40 CFR Table 29 to Subpart Uuu of... - HAP Emission Limits for Sulfur Recovery Units

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true HAP Emission Limits for Sulfur Recovery Units 29 Table 29 to Subpart UUU of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... to Subpart UUU of Part 63—HAP Emission Limits for Sulfur Recovery Units As stated in § 63.1568(a)(1...

Abnormal development of Dentalium due to the Amoco Cadiz oil spill

NARCIS (Netherlands)

Koster, A.SJ.; Biggelaar, J.A.M. van den

A comparison was made between the development of Dentalium eggs, spawned by animals, collected before and after the Amoco Cadiz oil spill. Development of eggs from animals collected before the oil spill was significantly better than development of eggs from animals collected after the oil spill. It

Amoco/Environmental Protection Agency Pollution Prevention Project, Yorktown refinery. Refinery release inventory. Final report

International Nuclear Information System (INIS)

Klee, H.; Kizier, G.J.; Baloo, S.; Hockman, E.L.; Couzens-Roberts, C.

1992-07-01

The report volume summarizes physical data obtained during a 2-year pollution prevention study of Amoco Oil Company's Yorktown Virginia Refinery. The study was jointly sponsored as a cooperative effort of Amoco Corporation and the United States Environmental Protection Agency. A multi-media sampling program was used to identify potential pollution sources within the Refinery. Sampling and analysis included air, surface water, groundwater, and solid waste data. Public perceptions about environmental issues of concern in the vicinity of the Refinery were also surveyed. The inventory showed that nearly 99 percent of the releases were airborne at the facility. Most of the remainder involved land disposal of solid wastes. Specific sources of major pollutants are identified

Amoco-US Environmental Protection Agency, pollution prevention project, Yorktown, Virginia: Yorktown refinery project workplan

International Nuclear Information System (INIS)

Curran, L.; Grieves, C.; Browning, R.; Hanlon, D.; Crane, C.

1990-09-01

The report provides a detailed workplan for obtaining data and analyzing results for a 2-year pollution prevention study of Amoco Oil Company's Yorktown Virginia Refinery. The study was jointly sponsored as a cooperative effort of Amoco Corporation and the United States Environmental Protection Agency. The goals of the study include (1) a multi-media inventory of all releases entering the environment from the Refinery, (2) development of possible engineering options to reduce the releases, (3) analysis of each option in terms of release reduction potential, impact on human health risk, ecological impact, changes in future liability, etc. and (4) identification of obstacles and incentives for implementation of any of the options considered

Screening study for waste biomass to ethanol production facility using the Amoco process in New York State. Appendices to the final report

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-08-01

The final report evaluates the economic feasibility of locating biomass-to-ethanol waste conversion facilities in New York State. Part 1 of the study evaluates 74 potential sites in New York City and identifies two preferred sites on Staten Island, the Proctor and Gamble and the Arthur Kill sites for further consideration. Part 2 evaluates upstate New York and determines that four regions surrounding the urban centers of Albany, Buffalo, Rochester, and Syracuse provide suitable areas from which to select specific sites for further consideration. A conceptual design and economic viability evaluation were developed for a minimum-size facility capable of processing 500 tons per day (tpd) of biomass consisting of wood or paper, or a combination of the two for upstate regions. The facility would use Amoco`s biomass conversion technology and produce 49,000 gallons per day of ethanol and approximately 300 tpd of lignin solid by-product. For New York City, a 1,000-tpd processing facility was also evaluated to examine effects of economies of scale. The reports evaluate the feasibility of building a biomass conversion facility in terms of city and state economic, environmental, and community factors. Given the data obtained to date, including changing costs for feedstock and ethanol, the project is marginally attractive. A facility should be as large as possible and located in a New York State Economic Development Zone to take advantage of economic incentives. The facility should have on-site oxidation capabilities, which will make it more financially viable given the high cost of energy. This appendix to the final report provides supplemental material supporting the evaluations.

Avoiding total reduced sulfur (TRS) emissions from sodium sulfite pulping recovery processes

International Nuclear Information System (INIS)

Norman, J.C.; Sell, N.J.; Ciriacks, J.C.

1990-01-01

This paper reports that one of the current trends in paper-making with cellulose pulping is the use of high-yield processes. With yields greater than 65%, these processes include mechanical pulps (groundwood and thermomechanical pulps or TMP), and semichemical types (chemi-TMP or CTMP). Groundwood and TMP make up about 10% of North American pulp production. Semichemical pulp makes up about 7% and is mostly used for corrugating medium. High-yield pulping for linerboard, particularly using the alkaline sulfite process, is also likely to be used in the future. High-yield pulping is based primarily on the sulfite process using mostly sodium-based chemicals. A disadvantage of this process is the unavailability of a recovery system for the inorganic pulping chemicals. Generally, mills have not accepted any particular recovery system for this process. For this and other reasons, sulfite processes constitute only 3-4% of the total North American pulp production. If high-yield processes continue to increase in popularity, a sodium sulfite chemical recovery system will be needed. A number of chemical recovery systems have been developed in the past 30 years for sodium-based sulfite pulping processes, with most of the mills successfully using this process located in Scandinavia

Leaching and recovery of zinc and copper from brass slag by sulfuric acid

OpenAIRE

Ahmed, I.M.; Nayl, A.A.; Daoud, J.A.

2016-01-01

Leaching and recovery processes for zinc and copper from brass slag by sulfuric acid were carried out and iron and aluminum were also precipitated as hydroxides in addition to silica gel. The factors affecting the performance and efficiency of the leaching processsuch as agitation rate, leaching time, acid concentration and temperature were separately investigated. The results obtained revealed that zinc and copper are successfully recovered from these secondary resources, where the percent r...

Process for recovery of sulfur from acid gases

Science.gov (United States)

Towler, Gavin P.; Lynn, Scott

1995-01-01

Elemental sulfur is recovered from the H.sub.2 S present in gases derived from fossil fuels by heating the H.sub.2 S with CO.sub.2 in a high-temperature reactor in the presence of a catalyst selected as one which enhances the thermal dissociation of H.sub.2 S to H.sub.2 and S.sub.2. The equilibrium of the thermal decomposition of H.sub.2 S is shifted by the equilibration of the water-gas-shift reaction so as to favor elemental sulfur formation. The primary products of the overall reaction are S.sub.2, CO, H.sub.2 and H.sub.2 O. Small amounts of COS, SO.sub.2 and CS.sub.2 may also form. Rapid quenching of the reaction mixture results in a substantial increase in the efficiency of the conversion of H.sub.2 S to elemental sulfur. Plant economy is further advanced by treating the product gases to remove byproduct carbonyl sulfide by hydrolysis, which converts the COS back to CO.sub.2 and H.sub.2 S. Unreacted CO.sub.2 and H.sub.2 S are removed from the product gas and recycled to the reactor, leaving a gas consisting chiefly of H.sub.2 and CO, which has value either as a fuel or as a chemical feedstock and recovers the hydrogen value from the H.sub.2 S.

Development of once-through hybrid sulfur process for nuclear hydrogen production

International Nuclear Information System (INIS)

Jung, Yong Hun

2010-02-01

without concentration process depending on the acid concentration they need. It is reasonable to assume that nearly all the recovered sulfur is reportedly consumed after first converted to sulfuric acid, which is the leading sulfur end-use in all forms. Ot-HyS could meet the additionally rising sulfuric acid demand by feeding severely increasing sulfur surplus. Flowsheet for the sulfur combustion and SCHRS (Sulfur Combustion Heat Recovery System) including Rankine cycle, developed by referring to the existing facilities under some assumptions, was simulated using Aspen Plus with an ideal Henry model and STEAMNBS model. Other part of the flowsheet, modified from the SRNL's work, was simulated using Aspen Plus with OLI-MSE model. Acid concentration of sulfuric acid product was set to be 75 wt% and SDE was treated as a black box under the reasonable assumptions including a cell potential of 0.6 V versus current density of 500 mA/cm 2 , which is a development performance target of the SRNL. As the results, it was demonstrated that net thermal efficiency of Ot-HyS is 47.1 % (based on LHV) and 55.7 % (based on HHV) assuming 33.3 % thermal-to-electric conversion efficiency of nuclear power plant. Hydrogen produced through the energy-efficient Ot-HyS would be used as off-peak electricity storage, to relieve the burden of load-following and help to expand applications of nuclear energy, which is regarded as a 'sustainable development' technology. Further detailed economic feasibility study could help to show the feasibility of Ot-HyS

Leaching and recovery of zinc and copper from brass slag by sulfuric acid

Directory of Open Access Journals (Sweden)

I.M. Ahmed

2016-09-01

Full Text Available Leaching and recovery processes for zinc and copper from brass slag by sulfuric acid were carried out and iron and aluminum were also precipitated as hydroxides in addition to silica gel. The factors affecting the performance and efficiency of the leaching processsuch as agitation rate, leaching time, acid concentration and temperature were separately investigated. The results obtained revealed that zinc and copper are successfully recovered from these secondary resources, where the percent recovery amounts to 95% and 99% for zinc and copper, respectively. The experimental data of this leaching process were well interpreted with the shrinking core model under chemically controlled processes. The apparent activation energy for the leaching of zinc has been evaluated using the Arrhenius expression. Based on the experimental results, a separation method and a flow sheet were developed and tested to separate zinc, copper, iron, aluminum and silica gel from the brass slag.

40 CFR Table 30 to Subpart Uuu of... - Operating Limits for HAP Emissions From Sulfur Recovery Units

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Operating Limits for HAP Emissions From Sulfur Recovery Units 30 Table 30 to Subpart UUU of Part 63 Protection of Environment ENVIRONMENTAL..., Table 30 Table 30 to Subpart UUU of Part 63—Operating Limits for HAP Emissions From Sulfur Recovery...

A sulfuric-lactic acid process for efficient purification of fungal chitosan with intact molecular weight.

Science.gov (United States)

Naghdi, Mitra; Zamani, Akram; Karimi, Keikhosro

2014-02-01

The most recent method of fungal chitosan purification, i.e., two steps of dilute sulfuric acid treatment, pretreatment of cell wall at room temperature for phosphate removal and extraction of chitosan from the phosphate free cell wall at high temperature, significantly reduces the chitosan molecular weight. This study was aimed at improvement of this method. In the pretreatment step, to choose the best conditions, cell wall of Rhizopus oryzae, containing 9% phosphate, 10% glucosamine, and 21% N-acetyl glucosamine, was treated with sulfuric, lactic, acetic, nitric, or hydrochloric acid, at room temperature. Sulfuric acid showed the best performance in phosphate removal (90%) and cell wall recovery (89%). To avoid depolymerisation of chitosan, hot sulfuric acid extraction was replaced with lactic acid treatment at room temperature, and a pure fungal chitosan was obtained (0.12 g/g cell wall). Similar pretreatment and extraction processes were conducted on pure shrimp chitosan and resulted in a chitosan recovery of higher than 87% while the reduction of chitosan viscosity was less than 15%. Therefore, the sulfuric-lactic acid method purified the fungal chitosan without significant molecular weight manipulation. Copyright © 2013 Elsevier B.V. All rights reserved.

Sulfur Removal by Adding Iron During the Digestion Process of High-sulfur Bauxite

Science.gov (United States)

Zhanwei, Liu; Hengwei, Yan; Wenhui, Ma; Keqiang, Xie; Dunyong, Li; Licong, Zheng; Pengfei, Li

2018-04-01

This paper proposes a novel approach to sulfur removal by adding iron during the digestion process. Iron can react with high-valence sulfur (S2O3 2-, SO3 2-, SO4 2-) to generate S2- at digestion temperature, and then S2- enter red mud in the form of Na3FeS3 to be removed. As iron dosage increases, high-valence sulfur concentration decreases, but the concentration of S2- increases; sulfur digestion rate decreases while sulfur content in red mud markedly increases; the alumina digestion rate, conversely, remains fairly stable. So sulfur can be removed completely by adding iron in digestion process, which provide a theoretical basis for the effective removal of sulfur in alumina production process.

Hydrometallurgical recovery of metal values from sulfuric acid leaching liquor of spent lithium-ion batteries.

Science.gov (United States)

Chen, Xiangping; Chen, Yongbin; Zhou, Tao; Liu, Depei; Hu, Hang; Fan, Shaoyun

2015-04-01

Environmentally hazardous substances contained in spent Li-ion batteries, such as heavy metals and nocuous organics, will pose a threat to the environment and human health. On the other hand, the sustainable recycling of spent lithium-ion batteries may bring about environmental and economic benefits. In this study, a hydrometallurgical process was adopted for the comprehensive recovery of nickel, manganese, cobalt and lithium from sulfuric acid leaching liquor from waste cathode materials of spent lithium-ion batteries. First, nickel ions were selectively precipitated and recovered using dimethylglyoxime reagent. Recycled dimethylglyoxime could be re-used as precipitant for nickel and revealed similar precipitation performance compared with fresh dimethylglyoxime. Then the separation of manganese and cobalt was conducted by solvent extraction method using cobalt loaded D2EHPA. And McCabe-Thiele isotherm was employed for the prediction of the degree of separation and the number of extraction stages needed at specific experimental conditions. Finally, cobalt and lithium were sequentially precipitated and recovered as CoC2O4 ⋅ 2H2O and Li2CO3 using ammonium oxalate solution and saturated sodium carbonate solution, respectively. Recovery efficiencies could be attained as follows: 98.7% for Ni; 97.1% for Mn, 98.2% for Co and 81.0% for Li under optimized experimental conditions. This hydrometallurgical process may promise a candidate for the effective separation and recovery of metal values from the sulfuric acid leaching liquor. Copyright © 2015 Elsevier Ltd. All rights reserved.

Removal of sulfur from process streams

International Nuclear Information System (INIS)

Brignac, D.G.

1984-01-01

A process wherein water is added to a non-reactive gas stream, preferably a hydrogen or hydrogen-containing gas stream, sufficient to raise the water level thereof to from about 0.2 percent to about 50 percent, based on the total volume of the process gas stream, and the said moist gas stream is contacted, at elevated temperature, with a particulate mass of a sulfur-bearing metal alumina spinel characterized by the formula MAl 2 O 4 , wherein M is chromium, iron, cobalt, nickel, copper, cadmium, mercury, or zinc to desorb sulfur thereon. In the sulfur sorption cycle, due to the simultaneous adsorption of water and sulfur, the useful life of the metal alumina spinel for sulfur adsorption can be extended, and the sorbent made more easily regenerable after contact with a sulfur-bearing gas stream, notably sulfur-bearing wet hydrogen or wet hydrogen-rich gas streams

Hydrometallurgical recovery of metal values from sulfuric acid leaching liquor of spent lithium-ion batteries

International Nuclear Information System (INIS)

Chen, Xiangping; Chen, Yongbin; Zhou, Tao; Liu, Depei; Hu, Hang; Fan, Shaoyun

2015-01-01

Highlights: • Selective precipitation and solvent extraction were adopted. • Nickel, cobalt and lithium were selectively precipitated. • Co-D2EHPA was employed as high-efficiency extraction reagent for manganese. • High recovery percentages could be achieved for all metal values. - Abstract: Environmentally hazardous substances contained in spent Li-ion batteries, such as heavy metals and nocuous organics, will pose a threat to the environment and human health. On the other hand, the sustainable recycling of spent lithium-ion batteries may bring about environmental and economic benefits. In this study, a hydrometallurgical process was adopted for the comprehensive recovery of nickel, manganese, cobalt and lithium from sulfuric acid leaching liquor from waste cathode materials of spent lithium-ion batteries. First, nickel ions were selectively precipitated and recovered using dimethylglyoxime reagent. Recycled dimethylglyoxime could be re-used as precipitant for nickel and revealed similar precipitation performance compared with fresh dimethylglyoxime. Then the separation of manganese and cobalt was conducted by solvent extraction method using cobalt loaded D2EHPA. And McCabe–Thiele isotherm was employed for the prediction of the degree of separation and the number of extraction stages needed at specific experimental conditions. Finally, cobalt and lithium were sequentially precipitated and recovered as CoC 2 O 4 ⋅2H 2 O and Li 2 CO 3 using ammonium oxalate solution and saturated sodium carbonate solution, respectively. Recovery efficiencies could be attained as follows: 98.7% for Ni; 97.1% for Mn, 98.2% for Co and 81.0% for Li under optimized experimental conditions. This hydrometallurgical process may promise a candidate for the effective separation and recovery of metal values from the sulfuric acid leaching liquor

Hydrometallurgical recovery of metal values from sulfuric acid leaching liquor of spent lithium-ion batteries

Energy Technology Data Exchange (ETDEWEB)

Chen, Xiangping; Chen, Yongbin; Zhou, Tao, E-mail: zhoutao@csu.edu.cn; Liu, Depei; Hu, Hang; Fan, Shaoyun

2015-04-15

Highlights: • Selective precipitation and solvent extraction were adopted. • Nickel, cobalt and lithium were selectively precipitated. • Co-D2EHPA was employed as high-efficiency extraction reagent for manganese. • High recovery percentages could be achieved for all metal values. - Abstract: Environmentally hazardous substances contained in spent Li-ion batteries, such as heavy metals and nocuous organics, will pose a threat to the environment and human health. On the other hand, the sustainable recycling of spent lithium-ion batteries may bring about environmental and economic benefits. In this study, a hydrometallurgical process was adopted for the comprehensive recovery of nickel, manganese, cobalt and lithium from sulfuric acid leaching liquor from waste cathode materials of spent lithium-ion batteries. First, nickel ions were selectively precipitated and recovered using dimethylglyoxime reagent. Recycled dimethylglyoxime could be re-used as precipitant for nickel and revealed similar precipitation performance compared with fresh dimethylglyoxime. Then the separation of manganese and cobalt was conducted by solvent extraction method using cobalt loaded D2EHPA. And McCabe–Thiele isotherm was employed for the prediction of the degree of separation and the number of extraction stages needed at specific experimental conditions. Finally, cobalt and lithium were sequentially precipitated and recovered as CoC{sub 2}O{sub 4}⋅2H{sub 2}O and Li{sub 2}CO{sub 3} using ammonium oxalate solution and saturated sodium carbonate solution, respectively. Recovery efficiencies could be attained as follows: 98.7% for Ni; 97.1% for Mn, 98.2% for Co and 81.0% for Li under optimized experimental conditions. This hydrometallurgical process may promise a candidate for the effective separation and recovery of metal values from the sulfuric acid leaching liquor.

Process for removing sulfur from sulfur-containing gases: high calcium fly-ash

Science.gov (United States)

Rochelle, Gary T.; Chang, John C. S.

1991-01-01

The present disclosure relates to improved processes for treating hot sulfur-containing flue gas to remove sulfur therefrom. Processes in accordance with the present invention include preparing an aqueous slurry composed of a calcium alkali source and a source of reactive silica and/or alumina, heating the slurry to above-ambient temperatures for a period of time in order to facilitate the formation of sulfur-absorbing calcium silicates or aluminates, and treating the gas with the heat-treated slurry components. Examples disclosed herein demonstrate the utility of these processes in achieving improved sulfur-absorbing capabilities. Additionally, disclosure is provided which illustrates preferred configurations for employing the present processes both as a dry sorbent injection and for use in conjunction with a spray dryer and/or bagfilter. Retrofit application to existing systems is also addressed.

Hot-Gas Desulfurization with Sulfur Recovery

International Nuclear Information System (INIS)

Portzer, Jeffrey W.; Damle, Ashok S.; Gangwal, Santosh K.

1997-01-01

The objective of this study is to develop a second generation HGD process that regenerates the sulfided sorbent directly to elemental sulfur using SO 2 , with minimal consumption of coal gas. The goal is to have better overall economics than DSRP when integrated with the overall IGCC system

Development of enhanced sulfur rejection processes

Energy Technology Data Exchange (ETDEWEB)

Yoon, R.H.; Luttrell, G.H.; Adel, G.T.; Richardson, P.E.

1996-03-01

Research at Virginia Tech led to the development of two complementary concepts for improving the removal of inorganic sulfur from many eastern U.S. coals. These concepts are referred to as Electrochemically Enhanced Sulfur Rejection (EESR) and Polymer Enhanced Sulfur Rejection (PESR) processes. The EESR process uses electrochemical techniques to suppress the formation of hydrophobic oxidation products believed to be responsible for the floatability of coal pyrite. The PESR process uses polymeric reagents that react with pyrite and convert floatable middlings, i.e., composite particles composed of pyrite with coal inclusions, into hydrophilic particles. These new pyritic-sulfur rejection processes do not require significant modifications to existing coal preparation facilities, thereby enhancing their adoptability by the coal industry. It is believed that these processes can be used simultaneously to maximize the rejection of both well-liberated pyrite and composite coal-pyrite particles. The project was initiated on October 1, 1992 and all technical work has been completed. This report is based on the research carried out under Tasks 2-7 described in the project proposal. These tasks include Characterization, Electrochemical Studies, In Situ Monitoring of Reagent Adsorption on Pyrite, Bench Scale Testing of the EESR Process, Bench Scale Testing of the PESR Process, and Modeling and Simulation.

Birds oiled during the Amoco Cadiz incident: an interim report

Energy Technology Data Exchange (ETDEWEB)

Jones, P.H.; Monnat, J.Y.; Cadbury, C.J.; Stowe, T.J.

1978-11-01

More than 4500 oiled birds were collected from beaches in Northwest France and the Channel Islands following the oil spillage from the super tanker Amoco Cadiz in March 1978. Some 33 bird species were recorded oiled. A notable feature of the incident was the high proportion of puffins among the birds known to have been oiled. In normal years, puffins are considered to be relatively uncommon off Brittany in spring, and so the high proportion of this species among the casualties was unexpected. A relatively large number of shags and divers were also oiled. (1 map, 8 references, 2 tables)

Technology of uranium recovery from wet-process phosphoric acid

Energy Technology Data Exchange (ETDEWEB)

Inoue, Katsutoshi [Saga Univ. (Japan). Faculty of Science and Engineering; Nakashio, Fumiyuki

1982-12-01

Rock phosphate contains from 0.005 to 0.02 wt.% of uranium. Though the content is a mere 5 to 10 % of that in uranium ore, the total recovery of uranium is significant since it is used for fertilizer manufacture in a large quantity. Wet-process phosphoric acid is produced by the reaction of rock phosphate with sulfuric acid. The recovery of uranium from this phosphoric acid is mostly by solvent extraction at present. According to U/sup 4 +/ or UO/sub 2//sup 2 +/ as the form of its existence, the technique of solvent extraction differs. The following matters are described: processing of rock phosphate; recovery techniques including the extraction by OPPA-octyl pyrophosphoric acid for U/sup 4 +/, and by mixed DEHPA-Di-(2)-ethylhexyl phosphoric acid and TOPO-tryoctyl phosphine oxide for UO/sub 2//sup 2 +/, and by OPAP-octylphenyl acid phosphate for U/sup 4 +/; the recent progress of the technology as seen in patents.

Once-through hybrid sulfur process for nuclear hydrogen production

International Nuclear Information System (INIS)

Jeong, Y. H.

2008-01-01

Increasing concern about the global climate change spurs the development of low- or zero-carbon energy system. Nuclear hydrogen production by water electrolysis would be the one of the short-term solutions, but low efficiency and high production cost (high energy consumption) is the technical hurdle to be removed. In this paper the once-through sulfur process composed of the desulfurization and the water electrolysis systems is proposed. Electrode potential for the conventional water electrolysis (∼2.0 V) can be reduced significantly by the anode depolarization using sulfur dioxide: down to 0.6 V depending on the current density This depolarized electrolysis is the electrolysis step of the hybrid sulfur process originally proposed by the Westinghouse. However; recycling of sulfur dioxide requires a high temperature heat source and thus put another technical hurdle on the way to nuclear hydrogen production: the development of high temperature nuclear reactors and corresponding sulfuric acid decomposition system. By the once-through use of sulfur dioxide rather than the closed recycle, the hurdle can be removed. For the sulfur feed, the desulfurization system is integrated into the water electrolysis system. Fossil fuels include a few percent of sulfur by weight. During the refinement or energy conversion, most of the sulfur should be separated The separated sulfur can be fed to the water electrolysis system and the final product would be hydrogen and sulfuric acid, which is number one chemical in the world by volume. Lowered electrode potential and additional byproduct, the sulfuric acid, can provide economically affordable hydrogen. In this study, the once-through hybrid sulfur process for hydrogen production was proposed and the process was optimized considering energy consumption in electrolysis and sulfuric acid concentration. Economic feasibility of the proposed process was also discussed. Based on currently available experimental data for the electrode

Advanced Byproduct Recovery: Direct Catalytic Reduction of Sulfur Dioxide to Elemental Sulfur.

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-06-01

More than 170 wet scrubber systems applied, to 72,000 MW of U.S., coal-fired, utility boilers are in operation or under construction. In these systems, the sulfur dioxide removed from the boiler flue gas is permanently bound to a sorbent material, such as lime or limestone. The sulfated sorbent must be disposed of as a waste product or, in some cases, sold as a byproduct (e.g. gypsum). Due to the abundance and low cost of naturally occurring gypsum, and the costs associated with producing an industrial quality product, less than 7% of these scrubbers are configured to produce usable gypsum (and only 1% of all units actually sell the byproduct). The disposal of solid waste from each of these scrubbers requires a landfill area of approximately 200 to 400 acres. In the U.S., a total of 19 million tons of disposable FGD byproduct are produced, transported and disposed of in landfills annually. The use of regenerable sorbent technologies has the potential to reduce or eliminate solid waste production, transportation and disposal. In a regenerable sorbent system, the sulfur dioxide in the boiler flue gas is removed by the sorbent in an adsorber. The S0{sub 2}s subsequently released, in higher concentration, in a regenerator. All regenerable systems produce an off-gas stream from the regenerator that must be processed further in order to obtain a salable byproduct, such as elemental sulfur, sulfuric acid or liquid S0{sub 2}.

Characterization of desulfurization, denitrogenation and process sulfur transfer during hydropyrolysis of Chinese high sulfur coals

Energy Technology Data Exchange (ETDEWEB)

Sun Chenggong; Li Baoqing [Chinese Academy of Sciences, Taiyuan (China). State Key Lab. of Coal Conversion; Snape, C.E. [Strathclyde Univ., Glasgow (United Kingdom). Dept. of Pure and Applied Chemistry

1997-12-31

The process desulphurization and denitrogenation of Chinese high sulfur coals and the characteristics of sulfur transformation during non-catalytic hydropyrolysis were investigated by a 10 g fixed-bed reactor and a small-scaled reactor with online spectrometry respectively. It was indicated that more than 70% of the total sulfur of the two high sulfur coals and almost all pyritic sulfur are removed as H{sub 2}S, leaving the char and tar products with much less sulfur distribution. The liability of sulfur transformation to tar products is closely related to the thiophenic structure forms rather than sulfidic forms. At the same time, the formation of trace amount of sulfur dioxide indicates the presence of inherent sulfur oxidation reactions inside coal frame structures even under H{sub 2} pressure. (orig.)

Desulfurisation and sulfur recovery

Energy Technology Data Exchange (ETDEWEB)

Hughes, P.; Finn, A.; Scott, L. [Costain Oil, Gas and Process Ltd (United Kingdom)

2001-09-01

This article highlights technical issues associated with different sulphur recovery processes in the hydrocarbon processing industry. Details are given of the Stretford process developed by British Gas for the removal of low concentrations of hydrogen sulphide from natural gas and other hydrocarbon gases; the SulFerox process developed by Shell and Dow for removing moderate amounts of sulphur from contaminated gases using a proprietary iron salt for extracting the sulphur; solvent systems for removing moderately high concentrations of hydrogen sulphide in sour gas or liquid petroleum gases (LPG); the simple Claus process involving the partial combustion of hydrogen sulphide forming sulphur dioxide which reacts with hydrogen sulphide to form sulphur; and enhanced Claus processes. Sour water stripping processes for hydrogen sulphide contaminated water from hydrocarbon processing, tail gas treatment of Claus plant offgases, and hydrotreating are also discussed.

Experimental study of desulfurization of Zhong Liang Shau high sulfur coal by flotation

Energy Technology Data Exchange (ETDEWEB)

Jiang, Z.; Huang, B.; Cao, J. [China University of Mining and Technology (China). Beijing Graduate School

1994-12-01

Emission of large amount of SO{sub 2} from combustion of high sulfur coal causes serious environmental pollution. Pre-combustion desulfurization of high sulfur coal has become a necessity. This paper reports test results of fine coal desulfurization with different flotation technology and the effect of pyrite depressant. Test work showed that when the coal sample from Zhong Liang Shau was processed with a Free Jet Flotation Column its pyritic sulfur content was reduced from 3.08% to 0.84%, with 72.22% recovery of combustible matter in clean coal. The concept of Desulfurization Efficiency Index E{sub ds} for comprehensive evaluation of desulfurization process is proposed, which is defined as the product of the ratio of sulfur content reduction of clean coal and the recovery of combustible matters. 6 refs., 4 figs., 3 tabs.

Reductive-sulfurizing smelting treatment of smelter slag for copper and cobalt recovery

Directory of Open Access Journals (Sweden)

Li Y.

2018-01-01

Full Text Available Recovery of copper and cobalt from smelter slag using reductive-sulfurizing smelting method was performed in this study. The effects of reductive agent (coke, sulfurizing agent (pyrite, slag modifier (CaO and smelting temperature and duration on the extractive efficiencies of Cu, Co and Fe were discussed. The phase compositions and microstructure of the materials, copper-cobalt matte and cleaned slag were determined. The results showed that copper and cobalt contents in cleaned slag could decrease averagely to 0.18% and 0.071% respectively after cleaning. 91.99% Cu and 92.94% Co and less than 38.73% Fe were recovered from the smelter slag under the optimum conditions: 6 wt.% coke, 20 wt.% pyrite and 6 wt.% CaO addition to the smelter slag, smelting temperature of 1350°C and smelting duration of 3h. The addition of CaO can increase the selectivity of Co recovery. The cleaning products were characterized by XRD and SEM-EDS analysis. The results showed that the main phases of copper-cobalt matte were iron sulfide (FeS, geerite (Cu8S5, iron cobalt sulfide (Fe0.92Co0.08S and Fe-Cu-Co alloy. The cleaned slag mainly comprised fayalite (Fe2SiO4, hedenbergite (CaFe(Si2O6 and magnetite (Fe3O4.

Significance of the Capacity Recovery Effect in Pouch Lithium-Sulfur Battery Cells

DEFF Research Database (Denmark)

Knap, Vaclav; Zhang, Teng; Stroe, Daniel Loan

2016-01-01

Lithium-Sulfur (Li-S) batteries are an emerging energy storage technology, which is technically-attractive due to its high theoretical limits; practically, it is expected that Li-S batteries will result into lighter energy storage devices with higher capacities than traditional Lithium-ion...... batteries. One of the actual disadvantages for this technology is the highly pronounced rate capacity effect, which reduces the available capacity to be discharged when high currents are used. This drawback might be addressed by the use of the capacity recovery effect, which by introducing relaxation...... periods between consecutive pulse discharges of the battery, increases the available discharge capacity of the cell. The capacity recovery effect of the Li-S cell is studied in this paper using the pulse discharge technique, considering its dependence on the applied current, discharge step length...

Petroleum Refineries (Catalytic Cracking, Catalytic Reforming and Sulfur Recovery Units): National Emission Standards for Hazardous Air Pollutants (NESHAP)

Science.gov (United States)

learn more about the NESHAP for catalytic cracking and reforming units, as well as sulfur recovery units in petroleum refineries by reading the rule history, rule summary, background information documents, and compliance information

Method of removing and recovering elemental sulfur from highly reducing gas streams containing sulfur gases

Science.gov (United States)

Gangwal, Santosh K.; Nikolopoulos, Apostolos A.; Dorchak, Thomas P.; Dorchak, Mary Anne

2005-11-08

A method is provided for removal of sulfur gases and recovery of elemental sulfur from sulfur gas containing supply streams, such as syngas or coal gas, by contacting the supply stream with a catalyst, that is either an activated carbon or an oxide based catalyst, and an oxidant, such as sulfur dioxide, in a reaction medium such as molten sulfur, to convert the sulfur gases in the supply stream to elemental sulfur, and recovering the elemental sulfur by separation from the reaction medium.

Clues to early diagenetic sulfurization processes from mild chemical cleavage of labile sulfur-rich geomacromolecules

Science.gov (United States)

Adam, P.; Schneckenburger, P.; Schaeffer, P.; Albrecht, P.

2000-10-01

Macromolecular fractions, isolated from the solvent extract of sulfur-rich Recent (Siders Pond, USA; Lake Cadagno, Switzerland; Walvis Bay, Namibia) and immature sediments (Gibellina, Messinian of Sicily; Vena del Gesso, Messinian of Italy), were investigated by chemical degradation using sodium ethanethiolate/methyliodide. This mild reagent which cleaves polysulfide bonds to yield methylsulfides has the advantage over other methods of leaving intact other functionalities (like double bonds) and preserving sulfur atoms at their incorporation site. The method is, therefore, well-suited to the molecular level investigation of sulfur-rich macromolecules from Recent sediments containing highly functionalized polysulfide-bound subunits. In Recent anoxic sulfur-rich sediments, the release of various methylthioethers clearly demonstrates that intermolecular sulfurization of organic matter does occur at the earliest stages of diagenesis. Steroids and phytane derivatives are the major sulfurized lipids, a feature also observed in more mature sulfur-rich sediments. Several phytene derivatives, such as cis and trans 1-methylthiophyt-2-enes, as well as methylthiosteroids, including 5α- and 5β-3-(methylthio)-cholest-2-enes, were identified by comparison with synthesized standards. Steroid methylthioenolethers are released from polysulfide-bound steroid enethiols present in the macromolecular fractions. The latter, which correspond to thioketones, can be considered as intermediates in the reductive sulfurization pathway leading from steroid ketones to polysulfide-bound saturated steroid skeletons and are characterized for the first time in the present study. Thus, it could be shown that the major part of the polysulfide-bound lipids occurring in Recent sediments is apparently the result of sulfurization processes affecting carbonyls (aldehydes and ketones). The unsaturated methylthioethers obtained from Recent sediments were not present in more mature evaporitic samples, which

Recovery of vanadium (V) from used catalysts in sulfuric acid production units by oxalic acid

International Nuclear Information System (INIS)

Abdulbaki, M.; Shino, O.

2009-07-01

Vanadium penta oxide (V 2 O 5 ), is used, in large quantities as a catalyst for the oxidation of SO 2 to SO 3 in sulfuric acid production units, during the oxidation process the level of the oxidation declines with the time because of catalyst poisoning. So the spent catalyst is usually through out in a specified special places by General Fertilizer Company which causes a pollution of the land. The present paper, studies the recovery of vanadium from the spent catalyst by using the oxalic acid. The optimal conditions of spent catalyst leaching have been studied. It has been shown that 2%(w/w) of oxalic acid is the most suitable for leaching process at 70 degree centigrade. The precipitation of vanadium using some alkaline media NH 4 OH has been also studied, it has been shown that ammonium hydroxide was the best at 50 degree centigrade. (author)

[Progress of sulfur fumigation and modern processing technology of Chinese traditional medicines].

Science.gov (United States)

Lu, Tu-Lin; Shan, Xin; Li, Lin; Mao, Chun-Qin; Ji, De; Yin, Fang-Zhou; Lang, Yong-Ying

2014-08-01

Infestation, moldy and other phenomenon in the processing and storage of Chinese herbal medicines is a problem that faced in the production of Chinese traditional medicine. The low productivity of traditional processing methods can not guarantee the quality of Chinese herbal medicines. Sulfur fumigation is the first choice of grassroots to process the Chinese herbal medicine with its low cost and easy operation. Sulfur fumigation can solve some problems in the processing and storage of Chinese herbal medicines, but modern pharmacological studies show that long-term use of Chinese traditional medicine which is fumigated by sulfur can cause some serious harm to human liver, kidney and other organs. This paper conducts a review about the application history of sulfur fumigation, its influence to the quality of Chinese herbal medicines as well as domestic and foreign limits to sulfur quantity, and a brief introduction of the status of modern processing technologies in the processing of food and some Chinese herbal medicines, the problems ex- isting in the Chinese herbal medicines processing, which can provide a reference basis for the further research, development and application of investigating alternative technologies of sulfur fumigation.

Advanced sulfur control concepts for hot gas desulfurization technology

International Nuclear Information System (INIS)

1998-01-01

The objective of this project is to develop a hot-gas desulfurization process scheme for control of H 2 S in HTHP coal gas that can be more simply and economically integrated with known regenerable sorbents in DOE/METC-sponsored work than current leading hot-gas desulfurization technologies. In addition to being more economical, the process scheme to be developed must yield an elemental sulfur byproduct. The Direct Sulfur Recovery Process (DSRP), a leading process for producing an elemental sulfur byproduct in hot-gas desulfurization systems, incurs a coal gas use penalty, because coal gas is required to reduce the SO 2 in regeneration off-gas to elemental sulfur. Alternative regeneration schemes, which avoid coal gas use and produce elemental sulfur, will be evaluated. These include (i) regeneration of sulfided sorbent using SO 2 ; (ii) partial oxidation of sulfided sorbent in an O 2 starved environment; and (iii) regeneration of sulfided sorbent using steam to produce H 2 S followed by direct oxidation of H 2 S to elemental sulfur. Known regenerable sorbents will be modified to improve the feasibility of the above alternative regeneration approaches. Performance characteristics of the modified sorbents and processes will be obtained through lab- and bench-scale testing. Technical and economic evaluation of the most promising processes concept(s) will be carried out

MHD (Magnetohydrodynamics) recovery and regeneration

Energy Technology Data Exchange (ETDEWEB)

McIlroy, R. A. [Babcock and Wilcox Co., Alliance, OH (United States). Research Center; Probert, P. B. [Babcock and Wilcox Co., Alliance, OH (United States). Research Center; Lahoda, E. J. [Westinghouse Electric Corp., Pittsburgh, PA (United States); Swift, W. M. [Argonne National Lab. (ANL), Argonne, IL (United States); Jackson, D. M. [Univ. of Tennessee Space Inst. (UTSI), Tullahoma, TN (United States); Prasad, J. [Univ. of Tennessee Space Inst. (UTSI), Tullahoma, TN (United States); Martin, J. [Hudson Engineering (United States); Rogers, C. [Hudson Engineering (United States); Ho, K. K. [Babcock and Wilcox Co., Alliance, OH (United States). Research Center; Senary, M. K. [Babcock and Wilcox Co., Alliance, OH (United States). Research Center; Lee, S. [Univ. of Akron, OH (United States)

1988-10-01

A two-phase program investigating MHD seed regeneration is described. In Phase I, bench scale experiments were carried out to demonstrate the technical feasibility of a proposed Seed Regeneration Process. The Phase I data has been used for the preliminary design of a Proof-of-Concept (POC) plant which will be built and tested in Phase II. The Phase I data will also be used to estimate the costs of a 300 Mw(t) demonstration plant for comparison with other processes. The Seed Regeneration Process consists of two major subprocesses; a Westinghouse Dry Reduction process and a modified Tampella (sulfur) Recovery process. The Westinghouse process reduces the recovered spent seed (i.e., potassium sulfate) to potassium polysulfide in a rotary kiln. The reduction product is dissolved in water to form green liquor, clarified to remove residual coal ash, and sent to the Tampella sulfur release system. The sulfur is released using carbon dioxide from flue gas in a two stage reaction. The sulfur is converted to elemental sulfur as a marketable by product. The potassium is crystallized from the green liquor and dried to the anhydrous form for return to the MHD unit.

Digestion of Bangka monazite with sulfuric acid

International Nuclear Information System (INIS)

Riesna Prassanti

2012-01-01

Technology of Bangka monazite processing with alkaline method has been mastered by PPGN BATAN with the product in the form of RE (Rare Earth) which is contain U < 2 ppm and Th 12 - 16 ppm. Hence, as comparator, the research of Bangka monazite processing with acid method using sulfuric acid has been done. The aim of this research is to obtain the optimal condition of Bangka monazite's digestion using sulfuric acid so that all elements contained in the monazite that are U, Th, RE, PO 4 dissolved as much as possible. The research parameter's arc monazite particle's size, sulfuric acid consumption (weight ratio of monazite ore : sulfuric acid), digestion temperature, digestion time and consumption of wash water. The results showed that the optimal conditions of digestion are 250+ 325 mesh of monazite particle's size, 1 : 2.5 of weight ratio of monazite ore: sulfuric acid, 190°C of digestion temperature, 3 hours of digestion time and 8 times of weight monazite's feed of wash water with the recovery of digested U = 99.90 %, Th = 99.44 %, RE = 98.64 % and PO 4 = 99.88 %. (author)

Effects of the ``Amoco Cadiz'' oil spill on zooplankton

Science.gov (United States)

Samain, J. F.; Moal, J.; Coum, A.; Le Coz, J. R.; Daniel, J. Y.

1980-03-01

A survey of zooplankton physiology on the northern coast of Brittany (France) was carried out over a one-year period by comparing two estuarine areas, one oil-polluted area (Aber Benoit) following the oil spill by the tanker “Amoco Cadiz” and one non-oil-polluted area (Rade de Brest). A new approach to an ecological survey was made by describing trophic relationships using analysis of digestive enzyme equipment (amylase and trypsin) of zooplankton organisms, mesoplankton populations and some selected species. These measurements allowed determination of (a) groups of populations with homogeneous trophic and faunistic characteristics and (b) groups of species with homogeneous trophic characteristics. The study of the appearance of these groups over a one-year period revealed the succession of populations and their adaptation to the environment on the basis of biochemical analysis. These phenomena observed in the compared areas showed marked differences in the most polluted areas during the productive spring period. Specific treatment of the data using unusual correlations between digestive enzymes is discussed in terms of the immediate effect on the whole population and on a copepod ( Anomalocera patersoni) living in the upper 10 cm.

40 CFR Table 31 to Subpart Uuu of... - Continuous Monitoring Systems for HAP Emissions From Sulfur Recovery Units

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Continuous Monitoring Systems for HAP Emissions From Sulfur Recovery Units 31 Table 31 to Subpart UUU of Part 63 Protection of Environment..., Subpt. UUU, Table 31 Table 31 to Subpart UUU of Part 63—Continuous Monitoring Systems for HAP Emissions...

40 CFR Table 34 to Subpart Uuu of... - Continuous Compliance With HAP Emission Limits for Sulfur Recovery Units

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Continuous Compliance With HAP Emission Limits for Sulfur Recovery Units 34 Table 34 to Subpart UUU of Part 63 Protection of Environment..., Subpt. UUU, Table 34 Table 34 to Subpart UUU of Part 63—Continuous Compliance With HAP Emission Limits...

ADVANCED BYPRODUCT RECOVERY: DIRECT CATALYTIC REDUCTION OF SO2 TO ELEMENTAL SULFUR

Energy Technology Data Exchange (ETDEWEB)

Robert S. Weber

1999-05-01

Arthur D. Little, Inc., together with its commercialization partner, Engelhard Corporation, and its university partner Tufts, investigated a single-step process for direct, catalytic reduction of sulfur dioxide from regenerable flue gas desulfurization processes to the more valuable elemental sulfur by-product. This development built on recently demonstrated SO{sub 2}-reduction catalyst performance at Tufts University on a DOE-sponsored program and is, in principle, applicable to processing of regenerator off-gases from all regenerable SO{sub 2}-control processes. In this program, laboratory-scale catalyst optimization work at Tufts was combined with supported catalyst formulation work at Engelhard, bench-scale supported catalyst testing at Arthur D. Little and market assessments, also by Arthur D. Little. Objectives included identification and performance evaluation of a catalyst which is robust and flexible with regard to choice of reducing gas. The catalyst formulation was improved significantly over the course of this work owing to the identification of a number of underlying phenomena that tended to reduce catalyst selectivity. The most promising catalysts discovered in the bench-scale tests at Tufts were transformed into monolith-supported catalysts at Engelhard. These catalyst samples were tested at larger scale at Arthur D. Little, where the laboratory-scale results were confirmed, namely that the catalysts do effectively reduce sulfur dioxide to elemental sulfur when operated under appropriate levels of conversion and in conditions that do not contain too much water or hydrogen. Ways to overcome those limitations were suggested by the laboratory results. Nonetheless, at the end of Phase I, the catalysts did not exhibit the very stringent levels of activity or selectivity that would have permitted ready scale-up to pilot or commercial operation. Therefore, we chose not to pursue Phase II of this work which would have included further bench-scale testing

Safety measures for integrity test apparatus for IS process. Sulfuric acid decomposition section

International Nuclear Information System (INIS)

Noguchi, Hiroki; Kubo, Shinji; Iwatsuki, Jin; Onuki, Kaoru

2013-07-01

Hazardous substances such as sulfuric acid, sulfur dioxide and hydrogen iodide acid are employed in thermochemical Iodine-Sulfur (IS) process. It is necessary to take safety measure against workers and external environments to study experimentally on IS process. Presently we have been conducting to verify the soundness of main components made of engineering material in actual corrosive condition. An integrity test apparatus for the components of sulfuric acid decomposition was set up. We will use the hazardous substances such as sulfuric acid and sulfur dioxide and perform the experiment in pressurized condition in this integrity test. Safety measures for the test apparatus, operation and abnormal situation were considered prior to starting the test. This report summarized the consideration results for the safety measures on the integrity test apparatus for the components of sulfuric acid decomposition. (author)

Design and cost of the sulfuric acid decomposition reactor for the sulfur based hydrogen processes - HTR2008-58009

International Nuclear Information System (INIS)

Hu, T. Y.; Connolly, S. M.; Lahoda, E. J.; Kriel, W.

2008-01-01

The key interface component between the reactor and chemical systems for the sulfuric acid based processes to make hydrogen is the sulfuric acid decomposition reactor. The materials issues for the decomposition reactor are severe since sulfuric acid must be heated, vaporized and decomposed. SiC has been identified and proven by others to be an acceptable material. However, SiC has a significant design issue when it must be interfaced with metals for connection to the remainder of the process. Westinghouse has developed a design utilizing SiC for the high temperature portions of the reactor that are in contact with the sulfuric acid and polymeric coated steel for low temperature portions. This design is expected to have a reasonable cost for an operating lifetime of 20 years. It can be readily maintained in the field, and is transportable by truck (maximum OD is 4.5 meters). This paper summarizes the detailed engineering design of the Westinghouse Decomposition Reactor and the decomposition reactor's capital cost. (authors)

40 CFR Table 33 to Subpart Uuu of... - Initial Compliance With HAP Emission Limits for Sulfur Recovery Units

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Initial Compliance With HAP Emission Limits for Sulfur Recovery Units 33 Table 33 to Subpart UUU of Part 63 Protection of Environment..., Subpt. UUU, Table 33 Table 33 to Subpart UUU of Part 63—Initial Compliance With HAP Emission Limits for...

Evidence of recovery of Juniperus virginiana trees from sulfur pollution after the Clean Air Act.

Science.gov (United States)

Thomas, Richard B; Spal, Scott E; Smith, Kenneth R; Nippert, Jesse B

2013-09-17

Using dendroisotopic techniques, we show the recovery of Juniperus virginiana L. (eastern red cedar) trees in the Central Appalachian Mountains from decades of acidic pollution. Acid deposition over much of the 20th century reduced stomatal conductance of leaves, thereby increasing intrinsic water-use efficiency of the Juniperus trees. These data indicate that the stomata of Juniperus may be more sensitive to acid deposition than to increasing atmospheric CO2. A breakpoint in the 100-y δ(13)C tree ring chronology occurred around 1980, as the legacy of sulfur dioxide emissions declined following the enactment of the Clean Air Act in 1970, indicating a gradual increase in stomatal conductance (despite rising levels of atmospheric CO2) and a concurrent increase in photosynthesis related to decreasing acid deposition and increasing atmospheric CO2. Tree ring δ(34)S shows a synchronous change in the sources of sulfur used at the whole-tree level that indicates a reduced anthropogenic influence. The increase in growth and the δ(13)C and δ(34)S trends in the tree ring chronology of these Juniperus trees provide evidence for a distinct physiological response to changes in atmospheric SO2 emissions since ∼1980 and signify the positive impacts of landmark environmental legislation to facilitate recovery of forest ecosystems from acid deposition.

Modeling of a Large-Scale High Temperature Regenerative Sulfur Removal Process

DEFF Research Database (Denmark)

Konttinen, Jukka T.; Johnsson, Jan Erik

1999-01-01

model that does not account for bed hydrodynamics. The pilot-scale test run results, obtained in the test runs of the sulfur removal process with real coal gasifier gas, have been used for parameter estimation. The validity of the reactor model for commercial-scale design applications is discussed.......Regenerable mixed metal oxide sorbents are prime candidates for the removal of hydrogen sulfide from hot gasifier gas in the simplified integrated gasification combined cycle (IGCC) process. As part of the regenerative sulfur removal process development, reactor models are needed for scale......-up. Steady-state kinetic reactor models are needed for reactor sizing, and dynamic models can be used for process control design and operator training. The regenerative sulfur removal process to be studied in this paper consists of two side-by-side fluidized bed reactors operating at temperatures of 400...

Recovery of vanadium (V) from spent catalysts used in sulfuric acid production units by acid or alkaline leaching

International Nuclear Information System (INIS)

Abdulbaki, M.; Stas, J.; Shino, O.; Asaad, K.; Al-Kassemi, H.; Al-Qabani, F.

2008-01-01

The present paper, studies the recovery of vanadium from the spent catalyst by using acidic or alkaline leaching technique. The optimal conditions of spent catalyst leaching have been studied. It has been shown that 20%(w/w) of sulfuric acid is the most suitable for leaching process at 70 Centigrade. The precipitation of vanadium using some alkaline media (Na 2 CO 3 , (NH 4 )CO 3 and NH 4 OH) has been also studied, it has been shown that ammonium hydroxide was the best at 60 degree, and iron was co-precipitated with vanadium which pollute the obtained red cake. So it is necessary to use liquid-liquid extraction technique for the separation between vanadium and iron and to have iron free red cake. (author)

Process for removal of sulfur compounds from fuel gases

Science.gov (United States)

Moore, Raymond H.; Stegen, Gary E.

1978-01-01

Fuel gases such as those produced in the gasification of coal are stripped of sulfur compounds and particulate matter by contact with molten metal salt. The fuel gas and salt are intimately mixed by passage through a venturi or other constriction in which the fuel gas entrains the molten salt as dispersed droplets to a gas-liquid separator. The separated molten salt is divided into a major and a minor flow portion with the minor flow portion passing on to a regenerator in which it is contacted with steam and carbon dioxide as strip gas to remove sulfur compounds. The strip gas is further processed to recover sulfur. The depleted, minor flow portion of salt is passed again into contact with the fuel gas for further sulfur removal from the gas. The sulfur depleted, fuel gas then flows through a solid absorbent for removal of salt droplets. The minor flow portion of the molten salt is then recombined with the major flow portion for feed to the venturi.

Reduction of produced elementary sulfur in denitrifying sulfide removal process.

Science.gov (United States)

Zhou, Xu; Liu, Lihong; Chen, Chuan; Ren, Nanqi; Wang, Aijie; Lee, Duu-Jong

2011-05-01

Denitrifying sulfide removal (DSR) processes simultaneously convert sulfide, nitrate, and chemical oxygen demand from industrial wastewater into elemental sulfur, dinitrogen gas, and carbon dioxide, respectively. The failure of a DSR process is signaled by high concentrations of sulfide in reactor effluent. Conventionally, DSR reactor failure is blamed for overcompetition for heterotroph to autotroph communities. This study indicates that the elementary sulfur produced by oxidizing sulfide that is a recoverable resource from sulfide-laden wastewaters can be reduced back to sulfide by sulfur-reducing Methanobacterium sp. The Methanobacterium sp. was stimulated with excess organic carbon (acetate) when nitrite was completely consumed by heterotrophic denitrifiers. Adjusting hydraulic retention time of a DSR reactor when nitrite is completely consumed provides an additional control variable for maximizing DSR performance.

Trace recovery of uranium and rare earth contained in phosphates by liquid-liquid extraction in sulfuric attack liquor

International Nuclear Information System (INIS)

Bousquet, F.; Foraison, D.; Leveque, A.; Sabot, J.L.

1980-06-01

Uranium and rare earths can be recovered in sedimentary phosphates during the wet processing of the ore by sulfuric acid giving raw phosphoric acid at 30 per cent of P 2 O 5 . Practically all the uranium contained and only part of rare earths are put into solution in this treatment. Separation of these elements in the phosphoric solution is obtained by liquid-liquid extraction with alkylphosphoric acids and especially with their mono and di esters. Partition isotherms are determined and counter-current tests are effected. Uranium and rare earths reextraction from these solvents can be simultaneous or separate with aqueous solutions alkaline or containing HF or by antisynergism. Pros and cons of each reextraction process are discussed. In conclusion HDEHP or OPPA are recommended because of availability, stability and hydrodynamic, OPPA less selective with rare earths allows the recovery with uranium of ceric earths, yttrium and yttric earths [fr

KINETICS OF DIRECT OXIDATION OF H2S IN COAL GAS TO ELEMENTAL SULFUR; F

International Nuclear Information System (INIS)

K.C. Kwon

2002-01-01

Removal of hydrogen sulfide (H(sub 2)S) from coal gasifier gas and sulfur recovery are key steps in the development of Department of Energy's (DOE's) advanced Vision 21 plants that employ coal and natural gas and produce electric power and clean transportation fuels. These Vision 21 plants will require highly clean coal gas with H(sub 2)S below 1 ppm and negligible amounts of trace contaminants such as hydrogen chloride, ammonia, alkali, heavy metals, and particulate. The conventional method of sulfur removal and recovery employing amine, Claus, and tail-gas treatment is very expensive. A second generation approach developed under DOE's sponsorship employs hot-gas desulfurization (HGD) using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process (DSRP). However, this process sequence does not remove trace contaminants and is targeted primarily towards the development of advanced integrated gasification combined cycle (IGCC) plants that produce electricity (not both electricity and transportation fuels). There is an immediate as well as long-term need for the development of cleanup processes that produce highly clean coal gas for next generation Vision 21 plants. To this end, a novel process is now under development at Research Triangle Institute (RTI) in which the H(sub 2)S in coal gas is directly oxidized to elemental sulfur over a selective catalyst. Such a process is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H(sub 2)S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and HGD/DSRP. The objective of this research is to support the near- and long-term DOE efforts to commercialize this direct oxidation technology. Specifically, we aim to: Measure the kinetics of direct oxidation of H(sub 2)S to elemental sulfur over selective catalysts in the presence of major

Improved Recovery Boiler Performance Through Control of Combustion, Sulfur, and Alkali Chemistry

Energy Technology Data Exchange (ETDEWEB)

Baxter, Larry L.

2008-06-09

This project involved the following objectives: 1. Determine black liquor drying and devolatilization elemental and total mass release rates and yields. 2. Develop a public domain physical/chemical kinetic model of black liquor drop combustion, including new information on drying and devolatilization. 3. Determine mechanisms and rates of sulfur scavenging in recover boilers. 4. Develop non-ideal, public-domain thermochemistry models for alkali salts appropriate for recovery boilers 5. Develop data and a one-dimensional model of a char bed in a recovery boiler. 6. Implement all of the above in comprehensive combustion code and validate effects on boiler performance. 7. Perform gasification modeling in support of INEL and commercial customers. The major accomplishments of this project corresponding to these objectives are as follows: 1. Original data for black liquor and biomass data demonstrate dependencies of particle reactions on particle size, liquor type, gas temperature, and gas composition. A comprehensive particle submodel and corresponding data developed during this project predicts particle drying (including both free and chemisorbed moisture), devolatilization, heterogeneous char oxidation, char-smelt reactions, and smelt oxidation. Data and model predictions agree, without adjustment of parameters, within their respective errors. The work performed under these tasks substantially exceeded the original objectives. 2. A separate model for sulfur scavenging and fume formation in a recovery boiler demonstrated strong dependence on both in-boiler mixing and chemistry. In particular, accurate fume particle size predictions, as determined from both laboratory and field measurements, depend on gas mixing effects in the boilers that lead to substantial particle agglomeration. Sulfur scavenging was quantitatively predicted while particle size required one empirical mixing factor to match data. 3. Condensed-phase thermochemistry algorithms were developed for salt

The Amoco CadizOil Spill: Evolution of Petroleum Hydrocarbons in the Ile Grande Salt Marshes (Brittany) after a 13-year Period

Science.gov (United States)

Mille, G.; Munoz, D.; Jacquot, F.; Rivet, L.; Bertrand, J.-C.

1998-11-01

The Ile Grande salt marshes (Brittany coast) were polluted by petroleum hydrocarbons after theAmoco Cadizgrounding in 1978. Thirteen years after the oil spill, sediments were analysed for residual hydrocarbons in order to monitor the aliphatic and aromatic hydrocarbon signatures and to assess both qualitatively and quantitatively the changes in composition of theAmoco Cadizoil. Six stations were selected in the Ile Grande salt marshes and sediments were sampled to a depth of 20 cm. For each sample, the hydrocarbon compositions were determined for alkanes, alkenes, aromatics and biomarkers (terpanes, steranes, diasteranes). Hydrocarbon levels drastically decreased between 1978 and 1991, but to different extents according to the initial degree of contamination. In 1991, hydrocarbon concentrations never exceeded 1·7 g kg-1sediment dry weight, and in most cases were less than 0·1 g kg-1sediment dry weight. Even though petroleum hydrocarbons are still present, natural hydrocarbons were also detected at several stations. Changes in some biomarker distributions were observed 13 years after the oil spill. Nevertheless, most of the biomarkers are very stable in the salt marsh environment and remain unaltered even after a 13-year period.

Test fabrication of sulfuric acid decomposer applied for thermochemical hydrogen production IS process

International Nuclear Information System (INIS)

Noguchi, Hiroki; Terada, Atsuhiko; Kubo, Shinji; Onuki, Kaoru; Hino, Ryutaro; Ota, Hiroyuki

2007-07-01

Thermo-chemical Iodine-Sulfur (IS) process produces large amount of hydrogen effectively without carbon dioxide emission. Since the IS process uses strong acids such as sulfuric acid and hydriodic acid, it is necessary to develop large-scale chemical reactors featuring materials that exhibit excellent heat and corrosion resistance. A sulfuric acid decomposer is one of the key components of the IS process plant, in which sulfuric acid is evaporated and decomposed into water and sulfur trioxide under temperature range from 300degC to 500degC using the heat supplied by high temperature helium gas. The decomposer is exposed to severe corrosion condition of sulfuric acid boiling flow, where only the SiC ceramics shows good corrosion resistance. However, at the current status, it is very difficult to manufacture the large-scale SiC ceramics structure required in the commercial plant. Therefore, we devised a new concept of the decomposer, which featured a counter flow type heat exchanger consisting of cylindrical blocks made of SiC ceramics. Scale up can be realized by connecting the blocks in parallel and/or in series. This paper describes results of the design work and the test-fabrication study of the sulfuric acid decomposer, which was carried out in order to confirm its feasibility. (author)

ADVANCED BYPRODUCT RECOVERY: DIRECT CATALYTIC REDUCTION OF SO2 TO ELEMENTAL SULFUR; FINAL

International Nuclear Information System (INIS)

Robert S. Weber

1999-01-01

Arthur D. Little, Inc., together with its commercialization partner, Engelhard Corporation, and its university partner Tufts, investigated a single-step process for direct, catalytic reduction of sulfur dioxide from regenerable flue gas desulfurization processes to the more valuable elemental sulfur by-product. This development built on recently demonstrated SO(sub 2)-reduction catalyst performance at Tufts University on a DOE-sponsored program and is, in principle, applicable to processing of regenerator off-gases from all regenerable SO(sub 2)-control processes. In this program, laboratory-scale catalyst optimization work at Tufts was combined with supported catalyst formulation work at Engelhard, bench-scale supported catalyst testing at Arthur D. Little and market assessments, also by Arthur D. Little. Objectives included identification and performance evaluation of a catalyst which is robust and flexible with regard to choice of reducing gas. The catalyst formulation was improved significantly over the course of this work owing to the identification of a number of underlying phenomena that tended to reduce catalyst selectivity. The most promising catalysts discovered in the bench-scale tests at Tufts were transformed into monolith-supported catalysts at Engelhard. These catalyst samples were tested at larger scale at Arthur D. Little, where the laboratory-scale results were confirmed, namely that the catalysts do effectively reduce sulfur dioxide to elemental sulfur when operated under appropriate levels of conversion and in conditions that do not contain too much water or hydrogen. Ways to overcome those limitations were suggested by the laboratory results. Nonetheless, at the end of Phase I, the catalysts did not exhibit the very stringent levels of activity or selectivity that would have permitted ready scale-up to pilot or commercial operation. Therefore, we chose not to pursue Phase II of this work which would have included further bench-scale testing

Process for removal of sulfur oxides from hot gases

International Nuclear Information System (INIS)

Bauerle, G. L.; Kohl, A. L.

1984-01-01

A process for the removal of sulfur oxides from two gas streams containing the same. One gas stream is introduced into a spray dryer zone and contacted with a finely dispersed spray of an aqueous medium containing an absorbent for sulfur oxides. The aqueous medium is introduced at a controlled rate so as to provide water to the gas in an amount to produce a cooled product gas having a temperature at least 7 0 C. above its adiabatic saturation temperature and from about 125-300% of the stoichiometric amount of absorbent required to react with the sulfur oxides to be removed from the gas stream. The effluent from the spray dryer zone comprises a gas stream of reduced sulfur oxide content and contains entrained dry particulate reaction products including unreacted absorbent. This gas stream is then introduced into a particulate removal zone from which is withdrawn a gas stream substantially free of particles and having a reduced sulfur oxide content. the dry particulate reaction products are collected and utilized as a source of absorbent for a second aqueous scrubbing medium containing unreacted absorbent for the sulfur oxides. An effluent gas stream is withdrawn from the aqueous scrubbing zone and comprises a water-saturated gas stream of reduced sulfur oxide content and substantially free of particles. The effluent gas streams from the particulate removal zone and the aqueous scrubbing zone are combined in such proportions that the combined gas stream has a temperature above its adiabatic saturation temperature

Changes in the levels of major sulfur metabolites and free amino acids in pea cotyledons recovering from sulfur deficiency

International Nuclear Information System (INIS)

Macnicol, P.K.; Randall, P.J.

1987-01-01

Changes in levels of sulfur metabolites and free amino acids were followed in cotyledons of sulfur-deficient, developing pea seeds (Pisum sativum L.) for 24 hours after resupply of sulfate, during which time the legumin mRNA levels returned almost to normal. Two recovery situations were studied: cultured seeds, with sulfate added to the medium, and seeds attached to the intact plant, with sulfate added to the roots. In both situations the levels of cysteine, glutathione, and methionine rose rapidly, glutathione exhibiting an initial lag. In attached but not cultured seeds methionine markedly overshot the level normally found in sulfur-sufficient seeds. In the cultured seed S-adenosylmethionine (AdoMet), but not S-methylmethionine, showed a sustained rise; in the attached seed the changes were slight. The composition of the free amino acid pool did not change substantially in either recovery situation. In the cultured seed the large rise in AdoMet level occurred equally in nonrecovering seeds. It was accompanied by 6-fold and 10-fold increases in γ-aminobutyrate and alanine, respectively. These effects are attributed to wounding resulting from excision of the seed. 35 S-labeling experiments showed that there was no significant accumulation of label in unidentified sulfur-containing amino compounds in either recovery situation. It was concluded from these results and those of other workers that, at the present level of knowledge, the most probable candidate for a signal compound, eliciting recovery of legumin mRNA level in response to sulfur-feeding, is cysteine

Biochemically enhanced oil recovery and oil treatment

Science.gov (United States)

Premuzic, Eugene T.; Lin, Mow

1994-01-01

This invention relates to the preparation of new, modified organisms, through challenge growth processes, that are viable in the extreme temperature, pressure and pH conditions and salt concentrations of an oil reservoir and that are suitable for use in microbial enhanced oil recovery. The modified microorganisms of the present invention are used to enhance oil recovery and remove sulfur compounds and metals from the crude oil.

Ultrasound-assisted oxidative process for sulfur removal from petroleum product feedstock.

Science.gov (United States)

Mello, Paola de A; Duarte, Fábio A; Nunes, Matheus A G; Alencar, Mauricio S; Moreira, Elizabeth M; Korn, Mauro; Dressler, Valderi L; Flores, Erico M M

2009-08-01

A procedure using ultrasonic irradiation is proposed for sulfur removal of a petroleum product feedstock. The procedure involves the combination of a peroxyacid and ultrasound-assisted treatment in order to comply with the required sulfur content recommended by the current regulations for fuels. The ultrasound-assisted oxidative desulfurization (UAOD) process was applied to a petroleum product feedstock using dibenzothiophene as a model sulfur compound. The influence of ultrasonic irradiation time, oxidizing reagents amount, kind of solvent for the extraction step and kind of organic acid were investigated. The use of ultrasonic irradiation allowed higher efficiency for sulfur removal in comparison to experiments performed without its application, under the same reactional conditions. Using the optimized conditions for UAOD, the sulfur removal was about 95% after 9min of ultrasonic irradiation (20kHz, 750W, run at 40%), using hydrogen peroxide and acetic acid, followed by extraction with methanol.

Advances in computational modeling of catalytic systems used in Claus sulfur recovery

Energy Technology Data Exchange (ETDEWEB)

Clark, P.D.; Lo, J. [Alberta Sulphur Research Ltd., Calgary, AB (Canada). Center for Applied Catalysis and Industrial Sulfur Chemistry

2010-01-15

This poster session discussed advances in computation modeling of catalytic systems used in Claus sulfur recovery, focusing on the hydrogen sulphide (H{sub 2}S) and sulphur dioxide (S{sub O}2) absorption of non-alumina Claus active metal oxides, such as titanium oxide and vanadium oxide. These metal oxides were chosen because they promote carbon disulphide (CS{sub 2}) conversion and have a potential use in olefin chemistry. The redox process of H{sub 2}S dissociation on vanadium pentoxide (V{sub 2}O{sub 2}) can take place in single-site reaction or multiple site reactions. Both mechanisms lead to the production of V{sub 2}O{sub 4}S, water (H{sub 2}O) and other species. The overall process of forming VO{sub 4}S is neutral, but kinetics is a controlling factor. The surface sulfidation to form V{sub 2}O{sub 3}S{sub 2} requires a small energy cost but possesses a huge reaction barrier. The formation of H{sub 2}S{sub 2} is energetically favorable. The silica (SiO{sub 2})-supported V{sub 2}O{sub 2} catalyst was described. A proposed mechanism of H{sub 2}S conversion to H{sub 2}O and V=S group was presented along with another reaction route in which the dissociative absorption of H{sub 2}S takes place on O-bridges instead of V=O. Two vanadia catalysts were compared: V{sub 2}O{sub 5} and V{sub 2}O{sub 5}/SiO{sub 2}. 7 figs.

The Effect of Fuel Mass Fraction on the Combustion and Fluid Flow in a Sulfur Recovery Unit Thermal Reactor

Directory of Open Access Journals (Sweden)

Chun-Lang Yeh

2016-11-01

Full Text Available Sulfur recovery unit (SRU thermal reactors are negatively affected by high temperature operation. In this paper, the effect of the fuel mass fraction on the combustion and fluid flow in a SRU thermal reactor is investigated numerically. Practical operating conditions for a petrochemical corporation in Taiwan are used as the design conditions for the discussion. The simulation results show that the present design condition is a fuel-rich (or air-lean condition and gives acceptable sulfur recovery, hydrogen sulfide (H2S destruction, sulfur dioxide (SO2 emissions and thermal reactor temperature for an oxygen-normal operation. However, for an oxygen-rich operation, the local maximum temperature exceeds the suggested maximum service temperature, although the average temperature is acceptable. The high temperature region must be inspected very carefully during the annual maintenance period if there are oxygen-rich operations. If the fuel mass fraction to the zone ahead of the choke ring (zone 1 is 0.0625 or 0.125, the average temperature in the zone behind the choke ring (zone 2 is higher than the zone 1 average temperature, which can damage the downstream heat exchanger tubes. If the zone 1 fuel mass fraction is reduced to ensure a lower zone 1 temperature, the temperature in zone 2 and the heat exchanger section must be monitored closely and the zone 2 wall and heat exchanger tubes must be inspected very carefully during the annual maintenance period. To determine a suitable fuel mass fraction for operation, a detailed numerical simulation should be performed first to find the stoichiometric fuel mass fraction which produces the most complete combustion and the highest temperature. This stoichiometric fuel mass fraction should be avoided because the high temperature could damage the zone 1 corner or the choke ring. A higher fuel mass fraction (i.e., fuel-rich or air-lean condition is more suitable because it can avoid deteriorations of both zone 1

Equipment and obtention process of phosphorus-32 starting from sulfur-32

International Nuclear Information System (INIS)

Alanis M, J.

2004-12-01

In the National Institute of Nuclear Research, it is the Radioisotopes Production plant, which covers in the area of the medicine 70% approximately of the national market and it exports to some countries of Latin America (Technetium-99, iodine-131, Sm-153 among other). At the moment the plant has modern facilities and certified with the ISO-9001-2000 standard, this, gives trust to the clients as for the quality of its products. Besides the production of radioisotopes dedicated for the medical area, the work of the plant tends to be more enlarged every time, producing new radioisotopes not only but with medical purposes but also industrial and agricultural ones, such it is the case of the production of Phosphorus-32 ( 32 P) that has applications with medical, industrial and in the agriculture purposes. The investigation studies from the prime matter (sulfur-32), sulfur purification, sulfur irradiation in the nuclear reactor and the obtaining process of 32 P in a prototype, its took us to design and to build the obtaining process from 32 P to more high level, which is presented in this work. To be able to select the obtaining method of 32 P that is presented it was necessary to study the methods that have been developed in the world, later on it was selected the way that is presented. In that way the physical and chemical properties of the sulfur were studied which is used as prime matter, the interest nuclear reaction was also studied to carry out the production of 32 P by means of the realization of mathematical calculations of irradiation of the sulfur in TRIGA Mark lll nuclear reactor. Once the sulfur is irradiated, it is necessary to carry out the radiochemical separation of the 32 P produced from the sulfur, for this, it was necessary to carry out experimental tests of this separation, later on it was developed a prototype where it was carried out this separation and finally it was developed the final equipment of production of 32 P mainly composed of three

Claus sulphur recovery potential approaches 99% while minimizing cost

Energy Technology Data Exchange (ETDEWEB)

Berlie, E M

1974-01-21

In a summary of a paper presented to the fourth joint engineering conference of the American Institute of Chemical Engineers and the Canadian Society for Chemical Engineering, the Claus process is discussed in a modern setting. Some problems faced in the operation of sulfur recovery plants include (1) strict pollution control regulations; (2) design and operation of existing plants; (3) knowledge of process fundamentals; (4) performance testing; (5) specification of feed gas; (6) catalyst life; (7) instrumentation and process control; and (8) quality of feed gas. Some of the factors which must be considered in order to achieve the ultimate capability of the Claus process are listed. There is strong evidence to support the contention that plant operators are reluctant to accept new fundamental knowledge of the Claus sulfur recovery process and are not taking advantage of its inherent potential to achieve the emission standards required, to minimize cost of tail gas cleanup systems and to minimize operating costs.

Using stable isotopes to monitor forms of sulfur during desulfurization processes: A quick screening method

Science.gov (United States)

Liu, Chao-Li; Hackley, Keith C.; Coleman, D.D.; Kruse, C.W.

1987-01-01

A method using stable isotope ratio analysis to monitor the reactivity of sulfur forms in coal during thermal and chemical desulfurization processes has been developed at the Illinois State Geological Survey. The method is based upon the fact that a significant difference exists in some coals between the 34S/32S ratios of the pyritic and organic sulfur. A screening method for determining the suitability of coal samples for use in isotope ratio analysis is described. Making these special coals available from coal sample programs would assist research groups in sorting out the complex sulfur chemistry which accompanies thermal and chemical processing of high sulfur coals. ?? 1987.

Effect of sulfur content in a sulfur-activated carbon composite on the electrochemical properties of a lithium/sulfur battery

Energy Technology Data Exchange (ETDEWEB)

Park, Jin-Woo; Kim, Changhyeon; Ryu, Ho-Suk; Cho, Gyu-Bong; Cho, Kwon-Koo; Kim, Ki-Won [School of Materials Science and Engineering, Gyeongsang National University, Jinju (Korea, Republic of); Ahn, Jou-Hyeon [Department of Chemical & Biological Engineering, Gyeongsang National University, Jinju (Korea, Republic of); Wang, Guoxiu [School of Chemistry and Forensic Science, University of Technology Sydney, Sydney, NSW 2007 (Australia); Ahn, Jae-Pyeung [Advanced Analysis Center, Research Planning & Coordination Division, KIST, Seoul (Korea, Republic of); Ahn, Hyo-Jun, E-mail: ahj@gnu.ac.kr [School of Materials Science and Engineering, Gyeongsang National University, Jinju (Korea, Republic of)

2015-09-15

Highlights: • The content of sulfur in activated carbon was controlled by solution process. • The sulfur electrode with low sulfur content shows the best performance. • The Li/S battery has capacity of 1360 mAh/g at 1 C and 702 mAh/g at 10 C. - Abstract: The content of sulfur in sulfur/activated carbon composite is controlled from 32.37 wt.% to 55.33 wt.% by a one-step solution-based process. When the sulfur content is limited to 41.21 wt.%, it can be loaded into the pores of an activated carbon matrix in a highly dispersed state. On the contrary, when the sulfur content is 55.33 wt.%, crystalline sulfur can be detected on the surface of the activated carbon matrix. The best electrochemical performance can be obtained for a sulfur electrode with the lowest sulfur content. The sulfur/activated carbon composite with 32.37 wt.% sulfur afforded the highest first discharge capacity of 1360 mAh g{sup −1} at 1 C rate and a large reversible capacity of 702 mAh g{sup −1} at 10 C (16.75 A/g)

Characterization and uranium bioleaching performance of mixed iron- and sulfur-oxidizers versus iron-oxidizers

International Nuclear Information System (INIS)

Qian Li; Jing Sun; Dexin Ding; Qingliang Wang; Wenge Shi; Eming Hu; Xiaoyu Jiang; University of South China, Hengyang; Xingxing Wang

2017-01-01

In order to develop and apply mixed iron- and sulfur-oxidizers in uranium bioleaching, the characteristics of a mixed iron- and sulfur-oxidizing consortium (Consortium ISO) were comparatively investigated versus an iron-oxidizing consortium (Consortium IO). The results showed, the Consortium ISO exerted stronger oxidative ability and acid-producing ability than Consortium IO did. The synergy of sulfur-oxidizers and iron-oxidizers could change the structure and properties of the passivation substance, and work positively for eliminating the accumulation of passivation substance. In the bioleaching process, the uranium bioleaching experiments showed the recovery percentage of uranium reached 99.5% with Consortium ISO, 6.3% more than that of Consortium IO. (author)

Accidents with sulfuric acid

Directory of Open Access Journals (Sweden)

Rajković Miloš B.

2006-01-01

Full Text Available Sulfuric acid is an important industrial and strategic raw material, the production of which is developing on all continents, in many factories in the world and with an annual production of over 160 million tons. On the other hand, the production, transport and usage are very dangerous and demand measures of precaution because the consequences could be catastrophic, and not only at the local level where the accident would happen. Accidents that have been publicly recorded during the last eighteen years (from 1988 till the beginning of 2006 are analyzed in this paper. It is very alarming data that, according to all the recorded accidents, over 1.6 million tons of sulfuric acid were exuded. Although water transport is the safest (only 16.38% of the total amount of accidents in that way 98.88% of the total amount of sulfuric acid was exuded into the environment. Human factor was the common factor in all the accidents, whether there was enough control of the production process, of reservoirs or transportation tanks or the transport was done by inadequate (old tanks, or the accidents arose from human factor (inadequate speed, lock of caution etc. The fact is that huge energy, sacrifice and courage were involved in the recovery from accidents where rescue teams and fire brigades showed great courage to prevent real environmental catastrophes and very often they lost their lives during the events. So, the phrase that sulfuric acid is a real "environmental bomb" has become clearer.

Indium recovery by solvent extraction

International Nuclear Information System (INIS)

Fortes, Marilia Camargos Botelho

1999-04-01

Indium has been recovered as a byproduct from residues generated from the sulfuric acid leaching circuits in mineral plants for zinc recovery. Once its recovery comes from the slags of other metals recovery, it is necessary to separate it from the other elements which usually are present in high concentrations. Many works have been approaching this separation and indicate the solvent extraction process as the main technique used. In Brazilian case, indium recovery depends on the knowledge of this technique and its development. This paper describes the solvent extraction knowledge for the indium recovery from aqueous solutions generated in mineral plants. The results for determination of the best experimental conditions to obtain a high indium concentration solution and minimum iron poisoning by solvent extraction with di (2-ethylhexyl)-phosphoric acid (D2EHPA) solubilized in isoparafin and exxsol has been presented. (author)

Desulfurization of organic sulfur from lignite by an electron transfer process

Energy Technology Data Exchange (ETDEWEB)

Demirbas, A. [Selcuk University, Konya (Turkey). Dept. for Chemical Engineering

2006-10-15

This study is an attempt to desulfurize organic sulfur from lignite samples with ferrocyanide ion as the electron transferring agent. Effect of temperature, particle size and concentration of ferrocyanide ion on desulfurization from the lignite samples has been investigated. The desulfurization process has been found to be continuous and gradually increases with increase of temperature from 298 to 368 K. The particle size has no significant impact on sulfur removal from the lignite samples. Particle size has no profound impact on the amount of sulfur removal. The desulfurization reaction has been found to be dependent on the concentration of potassium ferrocyanide. Gradual increase in the concentration of potassium ferrocyanide raised the magnitude of desulfurization, but at a higher concentration, the variation is not significant.

Aqueous process for recovering sulfur from hydrogen sulfide-bearing gas

Science.gov (United States)

Basu, Arunabha

2015-05-05

A process for recovering sulfur from a hydrogen sulfide-bearing gas utilizes an aqueous reaction medium, a temperature of about 110-150.degree. C., and a high enough pressure to maintain the aqueous reaction medium in a liquid state. The process reduces material and equipment costs and addresses the environmental disadvantages associated with known processes that rely on high boiling point organic solvents.

Process and device for liquid organic waste processing by sulfuric mineralization

International Nuclear Information System (INIS)

Aspart, A.; Gillet, B.; Lours, S.; Guillaume, B.

1990-01-01

In a chemical reactor containing sulfuric acid are introduced the liquid waste and nitric acid at a controlled flow rate for carbonization of the waste and oxidation of carbon on sulfur dioxide, formed during carbonization, regenerating simultaneously sulfuric acid. Optical density of the liquid is monitored to stop liquid waste feeding above a set-point. The liquid waste can be an organic solvent such as TBP [fr

Uranium and thorium recovery from a sub-product of monazite industrial processing

International Nuclear Information System (INIS)

Gomiero, L.A.; Ribeiro, J.S.; Scassiotti Filho, W.

1994-01-01

In the monazite alkaline leaching industrial process for the production of rare earth elements, a by-product is formed, which has a high concentration of thorium and a lower but significant one of uranium. A procedure for recovery of the thorium and uranium contents in this by-product is presented. The first step of this procedure is the leaching with sulfuric acid, followed by uranium extraction from the acid liquor with a tertiary amine, stripping with a Na Cl solutions and precipitation as ammonium diuranate with N H 4 O H. In order to obtain thorium concentrates with higher purity, it is performed by means of the extraction of thorium from the acid liquor, with a primary amine, stripping by a Na Cl solution and precipitation as thorium hydroxide or oxalate. (author)

Process for obtaining a distillation product free from sulfur

Energy Technology Data Exchange (ETDEWEB)

Heyl, G E

1920-06-12

A process is described of obtaining from shale a hydrocarbon product free from sulfur, by distillation, consisting in mixing with the shale a portion of mineral oil and metallic debris, such as turnings and drillings, heating the mixture in a rotary drum and recovering and condensing the vapors distilled.

Process for the removal of sulfur oxides and nitrogen oxides from flue gas

International Nuclear Information System (INIS)

Elshout, R.V.

1992-01-01

This patent describes a continuous process for removing sulfur oxide and nitrogen oxide contaminants from the flue gas generated by industrial power plants and boiler systems burning sulfur containing fossil fuels and for converting these contaminants, respectively, into recovered elemental liquid sulfur and nitrogen ammonia and mixtures thereof. It comprises removing at least a portion of the flue gas generated by a power plant or boiler system upstream of the stack thereof; passing the cooled and scrubbed flue gas through an adsorption system; combining a first portion of the reducing gas stream leaving the adsorbers of the adsorption system during regeneration thereof and containing sulfur oxide and nitrogen oxide contaminants with a hydrogen sulfide rich gas stream at a temperature of about 400 degrees F to about 600 degrees F and passing the combined gas streams through a Claus reactor-condenser system over a catalyst in the reactor section thereof which is suitable for promoting the equilibrium reaction between the hydrogen sulfide and the sulfur dioxide of the combined streams to form elemental sulfur

Catalytic processing of high-sulfur fuels for distributed hydrogen production

Energy Technology Data Exchange (ETDEWEB)

Muradov, Nazim; Ramasamy, Karthik; Huang, Cunping; T-Raissi, Ali [Central Florida Univ., FL (United States)

2010-07-01

In this work, the development of a new on-demand hydrogen production technology is reported. In this process, a liquid hydrocarbon fuel (e.g., high-S diesel) is first catalytically pre-reformed to shorter chain gaseous hydrocarbons (predominantly, C{sub 1}-C{sub 3}) before being directed to the steam reformer, where it is converted to syngas and then to high-purity hydrogen. In the pre-reformer, most sulfurous species present in the fuel are catalytically converted to H{sub 2}S. In the desulfurization unit, H{sub 2}S is scrubbed and converted to H{sub 2} and elemental sulfur. Desulfurization of the pre-reformate gas is carried out in a special regenerative redox system, which includes Fe(II)/Fe(III)-containing aqueous phase scrubber coupled with an electrolyzer. The integrated pre-reformer/scrubber/electrolyzer unit operated successfully on high-S diesel fuel for more than 100 hours meeting the required desulfurization target of >95 % sulfur removal. (orig.)

Extractive de-sulfurization and de-ashing of high sulfur coals by oxidation with ionic liquids

International Nuclear Information System (INIS)

Saikia, Binoy K.; Khound, Kakoli; Baruah, Bimala P.

2014-01-01

Highlights: • Extractive de-sulfurization and de-ashing process for cleaning high sulfur coals. • The process removes inorganic as well as organic sulfur components from high sulfur coals. • The process has less risk to chemists and other surroundings. - Abstract: The environmental consequences of energy production from coals are well known, and are driving the development of desulfurization technologies. In this investigation, ionic liquids were examined for extractive desulfurization and de-ashing in industrially important high sulfur sub-bituminous Indian coals. The ionic liquids, namely, 1-n-butyl-3-methylimidazolium tetrafluoroborate (IL1) and 1-n-butyl 3-methylimidazolium chloride (IL2) were employed for desulfurization of a few Indian coal samples in presence of HCOOH/H 2 O 2 and V 2 O 5 . Results show the maximum removal of 50.20% of the total sulfur, 48.00% of the organic sulfur, and 70.37 wt% of the ash in this process. The ionic liquids were recovered and subsequently used for further desulfurization. FT-IR spectra reveal the transformation of organic sulfur functionalities into the sulfoxides (S=O) and sulfones (-SO 2 ) due to the oxidative reactions. The sulfate, pyrite and sulfides (aryls) signals in the near edge X-ray absorption fine structure (NEXAFS) of the oxidized coal samples showed sulfur transformation during the desulfurization process. The study demonstrates the removal of significant amount of inorganic as well as organic sulfur (aryls) components from the original high sulfur coal samples to make them cleaner

Process and system for removing sulfur from sulfur-containing gaseous streams

Science.gov (United States)

Basu, Arunabha; Meyer, Howard S.; Lynn, Scott; Leppin, Dennis; Wangerow, James R.

2012-08-14

A multi-stage UCSRP process and system for removal of sulfur from a gaseous stream in which the gaseous stream, which contains a first amount of H.sub.2S, is provided to a first stage UCSRP reactor vessel operating in an excess SO.sub.2 mode at a first amount of SO.sub.2, producing an effluent gas having a reduced amount of SO.sub.2, and in which the effluent gas is provided to a second stage UCSRP reactor vessel operating in an excess H.sub.2S mode, producing a product gas having an amount of H.sub.2S less than said first amount of H.sub.2S.

Danburite decomposition by sulfuric acid

International Nuclear Information System (INIS)

Mirsaidov, U.; Mamatov, E.D.; Ashurov, N.A.

2011-01-01

Present article is devoted to decomposition of danburite of Ak-Arkhar Deposit of Tajikistan by sulfuric acid. The process of decomposition of danburite concentrate by sulfuric acid was studied. The chemical nature of decomposition process of boron containing ore was determined. The influence of temperature on the rate of extraction of boron and iron oxides was defined. The dependence of decomposition of boron and iron oxides on process duration, dosage of H 2 SO 4 , acid concentration and size of danburite particles was determined. The kinetics of danburite decomposition by sulfuric acid was studied as well. The apparent activation energy of the process of danburite decomposition by sulfuric acid was calculated. The flowsheet of danburite processing by sulfuric acid was elaborated.

Uranium and thorium recovery in thorianite ore-preliminary results

Energy Technology Data Exchange (ETDEWEB)

Gaiotte, Joao V.M. [Universidade Federal de Alfenas, Pocos de Caldas, MG (Brazil); Villegas, Raul A.S.; Fukuma, Henrique T., E-mail: rvillegas@cnen.gov.br, E-mail: htfukuma@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Pocos de Caldas, MG (Brazil). Lab. de Pocos de Caldas

2011-07-01

This work presents the preliminary results of the studies aiming to develop a hydrometallurgical process to produce uranium and thorium concentrates from thorianite ore from Amapa State, Brazil. This process comprises two major parts: acid leaching and Th/U recovery using solvent extraction strategies. Thorianite ore has a typical composition of 60 - 70% of thorium, 8 - 10% lead and 7 - 10% uranium. Sulfuric acid leaching operational conditions were defined as follows: acid/ore ratio 7.5 t/t, ore size below 65 mesh (Tyler), 2 hours leaching time and temperature of 100 deg C. Leaching tests results showed that uranium and thorium recovery exceeded 95%, whereas 97% of lead ore content remained in the solid form. Uranium and thorium simultaneous solvent extraction is necessary due to high sulfate concentration in the liquor obtained from leaching, so the Primene JM-T primary anime was used for this extraction step. Aqueous raffinate from extraction containing sulfuric acid was recycled to the leaching step, reducing acid uptake around 60%, to achieve a net sulfuric acid consumption of 3 t/t of ore. Uranium and thorium simultaneous stripping was performed using sodium carbonate solution. In the aqueous stripped it was added sulfuric acid at pH 1.5, followed by a second solvent extraction step using the tertiary amine Alamine 336. The following stripping step was done with a solution of sodium chloride, resulting in a final solution of 23 g L-1 uranium. (author)

Recovery of lithium and cobalt from waste lithium ion batteries of mobile phone.

Science.gov (United States)

Jha, Manis Kumar; Kumari, Anjan; Jha, Amrita Kumari; Kumar, Vinay; Hait, Jhumki; Pandey, Banshi Dhar

2013-09-01

In view of the stringent environmental regulations, availability of limited natural resources and ever increasing need of alternative energy critical elements, an environmental eco-friendly leaching process is reported for the recovery of lithium and cobalt from the cathode active materials of spent lithium-ion batteries of mobile phones. The experiments were carried out to optimize the process parameters for the recovery of lithium and cobalt by varying the concentration of leachant, pulp density, reductant volume and temperature. Leaching with 2M sulfuric acid with the addition of 5% H(2)O(2) (v/v) at a pulp density of 100 g/L and 75°C resulted in the recovery of 99.1% lithium and 70.0% cobalt in 60 min. H(2)O(2) in sulfuric acid solution acts as an effective reducing agent, which enhance the percentage leaching of metals. Leaching kinetics of lithium in sulfuric acid fitted well to the chemical controlled reaction model i.e. 1-(1-X)(1/3)=k(c)t. Leaching kinetics of cobalt fitted well to the model 'ash diffusion control dense constant sizes spherical particles' i.e. 1-3(1-X)(2/3)+2(1-X)=k(c)t. Metals could subsequently be separated selectively from the leach liquor by solvent extraction process to produce their salts by crystallization process from the purified solution. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects on the forest of sulfur dioxide from a sulfur fire near Edson, Alberta

Energy Technology Data Exchange (ETDEWEB)

Hocking, D

1975-01-01

Sulfur was burnt in a sanitary landfill during August 9 and 10, 1974. Resulting sulfur dioxide impinged on the surrounding mixed forest for 29 h. About 4 ha of forest displayed visible injury symptoms of varying intensity soon after. However, only .4 ha remained permanently injured the next season. Here, white spruce (Picea glauca (Moench) Voss) and scattered individuals of balsam poplar (Populus balsamifera L.), alder (Alnus tenuifolia Nutt.), and trembling aspen (Populus tremuloides Michx.) were killed. This report describes the extent of injury, relative sensitivities of affected plant species, and recovery in the spring in 1975.

Device for processing regenerative wastes of ion exchange resin

International Nuclear Information System (INIS)

Kuroda, Osamu; Ebara, Katsuya; Shindo, Toshikazu; Takahashi, Sankichi

1986-01-01

Purpose: To facilitate the operation and maintenance of a processing device by dividing radioactive wastes produced in the regenerative process of ion exchange resin into a regenerated usable recovery liquid and wastes. Constitution: Sulfuric acid is recovered by a diffusion dialysis method from wastes containing sulfuric acid that are generated in the regenerative process of cation-exchange resin and also caustic soda is recovered by the diffusion dialysis method from wastes containing caustic soda that are generated in the regenerative process of anion-exchange resin. The sulfuric acid and caustic soda thus recovered are used for the regeneration of ion-exchange resin. A concentrator is provided for concentrating the sulfuric acid and caustic soda water solution to concentration suitable for the regeneration of these ion-exchange resins. Also provided is a recovery device for recovering water generated from the concentrator. This device is of so simple a constitution that its operation and maintenance can be performed very easily, thereby greatly reducing the quantity of waste liquid required to be stored in drums. (Takahashi, M.)

Recovery of thorium and uranium from monazite processing Liquor produced by INB/Caldas, M G, by solvent extraction

International Nuclear Information System (INIS)

Amaral, Janubia Cristina Braganca da Silva

2006-01-01

This work describes the study of thorium and uranium recovery from sulfuric liquor generated in chemical monazite treatment by solvent extraction technique. The sulfuric liquor was produced by Industries Nuclear of Brazil - INB, Caldas - Minas Gerais State. The study was carried out in two steps: in the first the process variable were investigated through discontinuous experiments; in the second, the parameters were optimized by continuous solvent extraction experiments. The influence of the following process variables was investigated: type and concentration of extracting agents, contact time between phases and aqueous/organic volumetric ratio. Extractants used in this study included: Primene J M-T, Primene 81-R, Alamine 336 and Aliquat 336. Thorium and uranium were simultaneously extracted by a mixture of Primene J M-T and Alamine 336, into Exxsol D-100. The stripping was carried out by hydrochloric acid (HCl) 2.0 mol/L. The study was carried out at room temperature. After selected the best process conditions, two continuous experiments of extraction and stripping were carried out. In the first experiment a mixture of 0.15 mol/L Primene J M-T and 0.05 mol/L Alamine 336 were used. The second experiment was carried out using 0.15 mol/L Primene J M-T and 0.15 mol/L Alamine 336. Four extraction stages and five stripping stages were used in both experiments. The first experiment showed a ThU 2 and U 3 O 8 content in loaded strip solution of 34.3 g/L and 1.49 g/L respectively and 0.10 g/L Th) 2 and 0.05 g/L U 3 O 8 in the raffinate. In the second experiment a loaded strip solution with 29.3 g/L ThO 2 and 0.94 g/L U 3 O 8 was obtained. In this experiment, the metals content in raffinate was less than 0.001 g/L, indicating a thorium recovery over 99.9% and uranium recovery of 99.4%. (author)

Titanium leaching from red mud by diluted sulfuric acid at atmospheric pressure

International Nuclear Information System (INIS)

Agatzini-Leonardou, S.; Oustadakis, P.; Tsakiridis, P.E.; Markopoulos, Ch.

2008-01-01

Laboratory-scale research has focused on the recovery of titanium from red mud, which is obtained from bauxite during the Bayer process for alumina production. The leaching process is based on the extraction of this element with diluted sulfuric acid from red mud under atmospheric conditions and without using any preliminary treatment. Statistical design and analysis of experiments were used, in order to determine the main effects and interactions of the leaching process factors, which were: acid normality, temperature and solid to liquid ratio. The titanium recovery efficiency on the basis of red mud weight reached 64.5%. The characterization of the initial red mud, as well as this of the leached residues was carried out by X-ray diffraction, TG-DTA and scanning electron microscopy

Developing an energy efficient steam reforming process to produce hydrogen from sulfur-containing fuels

Science.gov (United States)

Simson, Amanda

Hydrogen powered fuel cells have the potential to produce electricity with higher efficiency and lower emissions than conventional combustion technology. In order to realize the benefits of a hydrogen fuel cell an efficient method to produce hydrogen is needed. Currently, over 90% of hydrogen is produced from the steam reforming of natural gas. However, for many applications including fuel cell vehicles, the use of a liquid fuel rather than natural gas is desirable. This work investigates the feasibility of producing hydrogen efficiently by steam reforming E85 (85% ethanol/15% gasoline), a commercially available sulfur-containing transportation fuel. A Rh-Pt/SiO2-ZrO2 catalyst has demonstrated good activity for the E85 steam reforming reaction. An industrial steam reforming process is often run less efficiently, with more water and at higher temperatures, in order to prevent catalyst deactivation. Therefore, it is desirable to develop a process that can operate without catalyst deactivation at more energy efficient conditions. In this study, the steam reforming of a sulfur-containing fuel (E85) was studied at near stoichiometric steam/carbon ratios and at 650C, conditions at which catalyst deactivation is normally measured. At these conditions the catalyst was found to be stable steam reforming a sulfur-free E85. However, the addition of low concentrations of sulfur significantly deactivated the catalyst. The presence of sulfur in the fuel caused catalyst deactivation by promoting ethylene which generates surface carbon species (coke) that mask catalytic sites. The amount of coke increased during time on stream and became increasingly graphitic. However, the deactivation due to both sulfur adsorption and coke formation was reversible with air treatment at 650°C. However, regenerations were found to reduce the catalyst life. Air regenerations produce exotherms on the catalyst surface that cause structural changes to the catalyst. During regenerations the

Recovery of lithium and cobalt from waste lithium ion batteries of mobile phone

Energy Technology Data Exchange (ETDEWEB)

Jha, Manis Kumar, E-mail: mkjha@nmlindia.org; Kumari, Anjan; Jha, Amrita Kumari; Kumar, Vinay; Hait, Jhumki; Pandey, Banshi Dhar

2013-09-15

Graphical abstract: Recovery of valuable metals from scrap batteries of mobile phone. - Highlights: • Recovery of Co and Li from spent LIBs was performed by hydrometallurgical route. • Under the optimum condition, 99.1% of lithium and 70.0% of cobalt were leached. • The mechanism of the dissolution of lithium and cobalt was studied. • Activation energy for lithium and cobalt were found to be 32.4 kJ/mol and 59.81 kJ/mol, respectively. • After metal recovery, residue was washed before disposal to the environment. - Abstract: In view of the stringent environmental regulations, availability of limited natural resources and ever increasing need of alternative energy critical elements, an environmental eco-friendly leaching process is reported for the recovery of lithium and cobalt from the cathode active materials of spent lithium-ion batteries of mobile phones. The experiments were carried out to optimize the process parameters for the recovery of lithium and cobalt by varying the concentration of leachant, pulp density, reductant volume and temperature. Leaching with 2 M sulfuric acid with the addition of 5% H{sub 2}O{sub 2} (v/v) at a pulp density of 100 g/L and 75 °C resulted in the recovery of 99.1% lithium and 70.0% cobalt in 60 min. H{sub 2}O{sub 2} in sulfuric acid solution acts as an effective reducing agent, which enhance the percentage leaching of metals. Leaching kinetics of lithium in sulfuric acid fitted well to the chemical controlled reaction model i.e. 1 − (1 − X){sup 1/3} = k{sub c}t. Leaching kinetics of cobalt fitted well to the model ‘ash diffusion control dense constant sizes spherical particles’ i.e. 1 − 3(1 − X){sup 2/3} + 2(1 − X) = k{sub c}t. Metals could subsequently be separated selectively from the leach liquor by solvent extraction process to produce their salts by crystallization process from the purified solution.

Research and development on process components for hydrogen production. (1) Test-fabrication of sulfuric acid transfer pump

International Nuclear Information System (INIS)

Iwatsuki, Jin; Terada, Atsuhiko; Hino, Ryutaro; Kubo, Shinji; Onuki, Kaoru; Watanabe, Yutaka

2009-01-01

Japan Atomic Energy Agency has been conducting a research and development on hydrogen production system using High Temperature Gas-Cooled Reactor. As a part of this effort, thermochemical water-splitting cycle featuring iodine- and sulfur-compounds (IS process) is under development considering its potential of large-scale economical hydrogen production. The IS process constitutes very severe environments to the materials of construction because of the corrosive nature of process chemicals, especially of the high temperature acidic solutions of sulfuric acid and hydriodic acid dissolving iodine. Therefore, selection of the corrosion-resistant materials and development of the components have been the crucial subjects of process development. This paper concerns the sulfuric acid transfer pump. The development has been implemented of a pump for transporting concentrated sulfuric acid at temperatures of higher than 300degC and at elevated pressure. Recent progress of these activities will be reported. (author)

Gasoline from coal in the state of Illinois: feasibility study. Volume I. Design. [KBW gasification process, ICI low-pressure methanol process and Mobil M-gasoline process

Energy Technology Data Exchange (ETDEWEB)

1980-01-01

Volume 1 describes the proposed plant: KBW gasification process, ICI low-pressure methanol process and Mobil M-gasoline process, and also with ancillary processes, such as oxygen plant, shift process, RECTISOL purification process, sulfur recovery equipment and pollution control equipment. Numerous engineering diagrams are included. (LTN)

Toluene destruction in the Claus process by sulfur dioxide: A reaction kinetics study

KAUST Repository

Sinha, Sourab

2014-10-22

The presence of aromatics such as benzene, toluene, and xylene (BTX) as contaminants in the H2S gas stream entering Claus sulfur recovery units has a detrimental effect on catalytic reactors, where BTX forms soot particles and clogs and deactivates the catalysts. BTX oxidation, before they enter catalyst beds, can solve this problem. A theoretical investigation is presented on toluene oxidation by SO2. Density functional theory is used to study toluene radical (benzyl, o-methylphenyl, m-methylphenyl, and p-methylphenyl)-SO2 interactions. The mechanism begins with SO2 addition on the radical through one of the O atoms rather than the S atom. This exothermic reaction involves energy barriers of 4.8-6.1 kJ/mol for different toluene radicals. Thereafter, O-S bond scission takes place to release SO. The reaction rate constants are evaluated to facilitate process simulations. Among four toluene radicals, the resonantly stabilized benzyl radical exhibited lowest SO2 addition rate. A remarkable similarity between toluene oxidation by O2 and by SO2 is observed.

Toluene destruction in the Claus process by sulfur dioxide: A reaction kinetics study

KAUST Repository

Sinha, Sourab; Raj, Abhijeet Dhayal; Alshoaibi, Ahmed S.; Alhassan, Saeed M.; Chung, Suk-Ho

2014-01-01

The presence of aromatics such as benzene, toluene, and xylene (BTX) as contaminants in the H2S gas stream entering Claus sulfur recovery units has a detrimental effect on catalytic reactors, where BTX forms soot particles and clogs and deactivates the catalysts. BTX oxidation, before they enter catalyst beds, can solve this problem. A theoretical investigation is presented on toluene oxidation by SO2. Density functional theory is used to study toluene radical (benzyl, o-methylphenyl, m-methylphenyl, and p-methylphenyl)-SO2 interactions. The mechanism begins with SO2 addition on the radical through one of the O atoms rather than the S atom. This exothermic reaction involves energy barriers of 4.8-6.1 kJ/mol for different toluene radicals. Thereafter, O-S bond scission takes place to release SO. The reaction rate constants are evaluated to facilitate process simulations. Among four toluene radicals, the resonantly stabilized benzyl radical exhibited lowest SO2 addition rate. A remarkable similarity between toluene oxidation by O2 and by SO2 is observed.

Environmental behavior and analysis of agricultural sulfur.

Science.gov (United States)

Griffith, Corey M; Woodrow, James E; Seiber, James N

2015-11-01

Sulfur has been widely used for centuries as a staple for pest and disease management in agriculture. Presently, it is the largest-volume pesticide in use worldwide. This review describes the sources and recovery methods for sulfur, its allotropic forms and properties and its agricultural uses, including development and potential advantages of nanosulfur as a fungicide. Chemical and microbial reactivity, interactions in soil and water and analytical methods for determination in environmental samples and foodstuffs, including inexpensive analytical methods for sulfur residues in wine, beer and other food/beverage substrates, will be reviewed. The toxicology of sulfur towards humans and agriculturally important fungi is included, with some restrictions on use to promote safety. The review concludes with areas for which more research is warranted. © 2015 Society of Chemical Industry.

Wolframite Conversion in Treating a Mixed Wolframite-Scheelite Concentrate by Sulfuric Acid

Science.gov (United States)

Shen, Leiting; Li, Xiaobin; Zhou, Qiusheng; Peng, Zhihong; Liu, Guihua; Qi, Tiangui; Taskinen, Pekka

2018-02-01

Complete wolframite conversion in sulfuric acid is significant for expanding the applicability of the sulfuric acid method for producing ammonium paratungstate. In this paper, the conversion of wolframite in treating a mixed wolframite-scheelite concentrate by sulfuric acid was studied systematically. The results show that the conversion of wolframite in sulfuric acid is more difficult than that of scheelite, requiring rigorous reaction conditions. A solid H2WO4 layer forms on the surfaces of the wolframite particles and becomes denser with increasing H2SO4 concentration, thus hindering the conversion. Furthermore, the difficulty in wolframite conversion can be mainly attributed to the accumulation of Fe2+ (and/or Mn2+) in the H2SO4 solution, which can be solved by reducing Fe2+ (and/or Mn2+) concentration through oxidization and/or a two-stage process. Additionally, the solid converted product of the mixed wolframite-scheelite concentrate has an excellent leachability of tungsten in an aqueous ammonium carbonate solution at ambient temperature, with approximately 99% WO3 recovery. This work presents a route for manufacturing ammonium paratungstate by treating the mixed concentrate in sulfuric acid followed by leaching in ammonium carbonate solution.

Gasoline from natural gas by sulfur processing

Energy Technology Data Exchange (ETDEWEB)

Erekson, E.J.; Miao, F.Q. [Institute of Gas Technology, Des Plaines, IL (United States)

1995-12-31

The overall objective of this research project is to develop a catalytic process to convert natural gas to liquid transportation fuels. The process, called the HSM (Hydrogen Sulfide-Methane) Process, consists of two steps that each utilize a catalyst and sulfur-containing intermediates: (1) converting natural gas to CS{sub 2} and (2) converting CS{sub 2} to gasoline range liquids. Catalysts have been found that convert methane to carbon disulfide in yields up to 98%. This exceeds the target of 40% yields for the first step. The best rate for CS{sub 2} formation was 132 g CS{sub 2}/kg-cat-h. The best rate for hydrogen production is 220 L H{sub 2} /kg-cat-h. A preliminary economic study shows that in a refinery application hydrogen made by the HSM technology would cost $0.25-R1.00/1000 SCF. Experimental data will be generated to facilitate evaluation of the overall commercial viability of the process.

Assessing the additional impact of Process Recovery Communications on Customer Outcomes: A Comprehensive Service Recovery Approach

OpenAIRE

Y. VAN VAERENBERGH; B. LARIVIÈRE; I. VERMEIR

2009-01-01

Purpose – Services recoveries following service failures not only imply customer recovery opportunities in which customer-company relationships can be restored, they can also result in process improvements (i.e. process recoveries in literature). This paper seeks to identify the additional impact of process recoveries on four customer outcome variables (satisfaction with service recovery, overall satisfaction, repurchase intent and word-of-mouth) by communicating these improvements back to th...

The life sulfuric: microbial ecology of sulfur cycling in marine sediments.

Science.gov (United States)

Wasmund, Kenneth; Mußmann, Marc; Loy, Alexander

2017-08-01

Almost the entire seafloor is covered with sediments that can be more than 10 000 m thick and represent a vast microbial ecosystem that is a major component of Earth's element and energy cycles. Notably, a significant proportion of microbial life in marine sediments can exploit energy conserved during transformations of sulfur compounds among different redox states. Sulfur cycling, which is primarily driven by sulfate reduction, is tightly interwoven with other important element cycles (carbon, nitrogen, iron, manganese) and therefore has profound implications for both cellular- and ecosystem-level processes. Sulfur-transforming microorganisms have evolved diverse genetic, metabolic, and in some cases, peculiar phenotypic features to fill an array of ecological niches in marine sediments. Here, we review recent and selected findings on the microbial guilds that are involved in the transformation of different sulfur compounds in marine sediments and emphasise how these are interlinked and have a major influence on ecology and biogeochemistry in the seafloor. Extraordinary discoveries have increased our knowledge on microbial sulfur cycling, mainly in sulfate-rich surface sediments, yet many questions remain regarding how sulfur redox processes may sustain the deep-subsurface biosphere and the impact of organic sulfur compounds on the marine sulfur cycle. © 2017 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

A Comparison of Organic and Steam Rankine Cycle Power Systems for Waste Heat Recovery on Large Ships

Directory of Open Access Journals (Sweden)

Jesper Graa Andreasen

2017-04-01

Full Text Available This paper presents a comparison of the conventional dual pressure steam Rankine cycle process and the organic Rankine cycle process for marine engine waste heat recovery. The comparison was based on a container vessel, and results are presented for a high-sulfur (3 wt % and low-sulfur (0.5 wt % fuel case. The processes were compared based on their off-design performance for diesel engine loads in the range between 25% and 100%. The fluids considered in the organic Rankine cycle process were MM(hexamethyldisiloxane, toluene, n-pentane, i-pentane and c-pentane. The results of the comparison indicate that the net power output of the steam Rankine cycle process is higher at high engine loads, while the performance of the organic Rankine cycle units is higher at lower loads. Preliminary turbine design considerations suggest that higher turbine efficiencies can be obtained for the ORC unit turbines compared to the steam turbines. When the efficiency of the c-pentane turbine was allowed to be 10% points larger than the steam turbine efficiency, the organic Rankine cycle unit reaches higher net power outputs than the steam Rankine cycle unit at all engine loads for the low-sulfur fuel case. The net power production from the waste heat recovery units is generally higher for the low-sulfur fuel case. The steam Rankine cycle unit produces 18% more power at design compared to the high-sulfur fuel case, while the organic Rankine cycle unit using MM produces 33% more power.

Laboratory simulated slipstream testing of novel sulfur removal processes for gasification application

International Nuclear Information System (INIS)

Schmidt, Roland; Tsang, Albert; Cross, Joe; Summers, Clinton; Kornosky, Bob

2008-01-01

The Wabash River Integrated Methanol and Power Production from Clean Coal Technologies (IMPPCCT) project is investigating an Early Entrance Coproduction Plant (EECP) concept to evaluate integrated electrical power generation and methanol production from coal and other carbonaceous feedstocks. Research, development and testing (RD and T) that is currently being conducted under the project is evaluating cost effective process systems for removing contaminants, particularly sulfur species, from the generated gas which contains mainly synthesis gas (syngas), CO 2 and steam at concentrations acceptable for the methanol synthesis catalyst. The RD and T includes laboratory testing followed by bench-scale and field testing at the SG Solutions Gasification Plant located in West Terre Haute, Indiana. Actual synthesis gas produced by the plant was utilized at system pressure and temperature for bench-scale field testing. ConocoPhillips Company (COP) developed a sulfur removal technology based on a novel, regenerable sorbent - S Zorb trademark - to remove sulfur contaminants from gasoline at high temperatures. The sorbent was evaluated for its sulfur removal performance from the generated syngas especially in the presence of other components such as water and CO 2 which often cause sorbent performance to decline over time. This publication also evaluates the performance of a regenerable activated carbon system developed by Nucon International, Inc. in polishing industrial gas stream by removing sulfur species to parts-per-billion (ppb) levels. (author)

Development of energy-efficient processes for natural gas liquids recovery

International Nuclear Information System (INIS)

Yoon, Sekwang; Binns, Michael; Park, Sangmin; Kim, Jin-Kuk

2017-01-01

A new NGL (natural gas liquids) recovery process configuration is proposed which can offer improved energy efficiency and hydrocarbon recovery. The new process configuration is an evolution of the conventional turboexpander processes with the introduction of a split stream transferring part of the feed to the demethanizer column. In this way additional heat recovery is possible which improves the energy efficiency of the process. To evaluate the new process configuration a number of different NGL recovery process configurations are optimized and compared using a process simulator linked interactively with external optimization methods. Process integration methodology is applied as part of the optimization to improve energy recovery during the optimization. Analysis of the new process configuration compared with conventional turbo-expander process designs demonstrates the benefits of the new process configuration. - Highlights: • Development of a new energy-efficient natural gas liquids recovery process. • Improving energy recovery with application of process integration techniques. • Considering multiple different structural changes lead to considerable energy savings.

ADVANCED SULFUR CONTROL CONCEPTS FOR HOT-GAS DESULFURIZATION TECHNOLOGY

Energy Technology Data Exchange (ETDEWEB)

A. LOPEZ ORTIZ; D.P. HARRISON; F.R. GROVES; J.D. WHITE; S. ZHANG; W.-N. HUANG; Y. ZENG

1998-10-31

a twenty-five-cycle test. The sorbent was exposed for 58 consecutive days to temperatures between 600°C and 800°C and gas atmospheres from highly reducing to highly oxidizing without measurable loss of sulfur capacity or reactivity. In the process analysis phase of this study, a two-stage desulfurization process using cerium sorbent with SO2 regeneration followed by zinc sorbent with dilute O2 regeneration was compared to a single-stage process using zinc sorbent and O2 regeneration with SO2 in the regeneration product gas converted to elemental sulfur using the direct sulfur recovery process (DSRP). Material and energy balances were calculated using the process simulation package PRO/II. Major process equipment was sized and a preliminary economic analysis completed. Sorbent replacement rate, which is determined by the multicycle sorbent durability, was found to be the most significant factor in both processes. For large replacement rates corresponding to average sorbent lifetimes of 250 cycles or less, the single-stage zinc sorbent process with DSRP was estimated to be less costly. However, the cost of the two-stage cerium sorbent process was more sensitive to sorbent replacement rate, and, as the required replacement rate decreased, the economics of the two-stage process improved. For small sorbent replacement rates corresponding to average sorbent lifetimes of 1000 cycles or more, the two-stage cerium process was estimated to be less costly. In the relatively wide middle range of sorbent replacement rates, the relative economics of the two processes depends on other factors such as the unit cost of sorbents, oxygen, nitrogen, and the relative capital costs.

Advanced sulfur control concepts for hot-gas desulfurization technology

International Nuclear Information System (INIS)

Lopez Ortiz, A.; Harrison, D.P.; Groves, F.R.; White, J.D.; Zhang, S.; Huang, W.N.; Zeng, Y.

1998-01-01

twenty-five-cycle test. The sorbent was exposed for 58 consecutive days to temperatures between 600C and 800C and gas atmospheres from highly reducing to highly oxidizing without measurable loss of sulfur capacity or reactivity. In the process analysis phase of this study, a two-stage desulfurization process using cerium sorbent with SO2 regeneration followed by zinc sorbent with dilute O2 regeneration was compared to a single-stage process using zinc sorbent and O2 regeneration with SO2 in the regeneration product gas converted to elemental sulfur using the direct sulfur recovery process (DSRP). Material and energy balances were calculated using the process simulation package PRO/II. Major process equipment was sized and a preliminary economic analysis completed. Sorbent replacement rate, which is determined by the multicycle sorbent durability, was found to be the most significant factor in both processes. For large replacement rates corresponding to average sorbent lifetimes of 250 cycles or less, the single-stage zinc sorbent process with DSRP was estimated to be less costly. However, the cost of the two-stage cerium sorbent process was more sensitive to sorbent replacement rate, and, as the required replacement rate decreased, the economics of the two-stage process improved. For small sorbent replacement rates corresponding to average sorbent lifetimes of 1000 cycles or more, the two-stage cerium process was estimated to be less costly. In the relatively wide middle range of sorbent replacement rates, the relative economics of the two processes depends on other factors such as the unit cost of sorbents, oxygen, nitrogen, and the relative capital costs

Recovery of hydrocarbon oils

Energy Technology Data Exchange (ETDEWEB)

1941-02-10

A process is disclosed for recovery of hydrocarbon oils, especially lubricating oils or diesel oils, through pressure hydrogenation of distillation, extraction of hydrogenation products from coal or coaly materials or from oils such as mineral oils or tars in liquid phase by use in a reaction vessel of fixed-bed catalysts, characterized in that as starting material is employed material which has been freed of asphaltic and resinous material by hydrogenation refining, vacuum-steam distillation, treatment with hydrogen-rich hydrocarbons (hydroforming), or sulfuric acid.

Recovery of Vanadium from Magnetite Ore Using Direct Acid Leaching: Optimization of Parameters by Plackett-Burman and Response Surface Methodologies

Science.gov (United States)

Nejad, Davood Ghoddocy; Khanchi, Ali Reza; Taghizadeh, Majid

2018-06-01

Recovery of vanadium from magnetite ore by direct acid leaching is discussed. The proposed process, which employs a mixture of nitric and sulfuric acids, avoids pyrometallurgical treatments since such treatment consumes a high amount of energy. To determine the optimum conditions of vanadium recovery, the leaching process is optimized through Plackett-Burman (P-B) design and response surface methodology (RSM). In this respect, temperature (80-95°C), liquid to solid ratio (L/S) (3-10 mL g-1), sulfuric acid concentration (3-6 M), nitric acid concentration (5-10 vol.%) and time (4-8 h) are considered as the independent variables. According to the P-B approach, temperature and acid concentrations are, respectively, the most effective parameters in the leaching process. These parameters are optimized using RSM to maximize recovery of vanadium by direct acid leaching. In this way, 86.7% of vanadium can be extracted from magnetic ore.

A Tire-Sulfur Hybrid Adsorption Denitrification (T-SHAD) process for decentralized wastewater treatment.

Science.gov (United States)

Krayzelova, Lucie; Lynn, Thomas J; Banihani, Qais; Bartacek, Jan; Jenicek, Pavel; Ergas, Sarina J

2014-09-15

Nitrogen discharges from decentralized wastewater treatment (DWT) systems contribute to surface and groundwater contamination. However, the high variability in loading rates, long idle periods and lack of regular maintenance presents a challenge for biological nitrogen removal in DWT. A Tire-Sulfur Hybrid Adsorption Denitrification (T-SHAD) process was developed that combines nitrate (NO3(-)) adsorption to scrap tire chips with sulfur-oxidizing denitrification. This allows the tire chips to adsorb NO3(-) when the influent loading exceeds the denitrification capacity of the biofilm and release it when NO3(-) loading rates are low (e.g. at night). Three waste products, scrap tire chips, elemental sulfur pellets and crushed oyster shells, were used as a medium in adsorption, leaching, microcosm and up-flow packed bed bioreactor studies of NO3(-) removal from synthetic nitrified DWT wastewater. Adsorption isotherms showed that scrap tire chips have an adsorption capacity of 0.66 g NO3(-)-N kg(-1) of scrap tires. Leaching and microcosm studies showed that scrap tires leach bioavailable organic carbon that can support mixotrophic metabolism, resulting in lower effluent SO4(2-) concentrations than sulfur oxidizing denitrification alone. In column studies, the T-SHAD process achieved high NO3(-)-N removal efficiencies under steady state (90%), variable flow (89%) and variable concentration (94%) conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Graphene oxide as a sulfur immobilizer in high performance lithium/sulfur cells

Science.gov (United States)

Zhang, Yuegang; Cairns, Elton J.; Ji, Liwen; Rao, Mumin

2017-06-06

The loss of sulfur cathode material as a result of polysulfide dissolution causes significant capacity fading in rechargeable lithium/sulfur cells. Embodiments of the invention use a chemical approach to immobilize sulfur and lithium polysulfides via the reactive functional groups on graphene oxide. This approach obtains a uniform and thin (.about.tens of nanometers) sulfur coating on graphene oxide sheets by a chemical reaction-deposition strategy and a subsequent low temperature thermal treatment process. Strong interaction between graphene oxide and sulfur or polysulfides demonstrate lithium/sulfur cells with a high reversible capacity of 950-1400 mAh g.sup.-1, and stable cycling for more than 50 deep cycles at 0.1 C.

Graphene oxide as a sulfur immobilizer in high performance lithium/sulfur cells

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yuegang; Cairns, Elton J.; Ji, Liwen; Rao, Mumin

2017-12-26

The loss of sulfur cathode material as a result of polysulfide dissolution causes significant capacity fading in rechargeable lithium/sulfur cells. Embodiments of the invention use a chemical approach to immobilize sulfur and lithium polysulfides via the reactive functional groups on graphene oxide. This approach obtains a uniform and thin (.about.tens of nanometers) sulfur coating on graphene oxide sheets by a chemical reaction-deposition strategy and a subsequent low temperature thermal treatment process. Strong interaction between graphene oxide and sulfur or polysulfides demonstrate lithium/sulfur cells with a high reversible capacity of 950-1400 mAh g.sup.-1, and stable cycling for more than 50 deep cycles at 0.1 C.

Recovery of transuranics from process residues

International Nuclear Information System (INIS)

Gray, J.H.; Gray, L.W.

1987-01-01

Process residues are generated at both the Rocky Flats Plant (RFP) and the Savannah River Plant (SRP) during aqueous chemical and pyrochemical operations. Frequently, process operations will result in either impure products or produce residues sufficiently contaminated with transuranics to be nondiscardable as waste. Purification and recovery flowsheets for process residues have been developed to generate solutions compatible with subsequent Purex operations and either solid or liquid waste suitable for disposal. The ''scrub alloy'' and the ''anode heel alloy'' are examples of materials generated at RFP which have been processed at SRP using the developed recovery flowsheets. Examples of process residues being generated at SRP for which flowsheets are under development include LECO crucibles and alpha-contaminated hydraulic oil

Selective catalytic reduction of sulfur dioxide to elemental sulfur. Final report

Energy Technology Data Exchange (ETDEWEB)

Liu, W.; Flytzani-Stephanopoulos, M.; Sarofim, A.F.

1995-06-01

This project has investigated new metal oxide catalysts for the single stage selective reduction of SO{sub 2} to elemental sulfur by a reductant, such as CO. Significant progress in catalyst development has been made during the course of the project. We have found that fluorite oxides, CeO{sub 2} and ZrO{sub 2}, and rare earth zirconates such as Gd{sub 2}Zr{sub 2}O{sub 7} are active and stable catalysts for reduction Of SO{sub 2} by CO. More than 95% sulfur yield was achieved at reaction temperatures about 450{degrees}C or higher with the feed gas of stoichiometric composition. Reaction of SO{sub 2} and CO over these catalysts demonstrated a strong correlation of catalytic activity with the catalyst oxygen mobility. Furthermore, the catalytic activity and resistance to H{sub 2}O and CO{sub 2} poisoning of these catalysts were significantly enhanced by adding small amounts of transition metals, such as Co, Ni, Co, etc. The resulting transition metal-fluorite oxide composite catalyst has superior activity and stability, and shows promise in long use for the development of a greatly simplified single-step sulfur recovery process to treat variable and dilute SO{sub 2} concentration gas streams. Among various active composite catalyst systems the Cu-CeO{sub 2} system has been extensively studied. XRD, XPS, and STEM analyses of the used Cu-CeO{sub 2} catalyst found that the fluorite crystal structure of ceria was stable at the present reaction conditions, small amounts of copper was dispersed and stabilized on the ceria matrix, and excess copper oxide particles formed copper sulfide crystals of little contribution to catalytic activity. A working catalyst consisted of partially sulfated cerium oxide surface and partially sulfided copper clusters. The overall reaction kinetics were approximately represented by a first order equation.

Hydrometallurgical process for the recovery of metal values from spent lithium-ion batteries in citric acid media.

Science.gov (United States)

Chen, Xiangping; Zhou, Tao

2014-11-01

In this paper, a hydrometallurgical process has been proposed to recover valuable metals from spent lithium-ion batteries in citric acid media. Leaching efficiencies as high as 97%, 95%, 94%, and 99% of Ni, Co, Mn, and Li were achieved under the optimal leaching experimental conditions of citric acid concentration of 2 mol L(-1), leaching temperature of 80 °C, leaching time of 90 min, liquid-solid ratio of 30 ml g(-1), and 2 vol. % H2O2. For the metals recovery process, nickel and cobalt were selectively precipitated by dimethylglyoxime reagent and ammonium oxalate sequentially. Then manganese was extracted by Na-D2EHPA and the manganese-loaded D2EHPA was stripped with sulfuric acid. The manganese was recovered as MnSO4 in aqueous phase and D2EHPA could be reused after saponification. Finally, lithium was precipitated by 0.5 mol L(-1) sodium phosphate. Under their optimal conditions, the recovery percentages of Ni, Co, Mn, and Li can reach 98%, 97%, 98%, and 89%, respectively. This is a relatively simple route in which all metal values could be effectively leached and recovered in citric acid media. © The Author(s) 2014.

FY1995 development of novel processes for copper concentrates without producing sulfuric acid; 1995 nendo hiryusan hasseigata no atarashii doshigen shori gijutsu no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

To develop a novel process for copper concentrates which includes leaching of copper with acidic cupric chloride solutions, aiming at the recovery of sulfur in its elemental form, and leaching of gold from the residue with dissolved bromine. The effect of bromide ions on the leaching of chalcopyrite with 1.0 mol dm{sup -3} CuCl{sub 2} has been investigated at 353 K, and it was found that bromide ions have no influence on the leaching rate and the morphology of elemental sulfur deposited on the surface of chalcopyrite. Dissolved bromine has trivial effects on the morphology and oxidation of porous elemental sulfur covering the residue. However, the dissolved bromine even at 0.02 mol dm-3 depresses the leaching rate of chalcopyrite significantly. Electrotechnical oxidation of cuprous ions, chloride ions and bromide ions in the solution has examined to understand the regeneration of leachant, and it was found that these ions are oxidized simultaneously on the anode surface under the condition of galvanostatic electrolysis, but these oxidants diffuse toward the bulk of solution and react with their reductants. Thus the redox potential of the solution increases gradually showing the temporary stagnation in potential for oxidation of Cu{sup +}, Br{sup -} and Cl{sup -} ions respectively. (NEDO)

Analysis of sulfur-iodine thermochemical cycle for solar hydrogen production. Part 1: decomposition of sulfuric acid

Energy Technology Data Exchange (ETDEWEB)

Huang, Cunping; T-Raissi, Ali [Central Florida Univ., Florida Solar Energy Center, Cocoa, FL (United States)

2005-05-01

The sulfur-iodine (S-I) thermochemical water splitting cycle is one of the most studied cycles for hydrogen (H{sub 2}) production. S-I cycle consists of four sections: (I) acid production and separation and oxygen purification, (II) sulfuric acid concentration and decomposition, (III) hydroiodic acid (HI) concentration, and (IV) HI decomposition and H{sub 2} purification. Section II of the cycle is an endothermic reaction driven by the heat input from a high temperature source. Analysis of the S-I cycle in the past thirty years have been focused mostly on the utilization of nuclear power as the high temperature heat source for the sulfuric acid decomposition step. Thermodynamic as well as kinetic considerations indicate that both the extent and rate of sulfuric acid decomposition can be improved at very high temperatures (in excess of 1000 deg C) available only from solar concentrators. The beneficial effect of high temperature solar heat for decomposition of sulfuric acid in the S-I cycle is described in this paper. We used Aspen Technologies' HYSYS chemical process simulator (CPS) to develop flowsheets for sulfuric acid (H{sub 2}SO{sub 4}) decomposition that include all mass and heat balances. Based on the HYSYS analyses, two new process flowsheets were developed. These new sulfuric acid decomposition processes are simpler and more stable than previous processes and yield higher conversion efficiencies for the sulfuric acid decomposition and sulfur dioxide and oxygen formation. (Author)

The effective synthesis of Insoluble sulfur using electron beam

Energy Technology Data Exchange (ETDEWEB)

Kim, Daejin; Yu, Kookhyun [Dongguk Univ., Seoul (Korea, Republic of)

2013-07-01

Vulcanization is process that formed crosslinking by Insoluble sulfur between linear structure of rubber polymer. Recently, Synthesis of Insoluble sulfur is used Thermal polymerization using about 250 {approx} 300 .deg. C and extraction process is used carbon disulfide(CS2) for separation between soluble sulfur and insoluble sulfur. But this process isn't environmental, economical and safety. This research was focus on developing of insoluble sulfur synthesis process using electron beam. This new process is using under the 140 .deg. C. Because of that, explosion risk is decrease, environmental and economical factor is increased. The sulfur can be melt by increase temperature or made solution using carbon disulfide. And electron beam is irradiated melting sulfur or sulfur solution. After irradiation, The high purity insoluble sulfur can be obtained by separation with carbon disulfide.

Uranium recovery from wet process phosphoric acid

International Nuclear Information System (INIS)

1980-01-01

In the field of metallurgy, specifically processes for recovering uranium from wet process phosphoric acid solution derived from the acidulation of uraniferous phosphate ores, problems of imbalance of ion exchange agents, contamination of recycled phosphoric acid with process organics and oxidizing agents, and loss and contamination of uranium product, are solved by removing organics from the raffinate after ion exchange conversion of uranium to uranous form and recovery thereof by ion exchange, and returning organics to the circuit to balance mono and disubstituted ester ion exchange agents; then oxidatively stripping uranium from the agent using hydrogen peroxide; then after ion exchange recovery of uranyl and scrubbing, stripping with sodium carbonate and acidifying the strip solution and using some of it for the scrubbing; regenerating the sodium loaded agent and recycling it to the uranous recovery step. Economic recovery of uranium as a by-product of phosphate fertilizer production is effected. (author)

The effect of the sulfur concentration on the phase transformation from the mixed CuO-Bi{sub 2}O{sub 3} system to Cu{sub 3}BiS{sub 3} during the sulfurization process

Energy Technology Data Exchange (ETDEWEB)

Zhang, Lijian; Jin, Xin; Yuan, Chenchen; Jiang, Guoshun; Liu, Weifeng, E-mail: liuwf@ustc.edu.cn; Zhu, Changfei, E-mail: cfzhu@ustc.edu.cn

2016-12-15

Highlights: • Cu{sub 3}BiS{sub 3} thin films were creatively fabricated by sulfurizing metal oxide precursor. • The phase transformation mechanism during the sulfurization process was studied. • The reason why the excess S restrained the formation of Cu{sub 3}BiS{sub 3} was discussed. • The effect of temperature on film morphology and bandgap was studied. - Abstract: The ternary semiconductor Cu{sub 3}BiS{sub 3}, as a promising light-absorber material for thin film solar cells, was creatively synthesized by sulfurizing the mixed metal oxides precursor film deposited by spin-coating chemical solution method. Two kinds of sulfurization techniques were introduced to study the effect of the sulfur concentration on the phase formation for the pure Cu{sub 3}BiS{sub 3}. It was found that Cu-poor S-rich phases such as Cu{sub 3}Bi{sub 3}S{sub 7} and Cu{sub 4}Bi{sub 4}S{sub 9} were easily generated at high S concentration and then can transform to Cu{sub 3}BiS{sub 3} phase by a simple desulphurization process, which means the sulfur concentration had a significant influence on the formation of Cu{sub 3}BiS{sub 3} during the sulfurization process. The probable transformation mechanism from the mixed metal oxides to the pure Cu{sub 3}BiS{sub 3} phase during the sulfurization process was studied in detail through the XRD analysis and thermodynamic calculation. In addition, the electrical properties were characterized by Hall measurement and the effects of sulfurization temperature on the phase transformation, morphology and optical band gap of the absorber layer were also studied in detail.

Sulfur isotope studies of biogenic sulfur emissions at Wallops Island, Virginia

International Nuclear Information System (INIS)

Hitchcock, D.R.; Black, M.S.; Herbst, R.P.

1978-03-01

This research attempted to determine whether it is possible to measure the stable sulfur isotope distributions of atmospheric particulate and gaseous sulphur, and to use this information together with measurements of the ambient levels of sulfur gases and particulate sulfate and sodium in testing certain hypotheses. Sulfur dioxide and particulate sulfur samples were collected at a coastal marine location and their delta (34)S values were determined. These data were used together with sodium concentrations to determine the presence of biogenic sulfur and the identity of the biological processes producing it. Excess (non-seasalt) sulfate levels ranged from 2 to 26 micrograms/cu m and SO2 from 1 to 9 ppb. Analyses of air mass origins and lead concentrations indicated that some anthropogenic contaminants were present on all days, but the isotope data revealed that most of the atmospheric sulfur originated locally from the metabolism of bacterial sulfate reducers on all days, and that the atmospheric reactions leading to the production of sulfate from this biogenic sulfur source are extremely rapid. Delta 34 S values of atmospheric sulfur dioxide correlated well with those of excess sulfate, and implied little or no sulfur isotope fractionation during the oxidation of sulfur gases to sulfate

Sulfuric acid baking and leaching of spent Co-Mo/Al2O3 catalyst.

Science.gov (United States)

Kim, Hong-In; Park, Kyung-Ho; Mishra, Devabrata

2009-07-30

Dissolution of metals from a pre-oxidized refinery plant spent Co-Mo/Al(2)O(3) catalyst have been tried through low temperature (200-450 degrees C) sulfuric acid baking followed by mild leaching process. Direct sulfuric acid leaching of the same sample, resulted poor Al and Mo recoveries, whereas leaching after sulfuric acid baking significantly improved the recoveries of above two metals. The pre-oxidized spent catalyst, obtained from a Korean refinery plant found to contain 40% Al, 9.92% Mo, 2.28% Co, 2.5% C and trace amount of other elements such as Fe, Ni, S and P. XRD results indicated the host matrix to be poorly crystalline gamma- Al(2)O(3). The effect of various baking parameters such as catalyst-to-acid ratio, baking temperature and baking time on percentage dissolutions of metals has been studied. It was observed that, metals dissolution increases with increase in the baking temperature up to 300 degrees C, then decreases with further increase in the baking temperature. Under optimum baking condition more than 90% Co and Mo, and 93% Al could be dissolved from the spent catalyst with the following leaching condition: H(2)SO(4)=2% (v/v), temperature=95 degrees C, time=60 min and Pulp density=5%.

The importance of pre-treatment of spent hydrotreating catalysts on metals recovery

Directory of Open Access Journals (Sweden)

Alexandre Luiz de Souza Pereira

2011-01-01

Full Text Available This work describes a three-step pre-treatment route for processing spent commercial NiMo/Al2O3 catalysts. Extraction of soluble coke with n-hexane and/or leaching of foulant elements with oxalic acid were performed before burning insoluble coke under air. Oxidized catalysts were leached with 9 mol L-1 sulfuric acid. Iron was the only foulant element partially leached by oxalic acid. The amount of insoluble matter in sulfuric acid was drastically reduced when iron and/or soluble coke were previously removed. Losses of active phase metals (Ni, Mo during leaching with oxalic acid were compensated by the increase of their recovery in the sulfuric acid leachate.

The importance of pre-treatment of spent hydrotreating catalysts on metals recovery

Energy Technology Data Exchange (ETDEWEB)

Pereira, Alexandre Luiz de Souza; Silva, Cristiano Nunes da; Afonso, Julio Carlos, E-mail: julio@iq.ufrj.b [Universidade Federal do Rio de Janeiro (IQ/UFRJ), RJ (Brazil). Inst. de Quimica. Dept. de Quimica Analitica; Mantovano, Jose Luiz [Instituto de Engenharia Nuclear (CNEN/IEN-RJ), Rio de Janeiro, RJ (Brazil). Dept. de Quimica e Materiais Nucleares

2011-07-01

This work describes a three-step pre-treatment route for processing spent commercial Ni Mo/Al{sub 2}O{sub 3} catalysts. Extraction of soluble coke with n-hexane and/or leaching of foulant elements with oxalic acid were performed before burning insoluble coke under air. Oxidized catalysts were leached with 9 mol L{sup -1} sulfuric acid. Iron was the only foulant element partially leached by oxalic acid. The amount of insoluble matter in sulfuric acid was drastically reduced when iron and/or soluble coke were previously removed. Losses of active phase metals (Ni, Mo) during leaching with oxalic acid were compensated by the increase of their recovery in the sulfuric acid leachate. (author)

Two-step rapid sulfur capture. Final report

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-04-01

The primary goal of this program was to test the technical and economic feasibility of a novel dry sorbent injection process called the Two-Step Rapid Sulfur Capture process for several advanced coal utilization systems. The Two-Step Rapid Sulfur Capture process consists of limestone activation in a high temperature auxiliary burner for short times followed by sorbent quenching in a lower temperature sulfur containing coal combustion gas. The Two-Step Rapid Sulfur Capture process is based on the Non-Equilibrium Sulfur Capture process developed by the Energy Technology Office of Textron Defense Systems (ETO/TDS). Based on the Non-Equilibrium Sulfur Capture studies the range of conditions for optimum sorbent activation were thought to be: activation temperature > 2,200 K for activation times in the range of 10--30 ms. Therefore, the aim of the Two-Step process is to create a very active sorbent (under conditions similar to the bomb reactor) and complete the sulfur reaction under thermodynamically favorable conditions. A flow facility was designed and assembled to simulate the temperature, time, stoichiometry, and sulfur gas concentration prevalent in the advanced coal utilization systems such as gasifiers, fluidized bed combustors, mixed-metal oxide desulfurization systems, diesel engines, and gas turbines.

Sulfur metabolism in the extreme acidophile Acidithiobacillus caldus

Directory of Open Access Journals (Sweden)

Stefanie eMangold

2011-02-01

Full Text Available Given the challenges to life at low pH, an analysis of inorganic sulfur compound oxidation was initiated in the chemolithoautotrophic extremophile Acidithiobacillus caldus. A. caldus is able to metabolize elemental sulfur and a broad range of inorganic sulfur compounds. It has been implicated in the production of environmentally damaging acidic solutions as well as participating in industrial bioleaching operations where it forms part of microbial consortia used for the recovery of metal ions. Based upon the recently published A. caldus type strain genome sequence, a bioinformatic reconstruction of elemental sulfur and inorganic sulfur compound metabolism predicted genes included: sulfide quinone reductase (sqr, tetrathionate hydrolase (tth, two sox gene clusters potentially involved in thiosulfate oxidation (soxABXYZ, sulfur oxygenase reductase (sor, and various electron transport components. RNA transcript profiles by semi-quantitative reverse transcription PCR suggested up-regulation of sox genes in the presence of tetrathionate. Extensive gel based proteomic comparisons of total soluble and membrane enriched protein fractions during growth on elemental sulfur and tetrathionate identified differential protein levels from the two Sox clusters as well as several chaperone and stress proteins up-regulated in the presence of elemental sulfur. Proteomics results also suggested the involvement of heterodisulfide reductase (HdrABC in A. caldus inorganic sulfur compound metabolism. A putative new function of Hdr in acidophiles is discussed. Additional proteomic analysis evaluated protein expression differences between cells grown attached to solid, elemental sulfur versus planktonic cells. This study has provided insights into sulfur metabolism of this acidophilic chemolithotroph and gene expression during attachment to solid elemental sulfur.

Resource recovery from bio-based production processes: a future necessity?

DEFF Research Database (Denmark)

Mansouri, Seyed Soheil; S.B.A. Udugama, Isuru; Cignitti, Stefano

2017-01-01

The promise of transforming waste streams with small economic value into valuable products makes resource recovery technologies in bio-based production processes an attractive proposition. However, the use of resource recovery technologies in industrial applications is still minimal, despite its...... technologies to industrial bio-based production processes. The role and importance of economics, technology readiness and socio-environmental impacts of resource recovery in successfully implementing resource recovery technologies in industrial bio-based production processes is also discussed. Finally, based...... wide use in closely related processes such as dairy production. In this paper, a perspective on the role of resource recovery in bio-based production processes is provided through reviewing the past practice and identifying the benefits, opportunities and challenges of introducing resource recovery...

Removing oxygen from a solvent extractant in an uranium recovery process

International Nuclear Information System (INIS)

Hurst, F.J.; Brown, G.M.; Posey, F.A.

1984-01-01

An improvement in effecting uranium recovery from phosphoric acid solutions is provided by sparging dissolved oxygen contained in solutions and solvents used in a reductive stripping stage with an effective volume of a nonoxidizing gas before the introduction of the solutions and solvents into the stage. Effective volumes of nonoxidizing gases, selected from the group consisting of argon, carbon dioxide, carbon monoxide, helium, hydrogen, nitrogen, sulfur dioxide, and mixtures thereof, displace oxygen from the solutions and solvents thereby reduce deleterious effects of oxygen such as excessive consumption of elemental or ferrous and accumulation of complex iron phosphates or cruds

Efficiency of the sulfur-iodine thermochemical water splitting process for hydrogen production based on ADS

International Nuclear Information System (INIS)

Gonzalez, D.; Garcia, L.; Garcia, C.; Garcia, L.; Brayner, C.

2013-01-01

The current hydrogel production is based on fossil fuels; they have a huge contribution to the atmosphere's pollution. thermochemical water splitting cycles don't present this issue because the required process heat is obtained from nuclear energy and therefore, the environmental impact is smaller than using conventional fuels. One of the promising approaches to produce large quantities of hydrogen in an efficient way using nuclear energy is the sulfur-iodine (S-I) thermochemical water splitting cycle. The nuclear source proposed in this paper is a pebble bed gas cooled transmutation facility. Pebble bed very high temperature advanced systems have great perspectives to assume the future nuclear energy. Software based on Chemical Process Simulation (CPS) can be used to simulate the thermochemical water splitting sulfur-iodine cycle for hydrogen production. In this paper, a model for analyzing the sulfur-iodine process sensibility is developed. Efficiency is also calculated and the influence of different parameters on this value. The behavior of the proposed model before different values of initial reactant's flow is analyzed. (Author)

Sulfur-oxidizing autotrophic and mixotrophic denitrification processes for drinking water treatment: elimination of excess sulfate production and alkalinity requirement.

Science.gov (United States)

Sahinkaya, Erkan; Dursun, Nesrin

2012-09-01

This study evaluated the elimination of alkalinity need and excess sulfate generation of sulfur-based autotrophic denitrification process by stimulating simultaneous autotrophic and heterotrophic (mixotrophic) denitrification process in a column bioreactor by methanol supplementation. Also, denitrification performances of sulfur-based autotrophic and mixotrophic processes were compared. In autotrophic process, acidity produced by denitrifying sulfur-oxidizing bacteria was neutralized by the external NaHCO(3) supplementation. After stimulating mixotrophic denitrification process, the alkalinity need of the autotrophic process was satisfied by the alkalinity produced by heterotrophic denitrifiers. Decreasing and lastly eliminating the external alkalinity supplementation did not adversely affect the process performance. Complete denitrification of 75 mg L(-1) NO(3)-N under mixotrophic conditions at 4 h hydraulic retention time was achieved without external alkalinity supplementation and with effluent sulfate concentration lower than the drinking water guideline value of 250 mg L(-1). The denitrification rate of mixotrophic process (0.45 g NO(3)-N L(-1) d(-1)) was higher than that of autotrophic one (0.3 g NO(3)-N L(-1) d(-1)). Batch studies showed that the sulfur-based autotrophic nitrate reduction rate increased with increasing initial nitrate concentration and transient accumulation of nitrite was observed. Copyright © 2012 Elsevier Ltd. All rights reserved.

Removal of Sulfur from CaF2 Containing Desulfurization Slag Exhausted from Secondary Steelmaking Process by Oxidation

Science.gov (United States)

Hiraki, Takehito; Kobayashi, Junichi; Urushibata, Satomi; Matsubae, Kazuyo; Nagasaka, Tetsuya

2012-08-01

The oxidation behavior of sulfur in desulfurization slag generated from the secondary steelmaking process with air has been investigated in the temperature range of 973 K to 1373 K (700 °C to 1100 °C). Although a high removal rate of sulfur is not achieved at temperatures lower than 1273 K (1000 °C) because of the formation of CaSO4, most of the sulfur is rapidly removed from slag as SO2 gas in the 1273 K to 1373 K (700 °C to 1100 °C) range. This finding indicates that the desulfurization slag generated from the secondary steelmaking process can be reused as a desulfurized flux through air oxidation, making it possible to reduce significantly the amount of desulfurization slag for disposal.

Demand outlook for sulfur and high-sulfur petroleum coke

Energy Technology Data Exchange (ETDEWEB)

Koshkarov, V.Ya.; Danil' yan, P.G.; Feotov, V.E.; Gimaev, R.N.; Koshkarova, M.E.; Sadykova, S.R.; Vodovichenko, N.S.

1980-01-01

The feasibility of using sulfur and high-sulfur petroleum coke fines in pyrometallurgical processes and also in the chemical and coal-tar chemical industry is examined. Results of industrial tests on briquetting fines of petroleum coke with a petroleum binder are presented. The feasibility of using the obtained briquets in shaft furnace smelting of oxidized nickel ores, production of anode stock, and also in the chemical industry are demonstrated.

Dramatic reduction of sulfur dioxide emission in Northeastern China in the last decade

Science.gov (United States)

Yuan, J.

2017-12-01

Analysis of spatial and temporal variations of sulfur dioxide concentration in planetary boundary layer were conducted. The data were generated by NASA satellite daily from October of 2004 and were obtained through NASA Giovanni. The global monthly mean spatial distribution of sulfur dioxide showed several hot spots including: several spots on some islands in the Pacific Ocean, several spots in central America, and central Africa. Most of these hot spots of sulfur dioxide are related to known active volcanos. The biggest hot spot of sulfur dioxide were observed in Northeastern China. While high concentration sulfur dioxide was still observed in Northeastern China in 2017. The area averaged concentration of sulfur dioxide declined dramatically since its peak in 2008. This temporal trend indicates that sulfur reduction effort has been effective in the last decade or post 2008 financial crisis recovery lead an industry less sulfur dioxide emission.

CLINSULF sub-dew-point process for sulphur recovery

Energy Technology Data Exchange (ETDEWEB)

Heisel, M.; Marold, F.

1988-01-01

In a 2-reactor system, the CLINSULF process allows very high sulphur recovery rates. When operated at 100/sup 0/C at the outlet, i.e. below the sulphur solidification point, a sulphur recovery rate of more than 99.2% was achieved in a 2-reactor series. Assuming a 70% sulphur recovery in an upstream Claus furnace plus sulphur condenser, an overall sulphur recovery of more than 99.8% results for the 2-reactor system. This is approximately 2% higher than in conventional Claus plus SDP units, which mostly consist of 4 reactors or more. This means the the CLINSULF SSP process promises to be an improvement both in respect of efficiency and low investment cost.

Biologically removing sulfur from dilute gas flows

Science.gov (United States)

Ruitenberg, R.; Dijkman, H.; Buisman, C. J. N.

1999-05-01

A biological process has been developed to clean off-gases containing sulfur dioxide from industrial installations. The sulfur dioxide is converted into hydrogen sulfide, which can then be oxidized to elemental sulfur if not used on-site. The process produces no waste products that require disposal and has a low reagent consumption.

Sulfur metabolism in phototrophic sulfur bacteria

DEFF Research Database (Denmark)

Frigaard, Niels-Ulrik; Dahl, Christiane

2008-01-01

Phototrophic sulfur bacteria are characterized by oxidizing various inorganic sulfur compounds for use as electron donors in carbon dioxide fixation during anoxygenic photosynthetic growth. These bacteria are divided into the purple sulfur bacteria (PSB) and the green sulfur bacteria (GSB......). They utilize various combinations of sulfide, elemental sulfur, and thiosulfate and sometimes also ferrous iron and hydrogen as electron donors. This review focuses on the dissimilatory and assimilatory metabolism of inorganic sulfur compounds in these bacteria and also briefly discusses these metabolisms...... in other types of anoxygenic phototrophic bacteria. The biochemistry and genetics of sulfur compound oxidation in PSB and GSB are described in detail. A variety of enzymes catalyzing sulfur oxidation reactions have been isolated from GSB and PSB (especially Allochromatium vinosum, a representative...

A Comparison of Organic and Steam Rankine Cycle Power Systems for Waste Heat Recovery on Large Ships

DEFF Research Database (Denmark)

Andreasen, Jesper Graa; Meroni, Andrea; Haglind, Fredrik

2017-01-01

%) fuel case. The processes were compared based on their off-design performance for diesel engine loads in the range between 25% and 100%. The fluids considered in the organic Rankine cycle process were MM(hexamethyldisiloxane), toluene, n-pentane, i-pentane and c-pentane. The results of the comparison....... The net power production from the waste heat recovery units is generally higher for the low-sulfur fuel case. The steam Rankine cycle unit produces 18% more power at design compared to the high-sulfur fuel case, while the organic Rankine cycle unit using MM produces 33% more power....

Characteristics and adaptability of iron- and sulfur-oxidizing microorganisms used for the recovery of metals from minerals and their concentrates

Directory of Open Access Journals (Sweden)

Rawlings Douglas E

2005-05-01

Full Text Available Abstract Microorganisms are used in large-scale heap or tank aeration processes for the commercial extraction of a variety of metals from their ores or concentrates. These include copper, cobalt, gold and, in the past, uranium. The metal solubilization processes are considered to be largely chemical with the microorganisms providing the chemicals and the space (exopolysaccharide layer where the mineral dissolution reactions occur. Temperatures at which these processes are carried out can vary from ambient to 80°C and the types of organisms present depends to a large extent on the process temperature used. Irrespective of the operation temperature, biomining microbes have several characteristics in common. One shared characteristic is their ability to produce the ferric iron and sulfuric acid required to degrade the mineral and facilitate metal recovery. Other characteristics are their ability to grow autotrophically, their acid-tolerance and their inherent metal resistance or ability to acquire metal resistance. Although the microorganisms that drive the process have the above properties in common, biomining microbes usually occur in consortia in which cross-feeding may occur such that a combination of microbes including some with heterotrophic tendencies may contribute to the efficiency of the process. The remarkable adaptability of these organisms is assisted by several of the processes being continuous-flow systems that enable the continual selection of microorganisms that are more efficient at mineral degradation. Adaptability is also assisted by the processes being open and non-sterile thereby permitting new organisms to enter. This openness allows for the possibility of new genes that improve cell fitness to be selected from the horizontal gene pool. Characteristics that biomining microorganisms have in common and examples of their remarkable adaptability are described.

Up-to-date prospects for development of natural gas and condensate processing in the USSR

International Nuclear Information System (INIS)

Gritsenko, A.I.; Tyurin, P.P.

1991-01-01

Three large gas processing complexes are expected to be guilt in North Kazakhstan, Western Siberia and Orenburg, in the USSR. With added low temperature emphasis on recovery of ethane, propane and butane, the operation of these complexes will hae an appreciable effect on both domestic and international markets. This paper reports that modifications of alumina and titanium oxide zeolites to new and existing Claus units will improve sulfur recovery by 3-4%. This will cut sulfur costs and improve the environment

Emission characteristics of nitrogen- and sulfur-containing odorous compounds during different sewage sludge chemical conditioning processes

Energy Technology Data Exchange (ETDEWEB)

Liu, Huan [State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074 (China); School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Luo, Guang-Qian; Hu, Hong-Yun [State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074 (China); Zhang, Qiang; Yang, Jia-Kuan [School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Yao, Hong, E-mail: hyao@hust.edu.cn [State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074 (China)

2012-10-15

Highlights: Black-Right-Pointing-Pointer NH{sub 3}, SO{sub 2}, H{sub 2}S and COS are emitted during different sludge conditioning processes. Black-Right-Pointing-Pointer H{sub 2}S and SO{sub 2} generation increase in the acidic environment created by H{sub 2}SO{sub 4}. Black-Right-Pointing-Pointer Fenton peroxidation facilitates the formation of COS. Black-Right-Pointing-Pointer CaO can reduce sulfur-containing gases emission via generation of calcium sulfate. Black-Right-Pointing-Pointer CaO leads to the conversion of free ammonia or protonated amine to volatile NH{sub 3}. - Abstract: Chemical conditioners are often used to enhance sewage sludge dewaterability through altering sludge properties and flocs structure, both affect odorous compounds emissions not only during sludge conditioning but also in subsequent sludge disposal. This study was to investigate emission characteristics of ammonia (NH{sub 3}), sulfur dioxide (SO{sub 2}), hydrogen sulfide (H{sub 2}S) and carbonyl sulfide (COS) generated from sewage sludge conditioned by three representative conditioners, i.e., organic polymers, iron salts and skeleton builders, F-S (Fenton's reagent and skeleton builders) composite conditioner. The results demonstrate that polyacrylamide (PAM) has an insignificant effect on emission characteristics of nitrogen- and sulfur-containing odorous compounds, because the properties, sulfur and nitrogen speciations are similar in PAM-conditioned sludge and raw sludge (RS). Significant increases of SO{sub 2} and H{sub 2}S emissions in the H{sub 2}SO{sub 4} conditioning process were observed due to the accelerated decomposition of sulfur-containing amino acids in acidic environment. Fenton peroxidation facilitates the formation of COS. CaO can reduce sulfur-containing gases emission via generation of calcium sulfate. However, under strong alkaline conditions, free ammonia or protonated amine in sludge can be easily converted to volatile ammonia, resulting in a significant

Biogenic sulfur compounds and the global sulfur cycle

International Nuclear Information System (INIS)

Aneja, V.P.; Aneja, A.P.; Adams, D.F.

1982-01-01

Field measurements of biogenic sulfur compounds shows a great variation in concentrations and emission rates for H 2 S, DMS, CS 2 and COS. Measurements by the chamber method and estimates from micrometeorological sampling are employed to determine the earth-atmosphere flux of these gases. Much of the variation can be attributed to differences of climate and surface conditions, with marshes being a large source of biogenic sulfur (mean contribution 4 x 10 to the 6th ton/year maximum contribution 142 x 10 to the 6th ton/year). Considering that the estimated biogenic contribution needed to balance the global sulfur cycle ranges from 40- 230 x 10 to the 6th tons/year, the mean values are not sufficient to balance this cycle. Further experimental investigations are suggested in order to characterize the biogenic processes adequately

Preliminary estimations on the heat recovery method for hydrogen production by the high temperature steam electrolysis

International Nuclear Information System (INIS)

Koh, Jae Hwa; Yoon, Duck Joo

2009-01-01

As a part of the project 'development of hydrogen production technologies by high temperature electrolysis using very high temperature reactor', we have developed an electrolyzer model for high temperature steam electrolysis (HTSE) system and carried out some preliminary estimations on the effects of heat recovery on the HTSE hydrogen production system. To produce massive hydrogen by using nuclear energy, the HTSE process is one of the promising technologies with sulfur-iodine and hybrid sulfur process. The HTSE produces hydrogen through electrochemical reaction within the solid oxide electrolysis cell (SOEC), which is a reverse reaction of solid oxide fuel cell (SOFC). The HTSE system generally operates in the temperature range of 700∼900 .deg. C. Advantages of HTSE hydrogen production are (a) clean hydrogen production from water without carbon oxide emission, (b) synergy effect due to using the current SOFC technology and (c) higher thermal efficiency of system when it is coupled nuclear reactor. Since the HTSE system operates over 700 .deg. C, the use of heat recovery is an important consideration for higher efficiency. In this paper, four different heat recovery configurations for the HTSE system have been investigated and estimated

Seed recovery and regeneration in coal-fired, open-cycle magnetohydrodynamic systems

International Nuclear Information System (INIS)

Sheth, A.C.; Jackson, D.M.; Attig, R.C.

1986-01-01

Coal-fired magnetohydrodynamic (MHD) power systems not only have high cycle efficiency, but they also have an inherent sulfur removal capability. The potassium compound uses as ''seed'' plays a dual role. It 1) increases the electrical conductivity of the plasma needed to produce power in the MHD electrical topping cycle, and 2) reacts with sulfur dioxide to form potassium sulfate, thereby eliminating most of the sulfur oxides from the gaseous effluent. For economical reasons, the spent seed must be recovered, desulfurized and recycled to the MHD power plant. This paper reviews some of the available experimental results and literature relating to SO 2 removal and seed recovery, and will also discuss several potential seed regeneration processes. Three methods of potassium extraction are discussed, i.e., hot aqueous digestion with CA(OH) 2 /NaOH, acid washing, and aqueous extraction. The selected candidate regeneration systems are discussed from the viewpoint of energy and process water requirements and environmental considerations such as waste discharges and emissions of gaseous, particulate and trace element pollutants

New insights into the extraction of invisible gold in a low-grade high-sulfur Carlin-type gold concentrate by bio-pretreatment

Science.gov (United States)

Qiu, Xiao-bin; Wen, Jian-kang; Huang, Song-tao; Yang, Hong-ying; Liu, Mei-lin; Wu, Biao

2017-10-01

To extract gold from a low-grade (13.43 g/t) and high-sulfur (39.94wt% sulfide sulfur) Carlin-type gold concentrate from the Nibao deposit, Guizhou, a bio-pretreatment followed by carbon-in-pulp (CIP) cyanide leaching process was used. Various methods were used to detect the low-grade gold in the concentrate; however, only time-of-flight secondary-ion mass spectrometry (TOF-SIMS) was successful. With bio-pretreatment, the gold recovery rate increased by approximately 70.16% compared with that obtained by direct cyanide leaching of the concentrate. Various attempts were made to increase the final gold recovery rate. However, approximately 20wt% of the gold was non-extractable. To determine the nature of this non-extractable gold, mineralogy liberation analysis (MLA), formation of secondary product during the bio-pretreatment, and the preg-robbing capacity of the carbonaceous matter in the ore were investigated. The results indicated that at least four factors affected the gold recovery rate: gold occurrence, tight junctions of gold-bearing pyrite with gangue minerals, jarosite coating of the ore, and the carbonaceous matter content.

Control of waste well casing vent gas from a thermal enhanced oil recovery operation

International Nuclear Information System (INIS)

Peavy, M.A.; Braun, J.E.

1991-01-01

This paper presents an overview of a waste gas treatment system designed to control emissions from thermally enhanced oil recovery wells. This case study discusses the need, design, installation and operations of the system. Oryx Energy Company (Oryx) operates approximately 940 wells in the Midway-Sunset (MWSS) field under casing vapor recovery systems. The emissions collected from well casing vent gas cotaining hydrocarbons and hydrogen sulfide that are collected and processed through casing vapor recovery skids. These skids are composed of condensers, compressors, and pumps that separate fluids from the waste gas stream. The non-condensible gas is then disposed of in incinerators that reduce the hydrocarbon and sulfur emissions into the atmosphere. Approximately 91,000 lbs/day of hydrocarbon and 10,116 lbs/day of sulfur dioxide are removed from the atmosphere from wells contained within these systems operated by Oryx. These hydrocarbons yield approximately 550 barrels of oil per day (BOPD). The system helps manage the pressure differential from the reservoir into each wellbore and contributes to improved ambient air quality in Kern County, California

Sulfur removal from low-sulfur gasoline and diesel fuel by metal-organic frameworks

Energy Technology Data Exchange (ETDEWEB)

Hagen, G.; Haemmerle, M.; Moos, R. [Functional Materials, University of Bayreuth, Bayreuth (Germany); Malkowsky, I.M.; Kiener, C. [BASF SE, Ludwigshafen (Germany); Achmann, S.

2010-02-15

Several materials in the class of metal-organic frameworks (MOF) were investigated to determine their sorption characteristics for sulfur compounds from fuels. The materials were tested using different model oils and common fuels such as low-sulfur gasoline or diesel fuel at room temperature and ambient pressure. Thiophene and tetrahydrothiophene (THT) were chosen as model substances. Total-sulfur concentrations in the model oils ranged from 30 mg/kg (S from thiophene) to 9 mg/kg (S from tetrahydrothiophene) as determined by elementary analysis. Initial sulfur contents of 8 mg/kg and 10 mg/kg were identified for low-sulfur gasoline and for diesel fuel, respectively, by analysis of the common liquid fuels. Most of the MOF materials examined were not suitable for use as sulfur adsorbers. However, a high efficiency for sulfur removal from fuels and model oils was noticed for a special copper-containing MOF (copper benzene-1,3,5-tricarboxylate, Cu-BTC-MOF). By use of this material, 78 wt % of the sulfur content was removed from thiophene containing model oils and an even higher decrease of up to 86 wt % was obtained for THT-based model oils. Moreover, the sulfur content of low-sulfur gasoline was reduced to 6.5 mg/kg, which represented a decrease of more than 22 %. The sulfur level in diesel fuel was reduced by an extent of 13 wt %. Time-resolved measurements demonstrated that the sulfur-sorption mainly occurs in the first 60 min after contact with the adsorbent, so that the total time span of the desulfurization process can be limited to 1 h. Therefore, this material seems to be highly suitable for sulfur reduction in commercial fuels in order to meet regulatory requirements and demands for automotive exhaust catalysis-systems or exhaust gas sensors. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

Personality and recovery: integrating personality assessment data to facilitate the recovery process.

Science.gov (United States)

Donat, D C

2001-01-01

The relatively enduring and persistent nature of personality traits means that they will likely continue to impact the course of psychiatric recovery after Axis I symptoms are stabilized. These traits can significantly impact the choices that recovering persons make and the quality of interpersonal relationships with care providers who are trying to facilitate the recovery process. Despite this, they are often inadequately assessed and considered in providing psychiatric care. This manuscript reviews the common combinations of personality traits that have emerged across a variety of clinical samples. The implications of these personality features for the provision of care in an inpatient setting to facilitate recovery are discussed.

Sulfur in serpentinized oceanic peridotites: Serpentinization processes and microbial sulfate reduction

Science.gov (United States)

Alt, J.C.; Shanks, Wayne C.

1998-01-01

The mineralogy, contents, and isotopic compositions of sulfur in oceanic serpentinites reflect variations in temperatures and fluid fluxes. Serpentinization of serpentinization of Iberian Margin peridotites occurred at low temperatures (???20??-200??C) and high water/rock ratios. Complete serpentinization and consumption of ferrous iron allowed evolution to higher fO2. Microbial reduction of seawater sulfate resulted in addition of low-??34S sulfide (-15 to -43???) and formation of higher-sulfur assemblages that include valleriite and pyrite. The high SO4/total S ratio of Hess Deep serpentinites (0.89) results in an increase of total sulfur and high ??34S of total sulfur (mean ??? 8???). In contrast, Iberian Margin serpentinites gained large amounts of 34S-poor sulfide (mean total S = 3800 ppm), and the high sulfide/total S ratio (0.61) results in a net decrease in ??34S of total sulfur (mean ??? -5???). Thus serpentinization is a net sink for seawater sulfur, but the amount fixed and its isotopic composition vary significantly. Serpentinization may result in uptake of 0.4-14 ?? 1012 g S yr-1 from the oceans, comparable to isotopic exchange in mafic rocks of seafloor hydrothermal systems and approaching global fluxes of riverine sulfate input and sedimentary sulfide output.

SULFUR POLYMER ENCAPSULATION

International Nuclear Information System (INIS)

KALB, P.

2001-01-01

Sulfur polymer cement (SPC) is a thermoplastic polymer consisting of 95 wt% elemental sulfur and 5 wt% organic modifiers to enhance long-term durability. SPC was originally developed by the U.S. Bureau of Mines as an alternative to hydraulic cement for construction applications. Previous attempts to use elemental sulfur as a construction material in the chemical industry failed due to premature degradation. These failures were caused by the internal stresses that result from changes in crystalline structure upon cooling of the material. By reacting elemental sulfur with organic polymers, the Bureau of Mines developed a product that successfully suppresses the solid phase transition and significantly improves the stability of the product. SPC, originally named modified sulfur cement, is produced from readily available, inexpensive waste sulfur derived from desulfurization of both flue gases and petroleum. The commercial production of SPC is licensed in the United States by Martin Resources (Odessa, Texas) and is marketed under the trade name Chement 2000. It is sold in granular form and is relatively inexpensive ((approx)$0.10 to 0.12/lb). Application of SPC for the treatment of radioactive, hazardous, and mixed wastes was initially developed and patented by Brookhaven National Laboratory (BNL) in the mid-1980s (Kalb and Colombo, 1985; Colombo et al., 1997). The process was subsequently investigated by the Commission of the European Communities (Van Dalen and Rijpkema, 1989), Idaho National Engineering Laboratory (Darnell, 1991), and Oak Ridge National Laboratory (Mattus and Mattus, 1994). SPC has been used primarily in microencapsulation applications but can also be used for macroencapsulation of waste. SPC microencapsulation has been demonstrated to be an effective treatment for a wide variety of wastes, including incinerator hearth and fly ash; aqueous concentrates such as sulfates, borates, and chlorides; blowdown solutions; soils; and sludges. It is not

Method for oxygen reduction in a uranium-recovery process. [US DOE patent application

Science.gov (United States)

Hurst, F.J.; Brown, G.M.; Posey, F.A.

1981-11-04

An improvement in effecting uranium recovery from phosphoric acid solutions is provided by sparging dissolved oxygen contained in solutions and solvents used in a reductive stripping stage with an effective volume of a nonoxidizing gas before the introduction of the solutions and solvents into the stage. Effective volumes of nonoxidizing gases, selected from the group consisting of argon, carbon dioxide, carbon monoxide, helium, hydrogen, nitrogen, sulfur dioxide, and mixtures thereof, displace oxygen from the solutions and solvents thereby reduce deleterious effects of oxygen such as excessive consumption of elemental or ferrous iron and accumulation of complex iron phosphates or cruds.

Study on the behavior of sulfur in hydrolysis process of titanyl sulfate solution

Energy Technology Data Exchange (ETDEWEB)

Zeng, Fanbo; Luo, Dongmei, E-mail: dmluo@scu.edu.cn; Zhang, Zhao; Liang, Bin; Yuan, Xizhi; Fu, Li

2016-06-15

The existing forms of sulfur in hydrolysis process of titanyl sulfate solution were studied. Also the effects of sulfur on crystal structure, crystallite size and crystal phase transition of the hydrated titanium dioxide(TiO{sub 2}·H{sub 2}O) and titanium dioxide (TiO{sub 2}) were conducted. The analysis and methods of thermogravimetric-differential scanning calorimet (TG-DSC), energy dispersive spectrometer (EDS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), UV–Vis diffuse reflectance spectra and Raman spectroscopy were employed to characterize. The results indicated that the sulfur was present in the form of SO{sub 4}{sup 2−} ions in the hydrolysate of titanyl sulfate solution, and a portion of SO{sub 4}{sup 2−} ions were combined on the surface of hydrated titanium dioxide by chemical adsorption in the forms of inorganic chelating bidentate coordination and covalent sulfate coordination, the residual SO{sub 4}{sup 2−} ions were adsorbed on the surface of hydrated titanium dioxide by physical adsorption. The chemical adsorption of SO{sub 4}{sup 2−} ions were conducive to the formation and stabilization of anatase, which changed the crystal structure, and hindered the transformation of the anatase into rutile. The results of Raman spectroscopy showed that the sulfur was dissociated in the forms of SO{sub 4}{sup 2−} and HSO{sub 4}{sup −} ions during the hydrolysis of titanyl sulfate solution. The characteristic peak at 1004 cm{sup −1} corresponding to a new complex has been observed, which was composed of SO{sub 4}{sup 2−} and hydrated titanium complex ions through the bonding on the surface. In basis of the above experimental results, the hydrolysis process of titanyl sulfate solution was illustrated from the microstructure with 3D atlas. - Highlights: • The SO{sub 4}{sup 2−} ions exist in TiO{sub 2}·H{sub 2}O by chemical and physical adsorption. • The SO{sub 4}{sup 2−} ions are conducive to the formation and

Global warming potential of the sulfur-iodine process using life cycle assessment methodology

International Nuclear Information System (INIS)

Lattin, William C.; Utgikar, Vivek P.

2009-01-01

A life cycle assessment (LCA) of one proposed method of hydrogen production - thermochemical water-splitting using the sulfur-iodine cycle couple with a very high-temperature nuclear reactor - is presented in this paper. Thermochemical water-splitting theoretically offers a higher overall efficiency than high-temperature electrolysis of water because heat from the nuclear reactor is provided directly to the hydrogen generation process, instead of using the intermediate step of generating electricity. The primary heat source for the S-I cycle is an advanced nuclear reactor operating at temperatures corresponding to those required by the sulfur-iodine process. This LCA examines the environmental impact of the combined advanced nuclear and hydrogen generation plants and focuses on quantifying the emissions of carbon dioxide per kilogram of hydrogen produced. The results are presented in terms of global warming potential (GWP). The GWP of the system is 2500 g carbon dioxide-equivalent (CO 2 -eq) per kilogram of hydrogen produced. The GWP of this process is approximately one-sixth of that for hydrogen production by steam reforming of natural gas, and is comparable to producing hydrogen from wind- or hydro-electric conventional electrolysis. (author)

Use of polymers in oil recovery processes

Energy Technology Data Exchange (ETDEWEB)

Stanislav, J.F.

Water-soluble polymers are used extensively in various stages of gas and oil production operations, typical examples being enhanced oil recovery, water production control, and well drilling. A variety of polymetric materials, both naturally occurring and synthetic ones, are currently used; guar and cellulose derivatives, xanthan gum, polysaccharides, polyacrylamides and others. In this work, only the application of polymeric materials to enhanced recovery processes is discussed.

A primer on sulfur for the planetary geologist

Science.gov (United States)

Theilig, E.

1982-01-01

Sulfur has been proposed as the dominant composition for the volcanic material on Io. Sulfur is a complex element which forms many intramolecular and intermolecular allotropes exhibiting a variety of physical properties. Cyclo-S8 sulfur is the most abundant and stable molecular form. The important molecular species within liquid sulfur change in concentration with temperature. Concentrations of the allotropes control the physical properties of the melt. Discontinuities in density, viscosity, and thermal properties reflect the polymerization process within liquid sulfur. Variations in the melting point are related to autodissociation of the liquid. Many solids forms of sulfur have been identified but only orthorhombic alpha and monoclinic beta sulfur, both composed of cyclo-S8 sulfur, are stable under terrestrial conditions. Physical properties of solid sulfur are dependent on the allotrope and, in some cases, the thermal history. Three natural terrestrial sulfur flows are described: (1) Siretoko-Iosan, Japan; (2) Volcan Azufre, Galapagos Islands; and (3) Mauna Loa, Hawaii. All of the flows are associated with fumarolic areas and are considered to have formed by the melting and mobilization of sulfur deposits. Surface textures of the flows indicate a behavior of molten sulfur similar to that of silicate lava. Channels, rivulets, and lobate edges were described for the flows. The solidification of man-made sulfur flows formed as part of the Frasch mining process by which sulfur is removed from the subsurface in a liquid state is described.

Process of recovering uranium from wet process acid

International Nuclear Information System (INIS)

York, W.R.

1983-01-01

Entrainment of contaminated water in the organic phase and poor phase disengagement is prevented in the second cycle scrubber, in a two cycle uranium recovery process, by washing the organic solvent stream containing entrained H 3 PO 4 from the second cycle extractor, with a dilute aqueous sulfuric or nitric acid solution in an acid scrubber, prior to passing the solvent stream into the second cycle stripper. (author)

Recovery and Separation of Valuable Metals from Spent Nickel-Metal Hydride Batteries using some Organophosphorus Extractants

International Nuclear Information System (INIS)

Aly, M.I.; Daoud, J.A.; ALy, H.F.

2012-01-01

The separation of cobalt, nickel, and rare earth elements from NiMH battery residues is evaluated in this paper. A hydrometallurgical process is developed for the recovery of metals from spent batteries and a selective separation of RE by precipitation of sodium RE double sulfate is performed. The methodology used benefits the solubility of the battery electrode materials in sulfuric or hydrochloric acids. The results obtained show that sulfuric acid is slightly less powerful in leaching (NiMH) compared to HCl acid. However, sulfuric acid was used on economic basis. Leaching solution was obtained by using 3 M H 2 SO 4 at 70 +1 degree C + 3% wt. H 2 O 2 for 5 hours. It has been shown that it is possible to recover about 98 % of the RE contained in spent NiMH batteries. The maximum recovery of nickel and cobalt metals was 99.9% and 99.4%, respectively. The effects of the main operating variables of both leaching and solvent extraction steps of nickel (II) and cobalt (II) from the leach solution using HDEHP (di-2-ethylhexyl phosphoric acid) and CYANEX 272 (di-(2,4,4 trimethyl pentyl) phosphinic acid) in kerosene were investigated aiming to maximize metal separation for recycling purposes. The developed process for the recovery and separation of nickel (II) , cobalt (II), and rare earth from spent NiMH batteries is tested and the obtained sulfate salts CoSO 4 and NiSO 4 have a high purity, suggesting that these recovered products could be used as chemical materials without further purification

Simultaneous heterotrophic and sulfur-oxidizing autotrophic denitrification process for drinking water treatment: control of sulfate production.

Science.gov (United States)

Sahinkaya, Erkan; Dursun, Nesrin; Kilic, Adem; Demirel, Sevgi; Uyanik, Sinan; Cinar, Ozer

2011-12-15

A long-term performance of a packed-bed bioreactor containing sulfur and limestone was evaluated for the denitrification of drinking water. Autotrophic denitrification rate was limited by the slow dissolution rate of sulfur and limestone. Dissolution of limestone for alkalinity supplementation increased hardness due to release of Ca(2+). Sulfate production is the main disadvantage of the sulfur autotrophic denitrification process. The effluent sulfate concentration was reduced to values below drinking water guidelines by stimulating the simultaneous heterotrophic and autotrophic denitrification with methanol supplementation. Complete removal of 75 mg/L NO(3)-N with effluent sulfate concentration of around 225 mg/L was achieved when methanol was supplemented at methanol/NO(3)-N ratio of 1.67 (mg/mg), which was much lower than the theoretical value of 2.47 for heterotrophic denitrification. Batch studies showed that sulfur-based autotrophic NO(2)-N reduction rate was around three times lower than the reduction rate of NO(3)-N, which led to NO(2)-N accumulation at high loadings. Copyright © 2011 Elsevier Ltd. All rights reserved.

Waste heat and water recovery opportunities in California tomato paste processing

International Nuclear Information System (INIS)

Amón, Ricardo; Maulhardt, Mike; Wong, Tony; Kazama, Don; Simmons, Christopher W.

2015-01-01

Water and energy efficiency are important for the vitality of the food processing industry as demand for these limited resources continues to increase. Tomato processing, which is dominated by paste production, is a major industry in California – where the majority of tomatoes are processed in the United States. Paste processing generates large amounts of condensate as moisture is removed from the fruit. Recovery of the waste heat in this condensate and reuse of the water may provide avenues to decrease net energy and water use at processing facilities. However, new processing methods are needed to create demand for the condensate waste heat. In this study, the potential to recover condensate waste heat and apply it to the tomato enzyme thermal inactivation processing step (the hot break) is assessed as a novel application. A modeling framework is established to predict heat transfer to tomatoes during the hot break. Heat recovery and reuse of the condensate water are related to energy and monetary savings gained through decreased use of steam, groundwater pumping, cooling towers, and wastewater processing. This analysis is informed by water and energy usage data from relevant unit operations at a commercial paste production facility. The case study indicates potential facility seasonal energy and monetary savings of 7.3 GWh and $166,000, respectively, with most savings gained through reduced natural gas use. The sensitivity of heat recovery to various process variables associated with heat exchanger design and processing conditions is presented to identify factors that affect waste heat recovery. - Highlights: • The potential to recovery waste heat in tomato paste processing is examined. • Heat transfer from evaporator condensate to tomatoes in the hot break is modeled. • Processing facility data is used in model to predict heat recovery energy savings. • The primary benefit of heat recovery is reduced use of natural gas in boilers. • Reusing

Complex processing of rubber waste through energy recovery

Directory of Open Access Journals (Sweden)

Roman Smelík

2015-12-01

Full Text Available This article deals with the applied energy recovery solutions for complex processing of rubber waste for energy recovery. It deals specifically with the solution that could maximize possible use of all rubber waste and does not create no additional waste that disposal would be expensive and dangerous for the environment. The project is economically viable and energy self-sufficient. The outputs of the process could replace natural gas and crude oil products. The other part of the process is also the separation of metals, which can be returned to the metallurgical secondary production.

Removal of organic and inorganic sulfur from Ohio coal by combined physical and chemical process. Final report

Energy Technology Data Exchange (ETDEWEB)

Attia, Y.A.; Zeky, M.El.; Lei, W.W.; Bavarian, F.; Yu, S. [Ohio State Univ., Columbus, OH (United States). Dept. of Materials Science and Engineering

1989-04-28

This project consisted of three sections. In the first part, the physical cleaning of Ohio coal by selective flocculation of ultrafine slurry was considered. In the second part, the mild oxidation process for removal of pyritic and organic sulfur.was investigated. Finally, in-the third part, the combined effects of these processes were studied. The physical cleaning and desulfurization of Ohio coal was achieved using selective flocculation of ultrafine coal slurry in conjunction with froth flotation as flocs separation method. The finely disseminated pyrite particles in Ohio coals, in particular Pittsburgh No.8 seam, make it necessary to use ultrafine ({minus}500 mesh) grinding to liberate the pyrite particles. Experiments were performed to identify the ``optimum`` operating conditions for selective flocculation process. The results indicated that the use of a totally hydrophobic flocculant (FR-7A) yielded the lowest levels of mineral matters and total sulfur contents. The use of a selective dispersant (PAAX) increased the rejection of pyritic sulfur further. In addition, different methods of floc separation techniques were tested. It was found that froth flotation system was the most efficient method for separation of small coal flocs.

Study on the Influence of Sulfur Fumigation on Chemical ...

African Journals Online (AJOL)

Purpose: To study the influence of different sulfur fumigation time and ... after sulfur fumigation though sulfur fumigation time and dosage were at low levels – 2 h ... Conclusion: Sulfur fumigation is not a desirable method for field processing of ...

Effect of Dietary Processed Sulfur Supplementation on Texture Quality, Color and Mineral Status of Dry-cured Ham.

Science.gov (United States)

Kim, Ji-Han; Ju, Min-Gu; Yeon, Su-Jung; Hong, Go-Eun; Park, WooJoon; Lee, Chi-Ho

2015-01-01

This study was performed to investigate the chemical composition, mineral status, oxidative stability, and texture attributes of dry-cured ham from pigs fed processed sulfur (S, 1 g/kg feed), and from those fed a basal diet (CON), during the period from weaning to slaughter (174 d). Total collagen content and soluble collagen of the S group was significantly higher than that of the control group (pham (pham from the control group, that from the S group exhibited lower springiness and gumminess; these results suggest that feeding processed sulfur to pigs can improve the quality of the texture and enhance the oxidative stability of dry-cured ham.

Effect of sulfur dioxide partial pressure on the reaction of iodine, sulfur dioxide and water

International Nuclear Information System (INIS)

Nakajima, Hayato; Imai, Yoshiyuki; Kasahara, Seiji; Kubo, Shinji; Onuki, Kaoru

2007-01-01

Effect of sulfur dioxide partial pressure on the reaction of iodine, sulfur dioxide and water, which is a unit reaction in the IS process for thermochemical hydrogen production, was studied experimentally at 323 K under iodine saturation. Quasi-equilibrium state was observed in the presence of sulfur dioxide gas at constant pressure. The composition of the poly-hydriodic acid solution formed was discussed assuming an ideal desulfurization by the reverse reaction of the Bunsen reaction. The value of HI/(HI+H 2 O) of the desulfurized solution was large at high sulfur dioxide pressure and reached the maximum of 15.7 ± 0.3 mol%. (author)

Simultaneous bioreduction of nitrate and chromate using sulfur-based mixotrophic denitrification process

Energy Technology Data Exchange (ETDEWEB)

Sahinkaya, Erkan, E-mail: erkansahinkaya@yahoo.com [Istanbul Medeniyet University, Bioengineering Department, Goztepe, Istanbul (Turkey); Kilic, Adem [Harran University, Environmental Engineering Department, Osmanbey Campus, 63000 Sanliurfa (Turkey); Calimlioglu, Beste; Toker, Yasemin [Istanbul Medeniyet University, Bioengineering Department, Goztepe, Istanbul (Turkey)

2013-11-15

Highlights: • Simultaneous heterotrophic and autotrophic denitrification was stimulated. • Simultaneous bioreduction of nitrate and chromate was achieved. • Total chromium decreased <50 μg/L when the influent Cr(VI) was ≤5 mg/L. -- Abstract: This study aims at evaluating simultaneous chromate and nitrate reduction using sulfur-based mixotrophic denitrification process in a column reactor packed with elemental sulfur and activated carbon. The reactor was supplemented with methanol at C/N ratio of 1.33 or 2. Almost complete denitrification was achieved at influent NO{sub 3}{sup −}–N and Cr(VI) concentrations of 75 mg/L and 10 mg/L, respectively, and 3.7 h HRT. Maximum denitrification rate was 0.5 g NO{sub 3}{sup −}–N/(L.d) when the bioreactor was fed with 75 mg/L NO{sub 3}{sup −}–N, 150 mg/L methanol and 10 mg/L Cr(VI). The share of autotrophic denitrification was between 12% and 50% depending on HRT, C/N ratio and Cr(VI) concentration. Effluent total chromium was below 50 μg/L provided that influent Cr(VI) concentration was equal or below 5 mg/L. DGGE results showed stable microbial community throughout the operation and the presence of sulfur oxidizing denitrifying bacteria (Thiobacillus denitrificans) and Cr(VI) reducing bacteria (Exiguobacterium spp.) in the column bed.

Io's theothermal (sulfur) - Lithosphere cycle inferred from sulfur solubility modeling of Pele's magma supply

Science.gov (United States)

Battaglia, Steven M.; Stewart, Michael A.; Kieffer, Susan W.

2014-06-01

Surface deposits of volatile compounds such as water (Earth) or sulfur (Io) on volcanically active bodies suggest that a magmatic distillation process works to concentrate volatiles in surface reservoirs. On Earth, this is the combined hydrologic and tectonic cycle. On Io, sulfurous compounds are transferred from the interior to the surface reservoirs through a combination of a mantle-sourced magmatic system, vertical cycling of the lithosphere, and a sulfur-dominated crustal thermal system that we here call the "theothermal" system. We present a geochemical analysis of this process using previously inferred temperature and oxygen fugacity constraints of Pele's basaltic magma to determine the behavior of sulfur in the ionian magmas. Sulfate to sulfide ratios of Pele's magma are -4.084 ± 0.6 and -6.442 ± 0.7 log10 units, comparable to or lower than those of mid-ocean ridge basalts. This reflects the similarity of Io's oxidation state with Earth's depleted mantle as previously suggested by Zolotov and Fegley (Zolotov, M.Y., Fegley, B. [2000]. Geophys. Res. Lett. 27, 2789-2792). Our calculated limits of sulfur solubility in melts from Pele's patera (˜1100-1140 ppm) are also comparable to terrestrial mid-ocean ridge basalts, reflecting a compositional similarity of mantle sources. We propose that the excess sulfur obvious on Io's surface comes from two sources: (1) an insoluble sulfide liquid phase in the magma and (2) theothermal near-surface recycling.

Les sulfures dans les filons Sn-W de Panasqueira (Portugal). Approche du problème de l'argent.

OpenAIRE

Pirard, Eric

1984-01-01

Etude des paragenèses minérales de la mine de Panasqueira. Microanalyses des sulfures. Pistes pour améliorer la récupération de l'argent dans les installations de traitement du minerai. Pavonite, Schapbachite, Mathildite. Detailed study of mineral parageneses in the Panasqueira ore deposit. Microanalysis of sulphide phases. Suggestions for better recovery of silver in the mineral processing plant. Pavonite, Schapbachite, Mathildite.

Membrane-based processes for wastewater nutrient recovery: Technology, challenges, and future direction.

Science.gov (United States)

Xie, Ming; Shon, Ho Kyong; Gray, Stephen R; Elimelech, Menachem

2016-02-01

Wastewater nutrient recovery holds promise for more sustainable water and agricultural industries. We critically review three emerging membrane processes - forward osmosis (FO), membrane distillation (MD) and electrodialysis (ED) - that can advance wastewater nutrient recovery. Challenges associated with wastewater nutrient recovery were identified. The advantages and challenges of applying FO, MD, and ED technologies to wastewater nutrient recovery are discussed, and directions for future research and development are identified. Emphasis is given to exploration of the unique mass transfer properties of these membrane processes in the context of wastewater nutrient recovery. We highlight that hybridising these membrane processes with existing nutrient precipitation process will lead to better management of and more diverse pathways for near complete nutrient recovery in wastewater treatment facilities. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Process of Divorce Recovery: A Review of the Research.

Science.gov (United States)

Gastil, Richard W.

Many researchers have speculated over the nature of the divorce recovery process. Is the process similar to Kubler-Ross's stages of grief or does divorce recovery follow a unique process? This paper examines the current body of empirical research in an attempt to answer these questions. From the 91 sources analyzed, it was discovered that most of…

Biological removal of sulfur from coal flotation concentrate by culture isolated from coal washery plant tailing dump

Energy Technology Data Exchange (ETDEWEB)

Jorjani, E. [Azad University, Tehran (Iran). Mining Engineering Dept.

2005-10-15

A combination of flotation and microbial leaching processes was used to achieve acceptable level of sulfur and ash in Tabas coal sample of Iran. Representative sample of the minus 500 micron size fraction was subjected to flotation separation for the removal of ash and sulfur. The final concentrate with recovery, combustion value and sulfur content of 86.03, 86.45 and 1.35% respectively was achieved at pH 8 and following reagent dosage and operating conditions: collector: diesel oil (1200 g/ton), frother: MIBC (5%) + pine oil (95%) with concentration of 120 (g/ton), depressant: sodium silicate (1000 g/ton), particle size: {lt} 500 {mu} m and pulp density: 7%. Because of fine distribution of sulfur on Tabas coal macerals and lithotypes, high percentage of total sulfur (79.9%) is distributed in flotation concentrate and only 20.1% is yielded in the tails. So microbial leaching using a species isolated from coal washery plant tailing dump was used in batch system to remove sulfur from flotation concentrate. The conditions were optimized for the maximum removal of sulfur. These conditions were found to be pH of 2, particle size less than 0.18 mm; pulp density: 8%, temperature: 30 {sup o}C, shaking rate: 150 rpm conditions. Total sulfur and ash content was reduced by bioleaching from 13.55 and 1.35 in flotation concentrate to 9.47 and 0.55 in the final leached concentrate, a reduction of 35 and 61.9% respectively. Sterilization of coal adversely affects the sulfur reduction. The results suggest that the isolated culture is sufficiently effective for depyritization of Tabas coal flotation concentrate in stirred system.

Poststroke Trajectories: The Process of Recovery Over the Longer Term Following Stroke.

Science.gov (United States)

Hawkins, Rebecca J; Jowett, Adam; Godfrey, Mary; Mellish, Kirste; Young, John; Farrin, Amanda; Holloway, Ivana; Hewison, Jenny; Forster, Anne

2017-01-01

We adopted a grounded theory approach to explore the process of recovery experienced by stroke survivors over the longer term who were living in the community in the United Kingdom, and the interacting factors that are understood to have shaped their recovery trajectories. We used a combination of qualitative methods. From the accounts of 22 purposively sampled stroke survivors, four different recovery trajectories were evident: (a) meaningful recovery, (b) cycles of recovery and decline, (c) ongoing disruption, (d) gradual, ongoing decline. Building on the concept of the illness trajectory, our findings demonstrate how multiple, interacting factors shape the process and meaning of recovery over time. Such factors included conception of recovery and meanings given to the changing self, the meanings and consequences of health and illness experiences across the life course, loss, sense of agency, and enacting relationships. Awareness of the process of recovery will help professionals better support stroke survivors.

Exploring identity within the recovery process of people with serious mental illnesses.

Science.gov (United States)

Buckley-Walker, Kellie; Crowe, Trevor; Caputi, Peter

2010-01-01

To examine self-identity within the recovery processes of people with serious mental illnesses using a repertory grid methodology. Cross-sectional study involving 40 mental health service consumers. Participants rated different "self" and "other" elements on the repertory grid against constructs related to recovery, as well as other recovery focused measures. Perceptions of one's "ideal self" represented more advanced recovery in contrast to perceptions of "a person mentally unwell." Current perceptions of self were most similar to perceptions of "usual self" and least similar to "a person who is mentally unwell." Increased identification with one's "ideal self" reflected increased hopefulness in terms of recovery. The recovery repertory grid shows promise in clinical practice, in terms of exploring identity as a key variable within mental health recovery processes. Distance measures of similarity between various self-elements, including perceptions of others, maps logically against the recovery process of hope.

Applicability test of glass lining material for high-temperature acidic solutions of sulfuric acid in thermochemical water-splitting IS process

International Nuclear Information System (INIS)

Iwatsuki, Jin; Tanaka, Nobuyuki; Terada, Atsuhiko; Onuki, Kaoru; Watanabe, Yutaka

2010-01-01

A key issue for realizing the thermochemical IS process for hydrogen production is the selection of materials for working with high-temperature acidic solutions of sulfuric acid and hydriodic acid. Glass lining material is a promising candidate, which is composed of steel having good strength and glass having good corrosion resistance. Since the applicability of glass lining material depends strongly on the service condition, corrosion tests using glass used in glass lining material and heat cycle tests using glass lining piping were carried out to examine the possibility of using the glass lining material with high-temperature acidic solutions of sulfuric acid. It was confirmed that the glass lining materials exhibited sufficient corrosion resistance and heat resistance in high-temperature sulfuric acid of the IS process. (author)

Process Design Aspects for Scandium-Selective Leaching of Bauxite Residue with Sulfuric Acid

OpenAIRE

Konstantinos Hatzilyberis; Theopisti Lymperopoulou; Lamprini-Areti Tsakanika; Klaus-Michael Ochsenkühn; Paraskevas Georgiou; Nikolaos Defteraios; Fotios Tsopelas; Maria Ochsenkühn-Petropoulou

2018-01-01

Aiming at the industrial scale development of a Scandium (Sc)-selective leaching process of Bauxite Residue (BR), a set of process design aspects has been investigated. The interpretation of experimental data for Sc leaching yield, with sulfuric acid as the leaching solvent, has shown significant impact from acid feed concentration, mixing time, liquid to solids ratio (L/S), and number of cycles of leachate re-usage onto fresh BR. The thin film diffusion model, as the fundamental theory for l...

The fine sand Abra alba community of the Bay of Morlaix twenty years after the Amoco Cadiz oil spill

International Nuclear Information System (INIS)

Dauvin, J.-C.

1998-01-01

The fine sand Abra alba community from the Bay of Morlaix (western English Channel) was strongly affected by the Amoco Cadiz oil spill of April 1978. The long term changes in the community (1977-1996) show that reconstitution of this community is slow (over 10 yr). A progressive recolonization by amphipod Ampelisca populations constituting the dominant species is observed. The results show that it is necessary to survey the affected communities for a long period of time (> 10 yr) after an event to identify the real ecological impact of an oil spill. The abiotic and biotic factor existing in the Bay of Morlaix are favorable to the establishment and the persistence of stable dominant Ampelisca populations in time. The 'climax' concept seems to be applicable to this type of stable environment. The soft-bottom Abra alba community of the Bay of Morlaix may only support a maximal carrying capacity of approximately 10-11 g m -2 (mean annual biomass in decalcified dry weight). The deficit of production during 11 annual cycles may have affected the fish biomass feeding on this community. (author)

The fine sand Abra alba community of the Bay of Morlaix twenty years after the Amoco Cadiz oil spill

Energy Technology Data Exchange (ETDEWEB)

Dauvin, J.-C. [CNRS-UPRES-A Elico, Wimereux (France). Station Marine de Wimereux

1998-09-01

The fine sand Abra alba community from the Bay of Morlaix (western English Channel) was strongly affected by the Amoco Cadiz oil spill of April 1978. The long term changes in the community (1977-1996) show that reconstitution of this community is slow (over 10 yr). A progressive recolonization by amphipod Ampelisca populations constituting the dominant species is observed. The results show that it is necessary to survey the affected communities for a long period of time (> 10 yr) after an event to identify the real ecological impact of an oil spill. The abiotic and biotic factor existing in the Bay of Morlaix are favorable to the establishment and the persistence of stable dominant Ampelisca populations in time. The `climax` concept seems to be applicable to this type of stable environment. The soft-bottom Abra alba community of the Bay of Morlaix may only support a maximal carrying capacity of approximately 10-11 g m{sup -2} (mean annual biomass in decalcified dry weight). The deficit of production during 11 annual cycles may have affected the fish biomass feeding on this community. (author)

The role of complaint management in the service recovery process.

Science.gov (United States)

Bendall-Lyon, D; Powers, T L

2001-05-01

Patient satisfaction and retention can be influenced by the development of an effective service recovery program that can identify complaints and remedy failure points in the service system. Patient complaints provide organizations with an opportunity to resolve unsatisfactory situations and to track complaint data for quality improvement purposes. Service recovery is an important and effective customer retention tool. One way an organization can ensure repeat business is by developing a strong customer service program that includes service recovery as an essential component. The concept of service recovery involves the service provider taking responsive action to "recover" lost or dissatisfied customers and convert them into satisfied customers. Service recovery has proven to be cost-effective in other service industries. The complaint management process involves six steps that organizations can use to influence effective service recovery: (1) encourage complaints as a quality improvement tool; (2) establish a team of representatives to handle complaints; (3) resolve customer problems quickly and effectively; (4) develop a complaint database; (5) commit to identifying failure points in the service system; and (6) track trends and use information to improve service processes. Customer retention is enhanced when an organization can reclaim disgruntled patients through the development of effective service recovery programs. Health care organizations can become more customer oriented by taking advantage of the information provided by patient complaints, increasing patient satisfaction and retention in the process.

One-Step Extraction of Antimony in Low Temperature from Stibnite Concentrate Using Iron Oxide as Sulfur-Fixing Agent

Directory of Open Access Journals (Sweden)

Yun Li

2016-07-01

Full Text Available A new process for one-step extraction of antimony in low temperature from stibnite concentrate by reductive sulfur-fixation smelting in sodium molten salt, using iron oxide as sulfur-fixing agent, was presented. The influences of molten salt addition and composition, ferric oxide dosage, smelting temperature and duration on extraction efficiency of antimony were investigated in details, respectively. The optimum conditions were determined as follows: 1.0 time stoichiometric requirement (α of mixed sodium salt (αsalt = 1.0, WNaCl:Wsalt = 40%, αFe2O3 = 1.0, Wcoke:Wstibnite = 40%, where W represents weight, smelting at 850 °C (1123 K for 60 min. Under the optimum conditions, the direct recovery rate of antimony can reach 91.48%, and crude antimony with a purity of 96.00% has been achieved. 95.31% of sulfur is fixed in form of FeS in the presence of iron oxide. Meanwhile, precious metals contained in stibnite concentrate are enriched and recovered comprehensively in crude antimony. In comparison to traditional antimony pyrometallurgical process, the smelting temperature of present process is reduced from 1150–1200 °C (1423–1473 K to 850–900 °C (1123–1173 K. Sulfur obtained in stibnite is fixed in FeS which avoids SO2 emission owing to the sulfur-fixing agent. Sodium salt can be regenerated and recycled in smelting system when the molten slag is operated to filter solid residue. The solid residue is subjected to mineral dressing operation to obtain iron sulfide concentrate which can be sold directly or roasted to regenerate into iron oxide.

Processing of spent nickelcatalyst for fat recovery

Directory of Open Access Journals (Sweden)

NASIR Mohammad Ibraim

2001-01-01

Full Text Available Spent nickel catalyst (SNC has the potential of insulting the quality of the environment in a number of ways. Its disposal has a pollution effect. Optimum recovery of fat from SNC, could save the environment and reduce the oil loss. Hexane has been the solvent of choice for oil extraction. Alternative solvents considered to have been safer have been evaluated. Hexane, isopropanol, ethanol and heptane were examined using soxhlet extraction. While hexane is more efficient in oil recovery from SNC, isopropanol proved to be very good in clear separation of oil from waste material and also provides high solvent recovery compared to other solvents. Isopropanol extraction with chill separation of miscella into lower oil-rich phase, and an upper, solvent-rich recyclable phase save mush energy of vaporization for distilling. An aqueous extraction process with immiscible solvent assisted was tested. Solvent like hexane added to SNC, and water added later with continuous stirring. The mixture was stirred for about 30 minutes, prior to centrifugation. Aqueous process extracted less amount of oil compared to solvent extraction.

Estimation of combustion flue gas acid dew point during heat recovery and efficiency gain

Energy Technology Data Exchange (ETDEWEB)

Bahadori, A. [Curtin University of Technology, Perth, WA (Australia)

2011-06-15

When cooling combustion flue gas for heat recovery and efficiency gain, the temperature must not be allowed to drop below the sulfur trioxide dew point. Below the SO{sub 3} dew point, very corrosive sulfuric acid forms and leads to operational hazards on metal surfaces. In the present work, simple-to-use predictive tool, which is easier than existing approaches, less complicated with fewer computations is formulated to arrive at an appropriate estimation of acid dew point during combustion flue gas cooling which depends on fuel type, sulfur content in fuel, and excess air levels. The resulting information can then be applied to estimate the acid dew point, for sulfur in various fuels up to 0.10 volume fraction in gas (0.10 mass fraction in liquid), excess air fractions up to 0.25, and elemental concentrations of carbon up to 3. The proposed predictive tool shows a very good agreement with the reported data wherein the average absolute deviation percent was found to be around 3.18%. This approach can be of immense practical value for engineers and scientists for a quick estimation of acid dew point during combustion flue gas cooling for heat recovery and efficiency gain for wide range of operating conditions without the necessity of any pilot plant setup and tedious experimental trials. In particular, process and combustion engineers would find the tool to be user friendly involving transparent calculations with no complex expressions for their applications.

RECYCLING OF PRINTED CIRCUIT BOARDS AIMING SILVER RECOVERY: A HYDROMETALLURGICAL ROUTE STUDY

Directory of Open Access Journals (Sweden)

Marcos Paulo Kohler Caldas

2015-06-01

Full Text Available The aim of this paper is characterize printed circuit board of computers and propose a hydrometallurgical route for silver recovery present in its composition. Initially, the printed circuit board was comminuted in both knife and hammer mills. The comminuted material was characterized by sieve analysis, chemical analysis by inductively coupled plasma optical emission spectrometry (ICP-OES and loss on ignition. Leaching tests were conducted in sulfuric acid, sulfuric acid in an oxidizing medium and nitric acid. The results indicated that the printed circuit board is mainly composed of copper (19.42%. Silver content of 0.045% was found. The route for silver recovery was leaching in sulfuric acid at 75°C for 18 hours. Then, leaching in sulfuric acid at 75°C in an oxidizing medium for 6 hours and nitric acid leaching at room temperature for 2 hours. Through of this route, 96.6% of silver was recovered.

Waste acid/metal solution reduction and recovery by vacuum distillation

International Nuclear Information System (INIS)

Jones, E.O.; Wilcox, W.A.; Johnson, N.T.; Bowdish, F.W.

1995-01-01

Processes involving distillation under reduced pressure were developed at the Pacific Northwest Laboratory several years ago to recover spent acid solutions generated during the manufacture of nuclear fuel for the N-Reactor at the Hanford site. Following construction and testing of a pilot-plant, the technology was licensed to Viatec Recovery Systems, Inc. for commercialization. The technology developed included specialized distillation and rectification of volatile acids, removal of water and/or volatile acid from sulfuric acid, and precipitation of salts. A key feature of the Waste Acid Detoxification and Reclamation (WADR) technology is the development and use of advanced thermoplastic and fluoropolymer materials of construction in all critical process equipment. The technology was then expanded to include crystallization to recover metal salts for possible reuse. Economic and environmental advantages of the procedures include recovery of acids for reuse, simplification or elimination of the disposal of waste solutions, and possible recovery of metals. Industries expected to benefit from such applications include galvanizing, electroplating, sand leaching and any where metals are cleaned in acid solutions. Currently a modular system has been assembled for recovery of several different spent acid solutions

Microbiological disproportionation of inorganic sulfur compounds

DEFF Research Database (Denmark)

Finster, Kai

2008-01-01

The disproportionation of inorganic sulfur intermediates at moderate temperatures (0-80 °C) is a microbiologically catalyzed chemolithotrophic process in which compounds like elemental sulfur, thiosulfate, and sulfite serve as both electron donor and acceptor, and generate hydrogen sulfide and su...

Preparation and electrochemical performance of sulfur-alumina cathode material for lithium-sulfur batteries

International Nuclear Information System (INIS)

Dong, Kang; Wang, Shengping; Zhang, Hanyu; Wu, Jinping

2013-01-01

Highlights: ► Micron-sized alumina was synthesized as adsorbent for lithium-sulfur batteries. ► Sulfur-alumina material was synthesized via crystallizing nucleation. ► The Al 2 O 3 can provide surface area for the deposition of Li 2 S and Li 2 S 2 . ► The discharge capacity of the battery is improved during the first several cycles. - Abstract: Nano-sized sulfur particles exhibiting good adhesion with conducting acetylene black and alumina composite materials were synthesized by means of an evaporated solvent and a concentrated crystallization method for use as the cathodes of lithium-sulfur batteries. The composites were characterized and examined by X-ray diffraction, environmental scanning electron microscopy and electrochemical methods, such as cyclic voltammetry, electrical impedance spectroscopy and charge–discharge tests. Micron-sized flaky alumina was employed as an adsorbent for the cathode material. The initial discharge capacity of the cathode with the added alumina was 1171 mAh g −1 , and the remaining capacity was 585 mAh g −1 after 50 cycles at 0.25 mA cm −2 . Compared with bare sulfur electrodes, the electrodes containing alumina showed an obviously superior cycle performance, confirming that alumina can contribute to reducing the dissolution of polysulfides into electrolytes during the sulfur charge–discharge process

Graphene-sulfur nanocomposites for rechargeable lithium-sulfur battery electrodes

Science.gov (United States)

Liu, Jun; Lemmon, John P; Yang, Zhenguo; Cao, Yuiliang; Li, Xiaolin

2014-06-17

Rechargeable lithium-sulfur batteries having a cathode that includes a graphene-sulfur nanocomposite can exhibit improved characteristics. The graphene-sulfur nanocomposite can be characterized by graphene sheets with particles of sulfur adsorbed to the graphene sheets. The sulfur particles have an average diameter less than 50 nm..

A process for uranium recovery in phosphoric acid

International Nuclear Information System (INIS)

Duarte Neto, J.

1984-01-01

Results are presented about studies carried out envisaging the development of a process for uranium recovery from phosphoric acid, produced from the concentrate obtained from phosphorus-uraniferous mineral from Itataia mines (CE, Brazil). This process uses a mixture of DEPA-TOPO as extractant and the extraction cycle involves the following stages: acid pre-treatment; adjustment of the oxidation potential so to ensure that all uranium is hexavalent; extraction of uranium from the acid; screening of the solvent to remove undesirable impurities; uranium re-extraction and precipitation; solvent recovery. A micro-pilot plant for continuous processing was built up. Data collected showed that uranium can be recovered with an yield greater than 99%, thus proving the feasibility of the process and encouraging the construction of a bigger scale plant. (Author) [pt

Quadruple sulfur isotope constraints on the origin and cycling of volatile organic sulfur compounds in a stratified sulfidic lake

Science.gov (United States)

Oduro, Harry; Kamyshny, Alexey; Zerkle, Aubrey L.; Li, Yue; Farquhar, James

2013-11-01

We have quantified the major forms of volatile organic sulfur compounds (VOSCs) distributed in the water column of stratified freshwater Fayetteville Green Lake (FGL), to evaluate the biogeochemical pathways involved in their production. The lake's anoxic deep waters contain high concentrations of sulfate (12-16 mmol L-1) and sulfide (0.12 μmol L-1 to 1.5 mmol L-1) with relatively low VOSC concentrations, ranging from 0.1 nmol L-1 to 2.8 μmol L-1. Sulfur isotope measurements of combined volatile organic sulfur compounds demonstrate that VOSC species are formed primarily from reduced sulfur (H2S/HS-) and zero-valent sulfur (ZVS), with little input from sulfate. Thedata support a role of a combination of biological and abiotic processes in formation of carbon-sulfur bonds between reactive sulfur species and methyl groups of lignin components. These processes are responsible for very fast turnover of VOSC species, maintaining their low levels in FGL. No dimethylsulfoniopropionate (DMSP) was detected by Electrospray Ionization Mass Spectrometry (ESI-MS) in the lake water column or in planktonic extracts. These observations indicate a pathway distinct from oceanic and coastal marine environments, where dimethylsulfide (DMS) and other VOSC species are principally produced via the breakdown of DMSP by plankton species.

Removal of mercury from coal via a microbial pretreatment process

Science.gov (United States)

Borole, Abhijeet P [Knoxville, TN; Hamilton, Choo Y [Knoxville, TN

2011-08-16

A process for the removal of mercury from coal prior to combustion is disclosed. The process is based on use of microorganisms to oxidize iron, sulfur and other species binding mercury within the coal, followed by volatilization of mercury by the microorganisms. The microorganisms are from a class of iron and/or sulfur oxidizing bacteria. The process involves contacting coal with the bacteria in a batch or continuous manner. The mercury is first solubilized from the coal, followed by microbial reduction to elemental mercury, which is stripped off by sparging gas and captured by a mercury recovery unit, giving mercury-free coal. The mercury can be recovered in pure form from the sorbents via additional processing.

Enhanced gas recovery program. Fourth annual report, October 1978-September 1979

Energy Technology Data Exchange (ETDEWEB)

Northrop, D A; Schuster, C L [eds.

1979-11-01

Massive hydraulic fracture diagnostic experiments continued in FY 79 with the major activity being focused on the development of wireline tool instrumentation. Nevada Test Site substantiate field data obtained in two experiments with Amoco in their Wattenberg field. A high-resolution, three-dimensional seismic survey program was initiated. The program will start with some experiments at shallow depths where the sand lenses outcrop and then move into greater depths to evaluate this technique. A logging program was also established to evaluate formation properties. Hydraulic and dynamic fracturing experiments were conducted adjacent to a tunnel complex at the Nevada Test Site and which are then directly observed by mining through the experiment area. Evaluation of fracturing tests at an interface between geologic formations with significantly different properties showed that the interface did not contain the fractures. A microcrack model has been formulated which downplays the importance of material properties and emphasizes the role of in-situ stresses for processes occurring at a crack tip. Multiple fracturing from a wellbore has been demonstrated for a High Energy Gas Frac concept. Finally, a Multi-Well Experiment has been defined whose objectives are to characterize in detail a lenticular gas reservoir of the Western United States and to evaluate state-of-the-art and developing technology for the recovery of gas from them.

Processing of combustible α-wastes. A summary of research and development to date with an evaluation of the development potential of the processes

International Nuclear Information System (INIS)

Wieczorek, H.; Hild, W.

On the basis of currently available literature six processes involving the oxidative treatment of combustible α-bearing wastes are described and discussed. The Wet Combustion in sulfuric/nitric acid at 250 0 C has the highest development potential. This is due to a relatively simple process, a relative low apparative requirement and the possibility of Plutonium recovery

Effect of commercial activated carbons in sulfur cathodes on the electrochemical properties of lithium/sulfur batteries

Energy Technology Data Exchange (ETDEWEB)

Park, Jin-Woo; Kim, Icpyo [School of Materials Science and Engineering, Gyeongsang National University, 501 Jinju-daero, Jinju, Gyeongnam 52828 (Korea, Republic of); Kim, Ki-Won; Nam, Tae-Hyun; Cho, Kwon-Koo; Ahn, Jou-Hyeon [Department of Materials Engineering and Convergence Technology, Gyeongsang National University, 501 Jinju-daero, Jinju, Gyeongnam 52828 (Korea, Republic of); Ryu, Ho-Suk [Department of Material and Energy Engineering, Gyeongwoon University, 730, Gangdong-ro, Sandong-myeon, Gumi, Gyeongbuk, 39160 (Korea, Republic of); Ahn, Hyo-Jun, E-mail: ahj@gnu.ac.kr [School of Materials Science and Engineering, Gyeongsang National University, 501 Jinju-daero, Jinju, Gyeongnam 52828 (Korea, Republic of); Department of Materials Engineering and Convergence Technology, Gyeongsang National University, 501 Jinju-daero, Jinju, Gyeongnam 52828 (Korea, Republic of)

2016-10-15

Highlights: • The sulfur/activated carbon composite is fabricated using commercial activated carbons. • The sulfur/activated carbon composite with coal shows the best performance. • The Li/S battery has capacities of 1240 mAh g{sup −1} at 1 C and 567 mAh g{sup −1} at 10 C. - Abstract: We prepared sulfur/active carbon composites via a simple solution-based process using the following commercial activated carbon-based materials: coal, coconut shells, and sawdust. Although elemental sulfur was not detected in any of the sulfur/activated carbon composites based on Thermogravimetric analysis, X-ray diffraction, and Raman spectroscopy, Energy-dispersive X-ray spectroscopy results confirmed its presence in the activated carbon. These results indicate that sulfur was successfully impregnated in the activated carbon and that all of the activated carbons acted as sulfur reservoirs. The sulfur/activated carbon composite cathode using coal exhibited the highest discharge capacity and best rate capability. The first discharge capacity at 1 C (1.672 A g{sup −1}) was 1240 mAh g{sup −1}, and a large reversible capacity of 567 mAh g{sup −1} was observed at 10 C (16.72 A g{sup −1}).

An efficient hybrid sulfur process using PEM electrolysis with a bayonet decomposition reactor - HTR2008-58207

International Nuclear Information System (INIS)

Gorensek, M. B.; Summers, W. A.; Lahoda, E. J.; Bolthrunis, C. O.; Greyvenstein, R.

2008-01-01

The Hybrid Sulfur (HyS) Process is being developed to produce hydrogen by water-splitting using heat from advanced nuclear reactors. It has the potential for high efficiency and competitive hydrogen production cost, and has been demonstrated at a laboratory scale. As a two-step process, the HyS is one of the simplest thermochemical cycles. The sulfuric acid decomposition reaction is common to all sulfur cycles, including the Sulfur-Iodine (SI) cycle. What distinguishes the HyS Process from the other sulfur cycles is the use of sulfur dioxide (SO 2 ) to depolarize the anode of a water electrolyzer. The two critical HyS Process components are the SO 2 - depolarized electrolyzer (SDE), and the high-temperature decomposition reactor. A proton exchange membrane (PEM)- type SDE and a silicon carbide bayonet-type high-temperature decomposition reactor are being developed for DOE's Nuclear Hydrogen Initiative (NHI) by Savannah River National Laboratory (SRNL) and by Sandia National Laboratories (SNL), respectively. The ultimate goal of the NHI-sponsored work is to couple the SDE and the reactor in an integrated laboratory scale experiment to prove the technical readiness of the HyS cycle for the NGNP demonstration. This paper describes the flowsheet that is being prepared to combine these two components into a viable process and presents the latest performance projections and economics for a HyS Process coupled to a PBMR heat source. The basic flowsheet for this process has been described elsewhere [4]. It requires an acid concentration section because the SDE product, which is limited to no more than 50% H 2 SO 4 by cell voltage considerations, is too dilute to be fed directly to the bayonet, which needs at least 65% H 2 SO 4 in the feed for acceptable performance. Optimization involved trade-offs between decomposition reaction and acid concentration heat requirements. The PBMR heat source can split its heat output between the decomposition reaction and either steam

Simultaneous nitrogen and phosphorus removal in the sulfur cycle-associated Enhanced Biological Phosphorus Removal (EBPR) process.

Science.gov (United States)

Wu, Di; Ekama, George A; Wang, Hai-Guang; Wei, Li; Lu, Hui; Chui, Ho-Kwong; Liu, Wen-Tso; Brdjanovic, Damir; van Loosdrecht, Mark C M; Chen, Guang-Hao

2014-02-01

Hong Kong has practiced seawater toilet flushing since 1958, saving 750,000 m(3) of freshwater every day. A high sulfate-to-COD ratio (>1.25 mg SO4(2-)/mg COD) in the saline sewage resulting from this practice has enabled us to develop the Sulfate reduction, Autotrophic denitrification and Nitrification Integrated (SANI(®)) process with minimal sludge production and oxygen demand. Recently, the SANI(®) process has been expanded to include Enhanced Biological Phosphorus Removal (EBPR) in an alternating anaerobic/limited-oxygen (LOS-EBPR) aerobic sequencing batch reactor (SBR). This paper presents further development - an anaerobic/anoxic denitrifying sulfur cycle-associated EBPR, named as DS-EBPR, bioprocess in an alternating anaerobic/anoxic SBR for simultaneous removal of organics, nitrogen and phosphorus. The 211 day SBR operation confirmed the sulfur cycle-associated biological phosphorus uptake utilizing nitrate as electron acceptor. This new bioprocess cannot only reduce operation time but also enhance volumetric loading of SBR compared with the LOS-EBPR. The DS-EBPR process performed well at high temperatures of 30 °C and a high salinity of 20% seawater. A synergistic relationship may exist between sulfur cycle and biological phosphorus removal as the optimal ratio of P-release to SO4(2-)-reduction is close to 1.0 mg P/mg S. There were no conventional PAOs in the sludge. Copyright © 2013 Elsevier Ltd. All rights reserved.

Formation of CuxS Layers on Polypropylene Sulfurized by Molten Sulfur

Directory of Open Access Journals (Sweden)

Rasa ALABURDAITĖ

2011-11-01

Full Text Available The processes of formation of electrically conductive layers of copper sulfides CuxS by the sorption-diffusion method on polypropylene (PP using molten sulfur as sulfurizing agent was investigated. The amount of sorbed sulfur increased with the increase of the duration of treatment. Copper sulfide layers were formed on the surface of polypropylene after the treatment of sulfurized polymer with Cu(II/I salt solution. The amount of copper sulfide in layer increased with the increase of treatment duration in copper salt solution. XRD spectra of PP films treated for 3 min with molten sulfur and then with Cu(II/I salt solution for the different time showed that the copper sulfide phases, mostly digenite, Cu2-xS and a-chalcocite, Cu2S were formed in the layers. Electromotive force measurement results confirmed the composition of formed CuxS layers on PP. The phase composition of layers also changed after the annealing. The value of electrical resistance of copper sulfide layers on PP varied from 20 W/cm2 to 80 W/cm2 and after annealing at 80 °C - in the interval of 10 W/cm2 - 60 W/cm2.http://dx.doi.org/10.5755/j01.ms.17.4.776

MATHEMATICAL SIMULATION OF THE INTERACTIONS AMONG CYANOBACTERIA, PURPLE SULFUR BACTERIA AND CHEMOTROPIC SULFUR BACTERIA IN MICROBIAL MAT COMMUNITIES

NARCIS (Netherlands)

DEWIT, R; VANDENENDE, FP; VANGEMERDEN, H

A deterministic one-dimensional reaction diffusion model was constructed to simulate benthic stratification patterns and population dynamics of cyanobacteria, purple and colorless sulfur bacteria as found in marine microbial mats. The model involves the major biogeochemical processes of the sulfur

FIELD DEMONSTRATION OF A MEMBRANE PROCESS TO RECOVER HEAVY HYDROCARBONS AND TO REMOVE WATER FROM NATURAL GAS

Energy Technology Data Exchange (ETDEWEB)

R. Baker; R. Hofmann; K.A. Lokhandwala

2003-02-14

The objective of this project is to design, construct and field demonstrate a membrane system to recover natural gas liquids (NGL) and remove water from raw natural gas. An extended field test to demonstrate system performance under real-world conditions would convince industry users of the efficiency and reliability of the process. The system has been designed and fabricated by Membrane Technology and Research, Inc. (MTR) and will be installed and operated at British Petroleum (BP)-Amoco's Pascagoula, MS plant. The Gas Research Institute will partially support the field demonstration and BP-Amoco will help install the unit and provide onsite operators and utilities. The gas processed by the membrane system will meet pipeline specifications for dewpoint and Btu value and can be delivered without further treatment to the pipeline. Based on data from prior membrane module tests, the process is likely to be significantly less expensive than glycol dehydration followed by propane refrigeration, the principal competitive technology. At the end of this demonstration project the process will be ready for commercialization. The route to commercialization will be developed during this project and may involve collaboration with other companies already servicing the natural gas processing industry.

Assessment of nanofiltration and reverse osmosis potentialities to recover metals, sulfuric acid, and recycled water from acid gold mining effluent.

Science.gov (United States)

Ricci, Bárbara C; Ferreira, Carolina D; Marques, Larissa S; Martins, Sofia S; Amaral, Míriam C S

This work assessed the potential of nanofiltration (NF) and reverse osmosis (RO) to treat acid streams contaminated with metals, such as effluent from the pressure oxidation process (POX) used in refractory gold ore processing. NF and RO were evaluated in terms of rejections of sulfuric acid and metals. Regarding NF, high sulfuric acid permeation (∼100%), was observed, while metals were retained with high efficiencies (∼90%), whereas RO led to high acid rejections (acid solutions contaminated by metals, such as POX effluent. In this context, a purified acid stream could be recovered in NF permeate, which could be further concentrated in RO. Recovered acid stream could be reused in the gold ore processing or commercialized. A metal-enriched stream could be also recovered in NF retentate and transferred to a subsequent metal recovery stage. In addition, considering the high acid rejection obtained through the proposed system, RO permeate could be used as recycling water.

Layered sulfur/PEDOT:PSS nano composite electrodes for lithium sulfur cell applications

Science.gov (United States)

Anilkumar, K. M.; Jinisha, B.; Manoj, M.; Pradeep, V. S.; Jayalekshmi, S.

2018-06-01

Lithium-Sulfur (Li-S) cells are emerging as the next generation energy storage devices owing to their impressive electrochemical properties with high theoretical specific capacity of 1675 mAh/g. Lack of electronic conductivity of sulfur, its volume expansion during high lithium intake and the shuttling effect due to the formation of soluble polysulfides are the main limitations, delaying the commercialization of this technology. To address these challenges, in the present work, the conducting polymer PEDOT:PSS is used as the covering matrix over the sulfur particles to improve their Li storage properties. The sulfur/PEDOT:PSS nanocomposite is synthesised using the hydrothermal process and its formation with the polymer coating over sulfur nanoparticles is established from the XRD, Raman spectroscopy, FE-SEM and TEM studies. The electrochemical studies show that the cells assembled using the sulfur/PEDOT:PSS nanocomposite as the cathode, with the components taken in the weight ratio of 9:1, offer a reversible capacity of 1191 mAh g-1 at 0.1C rate. These cells display stable electrochemical capacities over 200 cycles at gradually increasing current rates. The polymer layer facilitates electronic conduction and suppresses the polysulfide formation and the volume expansion of sulfur. A reversible capacity of 664 mAh g-1 is observed after 200 cycles at 1C rate with the capacity retention of 75 % of the initial stable capacity. The highlight of the present work is the possibility to achieve high discharge capacities at high C rates and the retention of a good percentage of the initial capacity over 200 cycles, for these Li-S cells.

Enhancement of the photo conversion efficiencies in Cu(In,Ga)(Se,S){sub 2} solar cells fabricated by two-step sulfurization process

Energy Technology Data Exchange (ETDEWEB)

Yang, JungYup; Nam, Junggyu; Kim, Dongseop; Lee, Dongho, E-mail: dhlee0333@gmail.com, E-mail: ddang@korea.ac.kr [Photovoltaic Development Team, Energy Storage Business Division, Samsung SDI, Cheonan-si 331-300 (Korea, Republic of); Kim, GeeYeong; Jo, William [Department of Physics and New and Renewable Energy Research Center, Ewha Womans University, Seoul 120-750 (Korea, Republic of); Kang, Yoonmook, E-mail: dhlee0333@gmail.com, E-mail: ddang@korea.ac.kr [KUKIST Green School, Graduate School of Energy and Environment, Korea University, Seoul 136-701 (Korea, Republic of)

2015-11-09

Cu(In,Ga)(Se,S){sub 2} (CIGSS) absorber layers were fabricated by using a modified two-stage sputter and a sequential selenization/sulfurization method, and the sulfurization process is changed from one-step to two-step. The two-step sulfurization was controlled with two different H{sub 2}S gas concentrations during the sulfurization treatment. This two-step process yielded remarkable improvements in the efficiency (+0.7%), open circuit voltage (+14 mV), short circuit current (+0.23 mA/cm{sup 2}), and fill factor (+0.21%) of a CIGSS device with 30 × 30 cm{sup 2} in size, owing to the good passivation at the grain boundary surface, uniform material composition among the grain boundaries, and modified depth profile of Ga and S. The deterioration of the P/N junction quality was prevented by the optimized S content in the CIGSS absorber layer. The effects of the passivation quality at the grain boundary surface, the material uniformity, the compositional depth profiles, the microstructure, and the electrical characteristics were examined by Kelvin probe force microscopy, X-ray diffraction, secondary ion mass spectrometry, scanning electron microscopy, and current-voltage curves, respectively. The two-step sulfurization process is experimentally found to be useful for obtaining good surface conditions and, enhancing the efficiency, for the mass production of large CIGSS modules.

Preparation and electrochemical performance of sulfur-alumina cathode material for lithium-sulfur batteries

Energy Technology Data Exchange (ETDEWEB)

Dong, Kang [Faculty of Material Science and Chemistry, China University of Geosciences, 388 Lumo Road, 430074 Wuhan (China); Wang, Shengping, E-mail: spwang@cug.edu.cn [Faculty of Material Science and Chemistry, China University of Geosciences, 388 Lumo Road, 430074 Wuhan (China); Zhang, Hanyu; Wu, Jinping [Faculty of Material Science and Chemistry, China University of Geosciences, 388 Lumo Road, 430074 Wuhan (China)

2013-06-01

Highlights: ► Micron-sized alumina was synthesized as adsorbent for lithium-sulfur batteries. ► Sulfur-alumina material was synthesized via crystallizing nucleation. ► The Al{sub 2}O{sub 3} can provide surface area for the deposition of Li{sub 2}S and Li{sub 2}S{sub 2}. ► The discharge capacity of the battery is improved during the first several cycles. - Abstract: Nano-sized sulfur particles exhibiting good adhesion with conducting acetylene black and alumina composite materials were synthesized by means of an evaporated solvent and a concentrated crystallization method for use as the cathodes of lithium-sulfur batteries. The composites were characterized and examined by X-ray diffraction, environmental scanning electron microscopy and electrochemical methods, such as cyclic voltammetry, electrical impedance spectroscopy and charge–discharge tests. Micron-sized flaky alumina was employed as an adsorbent for the cathode material. The initial discharge capacity of the cathode with the added alumina was 1171 mAh g{sup −1}, and the remaining capacity was 585 mAh g{sup −1} after 50 cycles at 0.25 mA cm{sup −2}. Compared with bare sulfur electrodes, the electrodes containing alumina showed an obviously superior cycle performance, confirming that alumina can contribute to reducing the dissolution of polysulfides into electrolytes during the sulfur charge–discharge process.

Uranium extraction process in a sulfuric medium by means of liquid emulsified membranes

International Nuclear Information System (INIS)

Monteillet, A.

1985-02-01

Uranium ore processing, after leaching by sulfuric acid, by liquid-liquid extraction is a rather heavy process, not suitable for small deposits. Extraction by emulsions was suggested. In this process the leachate is contacted with an oil in water type emulsion, a liquid organic membrane is formed by the continuous phase. Uranium complexes diffuse through the liquid membrane towards the dispersed aqueous phase of the emulsion (stripping solution). Uranium is recovered by breaking the emulsion. Are successively studied: development of stable emulsions, influence of emulsion composition on uranium transfer kinetics, transfer mechanisms through the membrane and modelling of kinetics data obtained in the experimental study [fr

Research and development on is process components for hydrogen production. (2) Corrosion resistance of glass lining in high temperature sulfuric acid

International Nuclear Information System (INIS)

Tanaka, Nobuyuki; Iwatsuki, Jin; Kubo, Shinji; Terada, Atsuhiko; Onuki, Kaoru

2009-01-01

Japan Atomic Energy Agency has been conducting a research and development on hydrogen production system using High Temperature Gas-Cooled Reactor. As a part of this effort, thermochemical water-splitting cycle featuring iodine- and sulfur-compounds (IS process) is under development considering its potential of large-scale economical hydrogen production. The IS process constitutes very severe environments on the materials of construction because of the corrosive nature of process chemicals, especially of the high temperature acidic solution of sulfuric acid and hydriodic acid dissolving iodine. Therefore, selection of the corrosion-resistant materials and development of the components has been studied as a crucial subject of the process development. This paper discusses corrosion resistance of commercially available glass-lining material in high temperature sulfuric acid. Corrosion resistance of a soda glass used for glass-lining was examined by immersion tests. The experiments were performed in 47-90wt% sulfuric acids at temperatures of up to 400degC and for the maximum immersion time of 100 hours using an autoclave designed for the concerned tests. In every condition tested, no indication of localized corrosion such as defect formation or pitting corrosion was observed. Also, the corrosion rates decreased with the progress of immersion, and were low enough (≅0.1 mm/year) after 60-90 hours of immersion probably due to formation of a silica rich surface. (author)

Recovery process of elite athletes: A review of contemporary methods

Directory of Open Access Journals (Sweden)

Veljović Draško

2012-01-01

Full Text Available A numerous training stimulus and competition as well can reduce level of abilities among athletes. This decline of performance can be a temporary phenomenon, with duration of several minutes or several hours after a workout, or take much longer, even a several days. The lack of adequate recovery process can influence on athletes not being able to train at the desired intensity or do not fully meet the tasks at the next training session. Chronic fatigue can lead to injuries, and therefore, full recovery is necessary for achieving optimal level of abilities that will ensure a better athletic performance. For this reasons, athletes often carry out a variety of techniques and methods aimed to recover after training or match. They have become a part of the training process and their purpose is reduction of stress and fatigue incurred as a result of daily exposure to intense training stimulus. There are numerous methods and techniques today that can accelerate the recovery process of athletes. For this reason it is necessary to know the efficiency of an adequate method which will be applied in the training process. The aim of this review article is to point to those currently used and their effects on the process of recovery after physical activity in elite sport.

Development of novel processes for Cu concentrates without producing sulfuric acid; Hiryusan hasseigata no atarashii doshigen shori gijutsu no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Awakura, Y; Hirato, T [Kyoto University, Kyoto (Japan)

1997-02-01

Studies are conducted to develop a new wet method for copper concentrates to replace the conventional dry smelting method for the settlement of problems involving the processing of impurities for environmental protection. A specimen of pyrites polycrystals is subjected to leaching at 80 {degree}C in a strongly acidic cupric solution. Findings are that the element sulfur generated in this process does not impede leaching and only approximately 4% of the sulfur is oxidized into sulfur ions; that the presence of more than 2g/liter of bromide ions produced during bromine-aid leaching of gold changes the structure of sulfur for the inhibition of leaching; that circulation of a bromine-containing leaching liquid is not desired since even a small amount of approximately 0.02mol/liter inhibits the leaching rate. Controlled potential electrolysis is performed for the anode in an acid solution containing CuCl, NaCl, and NaBr, for the observation of oxidation/reduction potentials predicted by Nernst`s equation. It is then disclosed that bromine is more effective than chlorine in gold leaching and that the solution potential during leaching agent regeneration enables the monitoring of solution constitution. 2 refs.

Process for recovery of lithium from spent lithium batteries

Energy Technology Data Exchange (ETDEWEB)

Kunugita, Eiichi; Jonghwa, Kim; Komasawa, Isao [Osaka Univ., Faculty of Engineering Science, Osaka, (Japan)

1989-07-10

An experimental study of the recovery and purification of lithium from spent lithium batteries was carried out, taking advantage of the characterisitics of lithium ion and its carbonate. More than 75% of the lithium contained in the whole battery or its anode component can be leached with sulfuric acid where the pH of the final pregnant liquor is 7.7 or higher, the other metals being left in the residue is their hydroxides. The extracted liquor is evaporated/concentrated, added with saturated sodium carbonate solution at around 100{sup 0}C to precipitate lithium as a carbonate. The coprecipitated sodium carbonate is washed/removed with a hotwater to give 99% pure lithium carbonate. Separation of lithium and sodium in the barren liquor is conducted with LIX 51, a chelating/extracting agent, and TOPO, a neutral organic phosphate, which have a synergic effect, to selectively extract lithium; the organic phase is reverse-extracted with a dilute hydrochloric acid to obtain lithium of 99% purity. 9 refs., 4 figs., 5 tabs.

Comparison of 2-Octanol and Tributyl Phosphate in Recovery of Tungsten from Sulfuric-Phosphoric Acid Leach Solution of Scheelite

Science.gov (United States)

Liao, Yulong; Zhao, Zhongwei

2018-04-01

Tungsten was recovered from sulfuric-phosphoric acid leach solution of scheelite using 2-octanol and tributyl phosphate (TBP). Approximately 76% of the tungsten and less than 6.2% of the iron were extracted when using 70% 2-octanol, showing good selectivity for tungsten over iron; the tungsten extraction could not be significantly enhanced using a three-stage countercurrent simulation test. Moreover, more than 99.2% of the W and 91.0% of the Fe were extracted when using 70% TBP, showing poor selectivity, but after pretreating the leach solution with iron powder, less than 5.5% of the Fe was extracted. The loaded phases were stripped using deionized water and ammonia solution. The maximum stripping rate of tungsten from loaded 2-octanol was 45.6% when using water, compared with only 13.1% from loaded TBP. Tungsten was efficiently stripped from loaded phases using ammonia solution without formation of Fe(OH)3 precipitate. Finally, a flow sheet for recovery of tungsten with TBP is proposed.

Sulfur and carbon geochemistry of the Santa Elena peridotites: Comparing oceanic and continental processes during peridotite alteration

Science.gov (United States)

Schwarzenbach, Esther M.; Gill, Benjamin C.; Gazel, Esteban; Madrigal, Pilar

2016-05-01

Ultramafic rocks exposed on the continent serve as a window into oceanic and continental processes of water-peridotite interaction, so called serpentinization. In both environments there are active carbon and sulfur cycles that contain abiogenic and biogenic processes, which are eventually imprinted in the geochemical signatures of the basement rocks and the calcite and magnesite deposits associated with fluids that issue from these systems. Here, we present the carbon and sulfur geochemistry of ultramafic rocks and carbonate deposits from the Santa Elena ophiolite in Costa Rica. The aim of this study is to leverage the geochemistry of the ultramafic sequence and associated deposits to distinguish between processes that were dominant during ocean floor alteration and those dominant during low-temperature, continental water-peridotite interaction. The peridotites are variably serpentinized with total sulfur concentrations up to 877 ppm that is typically dominated by sulfide over sulfate. With the exception of one sample the ultramafic rocks are characterized by positive δ34Ssulfide (up to + 23.1‰) and δ34Ssulfate values (up to + 35.0‰). Carbon contents in the peridotites are low and are isotopically distinct from typical oceanic serpentinites. In particular, δ13C of the inorganic carbon suggests that the carbon is not derived from seawater, but rather the product of the interaction of meteoric water with the ultramafic rocks. In contrast, the sulfur isotope data from sulfide minerals in the peridotites preserve evidence for interaction with a hydrothermal fluid. Specifically, they indicate closed system abiogenic sulfate reduction suggesting that oceanic serpentinization occurred with limited input of seawater. Overall, the geochemical signatures preserve evidence for both oceanic and continental water-rock interaction with the majority of carbon (and possibly sulfate) being incorporated during continental water-rock interaction. Furthermore, there is

The Chicxulub event - sulfur-bearing minerals and lithologies

Science.gov (United States)

Strauss, H.; Deutsch, A.

2003-04-01

Evaporates form a major target lithology at the Chicxulub impact site. One of the postulated effects of the impact event at the Cretaceous/Tertiary boundary is the impact-induced dissociation of anhydrite to form sulfur-oxides and a solid residue; large isotope fractionation effects in sulfur should accompany this process. We have analyzed the sulfur isotope composition of (i) annealed anhydrite clasts in impact melt breccias of PEMEX core Yucatan-6 N 19, (ii) unshocked anhydrite from the CSDP well Yaxcopoil-1, which belong to the megabreccia below the suevite layer (YAX-1 1369, and 1376 m depth), and (iii) sulfide grains of hydrothermal origin in a finest-grained breccia, which transects a large limestone block of this megabreccia at a depth of 1369 m. Samples of groups (i) and (ii) yielded δ34S values between 18.0 and 19.8 ppm CDT (unweighted mean is 18.3 ppm, n=7), with one slightly lower value of 15.3 ppm for an anhydrite clast in Y-6 N19/Part 6. These data are in agreement with the δ34S value for the Late Cretaceous seawater (Strauss 1999). The δ34S obviously remained unchanged despite the fact that textural features indicate a severe annealing of the clasts in the impact melt. Sulfides of group (iii) show δ34S values around 41 ppm CDT (n=7), which are quite unusual values if these minerals are of non-biogenic origin. In contrast, δ34S for the yellow glass from the K/T boundary at Haiti range from 1.5 to 13.2 ppm (Chaussidon et al. 1996). Using this preliminary evidence, we conclude that only distant ejecta lithologies, and probably secondary material inside the crater, may display impact-related fractionation of sulfur isotopes. This observation is consistent with petrologic data, modeling results as well as of shock recovery and annealing experiments: anhydrite obviously is quite resistant to shock-related dissociation.

Promoting information diffusion through interlayer recovery processes in multiplex networks

Science.gov (United States)

Wang, Xin; Li, Weihua; Liu, Longzhao; Pei, Sen; Tang, Shaoting; Zheng, Zhiming

2017-09-01

For information diffusion in multiplex networks, the effect of interlayer contagion on spreading dynamics has been explored in different settings. Nevertheless, the impact of interlayer recovery processes, i.e., the transition of nodes to stiflers in all layers after they become stiflers in any layer, still remains unclear. In this paper, we propose a modified ignorant-spreader-stifler model of rumor spreading equipped with an interlayer recovery mechanism. We find that the information diffusion can be effectively promoted for a range of interlayer recovery rates. By combining the mean-field approximation and the Markov chain approach, we derive the evolution equations of the diffusion process in two-layer homogeneous multiplex networks. The optimal interlayer recovery rate that achieves the maximal enhancement can be calculated by solving the equations numerically. In addition, we find that the promoting effect on a certain layer can be strengthened if information spreads more extensively within the counterpart layer. When applying the model to two-layer scale-free multiplex networks, with or without degree correlation, similar promoting effect is also observed in simulations. Our work indicates that the interlayer recovery process is beneficial to information diffusion in multiplex networks, which may have implications for designing efficient spreading strategies.

Recovery process for electroless plating baths

Science.gov (United States)

Anderson, Roger W.; Neff, Wayne A.

1992-01-01

A process for removing, from spent electroless metal plating bath solutions, accumulated byproducts and counter-ions that have deleterious effects on plating. The solution, or a portion thereof, is passed through a selected cation exchange resin bed in hydrogen form, the resin selected from strong acid cation exchangers and combinations of intermediate acid cation exchangers with strong acid cation exchangers. Sodium and nickel ions are sorbed in the selected cation exchanger, with little removal of other constituents. The remaining solution is subjected to sulfate removal through precipitation of calcium sulfate hemihydrate using, sequentially, CaO and then CaCO.sub.3. Phosphite removal from the solution is accomplished by the addition of MgO to form magnesium phosphite trihydrate. The washed precipitates of these steps can be safely discarded in nontoxic land fills, or used in various chemical industries. Finally, any remaining solution can be concentrated, adjusted for pH, and be ready for reuse. The plating metal can be removed from the exchanger with sulfuric acid or with the filtrate from the magnesium phosphite precipitation forming a sulfate of the plating metal for reuse. The process is illustrated as applied to processing electroless nickel plating baths.

Sulfur Earth

Science.gov (United States)

de Jong, B. H.

2007-12-01

Variations in surface tension affect the buoyancy of objects floating in a liquid. Thus an object floating in water will sink deeper in the presence of dishwater fluid. This is a very minor but measurable effect. It causes for instance ducks to drown in aqueous solutions with added surfactant. The surface tension of liquid iron is very strongly affected by the presence of sulfur which acts as a surfactant in this system varying between 1.9 and 0.4 N/m at 10 mass percent Sulfur (Lee & Morita (2002), This last value is inferred to be the maximum value for Sulfur inferred to be present in the liquid outer core. Venting of Sulfur from the liquid core manifests itself on the Earth surface by the 105 to 106 ton of sulfur vented into the atmosphere annually (Wedepohl, 1984). Inspection of surface Sulfur emission indicates that venting is non-homogeneously distributed over the Earth's surface. The implication of such large variation in surface tension in the liquid outer core are that at locally low Sulfur concentration, the liquid outer core does not wet the predominantly MgSiO3 matrix with which it is in contact. However at a local high in Sulfur, the liquid outer core wets this matrix which in the fluid state has a surface tension of 0.4 N/m (Bansal & Doremus, 1986), couples with it, and causes it to sink. This differential and diapiric movement is transmitted through the essentially brittle mantle (1024 Pa.s, Lambeck & Johnson, 1998; the maximum value for ice being about 1030 Pa.s at 0 K, in all likely hood representing an upper bound of viscosity for all materials) and manifests itself on the surface by the roughly 20 km differentiation, about 0.1 % of the total mantle thickness, between topographical heights and lows with concomitant lateral movement in the crust and upper mantle resulting in thin skin tectonics. The brittle nature of the medium though which this movement is transmitted suggests that the extremes in topography of the D" layer are similar in range to

Processing of LEU targets for 99Mo production--testing and modification of the Cintichem process

International Nuclear Information System (INIS)

Wu, D.; Landsberger, S.; Buchholz, B.

1995-09-01

Recent experimental results on testing and modification of the Cintichem process to allow substitution of low enriched uranium (LEU) for high enriched uranium (HEU) targets are presented in this report. The main focus is on 99 Mo recovery and purification by its precipitation with α-benzoin oxime. Parameters that were studied include concentrations of nitric and sulfuric acids, partial neutralization of the acids, molybdenum and uranium concentrations, and the ratio of α-benzoin oxime to molybdenum. Decontamination factors for uranium, neptunium, and various fission products were measured. Experiments with tracer levels of irradiated LEU were conducted for testing the 99 Mo recovery and purification during each step of the Cintichem process. Improving the process with additional processing steps was also attempted. The results indicate that the conversion of molybdenum chemical processing from HEU to LEU targets is possible

The fine sand Abra alba community of the Bay of Morlaix twenty years after the Amoco Cadiz oil spill

Energy Technology Data Exchange (ETDEWEB)

Dauvin, J.-C. [CNRS-UPRES-A Elico, Wimereux (France). Station Marine de Wimereux

1998-09-01

The fine sand Abra alba community from the Bay of Morlaix (western English Channel) was strongly affected by the Amoco Cadiz oil spill of April 1978. The long term changes in the community (1977-1996) show that reconstitution of this community is slow (over 10 yr). A progressive recolonization by amphipod Ampelisca populations constituting the dominant species is observed. The results show that it is necessary to survey the affected communities for a long period of time (> 10 yr) after an event to identify the real ecological impact of an oil spill. The abiotic and biotic factor existing in the Bay of Morlaix are favorable to the establishment and the persistence of stable dominant Ampelisca populations in time. The 'climax' concept seems to be applicable to this type of stable environment. The soft-bottom Abra alba community of the Bay of Morlaix may only support a maximal carrying capacity ofapproximately 10-11 g m{sup -2} (mean annual biomass in decalcified dry weight). The deficit of production during 11 annual cycles may have affected the fish biomass feeding on this community. (author)

Illness Insight and Recovery: How Important is Illness Insight in Peoples’ Recovery Process?

DEFF Research Database (Denmark)

Korsbek, Lisa

2013-01-01

. Sources Used:The writing is based on research literature related to illness insight and on personal recovery experiences.Conclusions and Implications for Practice: It is helpful to consider the integration of the issue of illness insight when addressing the questions and consequences of diagnosis......Topic: This account reflects on the topic of illness insight and recovery. Purpose: The purpose of the account is to clarify our understanding about the importance of illness insight in peoples’ recovery process, especially when relating the question of illness insight to the question of identity......, and to assist individuals to work through the false analogy between illness and identity while supporting the transformation from patient to person. It is also necessary for clinicians to develop a clear understanding of peoples’ actual needs and gain more knowledge about peoples’ own views and experiences...

Complementary Therapies – a spiritual resource in recovery-processes?

DEFF Research Database (Denmark)

Lunde, Anita; Dürr, Dorte Wiwe; Johannessen, Helle

rehabilitative treatments intends to support recovery processes of people with serious mental illness. Aim: To investigate how employees and residents perceive complementary therapies as an integral rehabilitative treatment, and to explore the recovery related implications of spirituality employed in the use...... and health as well as for the ethics of providing complementary treatment practice in social psychiatry....

Biologically produced sulfur

NARCIS (Netherlands)

Kleinjan, W.E.; Keizer, de A.; Janssen, A.J.H.

2003-01-01

Sulfur compound oxidizing bacteria produce sulfur as an intermediate in the oxidation of hydrogen sulfide to sulfate. Sulfur produced by these microorganisms can be stored in sulfur globules, located either inside or outside the cell. Excreted sulfur globules are colloidal particles which are

Auditory processing during deep propofol sedation and recovery from unconsciousness.

Science.gov (United States)

Koelsch, Stefan; Heinke, Wolfgang; Sammler, Daniela; Olthoff, Derk

2006-08-01

Using evoked potentials, this study investigated effects of deep propofol sedation, and effects of recovery from unconsciousness, on the processing of auditory information with stimuli suited to elicit a physical MMN, and a (music-syntactic) ERAN. Levels of sedation were assessed using the Bispectral Index (BIS) and the Modified Observer's Assessment of Alertness and Sedation Scale (MOAAS). EEG-measurements were performed during wakefulness, deep propofol sedation (MOAAS 2-3, mean BIS=68), and a recovery period. Between deep sedation and recovery period, the infusion rate of propofol was increased to achieve unconsciousness (MOAAS 0-1, mean BIS=35); EEG measurements of recovery period were performed after subjects regained consciousness. During deep sedation, the physical MMN was markedly reduced, but still significant. No ERAN was observed in this level. A clear P3a was elicited during deep sedation by those deviants, which were task-relevant during the awake state. As soon as subjects regained consciousness during the recovery period, a normal MMN was elicited. By contrast, the P3a was absent in the recovery period, and the P3b was markedly reduced. Results indicate that the auditory sensory memory (as indexed by the physical MMN) is still active, although strongly reduced, during deep sedation (MOAAS 2-3). The presence of the P3a indicates that attention-related processes are still operating during this level. Processes of syntactic analysis appear to be abolished during deep sedation. After propofol-induced anesthesia, the auditory sensory memory appears to operate normal as soon as subjects regain consciousness, whereas the attention-related processes indexed by P3a and P3b are markedly impaired. Results inform about effects of sedative drugs on auditory and attention-related mechanisms. The findings are important because these mechanisms are prerequisites for auditory awareness, auditory learning and memory, as well as language perception during anesthesia.

Shell launches its Claus off-gas desulfurization process

Energy Technology Data Exchange (ETDEWEB)

Groenendaal, W; van Meurs, H C.A.

1972-01-01

The Shell Flue Gas Desulfurization (SFGD) Process was developed for removal of sulfur oxides from flue gases originating from oil-fired boilers or furnaces. It can also be used to remove sulfur dioxide from Claus sulfur recovery tail gases if they are combined with boiler/furnace flue gases. For Claus tail gas only, the Shell Claus off-gas desulfurization process was developed. Claus unit operation and desulfurization by low temperature Claus processes and conversion/concentration processes are discussed. The new Shell process consists of a conversion/concentration process involving a reduction section and an amine absorption section. In the reduction section, all sulfur compounds and free sulfur are completely reduced to hydrogen sulfide with hydrogen, or hydrogen plus carbon monoxide, over a cobalt/molybdenum-on-alumina catalyst at a temperature of about 300/sup 0/C. Extensive bench scale studies on the reduction system have been carried out. A life test of more than 4000 hr showed a stable activity of the reduction catalyst, which means that in commercial units, very long catalyst lives can be expected. The commercial feasibility of the reduction section was further demonstrated in the Godorf refinery of Deutsche Shell AG. More than 80 absorption units using alkanolamine (AIDP) solutions have been installed. Bench scale studies of the ADIP absorption units were compared to commercial experience.The total capital investment of the new Shell process is 0.7, 2.0, and 3.2 $ times 10 to the 6th power for 100, 500, and 1000 tons of sulfur/sd capacity Claus units, respectively. The total operating costs for these units are, respectively, 610, 1930 and 3310 $/stream day. The capital investment corresponds to about 75% of the capital investment of the preceding Claus unit.

Oxidation of inorganic sulfur compounds in acidophilic prokaryotes

Energy Technology Data Exchange (ETDEWEB)

Rohwerder, T.; Sand, W. [Universitaet Duisburg-Essen, Biofilm Centre, Aquatic Biotechnology, Duisburg (Germany)

2007-07-15

The oxidation of reduced inorganic sulfur compounds to sulfuric acid is of great importance for biohydrometallurgical technologies as well as the formation of acidic (below pH 3) and often heavy metal-contaminated environments. The use of elemental sulfur as an electron donor is the predominant energy-yielding process in acidic natural sulfur-rich biotopes but also at mining sites containing sulfidic ores. Contrary to its significant role in the global sulfur cycle and its biotechnological importance, the microbial fundamentals of acidophilic sulfur oxidation are only incompletely understood. Besides giving an overview of sulfur-oxidizing acidophiles, this review describes the so far known enzymatic reactions related to elemental sulfur oxidation in acidophilic bacteria and archaea. Although generally similar reactions are employed in both prokaryotic groups, the stoichiometry of the key enzymes is different. Bacteria oxidize elemental sulfur by a sulfur dioxygenase to sulfite whereas in archaea, a sulfur oxygenase reductase is used forming equal amounts of sulfide and sulfite. In both cases, the activation mechanism of elemental sulfur is not known but highly reactive linear sulfur forms are assumed to be the actual substrate. Inhibition as well as promotion of these biochemical steps is highly relevant in bioleaching operations. An efficient oxidation can prevent the formation of passivating sulfur layers. In other cases, a specific inhibition of sulfur biooxidation may be beneficial for reducing cooling and neutralization costs. In conclusion, the demand for a better knowledge of the biochemistry of sulfur-oxidizing acidophiles is underlined. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

Progress in chemical treatment of LEU targets by the modified Cintichem process

International Nuclear Information System (INIS)

Wu, D.; Landsberger, S.; Vandegrift, G.F.

1996-01-01

Presented here are recent experimental results on tests of a modified Cintichem process for producing 99 Mo from low enriched uranium (LEU). Studies were focused in three areas: (1) testing the effects on 99 Mo recovery and purity of dissolving LEU foil in nitric acid alone, rather than in the sulfuric/nitric acid mixture currently used, (2) measuring decontamination factors for radionuclide impurities in each purification step, and (3) testing the effects on processing of adding barrier materials to the LEU metal-foil target. The experimental results show that switching from dissolving the target in the sulfuric/nitric mixture to using nitric acid alone should cause no significant difference in 99 Mo product yield or purity. Further, the results show that overall decontamination factors for gamma emitters in the LEU-target processing are high enough to meet the purity requirements for the 99 Mo product. The results also show that the selected barrier materials, Cu, Fe, and Ni, do not interfere with 99 Mo recovery and can be removed during chemical processing of the LEU target

Simple spectrophotometry method for the determination of sulfur dioxide in an alcohol-thionyl chloride reaction

Energy Technology Data Exchange (ETDEWEB)

Zheng, Jinjian, E-mail: jinjian.zheng@merck.com; Tan, Feng; Hartman, Robert

2015-09-03

negligible UV absorbance at 276 nm, and the UV absorbance is attributed only to sample matrix. Quantitation of sulfur dioxide is achieved by subtracting the UV absorbance of sample solution at pH 4.0 from that at pH 1.3. The method is simple but sensitive, with a limit of quantitation of 80 μg L{sup −1}. The method linearity was demonstrated from 2 mg L{sup −1} to 40 mg L{sup −1} with an R{sup 2} of 0.998, and the spiked recovery ranges from 94% to 105% within the same range. The results are comparable with those obtained using inductively coupled plasma–atomic emission spectrometry (ICP–AES) and gas chromatography–mass spectrometry (GC–MS), suggesting that this method is accurate. - Highlights: • Simple UV spectrometry method to quantitate sulfur dioxide in complex matrix. • Excellent sensitivity, linearity and accuracy. • Potential for real time monitoring using process analytical technology. • Possible applications in chemical, pharmaceutical, beverage and wine industries.

Mechanisms of Vanadium Recovery from Stone Coal by Novel BaCO3/CaO Composite Additive Roasting and Acid Leaching Technology

Directory of Open Access Journals (Sweden)

Zhenlei Cai

2016-03-01

Full Text Available In this report, the vanadium recovery mechanisms by novel BaCO3/CaO composite additive roasting and acid leaching technology, including the phase transformations and the vanadium leaching kinetics, were studied. The purpose of this manuscript is to realize and improve the vanadium recovery from stone coal using BaCO3/CaO as the composite additive. The results indicated that during the composite additive BaCO3/CaO roasting process, the monoclinic crystalline structure of muscovite (K(Al,V2[Si3AlO10](OH2 was converted into the hexagonal crystalline structure of BaSi4O9 and the tetragonal crystalline structure of Gehlenite (Ca2Al2SiO7, which could, therefore, facilitate the release and extraction of vanadium. Vanadium in leaching residue was probably in the form of vanadate or pyrovanadate of barium and calcium, which were hardly extracted during the sulfuric acid leaching process. The vanadium leaching kinetic analysis indicated that the leaching process was controlled by the diffusion through a product layer. The apparent activation energy could be achieved as 46.51 kJ/mol. The reaction order with respect to the sulfuric acid concentration was 1.1059. The kinetic model of vanadium recovery from stone coal using novel composite additive BaCO3/CaO could be finally established.

Tandem sulfur chemiluminescence and flame ionization detection with planar microfluidic devices for the characterization of sulfur compounds in hydrocarbon matrices.

Science.gov (United States)

Luong, J; Gras, R; Shellie, R A; Cortes, H J

2013-07-05

The detection of sulfur compounds in different hydrocarbon matrices, from light hydrocarbon feedstocks to medium synthetic crude oil feeds provides meaningful information for optimization of refining processes as well as demonstration of compliance with petroleum product specifications. With the incorporation of planar microfluidic devices in a novel chromatographic configuration, sulfur compounds from hydrogen sulfide to alkyl dibenzothiophenes and heavier distributions of sulfur compounds over a wide range of matrices spanning across a boiling point range of more than 650°C can be characterized, using one single analytical configuration in less than 25min. In tandem with a sulfur chemiluminescence detector for sulfur analysis is a flame ionization detector. The flame ionization detector can be used to establish the boiling point range of the sulfur compounds in various hydrocarbon fractions for elemental specific simulated distillation analysis as well as profiling the hydrocarbon matrices for process optimization. Repeatability of less than 3% RSD (n=20) over a range of 0.5-1000 parts per million (v/v) was obtained with a limit of detection of 50 parts per billion and a linear range of 0.5-1000 parts per million with a correlation co-efficient of 0.998. Copyright © 2013 Elsevier B.V. All rights reserved.

Extraction and Analysis of Sulfur Mustard (HD) from Various Food Matrices by Gas ChromatographyMass Spectrometry

Science.gov (United States)

2016-01-01

9 8. (a) GC chromatogram and (b) mass spectrum for HD extracted from hot dog; (c) mass spectrum at Rt = 5.08 min (benzoic acid ...shows the mass spectrum for benzoic acid . Percent recoveries were calculated based on an external calibration curve for HD (Figure 14). The recoveries...EXTRACTION AND ANALYSIS OF SULFUR MUSTARD ( HD ) FROM VARIOUS FOOD MATRICES BY GAS CHROMATOGRAPHY–MASS

Chemical process for improved oil recovery from Bakken shale

Energy Technology Data Exchange (ETDEWEB)

Shuler, Patrick; Tang, Hongxin; Lu, Zayne [ChemEOR Inc (United States); Tang, Youngchun [Power Environmental Energy Research Institute (United States)

2011-07-01

This paper presents the new chemically-improved oil recovery process (IOR) process for Bakken formation reservoirs. A custom surfactant agent can be used in standard hydraulic fracturing treatments in the Bakken to increase oil recovery. The rock formation consists of three members: the lower shale, middle dolostone and the upper shale. The dolostone was deposited as a coastal carbonate during shallower water and the shales were deposited in a relatively deep marine condition. With the widespread advent of horizontal well drilling and large-volume hydraulic fracturing treatments, production from the Bakken has become very active. The experimental results exhibited that specialized surfactant formulations will interact with this mixed oil-wet low permeability middle member to produce more oil. It was also observed that oil recovery by spontaneous imbibition was fast and significant. The best surfactant found in this study is compatible with a common fracture fluid system.

Improved analytical techniques of sulfur isotopic composition in nanomole quantities by MC-ICP-MS.

Science.gov (United States)

Yu, Tsai-Luen; Wang, Bo-Shian; Shen, Chuan-Chou; Wang, Pei-Ling; Yang, Tsanyao Frank; Burr, George S; Chen, Yue-Gau

2017-10-02

We propose an improved method for precise sulfur isotopic measurements by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) in conjunction with a membrane desolvation nebulization system. The problems of sulfur loss through the membrane desolvation apparatus are carefully quantified and resolved. The method overcomes low intrinsic sulfur transmission through the instrument, which was initially 1% when operating at a desolvation temperature of 160 °C. Sulfur loss through the membrane desolvation apparatus was resolved by doping with sodium. A Na/S ratio of 2 mol mol -1 produced sulfur transmissions with 98% recovery. Samples of 3 nmol (100 ng) sulfur achieved an external precision of ±0.18‰ (2 SD) for δ 34 S and ±0.10‰ (2 SD) for Δ 33 S (uppercase delta expresses the extent of mass-independent isotopic fractionation). Measurements made on certified reference materials and in-house standards demonstrate analytical accuracy and reproducibility. We applied the method to examine microbial-induced sulfur transformation in marine sediment pore waters from the sulfate-methane transition zone. The technique is quite versatile, and can be applied to a range of materials, including natural waters and minerals. Copyright © 2017 Elsevier B.V. All rights reserved.

Potentially beneficial spill-related effects of chemicals routinely added to crude oils

International Nuclear Information System (INIS)

Ross, S.; Maharaj, S.

1993-01-01

Amoco Trinidad Oil Company produces 60,000 bbl/d of oil from the Trinidadian offshore. The oil is pipelined ashore where it is processed and returned offshore to a buoy mooring for transport up Trinidad's east coast. Amoco Trinidad has developed comprehensive oil spill contingency plans, starting from computer models of spill scenarios. The models used initially assumed that the oils would emulsify quickly and the spills would become highly viscous and persistent, reaching the shoreline in 15-24 h. Such behavior would render ineffective the use of dispersants as a spill countermeasure. Studies showed a poor potential capability of physical recovery systems for spills off the Trinidad east coast due to high sea states, strong winds, and other factors. These results led to questioning of the spill model's assumptions, and laboratory tests were conducted to study the actual behavior of the crude oils. It was found that the oil was difficult to emulsify and highly prone to breakup and dispersion. These surprising results were explained by the presence of surfactants added during processing. A revised modelling exercise showed that if the surfactants stay with the oil, spills up to 100,000 bbl will dissipate in 15 h or less at average wind conditions. To guard against the possibility that the surfactants may not stay with the spilled oil, and to help accelerate dispersion of oil spills, Amoco Trinidad has developed a dispersant-use capacity for its spill contingency plan. It is suggested that additives normally added to crude oils during production and processing in other areas may also be providing spill cleanup benefits similar to those found in the Trinidad case. 9 refs., 1 fig., 4 tabs

Sulfur-Kβ /sub emission studies on sulfur-bearing heterocycles

International Nuclear Information System (INIS)

Phillips, D.R.; Andermann, G.G.; Fujiwara, F.

1986-01-01

Sulfur-K/β /sub x-ray fluorescence spectroscopy (XFS) has been used to study the electronic structure and bonding in sulfur-bearing heterocycles. XFS not only has the capability of experimentally measuring valence electron energies in molecular species, but can also provide intensity data which can help define the nature of the molecular orbitals defined by the electrons. This report discusses the feasibility of using XFS as an analytical tool for the determination of total and specific sulfur heterocycle content in samples. A variety of compounds were studied. These include thiophene, thiophene derivatives, tetranydrothiophene, several more complex saturated and unsaturated sulfur heterocycles, and heterocycles containing both sulfur and nitrogen. The sulfur-K/β /sub spectra were obtained using a double crystal spectrometer which provided an instrumental resolution of about 0.7 eV

Preparation of Cu2Sn3S7 Thin-Film Using a Three-Step Bake-Sulfurization-Sintering Process and Film Characterization

Directory of Open Access Journals (Sweden)

Tai-Hsiang Lui

2015-01-01

Full Text Available Cu2Sn3S7 (CTS can be used as the light absorbing layer for thin-film solar cells due to its good optical properties. In this research, the powder, baking, sulfur, and sintering (PBSS process was used instead of vacuum sputtering or electrochemical preparation to form CTS. During sintering, Cu and Sn powders mixed in stoichiometric ratio were coated to form the thin-film precursor. It was sulfurized in a sulfur atmosphere to form CTS. The CTS film metallurgy mechanism was investigated. After sintering at 500°C, the thin film formed the Cu2Sn3S7 phase and no impurity phase, improving its energy band gap. The interface of CTS film is continuous and the formation of intermetallic compound layer can increase the carrier concentration and mobility. Therefore, PBSS process prepared CTS can potentially be used as a solar cell absorption layer.

Measuring personal recovery - psychometric properties of the Swedish Questionnaire about the Process of Recovery (QPR-Swe).

Science.gov (United States)

Argentzell, Elisabeth; Hultqvist, Jenny; Neil, Sandra; Eklund, Mona

2017-10-01

Personal recovery, defined as an individual process towards meaning, is an important target within mental health services. Measuring recovery hence requires reliable and valid measures. The Process of Recovery Questionnaire (QPR) was developed for that purpose. The aim was to develop a Swedish version of the QPR (QPR-Swe) and explore its psychometric properties in terms of factor structure, internal consistency, construct validity and sensitivity to change. A total of 226 participants entered the study. The factor structure was investigated by Principal Component Analysis and Scree plot. Construct validity was addressed in terms of convergent validity against indicators of self-mastery, self-esteem, quality of life and self-rated health. A one-factor solution of QPR-Swe received better support than a two-factor solution. Good internal consistency was indicated, α = 0.92, and construct validity was satisfactory. The QPR-Swe showed preliminary sensitivity to change. The QPR-Swe showed promising initial psychometric properties in terms of internal consistency, convergent validity and sensitivity to change. The QPR-Swe is recommended for use in research and clinical contexts to assess personal recovery among people with mental illness.

Impact of burning oil as auxiliary fuel in kraft recovery furnaces upon SO2 emissions

International Nuclear Information System (INIS)

Someshwar, A.V.; Caron, A.L.; Pinkerton, J.E.

1990-01-01

The relationship between burning medium sulfur oil as auxiliary fuel in kraft recovery furnaces and SO 2 emissions was examined. Analysis of long-term CEMS SO 2 data from four furnaces shows no increase in SO 2 emissions as a result of oil burning. The results of field tests conducted at four furnaces while co-firing oil with liquor (up to 34% of total heat input) show that (1) average SO 2 emissions during the oil firing period either decreased or remained unchanged; (2) the overall sulfur retention within the furnace remained consistently high (more than 90%) with increasing levels of oil burning; (3) apportioning stack SO 2 emissions between those derived from oil and black liquor was infeasible. The results indicate that the same alkali fume generation processes that lead to the efficient capture of SO 2 resulting from black liquor combustion may be responsible for the capture of SO 2 resulting from sulfur-containing oil combustion

FIELD DEMONSTRATION OF A MEMBRANE PROCESS TO RECOVER HEAVY HYDROCARBONS AND TO REMOVE WATER FROM NATURAL GAS

Energy Technology Data Exchange (ETDEWEB)

R. Baker; T. Hofmann; J. Kaschemekat; K.A. Lokhandwala; Membrane Group; Module Group; Systems Group

2001-01-11

The objective of this project is to design, construct and field demonstrate a 3-MMscfd membrane system to recover natural gas liquids (NGL) and remove water from raw natural gas. An extended field test to demonstrate system performance under real-world conditions is required to convince industry users of the efficiency and reliability of the process. The system will be designed and fabricated by Membrane Technology and Research, Inc. (MTR) and then installed and operated at British Petroleum (BP)-Amoco's Pascagoula, MS plant. The Gas Research Institute will partially support the field demonstration and BP-Amoco will help install the unit and provide onsite operators and utilities. The gas processed by the membrane system will meet pipeline specifications for dewpoint and Btu value and can be delivered without further treatment to the pipeline. Based on data from prior membrane module tests, the process is likely to be significantly less expensive than glycol dehydration followed by propane refrigeration, the principal competitive technology. At the end of this demonstration project the process will be ready for commercialization. The route to commercialization will be developed during this project and may involve collaboration with other companies already servicing the natural gas processing industry.

Process Control for Precipitation Prevention in Space Water Recovery Systems

Science.gov (United States)

Sargusingh, Miriam; Callahan, Michael R.; Muirhead, Dean

2015-01-01

The ability to recover and purify water through physiochemical processes is crucial for realizing long-term human space missions, including both planetary habitation and space travel. Because of their robust nature, rotary distillation systems have been actively pursued by NASA as one of the technologies for water recovery from wastewater primarily comprised of human urine. A specific area of interest is the prevention of the formation of solids that could clog fluid lines and damage rotating equipment. To mitigate the formation of solids, operational constraints are in place that limits such that the concentration of key precipitating ions in the wastewater brine are below the theoretical threshold. This control in effected by limiting the amount of water recovered such that the risk of reaching the precipitation threshold is within acceptable limits. The water recovery limit is based on an empirically derived worst case wastewater composition. During the batch process, water recovery is estimated by monitoring the throughput of the system. NASA Johnson Space Center is working on means of enhancing the process controls to increase water recovery. Options include more precise prediction of the precipitation threshold. To this end, JSC is developing a means of more accurately measuring the constituent of the brine and/or wastewater. Another means would be to more accurately monitor the throughput of the system. In spring of 2015, testing will be performed to test strategies for optimizing water recovery without increasing the risk of solids formation in the brine.

Acidophilic sulfur disproportionation

Science.gov (United States)

Hardisty, Dalton S.; Olyphant, Greg A.; Bell, Jonathan B.; Johnson, Adam P.; Pratt, Lisa M.

2013-07-01

Bacterial disproportionation of elemental sulfur (S0) is a well-studied metabolism and is not previously reported to occur at pH values less than 4.5. In this study, a sediment core from an abandoned-coal-mine-waste deposit in Southwest Indiana revealed sulfur isotope fractionations between S0 and pyrite (Δ34Ses-py) of up to -35‰, inferred to indicate intense recycling of S0 via bacterial disproportionation and sulfide oxidation. Additionally, the chemistry of seasonally collected pore-water profiles were found to vary, with pore-water pH ranging from 2.2 to 3.8 and observed seasonal redox shifts expressed as abrupt transitions from Fe(III) to Fe(II) dominated conditions, often controlled by fluctuating water table depths. S0 is a common product during the oxidation of pyrite, a process known to generate acidic waters during weathering and production of acid mine drainage. The H2S product of S0 disproportionation, fractionated by up to -8.6‰, is rapidly oxidized to S0 near redox gradients via reaction with Fe(III) allowing for the accumulation of isotopically light S0 that can then become subject to further sulfur disproportionation. A mass-balance model for S0 incorporating pyrite oxidation, S0 disproportionation, and S0 oxidation readily explains the range of observed Δ34Ses-py and emphasizes the necessity of seasonally varying pyrite weathering and metabolic rates, as indicated by the pore water chemistry. The findings of this research suggest that S0 disproportionation is potentially a common microbial process at a pH < 4.5 and can create large sulfur isotope fractionations, even in the absence of sulfate reduction.

Graphene-wrapped sulfur nanospheres with ultra-high sulfur loading for high energy density lithium–sulfur batteries

Energy Technology Data Exchange (ETDEWEB)

Liu, Ya; Guo, Jinxin; Zhang, Jun, E-mail: zhangjun@zjnu.cn; Su, Qingmei; Du, Gaohui, E-mail: gaohuidu@zjnu.edu.cn

2015-01-01

Graphical abstract: - Highlights: • A graphene-wrapped sulfur nanospheres composite with 91 wt% S is prepared. • It shows highly improved electrochemical performance as cathode for Li–S cell. • The PVP coating and conductive graphene minimize polysulfides dissolution. • The flexible coatings with void space accommodate the volume expansion of sulfur. - Abstract: Lithium–sulfur (Li–S) battery with high theoretical energy density is one of the most promising energy storage systems for electric vehicles and intermittent renewable energy. However, due to the poor conductivity of the active material, considerable weight of the electrode is occupied by the conductive additives. Here we report a graphene-wrapped sulfur nanospheres composite (S-nanosphere@G) with sulfur content up to 91 wt% as the high energy density cathode material for Li–S battery. The sulfur nanospheres with diameter of 400–500 nm are synthesized through a solution-based approach with the existence of polyvinylpyrrolidone (PVP). Then the sulfur nanospheres are uniformly wrapped by conductive graphene sheets through the electrostatic interaction between graphene oxide and PVP, followed by reducing of graphene oxide with hydrazine. The design of graphene wrapped sulfur nanoarchitecture provides flexible conductive graphene coating with void space to accommodate the volume expansion of sulfur and to minimize polysulfide dissolution. As a result, the S-nanosphere@G nanocomposite with 91 wt% sulfur shows a reversible initial capacity of 970 mA h g{sup −1} and an average columbic efficiency > 96% over 100 cycles at a rate of 0.2 C. Taking the total mass of electrode into account, the S-nanosphere@G composite is a promising cathode material for high energy density Li–S batteries.

Multiple-heteroatom-containing sulfur compounds in a high sulfur coal

International Nuclear Information System (INIS)

Winans, R.E.; Neill, P.H.

1990-01-01

Flash vacuum pyrolysis of a high sulfur coal has been combined with high resolution mass spectrometry yielding information on aromatic sulfur compounds containing an additional heteroatom. Sulfur emission from coal utilization is a critical problem and in order to devise efficient methods for removing organic sulfur, it is important to know what types of molecules contain sulfur. A high sulfur Illinois No. 6 bituminous coal (Argonne Premium Coal Sample No. 3) was pyrolyzed on a platinum grid using a quartz probe inserted into a modified all glass heated inlet system and the products characterized by high resolution mass spectrometry (HRMS). A significant number of products were observed which contained both sulfur and an additional heteroatom. In some cases two additional heteroatoms were observed. These results are compared to those found in coal extracts and liquefaction products

Integration of the Mini-Sulfide Sulfite Anthraquinone (MSS-AQ) Pulping Process and Black Liquor Gasification in a Pulp Mill

Energy Technology Data Exchange (ETDEWEB)

Hasan Jameel, North Carolina State University; Adrianna Kirkman, North Carolina State University; Ravi Chandran,Thermochem Recovery International Brian Turk Research Triangle Institute; Brian Green, Research Triangle Institute

2010-01-27

As many of the recovery boilers and other pieces of large capital equipment of U.S. pulp mills are nearing the end of their useful life, the pulp and paper industry will soon need to make long-term investments in new technologies. The ability to install integrated, complete systems that are highly efficient will impact the industry’s energy use for decades to come. Developing a process for these new systems is key to the adoption of state-of-the-art technologies in the Forest Products industry. This project defined an integrated process model that combines mini-sulfide sulfite anthraquinone (MSS-AQ) pulping and black liquor gasification with a proprietary desulfurization process developed by the Research Triangle Institute. Black liquor gasification is an emerging technology that enables the use of MSS-AQ pulping, which results in higher yield, lower bleaching cost, lower sulfur emissions, and the elimination of causticization requirements. The recently developed gas cleanup/absorber technology can clean the product gas to a state suitable for use in a gas turbine and also regenerate the pulping chemicals needed to for the MSS-AQ pulping process. The combination of three advanced technologies into an integrated design will enable the pulping industry to achieve a new level of efficiency, environmental performance, and cost savings. Because the three technologies are complimentary, their adoption as a streamlined package will ensure their ability to deliver maximum energy and cost savings benefits. The process models developed by this project will enable the successful integration of new technologies into the next generation of chemical pulping mills. When compared to the Kraft reference pulp, the MSS-AQ procedures produced pulps with a 10-15 % yield benefit and the ISO brightness was 1.5-2 times greater. The pulp refined little easier and had a slightly lower apparent sheet density (In both the cases). At similar levels of tear index the MSS-AQ pulps also

Digestive recovery of sulfur-methyl-L-methionine and its bioaccessibility in Kimchi cabbages using a simulated in vitro digestion model system.

Science.gov (United States)

Lee, Hae-Rim; Cho, Sun-Duk; Lee, Woon Kyu; Kim, Gun-Hee; Shim, Soon-Mi

2014-01-15

Sulfur-methyl-L-methionine (SMM) has been known to provide various biological functions such as radical scavenging effect, inhibition of adipocyte differentiation, and prevention of gastric mucosal damage. Kimchi cabbages are known to be a major food source providing SMM but its bioaccessibility has not been studied. The objective of current study was to determine both the digestive stability of SMM and the amount released from Kimchi cabbages under a simulated in vitro digestion model system. The in vitro digestion model system simulating a human gastrointestinal tract was carried out for measuring digestive recovery and bioaccessibility of SMM. SMM was quantified by using high-performance liquid chromatography with a fluorescence detector. Recovery of an SMM standard after digestion was 0.68 and 0.65% for fasted and fed conditions, respectively, indicating that the digestive stability of the SMM standard was not affected by dietary energy or co-ingested food matrix. The SMM standard was also significantly stable in acidic pH (P < 0.05). The bioaccessibility of SMM from Kimchi cabbages was measured under a fasted condition, resulted in 8.83, 14.71 and 10.88%, for salivary, gastric and small intestinal phases, respectively. Results from our study suggest that SMM from Kimchi cabbages, a component of food sources, is more bioavailable than SMM by itself. © 2013 Society of Chemical Industry.

Insight into the loading temperature of sulfur on sulfur/carbon cathode in lithium-sulfur batteries

International Nuclear Information System (INIS)

Ye, Huan; Yin, Ya-Xia; Guo, Yu-Guo

2015-01-01

Highlights: • A cost-effective chemical activation method to prepare porous carbon nanospheres. • Carbon nanospheres with bimodal microporous structure show high specific area and large micropore volume. • The S/C composite cathodes with in-situformed S−C bond exhibit high sulfur activity with a reversible capacity of 1000 mA h g −1 . • S−C bond enables well confinement on sulfur and polysulfides. - Abstract: Lithium–sulfur batteries are highly desired because of their characteristics such as high energy density. However, the applications of Li-S batteries are limited because they exist dissolution of polysulfides into electrolytes. This study reports the preparation of sulfur cathodes by using bimodal microporous (0.5 nm and 0.8 nm to 2.0 nm) carbon spheres with high specific area (1992 m 2 g −1 ) and large micropore volume (1.2 g cm −1 ), as well as the encapsulation of polysulfides via formation of carbon–sulfur bonds in a sealed vacuum glass tube at high temperature. Given that sulfur and polysulfides are well confined by the S−C bond, the shuttle effect is effectively suppressed. The prepared S/C cathodes with a sulfur loading of up to 75% demonstrate high sulfur activity with reversible capacity of 1000 mA h g −1 at the current density of 0.1 A g −1 and good cycling stability (667 mA h g −1 after 100 cycles).

Recovery of acids from dilute streams : A review of process technologies

International Nuclear Information System (INIS)

Talnikar, Vivek Digambar; Mahajan, Yogesh Shankar

2014-01-01

Chemical process industries convert raw materials into useful products. Acids, among other chemicals, are used in many industries as reactants, solvents and also as catalysts in a few instances as well. Resulting streams are dilute, from which the acids must be recovered. For recovery, many technologies can be used by which acids can be regained as such or can be converted into other value-added products like esters. Membrane processes and biological processes are being researched academically and practiced industrially. These have their own advantages and disadvantages in view of conversion, energy consumption etc. These are not always advantageous and hence an alternate process technology is necessary like reactive separation (RS). RS is advantageous especially when the acid is to be converted to other useful products by reaction, due to additional advantages or because no other technology is well suited or due to cost considerations alone. Conventional process technologies use the reactor configuration followed by the subsequent separation sequence. This approach can sometimes suffer from lesser conversion, difficulties in separation etc. To overcome these problems, RS has an edge over other processes in terms of the recovery of the useful compounds. Reactive distillation (RD), reactive extraction (RE) and reactive chromatography (RC) are the separation technologies that can be useful for acid recovery in an economically feasible way. This review covers the various processes of acid recovery along with the recent work in the field of reactive separations

Getting sulfur on target

Energy Technology Data Exchange (ETDEWEB)

Halbert, T.R.; Brignac, G.B. [ExxonMobil Process Research Labs. (United States); Greeley, J.P.; Demmin, R.A.; Roundtree, E.M. [ExxonMobil Research and Engineering Co. (United States)

2000-06-01

The paper focuses on how the required reductions in sulfur levels in motor vehicle fuel may be achieved over about the next five years. It is said that broadly there are two possible approaches, they are: (a) to hydrotreat the feed to the FCC unit and (b) to treat the naphtha produced by the FCC unit. The difficulties associated with these processes are mentioned. The article is presented under the sub-headings of (i) technology options for cat naphtha desulfurisation; (ii) optimising fractionator design via improved VLE models; (iii) commercial experience with ICN SCANfining; (iv) mercaptan predictive models and (v) process improvements. It was concluded that the individual needs of the refiner can be addressed by ExxonMobil Research and Engineering (EMRE) and the necessary reductions in sulfur levels can be achieved.

Radiation induced sulfur dioxide removal

International Nuclear Information System (INIS)

Chmielewski, A.G.

2000-01-01

The biggest source of air pollution is the combustion of fossil fuels, were pollutants such as particulate, sulfur dioxide (SO 2 ), nitrogen oxides (NO x ), and volatile organic compounds (VOC) are emitted. Among these pollutants, sulfur dioxide plays the main role in acidification of the environment. The mechanism of sulfur dioxide transformation in the environment is partly photochemical. This is not direct photooxidation, however, but oxidation through formed radicals. Heterogenic reactions play an important role in this transformation as well; therefore, observations from environmental chemistry can be used in air pollution control engineering. One of the most promising technologies for desulfurization of the flue gases (and simultaneous denitrification) is radiation technology with an electron accelerator application. Contrary to the nitrogen oxides (NO x ) removal processes, which is based on pure radiation induced reactions, sulfur dioxide removal depends on two pathways: a thermochemical reaction in the presence of ammonia/water vapor and a radiation set of radiochemical reactions. The mechanism of these reactions and the consequent technological parameters of the process are discussed in this paper. The industrial application of this radiation technology is being implemented in an industrial pilot plant operated by INCT at EPS Kaweczyn. A full-scale industrial plant is currently in operation in China, and two others are under development in Japan and Poland. (author)

On the optimal design of the disassembly and recovery processes.

Science.gov (United States)

Xanthopoulos, A; Iakovou, E

2009-05-01

This paper tackles the problem of the optimal design of the recovery processes of the end-of-life (EOL) electric and electronic products, with a special focus on the disassembly issues. The objective is to recover as much ecological and economic value as possible, and to reduce the overall produced quantities of waste. In this context, a medium-range tactical problem is defined and a novel two-phased algorithm is presented for a remanufacturing-driven reverse supply chain. In the first phase, we propose a multicriteria/goal-programming analysis for the identification and the optimal selection of the most 'desirable' subassemblies and components to be disassembled for recovery, from a set of different types of EOL products. In the second phase, a multi-product, multi-period mixed-integer linear programming (MILP) model is presented, which addresses the optimization of the recovery processes, while taking into account explicitly the lead times of the disassembly and recovery processes. Moreover, a simulation-based solution approach is proposed for capturing the uncertainties in reverse logistics. The overall approach leads to an easy-to-use methodology that could support effectively middle level management decisions. Finally, the applicability of the developed methodology is illustrated by its application on a specific case study.

On the optimal design of the disassembly and recovery processes

International Nuclear Information System (INIS)

Xanthopoulos, A.; Iakovou, E.

2009-01-01

This paper tackles the problem of the optimal design of the recovery processes of the end-of-life (EOL) electric and electronic products, with a special focus on the disassembly issues. The objective is to recover as much ecological and economic value as possible, and to reduce the overall produced quantities of waste. In this context, a medium-range tactical problem is defined and a novel two-phased algorithm is presented for a remanufacturing-driven reverse supply chain. In the first phase, we propose a multicriteria/goal-programming analysis for the identification and the optimal selection of the most 'desirable' subassemblies and components to be disassembled for recovery, from a set of different types of EOL products. In the second phase, a multi-product, multi-period mixed-integer linear programming (MILP) model is presented, which addresses the optimization of the recovery processes, while taking into account explicitly the lead times of the disassembly and recovery processes. Moreover, a simulation-based solution approach is proposed for capturing the uncertainties in reverse logistics. The overall approach leads to an easy-to-use methodology that could support effectively middle level management decisions. Finally, the applicability of the developed methodology is illustrated by its application on a specific case study

Assessment of sulfide production risk in soil during the infiltration of domestic wastewater treated by a sulfur-utilizing denitrification process.

Science.gov (United States)

Ghorbel, L; Coudert, L; Gilbert, Y; Mercier, G; Blais, J F

2016-10-01

This study aimed to determine the potential of sulfide generation during infiltration through soil of domestic wastewater treated by a sulfur-utilizing denitrification process. Three types of soil with different permeability rates (K s = 0.028, 0.0013, and 0.00015 cm/s) were investigated to evaluate the potential risk of sulfur generation during the infiltration of domestic wastewater treated by a sulfur-utilizing denitrification system. These soils were thoroughly characterized and tested to assess their capacity to be used as drainages for wastewaters. Experiments were conducted under two operating modes (saturated and unsaturated). Sulfate, sulfide, and chemical oxygen demand (COD) levels were determined over a period of 100 days. Despite the high concentration of sulfates (200 mg/L) under anaerobic conditions (ORP = -297 mV), no significant amount of sulfide was generated in the aqueous (soil permeability did not have a noticeable effect on the infiltration of domestic wastewater treated by a sulfur-utilizing denitrification system due to low contents of organic matter (i.e., dissolved organic carbon, DOC). The autotrophic denitrification process used to treat the domestic wastewater allowed the reduction of the concentration of biochemical oxygen demand (BOD5) below 5 mg/L, of DOC below 7 mg/L, and of COD below 100 mg/L.

Improved method for minimizing sulfur loss in analysis of particulate organic sulfur.

Science.gov (United States)

Park, Ki-Tae; Lee, Kitack; Shin, Kyoungsoon; Jeong, Hae Jin; Kim, Kwang Young

2014-02-04

The global sulfur cycle depends primarily on the metabolism of marine microorganisms, which release sulfur gas into the atmosphere and thus affect the redistribution of sulfur globally as well as the earth's climate system. To better quantify sulfur release from the ocean, analysis of the production and distribution of organic sulfur in the ocean is necessary. This report describes a wet-based method for accurate analysis of particulate organic sulfur (POS) in the marine environment. The proposed method overcomes the considerable loss of sulfur (up to 80%) that occurs during analysis using conventional methods involving drying. Use of the wet-based POS extraction procedure in conjunction with a sensitive sulfur analyzer enabled accurate measurements of cellular POS. Data obtained using this method will enable accurate assessment of how rapidly sulfur can transfer among pools. Such information will improve understanding of the role of POS in the oceanic sulfur cycle.

Process options and projected mass flows for the HTGR refabrication scrap recovery system

International Nuclear Information System (INIS)

Tiegs, S.M.

1979-03-01

The two major uranium recovery processing options reviewed are (1) internal recovery of the scrap by the refabrication system and (2) transfer to and external recovery of the scrap by the head end of the reprocessing system. Each option was reviewed with respect to equipment requirements, preparatory processing, and material accountability. Because there may be a high cost factor on transfer of scrap fuel material to the reprocessing system for recovery, all of the scrap streams will be recycled internally within the refabrication system, with the exception of reject fuel elements, which will be transferred to the head end of the reprocessing system for uranium recovery. The refabrication facility will be fully remote; thus, simple recovery techniques were selected as the reference processes for scrap recovery. Crushing, burning, and leaching methods will be used to recover uranium from the HTGR refabrication scrap fuel forms, which include particles without silicon carbide coatings, particles with silicon carbide coatings, uncarbonized fuel rods, carbon furnace parts, perchloroethylene distillation bottoms, and analytical sample remnants. Mass flows through the reference scrap recovery system were calculated for the HTGR reference recycle facility operating with the highly enriched uranium fuel cycle. Output per day from the refabrication scrap recovery system is estimated to be 4.02 kg of 2355 U and 10.85 kg of 233 U. Maximum equipment capacities were determined, and future work will be directed toward the development and costing of the scrap recovery system chosen as reference

Determination of sulfur in food by high resolution continuum source flame molecular absorption spectrometry

Energy Technology Data Exchange (ETDEWEB)

Zambrzycka, Elżbieta; Godlewska-Żyłkiewicz, Beata, E-mail: bgodlew@uwb.edu.pl

2014-11-01

In the present work, a fast, simple and sensitive analytical method for determination of sulfur in food and beverages by high resolution continuum source flame molecular absorption spectrometry was developed. The determination was performed via molecular absorption of carbon monosulfide, CS. Different CS rotational lines (257.959 nm, 258.033 nm, 258.055 nm), number of pixels and types of standard solution of sulfur, namely: sulfuric acid, sodium sulfate, ammonium sulfate, sodium sulfite, sodium sulfide, DL-cysteine, and L-cystine, were studied in terms of sensitivity, repeatability of results as well as limit of detection and limit of quantification. The best results were obtained for measurements of absorption of the CS molecule at 258.055 nm at the wavelength range covering 3 pixels and DL-cysteine in 0.2 mol L{sup −1} HNO{sub 3} solution as a calibration standard. Under optimized conditions the limit of detection and the limit of quantification achieved for sulfur were 10.9 mg L{sup −1} and 36.4 mg L{sup −1}, respectively. The repeatability of the results expressed as relative standard deviation was typically < 5%. The accuracy of the method was tested by analysis of digested biological certified reference materials (soya bean flour, corn flour and herbs) and recovery experiment for beverage samples with added known amount of sulfur standard. The recovery of analyte from such samples was in the range of 93–105% with the repeatability in the range of 4.1–5.0%. The developed method was applied for the determination of sulfur in milk (194 ± 10 mg kg{sup −1}), egg white (2188 ± 29 mg kg{sup −1}), mineral water (31.0 ± 0.9 mg L{sup −1}), white wine (260 ± 4 mg L{sup −1}) and red wine (82 ± 2 mg L{sup −1}), as well as in sample rich in ions, such as bitter mineral water (6900 ± 100 mg L{sup −1}). - Highlights: • HR-CS FMAS technique was used for sulfur measurement via molecular absorption of carbon monosulfide, CS. • Organic DL

Identification of sulfur heterocycles in coal liquids and shale oils. Technical progress report, August 1, 1980-May 1, 1981

Energy Technology Data Exchange (ETDEWEB)

Lee, M. L.; Castle, R. N.

1981-01-01

The sulfur heterocycle separation scheme which was described in the last progress report was evaluated for quantitative recovery of individual components. The results indicate that recoveries can range from 10% to approx. 30% depending on the structure of the compound. During this period, 23 unsubstituted sulfur-containing heterocyclic ring systems were synthesized in oder to confirm GC/MS identifications and for biological testing. The four possible 3-ring heterocycles and the thirteen possible 4-ring heterocycles were tested for mutagenic activity in the histidine reversion (Ames assay) system. One of the 3-ring isomers, naphtho(1,2-b)-thiophene, and six of the 4-ring isomers induced mutations in Salmonella test strains. One of these compounds, phenanthro(3,4-b)thiophene, displayed approximately the same mutagenic activity as benzo(a)pyrene. A two-step adsorption chromatographic procedure was developed in order to fractionate synthetic fuels into various chemical-type classes for studying the relative concentrations and mutagenic activities of the various types. An SRC-II Heavy Distillate was fractionated into aliphatic hydrocarbons, polycyclic aromatic hydrocarbons, sulfur heterocycles, indoles and carbazoles, azaarenes, and amino polycyclic aromatic hydrocarbons. It was found that the amino-PAH fraction contained most of the mutagenic activity. A survey was made for compounds containing both nitrogen and sulfur heteroatoms in their structures. A number of these compounds were detected by GC using nitrogen- and sulfur-selective detection.

Isotope effects of sulfur in chemical reactions

International Nuclear Information System (INIS)

Mikolajczuk, A.

1999-01-01

Sulfur is an important component of organic matter because it forms compounds with many elements. Due to high chemical activity of sulfur, it takes part in biological and geological processes in which isotope effects are occurring. It has been shown during last years research of isotope effects that we have take into account not only mass difference but also many other physical properties of nuclides e.g. even or odd number of neutrons in nuclei, shape and distribution of charge, turn of nuclear spin etc. The factor remains that new theoretical ideas have been formed on the base of data, being obtained in fractionation processes of heavy element isotope, particularly uranium. Now it is being well known that effects unconnected with vibration energy have also caused an effect on fractionation of considerably lighter elements like iron and magnesium. The important question is, if these effects would come to light during the separation of sulfur isotopes. Sulfur have three even isotopes M = (32, 34, 36) and one odd M 33). This problem is still open. (author)

Process for uranium recovery in phosphorus compounds

International Nuclear Information System (INIS)

Demarthe, J.M.; Solar, Serge.

1980-01-01

Process for uranium recovery in phosphorus compounds with an organic phase containing a dialkylphosphoric acid. A solubilizing agent constituted of an heavy alcohol or a phosphoric acid ester or a tertiary phosphine oxide or octanol-2, is added to the organic phase for solubilization of the uranium and ammonium dialkyl pyrophosphate [fr

Conversion of Claus plants of Kirkuk-Iraq to produce hydrogen and sulfur

International Nuclear Information System (INIS)

Naman, S.A.; Veziroglu, A.

2009-01-01

'Full text': Hydrogen production from rich sub-quality natural gas (SQNG) is visible technically with assessment of cost, safety and environmental toxicology analysis of hydrogen sulfide, is summarized. There are two Claus plants in Kirkuk-Iraq, converting hydrogen sulfide to elemental sulfur capacity of 2200 ton/day. One of these plants is working with only 400 ton/day and it is an old Claus process. The other is a modified Claus sulfur recovery process with a capacity of 1800 ton/day. Both of these plants operate with low efficiency due to lack of maintenance and the present situation in Iraq. Therefore, the agricultural area around Kirkuk is very polluted by this gas. Two pilot plants have been constructed inside the modified Claus plant in Kirkuk The first one is based on the flow system tube furnace reactor containing mixed Titanium oxide/sulfide with a cold trap for sulfur separation and a bath of 30% dithanolamine to separate and recycle H 2 S from hydrogen. The second pilot plant consists of a thermal diffusion ceramic rod inside a silica column containing Zeolit 5A as a catalyst. This pilot plant also consists of a trap for continuous separation of sulfur and a system for separation of hydrogen from unreacted H 2 S to recycle. The efficiency of conversion of H 2 S to hydrogen and sulfur has been optimized as a function of catalyst type and mixture, temperature of furnace, flow rate of gas and reactor materials until the efficiency reaches more than 97%. The Kirkuk natural gas consists of a mixture of CO 2 10% and H 2 S 12%. We found that these pilot plants were suitable with Cadmium chalcogens catalysts to produce hydrogen, methane, ethane and sulphur, but with lower efficiency than H 2 S decomposition only. Our aim in the second pilot plant, which consists of a silica column, was to supply the heat by solar energy concentrator instead of electricity as our catalyst needs 450 o C. and the solar intensity is about 1000 w/m 2 during the summer. The idea of

Comparative analysis of the mechanisms of sulfur anion oxidation and reduction by dsr operon to maintain environmental sulfur balance.

Science.gov (United States)

Ghosh, Semanti; Bagchi, Angshuman

2015-12-01

Sulfur metabolism is one of the oldest known redox geochemical cycles in our atmosphere. These redox processes utilize different sulfur anions and the reactions are performed by the gene products of dsr operon from phylogenetically diverse sets of microorganisms. The operon is involved in the maintenance of environmental sulfur balance. Interestingly, the dsr operon is found to be present in both sulfur anion oxidizing and reducing microorganisms and in both types of organisms DsrAB protein complex plays a vital role. Though there are various reports regarding the genetics of dsr operon there are practically no reports dealing with the structural aspects of sulfur metabolism by dsr operon. In our present study, we tried to compare the mechanisms of sulfur anion oxidation and reduction by Allochromatium vinosum and Desulfovibrio vulgaris respectively through DsrAB protein complex. We analyzed the modes of bindings of sulfur anions to the DsrAB protein complex and observed that for sulfur anion oxidizers, sulfide and thiosulfate are the best substrates whereas for reducers sulfate and sulfite have the best binding abilities. We analyzed the binding interaction pattern of the DsrA and DsrB proteins while forming the DsrAB protein complexes in Desulfovibrio vulgaris and Allochromatium vinosum. To our knowledge this is the first report that analyzes the differences in binding patterns of sulfur substrates with DsrAB protein from these two microorganisms. This study would therefore be essential to predict the biochemical mechanism of sulfur anion oxidation and reduction by these two microorganisms i.e., Desulfovibrio vulgaris (sulfur anion reducer) and Allochromatium vinosum (sulfur anion oxidizer). Our observations also highlight the mechanism of sulfur geochemical cycle which has important implications in future study of sulfur metabolism as it has a huge application in waste remediation and production of industrial bio-products viz. vitamins, bio-polyesters and bio

[A Correlational Study of the Recovery Process in Patients With Mental Illness].

Science.gov (United States)

Huang, Yao-Hui; Lin, Yao-Yu; Lee, Shih-Kai; Lee, Ming-Feng; Lin, Ching-Lan Esther

2018-04-01

The ideology of recovery addresses the autonomy of patients with mental illness and their ability to reconstruct a normal life. Empirical knowledge of this process of recovery and related factors remains unclear. To assess the process of recovery and related factors in patients with mental illness. This cross-sectional, correlational study was conducted on a convenience sample in a psychiatric hospital. Two-hundred and fifty patients with mental illness were recruited and were assessed using 3 instruments: Questionnaire about the Process of Recovery (QPR), Perceived Psychiatric Stigma Scale (PPSS), and Personal and Social Performance Scale (PSP). Data were analyzed using descriptive statistics, χ 2 , analysis of variance, and multiple linear regression analysis. Most of the participants were male, middle-aged, unmarried, educated to the senior high school level, employed, receiving home-care treatment, and diagnosed with schizophrenia. Those who were unemployed, living in a community rehabilitative house, and living in the community, respectively, earned relatively higher recovery scores (p mental illness. Community psychiatric nurses should provide care to help employed patients adapt to stresses in the workplace, strengthen their stigma-coping strategies, and promote public awareness of mental health issues by increasing public knowledge and acceptance of mental illness in order to minimize patient-perceived stigma and facilitate their recovery.

Conceptual design model of the sulfur-iodine S-I thermochemical water splitting process for hydrogen production using nuclear heat source

International Nuclear Information System (INIS)

Gonzalez Rodriguez, Daniel; Parra, Lazaro Garcia

2011-01-01

Hydrogen is the most indicated candidate for its implementation as energy carrier in a future sustainable scenario. The current hydrogen production is based on fossils fuels; they have a huge contribution to the atmosphere pollution. Thermochemical water-splitting cycles do not have this issue because they use solar or nuclear heat; their environment impact is smaller than conventional fuels. The software based on chemical process simulation (CPS) can be used to simulate the thermochemical water splitting cycle Sulfur-Iodine for hydrogen production. In the paper is developed a model for Sulfur-Iodine process in order to analyze his sensibility and calculate the efficiency and the influence of many parameters on this value. (author)

Conceptual design model of the sulfur-iodine S-I thermochemical water splitting process for hydrogen production using nuclear heat source

Energy Technology Data Exchange (ETDEWEB)

Gonzalez Rodriguez, Daniel; Parra, Lazaro Garcia, E-mail: dgr@instec.cu, E-mail: lgarcia@instec.cu [Departamento de Ingenieria Nuclear, Instituto Superior de Ciencias y Tecnologias Aplicadas, La Habana (Cuba)

2011-07-01

Hydrogen is the most indicated candidate for its implementation as energy carrier in a future sustainable scenario. The current hydrogen production is based on fossils fuels; they have a huge contribution to the atmosphere pollution. Thermochemical water-splitting cycles do not have this issue because they use solar or nuclear heat; their environment impact is smaller than conventional fuels. The software based on chemical process simulation (CPS) can be used to simulate the thermochemical water splitting cycle Sulfur-Iodine for hydrogen production. In the paper is developed a model for Sulfur-Iodine process in order to analyze his sensibility and calculate the efficiency and the influence of many parameters on this value. (author)

A statistical approach to the experimental design of the sulfuric acid leaching of gold-copper ore

Directory of Open Access Journals (Sweden)

Mendes F.D.

2003-01-01

Full Text Available The high grade of copper in the Igarapé Bahia (Brazil gold-copper ore prevents the direct application of the classic cyanidation process. Copper oxides and sulfides react with cyanides in solution, causing a high consumption of leach reagent and thereby raising processing costs and decreasing recovery of gold. Studies have showm that a feasible route for this ore would be a pretreatment for copper minerals removal prior to the cyanidation stage. The goal of this experimental work was to study the experimental conditions required for copper removal from Igarapé Bahia gold-copper ore by sulfuric acid leaching by applying a statistical approach to the experimental design. By using the Plackett Burman method, it was possible to select the variables that had the largest influence on the percentage of copper extracted at the sulfuric acid leaching stage. These were temperature of leach solution, stirring speed, concentration of sulfuric acid in the leach solution and particle size of the ore. The influence of the individual effects of these variables and their interactions on the experimental response were analyzed by applying the replicated full factorial design method. Finally, the selected variables were optimized by the ascending path statistical method, which determined the best experimental conditions for leaching to achieve the highest percentage of copper extracted. Using the optimized conditions, the best leaching results showed a copper extraction of 75.5%.

Closed Process of Shale Oil Recovery from Circulating Washing Water by Hydrocyclones

Directory of Open Access Journals (Sweden)

Yuan Huang

2016-12-01

Full Text Available The conventional oil recovery system in the Fushun oil shale retorting plant has a low oil recovery rate. A large quantity of fresh water is used in the system, thereby consuming a considerable amount of water and energy, as well as polluting the environment. This study aims to develop a closed process of shale oil recovery from the circulating washing water for the Fushun oil shale retorting plant. The process would increase oil yield and result in clean production. In this process, oil/water hydrocyclone groups were applied to decrease the oil content in circulating water and to simultaneously increase oil yield. The oil sludge was removed by the solid/liquid hydrocyclone groups effectively, thereby proving the smooth operation of the devices and pipes. As a result, the oil recovery rate has increased by 5.3 %, which corresponds to 230 tonnes a month.

A microencapsulation process of liquid mercury by sulfur polymer stabilization/solidification technology. Part II: Durability of materials

Energy Technology Data Exchange (ETDEWEB)

Lopez-Delgado, A.; Guerrero, A.; Lopez, F. A.; Perez, C.; Alguacil, F. J.

2012-11-01

Under the European LIFE Program a microencapsulation process was developed for liquid mercury using Sulfur Polymer Stabilization/Solidification (SPSS) technology, obtaining a stable concrete-like sulfur matrix that allows the immobilization of mercury for long-term storage. The process description and characterization of the materials obtained were detailed in Part I. The present document, Part II, reports the results of different tests carried out to determine the durability of Hg-S concrete samples with very high mercury content (up to 30 % w/w). Different UNE and RILEM standard test methods were applied, such as capillary water absorption, low pressure water permeability, alkali/acid resistance, salt mist aging, freeze-thaw resistance and fire performance. The samples exhibited no capillarity and their resistance in both alkaline and acid media was very high. They also showed good resistance to very aggressive environments such as spray salt mist, freeze-thaw and dry-wet. The fire hazard of samples at low heat output was negligible. (Author)

Method for rendering harmless sulfur dioxide-carrying gases and sulfur-carrying waste water from pyrolysis of oil shale

Energy Technology Data Exchange (ETDEWEB)

Aspegren, O E.A.; Eklund, A J

1951-03-15

A method is described for rendering harmless sulfur dioxide-carrying gases, which are formed in processes for the manufacture of solid, liquid, or gaseous products by pyrolysis of oil shale, and thereby to extract valuable products, characterized in that the sulfur dioxide-carrying gases are washed with a solution or sludge obtained by leaching wholly or partly burned-out residues from the pyrolysis.

ENERGY EFFICIENCY LIMITS FOR A RECUPERATIVE BAYONET SULFURIC ACID DECOMPOSITION REACTOR FOR SULFUR CYCLE THERMOCHEMICAL HYDROGEN PRODUCTION

Energy Technology Data Exchange (ETDEWEB)

Gorensek, M.; Edwards, T.

2009-06-11

A recuperative bayonet reactor design for the high-temperature sulfuric acid decomposition step in sulfur-based thermochemical hydrogen cycles was evaluated using pinch analysis in conjunction with statistical methods. The objective was to establish the minimum energy requirement. Taking hydrogen production via alkaline electrolysis with nuclear power as the benchmark, the acid decomposition step can consume no more than 450 kJ/mol SO{sub 2} for sulfur cycles to be competitive. The lowest value of the minimum heating target, 320.9 kJ/mol SO{sub 2}, was found at the highest pressure (90 bar) and peak process temperature (900 C) considered, and at a feed concentration of 42.5 mol% H{sub 2}SO{sub 4}. This should be low enough for a practical water-splitting process, even including the additional energy required to concentrate the acid feed. Lower temperatures consistently gave higher minimum heating targets. The lowest peak process temperature that could meet the 450-kJ/mol SO{sub 2} benchmark was 750 C. If the decomposition reactor were to be heated indirectly by an advanced gas-cooled reactor heat source (50 C temperature difference between primary and secondary coolants, 25 C minimum temperature difference between the secondary coolant and the process), then sulfur cycles using this concept could be competitive with alkaline electrolysis provided the primary heat source temperature is at least 825 C. The bayonet design will not be practical if the (primary heat source) reactor outlet temperature is below 825 C.

Energy-neutral sustainable nutrient recovery incorporated with the wastewater purification process in an enlarged microbial nutrient recovery cell

Science.gov (United States)

Sun, Dongya; Gao, Yifan; Hou, Dianxun; Zuo, Kuichang; Chen, Xi; Liang, Peng; Zhang, Xiaoyuan; Ren, Zhiyong Jason; Huang, Xia

2018-04-01

Recovery of nutrient resources from the wastewater is now an inevitable strategy to maintain the supply of both nutrient and water for our huge population. While the intensive energy consumption in conventional nutrient recovery technologies still remained as the bottleneck towards the sustainable nutrient recycle. This study proposed an enlarged microbial nutrient recovery cell (EMNRC) which was powered by the energy contained in wastewater and achieved multi-cycle nutrient recovery incorporated with in situ wastewater treatment. With the optimal recovery solution of 3 g/L NaCl and the optimal volume ratio of wastewater to recovery solution of 10:1, >89% of phosphorus and >62% of ammonium nitrogen were recovered into struvite. An extremely low water input ratio of water. It was proved the EMNRC system was a promising technology which could utilize the chemical energy contained in wastewater itself and energy-neutrally recover nutrient during the continuous wastewater purification process.

Energy and nutrient recovery from anaerobic treatment of organic wastes

Science.gov (United States)

Henrich, Christian-Dominik

The objective of the research was to develop a complete systems design and predictive model framework of a series of linked processes capable of providing treatment of landfill leachate while simultaneously recovering nutrients and bioenergy from the waste inputs. This proposed process includes an "Ammonia Recovery Process" (ARP) consisting of: (1) ammonia de-sorption requiring leachate pH adjustment with lime or sodium hydroxide addition followed by, (2) ammonia re-absorption into a 6-molar sulfuric acid spray-tower followed by, (3) biological activated sludge treatment of soluble organic residuals (BOD) followed by, (4) high-rate algal post-treatment and finally, (5) an optional anaerobic digestion process for algal and bacterial biomass, and/or supplemental waste fermentation providing the potential for additional nutrient and energy recovery. In addition, the value provided by the waste treatment function of the overall processes, each of the sub-processes would provide valuable co-products offering potential GHG credit through direct fossil-fuel replacement, or replacement of products requiring fossil fuels. These valuable co-products include, (1) ammonium sulfate fertilizer, (2) bacterial biomass, (3) algal biomass providing, high-protein feeds and oils for biodiesel production and, (4) methane bio-fuels. Laboratory and pilot reactors were constructed and operated, providing data supporting the quantification and modeling of the ARP. Growth parameters, and stoichiometric coefficients were determined, allowing for design of the leachate activated sludge treatment sub-component. Laboratory and pilot algal reactors were constructed and operated, and provided data that supported the determination of leachate organic/inorganic-nitrogen ratio, and loading rates, allowing optimum performance of high-rate algal post-treatment. A modular and expandable computer program was developed, which provided a systems model framework capable of predicting individual component

Sulfur-Containing Agrochemicals.

Science.gov (United States)

Devendar, Ponnam; Yang, Guang-Fu

2017-10-09

Modern agricultural chemistry has to support farmers by providing innovative agrochemicals. In this context, the introduction of sulfur atoms into an active ingredient is still an important tool in modulating the properties of new crop-protection compounds. More than 30% of today's agrochemicals contain at least one sulfur atom, mainly in fungicides, herbicides and insecticides. A number of recently developed sulfur-containing agrochemical candidates represent a novel class of chemical compounds with new modes of action, so we intend to highlight the emerging interest in commercially active sulfur-containing compounds. This chapter gives a comprehensive overview of selected leading sulfur-containing pesticidal chemical families namely: sulfonylureas, sulfonamides, sulfur-containing heterocyclics, thioureas, sulfides, sulfones, sulfoxides and sulfoximines. Also, the most suitable large-scale synthetic methods of the recently launched or provisionally approved sulfur-containing agrochemicals from respective chemical families have been highlighted.

Hydrometallurgical process for recovering iron sulfate and zinc sulfate from baghouse dust

Science.gov (United States)

Zaromb, Solomon; Lawson, Daniel B.

1994-01-01

A process for recovering zinc/rich and iron-rich fractions from the baghouse dust that is generated in various metallurgical operations, especially in steel-making and other iron-making plants, comprises the steps of leaching the dust by hot concentrated sulfuric acid so as to generate dissolved zinc sulfate and a precipitate of iron sulfate, separating the precipitate from the acid by filtration and washing with a volatile liquid, such as methanol or acetone, and collecting the filtered acid and the washings into a filtrate fraction. The volatile liquid may be recovered distillation, and the zinc may be removed from the filtrate by alternative methods, one of which involves addition of a sufficient amount of water to precipitate hydrated zinc sulfate at 10.degree. C., separation of the precipitate from sulfuric acid by filtration, and evaporation of water to regenerate concentrated sulfuric acid. The recovery of iron may also be effected in alternative ways, one of which involves roasting the ferric sulfate to yield ferric oxide and sulfur trioxide, which can be reconverted to concentrated sulfuric acid by hydration. The overall process should not generate any significant waste stream.

PROPOSAL FOR THE IMPLEMENTATION OF SPRAY DRYING IN THE ACTIVATION PROCESS OF BENTONITE WITH SULFURIC ACID

OpenAIRE

Romero, P.; Otiniano, M.

2014-01-01

The present work propose the replacement of the three stages of the activation process of bentonite with sulfuric acid by the only stage spray drying. El presente trabajo propone reemplazar tres etapas del proceso de activación de la bentonita con ácido sulfúrico por una sola etapa, la del secado por atomización.

Sulfur and Its Role In Modern Materials Science.

Science.gov (United States)

Boyd, Darryl A

2016-12-12

Although well-known and studied for centuries, sulfur continues to be at the center of an extensive array of scientific research topics. As one of the most abundant elements in the Universe, a major by-product of oil refinery processes, and as a common reaction site within biological systems, research involving sulfur is both broad in scope and incredibly important to our daily lives. Indeed, there has been renewed interest in sulfur-based reactions in just the past ten years. Sulfur research spans the spectrum of topics within the physical sciences including research on improving energy efficiency, environmentally friendly uses for oil refinery waste products, development of polymers with unique optical and mechanical properties, and materials produced for biological applications. This Review focuses on some of the latest exciting ways in which sulfur and sulfur-based reactions are being utilized to produce materials for application in energy, environmental, and other practical areas. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

The analysis of thermoplastic characteristics of special polymer sulfur composite

Science.gov (United States)

Książek, Mariusz

2017-01-01

Specific chemical environments step out in the industry objects. Portland cement composites (concrete and mortar) were impregnated by using the special polymerized sulfur and technical soot as a filler (polymer sulfur composite). Sulfur and technical soot was applied as the industrial waste. Portland cement composites were made of the same aggregate, cement and water. The process of special polymer sulfur composite applied as the industrial waste is a thermal treatment process in the temperature of about 150-155°C. The result of such treatment is special polymer sulfur composite in a liquid state. This paper presents the plastic constants and coefficients of thermal expansion of special polymer sulfur composites, with isotropic porous matrix, reinforced by disoriented ellipsoidal inclusions with orthotropic symmetry of the thermoplastic properties. The investigations are based on the stochastic differential equations of solid mechanics. A model and algorithm for calculating the effective characteristics of special polymer sulfur composites are suggested. The effective thermoplastic characteristics of special polymer sulfur composites, with disoriented ellipsoidal inclusions, are calculated in two stages: First, the properties of materials with oriented inclusions are determined, and then effective constants of a composite with disoriented inclusions are determined on the basis of the Voigt or Rice scheme. A brief summary of new products related to special polymer sulfur composites is given as follows: Impregnation, repair, overlays and precast polymer concrete will be presented. Special polymer sulfur as polymer coating impregnation, which has received little attention in recent years, currently has some very interesting applications.

Design of Hybrid Steam-In Situ Combustion Bitumen Recovery Processes

International Nuclear Information System (INIS)

Yang Xiaomeng; Gates, Ian D.

2009-01-01

Given enormous capital costs, operating expenses, flue gas emissions, water treatment and handling costs of thermal in situ bitumen recovery processes, improving the overall efficiency by lowering energy requirements, environmental impact, and costs of these production techniques is a priority. Steam-assisted gravity drainage (SAGD) is the most widely used in situ recovery technique in Athabasca reservoirs. Steam generation is done on surface and consequently, because of heat losses, the energy efficiency of SAGD can never be ideal with respect to the energy delivered to the sandface. An alternative to surface steam generation is in situ combustion (ISC) where heat is generated within the formation through injection of oxygen at a sufficiently high pressure to initiate combustion of bitumen. In this manner, the heat from the combustion reactions can be used directly to mobilize the bitumen. As an alternative, the heat can be used to generate steam within the formation which then is the agent to move heat in the reservoir. In this research, alternative hybrid techniques with simultaneous and sequential steam-oxygen injection processes are examined to maximize the thermal efficiency of the recovery process. These hybrid processes have the advantage that during ISC, steam is generated within the reservoir from injected and formation water and as a product of oxidation. This implies that ex situ steam generation requirements are reduced and if there is in situ storage of combustion gases, that overall gas emissions are reduced. In this research, detailed reservoir simulations are done to examine the dynamics of hybrid processes to enable design of these processes. The results reveal that hybrid processes can lower emitted carbon dioxide-to-oil ratio by about 46%, decrease the consumed natural gas-to-oil ratio by about 73%, reduce the cumulative energy-to-oil ratio by between 40% and 70% compared to conventional SAGD, and drop water consumption per unit oil produced

Environmental aspects of the combustion of sulfur-bearing fuels

International Nuclear Information System (INIS)

Manowitz, B.; Lipfert, F.W.

1990-01-01

This paper describes the origins of sulfur in fossil fuels and the consequences of its release into the environment after combustion, with emphasis on the United States. Typical sulfur contents of fuels are given, together with fuel uses and the resulting air concentrations of sulfur air pollutants. Atmospheric transformation and pollutant removal processes are described, as they affect the pathways of sulfur through the environment. The environmental effects discussed include impacts on human health, degradation of materials, acidification of ecosystems, and effects on vegetation and atmospheric visibility. The paper concludes with a recommendation for the use of risk assessment to assess the need for regulations which may require the removal of sulfur from fuels or their combustion products

Spectral analysis of creep recovery process in finemet type amorphous alloy

NARCIS (Netherlands)

Jurikova, A; Csach, K; Miskuf, J; Bengus, VZ; Ocelik, Vaclav

2002-01-01

The creep recovery process in Finemet type amorphous alloy leas been analyzed using the method for calculating the relaxation tithe spectra. The influence of structural relaxation and temperature on the spectra shape lags been studied. The creep recovery spectrum of the anelastic deformation of the

Experiments on contrail formation from fuels with different sulfur content

Energy Technology Data Exchange (ETDEWEB)

Busen, R; Kuhn, M; Petzold, A; Schroeder, F; Schumann, U [Deutsche Forschungs- und Versuchsanstalt fuer Luft- und Raumfahrt e.V., Oberpfaffenhofen (Germany); Baumgardner, D [National Center for Atmospheric Research, Boulder, CO (United States); Borrmann, S [Mainz Univ. (Germany); Hagen, D; Whitefield, Ph [Missouri Univ., Rolla, MO (United States). Bureau of Mines; Stroem, J [Stockholm Univ. (Sweden)

1998-12-31

A series of both flight tests and ground experiments has been performed to evaluate the role of the sulfur contained in kerosene in condensation trail (contrail) formation processes. The results of the first experiments are compiled briefly. The last SULFUR 4 experiment dealing with the influence of the fuel sulfur content and different appertaining conditions is described in detail. Different sulfur mass fractions lead to different particle size spectra. The number of ice particles in the contrail increases by about a factor of 2 for 3000 ppm instead of 6 ppm sulfur fuel content. (author) 10 refs.

Experiments on contrail formation from fuels with different sulfur content

Energy Technology Data Exchange (ETDEWEB)

Busen, R.; Kuhn, M.; Petzold, A.; Schroeder, F.; Schumann, U. [Deutsche Forschungs- und Versuchsanstalt fuer Luft- und Raumfahrt e.V., Oberpfaffenhofen (Germany); Baumgardner, D. [National Center for Atmospheric Research, Boulder, CO (United States); Borrmann, S. [Mainz Univ. (Germany); Hagen, D.; Whitefield, Ph. [Missouri Univ., Rolla, MO (United States). Bureau of Mines; Stroem, J. [Stockholm Univ. (Sweden)

1997-12-31

A series of both flight tests and ground experiments has been performed to evaluate the role of the sulfur contained in kerosene in condensation trail (contrail) formation processes. The results of the first experiments are compiled briefly. The last SULFUR 4 experiment dealing with the influence of the fuel sulfur content and different appertaining conditions is described in detail. Different sulfur mass fractions lead to different particle size spectra. The number of ice particles in the contrail increases by about a factor of 2 for 3000 ppm instead of 6 ppm sulfur fuel content. (author) 10 refs.

Combined gettering and molten salt process for tritium recovery from lithium

International Nuclear Information System (INIS)

Sze, D.K.; Finn, P.A.; Bartlit, J.; Tanaka, S.; Teria, T.; Yamawaki, M.

1988-02-01

A new tritium recovery concept from lithium has been developed as part of the US/Japan collaboration on Reversed-Field Pinch Reactor Design Studies. This concept combines the γ-gettering process as the front end to recover tritium from the coolant, and a molten salt recovery process to extract tritium for fuel processing. A secondary lithium is used to regenerate the tritium from the gettering bed and, in the process, increases the tritium concentration by a factor of about 20. That way, the required size of the molten salt process becomes very small. A potential problem is the possible poisoning of the gettering bed by the salt dissolved in lithium. 16 refs., 6 figs

Pressurized Recuperator For Heat Recovery In Industrial High Temperature Processes

Directory of Open Access Journals (Sweden)

Gil S.

2015-09-01

Full Text Available Recuperators and regenerators are important devices for heat recovery systems in technological lines of industrial processes and should have high air preheating temperature, low flow resistance and a long service life. The use of heat recovery systems is particularly important in high-temperature industrial processes (especially in metallurgy where large amounts of thermal energy are lost to the environment. The article presents the process design for a high efficiency recuperator intended to work at high operating parameters: air pressure up to 1.2 MPa and temperature of heating up to 900°C. The results of thermal and gas-dynamic calculations were based on an algorithm developed for determination of the recuperation process parameters. The proposed technical solution of the recuperator and determined recuperation parameters ensure its operation under maximum temperature conditions.

Conceptual process synthesis for recovery of natural products from plants

DEFF Research Database (Denmark)

Malwade, Chandrakant R.; Qu, Haiyan; Rong, Ben-Guang

2013-01-01

) and purification of target compound(s) from the crude extract. Process analytical technology (PAT) is used in each step to understand the nature of material systems and separation characteristics of each separation method. In the present work, this methodology is applied to generate process flow sheet for recovery......A systematic method of conceptual process synthesis for recovery of natural products from their biological sources is presented. This methodology divides the task into two major subtasks namely, isolation of target compound from a chemically complex solid matrix of biological source (crude extract...... in individual unit operations of maceration, flash column chromatography, and crystallization are 90.0%, 87.1, and 47.6%, respectively. Results showed that the crystallization step is dominant to the overall yield of the process which was 37.3%....

Structural change of the porous sulfur cathode using gelatin as a binder during discharge and charge

International Nuclear Information System (INIS)

Wang You; Huang Yaqin; Wang Weikun; Huang Chongjun; Yu Zhongbao; Zhang, Hao; Sun Jing; Wang Anbang; Yuan Keguo

2009-01-01

The structural change of the porous sulfur cathode using gelatin as a binder was studied by means of scanning electron microscopy (SEM) and X-ray diffractometry (XRD). The original sulfur cathode exhibited a homogenous distribution of sulfur, carbon and pores. During the discharge process, the pores and elemental sulfur disappeared gradually. However, those changes were reversed and elemental sulfur was reformed after the charge process, which improved the electrochemical performance of lithium-sulfur batteries.

Sulfur K-edge absorption spectroscopy on selected biological systems

International Nuclear Information System (INIS)

Lichtenberg, Henning

2008-07-01

Sulfur is an essential element in organisms. In this thesis investigations of sulfur compounds in selected biological systems by XANES (X-ray Absorption Near Edge Structure) spectroscopy are reported. XANES spectroscopy at the sulfur K-edge provides an excellent tool to gain information about the local environments of sulfur atoms in intact biological samples - no extraction processes are required. Spatially resolved measurements using a Kirkpatrick-Baez mirror focusing system were carried out to investigate the infection of wheat leaves by rust fungi. The results give information about changes in the sulfur metabolism of the host induced by the parasite and about the extension of the infection into visibly uninfected plant tissue. Furthermore, XANES spectra of microbial mats from sulfidic caves were measured. These mats are dominated by microbial groups involved in cycling sulfur. Additionally, the influence of sulfate deprivation and H 2 S exposure on sulfur compounds in onion was investigated. To gain an insight into the thermal degradation of organic material the influence of roasting of sulfur compounds in coffee beans was studied. (orig.)

Pengaruh sulfur terhadap sifat fisika campuran pale crepe dan SBR untuk karet tahan panas

Directory of Open Access Journals (Sweden)

Arum Yuniari

2013-12-01

Full Text Available Sulfur plays an important role in the rubber vulcanization process especially in the formation of crosslinks. Heat resistant rubber made from mixing pale crepe and SBR requires the right amount of sulfur as crosslinking agent. The purpose of the study was to determine the effect of the addition of sulfur on the changes in physical properties before and after aging. Heat resistant rubber was made with variation of pale crepe/SBR: 80/20; 70/30; 60/40; 50/50 phr and sulfur variation of 1; 1.5 phr. The results showed that sulfur was influential in the crosslinks formation. The addition of 1 phr sulfur gave higher physical properties of the vulcanized with 1.5 phr sulfur. The changes of physical properties after aging process of the vulcanized with sulfur 1 phr was lower than the vulcanized with sulfur 1.5 phr. Vulcanized pale crepe/SBR (70/30 with 1 phr sulfur could be applied as heat-resistant rubber products.

[Sulfur dioxide limit standard and residues in Chinese medicinal materials].

Science.gov (United States)

Kang, Chuan-Zhi; Yang, Wan-Zhen; Mo, Ge; Zhou, Li; Jiang, Jing-Yi; Lv, Chao-Geng; Wang, Sheng; Zhou, Tao; Yang, Ye; Guo, Lan-Ping

2018-01-01

The traditional sulfur fumigation processing method has been widely used in the initial processing and storage of traditional Chinese medicinal materials due to its economy, efficiency, convenience, high operability and effect on mold and insect prevention. However, excessive sulfur fumigation of traditional Chinese medicinal materials would lead to the changes in chemical compositions, and even endanger human health. This study showed that traditional Chinese medicinal materials were sulfur fumigated directly after being harvested for quick drying, or fumigated after being weted in the storage process for preventing mold and insects. We found that the sulfur dioxide limits for traditional Chinese medicinal materials were stricter than those for foods. Based on the existing limit standards, we obtained the data of sulfur dioxide residues for 35 types of traditional Chinese medicinal materials in a total of 862 batches. According to the limit standard in the Chinese Pharmacopoeia (150， 400 mg·kg⁻¹), the average over-standard rate of sulfur dioxide was as high as 52.43%, but it was reduced to 29.47% if calculated based on the limit for vegetable additive standard (500 mg·kg⁻¹). Sulfur fumigation issue shall be considered correctly: sulfur dioxide is a type of low toxic substance and less dangerous than aflatoxin and other highly toxic substances, and a small amount of residue would not increase the toxicity of traditional Chinese medicinal materials. However, sulfur fumigation might change the content of chemical substances and affect the quality of traditional Chinese medicinal materials. Furthermore, the exposure hazards of toxic substances are comprehensively correlated with exposure cycle, exposure frequency, and application method. In conclusion, it is suggested to strengthen the studies on the limit standard of traditional Chinese medicinal materials, formulate practical and feasible limit standard for sulfur dioxide residues in traditional Chinese

Conditioning of red mud for subsequent titanium and scandium recovery. A conceptual design study

Energy Technology Data Exchange (ETDEWEB)

Alkan, G.; Xakalashe, B.; Kaussen, F.; Friedrich, Bernd [RWTH Aachen Univ. (Germany). IME Inst. of Process Metallurgy and Metal Recycling; Yagmurlu, B. [RWTH Aachen Univ. (Germany). IME Inst. of Process Metallurgy and Metal Recycling; MEAB Chemie Technik GmbH, Aachen (Germany)

2017-03-15

Leaching experiments were undertaken on red mud materials (red mud and red mud slag). The red mud slag was produced via the carbothermic reduction of red mud at high temperatures (T > 1500 C) via SAF treatment. Furthermore, iron was recovered in the smelting step to the metal phase. Ti and Sc were successfully recovered from the red mud materials by hydrometallurgical treatment. For both critical metals, it was found that sulfuric acid was the best mineral acid among others. Since direct red mud leaching had some shortcomings, a route designed to overcome them is proposed. For optimal Ti and Sc recovery from red mud a promising process flowsheet combining pyrometallurgical and hydrometallurgical treatment is proposed as follows: pyrometallurgical processing (fluxed smelting to produce calcium oxide based slag phases and controlled cooling for crystalline and glassy slags), leaching for maximized Ti- and Sc extraction and followed by a multistage precipitation (for metal recovery and solution purification). Initial trial results showed that the proposed process is promising.

In situ tribochemical sulfurization of molybdenum oxide nanotubes.

Science.gov (United States)

Rodríguez Ripoll, Manel; Tomala, Agnieszka; Gabler, Christoph; DraŽić, Goran; Pirker, Luka; Remškar, Maja

2018-02-15

MoS 2 nanoparticles are typically obtained by high temperature sulfurization of organic and inorganic precursors under a S rich atmosphere and have excellent friction reduction properties. We present a novel approach for making the sulfurization unnecessary for MoO 3 nanotubes during the synthesis process for friction and wear reduction applications while simultaneously achieving a superb tribological performance. To this end, we report the first in situ sulfurization of MoO 3 nanotubes during sliding contact in the presence of sulfur-containing lubricant additives. The sulfurization leads to the tribo-chemical formation of a MoS 2 -rich low-friction tribofilm as verified using Raman spectroscopy and can be achieved both during sliding contact and under extreme pressure conditions. Under sliding contact conditions, MoO 3 nanotubes in synergy with sulfurized olefin polysulfide and pre-formed zinc dialkyl dithiophosphate tribofilms achieve an excellent friction performance. Under these conditions, the tribochemical sulfurization of MoO 3 nanotubes leads to a similar coefficient of friction to the one obtained using a model nanolubricant containing MoS 2 nanotubes. Under extreme pressure conditions, the in situ sulfurization of MoO 3 nanotubes using sulfurized olefin polysulfide results in a superb load carrying capacity capable of outperforming MoS 2 nanotubes. The reason is that while MoO 3 nanotubes are able to continuously sulfurize during sliding contact conditions, MoS 2 nanotubes progressively degrade by oxidation thus losing lubricity.

Some information needs for air quality modeling. [Environmental effects of sulfur compounds

Energy Technology Data Exchange (ETDEWEB)

Hill, F B

1975-09-01

The following topics were considered at the workshop: perturbation of the natural sulfur cycle by human activity; ecosystem responses to a given environmental dose of sulfur compounds; movement of sulfur compounds within the atmosphere; air quality models; contribution of biogenic sulfur compounds to atmospheric burden of sulfur; production of acid rain from sulfur dioxide; meteorological processes; and rates of oxidation of SO/sub 2/ via direct photo-oxidation, oxidation resulting from photo-induced free radical chemistry, and catalytic oxidation in cloud droplets and on dry particles. (HLW)

Coal-gold agglomeration: an alternative separation process in gold recovery

Energy Technology Data Exchange (ETDEWEB)

Akcil, A.; Wu, X.Q.; Aksay, E.K. [Suleyman Demirel University, Isparta (Turkey). Dept. of Mining Engineering

2009-07-01

Considering the increasing environmental concerns and the potential for small gold deposits to be exploited in the future, the uses of environmentally friendly processes are essential. Recent developments point to the potential for greatly increased plant performance through a separation process that combines the cyanide and flotation processes. In addition, this kind of alternative treatment processes to the traditional gold recovery processes may reduce the environmental risks of present small-scale gold mining. Gold recovery processes that applied to different types of gold bearing ore deposits show that the type of deposits plays an important role for the selection of mineral processing technologies in the production of gold and other precious metals. In the last 25 years, different alternative processes have been investigated on gold deposits located in areas where environmental issues are a great concern. In 1988, gold particles were first recovered by successful pilot trial of coal-gold agglomeration (CGA) process in Australia. The current paper reviews the importance of CGA in the production of gold ore and identifies areas for further development work.

Recovery of phosphorus and aluminium from sewage sludge ash by a new wet chemical elution process (SESAL-Phos-recovery process).

Science.gov (United States)

Petzet, S; Peplinski, B; Bodkhe, S Y; Cornel, P

2011-01-01

The potential of a new wet chemical process for phosphorus and aluminium recovery from sewage sludge ash by sequential elution with acidic and alkaline solutions has been investigated: SESAL-Phos (sequential elution of sewage sludge ash for aluminium and phosphorus recovery). Its most innovative aspect is an acidic pre-treatment step in which calcium is leached from the sewage sludge ash. Thus the percentage of alkaline soluble aluminium phosphates is increased from 20 to 67%. This aluminium phosphate is then dissolved in alkali. Subsequently, the dissolved phosphorus is precipitated as calcium phosphate with low heavy metal content and recovered from the alkaline solution. Dissolved aluminium is recovered and may be reused as a precipitant in wastewater treatment plants.

Relationship between corrosion and the biological sulfur cycle: A review

Energy Technology Data Exchange (ETDEWEB)

Little, B.J.; Ray, R.I.; Pope, R.K.

2000-04-01

Sulfur and sulfur compounds can produce pitting, crevice corrosion, dealloying, stress corrosion cracking, and stress-oriented hydrogen-induced cracking of susceptible metals and alloys. Even though the metabolic by-products of the biological sulfur cycle are extremely corrosive, there are no correlations between numbers and types of sulfur-related organisms and the probability or rate of corrosion, Determination of specific mechanisms for corrosion caused by microbiologically mediated oxidation and reduction of sulfur and sulfur compounds is complicated by the variety of potential metabolic-energy sources and by-products; the coexistence of reduced and oxidized sulfur species; competing reactions with inorganic and organic compounds; and the versatility and adaptability of microorganisms in biofilms. The microbial ecology of sulfur-rich environments is poorly understood because of the association of aerobes and anaerobes and the mutualism or succession of heterotrophs to autotrophs. The physical scale over which the sulfur cycle influences corrosion varies with the environment. The complete sulfur cycle of oxidation and reduction reactions can take place in macroenvironments, including sewers and polluted harbors, or within the microenvironment of biofilms. In this review, reactions of sulfur and sulfur compounds resulting in corrosion were discussed in the context of environmental processes important to corrosion.

Catalyst for the reduction of sulfur dioxide to elemental sulfur

Science.gov (United States)

Jin, Y.; Yu, Q.; Chang, S.G.

1996-02-27

The inventive catalysts allow for the reduction of sulfur dioxide to elemental sulfur in smokestack scrubber environments. The catalysts have a very high sulfur yield of over 90% and space velocity of 10,000 h{sup {minus}1}. They also have the capacity to convert waste gases generated during the initial conversion into elemental sulfur. The catalysts have inexpensive components, and are inexpensive to produce. The net impact of the invention is to make this technology practically available to industrial applications. 21 figs.

Simulation of petroleum recovery in naturally fractured reservoirs: physical process representation

Energy Technology Data Exchange (ETDEWEB)

Paiva, Hernani P.; Miranda Filho, Daniel N. de [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil); Schiozer, Denis J. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil)

2012-07-01

The naturally fractured reservoir recovery normally involves risk especially in intermediate to oil wet systems because of the simulations poor efficiency results under waterflood displacement. Double-porosity models are generally used in fractured reservoir simulation and have been implemented in the major commercial reservoir simulators. The physical processes acting in petroleum recovery are represented in double-porosity models by matrix-fracture transfer functions, therefore commercial simulators have their own implementations, and as a result different kinetics and final recoveries are attained. In this work, a double porosity simulator was built with Kazemi et al. (1976), Sabathier et al. (1998) and Lu et al. (2008) transfer function implementations and their recovery results have been compared using waterflood displacement in oil-wet or intermediate-wet systems. The results of transfer function comparisons have showed recovery improvements in oil-wet or intermediate-wet systems under different physical processes combination, particularly in fully discontinuous porous medium when concurrent imbibition takes place, coherent with Firoozabadi (2000) experimental results. Furthermore, the implemented transfer functions, related to a double-porosity model, have been compared to double-porosity commercial simulator model, as well a discrete fracture model with refined grid, showing differences between them. Waterflood can be an effective recovery method even in fully discontinuous media for oil-wet or intermediate-wet systems where concurrent imbibition takes place with high enough pressure gradients across the matrix blocks. (author)

A binder-free sulfur/reduced graphene oxide aerogel as high performance electrode materials for lithium sulfur batteries

Science.gov (United States)

Nitze, Florian; Agostini, Marco; Lundin, Filippa; Palmqvist, Anders E. C.; Matic, Aleksandar

2016-12-01

Societies’ increasing need for energy storage makes it necessary to explore new concepts beyond the traditional lithium ion battery. A promising candidate is the lithium-sulfur technology with the potential to increase the energy density of the battery by a factor of 3-5. However, so far the many problems with the lithium-sulfur system have not been solved satisfactory. Here we report on a new approach utilizing a self-standing reduced graphene oxide based aerogel directly as electrodes, i.e. without further processing and without the addition of binder or conducting agents. We can thereby disrupt the common paradigm of “no battery without binder” and can pave the way to a lithium-sulfur battery with a high practical energy density. The aerogels are synthesized via a one-pot method and consist of more than 2/3 sulfur, contained inside a porous few-layered reduced graphene oxide matrix. By combining the graphene-based aerogel cathode with an electrolyte and a lithium metal anode, we demonstrate a lithium-sulfur cell with high areal capacity (more than 3 mAh/cm2 after 75 cycles), excellent capacity retention over 200 cycles and good sulfur utilization. Based on this performance we estimate that the energy density of this concept-cell can significantly exceed the Department of Energy (DEO) 2020-target set for transport applications.

Optimization of low sulfur jerusalem artichoke juice for fossil fuels biodesulfurization process

OpenAIRE

Silva, Tiago P.; Paixão, Susana M.; Roseiro, J. Carlos; Alves, Luís Manuel

2013-01-01

Most of the world’s energy is generated from the burning of fossil fuels such as oil and its derivatives. When burnt, these fuels release into the atmosphere volatile organic compounds, sulfur as sulfur dioxide (SO2) and the fine particulate matter of metal sulfates. These are pollutants which can be responsible for bronchial irritation, asthma attacks, cardio-pulmonary diseases and lung cancer mortality, and they also contribute for the occurrence of acid rains and the increase of the hole i...

Survivability Assessment: Modeling A Recovery Process

OpenAIRE

Paputungan, Irving Vitra; Abdullah, Azween

2009-01-01

Survivability is the ability of a system to continue operating, in a timely manner, in the presence ofattacks, failures, or accidents. Recovery in survivability is a process of a system to heal or recover from damageas early as possible to fulfill its mission as condition permit. In this paper, we show a preliminary recoverymodel to enhance the system survivability. The model focuses on how we preserve the system and resumes itscritical service under attacks as soon as possible.Keywords: surv...

Equipment and obtention process of phosphorus-32 starting from sulfur-32; Equipo y proceso de obtencion de fosforo-32 a partir del azufre-32

Energy Technology Data Exchange (ETDEWEB)

Alanis M, J. [ININ, Departamento de Materiales Radiactivos, 52045 Ocoyoacac, Estado de Mexico (Mexico)

2004-12-15

In the National Institute of Nuclear Research, it is the Radioisotopes Production plant, which covers in the area of the medicine 70% approximately of the national market and it exports to some countries of Latin America (Technetium-99, iodine-131, Sm-153 among other). At the moment the plant has modern facilities and certified with the ISO-9001-2000 standard, this, gives trust to the clients as for the quality of its products. Besides the production of radioisotopes dedicated for the medical area, the work of the plant tends to be more enlarged every time, producing new radioisotopes not only but with medical purposes but also industrial and agricultural ones, such it is the case of the production of Phosphorus-32 ({sup 32}P) that has applications with medical, industrial and in the agriculture purposes. The investigation studies from the prime matter (sulfur-32), sulfur purification, sulfur irradiation in the nuclear reactor and the obtaining process of {sup 32}P in a prototype, its took us to design and to build the obtaining process from {sup 32}P to more high level, which is presented in this work. To be able to select the obtaining method of {sup 32} P that is presented it was necessary to study the methods that have been developed in the world, later on it was selected the way that is presented. In that way the physical and chemical properties of the sulfur were studied which is used as prime matter, the interest nuclear reaction was also studied to carry out the production of {sup 32}P by means of the realization of mathematical calculations of irradiation of the sulfur in TRIGA Mark lll nuclear reactor. Once the sulfur is irradiated, it is necessary to carry out the radiochemical separation of the {sup 32}P produced from the sulfur, for this, it was necessary to carry out experimental tests of this separation, later on it was developed a prototype where it was carried out this separation and finally it was developed the final equipment of production of

Recovery of cobalt and lithium from spent Li-ion batteries

International Nuclear Information System (INIS)

Busnardo, Natalia Giovanini; Paulino, Jessica Frontino; Afonso, Julio Carlos

2007-01-01

The 'active mass' (cathode + anode + electrolyte) of spent Li-ion batteries was submitted to one of the following procedures: (a) it was calcined (500 deg C) and submitted to extraction with water to recover lithium salts. The residual solid was treated with sulfuric acid containing hydrogen peroxide. Cobalt was recovered as sulfate; (b) the 'active mass' was treated with potassium hydrogen sulfate (500 deg C) and dissolved in water. Cobalt was precipitated together with copper after addition of sodium hydroxide. Lithium was partially recovered as lithium fluoride. Co-processing of other battery components (aluminum and copper foils) affected negatively the behavior of the recovery procedures. Previous segregation of battery components is essential for an efficient and economical processing of the 'active mass'. (author)

Sulfur and octane trade off in FCC naphta conventional hydrotreating

Energy Technology Data Exchange (ETDEWEB)

Badra, C. [INTEVEP S.A. Research and Technological Support Center of Petroleos de Venzuela, Caracas (Venezuela). Dept. de Refinacion; Perez, J.A. [INTEVEP S.A. Research and Technological Support Center of Petroleos de Venzuela, Caracas (Venezuela). Dept. de Refinacion; Salazar, J.A. [INTEVEP S.A. Research and Technological Support Center of Petroleos de Venzuela, Caracas (Venezuela). Dept. de Refinacion; Cabrera, L. [INTEVEP S.A. Research and Technological Support Center of Petroleos de Venzuela, Caracas (Venezuela). Dept. de Refinacion; Gracia, W. [INTEVEP S.A. Research and Technological Support Center of Petroleos de Venzuela, Caracas (Venezuela). Dept. de Refinacion

1997-06-01

A model to predict the change of octane numbers expected in an FCC naphtha hydrotreating process as a function of the hydroprocessing severity (degree of sulfur removal) and the type of naphtha (expressed as the sulfur content and bromine number in the feedstock) is presented. When considering hydrotreating as an option for processing their catalytic naphthas, refiners search for the proper balance between the desired reduction of sulfur and olefins and the resulting undesired reduction of octane (RON and MON). In doing so, refiners should study the possibility of performing the hydrotreating at mild severities and/or the possibility of fractionating FCC naphthas to just treat a specific cut. This paper provides simple tools to study and analyze these study cases and to assess the sulfur-octane trade offs. (orig.)

Data warehousing methods and processing infrastructure for brain recovery research.

Science.gov (United States)

Gee, T; Kenny, S; Price, C J; Seghier, M L; Small, S L; Leff, A P; Pacurar, A; Strother, S C

2010-09-01

In order to accelerate translational neuroscience with the goal of improving clinical care it has become important to support rapid accumulation and analysis of large, heterogeneous neuroimaging samples and their metadata from both normal control and patient groups. We propose a multi-centre, multinational approach to accelerate the data mining of large samples and facilitate data-led clinical translation of neuroimaging results in stroke. Such data-driven approaches are likely to have an early impact on clinically relevant brain recovery while we simultaneously pursue the much more challenging model-based approaches that depend on a deep understanding of the complex neural circuitry and physiological processes that support brain function and recovery. We present a brief overview of three (potentially converging) approaches to neuroimaging data warehousing and processing that aim to support these diverse methods for facilitating prediction of cognitive and behavioral recovery after stroke, or other types of brain injury or disease.

The role of crystallization-driven exsolution on the sulfur mass balance in volcanic arc magmas

Science.gov (United States)

Su, Yanqing; Huber, Christian; Bachmann, Olivier; Zajacz, Zoltán; Wright, Heather M.; Vazquez, Jorge A.

2016-01-01

The release of large amounts of sulfur to the stratosphere during explosive eruptions affects the radiative balance in the atmosphere and consequentially impacts climate for up to several years after the event. Quantitative estimations of the processes that control the mass balance of sulfur between melt, crystals, and vapor bubbles is needed to better understand the potential sulfur yield of individual eruption events and the conditions that favor large sulfur outputs to the atmosphere. The processes that control sulfur partitioning in magmas are (1) exsolution of volatiles (dominantly H2O) during decompression (first boiling) and during isobaric crystallization (second boiling), (2) the crystallization and breakdown of sulfide or sulfate phases in the magma, and (3) the transport of sulfur-rich vapor (gas influx) from deeper unerupted regions of the magma reservoir. Vapor exsolution and the formation/breakdown of sulfur-rich phases can all be considered as closed-system processes where mass balance arguments are generally easier to constrain, whereas the contribution of sulfur by vapor transport (open system process) is more difficult to quantify. The ubiquitous “excess sulfur” problem, which refers to the much higher sulfur mass released during eruptions than what can be accounted for by amount of sulfur originally dissolved in erupted melt, as estimated from melt inclusion sulfur concentrations (the “petrologic estimate”), reflects the challenges in closing the sulfur mass balance between crystals, melt, and vapor before and during a volcanic eruption. In this work, we try to quantify the relative importance of closed- and open-system processes for silicic arc volcanoes using kinetic models of sulfur partitioning during exsolution. Our calculations show that crystallization-induced exsolution (second boiling) can generate a significant fraction of the excess sulfur observed in crystal-rich arc magmas. This result does not negate the important role of

Sulfur-binding in recent environments: II. Speciation of sulfur and iron and implications for the occurrence of organo-sulfur compounds

Science.gov (United States)

Hartgers, Walter A.; Lòpez, Jordi F.; Sinninghe Damsté, Jaap S.; Reiss, Christine; Maxwell, James R.; Grimalt, Joan O.

1997-11-01

Speciation of iron and sulfur species was determined for two recent sediments (La Trinitat and Lake Cisó) which were deposited in environments with a high biological productivity and sulfate-reducing activity. In sediments from calcite ponds of La Trinitat an excess of reactive iron species (iron monosulfides, iron hydroxides) results in a depletion of reactive sulfur which is accompanied by a virtual absence of organo-sulfur compounds, both in low (LMW) and high molecular-weight (HMW) fractions. Small amounts of phytanyl and highly branched isoprenoid (HBI) thiophenes in the extract demonstrate that these molecules exhibit a higher reactivity towards reduced sulfur species as compared to detrital iron. Euxinic sediments from Lake Cisó are characterised by an excess of reduced sulfur species which can rapidly trap reactive iron. High concentrations of H 2S results in the formation of organo-sulfur compounds which were encountered in both LMW and HMW fractions. The major part of the organic sulfur is bound to the carbohydrate portion of woody tissues, whose presence was revealed by a specific alkylthiophene distribution in the flash pyrolysate and by Li/EtNH 2 desulfurisation of the kerogen which resulted in the solubilisation of the sulfur-enriched hemicellulose fraction. Relatively high amounts of sulfurised C 25 HBI compounds in the sediment extract of Lake Cisó reflect the incorporation of sulfur into algal derived organic matter upon early diagenesis. The combined approach of the speciation of iron and sulfur species and the molecular analysis of sedimentary fractions demonstrates that abiotic sulfur binding to organic matter occurs at the earliest stages of diagenesis under specific depositional conditions (anoxic, stratified water column) in which an excess of reduced sulfur species relative to the amount of reactive iron is a controlling factor.

Large scale disposal of waste sulfur: From sulfide fuels to sulfate sequestration

International Nuclear Information System (INIS)

Rappold, T.A.; Lackner, K.S.

2010-01-01

Petroleum industries produce more byproduct sulfur than the market can absorb. As a consequence, most sulfur mines around the world have closed down, large stocks of yellow sulfur have piled up near remote operations, and growing amounts of toxic H 2 S are disposed of in the subsurface. Unless sulfur demand drastically increases or thorough disposal practices are developed, byproduct sulfur will persist as a chemical waste problem on the scale of 10 7 tons per year. We review industrial practices, salient sulfur chemistry, and the geochemical cycle to develop sulfur management concepts at the appropriate scale. We contend that the environmentally responsible disposal of sulfur would involve conversion to sulfuric acid followed by chemical neutralization with equivalent amounts of base, which common alkaline rocks can supply cheaply. The resulting sulfate salts are benign and suitable for brine injection underground or release to the ocean, where they would cause minimal disturbance to ecosystems. Sequestration costs can be recouped by taking advantage of the fuel-grade thermal energy released in the process of oxidizing reduced compounds and sequestering the products. Sulfate sequestration can eliminate stockpiles and avert the proliferation of enriched H 2 S stores underground while providing plenty of carbon-free energy to hydrocarbon processing.

Three-Dimensionally Hierarchical Graphene Based Aerogel Encapsulated Sulfur as Cathode for Lithium/Sulfur Batteries

Science.gov (United States)

Li, Haipeng; Sun, Liancheng; Wang, Zhuo; Zhang, Yongguang; Tan, Taizhe; Wang, Gongkai

2018-01-01

A simple and effective method was developed to obtain the electrode for lithium/sulfur (Li/S) batteries with high specific capacity and cycling durability via adopting an interconnected sulfur/activated carbon/graphene (reduced graphene oxide) aerogel (S/AC/GA) cathode architecture. The AC/GA composite with a well-defined interconnected conductive network was prepared by a reduction-induced self-assembly process, which allows for obtaining compact and porous structures. During this process, reduced graphene oxide (RGO) was formed, and due to the presence of oxygen-containing functional groups on its surface, it not only improves the electronic conductivity of the cathode but also effectively inhibits the polysulfides dissolution and shuttle. The introduced activated carbon allowed for lateral and vertical connection between individual graphene sheets, completing the formation of a stable three-dimensionally (3D) interconnected graphene framework. Moreover, a high specific surface area and 3D interconnected porous structure efficiently hosts a higher amount of active sulfur material, about 65 wt %. The designed S/AC/GA composite electrodes deliver an initial capacity of 1159 mAh g−1 at 0.1 C and can retain a capacity of 765 mAh g−1 after 100 cycles in potential range from 1 V to 3 V. PMID:29373525

Three-Dimensionally Hierarchical Graphene Based Aerogel Encapsulated Sulfur as Cathode for Lithium/Sulfur Batteries

Directory of Open Access Journals (Sweden)

Haipeng Li

2018-01-01

Full Text Available A simple and effective method was developed to obtain the electrode for lithium/sulfur (Li/S batteries with high specific capacity and cycling durability via adopting an interconnected sulfur/activated carbon/graphene (reduced graphene oxide aerogel (S/AC/GA cathode architecture. The AC/GA composite with a well-defined interconnected conductive network was prepared by a reduction-induced self-assembly process, which allows for obtaining compact and porous structures. During this process, reduced graphene oxide (RGO was formed, and due to the presence of oxygen-containing functional groups on its surface, it not only improves the electronic conductivity of the cathode but also effectively inhibits the polysulfides dissolution and shuttle. The introduced activated carbon allowed for lateral and vertical connection between individual graphene sheets, completing the formation of a stable three-dimensionally (3D interconnected graphene framework. Moreover, a high specific surface area and 3D interconnected porous structure efficiently hosts a higher amount of active sulfur material, about 65 wt %. The designed S/AC/GA composite electrodes deliver an initial capacity of 1159 mAh g−1 at 0.1 C and can retain a capacity of 765 mAh g−1 after 100 cycles in potential range from 1 V to 3 V.

Sulfur-oxidizing bacteria dominate the microbial diversity shift during the pyrite and low-grade pyrolusite bioleaching process.

Science.gov (United States)

Han, Yifan; Ma, Xiaomei; Zhao, Wei; Chang, Yunkang; Zhang, Xiaoxia; Wang, Xingbiao; Wang, Jingjing; Huang, Zhiyong

2013-10-01

The microbial ecology of the pyrite-pyrolusite bioleaching system and its interaction with ore has not been well-described. A 16S rRNA gene clone library was created to evaluate changes in the microbial community at different stages of the pyrite-pyrolusite bioleaching process in a shaken flask. The results revealed that the bacterial community was disturbed after 5 days of the reaction. Phylogenetic analysis of 16S rRNA sequences demonstrated that the predominant microorganisms were members of a genus of sulfur-oxidizing bacteria, Thiomonas sp., that subsequently remained dominant during the bioleaching process. Compared with iron-oxidizing bacteria, sulfur-oxidizing bacteria were more favorable to the pyrite-pyrolusite bioleaching system. Decreased pH due to microbial acid production was an important condition for bioleaching efficiency. Iron-oxidizing bacteria competed for pyrite reduction power with Mn(IV) in pyrolusite under specific conditions. These results extend our knowledge of microbial dynamics during pyrite-pyrolusite bioleaching, which is a key issue to improve commercial applications. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Lithium sulfur batteries and electrolytes and sulfur cathodes thereof

Science.gov (United States)

Visco, Steven J.; Goncharenko, Nikolay; Nimon, Vitaliy; Petrov, Alexei; Nimon, Yevgeniy S.; De Jonghe, Lutgard C.; Katz, Bruce D.; Loginova, Valentina

2017-05-23

Lithium sulfur battery cells that use water as an electrolyte solvent provide significant cost reductions. Electrolytes for the battery cells may include water solvent for maintaining electroactive sulfur species in solution during cell discharge and a sufficient amount of a cycle life-enhancing compound that facilitates charging at the cathode. The combination of these two components enhances one or more of the following cell attributes: energy density, power density and cycle life. For instance, in applications where cost per Watt-Hour (Wh) is paramount, such as grid storage and traction applications, the use of an aqueous electrolyte in combination with inexpensive sulfur as the cathode active material can be a key enabler for the utility and automotive industries, for example, providing a cost effective and compact solution for load leveling, electric vehicles and renewable energy storage. Sulfur cathodes, and methods of fabricating lithium sulfur cells, in particular for loading lithium sulfide into the cathode structures, provide further advantages.

Evaluating the potential of process sites for waste heat recovery

International Nuclear Information System (INIS)

Oluleye, Gbemi; Jobson, Megan; Smith, Robin; Perry, Simon J.

2016-01-01

Highlights: • Analysis considers the temperature and duties of the available waste heat. • Models for organic Rankine cycles, absorption heat pumps and chillers proposed. • Exploitation of waste heat from site processes and utility systems. • Concept of a site energy efficiency introduced. • Case study presented to illustrate application of the proposed methodology. - Abstract: As a result of depleting reserves of fossil fuels, conventional energy sources are becoming less available. In spite of this, energy is still being wasted, especially in the form of heat. The energy efficiency of process sites (defined as useful energy output per unit of energy input) may be increased through waste heat utilisation, thereby resulting in primary energy savings. In this work, waste heat is defined and a methodology developed to identify the potential for waste heat recovery in process sites; considering the temperature and quantity of waste heat sources from the site processes and the site utility system (including fired heaters and, the cogeneration, cooling and refrigeration systems). The concept of the energy efficiency of a site is introduced – the fraction of the energy inputs that is converted into useful energy (heat or power or cooling) to support the methodology. Furthermore, simplified mathematical models of waste heat recovery technologies using heat as primary energy source, including organic Rankine cycles (using both pure and mixed organics as working fluids), absorption chillers and absorption heat pumps are developed to support the methodology. These models are applied to assess the potential for recovery of useful energy from waste heat. The methodology is illustrated for an existing process site using a case study of a petroleum refinery. The energy efficiency of the site increases by 10% as a result of waste heat recovery. If there is an infinite demand for recovered energy (i.e. all the recoverable waste heat sources are exploited), the site

Development of techniques of production of sulfur-35 and its inorganic compounds

International Nuclear Information System (INIS)

Shikata, Eiji

1981-12-01

Techniques to produce routinely Curies of carrier-free sulfur-35 from neutron irradiated potassium chloride were developed. Firstly the ratio of sulfur-35 to phosphorus-32 produced respectively by the reactions 35 Cl(n,p) 35 S and 35 Cl(n,α) 32 P was determined. For the post-irradiation process, two processes of anion exchange and cation exchange were studied. The former process was based on the selective elution of carrier-free sulfate after precipitation of the bulk of potassium chloride by ethanol and the latter process on the selective adsorption of carrier-free phosphate on Fe +3 -cation exchange resin. A gloved box with various appendant equipments was constructed for routine production and a glass apparatus was installed in it. Sulfur-35 from 1 Ci to 5 Ci has been produced by the cation exchange process several times every year during past few years, and products of high quality have been obtained with yields higher than 90% without any troubles. In the studies on the synthesis of sulfur-35 labeled inorganic compounds, sulfate[ 35 S] was reduced with tin(II)-phosphoric acid to hydrogen sulfide[ 35 S], which was oxidized to elementary sulfur[ 35 S]. Sulfate[ 35 S] of sodium or copper(II) was precipitated from an aqueous solution of sodium or copper(II) chloride containing carrier-free sulfate [ 35 S] by adding carrier of either one of the sulfates and ethanol. Copper(II) sulfate[ 35 S] was pyrolyzed to evolve sulfur[ 35 S] dioxide, which was fixed in a sodium hydroxide solution as sodium sulfite[ 35 S]. This was allowed to react with colloidal sulfur in a boiling solution in the presence of 2-octanol to form thiosulfate[ 35 S] efficiently. By treating target potassium chloride before and after irradiation in an oxygen-free atmosphere, approximately 60% of sulfur-35 was recovered as thiosulfate. Reduction with nascent hydrogen and decomposition with acid of the thiosulfate were studied to prepare elementary sulfur [ 35 S]. (author)

Silver recovery from the waste materials by the method of flotation process

OpenAIRE

B. Oleksiak; G. Siwiec; A. Tomaszewska; D. Piękoś

2018-01-01

During the leaching process of zinc concentrates, the waste materials rich in various metals such as eg. silver are produced. So far no attempts of silver recovery from the mentioned waste materials have been made due to the lack of any method which would be both effective and beneficial. The paper presents some possibilities of application of flotation process in silver recovery form waste materials generated during zinc production.

A multi-stage oil-water-separating process design for the sea oil spill recovery robot

Science.gov (United States)

Zhang, Min-ge; Wu, Jian-guo; Lin, Xinhua; Wang, Xiao-ming

2018-03-01

Oil spill have the most common pollution to the marine ecological environment. In the late stage of physical method recovery, because of the thin oil and the strong sea breeze, the recovery vessels has low efficiency and high energy consumption. This paper develops a multi-stage oil-water-separating process carried by the sea oil spill recovery robot in severe conditions. This design consists of three separation process, among which both the first and third process adopt corrugated sheets horizontal oil-water separator, while the second is hydraulic rotary breaker. This design also equiptment with rectifier and cyclone separator and other important components. This process has high flexibility and high recovery efficiency. The implement effect is significant.

Determination of sulfur in bovine serum albumin and L-cysteine using high-resolution continuum source molecular absorption spectrometry of the CS molecule

Science.gov (United States)

Andrade-Carpente, Eva; Peña-Vázquez, Elena; Bermejo-Barrera, Pilar

2016-08-01

In this study, the content of sulfur in bovine serum albumin and L-cysteine was determined using high-resolution continuum source molecular absorption spectrometry of the CS molecule, generated in a reducing air-acetylene flame. Flame conditions (height above the burner, measurement time) were optimized using a 3.0% (v/v) sulfuric acid solution. A microwave lab station (Ethos Plus MW) was used for the digestion of both compounds. During the digestion step, sulfur was converted to sulfate previous to the determination. Good repeatability (4-10%) and analytical recovery (91-106%) was obtained.

Partial substitution of asphalt pavement with modified sulfur

Directory of Open Access Journals (Sweden)

E.R. Souaya

2015-12-01

Full Text Available The use of sulfur in pavement laying was developed in 1980 but it was restricted in the late 19th century due to its environmental problems and its high reactivity toward oxidation processes which give sulfuric acid products that are capable of destroying the asphalt mixture. The study involved the conversion of elemental sulfur to a more stable modified one using a combination of byproducts of olefin hydrocarbons that were obtained from petroleum fractional distillates and cyclic hydrocarbon bituminous residue at 145 °C. The changes in the structural characteristics and morphology of prepared modified sulfur were studied using XRD and SEM respectively. Also DSC curves help us to elucidate the changes in sulfur phases from α-orthorhombic to β-mono clinic structure. The technique of nanoindentation helps us to compare the mechanical properties of modified and pure sulfur including modulus of elasticity and hardness. The hot mixture asphalt designs were prepared according to the Marshall Method in which the asphalt binder content was partially substituted with 20%, 30%, 40%, and 50% modified sulfur. The mechanical properties were measured including Marshall Stability, flow, air voids, and Marshall Stiffness. From the overall study, the results indicated that asphalt could partially be substituted with modified sulfur with no significant deleterious effect on performance and durability of hot mixed asphalt.

Screen-Printed Carbon Electrodes Modified with Cobalt Phthalocyanine for Selective Sulfur Detection in Cosmetic Products

Directory of Open Access Journals (Sweden)

Ying Shih

2011-06-01

Full Text Available Cobalt phthalocyanine (CoPc films were deposited on the surface of a screen-printed carbon electrode using a simple drop coating method. The cyclic voltammogram of the resulting CoPc modified screen-printed electrode (CoPc/SPE prepared under optimum conditions shows a well-behaved redox couple due to the (CoI/CoII system. The CoPc/SPE surface demonstrates excellent electrochemical activity towards the oxidation of sulfur in a 0.01 mol·L−1 NaOH. A linear calibration curve with the detection limit (DL, S/N = 3 of 0.325 mg·L−1 was achieved by CoPc/SPE coupled with flow injection analysis of the sulfur concentration ranging from 4 to 1120 mg·L−1. The precision of the system response was evaluated (3.60% and 3.52% RSD for 12 repeated injections, in the range of 64 and 480 mg·L−1 sulfur. The applicability of the method was successfully demonstrated in a real sample analysis of sulfur in anti-acne creams, and good recovery was obtained. The CoPc/SPE displayed several advantages in sulfur determination including easy fabrication, high stability, and low cost.

Simulation of activational grinding for rhombic sulfur particles in a disintegrator (pinned disc mill

Directory of Open Access Journals (Sweden)

Farit Urakaev

2016-12-01

Full Text Available Based on the theoretical studies, complete picture of a mechanical processing of sulfur in the disintegrator is given. Kinematic and dynamic characteristics of elastic and inelastic collisions of particles of processed rhombic sulfur with rows of disintegrator fingers are calculated. Based on the analysis of the obtained dependency of the rotation frequency of the rotors offers, advices on selecting optimal conditions for activation milling of α-sulfur in the disintegrator are given. These results can be partially used in the processing of sulfur and in other types of shock grinding devices, in particular, jet mills.

Characterization and recovery of hexavalent chromium salts of an environmental liability

International Nuclear Information System (INIS)

Rangel C, A. A.; Isarain C, E.; Maldonado V, M.

2015-01-01

The purpose of this study was to examine a diverse group of washing solutions for its use in the recovery of the industrial waste hexavalent chromium, in compliance with the Mexican regulation NOM-147-SEMARNAT/SSA1-2004. The recovery process consisted of a simple random sampling and a physical-chemical characterization with consideration to the high solubility of hexavalent chromium compounds. A test was performed which implemented five different washing solutions (water, sulfuric acid, citric acid, sodium hydroxide, calcium and hydroxide). This was followed by a factorial experimental design to optimize resources with a removal efficiency of 80% and hence a recovery of 33 g/kg as CaCrO 4 (calcium chromate). Chromium hexavalent concentration in the leachate was quantified using UV-Vis spectrometry at a wavelength λ = 540 nm, while the salts recovered by evaporation were characterized using X-ray fluorescence analysis, leading to the conclusion that precipitate can be used as raw material, the main elements are Cr, Ca, Fe and Mg, and their concentration depends on the washing solution. (Author)

Vapor phase elemental sulfur amendment for sequestering mercury in contaminated soil

Science.gov (United States)

Looney, Brian B.; Denham, Miles E.; Jackson, Dennis G.

2014-07-08

The process of treating elemental mercury within the soil is provided by introducing into the soil a heated vapor phase of elemental sulfur. As the vapor phase of elemental sulfur cools, sulfur is precipitated within the soil and then reacts with any elemental mercury thereby producing a reaction product that is less hazardous than elemental mercury.

Sulfur impregnated in tunable porous N-doped carbon as sulfur cathode: effect of pore size distribution

International Nuclear Information System (INIS)

Wang, Sha; Zhao, Zhenxia; Xu, Hui; Deng, Yuanfu; Li, Zhong; Chen, Guohua

2015-01-01

Highlights: •Effects of pore size were investigated on electrochemistry for S cathode. •Activation energy of sulfur desorption from the PDA-C was estimated. •Strong interaction was formed between sulfur and porous N-doped carbon. •PDA-C@S showed good cycling performance of 608 mA h g −1 at 2 C over 300 cycles. •PDA-C@S showed good rate stability and high rate capacity. -- Abstract: A novel porous N-doped carbon microsphere (polymer-dopamine derived carbon, PDA-C) with high specific surface area was synthesized as sulfur host for high performance of lithium-sulfur batteries. We used KOH to adjust the pore size and surface area of the PDA-C materials, and then impregnated sulfur into the PDA-C samples by vapor-melting diffusion method. Effects of pore size of the PDA-C samples on the electrochemical performance of the PDA-C@sulfur cathodes were systematically investigated. Raman spectra indicated an enhanced trend of the degree of graphitization of the PDA-C samples with increasing calcination temperature. The surface area of the PDA-C samples increases with amount of the KOH in the pore-creating process. The graphitized porous N-doped carbon provides the high electronic conductive network. Meanwhile, the PDA-C with high surface area and uniform micropores ensures a high interaction toward sulfur as well as the high dispersion of nanoscale sulfur layer on it. The microporous PDA-C@S cathode material exhibits the excellent high rate discharge capability (636 mA h g −1 at 2.0 C) and good low/high-rate cycling stability (893 mA h g −1 (0.5 C) and 608 mA h g −1 (2.0 C) over 100 and 300 cycles). Cyclic voltammogram curves and electrochemical impedance plots show that both the impedance and polarization of the cells increase with decreasing pore size

Hydrometallurgical process for zinc recovery from electric arc furnace dust (EAFD)

International Nuclear Information System (INIS)

Oustadakis, P.; Tsakiridis, P.E.; Katsiapi, A.; Agatzini-Leonardou, S.

2010-01-01

The present paper is the first of a series of two articles dealing with the development of an integrated process for the recovery of zinc from electric arc furnace dust (EAFD), a hazardous industrial waste generated in the collection of particulate material during steelmaking process via electric arc furnace. Part I presents the EAFD characterization and its leaching process by diluted sulphuric acid, whereas Part II deals with the purification of the leach liquor and the recovery of zinc by solvent extraction/electrowinning. The characterization of the examined electric arc furnace dust was carried out by using granulometry analysis, chemical analysis, X-ray diffraction (XRD), thermogravimetric/differential thermal analysis (TG/DTA) and scanning electron microscopy (SEM). The leaching process was based on the Zn extraction with diluted sulphuric acid from EAFD under atmospheric conditions and without using any preliminary treatment. Statistical design and analysis of experiments were used, in order to determine the main effects and interactions of the leaching process factors, which were: acid normality, temperature and solid to liquid ratio. The zinc recovery efficiency on the basis of EAFD weight reached 80%. X-ray diffraction and scanning electron microscopy were used for the characterization of the leached residues.

Silver recovery from the waste materials by the method of flotation process

Directory of Open Access Journals (Sweden)

B. Oleksiak

2018-01-01

Full Text Available During the leaching process of zinc concentrates, the waste materials rich in various metals such as eg. silver are produced. So far no attempts of silver recovery from the mentioned waste materials have been made due to the lack of any method which would be both effective and beneficial. The paper presents some possibilities of application of flotation process in silver recovery form waste materials generated during zinc production.

Transcriptional and Proteomic Profiling of Aspergillus flavipes in Response to Sulfur Starvation.

Science.gov (United States)

El-Sayed, Ashraf S A; Yassin, Marwa A; Ali, Gul Shad

2015-01-01

Aspergillus flavipes has received considerable interest due to its potential to produce therapeutic enzymes involved in sulfur amino acid metabolism. In natural habitats, A. flavipes survives under sulfur limitations by mobilizing endogenous and exogenous sulfur to operate diverse cellular processes. Sulfur limitation affects virulence and pathogenicity, and modulates proteome of sulfur assimilating enzymes of several fungi. However, there are no previous reports aimed at exploring effects of sulfur limitation on the regulation of A. flavipes sulfur metabolism enzymes at the transcriptional, post-transcriptional and proteomic levels. In this report, we show that sulfur limitation affects morphological and physiological responses of A. flavipes. Transcription and enzymatic activities of several key sulfur metabolism genes, ATP-sulfurylase, sulfite reductase, methionine permease, cysteine synthase, cystathionine β- and γ-lyase, glutathione reductase and glutathione peroxidase were increased under sulfur starvation conditions. A 50 kDa protein band was strongly induced by sulfur starvation, and the proteomic analyses of this protein band using LC-MS/MS revealed similarity to many proteins involved in the sulfur metabolism pathway.

Obtention process of phosphorus 32 starting from commercial sulfur and design and construction of the radiochemical separation prototype

International Nuclear Information System (INIS)

Duarte A, C.; Alanis M, J.; Gutierrez R, C.

2002-01-01

In this work an obtention process of phosphorus 32 ( 32 P) in orthophosphoric acid form (H 3 32 PO 4 ) is described starting from commercial sulfur. Also the design and construction of the experimental prototype used in the radiochemical separation and their results in three tests carried out is reported. (Author)

Acceptance and Avoidance Processes at Different Levels of Psychological Recovery from Enduring Mental Illness.

Science.gov (United States)

Siqueira, Vinicius R; Oades, Lindsay G

2015-01-01

Objective. This study examined the use of psychological acceptance and experiential avoidance, two key concepts of Acceptance and Commitment Therapy (ACT), in the psychological recovery process of people with enduring mental illness. Method. Sixty-seven participants were recruited from the metropolitan, regional, and rural areas of New South Wales, Australia. They all presented some form of chronic mental illness (at least 12 months) as reflected in DSM-IV Axis I diagnostic criteria. The Acceptance and Action Questionnaire (AAQ-19) was used to measure the presence of psychological acceptance and experiential avoidance; the Recovery Assessment Scale (RAS) was used to examine the levels of psychological recovery; and the Scales of Psychological Well-Being was used to observe if there are benefits in utilizing psychological acceptance and experiential avoidance in the recovery process. Results. An analysis of objectively quantifiable measures found no clear correlation between the use of psychological acceptance and recovery in mental illness as measured by the RAS. The data, however, showed a relationship between psychological acceptance and some components of recovery, thereby demonstrating its possible value in the recovery process. Conclusion. The major contribution of this research was the emerging correlation that was observed between psychological acceptance and positive levels of psychological well-being among individuals with mental illness.

Nanostructured sulfur cathodes

KAUST Repository

Yang, Yuan

2013-01-01

Rechargeable Li/S batteries have attracted significant attention lately due to their high specific energy and low cost. They are promising candidates for applications, including portable electronics, electric vehicles and grid-level energy storage. However, poor cycle life and low power capability are major technical obstacles. Various nanostructured sulfur cathodes have been developed to address these issues, as they provide greater resistance to pulverization, faster reaction kinetics and better trapping of soluble polysulfides. In this review, recent developments on nanostructured sulfur cathodes and mechanisms behind their operation are presented and discussed. Moreover, progress on novel characterization of sulfur cathodes is also summarized, as it has deepened the understanding of sulfur cathodes and will guide further rational design of sulfur electrodes. © 2013 The Royal Society of Chemistry.

Development of an improved two-cycle process for recovering uranium from wet-process phosphoric acid

International Nuclear Information System (INIS)

Chen, H.M.; Chen, H.J.; Tsai, Y.M.; Lee, T.W.; Ting, G.

1987-01-01

An improved two-cycle separation process for the recovery of uranium from wet-process phosphoric acid by extraction with bis(2-ethylhexyl)phosphoric acid (D2EHPA) plus dibutyl butylphosphonate (DBBP) in kerosene has been developed and demonstrated successfully in bench-scale, continuous mixer-settler tests. The sulfuric acid and water scrubbing steps for the recycled extraction in the second cycle solve the problems of the contamination and dilution of the phosphoric acid by the ammonium ion and water and also avoid the formation of undesirable phosphatic precipitates during the subsequent extraction of uranium by recycled organic extractant

Investigation of the colour recovery processes in irradiated 'red acrylic' dosimeters

International Nuclear Information System (INIS)

Patko, J.; Beke, D.L.

1991-01-01

The kinetics of the colour recovery processes in irradiated 'Red Acrylic' dosimeters was studied. It was found that the decay is due to diffusion of oxygen into the matrix and a thermal decay takes place, too. The diffusion processes result in the appearance of a clear surface layer which becomes thicker and thicker. This layer is separated by a sharp boundary surface from the dark region. The activation energy of the oxygen diffusion was determined from the kinetics. In samples irradiated and heat-treated in noble gas this process does not take place but it was observed that in pure oxygen, chlorine and in air the colour recovery was similar. (author) 8 refs.; 3 figs

Large sulfur isotope fractionations in Martian sediments at Gale crater

Science.gov (United States)

Franz, H. B.; McAdam, A. C.; Ming, D. W.; Freissinet, C.; Mahaffy, P. R.; Eldridge, D. L.; Fischer, W. W.; Grotzinger, J. P.; House, C. H.; Hurowitz, J. A.; McLennan, S. M.; Schwenzer, S. P.; Vaniman, D. T.; Archer, P. D., Jr.; Atreya, S. K.; Conrad, P. G.; Dottin, J. W., III; Eigenbrode, J. L.; Farley, K. A.; Glavin, D. P.; Johnson, S. S.; Knudson, C. A.; Morris, R. V.; Navarro-González, R.; Pavlov, A. A.; Plummer, R.; Rampe, E. B.; Stern, J. C.; Steele, A.; Summons, R. E.; Sutter, B.

2017-09-01

Variability in the sulfur isotopic composition in sediments can reflect atmospheric, geologic and biological processes. Evidence for ancient fluvio-lacustrine environments at Gale crater on Mars and a lack of efficient crustal recycling mechanisms on the planet suggests a surface environment that was once warm enough to allow the presence of liquid water, at least for discrete periods of time, and implies a greenhouse effect that may have been influenced by sulfur-bearing volcanic gases. Here we report in situ analyses of the sulfur isotopic compositions of SO2 volatilized from ten sediment samples acquired by NASA’s Curiosity rover along a 13 km traverse of Gale crater. We find large variations in sulfur isotopic composition that exceed those measured for Martian meteorites and show both depletion and enrichment in 34S. Measured values of δ34S range from -47 +/- 14‰ to 28 +/- 7‰, similar to the range typical of terrestrial environments. Although limited geochronological constraints on the stratigraphy traversed by Curiosity are available, we propose that the observed sulfur isotopic signatures at Gale crater can be explained by equilibrium fractionation between sulfate and sulfide in an impact-driven hydrothermal system and atmospheric processing of sulfur-bearing gases during transient warm periods.

Determining total sulfur content in coal by MSC radiometric sulfur meter

Energy Technology Data Exchange (ETDEWEB)

Czerw, B; Sikora, T; Golebiowski, W

1976-01-01

The MSC radiometric sulfur meter is used to determine total sulfur content in brown and black coals. Sulfur content is determined by measuring intensity of radiation beam which has travelled through a coal sample with the optimum constant surface mass. Construction of the MSC, consisting of a measuring head and the electronic measuring system, is shown in a scheme. AM-241 (with activity of 50 mCi) is the source of radiation. Energy of 25.3 keV (tin disc) is selected as the optimum. The SSU-70 probe with NaJ/Tl crystal is the radiation detector. The black coal sample weighs 10 g and the brown coal sample weighs 18 g. Duration of sulfur determination is 10 min. Error of sulfur determination ranges from plus or minus 0.2% to 0.3%. The results of operational tests of MSC radiometric sulfur meters in black and brown coal mines are discussed. Accuracy of measurement is shown in 5 tables. (8 refs.)

Experiments of HI decomposition in Iodine-sulfur process

International Nuclear Information System (INIS)

Yoon, Ho Joon

2006-02-01

We performed an experimental study on the HI concentration and decomposition in Iodine-Sulfur process for thermochemical hydrogen production, which is the most expensive and energy consuming stage. For breaking azeotropic restrain, a partial condensing type, perforated plate type, and packed bed distillation column are employed. A Liebig-type condenser was used for a partial condensing distillation test. The perforated plate distillation column has 40 mm diameter and 5 stages with 8 holes per a plate. The packed bed distillation column has 40 mm diameter and was filled with 5 mm glass beads. While no distillation methods are able to change azeotropic conditions at atmospheric pressure, HI decomposition took place in a reboiler at 480 .deg. C. The vapor-liquid equilibrium curve was obtained from the experiment with binary mixtures (HI/H 2 O) at atmospheric pressure. Almost pure H 2 O was evaporated at the lower temperature than 125 .deg. C, and above that temperature binary mixtures (HI/H 2 O) were evaporated until the leftover solution became HI acid of 0.157mol, which was an azeotropic concentration of HI. With a consideration of heat loss, enthalpy of vaporization at azeotropic condition was estimated as 1131 kJ/kg

Experiments of HI decomposition in Iodine-sulfur process

Energy Technology Data Exchange (ETDEWEB)

Yoon, Ho Joon

2006-02-15

We performed an experimental study on the HI concentration and decomposition in Iodine-Sulfur process for thermochemical hydrogen production, which is the most expensive and energy consuming stage. For breaking azeotropic restrain, a partial condensing type, perforated plate type, and packed bed distillation column are employed. A Liebig-type condenser was used for a partial condensing distillation test. The perforated plate distillation column has 40 mm diameter and 5 stages with 8 holes per a plate. The packed bed distillation column has 40 mm diameter and was filled with 5 mm glass beads. While no distillation methods are able to change azeotropic conditions at atmospheric pressure, HI decomposition took place in a reboiler at 480 .deg. C. The vapor-liquid equilibrium curve was obtained from the experiment with binary mixtures (HI/H{sub 2}O) at atmospheric pressure. Almost pure H{sub 2}O was evaporated at the lower temperature than 125 .deg. C, and above that temperature binary mixtures (HI/H{sub 2}O) were evaporated until the leftover solution became HI acid of 0.157mol, which was an azeotropic concentration of HI. With a consideration of heat loss, enthalpy of vaporization at azeotropic condition was estimated as 1131 kJ/kg.

Valuable metals - recovery processes, current trends, and recycling strategies

Energy Technology Data Exchange (ETDEWEB)

Froehlich, Peter; Lorenz, Tom; Martin, Gunther; Brett, Beate; Bertau, Martin [Institut fuer Technische Chemie, TU Bergakademie Freiberg, Leipziger Strasse 29, 09599, Freiberg (Germany)

2017-03-01

This Review provides an overview of valuable metals, the supply of which has been classified as critical for Europe. Starting with a description of the current state of the art, novel approaches for their recovery from primary resources are presented as well as recycling processes. The focus lies on developments since 2005. Chemistry strategies which are used in metal recovery are summarized on the basis of the individual types of deposit and mineral. In addition, the economic importance as well as utilization of the metals is outlined. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Regularities of catalytic reactions of hydrogen, ethane and ethylene with elementary sulfur

International Nuclear Information System (INIS)

Zazhigalov, V.A.

1978-01-01

Shown is the decisive role of metal-sulfur bond stability for activity determination of metal sulfides (WS 2 , MoS 2 , CdS) in interaction reactions of elementary sulfur and hydrogen, ethane and ethylene. Found is the regularity of changing the relative reactiveness of the given substances and a conclusion is made about uniformity of the investigated catalyst processes. The results of hydrogen, ethane and ethylene oxidation by oxygen and sulfur are compared, the semilarity of these processes being pointed out

Comparison of comprehensive two-dimensional gas chromatography coupled with sulfur-chemiluminescence detector to standard methods for speciation of sulfur-containing compounds in middle distillates.

Science.gov (United States)

Ruiz-Guerrero, Rosario; Vendeuvre, Colombe; Thiébaut, Didier; Bertoncini, Fabrice; Espinat, Didier

2006-10-01

The monitoring of total sulfur content and speciation of individual sulfur-containing compounds in middle distillates is required for efficient catalyst selection and for a better understanding of the kinetics of the reactions involved in hydrotreament processes. Owing to higher resolution power and enhanced sensitivity, comprehensive two-dimensional gas chromatography (GCxGC) hyphenated to sulfur chemiluminescence detection (SCD) has recently evolved as a powerful tool for improving characterization and identification of sulfur compounds. The aim of this paper is to compare quantitatively GCxGC-SCD and various other methods commonly employed in the petroleum industry, such as X-ray fluorescence, conventional GC-SCD, and high-resolution mass spectrometry, for total sulfur content determination and speciation analysis. Different samples of middle distillates have been analyzed to demonstrate the high potential and important advantages of GCxGC-SCD for innovative and quantitative analysis of sulfur-containing compounds. More accurate and detailed results for benzothiophenes and dibenzothiophenes are presented, showing that GCxGC-SCD should become, in the future, an essential tool for sulfur speciation analysis.

A novel process for recovery of fermentation-derived succinic acid: process design and economic analysis.

Science.gov (United States)

Orjuela, Alvaro; Orjuela, Andrea; Lira, Carl T; Miller, Dennis J

2013-07-01

Recovery and purification of organic acids produced in fermentation constitutes a significant fraction of total production cost. In this paper, the design and economic analysis of a process to recover succinic acid (SA) via dissolution and acidification of succinate salts in ethanol, followed by reactive distillation to form succinate esters, is presented. Process simulation was performed for a range of plant capacities (13-55 million kg/yr SA) and SA fermentation titers (50-100 kg/m(3)). Economics were evaluated for a recovery system installed within an existing fermentation facility producing succinate salts at a cost of $0.66/kg SA. For a SA processing capacity of 54.9 million kg/yr and a titer of 100 kg/m(3) SA, the model predicts a capital investment of $75 million and a net processing cost of $1.85 per kg SA. Required selling price of diethyl succinate for a 30% annual return on investment is $1.57 per kg. Copyright © 2013 Elsevier Ltd. All rights reserved.

Methane oxidation in presence of sulfur dioxide

International Nuclear Information System (INIS)

Mantashyan, A.A.; Avetisyan, A.M.; Makaryan, E.M.; Wang, H.

2006-01-01

The emission of sulfurous gases including SO 2 from stationary power generation remains to be a serious environmental and ecological problem. Sulfurous gases are almost entirely produced from the combustion of sulfur-containing fuels. While fuel desulfurization and flue gas scrubbing is a viable solution, in the developing countries it remains to be an economical challenge to implement these SO x reduction technologies. The oxidation of methane in presence of sulfurous gas (SO 2 ) addition was studied experimentally. Te experiments were conducted in a static reactor at temperature of 728-786 K, and for mixture of C 4 /O 2 ≡ 1/2 at a pressure of 117 Torr with varying amount of SO 2 addition. It was observed that SO 2 addition accelerated the oxidation process, reduced the induction period and increased the extent of methane consumption. At the relatively short resident time (less than 50 sec) SO 3 was detected, but at longer residence time SO 3 was reduced spontaneously to SO 2

Antioxidants, mechanisms, and recovery by membrane processes.

Science.gov (United States)

Bazinet, Laurent; Doyen, Alain

2017-03-04

Antioxidants molecules have a great interest for bio-food and nutraceutical industries since they play a vital role for their capacity to reduce oxidative processes. Consequently, these molecules, generally present in complex matrices, have to be fractionated and purified to characterize them and to test their antioxidant activity. However, as natural or synthetics antioxidant molecules differ in terms of structural composition and physico-chemical properties, appropriate separation technologies must be selected. Different fractionation technologies are available but the most commonly used are filtration processes. Indeed, these technologies allow fractionation according to molecular size (pressure-driven processes), charge, or both size and charge (electrically driven processes). In this context, and after summarizing the reaction mechanisms of the different classes and nature of antioxidants as well as membrane fractionation technologies, this manuscript presents the specific applications of these membranes processes for the recovery of antioxidant molecules.

Linde Rectiscol{reg_sign} process. The most economic and experienced wash process for removal of sulfur compounds and CO{sub 2} from gasification gases

Energy Technology Data Exchange (ETDEWEB)

Kaballo, H.-P.; Kerestceciogly, U. [Linde AG, Hoellriegelskreuth (Germany). Linde Engineering Division

2006-07-01

The Recitsol{reg_sign} wash process is a well-proven process for the removal of H{sub 2}S/COS and CO{sub 2} from coal, asphalt, pitch or oil derived synthesis gas. It is a physical gas wash system using methanol as solvent at operating temperatures below water freezing point, to produce a synthesis gas with less than 0.1 vppm of total sulfur. The CO{sub 2} content can be adjusted in a range from several mol-percent down to a few ppm, as is required by the specified application. Its main advantages are the use of cheap and readily available methanol as solvent, the very flexible process configuration, and rather low utility consumption figures compared with other wash processes, like PEGE based process or chemical washes. A modern concept of a Rectisol{reg_sign} unit is described, to treat shifted and un-shifted gases in just one plant: shifted gas was used for hydrotreating in a refinery. Unshifted gas was used as fuel gas for power generation in an IGCC. CO{sub 2} of the unshifted feed gas was removed only partly, because the remaining CO{sub 2} was fed as inert gas together with the fuel gas to an IGCC. All sulfur compounds of both feed gases were concentrated in one single stream with a high H{sub 2}S concentration. Impurities like NH{sub 3}, HCN or metal carbonyls were eliminated nearly quantitatively. 4 refs., 4 figs., 3 tabs.

Graphene derived carbon confined sulfur cathodes for lithium-sulfur batteries: Electrochemical impedance studies

International Nuclear Information System (INIS)

Ganesan, Aswathi; Varzi, Alberto; Passerini, Stefano; Shaijumon, Manikoth M.

2016-01-01

Highlights: • Graphene-derived carbon (GDC) with distinctive porosity characteristics are prepared. • Effect of micro-/mesoporosity of GDC for improved Li-S battery performance is studied. • Impedance studies reveal insights into Li-S redox reactions and capacity fading phenomena. - Abstract: Sulfur nanocomposites are prepared by using graphene derived carbon (GDC), with controlled porosity characteristics, as confining matrix and are studied as efficient cathodes for lithium-sulfur (Li-S) batteries. To understand the effect of micro-/mesoporosity in porous carbon for the effective encapsulation of sulfur and polysulfides towards improved Li-S battery performance, two different GDC samples with controlled porosity characteristics, one with predominantly micropores (GDC-1) and a surface area of 1970 m 2 g −1 and the other with a surface area of 3239 m 2 g −1 , having more or less equal contribution of micro- and mesopores (GDC-2), are used to synthesize nanocomposite sulfur electrodes following melt diffusion process. Electrochemical studies are carried out by using cyclic voltammetry, galvanostatic charge/discharge cycling and electrochemical impedance spectroscopy (EIS). EIS spectra collected at different depth of discharge (DOD) in the first cycle as well as upon cycling give valuable insights into the Li-S redox reactions and capacity fading phenomena in these electrodes. The impedance response of GDC-S electrodes suggests a detrimental effect of the mesopores, where insoluble reaction products can easily accumulate, resulting in the loss of active material leading to capacity fading of Li-S cells.

Genomic Insights into the Sulfur Metabolism of Phototrophic Green Sulfur Bacteria

DEFF Research Database (Denmark)

Frigaard, Niels-Ulrik; Bryant, Donald A.

2008-01-01

Green sulfur bacteria (GSB) utilize various combinations of sulfide, elemental sulfur, thiosulfate, ferrous iron, and hydrogen for anaerobic photoautotrophic growth. Genome sequence data is currently available for 12 strains of GSB. We present here a genome-based survey of the distribution...... and phylogenies of genes involved in oxidation of sulfur compounds in these strains. Sulfide:quinone reductase, encoded by sqr, is the only known sulfur-oxidizing enzyme found in all strains. All sulfide-utilizing strains contain the dissimilatory sulfite reductase dsrABCEFHLNMKJOPT genes, which appear...... to be involved in elemental sulfur utilization. All thiosulfate-utilizing strains have an identical sox gene cluster (soxJXYZAKBW). The soxCD genes found in certain other thiosulfate-utilizing organisms like Paracoccus pantotrophus are absent from GSB. Genes encoding flavocytochrome c (fccAB), adenosine-5...

Capital cost: high and low sulfur coal plants-1200 MWe. [High sulfur coal

Energy Technology Data Exchange (ETDEWEB)

1977-01-01

This Commercial Electric Power Cost Study for 1200 MWe (Nominal) high and low sulfur coal plants consists of three volumes. The high sulfur coal plant is described in Volumes I and II, while Volume III describes the low sulfur coal plant. The design basis and cost estimate for the 1232 MWe high sulfur coal plant is presented in Volume I, and the drawings, equipment list and site description are contained in Volume II. The reference design includes a lime flue gas desulfurization system. A regenerative sulfur dioxide removal system using magnesium oxide is also presented as an alternate in Section 7 Volume II. The design basis, drawings and summary cost estimate for a 1243 MWe low sulfur coal plant are presented in Volume III. This information was developed by redesigning the high sulfur coal plant for burning low sulfur sub-bituminous coal. These coal plants utilize a mechanical draft (wet) cooling tower system for condenser heat removal. Costs of alternate cooling systems are provided in Report No. 7 in this series of studies of costs of commercial electrical power plants.

Modelling of a Naphtha Recovery Unit (NRU with Implications for Process Optimization

Directory of Open Access Journals (Sweden)

Jiawei Du

2018-06-01

Full Text Available The naphtha recovery unit (NRU is an integral part of the processes used in the oil sands industry for bitumen extraction. The principle role of the NRU is to recover naphtha from the tailings for reuse in this process. This process is energy-intensive, and environmental guidelines for naphtha recovery must be met. Steady-state models for the NRU system are developed in this paper using two different approaches. The first approach is a statistical, data-based modelling approach where linear regression models have been developed using Minitab® from plant data collected during a performance test. The second approach involves the development of a first-principles model in Aspen Plus® based on the NRU process flow diagram. A novel refinement to this latter model, called “withdraw and remix”, is proposed based on comparing actual plant data to model predictions around the two units used to separate water and naphtha. The models developed in this paper suggest some interesting ideas for the further optimization of the process, in that it may be possible to achieve the required naphtha recovery using less energy. More plant tests are required to validate these ideas.

Biodesulfurization of refractory organic sulfur compounds in fossil fuels.

Science.gov (United States)

Soleimani, Mehran; Bassi, Amarjeet; Margaritis, Argyrios

2007-01-01

The stringent new regulations to lower sulfur content in fossil fuels require new economic and efficient methods for desulfurization of recalcitrant organic sulfur. Hydrodesulfurization of such compounds is very costly and requires high operating temperature and pressure. Biodesulfurization is a non-invasive approach that can specifically remove sulfur from refractory hydrocarbons under mild conditions and it can be potentially used in industrial desulfurization. Intensive research has been conducted in microbiology and molecular biology of the competent strains to increase their desulfurization activity; however, even the highest activity obtained is still insufficient to fulfill the industrial requirements. To improve the biodesulfurization efficiency, more work is needed in areas such as increasing specific desulfurization activity, hydrocarbon phase tolerance, sulfur removal at higher temperature, and isolating new strains for desulfurizing a broader range of sulfur compounds. This article comprehensively reviews and discusses key issues, advances and challenges for a competitive biodesulfurization process.

Sulfur impacts on forest health in west-central Alberta

International Nuclear Information System (INIS)

Maynard, D.G.; Stadt, J.J.; Mallett, K.I.; Volney, W.J.A.

1994-01-01

A study was conducted to evaluate forest health and tree growth in relation to sulfur deposition in mature and immature lodgepole pine and mature trembling aspen. Soil samples were taken in forests near two sour gas processing plants in west-central Alberta. The soil sample sites were classified into high, medium and low deposition classes. The impact of sulfur deposition on soil and foliar chemistry, tree growth, and forest health was evaluated. The analysis of tree growth, using radial increments, revealed no impact associated with the sulfur deposition class. The only indicators of extensive sulfur impacts on major forest communities detected to date are elevated sulfur concentrations in the surface organic horizon and foliage, the proportion of healthy lodgepole pines, and a depression in the annual specific volume increment. No evidence of widespread forest decline has been found. 42 refs., 35 tabs., 29 figs

Sulfur in zircons: A new window into melt chemistry

Science.gov (United States)

Tang, H.; Bell, E. A.; Boehnke, P.; Barboni, M.; Harrison, T. M.

2017-12-01

The abundance and isotopic composition of sulfur are important tools for exploring the photochemistry of the atmosphere, the thermal history of mantle and igneous rocks, and ancient metabolic processes on the early Earth. Because the oldest terrestrial samples are zircons, we developed a new in-situ procedure to analyze the sulfur content of zircons using the CAMECA ims 1290 at UCLA. We analyzed zircons from three metaluminous/I-type granites (reduced and oxidized Peninsular range and Elba), which exhibit low sulfur abundance with the average of 0.5ppm, and one peraluminous/S-type zircon (Strathbogie Range), which shows an elevated sulfur level with the average of 1.5ppm. Additionally, we found that sulfur content ranges between 0.4 and 2.3 ppm in young volcanic zircons (St. Lucia). Our analyses of zircons from the Jack Hills, Western Australia, whose ages range between 3.4 and 4.1 Ga, show a variety of sulfur contents. Three out of the ten zircons are consistent with the sulfur contents of S-type zircons; the rest have low sulfur contents, which are similar to those of I-type zircons. The high sulfur content in some of these Jack Hills zircons can be interpreted as indicating their origin in either a S-type granite or a volcanic reservoir. We favor the former interpretation since the Ti-in-zircon temperatures of our Jack Hills zircons is lower than those of volcanic zircons. Future work will be undertaken to develop a systematic understanding of the relationship between melt volatile content, melt chemistry, and zircon sulfur content.

Modelling transport-limited discharge capacity of lithium-sulfur cells

International Nuclear Information System (INIS)

Zhang, Teng; Marinescu, Monica; Walus, Sylwia; Offer, Gregory J.

2016-01-01

Highlights: • We modelled the rate capability of a Li-S cell based on mass-transport limitation • The model predicts a discharged Li-S cell to regain capacity upon short relaxation • Modelled rate capability and capacity recovery effect validated with measurements - Abstract: Lithium-sulfur (Li-S) battery could bring a step-change in battery technology with a potential specific energy density of 500 - 600 Wh/kg. A key challenge for further improving the specific energy-density of Li-S cells is to understand the mechanisms behind reduced sulfur utilisation at low electrolyte loadings and high discharge currents. While several Li-S models have been developed to explore the discharge mechanisms of Li-S cells, they so far fail to capture the discharge profiles at high currents. In this study, we propose that the slow ionic transport in concentrated electrolyte is limiting the rate capability of Li-S cells. This transport-limitation mechanism is demonstrated through a one-dimensional Li-S model which qualitatively captures the discharge capacities of a sulfolane-based Li-S cell at different currents. Furthermore, our model predicts that a discharged Li-S cell is able regain some capacity with a short period of relaxation. This capacity recovery phenomenon is validated experimentally for different discharge currents and relaxation durations. The transport-limited discharge behavior of Li-S cells highlights the importance of optimizing the electrolyte loading and electrolyte transport property in Li-S cells.

RECOVERY OF LIQUID WASTE FROM A CURTIEMBRE STAGE UNHAIRING

OpenAIRE

Salas C., Gilberto

2014-01-01

An experimental study on precipitation and recovery of dissolved proteins in wastewater from a tannery, which is achieved is when its isoelectric point is reached pH between 4.6 to 5.5 using acid solutions in the present work sulfuric (H2SO4). The recovery of the protein is above 80% and the reduction of BOD in the effluent is greater than 50%. En el presente trabajo se presenta un estudio experimental sobre la precipitación y recuperación de proteínas disueltas contenidas en las aguas res...

Single and multiple ionization of sulfur atoms by electron impact

International Nuclear Information System (INIS)

Ziegler, D.L.

1982-01-01

Laboratory measurements of the cross sections for single, double, triple, and quadruple ionization of sulfur atoms by electron impact are presented for collision energies from threshold to 500 eV. The cross sections for single ionization of sulfur are measured relative to those of several elements whose absolute cross sections for single ionization are known. Cross sections for each multiple ionization process are then measured relative to those for single ionization. The configuration and operation of the apparatus for these measurements are described. The possible effects of excited sulfur reactants are examined, and the reported cross sections are felt to be characteristic of ground state sulfur atoms

In-situ sulfuration synthesis of sandwiched spherical tin sulfide/sulfur-doped graphene composite with ultra-low sulfur content

Science.gov (United States)

Zhao, Bing; Yang, Yaqing; Wang, Zhixuan; Huang, Shoushuang; Wang, Yanyan; Wang, Shanshan; Chen, Zhiwen; Jiang, Yong

2018-02-01

SnS is widely studied as anode materials since of its superior structural stability and physicochemical property comparing with other Sn-based composites. Nevertheless, the inconvenience of phase morphology control and excessive consumption of sulfur sources during synthesis hinder the scalable application of SnS nanocomposites. Herein, we report a facile in-situ sulfuration strategy to synthesize sandwiched spherical SnS/sulfur-doped graphene (SnS/S-SG) composite. An ultra-low sulfur content with approximately stoichiometric ratio of Sn:S can effectively promote the sulfuration reaction of SnO2 to SnS and simultaneous sulfur-doping of graphene. The as-prepared SnS/S-SG composite shows a three-dimensional interconnected spherical structure as a whole, in which SnS nanoparticles are sandwiched between the multilayers of graphene sheets forming a hollow sphere. The sandwiched sphere structure and high S doping amount can improve the binding force between SnS and graphene, as well as the structural stability and electrical conductivity of the composite. Thus, a high reversibility of conversion reaction, promising specific capacity (772 mAh g-1 after 100 cycles at 0.1 C) and excellent rate performance (705 and 411 mAh g-1 at 1 C and 10 C, respectively) are exhibited in the SnS/S-SG electrode, which are much higher than that of the SnS/spherical graphene synthesized by traditional post-sulfuration method.

Process for recovery of uranium from wet process phosphoric acid

International Nuclear Information System (INIS)

Wiewiorowski, T.K.; Thornsberry, W.L. Jr.

1978-01-01

Process is claimed for the recovery of uranium from wet process phosphoric acid solution in which an organic extractant, containing uranium values and dissolved iron impurities and comprising a dialkylphosphoric acid and a trialkylphosphine oxide dissolved in a water immiscible organic solvent, is contacted with a substantially iron-free dilute aqueous phosphoric acid to remove said iron impurities. The removed impurities are bled from the system by feeding the resulting iron-loaded phosphoric acid to a secondary countercurrent uranium extraction operation from which they leave as part of the uranium-depleted acid raffinate. Also, process for recovering uranium in which the extractant, after it has been stripped of uranium values by aqueous ammonium carbonate, is contacted with a dilute aqueous acid selected from the group consisting of H 2 SO 4 , HCl, HNO 3 and iron-free H 3 PO 4 to improve the extraction efficiency of the organic extractant

The significance of elemental sulfur dissolution in liquid electrolyte lithium sulfur batteries

NARCIS (Netherlands)

Harks, Peter Paul R.M.L.; Robledo, Carla B.; Verhallen, Tomas W.; Notten, Peter H.L.; Mulder, Fokko M.

2017-01-01

It is shown that the dissolution of elemental sulfur into, and its diffusion through, the electrolyte allows cycling of lithium–sulfur batteries in which the sulfur is initially far removed and electrically insulated from the current collector. These findings help to understand why liquid

Waste Processing Cost Recovery at Los Alamos National Laboratory-Analysis and Recommendations

International Nuclear Information System (INIS)

Booth, St. R.

2009-01-01

Los Alamos National Laboratory is implementing full cost recovery for waste processing in fiscal year 2009 (FY2009), after a transition year in FY2008. Waste processing cost recovery has been implemented in various forms across the nuclear weapons complex and in corporate America. The fundamental reasoning of sending accurate price signals to waste generators is economically sound, and leads to waste minimization and reduced waste expense over time. However, Los Alamos faces significant implementation challenges because of its status as a government-owned, contractor-operated national scientific institution with a diverse suite of experimental and environmental cleanup activities, and the fact that this represents a fundamental change in how waste processing is viewed by the institution. This paper describes the issues involved during the transition to cost recovery and the ultimate selection of the business model. Of the six alternative cost recovery models evaluated, the business model chosen to be implemented in FY2009 is Recharge Plus Generators Pay Distributed Direct. Under this model, all generators who produce waste must pay a distributed direct share associated with their specific waste type to use a waste processing capability. This cost share is calculated using the distributed direct method on the fixed cost only, i.e., the fixed cost share is based on each program's forecast proportion of the total Los Alamos volume forecast of each waste type. (Fixed activities are those required to establish the waste processing capability, i.e., to make the process ready, permitted, certified, and prepared to handle the first unit of waste. Therefore, the fixed cost ends at the point just before waste begins to be processed. The activities to actually process the waste are considered variable.) The volume of waste actually sent for processing is charged a unit cost based solely on the variable cost of disposing of that waste. The total cost recovered each year is the

The investigation of the colour recovery processes in irradiated 'Red Acrylic' dosimeters

International Nuclear Information System (INIS)

Patko, J.; Beke, D.L.; Herbak, J.

1983-01-01

The kinetics of the colour recovery processes in irradiated 'Red Acrylic' dosemeters was studied. It was found that the decay is due to diffusion of oxygen into the matrix and there is also a thermal decay. The diffusion process results in the appearance of a clear surface layer which becomes more and more thick. This layer is separated with a sharp boundary surface from the dark region. The activation energy of the oxygen diffusion was determined from the kinetics. With samples irradiated and heat-treated in noble gas, the process does not take place, but in pure oxygen, chlorine, and in air the colour recovery was similar. (author)

Sulfur biogeochemistry of oil sands composite tailings

Energy Technology Data Exchange (ETDEWEB)

Warren, Lesley; Stephenson, Kate [Earth Sciences, McMaster University (Canada)], email: warrenl@mcmaster.ca; Penner, Tara [Syncrude Environmental Research (Canada)

2011-07-01

This paper discusses the sulfur biogeochemistry of oil sands composite tailings (CT). The Government of Alberta is accelerating reclamation activities on composite tailings. As a CT pilot reclamation operation, Syncrude is currently constructing the first freshwater fen. Minor unpredicted incidents with H2S gas released from the dewatering process associated with these reclamations have been reported. The objective of this study is to ascertain the connection between microbial activity and H2S generation within CT and to assess the sulfur biogeochemistry of untreated and treated (fen) CT over seasonal and annual timescales. The microbial geochemical interactions taking place are shown using a flow chart. CT is composed of gypsum, sand, clay and organics like naphthenic acids and bitumen. Sulfur and Fe cycling in mining systems and their microbial activities are presented. The chemistry and the processes involved within CT are also given along with the results. It can be said that the diverse Fe and S metabolizing microorganisms confirm the ecology involved in H2S dynamics.

Self-assembled peptides for coating of active sulfur nanoparticles in lithium–sulfur battery

International Nuclear Information System (INIS)

Jewel, Yead; Yoo, Kisoo; Liu, Jin; Dutta, Prashanta

2016-01-01

Development of lithium–sulfur (Li–S) battery is hindered by poor cyclability due to the loss of sulfur, although Li–S battery can provide high energy density. Coating of sulfur nanoparticles can help maintain active sulfur in the cathode of Li–S battery, and hence increase the cyclability. Among myriad of coating materials, synthetic peptides are very attractive because of their spontaneous self-assembly as well as electrical conductive characteristics. In this study, we explored the use of various synthetic peptides as a coating material for sulfur nanoparticles. Atomistic simulations were carried out to identify optimal peptide structure and density for coating sulfur nanoparticles. Three different peptide models, poly-proline, poly(leucine–lysine) and poly-histidine, are selected for this study based on their peptide–peptide and peptide-sulfur interactions. Simulation results show that both poly-proline and poly(leucine–lysine) can form self-assembled coating on sulfur nanoparticles (2–20 nm) in pyrrolidinone, a commonly used solvent for cathode slurry. We also studied the structural integrity of these synthetic peptides in organic [dioxolane (DOL) and dimethoxyethane (DME)] electrolyte used in Li–S battery. Both peptides show stable structures in organic electrolyte (DOL/DME) used in Li–S battery. Furthermore, the dissolution of sulfur molecules in organic electrolyte is investigated in the absence and presence of these peptide coatings. It was found that only poly(leucine–lysine)-based peptide can most effectively suppress the sulfur loss in electrolyte, suggesting its potential applications in Li–S battery as a coating material.Graphical abstract

Process for treating the dialyzed spent liquor from sulphonic acid containing sulfur minerals or tar oils or ammonium salts

Energy Technology Data Exchange (ETDEWEB)

Wernicke, E A

1936-08-09

Process for working up the dialyzate from sulfonic acid, sulfur-containing mineral or tar oils, or their ammonium salts, characterized by the combination of known steps, in the dialyzate being reacted with alkaline-earth oxide, hydroxide, or carbonate, and the resulting slightly soluble sulfate being filtered off and evaporated if necessary.

Protein recovery from inclusion bodies of Escherichia coli using mild solubilization process.

Science.gov (United States)

Singh, Anupam; Upadhyay, Vaibhav; Upadhyay, Arun Kumar; Singh, Surinder Mohan; Panda, Amulya Kumar

2015-03-25

Formation of inclusion bodies in bacterial hosts poses a major challenge for large scale recovery of bioactive proteins. The process of obtaining bioactive protein from inclusion bodies is labor intensive and the yields of recombinant protein are often low. Here we review the developments in the field that are targeted at improving the yield, as well as quality of the recombinant protein by optimizing the individual steps of the process, especially solubilization of the inclusion bodies and refolding of the solubilized protein. Mild solubilization methods have been discussed which are based on the understanding of the fact that protein molecules in inclusion body aggregates have native-like structure. These methods solubilize the inclusion body aggregates while preserving the native-like protein structure. Subsequent protein refolding and purification results in high recovery of bioactive protein. Other parameters which influence the overall recovery of bioactive protein from inclusion bodies have also been discussed. A schematic model describing the utility of mild solubilization methods for high throughput recovery of bioactive protein has also been presented.

Sulfur-carbon nanocomposites and their application as cathode materials in lithium-sulfur batteries

Energy Technology Data Exchange (ETDEWEB)

Liang, Chengdu; Dudney, Nancy J.; Howe, Jane Y.

2017-08-01

The invention is directed in a first aspect to a sulfur-carbon composite material comprising: (i) a bimodal porous carbon component containing therein a first mode of pores which are mesopores, and a second mode of pores which are micropores; and (ii) elemental sulfur contained in at least a portion of said micropores. The invention is also directed to the aforesaid sulfur-carbon composite as a layer on a current collector material; a lithium ion battery containing the sulfur-carbon composite in a cathode therein; as well as a method for preparing the sulfur-composite material.

Corrosion resistance of materials of construction for high temperature sulfuric acid service in thermochemical IS process. Alloy 800, Alloy 600, SUSXM15J1 and SiC

International Nuclear Information System (INIS)

Tanaka, Nobuyuki; Onuki, Kaoru; Shimizu, Saburo; Yamaguchi, Akihisa

2006-01-01

Exposure tests of candidate materials were carried out up to 1000 hr in the sulfuric acid environments of thermochemical hydrogen production IS process, focusing on the corrosion of welded portion and of crevice area. In the gas phase sulfuric acid decomposition condition at 850degC, welded samples of Alloy 800 and of Alloy 600 showed the same good corrosion resistance as the base materials. In the boiling condition of 95 wt% sulfuric acid solution, test sample of SiC showed the same good corrosion resistance. Also negligible corrosion was observed in crevice corrosion. (author)

Analysis and optimal process development of the iodine-Sulfur cycle for nuclear hydrogen production

International Nuclear Information System (INIS)

Lee, Byung Jin

2009-02-01

Hydrogen is expected to be a main energy vector for the future society. Among many thermo-chemical water splitting technologies for mass production of hydrogen, Iodine-Sulfur (I-S) cycle is considered to be the most promising one. Originated in the 1980s by General Atomics in the United States, the I-S cycle utilizes high temperature heat from energy sources such as nuclear reactors. Despite its high viability relative to many other options, lots of technical challenges need to be resolved until it can practically contribute to the mass production of hydrogen. In the present work, based on the experimental data available from previous works and discussions collected through the literature survey, the optimal operating conditions were proposed for the Bunsen reaction, considering the key concerns of the I-S cycle: i.e., the liquid-liquid (L-L) phase separation performance, the water distributions between the sulfuric acid and poly-hydroiodic acid (HI x ) phases, the side reactions, and the operating cost due to the excess iodine and water. All the available experimental data were combined together, and a series of parametric studies were done to find out any trends among parameters. The optimal operating point is determined as 4 mol of excess iodine and 11 mol of excess water in the stoichiometry at temperature of 330K, while the allowable window ranges between 4∼6 mol for excess iodine, 11∼13 moles for excess water, and 330∼350K for temperature. As for the distribution of excess water after the Bunsen reaction and L-L phase separation, 5 mol moves to the sulfuric acid phase and 6∼8 mol to the HI x phase. By controlling the operation within this window, it should be possible to avoid the side reaction and iodine solidification, to increase the HI concentration well above the azeotrope in the HI x section, and to minimize the operating cost caused by the excess iodine and water. With the optimized Bunsen reaction process to yield an over-azeotropic HI liquid

Sulfurized carbon: a class of cathode materials for high performance lithium/sulfur batteries

Directory of Open Access Journals (Sweden)

Sheng S. Zhang

2013-12-01

Full Text Available Liquid electrolyte lithium/sulfur (Li/S batteries cannot come into practical applications because of many problems such as low energy efficiency, short cycle life, and fast self-discharge. All these problems are related to the dissolution of lithium polysulfide, a series of sulfur reduction intermediates, in the liquid electrolyte, and resulting parasitic reactions with the Li anode. Covalently binding sulfur onto carbon surface is a solution to completely eliminate the dissolution of lithium polysulfide and make the Li/S battery viable for practical applications. This can be achieved by replacing elemental sulfur with sulfurized carbon as the cathode material. This article reviews the current efforts on this subject and discusses the syntheses, electrochemical properties, and prospects of the sulfurized carbon as a cathode material in the rechargeable Li/S batteries.

Symbolic healing of early psychosis: psychoeducation and sociocultural processes of recovery.

Science.gov (United States)

Larsen, John Aggergaard

2007-09-01

This article analyzes sociocultural processes of recovery in a Danish mental health service providing two years of integrated biopsychosocial treatment following first-episode psychosis. The study is based on ethnographic research in the service and person-centered involvement with 15 clients. The analysis applies Dow's [1986 American Anthropologist 88:56-69] model of universal components of symbolic healing to elucidate sociocultural aspects of therapeutic efficacy that are alternatively disregarded as placebo or nonspecific effects. It is demonstrated how staff engaged with clients to deliver "psychoeducation" that provided scientific and biomedical theories about mental illness, constituting a shared "mythic world" that was accepted as an experiential truth and used to explain clients' illness experiences. The analysis highlights the need to supplement attention in Dow's model to the healing procedure with consideration of variability in the healing process. Depending on individual responses to the intervention, the staff's professional backgrounds and staff-client relationships different recovery models were applied. One suggested "episodic psychosis" and full recovery, and the other suggested "chronic schizophrenia" and the necessity of comprehensive life adjustments to the mental illness. The recovery models influenced clients' perspectives on illness and self as they engaged in identity work, negotiating future plans and individual life projects by including also alternative systems of explanation from the wider cultural repertoire.

Investigation of Multiscale and Multiphase Flow, Transport and Reaction in Heavy Oil Recovery Process

Energy Technology Data Exchange (ETDEWEB)

Yortsos, Yanis C.; Akkutlu, Yucel; Amilik, Pouya; Kechagia, Persefoni; Lu, Chuan; Shariati, Maryam; Tsimpanogiannis, Ioannis; Zhan, Lang

2000-01-19

The emphasis of this work was on investigating the mechanisms and factors that control the recovery of heavy oil, with the objective to improve recovery efficiencies. For this purpose, the interaction of flow, transport and reaction at various scales (from the pore-network to the field scales) were studied. Particular mechanisms investigated included the onset of gas flow in foamy oil production and in in-situ steam drive, gravity drainage in steam process, the development of sustained combustion fronts and the propagation of foams in porous media. Analytical, computational and experimental methods were utilized to advance the state of the art in heavy oil recovery. Successful completion of this research was expected to lead to improvements in the recovery efficiency of various heavy oil processes.

Facile synthesis, spectral properties and formation mechanism of sulfur nanorods in PEG-200

International Nuclear Information System (INIS)

Xie, Xin-yuan; Li, Li-yun; Zheng, Pu-sheng; Zheng, Wen-jie; Bai, Yan; Cheng, Tian-feng; Liu, Jie

2012-01-01

Graphical abstract: Homogeneous rod-like structure of sulfur with a typical diameter of about 80 nm and an average aspect ratio of about 6–8 was obtained. The sulfur nanoparticles could self-assemble from spherical particles to nanorods in PEG-200. During the self-assembling process, the absorption band showed a red shift which was due to the production of nanorods. Highlights: ► A novel, facile and greener method to synthesize sulfur nanorods by the solubilizing and templating effect of PEG-200 was reported. ► S 0 nanoparticles could self assemble in PEG-200 and finally form monodisperse and homogeneous rod-like structure with an average diameter of about 80 nm, the length ca. 600 nm. ► The absorption band showed a red shift and the RRS intensity enhanced continuously during the self-assembling process. ► PEG-200 induced the oriented attachment of sulfur nanoparticles by the terminal hydroxyl groups. -- Abstract: The synthesis of nano-sulfur sol by dissolving sublimed sulfur in a green solvent-PEG-200 was studied. Homogeneous rod-like structure of sulfur with a typical diameter of about 80 nm and an average aspect ratio of 6–8 was obtained. The structure, morphology, size, and stability of the products were investigated by transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and dynamic light scattering (DLS) measurements. The spectral properties of the products were investigated by ultraviolet-visible (UV–vis) absorption and resonance Rayleigh scattering spectroscopy (RRS). The results showed that the spherical sulfur nanoparticles could self-assemble into nanorods in PEG-200. During the self-assembling process, the absorption band showed a red shift and the RRS intensity enhanced continuously. There was physical cross-linking between PEG and sulfur nanoparticles. PEG-200 induced the oriented attachment of sulfur nanoparticles by the

Effect of different sulfur levels from various sources on brassica napus growth and soil sulfur fractions

International Nuclear Information System (INIS)

Khalid, R.; Khan, K.S.; Islam, M.; Yousaf, M.; Shabbir, G.

2012-01-01

A two year field study was conducted at two different locations in northern rain fed Punjab, Pakistan to assess the effect of different rates of sulfur application from various sources on soil sulfur fractions and growth of Brassica napus. The treatments included three sulfur sources i. e., single super phosphate, ammonium sulfate and gypsum each applied at five different rates (0, 10, 20, 30 and 40 kg S ha/sup -1/ ). Sulfur application had a significant positive effect on the growth and yield parameters of Brassica napus. Among the sulfur sources ammonium sulfate resulted in maximum increase in plant growth and yield parameters, followed by single super phosphate. Sulfur content and uptake by crop plants was significantly higher with ammonium sulfate application as compared to other two sulfur sources. Sulfur application also exerted a significant positive effect on different S fractions in the soils. On an average, 18.0% of the applied sulfur got incorporated into CaCl/sub 2/ extractable sulfur fraction, while 15.6% and 35.5% entered into adsorbed and organic sulfur fractions in the soils, respectively. The value cost ratio increased significantly by sulfur application up to 30 kg ha/sup -1/. Among sulfur sources, ammonium sulfate performed best giving the highest net return. (author)

A pilot test plan of the thermochemical water-splitting iodine-sulfur process

International Nuclear Information System (INIS)

Kubo, Shinji; Kasahara, Seiji; Okuda, Hiroyuki; Terada, Atsuhiko; Tanaka, Nobuyuki; Inaba, Yoshitomo; Ohashi, Hirofumi; Inagaki, Yoshiyuki; Onuki, Kaoru; Hino, Ryutaro

2004-01-01

Research and development (R and D) of hydrogen production systems using high-temperature gas-cooled reactors (HTGR) are being conducted by the Japan Atomic Research Institute (JAERI). To develop the systems, superior hydrogen production methods are essential. The thermochemical hydrogen production cycle, the IS (iodine-sulfur) process, is a prospective candidate, in which heat supplied by HTGR can be consumed for the thermal driving load. With this attractive feature, JAERI will conduct pilot-scale tests, aiming to establish technical bases for practical plant designs using HTGR. The hydrogen will be produced at a maximum rate of 30 m 3 /h, continuously using high-temperature helium gas supplied by a helium gas loop, with an electric heater of about 400 kW. The plant will employ an advanced hydroiodic acid-processing device for efficient hydrogen production, and the usefulness of the device was confirmed from mass and heat balance analysis. Through design works and the hydrogen production tests, valuable data for construction and operation will be acquired to evaluate detailed process performance for practical systems. After completing the pilot-scale tests, JAERI will move onto the next R and D step, which will be demonstrations of the IS process to which heat is supplied from a high-temperature engineering test reactor (HTTR)

Sulfur nanocrystals anchored graphene composite with highly improved electrochemical performance for lithium-sulfur batteries

Science.gov (United States)

Zhang, Jun; Dong, Zimin; Wang, Xiuli; Zhao, Xuyang; Tu, Jiangping; Su, Qingmei; Du, Gaohui

2014-12-01

Two kinds of graphene-sulfur composites with 50 wt% of sulfur are prepared using hydrothermal method and thermal mixing, respectively. Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray Spectra mapping show that sulfur nanocrystals with size of ∼5 nm dispersed on graphene sheets homogeneously for the sample prepared by hydrothermal method (NanoS@G). While for the thermal mixed graphene-sulfur composite (S-G mixture), sulfur shows larger and uneven size (50-200 nm). X-ray Photoelectron Spectra (XPS) reveals the strong chemical bonding between the sulfur nanocrystals and graphene. Comparing with the S-G mixture, the NanoS@G composite shows highly improved electrochemical performance as cathode for lithium-sulfur (Li-S) battery. The NanoS@G composite delivers an initial capacity of 1400 mAh g-1 with the sulfur utilization of 83.7% at a current density of 335 mA g-1. The capacity keeps above 720 mAh g-1 over 100 cycles. The strong adherence of the sulfur nanocrystals on graphene immobilizes sulfur and polysulfides species and suppressed the "shuttle effect", resulting higher coulombic efficiency and better capacity retention. Electrochemical impedance also suggests that the strong bonding enabled rapid electronic/ionic transport and improved electrochemical kinetics, therefore good rate capability is obtained. These results demonstrate that the NanoS@G composite is a very promising candidate for high-performance Li-S batteries.

Biodiesel as a lubricity additive for ultra low sulfur diesel

Directory of Open Access Journals (Sweden)

Subongkoj Topaiboul1 and 2,*

2010-05-01

Full Text Available With the worldwide trend to reduce emission from diesel engines, ultra low sulfur diesel has been introduced with thesulfur concentration of less than 10 ppm. Unfortunately, the desulfurization process inevitably reduces the lubricity of dieselfuel significantly. Alternatively, biodiesel, with almost zero sulfur content, has been added to enhance lubricity in an ultralow sulfur diesel. This work has evaluated the effectiveness of the biodiesel amount, sourced from palm and jatropha oil,and origin in ultra low sulfur diesel locally available in the market. Wear scar from a high-frequency reciprocating rig isbenchmarked to the standard value (460 m of diesel fuel lubricity. It was found that very small amount (less than 1% ofbiodiesel from either source significantly improves the lubricity in ultra low sulfur diesel, and the biodiesel from jatropha oilis a superior lubricity enhancer.

A slumbering beast

International Nuclear Information System (INIS)

Koch, G.

1995-01-01

Amoco Canada's bid to buy out Home Oil Co. Ltd., produced allegations against Amoco's position in the natural gas liquids (NGL) business, accusing it of monopolistic and obstructionist tactics which stifle competition. The charges were levelled by the president of Kinetic Resources, a subsidiary of PanCanadian Petroleum, and one of Amoco's main competitors. According to the charge Amoco, which owns or operates many of the fractionation and storage facilities , refused to ship other producer's NGL for a fair fee, forcing these producers without fractionation facilities of their own into selling their NGL to Amoco, thus significantly lessening competition . Amoco denied it engaged in unfair business practices. 2 ills

Engineering development of selective agglomeration: Task 5, Bench- scale process testing

Energy Technology Data Exchange (ETDEWEB)

1991-09-01

Under the overall objectives of DOE Contract ``Engineering Development of Selective Agglomeration,`` there were a number of specific objectives in the Task 5 program. The prime objectives of Task 5 are highlighted below: (1) Maximize process performance in pyritic sulfur rejection and BTU recovery, (2) Produce a low ash product, (3) Compare the performance of the heavy agglomerant process based on diesel and the light agglomerant process using heptane, (4) Define optimum processing conditions for engineering design, (5) Provide first-level evaluation of product handleability, and (6) Explore and investigate process options/ideas which may enhance process performance and/or product handleability.

Planning for high performance project teams

International Nuclear Information System (INIS)

Reed, W.; Keeney, J.; Westney, R.

1997-01-01

Both industry-wide research and corporate benchmarking studies confirm the significant savings in cost and time that result from early planning of a project. Amoco's Team Planning Workshop combines long-term strategic project planning and short-term tactical planning with team building to provide the basis for high performing project teams, better project planning, and effective implementation of the Amoco Common Process for managing projects

Simultaneous removal of nitrogen oxides and sulfur oxides from combustion gases

Science.gov (United States)

Clay, David T.; Lynn, Scott

1976-10-19

A process for the simultaneous removal of sulfur oxides and nitrogen oxides from power plant stack gases comprising contacting the stack gases with a supported iron oxide catalyst/absorbent in the presence of sufficient reducing agent selected from the group consisting of carbon monoxide, hydrogen, and mixtures thereof, to provide a net reducing atmosphere in the SO.sub.x /NO.sub.x removal zone. The sulfur oxides are removed by absorption substantially as iron sulfide, and nitrogen oxides are removed by catalytic reduction to nitrogen and ammonia. The spent iron oxide catalyst/absorbent is regenerated by oxidation and is recycled to the contacting zone. Sulfur dioxide is also produced during regeneration and can be utilized in the production of sulfuric acid and/or sulfur.

Chromic acid recovery by electro-electrodialysis. II. Pilot scal process, development, and optimization

NARCIS (Netherlands)

Frenzel, I.; Frenzel, I.; Holdik, H.; Stamatialis, Dimitrios; Pourcelly, G.; Wessling, Matthias

2005-01-01

Electro-electrodialysis is a promising technology for chromic acid recovery and static rinse water purification. It combines the recovery of the plating chemicals from rinse water, the elimination of metallic impurities from the process and rinse water treatment in one step. Previous industrial use

Coupled sulfur isotopic and chemical mass transfer modeling: Approach and application to dynamic hydrothermal processes

International Nuclear Information System (INIS)

Janecky, D.R.

1988-01-01

A computational modeling code (EQPSreverse arrowS) has been developed to examine sulfur isotopic distribution pathways coupled with calculations of chemical mass transfer pathways. A post processor approach to EQ6 calculations was chosen so that a variety of isotopic pathways could be examined for each reaction pathway. Two types of major bounding conditions were implemented: (1) equilibrium isotopic exchange between sulfate and sulfide species or exchange only accompanying chemical reduction and oxidation events, and (2) existence or lack of isotopic exchange between solution species and precipitated minerals, parallel to the open and closed chemical system formulations of chemical mass transfer modeling codes. All of the chemical data necessary to explicitly calculate isotopic distribution pathways is generated by most mass transfer modeling codes and can be input to the EQPS code. Routines are built in to directly handle EQ6 tabular files. Chemical reaction models of seafloor hydrothermal vent processes and accompanying sulfur isotopic distribution pathways illustrate the capabilities of coupling EQPSreverse arrowS with EQ6 calculations, including the extent of differences that can exist due to the isotopic bounding condition assumptions described above. 11 refs., 2 figs

Yolk-Shelled C@Fe3 O4 Nanoboxes as Efficient Sulfur Hosts for High-Performance Lithium-Sulfur Batteries.

Science.gov (United States)

He, Jiarui; Luo, Liu; Chen, Yuanfu; Manthiram, Arumugam

2017-09-01

Owing to the high theoretical specific capacity (1675 mA h g -1 ) and low cost, lithium-sulfur (Li-S) batteries offer advantages for next-generation energy storage. However, the polysulfide dissolution and low electronic conductivity of sulfur cathodes limit the practical application of Li-S batteries. To address such issues, well-designed yolk-shelled carbon@Fe 3 O 4 (YSC@Fe 3 O 4 ) nanoboxes as highly efficient sulfur hosts for Li-S batteries are reported here. With both physical entrapment by carbon shells and strong chemical interaction with Fe 3 O 4 cores, this unique architecture immobilizes the active material and inhibits diffusion of the polysulfide intermediates. Moreover, due to their high conductivity, the carbon shells and the polar Fe 3 O 4 cores facilitate fast electron/ion transport and promote continuous reactivation of the active material during the charge/discharge process, resulting in improved electrochemical utilization and reversibility. With these merits, the S/YSC@Fe 3 O 4 cathodes support high sulfur content (80 wt%) and loading (5.5 mg cm -2 ) and deliver high specific capacity, excellent rate capacity, and long cycling stability. This work provides a new perspective to design a carbon/metal-oxide-based yolk-shelled framework as a high sulfur-loading host for advanced Li-S batteries with superior electrochemical properties. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Health Endpoint Attributed to Sulfur Dioxide Air Pollutants

Directory of Open Access Journals (Sweden)

Geravandi

2015-07-01

Full Text Available Background Sulfur dioxide is a colorless gas, released from burning of coal, high-sulfur coal,s and diesel fuel. Sulfur dioxide harms human health by reacting with the moisture in the nose, nasal cavity and throat and this is the way by which it destroys the nerves in the respiratory system. Objectives The aim of this study was to focus on identifying the effects associated with sulfur dioxide on health in Ahvaz, Iran. Materials and Methods Data collections were performed by Ahvaz meteorological organization and the department of environment. Sampling was performed for 24 hours in four stations. Methods of sampling and analysis were according to US environmental protection agency (EPA guideline. Afterwards, we processed the raw data including instruction set correction of averaging, coding and filtering by Excel software and then, the impact of meteorological parameters were converted as the input file to the AirQ model. Finally, we calculated the health effects of exposure to sulfur dioxide. Results According to the findings, the concentration of sulfur dioxide in Ahvaz had an annual average of 51 μg/m3. Sum of the numbers of hospital admissions for respiratory diseases attributed to sulfur dioxide was 25 cases in 2012. Approximately, 5% of the total hospital admissions for respiratory disease and respiratory mortality happened when sulfur dioxide concentration was more than 10 mg/m3. Conclusions According to the results of this study, this increase could be due to higher fuel consumption, usage of gasoline in vehicles, oil industry, and steel and heavy industries in Ahwaz. The risk of mortality and morbidity were detected at the current concentrations of air pollutants.

Sulfur removal from fuel using zeolites/polyimide mixed matrix membrane adsorbents

International Nuclear Information System (INIS)

Lin, Ligang; Wang, Andong; Dong, Meimei; Zhang, Yuzhong; He, Benqiao; Li, Hong

2012-01-01

Graphical abstract: Membrane adsorption process is proposed for sulfur removal. Three-dimensional network structure is key to fulfill adsorption function of MMMs, which adsorption/desorption behavior is markedly related with binding force with sulfur molecules. Highlights: ► Membrane adsorption process is proposed for sulfur removal. ► Three-dimensional network structure of MMMs is key to fulfill adsorption function. ► Adsorption/desorption behavior is markedly related with binding force. - Abstract: A novel membrane adsorption process was proposed for the sulfur removal from fuels. The mixed matrix membranes (MMMs) adsorbents composed of polyimide (PI) and various Y zeolites were prepared. By the detailed characterization of FT-IR, morphology, thermal and mechanical properties of MMMs adsorbents, combining the adsorption and desorption behavior research, the process–structure–function relationship was discussed. Field-emission scanning electron microscope (FESEM) images show that the functional particles are incorporated into the three-dimensional network structure. MMMs adsorbents with 40% of zeolites content possess better physical properties, which was confirmed by mechanical strength and thermo stability analysis. Influence factors including post-treatment, content of incorporated zeolites, adsorption time, temperature, initial sulfur concentration as well as sulfur species on the adsorption performance of MMMs adsorbents have been evaluated. At 4 wt.% zeolites content, adsorption capacity for NaY/PI, AgY/PI and CeY/PI MMMs adsorbents come to 2.0, 7.5 and 7.9 mg S/g, respectively. And the regeneration results suggest that the corresponding spent membranes can recover about 98%, 90% and 70% of the desulfurization capacity, respectively. The distinct adsorption and desorption behavior of MMMs adsorbents with various functional zeolites was markedly related with their various binding force and binding mode with sulfur compounds.

Association of solvent extraction and liquid-liquid flotation processes for metal recovery

International Nuclear Information System (INIS)

Puget, Flavia P.; Mendonca, Luciano A. de; Massarani, Giulio

2000-01-01

From the batch solvent extraction process, in this work it has been carried out a preliminary study aiming the determination of the optimal operating conditions for zirconium recovery (10 ppm) using alamine 336 (tricaprylylamine) as extractor. The results have shown that the extraction takes place instantaneously (5s of manual agitation) and that at pH around 2.0 the extraction efficiency is up to 98-99% for an aqueous/organic phase volumetric ratio of 10. Based on these results, it is proposed to evaluate the possibility of using of a pioneering technology for metal recovery at low concentrations, using a experimental set-up that associates standard solvent extraction process with liquid-liquid flotation process. (author)

Sulphate removal from sodium sulphate-rich brine and recovery of barium as a barium salt mixture.

Science.gov (United States)

Vadapalli, Viswanath R K; Zvimba, John N; Mulopo, Jean; Motaung, Solly

2013-01-01

Sulphate removal from sodium sulphate-rich brine using barium hydroxide and recovery of the barium salts has been investigated. The sodium sulphate-rich brine treated with different dosages of barium hydroxide to precipitate barium sulphate showed sulphate removal from 13.5 g/L to less than 400 mg/L over 60 min using a barium to sulphate molar ratio of 1.1. The thermal conversion of precipitated barium sulphate to barium sulphide achieved a conversion yield of 85% using coal as both a reducing agent and an energy source. The recovery of a pure mixture of barium salts from barium sulphide, which involved dissolution of barium sulphide and reaction with ammonium hydroxide resulted in recovery of a mixture of barium carbonate (62%) and barium hydroxide (38%), which is a critical input raw material for barium salts based acid mine drainage (AMD) desalination technologies. Under alkaline conditions of this barium salt mixture recovery process, ammonia gas is given off, while hydrogen sulfide is retained in solution as bisulfide species, and this provides basis for ammonium hydroxide separation and recovery for reuse, with hydrogen sulfide also recoverable for further industrial applications such as sulfur production by subsequent stripping.

Energy efficiency improvement of a Kraft process through practical stack gases heat recovery

International Nuclear Information System (INIS)

Mostajeran Goortani, B.; Mateos-Espejel, E.; Moshkelani, M.; Paris, J.

2011-01-01

A process scheme for the optimal recovery of heat from stack gases considering energy and technical constraints has been developed and applied to an existing Kraft pulping mill. A system based on a closed loop recirculation of hot oil is used to recover the heat from stack gases and distribute it to the appropriate cold streams. The recovery of heat from stack gases is part of an overall optimization of the Kraft mill. Tools such as Pinch Analysis and exergy analysis are used to evaluate the process streams. The results indicate that 10.8 MW of heat from stack gases can be reused to heat process streams such as the deaerator water, hot water, drying filtrates, and black liquor. A simulation model of the recirculation loop has been developed to determine the specifications of the recovery system. The total heat exchanger surface area required by the system is 3460 m 2 , with a hot oil recirculation temperature of 137 o C. The anticipated total investment is $10.3 M, with a payback time of 1.8 years. - Highlights: → We developed a process design for recovering heat from stack gases in a Kraft mill. → The recovered heat is optimally distributed to the process cold streams. → Heat recovery system has a total surface area of 3500 m 2 without gases condensation. → A reduction of 7 percent in total process steam demand is anticipated. → A total investment of 10.3 M$ is needed with a payback time of less than two years

Release of Chlorine and Sulfur during Biomass Torrefaction and Pyrolysis

DEFF Research Database (Denmark)

Saleh, Suriyati Binti; Flensborg, Julie Pauline; Shoulaifar, Tooran Khazraie

2014-01-01

The release of chlorine (Cl) and sulfur (S) during biomass torrefaction and pyrolysis has been investigated via experiments in two laboratory-scale reactors: a rotating reactor and a fixed bed reactor. Six biomasses with different chemical compositions covering a wide range of ash content and ash...... reporting that biomasses with a lower chlorine content release a higher fraction of chlorine during the pyrolysis process. A significant sulfur release (about 60%) was observed from the six biomasses investigated at 350 degrees C. The initial sulfur content in the biomass did not influence the fraction...

Mechanism of the toxic action of sulfur dioxide on plants

Energy Technology Data Exchange (ETDEWEB)

Nikolaevskii, V S; Miroshnikova, A T; Firger, V V; Belokrylova, L M

1975-01-01

Experiments were performed to determine the effects of sulfur dioxide on U CO2 metabolism and photosynthesis in fescue and timothy grass and in maple and barberry branches. The free radical inhibitors, ascorbic acid and thiourea, were found to decrease the damaging effects of the sulfur dioxide. These results indicated that the processes involved are of the free-radical chain type. Even at low sulfur dioxide concentrations, photosphosphorylation and carbon dioxide assimilation were inhibited. In addition, starch and protein as well as the formation of polymeric substances were also inhibited.

Disproportionation of elemental sulfur by haloalkaliphilic bacteria from soda lakes.

Science.gov (United States)

Poser, Alexander; Lohmayer, Regina; Vogt, Carsten; Knoeller, Kay; Planer-Friedrich, Britta; Sorokin, Dimitry; Richnow, Hans-H; Finster, Kai

2013-11-01

Microbial disproportionation of elemental sulfur to sulfide and sulfate is a poorly characterized part of the anoxic sulfur cycle. So far, only a few bacterial strains have been described that can couple this reaction to cell growth. Continuous removal of the produced sulfide, for instance by oxidation and/or precipitation with metal ions such as iron, is essential to keep the reaction exergonic. Hitherto, the process has exclusively been reported for neutrophilic anaerobic bacteria. Here, we report for the first time disproportionation of elemental sulfur by three pure cultures of haloalkaliphilic bacteria isolated from soda lakes: the Deltaproteobacteria Desulfurivibrio alkaliphilus and Desulfurivibrio sp. AMeS2, and a member of the Clostridia, Dethiobacter alkaliphilus. All cultures grew in saline media at pH 10 by sulfur disproportionation in the absence of metals as sulfide scavengers. Our data indicate that polysulfides are the dominant sulfur species under highly alkaline conditions and that they might be disproportionated. Furthermore, we report the first organism (Dt. alkaliphilus) from the class Clostridia that is able to grow by sulfur disproportionation.

Biologically produced sulfur particles and polysulfide ions

NARCIS (Netherlands)

Kleinjan, W.E.

2005-01-01

This thesis deals with the effects of particles of biologically produced sulfur (or 'biosulfur') on a biotechnological process for the removal of hydrogen sulfide from gas streams. Particular emphasis is given to the role of polysulfide ions in such a process. These

Recovery of uranium in the production of concentrated phosphoric acid by a hemihydrate process

International Nuclear Information System (INIS)

Nakajima, S.; Miyamoto, M.

1983-01-01

Nissan Chemical Industries as manufacturers of phosphoric acid have studied the recovery of uranium, based on a concentrated phosphoric acid production process. The process consists of two stages, a hemihydrate stage with a formation of hemihydrate and a filtration section, followed by a dihydrate stage with hydration and a filtration section. In the hemihydrate stage, phosphate is treated with a mixture of phosphoric acid and sulphuric acid to produce phosphoric acid and hydrous calcium sulphate; the product is recovered in the filtration section and its concentration is 40-50% P 2 O 3 . In the dihydrate stage, the hemihydrate is transformed by re-dissolution and hydration, producing hydrous calcium sulphate, i.e. gypsum. This process therefore comprises two parts, each with different acid concentrations. As the extraction of uranium is easier in the case of a low concentration of phosphoric acid, the process consists of the recovery of uranium starting from the filtrate of the hydration section. The tests have shown that the yield of recovery of uranium was of the order of 80% disregarding the handling losses and no disadvantageous effect has been found in the combination of the process of uranium extraction with the process of concentrated phosphoric acid production. Compared with the classical process where uranium is recovered from acid with 30% P 2 O 5 , the process of producing high-concentration phosphoric acid such as the Nissan process, in which the uranium recovery is effected from acid with 15% P 2 O 5 from the hydration section, presents many advantages [fr

Conductive framework of inverse opal structure for sulfur cathode in lithium-sulfur batteries.

Science.gov (United States)

Jin, Lu; Huang, Xiaopeng; Zeng, Guobo; Wu, Hua; Morbidelli, Massimo

2016-09-07

As a promising cathode inheritor for lithium-ion batteries, the sulfur cathode exhibits very high theoretical volumetric capacity and energy density. In its practical applications, one has to solve the insulating properties of sulfur and the shuttle effect that deteriorates cycling stability. The state-of-the-art approaches are to confine sulfur in a conductive matrix. In this work, we utilize monodisperse polystyrene nanoparticles as sacrificial templates to build polypyrrole (PPy) framework of an inverse opal structure to accommodate (encapsulate) sulfur through a combined in situ polymerization and melting infiltration approach. In the design, the interconnected conductive PPy provides open channels for sulfur infiltration, improves electrical and ionic conductivity of the embedded sulfur, and reduces polysulfide dissolution in the electrolyte through physical and chemical adsorption. The flexibility of PPy and partial filling of the inverse opal structure endure possible expansion and deformation during long-term cycling. It is found that the long cycling stability of the cells using the prepared material as the cathode can be substantially improved. The result demonstrates the possibility of constructing a pure conductive polymer framework to accommodate insulate sulfur in ion battery applications.

Sulfur metabolism in Escherichia coli and related bacteria: facts and fiction.

Science.gov (United States)

Sekowska, A; Kung, H F; Danchin, A

2000-04-01

Living organisms are composed of macromolecules made of hydrogen, carbon, nitrogen, oxygen, phosphorus and sulfur. Much work has been devoted to the metabolism of the first five elements, but much remains to be understood about sulfur metabolism. We review here the situation in Escherichia coli and related bacteria, where more than one hundred genes involved in sulfur metabolism have already been discovered in this organism. Examination of the genome suggests that many more will be found, especially genes involved in regulation, scavenging of sulfur containing molecules and synthesis of coenzymes or prosthetic groups. Furthermore, the involvement of methionine as the universal start of proteins as well as that of its derivative S-adenosylmethionine in a vast variety of cell processes argue in favour of a major importance of sulfur metabolism in all organisms.

Biodiesel production process from microalgae oil by waste heat recovery and process integration.

Science.gov (United States)

Song, Chunfeng; Chen, Guanyi; Ji, Na; Liu, Qingling; Kansha, Yasuki; Tsutsumi, Atsushi

2015-10-01

In this work, the optimization of microalgae oil (MO) based biodiesel production process is carried out by waste heat recovery and process integration. The exergy analysis of each heat exchanger presented an efficient heat coupling between hot and cold streams, thus minimizing the total exergy destruction. Simulation results showed that the unit production cost of optimized process is 0.592$/L biodiesel, and approximately 0.172$/L biodiesel can be avoided by heat integration. Although the capital cost of the optimized biodiesel production process increased 32.5% and 23.5% compared to the reference cases, the operational cost can be reduced by approximately 22.5% and 41.6%. Copyright © 2015 Elsevier Ltd. All rights reserved.

Status of the INERI sulfur-iodine integrated-loop experiment

International Nuclear Information System (INIS)

Pickard, P.; Carles, Ph.; Buckingham, R.; Russ, B.; Besenbruch, G.

2007-01-01

The Sulfur-Iodine (S-I) thermochemical water-splitting cycle has been studied as a potential source of hydrogen on a large scale. Coupled to a nuclear reactor, an S-I hydrogen plant could efficiently produce hydrogen without greenhouse gas emissions. In the S-I cycle, iodine and sulfur dioxide are combined with water to create two immiscible acid phases - a light sulfuric acid phase, and a heavy hydriodic acid phase. The sulfuric acid phase is decomposed at temperatures near 850 C degrees, and the resulting sulfur dioxide is recycled back into the process. The hydriodic acid in the lower phase is separated from excess water and iodine, and is then decomposed into the product hydrogen and iodine. The water and iodine from these steps are also recycled. In an International Nuclear Energy Research Initiative (INERI) project supported by the US DOE Office of Nuclear Energy, Sandia National Labs (SNL) has teamed with Cea in France, and industrial partner General Atomics (GA) to construct and operate a closed-loop device for demonstration of hydrogen production by the S-I process. Previous work in Japan has demonstrated continuous closed-loop operation of the S-I cycle for up to one week using glass components at atmospheric pressure. This work will aim for operation under process conditions expected at the pilot plant-level and beyond pressures up to 20 bar using engineering materials of construction. Staff at Cea is responsible for the acid-generation step, known as the Bunsen reaction. SNL is handling the sulfuric acid decomposition step, and GA is providing equipment for decomposing hydriodic acid into the product hydrogen. All parties are assembling equipment at the GA site in San Diego, California. Operation of the closed-loop device is expected to commence in the second half of calendar year 2007. This paper will summarize project goals, work done to date, current status, and scheduled future work on the INERI S-I Integrated-Loop Experiment. (authors)

Vacuum pyrolysis and hydrometallurgical process for the recovery of valuable metals from spent lithium-ion batteries

International Nuclear Information System (INIS)

Sun, Liang; Qiu, Keqiang

2011-01-01

Highlights: → The cathode active materials LiCoO 2 from spent lithium-ion batteries peeled completely from aluminum foils by vacuum pyrolysis and hydrometallurgical process. → The aluminum foils were excellent without damage after vacuum pyrolysis. → The pyrolysis products organic fluorine compounds from organic electrolyte and binder were collected and enriched. → High leaching efficiencies of cobalt and lithium were obtained with H 2 SO 4 and H 2 O 2 . - Abstract: Spent lithium-ion batteries contain lots of strategic resources such as cobalt and lithium together with other hazardous materials, which are considered as an attractive secondary resource and environmental contaminant. In this work, a novel process involving vacuum pyrolysis and hydrometallurgical technique was developed for the combined recovery of cobalt and lithium from spent lithium-ion batteries. The results of vacuum pyrolysis of cathode material showed that the cathode powder composing of LiCoO 2 and CoO peeled completely from aluminum foils under the following experimental conditions: temperature of 600 o C, vacuum evaporation time of 30 min, and residual gas pressure of 1.0 kPa. Over 99% of cobalt and lithium could be recovered from peeled cobalt lithium oxides with 2 M sulfuric acid leaching solution at 80 o C and solid/liquid ratio of 50 g L -1 for 60 min. This technology offers an efficient way to recycle valuable materials from spent lithium-ion batteries, and it is feasible to scale up and help to reduce the environmental pollution of spent lithium-ion batteries.

Vacuum pyrolysis and hydrometallurgical process for the recovery of valuable metals from spent lithium-ion batteries

Energy Technology Data Exchange (ETDEWEB)

Sun, Liang [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Key Laboratory of Resources Chemistry of Nonferrous Metals, Central South University, Ministry of Education of the People' s Republic of China (China); Qiu, Keqiang, E-mail: qiuwhs@sohu.com [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Key Laboratory of Resources Chemistry of Nonferrous Metals, Central South University, Ministry of Education of the People' s Republic of China (China)

2011-10-30

Highlights: {yields} The cathode active materials LiCoO{sub 2} from spent lithium-ion batteries peeled completely from aluminum foils by vacuum pyrolysis and hydrometallurgical process. {yields} The aluminum foils were excellent without damage after vacuum pyrolysis. {yields} The pyrolysis products organic fluorine compounds from organic electrolyte and binder were collected and enriched. {yields} High leaching efficiencies of cobalt and lithium were obtained with H{sub 2}SO{sub 4} and H{sub 2}O{sub 2}. - Abstract: Spent lithium-ion batteries contain lots of strategic resources such as cobalt and lithium together with other hazardous materials, which are considered as an attractive secondary resource and environmental contaminant. In this work, a novel process involving vacuum pyrolysis and hydrometallurgical technique was developed for the combined recovery of cobalt and lithium from spent lithium-ion batteries. The results of vacuum pyrolysis of cathode material showed that the cathode powder composing of LiCoO{sub 2} and CoO peeled completely from aluminum foils under the following experimental conditions: temperature of 600 {sup o}C, vacuum evaporation time of 30 min, and residual gas pressure of 1.0 kPa. Over 99% of cobalt and lithium could be recovered from peeled cobalt lithium oxides with 2 M sulfuric acid leaching solution at 80 {sup o}C and solid/liquid ratio of 50 g L{sup -1} for 60 min. This technology offers an efficient way to recycle valuable materials from spent lithium-ion batteries, and it is feasible to scale up and help to reduce the environmental pollution of spent lithium-ion batteries.

Processes of recovery through routine or specialist treatment for borderline personality disorder (BPD): a qualitative study.

Science.gov (United States)

Katsakou, Christina; Pistrang, Nancy; Barnicot, Kirsten; White, Hayley; Priebe, Stefan

2017-07-04

Recovery processes in borderline personality disorder (BPD) are poorly understood. This study explored how recovery in BPD occurs through routine or specialist treatment, as perceived by service users (SUs) and therapists. SUs were recruited from two specialist BPD services, three community mental health teams, and one psychological therapies service. Semi-structured interviews were conducted with 48 SUs and 15 therapists. The "framework" approach was used to analyse the data. The findings were organized into two domains of themes. The first domain described three parallel processes that constituted SUs' recovery journey: fighting ambivalence and committing to taking action; moving from shame to self-acceptance and compassion; and moving from distrust and defensiveness to opening up to others. The second domain described four therapeutic challenges that needed to be addressed to support this journey: balancing self-exploration and finding solutions; balancing structure and flexibility; confronting interpersonal difficulties and practicing new ways of relating; and balancing support and independence. Therapies facilitating the identified processes may promote recovery. The recovery processes and therapeutic challenges identified in this study could provide a framework to guide future research.

Sulfur poisoning in cattle

Energy Technology Data Exchange (ETDEWEB)

Julian, R J; Harrison, K B

1975-01-01

A case of sulfur poisoning is described in which 12 of 20 cattle died following the feeding of sulfur. Respiratory distress and abdominal pain were the prominent signs. Examination of one animal revealed vasculitis and necrosis of the rumen and abomasal wall. The possible toxic effects of sulfur are discussed.

Sulfur isotope ratios and the origins of the aerosols and cloud droplets in California stratus

International Nuclear Information System (INIS)

Ludwig, F.L.

1976-01-01

Marine aerosols often have sulfur-to-chloride ratios greater than that found in seawater. Sulfur isotope ratios ( 34 S/ 32 S) were measured in aerosol and cloud droplet samples collected in the San Francisco Bay Area in an attempt to understand the processes that produce the observed sulfur-to-chloride ratios. Seawater sulfur usually has very high sulfur isotope ratios: fossil fuel sulfur tends to have smaller isotope ratios and sulfur of bacteriogenic origin still smaller. Samples collected in unpolluted marine air over the hills south of San Francisco had sulfur ratios that were significantly lower than the values for samples collected in nearby areas that were subject to urban pollution. The highest sulfur isotope ratios were found in the offshore seawater. The results suggest bacteriogenic origins, of the marine air sulfur aerosol material. The low isotope ratios in the marine air cannot be explained as a mixture of seawater sulfur and pollutant sulfur, because both tend to have higher isotope ratios. (Auth.)

Reshaping an enduring sense of self: the process of recovery from a first episode of schizophrenia.

Science.gov (United States)

Romano, Donna M; McCay, Elizabeth; Goering, Paula; Boydell, Katherine; Zipursky, Robert

2010-08-01

Although advances in the treatment of schizophrenia have been made, little is known about the process of recovery from first episode of schizophrenia (FES). To date, the study of recovery in the field of mental health has focused on long-term mental illness. This qualitative study addresses ways in which individuals with FES describe their process of recovery and how identified individuals (e.g. family members) describe their perceptions of and roles in the participant's process of recovery. Charmaz's constructivist grounded theory methodology was used to interview 10 young adults twice who self-identified as recovering from FES. In addition, 10 individuals were identified who had influenced their recovery and were interviewed once, for a total of 30 interviews. Data collection sources included in-depth semi-structured interviews. Data analysis methods were consistent with Charmaz's methodology and included coding, and constant comparison of data. The results provide a substantive theory of the process of recovery from FES that is comprised of the following phases: 'Who they were prior to the illness', 'Lives interrupted: Encountering the illness', 'Engaging in services and supports', 'Re-engaging in life', 'Envisioning the future'; and the core category, 'Re-shaping an enduring sense of self', that occurred throughout all phases. A prominent feature of this model is that participants' enduring sense of self were reshaped rather than reconstructed throughout their recovery. This model of recovery from FES is unique, and as such, provides implications for clinical care, research and policy development for these young adults and their families.

Pushing desalination recovery to the maximum limit: Membrane and thermal processes integration

KAUST Repository

Shahzad, Muhammad Wakil

2017-05-05

The economics of seawater desalination processes has been continuously improving as a result of desalination market expansion. Presently, reverse osmosis (RO) processes are leading in global desalination with 53% share followed by thermally driven technologies 33%, but in Gulf Cooperation Council (GCC) countries their shares are 42% and 56% respectively due to severe feed water quality. In RO processes, intake, pretreatment and brine disposal cost 25% of total desalination cost at 30–35% recovery. We proposed a tri-hybrid system to enhance overall recovery up to 81%. The conditioned brine leaving from RO processes supplied to proposed multi-evaporator adsorption cycle driven by low temperature industrial waste heat sources or solar energy. RO membrane simulation has been performed using WinFlow and IMSDesign commercial softwares developed by GE and Nitto. Detailed mathematical model of overall system is developed and simulation has been conducted in FORTRAN. The final brine reject concentration from tri-hybrid cycle can vary from 166,000ppm to 222,000ppm if RO retentate concentration varies from 45,000ppm to 60,000ppm. We also conducted economic analysis and showed that the proposed tri-hybrid cycle can achieve highest recovery, 81%, and lowest energy consumption, 1.76kWhelec/m3, for desalination reported in the literature up till now.

Two-step optimization of pressure and recovery of reverse osmosis desalination process.

Science.gov (United States)

Liang, Shuang; Liu, Cui; Song, Lianfa

2009-05-01

Driving pressure and recovery are two primary design variables of a reverse osmosis process that largely determine the total cost of seawater and brackish water desalination. A two-step optimization procedure was developed in this paper to determine the values of driving pressure and recovery that minimize the total cost of RO desalination. It was demonstrated that the optimal net driving pressure is solely determined by the electricity price and the membrane price index, which is a lumped parameter to collectively reflect membrane price, resistance, and service time. On the other hand, the optimal recovery is determined by the electricity price, initial osmotic pressure, and costs for pretreatment of raw water and handling of retentate. Concise equations were derived for the optimal net driving pressure and recovery. The dependences of the optimal net driving pressure and recovery on the electricity price, membrane price, and costs for raw water pretreatment and retentate handling were discussed.

Electrochemical evaluation of sulfur poisoning in a methane-fuelled solid oxide fuel cell: Effect of current density and sulfur concentration

DEFF Research Database (Denmark)

Hagen, Anke; Johnson, Gregory B.; Hjalmarsson, Per

2014-01-01

, the effect of sulfur was less pronounced on mass transfer/fuel reforming processes but quite significant on the charge transfer/TPB processes. Overall, sulfur related performance loss was more severe at the highest current density (1 A cm−2), due to the deactivation of catalytic fuel reforming reactions......A Ni/ScYSZ based SOFC was tested at 1, 0.5, 0.25, and 0 (OCV) A cm−2 in methane fuel containing 0–100 ppm H2S. Analysis of cell voltage loss during short-term H2S poisoning showed that SOFC performance loss was generally larger at higher current loads. Separating the effect of H2S on catalytic...... reforming and electrochemical activity by evaluating the relevant area specific resistances and charge transfer processes based on impedance spectroscopy revealed that the poisoning of electrochemical activity was not dependent on current density. Two major anode processes were significantly affected...

Novel separation process of gaseous mixture of SO2 and O2 with ionic liquid for hydrogen production in thermochemical sulfur-iodine water splitting cycle

International Nuclear Information System (INIS)

Kim, Chang Soo; Gong, Gyeong Taek; Yoo, Kye Sang; Kim, Honggon; Lee, Byoung Gwon; Ahn, Byoung Sung; Jung, Kwang Deog; Lee, Ki Yong; Song, Kwang Ho

2007-01-01

Sulfur-Iodine cycle is the most promising thermochemical cycle for water splitting to produce hydrogen which can replace the fossil fuels in the future. As a sub-cycle in the thermochemical Sulfur-Iodine water splitting cycle, sulfuric acid (H 2 SO 4 ) decomposes into oxygen (O 2 ) and sulfur dioxide (SO 2 ) which should be separated for the recycle of SO 2 into the sulfuric acid generation reaction (Bunsen Reaction). In this study, absorption and desorption process of SO 2 by ionic liquid which is useful for the recycle of SO 2 into sulfuric acid generation reaction after sulfuric acid decomposition in the thermochemical Sulfur-Iodine cycle is investigated. At first, the operability as an absorbent for the SO 2 absorption and desorption at high temperature without the volatilization of absorbents which is not suitable for the recycle of absorbent-free SO 2 after the absorption process. The temperature range of operability is determined by TGA and DTA analysis. Most of ionic liquids investigated are applicable at high temperature desorption without volatility around 300 deg. C except [BMIm] Cl, and [BMIm] OAc which show the decomposition of ionic liquids. To evaluate the capability of SO 2 absorption, each ionic liquid is located in the absorption tube and gaseous SO 2 is bubbled into the ionic liquid. During the bubbling, the weight of the system is measured and converted into the absorbed SO 2 amount at each temperature controlled by the heater. Saturated amounts of absorbed SO 2 by ionic liquids at 50 deg. C are presented. The effect of anions for the SO 2 absorption capability is shown in the order of Cl, OAc, MeSO 3 , BF 4 , MeSO 4 , PF 6 , and HSO 4 when they are combined with [BMIm] cation. [BMIm]Cl has the largest amount of SO 2 absorbed which can be the most promising absorbent; however, from the point of operability at high temperature which includes desorption process, [BMIm]Cl is vulnerable to high temperature around 250 deg. C based on the TGA

Technology Development of an Advanced Small-scale Microchannel-type Process Heat Exchanger (PHE) for Hydrogen Production in Iodine-sulfur Cycle

Energy Technology Data Exchange (ETDEWEB)

Sah, Injin; Kim, Chan Soo; Kim, Yong Wan; Park, Jae-Won; Kim, Eung-Seon; Kim, Min-Hwan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-10-15

In this study, ongoing manufacturing processes of the components employed in an advanced small-scale microchannel-type PHE are presented. The components, such as mechanically machined microchannels and a diffusion-bonded stack are introduced. Also, preliminary studies on surface treatment techniques for improving corrosion resistance from the corrosive sulfuric environment will be covered. Ongoing manufacturing process for an advanced small-size microchannel-type PHE in KAERI is presented. Through the preliminary studies for optimizing diffusion bonding condition of Hastelloy-X, a diffusion-bonded stack, consisting of primary and secondary side layer by layer, is scheduled to be fabricated in a few months. Also, surface treatment for enhancing the corrosion resistance from the sulfuric acid environment is in progress for the plates with microchannels. A massive production of hydrogen with electricity generation is expected in a Process Heat Exchanger (PHE) in a Very High Temperature gas-cooled Reactor (VHTR) system. For the application of hydrogen production, a small-scale gas loop for feasibility testing of a laboratory-scale has constructed and operated in Korea Atomic Energy Research Institute (KAERI) as a precursor to an experimental- and a pilot-scale gas loops.

Selective recovery of gold from waste mobile phone PCBs by hydrometallurgical process

International Nuclear Information System (INIS)

Kim, Eun-young; Kim, Min-seuk; Lee, Jae-chun; Pandey, B.D.

2011-01-01

Highlights: ► Selective leaching of Au from scrap mobile phone PCBs by two stage electro-generated chlorine and recovery by ion exchange. ► Copper leaching (97%) by 1st stage electro-generated leaching (ORP value Ag/AgCl ) with a minor gold (5%). ► Gold leaching (93%, ∼67 mg/L) by 2nd leaching (ORP value >1100 mV Ag/AgCl ) in 0.1 mol/L HCl at 25 °C. ► A concentrated gold solution, 6034 mg/L with 99.9% purity was obtained by ion exchange process. - Abstract: The leaching of gold from the scrap mobile phone PCBs by electro-generated chlorine as an oxidant and its recovery by ion exchange process was investigated. The leaching experiments were carried out by employing separate leaching reactor connected with the anode compartment of a Cl 2 gas generator. The leaching of gold increased with increase in temperature and initial concentration of chlorine, and was favorable even at low concentration of acid, whereas copper leaching increased with increase in concentration of acid and decrease in temperature. In a two-stage leaching process, copper was mostly dissolved (97%) in 165 min at 25 °C during the 1st stage leaching in 2.0 mol/L HCl by electro-generated chlorine at a current density of 714 A/m 2 along with a minor recovery of gold (5%). In the 2nd stage gold was mostly leached out (93% recovery, ∼67 mg/L) from the residue of the 1st stage by the electro-generated chlorine in 0.1 mol/L HCl. Gold recovery from the leach liquor by ion exchange using Amberlite XAD-7HP resin was found to be 95% with the maximum amount of gold adsorbed as 46.03 mg/g resin. A concentrated gold solution, 6034 mg/L with 99.9% purity was obtained in the ion exchange process.

Selective recovery of gold from waste mobile phone PCBs by hydrometallurgical process

Energy Technology Data Exchange (ETDEWEB)

Kim, Eun-young [Department of Material Science and Engineering, Penn State, University Park, PA 16802 (United States); Kim, Min-seuk [Mineral Resources Research Division, Korea Institute of Geoscience and Mineral Resources (KIGAM), Daejeon 305-350 (Korea, Republic of); Lee, Jae-chun, E-mail: jclee@kigam.re.kr [Mineral Resources Research Division, Korea Institute of Geoscience and Mineral Resources (KIGAM), Daejeon 305-350 (Korea, Republic of); Pandey, B.D. [Metal Extraction and Forming Division, National Metallurgical Laboratory (NML), Jamshedpur 831007 (India)

2011-12-30

Highlights: Black-Right-Pointing-Pointer Selective leaching of Au from scrap mobile phone PCBs by two stage electro-generated chlorine and recovery by ion exchange. Black-Right-Pointing-Pointer Copper leaching (97%) by 1st stage electro-generated leaching (ORP value <350 mV{sub Ag/AgCl}) with a minor gold (5%). Black-Right-Pointing-Pointer Gold leaching (93%, {approx}67 mg/L) by 2nd leaching (ORP value >1100 mV{sub Ag/AgCl}) in 0.1 mol/L HCl at 25 Degree-Sign C. Black-Right-Pointing-Pointer A concentrated gold solution, 6034 mg/L with 99.9% purity was obtained by ion exchange process. - Abstract: The leaching of gold from the scrap mobile phone PCBs by electro-generated chlorine as an oxidant and its recovery by ion exchange process was investigated. The leaching experiments were carried out by employing separate leaching reactor connected with the anode compartment of a Cl{sub 2} gas generator. The leaching of gold increased with increase in temperature and initial concentration of chlorine, and was favorable even at low concentration of acid, whereas copper leaching increased with increase in concentration of acid and decrease in temperature. In a two-stage leaching process, copper was mostly dissolved (97%) in 165 min at 25 Degree-Sign C during the 1st stage leaching in 2.0 mol/L HCl by electro-generated chlorine at a current density of 714 A/m{sup 2} along with a minor recovery of gold (5%). In the 2nd stage gold was mostly leached out (93% recovery, {approx}67 mg/L) from the residue of the 1st stage by the electro-generated chlorine in 0.1 mol/L HCl. Gold recovery from the leach liquor by ion exchange using Amberlite XAD-7HP resin was found to be 95% with the maximum amount of gold adsorbed as 46.03 mg/g resin. A concentrated gold solution, 6034 mg/L with 99.9% purity was obtained in the ion exchange process.