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1

Production of activated carbons from Illinois coals  

SciTech Connect

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

Hippo, E.J.; O`Brien, W.S. [Southern Illinois Univ., Carbondale, IL (United States); Sun, Jian [Univ. of Illinois, Champaign, IL (United States)

1996-12-31

2

The production of chemically-activated carbon  

Microsoft Academic Search

In an attempt to optimise the microporosity in an activated carbon, controlled heating of sucrose chars and other precursor materials was carried out in an inert environment with an excess of potassium or sodium hydroxide. Initially, the precursor materials were subjected to a regulated temperature–time profile to elevated temperatures (400–900°C) and subsequently cooled. The products were then exposed either to

M. J. B Evans; E Halliop; J. A. F MacDonald

1999-01-01

3

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

4

Production of active carbons from waste tyres––a review  

Microsoft Academic Search

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

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

2004-01-01

5

Production of charcoal and activated carbon at elevated pressure  

Microsoft Academic Search

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

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

1995-01-01

6

Production of fungicidal oil and activated carbon from pistachio shell  

Microsoft Academic Search

The main objective of this study was to evaluate the feasibility of pistachio shell as a biomass feedstock for the production of fungicidal oil and a precursor for the production of activated carbon by physical activation. For this purpose, pistachio shell was pyrolyzed in a fixed bed reactor at the different temperatures (300–600°C). The pyrolysis products were identified as gas,

Cagdas Okutucu; Gozde Duman; Suat Ucar; Ihsan Yasa; Jale Yanik

2011-01-01

7

Production of charcoal and activated carbon at elevated pressure  

SciTech Connect

With its wide range of properties, charcoal finds many commercial applications for domestic cooking, refining of metals (steel, copper, bronze, nickel, aluminum and electro-manganese), production of chemicals (carbon disulfide, calcium carbide, silicon carbide, sodium cyanide, carbon black, fireworks, gaseous chemicals, absorbents, soil conditioners and pharmaceuticals), as well as production of activated carbon and synthesis gas. In 1991, the world production of charcoal was 22.8 million cubic meters (3.8 million metric tons) as shown in Table 1. Brazil is the world`s largest charcoal producer --- 5.9 million cubic meters or one million metric tons was produced in 1991, most of which is used in steel and iron industry. African countries produced 45% of the world total amount of charcoal, where 86% of the wood-based energy is for domestic use, most of which is inefficiently used. Charcoal is produced commercially in kilns with a 25% to 30% yield by mass on a 7 to 12 day operating cycle. Until recently, the highest yield of good quality charcoal reported in the literature was 38%. In this paper, and ASME code rated experimental system is presented for producing charcoal and activated carbon from biomass.

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

1995-12-31

8

GRANULAR ACTIVATED CARBONS FROM AGRICULTURAL BY-PRODUCTS: PROCESS DESCRIPTION AND ESTIMATED COST OF PRODUCTION  

Technology Transfer Automated Retrieval System (TEKTRAN)

A number of laboratories have described the use of pecan shells and sugarcane bagasse as feedstocks for activated carbon production. These carbons have found utility in a variety of applications, including metal ion remediation, sugar decolorization and adsorption of different organic pollutants. ...

9

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

10

[Use of mycelial waste products as an additive in the manufacture of granulated active carbon].  

PubMed

The physico-chemical characteristics of type MAU active carbon manufactured with the use of the mycelial waste of tetracycline production and carbon residue are presented. Granulated active carbon MAU-5 was tested under laboratory conditions at the stage of the treatment of the antibiotic production waste. For the manufacture of the granulated active carbon the mycelial waste with the moisture content of 8 per cent and the carbon residue of weared tyres were used. The same as active carbon BAU it is useful in the sorption treatment of sewage. PMID:8593097

Iakubova, A R; Lagunov, V M; Fa?ngol'd, Z L; Nikolaev, V B

1995-06-01

11

Development of Activated Carbons from Coal Combustion By-Products.  

National Technical Information Service (NTIS)

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 ...

H. H. Schobert M. M. Maroto-Valer Z. Lu

2000-01-01

12

Activated Carbon Production from Date Stones Using Phosphoric Acid  

Microsoft Academic Search

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

F. Al-Qaessi; L. Abu-Farah

2010-01-01

13

Production of Activated Carbon from Date Stones by Using Zinc Chloride  

Microsoft Academic Search

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

F. A. H. Al-Qaessi

2010-01-01

14

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

PubMed

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

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

2000-11-01

15

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

PubMed

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

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

2004-01-01

16

Addition of Powdered Activated Carbon to Anaerobic Digesters: Effects on Methane Production.  

National Technical Information Service (NTIS)

A 2 to 4 fold increase in gas production was achieved in digesters dosed with small amounts of powdered activated carbon. The concentrations of carbon used in this investigation ranged from 500 to 4000 mg/1. Enhancement appeared to be proportional to the ...

R. R. Spencer A. J. Shuckrow J. F. Ferguson

1976-01-01

17

Hydrogen production by thermo-catalytic decomposition of methane: Regeneration of active carbons using CO 2  

Microsoft Academic Search

Thermo-catalytic decomposition of methane using carbons as catalyst is a very attractive process for free CO2–hydrogen production. One of the main drawbacks for the sustainability of the process is catalyst deactivation. In this work, regeneration of a deactivated active-carbon catalyst has been studied using CO2 as activating agent under different regeneration conditions. It has been stated that during the regeneration

J. L. Pinilla; I. Suelves; R. Utrilla; M. E. Gálvez; M. J. Lázaro; R. Moliner

2007-01-01

18

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

19

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.

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

2009-01-01

20

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

21

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

Microsoft Academic Search

The amount of deposited carbon on activated carbons was adjusted by varying the space time and the time on stream. Carbon\\u000a nuclei formation appeared to occur initially but was terminated soon and then the carbon crystallite growth became dominant.\\u000a The methane decomposition rate over activated carbons had a nearly linear relationship with the amount of carbon deposited.\\u000a This suggests that

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

2003-01-01

22

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

Microsoft Academic Search

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

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

2004-01-01

23

Utilization of date stones for production of activated carbon using phosphoric acid  

SciTech Connect

Date stone wastes have been utilized for production of activated carbon by chemical activation with phosphoric acid using a fluidized-bed reactor. The effects of the activation time, activation temperature, impregnation ratio, and particle size on the yield and the adsorptive capacity towards iodine were studied. The yield and the quality of the activated carbon prepared by using H{sub 3}PO{sub 4} were compared with that prepared from date stones using the same equipment, and under similar conditions by using ZnCl{sub 2} as an oxidizing agent. The maximum value of the iodine number of the activated carbon produced using H{sub 3}PO{sub 4} in this work was about 495 under the following conditions: impregnation ratio 0.4, activation time 60 min, activation temperature 800 deg. C, particle size 0.60 mm. The iodine number for the produced activated carbon was higher when phosphoric acid was used, compared to that when zinc chloride was used as impregnation reagent; however, the yield obtained when H{sub 3}PO{sub 4} was used was lower than the yield when ZnCl{sub 2} was used. The iodine number increases significantly with increasing the activation temperature. By increasing the impregnation ratio at the same temperature, the iodine number decreased sharply and an oscillation is noticed for all the cases but it was clearer at 800 deg. C. The average variation of the iodine number for the whole range of particle size used in this work is {+-}10%.

Haimour, N.M. [Department of Chemical Engineering, University of Jordan, Amman 11942 (Jordan)]. E-mail: nomanhaimour@hotmail.com; Emeish, S. [Department of Chemical Engineering, Faculty of Engineering Technology, Al-Balqa' Applied University, P.O. Box (15008), 11134 Marka, Amman (Jordan)]. E-mail: s_emiesh@yahoo.com

2006-07-01

24

Production of activated carbons from a washington lignite using phosphoric acid activation  

Microsoft Academic Search

Chemical activation of a Washington state lignite was studied using heat-treatment temperatures (HTT) between 250 and 650 °C. Thermal blanks were generated under similar conditions for comparison. Changes in chemical composition of both the thermal and acid-treated carbons were followed by elemental analysis and FTIR spectroscopy. With increasing HTT, acid-treatment promotes a more extensive loss of hydrogen. Fourier-transform infrared spectra

C. Toles; S. Rimmer; J. C. Hower

1996-01-01

25

Development of Activated Carbons from Coal Combustion By-Products. Annual Technical Progress Report, June 2002.  

National Technical Information Service (NTIS)

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 ...

H. H. Schobert M. M. Maroto-Valer Z. Lu

2002-01-01

26

Production of Carbon Dioxide  

NSDL National Science Digital Library

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

House, The S.

2013-05-15

27

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

PubMed

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

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

2011-09-21

28

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

29

ACTIVATED CARBON FROM BROILER LITTER: PROCESS DESCRIPTION AND COST OF PRODUCTION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Animal manure continues to represent a significantly large and problematic portion of the U.S. 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. Bas...

30

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...

31

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

PubMed

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

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

2009-03-14

32

Catalytic activation of carbon monoxide  

Microsoft Academic Search

Research into the catalytic activation of carbon monoxide has direct applications to the industrial use of synthesis gas as a feedstock for manufacturing synfuels and other organic chemicals. Synthesis gas is comprised of hydrogen\\/carbon monoxide mixtures produced from coal and other carbonaceous materials. Its potential uses include production of oxygenated organic material such as methanol and ethylene glycol, conversion to

Ford

1981-01-01

33

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

2008-03-03

34

Electrochemical battery including a product of activated carbon fiber as an electrode  

SciTech Connect

Disclosed herein is an electrochemical battery having electrodes immersed in an organic solvent electrolyte solution so that the electromotive force is generated by doping to and/or undoping from said electrodes. One electrode is made of metal which is electrochemically equilibrated with cations in the electrolyte, and the other electrode is made of carbon molded product having a specific surface area of 100 to 2,500 m/sup 2//g. The electrodes according to this invention are capable of accepting a large quantity of doping, light in weight and easy to handle.

Nogami, T.; Nawa, M.

1985-04-09

35

Carbon monoxide production by algae  

Microsoft Academic Search

Carbon monoxide production has been demonstrated in Egregia menzies, several other algae and in the higher plants, Zostera marina and Medicago saliva. The ability to produce carbon monoxide is not destroyed by heating the tissues. Oxygen is required for carbon monoxide production by Egregia menzies. A carbon monoxide-producing compound can be extracted by refluxing the macerated algal tissues in 0.01

M. W. Loewus; C. C. Delwiche

1963-01-01

36

Activated carbon material  

DOEpatents

Activated carbon particles for use as iodine trapping material are impregnated with a mixture of selected iodine and potassium compounds to improve the iodine retention properties of the carbon. The I/K ratio is maintained at less than about 1 and the pH is maintained at above about 8.0. The iodine retention of activated carbon previously treated with or coimpregnated with triethylenediamine can also be improved by this technique. Suitable flame retardants can be added to raise the ignition temperature of the carbon to acceptable standards.

Evans, A. Gary (North Augusta, SC)

1978-01-01

37

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

PubMed

The production of activated carbon from bagasse and rice husk by a single-stage chemical activation method in short retention times (30-60min) was examined in this study. The raw materials were subjected to a chemical pretreatment and were fed to the reactor in the form of a paste (75% moisture). Chemicals examined were ZnCl2, NaOH and H3PO4, for temperatures of 600, 700 and 800 degrees C. Of the three chemical reagents under evaluation only ZnCl2 produced activated carbons with high surface areas. BET surface areas for rice husk were up to 750m2/g for 1:1 ZnCl2:rice husk ratio. BET surface areas for bagasse were up to 674m2/g for 0.75:1 ZnCl2:bagasse ratio. Results were compared to regular two-stage physical activation methods. PMID:18364254

Kalderis, Dimitrios; Bethanis, Sophia; Paraskeva, Panagiota; Diamadopoulos, Evan

2008-03-24

38

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

39

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

40

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

41

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 ...

42

Activated carbons prepared from phosphoric acid activation of grain sorghum  

Microsoft Academic Search

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

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

2002-01-01

43

Activated Carbon Derived from Fast Pyrolysis Liquids Production of Agricultural Residues and Energy Crops  

Technology Transfer Automated Retrieval System (TEKTRAN)

Fast pyrolysis is a thermochemical method that can be used for processing energy crops such as switchgrass, alfalfa, soybean straw, corn stover as well as agricultural residuals (broiler litter) for bio-oil production. Researchers with the Agriculture Research Service (ARS) of the USDA developed a 2...

44

Carbonate Production by Coral Reefs.  

National Technical Information Service (NTIS)

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

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

1971-01-01

45

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

46

The influence of oxygen and carbon dioxide tension on the production of TNF alpha by activated macrophages.  

PubMed Central

The influence of oxygen tension and carbon dioxide levels on human TNF alpha (hTNF alpha) production by the monocyte/macrophage cell line U937 has been examined. The cells were stimulated under different oxygen and carbon dioxide concentrations in the presence and absence of the known TNF alpha inducer phorbol 12-myristate 13-acetate (PMA). The results indicated that U937 cells stimulated with PMA produced up to 10 times more TNF alpha when incubated under tumour-relevant oxygen tensions of 1% rather than under aerobic conditions, i.e. 21% O2. Increasing the carbon dioxide levels from 5% to 7% however decreased the amount of PMA-stimulated hTNF alpha produced. No hTNF alpha was produced in the unstimulated U937 cells, indicating that low oxygen tensions (hypoxia) alone did not induce the production of TNF alpha, in this case.

Sampson, L. E.; Chaplin, D. J.

1996-01-01

47

Environmental Study of an Activated Carbon Plant.  

National Technical Information Service (NTIS)

This report is a summary of the environmental aspects arising from the production of activated carbon. The methods for pollution control are specified and the emissions and predicted ambient concentrations given. Recommendations are made to achieve satisf...

P. Clayton S. C. Wallin

1978-01-01

48

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

49

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

PubMed Central

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

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

2000-01-01

50

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

51

An insight into the KOH activation mechanism through the production of microporous activated carbon for the removal of Pb2+ cations  

NASA Astrophysics Data System (ADS)

Chemical activation was used through direct mixing of KOH with maize stalks in the smallest amount of water to provide KOH-to-stalk ratios of 33, 50, 66 and 75% by weight. The KOH-treated stalks were carbonized at 700 °C to produce a series of four activated carbons, besides a non-activated sample that was prepared and carbonized at 550 °C. The porous properties of these carbons were characterized by the Langmuir, BET and Dubinin-Radushkevich linear equations as well as both ?s (alpha-s) and t methods based on nitrogen adsorption isotherms. The chemical reactions involved during the impregnation and the carbonization processes for these hydroxide/lignocellulose mixtures have been proposed. Deep insight has been obtained concerning the possible reactions mechanism. The results showed that the KOH ratio was found to be the basic indicator of micoporosity development. The increase in the concentration of KOH much increased the S? values of the resulting carbons reaching a maximum limit at 66 wt% KOH with S? of 1684 m2/g and micropore ratio of ˜85% displaying an inverse correlation thereafter. The thermal behaviour and the surface microstructure in addition to the surface functional groups of the maize stalks and their prepared carbons were investigated by TGA, SEM and FTIR. The investigated carbons took up significant amounts of Pb2+ ions from aqueous solutions, which are ascribed to both the porosity and surface chemical nature of the adsorbents.

El-Hendawy, Abdel-Nasser A.

2009-01-01

52

Production of granular activated carbon from waste Rosa canina sp. seeds and its adsorption characteristics for dye.  

PubMed

An activated carbon was developed from Rosa canina sp. seeds, characterized and used for the removal of methylene blue (basic dye) from aqueous solutions. Adsorption studies were carried out at 20 degrees C and various initial dye concentrations (20, 40, 60, 80, and 100 mg/L) for different times (15, 30, 60, and 120 min). The adsorption isotherm was obtained from data. The results indicate that the adsorption isotherm of methylene blue is typically S-shaped. The shape of isotherm is believed to reflect three distinct modes of adsorption. In region 1, the adsorption of methylene blue is carried out mainly by ion exchange. In region 2 by polarizations of pi-electrons established at cyclic parts of the previously adsorbed methylene blue molecules is occurred. However, it is not observed any change at the sign of the surface charge although zeta potential value is decreased with increase of amount adsorbed. In region 3, the slope of the isotherm is reduced, because adsorption now must overcome electrostatic repulsion between oncoming ions and the similarly charged solid. Adsorption in this fashion is usually complete when the surface is covered with a monolayer of methylene blue. To reveal the adsorptive characteristics of the produced active carbon, porosity and BET surface area measurements were made. Structural analysis was performed using SEM-EDS. The produced active carbon has the specific surface area of 799.2 m2 g-1 and the iodine number of 495 mg/g. PMID:16263211

Gürses, A; Do?ar, C; Karaca, S; Açikyildiz, M; Bayrak, R

2005-11-02

53

Activated carbon from municipal waste  

Microsoft Academic Search

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

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

2000-01-01

54

PRODUCTION OF CARBON PRODUCTS USING A COAL EXTRACTION PROCESS  

SciTech Connect

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

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

2005-12-12

55

Carbon Sequestration Monitoring Activities  

Microsoft Academic Search

In its 'Carbon Sequestration Technology Roadmap and Program Plan 2007' the U.S. Department of Energy (DOE)'s Office of Fossil Energy National Energy Technology Laboratory (NETL) identified as a major objective extended field tests to fully characterize potential carbon dioxide (CO) storage sites and to demonstrate the long-term storage of sequestered carbon (p. 5). Among the challenges in this area are

Carol Frost

2010-01-01

56

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

57

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...

58

Carbon Sequestration Monitoring Activities  

SciTech Connect

In its 'Carbon Sequestration Technology Roadmap and Program Plan 2007' the U.S. Department of Energy (DOE)'s Office of Fossil Energy National Energy Technology Laboratory (NETL) identified as a major objective extended field tests to fully characterize potential carbon dioxide (CO{sub 2}) storage sites and to demonstrate the long-term storage of sequestered carbon (p. 5). Among the challenges in this area are 'improved understanding of CO{sub 2} flow and trapping within the reservoir and the development and deployment of technologies such as simulation models and monitoring systems' (p. 20). The University of Wyoming (UW), following consultations with the NETL, the Wyoming State Geological Survey, and the Governor's office, identified potential for geologic sequestration of impure carbon dioxide (CO{sub 2}) in deep reservoirs of the Moxa Arch. The Moxa Arch is a 120-mile long north-south trending anticline plunging beneath the Wyoming Thrust Belt on the north and bounded on the south by the Uinta Mountains. Several oil and gas fields along the Moxa Arch contain accumulations of natural CO{sub 2}. The largest of these is the La Barge Platform, which encompasses approximately 800 square miles. Several formations may be suitable for storage of impure CO{sub 2} gas, foremost among them the Madison Limestone, Bighorn Dolomite, and Nugget Sandstone. This project responded to the challenges described above by preparing a geological site characterization study on the Moxa Arch. The project included four priority research areas: (A) geological characterization of geologic structure of the Arch, the fault, and fracture patterns of the target formations and caprocks, (B) experimental characterization of carbon dioxide-brine-rock reactions that may occur, (C) optimization of geophysical and numerical models necessary for measurement, monitoring and verification (MMV), and (D) a preliminary performance assessment. Research work to accomplish these goals was coordinated by one administrative task under the direction of Dr. Carol Frost, Professor of Geology and Geophysics (Task 1.0), and one task devoted to designing and creating an interdisciplinary, project-specific carbon cyberinfrastructure to support collaborative carbon dioxide sequestration research among University of Wyoming scientists and their collaborators, performed by Jeff Hammerlinck, Director of the Wyoming Geographic Information Science Center at the University of Wyoming (Task 1.5). The results of these tasks are presented in the Introduction and in Chapter 1, respectively.

Carol Frost

2010-11-30

59

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

60

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...

61

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

62

The influence of broiler activity, growth rate, and litter on carbon dioxide balances for the determination of ventilation flow rates in broiler production.  

PubMed

Carbon dioxide balances are useful in determining ventilation rates in livestock buildings. These balances need an accurate estimation of the CO(2) produced by animals and their litter to determine the ventilation flows. To estimate the daily variation in ventilation flow, it is necessary to precisely know the daily variation pattern of CO(2) production, which mainly depends on animal activity. The objective of this study was to explore the applicability of CO(2) balances for determining ventilation flows in broiler buildings. More specifically, this work aimed to quantify the amount of CO(2) produced by the litter, as well as the amount of CO(2) produced by the broilers, as a function of productive parameters, and to analyze the influence of broiler activity on CO(2) emissions. Gas concentrations and ventilation flows were simultaneously measured in 3 trials, with 1 under experimental conditions and the other 2 in a commercial broiler farm. In the experimental assay, broiler activity was also determined. At the end of the experimental trial, on the day after the removal of the broilers, the litter accounted for 20% of the total CO(2) produced, and the broilers produced 3.71 L/h of CO(2) per kg of metabolic weight. On the commercial farm, CO(2) production was the same for the 2 cycles (2.60 L/h per kg of metabolic weight, P > 0.05). However, substantial differences were found between CO(2) and broiler activity patterns after changes in light status. A regression model was used to explain these differences (R(2) = 0.52). Carbon dioxide increased with bird activity, being on average 3.02 L/h per kg of metabolic weight for inactive birds and 4.73 L/h per kg of metabolic weight when bird activity was highest. Overall, CO(2) balances are robust tools for determining the daily average ventilation flows in broiler farms. These balances could also be applied at more frequent intervals, but in this case, particular care is necessary after light status changes because of discrepancy between animal activity and CO(2) production. PMID:22010228

Calvet, S; Estellés, F; Cambra-López, M; Torres, A G; Van den Weghe, H F A

2011-11-01

63

Carbon dioxide adsorption in chemically activated carbon from sewage sludge.  

PubMed

In this work, sewage sludge was used as precursor in the production of activated carbon by means of chemical activation with KOH and NaOH. The sludge-based activated carbons were investigated for their gaseous adsorption characteristics using CO2 as adsorbate. Although both chemicals were effective in the development of the adsorption capacity, the best results were obtained with solid NaOH (SBA(T16)). Adsorption results were modeled according to the Langmuir and Freundlich models, with resulting CO2 adsorption capacities about 56 mg/g. The SBA(T16) was characterized for its surface and pore characteristics using continuous volumetric nitrogen gas adsorption and mercury porosimetry. The results informed about the mesoporous character of the SBA(T16) (average pore diameter of 56.5 angstroms). The Brunauer-Emmett-Teller (BET) surface area of the SBA(T16) was low (179 m2/g) in comparison with a commercial activated carbon (Airpel 10; 1020 m2/g) and was mainly composed of mesopores and macropores. On the other hand, the SBA(T16) adsorption capacity was higher than that of Airpel 10, which can be explained by the formation of basic surface sites in the SBA(T16) where CO2 experienced chemisorption. According to these results, it can be concluded that the use of sewage-sludge-based activated carbons is a promising option for the capture of CO2. Implications: Adsorption methods are one of the current ways to reduce CO2 emissions. Taking this into account, sewage-sludge-based activated carbons were produced to study their CO2 adsorption capacity. Specifically, chemical activation with KOH and NaOH of previously pyrolyzed sewage sludge was carried out. The results obtained show that even with a low BET surface area, the adsorption capacity of these materials was comparable to that of a commercial activated carbon. As a consequence, the use of sewage-sludge-based activated carbons is a promising option for the capture of CO2 and an interesting application for this waste. PMID:23786147

de Andrés, Juan Manuel; Orjales, Luis; Narros, Adolfo; de la Fuente, María del Mar; Encarnación Rodríguez, María

2013-05-01

64

Benthic respiration measured by total carbonate production  

Microsoft Academic Search

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

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

1986-01-01

65

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

66

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

Microsoft Academic Search

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

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

2010-01-01

67

Carbon Nanotube Production in CO Laser Pumped Carbon Monoxide Plasmas  

NASA Astrophysics Data System (ADS)

A novel method for the synthesis of carbon nanotubes will be presented. Carbon monoxide in a CO-Ar gas mixture is optically pumped using a continuous wave CO laser. The CO molecules absorb the laser radiation on the lowest 10 vibrational transitions and transfer energy to high vibrational states by vibration-vibration energy exchange collisions. This leads to a highly nonequilibrium energy distribution in the CO which provides enough energy for the CO disproportionation reaction to occur: CO + CO arrow C + CO_2. This experimental technique consequently produces the free carbon necessary for the growth of carbon nanotubes and other carbon clusters while maintaining near room temperature in the plasma. Our technique can produce substantial quantities of nanotubes at low pressure (50 Torr) due to the efficient carbon production and is scalable to higher pressures and therefore, to larger production quantities. We will present the effect of metal catalysts on production rates and nanotube quality for our experimental technique as well as effects of plasma temperature and gas pressures. Single- and multi-walled carbon nanotubes have been observed in the deposited material with concentrations of better than 50 %. The plasma conditions are monitored using emission spectroscopy.

Ploenjes, Elke; Palm, Peter; Subramaniam, Vish; Adamovich, Igor; Rich, William; Viswanathan, Babu; Fraser, Hamish

2000-10-01

68

Fossil carbon emissions associated with carbon flowsof wood products  

Microsoft Academic Search

Specific fossil carbon (C) emissions and primary energy useassociated with the manufacture of different wood product groups inFinland are estimated and expressed as emissions or energy use per amountof wood-based C in raw material and per amount in end product. Thecalculation includes both emissions from supplied fuels within the forestindustries, and from electricity and district heat purchased from externalsources. The

K. Pingoud; A. Lehtilä

2002-01-01

69

Photoconductivity of activated carbon fibers  

SciTech Connect

The photoconductivity is measured on a high-surface-area disordered carbon material, namely activated carbon fibers, to investigate their electronic properties. Measurements of decay time, recombination kinetics and temperature dependence of the photoconductivity generally reflect the electronic properties of a material. The material studied in this paper is a highly disordered carbon derived from a phenolic precursor, having a huge specific surface area of 1000--2000m{sup 2}/g. Our preliminary thermopower measurements suggest that this carbon material is a p-type semiconductor with an amorphous-like microstructure. The intrinsic electrical conductivity, on the order of 20S/cm at room temperature, increases with increasing temperature in the range 30--290K. In contrast with the intrinsic conductivity, the photoconductivity in vacuum decreases with increasing temperature. The recombination kinetics changes from a monomolecular process at room temperature to a biomolecular process at low temperatures. The observed decay time of the photoconductivity is {approx equal}0.3sec. The magnitude of the photoconductive signal was reduced by a factor of ten when the sample was exposed to air. The intrinsic carrier density and the activation energy for conduction are estimated to be {approx equal}10{sup 21}/cm{sup 3} and {approx equal}20meV, respectively. The majority of the induced photocarriers and of the intrinsic carriers are trapped, resulting in the long decay time of the photoconductivity and the positive temperature dependence of the conductivity. 54 refs., 11 figs., 3 tabs.

Kuriyama, K.; Dresselhaus, M.S. (Massachusetts Inst. of Tech., Cambridge, MA (USA))

1990-08-01

70

Primary radiolysis products of propylene glycol carbonate  

Microsoft Academic Search

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

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

1985-01-01

71

Solvent-regenerated activated carbon  

SciTech Connect

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

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

1988-07-01

72

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

73

Active carbon catalyst for heavy oil upgrading  

Microsoft Academic Search

The active carbon (AC) catalyst was studied by hydrocracking of Middle Eastern vacuum residue (VR) for heavy oil upgrading. It was observed that the active carbon has the affinity to heavy hydrocarbon compounds and adsorption selectivity to asphaltenes, and exhibits better ability to restrict the coke formation during the hydrocracking reaction of VR. The mesopore of active carbon was thought

Hidetsugu Fukuyama; Satoshi Terai; Masayuki Uchida; José L. Cano; Jorge Ancheyta

2004-01-01

74

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

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 further affect public water suppliers with

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

2001-01-01

75

Production Systems. Laboratory Activities.  

ERIC Educational Resources Information Center

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

Gallaway, Ann, Ed.

76

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

PubMed Central

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

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

2012-01-01

77

Phenol adsorption by activated carbon produced from spent coffee grounds.  

PubMed

The present work highlights the preparation of activated carbons (ACs) using spent coffee grounds, an agricultural residue, as carbon precursor and two different activating agents: water vapor (ACW) and K(2)CO(3) (ACK). These ACs presented the microporous nature and high surface area (620-950 m(2) g(-1)). The carbons, as well as a commercial activated carbon (CAC) used as reference, were evaluated as phenol adsorbent showing high adsorption capacity (?150 mg g(-1)). The investigation of the pH solution in the phenol adsorption was also performed. The different activating agents led to AC with distinct morphological properties, surface area and chemical composition, although similar phenol adsorption capacity was verified for both prepared carbons. The production of activated carbons from spent coffee grounds resulted in promising adsorbents for phenol removal while giving a noble destination to the residue. PMID:22105129

Castro, Cínthia S; Abreu, Anelise L; Silva, Carmen L T; Guerreiro, Mário C

2011-01-01

78

Black Carbon Production in Open Biomass Combustion  

NASA Astrophysics Data System (ADS)

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

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

2012-04-01

79

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

80

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

2009-10-24

81

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

Microsoft Academic Search

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

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

2006-01-01

82

PRODUCTION OF CARBON PRODUCTS USING A COAL EXTRACTION PROCESS  

SciTech Connect

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

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

2004-08-31

83

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

84

The Formation of Carbon Nanofibers on Powdered Activated Carbon Impregnated with Nickel  

NASA Astrophysics Data System (ADS)

In the present work, the production and characterization of carbon nanofibers (CNFs) composite is reported. Carbon nanofibers (CNF) were produced on powdered activated carbon PAC-impregnated with nickel-by Chemical Vapor Deposition (CVD) of a hydrocarbon in the presence of hydrogen at ~780° C. The flow rates of carbon source and hydrogen were fixed. The CNFs were formed directly over the impregnated AC. Variable weight percentage ratios of the catalyst salt (Ni+2) were used for the impregnation (1, 3, 5, 7 and 9%, respectively). The product displays a relatively high surface area, essentially constituted by the external surface, and the absence of the bottled pores encountered with activated carbon. FSEM, TEM and TGA were used for the characterization of the product.

Ahmed, Y. M.; Al-Mamun, A. A.; Muyibi, S. A.; Al-Khatib, M. F. R.; Jameel, A. T.; Alsaadi, M. A.

2009-06-01

85

Arg-Gly-Asp (RGD) peptide ameliorates carbon tetrachloride-induced liver fibrosis via inhibition of collagen production and acceleration of collagenase activity.  

PubMed

Liver cirrhosis is caused by a relative imbalance between synthesis and degradation of collagens. Arg-Gly-Asp (RGD) peptide is a major adhesive domain of several extracellular matrix (ECM) components, such as that involved in the binding of fibronectin to the alpha5beta1 integrin receptor. We previously reported that RGD peptide increased the expression of matrix metalloproteinase in hepatic stellate cells (HSCs) which play a major role in hepatic fibrosis. We evaluated whether RGD-peptides inhibit the progression of liver fibrosis in an animal model of carbon tetrachloride-induced hepatotoxicity. RGD peptide (GRGDS) (1 mg/kg body weight) was injected intraperitoneally (i.p.) 3 times a week for one month. The group treated with control peptide (GRGES) showed pathologically typical hepatic fibrosis, while the RGD-treated group showed minimal fibrotic changes. The liver contents of collagen and hydroxyproline in the RGD-treated group was significantly lower than that of the control group. Collagenase activity measured in liver homogenates was significantly higher in the treated group than in the control group. In an in vitro study using TWNT-4 cells derived from human HSCs, RGD peptide (100 mug/ml) reduced the expression of type I collagen and tissue inhibitor of matrix metalloproteinase-1, and increased that of matrix metalloproteinase-1. These results indicated that RGD peptides inhibited liver fibrosis associated with both decreased collagen production and increased collagenase acitivity, and suggested that RGD peptide might be useful for the therapy of hepatic fibrosis. PMID:15547672

Kotoh, Kazuhiro; Nakamuta, Makoto; Kohjima, Motoyuki; Fukushima, Marie; Morizono, Shusuke; Kobayashi, Naoya; Enjoji, Munechika; Nawata, Hajime

2004-12-01

86

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.  

PubMed

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 of NOM removal, the disinfection behaviour of the treated water, and the water quality in the distribution system. This is the first comprehensive assessment of the efficacy of plant-scale application of PAC combined with enhanced coagulation on an Australian source water. As a result of the PAC addition, the removal of NOM improved by 70%, which led to a significant reduction (80-95%) in the formation of DBPs. The water quality in the distribution system also improved, indicated by lower concentrations of DBPs in the distribution system and better maintenance of disinfectant residual at the extremities of the distribution system. The efficacy of the PAC treatment for NOM removal was shown to be a function of the characteristics of the NOM and the quality of the source water, as well as the PAC dose. PAC treatment did not have the capacity to remove bromide ion, resulting in the formation of more brominated DBPs. Since brominated DBPs have been found to be more toxic than their chlorinated analogues, their preferential formation upon PAC addition must be considered, especially in source waters containing high concentrations of bromide. PMID:21353285

Kristiana, Ina; Joll, Cynthia; Heitz, Anna

2011-02-25

87

Microbial Enzyme Activity and Carbon Cycling in Grassland Soil Fractions  

NASA Astrophysics Data System (ADS)

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

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

2004-12-01

88

SORPTION OF ELEMENTAL MERCURY BY ACTIVATED CARBONS  

EPA Science Inventory

The mechanisms and rate of elemental mercury (HgO) capture by activated carbons have been studied using a bench-scale apparatus. Three types of activated carbons, two of which are thermally activated (PC-100 and FGD) and one with elemental sulfur (S) impregnated in it (HGR), were...

89

New PHA products using unrelated carbon sources  

PubMed Central

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

Matias, Fernanda; de Andrade Rodrigues, Maria Filomena

2011-01-01

90

New PHA products using unrelated carbon sources.  

PubMed

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

Matias, Fernanda; de Andrade Rodrigues, Maria Filomena

2011-12-01

91

Mechanisms of Activated Carbon Degradation by Perspiration.  

National Technical Information Service (NTIS)

Amino acids harm the adsorption capacity of a carbon more than lactic or formic acid. Water can plug up carbon micropores. This water can be removed in a drying oven. In tests, the more harmful chemicals to adsorption capacity of an activated carbon were ...

L. L. Pytlewski

1976-01-01

92

Carbon dioxide utilization and seaweed production  

Microsoft Academic Search

Stronger growth in many plants stimulated by increased CO 2 concentration should lead to greater biological productivity with an expected increase in the photosynthetic storage of carbon. Thus, the biosphere will serve as a sink for CO 2 , though it will also act as a source too, because of respiration. Normally net photosynthesis dominates in summer and removes CO2

V. R. P. Sinha; Lowell Fraley

93

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

94

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

95

Comparison between activated carbon, carbon xerogel and carbon nanotubes for the adsorption of the antibiotic ciprofloxacin  

Microsoft Academic Search

A comparison was made for the adsorption capacity of ciprofloxacin (CPX) on three types of carbon-based materials: activated carbon, carbon nanotubes and carbon xerogel. The obtained samples were characterised by adsorption of N2 at ?196°C, determination of the point of zero charge and by temperature programmed desorption. The Langmuir and Freundlich models were used to describe the equilibrium isotherms obtained.

S. A. C. Carabineiro; T. Thavorn-amornsri; M. F. R. Pereira; P. Serp; J. L. Figueiredo

96

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

97

Effect of activated carbons modification on porosity, surface structure and phenol adsorption  

Microsoft Academic Search

The primary objective of this work was the examination of modified activated carbons with tailored adsorption capacity properties. Production of activated carbons with desired properties was accomplished by modification of surface functional groups and introduction of acidic\\/basic properties. Modification of an activated carbon was performed using partial oxygen gasification, nitric acid treatment, urea impregnation followed by pyrolysis and pyrolysis in

G. G. Stavropoulos; P. Samaras; G. P. Sakellaropoulos

2008-01-01

98

Activated carbon for gas phase arsenic capture  

Microsoft Academic Search

Investigation of activated carbon as a multifunctional sorbent for trace metal capture is the focus of this study. In addition to mercury and halides, selenium and arsenic represent two of the most volatile trace species that remain in gas phase in substantial amounts. In this work, fundamental sorption characteristics of the activated carbon for arsenic removal from the gas phase

R. Jadhav; H. Gupta; S. Misro; R. Agnihotri; L. S. Fan

1999-01-01

99

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

100

Persulfate regeneration of trichloroethylene spent activated carbon.  

PubMed

The objective of this study was to demonstrate the regeneration of trichloroethylene (TCE) spent activated carbon using persulfate oxidation and iron activated persulfate (IAP) oxidation. Both processes resulted in decreases in the adsorbability of regenerated activated carbons. IAP was shown to rapidly degrade the aqueous TCE and causes a significant mineralization of the TCE. The release of chloride ions provided evidence of this. Persulfate oxidation mainly resulted in desorption of TCE from the activated carbon and only partial mineralization of the TCE through a carbon activated persulfate reaction mechanism. Concerning destruction of the TCE, in the regeneration test using persulfate, 30% of the original TCE was present in the solution and 9% remained on the activated carbon after the first regeneration cycle. In contrast, in the test that used IAP, it was observed that no TCE was present in the solution and only approximately 5% of the original TCE remained on the activated carbon after the first regeneration. Following the regeneration cycles, elemental analysis was carried out on the samples. BET surface area and EDS analysis showed some effects on the physico-chemical properties of the activated carbon such as a slight decrease in the surface area and the presence of iron precipitates on the carbon. PMID:19264399

Liang, Chenju; Lin, Ya-Ting; Shin, Wu-Hang

2009-02-12

101

Activated carbon from peach stones using phosphoric acid activation at medium temperatures.  

PubMed

In the present study, the activation features of phosphoric acid have been investigated using waste peach stones as the raw material in the production of granular activated carbon. Thermogravimetry/differential thermal analysis was conducted to characterize the thermal behavior of peach stone and titration method was used to evaluate the adsorption capacity of the produced activated carbon. It was observed that the iodine value of the activated carbon increased with activation temperature. However, temperatures higher than 500 degrees C caused a thermal destruction, which resulted in the decrease of the adsorption capacity. Activation longer than 1.5 h at 500 degrees C resulted in thermal degradation of the porous structure of the activated carbon. The adsorption capacity was enhanced with increasing of amounts of phosphoric acid, however, excessive phosphoric acid caused a decrease in the iodine value. In addition, it was found that the carbon yields generally decreased with activation temperature and activation time. Scanning electron microscopy analysis was conducted to observe the changes in the poros structure of the activated carbon produced in different temperatures. Activation of carbon by phosphoric acid was found to be superior to that by CaCl2 and gas activation. The activated carbon produced from peach stone was applied as an adsorbent in the treatment of synthesized wastewater containing cadmium ion and its adsorption capacity was found to be as good as that of the commercial one. PMID:15137699

Kim, Dong-Su

2004-01-01

102

Catalytic Growth of Macroscopic Carbon Nanofibers Bodies with Activated Carbon  

SciTech Connect

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

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

2009-06-01

103

Dynamic pesticide removal with activated carbon fibers.  

PubMed

Rapid small-scale minicolumn tests were carried out to simulate the atrazine adsorption in water phase with three pelletized pitch-based activated carbon fibers (ACF) and one commercial granular activated carbon (GAC). Initial atrazine solutions were prepared with pretreated ground water. Minicolumn tests showed that the performance of highly activated carbon fibers (surface area of 1700 m2/g) is around 7 times better than the commercial GAC (with surface area at around 1100 m2/g), whereas carbon fibers with medium activation degree (surface area of 1500 m2/g) had a removal efficiency worse than the commercial carbon. The high removal efficiency of the highly activated ACF is due to the wide-opened microstructure of the material, with an appreciable contribution of the low size mesopores, maintaining at these conditions a fast kinetic adsorption rate rather than a selective adsorbent for micropollutants vs. natural organic matter. PMID:11229006

Martín-Gullón, I; Font, R

2001-02-01

104

Sorption of boron trifluoride by activated carbons  

SciTech Connect

The sorption of born trifluoride on AG-3, SKT, SKT-3, SKT-7, SKT-4A, SKT-6A, and SKT-2B carbons was investigated. The sorption isotherms for both vapors and gas were determined volumetrically. The coefficients of two equations described the sorption of BF/sub 3/ in the sorption of BF/sub 3/ on active carbons. Heats of sorption of BF/sub 3/ on the activated carbons are shown and the sorption isotherms and temperature dependences of the equilibrium pressure of BF/sub 3/ for activated carbons were presented. The values of the heats of sorption indicated the weak character of the reaction of BF/sub 3/ with the surface of the carbons. The equations can be used for calculating the phase equilibrium of BF/sub 3/ on carbons in a wider range of temperatures and pressures.

Polevoi, A.S.; Petrenko, A.E.

1988-01-10

105

Gold cyanide adsorption characteristics of activated carbon of non-coconut shell origin  

Microsoft Academic Search

Coconut shells are the most widely used raw material for the production of activated carbon suitable for gold production by cyanide leaching. However, increasing gold production is likely to necessitate the exploitation of other sources. Abundance and ready availability of hazelnut shells, apricot and peach stones make them a viable candidate for an alternative source. In this study, activated carbons

Mustafa Yalcin; Ali Ihsan Arol

2002-01-01

106

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

Microsoft Academic Search

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

Man S. Tam; Michael Jerry Antal

1999-01-01

107

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

108

Activated carbon sheet prepared from softwood acetic acid lignin  

Microsoft Academic Search

As an example of activated carbon (AC) moldings, AC sheets were prepared from thermoplastic acetic acid lignin by lamination.\\u000a The resulting AC sheets are a new type of product that can be applied as water and air cleaners. Powdered softwood acetic\\u000a acid lignin (SAL) was molded into sheets by a thermal pressing method. When the sheet was carbonized under a

Yasumitsu Uraki; Ryo Taniwatashi; Satoshi Kubo; Yoshihiro Sano

2000-01-01

109

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

SciTech Connect

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

Muradov, Nazim Z. (Melbourne, FL)

2011-08-23

110

Recover VOCs via adsorption on activated carbon  

SciTech Connect

One of the most effective methods of controlling emissions of volatile organic compounds (VOCs) is also one of the most economical--adsorption, usually using activated carbon as the adsorbent. This process is cost-effective because it is typically able to recover many VOCs for reuse. A particularly common application of carbon adsorption for VOC control is solvent recovery. In general, solvent recovery via carbon adsorption is a logical consideration for any industrial process exhausting sizable quantities of valuable solvent (subject, of course, to the solvent's suitability for adsorption by activated carbon, as discussed later). The most commonly recovered solvents include toluene; heptane; hexane; carbon tetrachloride; acetone; ethyl acetate; methyl ethyl ketone(MEK); naphthalene; and methylene chloride. Many other solvents are also suitable for recovery by carbon adsorption. A recent CEP article discussed the basics of carbon adsorption and application of the technology to water and wastewater treatment. This article takes an in-depth look at the use of activated carbon adsorption of the control of airborne VOC emissions and solvent recovery. It outlines how to decide if carbon adsorption is suitable for an application and then explains how to implement the technology.

Ruhl, M.J. (Dedert Corp., Olympia Falls, IL (United States). Solvent Recovery Div.)

1993-07-01

111

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

112

Black Carbon in the Soil Carbon Cycle: Is it an Oxidation Resistant EndProduct?  

Microsoft Academic Search

Black carbon (BC) is a very oxidation resistant product of incomplete combustion, and consists out of a range of combustion products such as char, charcoal, and soot. Due to its high recalcitrance, black carbon might act as a long-term carbon sink. Comparing the estimated production rate of BC with the eective pool, loss processes of BC must occur. However, the

Simone Bischofberger

2008-01-01

113

Fermentative production of ethanol from carbon monoxide.  

PubMed

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

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

2011-02-23

114

Transport properties of activated carbon fibers.  

National Technical Information Service (NTIS)

The transport properties of activated isotropic pitch-based carbon fibers with surface area 1000 m(sup 2)/g have been investigated. We report preliminary results on the electrical conductivity, the magnetoresistance, the thermal conductivity and the therm...

S. L. di Vittorio M. S. Dresselhaus M. Endo J. P. Issi L. Piraux

1990-01-01

115

Tertiary activated carbon treatment of paper and board industry wastewater.  

PubMed

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 was also investigated. Batch and column adsorption tests showed that activated carbon provides an excellent removal of cationic demand and color related compounds, the two most important representatives of organic compounds that have to be removed. Unexpectedly, higher water temperatures enhanced the performance of activated carbon. However, the treatment costs, mainly determined by transport and regeneration of the carbon, were very high. At long contact times between the wastewater and the carbon the occurrence of biodegradation was observed. Biological regeneration of the carbon may therefore provide a means to reduce the treatment costs, but a practical application requires further research. PMID:15935653

Temmink, Hardy; Grolle, Katja

2005-10-01

116

USE OF ACTIVATED CARBON FOR SOIL BIOREMEDIATION  

Microsoft Academic Search

The use of activated carbon may help overcome the toxicity of organic pollutants to microbes and plants during soil bioremediation.\\u000a Experiments were conducted with 3,4-dichloroaniline (DCA), 2,4,6-trinitrotoluene (TNT), and polychlorinated biphenyls (PCB)\\u000a to demonstrate that activated carbon (AC) can reduce the toxicity of readily available chemicals in soil by transferring them\\u000a to a less toxic soil fraction.

Galina K. Vasilyeva; Elena R. Strijakova; Patrick J. Shea

117

Catalytic decomposition of methane over activated carbon  

Microsoft Academic Search

Methane decomposition over activated carbons was carried out in a fixed bed, quartz-tube flow reactor. The kinetics of methane decomposition and surface properties changes before and after reaction was investigated. As a non-carbon based material, active alumina was also used to compare and understand the catalytic decomposition mechanism of methane over different materials. A reaction order of 0.5 is obtained

Zongqing Bai; Haokan Chen; Baoqing Li; Wen Li

2005-01-01

118

Fixation of potassium aurocyanide on active carbons  

Microsoft Academic Search

Active carbons of different origins (ex-coconut shell, ex-coal, ex-peat and ex-wood) have been used as adsorbents of potassium aurocyanide. Various treatments were applied to the active carbons: heat treatment at 800 °C, heat treatment at 800 °C followed by HCl (11) washing, heat treatment at 650 °C, washing with HCl 10%, esterification with methanol, oxidation with nitric acid and extraction

Eugène Papirer; Anundo Polania-Leon; Jean-Baptiste Donnet; Philippe Montagnon

1995-01-01

119

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

120

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

Microsoft Academic Search

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

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

2007-01-01

121

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

122

Pesticide removal by combined ozonation and granular activated carbon filtration  

Microsoft Academic Search

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

E. Orlandini

1999-01-01

123

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

124

X-RAY DIFFRACTION LINE PROFILES OF ELECTROGRAPHITIZED CARBON PRODUCTS  

Microsoft Academic Search

The (001) diffraction line profiles of electrographitized carbon ; products were graphically separated into profiles of their component carbons. ; The products used for this experiment were made from a petroleum coke, a thermal ; black, or a furnace black and a binder pitch. The ratios of the integrated ; difiraction intensities of the component carbons were in good agreement

T. Noda; M. Inagaki; C. Sugie

1961-01-01

125

Activated carbon for gas phase arsenic capture  

SciTech Connect

Investigation of activated carbon as a multifunctional sorbent for trace metal capture is the focus of this study. In addition to mercury and halides, selenium and arsenic represent two of the most volatile trace species that remain in gas phase in substantial amounts. In this work, fundamental sorption characteristics of the activated carbon for arsenic removal from the gas phase are investigated. Activated carbons with different structural properties are studied for their usefulness in removing arsenic species from flue gas. Arsenic oxide (As{sub 2}O{sub 3}) is used as the source of arsenic. Preliminary sorption studies indicate that arsenic removal occurs by physical adsorption, with increased capture by carbons with higher surface areas.

Jadhav, R.; Gupta, H.; Misro, S.; Agnihotri, R.; Fan, L.S.

1999-07-01

126

Special steel production on common carbon steel production line  

NASA Astrophysics Data System (ADS)

The equipment and technology of small bar tandem rolling line of Shijiazhuang Iron & Steel Co. in China has reached the 90's international advanced level in the 20th century, but products on the line are mostly of common carbon steel. Currently there are few steel plants in China to produce 45 steel bars for cold drawing, which is a kind of shortage product. Development of 45 steel for cold drawing has a wide market outlook in China. In this paper, continuous cooling transformation (CCT) curve of 45 steel for cold drawing used for rolling was set out first. According to the CCT curve, we determined some key temperature points such as Ac3 temperature and Ac1 temperature during the cooling procedure and discussed the precipitation microstructure at different cooling rate. Then by studying thermal treatment process of 45 steel bars for cold drawing, the influence of cooling time on microstructure was analyzed and the optimum cooling speed has been found. All results concluded from the above studies are the basis of regulating controlled cooling process of 45 steel bars for cold drawing. Finally, the feasible production process of 45 steel bars for cold drawing on common carbon steel production line combined with the field condition was recommended.

Pi, Huachun; Han, Jingtao; Hu, Haiping; Bian, Ruisheng; Kang, Jianjun; Xu, Manlin

2004-06-01

127

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

2012-05-22

128

Catalytic carbon membranes for hydrogen production  

SciTech Connect

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

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

1992-01-01

129

Surface studies of novel hydrophobic active carbons  

NASA Astrophysics Data System (ADS)

The efficient adsorption of toxic organic species from humid airstreams by active carbons is impeded by the competitive adsorption of water vapour which, at low values of p/ ps, occurs at specific (polar) adsorption sites located at the edges of the carbon layer-planes and at in-plane defects. At higher pressures, adsorption in micropores and mesopores also occurs. The concentration of polar adsorption sites therefore determines the hydrophilicity of the carbon structure and their accelerated formation, by exposure to air and water vapour, is also responsible for the 'ageing' of active carbons. Overall, the adsorption of water reduces the volume of porosity available for the adsorption of target species and the hydrophilic nature of active carbons is recognized as a major barrier to their effective use in many applications. We present here results for the adsorption of nitrogen, organic and water vapours by a hydrophobic respirator granular active carbon produced by the thermal treatment of a base carbon, to desorb polar oxygen groups, followed by use of a plasma enhanced chemical vapour deposition (PECVD) treatment to apply a hydrophobic, fluorine containing, surface nanolayer. We show that at equivalent %RH values the treated carbon adsorbs significantly less water compared to an untreated (control) carbon and that the treatment does not reduce the levels of open porosity or impede the adsorption of a range of organic vapours at ambient temperatures. Preliminary evidence for the presence, after treatment, of constrictions at pore entrances which act as molecular gates is also presented. The treated carbon (after ageing for 6 weeks at 80%RH) is shown to have greater adsorptivity than an untreated base carbon toward hexane present in a humid (80%RH) airstream. This results in a 39% increase in break-through time. These hydrophobic properties persist one year after manufacture. The mechanism leading to the modified water adsorption properties is the partial desorption of polar oxygen sites followed by deposition at the external carbon surfaces of hydrophobic plasma polymer species. This reduces the polar surface free energy of the carbon and hence the amount of water adsorption occurring by the primary mechanism. This in turn retards the diffusion of water molecules into the micropores and leads to lower adsorption volumes at higher pressures.

Bradley, Robert H.; Smith, Martin W.; Andreu, Aurik; Falco, Maurizio

2011-01-01

130

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

Microsoft Academic Search

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

Steven W. Wilhelm; Ralph E. H. Smith

2000-01-01

131

Photobiological hydrogen production and carbon dioxide sequestration  

NASA Astrophysics Data System (ADS)

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

Berberoglu, Halil

132

Comparative study of heavy metal ions sorption onto activated carbon, carbon nanotubes, and carbon-encapsulated magnetic nanoparticles  

Microsoft Academic Search

The paper presents the advantages and limitations of heavy metals sorption onto three different carbon materials: activated carbon, carbon nanotubes, and carbon-encapsulated magnetic nanoparticles. Studied carbon sorbents differed with the grain size, crystallinity, and active surface area, which were derived from electron microscopy, Raman spectroscopy, and methylene blue adsorption, respectively. Detailed sorption studies were based on two model metal ions,

Krystyna Pyrzy?ska; Micha? Bystrzejewski

2010-01-01

133

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...

134

Adsorption of Mercuric Ion from Aqueous Solutions Using Activated Carbon  

Microsoft Academic Search

Activated carbon (AC) was prepared from hazelnut shells using two steps of carbonization followed by steam activation. Methylene blue dye was used as a probe for evaluation of the prepared activated carbon. In order to have a better comparison, a commercial grade of activated carbon (powdered) obtained from the Merck Company has also been used in this research as standard.

R. Ansari Khalkhali; R. Omidvari

135

Activated Carbon from Dates' Stone by ZnCl2 Activation  

Microsoft Academic Search

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

Yahia A. Alhamed

136

Production of carbon isotopes by laser separation  

NASA Astrophysics Data System (ADS)

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

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

2000-07-01

137

Nitric acid vapor removal by activated, impregnated carbons  

SciTech Connect

Laboratory and industrial workers can be exposed to vapors of nitric acid, especially in accidents, such as spills. Nitric acid can also be a product of incineration for energy production or waste (e.g., CW agent) disposal. Activated carbons containing impregnants for enhancing vapor and gas removal have been tested for effectiveness in removing vapors of nitric acid from air. The nitric acid vapor was generated from concentrated acid solutions and detected by trapping in a water bubbler for pH measurements. Both low and moderate relative humidity conditions were used. All carbons were effective at vapor contact times representative of air-purifying respirator use. One surprising observation was the desorption of low levels of ammonia from impregnated carbons. This was apparently due to residual ammonia from the impregnation processes.

Wood, G.O.

1996-12-31

138

Waste management activities and carbon emissions in Africa  

SciTech Connect

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

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

2011-01-15

139

Sewage sludge effects on carbon dioxide?carbon production from a desurfaced soil  

Microsoft Academic Search

Desurfaced soils are found near cities in the Pampean Region of Argentina because A horizons were used for brick production. These soils are not suitable for agriculture. Application of sewage sludge is a tool for improving soil productivity, but its effects on the environment are not thoroughly understood. Production of carbon dioxide (C02)?carbon (C) in the field from a desurfaced

R. Alvarez; M. Alconada; R. Lavado

1999-01-01

140

Record Methane Storage in Monolithic and Powdered Activated Carbons  

Microsoft Academic Search

The Alliance for Collaborative Research in Alternative Fuel Technology (ALL-CRAFT) has developed activated carbons from corn cob as adsorbent materials for methane gas storage by physisorption at low pressures. KOH activated carbons were compressed into carbon monolith using chemical binders. High pressure methane isotherms up to 250 bar at room temperature on monolithic and powdered activated carbons were measured gravimetrically

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

2010-01-01

141

Thermal regeneration of granular activated carbons using inert atmospheric conditions.  

PubMed

Thermal regeneration is increasingly being used for the recovery of field-spent granular activated carbons (GAC) generated by the water treatment industry. Despite its commercial success, conventional methods using oxidising conditions (usually steam) are known to damage the porosity of the regenerated carbons, thus reducing their adsorption capacity and economic value. This paper presents a comparative investigation into the benefits of using inert conditions for the regeneration of field-spent GAC. For the purpose of this work, a sample of spent carbon was regenerated in nitrogen and in steam to different degrees of burn off. The resulting samples were analysed for their porosity and surface area characteristics using nitrogen gas adsorption, and for their aqueous adsorption capacities using phenol and methylene blue. Experimental results showed that steam was sightly more effective than nitrogen at regenerating the total micropore volume and BET surface area of the carbons. However, these benefits were largely counteracted by greater losses in the carbon yield and damage to the narrow microporosity. Carbons regenerated in nitrogen exhibited greater adsorption capacities for the adsorption of small molecular size compounds (phenol) from solution, while carbons regenerated in steam adsorbed larger molecular size compounds (methylene blue) more effectively. However, when product yields were taken into consideration, inert regeneration was found to produce significantly better results than steam regeneration. An optimum process temperature was determined to be 950 degrees C. PMID:12523505

San Miguel, G; Lambert, S D; Graham, N J D

2002-12-01

142

Microbial enhancement of oil production from carbonate reservoirs  

SciTech Connect

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

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

1991-01-01

143

Study of NO adsorption on activated carbons  

Microsoft Academic Search

Activated carbons (ACs) with varied porous textures and surface chemistry were studied for NO removal under different test conditions at temperatures below 100°C. When oxygen is absent, there is almost no NO removal. When oxygen is present ACs act both as a catalyst for NO oxidation and as an adsorbent for NO adsorption. NO conversion is correlated with the presence

W. J. Zhang; S. Rabiei; A. Bagreev; M. S. Zhuang; F. Rasouli

2008-01-01

144

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...

145

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...

146

Low frequency sound propagation in activated carbon.  

PubMed

Activated carbon can adsorb and desorb gas molecules onto and off its surface. Research has examined whether this sorption affects low frequency sound waves, with pressures typical of audible sound, interacting with granular activated carbon. Impedance tube measurements were undertaken examining the resonant frequencies of Helmholtz resonators with different backing materials. It was found that the addition of activated carbon increased the compliance of the backing volume. The effect was observed up to the highest frequency measured (500 Hz), but was most significant at lower frequencies (at higher frequencies another phenomenon can explain the behavior). An apparatus was constructed to measure the effective porosity of the activated carbon as well as the number of moles adsorbed at sound pressures between 104 and 118 dB and low frequencies between 20 and 55 Hz. Whilst the results were consistent with adsorption affecting sound propagation, other phenomena cannot be ruled out. Measurements of sorption isotherms showed that additional energy losses can be caused by water vapor condensing onto and then evaporating from the surface of the material. However, the excess absorption measured for low frequency sound waves is primarily caused by decreases in surface reactance rather than changes in surface resistance. PMID:22779473

Bechwati, F; Avis, M R; Bull, D J; Cox, T J; Hargreaves, J A; Moser, D; Ross, D K; Umnova, O; Venegas, R

2012-07-01

147

Dynamic changes of heme oxygenase-1 and carbon monoxide production in acute liver injury induced by carbon tetrachloride in rats  

Microsoft Academic Search

Heme oxygenase-1, a stress-responsive enzyme that catabolizes hemes into carbon monoxide, biliverdin, and iron, has been shown to play a pivotal role in many physiological and pathological situations. Here we investigated changes in HO-1 enzyme activity and protein expression, and its end product carbon monoxide concentrations in the liver of rats after CCl4 treatment. We found that CCl4 administration not

Tao Wen; Li Guan; Yan-Lin Zhang; Jin-Yuan Zhao

2006-01-01

148

Sorption of elemental mercury by activated carbons  

SciTech Connect

The paper gives results of a study of the mechanisms and rate of elemental mercury (Hg) capture by activated carbons, using a bench-scale apparatus. Three types of activated carbons, two thermally activated (PC-100 and FGD) and one impregnated with elemental sulfur (S) (HGR), were used to study the effects of surface area (approximately 550-1000 sq m/g), sorption temperature (23-140 C), and elemental Hg concentration (30 and 60 ppb of elemental Hg in nitrogen). Investigations revealed that sorption occurs in active sites in PC-100 and FGD which are either depleted or deactivated at 140 C. Desorption studies for PC-100 and HGR revealed the sorption mechanism to be a combination of physisorption and chemisorption at 23 C, whereas chemisorptionis the primary route at 140 C.

Krishnan, S.V.; Gullett, B.K.; Jozewicz, W.

1994-01-01

149

Hydrogen adsorption on modified activated carbon  

Microsoft Academic Search

The aim of this work is to investigate hydrogen adsorption on prepared super activated carbon (AC). Litchi trunk was activated by potassium hydroxide under N2 or CO2 atmosphere. Nanoparticles of palladium were impregnated in the prepared-AC. Hydrogen adsorption was accurately measured by a volumetric adsorption apparatus at 77, 87, 90 and 303K, up to 5MPa. Experimental results revealed that specific

Chen-Chia Huang; Hsiu-Mei Chen; Chien-Hung Chen

2010-01-01

150

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

151

Supercapacitor Electrodes from Activated Carbon Monoliths and Carbon Nanotubes  

NASA Astrophysics Data System (ADS)

Binderless monoliths of supercapacitor electrodes were prepared by the carbonization (N2) and activation (CO2) of green monoliths (GMs). GMs were made from mixtures of self-adhesive carbon grains (SACG) of fibers from oil palm empty fruit bunches and a combination of 5 & 6% KOH and 0, 5 & 6% carbon nanotubes (CNTs) by weight. The electrodes from GMs containing CNTs were found to have lower specific BET surface area (SBET). The electrochemical behavior of the supercapacitor fabricated using the prepared electrodes were investigated by electrochemical impedance spectroscopy (EIS) and galvanostatic charge-discharge (GCD). In general an addition of CNTs into the GMs reduces the equivalent series resistance (ESR) value of the cells. A cell fabricated using electrodes from GM with 5% CNT and 5% KOH was found to have the largest reduction of ESR value than that from the others GMs containing CNT. The cell has steeper Warburg's slope than that from its respective non-CNT GM, which reflect the smaller resistance for electrolyte ions to move into pores of electrodes despite these electrodes having largest reduction in specific BET surface area. The cell also has the smallest reduction of specific capacitance (Csp) and maintains the specific power range despite a reduction in the specific energy range due to the CNT addition.

Dolah, B. N. M.; Othman, M. A. R.; Deraman, M.; Basri, N. H.; Farma, R.; Talib, I. A.; Ishak, M. M.

2013-04-01

152

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

153

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

2006-10-07

154

Licorice residue and Pistachio-nut shell mixture: A promising precursor for activated carbon  

Microsoft Academic Search

As a continuation of previous research concerning preparation of activated carbon from agricultural by-products, applying a mixture of two kinds of lignocellulosic by-products with complementary properties as the parent material is investigated. Two kinds of activated carbons are prepared by chemical activation of the parent mixture – including residues of licorice and pistachio-nut shells – with H3PO4 and ZnCl2 solutions,

T. Kaghazchi; N. Asasian Kolur; M. Soleimani

2010-01-01

155

Tc99 Adsorption on Selected Activated Carbons - Batch Testing Results  

Microsoft Academic Search

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

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

2010-01-01

156

International patenting activity in the field of carbon nanotubes  

Microsoft Academic Search

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

R. K Gupta; I. Dwivedy

2005-01-01

157

MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT  

SciTech Connect

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

H.C. Maru; M. Farooque

2004-08-01

158

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

159

Catalytic wet air oxidation of phenol with modified activated carbons and Fe\\/activated carbon catalysts  

Microsoft Academic Search

A commercial activated carbon was modified by different oxidative treatments to introduce different oxygen surface groups. A gentle oxidation in gas phase with a poor oxygen stream and a more severe oxidation in liquid phase with a HNO3 solution were used. The resulting activated carbons and the corresponding Fe-impregnated (2.5% Fe) ones were tested for the wet air oxidation of

A. Quintanilla; J. A. Casas; J. J. Rodríguez

2007-01-01

160

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

161

MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT  

SciTech Connect

The ongoing program is designed to advance the carbonate fuel cell technology from full-size proof-of-concept field test to the commercial design. DOE has been funding Direct FuelCell{reg_sign} (DFC{reg_sign}) development at FuelCell Energy, Inc. (FCE) for stationary power plant applications. The program efforts are focused on technology and system optimization for cost reduction leading to commercial design development and prototype system field trials. FCE, Danbury, CT, is a world-recognized leader for the development and commercialization of high efficiency fuel cells that can generate clean electricity at power stations or in distributed locations near the customer, including hospitals, schools, universities, hotels and other commercial and industrial applications. FuelCell Energy has designed three different fuel cell power plant models (DFC300, DFC1500 and DFC3000). FCE's power plants are based on its patented Direct FuelCell technology, where the fuel is directly fed to fuel cell and hydrogen is generated internally. These power plants offer significant advantages compared to existing power generation technologies--higher fuel efficiency, significantly lower emissions, quieter operation, flexible siting and permitting requirements, scalability and potentially lower operating costs. Also, the exhaust heat by-product can be used for cogeneration applications such as high-pressure steam, district heating, and air conditioning. Several FCE sub-megawatt power plants are currently operating in Europe, Japan and the US. Because hydrogen is generated directly within the fuel cell module from readily available fuels such as natural gas and waste water treatment gas, DFC power plants are ready today and do not require the creation of a hydrogen infrastructure. Product improvement progress made during the reporting period in the areas of technology, manufacturing processes, cost reduction and balance of plant equipment designs is discussed in this report. FCE's DFC products development has been carried out under a joint public-private effort with DOE being the major contributor. Current funding is primarily under a Cooperative Agreement with DOE.

H. C. Maru; M. Farooque

2003-12-19

162

Regulation of ROS Production and Vascular Function by Carbon Monoxide  

PubMed Central

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

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

2012-01-01

163

The production of carbon materials by hydrothermal carbonization of cellulose  

Microsoft Academic Search

Highly functionalized carbonaceous materials were produced by means of the hydrothermal carbonization of cellulose at temperatures in the 220–250°C range. The formation of this material follows essentially the path of a dehydration process, similar to that previously observed for the hydrothermal transformation of saccharides such as glucose, sucrose or starch. The materials so formed are composed of agglomerates of carbonaceous

M. Sevilla; A. B. Fuertes

2009-01-01

164

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

165

Interactions of xanthines with activated carbon  

NASA Astrophysics Data System (ADS)

Because of their pharmaceutical and industrial applications, we have studied the adsorption of xanthine derivates (caffeine and theophylline) by activated carbon. To this end, we examined kinetic, equilibrium and thermodynamic aspects of the process. This paper reports the kinetics results. The experimental results indicate that the process was first order in C and the overall process was assumed to involve a single, reversible adsorption desorption process obeying a kinetic law postulated by us.

Navarrete Casas, R.; García Rodriguez, A.; Rey Bueno, F.; Espínola Lara, A.; Valenzuela Calahorro, C.; Navarrete Guijosa, A.

2006-06-01

166

Palladium catalysts on activated carbon supports  

Microsoft Academic Search

A number of activated carbons produced from peat, coconut shell, and by pyrolysis of hydrocarbons have been subjected to treatment with oxygen, chlorine, hydrogen or ammonia at elevated temperatures to get a representative series of catalyst supports differing in porous structure and surface chemistry (characterized by nitrogen adsorption and selective titrations). Palladium was deposited from anionic (H2PdCl4), neutral (Pd(OAc)2, in

M. Gurrath; T. Kuretzky; H. P. Boehm; L. B. Okhlopkova; A. S. Lisitsyn; V. A. Likholobov

2000-01-01

167

Biomorphic activated porous carbons with complex microstructures from lignocellulosic residues  

Microsoft Academic Search

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

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

2008-01-01

168

MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT  

SciTech Connect

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

H.C. Maru; M. Farooque

2005-03-01

169

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

PubMed

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

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

2013-01-14

170

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

171

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

Code of Federal Regulations, 2010 CFR

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

2009-07-01

172

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

Code of Federal Regulations, 2012 CFR

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

2012-07-01

173

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

Code of Federal Regulations, 2010 CFR

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

2009-07-01

174

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

Code of Federal Regulations, 2010 CFR

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

2010-07-01

175

Elimination of carcinogens (excluding haloforms) from water by active carbon  

Microsoft Academic Search

Elimination of carcinogens (excluding haloforms) from water by active carbon was studied in the laboratory. Ten activated carbons were tested for their ability to adsorb eight different polycyclic aromatic hydrocarbons (PAH). The PAH were introduced in acetone solution to synthetic sewage water. Activated carbon concentration was 1 g\\/l. and contact time was 30 min at 15° with a 500 rpm

Borneff

1978-01-01

176

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

SciTech Connect

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

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

1996-04-08

177

MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT  

SciTech Connect

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

H.C. Maru; M. Farooque

2002-02-01

178

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

179

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

2010-02-23

180

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

181

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

182

Calcium Carbonate Precipitation as Influenced by Stream Primary Production.  

National Technical Information Service (NTIS)

The water chemistry, hydrology, and benthic primary production of the Logan River, in the Bear River Mountains in northern Utah, were monitored for one year to study the potential influence of periphyton photosynthesis on calcium carbonate precipitation i...

G. L. Rupp V. D. Adams

1981-01-01

183

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

Microsoft Academic Search

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

Hidetsugu Fukuyama; Satoshi Terai

2008-01-01

184

Technological Intervention for Production of High Carbon Billets  

Microsoft Academic Search

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

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

2010-01-01

185

Carbonation of an active serpentinization system  

NASA Astrophysics Data System (ADS)

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

Klein, F.; McCollom, T. M.

2011-12-01

186

Studies on a novel carbon source and cosolvent for lipase production by Candida rugosa  

Microsoft Academic Search

Oleic acid esters were shown to be the best carbon source for both cell growth and lipase production by Candida rugosa. Use of a cosolvent, dodecane, in fermentations improved the solubility of solid substrates and increased oxygen solubility. This resulted in the highest lipase activity in batch fermentation with glycerol trioleate and dodecane. Lipase activity reached 77.1 units ml -1.

Dongzhi Wei; Li-ying Zhang; Qingxun Song

2004-01-01

187

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

PubMed

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

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

2009-06-21

188

Investigation kinetics mechanisms of adsorption malachite green onto activated carbon  

Microsoft Academic Search

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

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

2007-01-01

189

PRODUCTION OF URANIUM METAL BY CARBON REDUCTION  

DOEpatents

The preparation of uranium metal by the carbon reduction of an oxide of uranium is described. In a preferred embodiment of the invention a charge composed of carbon and uranium oxide is heated to a solid mass after which it is further heated under vacuum to a temperature of about 2000 deg C to produce a fused uranium metal. Slowly ccoling the fused mass produces a dendritic structure of uranium carbide in uranium metal. Reacting the solidified charge with deionized water hydrolyzes the uranium carbide to finely divide uranium dioxide which can be separated from the coarser uranium metal by ordinary filtration methods.

Holden, R.B.; Powers, R.M.; Blaber, O.J.

1959-09-22

190

Effects of carbon and nitrogen sources on rhamnolipid biosurfactant production by Pseudomonas nitroreducens isolated from soil.  

PubMed

Rhamnolipid biosurfactant production by Pseudomonas nitroreducens isolated from petroleum-contaminated soil was investigated. The effects of carbon, nitrogen and carbon to nitrogen ratio on biosurfactant production were examined using mineral salts medium as the growth medium. The tenso-active properties (surface activity and critical micelle concentrations of the produced biosurfactant were also evaluated. The best carbon source, nitrogen source were glucose and sodium nitrate giving rhamnolipid yields of 5.28 and 4.38 g l(-1), respectively. The maximum rhamnolipid production of 5.46 g l(-1) was at C/N (glucose/sodium nitrate) of 22. The rhamnolipid biosurfactant reduced the surface tension of water from 72 to ~37 mN/m. It also has critical micelle concentration of ~28 mg l(-1). Thus, the results presented in our reports show that the produced rhamnolipid can find wide applications in various bioremediation activities such as enhanced oil recovery and petroleum degradation. PMID:22805814

Onwosi, Chukwudi O; Odibo, Frederick John C

2011-09-25

191

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...

192

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, W.; Borong, B.; Ruimin, Z.; Jinliang, Z.; Longxin, H.

1998-10-01

193

Gold recovery by microwave augmented ashing of waste activated carbon  

Microsoft Academic Search

Gold ore processing plants that utilize carbon adsorption technologies generate a waste activated carbon, which contains very high gold values, and the recovery of this gold represents a significant source of extra revenue. In this research, microwave energy was utilized to combust the waste activated carbon and the resulting ash was treated by conventional cyanide leaching to recover the gold.

R. K. Amankwah; C. A. Pickles; W.-T. Yen

2005-01-01

194

BACTERIA ASSOCIATED WITH GRANULAR ACTIVATED CARBON PARTICLES IN DRINKING WATER  

EPA Science Inventory

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

195

Study of Multielemental Adsorption on Activated Carbon  

NASA Astrophysics Data System (ADS)

In this study, multielemental adsorption on activated carbon (AC) was investigated. The treatment parameters (pH, AC concentration, metal concentration and contact time) in the adsorption process of multiple metals such as Bi, Cd, Co, Ga, Mn, Mo, Ni, In, Pb, Pd, Sn, Rh, Ru and W were experimented. Three types of characteristic behaviors of analyte elements were observed when the pH was varied. The adsorption rate of Bi, Co, Ga, Ni, In, Pb, Sn, Ru and W were over 80% within 30 min.

Thuy, Le Thi Xuan; Yasuzawa, Mikito; Yabutani, Tomoki

196

Histochemical demonstration of carbonic anhydrase activity  

Microsoft Academic Search

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

Holger P. J. Hansson

1967-01-01

197

Preparation of binderless activated carbon monolith from pre-carbonization rubber wood sawdust by controlling of carbonization and activation condition  

NASA Astrophysics Data System (ADS)

Binderless activated carbon monolith (ACM) was prepared from pre-carbonized rubber wood sawdust (RWSD). The effect of the carbonization temperature (400, 500, 600, 700, 800 dan 900 °C) on porosity characteristic of the ACM have been studied. The optimum carbonization temperature for obtaining ACM with high surface area of 600 °C with CO2 activation at 800 °C for one hour. At this condition, the surface area as high as 733 m2 g-1 could be successfully obtained. By improved the activation temperature at 900 °C for 2.5 h, it was found that the surface area of 860 m2 g-1. For this condition, the ACM exhibit the specific capacitance of 90 F g-1. In addition the termogravimertic (TG)-differential termografimertic (DTG) and field emission scanning electron microscope (FESEM) measurement were also performed on the ACMs and the result has been studied. Finally, it was conclude that the high surface area of ACM from RWSD could be produced by proper selections of carbonization and activation condition.

Taer, E.; Deraman, M.; Taslim, R.; Iwantono

2013-09-01

198

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

Microsoft Academic Search

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

Sheikha S. Ashour

2010-01-01

199

DISINFECTION OF BACTERIA ATTACHED TO GRANULAR ACTIVATED CARBON  

EPA Science Inventory

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

200

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

National Technical Information Service (NTIS)

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

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

1982-01-01

201

Correlation between Carbonic Anhydrase Activity and Inorganic Carbon Internal Pool in Strain Synechocystis PCC 6174.  

PubMed

Existence of an internal carbonic anhydrase was demonstrated in the cyanobacterium Synechocystis PCC 6714. The enzyme, present at a low specific activity, was inducible by limitation in inorganic carbon and inhibited both in vivo and in vitro by acetazolamide. The internal inorganic carbon pool as determined by mass spectrometry, was similarly modulated by the actual inorganic carbon growth regime; its building up was also sensitive to acetazolamide. A possible role of carbonic anhydrase in inorganic carbon metabolism regulation through the control of the dimension and nature of the inorganic carbon pool is discussed. PMID:16666795

Bédu, S; Peltier, G; Joset, F

1989-06-01

202

Correlation between Carbonic Anhydrase Activity and Inorganic Carbon Internal Pool in Strain Synechocystis PCC 6174 1  

PubMed Central

Existence of an internal carbonic anhydrase was demonstrated in the cyanobacterium Synechocystis PCC 6714. The enzyme, present at a low specific activity, was inducible by limitation in inorganic carbon and inhibited both in vivo and in vitro by acetazolamide. The internal inorganic carbon pool as determined by mass spectrometry, was similarly modulated by the actual inorganic carbon growth regime; its building up was also sensitive to acetazolamide. A possible role of carbonic anhydrase in inorganic carbon metabolism regulation through the control of the dimension and nature of the inorganic carbon pool is discussed.

Bedu, Sylvie; Peltier, Gilles; Joset, Francoise

1989-01-01

203

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

204

NaCl adsorption in multi-walled carbon nanotube\\/active carbon combination electrode  

Microsoft Academic Search

In this paper, we proposed a new process for fabricating electrochemical double layer capacitors employing active carbon and multi-walled carbon nanotubes to adsorb Na+ and Cl- from NaCl solution. Due to their unique mesoporosity, active carbons have high ability to desalt NaCl solution. But they have many defects such as high electrical resistance, high-energy consumption and low intensity. Since carbon

Kai Dai; Liyi Shi; Dengsong Zhang; Jianhui Fang

2006-01-01

205

Quality of poultry litter-derived granular activated carbon  

Microsoft Academic Search

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

Guannan Qiu; Mingxin Guo

2010-01-01

206

Calculation of additional heart rates using oxygen consumption and carbon dioxide production: A comparative analysis  

Microsoft Academic Search

Research, to date, on the occurrence of additional heart rates during behavioral stressors has employed oxygen consumption\\u000a as the index of metabolic activity. Although this is the obvious first choice, in certain situations measures of carbon dioxide\\u000a production may be more readily obtained. The analysis presented in this paper explored the intuitively appealing notion that,\\u000a since oxygen consumption and carbon

Julian F. Thayer; L. J. P. van Doornen; J. Rick Turner

1991-01-01

207

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

Code of Federal Regulations, 2010 CFR

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

2010-07-01

208

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

Code of Federal Regulations, 2010 CFR

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

2009-07-01

209

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

210

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

PubMed

Hydrothermal carbonization (HTC) is a novel thermal conversion process that may be a viable means for managing solid waste streams while minimizing greenhouse gas production and producing residual material with intrinsic value. HTC is a wet, relatively low temperature (180-350 °C) thermal conversion process that has been shown to convert biomass to a carbonaceous residue referred to as hydrochar. Results from batch experiments indicate HTC of representative waste materials is feasible, and results in the majority of carbon (45-75% of the initially present carbon) remaining within the hydrochar. Gas production during the batch experiments suggests that longer reaction periods may be desirable to maximize the production of energy-favorable products. If using the hydrochar for applications in which the carbon will remain stored, results suggest that the gaseous products from HTC result in fewer g CO(2)-equivalent emissions than the gases associated with landfilling, composting, and incineration. When considering the use of hydrochar as a solid fuel, more energy can be derived from the hydrochar than from the gases resulting from waste degradation during landfilling and anaerobic digestion, and from incineration of food waste. Carbon emissions resulting from the use of the hydrochar as a fuel source are smaller than those associated with incineration, suggesting HTC may serve as an environmentally beneficial alternative to incineration. The type and extent of environmental benefits derived from HTC will be dependent on hydrochar use/the purpose for HTC (e.g., energy generation or carbon storage). PMID:22516099

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

2012-04-17

211

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

2013-05-03

212

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

2012-11-29

213

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

214

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

NASA Astrophysics Data System (ADS)

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

Kronrad, G. D.; Huang, C.

2005-12-01

215

DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS  

SciTech Connect

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

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

2005-06-08

216

Nitrification enhancement by powdered activated carbon addition in activated sludge  

SciTech Connect

Previous investigators provided evidence that the addition of powdered activated carbon (PAC) to nitrifying activated sludge (AS) can improve nitrification rates. Plausible but unsubstantiated mechanisms proposed to explain these observations include adsorption of compounds toxic to nitrifiers; enhanced growth of nitrifiers and/or concentration of trace nutrients on the carbon surface. The major objective of this research is to further define the mechanics of nitrification enhancement in PAC-AS. Using refinery and synthetic wastewater feed, a series of acute and chronic experiments, as well as experiments with variable carbon dosages, was conducted to evaluate the relative importance of adsorption, suspended solids, and microbial acclimation on AS nitrification rates. The general procedure was to compare the effect of a spiked adsorbable/non-adsorbable, inhibitory compound on nitrification rates in AS and in AS supplemented either with PAC or inert suspended solids (bentonite clay). With spiked adsorbable inhibitors, the acute experiments demonstrated nitrification enhancement due to PAC addition in unacclimated sludge cultures. Statistically significant enhancement due to either PAC or bentonite addition was not evident in any experiment where a nonadsorbable inhibitor was added. A chronic experiment gave evidence that the addition of PAC of AS can inhibit nitrification by virtue of desorption of a previously adsorbed inhibitor. In this same experiment, it was shown that an adequate dose of virgin PAC can dramatically arrest the effect of an adsorbable inhibitor and restore full nitrification capability.

Ng, A.S.

1985-01-01

217

Atypical ethanol production by carbon catabolite derepressed lactobacilli  

Microsoft Academic Search

Cost effective use of lignocellulosic biomass for bio-based chemical production requires the discovery of novel strains and processes. Lactobacillus pentosus JH5XP5 is a carbon catabolite repression negative mutant which utilizes glucose and pentoses derived from lignocellulosic biomass in the media simultaneously. With a broad range of carbon substrates, L. pentosus JH5XP5 produced a significant amount of ethanol without acetate formation.

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

2010-01-01

218

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

2013-05-07

219

Kinetics and isotherm studies on electrosorption of NaCl by activated carbon fiber, carbon nanotube and carbon nanotube-carbon nanofiber composite films  

Microsoft Academic Search

In this paper, the structures of commercial activated carbon fiber (ACF), carbon nanotube (CNT) and home-made carbon nanotube-carbon nanofiber (CNT-CNF) films are characrerized and compare their electrochemical behaviors in NaCl solutions in order to study the electrosorption mechanism.

Yankun Zhan; Chunyang Nie; Haibo Li; Taiqiang Chen; Likun Pan; Zhuo Sun

2010-01-01

220

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

SciTech Connect

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

Varma, R.; Nandi, S.P.

1991-01-01

221

Water adsorption with hysteresis effect onto microporous activated carbon fabrics  

Microsoft Academic Search

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

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

2007-01-01

222

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

223

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

Microsoft Academic Search

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

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

2009-01-01

224

Selective Catalytic Oxidation of Hydrogen Sulfide on Activated Carbons Impregnated with Sodium Hydroxide  

SciTech Connect

Two activated carbons of different origin were impregnated with the solution of sodium hydroxide (NaOH) of various concentrations up to 10 wt %, and the effect of impregnation on the catalytic performance of the carbons was evaluated. The catalytic activity was analyzed in terms of the capacity of carbons for hydrogen sulfide (H2S) conversion and removal from hydrogen-rich fuel streams and the emission times of H2S and the products of its oxidation [e.g., sulfur dioxide (SO2) and carbonyl sulfide (COS)]. The results of impregnation showed a significant improvement in the catalytic activity of both carbons proportional to the amount of NaOH introduced. NaOH introduces hydroxyl groups (OH-) on the surface of the activated carbon that increase its surface reactivity and its interaction with sulfur-containing compounds.

Schwartz, Viviane [ORNL; Baskova, Svetlana [ORNL; Armstrong, Timothy R. [ORNL

2009-01-01

225

High Surface Area Activated Carbon from Waste Biomass  

Microsoft Academic Search

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

C. Srinivasakannan

226

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

227

Hydrogen Adsorption on Activated Carbon an Carbon Nanotubes Using Volumetric Differential Pressure Technique  

Microsoft Academic Search

A simple hydrogen adsorption measurement system utilizing the volumetri differential pressure technique has been designed, fabricated and calibrated. Hydroge adsorption measurements have been carried out at temperatures 298 K and 77 K on activate carbon and carbon nanotubes with different surface areas. The adsorption data obtained will b helpful in understanding the adsorption property of the studied carbon materials using

S. M. Sanip; M. A. R. Saidin; M. Aziz; A. F. Ismail

2010-01-01

228

MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT  

SciTech Connect

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

Unknown

2000-01-01

229

Subthreshold antiproton production in proton carbon reactions  

NASA Astrophysics Data System (ADS)

Data from KEK on subthreshold \\barp as well as on pgr± and K± production in proton-nucleus reactions are described at projectile energies between 3.5 and 12.0 GeV. We use a model which considers a hadron-nucleus reaction as an incoherent sum over collisions of the projectile with a varying number of target nucleons. It samples complete events and thus allows for the simultaneous consideration of all particle species measured. The overall reproduction of the data is quite satisfactory. It is shown that the contributions from the interaction of the projectile with groups of several target nucleons are decisive for the description of subthreshold production. Since the collective features of subthreshold production become especially significant far below the threshold, the results are extrapolated down to COSY energies. It is concluded that an \\barp measurement at ANKE-COSY should be feasible, if the high background of other particles can be efficiently suppressed.

Komarov, V. I.; Müller, H.; Sibirtsev, A.

2004-07-01

230

Possible subsurface production of carbon-14  

NASA Astrophysics Data System (ADS)

A subsurface origin of 14C is rarely considered by researchers interested in dating groundwater. Theoretically, nuclear reactions induced by emissions from U and Th nuclei can produce measurable concentrations of 14C in groundwater. Under very special conditions, calculations indicate that subsurface production might cause significant errors in dates of less than 1 × 104 years, although normally such errors should not be important until after 5 × 104 years. However, some anomalous 14C concentrations reported recently for deep groundwater may possibly be caused in part by subsurface production of 14C.

Zito, Richard; Donahue, Douglas J.; Davis, Stanley N.; Bentley, Harold W.; Fritz, Peter

1980-04-01

231

Accelerated ethanol fermentation by Saccharomyces cerevisiae with addition of activated carbon  

Microsoft Academic Search

Fermentation with the addition of activated carbon at 100 g l-1 promoted the glucose consumption and ethanol production rates of Saccharomyces cerevisiae by 1.3 and 1.1 times, respectively. With fermentation using spent medium, the consumption rate was maintained at 90% of that in the fresh medium with the addition of activated carbon, while the rate without any addition decreased to about 70%.

Toru Ikegamai; Hiroshi Yanagishita; Dai Kitamoto; Kenji Haraya

2000-01-01

232

Modeling of solid carbon in the reaction products of explosives  

SciTech Connect

Several forms of carbon, including diamond, pyrolytic graphic, and amorphous carbon, are used to model the solid component of the reaction products of RDX and TNT. The fluid constituents of the reaction products are described using liquid-state perturbation theory. It is found that for TNT, the calculation which employs the amorphous phase in the EOS yield the best description of the Chapman-Jouguet (CJ) state. For RDX there is not sufficient evidence within the constraints of the present study to favor a single, distinct phase, though utilization of the pyrolytic representation gives adequate results.

Jones, H.D.; Gray, M.V.

1986-05-01

233

Carbon footprint and ammonia emissions of California beef production systems.  

PubMed

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

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

2012-09-05

234

Record Methane Storage in Monolithic and Powdered Activated Carbons  

NASA Astrophysics Data System (ADS)

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

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

2010-03-01

235

Possible subsurface production of carbon-14  

Microsoft Academic Search

A subsurface origin of 14C is rarely considered by researchers interested in dating groundwater. Theoretically, nuclear reactions induced by emissions from U and Th nuclei can produce measurable concentrations of 14C in groundwater. Under very special conditions, calculations indicate that subsurface production might cause significant errors in dates of less that 1×104 years, although normally such errors showld not be

Richard Zito; Douglas J. Donahue; Stanley N. Davis; Harold W. Bentley; Peter Fritz

1980-01-01

236

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

SciTech Connect

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

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

2001-01-01

237

Use of carbon dioxide in the chemical synthesis technologies, plasma gasification and carbon production  

NASA Astrophysics Data System (ADS)

The modern electric power sector is based on burning of carbonaceous substances (coal, oil, natural gas, etc.). Large power stations are powerful local sources of carbon dioxide. Inconstancy of the electric power demand leads to increase in CO2 specific emissions, as the output power is basically higher than required one by the power network. One of promising ways of increase of operating efficiency of power stations is use of surpluses of the generated electric power in plasma technologies. The paper deals with the opportunity to use the plasma technologies in processes of methanol and methane production from carbon dioxide. Comparison of ranges of key parameters of plasma gasification of wood by air, carbon dioxide, and steam is presented. Also, use of CO2 for pure carbon production is examined.

Rutberg, Ph G.; Kuznetsov, V. A.; Bratsev, A. N.; Popov, V. E.; Shtengel', S. V.; Ufimtsev, A. A.

2011-03-01

238

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

EPA Science Inventory

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

239

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

SciTech Connect

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

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

2005-10-16

240

Influence of molybdenum on the chemical vapour deposition production of carbon nanotubes  

NASA Astrophysics Data System (ADS)

Large numbers of multi-wall carbon nanotubes have been produced using a Co-Mo sol-gel catalyst with a high Mo/Co ratio. Carbon yields up to 4000% and carbon nanotubes with low levels of impurities have been obtained, pointing out the promoter character of Mo in the reaction. Therefore, the influence of Mo species has been studied in detail. The analysis of the different catalysts and samples shows that two magnesium molybdate phases can be present in the catalysts: MgMoO4 and MgMo2O7. However, the MgMoO4 one plays a dominant role in the production of the tubes by helping the dispersion of the active Co nanoparticles and promoting the aromatization of the carbon source. Such active metal nanoparticles come from the decomposition of the CoO phase existing in the catalyst.

Pérez-Mendoza, M.; Vallés, C.; Maser, W. K.; Martínez, M. T.; Benito, A. M.

2005-05-01

241

Possible subsurface production of carbon-14  

Microsoft Academic Search

A subsurface origin of ¹⁴C is rarely considered by researchers interested in dating groundwater. Theoretically, nuclear reactions induced by emissions from U and Th nuclei can produce measurable concentrations of ¹⁴C in groundwater. Under very special conditions, calculations indicate that subsurface production might cause significant errors in dates of less that 1 x 10⁴ years, although normally such errors showld

Richard Zito; Douglas J. Donahue; Stanley N. Davis; Harold W. Bentley; Peter Fritz

1980-01-01

242

Preparation and characterization of active carbon spheres prepared by chemical activation  

Microsoft Academic Search

Active carbon spheres were prepared by chemical activation using acid-pretreated resin beads, composed of sulfonated polystyrene divinylbenzene. Carbonization and activation were carried out simultaneously at various temperature ranges from 200 to 900°C for 4h, under gentle fluidization conditions facilitated with N2 flow. Effect of temperature on carbon burn-off of precursor and surface area of active carbon spheres was also studied.

Anuradha Baghel; Beer Singh; G. K. Prasad; Pratibha Pandey; P. K. Gutch

2011-01-01

243

IMPACT ASSESSMENT OF PRODUCT CARBON LABELLING - A COMPARISON STUDY AMONG DIFFERENT PRODUCT GROUPS  

Microsoft Academic Search

The Sustainable Consumption Institute of Manchester and Tesco commissioned a study to compare the potential impact of labelling different product groups with their lifetime carbon footprint (CFP). Research shows that there is increasing awareness among consumers to environment protection and climate change issues. As a response to CFP labelling, consumers may change their buying behaviour. Such changes may create carbon

Dong-Ling Xu; Chris Foster; Ying Hu

244

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

Microsoft Academic Search

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

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

2012-01-01

245

Heterogeneous mercury reaction chemistry on activated carbon.  

PubMed

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

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

2011-04-01

246

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

247

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

Microsoft Academic Search

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

Piotr Nowicki; Robert Pietrzak; Helena Wachowska

2010-01-01

248

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

249

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

250

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

Microsoft Academic Search

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

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

1998-01-01

251

Effect of Different Carbon Sources on Endochitinase Production by Colletotrichum gloeosporioides  

Microsoft Academic Search

The present work analyzes the production of endochitinase by Colletotrichum gloeosporioides, a phytopathogenic fungus, using six different carbon sources and two pH values. For quantitative assay of endochitinase activity in solution, the synthetic substrate 4-methylumbelliferyl-?-D-N,N’,N”-triacetylchitotrioside was used. The major productions were obtained at pH 7.0 and 9.0, when colloidal chitin and glucose were used, whereas xylose and lactose were not

R. F. Souza; R. M. A. Soares; R. P. Nascimento; R. R. R. Coelho; R. C. Gomes

2005-01-01

252

Condensed Products Formation in Aluminum Combustion in Carbon Dioxide  

Microsoft Academic Search

This paper presents experimental study of condensed phase (c- phase) formation in combustion of aluminium particles (single and collective) in carbon dioxide. Certain attention is paid to correlation between the combustion products morphology and characteristics of Al-droplet and its environment (droplet size, CO2-pressure). The single particle combustion was studied using a modified experimental installation with combustion chamber based on a

I. G. Assovskiy; A. N. Streletskiy; V. I. Kolesnikov-Svinarev; G. P. Kuznetsov

253

NET DISSOLVED ORGANIC CARBON PRODUCTION IN RECIRCULATING SALMONID CULTURE SYSTEM  

Technology Transfer Automated Retrieval System (TEKTRAN)

Ozonating a coldwater recirculating system (RAS) can help control the accumulation of fine suspended solids, micro-organisms, and components of dissolved organic carbon (DOC) that can negatively impact fish health and production efficiency. Ozone can oxidize relatively large non-biodegradable organ...

254

Clouds Versus Carbon: Predicting Vegetation Roughness by Maximizing Productivity  

Microsoft Academic Search

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,

L. M. Olsen; A. Kleidon

2004-01-01

255

Validation of Land Carbon Products over The Netherlands  

NASA Astrophysics Data System (ADS)

Most Land Surface Models do not take into account water table dynamics. In the Netherlands the water table is regulated. This poses a challenge to the accurate modeling of carbon and water fluxes and vegetation. We present the latest validation results for 1D and 2D products for these and other land surface parameters over the Netherlands, generated with the SURFEX model.

de Vries, J.

2012-04-01

256

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

PubMed

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

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

2013-04-01

257

Kinetics of Diuron Adsorption onto Activated Carbon Fiber  

Microsoft Academic Search

A study was conducted on the adsorption kinetics of diuron from aqueous solutions onto activated carbon fiber. The results showed that the formation of hydrogen bonds between diuron and water, and temperature variations may possibly affect the adsorption process. Furthermore, adsorption of diuron onto activated carbon fiber was affected remarkably by solution pH and the maximum adsorption amount was achieved

Jianhua Xu; Yabing Sun; Zhenyu Li; Jingwei Feng

2011-01-01

258

Ammoxidation of active carbons for improvement of supercapacitor characteristics  

Microsoft Academic Search

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

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

2003-01-01

259

Removal of target odorous molecules on to activated carbon cloths  

Microsoft Academic Search

Activated carbon materials are adsorbents whose physico-chemical properties are interesting for the treatment of odorous compounds like hydrogen sulfide. Indeed, their structural parameters (pore structure) and surface chemistry (presence of heteroatoms such as oxygen, hydrogen, nitrogen, sulfur, phosphorus) play an important role in H2S removal. The cloth texture of these adsorbents (activated carbon cloths) is particularly adapted for dealing with

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

2004-01-01

260

What Carbon Sources Support Groundwater Microbial Activity in Riparian Forests?  

NASA Astrophysics Data System (ADS)

A major question in riparian research is the source of energy to support subsurface microbial denitrification activity. The supply of microbially-available carbon frequently limits microbial activity in the subsurface. Therefore, identifying the relative importance of carbon sources in the riparian subsurface helps explain the sustainability and spatial heterogeneity of denitrification rates. We have investigated the importance of buried, carbon-rich soil horizons, deep roots and dissolved organic carbon as potential carbon sources to support groundwater denitrification in riparian forests in Rhode Island. We used field observations, laboratory incubations and in-situ experiments to evaluate these sources at four sites in different geomorphic settings. In particular, we measured the 14C-DIC signature and DIC concentration of ambient groundwater and groundwater that had been degassed, re-introduced into the well, and incubated in-situ. Buried horizons appear to be an important source of carbon in the subsurface, as shown by active respiration in laboratory incubations; greater microbial biomass in buried carbon-rich soils compared to surrounding carbon-poor soils; and the presence of very old carbon (>1,000 ybp) in DIC 225 cm beneath the surface. DIC collected from shallower wells showed no clear evidence of ancient carbon. Roots also appear to be important, creating hotspots of carbon availability and denitrification in the generally carbon poor subsurface matrix. Dissolved organic carbon did not stimulate denitrification in aquifer microcosms in the laboratory, suggesting that this was not an important carbon source for denitrification in our sites. Determining which carbon source is fueling denitrification has practical implications. Where buried horizons are the key source, surface management of the riparian zone will likely have little direct influence on groundwater denitrification. Where roots are the key source, changes in the plant community are likely to influence denitrification capacity in the subsurface.

Gurwick, N. P.; Groffman, P. M.; McCorkle, D. C.; Stolt, M. H.; Kellogg, D. Q.; Gold, A. J.

2004-05-01

261

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

262

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

263

The active site structure of Thalassiosira weissflogii carbonic anhydrase 1.  

PubMed

X-ray absorption spectroscopy at the Zn K-edge indicates that the active site of the marine diatom Thalassiosira weissflogii carbonic anhydrase is strikingly similar to that of mammalian alpha-carbonic anhydrase enzymes. The zinc has three histidine ligands and a single water at 1.98 A. This is quite different from the beta-carbonic anhydrases of higher plants in which zinc is coordinated by two cysteine thiolates, one histidine, and a water molecule. The diatom carbonic anhydrase shows no significant sequence similarity with other carbonic anhydrases and may represent an example of convergent evolution at the molecular level. PMID:11015190

Cox, E H; McLendon, G L; Morel, F M; Lane, T W; Prince, R C; Pickering, I J; George, G N

2000-10-10

264

Granular activated carbon pilot treatment studies for explosives removal from contaminated groundwater  

Microsoft Academic Search

Manufacturing activities at Army Ammunition Plants (AAPs) result in the production of organic wastewaters that contain both explosive residues and other organic chemicals. As a result of past waste practices at such plants, explosive residues may leach through the soil and contaminate groundwater. Two pilot studies were performed to evaluate the use of granular activated carbon (GAC) to treat groundwater

W. J. Wujcik; W. L. Lowe; P. J. Marks; W. E. Sisk

1992-01-01

265

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

266

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

267

Adsorption of the aurocyanide, Au ( CN ) 2 - complex on granular activated carbons derived from macadamia nut shells – A preliminary study  

Microsoft Academic Search

In this study, waste macadamia nut shells were investigated for potential use as a hard organic precursor for the production of a granular activated carbon material. The processing of the macadamia shells commenced with the carbonised of the shells under a nitrogen atmosphere. This was followed by the physical activation of the shells under a carbon dioxide atmosphere, which was

Gerrard Eddy Jai Poinern; Gamini Senanayake; Nikunj Shah; Xuan N. Thi-Le; Gordon M. Parkinson; Derek Fawcett

2011-01-01

268

Gas Adsorption by Activated and Impregnated Carbons.  

National Technical Information Service (NTIS)

In the period reported, equilibrium adsorption isotherms have been measured for CCl4 on carbons 4, 5, and 6. The results have been analyzed in terms of the Dubinin-Polanyi isotherm equation and compared with those obtained for carbons 1, 2, and 3. A brief...

P. J. Reucroft C. P. Madhusudhan

1976-01-01

269

PRODUCTION OF CARBON PRODUCTS USING A COAL EXTRACTION PROCESS  

SciTech Connect

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

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

2005-12-12

270

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

271

Sorption of native polyaromatic hydrocarbons (PAH) to black carbon and amended activated carbon in soil.  

PubMed

Organic pollutants (e.g. polyaromatic hydrocarbons (PAH)) strongly sorb to carbonaceous sorbents such as black carbon and activated carbon (BC and AC, respectively). For a creosote-contaminated soil (Sigma15PAH 5500 mg kg(dry weight(dw))(-1)) and an urban soil with moderate PAH content (Sigma15PAH 38 mg kg(dw)(-1)), total organic carbon-water distribution coefficients (K(TOC)) were up to a factor of 100 above values for amorphous (humic) organic carbon obtained by a frequently used Linear-Free-Energy Relationship. This increase could be explained by inclusion of BC (urban soil) or oil (creosote-contaminated soil) into the sorption model. AC is a manufactured sorbent for organic pollutants with similar strong sorption properties as the combustion by-product BC. AC has the potential to be used for in situ remediation of contaminated soils and sediments. The addition of small amounts of powdered AC (2%) to the moderately contaminated urban soil reduced the freely dissolved aqueous concentration of native PAH in soil/water suspensions up to 99%. For granulated AC amended to the urban soil, the reduction in freely dissolved concentrations was not as strong (median 64%), especially for the heavier PAH. This is probably due to blockage of the pore system of granulated AC resulting in AC deactivation by soil components. For powdered and granulated AC amended to the heavily contaminated creosote soil, median reductions were 63% and 4%, respectively, probably due to saturation of AC sorption sites by the high PAH concentrations and/or blockage of sorption sites and pores by oil. PMID:18842282

Brändli, Rahel C; Hartnik, Thomas; Henriksen, Thomas; Cornelissen, Gerard

2008-10-07

272

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

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

273

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

PubMed

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

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

2013-09-13

274

Production of Multiwalled Carbon Nanotubes Using the Aerosol Method  

NASA Astrophysics Data System (ADS)

A new synthesis method has been invented for the production of carbon nanotubes. We have called this method the aerosol method since the fundamental synthesis routine is to create aerosols of organic solvent and metal particles by atomising a solution of a metal salt in a solvent using pure hydrogen gas. This method enables us to easily control the size of the catalyst particles. Reactions have been carried out at 700°C and 1000°C and in both cases multi-walled carbon nanotubes have been produced. The tubes are characterised using scanning and transmission electron microscopy, and X-ray diffraction.

Glerup, Marianne; Kanzow, Henning; Almairac, Robert; Bernier, Patrick

2002-10-01

275

Studies relevant to the catalytic activation of carbon monoxide  

SciTech Connect

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

Ford, P.C.

1992-06-04

276

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

277

Adsorption of cadmium from aqueous solutions on sulfurized activated carbon prepared from nut shells  

Microsoft Academic Search

Low-cost activated carbon, derived from nut shells, and its modified sample have been used as replacements for the current expensive methods of removing cadmium from aqueous solutions and waste waters. Adsorption of cadmium onto four kinds of activated carbons has been studied; prepared activated carbon (PAC), commercial activated carbon (CAC), and the sulfurized ones (SPAC & SCAC). The activated carbon

Amir Fouladi Tajar; Tahereh Kaghazchi; Mansooreh Soleimani

2009-01-01

278

Grain-based activated carbons for natural gas storage.  

PubMed

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

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

2009-11-28

279

CCN activation of pure and coated carbon black particles.  

PubMed

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

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

2006-02-15

280

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

281

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

282

Performance of Carbon Hydrogen Storage Materials as a Function of Post-Production Thermal Treatment  

NASA Astrophysics Data System (ADS)

High-surface-area activated carbons for hydrogen storage were investigated as a function of post-synthesis surface treatment. Thermal treatment of the initial carbon in high vacuum at temperatures 200-1000 C leads to materials with significantly different surface chemistries and hydrogen storage capacities. Results from nitrogen pore-structure analyses, FT-IR spectroscopy before and after the treatment, and thermogravimetric analysis and mass spectroscopy of volatile reaction products during treatment, are reported. For treatment at 600 C, excess hydrogen adsorption at 80 K and 303 K is found to be 20-30% higher than for the untreated sample. At temperatures below 450 C, volatiles are mostly water and air; volatiles above 450 C are mostly carbon dioxide and carbon monoxide. The results are interpreted as that high-temperature treatment produces materials with a large fraction of high-binding-energy sites.

Dohnke, E.; Romanos, J.; Beckner, M.; Burress, J. W.; Yu, P.; Pfeifer, P.

2012-02-01

283

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-Mart?´n, M. L.; González-Garc?´a, C. M.; González, J. F.; Ramiro, A.; Sabio, E.; Bruque, J. M.; Encinar, J. M.

2002-05-01

284

DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS  

SciTech Connect

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

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

2005-08-11

285

Interactive effects of carbon footprint information and its accessibility on value and subjective qualities of food products.  

PubMed

We aimed to explore the interactive effects of the accessibility of information and the degree of carbon footprint score on consumers' value judgments of food products. Participants (n=151, undergraduate students in Japan) rated their maximum willingness to pay (WTP) for four food products varying in information accessibility (active-search or read-only conditions) and in carbon footprint values (low, middle, high, or non-display) provided. We also assessed further effects of information accessibly and carbon footprint value on other product attributes utilizing the subjective estimation of taste, quality, healthiness, and environmental friendliness. Results of the experiment demonstrated an interactive effect of information accessibility and the degree of carbon emission on consumer valuation of carbon footprint-labeled food. The carbon footprint value had a stronger impact on participants' WTP in the active-search condition than in the read-only condition. Similar to WTP, the results of the subjective ratings for product qualities also exhibited an interactive effect of the two factors on the rating of environmental friendliness for products. These results imply that the perceived environmental friendliness inferable from a carbon footprint label contributes to creating value for a food product. PMID:20600412

Kimura, Atsushi; Wada, Yuji; Kamada, Akiko; Masuda, Tomohiro; Okamoto, Masako; Goto, Sho-ichi; Tsuzuki, Daisuke; Cai, Dongsheng; Oka, Takashi; Dan, Ippeita

2010-06-25

286

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

287

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

288

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

2010-01-18

289

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

PubMed Central

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

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

2010-01-01

290

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

291

Nitrogen-promoted active carbons as catalytic supports  

Microsoft Academic Search

Catalytic properties of active carbons treated with N-compounds and promoted with manganese oxides were studied in selective catalytic reduction of NO with ammonia. The following elements of the preparation had a beneficial effect on activity and selectivity of the catalysts: pre-oxidation of active carbon prior to the introduction of N-species, the choice of N-compound, together with the post-treatment procedure, and

T. Grzybek; J. Klinik; M. Motak; H. Papp

2008-01-01

292

Production and Screening of Carbon Products Precursors from Coal  

SciTech Connect

Michael A. Nowak of DOE/FETC contacted Richard A. Winschel of CONSOL, Inc., for samples of coal-derived liquids for evaluation as feedstock materials for anode coke and binder pitch. Two samples have undergone preliminary evaluation by the Chemical Engineering Department at West Virginia University. The results of the tests are presented herein. The first sample is identified as Kerr-McGee Light Phase. The material was produced using the Kerr-McGee critical solvent deasher (CSD, also known as the ROSE process). The CSD unit produced three streams; an ash concentrate, heavy solvent refined coal (SRC), and light SRC products. The sample examined by WVU is claimed to be the light-stream SRC.

NONE

1997-04-01

293

Physical and electrochemical study of halide-modified activated carbons  

Microsoft Academic Search

The current thesis aims to improve the electrochemical capacity of activated carbon electrodes, which enjoy prominent position in commercial electrochemical capacitors. Our approach was to develop electrochemical capacity by developing faradaic pseudocapacitance in carbon through a novel mechanochemical modification using iodine and bromine. Various commercial carbons were mechanochemically modified via solid-state iodation and vapour phase iodine-incorporation. The halidation-induced changes in

Prabeer Barpanda

2009-01-01

294

Loss of phosphomannomutase activity enhances actinorhodin production in Streptomyces coelicolor.  

PubMed

Phosphomannomutase (ManB), whose main function is the conversion of mannose-6-phosphate to mannose-1-phosphate, is involved in biosynthesis of GDP-mannose for numerous processes such as synthesis of structural carbohydrates, production of alginates and ascorbic acid, and post-translational modification of proteins in prokaryotes and eukaryotes. ManB isolated from Streptomyces coelicolor was shown to have both phosphomannomutase and phosphoglucomutase activities. Deletion of manB in S. coelicolor caused a dramatic increase in actinorhodin (ACT) production in the low-glucose Difco nutrient (DN) medium, whereas the wild-type strain did not produce ACT on this medium. Experiments involving complementation of the manB deletion showed that increased ACT production in DN media was due to blockage of phosphomannomutase activity rather than phosphoglucomutase activity. This result therefore provides useful information for the design of strategies that enhance antibiotic production through the control of carbon flux. PMID:20024545

Yang, Yung-Hun; Song, Eunjung; Park, Sung-Hee; Kim, Ji-Nu; Lee, Kwangwon; Kim, Eunjung; Kim, Yun-Gon; Kim, Byung-Gee

2009-12-19

295

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

Microsoft Academic Search

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 1300–2800m2g?1, providing an extensive network of micropores. Their capability as active material for supercapacitors was evaluated

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

2006-01-01

296

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 alkalinity cycle. 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. Meanwhile, 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 will ultimately increase or decrease the globally-integrated pelagic calcification rate. Here, we assess the importance of this uncertainty by introducing a variable dependence of calcium carbonate (CaCO3) production on calcite saturation state (?CaCO3) in the University of Victoria Earth System Climate Model, an intermediate complexity coupled carbon-climate model. In a series of model simulations, we examine the impact of this parameterization on global ocean carbon cycling under two CO2 emissions scenarios, both integrated to the year 3500. The simulations show a significant sensitivity of the vertical and surface horizontal alkalinity gradients to the parameterization, as well as the removal of alkalinity from the ocean through CaCO3 burial. These sensitivities result in an additional oceanic uptake of carbon when calcification depends on ?CaCO3 (of up to 13 % of total carbon emissions), compared to the case where calcification is insensitive to acidification. In turn, this response causes a reduction of global surface air temperature of up to 0.4 °C in year 3500, a 13 % reduction in the amplitude of warming. Narrowing these uncertainties will require better understanding of both temperature and acidification effects on pelagic calcifiers. Preliminary examination suggests that alkalinity observations can be used to constrain the range of uncertainties and may exclude large sensitivities of CaCO3 production on ?CaCO3.

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

2011-12-01

297

Sediment production and evolution of Proterozoic carbonate platforms  

SciTech Connect

The development of early Proterozoic platforms was broadly similar to the growth of Phanerozoic platforms, although in detail, early Proterozoic platforms differ significantly from Phanerozoic and even middle to late Proterozoic platforms. Specific unresolved problems include the sources and mechanisms of early Proterozoic carbonate production, environmental versus biologic control on stromatolite morphology/microfabric, and temporal restriction of unique facies. Major sites of early Proterozoic carbonate production include stromatolite reefs, tidal flats, and early cementation of most facies. Carbonate production was prolific, marine cements were locally precipitated directly on the sea floor, and widespread sheets of tufa (precipitated crusts including microdigitate stromatolites) formed on tidal flats. Cyanobacteria probably induced carbonate precipitation during CO/sub 2/ degassing related to photosynthesis. The decline of microdigitate stromatolites and other nonstromatolitic forms of tufa at the end of the early Proterozoic is interpreted to reflect a long-term evolution of Precambrian sea water and perhaps atmospheric pCO/sub 2/. Other important features of early Proterozoic platforms include the absence of bedded (massive) gypsum before 1.2 Ga, the occurrence of abundant halite casts in many sequences with rare or absent gypsum/anhydrite casts, the absence of important Mississippi Valley-type lead-zinc deposits, the abundance of tidal-flat chert, and ubiquitous fine-grained dolomite. Collectively these observations suggest that early Proterozoic sea water alkalinity was increased, possibly due to much higher values of total inorganic carbon in sea water such that HCO/sub 3//sup -/ exceeded 2Ca/sup + +/; this may have resulted from higher atmospheric pCO/sub 2/ relative to younger Proterozoic and Phanerozoic pCO/sub 2/, although other possibilities exist.

Grotzinger, J.P.

1987-05-01

298

The regeneration of field-spent granular-activated carbons.  

PubMed

The thermal regeneration of field-spent granular-activated carbons (GAC) is being increasingly adopted as a cost-effective alternative to disposal. The success of this practice requires the adjustment of process conditions to maximise the recovery of the original carbon characteristics while minimising carbon loss. This paper describes an investigation into the regeneration of several field-spent GAC representative of those typically generated by the drinking water treatment industry. The carbons were initially investigated for their ash contents and inorganic compositions in order to determine the accumulation of metallic species that affect the regeneration process. Regeneration was conducted in steam at 800 degrees C over reaction times between 0 and 60 min in order to achieve different degrees of carbon gasification. Weight losses were determined for each condition and the resulting carbons characterised for their apparent density, porosity, surface area and aqueous adsorption characteristics. Results showed that spent carbons recovered most of their adsorption characteristics when heated to 800 degrees C under inert conditions. Steam gasification in the range of 5-10 wt% burn-off had some positive effects on the characteristics of the spent carbons which were in most cases counteracted by a reduction in the carbon yield. Steam gasification in excess of 15 wt% burn-off caused a rapid increase in the carbon mesoporosity but a significant deterioration in the carbon microporosity, BET surface area and adsorption capacity for organic species of small molecular size. PMID:11456174

Miguel, G S; Lambert, S D; Graham, N J

2001-08-01

299

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

300

Catalytic decomposition of methane over carbon blacks for CO 2-free hydrogen production  

Microsoft Academic Search

Catalytic characteristics of carbon blacks for methane decomposition were investigated. The reaction was carried out under atmospheric pressure at 1023–1323 K. Carbon blacks exhibited stable catalytic activity despite of carbon deposition. No trend could be induced between the activity and the surface area of fresh samples. The reaction order was near unity and the activation energies over carbon blacks were

Eun Kyoung Lee; Sang Yeob Lee; Gui Young Han; Byung Kwon Lee; Tae-Jin Lee; Jin Hyuk Jun; Ki June Yoon

2004-01-01

301

Preparation of activated carbon from bituminous coal with phosphoric acid activation  

Microsoft Academic Search

Activated carbons were prepared from an Australian bituminous coal in this study. The preparation process consisted of phosphoric acid impregnation followed by carbonization in nitrogen at 400–600°C for 1–3hours. The results reveal that the surface area and pore volume of the resulting carbons increase with the chemical ratio, H3PO4\\/coal. Within the ranges of carbonization temperature and time, the chemically activated

Hsisheng Teng; Tien-Sheng Yeh; Li-Yeh Hsu

1998-01-01

302

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

303

HARDWOOD-BASED GRANULAR ACTIVATED CARBON FOR METALS REMEDIATION  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

304

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...

305

Ignition and Combustion Properties of Activated Carbon Containing Adsorbed Hydrocarbons.  

National Technical Information Service (NTIS)

Activated carbon contained in large filter beds is used in nuclear submarines for removal of odors and trace contaminants. Because organic vapors are concentrated in this way in the carbon, a study was made to get information for assessing the fire hazard...

F. J. Woods J. E. Johnson

1964-01-01

306

Heterogeneity of active carbons in adsorption of phenol aqueous solutions  

Microsoft Academic Search

Energetic heterogeneity of activated carbons prepared from bituminous coals is investigated on the basis of adsorption isotherms of phenol from the dilute aqueous solutions. The Langmuir–Freundlich (L–F) equation has been used to estimate the monolayer capacity values of carbons studied. Adsorption energy distribution functions have been calculated by using algorithm INTEG based on a regularization method. Analysis of these functions

P. Podkoscielny; A. D; O. V. Marijuk

2003-01-01

307

Noncovalent functionalization of carbon nanotubes with redox active lignin derivatives  

Microsoft Academic Search

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

Grzegorz Milczarek

2009-01-01

308

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

309

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

Code of Federal Regulations, 2010 CFR

...the injection rate of activated carbon? 60.1330 Section...AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED...the injection rate of activated carbon? If your municipal...combustion unit uses activated carbon to control...

2010-07-01

310

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

Code of Federal Regulations, 2010 CFR

...the injection rate of activated carbon? 62.15275 Section...AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED...the injection rate of activated carbon? If your municipal...combustion unit uses activated carbon to control...

2009-07-01

311

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

Code of Federal Regulations, 2010 CFR

...the injection rate of activated carbon? 60.1820 Section...AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED...the injection rate of activated carbon? If your municipal...combustion unit uses activated carbon to control...

2010-07-01

312

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

Code of Federal Regulations, 2010 CFR

...the injection rate of activated carbon? 62.15275 Section...AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED...the injection rate of activated carbon? If your municipal...combustion unit uses activated carbon to control...

2010-07-01

313

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

Code of Federal Regulations, 2013 CFR

...monitor the injection rate of activated carbon? 62.15275 Section 62.15275 ...monitor the injection rate of activated carbon? If your municipal waste combustion unit uses activated carbon to control dioxins/furans or...

2013-07-01

314

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

Code of Federal Regulations, 2013 CFR

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

2013-07-01

315

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

2013-07-01

316

A More Energy Efficient Product for Carbon Dioxide Separation  

Microsoft Academic Search

Aqueous solutions of alkanolamines such as monoethanolamine (MEA) have been used for years to separate carbon dioxide and hydrogen sulfide from other gases in continuous absorption\\/desorption processes to meet very low treated gas specifications. However, MEA can undergo side reactions with CO2 which produce various types of degradation compounds. These by-products reduce performance of the solvent leading to increased energy

R. H. Niswander; D. J. Edwards; M. S. DuPart; J. P. Tse

1993-01-01

317

The production of horizontally aligned single-walled carbon nanotubes  

Microsoft Academic Search

The current progress on the production of aligned single-walled carbon nanotubes (SWCNTs), particularly the horizontally aligned ones, is reviewed. There are two main categories for the alignment of SWCNTs: the post synthesis assembly and the in situ growth approaches. The post synthesis assembly approach mainly involves dispersing SWCNTs in solutions and aligning SWCNTs using spin-coating, Langmuir–Blodgett assembly, mechanical shearing, or

Yanfeng Ma; Bin Wang; Yingpeng Wu; Yi Huang; Yongsheng Chen

2011-01-01

318

Transition metal-catalyzed carbon-carbon bond activation.  

PubMed

This tutorial review deals with recent developments in the activation of C-C bonds in organic molecules that have been catalyzed by transition metal complexes. Many chemists have devised a variety of strategies for C-C bond activation and significant progress has been made in this field over the past few decades. However, there remain only a few examples of the catalytic activation of C-C bonds, in spite of the potential use in organic synthesis, and most of the previously published reviews have dwelt mainly on the stoichiometric reactions. Consequently, this review will focus mainly on the catalytic reaction of C-C bond cleavage by homogeneous transition metal catalysts. The contents include cleavage of C-C bonds in strained and unstrained molecules, and cleavage of multiple C-C bonds such as C[triple bond]C triple bonds in alkynes. Multiple bond metathesis and heterogeneous systems are beyond the scope of this review, though they are also fascinating areas of C-C bond activation. In this review, the strategies and tactics for C-C bond activation will be explained. PMID:15592626

Jun, Chul-Ho

2004-11-04

319

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

320

TESTING GUIDELINES FOR TECHNETIUM-99 ABSORPTION ON ACTIVATED CARBON  

SciTech Connect

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

BYRNES ME

2010-09-08

321

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

Federal Register 2010, 2011, 2012, 2013

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

2011-03-21

322

Recovery efficiency of the hydrofluorocarbon (HFC?134a) by activated carbons of different physicochemical properties  

Microsoft Academic Search

The adsorption characteristics of 1,1,1,2?tetrafluoroethane (HFC?134a) on activated carbon were investigated to evaluate the recovery efficiency of HFC?134a by six activated carbons (two granular activated carbons (GAC1 and GAC2), one high?surface area activated carbon (HAC), and three activated carbon fibers (ACF10, ACF15, and ACF20)). HFC?134a adsorption on the activated carbons increased with increase in the specific surface area and pore

Naohito Kawasaki; Seiki Tanada; Takeo Nakamura; Takashi Ohue; Ikuo Abe

1999-01-01

323

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

Federal Register 2010, 2011, 2012, 2013

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

2010-05-28

324

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

Federal Register 2010, 2011, 2012, 2013

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

2010-01-11

325

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

326

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

327

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

328

Regeneration of Granular Activated Carbon Using Hydrothermal Technology.  

National Technical Information Service (NTIS)

The economic feasibility of using granular activated carbon (GAC) to remove organic contaminants from industrial and municipal wastewater is contingent upon its reuse during multiple adsorption-regeneration cycles (Van Vliet, 1991). The most common proces...

M. D. Sufnarski

1999-01-01

329

Activation Energy Asymptotics Applied to Burning Carbon Particles.  

National Technical Information Service (NTIS)

The method of activation energy asymptotics is used to describe the entire history of a carbon particle suddenly immersed in a hot oxidizing ambient. Under appropriate conditions which are established by the analysis, the history of the particle is shown ...

D. R. Kassoy P. A. Libby

1982-01-01

330

Removal of Trace Organics from Groundwater Using Granular Activated Carbons.  

National Technical Information Service (NTIS)

The purpose of this study was to determine the feasibility of using granular activated carbon for the removal of dissolved organics from ground water. The primary contaminant considered during the testing program was DIMP(Diisopropyl Methyl Phosphonate). ...

1977-01-01

331

Phytoplankton extracellular dissolved organic carbon production in a hypertrophic African Lake  

Microsoft Academic Search

The spatial and temporal changes in phytoplankton (predominantly Microcystis aeruginosa) production of particulate organic carbon (primary production) and extracellular dissolved organic carbon (EDOC) were measured in hypertrophic Hartbeespoort Dam, South Africa, for 5 years. The study objectives were to determine the significance of EDOC production to primary production estimates and to identify the dominant factors associated with EDOC production.

Richard D. Robarts; Lynne M. Sephton

1989-01-01

332

Deposition of anatase on the surface of activated carbon  

Microsoft Academic Search

As part of a program looking into utilization of activated carbon prepared from waste material, titanium dioxide was deposited on the surface of active carbon (AC). This will be used in future work as potential photo-catalyst for treatment of chlorinated phenols in aqueous medium. Three different techniques were used: chemical vapour deposition (CVD), direct air-hydrolysis (DAH) and high-temperature impregnation (HTI)

Amjad H. El-Sheikh; Alan P. Newman; Hafid Al-Daffaee; Suki Phull; Neil Cresswell; Steven York

2004-01-01

333

Antibacterial pitch-based activated carbon fiber supporting silver  

Microsoft Academic Search

Pitch-based activated carbon fiber (ACF) supporting silver (ACF(Ag)) was prepared by pre-oxidization, carbonization, activation, immersion and decomposition processes. The structures, surface photographs and functional groups of the ACF and the ACF(Ag) were investigated. The ACF exhibited increased oxygen-containing functional groups and decreased BET specific surface areas after supporting silver particles. The ACF(Ag) with C?OH, C?O, -COOH and -COOAg groups showed

Ch. Y. Li; Y. Z. Wan; J. Wang; Y. L. Wang; X. Q. Jiang; L. M. Han

1998-01-01

334

Preparation of titanium dioxide\\/activated carbon composites using supercritical carbon dioxide  

Microsoft Academic Search

The penetration of titanium tetraisopropoxide (TTIP) dissolved in supercritical CO2 into the nano-spaces of an activated carbon was studied for the preparation of a TiO2-coated activated carbon. The conversion of TTIP to TiO2 through thermal decomposition was confirmed by evolved gas analysis during heat treatment under a N2 flow. Acetone was detected in the evolved gas, which suggested that some

Narihito Tatsuda; Hiroshi Itahara; Norihiko Setoyama; Yoshiaki Fukushima

2005-01-01

335

Carbon Sequestration Monitoring Activities, (Final Report).  

National Technical Information Service (NTIS)

In its 'Carbon Sequestration Technology Roadmap and Program Plan 2007' the U.S. Department of Energy (DOE)'s Office of Fossil Energy National Energy Technology Laboratory (NETL) identified as a major objective extended field tests to fully characterize po...

C. Frost

2010-01-01

336

Biofilm processes in biologically active carbon water purification  

Microsoft Academic Search

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

David R. Simpson

2008-01-01

337

Study of activated nitrogen-enriched carbon and nitrogen-enriched carbon\\/carbon aerogel composite as cathode materials for supercapacitors  

Microsoft Academic Search

An activated nitrogen-enriched carbon (ANC) material and a novel activated nitrogen-enriched carbon\\/carbon aerogel (ANC\\/ACA) composite were prepared by carbonization and activation of melamine resin and melamine resin\\/carbon aerogel composite. These were characterized by SEM, XPS, nitrogen adsorption\\/desorption and electrochemical measurements. Findings indicated than the materials had a highly porous nanometer-sized honeycomb structure and high specific surface area. ANC and ANC\\/ACA

Chuanli Qin; Xing Lu; Geping Yin; Zheng Jin; Qiang Tan; Xuduo Bai

2011-01-01

338

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

Microsoft Academic Search

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

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

2002-01-01

339

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

Microsoft Academic Search

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

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

2008-01-01

340

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

Microsoft Academic Search

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

Ting Yang; Aik Chong Lua

2003-01-01

341

Towards efficient solar hydrogen production by intercalated carbon nitride photocatalyst.  

PubMed

The development of efficient photocatalytic material for converting solar energy to hydrogen energy as viable alternatives to fossil-fuel technologies is expected to revolutionize energy shortage and environment issues. However, to date, the low quantum yield for solar hydrogen production over photocatalysts has hindered advances in the practical applications of photocatalysis. Here, we show that a carbon nitride intercalation compound (CNIC) synthesized by a simple molten salt route is an efficient polymer photocatalyst with a high quantum yield. We found that coordinating the alkali metals into the C-N plane of carbon nitride will induce the un-uniform spatial charge distribution. The electrons are confined in the intercalated region while the holes are in the far intercalated region, which promoted efficient separation of photogenerated carriers. The donor-type alkali metal ions coordinating into the nitrogen pots of carbon nitrides increase the free carrier concentration and lead to the formation of novel nonradiative paths. This should favor improved transport of the photogenerated electron and hole and decrease the electron-hole recombination rate. As a result, the CNIC exhibits a quantum yield as high as 21.2% under 420 nm light irradiation for solar hydrogen production. Such high quantum yield opens up new opportunities for using cheap semiconducting polymers as energy transducers. PMID:24061109

Gao, Honglin; Yan, Shicheng; Wang, Jiajia; Huang, Yu An; Wang, Peng; Li, Zhaosheng; Zou, Zhigang

2013-10-01

342

Temperature and carbon source affect the production and secretion of a thermostable ?-xylosidase by Aspergillus fumigatus  

Microsoft Academic Search

The effect of the temperature of growth and carbon source on the production and secretion of ?-xylosidase (EC 3.2.1.37) by the thermotolerant fungi Aspergillus fumigatus was studied in submerged cultures. In cultures developed at optimal temperature (30°C), the enzyme was predominantly cell-bound, while in cultures developed at higher temperature (42°C), the ?-xylosidase activity was predominantly found in the cell-free filtrates.

Veridiana Lenartovicz; Cristina Giatti Marques de Souza; Fabiana Guillen Moreira; Rosane Marina Peralta

2003-01-01

343

Effect of carbon source on the antimicrobial activity of Corynebacterium kutscheri and Corynebacterium xerosis  

Microsoft Academic Search

In an attempt to screen out new potent antimicrobial substances producing bacteria, Corynebacterium kutscheri NB-1 and Corynebacterium xerosis NB-2 were isolated and were found antagonistic to bacteria and fungi. Antimicrobial substances production of the bacterial strains was greatly influenced by variation of carbon sources. Galactose and glucose strongly enhanced the antimicrobial activity of Corynebacterium kutscheri and Corynebacterium xerosis, respectively. But

Nasser M. El-Banna

344

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

345

The application of moment analysis to the dynamic adsorption of radon by activated carbon  

Microsoft Academic Search

The adsorption of radon by activated carbon has received a great deal of attention within the academic press because of the importance of determining the radon concentration in the living environment. The deposition of energy from 222Rn decay and the daughter products of 222Rn is considered significant probable cause agent for lung cancer in the general population. Therefore, study of

Wayne C. Gaul

2003-01-01

346

Activated carbon from cotton stalks by impregnation with phosphoric acid  

Microsoft Academic Search

Dried, crushed cotton stalks were impregnated with varying concentrations of phosphoric acid (20–85 wt.%), dried at 383 K and carbonized at 773 K for 2 h. Porosity was determined by analysis of N2\\/77 K adsorption isotherms. High adsorbing carbons with well developed mesoporosity were obtained. Analysis for microporosity, by the ?S-method, proved the presence of minor content in all products.

Badie S Girgis; Mona F Ishak

1999-01-01

347

Disinfection of bacteria attached to granular activated carbon.  

PubMed Central

Heterotrophic plate count bacteria, coliform organisms, and pathogenic microorganisms attached to granular activated carbon particles were examined for their susceptibility to chlorine disinfection. When these bacteria were grown on carbon particles and then disinfected with 2.0 mg of chlorine per liter (1.4 to 1.6 mg of free chlorine residual per liter after 1 h) for 1 h, no significant decrease in viable counts was observed. Washed cells attached to the surface of granular activated carbon particles showed similar resistance to chlorine, but a progressive increase in sublethal injury was found. Observations made by scanning electron microscope indicated that granular activated carbon was colonized by bacteria which grow in cracks and crevices and are coated by an extracellular slime layer. These data suggest a possible mechanism by which treatment and disinfection barriers can be penetrated and pathogenic bacteria may enter drinking water supplies. Images

LeChevallier, M W; Hassenauer, T S; Camper, A K; McFeters, G A

1984-01-01

348

Detecting Extracellular Carbonic Anhydrase Activity Using Membrane Inlet Mass Spectrometry  

PubMed Central

Current research into the function of carbonic anhydrases in cell physiology emphasizes the role of membrane-bound carbonic anhydrases, such as carbonic anhydrase IX that has been identified in malignant tumors and is associated with extracellular acidification as a response to hypoxia. We present here a mass spectrometric method to determine the extent to which total carbonic anhydrase activity is due to extracellular carbonic anhydrase in whole cell preparations. The method is based on the biphasic rate of depletion of 18O from CO2 measured by membrane inlet mass spectrometry. The slopes of the biphasic depletion are a sensitive measure of the presence of carbonic anhydrase outside and inside of the cells. This property is demonstrated here using suspensions of human red cells in which external carbonic anhydrase was added to the suspending solution. It is also applied to breast and prostate cancer cells which both express exofacial carbonic anhydrase IX. Inhibition of external carbonic anhydrase is achieved by use of a membrane impermeant inhibitor that was synthesized for this purpose, p-aminomethylbenzenesulfonamide attached to a polyethyleneglycol polymer.

Delacruz, Joannalyn; Mikulski, Rose; Tu, Chingkuang; Li, Ying; Wang, Hai; Shiverick, Kathleen T.; Frost, Susan C.; Horenstein, Nicole A.; Silverman, David N.

2010-01-01

349

Catalytic activity of palladium supported on single wall carbon nanotubes compared to palladium supported on activated carbon  

Microsoft Academic Search

Nanoparticles (2–10nm) of palladium have been deposited on single wall carbon nanotubes (SWNT) by spontaneous reduction from Pd(OAc)2 or from oxime carbapalladacycle. These catalysts exhibit higher catalytic activity than palladium over activated carbon (Pd\\/C) for the Heck reaction of styrene and iodobenzene and for the Suzuki coupling of phenylboronic and iodobenzene. This fact has been attributed as reflecting the dramatic

Avelino Corma; Hermenegildo Garcia; Antonio Leyva

2005-01-01

350

Preparation of mesoporous carbon by steam activation of commercial activated carbon in the presence of yttrium oxide  

Microsoft Academic Search

Mesoporous carbon was prepared by steam activation of commercial activated carbon in the presence of yttrium oxide. The loading of yttrium nitrate (precursor of yttrium oxide) was 0.2, 0.6, 1.0 and 2.0 wt%. The weight lost and gases formed during heating were detected by using thermogravimetric analysis and mass spectroscopy. The surface area and the total volume of the mesoporous

W. Z. Shen; J. T. Zheng; Y. L. Zhang; J. G. Wang; Z. F. Qin

2003-01-01

351

Effect of activated carbon content in TiO 2-loaded activated carbon on photodegradation behaviors of dichloromethane  

Microsoft Academic Search

The effect of the amount of TiO2 loading on activated carbon support on the photodecomposition of dichloromethane was studied. The apparent adsorption constant of the TiO2-loaded activated carbon for dichloromethane was found to decrease with increase of the fraction of the loaded TiO2. It was found that the apparent rate constant of CO2 evolution became small with increase of the

Tsukasa Torimoto; Yasuhiro Okawa; Norihiko Takeda; Hiroshi Yoneyama

1997-01-01

352

Mutagenic activity of the products of propylene photooxidation  

SciTech Connect

The reactants and products in irradiated propylene/NO/sub x/ mixtures were brought to a steady-state distribution in a Teflon smog chamber operated in a dynamic mode. The effluent from the chamber was then tested for total mutagenic activity by exposing Salmonella typhimurium strain TA100 to it. The data show an increased mutagenic activity for the products when compared with the reactants and controls. In addition, the mutagenic activity at long reaction times is substantially greater than at short reaction times. To examine a subset of the propylene/NO/sub x/ photooxidation products, an exposure of strain TA100 to the products of the propylene/N/sub 2/O/sub 5/ dark reaction was conducted. Although a small mutagenic activity was observed for this mixture, a number of mutagenic organic nitrates were identified. The results for the irradiated propylene/NO/sub x/ mixture were analyzed in terms of the mutagenic activities of the individual products. The major products (carbon monoxide, ozone, formaldehyde, acetaldehyde, nitric acid, and peroxyacetyl nitrate) account for no more than 20% of the observed mutagenic response, assuming additivity.

Kleindienst, T.E.; Shepson, P.B.; Edney, E.O.; Cupitt, L.T.; Claxton, L.D.

1985-07-01

353

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

354

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

PubMed

Mesoporous carbon frameworks were synthesized using the soft-template method. Ca(BH(4))(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. PMID:22948563

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

2012-09-05

355

Carbonate production of an emergent reef platform, Warraber Island, Torres Strait, Australia  

Microsoft Academic Search

Complex relationships exist between tropical reef ecology, carbonate (CaCO3) production and carbonate sinks. This paper investigated census-based techniques for determining the distribution and carbonate\\u000a production of reef organisms on an emergent platform in central Torres Strait, Australia, and compared the contemporary budget\\u000a with geological findings to infer shifts in reef productivity over the late Holocene. Results indicate that contemporary carbonate

Deirdre E. Hart; Paul S. Kench

2007-01-01

356

Carbonate production of an emergent reef platform, Warraber Island, Torres Strait, Australia  

Microsoft Academic Search

Complex relationships exist between tropical reef ecology, carbonate (CaCO3) production and carbonate sinks. This paper investigated census-based techniques for determining the distribution and carbonate production of reef organisms on an emergent platform in central Torres Strait, Australia, and compared the contemporary budget with geological findings to infer shifts in reef productivity over the late Holocene. Results indicate that contemporary carbonate

Deirdre E. Hart; Paul S. Kench

2007-01-01

357

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

358

Activated Carbon Composites for Air Separation  

Microsoft Academic Search

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

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

2008-01-01

359

Effect of carbon source and dissolved oxygen level on cell growth and pullulanase production by Bacillus stearothermophilus G-82  

Microsoft Academic Search

Cell growth and extracellular pullulanase production ofBacillus stearothermophilus G-82 were investigated in batch culture using a defined medium with glucose, maltose, pullulan or amylopectin as carbon source. Maximum enzyme activity was with pullulan or amylopectin. Cell growth in batch culture was better under oxygen unlimited conditions, while higher total and specific enzyme activities, using pullulan or amylopectin, were obtained in

E. I. Emanuilova; M. S. Kambourova

1992-01-01

360

U. S. energy production activity and innovation  

Microsoft Academic Search

Life-cycle studies provide a comprehensive insight into comparative innovation behavior and innovation constants. In this article a comparison of the life-cycle plots for the production and patent activity is made for US energy production categories. As has been shown previously for material production [TFSC, vol.78, 2011], the two activities may be correlated to such an extent that they may be

Michael C. Connelly; J. A. Sekhar

361

Microbial enhancement of oil production from carbonate reservoirs  

SciTech Connect

The objective of this research contract was to examine MEOR in carbonate reservoirs by reviewing the literature pertinent to MEOR in carbonate systems, determining the microbial ecology of carbonate reservoirs, examining the effect of microorganisms on carbonate matrices, documenting MEOR in model carbonate core systems, and constructing a mathematical model for MEOR in carbonates. 11 refs., 19 figs., 38 tabs. (VC)

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

1991-11-01

362

Preparation and characterization of activated carbon from sunflower seed oil residue via microwave assisted K 2CO 3 activation  

Microsoft Academic Search

Sunflower seed oil residue, a by-product of sunflower seed oil refining, was utilized as a feedstock for preparation of activated carbon (SSHAC) via microwave induced K2CO3 chemical activation. SSHAC was characterized by Fourier transform infrared spectroscopy, nitrogen adsorption–desorption and elemental analysis. Surface acidity\\/basicity was examined with acid–base titration, while the adsorptive properties of SSHAC were quantified using methylene blue (MB)

K. Y. Foo; B. H. Hameed

2011-01-01

363

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

364

RNA interference with carbon catabolite repression in Trichoderma koningii for enhancing cellulase production.  

PubMed

The cellulase and xylanase genes of filamentous Trichoderma fungi exist under carbon catabolite repression mediated by the regulator carbon catabolite repressor (CREI). Our objective was to find the role of CREI in a cellulase-hyperproducing mutant of Trichoderma koningii, and address whether enzyme production can be further improved by silencing the cre1 gene. cre1 partially silenced strains were constructed to improve enzyme production in T. koningii YC01, a cellulase-hyperproducing mutant. Silencing of cre1 resulted in derepression of cellulase gene expression in glucose-based cultivation. The cre1 interference strain C313 produced 2.1-, 1.4-, 0.8-, and 0.8-fold higher amounts of filter paper activity, ?-1,4-exoglucanase activity (?-nitrophenyl-?-D-cellobioside as substrate), ?-1,4-endoglucanase activity (sodium carboxymethyl cellulose as substrate), and xylanase activity, respectively, than the control strain, suggesting that silencing of cre1 resulted in enhanced enzyme production capability. In addition, downregulation of cre1 resulted in elevated expression of another regulator of xylanase and cellulase expression, xyr1, indicating that CREI also acted as a repressor of xyr1 transcription in T. koningii under inducing conditions. These results show that RNAi is a feasible method for analyzing the regulatory mechanisms of gene expression and improving xylanase and cellulase productivity in T. koningii. PMID:23769310

Wang, Shaowen; Liu, Gang; Yu, Jianteng; Tian, Shengli; Huang, Baiqu; Xing, Miao

2013-04-30

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

Ocean carbon cycling in the Indian Ocean: 2. Estimates of net community production  

Microsoft Academic Search

The spatiotemporal variability of ocean carbon cycling and air-sea CO2 exchange in the Indian Ocean was examined using inorganic carbon data collected as part of the World Ocean Circulation Experiment (WOCE) cruises in 1995. Several carbon mass balance approaches were used to estimate rates of net community production (NCP) in the Indian Ocean. Carbon transports into and out of the

Nicholas R. Bates; A. Christine Pequignet; Christopher L. Sabine

2006-01-01

367

Ocean carbon cycling in the Indian Ocean: 2. Estimates of net community production  

Microsoft Academic Search

(1) The spatiotemporal variability of ocean carbon cycling and air-sea CO2 exchange in the Indian Ocean was examined using inorganic carbon data collected as part of the World Ocean Circulation Experiment (WOCE) cruises in 1995. Several carbon mass balance approaches were used to estimate rates of net community production (NCP) in the Indian Ocean. Carbon transports into and out of

Nicholas R. Bates; A. Christine Pequignet; Christopher L. Sabine

2006-01-01

368

Chemical production from waste carbon monoxide: its potential for energy conservation  

Microsoft Academic Search

Results of a study of the potential for energy conservation by producing chemicals from by-product or waste carbon monoxide (CO) from industrial sources are summarized. Extensive compilations of both industrial sources and uses for carbon monoxide were developed and included. Reviews of carbon monoxide purification and concentration technology and preliminary economic evaluations of carbon monoxide concentration, pipeline transportation and utilization

C. A. Rohrmann; G. F. Schiefelbein; P. M. Molton; C. T. Li; D. C. Elliott; E. G. Baker

1977-01-01

369

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

370

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...

371

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

372

Removal of congo red using activated carbon and its regeneration.  

PubMed

Activated carbon is used for the removal of colored toxic congo red dye. The effects of different operating conditions like, initial dye concentration, contact time, pH and temperature are studied for adsorption of congo red by a known amount of activated carbon (1.0g/L) under stirred batch condition. The zero point of charge of the activated carbon is found about 6.6. About 90% dye is removed for initial concentration of 50 and 100mg/L, it is about 80% at pH 7.0. Maximum adsorption (about 100%) of dye is observed at pH 2.0 for the concentration range studied here. Freundlich isotherm is found to fit the equilibrium data more adequately. Pseudo second order kinetic model explain successfully the kinetic data. The surfactant enhanced carbon regeneration (SECR) technique using both cationic and anionic surfactants is adopted for the regeneration of spent carbon by desorbing the dye. A kinetic model for dye desorption from the commercial activated carbon (CAC) is also proposed. Anionic surfactants show better performance than the cationic ones. Efficiency of dye desorption using surfactants is also compared with the desorption using pH change. PMID:17178190

Purkait, M K; Maiti, A; DasGupta, S; De, S

2006-11-18

373

PREPARATION OF ACTIVATED CARBON FROM COCONUT SHELL IN A SMALL SCALE COCURRENT FLOW ROTARY KILN  

Microsoft Academic Search

Activated carbons were prepared at 800°C in a small scale rotary kiln fed either with fresh or precarbonized coconut shell, employing a mixture of steam and air, flowing cocurrently. Typical product rates obtained were 0.2 and 0.6g\\/min for fresh and precarbonized shell respectively. Product surface area increased with increasing water input concentration from about 0.5 to 5 g H2O\\/g feed, resulting

JORGE LAINE; SANTIAGO SIMONI; RICARDO CALLES

1991-01-01

374

Mechanisms of Activated Carbon Degradation by Perspiration.  

National Technical Information Service (NTIS)

These investigations covered two distinct subjects: activated charcoal degradation by perspiration and decomposition of chloramine B. Both untreated and treated activated charcoal samples were exposed to synthetic sweat solutions or aqueous solutions of i...

L. L. Pytlewski

1977-01-01

375

Production of a clean carbon fuel derived from coal for use in stationary and mobile heat engines. [HYDROCARB process for production of CARBOLINE or carbon  

Microsoft Academic Search

This paper describes the development of a new process called HYDROCARB and the production of a new fuel product called CARBOLINE (an acronym for carbon-gasoline), which has potential world-wide economic usefulness. It is a clean carbon fuel which can be used in stationary, steam, and electrical power generating plants and for mobile transportation engines. The HYDROCARB process converts any abundantly

Steinberg

1986-01-01

376

Influence of oxidation on the preparation of porous carbons from phenol-formaldehyde resins with KOH activation  

SciTech Connect

The influence of oxidation on the production of high-porosity carbons from phenol-formaldehyde resins with KOH activation were examined under various preparation conditions. The activation process principally consisted of KOH impregnation followed by carbonization. Experimental results showed that prior to carbonization treating the resins with oxygen at 120 C, either before or after KOH impregnation, enabled the enhancement of the yield of the carbon products. The porosity development was found to be hindered by conducting oxidation prior to the impregnation. For oxidation performed after the impregnation, at a low KOH/resin ratio the porosity was found to decrease upon oxidation, whereas the oxidation enhanced porosity development for activation performed at higher ratios. Varying the carbonization temperature and time did not show obvious influence on the effects of the oxidation.

Teng, H.; Wang, S.C.

2000-03-01

377

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

378

Survival of selected bacterial species in sterilized activated carbon filters and biological activated carbon filters.  

PubMed Central

The survival of selected hygienically relevant bacterial species in activated carbon (AC) filters on a bench scale was investigated. The results revealed that after inoculation of the test strains the previously sterilized AC absorbed all bacteria (10(6) to 10(7)). After a period of 6 to 13 days without countable bacteria in the effluent, the numbers of Escherichia coli, Pseudomonas aeruginosa, and Pseudomonas putida increased up to 10(4) to 10(5) CFU/ml of effluent and 10(6) to 10(7) CFU/g of AC. When Klebsiella pneumoniae and Streptococcus faecalis were used, no growth in filters could be observed. The numbers of E. coli, P. aeruginosa, and P. putida, however, decreased immediately and showed no regrowth in nonsterile AC from a filter which had been continuously connected to running tap water for 2 months. Under these conditions an autochthonous microflora developed on the carbon surface which could be demonstrated by scanning electron microscopy and culturing methods (heterotrophic plate count). These bacteria reduced E. coli, P. aeruginosa, and P. putida densities in the effluent by a factor of more than 10(5) within 1 to 5 days. The hypothesis that antagonistic substances of the autochthonous microflora were responsible for the elimination of the artificial contamination could not be confirmed because less than 1% of the isolates of the autochthonous microflora were able to produce such substances as indicated by in vitro tests. Competition for limiting nutrients was thought to be the reason for the observed effects.

Rollinger, Y; Dott, W

1987-01-01

379

Preparation of activated carbon microspheres from phenolic-resin by supercritical water activation  

Microsoft Academic Search

Supercritical water (SCW) has been employed as an efficient activating agent for the preparation of activated carbon microspheres (P-ACS) with developed mesopores from phenolic-resin. Several processing factors that influenced the activation reaction, including activation temperature, activation duration, supercritical pressure and water flow rate were investigated. Increasing activation temperature and duration lead to larger porosity and higher specific surface area as

Qiong Cai; Zheng-Hong Huang; Feiyu Kang; Jun-Bing Yang

2004-01-01

380

Removal of bromate ion using powdered activated carbon.  

PubMed

Bromate ion (BrO3-) removal from drinking water by powdered activated carbons (PACs) in bath mode was evaluated under various operational conditions. Six kinds of PACs, including wood-based carbon, fruit-based carbon, coal-based carbon, and these three carbons thermally deoxidized in a nitrogen atmosphere, were selected to investigate their capacity on BrO3- removal. With the highest zeta potential value and being richly mesoporous, coal-based carbon had a high and an excellent BrO3- adsorption efficiency. The removal content of BrO3- by per gram of coal-based carbon was 0.45 mg within 5 hr in 100 microg/L bromate solution. The surface characteristics of PACs and bromide formation revealed that both physical and chemical PACs properties simultaneously affected the adsorption-reduction process. Under acidic conditions, PACs possessed high zeta value and adequate basic groups and exhibited neutral or positive charges, promoting BrO3- adsorption-reduction on the carbon surface. Interestingly, the PACs thermally deoxidized in N2 atmosphere optimized their properties, e.g. increasing their zeta values and decreasing the oxygen content which accelerated the BrO3- removal rate. The maximum adsorption capacity of fruit-based carbon was the highest among all tested carbons (99.6 mg/g), possibly due to its highest pore volume. Remarkably, the thermal regeneration of PACs in N2 atmosphere could completely recover the adsorption capacity of PACs. The kinetic data obtained from carbons was analyzed using pseudo second-order and intraparticle diffusion models, with results showing that the intraparticle diffusion was the more applicable model to describe adsorption of BrO3- onto PACs. PMID:21462700

Wang, Lian; Zhang, Jie; Liu, Jingze; He, Hong; Yang, Min; Yu, Jianwei; Ma, Zichuan; Jiang, Feng

2010-01-01

381

Production of Carbon Nanoparticles Using Pulsed Arc Discharge Triggered by Dielectric Breakdown in Water  

Microsoft Academic Search

This paper describes a simple production method for carbon nanoparticles by pulsed arc discharge in water, which is triggered by the electrical breakdown of water between graphite electrodes. High-resolution transmission electron microscopy (HRTEM) observation revealed that the main products obtained by the proposed method were onion-like nanoparticles; while carbon nanotubes were not formed. The carbon nanoonions uniformly dispersed in water

Junya Suehiro; Kiminobu Imasaka; Yutaka Ohshiro; Guangbin Zhou; Masanori Hara; Noriaki Sano

2003-01-01

382

Physicochemical properties of carbons prepared from pecan shell by phosphoric acid activation.  

PubMed

Activated carbons were prepared from pecan shell by phosphoric acid activation. The pore structure and acidic surface groups of these carbons were characterized by nitrogen adsorption, Boehm titration and transmittance Fourier infrared spectroscopy (FTIR) techniques. The characterization results demonstrated that the development of pore structure was apparent at temperatures 250 degrees C, and reached 1130m(2)/g and 0.34cm(3)/g, respectively, at 500 degrees C. Impregnation ratio and soaking time at activation temperature also affected the pore development and pore size distribution of final carbon products. At an impregnation ratio of 1.5, activated carbon with BET surface area and micropore volume as high as 861m(2)/g and 0.289cm(3)/g was obtained at 400 degrees C. Microporous activated carbons were obtained in this study. Low impregnation ratio (less than 1.5) and activation temperature (less than 300 degrees C) are favorable to the formation of acidic surface functional groups, which consist of temperature-sensitive (unstable at high temperature) and temperature-insensitive (stable at high temperature) two parts. The disappearance of temperature-sensitive groups was significant at temperature 300 degrees C; while the temperature-insensitive groups are stable even at 500 degrees C. FTIR results showed that the temperature-insensitive part was mostly phosphorus-containing groups as well as some carbonyl-containing groups, while carbonyl-containing groups were the main contributor of temperature-sensitive part. PMID:16973352

Guo, Yanping; Rockstraw, David A

2006-09-14

383

Bacteria associated with granular activated carbon particles in drinking water.  

PubMed Central

A sampling protocol was developed to examine particles released from granular activated carbon filter beds. A gauze filter/Swinnex procedure was used to collect carbon fines from 201 granular activated carbon-treated drinking water samples over 12 months. Application of a homogenization procedure (developed previously) indicated that 41.4% of the water samples had heterotrophic plate count bacteria attached to carbon particles. With the enumeration procedures described, heterotrophic plate count bacteria were recovered at an average rate of 8.6 times higher than by conventional analyses. Over 17% of the samples contained carbon particles colonized with coliform bacteria as enumerated with modified most-probable-number and membrane filter techniques. In some instances coliform recoveries were 122 to 1,194 times higher than by standard procedures. Nearly 28% of the coliforms attached to these particles in drinking water exhibited the fecal biotype. Scanning electron micrographs of carbon fines from treated drinking water showed microcolonies of bacteria on particle surfaces. These data indicate that bacteria attached to carbon fines may be an important mechanism by which microorganisms penetrate treatment barriers and enter potable water supplies.

Camper, A K; LeChevallier, M W; Broadaway, S C; McFeters, G A

1986-01-01

384

Porous texture evolution in Nomex-derived activated carbon fibers.  

PubMed

In the present work, the textural evolution of a series of activated carbon fibers with increasing burn-off degree, prepared by the pyrolysis and steam activation of Nomex aramid fibers, is followed by measurements of physical adsorption of N(2) (77 K) and CO(2) (273 K) and immersion calorimetry into different liquids (dichloromethane, benzene, cyclohexane). The immersion calorimetry results are discussed in depth, paying special attention to the choice of the reference material. The activated carbon fibers studied possess an essentially homogeneous microporous texture, which suggests that these materials may be applied in gas separation, either directly or with additional CVD treatment. PMID:16290775

Villar-Rodil, S; Denoyel, R; Rouquerol, J; Martínez-Alonso, A; Tascón, J M D

2002-08-01

385

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

PubMed Central

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

Buesing, Nanna; Gessner, Mark O.

2006-01-01

386

Arundo donax cane as a precursor for activated carbons preparation by phosphoric acid activation  

Microsoft Academic Search

Canes from Arundo donax, a herbaceous rapid-growing plant, were used as precursor for activated carbon preparation by phosphoric acid activation under a self-generated atmosphere. The influence of the carbonization temperature in the range 400–550 °C and of the weight ratio phosphoric acid to precursor (R=1.5–2.5) on the developed porous structure of the resulting carbons was studied for 1 h of

T Vernersson; P. R Bonelli; E. G Cerrella; A. L Cukierman

2002-01-01

387

Activated Carbon Composites for Air Separation  

SciTech Connect

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

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

2008-03-01

388

Draft Guidance on Lanthanum Carbonate Active ingredient ...  

Center for Drug Evaluation (CDER)

Text Version... An f2 test should be performed using mean profiles to compare test (T) and reference (R) product drug release under a range of pH conditions. ... More results from www.fda.gov/downloads/drugs/guidancecomplianceregulatoryinformation

389

Carbonization of bamboo and consecutive low temperature air activation  

Microsoft Academic Search

Raw moso bamboo (Phyllostachys pubescens) was examined to optimize the carbonization and the consecutive air activation procedure. Influence of sample size, nitrogen\\u000a flow rate, heating rate and final temperature on the carbon yield and the pore structure was investigated for the raw bamboo.\\u000a The short length cutting along bamboo trunk and the increase in heating rate to 40°C\\/min and nitrogen

Noriyuki Yamashita; Motoi Machida

390

Analysis of carbon soil content by using tagged neutron activation  

NASA Astrophysics Data System (ADS)

Here we describe a prototype for non-destructive, in-situ, accurate and cost-effectively measurement procedure of carbon in soil based on neutron activation analysis using 14 MeV tagged neutron beam. This technology can be used for carbon baseline assessment on regional scale and for monitoring of its surface and depth storage due to the changes in agricultural practices undertaken in order to mitigate global climate change.

Obhodas, Jasmina; Sudac, Davorin; Matjacic, Lidija; Valkovic, Vladivoj

2012-05-01

391

Bioindication Potential of Carbonic Anhydrase Activity in Anemones and Corals  

Microsoft Academic Search

Activity levels of carbonic anhydrase (CA) were assessed in anemones Condylactis gigantea and Stichodactyla helianthus with laboratory exposures to copper, nickel, lead, and vanadium, and also in animals collected from polluted vs pristine field sites. CA activity was found to be decreased with increase in metal concentration and also in animals collected from the polluted field site. Preliminary assessments to

Aubrey L Gilbert; Héctor M Guzmán

2001-01-01

392

Evolution of carbon structure in chemically activated wood  

Microsoft Academic Search

13C NMR and FTIR analyses have been employed to follow the evolution of chemical structure in relation to porosity development, as a function of heat treatment temperature (HTT), for activated carbons produced from white oak by phosphoric acid activation. The chemical changes effected by acid treatment at low HTT are: by 50 °C there is significant alteration of the lignin

M. S. Solum; R. J. Pugmire; M. Jagtoyen; F. Derbyshire

1995-01-01

393

Influence of the precursor metamorphism degree on preparation of nitrogen-enriched activated carbons by ammoxidation and chemical activation of coals  

SciTech Connect

The paper presents results of a study on obtaining N-enriched active carbons from four hard coals with different degree of metamorphism. The starting materials were carbonized, activated with KOH, and ammoxidized by a mixture of ammonia and air at the ratio 1:3 at 300 and 350{sup o}C, at each stage of the active carbon production. The efficiency of ammoxidation was found to depend on the degree of metamorphism of the precursor, the stage of processing at which ammoxidation is performed, and the temperature of this process. Ammoxidation of the active carbon led to a decrease in their surface area and pore volume, whereas that performed both at the stage of the precursor and the carbonizate brought improvement of textural parameters of the active carbons obtained. The sequence of the carbonization, activation, and ammoxidation processes had a significant effect on the acid-base character of the active carbon samples obtained. The majority of the active carbons modified at the stage of precursor and carbonizate showed considerable prevalence of surface acidic groups, whereas the samples ammoxidized after activation showed an intermediate acidic-basic character of the surface. 25 refs., 4 figs., 9 tabs.

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

2009-04-15

394

Mechanochemical activation of high-carbon fly ash for enhanced carbon reburning  

Microsoft Academic Search

The focus of the present study is the reduction of the residual unburnt carbon contained in fly ash from PC-fired boilers by reburning and\\/or beneficiation. More specifically, the study addresses the potential of enhancing oxyreactivity of the residual carbon contained in fly ash by mechanochemical activation in order to improve the effectiveness of ash reburning.The concept is tested with reference

Osvalda Senneca; Piero Salatino; Riccardo Chirone; Luciano Cortese; Roberto Solimene

2011-01-01

395

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

SciTech Connect

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

Klasson, KT

2002-12-23

396

Catalytic carbon membranes for hydrogen production. Final report  

SciTech Connect

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

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

1992-01-01

397

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

Microsoft Academic Search

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

Lotfi Mouni; Djoudi Merabet; Abdelkarim Bouzaza; Lazhar Belkhiri

2010-01-01

398

Production of surface-active lipids by Corynebacterium lepus.  

PubMed Central

Corynebacterium lepus was grown in 20-liter batch fermentations with kerosene as the sole carbon source. Critical micelle concentration measurements indicated the production of appreciable quantities of biosurfactants. This surface activity of the culture medium was due to lipids, which were extracted and identified. Samples of C. lepus whole broth were taken during a fermentation and monitored for surface tension, amount of surfactant present, and lipid content. The changes in the surfactant measured correlated with concentration changes of several surface-active lipids. An early dramatic increase in surfactant concentration was attributed to the production of a mixture of corynomycolic acids (beta-hydroxy alpha-branched fatty acids). Surface activity at the end of the fermentation was due to a lipopeptide containing corynomycolic acids plus small amounts of several phospholipids and neutral lipids which were identified by thin-layer chromatography.

Cooper, D G; Zajic, J E; Gerson, D F

1979-01-01

399

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

Federal Register 2010, 2011, 2012, 2013

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

2013-03-29

400

78 FR 16247 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea; Final Results of...  

Federal Register 2010, 2011, 2012, 2013

...Trade Administration [A-580-816] Corrosion-Resistant Carbon Steel Flat Products...review of the antidumping duty order on corrosion-resistant carbon steel flat products...1\\ See Certain Corrosion-Resistant Carbon Steel Flat...

2013-03-14

401

77 FR 13093 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Final Results of...  

Federal Register 2010, 2011, 2012, 2013

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

2012-03-05

402

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

403

75 FR 13490 - Certain Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea: Notice of...  

Federal Register 2010, 2011, 2012, 2013

...Administration (A-580-816) Certain Corrosion-Resistant Carbon Steel Flat Products...duty administrative review for certain corrosion-resistant carbon steel flat products...Republic of Korea (Korea). See Certain Corrosion-Resistant Carbon Steel Flat...

2010-03-22

404

78 FR 55241 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Preliminary Results of...  

Federal Register 2010, 2011, 2012, 2013

...Trade Administration [C-580-818] Corrosion-Resistant Carbon Steel Flat Products...countervailing duty (CVD) order on corrosion-resistant carbon steel flat products...covered by this Order \\2\\ is certain corrosion- resistant carbon steel flat...

2013-09-10

405

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

Federal Register 2010, 2011, 2012, 2013

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

2013-09-27

406

76 FR 3613 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Final Results of...  

Federal Register 2010, 2011, 2012, 2013

...Trade Administration [C-580-818] Corrosion-Resistant Carbon Steel Flat Products...countervailing duty (CVD) order on corrosion-resistant carbon steel flat products...2008, through December 31, 2008. See Corrosion-Resistant Carbon Steel Flat...

2011-01-20

407

76 FR 15291 - Certain Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Notice of...  

Federal Register 2010, 2011, 2012, 2013

...Administration [A-580-816] Certain Corrosion-Resistant Carbon Steel Flat Products...duty administrative review for certain corrosion-resistant carbon steel flat products...Republic of Korea (Korea). See Certain Corrosion-Resistant Carbon Steel Flat...

2011-03-21

408

75 FR 43488 - Certain Hot-Rolled Carbon Steel Flat Products From India: Final Results of Countervailing Duty...  

Federal Register 2010, 2011, 2012, 2013

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

2010-07-26

409

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

410

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

411

Structure and antibacterial activity of silver-supporting activated carbon fibers  

Microsoft Academic Search

In this paper, several kinds of silver supporting activated carbon fibers (ACF-Ag) were prepared by the reduction adsorption\\u000a on activated carbon fiber (ACF) activated with steam or H3PO4 using sisal, viscose and pitch fiber as precursors. Their pore structure and surface chemistry were characterized using nitrogen\\u000a adsorption, XPS, WXRD and ICP quantitative analysis. Their antibacterial activities were tested. The results

Shuixia Chen; Jinrong Liu; Hanmin Zeng

2005-01-01

412

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

Microsoft Academic Search

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

Ting Yang; Aik Chong Lua

2003-01-01

413

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. Table 1 provides an overview of the major markets for carbon products. Current sources of materials for these processes generally rely on petroleum distillation products or coal tar distillates obtained as a byproduct of metcoke production facilities. In the former case, the American materials industry, just as the energy industry, is dependent upon foreign sources of petroleum. In the latter case, metcoke production is decreasing every year due to the combined difficulties associated with poor economics and a significant environmental burden. Thus, a significant need exists for an environmentally clean process which can used domestically obtained raw materials and which can still be very competitive economically.

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

2005-04-13

414

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)

1999-01-01

415

Impact of sulfur oxides on mercury capture by activated carbon  

SciTech Connect

Recent field tests of mercury removal with activated carbon injection (ACI) have revealed that mercury capture is limited in flue gases containing high concentrations of sulfur oxides (SOx). In order to gain a more complete understanding of the impact of SOx on ACI, mercury capture was tested under varying conditions of SO{sub 2} and SO{sub 3} concentrations using a packed bed reactor and simulated flue gas (SFG). The final mercury content of the activated carbons is independent of the SO{sub 2} concentration in the SFG, but the presence of SO{sub 3} inhibits mercury capture even at the lowest concentration tested (20 ppm). The mercury removal capacity decreases as the sulfur content of the used activated carbons increases from 1 to 10%. In one extreme case, an activated carbon with 10% sulfur, prepared by H{sub 2}SO{sub 4} impregnation, shows almost no mercury capacity. The results suggest that mercury and sulfur oxides are in competition for the same binding sites on the carbon surface. 30 refs., 3 figs., 2 tabs.

Albert A. Presto; Evan J. Granite [United States Department of Energy, Pittsburgh, PA (United States). National Energy Technology Laboratory

2007-09-15

416

Carbon Tetrachloride Replacement Compounds for Organic Vapor Air-Purifying Respirator Cartridge and Activated Carbon Testing—A Review  

Microsoft Academic Search

This article reviews efforts by researchers and organizations around the world to identify chemicals as substitutes for carbon tetrachloride in measuring activated carbon activity (adsorption capacity) or organic vapor air-purifying respirator cartridge (or other packed carbon bed) breakthrough times. Such measurements usually are done to determine if a minimum performance standard is met. Different criteria have been established, supporting data

Ernest S. Moyer; Simon J. Smith; Gerry O. Wood

2001-01-01

417

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

2013-07-05

418

Mechanisms of Activated Carbon Degradation by Perspiration.  

National Technical Information Service (NTIS)

Sweat degradation of activated charcoal was studied by static and dynamic test methods. For the static tests, both untreated and treated charcoal was immersed in a synthetic sweat solution or an aqueous solution of the individual components of the synthet...

L. L. Pytlewski

1977-01-01

419

Experiments on the generation of activated carbon from biomass  

Microsoft Academic Search

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

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

2007-01-01

420

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

421

Kinetic study of platinum sorption from solutions by active carbons  

SciTech Connect

The purpose of this work was to study the kinetics of sorption of platinum compounds from hydrochloric acid solutions by active carbons, to identify the controlling step of mass transfer during sorption, and to formulate a mathematical model of the kinetics of the given process. Experimental study of the kinetics of sorption of (PtCl/sub 6/)/sup 2 -/ anions from hydrochloric acid solutions by SKS-3 and SKN-2M artificial active carbons showed that the controlling step is mass transfer by internal diffusion.

Bagreev, A.A.; Tarasenko, Yu.A.; Mardanenko, V.K.; Potyazhenko, I.A.

1988-07-20

422

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

423

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

424

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

425

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

426

Particle characteristics in the reactor and pelletizing areas of carbon black production.  

PubMed

Physical and chemical characteristics of airborne particles (ultrafine, PM1, PM2.5, and PM10) in reactor and pelletizing areas during carbon black production were measured to assess process related sources of particles in work areas. Results from bagging areas within the same three facilities have been previously published. Particle number and mass concentration measurements were conducted in these work areas and at ambient comparison sites at each of the three carbon black plants. No elevated ultrafine particle number concentrations (UFP, <100 nm) with respect to ambient were determined in the work areas of Plant 1, intermittently elevated concentrations at Plant 2, and permanently elevated concentrations at Plant 3. The intermittently elevated UFP concentrations in the pelletizer and reactor areas of Plant 2 could be related to nearby traffic emissions. The ultrafine particle number concentrations at Plant 2 are comparable to those determined at urban traffic sites. Both work areas of Plant 3 showed elevated UFP concentrations in the pelletizer reactor and areas. In the case of the reactor, which was the only enclosed reactor area investigated among the three facilities, the source of the elevated UFP number concentration was most likely attributable to grease and oil fumes from maintenance activities, a conclusion supported by carbon fractionation analysis. The elevated UFP number concentrations in the pelletizing area in this same plant are related to leaks in the production line, which allowed particulate matter to escape to the surrounding areas. Absolute PM10 mass concentrations were all within normal ambient concentrations except for the pelletizing area in Plant 3, which showed continuous levels above ambient. One additional source contributing to peak level PM10 mass concentrations at Plant 2 was due to wind dispersion from a carbon black spill incident the day prior to measurements. It is concluded from these measurements that no carbon black is released in the reactor and pelletizing areas (as UFP or PM10) from the closed production lines under normal operating conditions. PMID:16998988

Kuhlbusch, T A J; Fissan, H

2006-10-01

427

Anaerobic degradation of phenol and bioregeneration of granular activated carbon  

SciTech Connect

The objectives of this research included evaluation and comparison of the occurrence of the biological removal of phenol adsorbed onto granular activated carbon (GAC), under anaerobic methanogenic conditions, and at different phenol gradients between the GAC and the bulk liquid. The scope included monitoring the degradation of radiolabeled phenol and production of radiolabeled methane in three column reactors operated in parallel under different gradients of phenol. Three columns were operated in semi-continuous mode at 35C. GAC was pre-loaded with radiolabeled phenol at an equilibrium concentration of approximately 100 mg/L. During Phase 1, phenol was fed daily at dosages that (a) increased the phenol concentration, (b) maintained approximately constant, and (c) decreased the phenol concentration, respectively in each of the three columns to establish different gradients between GAC and bulk liquid. The feeding scheme was reversed for Phase 2 in each of the columns. Conventional bottle-point procedures and desorption procedures were used to develop isotherms under anaerobic conditions.

Craveiro de Sa, Fernando Antonio.

1991-01-01

428

Dissolved organic carbon production by microbial populations in the Atlantic Ocean  

Microsoft Academic Search

Dissolved organic carbon (DOC) production by microbial populations was measured at 19 stations in the Atlantic Ocean to quantify the fraction of photoassimilated carbon that flows through the dissolved organic pool at basin scale and to assess the relationship between the percentage of DOC production, phytoplankton size structure, and rates of net community production. Experiments were conducted during four cruises

Eva Teira; María José Pazó; Pablo Serret; Emilio Fernández

2001-01-01

429

ORGANIC CARBON PRODUCTION ON THE WINDWARD REEF FLAT OF ENIWETOK ATOLL  

Microsoft Academic Search

Oxygen and carbon dioxide were used to make two separate but simultaneous estimates of organic carbon production on the windward reef flat of Eniwctok Atoll. The methods give correlated results, showing a metabolic ratio ( ACO,:AO,) of -1, uncorrected for gas exchange. A predominantly algal community had both a higher gross production and a higher ratio of gross production to

Stephen V. Smith; James A. Marsh

430

Effects of organic carbon sequestration strategies on soil enzymatic activities  

NASA Astrophysics Data System (ADS)

Greenhouse gases emissions can be counterbalanced with proper agronomical strategies aimed at sequestering carbon in soils. These strategies must be tested not only for their ability in reducing carbon dioxide emissions, but also for their impact on soil quality: enzymatic activities are related to main soil ecological quality, and can be used as early and sensitive indicators of alteration events. Three different strategies for soil carbon sequestration were studied: minimum tillage, protection of biodegradable organic fraction by compost amendment and oxidative polimerization of soil organic matter catalyzed by biometic porfirins. All strategies were compared with a traditional agricultural management based on tillage and mineral fertilization. Experiments were carried out in three Italian soils from different pedo-climatic regions located respectively in Piacenza, Turin and Naples and cultivated with maize or wheat. Soil samples were taken for three consecutive years after harvest and analyzed for their content in phosphates, ß-glucosidase, urease and invertase. An alteration index based on these enzymatic activities levels was applied as well. The biomimetic porfirin application didn't cause changes in enzymatic activities compared to the control at any treatment or location. Enzymatic activities were generally higher in the minimum tillage and compost treatment, while differences between location and date of samplings were limited. Application of the soil alteration index based on enzymatic activities showed that soils treated with compost or subjected to minimum tillage generally have a higher biological quality. The work confirms the environmental sustainability of the carbon sequestering agronomical practices studied.

Puglisi, E.; Suciu, N.; Botteri, L.; Ferrari, T.; Coppolecchia, D.; Trevisan, M.; Piccolo, A.

2009-04-01

431

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

PubMed

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

Gül, S; Eren, O; K?r, S; Onal, Y

2012-01-01

432

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

433

Effect of activated carbons modification on porosity, surface structure and phenol adsorption.  

PubMed

The primary objective of this work was the examination of modified activated carbons with tailored adsorption capacity properties. Production of activated carbons with desired properties was accomplished by modification of surface functional groups and introduction of acidic/basic properties. Modification of an activated carbon was performed using partial oxygen gasification, nitric acid treatment, urea impregnation followed by pyrolysis and pyrolysis in a urea saturated stream. The surface properties of the produced samples were estimated by the multibasic titration method of Boehm and by the CO/CO2 gas evolution profiles, while pore structure development was measured by the N2 and CO2 gas adsorption isotherms. Oxygen gasification resulted in samples with surface area slightly lower that the raw activated carbon; the introduction of surface functional groups depended upon the severity of the treatment: carbonylic and phenolic type groups were introduced in all partially gasified samples, while low temperatures and short reaction times enhanced the basic character of the carbon. However, nitric acid treatment resulted in the introduction of high nitrogen amounts in the samples, the reduction of surface area and the development of a surface containing carboxylic, lactonic, phenolic and carbonylic groups with negligible HCl neutralization capacity. Treatment of activated carbon by urea supported the formation of basic groups and carbonyls. The presence of surface functional groups affected the adsorption capacity of the produced samples for the removal of specific pollutants such as phenols. Urea treated samples with a basic character and high nitrogen content presented the highest phenol uptake capacity; nitric acid treated carbons and oxygen gasified samples presented an acidic surface functionality and a low phenol adsorption capacity. The beneficial role of nitrogen on phenol adsorption was attributed to adsorbate-adsorbent interactions. PMID:17644248

Stavropoulos, G G; Samaras, P; Sakellaropoulos, G P

2007-06-07

434

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

435

Comparisons of pore properties and adsorption performance of KOH-activated and steam-activated carbons  

Microsoft Academic Search

Carbonaceous adsorbents with controllable pore sizes derived from carbonized pistachio shells (i.e., char) were prepared by the KOH activation and steam activation methods in this work. The pore properties including the BET surface area, pore volume, pore size distribution, and pore diameter of these activated carbons were characterized by the t-plot method based on N2 adsorption isotherms. Through varying the

Feng-Chin Wu; Ru-Ling Tseng; Chi-Chang Hu

2005-01-01

436

Granular activated carbon for removal of organic matter and turbidity from secondary wastewater.  

PubMed

A range of commercial granular activated carbon (GAC) media have been assessed as pretreatment technologies for a downstream microfiltration (MF) process. Media were assessed on the basis of reduction in both organic matter and turbidity, since these are known to cause fouling in MF membranes. Isotherm adsorption analysis through jar testing with supplementary column trials revealed a wide variation between the different adsorbent materials with regard to organics removal and adsorption kinetics. Comparison with previous work using powdered activated carbon (PAC) revealed that for organic removal above 60% the use of GAC media incurs a significantly lower carbon usage rate than PAC. All GACs tested achieved a minimum of 80% turbidity removal. This combination of turbidity and organic removal suggests that GAC would be expected to provide a significant reduction in fouling of a downstream MF process with improved product water quality. PMID:23306264

Hatt, J W; Germain, E; Judd, S J

2013-01-01

437

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

438

Characterization of activated carbon prepared from a single cultivar of Jordanian Olive stones by chemical and physicochemical techniques  

Microsoft Academic Search

The yearly production of olives in Jordan is more than 100 kton of which a significant proportion is de-stoned prior to sale. In this work, olive stones from Jordan were used for the preparation of activated carbon with the aim of producing a water treatment product suitable for treatment of contaminated groundwater. The preparation conditions were varied to study their

Amjad H El-Sheikh; Alan P Newman; Hafid K Al-Daffaee; Suki Phull; Neil Cresswell

2004-01-01

439

Ammonia-Activated Mesoporous Carbon Membranes for Gas Separations  

SciTech Connect

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

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

2011-01-01

440

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

Microsoft Academic Search

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

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

441

Phytoplankton, not allochthonous carbon, sustains herbivorous zooplankton production.  

PubMed

Terrestrial organic matter inputs have long been thought to play an important role in aquatic food web dynamics. Results from recent whole lake (13)C 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 approximately 20% of the flux of particulate carbon available to herbivorous zooplankton, this food source accounted for approximately 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

2009-11-23

442

Carbonic anhydrase activity and photosynthesis in marine diatoms  

Microsoft Academic Search

The photosynthesis and carbonic anhydrase activity of four marine diatoms currently found in oyster-ponds near the French Atlantic coast, Haslea ostrearia, Navicula phyllepta, Entomoneis paludosa and Amphora coffeaeformis, were investigated. Photosynthetic parameters determined from photosynthesis versus irradiance curves showed that A. coffeaeformis (a benthic species) had lower maximum net photosynthesis but a higher light utilization coefficient than the other species

Annick Morant-Manceau; Thi Le Nhung Nguyen; Elisabeth Pradier; Gerard Tremblin

2007-01-01

443

Complement activation and protein adsorption by carbon nanotubes  

Microsoft Academic Search

As a first step to validate the use of carbon nanotubes as novel vaccine or drug delivery devices, their interaction with a part of the human immune system, complement, has been explored. Haemolytic assays were conducted to investigate the activation of the human serum complement system via the classical and alternative pathways. Western blot and sodium dodecyl sulphate-polyacrylamide gel electrophoresis

Carolina Salvador-Morales; Emmanuel Flahaut; Edith Sim; Jeremy Sloan; Malcolm L. H. Green; Robert B. Sim

2006-01-01

444

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...

445

Purification of wet phosphoric acid using modified activated carbon  

Microsoft Academic Search

Phosphoric acid is very important to the Tunisian economy. A new method has been developed to reduce the concentration of inorganic impurities present in commercial Tunisian phosphoric acid. This method is based on the modification of activated carbon with sodium dodecyl sulphonate to carry out the exchange of ions. The preliminary results with the column used for this purpose was

Lotfi Monser; Mohamed Ben Amor; Mohamed Ksibi

1999-01-01

446

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...

447

ACTIVATED CARBON TREATMENT OF INDUSTRIAL WASTEWATERS: SELECTED TECHNICAL PAPERS  

EPA Science Inventory

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

448

A quantitative cytochemical method for measuring carbonic anhydrase activity  

Microsoft Academic Search

Synopsis  Components of a histochemical method for demonstrating carbonic anhydrase activity have been investigated quantitatively. It was found that it is not necessary to use free-floating sections provided the reaction is done in a reaction medium of controlled depth. This permits the use of normal cryostat sections on glass slides, so making this technique applicable to the cytochemical bioassay of gastrin.

Nigel Loveridge; Bute Gardens

1978-01-01

449

POWDERED ACTIVATED CARBON ADSORPTION ISOTHERMS FOR SELECTED TANNERY EFFLUENTS  

EPA Science Inventory

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

450

ADSORPTION OF PROTEINS ONTO ACTIVATED CARBON AND PHENOLIC RESIN  

Microsoft Academic Search

Adsorption of BSA lysozyme and mixture of the two proteins from aqueous solution onto activated carbon and adsorption of BSA onto phenolic resin has been studied to develop design parameters for protein adsorption and to evaluate the effective diffusivity of the proteins. The findings then are used as the theoretical basis for the study of processes such as enzyme immobilization

REI-YOUNG AMOS WU

1982-01-01

451

Activated carbon injection - a mercury control success story  

SciTech Connect

Almost 100 full-scale activated carbon injection (ACI) systems have been ordered by US electric utilities. These systems have the potential to remove over 90% of the mercury in flue, at a cost below $10,000 per pound of mercury removal. Field trials of ACI systems arm outlined. 1 fig.

NONE

2008-07-01

452

POULTRY MANURE-BASED ACTIVATED CARBONS AS MERCURY ADSORBENTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

453

Acoustical evaluation of carbonized and activated cotton nonwovens  

Microsoft Academic Search

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

N. Jiang; J. Y. Chen; D. V. Parikh

2009-01-01