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1

Minimizing activated carbons production cost  

Microsoft Academic Search

A detailed economic evaluation of activated carbons production process from various raw materials is undertaken using the conventional economic indices (ROI, POT, and NPV). The fundamental factors that affect production cost were taken into account. It is concluded that for an attractive investment in activated carbons production one should select the raw material with the highest product yield, adopt a

G. G. Stavropoulos; A. A. Zabaniotou

2009-01-01

2

Reprocessing of used tires into activated carbon and other products  

Microsoft Academic Search

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

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

1995-01-01

3

Production and characterization of granular activated carbon from activated sludge  

Microsoft Academic Search

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

Z. Al-Qodah; R. Shawabkah

2009-01-01

4

DEVELOPMENT OF ACTIVATED CARBONS FROM COAL COMBUSTION BY-PRODUCTS  

SciTech Connect

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

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

2003-09-30

5

Reprocessing of used tires into activated carbon and other products  

SciTech Connect

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

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

1995-09-01

6

JV Task 90 - Activated Carbon Production from North Dakota Lignite  

SciTech Connect

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.

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

2008-03-31

7

Production and characterization of activated carbons from cereal grains  

SciTech Connect

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 a rate of increase of 7% each year. Activated carbons can be prepared from a variety of raw materials. Approximately, 60% of the activated carbons generated in the United States is produced from coal; 20%, from coconut shells; and the remaining 20% from wood and other sources of biomass. The pore structure and properties of activated carbons are influenced by the nature of the starting material and the initial physical and chemical conditioning as well as the process conditions involved in its manufacture. The porous structures of charcoals and activated carbons obtained by the carbonization of kernels have been characterized.

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

1996-12-31

8

Production Scale-Up or Activated Carbons for Ultracapacitors  

SciTech Connect

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

Dr. Steven D. Dietz

2007-01-10

9

Production of activated carbon from acorns and olive seeds  

Microsoft Academic Search

This study has been designed to produce activated carbon from acorns and olive seeds. The starting materials are low in cost and they are the cause of solid waste pollution problems in Jordan. A chemical procedure is used to produce the required activated carbon. The results indicate that activated carbon produced from acorns compares favorably with that from olive seeds

Walid K Lafi

2001-01-01

10

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

Microsoft Academic Search

To promote utilization of poultry litter as a source material for manufacturing low-cost activated carbon (AC) that can be used in wastewater treatment, this study investigated optimal production conditions and water-borne organic sorption potential of poultry litter-based AC. Pelletized broiler litter was carbonized at different temperatures for varied time periods and activated with steam at a range of flow rate

Mingxin Guo; Weiping Song

2011-01-01

11

DEVELOPMENT OF ACTIVATED CARBONS FROM COAL COMBUSTION BY-PRODUCTS  

Microsoft Academic Search

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

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

2000-01-01

12

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

Microsoft Academic Search

The process design and economic analysis of process plants to produce activated carbons from waste tires and coal have been performed. The potential range of products from each process has been considered, namely for waste tire – pyro-gas, active carbon, carbon black and pyro-oil; for coal – pyro-gas and active carbons. Sensitivity analyses have been carried out on the main

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

2004-01-01

13

PRODUCTION OF ACTIVATED CARBON FROM BAMBOO USING CHEMICAL AND STEAM ACTIVATIONS  

Microsoft Academic Search

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

E. Puad Mahanim; J. Rafidah

14

DEVELOPMENT OF ACTIVATED CARBONS FROM COAL COMBUSTION BY-PRODUCTS  

Microsoft Academic Search

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

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

2002-01-01

15

DEVELOPMENT OF ACTIVATED CARBONS FROM COAL COMBUSTION BY-PRODUCTS  

Microsoft Academic Search

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

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

2003-01-01

16

PRODUCTION OF ACTIVATED CARBON FROM SAWDUST USING FLUIDIZED BED REACTOR  

Microsoft Academic Search

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

MAN KEE LAM; RIDZUAN ZAKARIA

17

Experimental investigation of factors controlling the calcium carbonate ion activity product of shallow water carbonate-rich sediments  

E-print Network

EXPERIMENTAL INVESTIGATION OF FACTORS CONTROLLING THE CALCIUM CARBONATE ION ACTIVITY PRODUCT OF SHALLOW WATER CARBONATE-RICH SEDIMENTS A Thesis by LAWRENCE DOUGLAS BERNSTEIN Submitted to the Graduate College of Texas A&M University... in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE December 1983 Major Subject: Oceanography EXPERIMENTAL INVESTIGATION OF FACTORS CONTROLLING THE CALCIUM CARBONATE ION ACTIVITY PRODUCT OF SHALLOW WATER CARBONATE...

Bernstein, Lawrence Douglas

2012-06-07

18

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

PubMed

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

Guo, Mingxin; Song, Weiping

2011-12-01

19

Precursor materials suitability for super activated carbons production  

Microsoft Academic Search

Low cost-high availability materials (pet coke, charcoals, lignite and used tire char), not extensively investigated in the past, were chemically activated with KOH. Produced activated carbons demonstrated high adsorption capacities both in the gas and liquid phase as exemplified by N2 and methylene blue adsorption experiments and the application of BET and Langmuir equations and the DR method. An exception

G. G. Stavropoulos

2005-01-01

20

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

NASA Astrophysics Data System (ADS)

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

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

2013-08-01

21

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

SciTech Connect

Activated carbon is produced from coconut shell char using steam or carbon dioxide as the reacting gas in a 100 mm diameter fluidized bed reactor. The effect of process parameters such as reaction time, fluidizing velocity, particle size, static bed height, temperature of activation, fluidizing medium, and solid raw material on activation is studied. The product is characterized by determination of iodine number and BET surface area. The product obtained in the fluidized bed reactor is much superior in quality to the activated carbons produced by conventional processes. Based on the experimental observations, the optimum values of process parameters are identified.

Sai, P.M.S.; Ahmed, J. [Bhabha Atomic Research Centre, Kalpakkam (India). Centralised Waste Management Facility; Krishnaiah, K. [Indian Inst. of Tech., Madras (India). Dept. of Chemical Engineering

1997-09-01

22

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

Microsoft Academic Search

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

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

2007-01-01

23

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

Microsoft Academic Search

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

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

2005-01-01

24

Microwave-assisted catalytic decomposition of methane over activated carbon for CO 2 -free hydrogen production  

Microsoft Academic Search

The aim of this work was to combine microwave heating with the use of low-cost granular activated carbon as a catalyst for the production of CO2-free hydrogen by methane decomposition in a fixed bed quartz-tube flow reactor. In order to compare the results achieved, conventional heating was also applied to the catalytic decomposition reaction of methane over the activated carbon.

A. Domínguez; B. Fidalgo; Y. Fernández; J. J. Pis; J. A. Menéndez

2007-01-01

25

OPTIMIZATION STUDY OF A PILOT ROTARY KILN FOR ACTIVATED CARBON PRODUCTION  

Microsoft Academic Search

This work presents an optimization study of the steady operation of a pilot rotary kiln, used to manufacture activated carbon (AC) from eucalyptus wood. The main goal proposed is the maximization of a process operating profit, which has been achieved maintaining a good quality product and maximum production yield. The objective function represents the operating profit and includes incomes by

Oscar A. Ortiz; Nora D. Martínez; A. Mengual; Pablo M. Aballay

26

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

Microsoft Academic Search

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

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

2005-01-01

27

Improved Bioethanol Production Using Activated Carbon-treated Acid Hydrolysate from Corn Hull in Pachysolen tannophilus  

PubMed Central

To optimally convert corn hull, a byproduct from corn processing, into bioethanol using Pachysolen tannophlius, we investigated the optimal conditions for hydrolysis and removal of toxic substances in the hydrolysate via activated carbon treatment as well as the effects of this detoxification process on the kinetic parameters of bioethanol production. Maximum monosaccharide concentrations were obtained in hydrolysates in which 20 g of corn hull was hydrolyzed in 4% (v/v) H2SO4. Activated carbon treatment removed 92.3% of phenolic compounds from the hydrolysate. When untreated hydrolysate was used, the monosaccharides were not completely consumed, even at 480 h of culture. When activated carbon-treated hydrolysate was used, the monosaccharides were mostly consumed at 192 h of culture. In particular, when activated carbon-treated hydrolysate was used, bioethanol productivity (P) and specific bioethanol production rate (Qp) were 2.4 times and 3.4 times greater, respectively, compared to untreated hydrolysate. This was due to sustained bioethanol production during the period of xylose/arabinose utilization, which occurred only when activated carbon-treated hydrolysate was used. PMID:23983522

Seo, Hyeon-Beom; Kim, Seungseop; Lee, Hyeon-Yong

2009-01-01

28

Renewable phenols production by catalytic microwave pyrolysis of Douglas fir sawdust pellets with activated carbon catalysts.  

PubMed

The effects of different activated carbon (AC) catalysts based on various carbon sources on products yield and chemical compositions of upgraded pyrolysis oils were investigated using microwave pyrolysis of Douglas fir sawdust pellets. Results showed that high amounts of phenols were obtained (74.61% and 74.77% in the upgraded bio-oils by DARCO MRX (wood based) and DARCO 830 (lignite coal based) activated carbons, respectively). The catalysts recycling test of the selected catalysts indicated that the carbon catalysts can be reused for at least 3-4 times and produced high concentrations of phenol and phenolic compounds. The chemical reaction mechanism for phenolics production during microwave pyrolysis of biomass was analyzed. PMID:23765005

Bu, Quan; Lei, Hanwu; Wang, Lu; Wei, Yi; Zhu, Lei; Liu, Yupeng; Liang, Jing; Tang, Juming

2013-08-01

29

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

NASA Astrophysics Data System (ADS)

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 precursor (biochar) were used for production of activated carbons by two common methods of activation: physical and chemical activation in which steam and potassium hydroxide (KOH), respectively, were used. Experiments were designed by the statistical central composite design method. Two models were developed for the BET surface area and reaction yield of each activation process. These models showed the effects of operating conditions, such as activation temperature, mass ratio of activating agent to precursor, activation time, and nitrogen flowrate on the BET surface area and reaction yield for each activation method for each precursor. The optimum operating conditions were calculated using these models to produce activated carbons with relatively large BET surface area (> 500 m2/g) and high reaction yield (> 50 wt %). The BET surface area and reaction yield for activated carbons produced at optimum operating conditions showed maximum 7 and 7.4% difference, respectively, comparing to the values predicted by models. The activated carbons produced at optimum operating conditions were used as the base catalysts for the direct oxidation of 1 mol % hydrogen sulphide in nitrogen to sulphur at the temperature range of 160-205°C and pressure of 700 kPa. Originally activated carbons showed a good potential for oxidation of hydrogen sulphide by their selectivity for sulphur product and low amount of sulphur dioxide production. To improve the performance of steam-activated carbons, the catalysts were modified by acid-treatment followed by thermal desorption. This method increased the break-through times for coal-based and biomass-based catalysts to 115 and 141 minutes, respectively. The average amounts of sulphur dioxide produced during the reaction time were 0.14 and 0.03% (as % of hydrogen sulphide fed to the reactor) for modified activated carbons prepared from biochar and luscar char, respectively. The effects of porous structure, surface chemistry, and ash content on the performances of these activated carbon catalysts were investigated for the direct oxidation reaction of hydrogen sulphide. The acid-treatment followed by thermal desorption of activated carbons developed the porosity which produced more surface area for active sites and in addition, provided more space for sulphur product storage resulting in higher life time for catalyst. Boehm titration and temperature program desorption showed that the modification method increased basic character of carbon surface after thermal desorption in comparison to acid-treated sample. In addition, the effects of impregnating agents (potassium iodide and manganese nitrate) and two solvents for impregnation process were studied on the performance of the activated carbon catalysts for the direct oxidation of H2S to sulphur. Sulphur L-edge X-ray near edge structure (XANES) showed that the elemental sulphur was the dominant sulphur species in the product. The kinetic study for oxidation reaction of H2S over LusAC-O-D(650) was performed for temperature range of 160-190°C, oxygen to hydrogen sulphide molar ratio of 1-3, and H2S concentration of 6000-10000 ppm at 200 kPa. The values of activation energy were 26.6 and 29.3 kJ.gmol-1 for Eley-Rideal and Langmuir-Hinshelwood mechanisms, respectively.

Azargohar, Ramin

30

Process simulation of activated carbon production using a rotary kiln  

Microsoft Academic Search

The rotary kiln used for the activation of charcoal is simulated using mass and energy balances to obtain the temperature\\u000a distributions of environmental gas and solid in the kiln. The computed results are used to find the optimal operation condition.\\u000a In finding the optimal gas temperature for the reductive gas environment necessary to the charcoal activation, the outcome\\u000a gives the

Young Han Kim

2011-01-01

31

The production of activated silica with carbon dioxide gas  

E-print Network

IOD Figure Vl GEL TIME of ACTIVATED SILIA SOLS 2. 5 2. 1 1. 7 1. 3 0. 9 Run Conditions RE- 5000 % Si OE- 2. 50 % Rr-6, 25 SCFM M COz= H. ~ Oj 0. 5 500 700 900 1100 Gel Time, Seconds 1300 1500 1800 1900 Figure Vll SULFUR DIOXIDE CONTENT... IOD Figure Vl GEL TIME of ACTIVATED SILIA SOLS 2. 5 2. 1 1. 7 1. 3 0. 9 Run Conditions RE- 5000 % Si OE- 2. 50 % Rr-6, 25 SCFM M COz= H. ~ Oj 0. 5 500 700 900 1100 Gel Time, Seconds 1300 1500 1800 1900 Figure Vll SULFUR DIOXIDE CONTENT...

Hayes, William Bell

2012-06-07

32

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

SciTech Connect

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

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

2001-12-01

33

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

PubMed

Activated carbon has been prepared from molasses, a natural precursor of vegetable origin resulting from the sugar industry in Morocco. The preparation of the activated carbon from the molasses has been carried out by impregnation of the precursor with sulphuric acid, followed by carbonisation at varying conditions (temperature and gas coverage) in order to optimize preparation parameters. The influence of activation conditions was investigated by determination of adsorption capacity of methylene blue and iodine, the BET surface area, and the pore volume of the activated carbon were determined while the micropore volume was determined by the Dubinin-Radushkevich (DR) equation. The activated materials are mainly microporous and reveal the type I isotherm of the Brunauer classification for nitrogen adsorption. The activated carbons properties in this study were found for activation of the mixture (molasses/sulphuric acid) in steam at 750 degrees C. The samples obtained in this condition were highly microporous, with high surface area (> or =1200 m2/g) and the maximum adsorption capacity of methylene blue and iodine were 435 and 1430 mg/g, respectively. PMID:15721553

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

2005-02-14

34

Activated carbon from biomass  

NASA Astrophysics Data System (ADS)

Activated carbon are unique and versatile adsorbents having extended surface area, micro porous structure, universal adsorption effect, high adsorption capacity and high degree of surface reactivity. Activated carbons are synthesized from variety of materials. Most commonly used on a commercial scale are cellulosic based precursors such as peat, coal, lignite wood and coconut shell. Variation occurs in precursors in terms of structure and carbon content. Coir having very low bulk density and porous structure is found to be one of the valuable raw materials for the production of highly porous activated carbon and other important factor is its high carbon content. Exploration of good low cost and non conventional adsorbent may contribute to the sustainability of the environment and offer promising benefits for the commercial purpose in future. Carbonization of biomass was carried out in a horizontal muffle furnace. Both carbonization and activation were performed in inert nitrogen atmosphere in one step to enhance the surface area and to develop interconnecting porosity. The types of biomass as well as the activation conditions determine the properties and the yield of activated carbon. Activated carbon produced from biomass is cost effective as it is easily available as a waste biomass. Activated carbon produced by combination of chemical and physical activation has higher surface area of 2442 m2/gm compared to that produced by physical activation (1365 m2/gm).

Manocha, S.; Manocha, L. M.; Joshi, Parth; Patel, Bhavesh; Dangi, Gaurav; Verma, Narendra

2013-06-01

35

Toward Zero Carbon Energy Production Toward Zero Carbon Energy Production  

E-print Network

#12;Toward Zero Carbon Energy Production Toward Zero Carbon Energy Production Toward Zero Carbon Energy Production Toward Zero Carbon Energy Production Toward Zero Carbon Energy Production Toward Zero Carbon Energy Production Toward Zero Carbon Energy Production Toward Zero Carbon Energy Production Toward

Narasayya, Vivek

36

Liquid-phase adsorption: Characterization and use of activated carbon prepared from diosgenin production residue  

Microsoft Academic Search

The adsorption behavior of activated carbon (AC) prepared from the residue of diosgenin by-product was characterized. The adsorption capacities of AC such as iodine, phenol and methylene blue (MB) are 933.28, 145.38 and 165mg\\/g, respectively. The results of MP analysis and BJH method show AC has developed micropore and mesopore volumes, which are 0.1621 and 0.2623cm3\\/g respectively, with the mean

Caixiang Zhang; Yanxin Wang; Xifeng Yan

2006-01-01

37

Steam or carbon dioxide-activated carbons from almond shells: physical, chemical and adsorptive properties and estimated cost of production  

Microsoft Academic Search

A series of steam- or carbon dioxide (CO2)-activated, granular activated carbons (GACs) were made from almond shells using six different activation or activation\\/oxidation conditions for each series. Unoxidized\\/oxidized pairs of GACs were compared among treatments and to two commercial GACs in order to determine the relative value of the carbons. Comparative terms included yield, surface area, attrition, surface charge, copper

Christopher A Toles; Wayne E Marshall; Lynda H Wartelle; Andrew McAloon

2000-01-01

38

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

SciTech Connect

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

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

2001-12-01

39

Understanding activated carbons  

SciTech Connect

It would be fair to say that most chemical industry professionals can explain the differences between adsorption and absorption. But when asked which type of activated carbon would be best suited for a particular application, few chemists or chemical engineers would be able to identify what properties to look for. Activated carbon is used in a wide variety of applications such as purification or recovery of chemical products, catalysis or catalyst supports, and various environmental applications such as VPC abatement and wastewater purification. With such broad used in industry, it is critical for engineers and chemists to understand the differences between activated carbons in order to obtain the best performance from their processes.

Boppart, S.; Ingle, L.; Potwora, R.J.; Rester, D.O. [NORIT Americas Inc., Atlanta, GA (United States)

1996-09-01

40

Manufacturing and environmental applications of granular activated carbon from processed solid residue of olive mill products (JEFT)  

Microsoft Academic Search

A new technique for processing the soild residue of olive mill products (JEFT) to produce granular and powdered activated carbon has been developed. The activation process of JEFT is very cost effective and can be achieved without advanced technology. The manufactured activated carbon has been tested to treat drinking water containing: trace concentrations of Cr(III), Ni(II), Pb(II), Cd(II), and Zn(II);

S. H. Gharaibeh

1999-01-01

41

Granular activated carbon installations  

Microsoft Academic Search

This article 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 information to estimate costs for GAC treatment of water supplies is provided. In conjunction with previous reports, this article may

Russell L. Culp; Robert M. Clark

1983-01-01

42

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...

43

Treatment of olive mill waste water with activated carbons from agricultural by-products.  

PubMed

A series of activated carbons prepared by a two-step steam activation of olive stone and solvent extracted olive pulp (SEOP) have been used in an attempt to investigate the total phenol removal and chemical oxygen demand (COD) decrease in olive mill waste water (OMWW). The temperature of carbonization and activation were kept constant at 850 and 800 degrees C, respectively. One of the carbons was prepared by a single-step process at 800 degrees C. Activated carbons have been characterized by adsorption of N2 at 77 K and mercury porosimetry. Their iodine values were also determined. Surface oxides of activated carbons were determined using the Boehm's method. The porosity development and the surface chemistry of carbons were correlated to increasing removal ability of organic molecules. Kinetics of adsorption was evaluated by applying the Lagegren model while adsorption isotherm data were fitted to Langmuir model. Mesoporosity seems to be the key factor for total phenol removal while micoporosity controls the adsorption of total organics as expressed by the COD decrease in OMWW. For carbons with similar structure, the adsorption of phenols or total organics might be affected by the presence of carbonyls. PMID:12365783

Galiatsatou, Polymnia; Metaxas, Michail; Arapoglou, Dimitrios; Kasselouri-Rigopoulou, Vasilia

2002-01-01

44

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

Microsoft Academic Search

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

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

2009-01-01

45

Production and characterisation of activated carbon from wood components in powder: Cellulose, lignin, xylan  

Microsoft Academic Search

The aim of this work was to characterise the activated carbon produced from wood and its basic components: cellulose, lignin and xylan (hemicelluloses). Two ways of activation were tested: simple pyrolysis under N2 and thermal treatment of the material impregnated with KOH (KOH-activation). Concerning the pyrolysis, simultaneous measurements of DTA-TGA allowed to compare the heat of reaction and the decomposition

L. Khezami; A. Chetouani; B. Taouk; R. Capart

2005-01-01

46

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

Microsoft Academic Search

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

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

2008-01-01

47

Acid-activated carbons from almond shells: physical, chemical and adsorptive properties and estimated cost of production  

Microsoft Academic Search

A series of phosphoric-acid activated carbons were made from almond shells using six different activation or activation\\/oxidation methods. The carbons were compared to each other and to two commercial carbons in an effort to ascertain the relative value of the carbons in terms of yield, surface area, attrition, surface functional groups, organic uptake, metal uptake, as well as estimated cost

Christopher A Toles; Wayne E Marshall; Mitchell M Johns; Lynda H Wartelle; Andrew McAloon

2000-01-01

48

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

Microsoft Academic Search

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

Kaustubha Mohanty; Debabrata Das; Manindra Nath Biswas

2008-01-01

49

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...

50

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

Microsoft Academic Search

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

Ramin Azargohar

2009-01-01

51

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

PubMed

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

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

2009-01-01

52

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

Microsoft Academic Search

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

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

2007-01-01

53

Activated carbon gets revved up  

SciTech Connect

When it comes to adsorption, few products can match the low cost and efficient performance of activated carbon. That`s why the material is so widely used for wastewater treatment. But with processors looking for economical ways to achieve environmental compliance in other operations, the market s taking off in different directions, wit much attention focused on air purification, process water treatment and solvent recovery. It is the opportunity that manufacturers and marketers of activated carbon have been waiting for. All revved up, they are generating new products and regenerating spent carbon, and rounding out their offerings with equipment and technical service. The article discusses new products and applications, increasing regeneration capacity, and competition in the activated carbon industry.

Hairston, D.

1995-11-01

54

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

SciTech Connect

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

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

2012-10-01

55

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

PubMed

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

Shamsijazeyi, Hadi; Kaghazchi, Tahereh

2014-01-01

56

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

Microsoft Academic Search

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

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

2010-01-01

57

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

PubMed

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

Bae, Wookeun; Kim, Jongho; Chung, Jinwook

2014-08-01

58

Activated carbon gets revved up  

Microsoft Academic Search

When it comes to adsorption, few products can match the low cost and efficient performance of activated carbon. That`s why the material is so widely used for wastewater treatment. But with processors looking for economical ways to achieve environmental compliance in other operations, the market s taking off in different directions, wit much attention focused on air purification, process water

1995-01-01

59

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

SciTech Connect

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

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

2009-05-01

60

Biochar as a precursor of activated carbon  

Microsoft Academic Search

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

R. Azargohar; A. K. Dalai

2006-01-01

61

Biochar As a Precursor of Activated Carbon  

Microsoft Academic Search

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

R. Azargohar; A. K. Dalai

62

Surface properties of granular activated carbons from agricultural by-products and their effects on raw sugar decolorization  

Microsoft Academic Search

Granular activated carbons (GACs) were produced from sugarcane bagasse combined with one of two binders (corn syrup, coal tar) by physical activation and from pecan shells by physical and chemical activation. GACs were evaluated for their physical (hardness, bulk density), chemical (ash, pH), surface (surface area, pore size distribution, surface chemistry), and adsorption properties (molasses color removal, sugar decolorization) and

M Ahmedna; W. E Marshall; R. M Rao

2000-01-01

63

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 ...

64

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

EPA Science Inventory

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

65

Temperature effects on biohydrogen production in a granular sludge bed induced by activated carbon carriers  

Microsoft Academic Search

Temperature effects on H2 production performance of a novel carrier-induced granular sludge bed (CIGSB) reactor were investigated. Using sucrose-based synthetic wastewater as the feed, the CIGSB system was operated at 30–45?C to identify the optimal working temperature. It was found that H2 production was the most efficient at 40?C, especially when it was operated at a low hydraulic retention time

Kuo-Shing Lee; Ping-Jei Lin; Jo-Shu Chang

2006-01-01

66

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

Microsoft Academic Search

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

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

2001-01-01

67

Production and characterization of activated carbon prepared from safflower seed cake biochar and its ability to absorb reactive dyestuff  

NASA Astrophysics Data System (ADS)

The use of activated carbon obtained from biochar for the removal of reactive dyestuff from aqueous solutions at various contact times, pHs and temperatures was investigated. The biochar was chemically modified with potassium hydroxide. The surface area and micropore volume of activated carbon was 1277 m2/g and 0.4952 cm3/g, respectively. The surface characterization of both biochar and activated carbon was undertaken using by Fourier transform infrared spectroscopy and scanning electron microscopy. The experimental data indicated that the adsorption isotherms are well described by the Dubinin-Radushkevich (DR) isotherm equation. The adsorption kinetics of reactive dyestuff obeys the pseudo second-order kinetic model. The thermodynamic parameters such as ?G?, ?H? and ?S? were calculated to estimate the nature of adsorption. The activation energy of the system was calculated as 1.12 kJ/mol. According to these results, prepared activated carbon could be used as a low-cost adsorbent to compare with the commercial activated carbon for the removal reactive dyestuff from wastewater.

Ang?n, Dilek; Köse, T. Ennil; Selengil, U?ur

2013-09-01

68

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

Microsoft Academic Search

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

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

1993-01-01

69

Carbon Dioxide Production at Home  

NSDL National Science Digital Library

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

70

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

Microsoft Academic Search

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

Ina Kristiana; Cynthia Joll; Anna Heitz

2011-01-01

71

Optimization of activated carbon production from empty fruit bunch fibers in one-step steam pyrolysis for cadmium removal from aqueous solution  

Microsoft Academic Search

The fast growth of the palm oil industry in Malaysia is associated with various waste products, namely the empty fruit bunches\\u000a (EFB), which have a negative impact on the environment. Therefore, these wastes were utilized as a cheap raw material for\\u000a the production of activated carbon (AC) with less energy consumption. One-step steam pyrolysis was used to produce AC from

Ma’an F. Alkhatib; Suleyman A. Muyibi; Jeminat Omotayo Amode

72

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

SciTech Connect

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

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

2001-06-01

73

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...

74

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

SciTech Connect

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

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

2011-07-01

75

Dewatering Peat With Activated Carbon  

NASA Technical Reports Server (NTRS)

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

Rohatgi, N. K.

1984-01-01

76

Making Activated Carbon by Wet Pressurized Pyrolysis  

NASA Technical Reports Server (NTRS)

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

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

2006-01-01

77

Biochar as a precursor of activated carbon.  

PubMed

Biochar was evaluated as a precursor of activated carbon. This product was produced by chemical activation using potassium hydroxide. The effects of operating conditions of activation process, such as temperature, activating agent to biochar mass ratio, and nitrogen flow rate, on the textural and chemical properties of the product were investigated. Activated carbon produced by this method has internal surface area at least 50 times than that of the precursor and is highly microporous, which is also confirmed by scanning electron microscopy analysis. Fourier-transform infrared spectroscopy analysis showed development of aromatization in the structure of activated carbon. X-ray diffraction data indicated the formation of small, two-dimensional graphite-like structure at high temperatures. Thermogravimetric study showed that when potassium hydroxide to biochar mass ratio was more than one, the weight loss decreased. PMID:16915686

Azargohar, R; Dalai, A K

2006-01-01

78

Biochar as a precursor of activated carbon.  

PubMed

Biochar was evaluated as a precursor of activated carbon. This product was produced by chemical activation using potassium hydroxide. The effects of operating conditions of activation process, such as temperature, activating agent to biochar mass ratio, and nitrogen flow rate, on the textural and chemical properties of the product were investigated. Activated carbon produced by this method has internal surface area at least 50 times than that of the precursor and is highly microporous, which is also confirmed by scanning electron microscopy analysis. Fourier-transform infrared spectroscopy analysis showed development of aromatization in the structure of activated carbon. X-ray diffraction data indicated the formation of small, two-dimensional graphite-like structure at high temperatures. Thermogravimetric study showed that when potassium hydroxide to biochar mass ratio was more than one, the weight loss decreased. PMID:18563652

Azargohar, R; Dalai, A K

2006-03-01

79

Adsorption of methylene blue dye onto activated carbons based on agricultural by-products: equilibrium and kinetic studies.  

PubMed

Mixtures of novolac resin and olive stone biomass (20/80 and 40/60 w/w) were cured, pyrolyzed up to 1,000 °C and activated with CO2 under a continuous flow operation (named N20B-cCa and N40B-cCa respectively). Commercial activated charcoal was similarly re-activated with CO2 and used for comparison reasons (AC-a). The characterization of these materials was performed by Fourier transform Infrared (FTIR) analysis and their specific surface area was determined according to DIN 66132. The materials were tested for their adsorption abilities at different temperatures (298, 333 K) and initial dye concentrations (0.01-0.35 g/L) using 1 L of methylene blue (MB) solution in 10 g of activated carbon. MB adsorption kinetic was also studied. The FTIR spectra of all activated carbons show absorption peaks which correspond to -OH, -CH, -C-O-C- groups and to aromatic ring. The presence of the absorption peak at about 1,400 cm(-1) for N20B-cCa, N40B-cCa indicates more acidic groups on them compared to the commercial AC-a. The specific surface area of N20B-cCa, N40B-cCa and AC-a has values equal to 352, 342 and 760 m(2)/g respectively. From the applied kinetic models, pseudo-second-order equation could best describe MB adsorption. Consequently, such adsorbents can be used as filters to adsorb dyes from wastewaters. PMID:23579821

Ioannou, Z; Simitzis, J

2013-01-01

80

Carbon Dioxide Production in the Oxidation of Organic  

E-print Network

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

Steinbock, Oliver

81

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

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

82

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...

83

Identification of by-products and toxicity assessment in aqueous-phase hydrodechlorination of diuron with palladium on activated carbon catalysts.  

PubMed

The hydrodechlorination (HDC) of diuron in aqueous phase with hydrogen using two different activated carbon-supported Pd catalysts was studied. A commercial activated carbon and one prepared by chemical activation of grape seeds with phosphoric acid (GS) were evaluated as supports, being the catalysts tested in a wide range of temperature (30-100 °C) and space-time (78-311 kgcat h mol(-1)). Diuron conversion was above 70% under all the conditions tested. The Pd catalyst supported on GS showed the highest activity in terms of diuron conversion within the temperature range studied, allowing nearly complete conversion above 50 °C. However, a gradual loss of activity with time was observed for this catalyst. A complete route of hydrogenation of diuron was elucidated. Two reaction routes one leading to fenuron and another to aniline were identified. As the temperature and space-time were increased, the formation of fenuron (via monuron) was found to be favored. The toxicity of the reaction products was evaluated, being the route to fenuron and monuron, the one giving rise to a significant decrease of ecotoxicity. PMID:23562546

Al Bahri, M; Calvo, L; Polo, A M; Gilarranz, M A; Mohedano, A F; Rodriguez, J J

2013-05-01

84

Carbon activation diagnostic for tertiary neutron measurements  

NASA Astrophysics Data System (ADS)

The yield of tertiary neutrons with energies greater than 20 MeV has been proposed to determine the high ?R of inertial confinement fusion targets. The activation of carbon is a valuable measurement technique because of its high reaction threshold, the availability of high-purity samples, and relatively low cost. The 12C(n,2n)11C reaction has a Q value of 18.7 MeV, well above the 14.1 MeV primary DT neutron energy. The isotope 11C decays with a half-life of 20.3 min and emits a positron, resulting in the production of two back-to-back, 511 keV gamma rays upon annihilation. The positron decay of 11C is nearly identical to the copper decay used in the activation measurements of 14.1 MeV primary DT yields; therefore, the present copper activation gamma-detection system can be used to detect the tertiary-produced carbon activation. Because the tertiary neutron yield is more than six orders of magnitude lower than primary neutron yield, the carbon activation diagnostic requires ultrapure carbon samples, free from any positron-emitting contamination. In recent years we have developed carbon purification, packaging, and handling procedures that minimize the contamination signal to a level low enough to use carbon activation for tertiary neutron measurements in direct-drive implosion experiments with DT cryogenic targets on OMEGA. Experimental results of contamination measurements in carbon samples performed on high-neutron-yield shots on OMEGA in 2001-2002 will be presented. A concept for implementing a carbon activation system on the National Ignition Facility (NIF) will be discussed.

Glebov, V. Yu.; Stoeckl, C.; Sangster, T. C.; Meyerhofer, D. D.; Radha, P. B.; Padalino, S.; Baumgart, L.; Colburn, R.; Fuschino, J.

2003-03-01

85

Carbon dioxide effects on ethanol production, pyruvate decarboxylase, and alcohol dehydrogenase activities in anaerobic sweet potato roots.  

PubMed

The effect of varied anaerobic atmospheres on the metabolism of sweet potato (Ipomoea batatas [L.] Lam.) roots was studied. The internal gas atmospheres of storage roots changed rapidly when the roots were submerged under water. O(2) and N(2) gases disappeared quickly and were replaced by CO(2). There were no appreciable differences in gas composition among the four cultivars that were studied. Under different anaerobic conditions, ethanol concentration in the roots was highest in a CO(2) environment, followed by submergence and a N(2) environment in all the cultivars except one. A positive relationship was found between ethanol production and pyruvate decarboxylase activity from both 100% CO(2)-treated and 100% N(2)-treated roots. CO(2) atmospheres also resulted in higher pyruvate decarboxylase activity than did N(2) atmospheres. Concentrations of CO(2) were higher within anaerobic roots than those in the ambient anaerobic atmosphere. The level of pyruvate decarboxylase and ethanol in anaerobic roots was proportional to the ambient CO(2) concentration. The measurable activity of pyruvate decarboxylase that was present in the roots was about 100 times less than that of alcohol dehydrogenase. Considering these observations, it is suggested that the rate-limiting enzyme for ethanol biosynthesis in sweet potato storage roots under anoxia is likely to be pyruvate decarboxylase rather than alcohol dehydrogenase. PMID:16662798

Chang, L A; Hammett, L K; Pharr, D M

1983-01-01

86

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

EPA Science Inventory

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

87

Activated carbon to the rescue  

SciTech Connect

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.

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

1996-03-01

88

Modification of activated carbon with different agents and catalytic performance of products obtained in the process of ethylbenzene dehydrogenation coupled with nitrobenzene hydrogenation  

Microsoft Academic Search

Coupling of oxidative dehydrogenation of ethylbenzene with nitrobenzene hydrogenation (ODE-N), over activated carbons catalysts, has been investigated. Activated carbon was prepared from cherry stones and modified with different chemical agents in the liquid phase (HNO3, CH3COOOH, H2O2, (NH4)2S2O8) or gas phase (air, hydrogen, ammonia) or was subjected to thermal treatment to obtain materials with different surface properties. The initial carbon

Anna Malaika; Mieczys?aw Koz?owski

2011-01-01

89

PRODUCTION OF CARBON PRODUCTS USING A COAL EXTRACTION PROCESS  

Microsoft Academic Search

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

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

2004-01-01

90

Activated carbon from pecan shell: process description and economic analysis  

Microsoft Academic Search

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

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

2003-01-01

91

Paracrystalline structure of activated carbons  

NASA Astrophysics Data System (ADS)

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

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

2001-06-01

92

Hydrocarbon recovery with activated carbon  

Microsoft Academic Search

The principle of adsorption has been used extensively to remove water and to recover gasoline from natural gas with gel-type adsorbents in the quick cycle plants. With the gel adsorbents, water will be adsorbed and will actually replace any hydrocarbons being held by the adsorbent. However, with activated carbon, only heavier organic compounds will replace the lighter ones. The recently

Enneking

1968-01-01

93

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

SciTech Connect

Composite materials formed by impregnating a carbon or graphite fiber mat with plastic binders are being used increasingly in military, aerospace, sports and automotive applications. Carbon fibers are formed primarily from synthetic fibers carbonized in the absence of oxygen. Possibilities exist for the release of these fibers to ambient air during their formation, handling, weaving or impregnation, or during the manufacturing or incineration of composites. This study was concerned with characterizing the rate and physical/chemical properties of such emissions. Samples were collected from manufacturing operations. Operations considered included fiber winding, prepregging and weaving, as well as composity cutting, grinding, drilling, machining, sanding, and incineration. Release rates (fiber mass released per unit of material processed) ranged over several orders of magnitude with the largest releases being associated with weaving and incineration. Except for incineration where fiber diameters were reduced somewhat by burning, the original fiber diameters were maintained in the emitted material. Fiber lengths varied over wide ranges from tens to thousands of micrometers. Incineration experiments suggested that mechanical agitation and air flow in the incinerator would strongly affect releases. Electrical characterization of the fibers demonstrated that fibers will move and form chains in electrical fields.

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

1984-01-01

94

Understanding the link between aggregated industrial production and the carbon price  

E-print Network

the link between aggregated industrial production and the carbon price. In The Economics of Green Energy1 Understanding the link between aggregated industrial production and the carbon price Julien to which economic activity and the carbon price are linked. Carbon price drivers can be mainly related

Boyer, Edmond

95

77 FR 12614 - Activated Carbon From China; Institution of a Five-Year Review  

Federal Register 2010, 2011, 2012, 2013

...certain activated carbon, except California Carbon. The Commission found that appropriate circumstances existed to exclude California Carbon based on the related parties provision...supply and demand conditions or business cycle for the Domestic Like Product that...

2012-03-01

96

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

PubMed Central

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

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

2012-01-01

97

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

PubMed

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

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

2010-02-01

98

Metal salen catalyzed production of polytrimethylene carbonate  

E-print Network

Over the past decade the focus of our group has been production of polycarbonates through environmentally friendly routes. Continuing with this tradition, one such route is the ring opening polymerization of cyclic carbonates. The aliphatic...

Ganguly, Poulomi

2009-06-02

99

Natural products that inhibit carbonic anhydrase.  

PubMed

The chemical diversity, binding specificity and propensity to interact with biological targets has inspired many researchers to utilize natural products as molecular probes. Almost all reported carbonic anhydrase inhibitors comprise a zinc binding group in their structure of which the primary sulfonamide moiety (-SO2NH2) is the foremost example and to a lesser extent the primary sulfamate (-O-SO2NH2) and sulfamide (-NH-SO2NH2) groups. Natural products that comprise these zinc binding groups in their structure are however rare and relatively few natural products have been explored as a source for novel carbonic anhydrase inhibitors. This chapter will highlight the recent and growing interest in carbonic anhydrase inhibitors sourced from nature, demonstrating that natural product chemical space presents a rich source of potential alternate chemotypes for the discovery of novel drug-like carbonic anhydrase inhibitors. PMID:24146386

Poulsen, Sally-Ann; Davis, Rohan A

2014-01-01

100

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

Microsoft Academic Search

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

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

2001-01-01

101

(Data in metric tons of lithium content unless otherwise noted) Domestic Production and Use: The only active lithium carbonate plant in the United States was a brine operation in  

E-print Network

94 LITHIUM (Data in metric tons of lithium content unless otherwise noted) Domestic Production and Use: The only active lithium carbonate plant in the United States was a brine operation in Nevada. Two companies produced a large array of downstream lithium compounds in the United States from domestic or South

102

Carbon Dioxide: Production and Sequestration  

NSDL National Science Digital Library

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

103

Carbon source regulation of antibiotic production.  

PubMed

Antibiotics are low-molecular-mass products of secondary metabolism, nonessential for the growth of producing organisms, but very important for human health. They have unusual structures and are most often formed during the late growth phase of the producing microorganisms. Their production arises from intracellular intermediates, which are condensed into more complex structures through defined biochemical pathways. Their synthesis can be influenced by manipulating the type and concentration of nutrients formulating the culture media. Among them, the effect of the carbon source has been the subject of continuous studies for both industry and research groups. Glucose and other carbohydrates have been reported to interfere with antibiotic synthesis and this effect depends on the rapid utilization of the preferred carbon source. Different mechanisms have been described in bacteria and fungi to explain the negative effects of carbon catabolites on antibiotic production. They show important differences depending on the microbe being considered. Their understanding and manipulation have been useful for both perfecting fermentation conditions to produce anti-infectives and for strain improvement. To improve the production of antibiotics, carbon source repression can be decreased or abolished by mutations resulting in antimetabolite resistance. Enzymes reported as regulated by the carbon source have been used as targets for strain improvement. During the last few years, important advances have been reported elucidating the essential aspects of carbon source regulation on antibiotic production at biochemical and molecular levels. The aim of this review is to describe these advances, giving special emphasis to those reported for the genus Streptomyces. PMID:20664603

Sánchez, Sergio; Chávez, Adán; Forero, Angela; García-Huante, Yolanda; Romero, Alba; Sánchez, Mauricio; Rocha, Diana; Sánchez, Brenda; Avalos, Mariana; Guzmán-Trampe, Silvia; Rodríguez-Sanoja, Romina; Langley, Elizabeth; Ruiz, Beatriz

2010-08-01

104

Adsorbed natural gas storage with activated carbon  

SciTech Connect

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

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

1996-12-31

105

Sorption of petroleum products by carbon sorbents  

SciTech Connect

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

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

2009-07-01

106

Adsorption of herbicides using activated carbons  

SciTech Connect

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

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

1996-10-01

107

Tertiary activated carbon treatment of paper and board industry wastewater  

Microsoft Academic Search

The feasibility of activated carbon post-treatment of (biologically treated) wastewater from the paper and board industry was investigated, the goal being to remove refractory organic pollutants and produce water that can be re-used in the production process. Because closing water-circuits in the paper and board industry results in higher water temperatures, the effect of the temperature on activated carbon treatment

Hardy Temmink; Katja Grolle

2005-01-01

108

Carbon Dioxide Production and Sodium Transport by the Toad Bladder  

Microsoft Academic Search

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

Roy H. Maffly; Cecil H. Coggins

1965-01-01

109

Selecting activated carbon for water and wastewater treatability studies  

SciTech Connect

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

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

2007-10-15

110

A distributed approach to accounting for carbon in wood products  

SciTech Connect

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

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

2010-01-01

111

Carbon Footprint Analysis for a GRAPE Production Case Study  

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

112

CHARACTERIZATION OF ACTIVATED CARBONS PREPARED FROM SUGARCANE BAGASSE BY ZnCl2 ACTIVATION  

Microsoft Academic Search

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

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

2001-01-01

113

Activated carbon from vetiver roots: Gas and liquid adsorption studies  

Microsoft Academic Search

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

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

2007-01-01

114

ACTIVATED CARBON FROM LIGNITE FOR WATER TREATMENT  

Microsoft Academic Search

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

Edwin S. Olson; Daniel J. Stepan

2000-01-01

115

Natural gas storage with activated carbon from a bituminous coal  

USGS Publications Warehouse

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

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

1996-01-01

116

Integrating Steel Production with Mineral Carbon Sequestration  

SciTech Connect

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

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

2008-05-01

117

The carbon footprints of food crop production  

Microsoft Academic Search

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

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

2009-01-01

118

Photobiological hydrogen production and carbon dioxide sequestration  

Microsoft Academic Search

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

Halil Berberoglu

2008-01-01

119

Create a Consortium and Develop Premium Carbon Products from Coal  

SciTech Connect

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

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

2006-01-01

120

Catalytic Growth of Macroscopic Carbon Nanofibers Bodies with Activated Carbon  

NASA Astrophysics Data System (ADS)

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

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

2009-06-01

121

Production of precipitated calcium carbonate from calcium silicates and carbon dioxide  

Microsoft Academic Search

The possibilities for reducing carbon dioxide emissions from the pulp and paper industry by calcium carbonation are presented. The current precipitated calcium carbonate (PCC) production uses mined, crushed calcium carbonate as raw materials. If calcium silicates were used instead, carbon dioxide emissions from the calcination of carbonates would be eliminated. In Finland, there could, thus, be a potential for eliminating

Sebastian Teir; Sanni Eloneva; Ron Zevenhoven

2005-01-01

122

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

PubMed

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

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

2014-07-01

123

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

Microsoft Academic Search

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

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

124

Activated carbons derived from oil palm empty-fruit bunches: Application to environmental problems  

Microsoft Academic Search

Activated carbons derived from oil palm empty fruit bunches (EFB) were investigated to find the suitability of its application for removal of phenol in aqueous solution through adsorption process. Two types of activation namely; thermal activation at 300, 500 and 800°C and physical activation at 150°C (boiling treatment) were used for the production of the activated carbons. A control (untreated

Suleyman A. MUYIBI; Mariatul F. MANSOR; Radziah WAHID

2007-01-01

125

Activated carbon from grass -a green alternative catalyst support for water electrolysis Kalyani Palanichamy1,  

E-print Network

physical characterization, Pt@G-ABC sample has been tested for its catalytic activity in 1M sulphuric acid in the production of G-ABC has also been compared with the traditional commercially available carbon support carbon supported catalyst for H2 generation but also highlight the production of low-cost carbon

Paris-Sud XI, Université de

126

Quality of poultry litter-derived granular activated carbon.  

PubMed

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

Qiu, Guannan; Guo, Mingxin

2010-01-01

127

ACTIVATED CARBON FOR PRECIOUS METALS RECOVERY  

Microsoft Academic Search

Guidelines are presented for the selection, handling and regeneration of activated carbon used in gold recovery operations. The guidelines are based on Calgon Carbon Corporation's own investigations and experience gained in working with gold mine operators all over the world. Gold adsorption rate and adsorption capacity are shown to be independent variables thereby requiring testing of both properties when selecting

William D. Faulkner; John E. Urbanic; Robert W. Ruckel

128

Activated carbons and double layer capacitance  

Microsoft Academic Search

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

Hang Shi

1996-01-01

129

78 FR 13894 - Certain Activated Carbon From China  

Federal Register 2010, 2011, 2012, 2013

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

2013-03-01

130

Activated carbons from steam exploded wood  

SciTech Connect

Earlier work has focused on synthesis of activated carbons from hardwood-white oak and yellow poplar. Current studies have been aimed at understanding the role of biopolymer composition and structure on the porosity development in activated carbons. To this end, wood and wood fractions have been produced by steam explosion and extraction methods to provide starting materials with a range of different compositional characteristics. Powdered activated carbons have been synthesized from these precursors by phosphoric acid activation. The pore size distribution of the activated carbons is highly dependent upon the starting material, it varies with steam explosion conditions (ie, severity) as well as with fractionation protocol. Unfractionated steam exploded fibers produce carbons with different pore size distribution than those that have been extracted with water or alkali. The results suggest that there may be good possibilities for producing carbons with controlled porosity through blending appropriate fractions - hence broadening the range of applications for wood carbons. Studies are also under way to examine the ability to form high surface area extrudates from the wood fractions and their blends.

Jagtoyen, M.; Derbyshire, F.; Wright, R.S. [Univ. of Kentucky Center for Applied Energy Research, Lexington, KY (United States)] [and others

1995-12-01

131

Dimethyl carbonate production for fuel additives  

SciTech Connect

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

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

1996-12-31

132

Gas Adsorption by Activated and Impregnated Carbons.  

National Technical Information Service (NTIS)

HCN/H2O mixed vapor isotherms were measured on BPL activated and ASC whetlerite carbons maintaining an essentially constant relative water pressure and varying the relative HCN pressure. Chemisorption data on ASC whetlerite showed water vapor retention va...

G. B. Freeman, P. J. Reucroft

1977-01-01

133

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 ...

134

Decolorization of molasses' wastewater using activated carbon prepared from cane bagasse  

Microsoft Academic Search

The decolorization of synthetic melanoidin was studied using activated carbon from cane bagasse obtained from Thailand and Brazil. Melanoidin, a nitrogenous brown polymer present in molasses' wastewater, is formed on the interaction between amino acids and carbohydrates. Bagasse, another by-product in the sugar industry, is a cheap material suitable for the preparation of activated carbon.Samples of cane bagasse were carbonized

E. C. Bernardo; R. Egashira; J. Kawasaki

1997-01-01

135

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

Code of Federal Regulations, 2012 CFR

...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...

2012-07-01

136

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

Code of Federal Regulations, 2011 CFR

...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...

2011-07-01

137

Ris-R-Report Emerging product carbon footprint standards and  

E-print Network

Risø-R-Report Emerging product carbon footprint standards and schemes and their possible trade Bolwig and Peter Gibbon Title: Emerging product carbon footprint standards and schemes and their possible, use and disposal. The outcome of these calculations is referred to as "product carbon footprints

138

Adsorption of herbicides using activated carbons  

SciTech Connect

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

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

1996-12-31

139

Activated Carbons From Grape Seeds By Chemical Activation With Potassium Carbonate And Potassium Hydroxide  

NASA Astrophysics Data System (ADS)

Activated carbons were produced from grape seed using either potassium carbonate (K2CO3) or potassium hydroxide (KOH). The carbonization experiments were accomplished at 600 and 800 °C. The effects of the experimental conditions (i.e., type of activation reagents, reagent concentrations, and carbonization temperatures) on the yields and the properties of these activated carbons were analyzed under identical conditions. An increase in the temperature at the same concentrations for both K2CO3 and KOH led to a decrease in the yields of the activated carbons. The lowest activated carbon yields were obtained at 800 °C at the highest reagent concentration (100 wt%) for both K2CO3 and KOH. The activated carbon with the highest surface area of 1238 m2g-1 was obtained at 800 °C in K2CO3 concentration of 50 wt% while KOH produced the activated carbon with the highest surface area of 1222 m2g-1 in a concentration of 25wt% at 800 °C. The obtained activated carbons were mainly microporous.

Okman, Irem; Karagöz, Selhan; Tay, Turgay; Erdem, Murat

2014-02-01

140

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

Code of Federal Regulations, 2010 CFR

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

2010-07-01

141

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

Code of Federal Regulations, 2013 CFR

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

2013-07-01

142

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

Code of Federal Regulations, 2012 CFR

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

2012-07-01

143

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

Code of Federal Regulations, 2011 CFR

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

2011-07-01

144

Nanospace engineering of KOH activated carbon  

NASA Astrophysics Data System (ADS)

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.

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

2012-01-01

145

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

Microsoft Academic Search

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

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

1999-01-01

146

Microwave-assisted regeneration of activated carbon.  

PubMed

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

Foo, K Y; Hameed, B H

2012-09-01

147

Chemical activation of gasification carbon residue for phosphate removal  

NASA Astrophysics Data System (ADS)

Recycling of waste materials provides an economical and environmentally significant method to reduce the amount of waste. Bioash formed in the gasification process possesses a notable amount of unburned carbon and therefore it can be called a carbon residue. After chemical activation carbon residue could be use to replace activated carbon for example in wastewater purification processes. The effect of chemical activation process variables such as chemical agents and contact time in the chemical activation process were investigated. This study also explored the effectiveness of the chemically activated carbon residue for the removal of phosphate from an aqueous solution. The experimental adsorption study was performed in a batch reactor and the influence of adsorption time, initial phosphate concentration and pH was studied. Due to the carbon residue's low cost and high adsorption capacity, this type of waste has the potential to be utilised for the cost-effective removal of phosphate from wastewaters. Potential adsorbents could be prepared from these carbonaceous by-products and used as an adsorbent for phosphate removal.

Kilpimaa, Sari; Runtti, Hanna; Lassi, Ulla; Kuokkanen, Toivo

2012-05-01

148

Catalysts for Efficient Production of Carbon Nanotubes  

NASA Technical Reports Server (NTRS)

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

Sun, Ted X.; Dong, Yi

2009-01-01

149

Commercial Product Activation Using RFID  

NASA Technical Reports Server (NTRS)

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

Jedrey, Thomas

2008-01-01

150

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

NASA Astrophysics Data System (ADS)

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

Rankovi?, D.; Arsenijevi?, Z.; Radi?, N.; Grbi?, B.; Grbav?i?, Ž.

2007-09-01

151

Qualitative determination of carbon black in food products  

Microsoft Academic Search

Carbon black (C.I. 77266) is an insoluble pigment produced by the partial combustion of hydrocarbons. The pigment is known by several synonyms, including vegetable carbon, lamp black and carbon ash, that correspond to the raw materials and methods used for its production. Vegetable carbon (E153) is permitted for use in colouring food in the European Union. The US Food and

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

2011-01-01

152

Qualitative determination of carbon black in food products  

Microsoft Academic Search

Carbon black (C.I. 77266) is an insoluble pigment produced by the partial combustion of hydrocarbons. The pigment is known by several synonyms, including vegetable carbon, lamp black and carbon ash, that correspond to the raw materials and methods used for its production. Vegetable carbon (E153) is permitted for use in colouring food in the European Union. The US Food and

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

2012-01-01

153

TWO-STAGE GRANULAR ACTIVATED CARBON TREATMENT  

EPA Science Inventory

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

154

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...

155

DISPLAYING DYNAMIC CARBON FOOTPRINTS OF PRODUCTS ON MOBILE PHONES  

Microsoft Academic Search

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

Ali Dada; Felix von Reischach; Thorsten Staake

156

Activated carbon produced from an Illinois Basin coal  

Microsoft Academic Search

Activated carbons were produced from an Illinois Basin bituminous coal (IBC-106) by a three-step process: oxidation of the coal in air at 150–250 °C for 2–40 hours, devolatilization of these oxidized coals in nitrogen at 500–730 °C for 1 hour and activation (gasification) of the chars in 45% steam, 4% oxygen in nitrogen at 730–880 °C for 3.5–96 hours. Products

Jian Sun; E. J. Hippo; H. Marsh; W. S. O'Brien; J. C. Crelling

1997-01-01

157

MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT  

SciTech Connect

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

H.C. Maru; M. Farooque

2003-03-01

158

Molten Carbonate Fuel Cell Product Design Improvement  

SciTech Connect

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

NONE

1996-03-01

159

A novel activated carbon for supercapacitors  

SciTech Connect

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

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

2012-03-15

160

Carbon sequestration from boreal wildfires via Pyrogenic Carbon production  

NASA Astrophysics Data System (ADS)

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

Santin, Cristina; Doerr, Stefan; Preston, Caroline

2014-05-01

161

Fabrication of activated carbon fibers/carbon aerogels composites by gelation and supercritical drying  

E-print Network

Fabrication of activated carbon fibers/carbon aerogels composites by gelation and supercritical August 2003) Activated carbon fiber/carbon aerogel (ACF/CA) composites were fabricated by gelling. The ACFs can reinforce the related carbon aerogels when they originally have low mass density and are weak

Liu, Jie

162

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

E-print Network

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

Wu, Jianzhong

163

Activated carbon monoliths for methane storage  

NASA Astrophysics Data System (ADS)

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

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

2012-02-01

164

Waste management activities and carbon emissions in Africa.  

PubMed

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. PMID:20832276

Couth, R; Trois, C

2011-01-01

165

Preparation and characterization of activated carbon from demineralized tyre char  

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

166

Preparation of activated carbons with mesopores by use of organometallics  

SciTech Connect

Activated carbons are commercially produced by steam or CO{sub 2} activation of coal, coconut shell and so on. In general the carbons obtained give pores with a broad range of distribution. The objective of this study was to prepare activated carbons from coal by use of various organometallic compounds. The carbons were evaluated for pore size by nitrogen adsorption experiments.

Yamada, Yoshio; Yoshizawa, Noriko; Furuta, Takeshi [National Institute for Resources and Environment, Tsukuba, Ibaraki (Japan)] [and others

1996-12-31

167

Universal Product Design: Transforming User Activity Into Product Function  

E-print Network

is to develop a universal product method by understanding how user activity closely resembles product function. The research results include a twenty product pair study in which a universal and typical product were compared. An activity diagram and functional...

Kostovich, Vincent

2010-07-14

168

Characteristic and mercury adsorption of activated carbon produced by CO 2 of chicken waste  

Microsoft Academic Search

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°C, pyrolysis in N2 atmosphere, followed by CO2 activation) was used for the production of activated samples. The effects of carbonization temperature (400–600°C), activation temperature (700–900°C), and activation time (1–2.5 h) on the physicochemical properties

Yaji HUANG; Baosheng JIN; Zhaoping ZHONG; Wenqi ZHONG; Rui XIAO

2008-01-01

169

Carbon Monoxide Production Associated with Ineffective Erythropoiesis*  

PubMed Central

The rate of endogenous carbon monoxide production (?Vco), determined by the closed rebreathing system technique, was elevated above the normal range in four of five patients studied with ineffective erythropoiesis (four patients with primary refractory anemia, one with thalassemia). The mean molar ratio of ?Vco to ?Vheme (rate of circulating heme catabolism, determined from 51Cr red cell survival curves) was 3.0 ± 0.6 (SE), indicating that most of the CO originated from sources other than circulating erythrocyte hemoglobin, in contrast to previous findings in patients with hemolytic anemia, where ?Vco paralleled ?Vheme closely. After administration of glycine-2-14C to these patients, endogenous CO was isolated by washout of body CO stores at high pO2 or by reacting peripheral venous blood samples with ferricyanide. The CO was then oxidized to CO2 by palladium chloride and trapped for counting in a liquid scintillation spectrometer. “Early labeled” peaks of 14CO were demonstrated which paralleled “early labeled” peaks of stercobilin and preceded maximal labeling of circulating heme. Production of “early labeled” 14CO in patients with ineffective erythropoiesis was greatly increased, up to 14 times that found in a normal subject. The increased ?Vco and “early 14CO” production shown by these patients are presumably related mainly to heme catabolism in the marrow. The possibility exists that hepatic heme and porphyrin compounds may also contribute significantly to ?Vco, as suggested by the finding of a high ?Vco in an additional patient with porphyria cutanea tarda. PMID:6074003

White, Peter; Coburn, Ronald F.; Williams, William J.; Goldwein, Manfred I.; Rother, Mary L.; Shafer, Brenda C.

1967-01-01

170

USING POWDERED ACTIVATED CARBON: A CRITICAL REVIEW  

EPA Science Inventory

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

171

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...

172

Granular Activated Carbon Filter-Adsorber Systems  

Microsoft Academic Search

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

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

1987-01-01

173

ENGINEERING BULLETIN: GRANULAR ACTIVATED CARBON TREATMENT  

EPA Science Inventory

Granular activated carbon (GAC) treatment is a physicochemical process that removes a wide variety of contaminants by adsorbing them from liquid and gas streams [1, p. 6-3]. This treatment is most commonly used to separate organic contaminants from water or air; however, it can b...

174

ACTIVATED CARBON TREATMENT OF KRAFT BLEACHING EFFLUENTS  

EPA Science Inventory

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

175

Making Activated Carbon for Storing Gas  

NASA Technical Reports Server (NTRS)

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.

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

2005-01-01

176

Improved granular activated carbon for the stabilization of wastewater PH  

SciTech Connect

Laboratory studies have identified the cause of the pH rise, which occurs during water treatment with activated carbon, as an interaction between the naturally occurring anions and protons in the water and the carbon surface. The interaction can be described as an ion exchange type of phenomenon, in which the carbon surface sorbs the anions and corresponding hydronium ions from the water. These studies have shown that the anion sorption and resulting pH increase is independent of the raw material used for the activated carbon production, e.g. bituminous or subbituminous coal, peat, wood or coconut. Also, the pH excursions occur with virgin, reactivated, and acid washed granular carbons. Current pH control technologies focus on adjustment of the wastewater pH prior to discharge or recycle of the initial effluent water until the pH increase abates. However, improved water pH control options have been realized by altering the carbon surface through controlled oxidation rather than the water chemistry or extended preprocessing at the treatment site.

Farmer, R.W.; Dussert, B.W.; Kovacic, S.L. [Calgon Carbon Corp., Pittsburgh, PA (United States)

1996-12-31

177

Adsorption of methyl orange using activated carbon prepared from lignin by ZnCl2 treatment  

NASA Astrophysics Data System (ADS)

Lignocellulosic materials are good and cheap precursors for the production of activated carbon. In this study, activated carbons were prepared from the lignin at different temperatures (200 to 500°C) by ZnCl2. The effects influencing the surface area of the resulting activated carbon are activation temperature, activation time and impregnation ratio. The optimum condition, are found an impregnation ratio of 2, an activation temperature of 450°C, and an activation time of 2 h. The results showed that the surface area and micropores volume of activated carbon at the experimental conditions are achieved to 587 and 0.23 cm3 g-1, respectively. The adsorption behavior of methyl orange dye from aqueous solution onto activated lignin was investigated as a function of equilibrium time, pH and concentration. The Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms. A maximum adsorption capacity of 300 mg g-1 of methyl orange by activated carbon was achieved.

Mahmoudi, K.; Hamdi, N.; Kriaa, A.; Srasra, E.

2012-08-01

178

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

PubMed

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

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

2007-06-01

179

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

SciTech Connect

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

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

1999-11-01

180

Preparation of high-surface-area activated carbons from coconut shell  

Microsoft Academic Search

High-surface-area activated carbons were prepared by chemical activation of coconut shell with KOH as active agent. The influence of activation parameters on the final products was studied by varying the KOH-to-shell ratio, activation temperature and pre-heat temperatures. The samples were characterized by nitrogen adsorption isotherms at 77K. The surface area and pore volume of the carbons were estimated by BET,

Zhonghua Hu; M. P Srinivasan

1999-01-01

181

Pyrolysis of scrap tires and conversion of chars to activated carbon  

Microsoft Academic Search

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

Akbar A. Merchant; Mark A. Petrich

1993-01-01

182

Nano Structured Activated Carbon for Hydrogen Storge  

SciTech Connect

Development of a nanostructured synthetic carbons materials that have been synthesized by thermal-decomposition of aromatic rich polyether such as poly(ether ether ketone) (PEEK) is reported. These polymers based nanostructured carbons efficacious for gas adsorption and storage and have Brunauer-Emmett-Teller (BET) surface area of more than 3000 m2/g, and with average pore diameter of < 2nm. Surface-area, pore characteristics, and other critical variables for selecting porous materials of high gas adsorption capacities are presented. Analysis of the fragments evolved under various carbonization temperatures, and the correlation between the activation and carbonization temperatures provides a mechanistic perspective of the pore evolution during activation. Correlations between gas (N2 and H2) adsorption capacity and porous texture of the materials have been established. The materials possess excellent hydrogen storage properties, with hydrogen storage capacity up to 7.4 wt% (gravimetric) and ~ 45 g H2 L-1 (volumetric) at -196oC and 6.0 MPa.

Israel Cabasso; Youxin Yuan

2013-02-27

183

PRODUCTION OF CARBON 14 BY COSMIC-RAY NEUTRONS  

Microsoft Academic Search

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

R. E. Lingenfelter

1963-01-01

184

Sorption of cobalt on activated carbons from aqueous solutions  

SciTech Connect

The efficiencies of 15 commercially available activated carbons were tested for the separation of trace cobalt ({sup 60}Co) in buffer solutions at pH 5.0, 6.7, and 9.1. On the basis of the results four carbon products, Diahope-006, Eurocarb TN5, Hydraffin DG47, and Norit ROW Supra, were selected for further study. These carbons represented varying (low, medium and high) cobalt removal efficiencies and were prepared of three typical raw materials: peat, coconut shell, or coal. Study was made of the effects on sorption efficiencies of factors of interest in metal/radionuclide-bearing waste effluents. These factors were pH, sodium ions, borate, and citrate.

Paajanen, A.; Lehto, J.; Santapakka, T.; Morneau, J.P. [Univ. of Helsinki (Finland)

1997-01-01

185

Adsorption of Nonylphenol onto Granular Activated Carbon  

Microsoft Academic Search

The applicability of granular activated carbon (GAC)filtration for the removal of the xeno-estrogenicmicropollutant nonylphenol (NP) is evaluated using batchadsorption data. From the obtained adsorption data, it wasapparent that with contact times of 4 d and 24 hr and GACdosages of 1 and 0.1 g L-1 no saturationof the GAC could be obtained with NP total contaminantloadings up to 10 000

Tom Tanghe; Willy Verstraete

2001-01-01

186

Phenol degradation by microorganisms adsorbed on activated carbon  

Microsoft Academic Search

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

H. M. Ehrhardt; H. J. Rehm

1985-01-01

187

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

Microsoft Academic Search

The project deals with understanding the fundamental biochemical mechanisms that physiologically control and regulate carbon and electron flow in anaerobic chemosynthetic bacteria that couple metabolism of single carbon compounds and hydrogen to the production of organic acids (formic, acetic, butyric, and succinic) or methane. The authors compare the regulation of carbon dioxide and hydrogen metabolism by fermentation, enzyme, and electron

J. G. Zeikus; M. Jain

1993-01-01

188

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

NASA Astrophysics Data System (ADS)

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

Murakami, Masahiro; Amii, Hideki; Ito, Yoshihiko

1994-08-01

189

Production of precipitated calcium carbonate from industrial by-product slags (Slag2PCC)  

E-print Network

Production of precipitated calcium carbonate from industrial by-product slags (Slag2PCC) Saostetun for mineral carbonation. Owing to their high calcium con- tent, steelmaking slags could be very suitable for this method, which could safely store carbon di- oxide for a very long time. If calcium could be ex- tracted

Zevenhoven, Ron

190

Purification of Graphite used in Carbon Activation  

NASA Astrophysics Data System (ADS)

Carbon Activation has been developed as a diagnostic to determine the yield of tertiary neutrons. However, copious primary neutrons easily activate positron-emitting contaminants within the disks. To reduce contaminant levels, a thorough purification process has been developed. Detailed packaging and handling procedures are being perfected in order to minimize the gamma signal produced by contaminants. A vacuum oven was used to heat the graphite disks to 1000¢XC @ 200 microns for varying time intervals. The bakeout drove contaminants such as nitrogen, oxygen and hydrocarbons from the disks, which in turn has greatly reduced the number of gamma counts. Careful hermetic packaging procedures have been developed so that the disks do not come in contact with air or other surface contaminants after the bakeout. These techniques have been refined, significantly reducing the contamination signal seen on high-neutron-yield shots on OMEGA. The experimental results of contamination measurements in carbon samples performed in 2001¡V2002 will be presented, as well as the feasibility of implementing a carbon activation system at the National Ignition Facility. Research funded in part by the United States Department of Energy.

Voltz, Katie; Padalino, Stephen; Bamugart, Leigh; Jiang, Hui Ming; Smith, Elizabeth; Colburn, Robyn; Fuschino, Julia

2002-10-01

191

Elastic Pore Structure in Activated Carbon  

NASA Astrophysics Data System (ADS)

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.

Connolly, M. J.; Wexler, Carlos

2011-11-01

192

Carbon-based nanostructured materials for enhanced H2 production  

NASA Astrophysics Data System (ADS)

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

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

2006-03-01

193

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

SciTech Connect

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

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

2010-12-01

194

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

NASA Astrophysics Data System (ADS)

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

Qin, Nan

195

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.

196

Sustainable production of green feed from carbon dioxide and hydrogen.  

PubMed

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

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

2014-03-01

197

Regulation of ROS Production and Vascular Function by Carbon Monoxide  

PubMed Central

Carbon monoxide (CO) is a gaseous molecule produced from heme by heme oxygenase (HO). CO interacts with reduced iron of heme-containing proteins, leading to its involvement in various cellular events via its production of mitochondrial reactive oxygen species (ROS). CO-mediated ROS production initiates intracellular signal events, which regulate the expression of adaptive genes implicated in oxidative stress and functions as signaling molecule for promoting vascular functions, including angiogenesis and mitochondrial biogenesis. Therefore, CO generated either by exogenous delivery or by HO activity can be fundamentally involved in regulating mitochondria-mediated redox cascades for adaptive gene expression and improving blood circulation (i.e., O2 delivery) via neovascularization, leading to the regulation of mitochondrial energy metabolism. This paper will highlight the biological effects of CO on ROS generation and cellular redox changes involved in mitochondrial metabolism and angiogenesis. Moreover, cellular mechanisms by which CO is exploited for disease prevention and therapeutic applications will also be discussed. PMID:22928087

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

2012-01-01

198

Studies of activated carbons used in double-layer capacitors  

Microsoft Academic Search

Various kinds of activated carbon materials were investigated by means of nitrogen gas adsorption, AC impedance and constant current discharge techniques. The relation between the intrinsic pore size distribution of activated carbon materials and their electrochemical performance as electrodes of supercapacitor were discussed in detail. Activated carbons with larger pores are found to be more suitable for high power applications.

Deyang Qu; Hang Shi

1998-01-01

199

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

Microsoft Academic Search

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

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

200

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...

201

Adsorption of acid dye onto activated carbons prepared from agricultural waste bagasse by ZnCl 2 activation  

Microsoft Academic Search

A series of activated carbons were prepared from agricultural waste sugarcane bagasse by chemical activation with zinc chloride (ZnCl2) as an activating agent at 500°C and 0.5 h soaking time. The Langmuir surface area and total pore volume were used to estimate the average pore diameter of the carbon products. The values of the surface area and pore volume increased

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

2001-01-01

202

Carbon nano structures: Production and characterization  

NASA Astrophysics Data System (ADS)

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

Beig Agha, Rosa

203

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

PubMed

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

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

2001-02-01

204

Study of activated carbon modified with sodium carbonate as a possible antacid drug  

Microsoft Academic Search

Activated carbon was modified with different sodium carbonate solutions (0.5 to 3.0 M) to produce a series of possible antacids. The modified carbon was characterized by means of XRD and BET surface area measurements. XRD confirmed the presence of bicarbonate species on the surface of the modified carbons, while the surface areas indicated that microporous of the solids were partially

Carlos F. Linares; Alexia Palencia; Mireya R. Goldwasser; Karina Rodríguez

2006-01-01

205

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

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

2014-07-01

206

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

Code of Federal Regulations, 2013 CFR

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

2013-07-01

207

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

Code of Federal Regulations, 2012 CFR

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

2012-07-01

208

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

Code of Federal Regulations, 2010 CFR

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

2010-07-01

209

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

Code of Federal Regulations, 2011 CFR

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

2011-07-01

210

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

NASA Astrophysics Data System (ADS)

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

Obreja, Vasile V. N.

2008-05-01

211

Effects of globalisation on carbon footprints of products  

Microsoft Academic Search

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

I. T. Herrmann; M. Z. Hauschild

2009-01-01

212

Is Net Ecosystem Production Equal to Ecosystem Carbon Accumulation?  

E-print Network

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

Pace, Michael L.

213

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

National Technical Information Service (NTIS)

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

D. Dadyburjor

2006-01-01

214

CHROMIUM REMOVAL BY ACTIVATED CARBON PREPARED FROM COCONUT SHELL  

Microsoft Academic Search

One of the main fields of activated carbons employment is pollution control. The features ofactivated carbons features such as high adsorption capacity and low cost justify their use in the removal of different pollutant agents such as heavy metals. Chromium is one of the main pollutants and the comprehension of its uptake mechanism in the activated carbon is an important

R. M. Schneider

215

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...

216

The regeneration of polluted activated carbon by radiation techniques  

NASA Astrophysics Data System (ADS)

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

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

1998-10-01

217

Carbonate thermochemical cycle for the production of hydrogen  

DOEpatents

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

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

2010-02-23

218

Activation and Micropore Structure Determination of Activated Carbon-Fiber Composites  

SciTech Connect

Previous work focused on the production of carbon fiber composites and subsequently activating them to induce adsorbent properties. One problem related to this approach is the difficulty of uniformly activating large composites. In order to overcome this problem, composites have been made from pre-activated fibers. The loss of surface area upon forming the composites after activation of the fibers was investigated. The electrical resistivity and strength of these composites were compared to those made by activation after forming. It was found that the surface area is reduced by about 35% by forming the composite from pre-activated fibers. However, the properties of the activated sample are very uniform: the variation in surface area is less than {+-}0.5%. So, although the surface area is somewhat reduced, it is believed that making composites from pre-activated fibers could be useful in applications where the BET surface area is not required to be very high. The strength of the composites produced from pre-activated fibers is lower than for composites activated after forming when the carbon burnoff is below 45%. For higher burnoffs, the strength of composites made with pre-activated fibers is as good or better. In both cases, there is a dramatic decrease in strength when the fiber:binder ratio is reduced below 4:1. The electrical resistivity is slightly higher for composites made from pre-activated fibers than for composites that are activated after forming, other parameters being constant (P-200 fibers, similar carbon burnoffs). For both types of composite the resistivity was also found to increase with carbon burnoff. This is attributed to breakage of the fiber causing shorter conductive paths. The electrical resistivity also increases when the binder content is lowered, which suggests that there are fewer solid contact points between the fibers.

Jagtoyen, M.; Derbyshire, F.

1999-04-23

219

Preparation and characterization of activated carbon foam from phenolic resin.  

PubMed

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 727.62 m(2)/g was obtained. Moreover, the iodine value and carbon tetrachloride value of the activated carbon foam was 1050.28 mg/g and 401.37 mg/g, respectively. The pore size of the activated carbon foam was in the range of 3.5-5 nm which was determined through the N2 adsorption test. In addition, the yield of the activated carbon foam was 36.24%. The result of scanning electron microscopy (SEM) showed that the activated carbon foam became honeycomb structure, and its pore wall was thinner and smoother compared to the unactivated carbon foam. PMID:25084407

Zhao, Xuefei; Lai, Shiquan; Liu, Hongzha; Gao, Lijuan

2009-01-01

220

UBC Social Ecological Economic Development Studies (SEEDS) Student Report Development of sulfonated carbon catalysts for integrated biodiesel production  

E-print Network

in liquid fuming sulfuric acid was effective, but destroyed the internal pores of the char. The activity carbon catalysts for integrated biodiesel production Jidon Adrian Bin Janaun University of British of sulfonated carbon catalysts for integrated biodiesel production by Jidon Adrian Bin Janaun M.Sc. in Chemical

221

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...

222

Activated carbons from steam exploded wood  

SciTech Connect

In a continuing experimental program, we are investigating the conversion of hardwoods, such as white oak (Quercus alba) to activated carbons by chemical activation with phosphoric acid. The aims of the research are to establish the relationships between chemical and morphological change and porosity development, with the long term goal of developing new adsorbents with controlled porosity and surface chemistry, through the selection of the precursor, reagent, and reaction parameters. The research is further directed to enhancing the use of wood materials, some of which are not appropriate feedstocks for conventional industrial applications, and to providing potential solutions to the problem of the economic utilization of wood wastes from primary and secondary wood industries.

Jagtoyen, M.; Derbyshire, F. [Univ. of Kentucky, Lexington, KY (United States); Wright, R.S.; Glasser, W. [Virginia Polytechnical Institute, Blacksburg, VA (United States)

1995-12-31

223

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

NASA Technical Reports Server (NTRS)

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

Liebermeister, C.

1978-01-01

224

Production of silicon carbide whiskers from carbon nanoclusters  

NASA Astrophysics Data System (ADS)

We report on a method to produce SiC whiskers without the presence of metal catalysts by reacting carbon nanoclusters with SiO at 1700°C. The dark carbon nanotubes with hollow cores are converted to solid greenish SiC whiskers. Electron diffraction and EDX confirm that the product is SiC with a single crystalline hexagonal phase. TEM reveals the lattice image of the whisker with numerous defects. The formation of SiC whiskers produced from carbon nanotubes without using metal catalyst strongly suggests that the reactivity and atomic configuration of carbon nanotubes are crucial to the formation of whiskers.

Zhou, Dan; Seraphin, Supapan

1994-05-01

225

Adsorption of Carbon Dioxide onto Activated Carbon and Nitrogen-Enriched Activated Carbon: Surface Changes, Equilibrium, and Modeling of Fixed-Bed Adsorption  

Microsoft Academic Search

It has been reported that the CO2 adsorption capacity of the N-enriched activated carbon can increase or decrease. In this study a commercial activated carbon was functionalized with 3-chloropropylamine hydrochloride and its adsorption characteristics in a fixed-bed column were investigated. The N-enriched activated carbon presented lower BET surface area than the original activated carbon suggesting that the nitrogen incorporation partially

Tirzhá L. P. Dantas; Suélen M. Amorim; Francisco Murilo T. Luna; Ivanildo J. Silva Jr; Diana C. S. de Azevedo; Alírio E. Rodrigues; Regina F. P. M. Moreira

2009-01-01

226

Superhydrophobic activated carbon-coated sponges for separation and absorption.  

PubMed

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

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

2013-06-01

227

Role of activated carbon pellets in carbon dioxide removal  

Microsoft Academic Search

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

S. C Sarkar; A Bose

1997-01-01

228

High grade activated carbon matting derived from the chemical activation and pyrolysis of natural fibre textile waste  

Microsoft Academic Search

Waste generated as a by-product of the production and use of natural fibres in the textile industry is typically over 50wt.% and is normally landfilled. In this research, flax and hemp natural fibres have been manufactured into a non-woven, pre-formed matting material and subsequently treated via chemical activation and pyrolysis to produce activated carbon. The influence of chemical activation process

Paul T. Williams; Anton R. Reed

2004-01-01

229

The preparation of active carbons from coal by chemical and physical activation  

Microsoft Academic Search

A series of activated carbons was prepared from bituminous coal by chemical activation with potassium hydroxide and zinc chloride and also by physical activation with carbon dioxide. The effect of process variables such as carbonization time, temperature, particle size, chemical agents, method of mixing and impregnation ratio in the chemical activation process was studied in order to optimize those preparation

A. Ahmadpour; D. D. Do

1996-01-01

230

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

PubMed

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

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

2013-01-01

231

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...

232

Colonization of Biological Activated Carbon in Drinking Water Purification  

Microsoft Academic Search

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

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

2010-01-01

233

Adsorption of basic dyes from aqueous solution onto activated carbons  

Microsoft Academic Search

The aim of this research is to compare the adsorption capacity of different types of activated carbons produced by steam activation in small laboratory scale and large industrial scale processes. Equilibrium behaviour of the activated carbons was investigated by performing batch adsorption experiments using bottle-point method. Basic dyes (methylene blue (MB), basic red (BR) and basic yellow (BY)) were used

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

2008-01-01

234

Preparation and characterization of mesoporous activated carbon from waste tires  

Microsoft Academic Search

Activated carbons were produced from waste tires and their characteristics were investigated. Rubber separated from waste tires was first carbonized at 500°C in N2 atmosphere. Next, the obtained chars were activated with steam at 850°C. As a result, fairly mesoporous activated carbons with mesopore volumes and BET surface areas up to 1.09 cm3\\/g and 737 m2\\/g, respectively, were obtained. To

P Ariyadejwanich; W Tanthapanichakoon; K Nakagawa; S. R Mukai; H Tamon

2003-01-01

235

Competitive Carbon-Sulfur vs Carbon-Carbon Bond Activation of 2-Cyanothiophene with [Ni(dippe)H]2  

E-print Network

Competitive Carbon-Sulfur vs Carbon-Carbon Bond Activation of 2-Cyanothiophene with [Ni(dippe)H]2 Hydrodesulfurization (HDS) is the process by which sulfur is removed from hydrocarbons during the refinement of petroleum. Failure to remove sulfur during this process results in the formation of noxious sulfur oxides

Jones, William D.

236

Production of nitrogen and carbon dioxide  

Microsoft Academic Search

Apparatus for use in the separation of at least one gaseous component from the combustion products of a hydrocarbon fuel and air is described comprising: (a) a diesel engine in which a mixture of the fuel and air is subjected to a first stage of combustion yielding primary products of combustion containing at least 6% by volume of free oxygen,

1988-01-01

237

Carbon source regulation of antibiotic production  

Microsoft Academic Search

Antibiotics are low-molecular-mass products of secondary metabolism, nonessential for the growth of producing organisms, but very important for human health. They have unusual structures and are most often formed during the late growth phase of the producing microorganisms. Their production arises from intracellular intermediates, which are condensed into more complex structures through defined biochemical pathways. Their synthesis can be influenced

Sergio Sánchez; Adán Chávez; Angela Forero; Yolanda García-Huante; Alba Romero; Mauricio Sánchez; Diana Rocha; Brenda Sánchez; Mariana Ávalos; Silvia Guzmán-Trampe; Romina Rodríguez-Sanoja; Elizabeth Langley; Beatriz Ruiz

2010-01-01

238

Production and detection of carbon dioxide on Iapetus  

NASA Astrophysics Data System (ADS)

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

Palmer, Eric E.; Brown, Robert H.

2011-04-01

239

Enhanced Cellular Activation with Single Walled Carbon Nanotube Bundles  

E-print Network

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

Fahmy, Tarek

240

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

PubMed

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

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

2013-03-01

241

Activated carbon–carbon nanotube composite porous film for supercapacitor applications  

Microsoft Academic Search

Activated carbon\\/carbon nanotube composite electrodes have been assembled and tested in organic electrolyte (NEt4BF4 1.5M in acetonitrile). The performances of such cells have been compared with pure activated carbon-based electrodes. CNTs content of 15wt.% seems to be a good compromise between power and energy, with a cell series resistance of 0.6?cm2 and an active material capacitance as high as 88Fg?1.

Pierre-Louis Taberna; Geoffroy Chevallier; Patrice Simon; Dominique Plée; Thierry Aubert

2006-01-01

242

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

Microsoft Academic Search

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

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

243

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

Federal Register 2010, 2011, 2012, 2013

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

2013-03-11

244

Clouds Versus Carbon: Predicting Vegetation Roughness by Maximizing Productivity  

NASA Technical Reports Server (NTRS)

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

Olsen, Lola M.

2004-01-01

245

Continual production of glycerol from carbon dioxide by Dunaliella tertiolecta.  

PubMed

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

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

2013-05-01

246

DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS  

SciTech Connect

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

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

2006-03-27

247

Production of superconductor/carbon bicomponent fibers  

NASA Technical Reports Server (NTRS)

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

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

1991-01-01

248

Active carbon filter health condition detection with piezoelectric wafer active sensors  

Microsoft Academic Search

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;

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

2011-01-01

249

JPL Activated Carbon Treatment System (ACTS) for sewage  

NASA Technical Reports Server (NTRS)

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

1976-01-01

250

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

NASA Astrophysics Data System (ADS)

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

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

2013-10-01

251

Biomass Crop Production: Benefits for Soil Quality and Carbon Sequestration  

SciTech Connect

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

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

1999-08-29

252

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

SciTech Connect

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

V.J. Fabry, Ph.D.

2001-09-10

253

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

SciTech Connect

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

V.J. Fabry, Ph.D.

2002-04-05

254

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

SciTech Connect

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

V.J. Fabry

2001-07-01

255

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

SciTech Connect

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

V.J. Fabry, Ph.D.

2002-07-09

256

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

SciTech Connect

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

V.J. Fabry, Ph.D.

2002-09-30

257

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

SciTech Connect

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

V.J. Fabry, Ph.D.

2001-12-15

258

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

SciTech Connect

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

V.J. Fabry, Ph.D.

2002-12-15

259

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

SciTech Connect

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

V. J. Fabry

2005-01-24

260

Supporting Information Unexpected Role of Activated Carbon in Promoting  

E-print Network

-min/L and then air-dried; and (iii) PSC particles were baked at. Activated Carbons, Modifications and Characterization. The suite of activated carbon particles and fibers used in this study included: (i) synthetic Ambersorb 572 particles from Rohm and Haas (Philadelphia, PA

Huang, Ching-Hua

261

Bioindication Potential of Carbonic Anhydrase Activity in Anemones  

E-print Network

Bioindication Potential of Carbonic Anhydrase Activity in Anemones and Corals AUBREY L. GILBERT levels of carbonic anhydrase (CA) were assessed in anemones Condylactis gigantea and Stichodactyla he has been done on CA activity in anemones and corals, two potential candidates for coral reef

Bermingham, Eldredge

262

Improvements in Production of Single-Walled Carbon Nanotubes  

NASA Technical Reports Server (NTRS)

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

Balzano, Leandro; Resasco, Daniel E.

2009-01-01

263

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

Microsoft Academic Search

Agricultural by-products represent a considerable quantity of harvested commodity crops. The use of by-products as precursors for the production of widely used adsorbents, such as activated carbons, may impart a value-added component of the overall biomass harvested. Our objective in this paper is to show that flax shive and cotton gin waste can serve as a precursor for activated carbon

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

2009-01-01

264

Ozone Removal by Filters Containing Activated Carbon: A Pilot Study  

SciTech Connect

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

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

2009-09-01

265

A Carbon Arc Apparatus For Production Of Nanotubes In Microgravity  

NASA Technical Reports Server (NTRS)

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

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

2003-01-01

266

Carbon sink activity and GHG budget of managed European grasslands  

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

267

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

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

268

Basic dye adsorption on activated carbon  

Microsoft Academic Search

The adsorption of Victoria Blue dye (Basic Blue 26) on carbon has been investigated. Equilibrium data have been found to obey the Langmuir isotherm. The effects of contact time, agitation, initial dye concentration and carbon particle size range were also studied.

Gordon McKay

1979-01-01

269

Adsorbed natural gas storage with activated carbons made from Illinois coals and scrap tires  

USGS Publications Warehouse

Activated carbons for natural gas storage were produced from Illinois bituminous coals (IBC-102 and IBC-106) and scrap tires by physical activation with steam or CO2 and by chemical activation with KOH, H3PO4, or ZnCl2. The products were characterized for N2-BET area, micropore volume, bulk density, pore size distribution, and volumetric methane storage capacity (Vm/Vs). Vm/Vs values for Illinois coal-derived carbons ranged from 54 to 83 cm3/cm3, which are 35-55% of a target value of 150 cm3/cm3. Both granular and pelletized carbons made with preoxidized Illinois coal gave higher micropore volumes and larger Vm/Vs values than those made without preoxidation. This confirmed that preoxidation is a desirable step in the production of carbons from caking materials. Pelletization of preoxidized IBC-106 coal, followed by steam activation, resulted in the highest Vm/Vs value. With roughly the same micropore volume, pelletization alone increased Vm/Vs of coal carbon by 10%. Tire-derived carbons had Vm/Vs values ranging from 44 to 53 cm3/cm3, lower than those of coal carbons due to their lower bulk densities. Pelletization of the tire carbons increased bulk density up to 160%. However, this increase was offset by a decrease in micropore volume of the pelletized materials, presumably due to the pellet binder. As a result, Vm/Vs values were about the same for granular and pelletized tire carbons. Compared with coal carbons, tire carbons had a higher percentage of mesopores and macropores.

Sun, J.; Brady, T. A.; Rood, M. J.; Lehmann, C. M.; Rostam-Abadi, M.; Lizzio, A. A.

1997-01-01

270

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

Microsoft Academic Search

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

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

2011-01-01

271

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

NASA Astrophysics Data System (ADS)

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

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

2012-07-01

272

Clinical and radiographic study of activated carbon workers.  

PubMed Central

Activated carbon is made in Sri Lanka by passing steam through charcoal made from coconut shells. The carbon does not contain free silica. Sixty six men who had worked in a factory making activated carbon for an average of 7.2 years had no more respiratory symptoms than a control group, and none showed radiological evidence of pneumoconiosis. There was no evidence that people exposed to charcoal and pure carbon for up to 11 years are at risk of developing pneumoconiosis. PMID:2763231

Uragoda, C G

1989-01-01

273

Method for creating high carbon content products from biomass oil  

DOEpatents

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

Parker, Reginald; Seames, Wayne

2012-12-18

274

A microalgae residue based carbon solid acid catalyst for biodiesel production.  

PubMed

Biodiesel production from microalgae is recognized as one of the best solutions to deal with the energy crisis issues. However, after the oil extraction from the microalgae, the microalgae residue was generally discarded or burned. Here a novel carbon-based solid acid catalyst derived from microalgae residue by in situ hydrothermal partially carbonization were synthesized. The obtained catalyst was characterized and subjected to both the esterification of oleic acid and transesterification of triglyceride to produce biodiesel. The catalyst showed high catalytic activity and can be regenerated while its activity can be well maintained after five cycles. PMID:23953130

Fu, Xiaobo; Li, Dianhong; Chen, Jie; Zhang, Yuanming; Huang, Weiya; Zhu, Yi; Yang, Jun; Zhang, Chengwu

2013-10-01

275

Adsorption of radon and water vapor on commercial activated carbons  

SciTech Connect

Equilibrium adsorption isotherms are reported for radon and water vapor on two commercial activated carbons: coconut shell Type PCB and hardwood Type BD. The isotherms of the water vapor were measured gravimetrically at 298 K. The isotherms of radon from dry nitrogen were obtained at 293, 298, and 308 K while the data for the mixture of radon and water vapor were measured at 298 K. The concentrations of radon in the gas and solid phases were measured simultaneously, once the adsorption equilibrium and the radioactive equilibrium between the radon and its daughter products were established. The shape of the isotherms was of Type III for the radon and Type V for the water vapor, according to Brunauer`s classification. The adsorption mechanism was similar for both the radon and the water vapor, being physical adsorption on the macropore surface area in the low pressure region and micropore filling near saturation pressure. The uptake capacity of radon decreased both with increasing temperature and relative humidity. The heat of adsorption data indicated that the PCB- and the BD-activated carbons provided a heterogeneous surface for radon adsorption. The equilibrium data for radon were correlated with a modified Freundlich equation.

Hassan, N.M. [Westinghouse Savannah River Co., Aiken, SC (United States); Ghosh, T.K.; Hines, A.L.; Loyalka, S.K. [Univ. of Missouri, Columbia, MO (United States)

1995-02-01

276

Carbon dioxide concentration, photosynthesis, and dry matter production  

Microsoft Academic Search

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

Paul J. Kramer

1981-01-01

277

Create a Consortium and Develop Premium Carbon Products from Coal  

Microsoft Academic Search

The objective of these projects was to investigate alternative technologies for non-fuel uses of coal. Special emphasis was placed on developing premium carbon products from coal-derived feedstocks. A total of 14 projects, which are the 2003 Research Projects, are reported herein. These projects were categorized into three overall objectives. They are: (1) To explore new applications for the use of

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

2006-01-01

278

Carbon dioxide in soil profiles: Production and temperature dependence  

E-print Network

the diffusion of gas in response to a concentration gradient according to Fick's Law. In an ideal situationCarbon dioxide in soil profiles: Production and temperature dependence David Risk, Lisa Kellman 2002. [1] The temperature dependance of soil respiration has most commonly been addressed using surface

279

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

Microsoft Academic Search

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

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

2005-01-01

280

The Production of Carbon Monoxide from Hemoglobin In Vivo*  

PubMed Central

Dogs anesthetized with pentobarbital were shown to produce carbon monoxide at an average rate of 0.21 ± (SD) 0.05 ml per hour. After intravenous injection of erythrocytes damaged by incubation with N-ethylmaleimide, CO was produced in excess of base-line production for 3 to 4 hours with an average yield of 0.89 ± (SE) 0.046 ?mole of carbon monoxide to 1 ?mole of heme degraded. After intravenous injection of N-ethylmaleimide (NEM)-treated erythrocytes containing hemoglobin labeled with 14carbon, 14CO was produced. Its specific activity was approximately one-eighth that of the injected heme. It was also produced after intravenous injection of solutions of hemoglobin-14C and of reconstituted methemoglobin containing hemin-14C, but not after injections of methemoglobin containing globin-14C. The average yields of 14CO from metabolized heme in the experiments with damaged erythrocytes and hemoglobin solutions were 89 ± (SE) 4.6 and 97 ± (SE) 17.0%, respectively. These results demonstrate that the CO produced during hemoglobin degradation arises from the heme moiety. The yield of 14CO after injection of hemoglobin-14C solutions decreased significantly to values of 35 and 42% in two experiments when exogenous CO was added to the body stores, resulting in blood carboxyhemoglobin levels of 11.3 and 13.2% saturation. This finding suggests that oxidative metabolism is required during catabolism of hemoglobin to CO and that carboxy-hemoglobin levels in this range are sufficient to cause inhibition. After intravenous injection of either hemin-14C or protoporphyrin-14C, 14CO was also produced. After injection of protoporphyrin-14C labeled bilirubin was isolated from gall bladder bile, and labeled hemin was isolated from the liver. It is thus very likely that protoporphyrin is converted to heme before the formation of CO. There was a large difference between the maximal rates of catabolism of hemoglobin to CO observed after injection of damaged erythrocytes and hemoglobin solutions. The limiting parameters in these processes are not yet clear. PMID:6024892

Coburn, R. F.; Williams, W. J.; White, P.; Kahn, S. B.

1967-01-01

281

Methodology for calculation of carbon balances for biofuel crops production  

NASA Astrophysics Data System (ADS)

Understanding the carbon balance implications for different biofuel crop production systems is important for the development of decision making tools and policies. We present here a detailed methodology for assessing carbon balances in agricultural and natural ecosystems. We use 20 years of data from Long-term Ecological Research (LTER) experiments at the Kellogg Biological Station (KBS), combined with models to produce farm level CO2 balances for different management practices. We compared four grain and one forage systems in the U.S. Midwest: corn (Zea mays) - soybean (Glycine max) - wheat (Triticum aestivum) rotations managed with (1) conventional tillage, (2) no till, (3) low chemical input, and (4) biologically-based (organic) practices; and (5) continuous alfalfa (Medicago sativa). In addition we use an abandoned agricultural field (successionnal ecosystem) as reference system. Measurements include fluxes of N2O and CH4, soil organic carbon change, agricultural yields, and agricultural inputs (e.g. fertilization and farm fuel use). In addition to measurements, we model carbon offsets associated with the use of bioenergy from agriculturally produced crops. Our analysis shows the importance of establishing appropriate system boundaries for carbon balance calculations. We explore how different assumptions regarding production methods and emission factors affect overall conclusions on carbon balances of different agricultural systems. Our results show management practices that have major the most important effects on carbon balances. Overall, agricultural management with conventional tillage was found to be a net CO2 source to the atmosphere, while agricultural management under reduced tillage, low input, or organic management sequestered carbon at rates of 93, -23, -51, and -14 g CO2e m-2 yr-1, respectively for conventionally tilled, no-till, low-input, and organically managed ecosystems. Perennial systems (alfalfa and the successionnal fields) showed net carbon sequestration of -44 and -382 g CO2e m-2 yr-1, respectively. When studied systems were assumed to be used for bioenergy production, all system exhibited carbon sequestration -- between -149 and -841 g CO2e m-2 yr-1, for conventionally tilled and successionnal ecosystems, respectively.

Gerlfand, I.; Hamilton, S. K.; Snapp, S. S.; Robertson, G. P.

2012-04-01

282

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

NASA Astrophysics Data System (ADS)

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

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

283

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

PubMed

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

Centi, Gabriele; Iaquaniello, Gaetano; Perathoner, Siglinda

2011-09-19

284

Effects of acidic treatment of activated carbons on dye adsorption  

Microsoft Academic Search

The effect of acidic treatments of activated carbons on dye adsorption was investigated. The physico-chemical properties of activated carbons were characterised by N2 adsorption, mass titration, temperature-programmed desorption (TPD), and X-ray photoelectron spectrometry (XPS). It was found that surface chemistry plays an important role in dye adsorption. HNO3 treatment produces more active acidic surface groups such as carboxyl and lactone,

Shaobin Wang; Z. H. Zhu

2007-01-01

285

Thermodynamic characterization of a regenerated activated carbon surface  

NASA Astrophysics Data System (ADS)

Calorimetric measurements of the immersion enthalpy in different liquids of a set of regenerated activated carbons have been employed to analyze the effect of a regeneration process on the extension of the accessible surface area and the hydrophobic character of the carbons by comparison with the original carbon. The modifications in the hydrophobicity of the activated carbons are quantified by the analysis of the surface free energy of the solids and its dispersion and non-dispersion components. It has been found that regeneration treatment of the original carbon increases its accessible surface area and hydrophobicity. However, the opposite effects take place when regeneration is done on the same carbon previously saturated with p-nitrophenol (PNP) or p-chlorophenol (PClP).

González-Martín, M. L.; González-García, C. M.; González, J. F.; Ramiro, A.; Sabio, E.; Bruque, J. M.; Encinar, J. M.

2002-05-01

286

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

Microsoft Academic Search

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

P.-O. Lundquist

2005-01-01

287

Regional carbon dioxide implications of forest bioenergy production  

NASA Astrophysics Data System (ADS)

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.

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

2011-11-01

288

Pyrolysis of scrap tires and conversion of chars to activated carbon  

SciTech Connect

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

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

1993-08-01

289

Effects of activation method on the pore structure of activated carbons from apricot stones  

Microsoft Academic Search

Two series of activated carbons were prepared from apricot stones by using carbonization followed by steam activation and one-step pyrolysis\\/activation in steam. The pore structure of the activated carbons was characterized by CO2 adsorption at 273 K and by N2 adsorption at 77 K. The macro- and mesoporosity were determined by mercury porosimetry. Optical microscopy, scanning electron microscopy (SEM) and

K. Gergova; S. Eser

1996-01-01

290

Activated carbon fibers and engineered forms from renewable resources  

DOEpatents

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

Baker, Frederick S

2013-02-19

291

Mechanisms of Carbon Nanotube Production by Laser Ablation Process  

NASA Technical Reports Server (NTRS)

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

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

2000-01-01

292

Liquid-phase adsorption of organic compounds by granular activated carbon and activated carbon fibers  

SciTech Connect

Liquid-phase adsorption of organic compounds by granular activated carbon (GAC) and activated carbon fibers (ACFs) is investigated. Acetone, isopropyl alcohol (IPA), phenol, and tetrahydrofuran (THF) were employed as the model compounds for the present study. It is observed from the experimental results that adsorption of organic compounds by GAC and ACF is influenced by the BET (Brunauer-Emmett-Teller) surface area of adsorbent and the molecular weight, polarity, and solubility of the adsorbate. The adsorption characteristics of GAC and ACFs were found to differ rather significantly. In terms of the adsorption capacity of organic compounds, the time to reach equilibrium adsorption, and the time for complete desorption, ACFs have been observed to be considerably better than GAC. For the organic compounds tested here, the GAC adsorptions were shown to be represented well by the Langmuir isotherm while the ACF adsorption could be adequately described by the Langmuir or the Freundlich isotherm. Column adsorption tests indicated that the exhausted ACFs can be effectively regenerated by static in situ thermal desorption at 150 C, but the same regeneration conditions do not do as well for the exhausted GAC.

Lin, S.H.; Hsu, F.M. [Yuan Ze Inst. of Tech., Taoyuan (Taiwan, Province of China). Dept. of Chemical Engineering

1995-06-01

293

Physicochemical and porosity characteristics of thermally regenerated activated carbon polluted with biological activated carbon process.  

PubMed

The characteristics of thermally regenerated activated carbon (AC) polluted with biological activated carbon (BAC) process were investigated. The results showed that the true micropore and sub-micropore volume, pH value, bulk density, and hardness of regenerated AC decreased compared to the virgin AC, but the total pore volume increased. XPS analysis displayed that the ash contents of Al, Si, and Ca in the regenerated AC respectively increased by 3.83%, 2.62% and 1.8%. FTIR spectrum showed that the surface functional groups of virgin and regenerated AC did not change significantly. Pore size distributions indicated that the AC regeneration process resulted in the decrease of micropore and macropore (D>10?m) volume and the increase of mesopore and macropore (0.1?m

Dong, Lihua; Liu, Wenjun; Jiang, Renfu; Wang, Zhansheng

2014-11-01

294

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

PubMed

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

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

2014-10-01

295

Microstructure and surface properties of lignocellulosic-based activated carbons  

NASA Astrophysics Data System (ADS)

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.

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

2013-01-01

296

Carbon dioxide–nitrogen separation through adsorption on activated carbon in a fixed bed  

Microsoft Academic Search

The reduction of carbon dioxide emissions from flue gases can be achieved using post-combustion capture technologies such as adsorption. In this paper, we report experimental data for the fixed-bed adsorption of carbon dioxide and nitrogen on activated carbon. The breakthrough curves were obtained at different temperatures – 301–306, 323, 373 and 423K – using CO2\\/N2 mixtures. XPS and FTIR measurements

Tirzhá L. P. Dantas; Francisco Murilo T. Luna; Ivanildo J. Silva Jr.; Diana C. S. de Azevedo; Carlos A. Grande; Alírio E. Rodrigues; Regina F. P. M. Moreira

2011-01-01

297

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

PubMed

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

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

2002-04-01

298

Supporting information: ACTIVATED CARBON AND BIOCHAR AMENDMENTS DECREASE POREWATER  

E-print Network

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 as the measured distribution coefficients for unamended sediment normalized to sediment organic carbon content (Kd

Lehmann, Johannes

299

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...

300

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...

301

Activated carbon testing for the 200 area effluent treatment facility  

SciTech Connect

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

Wagner, R.N.

1997-01-17

302

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...

303

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

SciTech Connect

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

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

1992-01-01

304

Solar thermal decomposition of hydrocarbons and carbon monoxide for the production of catalytic filamentous carbon  

Microsoft Academic Search

Concentrated solar radiation is used as the clean source of process heat for the production of catalytic filamentous carbon (CFC) by thermal decomposition of gaseous hydrocarbons (CH4 and C4H10) and by CO disproportionation in the presence of small metal catalyst particles. Depending on the catalyst, two different types of CFC, namely nanotubes and nanofibers, are obtained in solar experiments. Nanotubes

A. Meier; V. A. Kirillov; G. G. Kuvshinov; Yu. I. Mogilnykh; A. Reller; A. Steinfeld; A. Weidenkaff

1999-01-01

305

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

Microsoft Academic Search

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

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

2009-01-01

306

Selection and preparation of activated carbon for fuel gas storage  

DOEpatents

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.

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

1990-10-02

307

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

E-print Network

Mechanistic Investigation of Catalytic Carbon-Carbon Bond Activation and Formation by Platinum). The breaking of C-C bonds is also crucial in coal liquefaction processes such as the Exxon Donor Solvent process or the Microcat Coal Liquefaction process. Presently cracking is achieved with heterogeneous

Jones, William D.

308

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

Federal Register 2010, 2011, 2012, 2013

...Carbon Plant; Ningxia Guanghua A/C Co., Ltd.; Ningxia Blue-White-Black Activated Carbon (BWB); Ningxia Fengyuan...Activated Carbon; Shanghai Xingchang Activated Carbon; Shanxi Blue Sky Purification Material Co., Ltd.; Shanxi Carbon...

2011-09-20

309

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...

310

GRANULAR ACTIVATED CARBON ADSORPTION AND INFRARED REACTIVATION: A CASE STUDY  

EPA Science Inventory

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

311

Calcium carbonate production response to future ocean warming and acidification  

NASA Astrophysics Data System (ADS)

Anthropogenic carbon dioxide (CO2) emissions are acidifying the ocean, affecting calcification rates in pelagic organisms, and thereby modifying the oceanic carbon and alkalinity cycles. However, the responses of pelagic calcifying organisms to acidification vary widely between species, contributing uncertainty to predictions of atmospheric CO2 and the resulting climate change. At the same time, ocean warming caused by rising CO2 is expected to drive increased growth rates of all pelagic organisms, including calcifiers. It thus remains unclear whether anthropogenic CO2 emissions will ultimately increase or decrease pelagic calcification rates. Here, we assess the importance of this uncertainty by introducing a dependence of calcium carbonate (CaCO3) production on calcite saturation state (?CaCO3) in an intermediate complexity coupled carbon-climate model. In a series of model simulations, we examine the impact of several variants of this dependence on global ocean carbon cycling between 1800 and 3500 under two different CO2 emissions scenarios. Introducing a calcification-saturation state dependence has a significant effect on the vertical and surface horizontal alkalinity gradients, as well as on the removal of alkalinity from the ocean through CaCO3 burial. These changes result in an additional oceanic uptake of carbon when calcification depends on ?CaCO3 (of up to 270 Pg C), compared to the case where calcification does not depend on acidification. In turn, this response causes a reduction of global surface air temperature of up to 0.4 °C in year 3500. Different versions of the model produced varying results, and narrowing this range of uncertainty will require better understanding of both temperature and acidification effects on pelagic calcifiers. Nevertheless, our results suggest that alkalinity observations can be used to constrain model results, and may not be consistent with the model versions that simulated stronger responses of CaCO3 production to changing saturation state.

Pinsonneault, A. J.; Matthews, H. D.; Galbraith, E. D.; Schmittner, A.

2012-06-01

312

Production and accumulation of calcium carbonate in the ocean: Budget of a nonsteady state  

Microsoft Academic Search

The calcium carbonate budget in the ocean has become of great interest to geochemists, sedimentologists and paleoceanographers. The carbonate system represents only a small part of the global carbon cycle, but it is intimately related to atmospheric carbon dioxide. This paper discusses calcium carbonate production and accumulations in the present-day marine environment and over the past 25,000 years. The new

John D. Milliman

1993-01-01

313

Life cycle inventories of roundwood production in northern Wisconsin: Inputs into an industrial forest carbon budget  

Microsoft Academic Search

Carbon budgets are developed to understand ecosystem dynamics and are increasingly being used to develop global change policy. Traditionally, forest carbon budgets have focused on the biological carbon cycle; however, it is important to include the industrial forest carbon cycle as well. The overall objective of this study was to quantify the major carbon fluxes associated with the production of

Molly K. White; Stith T. Gower; Douglas E. Ahl

2005-01-01

314

Porosity in granular carbons activated with phosphoric acid  

Microsoft Academic Search

Three series of activated carbon have been prepared by heat treatment of peach stones impregnated with solutions of phosphoric acid, in order to analyze the effect of phosphoric acid on the yield, bulk density and porosity of the resultant activated carbons. The analysis of the adsorption isotherms of N2 at 77 K. CO2 at 273 K and n-C4H10, at 273

M. Molina-Sabio; F. RodRíguez-Reinoso; F. Caturla; M. J. Sellés

1995-01-01

315

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

SciTech Connect

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

Schumacher, Katja; Sathaye, Jayant

1999-07-01

316

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

PubMed

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

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

2010-01-01

317

Carbon Nanotube Materials for Substrate Enhanced Control of Catalytic Activity  

SciTech Connect

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.

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

2007-05-01

318

Effects of CO 2 activation on porous structures of coconut shell-based activated carbons  

NASA Astrophysics Data System (ADS)

In this paper, textural characterization of an activated carbon derived from carbonized coconut shell char obtained at carbonization temperature of 600 °C for 2 h by CO 2 activation was investigated. The effects of activation temperature, activation time and flow rate of CO 2 on the BET surface area, total volume, micropore volume and yield of activated carbons prepared were evaluated systematically. The results showed that: (i) enhancing activation temperature was favorable to the formation of pores, widening of pores and an increase in mesopores; (ii) increasing activation time was favorable to the formation of micropores and mesopores, and longer activation time would result in collapsing of pores; (iii) increasing flow rate of CO 2 was favorable to the reactions of all active sites and formation of pores, further increasing flow rate of CO 2 would lead carbon to burn out and was unfavorable to the formation of pores. The degree of surface roughness of activated carbon prepared was measured by the fractal dimension which was calculated by FHH (Frenkel-Halsey-Hill) theory. The fractal dimensions of activated carbons prepared were greater than 2.6, indicating the activated carbon samples prepared had very irregular structures, and agreed well with those of average micropore size.

Guo, Shenghui; Peng, Jinhui; Li, Wei; Yang, Kunbin; Zhang, Libo; Zhang, Shimin; Xia, Hongying

2009-07-01

319

Activated carbon fiber composite material and method of making  

DOEpatents

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

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

2001-01-01

320

Activated carbon fiber composite material and method of making  

DOEpatents

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

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

2000-01-01

321

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

Federal Register 2010, 2011, 2012, 2013

...Foreign-Trade Zone 83--Huntsville, Alabama; Application for Production Authority; Toray Carbon Fibers America, Inc.; (Polyacrylonitrile Fiber/Carbon Fiber Production), Decatur, Alabama An application has been submitted to the...

2013-06-13

322

Production of carbonate sediments by a unicellular green alga  

Microsoft Academic Search

This study investigates the ability of the unicellular green alga Nannochloris atomusto precipitate CaCO3, quantifies mineral precipitation rates, estimates sediment production in a N. atomus bloom, and discusses the implications of microbial calcification for carbonate sediment deposition. A series of N. atomus cultures, isolated from Lake Reeve, Australia, were incubated at various pH and calcium concentrations to determine environmental pa-

KIMBERLY K. YATES; LISA L. ROBBINS

1998-01-01

323

[Effects of mixed carbon sources in cultivation of recombinant Pichia pastoris for polygalacturonate lyase production].  

PubMed

In order to increase the production and productivity of alkaline polygalacturonate lyase (PGL), we studied the mixed carbon sources feeding strategies during the induction phase by recombinant Pichia pastoris GS 115. Glycerol, sorbitol or lactic acid co-feeding with methanol all enhanced the PGL production. Among all the feeding strategies, the sorbitol co-feeding strategy was most significant. By using this strategy, the PGL activity and productivity reached 1593 U/mL and 16.7 U/(mL-h). Compared to the control, the enhancements of PGL activity and productivity were 84.6% and 45.2% respectively, when we set the sorbitol feeding rate at 3.6 g/(h x L). PMID:20352974

Wang, Zhihao; Zhang, Dongxu; Li, Jianghua; Du, Guocheng; Chen, Jian

2009-12-01

324

Extraordinary hydrogen evolution and oxidation reaction activity from carbon nanotubes and graphitic carbons.  

PubMed

The hydrogen evolution reaction, 2H(+) + 2e(–) ? H2, and its converse, the hydrogen oxidation reaction, H2 ? 2H(+) + 2e(–), are central to any realization of a hydrogen economy. Various forms of carbon have been used for decades as the precious metal catalyst support in these reactions. Here we report the unexpected result that single-wall carbon nanotubes and some graphitic carbons, activated by brief exposure to electrochemical potentials that induce hydrogen evolution in intercalating acids combined with extended soak times in such acids, acquire an activity for these reactions that exceeds that of known nonprecious metal catalysts. PMID:25017805

Das, Rajib Kumar; Wang, Yan; Vasilyeva, Svetlana V; Donoghue, Evan; Pucher, Ilaria; Kamenov, George; Cheng, Hai-Ping; Rinzler, Andrew G

2014-08-26

325

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

National Technical Information Service (NTIS)

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

D. Dadyburjor

2006-01-01

326

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

SciTech Connect

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

Schumacher, Katja; Sathaye, Jayant

1999-07-01

327

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...

328

Sorption of metallic compounds on activated carbon: application to exploration for concealed deposits in southern Spain  

Microsoft Academic Search

Metal transfer from three buried volcano-sedimentary massive sulphide deposits to the soil atmosphere has been studied using integrative collectors containing specific activated carbon products. The experimental sites are located in the southwest Iberian Pyrite Belt, where three orebodies (Los Frailes, Sierrecilla, Herrerias) lie beneath either overburden or several tens of metres of schist and volcanic country rocks. Soil-gas geochemistry profiles

Hélène Pauwels; Jean Claude Baubron; Philippe Freyssinet; Manuel Chesneau

1999-01-01

329

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

Microsoft Academic Search

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

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

2005-01-01

330

Adsorption of basic dye onto palm kernel shell activated carbon: sorption equilibrium and kinetics studies  

Microsoft Academic Search

Adsorbents prepared from palm kernel shell, an agricultural waste product, were used to remove a dye, Basic Blue 9, from an aqueous solution in batch mode at a constant temperature of 28 °C. The sorption kinetics and equilibrium of basic dye onto palm kernel shell activated carbon (PKSAC) were studied. The isotherm data were well described by the Redlich–Peterson isotherm

A. Jumasiah; T. G. Chuah; J. Gimbon; T. S. Y. Choong; I. Azni

2005-01-01

331

Ratio of Pion Kaon Production in Proton Carbon Interactions  

SciTech Connect

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

Lebedev, Andrey V.; /Harvard U.

2007-05-01

332

Bulk scale production of carbon nanofibers in an economical way  

NASA Astrophysics Data System (ADS)

An economical route for the scalable production of carbon nanofibers (CNFs) on a sodium chloride support has been developed. CNFs have been synthesized by chemical vapor deposition (CVD) method by using metal formate as catalyst precursors at 680°C. Products were characterized by SEM, TEM, Raman spectroscopy and XRD method. By thermal analysis, the purity of the as grown products and purified products were determined. This method avoids calcination and reduction process which was employed in commercial catalysts such as metal oxide or nitrate. The problems such as detrimental effect, environmental and even cost have been overcome by using sodium chloride as support. The yield of CNFs up to 7800 wt.% relative to the nickel catalyst has been achieved in the growth time of 15 min. The advantage of this synthesis technique is the simplicity and use of easily available low cost precursors.

Rajarao, Ravindra; Bhat, Badekai Ramachandra

2012-12-01

333

Analysis of structure and properties of active carbons and their copolymeric precursors  

NASA Astrophysics Data System (ADS)

The relations between chemical structures of BM-DVB copolymers obtained with various monomer molar ratios and their carbonization products were studied. Three porous copolymers 1:4, 1:1, and 4:1 of BM to DVB were the starting materials for preparation of active carbons. Two activation agents were employed: air and phosphoric acid. The carbonization process was performed in the same way in these two cases. To characterize the obtained materials FTIR spectroscopy, thermal and elemental analyses were applied. Porous structure parameters were obtained by means of nitrogen sorption. The results proved that differences in the molar ratio of monomers used in the syntheses of polymeric precursor play a key role for structure and properties of copolymers but have rather small influence on properties of the obtained carbons. Preliminary treatment is more effective during the activation process. The carbons obtained by activation with phosphoric acid are microporous and have well developed porous structures. The air activated carbons are mesoporous with specific surface areas similar to those of polymeric precursors.

Sobiesiak, M.; Gawdzik, B.; Puziy, A. M.; Poddubnaya, O. I.

2010-06-01

334

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

E-print Network

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

Borguet, Eric

335

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

Federal Register 2010, 2011, 2012, 2013

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

2011-07-19

336

Nanoconfinement in activated mesoporous carbon of calcium borohydride for improved reversible hydrogen storage  

NASA Astrophysics Data System (ADS)

Mesoporous carbon frameworks were synthesized using the soft-template method. Ca(BH4)2 was incorporated into activated mesoporous carbon by the incipient wetness method. The activation of mesoporous carbon was necessary to optimize the surface area and pore size. Thermal programmed absorption measurements showed that the confinement of this borohydride into carbon nanoscaffolds improved its reversible capacity (relative to the reactive portion) and performance of hydrogen storage compared to unsupported borohydride. Hydrogen release from the supported hydride started at a temperature as low as 100?°C and the dehydrogenation rate was fast compared to the bulk borohydride. In addition, the hydrogen pressure necessary to regenerate the borohydride from the dehydrogenation products was reduced.

Com?nescu, Cezar; Capurso, Giovanni; Maddalena, Amedeo

2012-09-01

337

[Effects of mixed carbon sources on glucose oxidase production by recombinant Pichia pastoris].  

PubMed

Glucose oxidase (GOD) is an important industrial enzyme with many potential applications. In order to increase the production and productivity of GOD by recombinant Pichia pastoris GS115, we investigated the feeding strategies of mixed carbon sources during induction phase, based on results of the optimization of initial cell and methanol concentration on GOD production. The optimal initial cell and methanol concentration were 100 g/L and 18 g/L. During induction phase, the mixed-carbon-sources strategies showed that glycerol, sorbitol or mannitol co-feeding with methanol could enhance GOD production. With mannitol co-feeding (20:1(W/W)), the maximum GOD production and maximum GOD productivity reached 711.3 U/mL and 4.60 U/(mL x h) after an induction period of 156 h. Compared to the control, the enhancements of GOD production and productivity were 66.3% and 67.9%, respectively. Meanwhile, we found an appropriate mannitol co-feeding strategy that would not inhibit the expression of promote. The activity of alcohol oxidase was 8.8 U/g, which was enhanced by 69.2% compared to the control (5.2 U/g). We can use the same optimization process to improve the production of other proteins from recombinant Pichia pastoris by changing the fermentation parameters. PMID:24195359

Shen, Yina; Gu, Lei; Zhang, Juan; Chen, Jian; Du, Guocheng

2013-07-01

338

Operational Characteristics of Effective Removal of H2S and NH3 Waste Gases by Activated Carbon Biofilter  

Microsoft Academic Search

Simultaneous removal of hydrogen sulfide (H2S) and am- gases. monia (NH3) gases from gaseous streams was studied in a biofilter packed with granule activated carbon. Extensive studies, including the effects of carbon (C) source on the growth of inoculated microorganisms and gas removal efficiency, product analysis, bioaerosol emission, pressure drop, and cost evaluation, were conducted. The results indicated that molasses

Ying-Chien Chung; Yu-Yen Lin; Ching-Ping Tseng

2004-01-01

339

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

NASA Astrophysics Data System (ADS)

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.

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

2013-09-01

340

Matrix infrared spectra of the products of uranium-atom reactions with carbon monoxide and carbon dioxide  

SciTech Connect

Uranium atoms from pulsed Nd:YAG laser ablation of a uranium metal target were codeposited with carbon monoxide and carbon dioxide in excess argon at 10K. Infrared spectra following the U + CO reaction revealed strong new absorption bands at 804.4 and 852.6 cm[sup [minus]1], which are assigned to the CUO product on the basis of isotopic shifts, FG matrix calculations, and ab initio pseudopotential calculations. An absorption at 2027.5 cm[sup [minus]1] is attributed to the asymmetric secondary reaction product CU(O)CO. In both the U + Co and U + CO[sub 2] reactions, bands at 870.9 and 1963.8 cm[sup [minus]1] were observed and assigned to the association product of UO[sub 2] and CO. Lastly, in the U + CO[sub 2] experiments, new absorption band pairs were observed at 804.4 and 1799.6 cm[sup [minus]1] and at 801.5 and 2011.7 cm[sup [minus]1]. The former pair was almost destroyed on annealing and is assigned to the OUCO insertion product. The latter pair is attributed to an OCU(O)CO species. The direct reaction of U atoms with CO and CO[sub 2] requires an activation energy, which is provided by hyperthermal U atoms from pulsed laser evaporation. 25 refs., 5 figs., 2 tabs.

Tague, T.J. Jr.; Andrews, L. (Univ. of Virginia, Charlotteville, VA (United States)); Hunt, R.D. (Oak Ridge National Lab., TN (United States))

1993-10-21

341

REMOVAL OF ORGANIC POLLUTANTS FROM SUBCRITICAL WATER WITH ACTIVATED CARBON  

SciTech Connect

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

Steven B. Hawthorne; Arnaud J. Lagadec

1999-08-01

342

Natural products and anti-inflammatory activity  

Microsoft Academic Search

The aim of this review paper was to summarise some commonly available natural products and their anti- inflammatory activity. We have collected data from MEDLINE, Current Contents and scientific journals, which included 92 publications. There are numerous natural products d etailed in this literature; however we have summarized a few of the most commonly available and potent ones. In this

Gaofeng Yuan; Mark L Wahlqvist; Min Yang; Duo Li

343

Glycerol as a carbon source for lipase production by the fungus rhizopus delemar  

Microsoft Academic Search

The ability of the fungus Rhizopus delemar to synthesize lipase (glycerol ester hydrolase, E.C. 3.1.1.3) when grown on glycerol as the prime carbon source was investigated. Glucose, glycerol and olive oil all supported fungal growth and lipase production. Maximum net and specific lipase activities obtained in glycerol were greater than those obtained in glucose and olive oil, and were reached

Michael J. Haas; David G. Bailey

1993-01-01

344

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

EPA Science Inventory

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

345

Helical graphitic carbon nitrides with photocatalytic and optical activities.  

PubMed

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

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

2014-10-27

346

Treatment of activated carbon to enhance catalytic activity for reduction of nitric oxide with ammonia  

SciTech Connect

Catalytic activity of activated carbon treated with various techniques was examined in a fixed bed reactor for the reduction of nitric oxide with ammonia at 150 C. Activated carbon derived from coconut shell impregnated with an aqueous solution of ammonium sulfate, further treated with sulfuric acid, dried at 120 C, and then heated in an inert gas stream at 400 C, showed the highest catalytic activity within the range of experimental conditions. The enhancement of catalytic activity of modified activated carbon could be attributed to the increase in the amount of oxygen function groups which increased the adsorption site for ammonia. Catalytic activity of activated carbons depended on the surface area and the oxygen content as well.

Ku, B.J.; Rhee, H.K. (Seoul National Univ. (Korea, Republic of). Dept. of Chemical Engineering); Lee, J.K.; Park, D. (Korea Inst. of Science and Technology, Seoul (Korea, Republic of))

1994-11-01

347

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

SciTech Connect

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.

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

1996-05-10

348

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

NASA Astrophysics Data System (ADS)

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.

Rivera-Utrilla, J.; SáNchez-Polo, M.

2003-09-01

349

Adsorption of gold cyanide complexes by activated carbon on non-coconut shell origin  

SciTech Connect

Coconut shells are the most widely used raw material for the production of activated carbon used in the gold production by cyanide leaching. There have been efforts to find alternatives to coconut shells. Shells and stones of certain fruits, have been tested. Although promising results to some extent were obtained, coconut shells remain the main source of activated carbon. Turkey has become a country of interest in terms of gold deposits of epithermal origin. Four deposits have already been discovered and, mining and milling operations are expected to start in the near future. Explorations are underway in many other areas of high expectations. Turkey is also rich in fruits which can be a valuable source of raw material for activated carbon production. In this study, hazelnut shells, peach and apricot stones, abundantly available locally, have been tested to determine whether they are suitable for the gold metallurgy. Parameters of carbonization and activation have been optimized. Gold loading capacity and adsorption kinetics have been studied.

Yalcin, M.; Arol, A.I. [Middle East Technical Univ., Ankara (Turkey). Mining Engineering Dept.

1995-12-31

350

Enzymatic production of glycerol carbonate from by-product after biodiesel manufacturing process.  

PubMed

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

Jung, Hongsub; Lee, Youngrak; Kim, Daeheum; Han, Sung Ok; Kim, Seung Wook; Lee, Jinwon; Kim, Yong Hwan; Park, Chulhwan

2012-08-10

351

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.

2011-07-25

352

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

PubMed Central

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

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

1984-01-01

353

Thermodynamics of adsorption of acetone on active carbon supported metal adsorbents  

Microsoft Academic Search

Adsorption of acetone on active carbon and active carbon supported metals (Ni, Cu, Zn and Cd) have been studied as a function of temperature. Thermodynamic parameters such as ?G0, ?H0, and ?S0 are calculated from virial and Langmuir isotherm expressions. It is observed that active carbon supported metals have more adsorption affinity for acetone as compared to active carbon. Results

M. Afzal; F. Mahmood; M. Saleem

1992-01-01

354

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

Microsoft Academic Search

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

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

2011-01-01

355

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

Microsoft Academic Search

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

Urs Jans; Jürg Hoigné

1998-01-01

356

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

Microsoft Academic Search

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

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

1997-01-01

357

Production of carbonate sediments by a unicellular green alga  

USGS Publications Warehouse

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

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

1998-01-01

358

Hydrogen and carbon nanotube production via catalytic decomposition of methane  

NASA Astrophysics Data System (ADS)

The future energy demand is expected to increase significantly due to an increasing world population and demands for higher standards of living and better air quality. Hydrogen is considered as an energy carrier because of its high conversion efficiency and low pollutant emissions. It can be produced from various sources and transformed into electricity and other energy forms with a low pollution. The catalytic decomposition of hydrocarbon has been seen as a really useful method for production of pure hydrogen and for the environmental concern. The objective of this study was to assess the impact of catalyst composition and processing parameters on COx-free hydrogen production and to produce an available solid form of co-product carbon as carbon nanotubes via catalytic decomposition of methane. The optimum experimental conditions for methane decomposition have been investigated. Fe, Co and Ni are used as catalysts (nano materials) over different substrates as SiO2 and MgO to produce hydrogen at optimum temperatures.

Deniz, Cansu; Karatepe, Nilgün

2013-09-01

359

DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS  

SciTech Connect

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

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

2006-03-07

360

Chars pyrolyzed from oil palm wastes for activated carbon preparation  

SciTech Connect

Chars pyrolyzed from extracted oil palm fibers for the preparation of activated carbons were studied. The effects of pyrolysis temperature and hold time on density, porosity, yield, BET and micropore surface areas, total pore volume, and pore size distributions of chars were investigated. The optimum conditions for pyrolysis were found to be at a pyrolysis temperature of 850 C for a hold time of 3.5 h. Scanning electron micrographs of the char surfaces verified the presence of porosities. The experimental results showed that it was feasible to produce chars with high BET and micropore surface areas from extracted oil palm fibers. The resulting chars will be subjected to steam or carbon dioxide activation to prepare activated carbons for use as gas adsorbents for air pollution control.

Lua, A.C.; Guo, J. [Nanyang Technological Univ., Singapore (Singapore)] [Nanyang Technological Univ., Singapore (Singapore)

1999-01-01

361

The environmental applications of activated carbon/zeolite composite materials.  

PubMed

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

Foo, K Y; Hameed, B H

2011-02-17

362

Studies relevant to the catalytic activation of carbon monoxide  

SciTech Connect

Research activity has included continued mechanistic investigations of the nucleophilic activation of carbon monoxide such as homogeneous catalysis of the water gas shift and key steps in the relevant catalytic cycles. Other investigations of related processes included the application of fast reaction techniques to prepare and to investigate quantitatively reactive organometallic intermediates relevant to the activation of hydrocarbons toward carbonylation and other functionalizations. 8 refs.

Ford, P.C.

1991-09-04

363

Active cycling of organic carbon in the central Arctic Ocean  

Microsoft Academic Search

THE notion of a barren central Arctic Ocean has been accepted since English's pioneering work1 on drifting ice-islands. The year-round presence of ice, a short photosynthetic season and low temperatures were thought to severely limit biological production1,2, although the paucity of data was often noted. Because primary production appeared to be low1,2, subsequent studies assumed that most organic carbon was

Patricia A. Wheeler; Michel Gosselin; Evelyn Sherr; Delphine Thibaultc; David L. Kirchman; Ronald Benner; Terry E. Whitledge

1996-01-01

364

Extracellular matrix production and calcium carbonate precipitation by coral cells in vitro  

E-print Network

Extracellular matrix production and calcium carbonate precipitation by coral cells in vitro Yael), which facilitates controlled deposition of a calcium carbonate skeleton; and (iii) the calcium carbonate to nematocysts, mucous glands, and sensory or nerve cells (2, 3). Many corals also precipitate calcium carbonate

365

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

Microsoft Academic Search

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

Joshua P. Newell; Robert O. Vos

2011-01-01

366

Improved granular activated carbon for the stabilization of wastewater pH  

SciTech Connect

Many times the start up of granular activated carbon adsorption systems for the control of organic contaminants in wastewater cm exhibit unacceptable increases in the adscurber effluent pH. Experience shows that the duration of the pH increase ranges from several hours to several days, during which time several hundred bed volumes of water can be discharged with a pH in excess of 9. Laboratory studies have identified the cause of the pH rise as an interaction between the naturally occurring anions and protons ar the water and the carbon surface. The interaction can be described as an ion exchange type of phenomenon, in which the carbon surface sorbs the anions and corresponding hydronium ions from the water. Capacities of the carbon for the anions range from 2 to 9 mg/g GAC, depending upon the water characteristics, the carbon type, the nature of the anion and its influent concentration. These studies have shown de the anion sorption and resulting pH increase is independent of the raw material used for die activated carbon production, e.g. bituminous or sub-bituminous coal, peat, wood or coconut. Also, the pH excursions occur with virgin, reactivated, and acid washed granular carbons. Current pH control technologies focus on adjustment of wastewater pH prior to discharge or recycle of the initial effluent water until the pH increase abates. However, improved water pH control options have been realized by altering the carbon surface rather than the water chemistry. The change to the carbon surface is accomplished through a controlled oxidation process. This process provides a more acidic carbon surface with a reduced affinity for the anions in the waste water. As a result, the pH excursions above 9 are eliminated and the initial effluent from the adsorption system can be discharged without further treatment.

NONE

1996-10-01

367

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

SciTech Connect

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.

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

368

Carbon monoxide activates autophagy via mitochondrial reactive oxygen species formation.  

PubMed

Autophagy, an autodigestive process that degrades cellular organelles and protein, plays an important role in maintaining cellular homeostasis during environmental stress. Carbon monoxide (CO), a toxic gas and candidate therapeutic molecule, confers cytoprotection in animal models of acute lung injury. The mechanisms underlying CO-dependent lung cell protection and the role of autophagy in this process remain unclear. Here, we demonstrate that CO exposure time-dependently increased the expression and activation of the autophagic protein, microtubule-associated protein-1 light chain-3B (LC3B) in mouse lung, and in cultured human alveolar (A549) or human bronchial epithelial cells. Furthermore, CO increased autophagosome formation in epithelial cells by electron microscopy and green fluorescent protein (GFP)-LC3 puncta assays. Recent studies indicate that reactive oxygen species (ROS) play an important role in the activation of autophagy. CO up-regulated mitochondria-dependent generation of ROS in epithelial cells, as assayed by MitoSOX fluorescence. Furthermore, CO-dependent induction of LC3B expression was inhibited by N-acetyl-L-cysteine and the mitochondria-targeting antioxidant, Mito-TEMPO. These data suggest that CO promotes the autophagic process through mitochondrial ROS generation. We investigated the relationships between autophagic proteins and CO-dependent cytoprotection using a model of hyperoxic stress. CO protected against hyperoxia-induced cell death, and inhibited hyperoxia-associated ROS production. The ability of CO to protect against hyperoxia-induced cell death and caspase-3 activation was compromised in epithelial cells infected with LC3B-small interfering (si)RNA, indicating a role for autophagic proteins. These studies uncover a new mechanism for the protective action of CO, in support of potential therapeutic application of this gas. PMID:21441382

Lee, Seon-Jin; Ryter, Stefan W; Xu, Jin-Fu; Nakahira, Kiichi; Kim, Hong Pyo; Choi, Augustine M K; Kim, Young Sam

2011-10-01

369

Production of carbon stripper foils for high-power cyclotrons  

NASA Astrophysics Data System (ADS)

TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics operates three industrial negative ion cyclotrons for commercial radioisotope production. Two of these cyclotrons (TR30 and TR30-2) can deliver 30 MeV protons at beam currents in excess of 1000 ?A and are designed for optional dual beam extraction and continuous operation. High-power negative ion accelerators use stripper foils as thick as 500 ?g/cm 2. It has been found that very smooth films with nanocrystalline microstructure perform the best in high-current applications. However, high-quality thick foils with good uniformity are difficult to manufacture. To meet our specific requirements, we have developed a carbon arc deposition system capable of producing durable, homogeneous carbon stripper foils. In this paper, we report on the fabrication of carbon foils with a thickness of 100-200 ?g/cm 2. The manufacturing equipment capable of producing ˜600 cm 2 of foil in a single run and the process details are described. Properties of these foils and their performance in the cyclotron are discussed.

Jaggi, V.; Pavan, R. A.; Zeisler, S. K.

2006-05-01

370

XPS of nitrogen-containing functional groups on activated carbon  

Microsoft Academic Search

XPS is used to study the binding energy of the Cls, Nls and Ols photoelectrons of surface groups on several nitrogen-containing activated carbons. Specific binding energies are assigned to amide (399.9 eV). lactam and imidc (399.7 eV). pyridine (398.7 eV), pyrrole (400.7 eV), alkylamine. secondary amide and N-alkylimide (399.9 eV) and trialkylaminc (399.7 cV) functional groups on activated carbon. Supporting

R. J. J. Jansen; H. van Bekkum

1995-01-01

371

Adsorption of uranium from aqueous solutions using activated carbon  

SciTech Connect

The adsorption of uranium from aqueous solution has been investigated using conventional commercially available activated carbons. It was found that treatment with hot nitric acid oxidized the surface of activated carbon and significantly increased the adsorption capacity for uranium in near-neutral and slightly acidic nitrate solutions. Equilibrium data were fitted to a simplified Freundlich isotherm for the purpose of comparison of oxidized and as-received samples. The decontamination of aqueous solutions was investigated in small column experiments. An ion-exchange mechanism of uranium sorption from aqueous solution is discussed. 43 refs., 11 figs., 1 tab.

Abbasi, W.A. (Pakistan Atomic Energy Commission, Islamabad (Pakistan)); Streat, M. (Loughborough Univ. of Technology, Leicestershire (United Kingdom))

1994-06-01

372

Removal of benzocaine from water by filtration with activated carbon  

USGS Publications Warehouse

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.

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

1990-01-01

373

Concomitant Production of High Purity Hydrogen and Sequestration Ready Carbon Dioxide From Coal  

Microsoft Academic Search

A novel process on the production of a high purity stream of hydrogen from gasification products with concomitant generation of sequestration-ready carbon dioxide stream is presented. The central theme of the process lies in the sequential use of a) an oxygen transfer compound (OTC) to oxidize carbon monoxide present in syngas and b) capture of CO2 using an appropriate carbon

Kanchan Mondal; Krzysztof Piotrowski; Tomasz Wiltowski

374

Oxygen production and carbon sequestration in an upwelling coastal Burke Hales,1  

E-print Network

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

Pierce, Stephen

375

The environmental impact on air quality and exposure to carbon monoxide from charcoal production in southern Brazil.  

PubMed

Black wattle silviculture is an important activity in southern Brazil. Much of the wood is used in the production of charcoal and the pyrolysis products impacts on air quality. This paper estimates the level of atmospheric contamination from the production of charcoal in one region of Brazil. We describe a low-cost charcoal kiln that can capture condensable gases and we estimate the levels of exposure of kiln workers to carbon monoxide. The latter results indicated that exposure to carbon monoxide can be reduced from an average of 950 ppm to 907 ppm and the mass of gases reduced by 16.8%. PMID:22541721

Gomes, Gabriel Meneghetti Faé; Encarnação, Fábio

2012-07-01

376

Removing lead in drinking water with activated carbon  

SciTech Connect

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

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

1994-02-01

377

Carbon-Based Supercapacitors Produced by Activation of Graphene  

SciTech Connect

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

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

2011-06-24

378

Carbon-based Supercapacitors Produced by Activation of Graphene  

SciTech Connect

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

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

2011-12-31

379

Pore structure of the activated coconut shell charcoal carbon  

NASA Astrophysics Data System (ADS)

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.

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

2014-09-01

380

Factors influencing the rate of gold cyanide leaching and adsorption on activated carbon, and their impact on the design of CIL and CIP circuits  

Microsoft Academic Search

The carbon in pulp (CIP) and carbon in leach (CIL) processes became firmly established in the gold mining industry in the 1980s, initially in South Africa and Australia, from where they spread rapidly to all the gold producing regions of the world. The percentage of annual global gold production by activated carbon-based processes grew from zero in the 1970s to

C. A. Fleming; A. Mezei; E. Bourricaudy; M. Canizares; M. Ashbury

2011-01-01

381

Transition metal activation and functionalization of carbon-hydrogen bonds  

SciTech Connect

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.

Jones, W.D.

1992-06-01

382

Adsorption studies of methylene blue and phenol onto vetiver roots activated carbon prepared by chemical activation  

Microsoft Academic Search

Vetiver roots have been utilized for the preparation of activated carbon (AC) by chemical activation with different impregnation ratios of phosphoric acid, XP (gH3PO4\\/g precursor): 0.5:1; 1:1 and 1.5:1. Textural characterization, determined by nitrogen adsorption at 77K shows that mixed microporous and mesoporous structures activated carbons (ACs) with high surface area (>1000m2\\/g) and high pore volume (up to 1.19cm3\\/g) can

Sandro Altenor; Betty Carene; Evens Emmanuel; Jacques Lambert; Jean-Jacques Ehrhardt; Sarra Gaspard

2009-01-01

383

Preparation and characteristics of agricultural waste activated carbon by physical activation having micro- and mesopores  

Microsoft Academic Search

Micro–mesoporous activated carbons were prepared from various agricultural wastes by physical activation. Agricultural wastes such as macadamia nut-shell, corncob, bagasse bottom ash, sawdust fly ash and rice husk fly ash, were optimized and processed to obtain the highest surface area. The effects of the amount of volatile matter in char, the activating agent, the activating temperature and kind of raw

Amphol Aworn; Paitip Thiravetyan; Woranan Nakbanpote

2008-01-01

384

Burners and combustion apparatus for carbon nanomaterial production  

DOEpatents

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.

Alford, J. Michael; Diener, Michael D; Nabity, James; Karpuk, Michael

2013-02-05

385

Managing Commercial Tree Species for Timber Production and Carbon Sequestration: Management Guidelines and Financial Returns  

SciTech Connect

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.

Gary D. Kronrad

2006-09-19

386

Estimating organic micro-pollutant removal potential of activated carbons using UV absorption and carbon characteristics.  

PubMed

Eight commercially available powdered activated carbons (PAC) were examined regarding organic micro-pollutant (OMP) removal efficiencies in wastewater treatment plant (WWTP) effluent. PAC characteristic numbers such as B.E.T. surface, iodine number and nitrobenzene number were checked for their potential to predict the OMP removal of the PAC products. Furthermore, the PAC-induced removal of UV254 nm absorption (UVA254) in WWTP effluent was determined and also correlated with OMP removal. None of the PAC characteristic numbers can satisfactorily describe OMP removal and accordingly, these characteristics have little informative value on the reduction of OMP concentrations in WWTP effluent. In contrast, UVA254 removal and OMP removal correlate well for carbamazepine, diclofenac, and several iodinated x-ray contrast media. Also, UVA254 removal can roughly describe the average OMP removal of all measured OMP, and can accordingly predict PAC performance in OMP removal. We therefore suggest UVA254 as a handy indicator for the approximation of OMP removal in practical applications where direct OMP concentration quantification is not always available. In continuous operation of large-scale plants, this approach allows for the efficient adjustment of PAC dosing to UVA254, in order to ensure reliable OMP removal whilst minimizing PAC consumption. PMID:24651017

Zietzschmann, Frederik; Altmann, Johannes; Ruhl, Aki Sebastian; Dünnbier, Uwe; Dommisch, Ingvild; Sperlich, Alexander; Meinel, Felix; Jekel, Martin

2014-06-01

387

Sulfurized activated carbon for high energy density supercapacitors  

NASA Astrophysics Data System (ADS)

Sulfurized activated carbon (SAC), made by coating the pore surface with thiophenic sulfur functional groups from the pyrolysis of sulfur flakes, were characterized and tested for supercapacitor applications. From X-ray photoelectron spectroscopy (XPS), the sulfur content in the SAC was found to be 2.7 at%. Electrochemical properties from potentiostatic and galvanostatic measurements, and electrochemical impedance spectroscopy (EIS) were used to evaluate the effect of sulfur on porous carbon electrodes. The SAC electrode exhibits better conductivity, and an obvious increase in specific capacitance that is almost 40% higher than plain activated carbons (ACs) electrode at a high current density of 1.4 A g-1. The proposed mechanism for improved conductivity and capacitive performance due to the sulfur functional groups on ACs will be discussed.

Huang, Yunxia; Candelaria, Stephanie L.; Li, Yanwei; Li, Zhimin; Tian, Jianjun; Zhang, Lili; Cao, Guozhong

2014-04-01

388

Carbon footprint of Canadian dairy products: calculations and issues.  

PubMed

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

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

2013-09-01

389

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

Federal Register 2010, 2011, 2012, 2013

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

2011-12-14

390

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

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

391

Kinetics of hydrocarbon adsorption on activated carbon and silica gel  

SciTech Connect

Experimental breakthrough results of methane, ethane and propane in activated carbon and silica gel obtained over a wide range of gas compositions, bed pressures, interstitial velocities, and column temperatures were analyzed using a dynamic, nonisothermal, nontrace column breakthrough model. A linear driving force (LDF) approximation is used for particle uptake, and the Langmuir-Freundlich isotherm represents adsorption equilibrium. The LDF mass-transfer-rate coefficient (and, hence, effective particle diffusivity) and column-wall heat-transfer coefficient were determined. The results show that hydrocarbon transport in the activated carbon particles used is essentially by Knudsen and surface flow, while for the silica gel used the transport is primarily by Knudsen flow. For activated carbon, the experimentally derived LDF coefficients for all three sorbates are well correlated using an average effective diffusivity value. With regard to heat transfer, the column-wall Nusselt number is approximately constant for the range of Reynolds numbers considered. Simulations of multicomponent breakthrough in the activated-carbon bed based on independently measured single-component kinetic parameters and the extended Langmuir-Freundlich isotherm agree very well with experimental results. The computational efficiency gained by adopting the simpler extended Langmuir isotherm model is also investigated.

Malek, A.; Farooq, S. [National Univ. of Singapore (Singapore). Dept. of Chemical Engineering] [National Univ. of Singapore (Singapore). Dept. of Chemical Engineering

1997-03-01

392

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...

393

Adsorption-induced Pore Expansion and Contraction in Activated Carbon  

NASA Astrophysics Data System (ADS)

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.

Connolly, Matthew; Wexler, Carlos

2012-02-01

394

Granulated activated carbon water treatment and potential radiation hazards  

Microsoft Academic Search

Early enthusiasm for granular activated carbon (GAC) as the radon treatment medium of choice for very small systems has diminished in consideration of the secondary radiation problems it presents. GAC remains a viable treatment method for radon only at the low end of the radon concentration range. In domestic water supplies this is 5000 pCi\\/l or less. The initial cost

S. Rydell; B. Keene; J. Lowry

1989-01-01

395

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...

396

Modification of the surface chemistry of activated carbons  

Microsoft Academic Search

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

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

1999-01-01

397

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...

398

Harnessing the Biological Activity of Natural Products  

Cancer.gov

Researchers have been intrigued by the potent and beneficial biological activity shown by some natural products and are testing ways to incorporate them into standard and experimental cancer treatment regimens, both to enhance the anticancer effects of therapy and reduce side effects.

399

Evaluation of the genetic activity of industrially produced carbon black  

SciTech Connect

Commercially produced oil furnace carbon black has been evaluated by five different assays for genetic activity. These were the Ames Salmonella typhimurium reverse mutation test, sister chromatid exchange test in CHO cells, mouse lymphoma test, cell transformation assay in C3H/10T 1/2 cells, and assay for genetic effects in Drosophila melanogaster. Limited cellular toxicity was exhibited but no significant genetic activity was noted.

Kirwin, C.J. (Phillips Petroleum Co., Bartlesville, OK); LeBlanc, J.V.; Thomas, W.C.; Haworth, S.R.; Kirby, P.E.; Thilagar, A.; Bowman, J.T.; Brusick, D.J.

1981-06-01

400

Intravascular Neutrophil Activation Due to Carbon Monoxide Poisoning  

Microsoft Academic Search

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

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

401

Activated carbon from co-pyrolysis of particle board and melamine (urea) formaldehyde resin: A techno-economic evaluation  

Microsoft Academic Search

The disposal and environmental problems associated with waste resin produced during the production of melamine (urea) formaldehyde and wood waste (i.e. particle board) containing these aminoplasts requires a processing technique which results in products of added value and which meets both ecological and economical needs. Several published results demonstrate that nitrogen incorporation in activated carbon can play a significant role

K. Vanreppelen; T. Kuppens; T. Thewys; R. Carleer; J. Yperman; S. Schreurs

2011-01-01

402

A review on soil carbon accumulation due to the management change of major Brazilian agricultural activities.  

PubMed

Agricultural areas deal with enormous CO2 intake fluxes offering an opportunity for greenhouse effect mitigation. In this work we studied the potential of soil carbon sequestration due to the management conversion in major agricultural activities in Brazil. Data from several studies indicate that in soybean/maize, and related rotation systems, a significant soil carbon sequestration was observed over the year of conversion from conventional to no-till practices, with a mean rate of 0.41 Mg C ha(-1) year(-1). The same effect was observed in sugarcane fields, but with a much higher accumulation of carbon in soil stocks, when sugarcane fields are converted from burned to mechanised based harvest, where large amounts of sugarcane residues remain on the soil surface (1.8 Mg C ha(-1) year(-1)). The higher sequestration potential of sugarcane crops, when compared to the others, has a direct relation to the primary production of this crop. Nevertheless, much of this mitigation potential of soil carbon accumulation in sugarcane fields is lost once areas are reformed, or intensive tillage is applied. Pasture lands have shown soil carbon depletion once natural areas are converted to livestock use, while integration of those areas with agriculture use has shown an improvement in soil carbon stocks. Those works have shown that the main crop systems of Brazil have a huge mitigation potential, especially in soil carbon form, being an opportunity for future mitigation strategies. PMID:23011303

La Scala jr, N; De Figueiredo, E B; Panosso, A R

2012-08-01

403

Combined effect of adsorption and biodegradation of biological activated carbon on H2S biotrickling filtration.  

PubMed

In order to evaluate the combined effect of adsorption and biodegradation of H(2)S on activated carbon surface in biotrickling filtration, four laboratory-scale biofiltration columns were operated simultaneously for 120h to investigate the mechanisms involved in treating synthetic H(2)S streams using biological activated carbon (BAC). The first three columns (A, B, C) contained a mixture of activated carbon and glass beads, with the carbons (BAC or virgin activated carbon (VAC)) and conditions (with or without liquid medium recirculation) differentiated. The last column (D) used 100% glass beads with liquid medium recirculation. Air streams containing 45ppmv H(2)S were passed through the columns at 4s of gas retention time (GRT) and liquid flow rate was set at 0.71mlmin(-1). Column D got its breakthrough in 3min of operation, indicating a negligible contribution of glass beads to the adsorption of H(2)S. The removal efficiency (RE) of Columns B and C using VAC dropped quickly to 30% within the first 8h, and afterwards continued to drop further but slowly. Column A using BAC stayed at 25% of RE throughout the operation time. A thorough investigation of the H(2)S oxidation products, i.e., various S species in both aqueous (recirculation media) and solid phases (BAC and VAC), was conducted using ICP-OES, IC, XRF, and CHNS elemental analyzer. BAC demonstrated a better performance than columns with adsorption only. Water film was found to enhance H(2)S removal. The percentage of sulphate in the total sulphur of the BAC system improved to twice of that of VAC system, indicating sulphate is the main product of H(2)S biofiltration. The observed pH drop in BAC system double confirmed that the presence of biodegradation in the biofilm over carbon surface did profound effect on the oxidation of H(2)S, compare to the systems with adsorption only. PMID:16930670

Duan, Huiqi; Yan, Rong; Koe, Lawrence Choon Chiaw; Wang, Xiaoling

2007-01-01

404

Bimodal activated carbons derived from resorcinol-formaldehyde cryogels  

NASA Astrophysics Data System (ADS)

Resorcinol-formaldehyde cryogels prepared at different dilution ratios have been activated with phosphoric acid at 450 °C and compared with their carbonaceous counterparts obtained by pyrolysis at 900 °C. Whereas the latter were, as expected, highly mesoporous carbons, the former cryogels had very different pore textures. Highly diluted cryogels allowed preparation of microporous materials with high surface areas, but activation of initially dense cryogels led to almost non-porous carbons, with much lower surface areas than those obtained by pyrolysis. The optimal acid concentration for activation, corresponding to stoichiometry between molecules of acid and hydroxyl groups, was 2 M l-1, and the acid-cryogel contact time also had an optimal value. Such optimization allowed us to achieve surface areas and micropore volumes among the highest ever obtained by activation with H3PO4, close to 2200 m2 g-1 and 0.7 cm3 g-1, respectively. Activation of diluted cryogels with a lower acid concentration of 1.2 M l-1 led to authentic bimodal activated carbons, having a surface area as high as 1780 m2 g-1 and 0.6 cm3 g-1 of microporous volume easily accessible through a widely developed macroporosity.

Szczurek, Andrzej; Amaral-Labat, Gisele; Fierro, Vanessa; Pizzi, Antonio; Celzard, Alain

2011-06-01

405

Influence of active sites organisation on calcium carbonate formation at model biomolecular interfaces  

E-print Network

Influence of active sites organisation on calcium carbonate formation at model biomolecular in the matrix. Formation of solid calcium carbonate with two- component monolayers on subphases containing.V. All rights reserved. Keywords: Mixed model monolayers; Calcium carbonate formation; Phospholipids

Hell, Stefan W.

406

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

SciTech Connect

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

None

2010-07-15

407

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

PubMed

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

Altaher, Hossam; Dietrich, Andrea M

2014-01-01

408

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

E-print Network

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

Wisconsin at Madison, University of

409

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

Microsoft Academic Search

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

Elena A Günter; Yury S Ovodov

2002-01-01

410

RESEARCH ON CARBON PRODUCTS FROM COAL USING AN EXTRACTIVE PROCESS  

SciTech Connect

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

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

2002-03-31

411

Electrocatalytic activity of nitrogen-doped carbon nanotube cups.  

PubMed

The electrochemical activity of stacked nitrogen-doped carbon nanotube cups (NCNCs) has been explored in comparison to commercial Pt-decorated carbon nanotubes. The nanocup catalyst has demonstrated comparable performance to that of Pt catalyst in oxygen reduction reaction. In addition to effectively catalyzing O(2) reduction, the NCNC electrodes have been used for H(2)O(2) oxidation and consequently for glucose detection when NCNCs were functionalized with glucose oxidase (GOx). Creating the catalysts entirely free of precious metals is of great importance for low-cost fuel cells and biosensors. PMID:19722487

Tang, Yifan; Allen, Brett L; Kauffman, Douglas R; Star, Alexander

2009-09-23

412

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

NASA Technical Reports Server (NTRS)

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

Kaloupis, P.; Sridhar, K. R.

1991-01-01

413

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

Microsoft Academic Search

Raman, infrared and X-ray photoelectron spectroscopies were used to characterize the thick coating of reaction products on carbon and MnO2 coated carbon cathodes produced during discharge of Li-air cells. The results show that neither Li2O2 or Li2O are major components of the insoluble discharge products; instead the products are largely composed of fluorine, lithium, and carbon, with surprisingly little oxygen.

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

2011-01-01

414

Production of cellulase from Trichoderma reesei in fed-batch fermentation from soluble carbon sources  

SciTech Connect

The use of a soluble carbon source in lieu of cellulose for the production of cellulase would allow greater control of the fermentation, since growth and enzyme production would no longer be dependent upon cellulose hydrolysis. Where carbon limitation is a requirement, fed-batch fermentation has proved successful. This article describes cellulase production from Trichoderma reesei using five different carbon sources, sophorose appearing to be a more likely candidate than cellobiose. (Refs. 22).

Allen, A.L.; Mortensen, R.E.

1981-11-01

415

Carbon catabolite repression-independent and pH-dependent production of indoles by Rubrivivax benzoatilyticus JA2.  

PubMed

Rubrivivax benzoatilyticus JA2 produces indole derivatives (indoles) from aniline, anthranilate or L-tryptophan. Glucose repressed indole production in R. benzoatilyticus JA2, while malate had no effect. Growth of R. benzoatilyticus JA2 on glucose resulted in decrease in culture pH (6.4) compared with malate (8.4). Growth of R. benzoatilyticus JA2 on sugar carbon sources decreased culture pH (6.4-6.6) and indole production. Further, culture pH of 6.4 repressed the indole production, and pH 8.4 promoted the production irrespective of carbon sources used for growth. Moreover, correlation between indole production and culture pH was observed, where acidic pH inhibited indole production, while alkaline pH promoted the production, suggesting the role of pH in indole production. Tryptophan-catabolizing enzyme activities are significantly high in malate-grown cultures (pH 8.4) compared with that of the glucose (pH 6.4)-grown cultures and corroborated well with indole production, indicating their role in indole production. These results confirm that indole production in R. benzoatilyticus JA2 is pH dependent rather than carbon catabolite repression. PMID:23666086

Mujahid, Md; Sasikala, Ch; Ramana, Ch V

2013-10-01

416

Improving Jet Reactor Configuration for Production of Carbon Nanotubes  

NASA Technical Reports Server (NTRS)

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

Povitsky, Alex

2000-01-01

417

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

Microsoft Academic Search

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

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

418

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

PubMed

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

Nuithitikul, Kamchai; Srikhun, Sarawut; Hirunpraditkoon, Samorn

2010-01-01

419

Phytoplankton, not allochthonous carbon, sustains herbivorous zooplankton production  

PubMed Central

Terrestrial organic matter inputs have long been thought to play an important role in aquatic food web dynamics. Results from recent whole lake 13C addition experiments suggest terrestrial particulate organic carbon (t-POC) inputs account for a disproportionate portion of zooplankton production. For example, several studies concluded that although t-POC only represented ?20% of the flux of particulate carbon available to herbivorous zooplankton, this food source accounted for ?50% of the C incorporated by zooplankton. We tested the direct dietary impact of t-POC (from the leaves of riparian vegetation) and various phytoplankton on Daphnia magna somatic growth, reproduction, growth efficiency, and lipid composition. By itself, t-POC was a very poor quality resource compared to cryptophytes, diatoms, and chlorophytes, but t-POC had similar food quality compared to cyanobacteria. Small additions of high quality Cryptomonas ozolinii to t-POC-dominated diets greatly increased Daphnia growth and reproduction. When offered alone, t-POC resulted in a Daphnia growth efficiency of 5 ± 1%, whereas 100% Cryptomonas and Scenedesmus obliquus diets resulted in growth efficiencies of 46 ± 8% (± SD) and 36 ± 3%, respectively. When offered in a 50:50 mixed diet with Cryptomonas or Scenedesmus, the t-POC fraction resulted in a partial growth efficiency of 22 ± 9% and 15 ± 6%, respectively. Daphnia that obtained 80% of their available food from t-POC assimilated 84% of their fatty acids from the phytoplankton component of their diet. Overall, our results suggest Daphnia selectively allocate phytoplankton-derived POC and lipids to enhance somatic growth and reproduction, while t-POC makes a minor contribution to zooplankton production. PMID:19934044

Brett, Michael T.; Kainz, Martin J.; Taipale, Sami J.; Seshan, Hari

2009-01-01

420

Active carbon filter health condition detection with piezoelectric wafer active sensors  

NASA Astrophysics Data System (ADS)

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.

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

2011-04-01

421

Removal of micropollutants from aerobically treated grey water via ozone and activated carbon  

Microsoft Academic Search

Ozonation and adsorption onto activated carbon were tested for the removal micropollutants of personal care products from aerobically treated grey water. MilliQ water spiked with micropollutants (100–1600 ?gL?1) was ozonated at a dosing rate of 1.22. In 45 min, this effectively removed (>99%): Four parabens, bisphenol-A, hexylcinnamic aldehyde, 4-methylbenzylidene-camphor (4MBC), benzophenone-3 (BP3), triclosan, galaxolide and ethylhexyl methoxycinnamate. After 60 min, the removal efficiency

L. Hernández-Leal; H. Temmink; G. Zeeman; C. J. N. Buisman

2011-01-01

422

Removal of micropollutants from aerobically treated grey water via ozone and activated carbon  

Microsoft Academic Search

Ozonation and adsorption onto activated carbon were tested for the removal micropollutants of personal care products from aerobically treated grey water. MilliQ water spiked with micropollutants (100–1600 ?gL?1) was ozonated at a dosing rate of 1.22. In 45 min, this effectively removed (>99%): Four parabens, bisphenol-A, hexylcinnamic aldehyde, 4-methylbenzylidene-camphor (4MBC), benzophenone-3 (BP3), triclosan, galaxolide and ethylhexyl methoxycinnamate. After 60 min,

L. Hernandez Leal; B. G. Temmink; G. Zeeman; C. J. N. Buisman

2011-01-01

423

Activated carbon from coconut coirpith as metal adsorbent: adsorption of Cd(II) from aqueous solution  

Microsoft Academic Search

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

K. Kadirvelu; C. Namasivayam

2003-01-01

424

Carbon export production in the subantarctic zone and polar front zone south of Tasmania  

NASA Astrophysics Data System (ADS)

We studied the water column distribution of total 234Th in subantarctic (SAZ) and polar front (PFZ) zone systems south of Tasmania during mid-austral summer 2007. The objective was to assess whether the observed zonal differences in biomass in this sector translated into variability of the carbon export and sequestration potential, and to identify possible causes inducing this variability. This study is part of a broader investigation focusing on macro- and micronutrient availability controlling ecosystem functioning in this area. Surface deficits in 234Th activities were observed at every station. 234Th export fluxes calculated from the 234Th activity deficits assuming steady state conditions showed higher 234Th export fluxes in the western than eastern SAZ, both of which were higher than those in the PFZ. 234Th fluxes sampled by free-drifting IRS and PPS-3 sediment traps at 150 and 170 m during short-term deployments (˜ 6 days) at the three process stations were significantly lower than those obtained by the 234Th-deficit method. Possible reasons for this discrepancy are discussed. Carbon export fluxes were calculated based on the total 234Th fluxes ( 234Th deficit method) and the C:Th ratio for the >54 ?m particle size fraction from the appropriate export depth. The >54 ?m C:Th ratio was significantly lower in the eastern SAZ than the western SAZ or PFZ, resulting in carbon export fluxes that were lowest in the eastern SAZ. Overall, export fluxes range from 3.6±1.5 to 13.2±3.1 mmol C m -2 d -1. Carbon export fluxes are compared with gross primary production, new production and mesopelagic remineralization fluxes obtained by others during the same cruise. Contrary to expectations, we found higher export production in the PFZ and the western SAZ where biomass and dissolved Fe were lower than in the eastern SAZ. Significant differences in community structure of both primary producers and consumers likely contributed to this difference between the three regions. This pattern of higher shallow export continued into the mesopelagic, with lower remineralization efficiency in PFZ and SAZ-West compared to SAZ-East. Within the SAZ, east and west sites thus differed in their efficiency of carbon sequestration into the deep (>600 m) water column, with SAZ-West exceeding the sequestration capacity of SAZ-East. If the SAZ-East region can be used as an analog for a future climate warming scenario, our results suggest that export production at high latitudes could decrease, despite increased primary production.

Jacquet, S. H. M.; Lam, P. J.; Trull, T.; Dehairs, F.

2011-11-01

425

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

PubMed Central

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

Ida, Takashi Y.; Kudo, Gaku

2008-01-01

426

Preparation of activated carbon using low temperature carbonisation and physical activation of high ash raw bagasse for acid dye adsorption  

Microsoft Academic Search

Activated carbons were prepared from bagasse through a low temperature (160 °C) chemical carbonisation treatment and gasification with carbon dioxide at 900 °C. The merit of low temperature chemical carbonisation in preparing chars for activation was assessed by comparing the physical and chemical properties of activated carbons developed by this technique to conventional methods involving the use of thermal and

M. Valix; W. H. Cheung; G. McKay

2004-01-01

427

Nomex-derived activated carbon fibers as electrode materials in carbon based supercapacitors  

NASA Astrophysics Data System (ADS)

Electrochemical characterization has been carried out for electrodes prepared of several activated carbon fiber samples derived from poly ( m-phenylene isophthalamide) (Nomex) in an aqueous solution. Depending on the burn-off due to activation the BET surface area of the carbons was in the order of 1300-2800 m 2 g -1, providing an extensive network of micropores. Their capability as active material for supercapacitors was evaluated by using cyclic voltammetry and impedance spectroscopy. Values for the capacitance of 175 F g -1 in sulfuric acid were obtained. Further on, it was observed that the specific capacitance and the performance of the electrode increase significantly with increasing burn-off degree. We believe that this fact can be attributed to the increase of surface area and porosity with increasing burn-off.

Leitner, K.; Lerf, A.; Winter, M.; Besenhard, J. O.; Villar-Rodil, S.; Suárez-García, F.; Martínez-Alonso, A.; Tascón, J. M. D.

428

Characterization and application of activated carbon produced from oak cups pulp  

Microsoft Academic Search

Activated carbons have been prepared from a lignocellulosic waste material by chemical activation. Phosphoric acid and zinc chloride have been used as activating agent. The influence of process variables on the carbons’ surface area was studied to optimize these parameters. The textural properties of active carbons were characterized by N2 adsorption at 77K and SEM analysis, while Boehm titration and

Serkan Timur; Ismail Cem Kantarli; Sermin Onenc; Jale Yanik

2010-01-01

429

Optimization of preparation conditions for activated carbons from coconut husk using response surface methodology  

Microsoft Academic Search

Coconut husk was used to prepare activated carbon using physiochemical activation method, consisted of potassium hydroxide (KOH) treatment and carbon dioxide (CO2) gasification. The effects of the preparation variables which were activation temperature, activation time and chemical impregnation (KOH:char) ratio on the adsorption capacity on methylene blue dye and carbon yield were investigated. Based on the central composite design (CCD),

I. A. W. Tan; A. L. Ahmad; B. H. Hameed

2008-01-01

430

Water vapor adsorption onto activated carbons prepared from cattle manure compost (CMC)  

Microsoft Academic Search

Activated carbons were prepared from cattle manure compost (CMC) using zinc chloride activation. The structural and surface chemical characteristics of CMC-based activated carbons were determined by N2 adsorption–desorption and Boehm titration, respectively. The water vapor adsorption properties of the prepared activated carbons with various pore structure and surface nature were examined, and the mechanism of water adsorbed onto activated carbon

Qingrong Qian; Satoshi Sunohara; Yuichi Kato; Muhammad Abbas Ahmad Zaini; Motoi Machida; Hideki Tatsumoto

2008-01-01

431

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

Code of Federal Regulations, 2013 CFR

...monitor the injection rate of activated carbon...municipal waste combustion unit uses activated carbon...calculate the carbon feed rate based on the operating...municipal waste combustion unit is operating and combusting...block average carbon feed rate in kilograms (or...

2013-07-01

432

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

Code of Federal Regulations, 2011 CFR

...monitor the injection rate of activated carbon...municipal waste combustion unit uses activated carbon...calculate the carbon feed rate based on the operating...municipal waste combustion unit is operating and combusting...block average carbon feed rate in kilograms (or...

2011-07-01

433