results on the carbonylation chemistry of bis(pentamethylcyclopentadienyl) thorium and uranium hydrocarbyl and dialkylamide complexes. Facile migratory insertion of carbon monoxide into metal-carbon and metal-nitrogen bonds is observed. In several cases bihaptoacyl and bihaptocarbamoyl complexes were isolated and characterized by single crystal x-ray diffraction. The great strength of the metal-oxygen bonding in these species is evident in metrical and spectral data, as well as in the reaction chemistry, which is decidedly alkoxycarbene-like. In the case of the bis(pentamethylcyclopentadienyl) actinide dialkyls, the final carbonylation products are C-C coupled cis-1,2-enediolate complexes, while for the corresponding bis(dialkylamides), the products are bis(carbamoyl) species. Both types of compound have been characterized by x-ray diffraction. The carbon monoxide chemistry observed here may be of relevance to mechanistic discussions of catalytic CO reduction, especially that involving actinide oxide or actinide oxide supported catalysts.

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

    PubMed Central

    2012-01-01

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

  4. Preparing and characterizing the active carbon produced by steam and carbon dioxide as a heavy oil hydrocracking catalyst support

    Microsoft Academic Search

    Hidetsugu Fukuyama; Satoshi Terai

    2008-01-01

    Active carbon was prepared from Yallourn brown coal char using steam and carbon dioxide activation in a laboratory rotary kiln. The activation rate with steam was faster than that with carbon dioxide. The pore structure of the active carbons was characterized using the nitrogen isotherms at 77K. The pore volume and specific surface area of the active carbon increased with

  5. Product Carbon Footprints and Their Uncertainties in Comparative Decision Contexts

    PubMed Central

    Dao, Hai M.; Phan, Lam T.; de Snoo, Geert R.

    2015-01-01

    In response to growing awareness of climate change, requests to establish product carbon footprints have been increasing. Product carbon footprints are life cycle assessments restricted to just one impact category, global warming. Product carbon footprint studies generate life cycle inventory results, listing the environmental emissions of greenhouse gases from a product’s lifecycle, and characterize these by their global warming potentials, producing product carbon footprints that are commonly communicated as point values. In the present research we show that the uncertainties surrounding these point values necessitate more sophisticated ways of communicating product carbon footprints, using different sizes of catfish (Pangasius spp.) farms in Vietnam as a case study. As most product carbon footprint studies only have a comparative meaning, we used dependent sampling to produce relative results in order to increase the power for identifying environmentally superior products. We therefore argue that product carbon footprints, supported by quantitative uncertainty estimates, should be used to test hypotheses, rather than to provide point value estimates or plain confidence intervals of products’ environmental performance. PMID:25781175

  6. Investigation kinetics mechanisms of adsorption malachite green onto activated carbon

    Microsoft Academic Search

    Y. Önal; C. Akmil-Ba?ar; Ç. Sar?c?-Özdemir

    2007-01-01

    Lignite was used to prepare activated carbon (T3K618) by chemical activation with KOH. Pore properties of the activated carbon such as BET surface area, pore volume, pore size distribution, and pore diameter were characterized by t-plot based on N2 adsorption isotherm. BET surface area of activated carbon is determined as 1000m2\\/g. Adsorption capacity of malachite green (MG) onto T3K618 activated

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

    Microsoft Academic Search

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

    2003-01-01

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

  8. Effect of Chemical Modification of Walnut Shell on the Yield and Pore Structure of Activated Carbon

    Microsoft Academic Search

    A. A. Bagreev; A. P. Broshnik; V. V. Strelko; Yu. A. Tarasenko

    2001-01-01

    The effect of walnut shell treatment with solutions of inorganic salts prior to carbonization on the yield and properties of the obtained activated carbon was studied. The possibility of controlling the pore structure of the products in thermal treatment is demonstrated.

  9. Analysis of Pion Production Near Threshold for Carbon and Helium

    E-print Network

    Saskatchewan, University of

    Analysis of Pion Production Near Threshold for Carbon and Helium Michael Barnett Subatomic Physics- der, energy dependent correction factor for pion photoproduction from nuclei, specifically helium and carbon. This was done by examining the pion production cross section at energies within about 25 Me

  10. Fossil-fuel carbon emission control in irrigated maize production

    Microsoft Academic Search

    B. D. Wind; W. W. Wallender

    1997-01-01

    To evaluate optimal management strategies which reduce fossil-fuel carbon emissions, an idealized gross returns objective function was developed for the production of irrigated maize with the inclusion of a disincetive carbon-taxing term. The gross returns objective function is multivariant and optimized through a gradient search procedure. Carbon emissions emanating from maize production stem from the utilization of fossil-fuel energy on

  11. Comparison of adsorption behavior of PCDD/Fs on carbon nanotubes and activated carbons in a bench-scale dioxin generating system.

    PubMed

    Zhou, Xujian; Li, Xiaodong; Xu, Shuaixi; Zhao, Xiyuan; Ni, Mingjiang; Cen, Kefa

    2015-07-01

    Porous carbon-based materials are commonly used to remove various organic and inorganic pollutants from gaseous and liquid effluents and products. In this study, the adsorption of dioxins on both activated carbons and multi-walled carbon nanotube was internally compared, via series of bench scale experiments. A laboratory-scale dioxin generator was applied to generate PCDD/Fs with constant concentration (8.3 ng I-TEQ/Nm(3)). The results confirm that high-chlorinated congeners are more easily adsorbed on both activated carbons and carbon nanotubes than low-chlorinated congeners. Carbon nanotubes also achieved higher adsorption efficiency than activated carbons even though they have smaller BET-surface. Carbon nanotubes reached the total removal efficiency over 86.8 % to be compared with removal efficiencies of only 70.0 and 54.2 % for the two other activated carbons tested. In addition, because of different adsorption mechanisms, the removal efficiencies of carbon nanotubes dropped more slowly with time than was the case for activated carbons. It could be attributed to the abundant mesopores distributed in the surface of carbon nanotubes. They enhanced the pore filled process of dioxin molecules during adsorption. In addition, strong interactions between the two benzene rings of dioxin molecules and the hexagonal arrays of carbon atoms in the surface make carbon nanotubes have bigger adsorption capacity. PMID:25728198

  12. Activated carbon and tungsten oxide supported on activated carbon catalysts for toluene catalytic combustion.

    PubMed

    Alvarez-Merino, M A; Ribeiro, M F; Silva, J M; Carrasco-Marín, F; Maldonado-Hódar, F J

    2004-09-01

    We have used activated carbon (AC) prepared from almond shells as a support for tungsten oxide to develop a series of WOx/AC catalysts for the catalytic combustion of toluene. We conducted the reaction between 300 and 350 degrees C, using a flow of 500 ppm of toluene in air and space velocity (GHSV) in the range 4000-7000 h(-1). Results show that AC used as a support is an appropriate material for removing toluene from dilute streams. By decreasing the GHSV and increasing the reaction temperature AC becomes a specific catalyst for the total toluene oxidation (SCO2 = 100%), but in less favorable conditions CO appears as reaction product and toluene-derivative compounds are retained inside the pores. WOx/AC catalysts are more selective to CO2 than AC due to the strong acidity of this oxide; this behavior improves with increased metal loading and reaction temperature and contact time. The catalytic performance depends on the nonstoichiometric tungsten oxide obtained during the pretreatment. In comparison with other supports the WOx/AC catalysts present, at low reaction temperatures, higher activity and selectivity than WO, supported on SiO2, TiO2, Al2O3, or Y zeolite. This is due to the hydrophobic character of the AC surface which prevents the adsorption of water produced from toluene combustion thus avoiding the deactivation of the active centers. However, the use of WOx/AC system is always restricted by its gasification temperature (around 400 degrees C), which limits the ability to increase the conversion values by increasing reaction temperatures. PMID:15461177

  13. Preparation of activated carbons from bituminous coal pitches

    Microsoft Academic Search

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

    2004-01-01

    High-porosity carbons were prepared from bituminous coal pitches by combining chemical and physical activation. The chemical activation process consisted of potassium hydroxide impregnation followed by carbonization in nitrogen atmosphere. The effect of the KOH impregnation ratio on the surface area and pore volumes evolution of the carbons derived from mesophase pitch was studied. The optimum KOH:pitch ratio was fixed to

  14. ENTRAINED-FLOW ADSORPTION OF MERCURY USING ACTIVATED CARBON

    EPA Science Inventory

    Bench-scale experiments were conducted in a flow reactor to simulate entrained-flow capture of elemental mercury (Hg) by activated carbon. Adsorption of Hg by several commercial activated carbons was examined at different carbon-to-mercury (C:Hg) ratios (by weight) (600:1 - 29000...

  15. 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...

  16. Vibration damping with active carbon fiber structures

    NASA Astrophysics Data System (ADS)

    Neugebauer, Reimund; Kunze, Holger; Riedel, Mathias; Roscher, Hans-Jürgen

    2007-04-01

    This paper presents a mechatronic strategy for active reduction of vibrations on machine tool struts or car shafts. The active structure is built from a carbon fiber composite with embedded piezofiber actuators that are composed of piezopatches based on the Macro Fiber Composite (MFC) technology, licensed by NASA and produced by Smart Material GmbH in Dresden, Germany. The structure of these actuators allows separate or selectively combined bending and torsion, meaning that both bending and torsion vibrations can be actively absorbed. Initial simulation work was done with a finite element model (ANSYS). This paper describes how state space models are generated out of a structure based on the finite element model and how controller codes are integrated into finite element models for transient analysis and the model-based control design. Finally, it showcases initial experimental findings and provides an outlook for damping multi-mode resonances with a parallel combination of resonant controllers.

  17. Beneficial Use of Carbon Dioxide in Precast Concrete Production

    SciTech Connect

    Shao, Yixin

    2014-03-31

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

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

    NSDL National Science Digital Library

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

  19. Charcoal and activated carbon at elevated pressure

    SciTech Connect

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

    1995-12-01

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

  20. 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...

  1. Quality of poultry litter-derived granular activated carbon

    Microsoft Academic Search

    Guannan Qiu; Mingxin Guo

    2010-01-01

    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

  2. Prevention of microparticle blocking in activated carbon membrane filtration with carbon whisker

    Microsoft Academic Search

    Sang-Dae Bae; Masaki Sagehashi; Akiyoshi Sakoda

    2005-01-01

    We have developed activated carbon membranes (ACM) that can remove not only particulate matters but also dissolved organic matters. Recently, we succeeded in growing carbon whiskers on activated carbon membranes (W-ACM). We hypothesize that the whiskers prevent the flux from lowering due to particle blocking on the membrane surface. In this study, we compared the filtration properties and blocking characteristics

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

    Microsoft Academic Search

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

    2007-01-01

    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

  4. Selecting activated carbon for water and wastewater treatability studies

    Microsoft Academic Search

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

    2007-01-01

    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

  5. Photorespiration and Carbon Limitation Determine Productivity in Temperate Seagrasses

    PubMed Central

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

    2013-01-01

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

  6. Photorespiration and carbon limitation determine productivity in temperate seagrasses.

    PubMed

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

    2013-01-01

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

  7. Active carbon filter health condition detection with piezoelectric wafer active sensors

    E-print Network

    Giurgiutiu, Victor

    ) and electrochemical impedance spectroscopy (ECIS). ECIS is currently being used to evaluate active carbon filtration the filtration performance. Hence, methods are sought to detect the degradation of impregnated active carbonActive carbon filter health condition detection with piezoelectric wafer active sensors Jingjing

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

    SciTech Connect

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

    1982-03-01

    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.

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

    PubMed

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

    2008-01-01

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

  10. 40 CFR 415.300 - Applicability; description of the calcium carbonate production subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...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....

  11. 40 CFR 415.300 - Applicability; description of the calcium carbonate production subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...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....

  12. 40 CFR 415.300 - Applicability; description of the calcium carbonate production subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...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....

  13. 40 CFR 415.300 - Applicability; description of the calcium carbonate production subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...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....

  14. 40 CFR 415.300 - Applicability; description of the calcium carbonate production subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...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....

  15. Catalytic ozonation of p-chlorobenzoic acid by activated carbon and nickel supported activated carbon prepared from petroleum coke

    Microsoft Academic Search

    Xukai Li; Qiuyun Zhang; Lili Tang; Ping Lu; Fengqiang Sun; Laisheng Li

    2009-01-01

    The aim of this research was to investigate catalytic activity of petroleum coke, activated carbon (AC) prepared from this material, Ni supported catalyst on activated carbon (Ni\\/AC) in the ozonation of aqueous phase p-chlorobenzoic acid (p-CBA). Activated carbon and Ni\\/AC catalyst were characterized by XRD and SEM. The presence of petroleum coke did not improve the degradation of p-CBA compared

  16. Siberian anthracite as a precursor material for microporous activated carbons

    Microsoft Academic Search

    Piotr Nowicki; Robert Pietrzak; Helena Wachowska

    2008-01-01

    The technology of obtaining active carbon from anthracite mined in Siberia is described. The effect of the activating agent, anthracite\\/activator ratio and activation temperature has been tested. The activation either with KOH or NaOH has been found to lead to microporous active carbon samples of well-developed surface area reaching from 588 to 2260m2\\/g and pore volume from 0.29 to 1.12m3\\/g.

  17. Lignin peroxidase and protease production by Streptomyces viridosporus T7A in the presence of calcium carbonate. Nutritional and regulatory carbon sources.

    PubMed

    Macedo, J M; Gottschalk, L M; Bon, E P

    1999-01-01

    Streptomyces are good producers of enzymes of industrial interest, such as lignin peroxidase (LiP) and proteases. To optimize production of these enzymes by Streptomyces viridosporus T7A, two parameters were evaluated: carbon sources and calcium carbonate. Shake-flask fermentations were performed using culture media, with and without CaCO3, contained yeast extract, mineral salts and either glucose, lactose, galactose, or corn oil. In the absence of calcium carbonate, the maximum values for LiP and protease activities occurred during the idiophase with LiP activity being favored by glucose, corn oil, and galactose, and protease activity being favored only by corn oil. Calcium carbonate affected the cell morphology by reducing the size of the pellets. Moreover, in the presence of the salt, LiP production was growth-associated in all media but the glucose medium. Higher enzyme levels were observed when galactose and glucose were used as carbon sources. Protease activity was repressed by both glucose and galactose, whereas corn oil was the best carbon source for the enzyme production. Calcium carbonate increased LiP production by up to 2.6-fold. Such improvement was not observed for protease production, suggesting a selective effect of CaCO3 on LiP activity. PMID:15304693

  18. Active carbons and clean briquettes from the modified Kansk-Achinsk brown coal

    SciTech Connect

    Kuznetsov, P.N.; Kuznetsova, L.I. [Russian Academy of Sciences, Krasnoyarsk (Russian Federation); Kontzevoi, A.A.; Pozharnikov, V.A. [Ministry of Fuel and Energetics, Krasnoyarsk (Russian Federation)

    1996-12-31

    The effect of modification of Kansk Achinsk Brown coal by means of chemical and mechanical pretreatments as well as by hydrolyzed lignin addition on coal briquetting was studied. Coal briquettes were then pyrolyzed and steam activated at 700--800 C to prepare the active carbons. The main focus was to analyze how macromolecular structure of brown coal affect the properties of briquettes and the sorption and mechanical properties of activated carbons and to investigate the potential for the production of clean briquetted fuel and high performance carbon adsorbents through the directive modification of coal.

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

    PubMed

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

    2013-01-01

    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

  20. PRODUCTION AND SCREENING OF CARBON PRODUCTS PRECURSORS FROM COAL

    SciTech Connect

    Caulton L. Irwin

    2001-05-31

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

  1. Universal Product Design: Transforming User Activity Into Product Function 

    E-print Network

    Kostovich, Vincent

    2010-07-14

    model for each product in the product pair were the design tools used for this comparison. User activities were used to cluster product function changes. In addition, design changes such as functional, morphological and parametric were identified between...

  2. Operation of Membrane Bioreactor with Powdered Activated Carbon Addition

    Microsoft Academic Search

    Choon Aun Ng; Darren Sun; Anthony G. Fane

    2006-01-01

    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

  3. Colonization of Biological Activated Carbon in Drinking Water Purification

    Microsoft Academic Search

    He Wang; Zhonglin Chen; Jimin Shen; Feifei Xiang; Yu Liu; Xu Zhai; Yue Liu

    2010-01-01

    The colonization of columnar activated carbon was developed. Some analysis of several physical–chemical, biochemical and microbiological methods (indicators) used to characterize the BAC biofilm's composition and activity was provided. The filtration column filled with columnar activated carbon was operated incessantly for 72 days in the condition of natural colonization in a dynamic flow and poor nutritional status. The mature biofilm

  4. 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...

  5. High Surface Area Activated Carbon from Waste Biomass

    Microsoft Academic Search

    C. Srinivasakannan

    The present work relates to efforts made towards developing a high surface area, activated carbon from rubber wood sawdust by a two-stage activation process with phosphoric acid as the activating agent. Experiments are conducted in lab scale using muffle furnace under static conditions in a self-generated atmosphere covering process parameters such as impregnation ratio, carbonization time and temperature. The process

  6. Preparation of silicon-carbide-coated activated carbon using a high-temperature fluidized bed reactor

    Microsoft Academic Search

    J. E. Atwater; J. R. Akse; T.-C. Wang; S. Kimura; D. C. Johnson

    2001-01-01

    Chemically and thermally stable high surface area catalyst supports are needed to facilitate a vast array of chemical reactions. One approach is to augment an otherwise vulnerable high surface area material such as activated carbon with a robust surface coating. Here a high-temperature fluidized bed reactor-based method for the production of silicon-carbide-(SiC) coated activated carbon is described. At 1350°C, gaseous

  7. Aqueous-phase adsorption of glycerol and propylene glycol onto activated carbon

    Microsoft Academic Search

    Lars Peereboom; Benjamin Koenigsknecht; Margaret Hunter; James E. Jackson; Dennis J. Miller

    2007-01-01

    Adsorption of reactant and product species can have a major effect on local pore concentrations in activated carbon-supported metal catalysts. Individual and combined adsorption of glycerol (GO) and propylene glycol (PG) onto activated carbon in aqueous solution is reported here at concentration ranges of 0.05–2.0M and temperatures from 25°C to 160°C. Langmuir and Freundlich isotherms are used to model the

  8. Adsorption of chromium by activated carbon from aqueous solution

    Microsoft Academic Search

    Diksha Aggarwal; Meenakshi Goyal; R. C. Bansal

    1999-01-01

    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

  9. Preparation of nitrogen-enriched activated carbons from brown coal

    Microsoft Academic Search

    Robert Pietrzak; Helena Wachowska; Piotr Nowicki

    2006-01-01

    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

  10. Phenol Adsorption in Immobilized Activated Carbon with Alginate Gels

    Microsoft Academic Search

    Y. Jodra; F. Mijangos

    2003-01-01

    Calcium alginate-activated carbon composites were used for phenol adsorption from aqueous solutions. These composites were prepared by mixing different amounts of powdered activated carbon with a 3% (w\\/v) sodium alginate solution, and then dripping the mix into a calcium solution. Spherical beads were obtained with different amounts of powder-activated carbon immobilized inside the calcium alginate matrix. The adsorption on immobilized

  11. Forest and wood products role in carbon sequestration

    SciTech Connect

    Sampson, R.N.

    1997-12-31

    An evaluation of the use of U.S. forests and forest products for carbon emission mitigation is presented. The current role of forests in carbon sequestration is described in terms of regional differences and forest management techniques. The potential for increasing carbon storage by converting marginal crop and pasture land, increasing timberland growth, reducing wildfire losses, and changing timber harvest methods is examined. Post-harvest carbon flows, environmental impacts of wood products, biomass energy crops, and increased use of energy-conserving trees are reviewed for their potential in reducing or offsetting carbon emissions. It is estimated that these techniques could offset 20 to 40 percent of the carbon emitted annually in the U.S. 39 refs., 5 tabs.

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

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

    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.

  13. A model of carbon storage in forests and forest products.

    PubMed

    Dewar, R C

    1990-12-01

    This paper discusses the general formulation of a model that describes carbon storage in a forest and its timber products as a function of the forest growth curve, the rotation period and the carbon retention curves for the timber products. After a number of rotations, the rotation-averaged quantity of stored carbon approaches an asymptotic value. It is shown that, when forests are managed for maximum sustained yield of biomass, the contribution to asymptotic carbon storage from timber products is about 2.5D/T* times the contribution from living trees, where D is the characteristic decay time for reconversion of timber products to carbon dioxide, and T* is the normal rotation period for maximum sustained yield. For a given value of D/T*, carbon storage can be optimized if the policy of maximizing sustained yield is relaxed. For D/T* < 1, as the rotation period is increased indefinitely, the asymptotic level of carbon storage increases monotonically toward the value of the carbon content of living trees at maturity, g(f). For D/T* > 1, there is a finite, optimal rotation period, T(o), greater than T*, for which asymptotic carbon storage is greater than g(f). As D/T* tends to large values, however, T(o) tends to T*, so that, in this limit, management for maximum sustained yield also ensures maximum carbon storage. From initial planting, the time taken to reach asymptotic carbon storage decreases as the normal rotation period, T*, decreases, but increases almost linearly with increasing decay time of timber products, D. This result qualifies the short-term value of any particular planting strategy. PMID:14972933

  14. Adsorption of natural gas and biogas components on activated carbon

    Microsoft Academic Search

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

    2008-01-01

    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

  15. Enhanced Cellular Activation with Single Walled Carbon Nanotube Bundles

    E-print Network

    Fahmy, Tarek

    focused on new methods of biochemical functionalization of carbon nano- tubes using various proteinsEnhanced Cellular Activation with Single Walled Carbon Nanotube Bundles Presenting Antibody Stimuli the body using single walled carbon nanotube (SWNT) bundles presenting antibody stimuli. Owing to the large

  16. MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT

    SciTech Connect

    H.C. Maru; M. Farooque

    2005-03-01

    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.

  17. Active Carbon and Oxygen Shell Burning Hydrodynamics

    E-print Network

    Casey Meakin; David Arnett

    2006-01-16

    We have simulated 2.5$\\times10^3$ s of the late evolution of a $23 \\rm M_\\odot$ star with full hydrodynamic behavior. We present the first simulations of a multiple-shell burning epoch, including the concurrent evolution and interaction of an oxygen and carbon burning shell. In addition, we have evolved a 3D model of the oxygen burning shell to sufficiently long times (300 s) to begin to assess the adequacy of the 2D approximation. We summarize striking new results: (1) strong interactions occur between active carbon and oxygen burning shells, (2) hydrodynamic wave motions in nonconvective regions, generated at the convective-radiative boundaries, are energetically important in both 2D and 3D with important consequences for compositional mixing, and (3) a spectrum of mixed p- and g-modes are unambiguously identified with corresponding adiabatic waves in these computational domains. We find that 2D convective motions are exaggerated relative to 3D because of vortex instability in 3D. We discuss the implications for supernova progenitor evolution and symmetry breaking in core collapse.

  18. Oxygen-alkylation of carbonous material and products thereof

    SciTech Connect

    Liotta, R.

    1981-11-17

    Disclosed is a method for improving the properties of carbonous materials and products thereof by oxygen-alkylation. The carbonous material is treated with a quaternary base then heated to temperatures from about 100/sup 0/C. to 400/sup 0/ C.

  19. Active carbon filter health condition detection with piezoelectric wafer active sensors

    Microsoft Academic Search

    Jingjing Bao; Victor Giurgiutiu; Glenn O. Rubel; Gregory W. Peterson; Thomas M. Ball

    2011-01-01

    The impregnated active carbon used in air purification systems degrades over time due to exposure to contamination and mechanical effects (packing, settling, flow channeling, etc.). A novel approach is proposed to detect contamination in active carbon filters by combining the electromechanical impedance spectroscopy (EMIS) and electrochemical impedance spectroscopy (ECIS). ECIS is currently being used to evaluate active carbon filtration material;

  20. Sorption properties of active carbons obtained from walnut shells by chemical and physical activation

    Microsoft Academic Search

    Piotr Nowicki; Robert Pietrzak; Helena Wachowska

    2010-01-01

    A technology of obtaining active carbon from common walnut shells is described. The effect of activation methods, temperature and heating mode on the surface properties has been tested. The resulting carbons were characterised by elemental analysis, low-temperature nitrogen sorption and determination of the number of surface oxygen groups. The sorption properties of the active carbons obtained were characterised by determination

  1. A study on the consecutive preparation of silica powders and active carbon from rice husk ash

    Microsoft Academic Search

    Dongmin An; Yupeng Guo; Bo Zou; Yanchao Zhu; Zichen Wang

    2011-01-01

    Rice husk ash (RHA) is an abundant agricultural by-product. The present research work deals with the production of silica powders and active carbon from RHA with a consecutive method. The RHA is firstly treated with acid leaching to remove mineral composition, and then is boiled with base to leach silica. The filtrate is used to synthesize silica powders with CO2

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

    Microsoft Academic Search

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

    2012-01-01

    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

  3. Molten carbonate fuel cell product development test

    NASA Astrophysics Data System (ADS)

    1993-12-01

    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.

  4. Preparation of activated carbons from bituminous coals with zinc chloride activation

    Microsoft Academic Search

    Hsisheng Teng; Tien-Sheng Yeh

    1998-01-01

    Activated carbons were prepared by chemical activation from two Australian bituminous coals in this study. The preparation process consisted of zinc chloride impregnation followed by carbonization in nitrogen. The carbonization temperature ranges from 400 to 700 C. Experimental results reveal that an acid-washing process following the carbonization with ZnClâ is necessary for preparing high-porosity carbons. Surface area, pore volume, and

  5. Molten Carbonate Fuel Cell (MCFC) Product Development Test. Second annual report

    SciTech Connect

    Not Available

    1994-12-15

    This is the second annual report covering progress made under DOE cooperative agreement DE-FC21-92MC29237, Molten Carbonate Fuel Cell Product Development Test. The project is for the design, construction, and testing of a 2MW carbonate fuel cell power plant in the City of Santa Clara, California. The report is divided into sections which describe the progress in various program activities, and provides an overview of the program, including the project objectives, site location, and schedule.

  6. An Appraisal of The Lignin\\/Activated Carbon Adsorption System

    Microsoft Academic Search

    Paul Rankin

    1975-01-01

    The pore structure of a wide array of activated carbons has been evaluated by nitrogen adsorption and mercury penetration techniques. Carbons were found to exhibit total surface areas and pore volumes in the range 93 - 1500 m²\\/g and 0.34 -1.8 cm³\\/g respectively. The Darco carbons contain significant pore structure in all pores up to 1000 ? radius. Columbia carbon

  7. Metal salen catalyzed production of polytrimethylene carbonate 

    E-print Network

    Ganguly, Poulomi

    2009-06-02

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

  8. MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT

    SciTech Connect

    H.C. Maru; M. Farooque

    2002-02-01

    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.

  9. JPL Activated Carbon Treatment System (ACTS) for sewage

    NASA Technical Reports Server (NTRS)

    1976-01-01

    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.

  10. CRADA Carbon Sequestration in Soils and Commercial Products

    SciTech Connect

    Jacobs, G.K.

    2002-01-31

    ORNL, through The Consortium for Research on Enhancing Carbon Sequestration in Terrestrial Ecosystems (CSiTE), collaborated with The Village Botanica, Inc. (VB) on a project investigating carbon sequestration in soils and commercial products from a new sustainable crop developed from perennial Hibiscus spp. Over 500 pre-treated samples were analyzed for soil carbon content. ORNL helped design a sampling scheme for soils during the planting phase of the project. Samples were collected and prepared by VB and analyzed for carbon content by ORNL. The project did not progress to a Phase II proposal because VB declined to prepare the required proposal.

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

    SciTech Connect

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

    2011-01-15

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

  12. Activated Carbon Modified with Copper for Adsorption of Propanethiol

    PubMed Central

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

    2010-01-01

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

  13. Activated carbon from coal tar pitch and furfural for the removal of p-nitrophenol and m-aminophenol

    Microsoft Academic Search

    Bilyana Petrova; Boyko Tsyntsarski; Temenuzhka Budinova; Nartzislav Petrov; Leticia F. Velasco; Conchi O. Ania

    2011-01-01

    Adsorption of m-aminophenol and p-nitrophenol from aqueous solution on activated carbon synthesized on the base of industrial by product (coal tar pitch) and furfural was investigated. The adsorption capacity of the activated carbon and its oxidized modification is related to the surface area and composition of the prepared materials, as well as to the nature of the adsorbents. Despite the

  14. Hydrogenation of anthracene over active carbon-supported nickel catalyst

    Microsoft Academic Search

    Z.-G Zhang; K Okada; M Yamamoto; T Yoshida

    1998-01-01

    Hydrogen transfer behavior over active carbon and carbon-supported Ni catalyst was examined in the hydrogenation of anthracene with three kinds of hydrogen sources: hydrogen gas, hydrogen-donor tetralin and the combination of both. In tetralin, active carbon itself provided higher conversions of anthracene in the temperature range of 350–400°C than Ni\\/C catalyst, while under the pressure of hydrogen gas, the addition

  15. Future productivity and carbon storage limited by terrestrial nutrient availability

    NASA Astrophysics Data System (ADS)

    Wieder, William R.; Cleveland, Cory C.; Smith, W. Kolby; Todd-Brown, Katherine

    2015-06-01

    The size of the terrestrial sink remains uncertain. This uncertainty presents a challenge for projecting future climate-carbon cycle feedbacks. Terrestrial carbon storage is dependent on the availability of nitrogen for plant growth, and nitrogen limitation is increasingly included in global models. Widespread phosphorus limitation in terrestrial ecosystems may also strongly regulate the global carbon cycle, but explicit considerations of phosphorus limitation in global models are uncommon. Here we use global state-of-the-art coupled carbon-climate model projections of terrestrial net primary productivity and carbon storage from 1860-2100 estimates of annual new nutrient inputs from deposition, nitrogen fixation, and weathering; and estimates of carbon allocation and stoichiometry to evaluate how simulated CO2 fertilization effects could be constrained by nutrient availability. We find that the nutrients required for the projected increases in net primary productivity greatly exceed estimated nutrient supply rates, suggesting that projected productivity increases may be unrealistically high. Accounting for nitrogen and nitrogen-phosphorus limitation lowers projected end-of-century estimates of net primary productivity by 19% and 25%, respectively, and turns the land surface into a net source of CO2 by 2100. We conclude that potential effects of nutrient limitation must be considered in estimates of the terrestrial carbon sink strength through the twenty-first century.

  16. Ammoxidation of active carbons for improvement of supercapacitor characteristics

    Microsoft Academic Search

    K. Jurewicz; K. Babe?; A. ?ió?kowski; H. Wachowska

    2003-01-01

    Modification of active carbon by ammoxidation was used to obtain electrode material with intermediate acidic–basic properties. It allowed advantage to be taken of the pseudocapacitance characteristics of the material for the improvement of the supercapacitor. Precursor fabric from regenerated cellulose was subjected to carbonization, followed by steam activation at 400 and 800°C, respectively. Ammoxidation was carried out with a mixture

  17. Acoustical Evaluation of Carbonized and Activated Cotton Nonwovens

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  18. Advanced purification of carbonization wastewater by activated sludge treatment

    Microsoft Academic Search

    W. H. Moerman; D. R. Bamelis; P. M. Van Holle; H. L. Vergote; W. H. Verstraete

    1995-01-01

    A full scale activated sludge plant has been developed treating 960 mof carbonization wastewater daily. Results and process parameters from the first three years of operation are described. In spite of intense physical?chemical pretreatment, the carbonization wastewater must still be diluted by 50% prior to biological processing due to the presence of inhibitory organic compounds. The activated sludge plant consists

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

    SciTech Connect

    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

    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).

  20. The performance of two adsorption ice making test units using activated carbon and a carbon composite as adsorbents

    Microsoft Academic Search

    L. W. Wang; R. Z. Wang; Z. S. Lu; C. J. Chen; K. Wang; J. Y. Wu

    2006-01-01

    The available adsorption working pairs applied to adsorption refrigeration system, which utilize activated carbon as adsorbent, are mainly activated carbon–methanol, activated carbon–ammonia, and composite adsorbent–ammonia. The adsorption properties and refrigeration application of these three types of adsorption working pairs are investigated. For the physical adsorbents, consolidated activated carbon showed best heat transfer performance, and activated carbon–methanol showed the best adsorption

  1. Production of single-walled carbon nanotube grids

    DOEpatents

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

    2013-12-03

    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.

  2. Determination of heavy metals in activated charcoals and carbon black for Lyocell fiber production using direct solid sampling high-resolution continuum source graphite furnace atomic absorption and inductively coupled plasma optical emission spectrometry

    Microsoft Academic Search

    Fábio G. Lepri; Daniel L. G. Borges; Rennan G. O. Araujo; Bernhard Welz; Frank Wendler; Marcus Krieg; Helmut Becker-Ross

    2010-01-01

    Reactivity and concentration of additives, especially activated charcoal, employed for the Lyocell process, enhance the complexity of reactions in cellulose\\/N-methylmorpholine-N-oxide monohydrate solutions. Analytical control of the starting materials is a basic requirement to know the concentration of heavy metals, which are potential initiators of autocatalytic reactions. Seven activated charcoal and two carbon black samples have been analyzed regarding their content

  3. Carbon sink activity and GHG budget of managed European grasslands

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

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

  4. DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS

    SciTech Connect

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

    2005-06-08

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

  5. Influence of activation temperature on adsorption characteristics of activated carbon fiber composites

    Microsoft Academic Search

    Soo-Jin Park; Ki-Dong Kim

    2001-01-01

    In this work, the effect of activation temperature on adsorption properties of activated carbon fiber-reinforced phenolic resin matrix composites has been investigated. The composites were manufactured via a molding process with unwoven carbon fabrics and phenolic resin. The green body mold was heated at 125°C to cure the phenolic resin and they were carbonized in an inert environment at 1000°C

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

    Microsoft Academic Search

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

    1995-01-01

    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

  7. LOW COST PRODUCTION OF CARBON FIBERS FROM LIGNIN MATERIALS

    SciTech Connect

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

    2009-01-01

    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.

  8. Studies relevant to the catalytic activation of carbon monoxide

    SciTech Connect

    Ford, P.C.

    1992-06-04

    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.

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

    Microsoft Academic Search

    P.-O. Lundquist

    2005-01-01

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

  10. Optimal Production Policy under the Carbon Emission Market

    E-print Network

    Touzi, Nizar

    with the reduction of the green- house gases including CO2 and is accepted by several countries e.g. Euro- pean Union Touzi§ August 14, 2011 Abstract The aim of this paper is to address the effect of the carbon emis- sion market on the production policy of the emitting production firms. We investigate this effect in the cases

  11. Carbon Footprint and Sustainability of Agricultural Production Systems in India

    Microsoft Academic Search

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

    2011-01-01

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

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

    Microsoft Academic Search

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

    2004-01-01

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

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

    PubMed

    Lu, Xiaowei; Jordan, Beth; Berge, Nicole D

    2012-07-01

    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 °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(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). PMID:22516099

  14. Carbon Nanotube Activities at NASA-Johnson Space Center

    NASA Technical Reports Server (NTRS)

    Arepalli, Sivaram

    2006-01-01

    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.

  15. Grain-based activated carbons for natural gas storage.

    PubMed

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

    2010-03-01

    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

  16. The preparation of activated carbon from macadamia nutshell by chemical activation

    Microsoft Academic Search

    A. Ahmadpour; D. D. Do

    1997-01-01

    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

  17. Preparation of activated carbons with mesopores by use of organometallics

    SciTech Connect

    Yamada, Y.; Yoshizawa, N.; Furuta, T.; Shiraishi, M. [National Inst. for Resources and Environment, Ibaraki (Japan)] [and others

    1996-10-01

    Mesopore carbons were prepared by steam activation of pitch or coal with metal chelate complexes. Yttrium acetylacetonate dispersed in a coal tar pitch enhanced the mesopore ratio in the activated carbon obtained. When Mike, Taiheiyo or Morwell coal was used in the place of the pitch, titanium oxide acetylacetonate was effective for the formation of the mesopore carbons. The specific surface areas and mesopore ratios were evaluated by measuring the nitrogen adsorption isotherms. In addition, the crystal size and the distribution of metals on the carbon were observed by transmission electron microscope and the formation mechanism of mesopores was estimated from these results.

  18. Clouds Versus Carbon: Predicting Vegetation Roughness by Maximizing Productivity

    NASA Technical Reports Server (NTRS)

    Olsen, Lola M.

    2004-01-01

    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.

  19. Impact of Sulfur Oxides on Mercury Capture by Activated Carbon

    SciTech Connect

    Presto, A.A.; Granite, E.J.

    2007-09-15

    Recent field tests of mercury removal with activated carbon injection (ACI) have revealed that mercury capture is limited in flue gases containing high concentrations of sulfur oxides (SOx). In order to gain a more complete understanding of the impact of SOx on ACI, mercury capture was tested under varying conditions of SO2 and SO3 concentrations using a packed bed reactor and simulated flue gas (SFG). The final mercury content of the activated carbons is independent of the SO2 concentration in the SFG, but the presence of SO3 inhibits mercury capture even at the lowest concentration tested (20 ppm). The mercury removal capacity decreases as the sulfur content of the used activated carbons increases from 1 to 10%. In one extreme case, an activated carbon with 10% sulfur, prepared by H2SO4 impregnation, shows almost no mercury capacity. The results suggest that mercury and sulfur oxides are in competition for the same binding sites on the carbon surface.

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

    NASA Astrophysics Data System (ADS)

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

    2012-07-01

    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.

  1. Changes in surface chemistry of activated carbons by wet oxidation

    Microsoft Academic Search

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

    2000-01-01

    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

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

    PubMed

    Azov, Y; Shelef, G; Moraine, R

    1982-03-01

    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

  3. Process for production of carbon black

    SciTech Connect

    Casperson, J. R.; Hann, P. D.

    1985-05-28

    A carbon black reactor employs the following components to produce non-uniform gas flow patterns. (a) a precombustion chamber skewed at an angle of 30-60 degrees from the reactor axis, comprising: (1) offset tangential hot gas entries (2) axial or offset miutiple oil feed entries (b) an optional venturi which can be offset from the reactor axis and/or asymmetric in form.

  4. MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT

    Microsoft Academic Search

    H. C. Maru; M. Farooque

    2003-01-01

    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

  5. MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT

    Microsoft Academic Search

    H. C. Maru; M. Farooque

    2005-01-01

    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

  6. MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT

    Microsoft Academic Search

    H. C. Maru; M. Farooque

    2004-01-01

    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

  7. Cellulosic carbon fibers with branching carbon nanotubes for enhanced electrochemical activities for bioprocessing applications.

    PubMed

    Zhao, Xueyan; Lu, Xin; Tze, William Tai Yin; Kim, Jungbae; Wang, Ping

    2013-09-25

    Renewable biobased carbon fibers are promising materials for large-scale electrochemical applications including chemical processing, energy storage, and biofuel cells. Their performance is, however, often limited by low activity. Herein we report that branching carbon nanotubes can enhance the activity of carbonized cellulosic fibers, such that the oxidation potential of NAD(H) was reduced to 0.55 V from 0.9 V when applied for bioprocessing. Coordinating with enzyme catalysts, such hierarchical carbon materials effectively facilitated the biotransformation of glycerol, with the total turnover number of NAD(H) over 3500 within 5 h of reaction. PMID:24020801

  8. 40 CFR 60.1330 - How do I monitor the injection rate of activated carbon?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  9. 40 CFR 60.1820 - How do I monitor the injection rate of activated carbon?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  10. 40 CFR 60.1330 - How do I monitor the injection rate of activated carbon?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

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

  11. 40 CFR 60.1820 - How do I monitor the injection rate of activated carbon?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

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

  12. The leaching of inorganic species from activated carbons produced from waste tyre rubber.

    PubMed

    San Miguel, G; Fowler, G D; Sollars, C J

    2002-04-01

    Waste tyre rubber can be used as a precursor for the production of high quality activated carbons. However, there is concern that inorganic impurities present in the rubber feed may restrict their use in liquid phase applications with high purity requirements. This paper presents an investigation of the presence and the leaching of inorganic species from activated carbons derived from waste tyre rubber. For the purpose of this work, a number of carbons were produced, characterised for their BET surface area and analysed for their inorganic composition. Subsequently, a number of tests were performed to evaluate the leaching of different inorganic species into solution at various pH values and carbon doses. Results showed that rubber-derived carbons contained elevated concentrations of sulphur and zinc, as well as traces of other metals such as lead, cadmium, chromium and molybdenum. Inorganic levels were significantly affected by production conditions, particularly degree of carbon activation and the nature of the gasification agent. However, leaching tests showed that the availability of these species in neutral pH conditions was very limited. Results demonstrated that, when using carbons doses comparable to those employed in water treatment works, only sulphur levels exceeded, in some occasions, health based quality standards proposed for drinking water. PMID:12092568

  13. Hygienic characteristics of carbon black used in tyre production.

    PubMed

    Rogaczewska, T; Ligocka, D; Nowicka, K

    1989-01-01

    Seven types of carbon black used in type production were subjected to hygienic evaluation. The coal tar pitch volatiles (CTPVs), toluene solubles, were determined by the gravimetric method and benzo/a/pyrene by HPLC with a spectrophotometric detector. Toluene solubles were found to amount to 0.12-0.25% (by weight). Benzo/a/pyrene (1.44-3.07 ppm) was detected in five out of the seven carbon blacks examined. PMID:2489438

  14. The production of phytolith-occluded carbon in China's forests: implications to biogeochemical carbon sequestration.

    PubMed

    Song, Zhaoliang; Liu, Hongyan; Li, Beilei; Yang, Xiaomin

    2013-09-01

    The persistent terrestrial carbon sink regulates long-term climate change, but its size, location, and mechanisms remain uncertain. One of the most promising terrestrial biogeochemical carbon sequestration mechanisms is the occlusion of carbon within phytoliths, the silicified features that deposit within plant tissues. Using phytolith content-biogenic silica content transfer function obtained from our investigation, in combination with published silica content and aboveground net primary productivity (ANPP) data of leaf litter and herb layer in China's forests, we estimated the production of phytolith-occluded carbon (PhytOC) in China's forests. The present annual phytolith carbon sink in China's forests is 1.7 ± 0.4 Tg CO2  yr(-1) , 30% of which is contributed by bamboo because the production flux of PhytOC through tree leaf litter for bamboo is 3-80 times higher than that of other forest types. As a result of national and international bamboo afforestation and reforestation, the potential of phytolith carbon sink for China's forests and world's bamboo can reach 6.8 ± 1.5 and 27.0 ± 6.1 Tg CO2  yr(-1) , respectively. Forest management practices such as bamboo afforestation and reforestation may significantly enhance the long-term terrestrial carbon sink and contribute to mitigation of global climate warming. PMID:23729188

  15. Labile carbon concentrations are strongly linked to plant production in Arctic tussock tundra soils

    NASA Astrophysics Data System (ADS)

    Darrouzet-Nardi, A.; Weintraub, M. N.; Euskirchen, E. S.; Steltzer, H.; Sullivan, P.

    2013-12-01

    The exchange of carbon and nutrients between plants and microbes is a key determinant of carbon balance in Arctic soils. Microbes rely on labile plant carbon for the energy they need to produce enzymes that can release nutrients and less energetically favorable carbon from soil organic matter. One of the main mechanisms of carbon transfer is rhizodeposition, the exudation of labile plant carbon such as sugars from roots into the rhizosphere. Despite the importance of this flow of energy and materials from plants to microbes, there have been few attempts to quantify labile carbon pools or fluxes in Arctic soils. To improve our knowledge of labile carbon dynamics in Arctic soils, we address two basic questions: (1) What are the seasonal patterns of labile carbon concentrations? and (2) How do seasonal patterns in labile carbon correlate with plant production, microbial biomass, and soil nutrients? We measured concentrations of total reducing sugars (TRS) in the soil solution of moist acidic tussock tundra on 28 dates during the 2012 growing season in 20 plots of an early snowmelt × warming experiment. We evaluated these total reducing sugar concentrations in the context of eddy flux carbon exchange data, plant NDVI, total dissolved carbon in soils, microbial biomass, and soil nutrients. Though we did not see treatment effects of the snowmelt × warming experiment, we did observe a clear seasonal pattern in TRS concentrations in which they started low at the time of thaw, then built to a maximum value around the time of peak plant physiology in July, followed by a decline as plants senesced. We observed a clear correlation between TRS and gross primary production (GPP). NDVI values also increased with TRS concentrations during the first half of the season and then leveled off as TRS began its decline. These relationships were in contrast to labile N concentrations, which remained at low concentrations all season. Our data suggest that rhizodeposition of labile carbon compounds in Arctic tundra ecosystems has a strong seasonal pattern that closely tracks plant production. This connection suggests that if plant production increases in a warmer Arctic, plants may ease carbon limitation to summer microbial activity.

  16. Activated carbon for aerobic oxidation: Benign approach toward 2-benzoylbenzimidazoles and 2-benzoylbenzoxazoles synthesis.

    PubMed

    Bao, Kai; Li, Fuqing; Liu, Hanjing; Wang, Zhiwei; Shen, Qirong; Wang, Jian; Zhang, Weige

    2015-01-01

    A general strategy involving a novel and highly efficient aerobic benzylic oxidation promoted by cheap, reusable activated carbon in water is developed. Application of this method has been demonstrated in the benign synthesis of bioactive 2-benzoylbenzimidazoles and 2-benzoylbenzoxazoles derivatives. Furthermore, the activated carbon catalyst could be recovered and reused at least three times without significantly losing its activity. Preliminary research suggests that the oxidation mechanism may involve intermediate hydroperoxidation and that a portion of the final carbonyl product is obtained through a secondary benzylic alcohol intermediate. Finally, theoretical calculations reveal that the oxidation yield is closely associated with the electric density at the benzylic position of the substrate. PMID:26041483

  17. Preparation of activated carbons from agricultural residues for pesticide adsorption.

    PubMed

    Ioannidou, Ourania A; Zabaniotou, Anastasia A; Stavropoulos, George G; Islam, Md Azharul; Albanis, Triantafyllos A

    2010-09-01

    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 the characterization of the activated carbons ICP, SEM, FTIR and XRD analyses were performed. Adsorption kinetics and equilibrium isotherms were investigated for all biomass activated carbons in aqueous solutions. Experimental data of BP adsorption have fitted best to the pseudo 2nd-order kinetic model and Langmuir isotherm. The study resulted that corn cobs showed better adsorption capacity than the other biomass ACs. Comparison among ACs from biomass and commercial ones (F400 and Norit GL50) revealed that the first can be equally effective for the removal of BP from water with the latter. PMID:20598734

  18. Activated carbon fibers and engineered forms from renewable resources

    DOEpatents

    Baker, Frederick S

    2013-02-19

    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.

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

    PubMed Central

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

    2014-01-01

    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

  20. Microstructure and surface properties of lignocellulosic-based activated carbons

    NASA Astrophysics Data System (ADS)

    González-García, P.; Centeno, T. A.; Urones-Garrote, E.; Ávila-Brande, D.; Otero-Díaz, L. C.

    2013-01-01

    Low cost activated carbons have been produced via chemical activation, by using KOH at 700 °C, from the bamboo species Guadua Angustifolia and Bambusa Vulgaris Striata and the residues from shells of the fruits of Castanea Sativa and Juglans Regia as carbon precursors. The scanning electron microscopy micrographs show the conservation of the precursor shape in the case of the Guadua Angustifolia and Bambusa Vulgaris Striata activated carbons. Transmission electron microscopy analyses reveal that these materials consist of carbon platelet-like particles with variable length and thickness, formed by highly disordered graphene-like layers with sp2 content ? 95% and average mass density of 1.65 g/cm3 (25% below standard graphite). Textural parameters indicate a high porosity development with surface areas ranging from 850 to 1100 m2/g and average pore width centered in the supermicropores range (1.3-1.8 nm). The electrochemical performance of the activated carbons shows specific capacitance values at low current density (1 mA/cm2) as high as 161 F/g in the Juglans Regia activated carbon, as a result of its textural parameters and the presence of pseudocapacitance derived from surface oxygenated acidic groups (mainly quinones and ethers) identified in this activated carbon.

  1. Estimation of the carbon footprint of the Galician fishing activity (NW Spain).

    PubMed

    Iribarren, Diego; Vázquez-Rowe, Ian; Hospido, Almudena; Moreira, María Teresa; Feijoo, Gumersindo

    2010-10-15

    The food production system as a whole is recognized as one of the major contributors to environmental impacts. Accordingly, food production, processing, transport and consumption account for a relevant portion of the greenhouse gas (GHG) emissions associated with any country. In this context, there is an increasing market demand for climate-relevant information regarding the global warming impact of consumer food products throughout the supply chains. This article deals with the assessment of the carbon footprint of seafood products as a key subgroup in the food sector. Galicia (NW Spain) was selected as a case study. The analysis is based on a representative set of species within the Galician fishing sector, including species obtained from coastal fishing (e.g. horse mackerel, Atlantic mackerel, European pilchard and blue whiting), offshore fishing (e.g. European hake, megrim and anglerfish), deep-sea fishing (skipjack and yellowfin tuna), extensive aquaculture (mussels) and intensive aquaculture (turbot). The carbon footprints associated with the production-related activities of each selected species were quantified following a business-to-business approach on the basis of 1year of fishing activity. These individual carbon footprints were used to calculate the carbon footprint for each of the different Galician fisheries and culture activities. Finally, the lump sum of the carbon footprints for coastal, offshore and deep-sea fishing and extensive and intensive aquaculture brought about the carbon footprint of the Galician fishing activity (i.e., capture and culture). A benchmark for quantifying and communicating emission reductions was then provided, and opportunities to reduce the GHG emissions associated with the Galician fishing activity could be prioritized. PMID:20800266

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

    NASA Astrophysics Data System (ADS)

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

    2013-08-01

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

  3. Physical and electrochemical study of halide-modified activated carbons

    NASA Astrophysics Data System (ADS)

    Barpanda, Prabeer

    The current thesis aims to improve the electrochemical capacity of activated carbon electrodes, which enjoy prominent position in commercial electrochemical capacitors. Our approach was to develop electrochemical capacity by developing faradaic pseudocapacitance in carbon through a novel mechanochemical modification using iodine and bromine. Various commercial carbons were mechanochemically modified via solid-state iodation and vapour phase iodine-incorporation. The halidation-induced changes in the structure, composition, morphology, electrical and electrochemical properties of carbon materials were studied using different characterization techniques encompassing XRD, XRF, XPS, Raman spectroscopy, BET study, TEM, SAXS and electrochemical testing followed by an intensive battery of physical and electrochemical characterization. The introduction of iodine into carbon system led to the formation of polyiodide species that were preferentially reacted within the micropore voids within the carbon leading to the development of a faradaic reaction at 3.1V. In spite of the lower surface area of modified carbon, we observed manyfold increase in its electrochemical capacity. Parallel inception of non-faradaic development and faradaic pseudocapacitive reaction led to promising gravimetric, surface area normalized and volumetric capacity in iodated carbons. With promising electrochemical improvement post halidation process, the chemical halidation method was extended to different class of carbons and halides. Carbons ranging from amorphous (activated) carbons to crystalline carbons (graphites, fluorographites) were iodine-modified to gain further insight on the local graphite-iodine chemical interaction. In addition, the effect of pore size distribution on chemical iodation process was studied by using in-house fabricated microporous carbon. A comparative study of commercial mesoporous carbons and in-house fabricated microporous carbons showed higher iodine-uptake ability and larger volumetric capacity development in case of microporous carbons. For halides, bromine was also tested in activated carbons, which showed similar set of physical and electrochemical modification, but to a smaller degree. Carbon-polyhalide nanocomposites form a very interesting system both for fundamental research and as new electrode systems for asymmetric hybrid capacitor and low-voltage high power battery type applications.

  4. HARDWOOD-BASED GRANULAR ACTIVATED CARBON FOR METALS REMEDIATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  5. Dynamics of natural gas adsorption storage systems employing activated carbon

    Microsoft Academic Search

    J. P. Barbosa Mota; A. E. Rodrigues; E. Saatdjian; D. Tondeur

    1997-01-01

    Various aspects of the dynamics of natural gas adsorption storage systems employing activated carbon are studied theoretically. The fast charge of the storage system is the first subject addressed. Emphasis is given to thermal effects and hydrodynamics of flow through the carbon bed. In order to study the influence of diffusional resistances on charge dynamics, an intraparticle transport equation governed

  6. ELEMENTAL MERCURY CAPTURE BY ACTIVATED CARBON IN A FLOW REACTOR

    EPA Science Inventory

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

  7. Activated carbon testing for the 200 area effluent treatment facility

    SciTech Connect

    Wagner, R.N.

    1997-01-17

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

  8. 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...

  9. HARDWOOD-BASED GRANULAR ACTIVATED CARBON FOR METALS REMEDIATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  10. 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...

  11. SYNTHETIC ORGANIC CHEMICAL REMOVAL BY GRANULAR ACTIVATED CARBON

    EPA Science Inventory

    The paper is an overview of the adsorbability of synthetic organic chemicals (SOC) by granular activated carbon (GAC). The paper demonstrates the adsorbability by presenting data on the removal of SOCs and organic surrogates such as total organic carbon and total organic halide b...

  12. Preparing activated carbon from various nutshells by chemical activation with K 2CO 3

    Microsoft Academic Search

    Jun’ichi Hayashi; Toshihide Horikawa; Isao Takeda; Katsuhiko Muroyama; Farid Nasir Ani

    2002-01-01

    We have prepared activated carbons by chemical activation with K2CO3 from five kinds of nutshells: almond shell (AM), coconut shell (CN), oil palm shell (OP), pistachio shell (PT) and walnut shell (WN). When prepared at 1073 K, the activated carbons from all the nutshells had the maximum specific surface areas. According to the maximum values of specific surface areas, the

  13. Effect of silicate modulus and metakaolin incorporation on the carbonation of alkali silicate-activated slags

    SciTech Connect

    Bernal, Susan A., E-mail: susana.bernal@gmail.co [Materials Engineering Department, Composite Materials Group, CENM, Universidad del Valle, Cali (Colombia); Mejia de Gutierrez, Ruby [Materials Engineering Department, Composite Materials Group, CENM, Universidad del Valle, Cali (Colombia); Provis, John L., E-mail: jprovis@unimelb.edu.a [Department of Chemical and Biomolecular Engineering, University of Melbourne, Victoria 3010 (Australia); Rose, Volker [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

    2010-06-15

    Accelerated carbonation is induced in pastes and mortars produced from alkali silicate-activated granulated blast furnace slag (GBFS)-metakaolin (MK) blends, by exposure to CO{sub 2}-rich gas atmospheres. Uncarbonated specimens show compressive strengths of up to 63 MPa after 28 days of curing when GBFS is used as the sole binder, and this decreases by 40-50% upon complete carbonation. The final strength of carbonated samples is largely independent of the extent of metakaolin incorporation up to 20%. Increasing the metakaolin content of the binder leads to a reduction in mechanical strength, more rapid carbonation, and an increase in capillary sorptivity. A higher susceptibility to carbonation is identified when activation is carried out with a lower solution modulus (SiO{sub 2}/Na{sub 2}O ratio) in metakaolin-free samples, but this trend is reversed when metakaolin is added due to the formation of secondary aluminosilicate phases. High-energy synchrotron X-ray diffractometry of uncarbonated paste samples shows that the main reaction products in alkali-activated GBFS/MK blends are C-S-H gels, and aluminosilicates with a zeolitic (gismondine) structure. The main crystalline carbonation products are calcite in all samples and trona only in samples containing no metakaolin, with carbonation taking place in the C-S-H gels of all samples, and involving the free Na{sup +} present in the pore solution of the metakaolin-free samples. Samples containing metakaolin do not appear to have the same availability of Na{sup +} for carbonation, indicating that this is more effectively bound in the presence of a secondary aluminosilicate gel phase. It is clear that claims of exceptional carbonation resistance in alkali-activated binders are not universally true, but by developing a fuller mechanistic understanding of this process, it will certainly be possible to improve performance in this area.

  14. Improvements in Production of Single-Walled Carbon Nanotubes

    NASA Technical Reports Server (NTRS)

    Balzano, Leandro; Resasco, Daniel E.

    2009-01-01

    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.

  15. TESTING GUIDELINES FOR TECHNETIUM-99 ABSORPTION ON ACTIVATED CARBON

    SciTech Connect

    BYRNES ME

    2010-09-08

    CH2M HILL Plateau Remediation Company (CHPRC) is currently evaluating the potential use of activated carbon adsorption for removing technetium-99 from groundwater as a treatment method for the Hanford Site's 200 West Area groundwater pump-and-treat system. The current pump-and-treat system design will include an ion-exchange (IX) system for selective removal of technetium-99 from selected wells prior to subsequent treatment of the water in the central treatment system. The IX resin selected for technetium-99 removal is Purolite A530E. The resin service life is estimated to be approximately 66.85 days at the design technetium-99 loading rate, and the spent resin must be replaced because it cannot be regenerated. The resulting operating costs associated with resin replacement every 66.85 days are estimated at $0.98 million/year. Activated carbon pre-treatment is being evaluated as a potential cost-saving measure to offset the high operating costs associated with frequent IX resin replacement. This document is preceded by the Literature Survey of Technetium-99 Groundwater Pre-Treatment Option Using Granular Activated Carbon (SGW-43928), which identified and evaluated prior research related to technetium-99 adsorption on activated carbon. The survey also evaluated potential operating considerations for this treatment approach for the 200 West Area. The preliminary conclusions of the literature survey are as follows: (1) Activated carbon can be used to selectively remove technetium-99 from contaminated groundwater. (2) Technetium-99 adsorption onto activated carbon is expected to vary significantly based on carbon types and operating conditions. For the treatment approach to be viable at the Hanford Site, activated carbon must be capable of achieving a designated minimum technetium-99 uptake. (3) Certain radionuclides known to be present in 200 West Area groundwater are also likely to adsorb onto activated carbon. (4) Organic solvent contaminants of concern (COCs) will load heavily onto activated carbon and should be removed from groundwater upstream of the activated carbon pre-treatment system. Unless removed upstream, the adsorbed loadings of these organic constituents could exceed the land disposal criteria for carbon.

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

    SciTech Connect

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

    2001-01-01

    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.

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

    PubMed

    Centi, Gabriele; Iaquaniello, Gaetano; Perathoner, Siglinda

    2011-09-19

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

  18. Activated carbon from coal refuse for water purification

    Microsoft Academic Search

    S. J. Broderick; E. S. Hertzog

    1941-01-01

    Preparation of activated carbon or char from high-coal fraction of coal refuse is described and these chars are evaluated to determine their suitability for removing tastes and odors from municipal water supplies.

  19. GROWTH AND PERSISTENCE OF PATHOGENS ON GRANULAR ACTIVATED CARBON FILTERS

    EPA Science Inventory

    Three enteric pathogens Yersinia enterocolitica 0:8, Salmonella typhimurium, and enterotoxigenic Escherichia coli, were examined for their ability to colonize granular activated carbon (GAC) in pure cultures and in the presence of autochthonous river water organisms. All three or...

  20. Sustainable Regeneration of Nanoparticle Enhanced Activated Carbon in Water

    EPA Science Inventory

    The regeneration and reuse of exhausted granular activated carbon (GAC) is an appropriate method for lowering operational and environmental costs. Advanced oxidation is a promising environmental friendly technique for GAC regeneration. The main objective of this research was to ...

  1. Selection and preparation of activated carbon for fuel gas storage

    DOEpatents

    Schwarz, James A. (Fayetteville, NY); Noh, Joong S. (Syracuse, NY); Agarwal, Rajiv K. (Las Vegas, NV)

    1990-10-02

    Increasing the surface acidity of active carbons can lead to an increase in capacity for hydrogen adsorption. Increasing the surface basicity can facilitate methane adsorption. The treatment of carbons is most effective when the carbon source material is selected to have a low ash content i.e., below about 3%, and where the ash consists predominantly of alkali metals alkali earth, with only minimal amounts of transition metals and silicon. The carbon is washed in water or acid and then oxidized, e.g. in a stream of oxygen and an inert gas at an elevated temperature.

  2. Biofilm processes in biologically active carbon water purification

    Microsoft Academic Search

    David R. Simpson

    2008-01-01

    This review paper serves to describe the composition and activity of a biologically active carbon (BAC) biofilm used in water purification. An analysis of several physical–chemical, biochemical and microbiological methods (indicators) used to characterize the BAC biofilm's composition and activity is provided. As well, the ability of the biofilm to remove and biodegrade waterborne organic substances and pollutants will be

  3. Catalytic Carbon-Carbon Bond Activation and Functionalization by Nickel Complexes

    E-print Network

    Jones, William D.

    Catalytic Carbon-Carbon Bond Activation and Functionalization by Nickel Complexes Brian L. Edelbach, New York 14627 Received May 24, 1999 The nickel alkyne complexes (dippe)Ni(PhCtCPh), 1, (dippe reported using (C5Me5)Rh- (PMe3)H2 5e and several platinum, palladium, and nickel phosphine complexes.5i

  4. Using active haptic feedback in everyday products

    Microsoft Academic Search

    A. F. Rovers; H. A. van Essen

    2006-01-01

    This paper focuses on the introduction and design of active haptic feedback in everyday household and office products. Everyday products allow many opportunities to improve interaction. Over time, performance and number of features have been increased, but the interface became hidden and more difficult to use. Active haptic control elements can be used to approximate the richness of traditional mechanical

  5. Influence of anthracite pretreatment in the preparation of activated carbons

    Microsoft Academic Search

    Christine Daulan; Svetlana B. Lyubchik; Jean-Noël Rouzaud; François Béguin

    1998-01-01

    Chemical modification by HClO4 was used prior to physical gasification with CO2 to produce activated carbon from La Mure (France) anthracite. BET surface areas as high as 1600 m2 g?1 and a total pore volume of ?1 cm3 g?1 were obtained for this activated carbon. XPS studies have shown that a part of the chlorine had reacted with the anthracite,

  6. Perchlorate Sorption\\/Transformation from Solution Using Activated Carbon

    Microsoft Academic Search

    E. L. Pyatt; A. P. Jackman; D. Rolston

    2002-01-01

    Because perchlorate (ClO4-) inhibits iodide uptake it is a contaminant of concern in groundwater. Therefore ClO4- contaminated drinking water must be treated to either remove ClO4- or reduce ClO4- to chloride (Cl-). Batch and column experiments using varying operational conditions with powdered activated carbon (PAC) and granular activated carbon (PAC) were performed to evaluate PAC and GAC capacity to adsorb

  7. Sorption of acid dyes from effluents using activated carbon

    Microsoft Academic Search

    Keith K. H. Choy; Gordon McKay; John F. Porter

    1999-01-01

    The sorption of three acid dyes, namely, Acid Red 114, Polar Yellow and Polar Blue RAWL, onto activated carbon, has been studied. Equilibrium isotherms have been measured for three single component systems (AB, AR, AY) and one binary component system (AB+AY). The isotherms were determined by shaking 0.05 g activated carbon, particle size range 500–710 ?m, with 0.05 dm3 dye

  8. Water purification by sulfide-containing activated carbon

    Microsoft Academic Search

    Franz D. Oeste; Rainer Haas; Lothar Kaminski

    2000-01-01

    We investigated a new kind of activated carbon named gaiasafe-Formstoff [1] as an agent for powerful heavy metal reduction.\\u000a This activated carbon contains highly dispersed sulfide compounds. Our investigations with lead containing wastewaters showed\\u000a an outstanding metal sulfide precipitation power of the new agent. The lead reduction rates are independent of wastewater\\u000a parameters like lead concentration and complexing agent concentration.

  9. MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT

    SciTech Connect

    Unknown

    2000-01-01

    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.

  10. Activated Carbons from Flax Shive and Cotton Gin Waste as Environmental Adsorbents for the Chlorinated Hydrocarbon Trichloroethylene

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural by-products represent a considerable quantity of harvested commodity crops. The use of by-products as a starting material 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...

  11. ALTERNATIVE DISINFECTANTS AND GRANULAR ACTIVATED CARBON EFFECTS ON TRACE ORGANIC CONTAMINANTS

    EPA Science Inventory

    The effects of alternative disinfectants on drinking water quality were examined along with the ability of granular activated carbon (GAC) to remove disinfection by-products and organic contaminants from lower Mississippi River source water. In addition, the study obtained bacter...

  12. Ion coordination significantly enhances the photocatalytic activity of graphitic-phase carbon nitride.

    PubMed

    Gao, Honglin; Yan, Shicheng; Wang, Jiajia; Zou, Zhigang

    2014-06-14

    Here we report a facile surface modification route, metal ion coordination, to improve the photoactivity of carbon nitride. The metal ions coordinating into the plane of g-C3N4 significantly contribute to a drastic increase of the photocatalytic activity in solar hydrogen production as well as in the photodegradation of organic pollutants. PMID:24781099

  13. Preparation and characterization of activated carbon derived from the thermo-chemical conversion of chicken manure.

    PubMed

    Koutcheiko, S; Monreal, C M; Kodama, H; McCracken, T; Kotlyar, L

    2007-09-01

    Physico-chemical properties of a bioorganic char were modified by pyrolysis in the presence of NaOH, and with subsequent physical activation of carbonaceous species with CO2 a value-added activated carbon was fabricated. Bioorganic char is produced as a co-product during the production of bio-fuel from the pyrolysis of chicken litter. Untreated char contains approximately 37 wt% of C and approximately 43-45 wt% of inorganic minerals containing K, Ca, Fe, P, Cu, Mg, and Si. Carbonization and chemical activation of the char at 600 degrees C in the presence of NaOH in forming gas (4% H2 balanced with Ar) produced mainly demineralized activated carbon having BET (Brunauer, Emmett, and Teller) surface area of 486 m2/g and average pore size of 2.8 nm. Further physical activation with CO2 at 800 degrees C for 30 min resulted in activated carbon with BET surface area of 788 m2/g and average pore size of 2.2 nm. The mineral content was 10 wt%. X-ray photoelectron spectroscopy (XPS) indicated that the latter activation process reduced the pyrrolic- and/or pyridonic-N, increased pyridinic-N and formed quaternary-N at the expense of pyrrolic- and/or pyridonic-N found in the untreated char. PMID:17098423

  14. Carbon Nanotube Materials for Substrate Enhanced Control of Catalytic Activity

    SciTech Connect

    Heben, M.; Dillon, A. C.; Engtrakul, C.; Lee, S.-H.; Kelley, R. D.; Kini, A. M.

    2007-05-01

    Carbon SWNTs are attractive materials for supporting electrocatalysts. The properties of SWNTs are highly tunable and controlled by the nanotube's circumferential periodicity and their surface chemistry. These unique characteristics suggest that architectures constructed from these types of carbon support materials would exhibit interesting and useful properties. Here, we expect that the structure of the carbon nanotube support will play a major role in stabilizing metal electrocatalysts under extreme operating conditions and suppress both catalyst and support degradation. Furthermore, the chemical modification of the carbon nanotube surfaces can be expected to alter the interface between the catalyst and support, thus, enhancing the activity and utilization of the electrocatalysts. We plan to incorporate discrete reaction sites into the carbon nanotube lattice to create intimate electrical contacts with the catalyst particles to increase the metal catalyst activity and utilization. The work involves materials synthesis, design of electrode architectures on the nanoscale, control of the electronic, ionic, and mass fluxes, and use of advanced optical spectroscopy techniques.

  15. Carbon Monoxide Production in Compartment Fires

    Microsoft Academic Search

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

    1992-01-01

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

  16. Molten carbonate fuel cell product design improvement

    Microsoft Academic Search

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

    1998-01-01

    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

  17. Detection of low concentration oxygen containing functional groups on activated carbon fiber surfaces through fluorescent labeling

    E-print Network

    Borguet, Eric

    carbon, activated carbon fibers and carbon nano- tubes, are based on the presence of oxygen containingDetection of low concentration oxygen containing functional groups on activated carbon fiber of surface functional groups (OH, COOH and CHO) on activated carbon fiber surfaces. The chromophores were

  18. Activated carbon fiber composite material and method of making

    DOEpatents

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

    2001-01-01

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

  19. Activated carbon from jackfruit peel waste by H 3PO 4 chemical activation: Pore structure and surface chemistry characterization

    Microsoft Academic Search

    Devarly Prahas; Y. Kartika; N. Indraswati; S. Ismadji

    2008-01-01

    The effects of activation temperature and impregnation ratio on the pore structure and surface chemistry of activated carbons derived from jackfruit peel with chemical activation method using phosphoric acid as activating agent were studied. Activated carbons with well-developed pore sizes were produced at activation temperatures of 450 and 550°C. The BET surface areas and total pore volumes of the carbons

  20. Catalytic ozonation of p-chlorobenzoic acid by activated carbon and nickel supported activated carbon prepared from petroleum coke.

    PubMed

    Li, Xukai; Zhang, Qiuyun; Tang, Lili; Lu, Ping; Sun, Fengqiang; Li, Laisheng

    2009-04-15

    The aim of this research was to investigate catalytic activity of petroleum coke, activated carbon (AC) prepared from this material, Ni supported catalyst on activated carbon (Ni/AC) in the ozonation of aqueous phase p-chlorobenzoic acid (p-CBA). Activated carbon and Ni/AC catalyst were characterized by XRD and SEM. The presence of petroleum coke did not improve the degradation of p-CBA compared to ozonation alone, but it was advantageous for p-CBA mineralization (total organic carbon, TOC, reduction), indicating the generation of highly oxidant species (*OH) in the medium. The presence of either activated carbon or Ni/AC considerably improves TOC removal during p-CBA ozonation. Ni/AC catalyst shows the better catalytic activity and stability based on five repeated tests during p-CBA ozonation. During the ozonation (50 mg/h ozone flow rate) of a 10 mg/L p-CBA (pH 4.31), it can be more mineralized in the presence of Ni/AC catalyst (5.0 g/L), TOC removal rate is over 60% in 60 min, 43% using activated carbon as catalyst, only 30% with ozonation alone. PMID:18667273

  1. Constraints on carbon dioxide production from fossil fuel use

    Microsoft Academic Search

    R. M. Rotty; G. Marland

    1980-01-01

    The exponential growth of fossil fuel use over recent decades has resulted in a 4.3% annual increase in the carbon dioxide emitted to the atmosphere. The question addressed here is, when (and to what extent) will constraints limit the use of fossil fuels and the subsequent production of COâ. Three types of possible constraints are discussed: resource constraints, fuel-demand constraints,

  2. The GLOBCARBON initiative global biophysical products for terrestrial carbon studies

    Microsoft Academic Search

    Stephen Plummer; Olivier Arino; Franck Ranera; Kevin Tansey; Jing Chen; G. Dedieu; H. Eva; I. Piccolini; R. Leigh; G. Borstlap; B. Beusen; Walter Heyns; Riccardo Benedetti

    2007-01-01

    Understanding the spatial and temporal variation in carbon fluxes is essential to constrain models that predict climate change. However, our current knowledge of spatial and temporal patterns is uncertain, particularly over land. The ESA GLOBCARBON project aims to generate estimates of at-land products quasi-independent of the original Earth Observation source for use in Dynamic Global Vegetation Models, a central component

  3. Laser-Induced Production of Large Carbon-Based Toriods

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  4. Nucleophilic ?-Carbon Activation of Propionic Acid as a 3-Carbon Synthon by Carbene Organocatalysis.

    PubMed

    Jin, Zhichao; Jiang, Ke; Fu, Zhenqian; Torres, Jaume; Zheng, Pengcheng; Yang, Song; Song, Bao-An; Chi, Yonggui Robin

    2015-06-22

    Direct ?-carbon activation of propionic acid (C2 H5 CO2 H) by carbene organocatalysis has been developed. This activation affords the smallest azolium homoenolate intermediate (without any substituent) as a 3-carbon nucleophile for enantioselective reactions. Propionic acid is an excellent raw material because it is cheap, stable, and safe. This approach provides a much better solution to azolium homoenolate synthesis than the previously established use of acrolein (enal without any substituent), which is expensive, unstable, and toxic. PMID:26013883

  5. Combined hydrogen production and storage with subsequent carbon crystallization.

    PubMed

    Lueking, Angela D; Gutierrez, Humberto R; Fonseca, Dania A; Narayanan, Deepa L; Van Essendelft, Dirk; Jain, Puja; Clifford, Caroline E B

    2006-06-21

    We provide evidence of low-temperature hydrogen evolution and possible hydrogen trapping in an anthracite coal derivative, formed via reactive ball milling with cyclohexene. No molecular hydrogen is added to the process. Raman-active molecular hydrogen vibrations are apparent in samples at atmospheric conditions (300 K, 1 bar) for samples prepared 1 year previously and stored in ambient air. Hydrogen evolves slowly at room temperature and is accelerated upon sample heating, with a first increase in hydrogen evolution occurring at approximately 60 degrees C. Subsequent chemical modification leads to the observation of crystalline carbons, including nanocrystalline diamond surrounded by graphene ribbons, other sp2-sp3 transition regions, purely graphitic regions, and a previously unidentified crystalline carbon form surrounded by amorphous carbon. The combined evidence for hydrogen trapping and carbon crystallization suggests hydrogen-induced crystallization of the amorphous carbon materials, as metastable hydrogenated carbons formed via the high-energy milling process rearrange into more thermodynamically stable carbon forms and molecular hydrogen. PMID:16771488

  6. Electroadsorption of Arsenic from natural water in granular activated carbon

    NASA Astrophysics Data System (ADS)

    Beralus, Jean-Mackson; Ruiz Rosas, Ramiro; Cazorla-Amoros, Diego; Morallon, Emilia

    2014-11-01

    The adsorption and electroadsorption of arsenic from a natural water has been studied in a filter-press electrochemical cell using a commercial granular activated carbon as adsorbent and Pt/Ti and graphite as electrodes. A significant reduction of the arsenic concentration is achieved when current is imposed between the electrodes, especially when the activated carbon was located in the vicinity of the anode. This enhancement can be explained in terms of the presence of electrostatic interactions between the polarized carbon surface and the arsenic ions, and changes in the distribution of most stable species of arsenic in solution due to As(III) to As(V) oxidation. In summary, electrochemical adsorption on a filter press cell can be used for enhancement the arsenic remediation with activated carbon in the treatment of a real groundwater.

  7. Degradation and removal of naphthalenesulphonic acids by means of adsorption and ozonation catalyzed by activated carbon in water

    NASA Astrophysics Data System (ADS)

    Rivera-Utrilla, J.; SáNchez-Polo, M.

    2003-09-01

    Studies were conducted on the efficiency of systems based on the use of ozone, activated carbon, and ozone/activated carbon in the treatment of waters containing 1-naphthalenesulphonic acid, 1,5-naphthalenedisulphonic acid, and 1,3,6-naphthalenetrisulphonic acid. In the removal of these acids by adsorption on activated carbon the elevated heights of the mass transfer zone columns and the low values of the breakthrough volumes indicated that a system exclusively based on the use of activated carbon is not appropriate for the removal of these pollutants. In the ozonation of these acids the reactivity of naphthalenesulphonic acid with ozone is low. In addition, the initial concentration of total organic carbon (TOC) was not reduced during naphthalenesulphonic acids ozonation. These results indicate that a system exclusively based on the use of ozone is not adequate to decontaminate water where these acids are present. These ozonation processes were also studied in the presence of activated carbon. The presence of activated carbon enhanced the elimination rate, probably by enhancing ozone decomposition in aqueous phase in highly oxidative species. These catalytic properties seem to be favored by both the basicity of the carbon surface and the higher macropore volume. The catalytic properties of activated carbon were reduced by ozonation. New acid groups such as anhydride, lactones, and carboxylic acid were generated on the activated carbon surface during ozone treatment. This effect reduced the reactivity of the activated carbon to ozone and therefore the capacity to enhance ozone decomposition in aqueous phase. The presence of activated carbon during naphthalenesulphonic acid ozonation produced a reduction in the TOC concentration and in the genotoxicity of the degradation products. All these results indicate that this novel combined system is very promising for the treatment of water polluted with organic matter.

  8. 78 FR 26748 - Certain Activated Carbon From the People's Republic of China: Preliminary Results of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-08

    ...Administration [A-570-904] Certain Activated Carbon From the People's Republic of China...antidumping duty order on certain activated carbon from the People's Republic of China...order, in part, with respect to Jacobi Carbons AB (``Jacobi''). DATES:...

  9. Copper nanocrystal modified activated carbon for supercapacitors with enhanced volumetric energy and power density

    E-print Network

    Cao, Guozhong

    Copper nanocrystal modified activated carbon for supercapacitors with enhanced volumetric energy of copper nanocrystals in AC has little effect on the surface area and porosity of activated carbon. copper nanocrystals improves the electrical conductivity of the carbon network.

  10. Preparation of activated carbons from Spanish anthracite

    Microsoft Academic Search

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

    2001-01-01

    This paper complements the previous one (activation with KOH) analysing the development of porosity of a Spanish anthracite by chemical activation with NaOH. The preparation method has been optimised through the analysis of diverse experimental variables. Among them, activating agent\\/coal ratio, drying process, method of mixing of the activating agent and coal, nitrogen flow during pyrolysis and mineral matter content

  11. Isosteric heats of adsorption for activated carbons made from corn cob

    NASA Astrophysics Data System (ADS)

    Beckner, M.; Olsen, R.; Romanos, J.; Burress, J.; Dohnke, E.; Carter, S.; Casteel, G.; Wexler, C.; Pfeifer, P.

    2010-03-01

    Activated carbons made from corn cob show promise as materials for high-capacity hydrogen storage. As part of our characterization of these materials, we are interested in learning how different production methods affect the adsorption energies. In this talk, we will present experimentally measured isosteric heats of adsorption for various activated carbons calculated using the Clausius-Clayperon equation and hydrogen isotherms at temperatures of 80 and 90K and pressures up to 100 bar measured on a volumetric instrument. We discuss differences observed between isosteric heats determined from Gibbs excess adsorption vs. absolute adsorption curves.

  12. Influence of preparation conditions on the characteristics of activated carbons produced in laboratory and pilot scale systems

    Microsoft Academic Search

    Emad N. El Qada; Stephen J. Allen; Gavin M. Walker

    2008-01-01

    The central theme of this investigation is to evaluate the feasibility of using bituminous coal as a precursor material for the production of chars and activated carbons using physical and chemical activation processes. The chemical activation process was accomplished by impregnating the raw materials with different dehydrating agents in different ratios and concentrations, prior to heat treatment (ZnCl2, KCl, KOH,

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

    PubMed

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

    2015-03-01

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

  14. Molten carbonate fuel cell product design improvement

    SciTech Connect

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

    1998-12-20

    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.

  15. 76 FR 58246 - Certain Activated Carbon From the People's Republic of China: Notice of Partial Rescission of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-20

    ...Jing Mao (Dongguan) Activated Carbon Co., Ltd.; Kaihua...Kunshan Actview Carbon Technology Co., Ltd.; Langfang Winfield Filtration Co.; Link Shipping Limited; Longyan Wanan Activated Carbon; Mindong Lianyi...

  16. Regional carbon dioxide implications of forest bioenergy production

    NASA Astrophysics Data System (ADS)

    Hudiburg, Tara W.; Law, Beverly E.; Wirth, Christian; Luyssaert, Sebastiaan

    2011-11-01

    Strategies for reducing carbon dioxide emissions include substitution of fossil fuel with bioenergy from forests, where carbon emitted is expected to be recaptured in the growth of new biomass to achieve zero net emissions, and forest thinning to reduce wildfire emissions. Here, we use forest inventory data to show that fire prevention measures and large-scale bioenergy harvest in US West Coast forests lead to 2-14% (46-405TgC) higher emissions compared with current management practices over the next 20 years. We studied 80 forest types in 19 ecoregions, and found that the current carbon sink in 16 of these ecoregions is sufficiently strong that it cannot be matched or exceeded through substitution of fossil fuels by forest bioenergy. If the sink in these ecoregions weakens below its current level by 30-60gCm-2yr-1 owing to insect infestations, increased fire emissions or reduced primary production, management schemes including bioenergy production may succeed in jointly reducing fire risk and carbon emissions. In the remaining three ecoregions, immediate implementation of fire prevention and biofuel policies may yield net emission savings. Hence, forest policy should consider current forest carbon balance, local forest conditions and ecosystem sustainability in establishing how to decrease emissions.

  17. DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS

    SciTech Connect

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

    2005-08-11

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

  18. Carbon atom-initiated degradation of carbon tetrachloride in the presence of molecular oxygen: A product and mechanistic study

    SciTech Connect

    Nicoll, G.; Francisco, J.S. [Purdue Univ., West Lafayette, IN (United States)] [Purdue Univ., West Lafayette, IN (United States)

    1998-10-15

    This paper reports an investigation of the gas-phase reaction of atomic carbon with carbon tetrachloride in the presence of molecular oxygen. It is demonstrated that carbon tetrachloride can be oxidatively degraded by this method. Results from FT-IR and GC/MS studies suggest that the major products from the reaction are phosgene and carbon dioxide. The initial step involves breaking the carbon-chlorine bond as a result of the reaction of atomic carbon with carbon tetrachloride. Laser-induced fluorescence studies have shown the presence of CCl as an intermediate produced from this reaction. A tentative mechanism is proposed to describe the details of the chemistry.

  19. Sustainable Production of Cannabinoids with Supercritical Carbon Dioxide Technologies

    Microsoft Academic Search

    H. Perrotin-Brunel

    2011-01-01

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

  20. Composite electrodes of activated carbon derived from cassava peel and carbon nanotubes for supercapacitor applications

    NASA Astrophysics Data System (ADS)

    Taer, E.; Iwantono, Yulita, M.; Taslim, R.; Subagio, A.; Salomo, Deraman, M.

    2013-09-01

    In this paper, a composite electrode was prepared from a mixture of activated carbon derived from precarbonization of cassava peel (CP) and carbon nanotubes (CNTs). The activated carbon was produced by pyrolysis process using ZnCl2 as an activation agent. A N2 adsorption-desorption analysis for the sample indicated that the BET surface area of the activated carbon was 1336 m2 g-1. Difference percentage of CNTs of 0, 5, 10, 15 and 20% with 5% of PVDF binder were added into CP based activated carbon in order to fabricate the composite electrodes. The morphology and structure of the composite electrodes were investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. The SEM image observed that the distribution of CNTs was homogeneous between carbon particles and the XRD pattern shown the amorphous structure of the sample. The electrodes were fabricated for supercapacitor cells with 316L stainless steel as current collector and 1 M sulfuric acid as electrolyte. An electrochemical characterization was performed by using an electrochemical impedance spectroscopy (EIS) method using a Solatron 1286 instrument and the addition of CNTs revealed to improve the resistant and capacitive properties of supercapacitor cell.

  1. Nitrogen-enriched bituminous coal-based active carbons as materials for supercapacitors

    Microsoft Academic Search

    R. Pietrzak; K. Jurewicz; P. Nowicki; K. Babe?; H. Wachowska

    2010-01-01

    The paper presents the results of a study on obtaining N-enriched active carbons from bituminous coal and on testing its use as an electrode material in supercapacitors. The coal was carbonised, activated with KOH and ammoxidised by a mixture of ammonia and air at the ratio 1:3 at 300°C or 350°C, at different stages of the production, that is, at

  2. Influence of carbon and nitrogen sources on growth, nitrogenase activity, and carbon metabolism of Gluconacetobacter diazotrophicus.

    PubMed

    Tejera, Noel A; Ortega, Eduardo; Rodés, Rosa; Lluch, Carmen

    2004-09-01

    The effects of different carbon and nitrogen sources on the growth, nitrogenase activity, and carbon metabolism of Gluconacetobacter diazotrophicus were investigated. The amino acids asparagine, aspartic acid, and glutamic acid affected microbial growth and nitrogenase activity. Several enzymatic activities involved in the tricarboxylic acid cycle were affected by the carbon source used. In addition, glucose and gluconate significantly increased the oxygen consumption (respiration rate) of whole cells of G. diazotrophicus grown under aerobic conditions. Enzymes responsible for direct oxidation of glucose and gluconate were especially active in cells grown with sucrose and gluconate. The presence of amino acids in the apoplastic and symplastic sap of sugarcane stems suggests that these compounds might be of importance in the regulation of growth and nitrogenase activity during the symbiotic association. The information obtained from the plant-bacterium association together with the results of other biochemical studies could contribute to the development of biotechnological applications of G. diazotrophicus. PMID:15644929

  3. Pore Size Analysis of Activated Carbons from Argon and Nitrogen Porosimetry Using Density Functional Theory

    E-print Network

    Lastoskie, Christian M.

    Pore Size Analysis of Activated Carbons from Argon and Nitrogen Porosimetry Using Density interactions of the nitrogen molecules with functional groups on the carbon surface. 1. Introduction Activated involving the use of activated carbons. Commercial activated carbons are manufactured by thermolytic

  4. Semicontinuous and continuous degradation of phenol by Pseudomonas putida P8 adsorbed on activated carbon

    Microsoft Academic Search

    H. M. Ehrhardt; H. J. Rehm

    1989-01-01

    The semicontinuous and continuous degradation of phenol by Pseudomonas putida P8 which was immobilized on activated carbon was investigated. The amount of bacteria immobilized on the activated carbon surface dependend on the cell concentration in the suspension and on the type of activated carbon. In a continuous process running for four weeks the biomass, which accumulated in the activated carbon

  5. Catalytic ozonation of sulfonated aromatic compounds in the presence of activated carbon

    Microsoft Academic Search

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

    2008-01-01

    The ozonation of two model compounds (benzenesulfonic acid and sulfanilic acid) was carried out in the presence of activated carbon. With the aim of evaluating the role of the activated carbon surface chemistry during the ozonation, two activated carbon samples were assessed. Activated carbon promoted ozonation increased the rate of removal of the selected aromatic compounds and, most of all,

  6. Removal efficiency of radioactive methyl iodide on TEDA-impregnated activated carbons

    Microsoft Academic Search

    C. M. González-García; J. F. González; S. Román

    2011-01-01

    Activated carbons were prepared by different series of carbon dioxide and steam activation from walnut shells for their optimal use as radioactive methyl iodide adsorbents in Nuclear Plants. The knowledge of the most favourable textural characteristics of the activated carbons was possible by the previous study of the commercial activated carbon currently used for this purpose. In order to increase

  7. Preparation and characteristics of activated carbon from olive stones and walnut shells

    Microsoft Academic Search

    M. L. Martínez; M. M. Torres; C. A. Guzmán; D. M. Maestri

    2006-01-01

    The preparation of activated carbon from agricultural waste could increase economic return and reduce pollution. Activated carbon has been processed from different types of agricultural material, such as olive stone, acorn, pecan, walnut shells, and stone fruits. The objectives of this study were to prepare and to characterize activated carbon from two abundant waste material produced in Argentina. Activated carbon

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

    E-print Network

    Estimates of carbon stored in harvested wood products from United States Forest Service Southern amounts of carbon through photosynthesis. When carbon is removed from forests through harvest, a portion of the harvested carbon is stored in wood products, often for many decades. The United States Forest Service (USFS

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

    E-print Network

    Estimates of carbon stored in harvested wood products from United States Forest Service Eastern amounts of carbon through photosynthesis. When carbon is removed from forests through harvest, a portion of the harvested carbon is stored in wood products, often for many decades. The United States Forest Service (USFS

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

    E-print Network

    Estimates of carbon stored in harvested wood products from United States Forest Service Alaska amounts of carbon through photosynthesis. When carbon is removed from forests through harvest, a portion of the harvested carbon is stored in wood products, often for many decades. The United States Forest Service (USFS

  11. Environmental remediation and conversion of carbon dioxide (CO(2)) into useful green products by accelerated carbonation technology.

    PubMed

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

    2010-01-01

    This paper reviews the application of carbonation technology to the environmental industry as a way of reducing carbon dioxide (CO(2)), a green house gas, including the presentation of related projects of our research group. An alternative technology to very slow natural carbonation is the co-called 'accelerated carbonation', which completes its fast reaction within few hours by using pure CO(2). Carbonation technology is widely applied to solidify or stabilize solid combustion residues from municipal solid wastes, paper mill wastes, etc. and contaminated soils, and to manufacture precipitated calcium carbonate (PCC). Carbonated products can be utilized as aggregates in the concrete industry and as alkaline fillers in the paper (or recycled paper) making industry. The quantity of captured CO(2) in carbonated products can be evaluated by measuring mass loss of heated samples by thermo-gravimetric (TG) analysis. The industrial carbonation technology could contribute to both reduction of CO(2) emissions and environmental remediation. PMID:20195442

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

    PubMed Central

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

    2010-01-01

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

  13. Surface functional groups on acid-activated nutshell carbons

    Microsoft Academic Search

    Christopher A. Toles; Wayne E. Marshall; Mitchell M. Johns

    1999-01-01

    Nutshells from agriculturally important nut crops (almond, black walnut, English walnut, macadamia nut and pecan) were converted to granular activated carbon using phosphoric acid activation in nitrogen or air. Surface functional groups (carbonyl, phenols, lactones, carboxyl) were quantified by titration with bases of different ionization potential. The degree of copper uptake was correlated with the presence of various functional groups

  14. Activated Carbon Composites for Air Separation

    Microsoft Academic Search

    Cristian I Contescu; Frederick S Baker; Costas Tsouris; Joanna McFarlane

    2008-01-01

    In continuation of the development of composite materials for air separation based on molecular sieving properties and magnetic fields effects, several molecular sieve materials were tested in a flow system, and the effects of temperature, flow conditions, and magnetic fields were investigated. New carbon materials adsorbents, with and without pre-loaded super-paramagnetic nanoparticles of Fe3O4 were synthesized; all materials were packed

  15. Gel nanostructure in alkali-activated binders based on slag and fly ash, and effects of accelerated carbonation

    SciTech Connect

    Bernal, Susan A., E-mail: s.bernal@sheffield.ac.uk [Department of Chemical and Biomolecular Engineering, The University of Melbourne, Victoria 3010 (Australia); Department of Materials Science and Engineering, The University of Sheffield, Sheffield S1 3JD (United Kingdom); Provis, John L., E-mail: j.provis@sheffield.ac.uk [Department of Chemical and Biomolecular Engineering, The University of Melbourne, Victoria 3010 (Australia); Department of Materials Science and Engineering, The University of Sheffield, Sheffield S1 3JD (United Kingdom); Walkley, Brant; San Nicolas, Rackel [Department of Chemical and Biomolecular Engineering, The University of Melbourne, Victoria 3010 (Australia)] [Department of Chemical and Biomolecular Engineering, The University of Melbourne, Victoria 3010 (Australia); Gehman, John D. [School of Chemistry and Bio21 Institute, The University of Melbourne, Victoria 3010 (Australia)] [School of Chemistry and Bio21 Institute, The University of Melbourne, Victoria 3010 (Australia); Brice, David G.; Kilcullen, Adam R. [Department of Chemical and Biomolecular Engineering, The University of Melbourne, Victoria 3010 (Australia) [Department of Chemical and Biomolecular Engineering, The University of Melbourne, Victoria 3010 (Australia); Zeobond Pty Ltd, P.O. Box 23450, Docklands, Victoria 8012 (Australia); Duxson, Peter [Zeobond Pty Ltd, P.O. Box 23450, Docklands, Victoria 8012 (Australia)] [Zeobond Pty Ltd, P.O. Box 23450, Docklands, Victoria 8012 (Australia); Deventer, Jannie S.J. van [Department of Chemical and Biomolecular Engineering, The University of Melbourne, Victoria 3010 (Australia); Zeobond Pty Ltd, P.O. Box 23450, Docklands, Victoria 8012 (Australia)

    2013-11-15

    Binders formed through alkali-activation of slags and fly ashes, including ‘fly ash geopolymers’, provide appealing properties as binders for low-emissions concrete production. However, the changes in pH and pore solution chemistry induced during accelerated carbonation testing provide unrealistically low predictions of in-service carbonation resistance. The aluminosilicate gel remaining in an alkali-activated slag system after accelerated carbonation is highly polymerised, consistent with a decalcification mechanism, while fly ash-based binders mainly carbonate through precipitation of alkali salts (bicarbonates at elevated CO{sub 2} concentrations, or carbonates under natural exposure) from the pore solution, with little change in the binder gel identifiable by nuclear magnetic resonance spectroscopy. In activated fly ash/slag blends, two distinct gels (C–A–S–H and N–A–S–H) are formed; under accelerated carbonation, the N–A–S–H gel behaves comparably to fly ash-based systems, while the C–A–S–H gel is decalcified similarly to alkali-activated slag. This provides new scope for durability optimisation, and for developing appropriate testing methodologies. -- Highlights: •C-A-S-H gel in alkali-activated slag decalcifies during accelerated carbonation. •Alkali-activated fly ash gel changes much less under CO{sub 2} exposure. •Blended slag-fly ash binder contains two coexisting gel types. •These two gels respond differently to carbonation. •Understanding of carbonation mechanisms is essential in developing test methods.

  16. Measured Enthalpies of Adsorption of Boron-Doped Activated Carbons

    NASA Astrophysics Data System (ADS)

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

    2012-02-01

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

  17. PRODUCTION OF CARBON PRODUCTS USING A COAL EXTRACTION PROCESS

    SciTech Connect

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

    2005-12-12

    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.

  18. Sorption of heavy metal cations on activated carbon

    SciTech Connect

    Wilczak, A.

    1988-01-01

    Activated carbon is used to remove trace amounts of organic compounds from waters and wastewaters. An experimental program was conducted to determine the kinetics of sorption of lead, copper, and zinc on the surface of the powdered activated carbon Nuchar SA, and on granular activated carbon Filtrasorb 400. The results of the experimental program showed that sorption of heavy metals on activated carbon was a two-step process with a rapid initial uptake step followed by a slow approach to equilibrium extending over a period of several weeks. Desorption of heavy metals from the surface of activated carbon was very rapid and indicated no evidence of sorption irreversibility. The sorption isotherms for heavy metals on Nuchar SA were noted to be nonunique and depended on the initial concentration of the metal ions present in the system. The results obtained suggested that lead species precipitated on the surface of Nuchar SA, whereas copper and zinc ions adsorbed on the surface sites with variable affinity for the heavy metals. Sorption of lead and copper was not affected by the presence of weakly sorbing zinc ions, whereas the sorption capacity for zinc was considerably decreased in the presence of strongly sorbed copper or lead. A double-exponential faction and equilibration criteria were demonstrated for determination of the required equilibration time for batch equilibrium sorption experiments. The numerical technique proposed for fitting sorption isotherms enabled calculation of the least squares estimates of isotherm parameters. A similar technique was proposed for fitting bi-solute sorption isotherms.

  19. Removing lead in drinking water with activated carbon

    Microsoft Academic Search

    Roy M. Taylor; Roy W. Kuennen

    1994-01-01

    A point-of-use (POU) granular activated carbon (GAC) fixed bed adsorber (FBA) was evaluated for reduction of soluble and insoluble lead from drinking water. Some of the factors which affect lead removal by GAC were evaluated, such as carbon type, solution pH, and a limited amount of work on competitive interactions. The design criteria for lead reduction by a POU device

  20. Carbon nanocoatings on active materials for Li-ion batteries

    Microsoft Academic Search

    R. Dominko; M. Gaberscek; M. Bele; D. Mihailovic; J. Jamnik

    2007-01-01

    Carbon coatings were prepared on various submicrometre-sized particles that can be used as active materials in lithium rechargeable batteries. As a precursor citrate anion was used which, after carbonization at 500–600°C, transforms into a uniform, several-nanometre-thick film that is tightly adhered to the surface of substrate particles. The coatings on Li4Ti5O12 and TiO2 increased significantly the average electron conductivity of

  1. 75 FR 29976 - Certain Cut-to-Length Carbon-Quality Steel Plate Products From Italy: Extension of the Final...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-28

    ...Cut-to-Length Carbon-Quality Steel Plate Products From Italy: Extension...cut-to-length carbon-quality steel plate products from Italy. See Certain Cut-to-Length Carbon-Quality Steel Plate Products From Italy:...

  2. 75 FR 1495 - Certain Hot-Rolled Carbon Steel Flat Products From India: Preliminary Results of Countervailing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-11

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

  3. 76 FR 42679 - Certain Hot-Rolled Carbon Steel Flat Products From India: Final Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-19

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

  4. A comparison of the electrochemical behavior of carbon aerogels and activated carbon fiber cloths

    SciTech Connect

    Tran, T.D.; Alviso, C.T.; Hulsey, S.S.; Nielsen, J.K.; Pekala, R.W.

    1996-05-10

    Electrochemical capacitative behavior of carbon aerogels and commercial carbon fiber cloths was studied in 5M KOH, 3M sulfuric acid, and 0.5M tetrethylammonium tetrafluoroborate/propylene carbonate electrolytes. The resorcinol-formaldehyde based carbon aerogels with a range of denisty (0.2-0.85 g/cc) have open-cell structures with ultrafine pore sizes (5-50 nm), high surface area (400-700 m{sup 2}/g), and a solid matrix composed of interconnected particles or fibers with characteristic diameters of 10 nm. The commercial fiber cloths in the density range 0.2-04g/cc have high surface areas (1000-2500 m{sup 2}/g). The volumetric capacitances of high-density aerogels are shown to be comparable to or exceeding those from activated carbon fibers. Electrochemical behavior of these materials in various electrolytes is compared and related to their physical properties.

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

    E-print Network

    Borenstein, Elhanan

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

  6. 76 FR 15299 - Certain Hot-Rolled Carbon Steel Flat Products From India: Preliminary Rescission of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-21

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

  7. Experiments on the generation of activated carbon from biomass

    Microsoft Academic Search

    Elisabeth Schröder; Klaus Thomauske; Christine Weber; Andreas Hornung; Vander Tumiatti

    2007-01-01

    Activated carbon is generated from various waste biomass sources like rice straw, wheat straw, wheat straw pellets, olive stones, pistachios shells, walnut shells, beech wood and hardcoal. After drying the biomass is pyrolysed in the temperature range of 500–600°C at low heating rates of 10K\\/min. The activation of the chars is performed as steam activation at temperatures between 800°C and

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

    Microsoft Academic Search

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

    2011-01-01

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

  9. Activated Carbon and Carbon Black Catalyzed Transformation of Aqueous Ozone into OH-Radicals

    Microsoft Academic Search

    Urs Jans; Jürg Hoigné

    1998-01-01

    In an ozone-containing water a suspension of a few milligrams per liter of activated carbon (AQ or carbon black (CB) initiates a radical-type chain reaction that then proceeds in the aqueous phase and accelerates the transformation of O3 into secondary radicals, such as hydroxyl radicals (°OH). This results in an Advanced Oxidation Process (AOP) that is similar to an O3-based

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

    SciTech Connect

    Klasson, KT

    2002-12-23

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

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

    Microsoft Academic Search

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

    1996-01-01

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

  12. Activated Carbon Composites for Air Separation

    SciTech Connect

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

    2008-03-01

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

  13. Formation of chlorinated hydrocarbons from the reaction of chlorine atoms and activated carbon.

    PubMed

    Khachatryan, Lavrent; Dellinger, Barry

    2003-07-01

    The reactions of chlorine atoms and activated carbon have been studied over the temperature range of 200-400 degrees C using an isothermal flow reactor in conjunction with 337 nm laser photolysis of Cl2. These studies have shown that carbon tetrachloride is the major product, with chloroform, methylene chloride, and methyl chloride being formed in progressively decreasing yields. Trace quantities of methane, ethane, and dichloroethylenes were also observed. Mechanisms of carbon fragmentation by successive addition of chlorine atoms are proposed. The formation of small chlorinated hydrocarbons by the direct reaction of chlorine with carbon may be a key link in both the de novo and precursor pathways of formation of PCDD/F. PMID:12738284

  14. HRTEM study of activated carbons prepared by alkali hydroxide activation of anthracite

    Microsoft Academic Search

    M. A. Lillo-Ródenas; D. Cazorla-Amorós; A. Linares-Solano; F. Béguin; C. Clinard; J. N. Rouzaud

    2004-01-01

    A high-resolution transmission electron microscopy study has been made of the structure and porosity of activated carbons prepared by activation of anthracites by hydroxides. The results show the structural changes occurring during chemical activation and present several experimental parameters that can be observed to determine the activation degree of the materials.

  15. Adsorption of naphthenic acids on high surface area activated carbons.

    PubMed

    Iranmanesh, Sobhan; Harding, Thomas; Abedi, Jalal; Seyedeyn-Azad, Fakhry; Layzell, David B

    2014-01-01

    In oil sands mining extraction, water is an essential component; however, the processed water becomes contaminated through contact with the bitumen at high temperature, and a portion of it cannot be recycled and ends up in tailing ponds. The removal of naphthenic acids (NAs) from tailing pond water is crucial, as they are corrosive and toxic and provide a substrate for microbial activity that can give rise to methane, which is a potent greenhouse gas. In this study, the conversion of sawdust into an activated carbon (AC) that could be used to remove NAs from tailings water was studied. After producing biochar from sawdust by a slow-pyrolysis process, the biochar was physically activated using carbon dioxide (CO2) over a range of temperatures or prior to producing biochar, and the sawdust was chemically activated using phosphoric acid (H3PO4). The physically activated carbon had a lower surface area per gram than the chemically activated carbon. The physically produced ACs had a lower surface area per gram than chemically produced AC. In the adsorption tests with NAs, up to 35 mg of NAs was removed from the water per gram of AC. The chemically treated ACs showed better uptake, which can be attributed to its higher surface area and increased mesopore size when compared with the physically treated AC. Both the chemically produced and physically produced AC provided better uptake than the commercially AC. PMID:24766592

  16. The Nanotech Academy Activity E: Consumer Products

    NSDL National Science Digital Library

    This lesson plan from the Nanotechnology Applications and Career Knowledge (NACK) Center provides an activity which will illustrate how nanotechnology is impacting the consumer products market. The activity is intended to help students understand the practical applications of nanotechnology while actively participating in the classroom.The exercise should take about 45 minutes of classroom time. This and all other resources from the NACK Center require a fast, easy, free log-in.

  17. A comparison of different activated carbon performances on catalytic ozonation of a model azo reactive dye.

    PubMed

    Gül, S; Eren, O; K?r, S; Onal, Y

    2012-01-01

    The objective of this study is to compare the performances of catalytic ozonation processes of two activated carbons prepared from olive stone (ACOS) and apricot stone (ACAS) with commercial ones (granular activated carbon-GAC and powder activated carbon-PAC) in degradation of reactive azo dye (Reactive Red 195). The optimum conditions (solution pH and amount of catalyst) were investigated by using absorbencies at 532, 220 and 280 nm wavelengths. Pore properties of the activated carbon (AC) such as BET surface area, pore volume, pore size distribution, and pore diameter were characterized by N(2) adsorption. The highest BET surface area carbon (1,275 m(2)/g) was obtained from ACOS with a particle size of 2.29 nm. After 2 min of catalytic ozonation, decolorization performances of ACOS and ACAS (90.4 and 91.3%, respectively) were better than that of GAC and PAC (84.6 and 81.2%, respectively). Experimental results showed that production of porous ACs with high surface area from olive and apricot stones is feasible in Turkey. PMID:22678216

  18. Trihalomethane formation potential of aquatic and terrestrial fulvic and humic acids: Sorption on activated carbon.

    PubMed

    Abouleish, Mohamed Y Z; Wells, Martha J M

    2015-07-15

    Humic substances (HSs) are precursors for the formation of hazardous disinfection by-products (DBPs) during chlorination of water. Various surrogate parameters have been used to investigate the generation of DBPs by HS precursors and the removal of these precursors by activated carbon treatment. Dissolved organic carbon (DOC)- and ultraviolet absorbance (UVA254)-based isotherms are commonly reported and presumed to be good predictors of the trihalomethane formation potential (THMFP). However, THMFP-based isotherms are rarely published such that the three types of parameters have not been compared directly. Batch equilibrium experiments on activated carbon were used to generate constant-initial-concentration sorption isotherms for well-characterized samples obtained from the International Humic Substances Society (IHSS). HSs representing type (fulvic acid [FA], humic acid [HA]), origin (aquatic, terrestrial), and geographical source (Nordic, Suwannee, Peat, Soil) were examined at pH6 and pH9. THMFP-based isotherms were generated and compared to determine if DOC- and UVA254-based isotherms were good predictors of the THMFP. The sorption process depended on the composition of the HSs and the chemical nature of the activated carbon, both of which were influenced by pH. Activated carbon removal of THM-precursors was pH- and HS-dependent. In some instances, the THMFP existed after UVA254 was depleted. PMID:25847173

  19. Bacterial activity and production in near-surface estuarine and freshwater sediments

    Microsoft Academic Search

    Peter Wellsbury; Rodney A. Herbert; R. John Parkes

    1996-01-01

    Two indices of bacterial production, thymidine incorporation and the frequency of divided and dividing cells were measured, along with a suite of measurements of aerobic and anaerobic bacterial activity, to investigate the relationship between bacterial cell production and organic carbon mineralisation at three different sediment sites: a sheltered intertidal estuarine mudflat (Kingoodie Bay), a riverside mudbank (Ashleworth Quay) and an

  20. Pore structure of the activated coconut shell charcoal carbon

    NASA Astrophysics Data System (ADS)

    Budi, E.; Nasbey, H.; Yuniarti, B. D. P.; Nurmayatri, Y.; Fahdiana, J.; Budi, A. S.

    2014-09-01

    The development of activated carbon from coconut shell charcoal has been investigated by using physical method to determine the influence of activation parameters in term of temperature, argon gas pressure and time period on the pore structure of the activated carbon. The coconut shell charcoal was produced by pyrolisis process at temperature of about 75 - 150 °C for 6 hours. The charcoal was activated at various temperature (532, 700 and 868 °C), argon gas pressure (6.59, 15 and 23.4 kgf/cm2) and time period of (10, 60 and 120 minutes). The results showed that the pores size were reduced and distributed uniformly as the activation parameters are increased.

  1. COMPARISON OF VARIOUS SOURCES OF HIGH SURFACE AREA CARBON PREPARED BY DIFFERENT TYPES OF ACTIVATION

    Microsoft Academic Search

    Abdul Rahim Yacob; Zaiton Abdul Majid; Ratna Sari; Dewi Dasril

    Activated carbon has been known as an excellent adsorbent and is widely used due to its large adsorption capacity. Activation condition and types of activation influence the surface area and porosity of the activated carbon produced. In this study, palm kernel shells and commercially activated carbon were used. To convert palm kernel shells into coal, two methods were employed, namely

  2. Magnetically Active Carbon Nanotubes at Work.

    PubMed

    Stopin, Antoine; Pineux, Florent; Marega, Riccardo; Bonifazi, Davide

    2015-06-22

    Endohedral and exohedral assembly of magnetic nanoparticles (MNPs) and carbon nanotubes (CNTs) recently gave birth to a large body of new hybrid nanomaterials (MNPs-CNTs) featuring properties that are otherwise not in reach with only the graphitic or metallic cores themselves. These materials feature enhanced magnetically guided motions (rotation and translation), magnetic saturation and coercivity, large surface area, and thermal stability. By guiding the reader through the most significant examples in this Concept paper, we describe how researchers in the field engineered and exploited the synergistic combination of these two types of nanoparticles in a large variety of current and potential applications, such as magnetic fluid hyperthermia therapeutics and in magnetic resonance imaging to name a few. PMID:26017389

  3. Transition metal activation and functionalization of carbon-hydrogen bonds

    SciTech Connect

    Jones, W.D.

    1992-06-01

    We are investigating the fundamental thermodynamic and kinetic factors that influence carbon-hydrogen bond activation at homogeneous transition metal centers and the conversion of hydrocarbons into functionalized products of potential use to the chemical industry. Advances have been made in both understanding the interactions of hydrocarbons with metals and in the functionalization of hydrocarbons. We have found that RhCl(PR{sub 3}){sub 2}(CNR) complexes can catalyze the insertion of isonitriles into the C-H bonds or arenes upon photolysis. The mechanism of these reactions was found to proceed by way of initial phosphine dissociation, followed by C-H activation and isonitrile insertion. We have also examined reactions of a series of arenes with (C{sub 5}Me{sub 5})Rh(PMe{sub 3})PhH and begun to map out the kinetic and thermodynamic preferences for arene coordination. The effects of resonance, specifically the differences in the Hueckel energies of the bound vs free ligand, are now believed to fully control the C-H activation/{eta}{sup 2}-coordination equilibria. We have begun to examine the reactions of rhodium isonitrile pyrazolylborates for alkane and arene C-H bond activation. A new, labile, carbodiimide precursor has been developed for these studies. We have completed studies of the reactions of (C{sub 5}Me{sub 5})Rh(PMe{sub 3})H{sub 2} with D{sub 2} and PMe{sub 3} that indicate that both {eta}{sup 5} {yields} {eta}{sup 3} ring slippage and metal to ring hydride migration occur more facilely than thermal reductive elimination of H{sub 2}. We have examined the reactions of heterocycles with (C{sub 5}Me{sub 5})Rh(PMe{sub 3})PhH and found that pyrrole and furan undergo C-H or N-H activation. Thiophene, however, undergoes C-S bond oxidative addition, and the mechanism of activation has been shown to proceed through sulfur coordination prior to C-S insertion.

  4. Ratio of Pion Kaon Production in Proton Carbon Interactions

    SciTech Connect

    Lebedev, Andrey V.; /Harvard U.

    2007-05-01

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

  5. Removal of benzocaine from water by filtration with activated carbon

    USGS Publications Warehouse

    Howe, G.E.; Bills, T.D.; Marking, L.L.

    1990-01-01

    Benzocaine is a promising candidate for registration with the U.S. Food and Drug Administration for use as an anesthetic in fish culture, management, and research. A method for the removal of benzocaine from hatchery effluents could speed registration of this drug by eliminating requirements for data on its residues, tolerances, detoxification, and environmental hazards. Carbon filtration effectively removes many organic compounds from water. This study tested the effectiveness of three types of activated carbon for removing benzocaine from water by column filtration under controlled laboratory conditions. An adsorptive capacity was calculated for each type of activated carbon. Filtrasorb 400 (12 x 40 mesh; U.S. standard sieve series) showed the greatest capacity for benzocaine adsorption (76.12 mg benzocaine/g carbon); Filtrasorb 300 (8 x 30 mesh) ranked next (31.93 mg/g); and Filtrasorb 816 (8 x 16 mesh) absorbed the least (1.0 mg/g). Increased adsorptive capacity was associated with smaller carbon particle size; however, smaller particle size also impeded column flow. Carbon filtration is a practical means for removing benzocaine from treated water.

  6. Pseudomonas aeruginosa biosurfactant production in continuous culture with glucose as carbon source.

    PubMed Central

    Guerra-Santos, L; Käppeli, O; Fiechter, A

    1984-01-01

    Rsan-ver, a strain of Pseudomonas aeruginosa isolated at this department, was used for the development of a continuous process for biosurfactant production. The active compounds were identified as rhamnolipids. A final medium for production was designed in continuous culture by means of medium shifts, since the formation of surface-active compounds was decisively influenced by the composition and concentration of the medium components. In the presence of yeast extract, biosurfactant production was poor. For the nitrogen-source nitrate, which was superior to ammonium, an optimum carbon-to-nitrogen ratio of ca. 18 existed. The iron concentration needed to be minimized to 27.5 micrograms of FeSO4 X 7H2O per g of glucose. A carbon-to-phosphate ratio below 16 yielded the maximum production of rhamnolipids. The final productivity dilution rate diagram indicated that biosurfactant production was correlated to low growth rates (dilution rate below 0.15 h-1). With a medium containing 18.2 g of glucose liter-1, a biosurfactant concentration (expressed as rhamnolipids) of up to 1.5 g liter-1 was obtained in the cell-free culture liquid. PMID:6435520

  7. Carbon-based Supercapacitors Produced by Activation of Graphene

    SciTech Connect

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

    2011-12-31

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

  8. Carbon-Based Supercapacitors Produced by Activation of Graphene

    SciTech Connect

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

    2011-06-24

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

  9. Atypical Hydrogen Uptake on Chemically Activated, Ultramicroporous Carbon

    SciTech Connect

    Bhat, Vinay V [ORNL; Contescu, Cristian I [ORNL; Gallego, Nidia C [ORNL; Baker, Frederick S [ORNL

    2010-01-01

    Hydrogen adsorption at near-ambient temperatures on ultramicroporous carbon (UMC), derived through secondary chemical activation from a wood-based activated carbon was studied using volumetric and gravimetric methods. The results showed that physisorption is accompanied by a process of different nature that causes slow uptake at high pressures and hysteresis on desorption. In combination, this results in unusually high levels of hydrogen uptake at near-ambient temperatures and pressures (e.g. up to 0.8 wt % at 25 oC and 2 MPa). The heat of adsorption corresponding to the slow process leading to high uptake (17 20 kJ/mol) is higher than usually reported for carbon materials, but the adsorption kinetics is slow, and the isotherms exhibit pronounced hysteresis. These unusual properties were attributed to contributions from polarization-enhanced physisorption caused by traces of alkali metals residual from chemical activation. The results support the hypothesis that polarization-induced physisorption in high surface area carbons modified with traces of alkali metal ions is an alternate route for increasing the hydrogen storage capacity of carbon adsorbents.

  10. Wellbore stability analysis during the production of a carbonate reservoir

    NASA Astrophysics Data System (ADS)

    Alves, J.-L.; Coehlo, L.; Baud, P.; Guevara Junior, N.

    2009-04-01

    Carbonate reservoirs represent a major part of the world oil and gas reserves. During production, the extraction of hydrocarbons reduces pore pressure and thus causes an increase in the effective stress and mechanical compaction in the reservoir. The compactive deformation and failure may be spatially extensive or localized to the vicinity of the wellbore, but in either case the consequences can be economically severe involving surface subsidence, well failure and various production problems. The analysis of wellbore stability and more generally of deformation and failure in carbonate environments hinges upon a relevant constitutive modeling of carbonate rocks over a wide range of porosities. In this study, we performed a wellbore stability analysis for a lateral wellbore junction in three dimensions. The complex geometry for the wellbore junction was modeled with tetrahedral finite elements considering a rate independent elastic-plastic isotropic material that presented linear behavior during elastic strain and associated flow rule. A finite element model simulating drilling and production phases were done for field conditions from a deep water reservoir in Campos basin, offshore Brazil. In this context, several scenarios were studied considering true 3D orientation for both in situ stresses and geometry of the wellbore junction itself. We discussed the impact of constitutive modeling on the wellbore stability, based on new experimental data on two micritic porous carbonates. Series of conventional triaxial experiments were performed at room temperature in dry and wet conditions on samples of Comiso and Tavel limestones of respective porosity 17 and 16%. The wet samples were deformed in drained conditions with 10 MPa pore pressure. The initial yield stresses were identified as the critical stresses at the onset of shear-enhanced compaction, subsequent yield stresses were considered to depend on hardening given by the plastic volumetric strain. For both limestones, we found that water had a moderate effect on the yield stresses but influenced significantly the hardening behavior of the rocks.

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

    PubMed Central

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

    2015-01-01

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

  12. Preparation of paper mill sludge-based granular activated carbon fillers for fluidized-bed bioreactor (FBBR)

    Microsoft Academic Search

    Yanjie Li; Qinyan Yue; Yuanfeng Qi; Wenhong Li; Haixia Zhao; Yaqin Zhao; Jiadan Du

    2012-01-01

    Paper mill sludge (PMS) was utilized to prepare granular activated carbon (GAC) fillers for fluidized-bed bioreactor (FBBR) through stream activation. The properties of the PMS were tested and the optimum conditions for the production process were determined. Then, the GAC fillers were used in the FBBR to investigate the capacity for wastewater treatment. The results showed that the optimal conditions

  13. INFLUENCE OF INORGANIC CONTAMINATIONS AND THERMAL TREATMENT CONDITIONS OF BIOMASS ON CHANGES IN CAPILLARY STRUCTURE OF ACTIVATED CARBONS

    Microsoft Academic Search

    M. Kielczewski; B. Mazela; R. Zakrzewski; S. Zietek; A. Swiatkowski

    The production of carbonaceous adsorption materials from biomass seems to be advantageos and promising upgrading innovation of this residues. This paper presents the result of an investigationon characteristics of activated carbons made from lignocellulosic wastes (solid bio-fuel) conaminated by Cr, Cu, B, Zn salt as well as some oils obtained from the pyrolysis ana destillation of coals. Charcoal and activated

  14. DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS

    SciTech Connect

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

    2006-03-07

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

  15. EVALUATION OF PROCEDURES TO DESORB BACTERIA FROM GRANULAR ACTIVATED CARBON

    EPA Science Inventory

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

  16. CONSIDERATIONS IN GRANULAR ACTIVATED CARBON TREATMENT OF COMBINED INDUSTRIAL WASTEWATERS

    EPA Science Inventory

    The objective of this project was to examine the use of activated carbon in reducing the content of biologically resistant organic compounds in a combined industrial wastewater treatment system. The invvestigation was conducted in two stages: (1) characterize organic priority pol...

  17. MICROBIOLOGY OF GRANULAR ACTIVATED CARBON HOME TREATMENT DEVICES

    EPA Science Inventory

    Consumer usage of point-of-use granular activated carbon filtration devices is increasing rapidly, yet there is little information available to the consumer concerning the efficacy of these devices. In particular, the consumer is very likely to be unaware of the fact that these d...

  18. Analysis of a Thin Activated Carbon Loaded Adsorption Medium

    Microsoft Academic Search

    Wayne T. Davis; Christopher C. Hood; Maureen Dever

    1995-01-01

    Thin adsorption media are being investigated for use in a variety of applications including protective clothing for military use and hazardous waste cleanup, as well as in indoor air quality within a variety of filtration media. The objective of this study was to evaluate the dynamics of adsorption of a chlorinated organic gas on activated carbon impregnated meltblown laminates. The

  19. BACTERIA ATTACHED TO GRANULAR ACTIVATED CARBON IN DRINKING WATER

    EPA Science Inventory

    Laboratory and field studies were undertaken to answer basic questions about the influence of granular activated carbon (GAC) on the bacteriological quality of drinking water. A sampling apparatus consisting of a 47-mm Swinnex/and a 16-layer filter was developed to trap filter fi...

  20. Removal of antibiotics by coagulation and granular activated carbon filtration

    Microsoft Academic Search

    Keun-Joo Choi; Sang-Goo Kim; Seung-Hyun Kim

    2008-01-01

    Treatment of seven tetracycline classes of antibiotic (TAs) from raw waters (synthetic and river) was evaluated using coagulation and granular activated carbon (GAC) filtration in this study. Both coagulation and GAC filtration were effective for removal of TAs, and the removal efficiency depended on the type of TAs. GAC filtration was relatively more effective for removal of tetracycline (TC), doxycycline-hyclate

  1. ADSORPTION OF LEVODOPA FROM AQUEOUS SOLUTION ON GRANULAR ACTIVATED CARBON

    Microsoft Academic Search

    JULCOUR-LEBIGUE Carine; Centro de Química Farmacéutica

    Granular activated carbon filtration has been successfully used in wastewater and drinking water treatment plants, for removal of different pollutants and it is the most efficient conventional treatment method for the purification of water contaminated by other pollutants like pesticides. Levodopa is a drug used to treat Parkinson disease, a progressive condition in which the part of the brain responsible

  2. Surface chemistry of active carbon: Specific adsorption of phenols

    Microsoft Academic Search

    JAMES S. MATTSON; HARRY B. MARK; MICHAEL D. MALBIN; WALTER J. WEBER; JOHN C. CRITTENDEN

    1969-01-01

    The characteristics of the uptake of phenol and nitrophenols by active carbon have been investigated. The measurements of solution equilibrium parameters as well as surface structural characteristics determined by infrared internal reflection spec- troscopy are presented. A charge-transfer interaction is postulated which explains the observed adsorption and spectroscopic characteristics on the basis of the electron densities in the sorbate molecule,

  3. Modification of the surface chemistry of activated carbons

    Microsoft Academic Search

    J. L Figueiredo; M. F. R Pereira; M. M. A Freitas; J. J. M Órfão

    1999-01-01

    A NORIT activated carbon was modified by different chemical and thermal treatments (including oxidation in the gas and liquid phases) in order to obtain materials with different surface properties. Several techniques were used to characterize these materials including nitrogen adsorption, chemical and thermal analyses, XPS, TPD and DRIFTS. The results obtained by TPD agree quantitatively with the elemental and proximate

  4. Relationship between chemical and physical surface properties of activated carbon

    Microsoft Academic Search

    F. Julien; M. Baudu; M. Mazet

    1998-01-01

    The relationships between structural (chemical or physical) and more general properties such as the surface electrokinetic potential (zeta potential or isoelectric point) or spreading pressure of water were investigated for three powder activated carbon (PAC) samples (manufactured from woods, coconut shell and coal). The PAC samples were characterized by physical parameter measurements (such as zeta potential, specific surface area, spreading

  5. Activated carbons from bituminous coal: effect of mineral matter content

    Microsoft Academic Search

    A. Linares-Solano; I. Mart??n-Gullon; C. Salinas-Mart??nez de Lecea; B. Serrano-Talavera

    2000-01-01

    A bituminous coal from Puertollano Basin (Spain) was selected on the basis of previous study as the most suitable raw precursor to prepare activated carbons. In fact, this coal gave the best results among a total of 10 different Spanish coals that covered a wide range of coal rank. Its initial ash level (19wt%) was decreased in the coal mine

  6. POWDERED ACTIVATED CARBON ADSORPTION ISOTHERMS FOR SELECTED TANNERY EFFLUENTS

    EPA Science Inventory

    Two raw untreated tanning effluents were initially tested for the removal of COD, BOD, TOC, total and specific phenols, oil and grease, and total chromium, using the following six individual powdered activated carbons (PAC): ICI-HDC, ICI-HDH, Nuchar SA-15, Amoco PX-21, Norit FQA,...

  7. ACTIVATED CARBON TREATMENT OF INDUSTRIAL WASTEWATERS: SELECTED TECHNICAL PAPERS

    EPA Science Inventory

    Because of the tremendous interest in the organic constituent removal by activated carbon, the two industrial categories displaying the most interest are the petroleum refining and petrochemical industries. EPA's Office of Research and Development has co-sponsored two technical s...

  8. Detonation characteristics of ammonium nitrate and activated carbon mixtures

    Microsoft Academic Search

    Atsumi Miyake; Hidefumi Kobayashi; Hiroshi Echigoya; Shiro Kubota; Yuji Wada; Yuji Ogata; Hiroyuki Arai; Terushige Ogawa

    2007-01-01

    To better understand the detonation characteristics of ammonium nitrate (AN) and activated carbon (AC) mixtures, steel tube tests were carried out for AN\\/AC mixtures of various compositions and different forms of AN (powdered, prilled, phase stabilized and granular), and the detonation velocity was measured. The powdered AN\\/AC mixtures gave higher detonation velocities than the other AN forms. For all the

  9. Supporting information: ACTIVATED CARBON AND BIOCHAR AMENDMENTS DECREASE POREWATER

    E-print Network

    Lehmann, Johannes

    Supporting information: ACTIVATED CARBON AND BIOCHAR AMENDMENTS DECREASE POREWATER CONCENTRATIONS of tables: 2 #12;Calculation of KAC/Kbiochar for sewage sludge with AC/biochar Sorption to AC in an AC of equation (2) for biochar in biochar-amended sewage sludge MG PMWPAHs Biochar dose [%] Biochar dose [%] 0

  10. Adsorption-induced Pore Expansion and Contraction in Activated Carbon

    NASA Astrophysics Data System (ADS)

    Connolly, Matthew; Wexler, Carlos

    2012-02-01

    Adsorbent materials such as activated carbon and Metal-Organic Frameworks (MOFs) have received significant attention as a potential storage material for hydrogen and natural gas.1 Typically the adsorbent material is assumed to consist of rigid slit- or cylindrical-shaped pores. Recent work has revealed the importance of the mechanical response of the adsorbent in the presence of an adsorbate. Here, we first demonstrate the flexibility of pore walls in activated carbon and the effect this has on the pore structure of the bulk samples. The interaction is modeled as a competition between Van der Waals interactions between neighboring walls and a resistance to bending due to the rigidity of graphene. Minimal energy configurations were calculated analytically for a simplified potential and numerically for a more realistic potential. The pore structures are discussed in the context of pore measurements on activated carbon samples. Following recent work by Cole and Neimark, large pressures due to an adsorbed film are predicted in the narrow pores of activated carbon. The coverage-dependent nature of adsorbed-film pressure, indicating a pressure-variant pore structure, is discussed in terms of adsorption isotherms.

  11. Acoustical Evaluation of Carbonized and Activated Cotton Nonwovens

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  12. GAC (GRANULAR ACTIVATED CARBON) TREATMENT COSTS: A SENSITIVITY ANALYSIS

    EPA Science Inventory

    Although admittedly effective for removing organic compounds, concerns have been raised about the cost of using GAC for treating drinking water. This paper is devoted to the discussion of the cost of granular activated carbon for removing organic compounds from drinking water. Ac...

  13. SUPERCRITICAL FLUID REGENERATION OF ACTIVATED CARBON FOR ADSORPTION OF PESTICIDES

    EPA Science Inventory

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

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

    PubMed Central

    Buesing, Nanna; Gessner, Mark O.

    2006-01-01

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

  15. Carbonic anhydrase activity in isolated chloroplasts of chlamydomonas reinhardtii

    Microsoft Academic Search

    G. Katzman; R. K. Togasaki; Y. Marcus; J. V. Moroney

    1989-01-01

    In a new assay of carbonic anhydrase, NaH¹⁴COâ solution at the bottom of a sealed vessel releases ¹⁴COâ which diffuses to the top of the vessel to be assimilated by actively photosynthesizing Chlamydomonas cells. The assay is initiated by illuminating cells and stopped by turning the light off and killing the cells with acid. Enzyme activity was estimated from acid

  16. Adsorption of 6-aminopenicillanic acid on activated carbon

    Microsoft Academic Search

    M. Dutta; R. Baruah; N. N. Dutta

    1997-01-01

    The adsorption and desorption of 6-aminopenicillanic acid (6-APA) in aqueous solution has been studied using activated carbon as the adsorbent. The extent of adsorption was found to be strongly dependent on the aqueous phase pH and this dependence could be interpreted from a model for neutral species adsorption. Desorptionstudies suggest that a small fraction of 6-APA adsorbs irreversibly on activated

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

    Microsoft Academic Search

    Joshua P. Newell; Robert O. Vos

    2011-01-01

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

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

    E-print Network

    Estimates of carbon stored in harvested wood products from United States Forest Service Pacific significant amounts of carbon through photosynthesis. When carbon is removed from forests through harvest Forest Service (USFS) and other agencies are interested in accurately accounting for carbon flux

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

    E-print Network

    Estimates of carbon stored in harvested wood products from United States Forest Service Rocky significant amounts of carbon through photosynthesis. When carbon is removed from forests through harvest Forest Service (USFS) and other agencies are interested in accurately accounting for carbon flux

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

    E-print Network

    Estimates of carbon stored in harvested wood products from United States Forest Service and store significant amounts of carbon through photosynthesis. When carbon is removed from forests through States Forest Service (USFS) and other agencies are interested in accurately accounting for carbon flux

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

    E-print Network

    Estimates of carbon stored in harvested wood products from United States Forest Service Pacific and store significant amounts of carbon through photosynthesis. When carbon is removed from forests through States Forest Service (USFS) and other agencies are interested in accurately accounting for carbon flux

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

    E-print Network

    Estimates of carbon stored in harvested wood products from United States Forest Service Northern significant amounts of carbon through photosynthesis. When carbon is removed from forests through harvest Forest Service (USFS) and other agencies are interested in accurately accounting for carbon flux

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

    E-print Network

    Estimates of carbon stored in harvested wood products from United States Forest Service significant amounts of carbon through photosynthesis. When carbon is removed from forests through harvest Forest Service (USFS) and other agencies are interested in accurately accounting for carbon flux

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

    EPA Science Inventory

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

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

    EPA Science Inventory

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

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

    PubMed

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

    2015-01-21

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

  7. Enzymatic production of glycerol carbonate from by-product after biodiesel manufacturing process.

    PubMed

    Jung, Hongsub; Lee, Youngrak; Kim, Daeheum; Han, Sung Ok; Kim, Seung Wook; Lee, Jinwon; Kim, Yong Hwan; Park, Chulhwan

    2012-08-10

    Glycerol carbonate is one of the higher value-added products derived from glycerol. In this study, glycerol carbonate (GC) was synthesized by transesterification of glycerol and dimethyl carbonate (DMC) using Novozym 435 (Candida antarctica Lipase B) at various conditions. For the enzymatic production of GC, the optimum conditions were the amount of enzyme (75 g/L), DMC/glycerol molar ratio (2.00), reaction temperature (60°C) and organic solvent (acetonitrile). Experimental investigation of the effect of water content revealed that the conversion of GC was maximized with no added water. The addition of surfactant such as Tween 80 increased the GC conversion, which finally reached 96.25% under the optimum condition and with surfactant addition. PMID:22759533

  8. Oxygen production and carbon sequestration in an upwelling coastal Burke Hales,1

    E-print Network

    Pierce, Stephen

    Oxygen production and carbon sequestration in an upwelling coastal margin Burke Hales,1 Lee Karp), Oxygen production and carbon sequestration in an upwelling coastal margin, Global Biogeochem. Cycles, 20 of particulate organic carbon (POC) and dissolved O2 during the upwelling season off the Oregon coast. Oxygen

  9. Water quality factors affecting bromate reduction in biologically active carbon filters

    Microsoft Academic Search

    Mary Jo Kirisits; VERNON L. SNOEYINK; Hatice Inan; JOANNE C. CHEE-SANFORD; Lutgarde Raskin; JESS C. BROWN

    2001-01-01

    Biological removal of the ozonation by-product, bromate, was demonstrated in biologically active carbon (BAC) filters. For example, with a 20-min EBCT, pH 7.5, and influent dissolved oxygen (DO) and nitrate concentrations 2.1 and 5.1mg\\/l, respectively, 40% bromate removal was obtained with a 20?g\\/l influent bromate concentration. In this study, DO, nitrate and sulfate concentrations, pH, and type of source water

  10. Activated carbon from coconut coirpith as metal adsorbent: adsorption of Cd(II) from aqueous solution

    Microsoft Academic Search

    K. Kadirvelu; C. Namasivayam

    2003-01-01

    Activated carbon prepared from coirpith, an agricultural solid waste by-product, has been used for the adsorption of Cd(II) from aqueous solution. Parameters such as the agitation time, metal ion concentration, adsorbent dose and pH were studied. The adsorption data fit well with the Langmuir and Freundlich isotherm models. The adsorption capacity (Q0) calculated from the Langmuir isotherm was 93.4 mg

  11. Adsorption of basic dye (methylene blue) onto activated carbon prepared from rattan sawdust

    Microsoft Academic Search

    B. H. Hameed; A. L. Ahmad; K. N. A. Latiff

    2007-01-01

    Activated carbon prepared from non-wood forest product waste (rattan sawdust) has been utilized as the adsorbent for the removal of methylene blue dye from an aqueous solution. The experimental data were analyzed by the Langmuir and Freundlich models of adsorption. Equilibrium data fitted well with the Langmuir model with maximum monolayer adsorption capacity of 294.14mg\\/g. The dimensionless factor, RL revealed

  12. Evaluation of the isosteric heat of adsorption at zero coverage for hydrogen on activated carbons

    NASA Astrophysics Data System (ADS)

    Dohnke, E.; Beckner, M.; Romanos, J.; Olsen, R.; Wexler, C.; Pfeifer, P.

    2011-03-01

    Activated carbons made from corn cob show promise as materials for high-capacity hydrogen storage. As part of our characterization of these materials, we are interested in learning how different production methods affect the adsorption energies. In this talk, we will show how hydrogen adsorption isotherms may be used to calculate these adsorption energies at zero coverage using Henry's law. We will additionally discuss differences between the binding energy and the isosteric heat of adsorption by applying this analysis at different temperatures.

  13. Distribution of and changes in industrial carbon dioxide production

    NASA Astrophysics Data System (ADS)

    Rotty, Ralph M.

    1983-02-01

    The burning of fossil fuels is believed to be the major source responsible for an observed increase in the concentration of carbon dioxide in the atmosphere now measured at many locations around the world. This paper revises earlier published data on the annual amounts of carbon released to the atmosphere during the period 1950-1978 and updates the record through 1980. A latitudinal distribution of the fossil fuel source is presented as an aid in explaining the differences in the observed CO2 concentrations at several stations. Data from Mauna Loa Observatory, the South Pole, and elsewhere around the world [Keeling et al., 1978a, b; Bolin and Bischof, 1970; Herbert, 1980] show an increase in the concentration of carbon dioxide in the atmosphere. Attempts to deduce from these records information about the global carbon cycle depend upon data pertaining to the sources of CO2 introduced by man-burning of fossil fuels and conversion of the world's forests. The latitudinal distribution of the fossil fuel production of CO2 should be an important aid in carbon-cycle analysis. Observations in the atmosphere show that the Northern Hemisphere CO2 concentration is increasing more rapidly than the Southern Hemisphere concentration and that the most rapid increase is at 50°-60°N latitude. The greatest seasonal variation also occurs in this latitude band. This paper updates and documents the fossil fuel sources of CO2. It revises global CO2 emission values for 1950-1978 published earlier; it demonstrates that a change in the rate of increase of annual CO2 emissions occurred in 1973; and it attempts to delineate the regional distribution of this source of CO2.

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

    PubMed

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

    2014-07-01

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

  15. One-carbon substrate-based biohydrogen production: microbes, mechanism, and productivity.

    PubMed

    Rittmann, Simon K-M R; Lee, Hyun Sook; Lim, Jae Kyu; Kim, Tae Wan; Lee, Jung-Hyun; Kang, Sung Gyun

    2015-01-01

    Among four basic mechanisms for biological hydrogen (H2) production, dark fermentation has been considered to show the highest hydrogen evolution rate (HER). H2 production from one-carbon (C1) compounds such as formate and carbon monoxide (CO) is promising because formate is an efficient H2 carrier, and the utilization of CO-containing syngas or industrial waste gas may render the industrial biohydrogen production process cost-effective. A variety of microbes with the formate hydrogen lyase (FHL) system have been identified from phylogenetically diverse groups of archaea and bacteria, and numerous efforts have been undertaken to improve the HER for formate through strain optimization and bioprocess development. CO-dependent H2 production has been investigated to enhance the H2 productivity of various carboxydotrophs via an increase in CO gas-liquid mass transfer rates and the construction of genetically modified strains. Hydrogenogenic CO-conversion has been applied to syngas and by-product gas of the steel-mill process, and this low-cost feedstock has shown to be promising in the production of biomass and H2. Here, we focus on recent advances in the isolation of novel phylogenetic groups utilizing formate or CO, the remarkable genetic engineering that enhances H2 productivity, and the practical implementation of H2 production from C1 substrates. PMID:25461503

  16. [Removal of fluorescent whitening agent by hydrogen peroxide oxidation catalyzed by activated carbon].

    PubMed

    Liu, Hai-Long; Zhang, Zhong-Min; Zhao, Xia; Jiao, Ru-Yuan

    2014-06-01

    Degradation of fluorescent whitening agent VBL in the processes of activated carbon (AC) and activated carbon modified (ACM) adsorptions, hydrogen peroxide (H2O2) oxidation, and hydrogen peroxide oxidation catalyzed by activated carbon were studied. Mechanism of the above catalytic oxidation was also investigated by adding tert-Butyl alcohol (TBA), the free radical scavenger, and detecting the released gases. The results showed that: the activated carbon modified by Fe (NO3)3 (ACM)exhibited better adsorption removal than AC. Catalytic oxidation showed efficient removal of VBL, and the catalytic removal of AC (up to 95%) was significantly higher than that of ACM (58% only). Catalytic oxidation was inhibited by TBA, which indicates that the above reaction involved *OH radicals and atom oxygen generated by hydrogen peroxide with the presence of AC. The results of H2O2 decomposition and released gases detection involved in the process showed that activated carbon enhanced the decomposition of H2O2 which released oxygen and heat. More O2 was produced and higher temperature of the reactor was achieved, which indicated that H2O2 decomposition catalyzed by ACM was significantly faster than that of AC. Combining the results of VBL removal, it could be concluded that the rate of active intermediates (*OH radicals and atom oxygen) production by ACM catalytic reaction was faster than that of AC. These intermediates consumed themselves and produced O2 instead of degrading VBL. It seemed that the improper mutual matching of the forming rate of activating intermediates and the supply rate of reactants was an important reason for the lower efficiency of ACM catalytic reaction comparing with AC. PMID:25158496

  17. 75 FR 43488 - Certain Hot-Rolled Carbon Steel Flat Products From India: Final Results of Countervailing Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-26

    ...Trade Administration [C-533-821] Certain Hot-Rolled Carbon Steel Flat Products From India...the countervailing duty (CVD) order on certain hot-rolled carbon steel flat products (hot-rolled carbon steel) from India for the...

  18. Adsorption of nickel(II) from aqueous solution onto activated carbon prepared from coirpith

    Microsoft Academic Search

    K. Kadirvelu; K. Thamaraiselvi; C. Namasivayam

    2001-01-01

    Activated carbon has been prepared from coirpith by chemical activation and characterized. Carbonised coirpith is able to adsorb Ni(II) from aqueous solution. It was noted that a decreasing in the carbon concentration with constant Ni concentration, or an increase in the Ni concentration with constant carbon concentration resulted in a higher nickel uptake per unit weight of carbon. The Langmuir

  19. Active carbon filter health condition detection with piezoelectric wafer active sensors

    NASA Astrophysics Data System (ADS)

    Bao, Jingjing; Giurgiutiu, Victor; Rubel, Glenn O.; Peterson, Gregory W.; Ball, Thomas M.

    2011-04-01

    The impregnated active carbon used in air purification systems degrades over time due to exposure to contamination and mechanical effects (packing, settling, flow channeling, etc.). A novel approach is proposed to detect contamination in active carbon filters by combining the electromechanical impedance spectroscopy (EMIS) and electrochemical impedance spectroscopy (ECIS). ECIS is currently being used to evaluate active carbon filtration material; however, it cannot differentiate the impedance changes due to chemical contamination from those due to mechanical changes. EMIS can detect impedance changes due to mechanical changes. For the research work presented in this paper, Piezoelectric wafer active sensor (PWAS) was used for the EMIS method. Some remarkable new phenomena were unveiled in the detection of carbon filter status. 1. PWAS EMIS can detect the presence of contaminants, such as water and kerosene in the carbon bed 2. PWAS EMIS can monitor changes in mechanical pressure that may be associated with carbon bed packing, settling and flow channeling 3. EMIS and ECIS measurements are consistent with each other and complimentary A tentative simplified impedance model was created to simulate the PWAS-carbon bed system under increasing pressure. Similar impedance change pattern was observed when comparing the simulation results with experimental data.

  20. Lipid production for biofuels from hydrolyzate of waste activated sludge by heterotrophic Chlorella protothecoides.

    PubMed

    Wen, Qinxue; Chen, Zhiqiang; Li, Pengfei; Duan, Ran; Ren, Nanqi

    2013-09-01

    Microalga Chlorella protothecoides can accumulate high proportion of lipids during the heterotrophic growth with glucose as the carbon source. However, its commercial application is restricted due to the high cost of the carbon source. In this study, the wasted activated sludge (WAS) was hydrolyzed after ultrasonic pre-treatment and the hydrolyzate obtained was used as an alternative carbon source for algal biomass and biodiesel production. The results indicate that C. protothecoides can proliferate in the WAS hydrolyzate and accumulate biolipid. The final lipid content of the culture fed with the hydrolyzate was 21.5±1.44% (weight percent) after 156 h cultivation in flasks and the maximum biomass obtained was 0.5 g L(-1). Acetic acid and isovaleric acid were favorable carbon sources for cell growth. The soluble microbial products (SMP) presents in the hydrolyzate can also be used as a carbon source for cell growth. PMID:23856018

  1. Degradation of Refractory Organic Pollutants by Catalytic Ozonation—Activated Carbon and Mn-Loaded Activated Carbon as Catalysts

    Microsoft Academic Search

    Jun Ma; Ming-Hao Sui; Zhong-Lin Chen; Li-Ning Wang

    2004-01-01

    A novel catalyst for the ozonation process was prepared by loading manganese on the granular activated carbon (GAC). Nitrobenzene was used as a model refractory organic micropollutant in this study. The catalytic activity of GAC and the Mn-loaded GAC were studied respectively. The removal efficiency of nitrobenzene by Mn-loaded GAC catalyzed ozonation could reach 34.2–49.9%, with the oxidation efficiency being

  2. Adsorption of carbon monoxide on activated carbon impregnated with metal halide

    SciTech Connect

    Tamon, Hajime; Kitamura, Kenji; Okazaki, Morio [Kyoto Univ. (Japan). Dept. of Chemical Engineering] [Kyoto Univ. (Japan). Dept. of Chemical Engineering

    1996-02-01

    Carbon monoxide (CO) removal is important in the purification of ammonia-synthesis gas produced by the partial oxidation of hydrocarbons, the water-gas reaction, or the steam reforming of hydrocarbons. A coke-oven gas, a blast-furnace gas, and a converter gas also contain 8--89% CO. Activated carbon was impregnated with a metal halide, and adsorption and desorption characteristics of CO on the carbon were measured by fixed-bed runs. It was found that the impregnation of PdCl{sub 2} or CuCl effectively increases CO absorption. PdCl{sub 2}/CuCl-impregnated carbons were characterized by N{sub 2} adsorption, SEM, EPMA, and XPS. Adsorption isotherms of CO were also measured on these carbons, and the influence of the loading of impregnant on CO adsorption was experimentally elucidated. A selection procedure of impregnant was proposed based on the frontier orbital theory. The perturbation energy for molecular orbital mixing was estimated by the HOMO-LUMO interaction. CO adsorption on impregnated carbons was qualitatively interpreted using the perturbation energy, and the energy was regarded as an index of impregnant selection.

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

    PubMed

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

    2007-01-01

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

  4. Managing Commercial Tree Species for Timber Production and Carbon Sequestration: Management Guidelines and Financial Returns

    SciTech Connect

    Gary D. Kronrad

    2006-09-19

    A carbon credit market is developing in the United States. Information is needed by buyers and sellers of carbon credits so that the market functions equitably and efficiently. Analyses have been conducted to determine the optimal forest management regime to employ for each of the major commercial tree species so that profitability of timber production only or the combination of timber production and carbon sequestration is maximized. Because the potential of a forest ecosystem to sequester carbon depends on the tree species, site quality and management regimes utilized, analyses have determined how to optimize carbon sequestration by determining how to optimally manage each species, given a range of site qualities, discount rates, prices of carbon credits and other economic variables. The effects of a carbon credit market on the method and profitability of forest management, the cost of sequestering carbon, the amount of carbon that can be sequestered, and the amount of timber products produced has been determined.

  5. Presentation 2.3: The sustainable forest products industry, carbon and climate change Mikael Hannus

    E-print Network

    : · The connections between the forest products industry and the global carbon cycle are complex, and hastily enacted and the global carbon cycle are complex, and hastily enacted climate change policies can have unintended

  6. Preparation of activated carbons from walnut shells via vacuum chemical activation and their application for methylene blue removal

    Microsoft Academic Search

    Juan Yang; Keqiang Qiu

    2010-01-01

    Activated carbons were prepared from walnut shells by vacuum chemical activation with zinc chloride as the activation agent. To optimize the preparation method, the effects of the main process parameters (such as system pressure, activation temperature, and impregnation ratio) on the properties (expressed in terms of specific surface area and pore volume) of the obtained activated carbons were studied. It

  7. Activation and micropore structure determination of activated carbon-fiber composites

    SciTech Connect

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

    1997-09-05

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

  8. Irreversible adsorption of phenolic compounds by activated carbons

    SciTech Connect

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

    1988-12-01

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

  9. 76 FR 60803 - Fourth Administrative Review of Certain Activated Carbon From the People's Republic of China...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-30

    ...A-570-904] Fourth Administrative Review of Certain Activated Carbon From the People's Republic of China: Extension...initiation of an administrative review of certain activated carbon from the People's Republic of China...

  10. A Model-Based Framework to Overlap Product Development Activities

    Microsoft Academic Search

    Viswanathan Krishnan; Steven D. Eppinger; Daniel E. Whitney

    1997-01-01

    Intense competition in many industries forces manufacturing firms to develop new, higher quality products at an increasingly rapid pace. Overlapping product development activities is an important component of concurrent product development that can help firms develop products faster. However, since product development activities may be coupled in complex ways, overlapping interrelated activities can present many difficulties. Without careful management of

  11. A comparative study of carbon dioxide adsorption on multi-walled carbon nanotubes versus activated charcoal

    NASA Astrophysics Data System (ADS)

    Khalili, S.; Ghoreyshi, A. A.; Jahanshahi, M.; Davoodi, M.

    2012-09-01

    In this study, the quilibrium adsorption of CO2 on activated charcoal and multi-walled carbon nanotube (MWCNT) were experimentally investigated at temperature range of 298-318 K and pressures up to 40 bars. The maximum storage capacity for both materials was obtained at lowest temperature and highest pressure under study. The amount of CO2 adsorbed on MWCNT is 2 times higher than that of activated Charcoal whereas the specific surface area of activated carbon is aboute 2 times higher than MWNT. The experimental data of CO2 adsorption have been analyzed using different model isotherms such as the Freundlich and Langmuir. Heat of adsorption evaluated from a set of isotherms based on the Clausius-Clapeyron equation indicated physical nature of adsorption mechanism.

  12. N-Doped carbon hybrid conjugates as vectors for photocatalytic CS2 production

    NASA Astrophysics Data System (ADS)

    Jiang, Tengteng; Jiang, Guohua; Li, Lei; Chen, Hua; Zhou, Huijie; Yao, Juming; Kong, Xiangdong; Chen, Wenxing

    2015-04-01

    Nanostructured carbon materials have attracted much attention, because the doping or modification can efficiently induce charge delocalization and tune the work function of carbon. Herein, we report that N-doped carbon hybrid conjugates are highly sensitive in photocatalytic CS2 production due to the energy transfer and electron transfer between carbon and organic ligands. The key towards success was opening a new avenue for the cheap and rapid release of a potential therapeutic agent using carbon materials as vectors.

  13. Adsorption of malachite green on groundnut shell waste based powdered activated carbon

    SciTech Connect

    Malik, R. [Environmental Impact and Risk Assessment Division, National Environmental Engineering Research Institute, Nagpur 440 020, Maharashtra (India); Ramteke, D.S. [Environmental Impact and Risk Assessment Division, National Environmental Engineering Research Institute, Nagpur 440 020, Maharashtra (India)], E-mail: dsramteke@rediffmail.com; Wate, S.R. [Environmental Impact and Risk Assessment Division, National Environmental Engineering Research Institute, Nagpur 440 020, Maharashtra (India)

    2007-07-01

    In the present technologically fast changing situation related to waste management practices, it is desirable that disposal of plant waste should be done in a scientific manner by keeping in view economic and pollution considerations. This is only possible when the plant waste has the potential to be used as raw material for some useful product. In the present study, groundnut shell, an agricultural waste, was used for the preparation of an adsorbent by chemical activation using ZnCl{sub 2} under optimized conditions and its comparative characterisation was conducted with commercially available powdered activated carbon (CPAC) for its physical, chemical and adsorption properties. The groundnut shell based powdered activated carbon (GSPAC) has a higher surface area, iodine and methylene blue number compared to CPAC. Both of the carbons were used for the removal of malachite green dye from aqueous solution and the effect of various operating variables, viz. adsorbent dose (0.1-1 g l{sup -1}), contact time (5-120 min) and adsorbate concentrations (100-200 mg l{sup -1}) on the removal of dye, has been studied. The experimental results indicate that at a dose of 0.5 g l{sup -1} and initial concentration of 100 mg l{sup -1}, GSPAC showed 94.5% removal of the dye in 30 min equilibrium time, while CPAC removed 96% of the dye in 15 min. The experimental isotherm data were analyzed using the linearized forms of Freundlich, Langmuir and BET equations to determine maximum adsorptive capacities. The equilibrium data fit well to the Freundlich isotherm, although the BET isotherm also showed higher correlation for both of the carbons. The results of comparative adsorption capacity of both carbons indicate that groundnut shell can be used as a low-cost alternative to commercial powdered activated carbon in aqueous solution for dye removal.

  14. Catalytic carbon membranes for hydrogen production. Final report

    SciTech Connect

    Damle, A.S.; Gangwal, S.K.

    1992-01-01

    Commercial carbon composite microfiltration membranes may be modified for gas separation applications by providing a gas separation layer with pores in the 1- to 10-nm range. Several organic polymeric precursors and techniques for depositing a suitable layer were investigated in this project. The in situ polymerization technique was found to be the most promising, and pure component permeation tests with membrane samples prepared with this technique indicated Knudsen diffusion behavior. The gas separation factors obtained by mixed-gas permeation tests were found to depend strongly on gas temperature and pressure indicating significant viscous flow at high-pressure conditions. The modified membranes were used to carry out simultaneous water gas shift reaction and product hydrogen separation. These tests indicated increasing CO conversions with increasing hydrogen separation. A simple process model was developed to simulate a catalytic membrane reactor. A number of simulations were carried out to identify operating conditions leading to product hydrogen concentrations over 90 percent. (VC)

  15. The Use of Activated Carbon Prepared from Jackfruit (Artocarpus heterophyllus) Peel Waste for Methylene Blue Removal

    Microsoft Academic Search

    Devarly PRAHAS; Yoga KARTIKA; Nani INDRASWATI; Suryadi ISMADJI

    Jackfruit peel waste which has no economic value has been utilized for activated carbon preparation. The preparation of the activated carbon was carried out using chemical activation with phosphoric acid as activating agent. The impregnation ratio was 4:1 (g H3PO4\\/g raw material) and semi carbonization process was conducted at 200oC and followed with carbonization at 550oC. The applicability of this

  16. Effects of iron-based additives in the preparation of magnetic coal-based activated carbon

    Microsoft Academic Search

    Jun Zhang; Qiang Xie; Xi Chen; Juan Liu; Xin Yao

    2011-01-01

    Magnetization of activated carbon is one of the promising ways for separation of spent activated carbon from contaminants and regeneration. Magnetic coal-based activated carbons(MAC) were prepared from Taixi anthracite in the presence of Fe3O4, Fe2(C2O4)3 and Fe(NO3)3 respectively. The magnetic activated carbon samples were characterized by vibrating sample magnetometer (VSM), X-ray diffraction (XRD), N2 adsorption and scanning electric microscope (SEM).

  17. Influence of different chemical reagents on the preparation of activated carbons from bituminous coal

    Microsoft Academic Search

    Li-Yeh Hsu; Hsisheng Teng

    2000-01-01

    Activated carbons were prepared by chemical activation from bituminous coal with three chemical reagents, ZnCl2, H3PO4 and KOH. The activation consisted of impregnation of a reagent followed by carbonization in nitrogen at various temperatures. A thermogravimetric study showed that these reagents were capable of suppressing the evolution of tarry substances during carbonization. Because of carbon oxidation and gasification mechanisms, activation

  18. Simultaneous removal of H 2S and COS using activated carbons and their supported catalysts

    Microsoft Academic Search

    Kinya Sakanishi; Zhiheng Wu; Akimitsu Matsumura; Ikuo Saito; Toshiaki Hanaoka; Tomoaki Minowa; Mitsuhiro Tada; Toshihiko Iwasaki

    2005-01-01

    Adsorption and catalytic decomposition of H2S and COS were investigated over active carbons using a flow reactor with fixed bed in the temperature range from 300 to 450°C. Active carbons removed very effectively COS at a relatively high temperature of 400°C, some portion being decomposed to CO over active carbons. Although H2S was also removed by active carbons at 400°C,

  19. Active dissolution and natural passivation of carbon steel in carbon dioxide-loaded alkanolamine solutions

    SciTech Connect

    Tomoe, Y.; Shimizu, M.; Kaneta, H. [Teikoku Oil Co., Ltd., Tokyo (Japan)

    1996-08-01

    Corrosion rates of carbon steel specimens were measured in carbon dioxide(CO{sub 2})-loaded alkanolamine(amine) solutions by weight-loss tests and by the polarization resistance method. In dilute amine solutions, lower than 10{sup {minus}2} M, corrosion rates were controlled by the formation of protective FeCO{sub 3} scale as in hot, CO{sub 2}-H{sub 2}O environments. Tested amines inhibited CO{sub 2} induced corrosion in the concentration range between 10{sup {minus}2} and 2M. In concentrated amine solutions, higher than 3M, primary and tertiary amines showed markedly different effects on carbon steel corrosion. The corrosion rates of carbon steel rose with the increase in primary amine concentration, whereas the corrosion rates of carbon steel stayed low in tertiary amine solutions even at 6M, due to the formation of protective FeCO{sub 3} scale. Tertiary amines absorb CO{sub 2} as HCO{sub 3}{sup {minus}} in the presence of water. On the contrary, primary amines absorb CO{sub 2} by two ways. One is as HCO{sub 3}{sup {minus}} like tertiary amines, and the other is direct absorption of CO{sub 2} without water, producing amine-carbamate. The chemical substances produced due to the absorption of CO{sub 2} by amines are considered to play important roles not only on corrosion rates but also on the morphology and protectiveness of corrosion products.

  20. Mutagenic activity of disinfection by-products

    SciTech Connect

    Cognet, L.; Courtois, Y.; Mallevialle, J.

    1986-11-01

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

  1. The adsorption of pharmaceutically active compounds from aqueous solutions onto activated carbons.

    PubMed

    Raki?, Vesna; Rac, Vladislav; Krmar, Marija; Otman, Otman; Auroux, Aline

    2015-01-23

    In this study, the adsorption of pharmaceutically active compounds - salicylic acid, acetylsalicylic acid, atenolol and diclofenac-Na onto activated carbons has been studied. Three different commercial activated carbons, possessing ?650, 900 or 1500m(2)g(-1) surface areas were used as solid adsorbents. These materials were fully characterized - their textural, surface features and points of zero charge have been determined. The adsorption was studied from aqueous solutions at 303K using batch adsorption experiments and titration microcalorimetry, which was employed in order to obtain the heats evolved as a result of adsorption. The maximal adsorption capacities of investigated solids for all target pharmaceuticals are in the range of 10(-4)molg(-1). The obtained maximal retention capacities are correlated with the textural properties of applied activated carbon. The roles of acid/base features of activated carbons and of molecular structures of adsorbate molecules have been discussed. The obtained results enabled to estimate the possibility to use the activated carbons in the removal of pharmaceuticals by adsorption. PMID:24857621

  2. Burners and combustion apparatus for carbon nanomaterial production

    DOEpatents

    Alford, J. Michael; Diener, Michael D; Nabity, James; Karpuk, Michael

    2013-02-05

    The invention provides improved burners, combustion apparatus, and methods for carbon nanomaterial production. The burners of the invention provide sooting flames of fuel and oxidizing gases. The condensable products of combustion produced by the burners of this invention produce carbon nanomaterials including without limitation, soot, fullerenic soot, and fullerenes. The burners of the invention do not require premixing of the fuel and oxidizing gases and are suitable for use with low vapor pressure fuels such as those containing substantial amounts of polyaromatic hydrocarbons. The burners of the invention can operate with a hot (e.g., uncooled) burner surface and require little, if any, cooling or other forms of heat sinking. The burners of the invention comprise one or more refractory elements forming the outlet of the burner at which a flame can be established. The burners of the invention provide for improved flame stability, can be employed with a wider range of fuel/oxidizer (e.g., air) ratios and a wider range of gas velocities, and are generally more efficient than burners using water-cooled metal burner plates. The burners of the invention can also be operated to reduce the formation of undesirable soot deposits on the burner and on surfaces downstream of the burner.

  3. Burners and combustion apparatus for carbon nanomaterial production

    DOEpatents

    Alford, J. Michael (Lakewood, CO); Diener, Michael D. (Denver, CO); Nabity, James (Arvada, CO); Karpuk, Michael (Boulder, CO)

    2007-10-09

    The invention provides improved burners, combustion apparatus, and methods for carbon nanomaterial production. The burners of the invention provide sooting flames of fuel and oxidizing gases. The condensable products of combustion produced by the burners of this invention produce carbon nanomaterials including without limitation, soot, fullerenic soot, and fullerenes. The burners of the invention do not require premixing of the fuel and oxidizing gases and are suitable for use with low vapor pressure fuels such as those containing substantial amounts of polyaromatic hydrocarbons. The burners of the invention can operate with a hot (e.g., uncooled) burner surface and require little, if any, cooling or other forms of heat sinking. The burners of the invention comprise one or more refractory elements forming the outlet of the burner at which a flame can be established. The burners of the invention provide for improved flame stability, can be employed with a wider range of fuel/oxidizer (e.g., air) ratios and a wider range of gas velocities, and are generally more efficient than burners using water-cooled metal burner plates. The burners of the invention can also be operated to reduce the formation of undesirable soot deposits on the burner and on surfaces downstream of the burner.

  4. 78 FR 70533 - Certain Activated Carbon From the People's Republic of China: Final Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-26

    ...Administration [A-570-904] Certain Activated Carbon From the People's Republic of China...administrative review on certain activated carbon from the People's Republic of China...1\\ See Certain Activated Carbon From the People's Republic of...

  5. 40 CFR 60.2115 - What if I do not use a wet scrubber, fabric filter, activated carbon injection, selective...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...wet scrubber, fabric filter, activated carbon injection, selective noncatalytic reduction...wet scrubber, fabric filter, activated carbon injection, selective noncatalytic reduction...other than a wet scrubber, activated carbon injection, selective...

  6. 77 FR 67337 - Certain Activated Carbon From the People's Republic of China; 2010-2011; Final Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-09

    ...Administration [A-570-904] Certain Activated Carbon From the People's Republic of China...antidumping duty order on certain activated carbon from the People's Republic of China...1\\ See Certain Activated Carbon From the People's Republic of...

  7. 75 FR 48644 - Certain Activated Carbon From the People's Republic of China: Notice of Partial Rescission of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-11

    ...Ningxia Tianfu Activated Carbon Co., Ltd.; Ningxia Tongfu Coking Co., Ltd.; Ningxia Weining Active Carbon Co., Ltd...Ltd.; Shanghai Activated Carbon Co. Ltd.; Shanghai Coking and Chemical Corporation; Shanghai Goldenbridge...

  8. 77 FR 72824 - Certain Activated Carbon From the People's Republic of China; 2011-2012; Partial Rescission of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-06

    ...Administration [A-570-904] Certain Activated Carbon From the People's Republic...antidumping duty order on certain activated carbon from the People's Republic...antidumping duty order on certain activated carbon from the PRC (``the...

  9. 75 FR 61697 - Certain Activated Carbon From the People's Republic of China: Extension of Time Limits for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-06

    ...Administration [A-570-904] Certain Activated Carbon From the People's Republic...antidumping duty order on certain activated carbon from the People's Republic...Administrative Review of Certain Activated Carbon from the People's...

  10. 76 FR 39851 - Certain Activated Carbon From the People's Republic of China: Notice of Partial Rescission of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ...Administration [A-570-904] Certain Activated Carbon From the People's Republic...antidumping duty order on certain activated carbon from the People's Republic...CCT'') and Ningxia Huahui Activated Carbon Co., Ltd....

  11. 78 FR 77419 - Certain Activated Carbon From the People's Republic of China; 2012-2013; Partial Rescission of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-23

    ...Administration [A-570-904] Certain Activated Carbon From the People's Republic...antidumping duty order on certain activated carbon from the People's Republic...antidumping duty order on certain activated carbon from the PRC (``the...

  12. 75 FR 61126 - Certain Activated Carbon From the People's Republic of China: Extension of Time Limit for Final...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-04

    ...Administration [A-570-904] Certain Activated Carbon From the People's Republic...administrative review on certain activated carbon from the People's Republic...of this review. See Certain Activated Carbon From the People's...

  13. 76 FR 43654 - Certain Activated Carbon From the People's Republic of China: Extension of Time Limit for Final...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-21

    ...Administration [A-570-904] Certain Activated Carbon From the People's Republic...administrative review on certain activated carbon from the People's Republic...April 30, 2011. See Certain Activated Carbon From the People's...

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

    NASA Technical Reports Server (NTRS)

    Kaloupis, P.; Sridhar, K. R.

    1991-01-01

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

  15. Determination of heavy metals in activated charcoals and carbon black for Lyocell fiber production using direct solid sampling high-resolution continuum source graphite furnace atomic absorption and inductively coupled plasma optical emission spectrometry.

    PubMed

    Lepri, Fábio G; Borges, Daniel L G; Araujo, Rennan G O; Welz, Bernhard; Wendler, Frank; Krieg, Marcus; Becker-Ross, Helmut

    2010-05-15

    Reactivity and concentration of additives, especially activated charcoal, employed for the Lyocell process, enhance the complexity of reactions in cellulose/N-methylmorpholine-N-oxide monohydrate solutions. Analytical control of the starting materials is a basic requirement to know the concentration of heavy metals, which are potential initiators of autocatalytic reactions. Seven activated charcoal and two carbon black samples have been analyzed regarding their content of seven elements, Cr, Cu, Fe, Mn, Mo, Ni and V using direct solid sampling high-resolution continuum source graphite furnace AAS (SS-HR-CS GF AAS) and inductively coupled plasma optical emission spectrometry (ICP OES) after microwave-assisted acidic digestion as a reference method. The limits of detection of the former technique are 1-2 orders of magnitude lower than those of ICP OES and comparable to those of more sophisticated techniques. For iron the working range of HR-CS GF AAS has been expanded by simultaneous measurement at two secondary absorption lines (344,099nm and 344,399nm). Partial least-squares regression between measured and calculated temperatures for beginning exothermicity (T(on)) has been used to investigate the prediction capability of the investigated techniques. Whereas the ICP OES measurements for seven elements resulted in an error of prediction of 3.67%, the results obtained by SS-HR-CS GF AAS exhibited a correlation coefficient of 0.99 and an error of prediction of only 0.68%. Acceptable correlation has been obtained with the latter technique measuring only three to four elements. PMID:20298882

  16. Magnetron Sputtering of Gold Nanoparticles onto WO3 and Activated Carbon

    SciTech Connect

    Veith, Gabriel M [ORNL; Lupini, Andrew R [ORNL; Pennycook, Stephen J [ORNL; Villa, Alberto [Universita di Milano, Italy; Prati, Laura [Universita di Milano, Italy; Dudney, Nancy J [ORNL

    2007-01-01

    In this paper we describe the production and investigation of two supported gold catalyst systems prepared by magnetron sputtering: Au on WO3 and Au on activated carbon. The magnetron sputtering technique entails the sputtering of a high purity gold metal target, with an argon plasma, to produce a flux of gold atoms onto a constantly tumbling support material. This technique offers a number of advantages over conventional chemical preparation methods including the flexibility to create gold nanoparticles (diameters < 3 nm) on unusual support materials, such as WO3 and carbon, which are generally not accessible using the ubiquitous deposition-precipitation technique. We present data demonstrating the formation of catalytic gold nanoparticles with average diameters of 1.7 nm (Au/C) and 2.1 nm (Au/WO3) as well as a substantial number of single atom species on the Au/C sample. Prototypical carbon monoxide oxidation (Au/WO3) and glycerol oxidation (Au/C) reactions were performed in order to gauge the activity of these catalysts. The WO3 supported catalyst exhibits substantial catalytic activity from room temperature to 135oC (0.0018 - 0.082 mole CO/mole Au sec) with an apparent transition around 75oC to a more active catalyst. The activity 1 of the Au/C catalysts was compared to a Au/C catalysts prepared from a PVA sol. The smaller catalysts prepared by sputtering are more active than the large gold particles prepared using the PVA sol. However, the larger gold catalyst are substaintially more selective towards the production of intermediate products from the oxidation of glycerol.

  17. Highly Active Palladium\\/Activated Carbon Catalysts for Heck Reactions: Correlation of Activity, Catalyst Properties, and Pd Leaching

    Microsoft Academic Search

    Klaus Khler; Roland G. Heidenreich; Jürgen G. E. Krauter; Jörg Pietsch

    2002-01-01

    A variety of palladium on activated carbon catalysts differing in Pd dispersion, Pd distribution, Pd oxi- dation state, and water content were tested in Heck reactions of aryl bro- mides with olefins. The optimization of the catalyst (structure ± activity relation- ship) and reaction conditions (temper- ature, solvent, base, and Pd loading) allowed Pd\\/C catalysts with very high activity for

  18. Adsorption characteristics of phenol and chlorophenols on granular activated carbons (GAC)

    Microsoft Academic Search

    Min-Woo Jung; Kyu-Hong Ahn; Yonghun Lee; Ki-Pal Kim; Jae-Seong Rhee; Jung Tae Park; Ki-Jung Paeng

    2001-01-01

    The adsorption of phenol and chlorophenols on four commercial granular activated carbons (GAC) was investigated by batch experiment to correlate with the structure of activated carbons. Physical properties including surface area, average pore diameter and micropore volume and chemical structure of the activated carbons were characterized by N2 adsorption experiment, scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, elemental analysis,

  19. Letters to the Editor STEM imaging of single Pd atoms in activated carbon fibers

    E-print Network

    Pennycook, Steve

    Letters to the Editor STEM imaging of single Pd atoms in activated carbon fibers considered individual Pd atoms that are highly dispersed throughout the vol- ume of activated carbon fibers by adding transition metals to their microstructure [1]. For instance, activated carbon fibers (ACFs

  20. Adsorption of methylene blue onto bamboo-based activated carbon: Kinetics and equilibrium studies

    Microsoft Academic Search

    B. H. Hameed; A. T. M. Din; A. L. Ahmad

    2007-01-01

    Bamboo, an abundant and inexpensive natural resource in Malaysia was used to prepare activated carbon by physiochemical activation with potassium hydroxide (KOH) and carbon dioxide (CO2) as the activating agents at 850°C for 2h. The adsorption equilibrium and kinetics of methylene blue dye on such carbon were then examined at 30°C. Adsorption isotherm of the methylene blue (MB) on the