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Sample records for giammarco vetrocoke sulfur process

  1. Elemental sulfur recovery process

    DOEpatents

    Flytzani-Stephanopoulos, Maria (Winchester, MA); Hu, Zhicheng (Somerville, MA)

    1993-01-01

    An improved catalytic reduction process for the direct recovery of elemental sulfur from various SO.sub.2 -containing industrial gas streams. The catalytic process provides combined high activity and selectivity for the reduction of SO.sub.2 to elemental sulfur product with carbon monoxide or other reducing gases. The reaction of sulfur dioxide and reducing gas takes place over certain catalyst formulations based on cerium oxide. The process is a single-stage, catalytic sulfur recovery process in conjunction with regenerators, such as those used in dry, regenerative flue gas desulfurization or other processes, involving direct reduction of the SO.sub.2 in the regenerator off gas stream to elemental sulfur in the presence of a catalyst.

  2. Elemental sulfur recovery process

    DOEpatents

    Flytzani-Stephanopoulos, M.; Zhicheng Hu.

    1993-09-07

    An improved catalytic reduction process for the direct recovery of elemental sulfur from various SO[sub 2]-containing industrial gas streams. The catalytic process provides combined high activity and selectivity for the reduction of SO[sub 2] to elemental sulfur product with carbon monoxide or other reducing gases. The reaction of sulfur dioxide and reducing gas takes place over certain catalyst formulations based on cerium oxide. The process is a single-stage, catalytic sulfur recovery process in conjunction with regenerators, such as those used in dry, regenerative flue gas desulfurization or other processes, involving direct reduction of the SO[sub 2] in the regenerator off gas stream to elemental sulfur in the presence of a catalyst. 4 figures.

  3. Processing high sulfur coal

    SciTech Connect

    Sooter, M.C.

    1981-09-29

    Coal is fed to a liquefaction process, and a resulting slurry of ash, unconverted coal, and liquids is fed to a delayed coker. Distillates are hydrotreated and stored or recycled, and the coke is calcined at high temperature to reduce the sulfur content.

  4. Process for forming sulfuric acid

    DOEpatents

    Lu, Wen-Tong P. (Upper St. Clair, PA)

    1981-01-01

    An improved electrode is disclosed for the anode in a sulfur cycle hydrogen generation process where sulfur dioxie is oxidized to form sulfuric acid at the anode. The active compound in the electrode is palladium, palladium oxide, an alloy of palladium, or a mixture thereof. The active compound may be deposited on a porous, stable, conductive substrate.

  5. Microbial Architecture of Environmental Sulfur Processes: A

    E-print Network

    Hitchcock, Adam P.

    Microbial Architecture of Environmental Sulfur Processes: A Novel Syntrophic Sulfur, 2009. Accepted July 9, 2009. Microbial oxidation of sulfur-rich mining waste materials drives acid mine drainage (AMD) and affects the global sulfur biogeochemical cycle. The generation of AMD is a complex

  6. Process for removing sulfur from sulfur-containing gases

    DOEpatents

    Rochelle, Gary T. (Austin, TX); Jozewicz, Wojciech (Chapel Hill, NC)

    1989-01-01

    The present disclosure relates to improved processes for treating hot sulfur-containing flue gas to remove sulfur therefrom. Processes in accorda The government may own certain rights in the present invention pursuant to EPA Cooperative Agreement CR 81-1531.

  7. Catalyst for elemental sulfur recovery process

    DOEpatents

    Flytzani-Stephanopoulos, M.; Liu, W.

    1995-01-24

    A catalytic reduction process is described for the direct recovery of elemental sulfur from various SO[sub 2]-containing industrial gas streams. The catalytic process provides high activity and selectivity, as well as stability in the reaction atmosphere, for the reduction of SO[sub 2] to elemental sulfur product with carbon monoxide or other reducing gases. The reaction of sulfur dioxide and reducing gas takes place over a metal oxide composite catalyst having one of the following empirical formulas: [(FO[sub 2])[sub 1[minus]n](RO)[sub n

  8. Process for removing sulfur from coal

    DOEpatents

    Aida, T.; Squires, T.G.; Venier, C.G.

    1983-08-11

    A process is disclosed for the removal of divalent organic and inorganic sulfur compounds from coal and other carbonaceous material. A slurry of pulverized carbonaceous material is contacted with an electrophilic oxidant which selectively oxidizes the divalent organic and inorganic compounds to trivalent and tetravalent compounds. The carbonaceous material is then contacted with a molten caustic which dissolves the oxidized sulfur compounds away from the hydrocarbon matrix.

  9. Development of enhanced sulfur rejection processes

    SciTech Connect

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

    1993-03-23

    Research at Virginia Tech led to two complementary concepts for improving the removal of inorganic sulfur from much of the Eastern US coals. One controls the surface properties of coal pyrite (FeS[sub 2]) by electrochemical-.potential control, referred to as the Electrochemically Enhanced Sulfur Rejection (EESR) Process: The second controls the flotation of middlings, i.e., particles composed of pyrite with coal inclusions by using polymeric reagents to react with pyrite and convert the middlings to hydrophilic particles, and is termed the Polymer Enhanced Sulfur Rejection (PESR) Process. These new concepts are based on recent research establishing the two main reasons why flotation fails to remove more than about 50% of the pyritic sulfur from coal: superficial oxidization of liberated pyrite to form polysulfide oxidation products so that a part of the liberated pyrite floats with the coal; and hydrophobic coal inclusions in the middlings dominating their flotation so that the middlings also float with the coal. These new pyritic-sulfur rejection processes do not require significant modifications of existing coal preparation facilities, enhancing their adoptability by the coal industry. It is believed that they can be used simultaneously to achieve both free pyrite and locked pyrite rejection.

  10. Development of enhanced sulfur rejection processes

    SciTech Connect

    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.

  11. Catalyst for elemental sulfur recovery process

    DOEpatents

    Flytzani-Stephanopoulos, Maria (Winchester, MA); Liu, Wei (Cambridge, MA)

    1995-01-01

    A catalytic reduction process for the direct recovery of elemental sulfur from various SO.sub.2 -containing industrial gas streams. The catalytic process provides high activity and selectivity, as well as stability in the reaction atmosphere, for the reduction of SO.sub.2 to elemental sulfur product with carbon monoxide or other reducing gases. The reaction of sulfur dioxide and reducing gas takes place over a metal oxide composite catalyst having one of the following empirical formulas: [(OF.sub.2).sub.1-n (RO.sub.1)n].sub.1-k M.sub.k, [(FO.sub.2).sub.1-n (RO.sub.1.5).sub.n ].sub.1-k M.sub.k, or [Ln.sub.x Zr.sub.1-x O.sub.2-0.5x ].sub.1-k M.sub.k wherein FO.sub.2 is a fluorite-type oxide; RO represents an alkaline earth oxide; RO.sub.1.5 is a Group IIIB or rare earth oxide; Ln is a rare earth element having an atomic number from 57 to 65 or mixtures thereof; M is a transition metal or a mixture of transition metals; n is a number having a value from 0.0 to 0.35; k is a number having a value from 0.0 to about 0.5; and x is a number having a value from about 0.45 to about 0.55.

  12. Process for the separation of sulfur oxides from a gaseous mixture containing sulfur oxides and oxygen

    SciTech Connect

    Derosset, A.J.; Ginger, E.A.

    1980-12-23

    An improved process for the separation of sulfur oxides from a gaseous mixture containing sulfur oxides and oxygen is disclosed. The gaseous mixture is contacted with a solid sulfur oxide acceptor comprising copper, copper oxide, or a mixture thereof dispersed on a carrier material in combination with a platinum group metal component and a component selected from the group consisting of rhenium, germanium and tin.

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

    DOEpatents

    Rochelle, Gary T. (Austin, TX); Chang, John C. S. (Cary, NC)

    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.

  14. Process for production of synthesis gas with reduced sulfur content

    DOEpatents

    Najjar, Mitri S. (Hopewell Junction, NY); Corbeels, Roger J. (Wappingers Falls, NY); Kokturk, Uygur (Wappingers Falls, NY)

    1989-01-01

    A process for the partial oxidation of a sulfur- and silicate-containing carbonaceous fuel to produce a synthesis gas with reduced sulfur content which comprises partially oxidizing said fuel at a temperature in the range of 1800.degree.-2200.degree. F. in the presence of a temperature moderator, an oxygen-containing gas and a sulfur capture additive which comprises an iron-containing compound portion and a sodium-containing compound portion to produce a synthesis gas comprising H.sub.2 and CO with a reduced sulfur content and a molten slag which comprises (i) a sulfur-containing sodium-iron silicate phase and (ii) a sodium-iron sulfide phase. The sulfur capture additive may optionally comprise a copper-containing compound portion.

  15. Process for removing pyritic sulfur from bituminous coals

    DOEpatents

    Pawlak, Wanda (Edmonton, CA); Janiak, Jerzy S. (Edmonton, CA); Turak, Ali A. (Edmonton, CA); Ignasiak, Boleslaw L. (Edmonton, CA)

    1990-01-01

    A process is provided for removing pyritic sulfur and lowering ash content of bituminous coals by grinding the feed coal, subjecting it to micro-agglomeration with a bridging liquid containing heavy oil, separating the microagglomerates and separating them to a water wash to remove suspended pyritic sulfur. In one embodiment the coal is subjected to a second micro-agglomeration step.

  16. Processing of heavy high-sulfur feedstocks

    SciTech Connect

    Boyer, L.D.; Newman, B.A.

    1982-09-28

    A heavy high-sulfur hydrocarbonaceous feedstock is partially delayed coked and partially formcoked. The coke products are screened, with larger particles being calcined at desulfurizing temperatures and smaller particles being recycled to the formcoker. Overhead products from both coking operations are combined, fractionated, and desulfurized. The heaviest cut from the fractionator is combined with the feedstock as recycle.

  17. HYBRID SULFUR RECOVERY PROCESS FOR NATURAL GAS UPGRADING

    SciTech Connect

    Dennis Dalrymple

    2004-04-01

    This first quarter report of 2004 describes progress on a project funded by the U.S. Department of Energy (DOE) to test a hybrid sulfur recovery process for natural gas upgrading. The process concept represents a low-cost option for direct treatment of natural gas streams to remove H{sub 2}S in quantities equivalent to 0.2-25 metric tons (LT) of sulfur per day. This process is projected to have lower capital and operating costs than the competing technologies, amine/aqueous iron liquid redox and amine/Claus/tail gas treating, and have a smaller plant footprint, making it well suited to both on-shore and off-shore applications. CrystaSulf{reg_sign} (service mark of CrystaTech, Inc.) is a new nonaqueous sulfur recovery process that removes hydrogen sulfide (H{sub 2}S) from gas streams and converts it into elemental sulfur. CrystaSulf features high sulfur recovery similar to aqueous-iron liquid redox sulfur recovery processes, but differs from the aqueous processes in that CrystaSulf controls the location where elemental sulfur particles are formed. In the hybrid process, approximately 1/3 of the total H{sub 2}S in the natural gas is first oxidized to SO{sub 2} at low temperatures over a heterogeneous catalyst. Low temperature oxidation is done so that the H{sub 2}S can be oxidized in the presence of methane while avoiding methane oxidation and fouling due to coking from other hydrocarbon contaminants. The project involves the development of a catalyst using laboratory/bench-scale catalyst testing, and then demonstration of the catalyst at CrystaTech's pilot plant site in west Texas.

  18. Process for making formed coke from high sulfur coal

    SciTech Connect

    Holowaty, M.O.

    1982-08-03

    In a formed coke process of the type in which carbonization and calcination of coal is carried out prior to briquetting, the hot calcined char is cooled by means of a hydrogen-rich gas at superatmospheric pressure so as to effect concurrent cooling and desulfurization of the char. High sulfur coal containing 1.5 to 4 wt. % sulfur can be used while obtaining a char and a formed coke product with a sulfur content of 0.8 wt. % or less. The cooling can be done in two stages: (1) a first stage in which sulfur removal and cooling to a temperature not lower than about 800/sup 0/F are accomplished with a hydrogen-rich gas, and (2) a second stage in which further cooling to about 200/sup 0/F or less is accomplished with an inert gas.

  19. Reduction of produced elementary sulfur in denitrifying sulfide removal process.

    PubMed

    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. PMID:21286712

  20. Membrane Separation Processes for the Benefit of the Sulfur-Iodine and Hybrid Sulfur Thermochemical Cycles

    SciTech Connect

    Christopher J. Orme; John R. Klaehn; Frederick F. Stewart

    2009-05-01

    Thermochemical cycles have been proposed as processes for the manufacture of hydrogen from water in which the only effluent is oxygen. In this paper, membrane-based technologies are described that have the promise of enabling the further development of thermochemical cycle processes. In direct service of the sulfur-iodine (S-I) cycle, membranes have been studied for the concentration of HI and sulfuric acid using pervaporation. In this work, Nafion® and SPEEK membranes have effectively concentrated both acids at temperatures as high as 134 ºC without any significant degradation. Measured fluxes of water and separation factors are commercially competitive and have been characterized with respect to acid concentration in the feed streams. Further, hydrogen permeability is discussed at 300 ºC with the goal of providing a method for the removal of the product gas from HI in the decomposition step, thus increasing the productiveness of the equilibrium limited reaction.

  1. Durability Testing of the Direct Sulfur Recovery Process

    SciTech Connect

    Portzer, Jeffrey W.; Turk, Brian S.; Gangwal, Santosh K.

    1996-12-31

    Designs for advanced integrated gasification combined cycle (IGCC) power systems call for desulfurization of coal gasifier gas at high-temperature, high-pressure (HTHP) conditions using highly efficient, regenerable metal oxides such as zinc titanate. Regeneration of the sulfided sorbent using an oxygen-containing gas stream results in a sulfur dioxide (SO{sub 2})-containing off-gas at HTHP conditions. The patented Direct Sulfur Recovery Process (DSRP) developed by the Research Triangle Institute (RTI) with Morgantown Energy Technology Center (METC) support is an attractive option for treatment of this regeneration off-gas. Using a slipstream of coal gas as a reducing agent, it efficiently converts the SO{sub 2} to elemental sulfur, an essential industrial commodity that is easily stored and transported.

  2. Performance and cost models for the direct sulfur recovery process. Task 1 Topical report, Volume 3

    SciTech Connect

    Frey, H.C.; Williams, R.B.

    1995-09-01

    The purpose of this project is to develop performance and cost models of the Direct Sulfur Recovery Process (DSRP). The DSRP is an emerging technology for sulfur recovery from advanced power generation technologies such as Integrated Gasification Combined Cycle (IGCC) systems. In IGCC systems, sulfur present in the coal is captured by gas cleanup technologies to avoid creating emissions of sulfur dioxide to the atmosphere. The sulfur that is separated from the coal gas stream must be collected. Leading options for dealing with the sulfur include byproduct recovery as either sulfur or sulfuric acid. Sulfur is a preferred byproduct, because it is easier to handle and therefore does not depend as strongly upon the location of potential customers as is the case for sulfuric acid. This report describes the need for new sulfur recovery technologies.

  3. HYBRID SULFUR RECOVERY PROCESS FOR NATURAL GAS UPGRADING

    SciTech Connect

    Dennis Dalrymple

    2004-06-01

    This final report describes the objectives, technical approach, results and conclusions for a project funded by the U.S. Department of Energy to test a hybrid sulfur recovery process for natural gas upgrading. The process concept is a configuration of CrystaTech, Inc.'s CrystaSulf{reg_sign} process which utilizes a direct oxidation catalyst upstream of the absorber tower to oxidize a portion of the inlet hydrogen sulfide (H{sub 2}S) to sulfur dioxide (SO{sub 2}) and elemental sulfur. This hybrid configuration of CrystaSulf has been named CrystaSulf-DO and represents a low-cost option for direct treatment of natural gas streams to remove H{sub 2}S in quantities equivalent to 0.2-25 metric tons (LT) of sulfur per day and more. This hybrid process is projected to have lower capital and operating costs than the competing technologies, amine/aqueous iron liquid redox and amine/Claus/tail gas treating, and have a smaller plant footprint, making it well suited to both onshore and offshore applications. CrystaSulf is a nonaqueous sulfur recovery process that removes H{sub 2}S from gas streams and converts it to elemental sulfur. In CrystaSulf, H{sub 2}S in the inlet gas is reacted with SO{sub 2} to make elemental sulfur according to the liquid phase Claus reaction: 2H{sub 2}S + SO{sub 2} {yields} 2H{sub 2}O + 3S. The SO{sub 2} for the reaction can be supplied from external sources by purchasing liquid SO{sub 2} and injecting it into the CrystaSulf solution, or produced internally by converting a portion of the inlet gas H{sub 2}S to SO{sub 2} or by burning a portion of the sulfur produced to make SO{sub 2}. CrystaSulf features high sulfur recovery similar to aqueous-iron liquid redox sulfur recovery processes, but differs from the aqueous processes in that CrystaSulf controls the location where elemental sulfur particles are formed. In the hybrid process, the needed SO{sub 2} is produced by placing a bed of direct oxidation catalyst in the inlet gas stream to oxidize a portion of the inlet H{sub 2}S. Oxidation catalysts may also produce some elemental sulfur under these conditions, which can be removed and recovered prior to the CrystaSulf absorber. The CrystaSulf-DO process can utilize direct oxidation catalyst from many sources. Numerous direct oxidation catalysts are available from many suppliers worldwide. They have been used for H{sub 2}S oxidation to sulfur and/or SO{sub 2} for decades. It was believed at the outset of the project that TDA Research, Inc., a subcontractor, could develop a direct oxidation catalyst that would offer advantages over other commercially available catalysts for this CrystaSulf-DO process application. This project involved the development of several of TDA's candidate proprietary direct oxidation catalysts through laboratory bench-scale testing. These catalysts were shown to be effective for conversion of H{sub 2}S to SO{sub 2} and to elemental sulfur under certain operating conditions. One of these catalysts was subsequently tested on a commercial gas stream in a bench-scale reactor at CrystaTech's pilot plant site in west Texas with good results. However, commercial developments have precluded the use of TDA catalysts in the CrystaSulf-DO process. Nonetheless, this project has advanced direct oxidation catalyst technology for H{sub 2}S control in energy industries and led to several viable paths to commercialization. TDA is commercializing the use of its direct oxidation catalyst technology in conjunction with the SulfaTreat{reg_sign} solid scavenger for natural gas applications and in conjunction with ConocoPhillips and DOE for gasification applications using ConocoPhillips gasification technology. CrystaTech is commercializing its CrystaSulf-DO process in conjunction with Gas Technology Institute for natural gas applications (using direct oxidation catalysts from other commercial sources) and in conjunction with ChevronTexaco and DOE for gasification applications using ChevronTexaco's gasification technology.

  4. Sulfur-modified iron (SMI) process for arsenic removal

    SciTech Connect

    Reinsel, M.A.; Santina, P.F.

    1999-07-01

    Many waters associated with mining and mineral processing contain high concentrations of arsenic, and effluent typically must meet increasingly stringent human health standards. A new proprietary technology for arsenic removal has been developed by Peter F. Santina to cost-effectively meet these discharge limits. Hydrometrics, Inc., has performed, under contract to peter F. Santina, further lab tests to prove and test limits of the efficacy of the process. In the sulfur-modified iron (SMI) process, arsenic is removed by an iron-sulfur matrix. Arsenic concentrations blow 0.005 mg/L have been obtained using SMI in jar tests and column tests, and the iron/sulfur residue has passed the US EPA Toxicity Characteristic Leaching Procedure (TCLP) test. A 10-gpm federally-funded pilot test is underway to further develop this promising technology. the purpose of pilot testing is to identify specific design parameters and operational procedures which can be used for full-scale production application of the SMI process. Projected operating costs for SMI are lower than alternative arsenic removal technologies such as iron salt addition, reverse osmosis and activated alumina. Cost savings would increase proportionally with higher flow rates and higher arsenic concentrations. The SMI process is potentially very promising for simple, cost-effective treatment of mining and other industrial effluents, drinking water and other arsenic-containing waters.

  5. Conversion of Sulfur by Wet Oxidation in the Bayer Process

    NASA Astrophysics Data System (ADS)

    Liu, Zhanwei; Li, Wangxing; Ma, Wenhui; Yin, Zhonglin; Wu, Guobao

    2015-08-01

    In this paper, the effects of temperature, oxidation time, and oxygen concentration on the conversion of sulfur by wet oxidation in the Bayer process were investigated at length. The results show that active sulfur S2- and S2O3 2- in sodium aluminate solution can be converted completely by wet oxidation during the digestion process, thus the effects of S2- and S2O3 2- on alumina product quality are eliminated; increased temperature, oxidation time, and oxygen concentration are conducive to conversion of S2- and S2O3 2-. At the same time, part of the organic carbon in the sodium aluminate solution is also oxidized by wet oxidation, and the color of the sodium aluminate solution noticeably fades.

  6. Assessment of hidden sulfur cycling processes through modeling of sulfur and oxygen isotope signatures of pore-water sulfate

    NASA Astrophysics Data System (ADS)

    Arnold, G. L.; Liu, B.; Henkel, S.; Sawicka, J.; Kasten, S.; Khalili, A.; Brunner, B.

    2012-12-01

    We developed a numerical model to simulate/predict the sulfur and oxygen isotope composition of pore-water sulfate in sediment pore-water profiles where sulfate concentrations decrease linearly with depth, presumably under steady-state conditions. We considered the effects of sulfate consumption due to the anaerobic oxidation of methane (AOM) alone and in combination with organoclastic sulfate reduction Linear sulfate concentration profiles are commonly associated with sulfate loss at depth driven by sulfate reduction coupled to AOM presumably under steady-state conditions. During this reaction the net consumption of sulfate and methane are balanced. The general assumption is that under steady-state conditions there is little to no sulfate loss due to organoclastic sulfate reduction and negligible sulfate gain due to other sulfur cycling processes above the sulfate-methane transition zone (SMTZ). When model results are compared to pore-water sulfate data from sediment cores obtained from the Argentine Basin, we see that sulfate reduction coupled to AOM alone cannot produce the measured sulfur and oxygen isotope patterns. Modeled isotope profiles including organoclastic sulfate reduction above the SMTZ provide a good match to the observations. The model comparison to our data reveals large sulfur isotope fractionation effects, with sulfur isotope enrichment factors (?34S) exceeding 50‰, consistent with the observed sulfur isotope offset between sulfate and sulfide. Furthermore, our model requires oxygen isotope exchange factors (?O) equal to or exceeding 10. Linear sulfate concentration profiles do not readily reveal the complexity and richness of sulfur cycling processes above the SMTZ and are able to 'hide' the effects of organoclastic sulfate reduction and additional sulfur cycling. Hence, the use of combined sulfur and oxygen isotope analysis is a valuable tool that can be used to gain insight into sulfur cycling not revealed by traditional means.

  7. A Development of Ceramics Cylinder Type Sulfuric Acid Decomposer for Thermo-Chemical Iodine-Sulfur Process Pilot Plant

    SciTech Connect

    Hiroshi Fukui; Isao Minatsuki; Kazuo Ishino

    2006-07-01

    The hydrogen production method applying thermo-chemical Iodine-Sulfur process (IS process) which uses a nuclear high temperature gas cooled reactor is world widely greatly concerned from the view point of a combination as a clean method, free carbon dioxide in essence. In this process, it is essential a using ceramic material, especially SiC because a operation condition of this process is very corrosive due to a sulfuric acid atmosphere with high temperature and high pressure. In the IS process, a sulfuric acid decomposer is the key component which performs evaporating of sulfuric acid from liquid to gas and disassembling to SO{sub 2} gas. SiC was selected as ceramic material to apply for the sulfuric acid decomposer and a new type of binding material was also developed for SiC junction. This technology is expected to wide application not only for a sulfuric acid decomposer but also for various type components in this process. Process parameters were provided as design condition for the decomposer. The configuration of the sulfuric acid decomposer was studied, and a cylindrical tubes assembling type was selected. The advantage of this type is applicable for various type of components in the IS process due to manufacturing with using only simple shape part. A sulfuric acid decomposer was divided into two regions of the liquid and the gaseous phase of sulfuric acid. The thermal structural integrity analysis was studied for the liquid phase part. From the result of this analysis, it was investigated that the stress was below the strength of the breakdown probability 1/100,000 at any position, base material or junction part. The prototype model was manufactured, which was a ceramic portion in the liquid phase part, comparatively complicated configuration, of a sulfuric acid decomposer. The size of model was about 1.9 m in height, 1.0 m in width. Thirty-six cylinders including inlet and outlet nozzles were combined and each part article was joined using the new binder (slurry binder) and calcinated. Final polishing of the flange faces established in the entrance nozzles was also satisfactory. Many parts were joinable using new technology (new binder). For this reason, new technology is applicable to manufacture of not only a sulfuric acid decomposer but the instruments in the IS process, or other chemical processes. (authors)

  8. Low Quality Natural Gas Sulfur Removal and Recovery CNG Claus Sulfur Recovery Process

    SciTech Connect

    Klint, V.W.; Dale, P.R.; Stephenson, C.

    1997-10-01

    Increased use of natural gas (methane) in the domestic energy market will force the development of large non-producing gas reserves now considered to be low quality. Large reserves of low quality natural gas (LQNG) contaminated with hydrogen sulfide (H{sub 2}S), carbon dioxide (CO{sub 2}) and nitrogen (N) are available but not suitable for treatment using current conventional gas treating methods due to economic and environmental constraints. A group of three technologies have been integrated to allow for processing of these LQNG reserves; the Controlled Freeze Zone (CFZ) process for hydrocarbon / acid gas separation; the Triple Point Crystallizer (TPC) process for H{sub 2}S / C0{sub 2} separation and the CNG Claus process for recovery of elemental sulfur from H{sub 2}S. The combined CFZ/TPC/CNG Claus group of processes is one program aimed at developing an alternative gas treating technology which is both economically and environmentally suitable for developing these low quality natural gas reserves. The CFZ/TPC/CNG Claus process is capable of treating low quality natural gas containing >10% C0{sub 2} and measurable levels of H{sub 2}S and N{sub 2} to pipeline specifications. The integrated CFZ / CNG Claus Process or the stand-alone CNG Claus Process has a number of attractive features for treating LQNG. The processes are capable of treating raw gas with a variety of trace contaminant components. The processes can also accommodate large changes in raw gas composition and flow rates. The combined processes are capable of achieving virtually undetectable levels of H{sub 2}S and significantly less than 2% CO in the product methane. The separation processes operate at pressure and deliver a high pressure (ca. 100 psia) acid gas (H{sub 2}S) stream for processing in the CNG Claus unit. This allows for substantial reductions in plant vessel size as compared to conventional Claus / Tail gas treating technologies. A close integration of the components of the CNG Claus process also allow for use of the methane/H{sub 2}S separation unit as a Claus tail gas treating unit by recycling the CNG Claus tail gas stream. This allows for virtually 100 percent sulfur recovery efficiency (virtually zero SO{sub 2} emissions) by recycling the sulfur laden tail gas to extinction. The use of the tail gas recycle scheme also deemphasizes the conventional requirement in Claus units to have high unit conversion efficiency and thereby make the operation much less affected by process upsets and feed gas composition changes. The development of these technologies has been ongoing for many years and both the CFZ and the TPC processes have been demonstrated at large pilot plant scales. On the other hand, prior to this project, the CNG Claus process had not been proven at any scale. Therefore, the primary objective of this portion of the program was to design, build and operate a pilot scale CNG Claus unit and demonstrate the required fundamental reaction chemistry and also demonstrate the viability of a reasonably sized working unit.

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

    DOEpatents

    Basu, Arunabha (Aurora, IL); Meyer, Howard S. (Hoffman Estates, IL); Lynn, Scott (Pleasant Hill, CA); Leppin, Dennis (Chicago, IL); Wangerow, James R. (Medinah, IL)

    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.

  10. Integrated Process Configuration for High-Temperature Sulfur Mitigation during Biomass Conversion via Indirect Gasification

    SciTech Connect

    Dutta. A.; Cheah, S.; Bain, R.; Feik, C.; Magrini-Bair, K.; Phillips, S.

    2012-06-20

    Sulfur present in biomass often causes catalyst deactivation during downstream operations after gasification. Early removal of sulfur from the syngas stream post-gasification is possible via process rearrangements and can be beneficial for maintaining a low-sulfur environment for all downstream operations. High-temperature sulfur sorbents have superior performance and capacity under drier syngas conditions. The reconfigured process discussed in this paper is comprised of indirect biomass gasification using dry recycled gas from downstream operations, which produces a drier syngas stream and, consequently, more-efficient sulfur removal at high temperatures using regenerable sorbents. A combination of experimental results from NREL's fluidizable Ni-based reforming catalyst, fluidizable Mn-based sulfur sorbent, and process modeling information show that using a coupled process of dry gasification with high-temperature sulfur removal can improve the performance of Ni-based reforming catalysts significantly.

  11. Test of TDA's Direct Oxidation Process for Sulfur Recovery

    SciTech Connect

    Girish Srinivas; Steven C. Gebhard; Eugene Peeples; Sandra Huzyk; Randy Welch

    2005-01-01

    This project was a Phase III pilot plant test of TDA's gas sweetening process done under realistic conditions. TDA Research Inc successfully completed the test at Whiting Petroleum's Sable San Andreas Gas Plant. The feed was approximately 228,000 standard cubic feet per day (SCFD) of gas that contained approximately 60 vol% CO{sub 2}, 20 vol% CH{sub 4} and 10 vol% C{sub 3}+ and higher hydrocarbons. The feed was associated gas from CO{sub 2} flooding operations carried out on Whiting's oil wells. The gas is collected and piped to the Sable gas plant where it is normally flared. We sited our pilot plant in line with the flare so that we could remove the hydrogen sulfide (H{sub 2}S) prior to flaring. The average H{sub 2}S concentration in the gas during the field test was 7341 ppm. The selectivity of our process for converting H{sub 2}S into elemental sulfur was essentially 100% and the catalyst converted 90% of the H{sub 2}S into sulfur and water (the remaining 10% of the H{sub 2}S passed through unconverted). Importantly, no catalyst deactivation was observed for over the course of the 1000+ hour test. Minimal (ca. 10-15 ppm) of SO{sub 2} was formed during the test. Approximately 3.6 tons of elemental sulfur was recovered from a total inlet of 3.9 tons of sulfur (as H{sub 2}S). The total amount of SO{sub 2} released from the plant (taking into account flaring of the unconverted 10% H2S) was 0.86 tons. This amount of SO{sub 2} is much lower than the normal 8 tons that would have been emitted if all of the H{sub 2}S were flared over the time of the pilot plant test. The pilot plant was simple to operate and required much less operator intervention than is typical for a new unit being commissioned. Our operator (Mr. Eugene Peeples) has more than 30 years of experience operating commercial scale liquid redox sulfur recovery processes and in his opinion, TDA's Direct Oxidation pilot plant is easier to operate than liquid systems. The ease of use and low capital and operating costs of TDA's Direct Oxidation process makes it an attractive technology to be used where traditional sulfur recovery technologies are too expensive (e.g. small to medium sized plants). Currently, TDA's direct oxidation process has been exclusively licensed to SulfaTreat, and is being offered commercially under the trade name SulfaTreat-DO{reg_sign}. We anticipate that the first plant will be installed in 2005.

  12. SULFURIC ACID REMOVAL PROCESS EVALUATION: SHORT-TERM RESULTS

    SciTech Connect

    Gary M. Blythe; Richard McMillan

    2002-03-04

    The objective of this project is to demonstrate the use of alkaline reagents injected into the furnace of coal-fired boilers as a means of controlling sulfuric acid emissions. Sulfuric acid controls are becoming of increasing interest to utilities with coal-fired units for a number of reasons. Sulfuric acid is a Toxic Release Inventory species, a precursor to acid aerosol/condensable emissions, and can cause a variety of plant operation problems such as air heater plugging and fouling, back-end corrosion, and plume opacity. These issues will likely be exacerbated with the retrofit of SCR for NOX control on some coal-fired plants, as SCR catalysts are known to further oxidize a portion of the flue gas SO{sub 2} to SO{sub 3}. The project is testing the effectiveness of furnace injection of four different calcium- and/or magnesium-based alkaline sorbents on full-scale utility boilers. These reagents have been tested during four one- to two-week tests conducted on two FirstEnergy Bruce Mansfield Plant units. One of the sorbents tested was a magnesium hydroxide slurry produced from a wet flue gas desulfurization system waste stream, from a system that employs a Thiosorbic{reg_sign} Lime scrubbing process. The other three sorbents are available commercially and include dolomite, pressure-hydrated dolomitic lime, and commercial magnesium hydroxide. The dolomite reagent was injected as a dry powder through out-of-service burners, while the other three reagents were injected as slurries through air-atomizing nozzles into the front wall of upper furnace, either across from the nose of the furnace or across from the pendant superheater tubes. After completing the four one- to two-week tests, the most promising sorbents were selected for longer-term (approximately 25-day) full-scale tests. The longer-term tests are being conducted to confirm the effectiveness of the sorbents tested over extended operation and to determine balance-of-plant impacts. This reports presents the results of the short-term tests; the long-term test results will be reported in a later document. The short-term test results showed that three of the four reagents tested, dolomite powder, commercial magnesium hydroxide slurry, and byproduct magnesium hydroxide slurry, were able to achieve 90% or greater removal of sulfuric acid compared to baseline levels. The molar ratio of alkali to flue gas sulfuric acid content (under baseline conditions) required to achieve 90% sulfuric acid removal was lowest for the byproduct magnesium hydroxide slurry. However, this result may be confounded because this was the only one of the three slurries tested with injection near the top of the furnace across from the pendant superheater platens. Injection at the higher level was demonstrated to be advantageous for this reagent over injection lower in the furnace, where the other slurries were tested.

  13. SULFURIC ACID REMOVAL PROCESS EVALUATION: SHORT-TERM RESULTS

    SciTech Connect

    Gary M. Blythe; Richard McMillan

    2002-02-04

    The objective of this project is to demonstrate the use of alkaline reagents injected into the furnace of coal-fired boilers as a means of controlling sulfuric acid emissions. Sulfuric acid controls are becoming of increasing interest to utilities with coal-fired units for a number of reasons. Sulfuric acid is a Toxic Release Inventory species, a precursor to acid aerosol/condensable emissions, and can cause a variety of plant operation problems such as air heater plugging and fouling, back-end corrosion, and plume opacity. These issues will likely be exacerbated with the retrofit of SCR for NO{sub x} control on some coal-fired plants, as SCR catalysts are known to further oxidize a portion of the flue gas SO{sub 2} to SO{sub 3}. The project is testing the effectiveness of furnace injection of four different calcium- and/or magnesium-based alkaline sorbents on full-scale utility boilers. These reagents have been tested during four one- to two-week tests conducted on two First Energy Bruce Mansfield Plant units. One of the sorbents tested was a magnesium hydroxide slurry produced from a wet flue gas desulfurization system waste stream, from a system that employs a Thiosorbic{reg_sign} Lime scrubbing process. The other three sorbents are available commercially and include dolomite, pressure-hydrated dolomitic lime, and commercial magnesium hydroxide. The dolomite reagent was injected as a dry powder through out-of-service burners, while the other three reagents were injected as slurries through air-atomizing nozzles into the front wall of upper furnace, either across from the nose of the furnace or across from the pendant superheater tubes. After completing the four one- to two-week tests, the most promising sorbents were selected for longer-term (approximately 25-day) full-scale tests. The longer-term tests are being conducted to confirm the effectiveness of the sorbents tested over extended operation and to determine balance-of-plant impacts. This reports presents the results of the short-term tests; the long-term test results will be reported in a later document. The short-term test results showed that three of the four reagents tested, dolomite powder, commercial magnesium hydroxide slurry, and byproduct magnesium hydroxide slurry, were able to achieve 90% or greater removal of sulfuric acid compared to baseline levels. The molar ratio of alkali to flue gas sulfuric acid content (under baseline conditions) required to achieve 90% sulfuric acid removal was lowest for the byproduct magnesium hydroxide slurry. However, this result may be confounded because this was the only one of the three slurries tested with injection near the top of the furnace across from the pendant superheater platens. Injection at the higher level was demonstrated to be advantageous for this reagent over injection lower in the furnace, where the other slurries were tested.

  14. RECENT ADVANCES IN THE DEVELOPMENT OF THE HYBRID SULFUR PROCESS FOR HYDROGEN PRODUCTION

    SciTech Connect

    Hobbs, D.

    2010-07-22

    Thermochemical processes are being developed to provide global-scale quantities of hydrogen. A variant on sulfur-based thermochemical cycles is the Hybrid Sulfur (HyS) Process, which uses a sulfur dioxide depolarized electrolyzer (SDE) to produce the hydrogen. In the HyS Process, sulfur dioxide is oxidized in the presence of water at the electrolyzer anode to produce sulfuric acid and protons. The protons are transported through a cation-exchange membrane electrolyte to the cathode and are reduced to form hydrogen. In the second stage of the process, the sulfuric acid by-product from the electrolyzer is thermally decomposed at high temperature to produce sulfur dioxide and oxygen. The two gases are separated and the sulfur dioxide recycled to the electrolyzer for oxidation. The Savannah River National Laboratory (SRNL) has been exploring a fuel-cell design concept for the SDE using an anolyte feed comprised of concentrated sulfuric acid saturated with sulfur dioxide. The advantages of this design concept include high electrochemical efficiency and small footprint compared to a parallel-plate electrolyzer design. This paper will provide a summary of recent advances in the development of the SDE for the HyS process.

  15. A simple synthesis of hollow carbon nanofiber-sulfur composite via mixed-solvent process for lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Li, Qiang; Zhang, Zhian; Zhang, Kai; Fang, Jing; Lai, Yanqing; Li, Jie

    2014-06-01

    A hollow carbon nanofiber supported sulfur (HCNF-S) composite cathode material is prepared by a mixed-solvent (DMF/CS2) process in an organic solution for lithium-sulfur batteries. Scanning electron microscope (SEM) and transmission electron microscope (TEM) observations show the hollow structures of the HCNF and the homogeneous distribution of sulfur in the composite. The performance of the HCNF-S cathode is evaluated in lithium-sulfur batteries using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. It is found that the HCNF-S cathode shows perfect cycling stability. The results exhibit an initial discharge capacity of 1090 mAh g-1 and retains 600 mAh g-1 after 100 discharge/charge cycles at a high rate of 1 C. The excellent electrochemical properties benefit from the hollow and highly conductive network-like structure of HCNFs, which contribute to disperse sulfur and absorb polysulfides, and suppress the formation of residual Li2S layer.

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

    USGS Publications Warehouse

    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.

  17. [Effect of different processing methods on active ingredient contents and sulfur dioxide residue in Astragali Radix].

    PubMed

    Ji, Lin; Mao, Chun-Qin; Lu, Tu-Lin; Li, Lin; Ji, De; Ning, Zi-Wan; Liu, Jing

    2014-08-01

    To compare the differences of the active ingredient contents and the sulfur dioxide residue in Astragali Radix before and after sulfur fumigation and provide a basis for establishing an alternative processing method. Astragali Radix, harvested at the same time in Longxi Gansu, were processed with different methods. high performance liquid chromatography (HPLC) was used to determine the contents of the active ingredients in Astragali Radix and the revised method of the pharmacopoeia of China in 2011 was applied to determine the sulfur dioxide residue. The results show that the three-fold sulfur-fumigation group has the highest level of astragaloside IV and the dried sulfur-fumigation group with 10% water has the lowest level; the content of calycosin-7-O-?-D-glucoside is the highest in naturally dried group and the lowest in the group of sulfur fumigating for 3 times; the sulfur dioxide residue of all sulfur-fumigation groups exceeds certain limit significantly and the group of sulfur fumigating for 3 times reaches the highest level. PMID:25423815

  18. [Effect of different processing methods on active ingredient contents and sulfur dioxide residue in Astragali Radix].

    PubMed

    Ji, Lin; Mao, Chun-Qin; Lu, Tu-Lin; Li, Lin; Ji, De; Ning, Zi-Wan; Liu, Jing

    2014-08-01

    To compare the differences of the active ingredient contents and the sulfur dioxide residue in Astragali Radix before and after sulfur fumigation and provide a basis for establishing an alternative processing method. Astragali Radix, harvested at the same time in Longxi Gansu, were processed with different methods. high performance liquid chromatography (HPLC) was used to determine the contents of the active ingredients in Astragali Radix and the revised method of the pharmacopoeia of China in 2011 was applied to determine the sulfur dioxide residue. The results show that the three-fold sulfur-fumigation group has the highest level of astragaloside IV and the dried sulfur-fumigation group with 10% water has the lowest level; the content of calycosin-7-O-?-D-glucoside is the highest in naturally dried group and the lowest in the group of sulfur fumigating for 3 times; the sulfur dioxide residue of all sulfur-fumigation groups exceeds certain limit significantly and the group of sulfur fumigating for 3 times reaches the highest level. PMID:25507537

  19. Wednesday, March 25, 2009 SULFUR ON MARS: ROCKS, SOILS, AND CYCLING PROCESSES

    E-print Network

    Rathbun, Julie A.

    Wednesday, March 25, 2009 SULFUR ON MARS: ROCKS, SOILS, AND CYCLING PROCESSES 1:30 p.m. Waterway and the Sulfur Cycle on Mars [#2152] Elevated S in martian mantle/crust and absence of plate tectonics results in a S-enriched sedimentary mass. The S-cycle of Mars is analogous to the Earth's C-cycle, with long

  20. SUMMARY REPORT: SULFUR OXIDES CONTROL TECHNOLOGY SERIES: FLUE GAS DESULFURIZATION - SPRAY DRYER PROCESS

    EPA Science Inventory

    Described spray dryer flue gas desulfurization (FGD), which is a throwaway process in which sulfur dioxide (SO2) is removed from flue gas by an atomized lime slurry [Ca(OH)2]. he hot flue gas dries the droplets to form a dry waste product, while the absorbent reacts with sulfur d...

  1. Slipstream testing of the Direct Sulfur Recovery Process

    SciTech Connect

    Gangwal, S.K.; Portzer, J.W.; Howe, G.B.; Chen, D.H.; McMillian, M.H.

    1994-10-01

    The objective of this work is to continue further development of the zinc titanate fluidized-bed desulfurization (ZTFBD) and the Direct Sulfur Recovery Process (DSRP) technologies for hot gas cleanup in integrated gasification combined cycle (IGCC) power generating systems. There are three main goals of this project: development of an integrated, skid-mounted, bench-scale ZTFBD/DSRP reactor system; testing the integrated system over an extended period with a slipstream of coal gas from an operating gasifier to quantify the degradation in performance, if any, caused by the trace contaminants present in coal gas (including heavy metals, chlorides, fluorides, and ammonia); and design, fabrication, and commissioning of a larger, pilot-plant scale DSRP reactor system capable of operating on a six-fold volume of gas greater than the reactors used in the bench-scale field tests. The results so far on the first phase are limited to design and construction of the test apparatus. This report describes DSRP technology and equipment that will be used to test it.

  2. Development and Implementation of a Novel Sulfur Removal Process from H2S Containing Wastewaters.

    PubMed

    Daigger, Glen T; Hodgkinson, Andrew; Aquilina, Simon; Fries, M Kim

    2015-07-01

    A novel process for removing sulfur from wastewater containing dissolved sulfide has been developed and implemented in a membrane bioreactor (MBR) process treating anaerobically pretreated industrial (pulp and paper) wastewater at the Gippsland Water Factory. Controlled oxygen addition to the first bioreactor zone (constituting 27.7% of the total bioreactor volume) to create oxygen-limiting conditions, followed by oxygen-sufficient conditions in the remaining zones of the bioreactor, provide the necessary conditions. Dissolved sulfide is oxidized to elemental sulfur in the first zone, and the accumulated sulfur is retained in the bioreactor mixed liquor suspended solids (MLSS) in the remaining zones. Accumulated sulfur is removed from the process in the waste activated sludge (WAS). Oxidation of dissolved sulfide to elemental sulfur reduces the associated process oxygen requirement by 75% compared to oxidation to sulfate. Microscopic examinations confirm that biological accumulation of elemental sulfur occurs. Process performance was analyzed during a nearly 2-year commissioning and optimization period. Addition of air in proportion to the process influent dissolved sulfide loading proved the most effective process control approach, followed by the maintenance of dissolved oxygen concentrations of 1.0 and 1.5 mg/L in the two downstream bioreactor zones. Sufficient oxygen is added for the stoichiometric conversion of dissolved sulfide to elemental sulfur. Enhanced biological phosphorus removal also occurred under these conditions, thereby simplifying supplemental phosphorus addition. These operating conditions also appear to lead to low and stable capillary suction time values for the MBR mixed liquor. PMID:26163497

  3. Sulfur tolerant molten carbonate fuel cell anode and process

    DOEpatents

    Remick, Robert J. (Naperville, IL)

    1990-01-01

    Molten carbonate fuel cell anodes incorporating a sulfur tolerant carbon monoxide to hydrogen water-gas-shift catalyst provide in situ conversion of carbon monoxide to hydrogen for improved fuel cell operation using fuel gas mixtures of over about 10 volume percent carbon monoxide and up to about 10 ppm hydrogen sulfide.

  4. HYBRID SULFUR PROCESS REFERENCE DESIGN AND COST ANALYSIS

    SciTech Connect

    Gorensek, M.; Summers, W.; Boltrunis, C.; Lahoda, E.; Allen, D.; Greyvenstein, R.

    2009-05-12

    This report documents a detailed study to determine the expected efficiency and product costs for producing hydrogen via water-splitting using energy from an advanced nuclear reactor. It was determined that the overall efficiency from nuclear heat to hydrogen is high, and the cost of hydrogen is competitive under a high energy cost scenario. It would require over 40% more nuclear energy to generate an equivalent amount of hydrogen using conventional water-cooled nuclear reactors combined with water electrolysis compared to the proposed plant design described herein. There is a great deal of interest worldwide in reducing dependence on fossil fuels, while also minimizing the impact of the energy sector on global climate change. One potential opportunity to contribute to this effort is to replace the use of fossil fuels for hydrogen production by the use of water-splitting powered by nuclear energy. Hydrogen production is required for fertilizer (e.g. ammonia) production, oil refining, synfuels production, and other important industrial applications. It is typically produced by reacting natural gas, naphtha or coal with steam, which consumes significant amounts of energy and produces carbon dioxide as a byproduct. In the future, hydrogen could also be used as a transportation fuel, replacing petroleum. New processes are being developed that would permit hydrogen to be produced from water using only heat or a combination of heat and electricity produced by advanced, high temperature nuclear reactors. The U.S. Department of Energy (DOE) is developing these processes under a program known as the Nuclear Hydrogen Initiative (NHI). The Republic of South Africa (RSA) also is interested in developing advanced high temperature nuclear reactors and related chemical processes that could produce hydrogen fuel via water-splitting. This report focuses on the analysis of a nuclear hydrogen production system that combines the Pebble Bed Modular Reactor (PBMR), under development by PBMR (Pty.) Ltd. in the RSA, with the Hybrid Sulfur (HyS) Process, under development by the Savannah River National Laboratory (SRNL) in the US as part of the NHI. This work was performed by SRNL, Westinghouse Electric Company, Shaw, PBMR (Pty) Ltd., and Technology Insights under a Technical Consulting Agreement (TCA). Westinghouse Electric, serving as the lead for the PBMR process heat application team, established a cost-shared TCA with SRNL to prepare an updated HyS thermochemical water-splitting process flowsheet, a nuclear hydrogen plant preconceptual design and a cost estimate, including the cost of hydrogen production. SRNL was funded by DOE under the NHI program, and the Westinghouse team was self-funded. The results of this work are presented in this Final Report. Appendices have been attached to provide a detailed source of information in order to document the work under the TCA contract.

  5. Isotopic evidence for processes of sulfur retention/release in 13 forested catchments spanning a strong pollution gradient

    E-print Network

    Kirchner, James W.

    Isotopic evidence for processes of sulfur retention/release in 13 forested catchments spanning. [1] Sulfur isotope systematics were studied in 13 small catchments in the Czech Republic, similar started to decrease in 1987. Sites retaining S were located in the relatively unpolluted south. Sulfur

  6. Process for recovery of sulfur from acid gases

    DOEpatents

    Towler, Gavin P. (Kirkbymoorside, GB2); Lynn, Scott (Pleasant Hill, CA)

    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.

  7. Sulfur fumigation processing of traditional chinese medicinal herbs: beneficial or detrimental?

    PubMed

    Kan, Winnie Lai Ting; Ma, Bin; Lin, Ge

    2011-01-01

    Majority of traditional Chinese medicine (TCM) herbs need to undergo post-harvesting processing to convert raw material into the form readily used for prescription. In general, processing procedures are either according to China Pharmacopeia or based on traditional methods. Recently sulfur fumigation is increasingly used to replace traditional sun-drying for its pesticidal and anti-bacterial properties in a cheap and convenient manner. However, to date information on effects of sulfur fumigation on herbal safety and efficacy are limited. This article addresses potential destructive effects of sulfur fumigation on herbal efficacy and safety through reviewing currently available information. Since recently increased numbers of studies have demonstrated that sulfur fumigation-induced dramatic changes in chemical profiles of various sulfur-fumigated herbs, consequent alteration of efficacy, and/or potential incidence of toxicity are suspected. Therefore comprehensive investigations on effects of sulfur fumigation on toxicity, chemical profiles, pharmacokinetics, and bioactivities of TCM herbs are timely to provide scientific basis for standardization and regulation of this currently common but potentially harmful processing method. PMID:22207851

  8. Sulfur Iodine Process Summary for the Hydrogen Technology Down-Selection: Process Performance Package

    SciTech Connect

    Benjamin Russ

    2009-06-01

    This document describes the details of implementing a Sulfur-Iodine (S-I) hydrogen production plant to deploy with the Next General Nuclear Power Plant (NGNP). Technical requirements and specifications are included, and a conceptual plant design is presented. The following areas of interest are outlined in particular as a baseline for the various technology comparisons: (1) Performance Criteria - (a) Quantity of hydrogen produced, (b) Purity of hydrogen produced, (c) Flexibility to serve various applications, (d) Waste management; (2) Economic Considerations - (a) Cost of hydrogen, (b) Development costs; and (3) Risk - (a) Technical maturity of the S-I process, (b) Development risk, (c) Scale up options.

  9. SULFURIC ACID REMOVAL PROCESS EVALUATION: LONG-TERM RESULTS

    SciTech Connect

    Gary M. Blythe; Richard McMillan

    2002-07-03

    The objective of this project is to demonstrate the use of alkaline reagents injected into the furnace of coal-fired boilers as a means of controlling sulfuric acid emissions. The project is being co-funded by the U.S. DOE National Energy Technology Laboratory, under Cooperative Agreement DE-FC26-99FT40718, along with EPRI, the American Electric Power Company (AEP), FirstEnergy Corp., the Tennessee Valley Authority, and Dravo Lime, Inc. Sulfuric acid controls are becoming of increasing interest to power generators with coal-fired units for a number of reasons. Sulfuric acid is a Toxic Release Inventory species and can cause a variety of plant operation problems such as air heater plugging and fouling, back-end corrosion, and plume opacity. These issues will likely be exacerbated with the retrofit of selective catalytic reduction (SCR) for NO{sub x} control on many coal-fired plants, as SCR catalysts are known to further oxidize a portion of the flue gas SO{sub 2} to SO{sub 3}. The project previously tested the effectiveness of furnace injection of four different calcium-and/or magnesium-based alkaline sorbents on full-scale utility boilers. These reagents were tested during four one- to two-week tests conducted on two FirstEnergy Bruce Mansfield Plant (BMP) units. One of the sorbents tested was a magnesium hydroxide byproduct slurry produced from a modified Thiosorbic{reg_sign} Lime wet flue gas desulfurization system. The other three sorbents are available commercially and include dolomite, pressure-hydrated dolomitic lime, and commercial magnesium hydroxide. The dolomite reagent was injected as a dry powder through out-of-service burners, while the other three reagents were injected as slurries through air-atomizing nozzles inserted through the front wall of the upper furnace, either across from the nose of the furnace or across from the pendant superheater tubes. After completing the four one- to two-week tests, the most promising sorbents were selected for longer-term (approximately 25-day) full-scale tests on two different units. The longer-term tests were conducted to confirm the effectiveness of the sorbents tested over extended operation on two different boilers, and to determine balance-of-plant impacts. The first long-term test was conducted on FirstEnergy's BMP, Unit 3, and the second test was conducted on AEP's Gavin Plant, Unit 1. The Gavin Plant testing provided an opportunity to evaluate the effects of sorbent injected into the furnace on SO{sub 3} formed across an operating SCR reactor. This report presents the results from those long-term tests. The tests determined the effectiveness of injecting commercially available magnesium hydroxide slurry (Gavin Plant) and byproduct magnesium hydroxide slurry (both Gavin Plant and BMP) for sulfuric acid control. The results show that injecting either slurry could achieve up to 70 to 75% overall sulfuric acid removal. At BMP, this overall removal was limited by the need to maintain acceptable electrostatic precipitator (ESP) particulate control performance. At Gavin Plant, the overall sulfuric acid removal was limited because the furnace injected sorbent was less effective at removing SO{sub 3} formed across the SCR system installed on the unit for NOX control than at removing SO{sub 3} formed in the furnace. The long-term tests also determined balance-of-plant impacts from slurry injection during the two tests. These include impacts on boiler back-end temperatures and pressure drops, SCR catalyst properties, ESP performance, removal of other flue gas species, and flue gas opacity. For the most part the balance-of-plant impacts were neutral to positive, although adverse effects on ESP performance became an issue during the BMP test.

  10. Process and apparatus for generating elemental sulfur and re-usable metal oxide from spent metal sulfide sorbents

    DOEpatents

    Ayala, Raul E. (Clifton Park, NY); Gal, Eli (Lititz, PA)

    1995-01-01

    A process and apparatus for generating elemental sulfur and re-usable metal oxide from spent metal-sulfur compound. Spent metal-sulfur compound is regenerated to re-usable metal oxide by moving a bed of spent metal-sulfur compound progressively through a single regeneration vessel having a first and second regeneration stage and a third cooling and purging stage. The regeneration is carried out and elemental sulfur is generated in the first stage by introducing a first gas of sulfur dioxide which contains oxygen at a concentration less than the stoichiometric amount required for complete oxidation of the spent metal-sulfur compound. A second gas containing sulfur dioxide and excess oxygen at a concentration sufficient for complete oxidation of the partially spent metal-sulfur compound, is introduced into the second regeneration stage. Gaseous sulfur formed in the first regeneration stage is removed prior to introducing the second gas into the second regeneration stage. An oxygen-containing gas is introduced into the third cooling and purging stage. Except for the gaseous sulfur removed from the first stage, the combined gases derived from the regeneration stages which are generally rich in sulfur dioxide and lean in oxygen, are removed from the regenerator as an off-gas and recycled as the first and second gas into the regenerator. Oxygen concentration is controlled by adding air, oxygen-enriched air or pure oxygen to the recycled off-gas.

  11. Thermodynamic analysis of the process of formation of sulfur compounds in oxygen gasification of coal

    SciTech Connect

    G.Ya. Gerasimov; T.M. Bogacheva

    2001-05-15

    A thermodynamic approach to the description of the behavior of the system fuel-oxidizer in oxygen gasification of coal is used to reveal the main mechanisms of the process of capture of sulfur by the mineral part of the coal and to determine the fundamental possibility of the process for coals from different coal fields.

  12. Sulfur Iodine Process Summary for the Hydrogen Technology Down-Selection

    SciTech Connect

    Benjamin Russ

    2009-05-01

    This report summarizes the sulfur-iodine (SI) thermochemical water splitting process for the purpose of supporting the process for evaluating and recommending a hydrogen production technology to deploy with the Next Generation Nuclear Plant (NGNP). This package provides the baseline process description as well as a comparison with the process as it was implemented in the Integrated Lab Scale (ILS) experiment conducted at General Atomics from 2006-2009.

  13. Using Mars's Sulfur Cycle to Constrain the Duration and Timing of Fluvial Processes

    NASA Technical Reports Server (NTRS)

    Blaney, D. L.

    2002-01-01

    Sulfur exists in high abundances at diverse locations on Mars. This work uses knowledge of the Martian sulfate system to discriminate between leading hypotheses and discusses the implications for duration and timing of fluvial processes. Additional information is contained in the original extended abstract.

  14. DEVELOPMENT OF INFRARED METHODS FOR CHARACTERIZATION OF INORGANIC SULFUR SPECIES RELATED TO INJECTION DESULFURIZATION PROCESSES

    EPA Science Inventory

    Current methods designed to control and reduce the amount of sulfur dioxide emitted into the atmosphere from coal-fired power plants and factories rely upon the reaction between SO2 and alkaline earth compounds and are called flue gas desulfurization (FGD) processes. Of these met...

  15. Aqueous process for recovering sulfur from hydrogen sulfide-bearing gas

    SciTech Connect

    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.

  16. Sulfur cement production using by products of the perchloroethylene coal cleaning process and the FC4-1 cleaned soil

    SciTech Connect

    Bassam Masri, K.L.; Fullerton, S.L.

    1995-12-31

    An introductory set of experiments to show the feasibility of making sulfur cement were carried out at the University of Akron according to Parrett and Currett`s patent which requires the use of sulfur, a filler, a plasticizer, and a vulcanization accelerator. Small blocks of cement were made using byproducts of the perchloroethylene coal cleaning process. Extracted elemental and organic sulfur, ash and mineral matters from the float sink portion of the PCE process, and FC4-1 cleaned soil were used as substitutes for sulfur and filler needed for the production of sulfur cement. Leaching tests in different solutions and under different conditions were conducted on the sulfur blocks. Other tests such as strength, durability, resistance to high or low temperatures will be conducted in the future. Sulfur cement can be used as a sealing agent at a joint, roofing purposes, forming ornamental figures, and coating of exposed surfaces of iron or steel. When mixed with an aggregate, sulfur concrete is formed. This concrete can be used for structural members, curbings, guthers, slabs, and can be precast or cast at the job site. An advantage of sulfur cement over Portland cement is that it reaches its design strength in two to three hours after processing and it can be remelted and recast.

  17. The GA sulfur-iodine water-splitting process - A status report

    NASA Technical Reports Server (NTRS)

    Besenbruch, G. E.; Chiger, H. D.; Mccorkle, K. H.; Norman, J. H.; Rode, J. S.; Schuster, J. R.; Trester, P. W.

    1981-01-01

    The development of a sulfur-iodine thermal water splitting cycle is described. The process features a 50% thermal efficiency, plus all liquid and gas handling. Basic chemical investigations comprised the development of multitemperature and multistage sulfuric acid boost reactors, defining the phase behavior of the HI/I2/H2O/H3PO4 mixtures, and development of a decomposition process for hydrogen iodide in the liquid phase. Initial process engineering studies have led to a 47% efficiency, improvements of 2% projected, followed by coupling high-temperature solar concentrators to the splitting processes to reduce power requirements. Conceptual flowsheets developed from bench models are provided; materials investigations have concentrated on candidates which can withstand corrosive mixtures at temperatures up to 400 deg K, with Hastelloy C-276 exhibiting the best properties for containment and heat exchange to I2.

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

    NASA Astrophysics Data System (ADS)

    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 accessibility of the precious metal particles is reduced which causes the catalyst to deactivate more rapidly during subsequent steam reforming cycles. Changes to the carrier morphology also occur at these conditions. Regenerating the catalyst before significant deactivation is measured can improve the stability of the catalyst. Thus a process with preemptive controlled air regenerations is proposed in order to run a steam reforming process with sulfur containing fuels.

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

    PubMed

    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. PMID:24922353

  20. Process for sequestering carbon dioxide and sulfur dioxide

    DOEpatents

    Maroto-Valer, M. Mercedes (State College, PA); Zhang, Yinzhi (State College, PA); Kuchta, Matthew E. (State College, PA); Andresen, John M. (State College, PA); Fauth, Dan J. (Pittsburgh, PA)

    2009-10-20

    A process for sequestering carbon dioxide, which includes reacting a silicate based material with an acid to form a suspension, and combining the suspension with carbon dioxide to create active carbonation of the silicate-based material, and thereafter producing a metal salt, silica and regenerating the acid in the liquid phase of the suspension.

  1. Development of a new FGD process that converts sulfur dioxide to salable ammonium phosphate fertilizer

    SciTech Connect

    Ji-lu Chen

    1993-12-31

    Rich mineral resources have enabled Chinese coal output and energy consumption to rank second and third in the world, respectively. In 1992, up to 70 percent of the country`s electric power was generated by the combustion of some 300 million tons of coal. Although the average sulfur content level in Chinese coals is only about 0.8 percent, the share of high- sulfur coals with 2 percent or more sulfur content is as high as 18 percent. As a result, air pollution accompanied by acid rain now occurs over most of the country, especially in southwestern China. Currently, the area comprising Guangdong, Guangxi, the Sichuan Basin, and the greater part of Gueizhou, where the sulfur content in coal is between 2 and 7 percent and the average pH values of rain water are between 4 and 5 per annum, has become one of the three biggest acid rain-affected areas in the world. In 1992, the national installed coal-fired electricity generation capacity exceeded 100,000 MWe. By the year 2000, it is expected to reach as much as 200,000 MWe, according to a new scheduled program. Environmental pollution caused by large-scale coal combustion is a very important issue that needs to be considered in the implementation of the program. To ensure that the effects of coal-fired power generation on the environment can be properly controlled in the near future, TPRI (Thermal Power Research Institute), the sole thermal power engineering research institution within the Ministry of Electric Power Industry (MOEPI), has conducted a long-term research program to develop sulfur emission control technologies suitable to the special conditions prevalent in China since the early 1970s. The details are summarized. The objective of this chapter is to describe the fundamental concept and major pilot test results and present an economic evaluation of a new process combining flue gas desulfurization (FGD) and ammonium phosphate fertilizer production.

  2. Effect of Dietary Supplementation with Processed Sulfur on Meat Quality and Oxidative Stability in Longissimus dorsi of Pigs

    PubMed Central

    Noh, Ha-Young; Kim, Gyeom-Heon; Kim, Soo-Ki

    2015-01-01

    The effects of dietary supplementation of processed sulfur in pigs according to the level provided during the fattening phase were examined. The pigs were divided into three groups: control (CON), non-sulfur fed pigs; T1, 0.1% processed sulfur fed pigs; T2, 0.3% processed sulfur fed pigs. Physicochemical and sensory properties, as well as meat quality and oxidative stability of the Longissimus dorsi muscle were investigated. The feeding of processed sulfur did not affect moisture and protein contents (p>0.05). However, the crude fat content of T2 was significantly decreased compared to CON (p<0.05), while the pH value of T2 was significantly higher than those of both CON and T1 (p<0.05). Cooking loss and expressible drip of T2 were also significantly lower than that of CON (p<0.05). The redness of meat from T1 was significantly higher than both CON and T2 (p<0.01). During storage, lipid oxidation of the meat from sulfur fed pigs (T1 and T2) was inhibited compared to CON. Examination of omega-3 polyunsaturated fatty acids revealed T2 to have significantly higher content than CON (p<0.05). In the sensory test, the juiciness and overall acceptability of T2 recorded higher scores than CON. This study demonstrated that meat from 0.3% processed sulfur fed pigs had improved nutrition and quality, with extended shelf-life.

  3. Processing of the Presequence of the Schizosaccharomyces pombe Rieske Iron-Sulfur Protein Occurs in a Single Step and Can Be

    E-print Network

    Trumpower, Bernard L.

    Processing of the Presequence of the Schizosaccharomyces pombe Rieske Iron-Sulfur Protein Occurs¨r Biochemie I, D-60590 Frankfurt, Germany The iron-sulfur proteins of the cytochrome bc1 com- plexes sequence the S. pombe iron-sulfur protein is processed only once during import into mitochondria, whereas

  4. Sulfuric acid on Europa and the radiolytic sulfur cycle

    NASA Technical Reports Server (NTRS)

    Carlson, R. W.; Johnson, R. E.; Anderson, M. S.

    1999-01-01

    A comparison of laboratory spectra with Galileo data indicates that hydrated sulfuric acid is present and is a major component of Europa's surface. In addition, this moon's visually dark surface material, which spatially correlates with the sulfuric acid concentration, is identified as radiolytically altered sulfur polymers. Radiolysis of the surface by magnetospheric plasma bombardment continuously cycles sulfur between three forms: sulfuric acid, sulfur dioxide, and sulfur polymers, with sulfuric acid being about 50 times as abundant as the other forms. Enhanced sulfuric acid concentrations are found in Europa's geologically young terrains, suggesting that low-temperature, liquid sulfuric acid may influence geological processes.

  5. Process for the hydroformylation of sulfur-containing thermally cracked petroleum residue and novel products thereof

    SciTech Connect

    Oswald, A.A.; Bhatia, R.N.; Mozeleski, E.J.; Glivicky, A.P.; Brueggeman, B.G.; Hooten, J.R.; Smith, C.M.; Hsu, C.S.

    1991-07-09

    This patent describes a hydroformylation-hydrogenation process comprising reacting an olefinic cracked petroleum distillate feed, produced from petroleum residue by high temperature thermal cracking, and containing C{sub 5} to C{sub 35}-1-n-alkyl olefins as the major type of olefin components, and organic sulfur compounds in concentrations exceeding 0.1% sulfur. It comprises at first with carbon monoxide and hydrogen at temperatures between about 50 and 250{degrees} C and pressures in the range of 50 to 6000 psi; in the presence of a Group VIII transition metal carbonyl complex catalyst in effective amounts to produce aldehydes of a semilinear character having an average of less than one alkyl branch per molecule and 20% by weight or more linear isomers, then with molecular hydrogen at temperatures between 100 and 250{degrees} C and pressures between 200 psi and 5000 psi (13.6 and 340 atm) in the presence of a hydrogenation catalyst in effective amounts the catalyst being sulfur resistant cobalt, molybdenum, nickel, or tungsten or a sulfide thereof to produce the corresponding alcohols of a semilinear character having an average of less than one alkyl branch per molecule and 20% by weight or more linear isomers, then with molecular hydrogen at temperatures between 100 and 250{degrees} C and pressures between 200 psi and 5000 psi (13.6 and 340 atm) in the presence of a hydrogenation catalyst in effective amounts the catalyst being sulfur resistant cobalt, molybdenum, nickel, or tungsten or a sulfide thereof to produce the corresponding alcohols of a semilinear character having an average of less than one alkyl branch per molecule.

  6. Two-step Processing Is Not Essential for the Import and Assembly of Functionally Active Iron-Sulfur Protein into the Cytochrome bc1

    E-print Network

    Trumpower, Bernard L.

    Two-step Processing Is Not Essential for the Import and Assembly of Functionally Active Iron-Sulfur From the Department of Biochemistry, Dartmouth Medical School, Hanover, New Hampshire 03755 The iron-sulfur for import and assembly of the iron-sulfur protein into the cytochrome bc1 complex, we mutagenized the prese

  7. THE EFFECT OF SULFUR ON METHANE PARTIAL OXIDATION AND REFORMING PROCESSES FOR LEAN NOX TRAP CATALYSIS

    SciTech Connect

    Parks, II, James E; Ponnusamy, Senthil

    2006-01-01

    Lean NOx trap catalysis has demonstrated the ability to reduce NOx emissions from lean natural gas reciprocating engines by >90%. The technology operates in a cyclic fashion where NOx is trapped on the catalyst during lean operation and released and reduced to N2 under rich exhaust conditions; the rich cleansing operation of the cycle is referred to as "regeneration" since the catalyst is reactivated for more NOx trapping after NOx purge. Creating the rich exhaust conditions for regeneration can be accomplished by catalytic partial oxidation of methane in the exhaust system. Furthermore, catalytic reforming of partial oxidation exhaust can enable increased quantities of H2 which is an excellent reductant for lean NOx trap regeneration. It is critical to maintain clean and efficient partial oxidation and reforming processes to keep the lean NOx trap functioning properly and to reduce extra fuel consumption from the regeneration process. Although most exhaust constituents do not impede partial oxidation and reforming, some exhaust constituents may negatively affect the catalysts and result in loss of catalytic efficiency. Of particular concern are common catalyst poisons sulfur, zinc, and phosphorous. These poisons form in the exhaust through combustion of fuel and oil, and although they are present at low concentrations, they can accumulate to significant levels over the life of an engine system. In the work presented here, the effects of sulfur on the partial oxidation and reforming catalytic processes were studied to determine any durability limitations on the production of reductants for lean NOx trap catalyst regeneration.

  8. The Role of Mitochondria in Cellular Iron–Sulfur Protein Biogenesis: Mechanisms, Connected Processes, and Diseases

    PubMed Central

    Stehling, Oliver; Lill, Roland

    2013-01-01

    Iron–sulfur (Fe/S) clusters belong to the most ancient protein cofactors in life, and fulfill functions in electron transport, enzyme catalysis, homeostatic regulation, and sulfur activation. The synthesis of Fe/S clusters and their insertion into apoproteins requires almost 30 proteins in the mitochondria and cytosol of eukaryotic cells. This review summarizes our current biochemical knowledge of mitochondrial Fe/S protein maturation. Because this pathway is essential for various extramitochondrial processes, we then explain how mitochondria contribute to the mechanism of cytosolic and nuclear Fe/S protein biogenesis, and to other connected processes including nuclear DNA replication and repair, telomere maintenance, and transcription. We next describe how the efficiency of mitochondria to assemble Fe/S proteins is used to regulate cellular iron homeostasis. Finally, we briefly summarize a number of mitochondrial “Fe/S diseases” in which various biogenesis components are functionally impaired owing to genetic mutations. The thorough understanding of the diverse biochemical disease phenotypes helps with testing the current working model for the molecular mechanism of Fe/S protein biogenesis and its connected processes. PMID:23906713

  9. H[sub 2]S-removal and sulfur-recovery processes using metal salts

    SciTech Connect

    Lynn, S.; Cairns, E.J.

    1992-01-01

    Scrubbing a sour gas stream with a solution of copper sulfate allows the clean-up temperature to be increased from ambient to the adiabatic saturation temperature of the gas. The copper ion in solution reacts with the H[sub 2]S to produce insoluble CuS. The choice of copper sulfate was set by the very low solubility of CuS and the very rapid kinetics of the Cus formation. Since the copper sulfate solutions used are acidic, CO[sub 2] will not be co-absorbed. In a subsequent step the solid CuS is oxidized by a solution of ferric sulfate. The copper sulfate is regenerated, and elemental sulfur is formed together with ferrous sulfate. The ferrous sulfate is reoxidized to ferric sulfate using air. Since the copper sulfate and ferric solutions are regenerated, the overall reaction in this process is the oxidation of hydrogen sulfide with oxygen to form sulfur. The use of copper sulfate has the further advantage that the presence of sulfuric acid, even as concentrated as 1 molar, does not inhibit the sorption of H[sub 2]S. Furthermore, the absorption reaction remains quite favorable thermodynamically over the temperature range of interest. Because the reaction goes to completion, only a single theoretical stage is required for complete H[sub 2]S removal and cocurrent gas/liquid contacting may be employed. The formation of solids precludes the use of a packed column for the contacting device. However, a venturi scrubber would be expected to perform satisfactorily. The kinetics of the oxidation of metal sulfides, in particular zinc and copper sulfide, is reported in the literature to be slow at near-ambient temperatures. The proposed process conditions for the oxidation step are different from those reported in the literature, most notably the higher temperature. The kinetics of the reaction must be studied at high temperatures and corresponding pressures. An important goal is to obtain sulfur of high purity, which is a salable product.

  10. H{sub 2}S-removal and sulfur-recovery processes using metal salts

    SciTech Connect

    Lynn, S.; Cairns, E.J.

    1992-11-01

    Scrubbing a sour gas stream with a solution of copper sulfate allows the clean-up temperature to be increased from ambient to the adiabatic saturation temperature of the gas. The copper ion in solution reacts with the H{sub 2}S to produce insoluble CuS. The choice of copper sulfate was set by the very low solubility of CuS and the very rapid kinetics of the Cus formation. Since the copper sulfate solutions used are acidic, CO{sub 2} will not be co-absorbed. In a subsequent step the solid CuS is oxidized by a solution of ferric sulfate. The copper sulfate is regenerated, and elemental sulfur is formed together with ferrous sulfate. The ferrous sulfate is reoxidized to ferric sulfate using air. Since the copper sulfate and ferric solutions are regenerated, the overall reaction in this process is the oxidation of hydrogen sulfide with oxygen to form sulfur. The use of copper sulfate has the further advantage that the presence of sulfuric acid, even as concentrated as 1 molar, does not inhibit the sorption of H{sub 2}S. Furthermore, the absorption reaction remains quite favorable thermodynamically over the temperature range of interest. Because the reaction goes to completion, only a single theoretical stage is required for complete H{sub 2}S removal and cocurrent gas/liquid contacting may be employed. The formation of solids precludes the use of a packed column for the contacting device. However, a venturi scrubber would be expected to perform satisfactorily. The kinetics of the oxidation of metal sulfides, in particular zinc and copper sulfide, is reported in the literature to be slow at near-ambient temperatures. The proposed process conditions for the oxidation step are different from those reported in the literature, most notably the higher temperature. The kinetics of the reaction must be studied at high temperatures and corresponding pressures. An important goal is to obtain sulfur of high purity, which is a salable product.

  11. Pretreatment of rice straw with combined process using dilute sulfuric acid and aqueous ammonia

    PubMed Central

    2013-01-01

    Background Use of lignocellulosic biomass has received attention lately because it can be converted into various versatile chemical compounds by biological processes. In this study, a two-step pretreatment with dilute sulfuric acid and aqueous ammonia was performed efficiently on rice straw to obtain fermentable sugar. The soaking in aqueous ammonia process was also optimized by a statistical method. Results Response surface methodology was employed. The determination coefficient (R2) value was found to be 0.9607 and the coefficient of variance was 6.77. The optimal pretreatment conditions were a temperature of 42.75°C, an aqueous ammonia concentration of 20.93%, and a reaction time of 48 h. The optimal enzyme concentration for saccharification was 30 filter paper units. The crystallinity index was approximately 60.23% and the Fourier transform infrared results showed the distinct peaks of glucan. Ethanol production using Saccharomyces cerevisiae K35 was performed to verify whether the glucose saccharified from rice straw was fermentable. Conclusions The combined pretreatment using dilute sulfuric acid and aqueous ammonia on rice straw efficiently yielded fermentable sugar and achieved almost the same crystallinity index as that of ?-cellulose. PMID:23898802

  12. Regenerative process and system for the simultaneous removal of particulates and the oxides of sulfur and nitrogen from a gas stream

    DOEpatents

    Cohen, Mitchell R. (Troy, NY); Gal, Eli (Lititz, PA)

    1993-01-01

    A process and system for simultaneously removing from a gaseous mixture, sulfur oxides by means of a solid sulfur oxide acceptor on a porous carrier, nitrogen oxides by means of ammonia gas and particulate matter by means of filtration and for the regeneration of loaded solid sulfur oxide acceptor. Finely-divided solid sulfur oxide acceptor is entrained in a gaseous mixture to deplete sulfur oxides from the gaseous mixture, the finely-divided solid sulfur oxide acceptor being dispersed on a porous carrier material having a particle size up to about 200 microns. In the process, the gaseous mixture is optionally pre-filtered to remove particulate matter and thereafter finely-divided solid sulfur oxide acceptor is injected into the gaseous The government of the United States of America has rights in this invention pursuant to Contract No. DE-AC21-88MC 23174 awarded by the U.S. Department of Energy.

  13. Regenerative process and system for the simultaneous removal of particulates and the oxides of sulfur and nitrogen from a gas stream

    DOEpatents

    Cohen, M.R.; Gal, E.

    1993-04-13

    A process and system are described for simultaneously removing from a gaseous mixture, sulfur oxides by means of a solid sulfur oxide acceptor on a porous carrier, nitrogen oxides by means of ammonia gas and particulate matter by means of filtration and for the regeneration of loaded solid sulfur oxide acceptor. Finely-divided solid sulfur oxide acceptor is entrained in a gaseous mixture to deplete sulfur oxides from the gaseous mixture, the finely-divided solid sulfur oxide acceptor being dispersed on a porous carrier material having a particle size up to about 200 microns. In the process, the gaseous mixture is optionally pre-filtered to remove particulate matter and thereafter finely-divided solid sulfur oxide acceptor is injected into the gaseous mixture.

  14. Production, preservation, and biological processing of mass-independent sulfur isotope fractionation in the Archean surface environment

    PubMed Central

    Halevy, Itay

    2013-01-01

    Mass-independent fractionation of sulfur isotopes (S MIF) in Archean and Paleoproterozoic rocks provides strong evidence for an anoxic atmosphere before ?2,400 Ma. However, the origin of this isotopic anomaly remains unclear, as does the identity of the molecules that carried it from the atmosphere to Earth’s surface. Irrespective of the origin of S MIF, processes in the biogeochemical sulfur cycle modify the primary signal and strongly influence the S MIF preserved and observed in the geological record. Here, a detailed model of the marine sulfur cycle is used to propagate and distribute atmospherically derived S MIF from its delivery to the ocean to its preservation in the sediment. Bulk pyrite in most sediments carries weak S MIF because of microbial reduction of most sulfur compounds to form isotopically homogeneous sulfide. Locally, differential incorporation of sulfur compounds into pyrite leads to preservation of S MIF, which is predicted to be most highly variable in nonmarine and shallow-water settings. The Archean ocean is efficient in diluting primary atmospheric S MIF in the marine pools of sulfate and elemental sulfur with inputs from SO2 and H2S, respectively. Preservation of S MIF with the observed range of magnitudes requires the S MIF production mechanism to be moderately fractionating (20–40‰). Constraints from the marine sulfur cycle allow that either elemental sulfur or organosulfur compounds (or both) carried S MIF to the surface, with opposite sign to S MIF in SO2 and H2SO4. Optimal progress requires observations from nonmarine and shallow-water environments and experimental constraints on the reaction of photoexcited SO2 with atmospheric hydrocarbons. PMID:23572589

  15. Sulfuric acid-sulfur heat storage cycle

    DOEpatents

    Norman, John H. (LaJolla, CA)

    1983-12-20

    A method of storing heat is provided utilizing a chemical cycle which interconverts sulfuric acid and sulfur. The method can be used to levelize the energy obtained from intermittent heat sources, such as solar collectors. Dilute sulfuric acid is concentrated by evaporation of water, and the concentrated sulfuric acid is boiled and decomposed using intense heat from the heat source, forming sulfur dioxide and oxygen. The sulfur dioxide is reacted with water in a disproportionation reaction yielding dilute sulfuric acid, which is recycled, and elemental sulfur. The sulfur has substantial potential chemical energy and represents the storage of a significant portion of the energy obtained from the heat source. The sulfur is burned whenever required to release the stored energy. A particularly advantageous use of the heat storage method is in conjunction with a solar-powered facility which uses the Bunsen reaction in a water-splitting process. The energy storage method is used to levelize the availability of solar energy while some of the sulfur dioxide produced in the heat storage reactions is converted to sulfuric acid in the Bunsen reaction.

  16. Development of enhanced sulfur rejection processes. First Quarterly technical progress report, October 1, 1992--December 31, 1992

    SciTech Connect

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

    1993-03-23

    Research at Virginia Tech led to two complementary concepts for improving the removal of inorganic sulfur from much of the Eastern US coals. One controls the surface properties of coal pyrite (FeS{sub 2}) by electrochemical-.potential control, referred to as the Electrochemically Enhanced Sulfur Rejection (EESR) Process: The second controls the flotation of middlings, i.e., particles composed of pyrite with coal inclusions by using polymeric reagents to react with pyrite and convert the middlings to hydrophilic particles, and is termed the Polymer Enhanced Sulfur Rejection (PESR) Process. These new concepts are based on recent research establishing the two main reasons why flotation fails to remove more than about 50% of the pyritic sulfur from coal: superficial oxidization of liberated pyrite to form polysulfide oxidation products so that a part of the liberated pyrite floats with the coal; and hydrophobic coal inclusions in the middlings dominating their flotation so that the middlings also float with the coal. These new pyritic-sulfur rejection processes do not require significant modifications of existing coal preparation facilities, enhancing their adoptability by the coal industry. It is believed that they can be used simultaneously to achieve both free pyrite and locked pyrite rejection.

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

    NASA Astrophysics Data System (ADS)

    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.

  18. Sulfur Mustard

    MedlinePLUS

    ... Matters What's New A - Z Index Facts About Sulfur Mustard What sulfur mustard is Sulfur mustard is a type of ... it is in liquid or solid form. Where sulfur mustard is found and how it is used ...

  19. Process for producing low-sulfur boiler fuel by hydrotreatment of solvent deashed SRC

    DOEpatents

    Roberts, George W. (Emmaus, PA); Tao, John C. (Perkiomenville, PA)

    1985-01-01

    In this invention, a process is disclosed characterized by heating a slurry of coal in the presence of a process-derived recycle solvent and passing same to a dissolver zone, separating the resultant gases and liquid/solid products therefrom, vacuum distilling the liquid/solids products, separating the portions of the liquid/solids vacuum distillation effluent into a solid ash, unconverted coal particles and SRC material having a boiling point above 850.degree. F. and subjecting same to a critical solvent deashing step to provide an ash-free SRC product. The lighter liquid products from the vacuum distillation possess a boiling point below 850.degree. F. and are passed through a distillation tower, from which recycled solvent is recovered in addition to light distillate boiling below 400.degree. F. (overhead). The ash-free SRC product in accompanyment with at least a portion of the process derived solvent is passed in combination to a hydrotreating zone containing a hydrogenation catalyst and in the presence of hydrogen is hydroprocessed to produce a desulfurized and denitrogenized low-sulfur, low-ash boiler fuel and a process derived recycle solvent which is recycled to slurry the coal in the beginning of the process before heating.

  20. Sulfur barrier for use with in situ processes for treating formations

    DOEpatents

    Vinegar, Harold J. (Bellaire, TX); Christensen, Del Scot (Friendswood, TX)

    2009-12-15

    Methods for forming a barrier around at least a portion of a treatment area in a subsurface formation are described herein. Sulfur may be introduced into one or more wellbores located inside a perimeter of a treatment area in the formation having a permeability of at least 0.1 darcy. At least some of the sulfur is allowed to move towards portions of the formation cooler than the melting point of sulfur to solidify the sulfur in the formation to form the barrier.

  1. Sulfur behavior in the Sasol-Lurgi fixed-bed dry-bottom gasification process

    SciTech Connect

    M. Pat Skhonde; R. Henry Matjie; J. Reginald Bunt; A. Christien Strydom; H. Schobert

    2009-01-15

    This article reports on the findings of a study regarding the sulfur behavior across a Sasol-Lurgi gasifier. This was undertaken to understand the behavior of the various sulfur-bearing components in the coal, as they are exposed to the conditions in the gasifier. In this study, conventional characterization techniques were employed to monitor the behavior of sulfur-bearing mineral matter across the gasifier. It was observed from the study that the sulfur-bearing mineral (pyrite) in the coal structure undergoes various changes with pyrite being transformed to pyrrhotite and then to various oxides of iron with the subsequent loss of sulfur to form H{sub 2}S. A low proportion of the sulfur species including the organically associated sulfur was encapsulated by a melt that was formed by the interaction between kaolinite and fluxing minerals (pyrite, calcite, and dolomite/ankerite) present in the coal at elevated temperatures and pressure, thereby ending up in the ash. The remaining small proportions of sulfur-bearing mineral matter including pyrite and organically bound sulfur in the unburned carbon in the carbonaceous shales also report to the ash. 18 refs., 8 figs., 2 tabs.

  2. Conjugated processes of the chemical transformation of sulfur dioxide under the effect of chain gas-phase reactions

    NASA Astrophysics Data System (ADS)

    Mantashyan, A. A.

    2015-01-01

    The effect sulfur dioxide has on the dynamics of the spontaneous ignition of hydrogen-oxygen mixtures is studied. Additives of SO2 have no negative effect on spontaneous ignition and undergo chemical conversion to form elemental sulfur. The results are analyzed using the theory of branched chain reactions along with data on SO2 conversion under the action of chain reactions of hydrocarbon oxidation and slow hydrogen oxidation. The transformations classified as parallel reactions from the viewpoint of formal kinetics could actually be conjugated radical-chain processes.

  3. Development of enhanced sulfur rejection processes. Second quarterly technical progress report, January 1, 1993--March 31, 1993

    SciTech Connect

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

    1993-06-14

    Research at Virginia Tech led to the development of two complementary concepts for improving the removal of inorganic sulfur from many eastern US coals. These concepts are referred to as Electrochemically Enhanced Sulfur Rejection (EESR) and Polymer Enhanced Sulfur Rejection (PESR). 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 technical research was initiated on October 1, 1992, and a detailed work plan and work schedule were developed. During this reporting period, research was conducted to evaluate the liberation characteristics of various pyrite samples, to determine the electrochemical reactions that influence the hydrophobicity of pyrite, and to examine the potential use of electrochemical methods for controlling the flotation and depression of pyrite.

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

    PubMed

    Liu, Huan; Luo, Guang-Qian; Hu, Hong-Yun; Zhang, Qiang; Yang, Jia-Kuan; Yao, Hong

    2012-10-15

    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(3)), sulfur dioxide (SO(2)), hydrogen sulfide (H(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(2) and H(2)S emissions in the H(2)SO(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 release of NH(3). PMID:22902143

  5. Early diagenetic processes of saline meromictic Lake Kai-ike, southwest Japan: III. Sulfur speciation and isotopes

    NASA Astrophysics Data System (ADS)

    Sakai, N.; Yamaguchi, K. E.; Oguri, K.

    2014-12-01

    Lake Kai-ike is a saline meromictic lake located along the coast of Kami-Koshiki Island. The lake is isolated from ocean by a gravel bar, through which seawater infiltrates by tidal pumping. The lake is permanently redox (density)-stratified with a mid-depth development of photic zone anoxia and a dense community of photosynthetic bacteria pinkish "bacterial plate". The early diagenesis of sulfur in sediments overlain by an anoxic water body was investigated using a sediment core (KAI4) from the lake. We determined abundance of various S-bearing species (i.e., Cr-reducible sulfide (= pyrite S: Spy), acid-volatile sulfide (AVS), sulfate sulfur (SSO4), elemental sulfur (S0), and organic sulfur) by an improved sequential extraction method. Here we focus on drastic and rapid changes on sulfur biogeochemistry found in the uppermost 5cm layer. With increasing depth, abundance of Spy increased but that of SSO4 and ?34S value of Spy (?34Spy) decreased. These results suggest progressive formation of bacteriogenic pyrite. The ?34S values of SSO4 (?34SSO4) ranged from 25.1 ‰ (at sediment surface) to 3.8 ‰ in the uppermost 5 cm layer. This ?34SSO4 decrease in the top 5 cm sediment suggests that SSO4 in the surface sediment inherits SO42- with elevated ?34S values (higher than typical seawater ?34S value of 21‰) in the water column, which is due to extensive bacterial sulfate reduction with preferential removal of low-?34S sulfur as sulfide. In the lower part of the uppermost 5 cm layer, SO42- formed by oxidation of S0, AVS, and/or Spy with low-?34S values by SO42--bearing seawater introduced by infiltration through the gravel bar. Increasing ?34Spy values with increasing depth suggest near complete consumption of SO42- by active bacterial sulfate reduction, and this process could be explained by Rayleigh distillation model. Early diagenesis of sulfur does occur in whole section of 25cm-long KAI4 core that accumulated for the last ~60 years (Yamaguchi et al., 2010; Palaeo3). Geochemical characteristics of sulfur in the uppermost part of Lake Kai-ike sediment were significantly modified during early diagenesis. Such diagenetic modification for sulfur isotopes should be fully taken into account to better reconstruct past anoxic environment such as Cretaceous OAEs and Archean oceans.

  6. Contributions of organic matter and organic sulfur redox processes to electron flow in anoxic incubations of peat

    NASA Astrophysics Data System (ADS)

    YU, Zhiguo; Peiffer, Stefan; Göttlicher, Jörg; Knorr, Klaus-Holger

    2015-04-01

    Anaerobic decomposition of peat soils involves a number of interdependent microbial processes that ultimately generate CO2 and CH4. In many peat soils, a high ratio of CO2:CH4 was reported, which presumably results from a direct or indirect role of soil organic matter serving as an electron acceptor. Therefore, in this study we intended to test the hypothesis that organic matter (OM) suppresses methanogenesis and sustains anaerobic CO2 production, serving as i) direct electron acceptor or ii) via supporting internal sulfur cycling to maintains CO2 production through bacterial sulfate reduction (BSR). We incubated peat samples of commercial bog peat, inoculated with a small amount of fresh peat to introduce an active microbial community. Samples were amended with sulfate or sulfide and incubated under anoxic conditions for 6 weeks at 30 ° C. Upon anaerobic incubation of peat virtually devoid of inorganic electron acceptors, CO2 and CH4 were produced at a ratio of 3.2. According to the electron budget, the calculated electron accepting capacity (EAC) of OM was 2.36 ?eq cm3 d-1. Addition of sulfate significantly increased CO2 production and effectively suppressed CH4 production. After subtracting the EAC provided though sulfate addition (0.97~2.81 ?eq cm-3 d-1), EACs supplied by OM reached 3.88 to 4.85 ?eq cm-3 d-1.The contribution of organic sulfur was further evaluated by XANES spectroscopy and using natural abundance of ?34S as a tracer. Results demonstrated that BSR involved both addition of H2S and sulfate to OM leading to a formation of reduced organic sulfur and partial changes of oxidized organic sulfur species. The original peat prior to incubation contained 70.5% reduced organic S (R-S-H, R-S-R, R-S-S-R), and 25.9% oxidized S (R-SO3, R-SO2-R, R-SO4-R), whereas the treatment with H2S or sulfate addition comprised 75.7~ 81.1% reduced organic S, and only 21.1~18.9 % oxidized S. Our results imply that that organic matter contributes to anaerobic respiration i) directly by electron accepting capacity of redox active functional groups ii) directly by oxidized organic sulfur and iii) indirectly by recycling of sulfide to maintain BSR. Moreover, investigating the stability of organic sulfur compounds in peat soil towards abiotic and biotic reduction and oxidation is essential for the understanding of environmental sulfur cycling in anaerobic systems. Keywords: Methanogenesis; Electron transfer; organic sulfur; Redox processes; Freshwater systems;

  7. USING THE SULFUR POLYMER STABILIZATION SOLIDIFICATION PROCESS TO TREAT RESIDUAL MERCURY WASTES FROM GOLD MINING OPERATIONS.

    SciTech Connect

    BOWERMAN,B.ADAMS,J.KALB,P.WAN,R.Y.LEVIER,M.

    2003-02-24

    Large quantities of mercury are generated as a by-product during the processing of gold ore following mining operations. Newmont Mining Corporation (NMC), which operates some of the world's largest gold mines, sought a method to permanently ''retire'' its mercury by-products, thereby avoiding potential environmental liability. Sulfur Polymer Stabilization-Solidification (SPSS) is an innovative technology developed at Brookhaven National Laboratory (BNL) for treatment of mercury and mercury contaminated materials, such as soil, sludge and debris. BNL conducted a treatability study to determine the potential applicability of SPSS for treatment of Newmont mercury, and the treated product passed the U.S. Environmental Protection Agency (EPA) test for toxicity. The SPSS process has been shown to be effective on radioactive and nonradioactive mercury and mercury-contaminated materials with a pilot-scale batch system capable of producing 0.03 m{sup 3} (1 ft{sup 3}) per batch. Engineering scale-up issues are discussed and material property tests addressing these issues are described.

  8. [Microbiological processes of the carbon and sulfur cycle in cold methane seeps in the North Atlantic].

    PubMed

    Pimenov, N V; Savvichev, A S; Rusanov, I I; Lein, A Iu; Ivanov, M V

    2000-01-01

    Functioning of microbial communities in surface sediments of the Haakon Mosby underwater mud volcano (lat. 72 degrees N) and in gas seepage fields of the Vestnesa Ridge was investigated using Mir-1 and Mir-2 deep-sea submersibles during the 40th expedition of the research vessel Academician Mstislav Keldysh. Large areas of sedimentary deposits of the Haakon Mosby mud volcano (HMMV) and pockmarks of the Vestnesa Ridge (VR) are covered with bacterial mats 0.1 to 0.5 cm thick. The microbial community making up bacterial mats of the HMMV was predominated by large filamentous bacteria with filaments measuring up to 100 microns in length and 2 to 8 microns in width. The occurrence of rosettes allowed the observed filamentous bacteria to be referred to the morphologically similar genera Leucothrix or Thiothrix. Three morphological types of filamentous bacteria were identified in bacterial mats covering VR pockmarks. Filaments of type one are morphologically similar with representatives of the genera Thioploca or Desmanthos. Type two filaments had numerous inclusions of sulfur and resembled representatives of the genus Thiothrix. The third morphological type was constituted by single filaments made up of tightly connected disk-like cells and can, apparently, be assigned to the genus Beggiatoa. The rates of methane oxidation (up to 1570 microliters C/(dm3 day)) and sulfate reduction (up to 17 mg S/(dm3 day)) measured in surface sediments of HMMV and VR were close to the maximum rates of these processes observed in badly polluted regions of the northwestern shelf of the Black Sea. High rates of microbiological processes correlated with the high number of bacteria. The rate of methane production in sediments studied was notably lower and ranged from 0.1 to 3.5 microliters CH4/(dm3 day). Large areas of the HMMV caldera were populated by pogonophoras, represented by the two species, Sclerolinum sp. and Oligobrachia sp. The mass development of Sclerolinum sp. in the HMMV caldera was by the activity of aerobic methane-oxidizing bacteria localized inside the cells of these animals. Bacterial cells were also found in the trophosome tissue of Oligobrachia sp., but in cells of these bacteria, we did not observe the membrane structures typical of methanotrophs. The localization pattern of pogonophoras on the surface of reduced sediments suggests that the predominant bacteria in Oligobrachia tissues are sulfur-oxidizing endosymbionts. PMID:11195584

  9. ADVANCED SULFUR CONTROL CONCEPTS

    SciTech Connect

    Apostolos A. Nikolopoulos; Santosh K. Gangwal; William J. McMichael; Jeffrey W. Portzer

    2003-01-01

    Conventional sulfur removal in integrated gasification combined cycle (IGCC) power plants involves numerous steps: COS (carbonyl sulfide) hydrolysis, amine scrubbing/regeneration, Claus process, and tail-gas treatment. Advanced sulfur removal in IGCC systems involves typically the use of zinc oxide-based sorbents. The sulfides sorbent is regenerated using dilute air to produce a dilute SO{sub 2} (sulfur dioxide) tail gas. Under previous contracts the highly effective first generation Direct Sulfur Recovery Process (DSRP) for catalytic reduction of this SO{sub 2} tail gas to elemental sulfur was developed. This process is currently undergoing field-testing. In this project, advanced concepts were evaluated to reduce the number of unit operations in sulfur removal and recovery. Substantial effort was directed towards developing sorbents that could be directly regenerated to elemental sulfur in an Advanced Hot Gas Process (AHGP). Development of this process has been described in detail in Appendices A-F. RTI began the development of the Single-step Sulfur Recovery Process (SSRP) to eliminate the use of sorbents and multiple reactors in sulfur removal and recovery. This process showed promising preliminary results and thus further process development of AHGP was abandoned in favor of SSRP. The SSRP is a direct Claus process that consists of injecting SO{sub 2} directly into the quenched coal gas from a coal gasifier, and reacting the H{sub 2}S-SO{sub 2} mixture over a selective catalyst to both remove and recover sulfur in a single step. The process is conducted at gasifier pressure and 125 to 160 C. The proposed commercial embodiment of the SSRP involves a liquid phase of molten sulfur with dispersed catalyst in a slurry bubble-column reactor (SBCR).

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

    USGS Publications Warehouse

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

    1998-01-01

    The mineralogy, contents, and isotopic compositions of sulfur in oceanic serpentinites reflect variations in temperatures and fluid fluxes. Serpentinization of <1 Ma peridotites at Hess Deep occurred at high temperatures (200??-400??C) and low water/rock ratios. Oxidation of ferrous iron to magnetite maintained low fO2and produced a reduced, low-sulfur assemblage including NiFe alloy. Small amounts of sulfate reduction by thermophilic microbes occurred as the system cooled, producing low-??34S sulfide (1.5??? to -23.7???). In contrast, 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.

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

    PubMed Central

    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 (p<0.05). The pH of the S group was significantly higher than that of the control group, whereas the S group had a lower expressible drip compared to the control group. The S group also showed the lower lightness compared to the control group (p<0.05). In regard to the mineral status, the S group had significantly lower Fe2+ and Ca2+ content than the control group (p<0.05), whereas the proteolysis index of the S group was significantly increased compared to the control group (p<0.05). The feeding of processed sulfur to pigs led to increased oxidative stability, related to lipids and pigments, in the dry-cured ham (p<0.05). Compared to the dry-cured ham 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.

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

    SciTech Connect

    Attia, Y.A.; Zeky, M.El.; Lei, W.W.; Bavarian, F.; Yu, S.

    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.

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

    PubMed

    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. PMID:24342048

  14. Decoupling of sulfur and nitrogen cycling due to biotic processes in a tropical rainforest

    NASA Astrophysics Data System (ADS)

    Yi-Balan, Simona A.; Amundson, Ronald; Buss, Heather L.

    2014-10-01

    We examined the terrestrial sulfur (S) cycle in the wet tropical Luquillo Experimental Forest (LEF), Puerto Rico. In two previously instrumented watersheds (Icacos and Bisley), chemical and isotopic measurements of carbon (C), nitrogen (N) and S were used to explore the inputs, in-soil processing, and losses of S through comparison to the N cycle. Additionally, the impact of soil forming factors (particularly climate, organisms, topography and parent material) on S cycling in this system was considered. Atmospheric inputs (?34S values of 16.1 ± 2.8‰), from a mixture of marine and anthropogenic sources, delivered an estimated 2.2 g S/(m2yr) at Icacos, and 1.8 g S/(m2yr) at Bisley. Bedrock N and S inputs to soil were minimal. We estimated a hydrologic export of 1.7 ± 0.1 g S/(m2yr) at Icacos, and 2.5 ± 0.2 g S/(m2yr) at Bisley. Stream baseflow S isotope data revealed significant bedrock S in the hydrologic export at Bisley (with a distinctive ?34S values of 1.6 ± 0.7‰), but not at Icacos. Pore water data supported the co-occurrence of at least three major biological S-fractionating processes in these soils: plant uptake, oxidative degradation of organic S and bacterial sulfate reduction. The rates and relative importance of these processes varied in time and space. Vegetation litter was 3-5‰ depleted in 34S compared to the average pore water, providing evidence for fractionation during uptake and assimilation. Out of all abiotic soil forming factors, climate, especially the high rainfall, was the main driver of S biogeochemistry in the LEF by dictating the types and rates of processes. Topography appeared to impact S cycling by influencing redox conditions: C, N and S content decrease downslope at all sites, and the Bisley lower slope showed strongest evidence of bacterial sulfate reduction. Parent material type did not impact the soil S cycle significantly. To compare the fate of S and N in the soil, we used an advection model to describe the isotopic fractionation of total S and N associated with downward movement of organic matter in both dissolved and solid fractions. This model worked well for N, but the assumption of a constant fractionation factor ? with depth failed to describe S transformations. This result revealed a fundamental difference between N and S cycling in these soils, indicating an apparent greater sensitivity of S isotopes to fluctuating redox conditions.

  15. Surface acoustic wave sensors/gas chromatography; and Low quality natural gas sulfur removal and recovery CNG Claus sulfur recovery process

    SciTech Connect

    Klint, B.W.; Dale, P.R.; Stephenson, C.

    1997-12-01

    This topical report consists of the two titled projects. Surface Acoustic Wave/Gas Chromatography (SAW/GC) provides a cost-effective system for collecting real-time field screening data for characterization of vapor streams contaminated with volatile organic compounds (VOCs). The Model 4100 can be used in a field screening mode to produce chromatograms in 10 seconds. This capability will allow a project manager to make immediate decisions and to avoid the long delays and high costs associated with analysis by off-site analytical laboratories. The Model 4100 is currently under evaluation by the California Environmental Protection Agency Technology Certification Program. Initial certification focuses upon the following organics: cis-dichloroethylene, chloroform, carbon tetrachloride, trichlorethylene, tetrachloroethylene, tetrachloroethane, benzene, ethylbenzene, toluene, and o-xylene. In the second study the CNG Claus process is being evaluated for conversion and recovery of elemental sulfur from hydrogen sulfide, especially found in low quality natural gas. This report describes the design, construction and operation of a pilot scale plant built to demonstrate the technical feasibility of the integrated CNG Claus process.

  16. Solution processable, cross-linked sulfur polymers as solid electrolytes in dye-sensitized solar cells.

    PubMed

    Liu, Peng; Gardner, James M; Kloo, Lars

    2015-09-17

    Inverse-vulcanized polymeric sulfur has been prepared and utilized for solid-state dye sensitized solar cells. A power conversion efficiency of 1.5% was recorded with a short-circuit current of 4.1 mA cm(-2) and an open-circuit voltage of 0.75 V under standard AM 1.5G illumination (1000 W m(-2)). The results in the present study qualify the new polymeric sulfur material as a future candidate as low-cost, hole-transport material for solid-state dye-sensitized solar cells. PMID:26291876

  17. Fly ash sulfur concrete

    SciTech Connect

    Head, W.J.; Liao, M.

    1981-05-01

    Two waste products, flyash and elemental sulfur, can be combined with a modifying agent to produce a potentially useful construction material, flyash sulfur concrete. Manufacturing processes and characteristics of this concrete are described. Compared with a conventional crushed stone aggregate, flyash sulfur concrete is a viable highway pavement base course material. The material's strength characteristics are analyzed. (1 diagram, 4 graphs, 2 photos, 9 references, 5 tables)

  18. Coal liquefaction process streams characterization and evaluation: Investigation of the forms of sulfur in five Wilsonville resid samples by XAFS and moessbauer spectroscopy

    SciTech Connect

    Huffman, G.P.; Huggins, F.E.; Shah, N.

    1992-11-01

    This study demonstrated the feasibility of using XAFS and Moessbauer spectroscopy for the examination of distillation resid materials derived from direct coal liquefaction. The least-squares analysis of the XANES region of the K-shell XAFS spectra was shown to be technique which can be used to determine the sulfur forms in coal liquefaction-derived resid samples. The large amount of pyrrhotite in the resid samples (71 to 99% {plus_minus}10% of the total sulfur) interfered with the precise quantitative analysis of the organic sulfur. However, a spectral subtraction routine was successfully used to provide semi-quantitative results for sulfur species other than the pyrrhotite. Moessbauer spectroscopy, considered a more accurate method than XAFS for the quantitative analysis of inorganic iron-sulfur species (pyrite, pyrrhotite, iron sulfates), was successfully used to speciate these materials in the coal liquefaction resids. Further application of XAFS and Moessbauer spectroscopy as process development tools appears justified by these results.

  19. Coal liquefaction process streams characterization and evaluation: Investigation of the forms of sulfur in five Wilsonville resid samples by XAFS and moessbauer spectroscopy

    SciTech Connect

    Huffman, G.P.; Huggins, F.E.; Shah, N. . Consortium for Fossil Fuel Science)

    1992-11-01

    This study demonstrated the feasibility of using XAFS and Moessbauer spectroscopy for the examination of distillation resid materials derived from direct coal liquefaction. The least-squares analysis of the XANES region of the K-shell XAFS spectra was shown to be technique which can be used to determine the sulfur forms in coal liquefaction-derived resid samples. The large amount of pyrrhotite in the resid samples (71 to 99% [plus minus]10% of the total sulfur) interfered with the precise quantitative analysis of the organic sulfur. However, a spectral subtraction routine was successfully used to provide semi-quantitative results for sulfur species other than the pyrrhotite. Moessbauer spectroscopy, considered a more accurate method than XAFS for the quantitative analysis of inorganic iron-sulfur species (pyrite, pyrrhotite, iron sulfates), was successfully used to speciate these materials in the coal liquefaction resids. Further application of XAFS and Moessbauer spectroscopy as process development tools appears justified by these results.

  20. Development of a solid absorption process for removal of sulfur from fuel gas. First quarterly technical report

    SciTech Connect

    Stegen, G.E.; Olson, K.M.

    1980-05-01

    Battelle Pacific Northwest Laboratories has begun to develop a project for removing sulfur compounds from fuel gases at elevated temperature (> 700/sup 0/C) based on the use of molten mixtures of alkali metal carbonates and calcium carbonate as the active reactants. The sulfur removal capacity of the molten salt mixture may be regenerated by stripping with CO/sub 2/ and steam, usually at a reduced temperature. In this process, the molten salt mixture is contained within the pores of a porous ceramic substrate material which may be used in a packed bed, moving bed, or fluidized bed absorber. The process would be used most advantageously in applications where it is desirable to reduce or eliminate any cooling of the fuel gas between the gasifier outlet and the gas user. Examples of such applications include gas turbines, high temperature fuel cells, boilers, and furnaces which operate in relatively close proximity to a coal gasifier. In these applications, reduction or elimination of the gas cooling requirements will generally improve thermal efficiency by retaining the sensible heat in the gas and may result in simplification of the process by elimination of gas cooling (and in some cases reheating) equipment and by elimination of process condensates and the equipment required for their handling and treatment. The objectives of the program are to obtain process and materials data sufficient to demonstrate feasibility of the process at bench scale and to allow preliminary economic analysis. Process data to be obtained include sorbent sulfur capacity, reaction kinetics, and other operating characteristics. Various candidate materials will be purchased or fabricated and tested for suitability as porous ceramic substrate materials.

  1. The Sulfur-Iodine Cycle: Process Analysis and Design Using Comprehensive Phase Equilibrium Measurements and Modeling

    SciTech Connect

    Thies, Mark C.; O'Connell, J. P.; Gorensek, Maximilian B.

    2010-01-10

    Of the 100+ thermochemical hydrogen cycles that have been proposed, the Sulfur-Iodine (S-I) Cycle is a primary target of international interest for the centralized production of hydrogen from nuclear power. However, the cycle involves complex and highly nonideal phase behavior at extreme conditions that is only beginning to be understood and modeled for process simulation. The consequence is that current designs and efficiency projections have large uncertainties, as they are based on incomplete data that must be extrapolated from property models. This situation prevents reliable assessment of the potential viability of the system and, even more, a basis for efficient process design. The goal of this NERI award (05-006) was to generate phase-equilibrium data, property models, and comprehensive process simulations so that an accurate evaluation of the S-I Cycle could be made. Our focus was on Section III of the Cycle, where the hydrogen is produced by decomposition of hydroiodic acid (HI) in the presence of water and iodine (I2) in a reactive distillation (RD) column. The results of this project were to be transferred to the nuclear hydrogen community in the form of reliable flowsheet models for the S-I process. Many of the project objectives were achieved. At Clemson University, a unique, tantalum-based, phase-equilibrium apparatus incorporating a view cell was designed and constructed for measuring fluid-phase equilibria for mixtures of iodine, HI, and water (known as HIx) at temperatures to 350 °C and pressures to 100 bar. Such measurements were of particular interest for developing a working understanding of the expected operation of the RD column in Section III. The view cell allowed for the IR observation and discernment of vapor-liquid (VL), liquid-liquid, and liquid-liquid-vapor (LLVE) equilibria for HIx systems. For the I2-H2O system, liquid-liquid equilibrium (LLE) was discovered to exist at temperatures up to 310-315 °C, in contrast to the models and predictions of earlier workers. For the I2-HI-H2O ternary, LLE and LLVE were all observed for the first time at temperatures of 160 and 200 °C. Three LLE tie-lines were measured at 160 °C, and preliminary indications are that the underlying phase behavior could result in further improvements in the performance of the S-I Cycle. Unfortunately, these new results were obtained too late in the project to be incorporated into the modeling and simulation work described below. At the University of Virginia, a uniquely complete and reliable model was developed for the thermodynamic properties of HIx, covering the range of conditions expected for the separation of product hydrogen and recycled iodine in the RD column located in Section III. The model was validated with all available property spectroscopy data. The results provide major advances over prior understanding of the chemical speciation involved. The model was implemented in process simulation studies of the S-I Cycle, which showed improvement in energy efficiency to 42%, as well as significantly smaller capital requirements due to lower pressure operation and much smaller equipment sizes. The result is that the S-I Cycle may be much more economically feasible than was previously thought. If both the experimental and modeling work described above were to be continued to ultimate process optimization, both the American public and the global community would benefit from this alternative energy source that does not produce carbon emissions.

  2. The global sulfur cycle

    NASA Technical Reports Server (NTRS)

    Sagan, D. (editor)

    1985-01-01

    The results of the planetary biology microbial ecology's 1984 Summer Research Program, which examined various aspects of the global sulfur cycle are summarized. Ways in which sulfur flows through the many living and chemical species that inhabit the surface of the Earth were investigated. Major topics studied include: (1) sulfur cycling and metabolism of phototropic and filamentous sulfur bacteria; (2) sulfur reduction in sediments of marine and evaporite environments; (3) recent cyanobacterial mats; (4) microanalysis of community metabolism in proximity to the photic zone in potential stromatolites; and (5) formation and activity of microbial biofilms on metal sulfides and other mineral surfaces. Relationships between the global sulfur cycle and the understanding of the early evolution of the Earth and biosphere and current processes that affect global habitability are stressed.

  3. Controlled Nucleation and Growth Process of Li2S2/Li2S in Lithium-Sulfur Batteries

    SciTech Connect

    Zheng, Jianming; Gu, Meng; Wang, Chong M.; Zuo, Pengjian; Koech, Phillip K.; Zhang, Jiguang; Liu, Jun; Xiao, Jie

    2013-09-20

    Lithium-sulfur battery is a promising next-generation energy storage system because of its potentially three to five times higher energy density than that of traditional lithium ion batteries. However, the dissolution and precipitation of soluble polysulfides during cycling initiate a series of key-chain reactions that significantly shorten battery life. Herein, we demonstrate that through a simple but effective strategy, significantly improved cycling performance is achieved for high sulfur loading electrodes through controlling the nucleation and precipitation of polysulfieds on the electrode surface. More than 400 or 760 stable cycling are successfully displayed in the cells with locked discharge capacity of 625 mAh g-1 or 500 mAh g-1, respectively. The nucleation and growth process of dissolved polysulfides has been electrochemically altered to confine the thickness of discharge products passivated on the cathode surface, increasing the utilization rate of sulfur while avoiding severe morphology changes on the electrode. More importantly, the exposure of new lithium metal surface to the S-containing electrolyte is also greatly reduced through this strategy, largely minimizing the anode corrosion caused by polysulfides. This work interlocks the electrode morphologies and its evolution with electrochemical interference to modulate cell performances by using Li-S system as a platform, providing different but critical directions for this community.

  4. Controlled comparison of advanced froth flotation process technology and economic evaluations for maximizing BTU recovery and pyritic sulfur rejection

    SciTech Connect

    Harrison, K.E.; Ferris, D.D. ); Kosky, R.M. ); Warchol, J.J.; Musiol, W.F.; Shiao, S.Y. ); Luttrell, G.H.; Adel, G.T.; Yoon, R.H. )

    1990-01-01

    The overall objective of this round robin project was to select the most efficient, as determined by the efficiency index, cost effective, as determined by the annual cost per ton of SO{sub 2} removed, advanced flotation device available. This machine was to process ultra fine coal, maximize Btu recovery and maximize pyritic sulfur rejection. The device will first be installed as a one hundred pound per hour capacity unit and, subject to the outcome of Task 6 of the Engineering Development Contract, increased to a 3 ton per hour capacity unit for installation into a proof-of-concept preparation plant. All of the technical and economic results were submitted to the TST for consideration. The TST members evaluated the data and determined to rank each of the participants 50% on technical merit and 50% on economic merit. The technical merit was to be the efficiency index. The economical merit was to be the annual dollars per ton of clean coal corrected for carrying capacity and frother concentration and the results of Test No. 4. This factor does not penalize a particular technology for not meeting a 90% pyritic sulfur rejection and therefore leaves something to be desired as the only economic basis for decision. A second economic evaluation criteria was required that considered the $/ton of sulfur dioxide removed. The technical and economic factors were calculated and added together for the final evaluation ranking. The technical factor was calculated by multiplying the efficiency index for each participant by 0.5. The two economic factors were calculated by dividing 1000 by the $/ton of clean coal and multiplying by 0.5 and by dividing 10,000 by the $/ton of sulfur dioxide removed and multiply by 0.5. The 1000 and 10,000 are numbers selected such that when divided by their economic factors, respective numbers resulted in a two digit number. The results of these calculations are discussed. 4 refs., 18 figs., 27 tabs.

  5. Development of instrumental methods of analysis of sulfur compounds in coal process streams. Quarterly technical progress report for October-December 1980

    SciTech Connect

    Jordan, J.; Stutts, J. D.; Ankabrandt, S. J.; Stahl, J.; Yakupkovic, J. E.

    1981-01-01

    Work is in progress on the preparation of a user-oriented computer software manual, for estimating sulfur speciation in aqueous coal process streams form a thermodynamic data base. Capabilities and limitations of sulfide and polysulfide analysis by differential pulse polarography at a dropping mercury anode are assessed critically. Thallous nitrate used as the titrant reagent in a thermometric enthalpy titration yields the molar sum of monosulfide and polysulfide. Inorganic sulfur has been successfully speciated in coal conversion by-product water samples. A combination of differential pulse voltammetry, thermometric enthalpy titrations and classical methods was used. One hundred percent of the total sulfur present was quantitatively accounted for.

  6. Zeolites Remove Sulfur From Fuels

    NASA Technical Reports Server (NTRS)

    Voecks, Gerald E.; Sharma, Pramod K.

    1991-01-01

    Zeolites remove substantial amounts of sulfur compounds from diesel fuel under relatively mild conditions - atmospheric pressure below 300 degrees C. Extracts up to 60 percent of sulfur content of high-sulfur fuel. Applicable to petroleum refineries, natural-gas processors, electric powerplants, and chemical-processing plants. Method simpler and uses considerably lower pressure than current industrial method, hydro-desulfurization. Yields cleaner emissions from combustion of petroleum fuels, and protects catalysts from poisoning by sulfur.

  7. Identification of sources and formation processes of atmospheric sulfate by sulfur isotope and scanning electron microscope measurements

    NASA Astrophysics Data System (ADS)

    Guo, Zhaobing; Li, Zhanqing; Farquhar, James; Kaufman, Alan J.; Wu, Nanping; Li, Can; Dickerson, Russell R.; Wang, Pucai

    2010-04-01

    Atmospheric sulfate aerosols have a cooling effect on the Earth's surface and can change cloud microphysics and precipitation. China has heavy loading of sulfate, but their sources and formation processes remain uncertain. In this study we characterize possible sources and formation processes of atmospheric sulfate by analyzing sulfur isotope abundances (32S, 33S, 34S, and 36S) and by detailed X-ray diffraction and scanning electron microscope (SEM) imaging of aerosol samples acquired at a rural site in northern China from March to August 2005. The comparison of SEM images from coal fly ash and the atmospheric aerosols suggests that direct emission from coal combustion is a substantial source of primary atmospheric sulfate in the form of CaSO4. Airborne gypsum (CaSO4·2H2O) is usually attributed to eolian dust or atmospheric reactions with H2SO4. SEM imaging also reveals mineral particles with soot aggregates adhered to the surface where they could decrease the single scattering albedo of these aerosols. In summer months, heterogeneous oxidation of SO2, derived from coal combustion, appears to be the dominant source of atmospheric sulfate. Our analyses of aerosol sulfate show a seasonal variation in ?33S (?33S describes either a 33S excess or depletion relative to that predicted from consideration of classical mass-dependent isotope effects). Similar sulfur isotope variations have been observed in other atmospheric samples and in (homogenous) gas-phase reactions. On the basis of atmospheric sounding and satellite data as well as a possible relationship between ?33S and Convective Available Potential Energy (CAPE) during the sampling period, we attribute the sulfur isotope anomalies (?33S and ?36S) in Xianghe aerosol sulfates to another atmospheric source (upper troposphere or lower stratosphere).

  8. Initial Assessment of Sulfur-Iodine Process Safety Issues and How They May Affect Pilot Plant Design and Operation

    SciTech Connect

    Robert S. Cherry

    2006-09-01

    The sulfur-iodine process to make hydrogen by the thermochemical splitting of water is under active development as part of a U.S. Department of Energy program. An integrated lab scale system is currently being designed and built. The next planned stage of development is a pilot plant with a thermal input of about 500 kW, equivalent to about 30,000 standard liters per hour of hydrogen production. The sulfur-iodine process contains a variety of hazards, including temperatures up to 850 ºC and hazardous chemical species including SO2, H2SO4, HI, I2, and of course H2. The siting and design of a pilot plant must consider these and other hazards. This report presents an initial analysis of the hazards that might affect pilot plant design and should be considered in the initial planning. The general hazards that have been identified include reactivity, flammability, toxicity, pressure, electrical hazards, and industrial hazards such as lifting and rotating equipment. Personnel exposure to these hazards could occur during normal operations, which includes not only running the process at the design conditions but also initial inventory loading, heatup, startup, shutdown, and system flushing before equipment maintenance. Because of the complexity and severity of the process, these ancillary operations are expected to be performed frequently. In addition, personnel could be exposed to the hazards during various abnormal situations which could include unplanned phase changes of liquids or solids, leaks of process fluids or cooling water into other process streams, unintentional introducion of foreign species into the process, and unexpected side reactions. Design of a pilot plant will also be affected by various codes and regulations such as the International Building Code, the International Fire Code, various National Fire Protection Association Codes, and the Emergency Planning and Community Right-to-Know Act.

  9. Determination of sulfur and nitrogen compounds during the processing of dry fermented sausages and their relation to amino acid generation.

    PubMed

    Corral, Sara; Leitner, Erich; Siegmund, Barbara; Flores, Mónica

    2016-01-01

    The identification of odor-active sulfur and nitrogen compounds formed during the processing of dry fermented sausages was the objective of this study. In order to elucidate their possible origin, free amino acids (FAAs) were also determined. The volatile compounds present in the dry sausages were extracted using solvent assisted flavor evaporation (SAFE) and monitored by one and two-dimensional gas chromatography with different detectors: mass spectrometry (MS), nitrogen phosphorous (NPD), flame photometric (FPD) detectors, as well as gas chromatography-olfactometry. A total of seventeen sulfur and nitrogen compounds were identified and quantified. Among them, 2-acetyl-1-pyrroline was the most potent odor active compound, followed by methional, ethylpyrazine and 2,3-dihydrothiophene characterized by toasted, cooked potato, and nutty notes. The degradation of FAAs, generated during processing, was related to the production of aroma compounds, such as methionine forming methional and benzothiazole while ornithine was the precursor compound for 2-acetyl-1-pyrroline and glycine for ethylpyrazine. PMID:26213023

  10. Sulfur isotope analysis of individual aerosol particles - a new tool for studying heterogeneous oxidation processes in the marine environment

    NASA Astrophysics Data System (ADS)

    Sinha, B. W.; Hoppe, P.; Huth, J.; Foley, S.; Andreae, M. O.

    2009-02-01

    Understanding the importance of the different oxidation pathways of sulfur dioxide (SO2) to sulfate is crucial for an interpretation of the climate effects of sulfate aerosols. Sulfur isotope analysis of atmospheric aerosol is a well established tool for identifying sources of sulfur in the atmosphere and assessment of anthropogenic influence. The power of this tool is enhanced by a new ion microprobe technique that permits isotope analysis of individual aerosol particles as small as 0.5 ?m diameter. With this new single particle technique, different types of primary and secondary sulfates are first identified based on their chemical composition, and then their individual isotopic signature is measured. Our samples were collected at Mace Head, Ireland, a remote coastal station on the North Atlantic Ocean. Sea-salt-sulfate (10-60%), ammonium sulfate/sulfuric acid particles (15-65%), and non-sea-salt-sulfate (nss-sulfate) on aged salt particles all contributed significantly to sulfate loadings in our samples. The isotopic composition of secondary sulfates depends on the isotopic composition of precursor SO2 and the oxidation process. The fractionation with respect to the source SO2 is poorly characterized. In the absence of conclusive laboratory experiments, we consider the kinetic fractionation of -9‰ during the gas phase oxidation of SO2 by OH as suggested by Saltzman et al. (1983) and Tanaka et al. (1994) to be the most reasonable estimate for the isotope fractionation during gas phase oxidation of SO2 (?hom=0.991) and the equilibrium fractionation for the uptake of SO2(g) into the aqueous phase and the dissociation to HSO3- of +16.5‰ measured by Eriksen (1972a) to be the best approximation for the fractionation during oxidation in the aqueous phase (?het=1.0165). The sulfur isotope ratio of secondary sulfate particles can therefore be used to identify the oxidation pathway by which this sulfate was formed. However, the fraction of heterogeneous and homogeneous oxidation pathway calculated is very sensitive to the isotope fractionation assumed for both pathways. Particles with known oxidation pathway (fine mode ammonium sulfate) are used to estimate the isotopic composition of the source SO2. It ranged from ?34SVCDT=0±3‰ to ?34SVCDT=(14±3)‰ under clean conditions and ?34SVCDT=(3±1)‰ under polluted condition. Condensation of H2SO4(g) onto sea salt aerosol produces an isotopic ratio that, when plotted against the sea-salt-sulfate content of the sample, lies on a mixing line between sea salt and ammonium sulfate. The contribution of heterogeneous oxidation is estimated based on the deviation of non-sea-salt-sulfate from this isotopic mixing line. The contribution of heterogeneous oxidation to nss-sulfate formation on aged sea salt sodium sulfate, magnesium sulfate gypsum and mixed sulfate particles under clean conditions is on average 10% for coarse and 25% for fine mode particles. Under polluted conditions, the contribution of heterogeneous oxidation to nss-sulfate formation increased to 60% on coarse mode and 75% on fine mode particles. However, large day-to-day variations in the contribution of heterogeneous oxidation to nss-sulfate formation occurred. Our results suggest that a~significant portion of SO2 in coastal regions is converted to fine mode ammonium sulfate/sulfuric acid particles (40-80% of nss-sulfate) and that condensation of H2SO4(g) contributes significantly even to the nss-sulfate in aged sea salt particles (20-85%).

  11. Structural insight into SoxC and SoxD interaction and their role in electron transport process in the novel global sulfur cycle in Paracoccus pantotrophus

    SciTech Connect

    Bagchi, Angshuman . E-mail: prodosh@bic.boseinst.ernet.in

    2005-06-17

    Microbial oxidation of reduced inorganic sulfur compounds mainly sulfur anions in the environment is one of the major reactions of the global sulfur cycle mediated by phylogenetically diverse prokaryotes. The sulfur oxidizing gene cluster (sox) of {alpha}-Proteobacteria comprises of at least 16 genes, which form two transcriptional units, viz., soxSRT and soxVWXYZABCDEFGH. Sequence analysis reveals that soxD gene product (SoxD) belongs to the di-heme cytochrome c family of electron transport proteins whereas soxC gene product (SoxC) is a sulfur dehydrogenase. We employed homology modeling to construct the three-dimensional structures of the SoxC and SoxD from Paracoccus pantotrophus. SoxD protein is known to interact with SoxC. With the help of docking studies we have identified the residues involved in the interaction of SoxC and SoxD. The putative active site geometries of these two proteins as well as the structural basis of the involvements of these proteins in electron transport process during the oxidation of sulfur anions are also investigated.

  12. Sulfuric Acid in the Venus Clouds

    NASA Technical Reports Server (NTRS)

    Sill, G. T.

    1972-01-01

    The visible and ultraviolet transmission features of a thin layer of elemental bromine and hydrobromic acid dissolved in sulfuric acid somewhat resemble the Venus spectrum, up to 14 microns. The chemical process postulated for forming sulfuric acid involves the oxidation of sulfur and its compounds to sulfuric acid through the agency of elemental bromine, produced by the photolytic decomposition of hydrogen bromide.

  13. A Summary of Experiments in Converting Copper Oxide Process Regenerator Off-Gases to Elemental Sulfur, CRADA 97-F006, Final Report

    SciTech Connect

    Brian C. Cianciolo; Richard J. Oehlberg; Sidney G. Nelson

    1999-01-22

    Sorbent Technologies Corporation (Sorbtech) of Twinsburg, Ohio has developed a new technology for converting SO{sub 2}-rich gas streams directly to elemental sulfur. Key to the technology is a special catalyst that promotes the reaction of SO{sub 2} with reformed natural gas. The technology evolved from earlier flue-gas desulfurization (FGD) work that Sorbtech engineers performed in the late 1980's. In 1995, with U.S. Department of Energy (DOE) support, Sorbtech designed and constructed a larger, skid-mounted pilot-test unit suitable for demonstrating the new technology in field tests. This Report summarizes months of preparation work and eight days of testing that were performed at FETC'S facilities during late September and early October, 1997. On the basis of the results of this phase of the project, the following conclusions were made: (1) The chemistry of the new technology was well proven and demonstrated at FETC. The overall S0{sub 2}-to-elemental sulfur yields were typically in the range of 93 to 98 percent. (The project goal was 95 percent, so the goal was exceeded). (2) Sulfur selectivity values, indicating the tendency of S0{sub 2} to be converted to elemental sulfur in preference to H{sub 2}S or COS, were typically in the range of 98 to 100 percent. (3) Bright yellow sulfur of high quality was produced at FETC. (4) The FETC regenerator exhaust gas presented no processing difficulties. Swings in the level of methane in the exhaust gas were handled with relative ease. (5) With the exception of the water condenser, all system components performed well. (6) Condensing of the sulfur after its production was a serious problem at FETC. Solid sulfur deposits built up in the process-gas lines at several locations in the system. Clogging of the lines necessitated terminating runs typically after 2 to 4 hours of operation. Clogging problems were most severe in the water condenser. Many planned parametric tests were not run because of the sulfur plugging problems. (7) Several suggestions were made by BP Oil Company for solving the sulfur pl ugging problems. Among the suggestions were to never allow the temperature of the process gas to fall below 118{degree}C, to increase the temperature of the sulfur condenser to 148{degree}C, and to eliminate the water condenser from the system entirely.

  14. Calcium looping process for high purity hydrogen production integrated with capture of carbon dioxide, sulfur and halides

    DOEpatents

    Ramkumar, Shwetha; Fan, Liang-Shih

    2013-07-30

    A process for producing hydrogen comprising the steps of: (i) gasifying a fuel into a raw synthesis gas comprising CO, hydrogen, steam, sulfur and halide contaminants in the form of H.sub.2S, COS, and HX, wherein X is a halide; (ii) passing the raw synthesis gas through a water gas shift reactor (WGSR) into which CaO and steam are injected, the CaO reacting with the shifted gas to remove CO.sub.2, sulfur and halides in a solid-phase calcium-containing product comprising CaCO.sub.3, CaS and CaX.sub.2; (iii) separating the solid-phase calcium-containing product from an enriched gaseous hydrogen product; and (iv) regenerating the CaO by calcining the solid-phase calcium-containing product at a condition selected from the group consisting of: in the presence of steam, in the presence of CO.sub.2, in the presence of synthesis gas, in the presence of H.sub.2 and O.sub.2, under partial vacuum, and combinations thereof.

  15. Calcium looping process for high purity hydrogen production integrated with capture of carbon dioxide, sulfur and halides

    DOEpatents

    Ramkumar, Shwetha; Fan, Liang-Shih

    2015-11-04

    A process for producing hydrogen comprising the steps of: (i) gasifying a fuel into a raw synthesis gas comprising CO, hydrogen, steam, sulfur and halide contaminants in the form of H.sub.2S, COS, and HX, wherein X is a halide; (ii) passing the raw synthesis gas through a water gas shift reactor (WGSR) into which CaO and steam are injected, the CaO reacting with the shifted gas to remove CO.sub.2, sulfur and halides in a solid-phase calcium-containing product comprising CaCO.sub.3, CaS and CaX.sub.2; (iii) separating the solid-phase calcium-containing product from an enriched gaseous hydrogen product; and (iv) regenerating the CaO by calcining the solid-phase calcium-containing product at a condition selected from the group consisting of: in the presence of steam, in the presence of CO.sub.2, in the presence of synthesis gas, in the presence of H.sub.2 and O.sub.2, under partial vacuum, and combinations thereof.

  16. EFFECT OF ELECTROLYZER CONFIGURATION AND PERFORMANCE ON HYBRID SULFUR PROCESS NET THERMAL EFFICIENCY

    SciTech Connect

    Gorensek, M

    2007-03-16

    Hybrid Sulfur cycle is gaining popularity as a possible means for massive production of hydrogen from nuclear energy. Several different ways of carrying out the SO{sub 2}-depolarized electrolysis step are being pursued by a number of researchers. These alternatives are evaluated with complete flowsheet simulations and on a common design basis using Aspen Plus{trademark}. Sensitivity analyses are performed to assess the performance potential of each configuration, and the flowsheets are optimized for energy recovery. Net thermal efficiencies are calculated for the best set of operating conditions for each flowsheet and the results compared. This will help focus attention on the most promising electrolysis alternatives. The sensitivity analyses should also help identify those features that offer the greatest potential for improvement.

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

    NASA Astrophysics Data System (ADS)

    Yang, JungYup; Nam, Junggyu; Kim, Dongseop; Kim, GeeYeong; Jo, William; Kang, Yoonmook; Lee, Dongho

    2015-11-01

    Cu(In,Ga)(Se,S)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 H2S 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/cm2), and fill factor (+0.21%) of a CIGSS device with 30 × 30 cm2 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.

  18. Sulfur compounds in coal

    NASA Technical Reports Server (NTRS)

    Attar, A.; Corcoran, W. H.

    1977-01-01

    The literature on the chemical structure of the organic sulfur compounds (or functional groups) in coal is reviewed. Four methods were applied in the literature to study the sulfur compounds in coal: direct spectrometric and chemical analysis, depolymerization in drastic conditions, depolymerization in mild conditions, and studies on simulated coal. The data suggest that most of the organic sulfur in coal is in the form of thiophenic structures and aromatic and aliphatic sulfides. The relative abundance of the sulfur groups in bituminous coal is estimated as 50:30:20%, respectively. The ratio changes during processing and during the chemical analysis. The main effects are the transformation during processing of sulfides to the more stable thiophenic compounds and the elimination of hydrogen sulfide.

  19. Comparison of fixation and processing methods for hairless guinea pig skin following sulfur mustard exposure. (Reannouncement with new availability information)

    SciTech Connect

    Bryant, M.A.; Braue Jr, E.H.

    1992-12-31

    Ten anesthetized hairless guinea pigs Crl:IAF(HA)BR were exposed to 10 pi of neat sulfur mustard (HD) in a vapor cup on their skin for 7 min. At 24 h postexposure, the guinea pigs were euthanatized and skin sections taken for histologic evaluation. The skin was fixed using either 10% neutral buffered formalin (NBF), McDowell Trump fixative (4CF-IG), Zenker`s formol-saline (Helly`s fluid), or Zenker`s fluid. Fixed skin sections were cut in half: one half was embedded in paraffin and the other half in plastic (glycol methacrylate). Paraffin-embedded tissue was stained with hematoxylin and eosin; plastic-embedded tissue was stained with Lee`s methylene blue basic fuchsin. Skin was also frozen unfixed, sectioned by cryostat, and stained with pinacyanole. HD-exposed skin was evaluated histologically for the presence of epidermal and follicular necrosis, microblister formation, epidermitis, and intracellular edema to determine the optimal fixation and embedding method for lesion preservation. The percentage of histologic sections with lesions varied little between fixatives and was similar for both paraffin and plastic embedding material. Plastic-embedded sections were thinner, allowing better histologic evaluation, but were more difficult to stain. Plastic embedding material did not infiltrate tissue fixed in Zenker`s fluid or Zenker`s formol-saline. Frozen tissue sections were prepared in the least processing time and lesion preservation was comparable to fixed tissue. It was concluded that standard histologic processing using formalin fixation and paraffin embedding is adequate for routine histopathological evaluation of HD skin lesions in the hairless guinea pig.... Sulfur mustard, Vesicating agents, Pathology, Hairless guinea pig model, Fixation.

  20. Determination of sulfuric acid concentration for anti-cavitation characteristics of Al alloy by two step anodizing process to forming nano porous.

    PubMed

    Lee, Seung-Jun; Kim, Seong-Kweon; Jeong, Jae-Yong; Kim, Seong-Jong

    2014-12-01

    Al alloy is a highly active metal but forms a protective oxide film having high corrosion resistance in atmosphere environment. However, the oxide film is not suitable for practical use, since the thickness of the film is not uniform and it is severly altered with formation conditions. This study focused on developing an aluminum anodizing layer having hardness, corrosion resistance and abrasion resistance equivalent to a commercial grade protective layer. Aluminum anodizing layer was produced by two-step aluminum anodizing oxide (AAO) process with different sulfuric acid concentrations, and the cavitation characteristics of the anodized coating layer was investigated. In hardness measurement, the anodized coating layer produced with 15 vol.% of sulfuric acid condition had the highest value of hardness but exhibited poor cavitation resistance due to being more brittle than those with other conditions. The 10 vol.% of sulfuric acid condition was thus considered to be the optimum condition as it had the lowest weight loss and damage depth. PMID:25971100

  1. Novel characterization of Radix Angelicae Dahuricae before and after the sulfur-fumigation process by combining high performance liquid chromatographic fingerprint and multi-ingredients determination

    PubMed Central

    Liu, Xiao; Liu, Jingjing; Cai, Hao; Li, Songlin; Ma, Xiaoqing; Lou, Yajing; Qin, Kunming; Guan, Hongyue; Cai, Baochang

    2014-01-01

    Background: Harmful sulfur-fumigation processing method is abused during Radix Angelicae Dahuricae preparation. However, the analytical technique characterizing Radix Angelicae Dahuricae before and after the sulfur-fumigation process is absent. Materials and Methods: The high performance liquid chromatography (HPLC) technique was adopted to develop methods combining finger-print analysis and multi-ingredients simultaneous determination for quality evaluation of Radix Angelicae Dahuricae before and after the sulfur-fumigation process. The chromatographic fingerprint method was established for qualitative analysis coupled with statistical cluster analysis basing on Euclidean distance. Additionally, a determination method was developed for quantitative analysis, which was able to assay the concentrations of the major coumarins including imperatorin, isoimperatorin, xanthotoxin, xanthotoxol, isoimpinellin, oxypeucedanin, and bergapten in Radix Angelicae Dahuricae simultaneously. The separations of the two methods were both achieved on a Hypersil octadecylsilyl C18 column (250 mm × 4.6 mm, 5 ?m) at 35°C under different strategic gradient elution programs. The detection wavelength was set at 254 nm all the time. Method validation data indicated that the methods were both reliable and applicable. They were then used to assay different Radix Angelicae Dahuricae samples collected from good agricultural practice (GAP) bases and local herbal markets. Results: The successful application demonstrated that the combination of HPLC fingerprint and simultaneous quantification of multi-ingredients offers an efficient approach for quality evaluation of Radix Angelicae Dahuricae before and after the sulfur-fumigation process. Conclusion: In order to discriminate Radix Angelicae Dahuricae before and after the sulfur-fumigation process, oxypeucedanin, and xanthotoxol were the most sensitive biomarkers and should be determined. PMID:25210323

  2. Lunar sulfur

    NASA Technical Reports Server (NTRS)

    Kuck, David L.

    1991-01-01

    Ideas introduced by Vaniman, Pettit and Heiken in their 1988 Uses of Lunar Sulfur are expanded. Particular attention is given to uses of SO2 as a mineral-dressing fluid. Also introduced is the concept of using sulfide-based concrete as an alternative to the sulfur-based concretes proposed by Leonard and Johnson. Sulfur is abundant in high-Ti mare basalts, which range from 0.16 to 0.27 pct. by weight. Terrestrial basalts with 0.15 pct. S are rare. For oxygen recovery, sulfur must be driven off with other volatiles from ilmenite concentrates, before reduction. Troilite (FeS) may be oxidized to magnetite (Fe3O4) and SO2 gas, by burning concentrates in oxygen within a magnetic field, to further oxidize ilmenite before regrinding the magnetic reconcentration. SO2 is liquid at -20 C, the mean temperature underground on the Moon, at a minimum of 0.6 atm pressure. By using liquid SO2 as a mineral dressing fluid, all the techniques of terrestrial mineral separation become available for lunar ores and concentrates. Combination of sulfur and iron in an exothermic reaction, to form iron sulfides, may be used to cement grains of other minerals into an anhydrous iron-sulfide concrete. A sulfur-iron-aggregate mixture may be heated to the ignition temperature of iron with sulfur to make a concrete shape. The best iron, sulfur, and aggregate ratios need to be experimentally established. The iron and sulfur will be by-products of oxygen production from lunar minerals.

  3. Hydrometallurgical process for producing lead and elemental sulfur from galena concentrates

    SciTech Connect

    Lee, A.Y.; Wethington, A.M.; Cole, E.R. Jr.

    1986-01-01

    The Bureau of Mines has developed an effective hydrometallurgical method to recover high-purity Pb metal and elemental S from galena concentrates. This low-temperature process eliminates S gases and Pb emissions, in contrast to the current high-temperature smelting technology. Spent electrolyte was recycled repeatedly, with impurity buildup controlled by controlling the leach parameters.

  4. The development of autocatalytic structural materials for use in the sulfur-iodine process for the production of hydrogen

    E-print Network

    Miu, Kevin (Kevin K.)

    2006-01-01

    The Sulfur-Iodine Cycle for the thermochemical production of hydrogen offers many benefits to traditional methods of hydrogen production. As opposed to steam methane reforming - the most prevalent method of hydrogen ...

  5. Processes for preparing carbon fibers using sulfur trioxide in a halogenated solvent

    DOEpatents

    Patton, Jasson T.; Barton, Bryan E.; Bernius, Mark T.; Chen, Xiaoyun; Hukkanen, Eric J.; Rhoton, Christina A.; Lysenko, Zenon

    2015-12-29

    Disclosed here are processes for preparing carbonized polymers (preferably carbon fibers), comprising sulfonating a polymer with a sulfonating agent that comprises SO.sub.3 dissolved in a solvent to form a sulfonated polymer; treating the sulfonated polymer with a heated solvent, wherein the temperature of the solvent is at least 95.degree. C.; and carbonizing the resulting product by heating it to a temperature of 500-3000.degree. C. Carbon fibers made according to these methods are also disclosed herein.

  6. Crystallization behaviour of co-sputtered Cu?ZnSnS? precursor prepared by sequential sulfurization processes.

    PubMed

    Han, Junhee; Shin, Seung Wook; Gang, Myeong Gil; Kim, Jin Hyeok; Lee, Jeong Yong

    2013-03-01

    Cu(2)ZnSnS(4) (CZTS) thin films were prepared by the sequential sulfurization of a co-sputtered precursor with a multitarget (Cu, ZnS, and SnS(2)) sputtering system. In order to investigate the crystallization behaviour of the thin films, the precursors were sulfurized in a tube furnace at different temperatures for different time durations. The Raman spectra of the sulfurized thin films showed that their crystallinity gradually improved with an increase in the sulfurization temperature and duration. However, transmission electron microscopy revealed an unexpected result-the precursor thin films were not completely transformed to the CZTS phase and showed the presence of uncrystallized material when sulfurized at 250-400?°C for 60 min and at 500?°C for 30 min. Thus, the crystallization of the co-sputtered precursor thin films showed a strong dependence on the sulfurization temperature and duration. The crystallization mechanism of the precursor thin films was understood on the basis of these results and has been described in this paper. The understanding of this mechanism may improve the standard preparation method for high-quality CZTS absorber layers. PMID:23396187

  7. Method and system for the removal of oxides of nitrogen and sulfur from combustion processes

    DOEpatents

    Walsh, John V. (Glendora, CA)

    1987-12-15

    A process for removing oxide contaminants from combustion gas, and employing a solid electrolyte reactor, includes: (a) flowing the combustion gas into a zone containing a solid electrolyte and applying a voltage and at elevated temperature to thereby separate oxygen via the solid electrolyte, (b) removing oxygen from that zone in a first stream and removing hot effluent gas from that zone in a second stream, the effluent gas containing contaminant, (c) and pre-heating the combustion gas flowing to that zone by passing it in heat exchange relation with the hot effluent gas.

  8. Reaction Mechanism for m-Xylene Oxidation in the Claus Process by Sulfur Dioxide.

    PubMed

    Sinha, Sourab; Raj, Abhijeet; Al Shoaibi, Ahmed S; Chung, Suk Ho

    2015-09-24

    In the Claus process, the presence of aromatic contaminants such benzene, toluene, and xylenes (BTX), in the H2S feed stream has a detrimental effect on catalytic reactors, where BTX form soot particles and clog and deactivate the catalysts. Among BTX, xylenes are proven to be most damaging contaminant for catalysts. BTX oxidation in the Claus furnace, before they enter catalyst beds, provides a solution to this problem. A reaction kinetics study on m-xylene oxidation by SO2, an oxidant present in Claus furnace, is presented. The density functional theory is used to study the formation of m-xylene radicals (3-methylbenzyl, 2,6-dimethylphenyl, 2,4-dimethylphenyl, and 3,5-dimethylphenyl) through H-abstraction and their oxidation by SO2. The mechanism begins with SO2 addition on the radicals through an O-atom rather than the S-atom with the release of 180.0-183.1 kJ/mol of reaction energies. This exothermic reaction involves energy barriers in the range 3.9-5.2 kJ/mol for several m-xylene radicals. Thereafter, O-S bond scission takes place to release SO, and the O-atom remaining on aromatics leads to CO formation. Among four m-xylene radicals, the resonantly stabilized 3-methylbenzyl exhibited the lowest SO2 addition and SO elimination rates. The reaction rate constants are provided to facilitate Claus process simulations to find conditions suitable for BTX oxidation. PMID:26334187

  9. Effects of processing on the transverse fatigue properties of low-sulfur AISI 4140 steel

    NASA Astrophysics Data System (ADS)

    Collins, Sunniva R.; Michal, Gary M.

    1993-12-01

    The effects of inclusions due to steelmaking processes on the fatigue life of AISI 4140 have been investigated. The test matrix consisted of three commercially produced heats of AISI 4140 of comparable cleanliness: one was conventionally cast (CC), and two were inert gas-shielded/ bottom-poured (IGS). One of the IGS heats was calcium-treated to explore the effects of inclusion shape control (IGS/SC). All heats were hot-rolled and reduced over 95 pct to produce bar stock of 127 to 152 mm (5 to 6 in.) in diameter. Transverse axial specimens conforming to ASTM E466 were machined, quenched, and tempered to approximately 40 HRC, and they were fatigue tested in tension-tension cycling ( R = 0.1). Test results and statistical analyses of the stress-life data show that the IGS grade has several times the fatigue strength of the CC grade at 107 cycles. Lower-limit fatigue strengths calculated at a 99.9 pct probability were 518.5 MPa (75.2 ksi) for IGS vs 55.6 MPa (8.1 ksi) for the CC grade. The IGS/SC grade had the best performance at all stress and life levels. The results obtained indicate that fatigue performance can be improved by choosing a processing method that reduces the incidence of exogenous oxides and by controlling the shape of the sulfides.

  10. Rethinking the Ancient Sulfur Cycle

    NASA Astrophysics Data System (ADS)

    Fike, David A.; Bradley, Alexander S.; Rose, Catherine V.

    2015-05-01

    The sulfur biogeochemical cycle integrates the metabolic activity of multiple microbial pathways (e.g., sulfate reduction, disproportionation, and sulfide oxidation) along with abiotic reactions and geological processes that cycle sulfur through various reservoirs. The sulfur cycle impacts the global carbon cycle and climate primarily through the remineralization of organic carbon. Over geological timescales, cycling of sulfur is closely tied to the redox state of Earth's exosphere through the burial of oxidized (sulfate) and reduced (sulfide) sulfur species in marine sediments. Biological sulfur cycling is associated with isotopic fractionations that can be used to trace the fluxes through various metabolic pathways. The resulting isotopic data provide insights into sulfur cycling in both modern and ancient environments via isotopic signatures in sedimentary sulfate and sulfide phases. Here, we review the deep-time δ34S record of marine sulfates and sulfides in light of recent advances in understanding how isotopic signatures are generated by microbial activity, how these signatures are encoded in marine sediments, and how they may be altered following deposition. The resulting picture shows a sulfur cycle intimately coupled to ambient carbon cycling, where sulfur isotopic records preserved in sedimentary rocks are critically dependent on sedimentological and geochemical conditions (e.g., iron availability) during deposition.

  11. Genetic engineering of sulfur-degrading Sulfolobus

    SciTech Connect

    Ho, N.W.Y.

    1991-01-01

    The objectives of the proposed research is to first establish a plasmid-mediated genetic transformation system for the sulfur degrading Sulfolobus, and then to clone and overexpress the genes encoding the organic-sulfur-degrading enzymes from Sulfolobus- as well as from other microorganisms, to develop a Sulfolobus-based microbial process for the removal of both organic and inorganic sulfur from coal.

  12. SULFUR ASSIMILATION IN PLANTS AND WEED CONTROL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sulfur is an indispensable element for plants. It is found in sulfur-containing amino acids, cysteine and methionine, and in various other important biochemical components and processes. Inhibitors of sulfur assimilation, or cysteine and methionine synthesis, could be potential herbicides. The sulf...

  13. Process for sulfur removal and recovery from a power generation plant using physical solvent

    SciTech Connect

    Hegarty, W.P.

    1993-08-31

    A process is described for producing a H[sub 2]S-free fuel gas for combustion in a gas turbine to produce power using a raw fuel feed gas from an oxygen-enriched gasification, comprising the steps of: (a) introducing a raw fuel feed gas which is contaminated with H[sub 2]S and CO[sub 2] into a first separation zone; (b) contacting the raw fuel feed gas with a CO[sub 2]-loaded liquid solvent selective for the H[sub 2]S in the first separation zone; (c) removing a H[sub 2]S-free, CO[sub 2]-containing fuel gas from the first separation zone, combusting the H[sub 2]S-free, CO[sub 2]-containing fuel gas in a gas turbine and recovering power from the gas turbine; (d) removing a H[sub 2]S-rich, CO[sub 2]-containing solvent from the first separation zone and reducing the solvent in pressure; (e) heating the reduced pressure solvent to an elevated temperature before separating the reduced pressure solvent into a CO[sub 2]-rich stream and a second H[sub 2]S-rich solvent containing residual CO[sub 2]; (f) stripping the residual CO[sub 2] from the second H[sub 2]S-rich solvent with nitrogen-rich gas at a pressure below approximately 300 psia to recover a residual CO[sub 2] containing nitrogen stripping gas; (g) combining the CO[sub 2]-rich stream of step (e) and the residual CO[sub 2] containing nitrogen stripping gas of step (f) and recycling the resulting combined stream to the H[sub 2]S-free, CO[sub 2]-containing fuel gas; (h) stripping the H[sub 2]S from the second H[sub 2]S-rich solvent in a regeneration zone using steam to recover a H[sub 2]S-rich product stream and a H[sub 2]S-lean solvent; and (i) combining the H[sub 2]S-lean solvent with the H[sub 2]S-free, CO[sub 2]-containing fuel gas either outside the first separation zone or in a top tray of the first separation zone, cooling them and separating them into the CO[sub 2]-loaded liquid solvent of step (b) and a final H[sub 2]S-free, CO[sub 2]-containing fuel gas for introduction into the gas turbine.

  14. Sulfur Dioxide Emissions

    EPA Science Inventory

    This indicator presents regional and national sulfur dioxide (SO2) emissions data for 1990, 1996 to 2002, and 2005. SO2 emissions (combined with atmospheric fate and transport processes) determine corresponding ambient SO2 concentration levels ...

  15. Synthesis and development of processes for the recovery of sulfur from acid gases. Part 1, Development of a high-temperature process for removal of H{sub 2}S from coal gas using limestone -- thermodynamic and kinetic considerations; Part 2, Development of a zero-emissions process for recovery of sulfur from acid gas streams

    SciTech Connect

    Towler, G.P.; Lynn, S.

    1993-05-01

    Limestone can be used more effectively as a sorbent for H{sub 2}S in high-temperature gas-cleaning applications if it is prevented from undergoing calcination. Sorption of H{sub 2}S by limestone is impeded by sintering of the product CaS layer. Sintering of CaS is catalyzed by CO{sub 2}, but is not affected by N{sub 2} or H{sub 2}. The kinetics of CaS sintering was determined for the temperature range 750--900{degrees}C. When hydrogen sulfide is heated above 600{degrees}C in the presence of carbon dioxide elemental sulfur is formed. The rate-limiting step of elemental sulfur formation is thermal decomposition of H{sub 2}S. Part of the hydrogen thereby produced reacts with CO{sub 2}, forming CO via the water-gas-shift reaction. The equilibrium of H{sub 2}S decomposition is therefore shifted to favor the formation of elemental sulfur. The main byproduct is COS, formed by a reaction between CO{sub 2} and H{sub 2}S that is analogous to the water-gas-shift reaction. Smaller amounts of SO{sub 2} and CS{sub 2} also form. Molybdenum disulfide is a strong catalyst for H{sub 2}S decomposition in the presence of CO{sub 2}. A process for recovery of sulfur from H{sub 2}S using this chemistry is as follows: Hydrogen sulfide is heated in a high-temperature reactor in the presence of CO{sub 2} and a suitable catalyst. The primary products of the overall reaction are S{sub 2}, CO, H{sub 2} and H{sub 2}O. Rapid quenching of the reaction mixture to roughly 600{degrees}C prevents loss Of S{sub 2} during cooling. Carbonyl sulfide is removed from the product gas by hydrolysis 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 recovers the hydrogen value from the H{sub 2}S. This process is economically favorable compared to the existing sulfur-recovery technology and allows emissions of sulfur-containing gases to be controlled to very low levels.

  16. Sulfur degassing at Erta Ale (Ethiopia) and Masaya (Nicaragua) volcanoes: Implications for degassing processes and oxygen fugacities of basaltic systems

    NASA Astrophysics Data System (ADS)

    Moor, J. M.; Fischer, T. P.; Sharp, Z. D.; King, P. L.; Wilke, M.; Botcharnikov, R. E.; Cottrell, E.; Zelenski, M.; Marty, B.; Klimm, K.; Rivard, C.; Ayalew, D.; Ramirez, C.; Kelley, K. A.

    2013-10-01

    We investigate the relationship between sulfur and oxygen fugacity at Erta Ale and Masaya volcanoes. Oxygen fugacity was assessed utilizing Fe3+/?Fe and major element compositions measured in olivine-hosted melt inclusions and matrix glasses. Erta Ale melts have Fe3+/?Fe of 0.15-0.16, reflecting fO2 of ?QFM 0.0 ± 0.3, which is indistinguishable from fO2 calculated from CO2/CO ratios in high-temperature gases. Masaya is more oxidized at ?QFM +1.7 ± 0.4, typical of arc settings. Sulfur isotope compositions of gases and scoria at Erta Ale (?34Sgas - 0.5‰; ?34Sscoria + 0.9‰) and Masaya (?34Sgas + 4.8‰; ?34Sscoria + 7.4‰) reflect distinct sulfur sources, as well as isotopic fractionation during degassing (equilibrium and kinetic fractionation effects). Sulfur speciation in melts plays an important role in isotope fractionation during degassing and S6+/?S is <0.07 in Erta Ale melt inclusions compared to >0.67 in Masaya melt inclusions. No change is observed in Fe3+/?Fe or S6+/?S with extent of S degassing at Erta Ale, indicating negligible effect on fO2, and further suggesting that H2S is the dominant gas species exsolved from the S2--rich melt (i.e., no redistribution of electrons). High SO2/H2S observed in Erta Ale gas emissions is due to gas re-equilibration at low pressure and fixed fO2. Sulfur budget considerations indicate that the majority of S injected into the systems is emitted as gas, which is therefore representative of the magmatic S isotope composition. The composition of the Masaya gas plume (+4.8‰) cannot be explained by fractionation effects but rather reflects recycling of high ?34S oxidized sulfur through the subduction zone.

  17. Excess carrier generation in femtosecond-laser processed sulfur doped silicon by means of sub-bandgap illumination

    SciTech Connect

    Guenther, Kay-Michael; Gimpel, Thomas; Ruibys, Augustinas; Kontermann, Stefan; Tomm, Jens W.; Winter, Stefan; Schade, Wolfgang

    2014-01-27

    With Fourier-transform photocurrent spectroscopy and spectral response measurements, we show that silicon doped with sulfur by femtosecond laser irradiation generates excess carriers, when illuminated with infrared light above 1100?nm. Three distinct sub-bandgap photocurrent features are observed. Their onset energies are in good agreement with the known sulfur levels S{sup +}, S{sup 0}, and S{sub 2}{sup 0}. The excess carriers are separated by a pn-junction to form a significant photocurrent. Therefore, this material likely demonstrates the impurity band photovoltaic effect.

  18. Preparation of lower sulfur and higher sulfur cokes

    SciTech Connect

    Newman, B.A.; Chahar, B.S.

    1990-01-16

    This patent describes a process for producing a lower sulfur coke and higher sulfur coke from a single feedstock. It comprises: catalytically hydrotreating a virgin heavy oil having an API gravity of from about {minus}5 to about 25 and an initial boiling point of from about 550{degrees}F to bout 1,000{degrees}F to reduce the sulfur content of the hydrotreated product to not more than about 0.75 weight percent, separating the hydrotreated product into a heavy fraction and a light fraction, separately subjecting each fraction to delayed coking, calcining the resulting green coke products to obtain from the coked light fraction a low sulfur calcined coke, and from the coked heavy fraction a higher sulfur calcined coke.

  19. Experimental Behavior of Sulfur Under Primitive Planetary Differentiation Processes, the Sulfide Formations in Enstatite Meteorites and Implications for Mercury.

    NASA Technical Reports Server (NTRS)

    Malavergne, V.; Brunet, F.; Righter, K.; Zanda, B.; Avril, C.; Borensztajn, S.; Berthet, S.

    2012-01-01

    Enstatite meteorites are the most reduced naturally-occuring materials of the solar system. The cubic monosulfide series with the general formula (Mg,Mn,Ca,Fe)S are common phases in these meteorite groups. The importance of such minerals, their formation, composition and textural relationships for understanding the genesis of enstatite chondrites (EC) and aubrites, has long been recognized (e.g. [1]). However, the mechanisms of formation of these sulfides is still not well constrained certainly because of possible multiple ways to produce them. We propose to simulate different models of formation in order to check their mineralogical, chemical and textural relevancies. The solubility of sulfur in silicate melts is of primary interest for planetary mantles, particularly for the Earth and Mercury. Indeed, these two planets could have formed, at least partly, from EC materials (e.g. [2, 3, 4]). The sulfur content in silicate melts depends on the melt composition but also on pressure (P), temperature (T) and oxygen fugacity fO2. Unfortunately, there is no model of general validity in a wide range of P-T-fO2-composition which describes precisely the evolution of sulfur content in silicate melts, even if the main trends are now known. The second goal of this study is to constrain the sulfur content in silicate melts under reducing conditions and different temperatures.

  20. Effect of Sulfurization Temperature on Solution-Processed Cu2ZnSnS4 Thin Films.

    PubMed

    Park, Si-Nae; Sung, Shi-Joon; Son, Dae-Ho; Kim, Dae-Hwan; Sim, Jun-Hyoung; Kang, Jin-Kyu

    2015-03-01

    Cu2ZnSnS4 (CZTS) solar cells are attracting significant attention as an alternative to CIGS (Culn1-xGa(x)S2) solar cells because of the non-toxic and inexpensive constituent elements of CZTS. Recently, solution-based deposition methods are being developed because they have advantages such as suitability for use in large-area deposition, high-throughput manufacturing, and a very short energy payback time with drastically lower manufacturing costs. In this work, we fabricated solution-based CZTS thin films and investigated them in order to observe the effects of sulfurization temperature on CZTS thin films. We confirmed the grain size, morphology, chemical composition, crystallinity, and electrical properties of CZTS thin films depending on various sulfurization temperatures. PMID:26413693

  1. SULFUR POLYMER ENCAPSULATION.

    SciTech Connect

    KALB, P.

    2001-08-22

    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 recommended for treatment of wastes containing high concentrations of nitrates because of potentially dangerous reactions between sulfur, nitrate, and trace quantities of organics. Recently, the process has been adapted for the treatment of liquid elemental mercury and mercury contaminated soil and debris.

  2. Role of RIS/APC for manufacturing RFG/LSD. [Refinery Information Systems/Advanced Process Control, ReFormulated Gasoline/Low Sulfur Diesels

    SciTech Connect

    Latour, P.R. )

    1994-01-01

    Revolutionary changes in quality specifications (number, complexity, uncertainty, economic sensitivity) for reformulated gasolines (RFG) and low-sulfur diesels (LSD) are being addressed by powerful, new, computer-integrated manufacturing technology for Refinery Information Systems and Advanced Process Control (RIS/APC). This paper shows how the five active RIS/APC functions: performance measurement, optimization, scheduling, control and integration are used to manufacture new, clean fuels competitively. With current industry spending for this field averaging 2 to 3 cents/bbl crude, many refineries can capture 50 to 100 cents/bbl if the technology is properly employed and sustained throughout refining operations, organizations, and businesses.

  3. A novel approach to realize SANI process in freshwater sewage treatment--Use of wet flue gas desulfurization waste streams as sulfur source.

    PubMed

    Jiang, Feng; Zhang, Liang; Peng, Guo-Liang; Liang, Si-Yun; Qian, Jin; Wei, Li; Chen, Guang-Hao

    2013-10-01

    SANI (Sulfate reduction, Autotrophic denitrification and Nitrification Integrated) process has been approved to be a sludge-minimized sewage treatment process in warm and coastal cities with seawater supply. In order to apply this sulfur-based process in inland cold areas, wet flue gas desulfurization (FGD) can be simplified and integrated with SANI process, to provide sulfite as electron carrier for sulfur cycle in sewage treatment. In this study, a lab-scale system of the proposed novel process was developed and run for over 200 days while temperature varied between 30 and 5 °C, fed with synthetic FGD wastewaters and sewage. The sulfite-reducing upflow anaerobic sludge bed (SrUASB) reactor, as the major bioreactor of the system, removed 86.9% of organics while the whole system removed 94% of organics even when water temperature decreased to around 10 °C. The bactericidal effect of sulfite was not observed in the SrUASB reactor, while thiosulfate was found accumulated under psychrophilic conditions. The sludge yield of the SrUASB reactor was determined to be 0.095 kg VSS/kg COD, higher than of sulfate reduction process but still much lower than of conventional activated sludge processes. The dominant microbes in the SrUASB reactor were determined as Lactococcus spp. rather than sulfate-reducing bacteria, but sulfite reduction still contributed 85.5% to the organic carbon mineralization in this reactor. Ammonia and nitrate were effectively removed in the aerobic and anoxic filters, respectively. This study confirms the proposed process was promising to achieve sludge-minimized sewage treatment integrating with flue gas desulfurization in inland and cold areas. PMID:23886546

  4. Uses of lunar sulfur

    NASA Technical Reports Server (NTRS)

    Vaniman, D.; Pettit, D.; Heiken, G.

    1992-01-01

    Sulfur and sulfur compounds have a wide range of applications for their fluid, electrical, chemical, and biochemical properties. Although known abundances on the Moon are limited (approximately 0.1 percent in mare soils), sulfur is relatively extractable by heating. Coproduction of sulfur during oxygen extraction from ilmenite-rich mare soils could yield sulfur in masses up to 10 percent of the mass of oxygen produced. Sulfur deserves serious consideration as a lunar resource.

  5. Uses of lunar sulfur

    SciTech Connect

    Vaniman, D.T.; Pettit, D.R.; Heiken, G.

    1988-01-01

    Sulfur and sulfur compounds have a wide range of applications for their fluid, electrical, chemical and biochemical properties. Although low in abundance on the Moon (/approximately/0.1% in mare soils), sulfur is surface-correlated and relatively extractable. Co-production of sulfur during oxygen extraction from ilmenite-rich soils could yield sulfur in masses up to 10% of the mass of oxygen produced. Sulfur deserves serious consideration as a lunar resource. 29 refs., 3 figs.

  6. Production of elemental sulfur and methane from H{sub 2}S and CO{sub 2} derived from a coal desulfurization process. Quaterly technical progress report, October 1, 1996--December 31, 1996

    SciTech Connect

    Jiang, Xueyu; Khang, Soon-Jai; Keener, T.C.

    1997-06-01

    During the thirteenth quarter of the project, the catalytic reaction of H{sub 2}S and CO{sub 2} was carried out around the temperature of 450 to 550{degrees}C to explore the possibility of sulfur removal by solid adsorbents. The experiments combined two unit operations of catalysis and adsorption. A thermogravimetric analyzer (TGA) and a total sulfur analyzer (TSA) were used to investigate the effectiveness of the selected adsorbents used in the H{sub 2}S decomposition process. Three adsorbents, activated carbon, iron sulfide and sulfided Co-Mo-alumina catalyst in the form of powder, were selected for the experiments. The results showed that activated carbon and Co-Mo-Alumina catalyst powder could adsorb up to 9 percent of sulfur in weight. However, the experimental results indicated that there were only trace amount of elemental sulfur produced during the desorption test for the adsorbents.

  7. Development of enhanced sulfur rejection processes. Third quarterly technical progress report, April 1, 1993--June 31, 1993

    SciTech Connect

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

    1993-10-12

    Conclusions: Release analyses of Pittsburgh No. 8 and Illinois No. 6 coals show that the {minus}28 mesh size fraction is fine enough to liberate ash and pyrite. Galvanic coupling with sacrificial anodes such as zinc, manganese and aluminum can effectively lower the potential of pyrite. This effect is more significant at pH 4.6 than at pH 9.2. The most negative pyrite potential is achieved when the surface area ratio of anode to pyrite is approximately 4:1. When coupled with pyrite at pH 9.2, the zinc anode exhibited unique potential vs time behavior which is different from that observed with manganese and aluminum. This is believed to be related to the build- up and break-down of zinc hydroxides on the surface. Voltammograms of pyrite at pH 9.2 and 4.6 demonstrated that pyrite surfaces can be significantly changed by galvanic coupling with sacrificial anodes. In flotation tests, metal powders were used as galvanic contactors to reduce the potential and depress pyrite. The potenial may be low enough to remove sulfur species from the surface. Stirred solutions are preferred for the removal of oxidized sulfur species by galvanic coupling; oxygen in solution must to be depleted prior to the addition of sacrificial anodes to effectively lower the pyrite potential. Microflotation studies show that zinc, manganese and iron all depress pyrite. Zinc appears to be the most effective, followed by manganese and then iron. Voltammetry studies indicated that coupling pyrite with zinc, manganese and aluminum reduces and desorbs hydrophobic sulfur products on the surface of pyrite.

  8. Lunar Sulfur Capture System

    NASA Technical Reports Server (NTRS)

    Berggren, Mark; Zubrin, Robert; Bostwick-White, Emily

    2013-01-01

    The Lunar Sulfur Capture System (LSCS) protects in situ resource utilization (ISRU) hardware from corrosion, and reduces contaminant levels in water condensed for electrolysis. The LSCS uses a lunar soil sorbent to trap over 98 percent of sulfur gases and about two-thirds of halide gases evolved during hydrogen reduction of lunar soils. LSCS soil sorbent is based on lunar minerals containing iron and calcium compounds that trap sulfur and halide gas contaminants in a fixed-bed reactor held at temperatures between 250 and 400 C, allowing moisture produced during reduction to pass through in vapor phase. Small amounts of Earth-based polishing sorbents consisting of zinc oxide and sodium aluminate are used to reduce contaminant concentrations to one ppm or less. The preferred LSCS configuration employs lunar soil beneficiation to boost concentrations of reactive sorbent minerals. Lunar soils contain sulfur in concentrations of about 0.1 percent, and halogen compounds including chlorine and fluorine in concentrations of about 0.01 percent. These contaminants are released as gases such as H2S, COS, CS2,HCl, and HF during thermal ISRU processing with hydrogen or other reducing gases. Removal of contaminant gases is required during ISRU processing to prevent hardware corrosion, electrolyzer damage, and catalyst poisoning. The use of Earth-supplied, single-use consumables to entirely remove contaminants at the levels existing in lunar soils would make many ISRU processes unattractive due to the large mass of consumables relative to the mass of oxygen produced. The LSCS concept of using a primary sorbent prepared from lunar soil was identified as a method by which the majority of contaminants could be removed from process gas streams, thereby substantially reducing the required mass of Earth-supplied consumables. The LSCS takes advantage of minerals containing iron and calcium compounds that are present in lunar soil to trap sulfur and halide gases in a fixedbed reactor downstream of an in-ISRU process such as hydrogen reduction. The lunar-soil-sorbent trap is held at a temperature significantly lower than the operating temperature of the hydrogen reduction or other ISRU process in order to maximize capture of contaminants, but is held at a high enough temperature to allow moisture to pass through without condensing. The lunar soil benefits from physical beneficiation to remove ultrafine particles (to reduce pressure drop through a fixed bed reactor) and to upgrade concentrations of iron and/or calcium compounds (to improve reactivity with gaseous contaminants).

  9. 40 CFR 80.585 - What is the process for approval of a test method for determining the sulfur content of diesel or...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...approval of a test method for determining the sulfur content of diesel or ECA marine fuel...approval of a test method for determining the sulfur content of diesel or ECA marine fuel...approved as a test method for determining the sulfur content of diesel fuel if it...

  10. 40 CFR 80.585 - What is the process for approval of a test method for determining the sulfur content of diesel or...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...approval of a test method for determining the sulfur content of diesel or ECA marine fuel...approval of a test method for determining the sulfur content of diesel or ECA marine fuel...approved as a test method for determining the sulfur content of diesel fuel if it...

  11. 40 CFR 80.585 - What is the process for approval of a test method for determining the sulfur content of diesel or...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...approval of a test method for determining the sulfur content of diesel or ECA marine fuel...approval of a test method for determining the sulfur content of diesel or ECA marine fuel...approved as a test method for determining the sulfur content of diesel fuel if it...

  12. 40 CFR 80.585 - What is the process for approval of a test method for determining the sulfur content of diesel or...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...approval of a test method for determining the sulfur content of diesel or ECA marine fuel...approval of a test method for determining the sulfur content of diesel or ECA marine fuel...approved as a test method for determining the sulfur content of diesel fuel if it...

  13. 40 CFR 80.585 - What is the process for approval of a test method for determining the sulfur content of diesel or...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...approval of a test method for determining the sulfur content of diesel or ECA marine fuel...approval of a test method for determining the sulfur content of diesel or ECA marine fuel...approved as a test method for determining the sulfur content of diesel fuel if it...

  14. Sulfur minimization in bacterial leaching

    SciTech Connect

    Seth, R.; Prasad, D.; Henry, J.G.

    1996-11-01

    The production of sewage biosolids in Ontario in 1989 was estimated to be 7 million m{sup 3} of wet sludge per year. Of this amount, land application accounts for between 20 and 30% of the total. Unfortunately, the use of sewage biosolids on agricultural land is often prohibited because of heavy metal contamination of the biosolids. High cost and operational problems have made chemical methods of metal extraction unattractive. Consequently, microbiological methods of leaching of heavy metals have been studied for over a decade. A relatively simple microbiological process has been investigated in recent years in flask level experiments and recently in a semicontinuous system. The process exploits nonacidophilic and acidophilic indigenous thiobacilli to extract heavy metals from sewage biosolids. These thiobacilli use elemental sulfur as the energy source, producing sulfuric acid. However, the resulting decontaminated biosolids can cause environmental problems like acidification of the soil, when acid is generated from the residual sulfur in the biosolids. The present study examines the possibility of reducing the amount of sulfur added in batch and semicontinuous bacterial leaching systems, and maximizing sulfur oxidation efficiency, thereby reducing the residual sulfur in leached biosolids.

  15. Theoretical investigation of the anomalous equilibrium fractionation of multiple sulfur isotopes during adsorption

    E-print Network

    Cartigny, Pierre

    Theoretical investigation of the anomalous equilibrium fractionation of multiple sulfur isotopes-independent isotopic fractionation Adsorption Sulfur Morse potential Adsorption processes of gaseous molecules) Anomalous fractionation of sulfur isotopes during heterogeneous reactions Earth and Planetary Science

  16. Development of a novel process for the biological conversion of H2S and methanethiol to elemental sulfur.

    PubMed

    Sipma, Jan; Janssen, Albert J H; Pol, Look W Hulshoff; Lettinga, Gatze

    2003-04-01

    The feasibility of anaerobic treatment of wastewater containing methanethiol (MT), an extremely volatile and malodorous sulfur compound, was investigated in lab-scale bioreactors. Inoculum biomass originating from full-scale anaerobic wastewater treatment facilities was used. Several sludges, tested for their ability to degrade MT, revealed the presence of organisms capable of metabolizing MT as their sole source of energy. Furthermore, batch tests were executed to gain a better understanding of the inhibition potential of MT. It was found that increasing MT concentrations affected acetotrophic organisms more dramatically than methylotrophic organisms. Continuous reactor experiments, using two lab-scale upflow anaerobic sludge bed (UASB) reactors (R1 and R2), aimed to determine the maximal MT load and the effect of elevated sulfide concentrations on MT conversion. Both reactors were operated at a hydraulic retention time (HRT) of about 7 hours, a temperature of 30 degrees C, and a pH of between 7.3 and 7.6. At the highest influent MT concentration applied, 14 mM in R1, corresponding to a volumetric loading rate of about 50 mM MT per day, 87% of the organic sulfur was recovered as hydrogen sulfide (12.2 mM) and the remainder as volatile organic sulfur compounds (VOSCs). Upon decreasing the HRT to 3.5 to 4.0 h at a constant MT loading rate, the sulfide concentration in the reactor decreased to 8 mM and MT conversion efficiency increased to values near 100%. MT conversion was apparently inhibited by the high sulfide concentrations in the reactor. The specific MT degradation rate, as determined after 120 days of operation in R1, was 2.83 +/- 0.27 mmol MT g VSS(-1) day(-1). During biological desulfurization of liquid hydrocarbon phases, such as with liquefied petroleum gas (LPG), the combined removal of hydrogen sulfide and MT is desired. In R2, the simultaneous addition of sodium sulfide and MT was therefore studied and the effect of elevated sulfide concentrations was investigated. The addition of sodium sulfide resulted in enhanced disintegration of sludge granules, causing significant washout of biomass. Additional acetate, added to stimulate growth of methanogenic bacteria to promote granulation, was hardly converted at the termination of the experimental period. PMID:12569619

  17. Stable isotope compositions of serpentinite seamounts in the Mariana forearc: Serpentinization processes, fluid sources and sulfur metasomatism

    USGS Publications Warehouse

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

    2006-01-01

    The Mariana and Izu-Bonin arcs in the western Pacific are characterized by serpentinite seamounts in the forearc that provide unique windows into the mantle wedge. We present stable isotope (O, H, S, and C) data for serpentinites from Conical seamount in the Mariana forearc and S isotope data for Torishima seamount in the Izu-Bonin forearc in order to understand the compositions of fluids and temperatures of serpentinization in the mantle wedge, and to investigate the transport of sulfur from the slab to the mantle wedge. Six serpentine mineral separates have a restricted range of ??18O (6.5-8.5???). Antigorite separates have ??D values of -29.5??? to -45.5??? that reflect serpentinization within the mantle wedge whereas chrysotile has low ??D values (-51.8??? to -84.0???) as the result of re-equilibration with fluids at low temperatures. Fractionation of oxygen isotopes between serpentine and magnetite indicate serpentinization temperatures of 300-375 ??C. Two late cross-fiber chrysotile veins have higher ??18O values of 8.9??? to 10.8??? and formed at lower temperatures (as low as ???100 ??C). Aqueous fluids in equilibrium with serpentine at 300-375 ??C had ??18O = 6.5-9??? and ??D = -4??? to -26???, consistent with sediment dehydration reactions at temperatures <200 ??C in the subducting slab rather than a basaltic slab source. Three aragonite veins in metabasalt and siltstone clasts within the serpentinite flows have ??18O = 16.7-24.5???, consistent with the serpentinizing fluids at temperatures <250 ??C. ??13C values of 0.1-2.5??? suggest a source in subducting carbonate sediments. The ??34S values of sulfide in serpentinites on Conical Seamount (-6.7??? to 9.8???) result from metasomatism through variable reduction of aqueous sulfate (??34S = 14???) derived from slab sediments. Despite sulfur metasomatism, serpentinites have low sulfur contents (generally < 164 ppm) that reflect the highly depleted nature of the mantle wedge. The serpentinites are mostly enriched in 34S (median ??34Ssulfide = 4.5???), consistent with a 34S-enriched mantle wedge as inferred from arc lavas. ?? 2006 Elsevier B.V. All rights reserved.

  18. Production of sulfur from sulfur dioxide obtained from flue gas

    SciTech Connect

    Miller, R.

    1989-06-06

    This patent describes a regenerable process for recovery of elemental sulfur from a gas containing sulfur dioxide comprising the steps of: contacting the gas with an aqueous, alkaline reaction medium containing sodium sulfite in concentration sufficient so that a slurry containing solid sodium sulfide is formed to react sulfur dioxide with sodium sulfite to form a solution containing dissolved sodium pyrosulfite and sodium sulfite; separating sulfur dioxide from the solution produced to leave a residual mixture containing water, sodium sulfite and a sodium pyrosulfite, the amount of sulfur dioxide separated being equal to about one-third the amount of sulfur dioxide which reacted with sodium sulfite; adding, in substantial absence of air, sufficient water and sodium bicarbonate to the residual mixture to react with the dissolved sodium pyrsulfide and form a slurry of solid sodium sulfite suspended in the resulting aqueous, alkaline reaction medium and gaseous carbon dioxide; separating the gaseous carbon dioxide; separating the solid sodium sulfite from the aqueous alkaline reaction medium and recycling the separated reaction medium; reducing the separated sodium sulfite to sodium sulfide; adding the sodium sulfide to an aqueous reaction medium containing sodium bicarbonate and, in the substantial absence of air, carbonating the resulting mixture with the gaseous carbon dioxide to form a slurry of solid particles of sodium bicarbonate dispersed in an aqueous reactor medium containing sodium bicarbonate, along with a gas composed primarily of hydrogen sulfide.

  19. A New Use for High-Sulfur Coal

    NASA Technical Reports Server (NTRS)

    Lawson, D. D.; England, C.

    1982-01-01

    New process recovers some of economic value of high-sulfur coal. Although high-sulfur content is undesirable in most coal-utilization schemes (such as simple burning), proposed process prefers high-sulfur coal to produce electrical power or hydrogen. Potential exists for widespread application in energy industry.

  20. A primer on sulfur for the planetary geologist

    NASA Technical Reports Server (NTRS)

    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.

  1. Elemental sulfur in Eddy County, New Mexico

    USGS Publications Warehouse

    Hinds, Jim S.; Cunningham, Richard R.

    1970-01-01

    Sulfur has been reported in Eddy County, N. Mex., in rocks ranging from Silurian to Holocene in age at depths of 0-15,020 feet. Targets of present exploration are Permian formations in the Delaware Basin and northwest shelf areas at depths of less than 4,000 feet. Most of the reported sulfur occurrences in the shelf area are in the 'Abo' (as used by some subsurface geologists), Yeso, and San Andres Formations and the Artesia Group. Sulfur deposition in the dense dolomites of the 'Abo,' Yeso, and San Andres Formations is attributed to the reduction of ionic sulfate by hydrogen sulfide in formation waters in zones of preexisting porosity and permeability. A similar origin accounts for most of the sulfur deposits in the formations of the Artesia Group, but some of the sulfur in these formations may have originated in place through the alteration of anhydrite to carbonate and sulfur by the metabolic processes of bacteria in the presence of hydrocarbons. Exploration in the Delaware Basin area is directed primarily toward the Castile Formation. Sulfur deposits in the Castile Formation are found in irregular masses of cavernous brecciated secondary carbonate rock enveloped by impermeable anhydrite. The carbonate masses, or 'castiles,' probably originated as collapse features resulting from subsurface solution and upward stopping. Formation of carbonate rock and sulfur in the castiles is attributed to the reduction of brecciated anhydrite by bacteria and hydrocarbons in the same process ascribed to the formation of carbonate and sulfur in the caprocks of salt domes.

  2. MVC: A user-based on-line optimal control system for gas processing and treating plants. Development and results for claus sulfur recovery and sweetening modules. Topical report, June 1992-September 1993

    SciTech Connect

    Berkowitz, P.N.; Papadopoulos, M.N.; Colwell, L.W.; Poe, W.; Yiu, Y.

    1993-09-01

    The objective of this project was to develop and field validate modular, on-line, advanced control systems to optimize the operation of Claus sulfur recovery and sweetening in gas processing plants with emphasis on small and mid-sized facilities.

  3. Micro-textures and in situ sulfur isotopic analysis of spheroidal and zonal sulfides in the giant Jinding Zn-Pb deposit, Yunnan, China: Implications for biogenic processes

    NASA Astrophysics Data System (ADS)

    Xue, Chunji; Chi, Guoxiang; Fayek, Mostafa

    2015-05-01

    The Jinding deposit in Yunnan, southwest China, is the largest sandstone- and conglomerate-hosted Zn-Pb deposit in the world. In this paper, we report various micro-textures of spheroidal and zonal sulfides, such as pellet-shaped and colloform aggregates of pyrite and sphalerite, from the deposit and interpret them to be possibly related to micro-colonies of sulfate reducing bacteria, probably supporting an in situ BSR hypothesis. Micro-scale sulfur isotope analysis in different parts of the spheroidal and zonal sulfide aggregates, using secondary ion mass spectrometry (SIMS), revealed ?34S (VCDT) values as low as -48.4‰ for sulfides formed in the early-main stage disseminated ores in the western part of the deposit, possibly suggesting maximum sulfur isotopic fractionation through BSR. Relatively elevated ?34S (VCDT) values (-7.7‰ to -34.8‰, mainly from -10‰ to -20‰) for the late-stage, cavity-filling ores in the eastern part of the deposit, are interpreted to be possibly related to elevated temperatures close to the hydrothermal conduit and elevated ?34S values of the remaining sulfates resulting from the preceding BSR processes. The apparent discrepancy between the low temperatures required for BSR and the high temperatures indicated by fluid inclusions (>120 °C) may be reconciled through invoking episodic influx of ore-forming hydrothermal fluids into a shallow, relatively cool environment. It is proposed that the host rocks of the Jinding deposit have not been buried to great depths (?1 km), which, combined with the availability of hydrocarbons in the Jinding dome (a paleo-oil and gas reservoir), provides an ideal environment for BSR. Episodic influx of metal-carrying hydrothermal fluids temporarily and locally suppressed BSR and promoted thermo-chemical sulfate reduction (TSR), resulting in deposit- and micro-scale variations of ?34S.

  4. 40 CFR 60.642 - Standards for sulfur dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standards for sulfur dioxide. 60.642... Gas Processing: SO2 Emissions § 60.642 Standards for sulfur dioxide. (a) During the initial... reduction efficiency (Zi) to be determined from table 1 based on the sulfur feed rate (X) and the...

  5. 40 CFR 60.642 - Standards for sulfur dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standards for sulfur dioxide. 60.642... Gas Processing: SO2 Emissions § 60.642 Standards for sulfur dioxide. (a) During the initial... reduction efficiency (Zi) to be determined from table 1 based on the sulfur feed rate (X) and the...

  6. 40 CFR 60.642 - Standards for sulfur dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards for sulfur dioxide. 60.642... Gas Processing: SO2 Emissions § 60.642 Standards for sulfur dioxide. (a) During the initial... reduction efficiency (Zi) to be determined from table 1 based on the sulfur feed rate (X) and the...

  7. The Sulfur Cycle

    ERIC Educational Resources Information Center

    Kellogg, W. W.; And Others

    1972-01-01

    A model estimating the contributions of sulfur compounds by natural and human activities, and the rate of removal of sulfur from the atmosphere, is based on a review of the existing literature. Areas requiring additional research are identified. (AL)

  8. Sulfuric acid poisoning

    MedlinePLUS

    Sulfuric acid is a very strong chemical that is corrosive. Corrosive means it can cause severe burns and ... or mucous membranes. This article discusses poisoning from sulfuric acid. This is for information only and not for ...

  9. Tailoring Pore Size of Nitrogen-Doped Hollow Carbon Nanospheres for Confi ning Sulfur in Lithium–Sulfur Batteries

    SciTech Connect

    Zhou, Weidong; Wang, Chong M.; Zhang, Quiglin; Abruna, Hector D.; He, Yang; Wang, Jiangwei; Mao, Scott X.; Xiao, Xingcheng

    2015-08-19

    Three types of nitrogen-doped hollow carbon spheres with different pore sized porous shells are prepared to investigate the performance of sulfur confinement. The reason that why no sulfur is observed in previous research is determined and it is successfully demonstrated that the sulfur/polysulfide will overflow the porous carbon during the lithiation process.

  10. A mesoporous carbon–sulfur composite as cathode material for high rate lithium sulfur batteries

    SciTech Connect

    Choi, Hyunji; Zhao, Xiaohui; Kim, Dul-Sun; Ahn, Hyo-Jun; Kim, Ki-Won; Cho, Kwon-Koo; Ahn, Jou-Hyeon

    2014-10-15

    Highlights: • CMK-3 mesoporous carbon was synthesized as conducting reservoir for housing sulfur. • Sulfur/CMK-3 composites were prepared by two-stage thermal treatment. • The composite at 300 °C for 20 h shows improved electrochemical properties. - Abstract: Sulfur composite was prepared by encapsulating sulfur into CMK-3 mesoporous carbon with different heating times and then used as the cathode material for lithium sulfur batteries. Thermal treatment at 300 °C plays an important role in the sulfur encapsulation process. With 20 h of heating time, a portion of sulfur remained on the surface of carbon, whereas with 60 h of heating time, sulfur is confined deeply in the small pores of carbon that cannot be fully exploited in the redox reaction, thus causing low capacity. The S/CMK-3 composite with thermal treatment for 40 h at 300 °C contained 51.3 wt.% sulfur and delivered a high initial capacity of 1375 mA h g{sup ?1} at 0.1 C. Moreover, it showed good capacity retention of 704 mA h g{sup ?1} at 0.1 C and 578 mA h g{sup ?1} at 2 C even after 100 cycles, which proves its potential as a cathode material for high capability lithium sulfur batteries.

  11. CATALYST EVALUATION FOR A SULFUR DIOXIDE-DEPOLARIZED ELECTROLYZER

    SciTech Connect

    Hobbs, D; Hector Colon-Mercado, H

    2007-01-31

    Thermochemical processes are being developed to provide global-scale quantities of hydrogen. A variant on sulfur-based thermochemical cycles is the Hybrid Sulfur (HyS) Process which uses a sulfur dioxide depolarized electrolyzer (SDE) to produce the hydrogen. Testing examined the activity and stability of platinum and palladium as the electrocatalyst for the SDE in sulfuric acid solutions. Cyclic and linear sweep voltammetry revealed that platinum provided better catalytic activity with much lower potentials and higher currents than palladium. Testing also showed that the catalyst activity is strongly influenced by the concentration of the sulfuric acid electrolyte.

  12. Sulfur tolerant anode materials

    SciTech Connect

    Not Available

    1987-02-01

    The goal of this program is the development of a molten carbonate fuel cell (MCFC) anode which is more tolerant of sulfur contaminants in the fuel than the current state-of-the-art nickel-based anode structures. This program addresses two different but related aspects of the sulfur contamination problem. The primary aspect is concerned with the development of a sulfur tolerant electrocatalyst for the fuel oxidation reaction. A secondary issue is the development of a sulfur tolerant water-gas-shift reaction catalyst and an investigation of potential steam reforming catalysts which also have some sulfur tolerant capabilities. These two aspects are being addressed as two separate tasks.

  13. Neutralization and biodegradation of sulfur mustard. Final report, October 1995-June 1996

    SciTech Connect

    Harvey, S.P.; Szafraniec, L.L.; Beaudry, W.T.; Earley, J.T.; Irvine, R.L.

    1997-02-01

    The chemical warfare agent sulfur mustard was hydrolyzed to products that were biologically mineralized in sequencing batch reactors seeded with activated sludge. Greater than 90% carbon removal was achieved using laboratory scale bioreactors processing hydrolyzed munitions grade sulfur mustard obtained directly from the U.S. Chemical Stockpile. The bioreactor effluent was nontoxic and contained no detectable sulfur mustard or priority pollutants. The sulfur mustard hydrolysis biodegradation process has potential application to the congressionally mandated disposal of sulfur mustard stockpiles.

  14. 40 CFR 436.190 - Applicability; description of the Frasch sulfur subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Frasch sulfur subcategory. 436.190 Section 436.190 Protection of Environment ENVIRONMENTAL PROTECTION... Frasch Sulfur Subcategory § 436.190 Applicability; description of the Frasch sulfur subcategory. The provisions of this subpart are applicable to the processing of sulfur on shore and in marshes and...

  15. 40 CFR 436.190 - Applicability; description of the Frasch sulfur subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Frasch sulfur subcategory. 436.190 Section 436.190 Protection of Environment ENVIRONMENTAL PROTECTION... Frasch Sulfur Subcategory § 436.190 Applicability; description of the Frasch sulfur subcategory. The provisions of this subpart are applicable to the processing of sulfur on shore and in marshes and...

  16. 40 CFR 436.190 - Applicability; description of the Frasch sulfur subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Frasch sulfur subcategory. 436.190 Section 436.190 Protection of Environment ENVIRONMENTAL PROTECTION... SOURCE CATEGORY Frasch Sulfur Subcategory § 436.190 Applicability; description of the Frasch sulfur subcategory. The provisions of this subpart are applicable to the processing of sulfur on shore and in...

  17. 40 CFR 436.190 - Applicability; description of the Frasch sulfur subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Frasch sulfur subcategory. 436.190 Section 436.190 Protection of Environment ENVIRONMENTAL PROTECTION... SOURCE CATEGORY Frasch Sulfur Subcategory § 436.190 Applicability; description of the Frasch sulfur subcategory. The provisions of this subpart are applicable to the processing of sulfur on shore and in...

  18. 40 CFR 436.190 - Applicability; description of the Frasch sulfur subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Frasch sulfur subcategory. 436.190 Section 436.190 Protection of Environment ENVIRONMENTAL PROTECTION... SOURCE CATEGORY Frasch Sulfur Subcategory § 436.190 Applicability; description of the Frasch sulfur subcategory. The provisions of this subpart are applicable to the processing of sulfur on shore and in...

  19. Evaluation of the Cell Voltage of Electrolytic HI Concentration for Thermochemical Water-Splitting Iodine-Sulfur Process

    SciTech Connect

    Tanaka, Nobuyuki; Yoshida, Mitsunori; Okuda, Hiroyuki; Sato, Hiroyuki; Kubo, Shinji; Onuki, Kaoru

    2007-07-01

    Breakdown of the cell voltage in the electro-dialysis process for concentrating HIx solution (HI-H{sub 2}O-I{sub 2} mixture) was preliminarily examined in an effort to clarify the optimal operation condition as well as to optimize the cell design for the application to the thermochemical water-splitting IS process for large-scale hydrogen production. Basic data such as electric resistance of HIx solution, overvoltage of the iodine-iodide ion redox reaction at graphite electrode, and the membrane voltage drop, were measured using HIx solution with composition of interest. Also, a methodology for estimating the cell voltage was discussed. The calculated cell voltage agreed well with the experimental one indicating the validity of the procedure adopted. (authors)

  20. The nature of the sulfur in petroleum cokes

    SciTech Connect

    Varfolomeev, D.F.; Akhmetov, M.M.; Kairudinov, I.R.; Mukhametzyanova, R.M.

    1984-01-01

    The method of radioactive indicators has been used to investigate the nature of the sulfur fixed in coking residues and crude and calcined cokes obtained from a sulfurous petroleum residue. It has been shown that the sulfur compounds with a sulfide structure are unstable and are eliminated from the reaction mixture even during the coking process. The sulfur passes into the coke only from the components of the raw material that contain dibenzothiophene fragments or more aromatic thiophene fragments. In the process of heat treatment at temperatures up to 2000/sup 0/C, radioactive sulfur introduced into the coke with these components behaves in exactly the same way as the sulfur determined by the usual method of analysis, which confirms the thiophene nature of sulfur in cokes.

  1. Relationship between corrosion and the biological sulfur cycle: A review

    SciTech Connect

    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.

  2. Io - Geochemistry of sulfur

    NASA Technical Reports Server (NTRS)

    Lewis, J. S.

    1982-01-01

    The evidence from Voyager imaging, Earth-based spectral reflectivity studies, and thermal emission measurements combine to suggest an extremely fresh, volcanically recycled sulfur-rich crust for Io, with very shallow large-scale melting. Two present styles of volcanism are possible, depending on the thickness of local deposits of sulfur: shallow liquid sulfur magma generation with quiescent flooding, and high-temperature volcanism with violet eruption of a sulfur-iron magma driven by SO2. Evolutionary considerations preclude direct derivation of Io's lithosphere from any metal-bearing chondritic source material. Metal-free C3V- or C2M-type parent material of either primary or secondary origin is the most plausible direct antecedent of the present sulfur-rich crust. Sulfates are almost certainly important constituents of the mantle, and can participate in the recycling of reduced, dense sulfide species to prevent total extraction of sulfur into the core.

  3. Development of lysozyme-combined antibacterial system to reduce sulfur dioxide and to stabilize Italian Riesling ice wine during aging process

    PubMed Central

    Chen, Kai; Han, Shun-yu; Zhang, Bo; Li, Min; Sheng, Wen-jun

    2015-01-01

    For the purpose of SO2 reduction and stabilizing ice wine, a new antibacterial technique was developed and verified in order to reduce the content of sulfur dioxide (SO2) and simultaneously maintain protein stability during ice wine aging process. Hazardous bacterial strain (lactic acid bacteria, LAB) and protein stability of Italian Riesling ice wine were evaluated in terms of different amounts of lysozyme, SO2, polyphenols, and wine pH by single-factor experiments. Subsequently, a quadratic rotation-orthogonal composite design with four variables was conducted to establish the multiple linear regression model that demonstrated the influence of different treatments on synthesis score between LAB inhibition and protein stability of ice wine. The results showed that, synthesis score can be influenced by lysozyme and SO2 concentrations on an extremely significant level (P < 0.01). Furthermore, the lysozyme-combined antibacterial system, which is specially designed for ice wine aging, was optimized step by step by response surface methodology and ridge analysis. As a result, the optimal proportion should be control in ice wine as follows: 179.31 mg L?1 lysozyme, 177.14 mg L?1 SO2, 0.60 g L?1 polyphenols, and 4.01 ice wine pH. Based on this system, the normalized synthesis score between LAB inhibition and protein stability can reach the highest point 0.920. Finally, by the experiments of verification and comparison, it was indicated that lysozyme-combined antibacterial system, which was a practical and prospective method to reduce SO2 concentration and effectively prevent contamination from hazardous LAB, can be used to stabilize ice wine during aging process. PMID:26405531

  4. Development of lysozyme-combined antibacterial system to reduce sulfur dioxide and to stabilize Italian Riesling ice wine during aging process.

    PubMed

    Chen, Kai; Han, Shun-Yu; Zhang, Bo; Li, Min; Sheng, Wen-Jun

    2015-09-01

    For the purpose of SO2 reduction and stabilizing ice wine, a new antibacterial technique was developed and verified in order to reduce the content of sulfur dioxide (SO2) and simultaneously maintain protein stability during ice wine aging process. Hazardous bacterial strain (lactic acid bacteria, LAB) and protein stability of Italian Riesling ice wine were evaluated in terms of different amounts of lysozyme, SO2, polyphenols, and wine pH by single-factor experiments. Subsequently, a quadratic rotation-orthogonal composite design with four variables was conducted to establish the multiple linear regression model that demonstrated the influence of different treatments on synthesis score between LAB inhibition and protein stability of ice wine. The results showed that, synthesis score can be influenced by lysozyme and SO2 concentrations on an extremely significant level (P < 0.01). Furthermore, the lysozyme-combined antibacterial system, which is specially designed for ice wine aging, was optimized step by step by response surface methodology and ridge analysis. As a result, the optimal proportion should be control in ice wine as follows: 179.31 mg L(-1) lysozyme, 177.14 mg L(-1) SO2, 0.60 g L(-1) polyphenols, and 4.01 ice wine pH. Based on this system, the normalized synthesis score between LAB inhibition and protein stability can reach the highest point 0.920. Finally, by the experiments of verification and comparison, it was indicated that lysozyme-combined antibacterial system, which was a practical and prospective method to reduce SO2 concentration and effectively prevent contamination from hazardous LAB, can be used to stabilize ice wine during aging process. PMID:26405531

  5. Development of a solid absorption process for removal of sulfur from fuel gas. Second quarterly technical report

    SciTech Connect

    Stegen, G.E.

    1980-05-01

    Progress on development of the Solid Supported Molten Salt (SSMS) Process is reported. Absorption and regeneration reaction rate data were obtained using a gravimetric technique. Durability and salt impregnation tests were also performed on a number of commercially available and custom fabricated ceramic samples. Results to date indicate that lithium aluminate, magnesium oxide, and zirconium oxide may all be suitable ceramic support materials. Gravimetric reaction rate data has been developed which gives an estimate of reaction rates expected with the solid supported molten salt sorbent. Soaking the ceramic in a bath of the molten salt has been shown to be effective in filling the pores with salt. With some materials it is necessary to draw a vacuum on the bath during soaking in order to remove trapped gases.

  6. Implications for eruptive processes as indicated by sulfur dioxide emissions from Kilauea Volcano, Hawai'i, 1979-1997

    USGS Publications Warehouse

    Sutton, A.J.; Elias, T.; Gerlach, T.M.; Stokes, J.B.

    2001-01-01

    Ki??lauea Volcano, Hawai'i, currently hosts the longest running SO2 emission-rate data set on the planet, starting with initial surveys done in 1975 by Stoiber and his colleagues. The 17.5-year record of summit emissions, starting in 1979, shows the effects of summit and east rift eruptive processes, which define seven distinctly different periods of SO2 release. Summit emissions jumped nearly 40% with the onset (3 January 1983) of the Pu'u 'O??'o??-Ku??paianaha eruption on the east rift zone (ERZ). Summit SO2 emissions from Ki??lauea showed a strong positive correlation with short-period, shallow, caldera events, rather than with long-period seismicity as in more silicious systems. This correlation suggests a maturation process in the summit magma-transport system from 1986 through 1993. During a steady-state throughput-equilibrium interval of the summit magma reservoir, integration of summit-caldera and ERZ SO2 emissions reveals an undegassed volume rate of effusion of 2.1 ?? 105 m3/d. This value corroborates the volume-rate determined by geophysical methods, demonstrating that, for Ki??lauea, SO2 emission rates can be used to monitor effusion rate, supporting and supplementing other, more established geophysical methods. For the 17.5 years of continuous emission rate records at Ki??lauea, the volcano has released 9.7 ?? 106 t (metric tonnes) of SO2, 1.7 ?? 106 t from the summit and 8.0 ?? 106 t from the east rift zone. On an annual basis, the average SO2 release from Ki??lauea is 4.6 ?? 105 t/y, compared to the global annual volcanic emission rate of 1.2 ?? 107 t/y. ?? 2001 Elsevier Science B.V. All rights reserved.

  7. 40 CFR 436.190 - Applicability; description of the Frasch sulfur subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) MINERAL MINING AND PROCESSING POINT SOURCE CATEGORY Frasch Sulfur Subcategory...provisions of this subpart are applicable to the processing of sulfur on shore and in marshes and...

  8. 40 CFR 436.190 - Applicability; description of the Frasch sulfur subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...CONTINUED) EFFLUENT GUIDELINES AND STANDARDS MINERAL MINING AND PROCESSING POINT SOURCE CATEGORY Frasch Sulfur Subcategory...provisions of this subpart are applicable to the processing of sulfur on shore and in marshes and...

  9. 40 CFR 436.190 - Applicability; description of the Frasch sulfur subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) MINERAL MINING AND PROCESSING POINT SOURCE CATEGORY Frasch Sulfur Subcategory...provisions of this subpart are applicable to the processing of sulfur on shore and in marshes and...

  10. 40 CFR 436.190 - Applicability; description of the Frasch sulfur subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) MINERAL MINING AND PROCESSING POINT SOURCE CATEGORY Frasch Sulfur Subcategory...provisions of this subpart are applicable to the processing of sulfur on shore and in marshes and...

  11. 40 CFR 436.190 - Applicability; description of the Frasch sulfur subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...CONTINUED) EFFLUENT GUIDELINES AND STANDARDS MINERAL MINING AND PROCESSING POINT SOURCE CATEGORY Frasch Sulfur Subcategory...provisions of this subpart are applicable to the processing of sulfur on shore and in marshes and...

  12. Biostimulation of Oil Sands Process-Affected Water with Phosphate Yields Removal of Sulfur-Containing Organics and Detoxification.

    PubMed

    Quesnel, Dean M; Oldenburg, Thomas B P; Larter, Stephen R; Gieg, Lisa M; Chua, Gordon

    2015-11-01

    The ability to mitigate toxicity of oil sands process-affected water (OSPW) for return into the environment is an important issue for effective tailings management in Alberta, Canada. OSPW toxicity has been linked to classical naphthenic acids (NAs), but the toxic contribution of other acid-extractable organics (AEOs) remains unknown. Here, we examine the potential for in situ bioremediation of OSPW AEOs by indigenous algae. Phosphate biostimulation was performed in OSPW to promote the growth of indigenous photosynthetic microorganisms and subsequent toxicity and chemical changes were determined. After 12 weeks, the AEO fraction of phosphate-biostimulated OSPW was significantly less toxic to the fission yeast Schizosaccharomyces pombe than unstimulated OSPW. Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) analysis of the AEO fraction in phosphate-biostimulated OSPW showed decreased levels of SO3 class compounds, including a subset that may represent linear arylsulfonates. A screen with S. pombe transcription factor mutant strains for growth sensitivity to the AEO fraction or sodium dodecylbenzenesulfonate revealed a mode of toxic action consistent with oxidative stress and detrimental effects on cellular membranes. These findings demonstrate a potential algal-based in situ bioremediation strategy for OSPW AEOs and uncover a link between toxicity and AEOs other than classical NAs. PMID:26448451

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

    E-print Network

    Jones, William D.

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

  14. Economic feasibility of biochemical processes for the upgrading of crudes and the removal of sulfur, nitrogen, and trace metals from crude oil -- Benchmark cost establishment of biochemical processes on the basis of conventional downstream technologies. Final report FY95

    SciTech Connect

    Premuzic, E.T.

    1996-08-01

    During the past several years, a considerable amount of work has been carried out showing that microbially enhanced oil recovery (MEOR) is promising and the resulting biotechnology may be deliverable. At Brookhaven National Laboratory (BNL), systematic studies have been conducted which dealt with the effects of thermophilic and thermoadapted bacteria on the chemical and physical properties of selected types of crude oils at elevated temperatures and pressures. Current studies indicate that during the biotreatment several chemical and physical properties of crude oils are affected. The oils are (1) emulsified; (2) acidified; (3) there is a qualitative and quantitative change in light and heavy fractions of the crudes; (4) there are chemical changes in fractions containing sulfur compounds; (5) there is an apparent reduction in the concentration of trace metals; and (6) the qualitative and quantitative changes appear to be microbial species dependent; and (7) there is a distinction between biodegraded and biotreated oils. The downstream biotechnological crude oil processing research performed thus far is of laboratory scale and has focused on demonstrating the technical feasibility of downstream processing with different types of biocatalysts under a variety of processing conditions. Quantitative economic analysis is the topic of the present project which investigates the economic feasibility of the various biochemical downstream processes which hold promise in upgrading of heavy crudes, such as those found in California, e.g., Monterey-type, Midway Sunset, Honda crudes, and others.

  15. The Phases of Sulfur.

    ERIC Educational Resources Information Center

    Birdwhistell, Kurt R.

    1995-01-01

    Presents a demonstration that illustrates the dramatic changes that sulfur undergoes upon heating to 200 degrees centigrade and then cooling to room temperature. Supplements the demonstration of the rubberlike properties of catenasulfur made by rapid cooling of the sulfur melt in ice water. (JRH)

  16. Sulfur isotopic data

    SciTech Connect

    Rye, R.O.

    1987-01-01

    Preliminary sulfur isotope data have been determined for samples of the Vermillion Creek coal bed and associated rocks in the Vermillion Creek basin and for samples of evaporites collected from Jurassic and Triassic formations that crop out in the nearby Uinta Mountains. The data are inconclusive, but it is likely that the sulfur in the coal was derived from the evaporites.

  17. 40 CFR 52.1881 - Control strategy: Sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...remove sulfur oxides. (iii) Fossil fuel means natural gas, refinery...from such materials. (iv) Fossil fuel-fired steam generating unit...used in the process of burning fossil fuel for the purpose of producing...

  18. 40 CFR 52.1881 - Control strategy: Sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...remove sulfur oxides. (iii) Fossil fuel means natural gas, refinery...from such materials. (iv) Fossil fuel-fired steam generating unit...used in the process of burning fossil fuel for the purpose of producing...

  19. 40 CFR 52.1881 - Control strategy: Sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...remove sulfur oxides. (iii) Fossil fuel means natural gas, refinery...from such materials. (iv) Fossil fuel-fired steam generating unit...used in the process of burning fossil fuel for the purpose of producing...

  20. 40 CFR 52.1881 - Control strategy: Sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...remove sulfur oxides. (iii) Fossil fuel means natural gas, refinery...from such materials. (iv) Fossil fuel-fired steam generating unit...used in the process of burning fossil fuel for the purpose of producing...

  1. 40 CFR 52.1881 - Control strategy: Sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...remove sulfur oxides. (iii) Fossil fuel means natural gas, refinery...from such materials. (iv) Fossil fuel-fired steam generating unit...used in the process of burning fossil fuel for the purpose of producing...

  2. Direct Observation of Sulfur Radicals as Reaction Media in lithium Sulfur Batteries

    SciTech Connect

    Wang, Qiang; Zheng, Jianming; Walter, Eric D.; Pan, Huilin; Lu, Dongping; Zuo, Pengjian; Chen, Honghao; Deng, Zhiqun; Liaw, Bor Yann; Yu, Xiqian; Yang, Xiaoning; Zhang, Jiguang; Liu, Jun; Xiao, Jie

    2014-12-09

    Lithium sulfur (Li-S) battery has been regaining tremendous interest in recent years because of its attractive attributes such as high gravimetric energy, low cost and environmental benignity. However, it is still not conclusively known how polysulfide ring/chain participates in the whole cycling and whether the discharge and charge process follow the same pathway. Herein, we demonstrate the direct observation of sulfur radicals by using in situ electron paramagnetic resonance (EPR) technique. Based on the concentration changes of sulfur radicals at different potentials, it is revealed that the chemical and electrochemical reactions in Li-S cell are driven each other to proceed through sulfur radicals, leading to two completely different reaction pathways during discharge and charge. The proposed radical mechanism may provide new insights to investigate the interactions between sulfur species and the electrolyte, inspiring novel strategies to develop Li-S battery technology.

  3. Direct Observation of Sulfur Radicals as Reaction Media in Lithium Sulfur Batteries

    SciTech Connect

    Wang, Qiang; Zheng, Jianming; Walter, Eric; Pan, Huilin; Lv, Dongping; Zuo, Pengjian; Chen, Honghao; Deng, Z. D.; Liaw, Bor Y.; Yu, Xiqian; Yang, Xiao-Qing; Zhang, Ji-Guang; Liu, Jun; Xiao, Jie

    2015-01-09

    Lithium sulfur (Li-S) battery has been regaining tremendous interest in recent years because of its attractive attributes such as high gravimetric energy, low cost and environmental benignity. However, it is still not conclusively known how polysulfide ring/chain participates in the whole cycling and whether the discharge and charge processes follow the same pathway. Herein, we demonstrate the direct observation of sulfur radicals by using in situ electron paramagnetic resonance (EPR) technique. Based on the concentration changes of sulfur radicals at different potentials and the electrochemical characteristics of the cell, it is revealed that the chemical and electrochemical reactions in Li-S cell are driving each other to proceed through sulfur radicals, leading to two completely different reaction pathways during discharge and charge. The proposed radical mechanism may provide new perspectives to investigate the interactions between sulfur species and the electrolyte, inspiring novel strategies to develop Li-S battery technology.

  4. Direct Observation of Sulfur Radicals as Reaction Media in Lithium Sulfur Batteries

    DOE PAGESBeta

    Wang, Qiang; Zheng, Jianming; Walter, Eric; Pan, Huilin; Lv, Dongping; Zuo, Pengjian; Chen, Honghao; Deng, Z. D.; Liaw, Bor Y.; Yu, Xiqian; et al

    2015-01-09

    Lithium sulfur (Li-S) battery has been regaining tremendous interest in recent years because of its attractive attributes such as high gravimetric energy, low cost and environmental benignity. However, it is still not conclusively known how polysulfide ring/chain participates in the whole cycling and whether the discharge and charge processes follow the same pathway. Herein, we demonstrate the direct observation of sulfur radicals by using in situ electron paramagnetic resonance (EPR) technique. Based on the concentration changes of sulfur radicals at different potentials and the electrochemical characteristics of the cell, it is revealed that the chemical and electrochemical reactions in Li-Smore »cell are driving each other to proceed through sulfur radicals, leading to two completely different reaction pathways during discharge and charge. The proposed radical mechanism may provide new perspectives to investigate the interactions between sulfur species and the electrolyte, inspiring novel strategies to develop Li-S battery technology.« less

  5. Metal-Sulfur Battery Cathodes Based on PAN-Sulfur Composites.

    PubMed

    Wei, Shuya; Ma, Lin; Hendrickson, Kenville E; Tu, Zhengyuan; Archer, Lynden A

    2015-09-23

    Sulfur/polyacrylonitrile composites provide a promising route toward cathode materials that overcome multiple, stubborn technical barriers to high-energy, rechargeable lithium-sulfur (Li-S) cells. Using a facile thermal synthesis procedure in which sulfur and polyacrylonitrile (PAN) are the only reactants, we create a family of sulfur/PAN (SPAN) nanocomposites in which sulfur is maintained as S3/S2 during all stages of the redox process. By entrapping these smaller molecular sulfur species in the cathode through covalent bonding to and physical confinement in a conductive host, these materials are shown to completely eliminate polysulfide dissolution and shuttling between lithium anode and sulfur cathode. We also show that, in the absence of any of the usual salt additives required to stabilize the anode in traditional Li-S cells, Li-SPAN cells cycle trouble free and at high Coulombic efficiencies in simple carbonate electrolytes. Electrochemical and spectroscopic analysis of the SPAN cathodes at various stages of charge and discharge further show a full and reversible reduction and oxidation between elemental sulfur and Li-ions in the electrolyte to produce Li2S as the only discharge product over hundreds of cycles of charge and discharge at fixed current densities. PMID:26325146

  6. Determination of free sulfites (SO3-2) in dried fruits processed with sulfur dioxide by ion chromatography through anion exchange column and conductivity detection.

    PubMed

    Liao, Benjamin S; Sram, Jacqueline C; Files, Darin J

    2013-01-01

    A simple and effective anion ion chromatography (IC) method with anion exchange column and conductivity detector has been developed to determine free sulfites (SO3-2) in dried fruits processed with sulfur dioxide. No oxidation agent, such as hydrogen peroxide, is used to convert sulfites to sulfates for IC analysis. In addition, no stabilizing agent, such as formaldehyde, fructose or EDTA, is required during the sample extraction. This method uses aqueous 0.2 N NaOH as the solvent for standard preparation and sample extraction. The sulfites, either prepared from standard sodium sulfite powder or extracted from food samples, are presumed to be unbound SO3-2 in aqueous 0.2 N NaOH (pH > 13), because the bound sulfites in the sample matrix are released at pH > 10. In this study, sulfites in the standard solutions were stable at room temperature (i.e., 15-25 degrees C) for up to 12 days. The lowest standard of the linear calibration curve is set at 1.59 microg/mL SO3-2 (equivalent to 6.36 microg/g sample with no dilution) for analysis of processed dried fruits that would contain high levels (>1000 microg/g) of sulfites. As a consequence, this method typically requires significant dilution of the sample extract. Samples are prepared with a simple procedure of sample compositing, extraction with aqueous 0.2 N NaOH, centrifugation, dilution as needed, and filtration prior to IC. The sulfites in these sample extracts are stable at room temperature for up to 20 h. Using anion IC, the sulfites are eluted under isocratic conditions with 10 mM aqueous sodium carbonate solution as the mobile phase passing through an anion exchange column. The sulfites are easily separated, with an analysis run time of 18 min, regardless of the dried fruit matrix. Recoveries from samples spiked with sodium sulfites were demonstrated to be between 81 and 105% for five different fruit matrixes (apricot, golden grape, white peach, fig, and mango). Overall, this method is simple to perform and effective for the determination of high levels of sulfites in dried fruits. PMID:24282955

  7. ENGINEERING/ECONOMIC ANALYSES OF COAL PREPARATION WITH SO2 CLEANUP PROCESSES FOR KEEPING HIGHER SULFUR COALS IN THE ENERGY MARKET

    EPA Science Inventory

    For purposes of this study, higher sulfur coals from the Northern Appalachian and Eastern Interior Regions were selected since they have been shown to have reasonable physical cleaning potential. Then, possible users of these coals in the electric power generating industry were e...

  8. Sulfuric Acid on Europa

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Frozen sulfuric acid on Jupiter's moon Europa is depicted in this image produced from data gathered by NASA's Galileo spacecraft. The brightest areas, where the yellow is most intense, represent regions of high frozen sulfuric acid concentration. Sulfuric acid is found in battery acid and in Earth's acid rain.

    This image is based on data gathered by Galileo's near infrared mapping spectrometer.

    Europa's leading hemisphere is toward the bottom right, and there are enhanced concentrations of sulfuric acid in the trailing side of Europa (the upper left side of the image). This is the face of Europa that is struck by sulfur ions coming from Jupiter's innermost moon, Io. The long, narrow features that crisscross Europa also show sulfuric acid that may be from sulfurous material extruded in cracks.

    Galileo, launched in 1989, has been orbiting Jupiter and its moons since December 1995. JPL manages the Galileo mission for NASA's Office of Space Science, Washington DC. JPL is a division of the California Institute of Technology, Pasadena, CA.

  9. Are we getting enough sulfur in our diet?

    PubMed Central

    Nimni, Marcel E; Han, Bo; Cordoba, Fabiola

    2007-01-01

    Sulfur, after calcium and phosphorus, is the most abundant mineral element found in our body. It is available to us in our diets, derived almost exclusively from proteins, and yet only 2 of the 20 amino acids normally present in proteins contains sulfur. One of these amino acids, methionine, cannot be synthesized by our bodies and therefore has to be supplied by the diet. Cysteine, another sulfur containing amino acid, and a large number of key metabolic intermediates essential for life, are synthesized by us, but the process requires a steady supply of sulfur. Proteins contain between 3 and 6% of sulfur amino acids. A very small percentage of sulfur comes in the form of inorganic sulfates and other forms of organic sulfur present in foods such as garlic, onion, broccoli, etc. The minimal requirements (RDA) for all the essential amino acids have always been estimated in terms of their ability to maintain a nitrogen balance. This method asses amino acid requirements for protein synthesis, only one of the pathways that methionine follows after ingestion. To adequately evaluate the RDA for methionine, one should perform, together with a nitrogen balance a sulfur balance, something never done, neither in humans nor animals. With this in mind we decided to evaluate the dietary intake of sulfur (as sulfur amino acids) in a random population and perform sulfur balance studies in a limited number of human volunteers. Initially this was done to try and gain some information on the possible mode of action of a variety of sulfur containing compounds (chondroitin sulfate, glucosamine sulfate, and others, ) used as dietary supplements to treat diseases of the joints. Out of this study came information that suggested that a significant proportion of the population that included disproportionally the aged, may not be receiving sufficient sulfur and that these dietary supplements, were very likely exhibiting their pharmacological actions by supplying inorganic sulfur. PMID:17986345

  10. Sulfur removal from high-sulfur Illinois coal by low-temperature perchloroethylene (PCE) extraction. Final technical report, 1 September, 1992--31 August, 1993

    SciTech Connect

    Chou, M.I.M.; Lytle, J.M.; Ruch, R.R.; Kruse, C.W.; Chaven, C.; Hackley, K.C.; Hughes, R.E.; Harvey, R.D.; Frost, J.K.; Buchanan, D.H.; Stucki, J.W.; Huffman, G.P.; Huggins, F.E.

    1993-12-31

    The Midwest Ore Processing Co. (MWOPC) has reported a precombustion coal desulfurization process using perchloroethylene (PCE) at 120 C to remove up to 70% of the organic sulfur. The purposes of this research were to independently confirm and possibly to improve the organic sulfur removal from Illinois coals with the PCE desulfurization and to verify the ASTM forms-of-sulfur determination for evaluation of the process. An additional goal was to develop a dechlorination procedure to remove excess PCE from the PCE-treated coal. A laboratory scale operation of the MWOPC PCE desulfurization process was demonstrated, and a dechlorination procedure to remove excess PCE from the PCE-treated coal was developed. The authors have determined that PCE desulfurization removed mainly elemental sulfur from coal. The higher the level of coal oxidization, the larger the amount of elemental sulfur that is removed by PCE extraction. The increased elemental sulfur during short-term preoxidation is found to be pH dependent and is attributed to coal pyrite oxidation under acidic (pH < 2) conditions. The non-ASTM sulfur analyses confirmed the hypothesis that the elemental sulfur produced by oxidation of pyrite complicates the interpretation of analytical data for PCE process evaluations when only the ASTM forms-of-sulfur is used. When the ASTM method is used alone, the elemental sulfur removed during PCE desulfurization is counted as organic sulfur. A study using model compounds suggests that mild preoxidation treatment of coal described by MWOPC for removal of organic sulfur does not produce enough oxidized organic sulfur to account for the amounts of sulfur removal reported. Furthermore, when oxidation of coal-like organosulfur compounds does occur, the products are inconsistent with production of elemental sulfur, the product reported by MWOPC. Overall, it is demonstrated that the PCE process is not suitable for organic sulfur removal.

  11. Deep sulfur cycle

    NASA Astrophysics Data System (ADS)

    Shimizu, N.; Mandeville, C. W.

    2009-12-01

    Geochemical cycle of sulfur in near-surface reservoirs has been a subject of intense studies for decades. It has been shown that sulfur isotopic compositions of sedimentary sulfides and sulfates record interactions of the atmosphere, hydrosphere, biosphere and lithosphere, with ?34S of sedimentary sulfides continuously decreasing from 0‰ toward present-day values of ~-30 to -40‰ over the Phanerozoic (e.g., Canfield, 2004). It has also been shown that microbial reduction of the present-day seawater sulfate (?34S=+21‰) results in large shifts in isotopic compositions of secondary pyrites in altered oceanic crust (to ?34S=-70‰: Rouxel et al., 2009). How much of these near surface isotopic variations survive during deep geochemical cycle of sulfur interacting with the mantle infinite reservoir with ?34S=0‰? Could extent of their survival be used as a tracer of processes and dynamics involved in deep geochemical cycle? As a first step toward answering these questions, ?34S was determined in-situ using a Cameca IMS 1280 ion microprobe at Woods Hole Oceanographic Institution in materials representing various domains of deep geochemical cycle. They include pyrites in altered MORB as potential subducting materials and pyrites in UHP eclogites as samples that have experienced subduction zone processes, and mantle-derived melts are represented by olivine-hosted melt inclusions in MORB and those in IAB, and undegassed submarine OIB glasses. Salient features of the results include: (1) pyrites in altered MORB (with O. Rouxel; from ODP site 801 and ODP Hole 1301B) range from -70 to +19‰, (2) pyrites in UHP eclogites from the Western Gneiss Region, Norway (with B. Hacker and A. Kylander-Clark) show a limited overall range from -3.4 to + 2.8‰ among five samples, with one of them covering almost the entire range, indicating limited scale lengths of isotopic equilibration during subduction, (3) olivine-hosted melt inclusions in arc basalts from Galunggung (-2.8 - +5.2‰ with majority between +3 and +5), Krakatau (+1.5 - +8.6‰ with a cluster around +3 - +5), and Augustine (+8 - +12‰) show larger variations among arc magmas than previously known, (4) olivine-hosted melt inclusions from a FAMOUS lava (519-4-1) range from -9.5 to +10.5‰, and (5) undegassed submarine glasses from Samoa (with M. Jackson) appear to show separate ranges for individual islands, including Vailulu clustering around -1.9 to +2.1‰ and Malumalu ranging from -0.9 to -12.1‰. Overall, the results clearly show that low temperature signatures are not completely erased during recycling and isotopic exchange with the mantle infinite reservoir, and that mantle-derived melts still display large isotopic variations for small sampling scales, similar to observations on other isotope systems. Canfield, D. E. (2004) Amer. Jour. Sci., 304, 839-861. Rouxel, O. et al., (2009) Goldschmidt Conf. Abstract.

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

    PubMed

    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-hydrogen. PMID:26551237

  13. Active Microbial Sulfur Disproportionation in

    E-print Network

    Kaufman, Alan Jay

    Active Microbial Sulfur Disproportionation in the Mesoproterozoic David T. Johnston,1 *. Boswell A E. Canfield5 The environmental expression of sulfur compound disproportionation has been placed sulfur isotope 33S. These measurements imply that sulfur compound disproportionation was an active part

  14. Radiolysis of Sulfuric Acid, Sulfuric Acid Monohydrate, and Sulfuric Acid Tetrahydrate and Its Relevance to Europa

    NASA Technical Reports Server (NTRS)

    Loeffler, M. J.; Hudson, R. L.; Moore, M. H.; Carlson, R. W.

    2011-01-01

    We report laboratory studies on the 0.8 MeV proton irradiation of ices composed of sulfuric acid (H2SO4), sulfuric acid monohydrate (H2SO4 H2O), and sulfuric acid tetrahydrate (H2SO4 4H2O) between 10 and 180 K. Using infrared spectroscopy, we identify the main radiation products as H2O, SO2, (S2O3)x, H3O+, HSO4(exp -), and SO4(exp 2-). At high radiation doses, we find that H2SO4 molecules are destroyed completely and that H2SO4 H2O is formed on subsequent warming. This hydrate is significantly more stable to radiolytic destruction than pure H2SO4, falling to an equilibrium relative abundance of 50% of its original value on prolonged irradiation. Unlike either pure H2SO4 or H2SO4 H2O, the loss of H2SO4 4H2O exhibits a strong temperature dependence, as the tetrahydrate is essentially unchanged at the highest irradiation temperatures and completely destroyed at the lowest ones, which we speculate is due to a combination of radiolytic destruction and amorphization. Furthermore, at the lower temperatures it is clear that irradiation causes the tetrahydrate spectrum to transition to one that closely resembles the monohydrate spectrum. Extrapolating our results to Europa s surface, we speculate that the variations in SO2 concentrations observed in the chaotic terrains are a result of radiation processing of lower hydration states of sulfuric acid and that the monohydrate will remain stable on the surface over geological times, while the tetrahydrate will remain stable in the warmer regions but be destroyed in the colder regions, unless it can be reformed by other processes, such as thermal reactions induced by diurnal cycling.

  15. Sedimentary sulfur geochemistry of the Paleogene Green River Formation, western USA: Implications for interpreting depositional and diagenetic processes in saline alkaline lakes

    NASA Astrophysics Data System (ADS)

    Tuttle, Michele L.; Goldhaber, Martin B.

    1993-07-01

    The sulfur geochemistry of the lacustrine Paleogene Green River Formation (Colorado, Utah, and Wyoming, USA) is unlike that of most marine and other lacustrine rocks. Distinctive chemical, isotopic, and mineralogical characteristics of the formation are pyrrhotite and marcasite, high contents of iron mineral sulfides strikingly enriched in 34S, cyclical trends in sulfur abundance and ? 34S values, and long-term evolutionary trends in ? 34S values. Analyses that identified and quantified these characteristics include carbonate-free abundance of organic carbon (0.13-47 wt%), total iron (0.31-13 wt%), reactive iron (>70% of total iron), total sulfur (0.02-16 wt%), acid-volatile monosulfide (S Av), disulfide (S Di > 70% of total sulfur), sulfate (S SO4) and organosulfur (S Org); isotopic composition of separated sulfur phases (? 34S Di,Av up to +49‰); and mineralogy, morphology and paragenesis of sulfide minerals. Mineralogy, morphology, ? 34S Di,Av, and ? 34S Org have a distinctive relation, reflecting variable and unique depositional and early diagenetic conditions in the Green River lakes. When the lakes were brackish, dissimilatory sulfate-reducing bacteria in the sediment produced H 2S, which initially reacted with labile iron to form pyrite framboids and more gradually with organic matter to form organosulfur compounds. During a long-lived stage of saline lake water, the amount of sulfate supplied by inflow decreased and alkalinity and pH of lake waters increased substantially. Extensive bacterial sulfate reduction in the water column kept lake waters undersaturated with sulfate minerals. A very high H 2S:SO 4 ratio developed in stagnant bottom water aided by the high pH that kinetically inhibited iron sulfidization. Progressive removal of H 2S by coeval formation of iron sulfides and organosulfur compounds caused the isotopic composition of the entire dissolved sulfur reservoir to evolve to ? 34S values much greater than that of inflow sulfate, which is estimated to have been +20‰ A six-million-year interval within Lake Uinta cores records this evolution as well as smaller systematic changes in ? 34S, interpreted to reflect ~ 100,000-year lake-level cycles. When porewater was exceptionally reducing, unstable FeS phases eventually recrystallized to pyrrhotite during diagenesis. A much later reaction related to weathering altered pyrrhotite to marcasite.

  16. Sedimentary sulfur geochemistry of the Paleogene Green River Formation, western USA: Implications for interpreting depositional and diagenetic processes in saline alkaline lakes

    USGS Publications Warehouse

    Tuttle, M.L.; Goldhaber, M.B.

    1993-01-01

    The sulfur geochemistry of the lacustrine Paleogene Green River Formation (Colorado, Utah, and Wyoming, USA) is unlike that of most marine and other lacustrine rocks. Distinctive chemical, isotopic, and mineralogical characteristics of the formation are pyrrhotite and marcasite, high contents of iron mineral sulfides strikingly enriched in 34S, cyclical trends in sulfur abundance and ??34S values, and long-term evolutionary trends in ??34S values. Analyses that identified and quantified these characteristics include carbonate-free abundance of organic carbon (0.13-47 wt%), total iron (0.31-13 wt%), reactive iron (>70% of total iron), total sulfur (0.02-16 wt%), acid-volatile monosulfide (SAv), disulfide (SDi > 70% of total sulfur), sulfate (SSO4) and organosulfur (SOrg); isotopic composition of separated sulfur phases (??34SDi,Av up to +49???); and mineralogy, morphology and paragenesis of sulfide minerals. Mineralogy, morphology, ??34SDi,Av, and ??34SOrg have a distinctive relation, reflecting variable and unique depositional and early diagenetic conditions in the Green River lakes. When the lakes were brackish, dissimilatory sulfate-reducing bacteria in the sediment produced H2S, which initially reacted with labile iron to form pyrite framboids and more gradually with organic matter to form organosulfur compounds. During a long-lived stage of saline lake water, the amount of sulfate supplied by inflow decreased and alkalinity and pH of lake waters increased substantially. Extensive bacterial sulfate reduction in the water column kept lake waters undersaturated with sulfate minerals. A very high H2S:SO4 ratio developed in stagnant bottom water aided by the high pH that kinetically inhibited iron sulfidization. Progressive removal of H2S by coeval formation of iron sulfides and organosulfur compounds caused the isotopic composition of the entire dissolved sulfur reservoir to evolve to ??34S values much greater than that of inflow sulfate, which is estimated to have been +20??? A six-million-year interval within Lake Uinta cores records this evolution as well as smaller systematic changes in ??34S, interpreted to reflect ~ 100,000-year lake-level cycles. When porewater was exceptionally reducing, unstable FeS phases eventually recrystallized to pyrrhotite during diagenesis. A much later reaction related to weathering altered pyrrhotite to marcasite. ?? 1993.

  17. Mass-dependent sulfur isotope fractionation during reoxidative sulfur cycling: A case study from Mangrove Lake, Bermuda

    NASA Astrophysics Data System (ADS)

    Pellerin, André; Bui, Thi Hao; Rough, Mikaella; Mucci, Alfonso; Canfield, Donald E.; Wing, Boswell A.

    2015-01-01

    The multiple sulfur isotope composition of porewater sulfate from the anoxic marine sapropel of Mangrove Lake, Bermuda was measured in order to establish how multiple sulfur isotopes are fractionated during reoxidative sulfur cycling. The porewater-sulfate ?34S and ?33S dataset exhibits the distinct isotopic signatures of microbial sulfate reduction and sulfur reoxidation. We reproduced the measurements with a simple diagenetic model that yielded fractionation factors for net sulfate removal of between -29.2‰ and -32.5‰. A new approach to isotopic modeling of the sulfate profiles, informed by the chemistry of sulfur intermediate compounds in Mangrove Lake, reveals that sulfate reduction produces a relatively small intrinsic fractionation and that an active reoxidative sulfur cycle increases the fractionation of the measured values. Based on the model results, the reoxidative cycle of Mangrove Lake appears to include sulfide oxidation to elemental sulfur followed by the disproportionation of the elemental sulfur to sulfate and sulfide. This model also indicates that the reoxidative sulfur cycle of Mangrove Lake turns over from 50 to 80% of the sulfide produced by microbial sulfate reduction. The Mangrove Lake case study shows how sulfur isotope fractionations can be separated into three different “domains” in ?33S-?34S space based on their ability to resolve reductive and reoxidative sulfur transformations. The first domain that differentiates reductive and reoxidative sulfur cycling is well illustrated by previous studies and requires 34S-32S fractionations more negative than ?-70‰, beyond the fractionation limit of microbial sulfate reduction at earth surface temperatures. The second domain that distinguishes reductive and reoxidative processes is between 34S-32S fractionations of -40‰ and 0‰, where the 33S-32S fractionations of sulfate reduction and reoxidation are significantly different. In the remaining domain (between 34S-32S fractionations -70‰ and -40‰), the similarity of the multiple sulfur isotope signals from microbial sulfate reduction and disproportionation means that the two processes cannot be discriminated from each other.

  18. Under sulfur's spell

    NASA Astrophysics Data System (ADS)

    Rauchfuss, Thomas

    2011-08-01

    Thomas Rauchfuss marvels at the diversity of sulfur reactivity. Although it poisons most industrial catalysts, it adopts many forms in nature and takes on a variety of biological roles -- including that of a biocatalyst.

  19. Two-step rapid sulfur capture. Final report

    SciTech Connect

    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.

  20. The sulfur metabolism of Cytophaga johnsonae

    SciTech Connect

    Gilmore, D.F.

    1989-01-01

    Because the cellular sulfur of most bacteria is essentially reduced sulfur form, the energetically expensive process of assimilatory sulfate reduction is prevented by various regulatory mechanisms when reduced sulfur is available. However, members of the Cytophaga-Flexibacter group of gliding bacteria contain 20% or more of their sulfur in the form of the sulfonate moiety of sulfonolipids, which is derived from cysteate; thus a large portion of their cellular sulfur is only one step more reduced than sulfate. Regulation of sulfate assimilation by Cytophaga johnsonae differs from that in other bacteria studied in that, when reduced sulfur sources such as a low concentration of cystine or a peptide-containing medium are available, the initial steps of sulfate assimilation that lead to cysteate, and thus sulfonolipid synthesis are operative, whereas the terminal steps of sulfate assimilation leading to cysteine and methionine (reduced sulfur) synthesis are repressed. The biosynthetic pathway leading to cysteate has not yet been elucidated. Cysteate sulfur can be derived from either sulfate or cystine, but the origin of the carbon is an enigma. It appears that cysteate carbon arises from a glycolytic intermediate. In a series of experiments with cell-free extracts, no evidence was obtained for the participation of phosphoenolpyruvate as a precursor to cysteate. Two lines of evidence support the hypothesis that phosphoserine is the ultimate precursor to cysteate: (a) this pathway does not require the existence of sulfonate intermediates (none have ever been detected), and (b) addition of phosphoserine to a cell extract incubated with ({sup 35}S)cysteine stimulated the incorporation of {sup 35}S into cysteate.

  1. No sulfur flows on Io

    NASA Technical Reports Server (NTRS)

    Young, A. T.

    1984-01-01

    Physical and chemical properties of elemental sulfur are incompatible with the suggestion that the colored flows associated with volcanoes on Io are quenched unstable allotropes of sulfur. Either the volcanic flows are not sulfur, or some mechanism other than quenching is required to produce colored forms of sulfur in them. The properties of sulfur are unsuited to the production and survival of colored unstable allotropes on Io. The color of this object is probably due to some other material, possibly iron compounds.

  2. The Biogeochemistry of Sulfur in Hydrothermal Systems

    NASA Technical Reports Server (NTRS)

    Schulte, Mitchell; Rogers, K. L.; DeVincenzi, Donald L. (Technical Monitor)

    2001-01-01

    The incorporation of sulfur into many biomolecules likely dates back to the development of the earliest metabolic strategies. Sulfur is common in enzymes and co-enzymes and is an indispensable structural component in many peptides and proteins. Early metabolism may have been heavily influenced by the abundance of sulfide minerals in hydrothermal systems. The incorporation of sulfur into many biomolecules likely dates back to the development of the earliest metabolic strategies. Sulfur is common in enzymes and co-enzymes and is an indispensable structural component in many peptides and proteins. Early metabolism may have been heavily influenced by the abundance of sulfide minerals in hydrothermal systems. Understanding how sulfur became prevalent in biochemical processes and many biomolecules requires knowledge of the reaction properties of sulfur-bearing compounds. We have previously estimated thermodynamic data for thiols, the simplest organic sulfur compounds, at elevated temperatures and pressures. If life began in hydrothermal environments, it is especially important to understand reactions at elevated temperatures among sulfur-bearing compounds and other organic molecules essential for the origin and persistence of life. Here we examine reactions that may have formed amino acids with thiols as reaction intermediates in hypothetical early Earth hydrothermal environments. (There are two amino acids, cysteine and methionine, that contain sulfur.) Our calculations suggest that significant amounts of some amino acids were produced in early Earth hydrothermal fluids, given reasonable concentrations H2, NH3, H2S and CO. For example, preliminary results indicate that glycine activities as high as 1 mmol can be reached in these systems at 100 C. Alanine formation from propanethiol is also a favorable reaction. On the other hand, the calculated equilibrium log activities of cysteine and serine from propanethiol are -21 and -19, respectively, at 100 C. These results indicate that while amino acid formation with thiols as intermediates is favored in some cases, other mechanisms may have been necessary to produce significant amounts of other amino acids. Coupled with our previous results for thiols, these studies imply that sulfur may have been easily incorporated into the organic geochemistry of early Earth hydrothermal systems, leading to its widespread use in biomolecules. Formation of more complex biomolecules in hydrothermal systems may have required sulfur-bearing organic compounds as reaction intermediates.

  3. Low-cost silica, calcite and metal sulfide scale control through on-site production of sulfurous acid from H{sub 2}S or elemental sulfur

    SciTech Connect

    Gallup, D.L.; Kitz, K.

    1997-12-31

    UNOCAL Corporation currently utilizes brine pH modification technology to control scale deposition. Acids utilized in commercial operations include, sulfuric and hydrochloric. A new process reduces costs by producing acid on-site by burning hydrogen sulfide or elemental sulfur. Hydrogen sulfide in non-condensible gas emissions is reduced by oxidization to sulfurous acid. Brine or condensate is treated with sulfurous acid to control scale deposition, mitigate corrosion and improve gas partitioning in condensers.

  4. Biotic and abiotic carbon to sulfur bond cleavage

    SciTech Connect

    Frost, J.W.

    1991-01-01

    Cleavage of aliphatic organosulfonate carbon to sulfur (C-S) bonds, a critical link in the global biogeochemical sulfur cycle, has been identified in Escherichia coli K-12. Enormous quantities of inorganic sulfate are continuously converted (Scheme I) into methanesulfonic acid 1 and acylated 3-(6-sulfo-{alpha}-D-quinovopyranosyl)-L-glycerol 2. Biocatalytic desulfurization (Scheme I) of 1 and 2, which share the structural feature of an aliphatic carbon bonded to a sulfonic acid sulfur, completes the cycle, Discovery of this desulfurization in E. coli provides an invaluable paradigm for study of a biotic process which, via the biogeochemical cycle, significantly influences the atmospheric concentration of sulfur-containing molecules.

  5. Multiple sulfur isotopes fractionations associated with abiotic sulfur transformations in Yellowstone National Park geothermal springs

    PubMed Central

    2014-01-01

    Background The paper presents a quantification of main (hydrogen sulfide and sulfate), as well as of intermediate sulfur species (zero-valent sulfur (ZVS), thiosulfate, sulfite, thiocyanate) in the Yellowstone National Park (YNP) hydrothermal springs and pools. We combined these measurements with the measurements of quadruple sulfur isotope composition of sulfate, hydrogen sulfide and zero-valent sulfur. The main goal of this research is to understand multiple sulfur isotope fractionation in the system, which is dominated by complex, mostly abiotic, sulfur cycling. Results Water samples from six springs and pools in the Yellowstone National Park were characterized by pH, chloride to sulfate ratios, sulfide and intermediate sulfur species concentrations. Concentrations of sulfate in pools indicate either oxidation of sulfide by mixing of deep parent water with shallow oxic water, or surface oxidation of sulfide with atmospheric oxygen. Thiosulfate concentrations are low (<6 ?mol L-1) in the pools with low pH due to fast disproportionation of thiosulfate. In the pools with higher pH, the concentration of thiosulfate varies, depending on different geochemical pathways of thiosulfate formation. The ?34S values of sulfate in four systems were close to those calculated using a mixing line of the model based on dilution and boiling of a deep hot parent water body. In two pools ?34S values of sulfate varied significantly from the values calculated from this model. Sulfur isotope fractionation between ZVS and hydrogen sulfide was close to zero at pH?sulfur is slightly heavier than hydrogen sulfide due to equilibration in the rhombic sulfur–polysulfide – hydrogen sulfide system. Triple sulfur isotope (32S, 33S, 34S) fractionation patterns in waters of hydrothermal pools are more consistent with redox processes involving intermediate sulfur species than with bacterial sulfate reduction. Small but resolved differences in ?33S among species and between pools are observed. Conclusions The variation of sulfate isotopic composition, the origin of differences in isotopic composition of sulfide and zero–valent sulfur, as well as differences in ?33S of sulfide and sulfate are likely due to a complex network of abiotic redox reactions, including disproportionation pathways. PMID:24959098

  6. Hydrogen and Sulfur Production from Hydrogen Sulfide Wastes 

    E-print Network

    Harkness, J.; Doctor, R. D.

    1993-01-01

    A new hydrogen sulfide waste-treatment process that uses microwave plasma-chemical technology is currently under development in the Soviet Union and in the United States. Whereas the present waste treatment process only recovers sulfur at best...

  7. Are sulfur isotope ratios sufficient to determine the antiquity of sulfate reduction. [implications for chemical evolution

    NASA Technical Reports Server (NTRS)

    Ashendorf, D.

    1980-01-01

    Possible limitations on the use of sulfur isotope ratios in sedimentary sulfides to infer the evolution of microbial sulfate reduction are discussed. Current knowledge of the ways in which stable sulfur isotope ratios are altered by chemical and biological processes is examined, with attention given to the marine sulfur cycle involving various microbial populations, and sulfur reduction processes, and it is noted that satisfactory explanations of sulfur isotope ratios observed in live organisms and in sediments are not yet available. It is furthermore pointed out that all members of the same genus of sulfate reducing bacteria do not always fractionate sulfur to the same extent, that the extent of sulfur fractionation by many sulfate-reducing organisms has not yet been determined, and that inorganic processes can also affect sulfur isotope fractionation values. The information currently available is thus concluded to be insufficient to determine the time of initial appearance of biological sulfate reduction.

  8. Comparative aspects of sulfur mineralization in sediments of a eutrophic lake basin.

    PubMed

    King, G M; Klug, M J

    1982-06-01

    The net mineralization of organic sulfur compounds in surface sediments of Wintergreen Lake was estimated from a mass-balance budget of sulfur inputs and sediment sulfur concentrations. The net mineralization of organic sulfur inputs is <50% complete, which is consistent with the dominance of organic sulfur (>80% of total sulfur) in sediment. Although sediment sulfur is predominantly organic, sulfate reduction is the most significant process in terms of the quantities of sulfur transformed in surface sediments. Rates of sulfate reduction in these sediments average 7 mmol/m per day. On an annual basis, this rate is 19-fold greater than net rates of organic sulfur mineralization and 65-fold greater than sulfate ester hydrolysis. PMID:16346037

  9. Analytical method for the evaluation of sulfur functionalities in American coals. Final report

    SciTech Connect

    Attar, A.

    1983-05-01

    This investigation consisted of the following 6 tasks: (1) improve the instrumentation for the sulfur functional groups analysis and make it more reliable. (2) create a set of reference standards of sulfur-containing compounds. (3) examine the sulfur groups distribution in untreated and desulfurized coals. (4) examine the sulfur functionalities in raw and processed coals, i.e., liquefied coals. (5) determine the distribution of sulfur functionalities in modified coals. (6) prepare computer programs for calculations related to the distribution of sulfur functional groups in coal. Each task is discussed and results are presented. Appendix A contains the computer program used to interpret the data. 31 references, 56 figures, 17 tables.

  10. Onboard Detection of Active Canadian Sulfur Springs: A Europa Analogue

    E-print Network

    Onboard Detection of Active Canadian Sulfur Springs: A Europa Analogue Rebecca Castano (1) Kiri of in- situ onboard detection in which the Earth Observing-1 spacecraft detects surface sulfur deposits analogue for the Europan surface. In this paper, we describe the process of developing the onboard

  11. Sulfur copolymers for infrared optical imaging

    NASA Astrophysics Data System (ADS)

    Namnabat, S.; Gabriel, J. J.; Pyun, J.; Norwood, R. A.; Dereniak, E. L.; van der Laan, J.

    2014-06-01

    The development of organic polymers with low infrared absorption has been investigated as a possible alternative to inorganic metal oxide, semiconductor, or chalcogenide-based materials for a variety of optical devices and components, such as lenses, goggles, thermal imaging cameras and optical fibers. In principle, organic-based polymers are attractive for these applications because of their low weight, ease of processing, mechanical toughness, and facile chemical variation using commercially available precursors. Herein we report on the optical characterization of a new class of sulfur copolymers that are readily moldable, transparent above 500 nm, possess high refractive index (n > 1.8) and take advantage of the low infrared absorption of S-S bonds for potential use in the mid-infrared at 3-5 microns. These materials are largely made from elemental sulfur by an inverse vulcanization process; in the current study we focus on the properties of a chemically stable, branched copolymer of poly(sulfur-random-1,3-diisopropenylbenzene) (poly(S-r- DIB). Copolymers with elemental sulfur content ranging from 50% to 80% by weight were studied by UV-VIS spectroscopy, FTIR, and prism coupling for refractive index measurement. Clear correlation between material composition and the optical properties was established, confirming that the high polarizability of the sulfur atom leads to high refractive index while also maintaining low optical loss in the infrared.

  12. Phase transformations and the spectral reflectance of solid sulfur - Can metastable sulfur allotropes exist on Io?

    NASA Technical Reports Server (NTRS)

    Moses, Julianne I.; Nash, Douglas B.

    1991-01-01

    Laboratory investigations have been conducted on the effects of variations in sulfur sample histories on their solid-state transformation rate and the corresponding spectral variation of freshly frozen sulfur. The temporal variations in question may be due to differences in the amount and type of metastable allotropes present in the sulfur after solidification, as well as to the physics of the phase-transformation process itself. The results obtained are pertinent to the physical behavior and spectral variation of such freshly solidified sulfur as may exist on the Jupiter moon Io; this would initially solidify into a glassy solid or monoclinic crystalline lattice, then approach ambient dayside temperatures. Laboratory results imply that the monoclinic or polymeric allotropes can in these circumstances be maintained, and will take years to convert to the stable orthorhombic crystalline form.

  13. Sulfurized metal borohydrides.

    PubMed

    Paskevicius, M; Richter, B; Pola?ski, M; Thompson, S P; Jensen, T R

    2015-12-22

    The reactions between metal borohydrides and elemental sulfur are investigated in situ during thermal treatment and are found to be highly exothermic (up to 700 J g(-1)). These reactions are exceptionally rapid, occurring below 200 °C, also resulting in the sudden release of substantial quantities of hydrogen gas. For NaBH4 this hydrogen release is pure, with no detectable levels of H2S or B2H6. The reaction results in the formation of an array of metal-boron-sulfur compounds. These MBH4-S compounds are interesting for possible uses in high energy applications (fuels or explosives), hydrogen generation, and metal-boron-sulfur precursors. PMID:26615897

  14. Sodium sulfur battery seal

    DOEpatents

    Mikkor, Mati (Ann Arbor, MI)

    1981-01-01

    This disclosure is directed to an improvement in a sodium sulfur battery construction in which a seal between various battery compartments is made by a structure in which a soft metal seal member is held in a sealing position by holding structure. A pressure applying structure is used to apply pressure on the soft metal seal member when it is being held in sealing relationship to a surface of a container member of the sodium sulfur battery by the holding structure. The improvement comprises including a thin, well-adhered, soft metal layer on the surface of the container member of the sodium sulfur battery to which the soft metal seal member is to be bonded.

  15. Catalyst for the reduction of sulfur dioxide to elemental sulfur

    DOEpatents

    Jin, Yun (Peking, CN); Yu, Qiquan (Peking, CN); Chang, Shih-Ger (El Cerrito, CA)

    1996-01-01

    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.-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.

  16. Microbial stabilization of sulfur-laden sorbents. Final technical report, September 1, 1992--August 31, 1993

    SciTech Connect

    Miller, K.W.; Hillyer, D.

    1993-12-31

    Clean coal technologies that involve limestone for sulfur capture generate lime/limestone products laden with sulfur at various oxidation states. If sulfur is completely stabilized as sulfate, the spent sorbent is ready for commercial utilization as gypsum. However, the presence of reduced sulfur species requires additional processing. Thermal oxidation of reduced sulfur can result in undesirable release of SO{sub 2}. Microbial oxidation might provide an inexpensive and effective alternative. Sorbents laden with reduced forms of sulfur such as sulfide or sulfite can serve as growth substrates for sulfur-oxidizing bacteria, which convert all sulfur to sulfate. The goals of this project are the following: (1) to optimize conditions for sulfate generation from sulfide, thiosulfate, and sulfite; (2) to test and optimize the effectiveness of microbial processing on spent sorbents from flue gas desulfurization, coal gasification, and fluidized bed combustion; (3) to search for hyperalkalinophilic thiobacilli, which would be effective up to pH 11.

  17. ORIGINAL ARTICLE Sulfur oxidizers dominate carbon fixation

    E-print Network

    Hansell, Dennis

    ORIGINAL ARTICLE Sulfur oxidizers dominate carbon fixation at a biogeochemical hot spot in the dark clade of marine gamma-proteobacterial sulfur oxidizers (GSOs) are distributed throughout proteins for sulfur oxidation (adenosine phosphosulfate reductase, sox (sulfur oxidizing system

  18. Sulfurization induced surface constitution and its correlation to the performance of solution-processed Cu2ZnSn(S,Se)4 solar cells

    PubMed Central

    Zhong, Jie; Xia, Zhe; Luo, Miao; Zhao, Juan; Chen, Jie; Wang, Liang; Liu, Xinsheng; Xue, Ding-Jiang; Cheng, Yi-Bing; Song, Haisheng; Tang, Jiang

    2014-01-01

    To obtain high photovoltaic performances for the emerging copper zinc tin sulfide/selenide (CZTSSe) thin film solar cells, much effort has deservedly been placed on CZTSSe phase purification and CZTSSe grain size enhancement. Another highly crucial but less explored factor for device performance is the elemental constitution of CZTSSe surface, which is at the heart of p-n junction where major photogenerated carriers generate and separate. In this work we demonstrate that, despite the well-built phase and large grained films are observed by common phases and morphology characterization (XRD, Raman and SEM), prominent device efficiency variations from short circuited to 6.4% are obtained. Insight study highlights that the surface (0–250?nm) compositions variation results in different bulk defect depths and doping densities in the depletion zone. We propose that suitable sulfurization (at ~10?kPa sulfur pressure) drives optimization of surface constitution by managing the Cu, Zn and Sn diffusion and surface reaction. Therefore, our study reveals that the balance of elemental diffusion and interface reactions is the key to tuning the surface quality CZTSSe film and thus the performance of as resulted devices. PMID:25190491

  19. Sulfurization induced surface constitution and its correlation to the performance of solution-processed Cu2ZnSn(S,Se)4 solar cells.

    PubMed

    Zhong, Jie; Xia, Zhe; Luo, Miao; Zhao, Juan; Chen, Jie; Wang, Liang; Liu, Xinsheng; Xue, Ding-Jiang; Cheng, Yi-Bing; Song, Haisheng; Tang, Jiang

    2014-01-01

    To obtain high photovoltaic performances for the emerging copper zinc tin sulfide/selenide (CZTSSe) thin film solar cells, much effort has deservedly been placed on CZTSSe phase purification and CZTSSe grain size enhancement. Another highly crucial but less explored factor for device performance is the elemental constitution of CZTSSe surface, which is at the heart of p-n junction where major photogenerated carriers generate and separate. In this work we demonstrate that, despite the well-built phase and large grained films are observed by common phases and morphology characterization (XRD, Raman and SEM), prominent device efficiency variations from short circuited to 6.4% are obtained. Insight study highlights that the surface (0-250 nm) compositions variation results in different bulk defect depths and doping densities in the depletion zone. We propose that suitable sulfurization (at ~ 10 kPa sulfur pressure) drives optimization of surface constitution by managing the Cu, Zn and Sn diffusion and surface reaction. Therefore, our study reveals that the balance of elemental diffusion and interface reactions is the key to tuning the surface quality CZTSSe film and thus the performance of as resulted devices. PMID:25190491

  20. Measurement and prediction of the resistivity of ash/sorbent mixtures produced by sulfur oxide control processes. Final report, Sep 86-Jun 88

    SciTech Connect

    Young, R.P.

    1991-12-01

    The report describes the development of (1) a modified procedure for obtaining consistent and reproducible laboratory resistivity values for mixtures of coal fly ash and partially spent sorbent, and (2) an approach for predicting resistivity based on the chemical composition of the sample and the resistivities of the key compounds in the sample that are derived from the sorbent. Furnace and cold-side sorbent injection technologies for reducing the emission of sulfur oxides from electric generating plants firing medium- to high-sulfur coal are under development for retrofit applications. The particulate resulting from injecting this sorbent will be a mixture of coal fly ash and partially spent sorbent. The presence of this sorbent causes the resistivity of the mixture to be significantly higher than that of the fly ash alone. Since higher resistivity dusts are more difficult to collect in an electrostatic precipitator (ESP), accurate knowledge of the resistivity of the mixture is needed to determine if the ESP will operate within an acceptable efficiency range.

  1. The role of cluster energy nonaccommodation in atmospheric sulfuric acid Theo Kurtn,1,a

    E-print Network

    collision geometries will lead to cluster formation. For the specific case of sulfuric acid clustersThe role of cluster energy nonaccommodation in atmospheric sulfuric acid nucleation Theo Kurtén,1,a formation due to liberated excess energy in atmospheric nucleation processes involving sulfuric acid

  2. Mechanistic Modeling of Sulfur-Deprived Photosynthesis and Hydrogen Production in

    E-print Network

    Mechanistic Modeling of Sulfur-Deprived Photosynthesis and Hydrogen Production in Suspensions temporally for sustained photo-production. Under illumination, sulfur-deprivation has been shown to accom of the essential pathways and processes. The role of sulfur in photosynthesis (via PSII) and the storage

  3. Vapor phase elemental sulfur amendment for sequestering mercury in contaminated soil

    SciTech Connect

    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.

  4. Room-Temperature Carbon-Sulfur Bond Activation by a Reactive (dippe)Pd Fragment

    E-print Network

    Jones, William D.

    Room-Temperature Carbon-Sulfur Bond Activation by a Reactive (dippe)Pd Fragment Lloyd Munjanja of hydrodesulfurization (HDS) in the petroleum refining industry. HDS is the catalytic process for the removal of sulfur reduce the sulfur content of oil from 1-5% to 300 ppm in fuels.1 With new mandates by the Environmental

  5. Genetic engineering of sulfur-degrading Sulfolobus. Final technical report, September 1, 1990--August 31, 1991

    SciTech Connect

    Ho, N.W.Y.

    1991-12-31

    The objectives of the proposed research is to first establish a plasmid-mediated genetic transformation system for the sulfur degrading Sulfolobus, and then to clone and overexpress the genes encoding the organic-sulfur-degrading enzymes from Sulfolobus- as well as from other microorganisms, to develop a Sulfolobus-based microbial process for the removal of both organic and inorganic sulfur from coal.

  6. Enhanced electrochemical performance of a crosslinked polyaniline-coated graphene oxide-sulfur composite for rechargeable lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Moon, San; Jung, Young Hwa; Kim, Do Kyung

    2015-10-01

    Due to the extraordinarily high theoretical capacity of sulfur (1675 mAh g-1), the lithium-sulfur (Li-S) battery has been considered a promising candidate for future high-energy battery applications. Li-S batteries, however, have suffered from limited cycle lives, mainly due to the formation of soluble polysulfides, which prevent the practical application of this attractive technology. The encapsulation of sulfur with various conductive materials has addressed this issue to some extent. Nevertheless, most approaches still present partial encapsulation of sulfur and moreover require a large quantity of conductive material (typically, >30 wt%), making the use of sulfur less desirable from the viewpoint of capacity. Here, we address these chronic issues of Li-S cells by developing a graphene oxide-sulfur composite with a thin crosslinked polyaniline (PANI) layer. Graphene oxide nanosheets with large surface area, high conductivity and a uniform conductive PANI layer, which are synthesized by a layer-by-layer method, have a synergetic interaction with a large portion of the sulfur in the active material. Furthermore, a simple crosslinking process efficiently prevents polysulfide dissolution, resulting in unprecedented electrochemical performance, even with a high sulfur content (?75%): a high capacity retention of ?80% is observed, in addition to 97.53% of the average Coulombic efficiency being retained after 500 cycles. The performance we demonstrate represents an advance in the field of lithium-sulfur batteries for applications such as power tools.

  7. Hot-Gas Desulfurization with Sulfur Recovery

    SciTech Connect

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

    1997-07-01

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

  8. Sulfur 'Concrete' for Lunar Applications - Environmental Considerations

    NASA Technical Reports Server (NTRS)

    Grugel, R. N.

    2008-01-01

    Commercial use of sulfur concrete on Earth is well established, particularly in corrosive, e.g., acid and salt, environments. Having found troilite (FeS) on the Moon raises the question of using extracted sulfur as a lunar construction material, an attractive alternative to conventional concrete as it does not require water. For the purpose of this Technical Memorandum, it is assumed that lunar ore is mined, refined, and the raw sulfur processed with appropriate lunar regolith to form, for example, bricks. With this stipulation, it is then noted that the viability of sulfur concrete in a lunar environment, which is characterized by lack of an atmosphere and extreme temperatures, is not well understood. The work presented here evaluates two sets of small sulfur concrete samples that have been prepared using JSC-1 lunar simulant as an aggregate addition. One set was subjected to extended periods in high vacuum to evaluate sublimation issues, and the other was cycled between room and liquid nitrogen temperatures to investigate their subsequent mechanical integrity. Results are presented from both investigations, discussed, and put into the context of the lunar environment.

  9. Sulfuric acid in the Venus clouds.

    NASA Technical Reports Server (NTRS)

    Sill, G. T.

    1972-01-01

    The extremely dry nature of the Venus upper atmosphere appears to demand the presence of an efficient desiccating agent as the chief constituent of the clouds of Venus. On the basis of polarization measures it is to be expected that this substance is present as spherical droplets, 1 to 2 microns in diameter, with a refractive index n of 1.46 plus or minus 0.02 at 3500A in the observed region of the atmosphere, with T about equal to 235 K. This substance must have ultraviolet, visible, and infrared reflection properties not inconsistent with the observed spectrum of Venus. Sulfuric acid, of about 86% by weight composition, roughly fulfills the first of these properties. The visible and ultraviolet transmission features of a thin layer of elemental bromine and hydrobromic acid dissolved in sulfuric acid somewhat resemble the Venus spectrum, up to 14 microns. The chemical process postulated for forming sulfuric acid involves the oxidation of sulfur and its compounds to sulfuric acid through the agency of elemental bromine produced by the photolytic decomposition of hydrogen bromide.

  10. The use of elemental sulfur as an alternative feedstock for polymeric materials

    NASA Astrophysics Data System (ADS)

    Chung, Woo Jin; Griebel, Jared J.; Kim, Eui Tae; Yoon, Hyunsik; Simmonds, Adam G.; Ji, Hyun Jun; Dirlam, Philip T.; Glass, Richard S.; Wie, Jeong Jae; Nguyen, Ngoc A.; Guralnick, Brett W.; Park, Jungjin; Somogyi, Árpád; Theato, Patrick; Mackay, Michael E.; Sung, Yung-Eun; Char, Kookheon; Pyun, Jeffrey

    2013-06-01

    An excess of elemental sulfur is generated annually from hydrodesulfurization in petroleum refining processes; however, it has a limited number of uses, of which one example is the production of sulfuric acid. Despite this excess, the development of synthetic and processing methods to convert elemental sulfur into useful chemical substances has not been investigated widely. Here we report a facile method (termed ‘inverse vulcanization’) to prepare chemically stable and processable polymeric materials through the direct copolymerization of elemental sulfur with vinylic monomers. This methodology enabled the modification of sulfur into processable copolymer forms with tunable thermomechanical properties, which leads to well-defined sulfur-rich micropatterned films created by imprint lithography. We also demonstrate that these copolymers exhibit comparable electrochemical properties to elemental sulfur and could serve as the active material in Li-S batteries, exhibiting high specific capacity (823 mA h g-1 at 100 cycles) and enhanced capacity retention.

  11. The use of elemental sulfur as an alternative feedstock for polymeric materials.

    PubMed

    Chung, Woo Jin; Griebel, Jared J; Kim, Eui Tae; Yoon, Hyunsik; Simmonds, Adam G; Ji, Hyun Jun; Dirlam, Philip T; Glass, Richard S; Wie, Jeong Jae; Nguyen, Ngoc A; Guralnick, Brett W; Park, Jungjin; Somogyi, Arpád; Theato, Patrick; Mackay, Michael E; Sung, Yung-Eun; Char, Kookheon; Pyun, Jeffrey

    2013-06-01

    An excess of elemental sulfur is generated annually from hydrodesulfurization in petroleum refining processes; however, it has a limited number of uses, of which one example is the production of sulfuric acid. Despite this excess, the development of synthetic and processing methods to convert elemental sulfur into useful chemical substances has not been investigated widely. Here we report a facile method (termed 'inverse vulcanization') to prepare chemically stable and processable polymeric materials through the direct copolymerization of elemental sulfur with vinylic monomers. This methodology enabled the modification of sulfur into processable copolymer forms with tunable thermomechanical properties, which leads to well-defined sulfur-rich micropatterned films created by imprint lithography. We also demonstrate that these copolymers exhibit comparable electrochemical properties to elemental sulfur and could serve as the active material in Li-S batteries, exhibiting high specific capacity (823 mA h g(-1) at 100 cycles) and enhanced capacity retention. PMID:23695634

  12. An Aerosol Condensation Model for Sulfur Trioxide

    SciTech Connect

    Grant, K E

    2008-02-07

    This document describes a model for condensation of sulfuric acid aerosol given an initial concentration and/or source of gaseous sulfur trioxide (e.g. fuming from oleum). The model includes the thermochemical effects on aerosol condensation and air parcel buoyancy. Condensation is assumed to occur heterogeneously onto a preexisting background aerosol distribution. The model development is both a revisiting of research initially presented at the Fall 2001 American Geophysical Union Meeting [1] and a further extension to provide new capabilities for current atmospheric dispersion modeling efforts [2]. Sulfuric acid is one of the most widely used of all industrial chemicals. In 1992, world consumption of sulfuric acid was 145 million metric tons, with 42.4 Mt (mega-tons) consumed in the United States [10]. In 2001, of 37.5 Mt consumed in the U.S., 74% went into producing phosphate fertilizers [11]. Another significant use is in mining industries. Lawuyi and Fingas [7] estimate that, in 1996, 68% of use was for fertilizers and 5.8% was for mining. They note that H{sub 2}SO{sub 4} use has been and should continue to be very stable. In the United States, the elimination of MTBE (methyl tertiary-butyl ether) and the use of ethanol for gasoline production are further increasing the demand for petroleum alkylate. Alkylate producers have a choice of either a hydrofluoric acid or sulfuric acid process. Both processes are widely used today. Concerns, however, over the safety or potential regulation of hydrofluoric acid are likely to result in most of the growth being for the sulfuric acid process, further increasing demand [11]. The implication of sulfuric acid being a pervasive industrial chemical is that transport is also pervasive. Often, this is in the form of oleum tankers, having around 30% free sulfur trioxide. Although sulfuric acid itself is not a volatile substance, fuming sulfuric acid (referred to as oleum) is [7], the volatile product being sulfur trioxide. Sulfate aerosols and mist may form in the atmosphere on tank rupture. From chemical spill data from 1990-1996, Lawuyi02 and Fingas [7] prioritize sulfuric acid as sixth most serious. During this period, they note 155 spills totaling 13 Mt, out of a supply volume of 3700 Mt. Lawuyi and Fingas [7] summarize information on three major sulfuric acid spills. On 12 February 1984, 93 tons of sulfuric acid were spilled when 14 railroad cars derailed near MacTier, Parry Sound, Ontario. On 13 December 1978, 51 railroad cars derailed near Springhill, Nova Scotia. One car, containing 93% sulfuric acid, ruptured, spilling nearly its entire contents. In July 1993, 20 to 50 tons of fuming sulfuric acid spilled at the General Chemical Corp. plant in Richmond, California, a major industrial center near San Francisco. The release occurred when oleum was being loaded into a nonfuming acid railroad tank car that contained only a rupture disk as a safety device. The tank car was overheated and this rupture disk blew. The resulting cloud of sulfuric acid drifted northeast with prevailing winds over a number of populated areas. More than 3,000 people subsequently sought medical attention for burning eyes, coughing, headaches, and nausea. Almost all were treated and released on the day of the spill. By the day after the release, another 5,000 people had sought medical attention. The spill forced the closure of five freeways in the region as well as some Bay Area Rapid Transit System stations. Apart from corrosive toxicity, there is the additional hazard that the reactions of sulfur trioxide and sulfuric acid vapors with water are extremely exothermic [10, 11]. While the vapors are intrinsically denser than air, there is thus the likelihood of strong, warming-induced buoyancy from reactions with ambient water vapor, water-containing aerosol droplets, and wet environmental surface. Nordin [12] relates just such an occurrence following the Richmond, CA spill, with the plume observed to rise to 300 m. For all practical purposes, sulfur trioxide was the constituent released from the heated tank

  13. Sodium sulfur battery seal

    DOEpatents

    Topouzian, Armenag (Birmingham, MI)

    1980-01-01

    This invention is directed to a seal for a sodium sulfur battery in which a flexible diaphragm sealing elements respectively engage opposite sides of a ceramic component of the battery which separates an anode compartment from a cathode compartment of the battery.

  14. Sulfur Dioxide Pollution Monitor.

    ERIC Educational Resources Information Center

    National Bureau of Standards (DOC), Washington, DC.

    The sulfur dioxide pollution monitor described in this document is a government-owed invention that is available for licensing. The background of the invention is outlined, and drawings of the monitor together with a detailed description of its function are provided. A sample stream of air, smokestack gas or the like is flowed through a…

  15. COAL SULFUR MEASUREMENTS

    EPA Science Inventory

    The report describes a new technique for sulfur forms analysis based on low-temperature oxygen plasma ashing. The technique involves analyzing the low-temperature plasma ash by modified ASTM techniques after selectively removing the organic material. The procedure has been tested...

  16. Meteoritic Sulfur Isotopic Analysis

    NASA Technical Reports Server (NTRS)

    Thiemens, Mark H.

    1996-01-01

    Funds were requested to continue our program in meteoritic sulfur isotopic analysis. We have recently detected a potential nucleosynthetic sulfur isotopic anomaly. We will search for potential carriers. The documentation of bulk systematics and the possible relation to nebular chemistry and oxygen isotopes will be explored. Analytical techniques for delta(sup 33), delta(sup 34)S, delta(sup 36)S isotopic analysis were improved. Analysis of sub milligram samples is now possible. A possible relation between sulfur isotopes and oxygen was detected, with similar group systematics noted, particularly in the case of aubrites, ureilites and entstatite chondrites. A possible nucleosynthetic excess S-33 has been noted in bulk ureilites and an oldhamite separate from Norton County. High energy proton (approximately 1 GeV) bombardments of iron foils were done to experimentally determine S-33, S-36 spallogenic yields for quantitation of isotopic measurements in iron meteorites. Techniques for measurement of mineral separates were perfected and an analysis program initiated. The systematic behavior of bulk sulfur isotopes will continue to be explored.

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

    SciTech Connect

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

    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.

  18. Porous spherical polyacrylonitrile-carbon nanocomposite with high loading of sulfur for lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Sohn, Hiesang; Gordin, Mikhail L.; Regula, Michael; Kim, Dong Hyeon; Jung, Yoon Seok; Song, Jiangxuan; Wang, Donghai

    2016-01-01

    Pyrolyzed porous spherical composites of polyacrylonitrile-Ketjenblack carbon and sulfur (pPAN-KB/S) with a high sulfur content (ca. 72%) and enhanced conductivity and porosity (pore volume: 1.42 cm3/g; BET surface area: 727 m2/g) were prepared by an aerosol-assisted process and applied as cathode for lithium-sulfur batteries. Electrochemical tests showed that the pPAN-KB/S composite exhibited a high capacity of 866 mAh/g (based on sulfur) after 100 cycles at 0.5C (1C = 1.68 A/g) and a good rate performance at high current density (431 mAh/g at 5C). In addition, a pPAN-KB/S composite electrode with high sulfur loading (ca. 4.4 mg-S/cm2) exhibited impressive electrochemical performance with a reversible capacity of 513 mAh/g and 576 mAh/cm3 (based on sulfur) and a coulombic efficiency >99% after 100 cycles at 0.5C.

  19. Consistency Between Measurements and Theory for Sulfur Gases and Oxidants During the Pacific Atmospheric Sulfur Experiment

    NASA Astrophysics Data System (ADS)

    Heikes, B. G.; Higbie, A.; O'Sullivan, D. W.; Bandy, A. R.; Mauldin, L.; Cantrell, C.; Anderson, R. S.; Campos, T.; Huebert, B.; Bloomquist, B.; Wang, Y.; Heizer, C. G.; Pollack, I. B.; Weinheimer, A. J.

    2008-12-01

    Airborne gas phase measurements of sulfur dioxide, dimethylsulfide, dimethylsulfoxide, methane sulfonic acid, sulfuric acid, hydroxyl, perhydroxyl, hydrogen peroxide, methylhydroperoxide, ozone, and carbon monoxide together with aerosol microphysical properties and bulk and size-dependent aerosol composition are examined for consistency with photochemical theory. The observations come from 14 research flights using the NCAR C-130 flown mostly southeast of Kiritimati in relatively cloud-free marine boundary layer air. This region was chosen because of its extremely low nitrogen oxide mixing ratios and minimal horizontal gradients in composition. A size-dependent gas-particle mass-transfer model is used to calculate the exchange rates of dimethylsulfoxide, methanesulfonic acid and sulfuric acid between the gas and aerosol. Gas kinetic reactions, aqueous reactions, and heterogeneous processes are used in the evaluation. Mass accommodation coefficients, Henry's Law solubilities, and the effective yields of methanesulfonic acid, sulfur dioxide, sulfuric acid and dimethylsulfoxide from dimethylsulfide are estimated and consistent with the literature. Gas phase hydroxyl chemistry alone is sufficient to explain observed methanesulfonic acid and sulfuric acid vapor concentrations.

  20. Correlation for the total sulfur content in char after devolatilization

    SciTech Connect

    Vasilije Manovic; Borislav Grubor

    2006-02-01

    The overall process of coal combustion takes place in two successive steps: devolatilization and char combustion. The fate of sulfur during the devolatilization of coal of different rank was investigated. The significance of the investigation is in fact that a major part of sulfur release occurs during devolatilization of coal, (i.e., emission of sulfur oxides during combustion of coal largely depends on sulfur release during devolatilization). The experimental investigations were conducted to obtain the data about the quantitative relation between sulfur content in the coal and sulfur content in the char. Standard procedures were used for obtaining the chars in a laboratory oven and determining the sulfur forms in the coal and char samples. The experiments were done with ground coal samples ({lt}0.2 mm), at the temperatures in the range of 500-1000{sup o}C. We showed that the amount of sulfur remaining in the char decreases, but not significantly in the temperature range 600-900{sup o}C. On the basis of the theoretical consideration of behavior of sulfur forms during devolatilization, certain simplifying assumptions, and obtained experimental data, we propose two correlations to associate the content of sulfur in the coal and in the char. The correlations are based on the results of the proximate analysis and sulfur forms in coal. Good agreement was found when the proposed correlations were compared with the experimental results obtained for investigated coals. Moreover, the correlations were verified by results found in the literature for numerous Polish, Albanian, and Turkish coals. Significant correlations (P {lt}0.05) between observed and calculated data with correlation coefficient, R {gt}0.9, were noticed in the case of all coals. 25 refs., 3 figs., 2 tabs.

  1. Isotope Dilution Mass Spectrometry for the Quantification of Sulfane Sulfurs

    PubMed Central

    Liu, Chunrong; Zhang, Faya; Munske, Gerhard; Zhang, Hui

    2014-01-01

    Sulfane sulfurs are one type of important reactive sulfur species. These molecules have unique reactivity that can attach reversibly to other sulfur atoms and exhibit regulatory effects in diverse biological systems. Recent studies have suggested that sulfane sulfurs are involved in signal transduction processes regulated by hydrogen sulfide (H2S). Accurate and reliable measurements of sulfane sulfurs in biological samples are thus needed to reveal their production and mechanisms of actions. Herein we report a convenient and accurate method for the determination of sulfane sulfurs concentrations. The method employs a triphenylphosphine derivative (P2) to capture sulfane sulfurs as a stable phosphine sulphide product PS2. The concentration of PS2 was then determined by isotope dilution mass spectrometry, using a 13C3-labelled phosphine sulfide PS1 as the internal standard. The specificity and efficiency of the method were proved by model reactions. It was also applied in the measurement of sulfane sulfurs in mice tissues including brain, kidney, lung, liver, heart, spleen, and blood. PMID:25152234

  2. Ultrasonic coal-wash for de-sulfurization.

    PubMed

    Ambedkar, B; Nagarajan, R; Jayanti, S

    2011-05-01

    Coal is the one of the world's most abundant fossil fuel resources. It is not a clean fuel, as it contains ash and sulfur. SOx as a pollutant are a real threat to both the ecosystem and to human health. There are numerous de-sulfurization methods to control SO(2) emissions. Nowadays, online flue gas de-sulfurization is being used as one such method to remove sulfur from coal during combustion. The biggest disadvantage associated with this method is formation of by-products (FGD gypsum). A way for effective usage of FGD gypsum has not yet been found. This will lead to acute and chronic effects to humans as well as plants. Power ultrasound can be used for the beneficiation of coal by the removal of sulfur from coal prior to coal combustion. The main effects of ultrasound in liquid medium are acoustic cavitation and acoustic streaming. The process of formation, growth and implosion of bubbles is called cavitation. Bulk fluid motion due to sound energy absorption is known as acoustic streaming. In addition, coupling of an acoustic field to water produces OH radicals, H(2)O(2), O(2), ozone and HO(2) that are strong oxidizing agents. Oxidation that occurs due to ultrasound is called Advanced Oxidation Process (AOP). It converts sulfur from coal to water-soluble sulphates. Conventional chemical-based soaking and stirring methods are compared here to ultrasonic methods of de-sulfurization. The main advantages of ultrasonic de-sulfurization over conventional methods, the mechanism involved in ultrasonic de-sulfurization and the difference between aqueous-based and solvent-based (2N HNO(3), 3-volume percentage H(2)O(2)) de-sulfurization are investigated experimentally. PMID:21115263

  3. Sulfur plumes off Namibia

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Sulfur plumes rising up from the bottom of the ocean floor produce colorful swirls in the waters off the coast of Namibia in southern Africa. The plumes come from the breakdown of marine plant matter by anaerobic bacteria that do not need oxygen to live. This image was acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite on April 24, 2002 Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  4. The continuous crystallization of sulfur formed by the liquid-phase reaction of hydrogen sulfide and sulfur dioxide

    SciTech Connect

    Stevens, C.A.; Lynn, S.

    1989-09-01

    The crystallization of elemental sulfur is a unit operation in a process being developed to remove hydrogen sulfide from industrial gas streams. The sulfur is formed by the irreversible, liquid-phase reaction of hydrogen sulfide (H{sub 2}S) and sulfur dioxide (SO{sub 2}). Low-temperature sulfur solubility data in triethylene glycol dimethyl ether (Triglyme) and diethylene glycol methyl ether (DGM) were collected. The effects of temperature and water concentration in the solvents on sulfur solubility were correlated. The thermal crystallization of sulfur from Triglyme was studied in a laboratory-scale experimental crystallizer. The dependence of crystal-size distribution on residence time, slurry density, impeller power input, and water concentration in the solvent was determined. A crystallization model, applicable to the experimental crystallizer, was derived from population balance theory and verified using the experimental data. The crystallization kinetics of the sulfur/Triglyme system were obtained from the crystallization model. The reactive crystallization of sulfur formed by the reaction between H{sub 2}S and SO{sub 2} was also studied. A reactor/crystallizer model was developed from the reaction kinetics and from the thermal crystallization kinetics. Reactive crystallization experiments verified the model. An industrial-sized reactor/crystallizer was designed from the model. 53 refs., 44 figs., 18 tabs.

  5. Mössbauer study of the inorganic sulfur removal from coals

    NASA Astrophysics Data System (ADS)

    Reyes Caballero, F.; Martínez Ovalle, S. A.

    2014-01-01

    Mössbauer Spectroscopy (MS) was applied to study the occurrence and behavior of the iron-sulfur-containing minerals in coal and coal fractions obtained by different separation methods: hydrocyclonic, flotation and chemical removal process. Samples of one high sulfur coal from Guachinte mine (Valle, Colombia) and three low sulfur coals from the El Salitre zone (Paipa-Boyacá, Colombia) were analyzed. MS evidenced only the presence of pyrite in Esmeralda and Las Casitas coals, while it identified pyrite and siderite on Cerezo coal. MS and SEM- EDX confirm the inorganic sulfur removal on Guachinte coal submitted to hydrocyclonic removal process. MS of the precipitated coal fraction from Las Casitas mine obtained by flotation in water showed the presence of ferrous sulfate because of coal-weathering process. Treatment with hot diluted HNO3 equal to 27 acid on raw coal sample from Las Casitas mine showed that almost all of the pyrite in raw coal was removed.

  6. Evolution of insoluble eutectic Si particles in anodic oxidation films during adipic-sulfuric acid anodizing processes of ZL114A aluminum alloys

    NASA Astrophysics Data System (ADS)

    Hua, Lei; Liu, Jian-hua; Li, Song-mei; Yu, Mei; Wang, Lei; Cui, Yong-xin

    2015-03-01

    The effects of insoluble eutectic Si particles on the growth of anodic oxide films on ZL114A aluminum alloy substrates were investigated by optical microscopy (OM) and scanning electron microscopy (SEM). The anodic oxidation was performed at 25°C and a constant voltage of 15 V in a solution containing 50 g/L sulfuric acid and 10 g/L adipic acid. The thickness of the formed anodic oxidation film was approximately 7.13 ?m. The interpore distance and the diameters of the major pores in the porous layer of the film were within the approximate ranges of 10-20 nm and 5-10 nm, respectively. Insoluble eutectic Si particles strongly influenced the morphology of the anodic oxidation films. The anodic oxidation films exhibited minimal defects and a uniform thickness on the ZL114A substrates; in contrast, when the front of the oxide oxidation films encountered eutectic Si particles, defects such as pits and non-uniform thickness were observed, and pits were observed in the films.

  7. Influence of sulfurization pressure on Cu2ZnSnS4 thin films and solar cells prepared by sulfurization of metallic precursors

    NASA Astrophysics Data System (ADS)

    He, Jun; Sun, Lin; Chen, Ye; Jiang, Jinchun; Yang, Pingxiong; Chu, Junhao

    2015-01-01

    Effects of sulfurization pressure on composition, morphology and microstructure of kesterite Cu2ZnSnS4 (CZTS) thin films obtained by sulfurization of the metallic layers have been investigated in detail. It is found that the S content in the CZTS thin films is strongly dependent on the sulfurization pressure. The CZTS thin films sulfurized under low sulfurization pressure have S-poor state with a bilayer structure, while it exhibits sufficient amounts of sulfur under high sulfurization pressure with grain growth throughout the entire absorber film. X-ray diffraction data indicate lower sulfurization pressure during the CZTS grain growth process can induce the formation of more structural defects in the CZTS lattice and the CZTS thin films sulfurized under high sulfurization pressure have more random orientation. Furthermore, ZnS and MoS2 phase exist in all samples determined by Fourier transform infrared reflectance spectroscopy as complementary to Raman spectroscopy. The solar cell fabricated with the CZTS thin film under 10 Torr sulfurization pressure shows the best conversion efficiency of 3.52% (VOC = 484 mV, JSC = 14.56 mA cm-2, FF = 50.1%).

  8. Catalyst for the reduction of sulfur dioxide to elemental sulfur

    DOEpatents

    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.

  9. Development of the Hybrid Sulfur Thermochemical Cycle

    SciTech Connect

    Summers, William A.; Steimke, John L

    2005-09-23

    The production of hydrogen via the thermochemical splitting of water is being considered as a primary means for utilizing the heat from advanced nuclear reactors to provide fuel for a hydrogen economy. The Hybrid Sulfur (HyS) Process is one of the baseline candidates identified by the U.S. Department of Energy [1] for this purpose. The HyS Process is a two-step hybrid thermochemical cycle that only involves sulfur, oxygen and hydrogen compounds. Recent work has resulted in an improved process design with a calculated overall thermal efficiency (nuclear heat to hydrogen, higher heating value basis) approaching 50%. Economic analyses indicate that a nuclear hydrogen plant employing the HyS Process in conjunction with an advanced gas-cooled nuclear reactor system can produce hydrogen at competitive prices. Experimental work has begun on the sulfur dioxide depolarized electrolyzer, the major developmental component in the cycle. Proof-of-concept tests have established proton-exchange-membrane cells (a state-of-the-art technology) as a viable approach for conducting this reaction. This is expected to lead to more efficient and economical cell designs than were previously available. Considerable development and scale-up issues remain to be resolved, but the development of a viable commercial-scale HyS Process should be feasible in time to meet the commercialization schedule for Generation IV gas-cooled nuclear reactors.

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

    PubMed Central

    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 ?- and ?-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. PMID:26633307

  11. Identification of sulfur fumed Pinelliae Rhizoma using an electronic nose

    PubMed Central

    Zhou, Xia; Wan, Jun; Chu, Liang; Liu, Wengang; Jing, Yafeng; Wu, Chunjie

    2014-01-01

    Background: Pinelliae Rhizoma is a commonly used Chinese herb which will change brown during the natural drying process. However, sulfur fumed Pinelliae Rhizoma will get a better appearance than naturally dried one. Sulfur fumed Pinelliae Rhizoma is potentially toxical due to sulfur dioxide and sulfites formed during the fuming procedures. The odor components in sulfur fumed Pinelliae Rhizoma is complex. At present, there is no analytical method available to determine sulfur fumed Pinelliae Rhizoma simply and rapidly. To ensure medication safety, it is highly desirable to have an effective and simple method to identify sulfur fumed Pinelliae Rhizoma. Materials and Methods: This paper presents a novel approach using an electronic nose based on metal oxide sensors to identify whether Pinelliae Rhizoma was fumed with sulfur, and to predict the fuming degree of Pinelliae Rhizoma. Multivariate statistical methods such as principal components analysis (PCA), discriminant factorial analysis (DFA) and partial least squares (PLS) were used for data analyzing and identification. The use of the electronic nose to discriminate between different fuming degrees Pinelliae Rhizoma and naturally dried Pinelliae Rhizoma was demonstrated. Results: The electronic nose was also successfully applied to identify unknown samples including sulfur fumed samples and naturally dried samples, high recognition value was obtained. Quantitative analysis of fuming degree of Pinelliae Rhizoma was also demonstrated. The method developed is simple and fast, which provides a new quality control method of Chinese herbs from the aspect of odor. Conclusion: It has shown that this electronic nose based metal oxide sensor is sensitive to sulfur and sulfides. We suggest that it can serve as a supportive method to detect residual sulfur and sulfides. PMID:24914293

  12. The fate of sulfur in mild gasification liquids

    SciTech Connect

    Knight, R.A.; Koncar, G.J.; Babu, S.P.

    1991-01-01

    This investigation addresses the determination of sulfur distribution in mild gasification liquids produced from untreated coal and from modified in two ways to reduce sulfur in the products: (a) physical mixing with a sulfur scavenger (CaO), and (b) pretreatment with aqueous alkali followed by mixing with CaO. Coal pyrolysis in the presence of CaO has previously been investigated, (3,5) showing that CaO can be effective in reducing the sulfur content of the fuel gas, and possibly that of the product liquids. Pretreatment of coals with alkaline chemicals has also been studied,(6,7) showing reduced sulfur and other changes in the liquid products.(8) Data on sulfur distribution in the liquid products could be useful for understanding the chemistry of alkali pretreatment and CaO interaction with coal sulfur during pyrolysis. In this work, a pyrolysis-gas chromatography (Py-GC) technique that simulates mild gasification on a milligram scale was used in conjunction with a carbon-specific flame ionization detector (FID) and a sulfur-specific flame photometric detector (FPD) to determine the sulfur distribution in oils/tars from Illinois No. 6 coal. A low-resolution packed GC column was employed to resolve oils/tars by carbon number, with ranges selected to approximate distillation fractions which might be recovered from a commercial mild gasification process. Oils/tars up to C{sub 18} were also collected from the pyro-probe effluent into dichloromethane for off-line study using a high-resolution GC with atomic emission detector (GC/AED) and with GC-mass spectrometry (GC/MS) to measure specific sulfur compounds. 9 refs., 1 tab.

  13. 40 CFR 50.4 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...National primary ambient air quality standards for sulfur oxides (sulfur dioxide). 50.4 Section 50.4 Protection...National primary ambient air quality standards for sulfur oxides (sulfur dioxide). Link to an...

  14. 40 CFR 50.5 - National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...National secondary ambient air quality standard for sulfur oxides (sulfur dioxide). 50.5 Section 50.5 Protection...National secondary ambient air quality standard for sulfur oxides (sulfur dioxide). (a) The...

  15. 40 CFR 50.17 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...National primary ambient air quality standards for sulfur oxides (sulfur dioxide). 50.17 Section 50.17 Protection...National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level...

  16. 40 CFR 50.5 - National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...National secondary ambient air quality standard for sulfur oxides (sulfur dioxide). 50.5 Section 50.5 Protection...National secondary ambient air quality standard for sulfur oxides (sulfur dioxide). (a) The...

  17. 40 CFR 50.4 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...National primary ambient air quality standards for sulfur oxides (sulfur dioxide). 50.4 Section 50.4 Protection...National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The...

  18. 40 CFR 50.17 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...National primary ambient air quality standards for sulfur oxides (sulfur dioxide). 50.17 Section 50.17 Protection...National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level...

  19. 40 CFR 50.17 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...National primary ambient air quality standards for sulfur oxides (sulfur dioxide). 50.17 Section 50.17 Protection...National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level...

  20. 40 CFR 50.4 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...National primary ambient air quality standards for sulfur oxides (sulfur dioxide). 50.4 Section 50.4 Protection...National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The...

  1. 40 CFR 50.5 - National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...National secondary ambient air quality standard for sulfur oxides (sulfur dioxide). 50.5 Section 50.5 Protection...National secondary ambient air quality standard for sulfur oxides (sulfur dioxide). (a) The...

  2. 40 CFR 50.4 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...National primary ambient air quality standards for sulfur oxides (sulfur dioxide). 50.4 Section 50.4 Protection...National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The...

  3. 40 CFR 50.5 - National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...National secondary ambient air quality standard for sulfur oxides (sulfur dioxide). 50.5 Section 50.5 Protection...National secondary ambient air quality standard for sulfur oxides (sulfur dioxide). (a) The...

  4. 40 CFR 50.5 - National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...National secondary ambient air quality standard for sulfur oxides (sulfur dioxide). 50.5 Section 50.5 Protection...National secondary ambient air quality standard for sulfur oxides (sulfur dioxide). (a) The...

  5. 40 CFR 50.4 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...National primary ambient air quality standards for sulfur oxides (sulfur dioxide). 50.4 Section 50.4 Protection...National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The...

  6. 40 CFR 50.17 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...National primary ambient air quality standards for sulfur oxides (sulfur dioxide). 50.17 Section 50.17 Protection...National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level...

  7. 40 CFR 50.17 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...National primary ambient air quality standards for sulfur oxides (sulfur dioxide). 50.17 Section 50.17 Protection...National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level...

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

    DOEpatents

    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.

  9. Yolk-shell structure of polyaniline-coated sulfur for lithium-sulfur batteries.

    PubMed

    Zhou, Weidong; Yu, Yingchao; Chen, Hao; DiSalvo, Francis J; Abruña, Héctor D

    2013-11-01

    Lithium–sulfur batteries have attracted much attention in recent years due to their high theoretical capacity of 1672 mAh g(–1) and low cost. However, a rapid capacity fade is normally observed, attributed mainly to polysulfide dissolution and volume expansion. Although many strategies have been reported to prolong the cyclability, the high cost and complex preparation processes still hinder their practical application. Here, we report the synthesis of a polyaniline–sulfur yolk–shell nanocomposite through a heating vulcanization of a polyaniline–sulfur core–shell structure. We observed that this heating treatment was much more effective than chemical leaching to prepare uniform yolk–shell structures. Compared with its sulfur–polyaniline core–shell counterparts, the yolk–shell nanostructures delivered much improved cyclability owing to the presence of internal void space inside the polymer shell to accommodate the volume expansion of sulfur during lithiation. The yolk–shell material exhibited a stable capacity of 765 mAh g(–1) at 0.2 C after 200 cycles, representing a promising future for industrial scale Li–S batteries. PMID:24112042

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

    NASA Astrophysics Data System (ADS)

    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 ?mol L-1 to 1.5 mmol L-1) with relatively low VOSC concentrations, ranging from 0.1 nmol L-1 to 2.8 ?mol 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.

  11. Influence of different sulfur to selenium ratios on the structural and electronic properties of Cu(In,Ga)(S,Se){sub 2} thin films and solar cells formed by the stacked elemental layer process

    SciTech Connect

    Mueller, B. J.; Zimmermann, C.; Haug, V. Koehler, T.; Zweigart, S.; Hergert, F.; Herr, U.

    2014-11-07

    In this study, we investigate the effect of different elemental selenium to elemental sulfur ratios on the chalcopyrite phase formation in Cu(In,Ga)(S,Se){sub 2} thin films. The films are formed by the stacked elemental layer process. The structural and electronic properties of the thin films and solar cells are analyzed by means of scanning electron microscopy, glow discharge optical emission spectrometry, X-ray diffraction, X-ray fluorescence, Raman spectroscopy, spectral photoluminescence as well as current-voltage, and quantum efficiency measurements. The influence of different S/(S+Se) ratios on the anion incorporation and on the Ga/In distribution is investigated. We find a homogenous sulfur concentration profile inside the film from the top surface to the bottom. External quantum efficiency measurements show that the band edge of the solar cell device is shifted to shorter wavelength, which enhances the open-circuit voltages. The relative increase of the open-circuit voltage with S/(S+Se) ratio is lower than expected from the band gap energy trend, which is attributed to the presence of S-induced defects. We also observe a linear decrease of the short-circuit current density with increasing S/(S+Se) ratio which can be explained by a reduced absorption. Above a critical S/(S+Se) ratio of around 0.61, the fill factor drops drastically, which is accompanied by a strong series resistance increase which may be attributed to changes in the back contact or p-n junction properties.

  12. Identification of sulfur sources and isotopic equilibria in submarine hot-springs using multiple sulfur isotopes

    NASA Astrophysics Data System (ADS)

    McDermott, Jill M.; Ono, Shuhei; Tivey, Margaret K.; Seewald, Jeffrey S.; Shanks, Wayne C.; Solow, Andrew R.

    2015-07-01

    Multiple sulfur isotopes were measured in metal sulfide deposits, elemental sulfur, and aqueous hydrogen sulfide to constrain sulfur sources and the isotopic systematics of precipitation in seafloor hydrothermal vents. Areas studied include the Eastern Manus Basin and Lau Basin back-arc spreading centers and the unsedimented basalt-hosted Southern East Pacific Rise (SEPR) and sediment-hosted Guaymas Basin mid-ocean ridge spreading centers. Chalcopyrite and dissolved hydrogen sulfide (H2S) ?34S values range from -5.5‰ to +5.6‰ in Manus Basin samples, +2.4‰ to +6.1‰ in Lau Basin samples, and +3.7‰ to +5.7‰ in SEPR samples. Values of ?34S for cubic cubanite and H2S range from -1.4‰ to +4.7‰ in Guaymas Basin samples. Multiple sulfur isotope systematics in fluid-mineral pairs from the SEPR and Lau Basin show that crustal host rock and thermochemical reduction of seawater-derived dissolved sulfate (SO4) are the primary sources of sulfur in mid-ocean ridge and some back-arc systems. At PACMANUS and SuSu Knolls hydrothermal systems in the Eastern Manus Basin, a significant contribution of sulfur is derived from disproportionation of magmatic sulfur dioxide (SO2), while the remaining sulfur is derived from crustal host rocks and SO4 reduction. At the sedimented Guaymas Basin hydrothermal system, sulfur sources include crustal host rock, reduced seawater SO4, and biogenic sulfide. Vent fluid flow through fresher, less-mature sediment supplies an increased quantity of reactant organic compounds that may reduce 34S-enriched SO4, while fluid interaction with more highly-altered sediments results in H2S characterized by a small, but isotopically-significant input of 34S-depleted biogenic sulfides. Near-zero ?33S values in all samples implicate the abiotic processes of SO4 reduction and leaching of host rock as the major contributors to sulfur content at a high temperature unsedimented mid-ocean ridge and at a back-arc system. ?33S values indicate that SO2 disproportionation is an additional process that contributes sulfur to a different back-arc system and to acid spring-type hydrothermal fluid circulation. At the sedimented Guaymus Basin, near-zero ?33S values are also observed, despite negative ?34S values that indicate inputs of biogenic pyrite for some samples. In contrast with previous studies reporting isotope disequilibrium between H2S and chalcopyrite, the ?34S values of chalcopyrite sampled from the inner 1-2 mm of a chimney wall are within ±1‰ of ?34S values for H2S in the paired vent fluid, suggesting equilibrium fluid-mineral sulfur isotope exchange at 300-400 °C. Isotopic equilibrium between hydrothermal fluid H2S and precipitating chalcopyrite implies that sulfur isotopes in the chalcopyrite lining across a chimney wall may accurately record past hydrothermal activity.

  13. Biotic and abiotic carbon to sulfur bond cleavage. Final report

    SciTech Connect

    Frost, J.W.

    1994-05-01

    The microbial desulfurization of organosulfur compounds occurs by unprecedented and largely unexplored biochemical processes. A study of such biotic desulfurizations can be expected to give rise to new and useful chemistry and enzymology. The potential value of understanding and harnessing these processes is seen in relation to the need for methods for the removal of organically bound sulfur from coal and the degradation of organic sulfur-containing pollutants. This research effort has been directed towards an examination of desulfurization ability in well characterized microorganisms, the isolation of bacteria with desulfurization ability from natural sources, the characterization and mechanistic evaluation of the observed biocatalytic processes, the development of biomimetic synthetic organic chemistry based on biotic desulfurization mechanisms and the design and preparation of improved coal model compounds for use in microbial selection processes. A systematic approach to studying biodesulfurizations was undertaken in which organosulfur compounds have been broken down into classes based on the oxidation state of the sulfur atom and the structure of the rest of the organic material. Microbes have been evaluated in terms of ability to degrade organosulfur compounds with sulfur in its sulfonic acid oxidation state. These compounds are likely intermediates in coal desulfurization and are present in the environment as persistent pollutants in the form of detergents. It is known that oxygen bonded to sulfur lowers the carbon-sulfur bond energy, providing a thermodynamic basis for starting with this class of compounds.

  14. 40 CFR 50.4 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.4 Section 50.4 Protection of Environment ENVIRONMENTAL....4 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level...). (c) Sulfur oxides shall be measured in the ambient air as sulfur dioxide by the reference...

  15. 40 CFR 50.4 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.4 Section 50.4 Protection of Environment ENVIRONMENTAL....4 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level...). (c) Sulfur oxides shall be measured in the ambient air as sulfur dioxide by the reference...

  16. 40 CFR 50.4 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.4 Section 50.4 Protection of Environment ENVIRONMENTAL....4 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level...). (c) Sulfur oxides shall be measured in the ambient air as sulfur dioxide by the reference...

  17. 40 CFR 50.4 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.4 Section 50.4 Protection of Environment ENVIRONMENTAL....4 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level...). (c) Sulfur oxides shall be measured in the ambient air as sulfur dioxide by the reference...

  18. Sulfuric acid as autocatalyst in the formation of sulfuric acid.

    PubMed

    Torrent-Sucarrat, Miquel; Francisco, Joseph S; Anglada, Josep M

    2012-12-26

    Sulfuric acid can act as a catalyst of its own formation. We have carried out a computational investigation on the gas-phase formation of H(2)SO(4) by hydrolysis of SO(3) involving one and two water molecules, and also in the presence of sulfuric acid and its complexes with one and two water molecules. The hydrolysis of SO(3) requires the concurrence of two water molecules, one of them acting as a catalyzer, and our results predict an important catalytic effect, ranging between 3 and 11 kcal·mol(-1) when the catalytic water molecule is substituted by a sulfuric acid molecule or one of its hydrates. In these cases, the reaction products are either bare sulfuric acid dimer or sulfuric acid dimer complexed with a water molecule. There are broad implications from these new findings. The results of the present investigation show that the catalytic effect of sulfuric acid in the SO(3) hydrolysis can be important in the Earth's stratosphere, in the heterogeneous formation of sulfuric acid and in the formation of aerosols, in H(2)SO(4) formation by aircraft engines, and also in understanding the formation of sulfuric acid in the atmosphere of Venus. PMID:23198746

  19. Multiple sulfur isotope fractionation and mass transfer processes during pyrite precipitation and recrystallization: An experimental study at 300 and 350 °C

    NASA Astrophysics Data System (ADS)

    Syverson, Drew D.; Ono, Shuhei; Shanks, Wayne C.; Seyfried, William E.

    2015-09-01

    Equilibrium multiple sulfur isotope fractionation factors (33S/32S and 34S/32S) between aqueous SO4, H2S, and coexisting pyrite under hydrothermal conditions were determined experimentally at 300-350 °C and 500 bars. Two different experimental techniques were used to determine the fractionation factors and the rate of S isotope exchange between pyrite and constituent aqueous species, H2S and SO4; (1) closed system gold capsule pyrite-H2S exchange experiments and (2) complimentary time-series experiments at 300 and 350 °C, 500 bars using flexible gold cell hydrothermal equipment, which allowed monitoring the multiple S isotope composition of dissolved S species during pyrite precipitation and subsequent recrystallization. The three isotope technique was applied to the multiple S isotope data to demonstrate equilibrium S isotope fractionation between pyrite and H2S. Results at 350 °C indicate ln34?Pyrite/H2S = -1.9‰ and ln33?Pyrite/H2S = -1.0‰. The ln34?Pyrite/H2S is not only different in magnitude but also in sign from the commonly used value of 1‰ from Ohmoto and Rye (1979). This experimental study also demonstrated initial S isotope disequilibrium amongst the aqueous S-species and pyrite during rapid precipitation, despite aqueous speciation indicating pyrite saturation at all stages. Textural, crystallographic, and S isotope interpretations suggest that pyrite formed by means of the FeS pathway. The initial S isotope disequilibrium between formed pyrite and dissolved S-species was effectively erased and approached isotopic equilibrium upon recrystallization during the course of 4297 h. Interpretation of seafloor hydrothermal vent sulfides using the revised equilibrium 34S/32S fractionation between pyrite and H2S suggests that pyrite is close to S isotope equilibrium with vent H2S, contrary to previous conclusions. The experimental data reported here broaden the range of pyrite formation mechanisms at seafloor hydrothermal vents, in that mineral formation pathway and equilibration rates need to be considered to account for the well-recognized S isotope variability that often characterizes these systems.

  20. Petrographic and SIMS pyrite sulfur isotope analyses of Ediacaran chert nodules: Implications for microbial processes in pyrite rim formation, silicification, and exceptional fossil preservation

    NASA Astrophysics Data System (ADS)

    Xiao, Shuhai; Schiffbauer, James D.; McFadden, Kathleen A.; Hunter, Jerry

    2010-09-01

    The lower Ediacaran Doushantuo Formation in the Yangtze Gorges area contains exceptionally preserved microfossils, including the earliest known animal resting eggs and embryos. These fossils are preserved in cm-sized chert nodules, which typically have a microbial mat fragment in the center, a silica cortex, a pyrite rim, and an outer rim of blocky calcite. Petrographic analysis indicates that the formation of the blocky calcite rim postdates that of the pyrite rim and silica cortex. The pyrite rim grew centripetally during early diagenesis, representing a reaction front that was determined by the dynamics between ambient Fe 2+ and H 2S, the latter of which was derived from bacterial sulfate reduction (BSR) of mat fragment in nodule center. The silica cortex was formed pervasively through replacement of carbonate sediments prior to compaction. Secondary ion mass spectroscopy (SIMS) sulfur isotopes of individual pyrite crystals (? 34S py - SIMS) in pyrite rims and matrices show highly positive values (15.2-39.8‰). The pyrite rims do not show an isotopic gradient between small crystals formed in outer rim during early diagenesis and large crystals formed in inner rim during subsequent overgrowth. Although rim pyrite in the same chert nodule has consistent ? 34S py - SIMS values, there are significant spatial and stratigraphic variations in ? 34S py - SIMS values of both matrix and rim pyrite. Overall, isotopic fractionation between pyrite and carbonate associated sulfate (CAS) is small (< 22‰). The isotopic and petrographic data can be interpreted as evidence for rapid BSR of highly metabolizable organic matter in a diagenetic environment with limited sulfate availability, local anoxia, high Fe 2+ concentration, and low sedimentation rate. The embryonic nodules nucleated on microbial mat fragments and stayed in the BSR zone during early diagenesis, when rapid BSR in the nodule center generated outward-diffusing H 2S that was confined by readily available Fe 2+ to precipitate the pyrite rim. The precipitation of the silica cortex was facilitated by localized pH change related to BSR and pyrite precipitation, with silica sourced from silica-rich Precambrian seawater and from microbially mediated clay diagenesis. Like the pyrite rim, the silica cortex was also formed rapidly during early diagenesis, leading to the exceptional preservation of microfossils within these nodules.

  1. In situ Raman spectroscopy of sulfur speciation in lithium-sulfur batteries.

    PubMed

    Wu, Heng-Liang; Huff, Laura A; Gewirth, Andrew A

    2015-01-28

    In situ Raman spectroscopy and cyclic voltammetry were used to investigate the mechanism of sulfur reduction in lithium-sulfur battery slurry cathodes with 1 M lithium bis(trifluoromethane sulfonyl)imide (LiTFSI) and tetraethylene glycol dimethyl ether (TEGDME)/1,3-dioxolane (DIOX) (1/1, v/v). Raman spectroscopy shows that long-chain polysulfides (S8(2-)) were formed via S8 ring opening in the first reduction process at ?2.4 V vs Li/Li(+) and short-chain polysulfides such as S4(2-), S4(-), S3(•-), and S2O4(2-) were observed with continued discharge at ?2.3 V vs Li/Li(+) in the second reduction process. Elemental sulfur can be reformed in the end of the charge process. Rate constants obtained for the appearance and disappearance polysulfide species shows that short-chain polysulfides are directly formed from S8 decomposition. The rate constants for S8 reappearance and polysulfide disappearance on charge were likewise similar. The formation of polysulfide mixtures at partial discharge was found to be quite stable. The CS2 additive was found to inhibit the sulfur reduction mechanism allowing the formation of long-chain polysulfides during discharge only and stabilizing the S8(2-) product. PMID:25543831

  2. Membranes for the Sulfur-Iodine Integrated Laboratory Scale Demonstration

    SciTech Connect

    Frederick F. Stewart

    2007-08-01

    INL has developed polymeric membrane-based chemical separations to enable the thermochemical production of hydrogen. Major activities included studies of sulfuric acid concentration membranes, hydriodic acid concentration membranes, SO2/O2 separation membranes, potential applications of a catalyst reactor system for the decomposition of HI, and evaluation of the chemical separation needs for alternate thermochemical cycles. Membranes for the concentration of sulfuric acid were studied using pervaporation. The goal of this task was to offer the sulfur-iodine (S-I) and the hybrid sulfur (HyS) cycles a method to concentrate the sulfuric acid containing effluent from the decomposer without boiling. In this work, sulfuric acid decomposer effluent needs to be concentrated from ~50 % acid to 80 %. This task continued FY 2006 efforts to characterize water selective membranes for use in sulfuric acid concentration. In FY 2007, experiments were conducted to provide specific information, including transmembrane fluxes, separation factors, and membrane durability, necessary for proper decision making on the potential inclusion of this process into the S-I or HyS Integrated Laboratory Scale demonstration.

  3. Intermediate Length Rieske Iron-Sulfur Protein Is Present and Functionally Active in the Cytochrome bc1 Complex of

    E-print Network

    Trumpower, Bernard L.

    Intermediate Length Rieske Iron-Sulfur Protein Is Present and Functionally Active in the Cytochrome-transla- tional processing of the Rieske iron-sulfur protein of Saccharomyces cerevisiae and its assembly been changed by site-directed mutagenesis of the cloned iron- sulfur protein gene, so

  4. Iron-Sulfur Cluster Biogenesis in Chloroplasts. Involvement of the Scaffold Protein CpIscA1

    E-print Network

    Iron-Sulfur Cluster Biogenesis in Chloroplasts. Involvement of the Scaffold Protein CpIscA1 Salah E contains many iron (Fe)-sulfur (S) proteins for the processes of photosynthesis and nitrogen assembly. Iron (Fe)-sulfur (S) clusters are cofactors of proteins that perform a number of biological roles

  5. 11704 J. Am. Chem. SOC.1995,117, 11704-11709 Regiochemical Selectivity in the Carbon-Sulfur Bond Cleavage

    E-print Network

    Jones, William D.

    11704 J. Am. Chem. SOC.1995,117, 11704- 11709 Regiochemical Selectivity in the Carbon- Sulfur Bond be an importantstep in the removal of sulfur from thiophene in the hydrodesulfur- ization (HDS) process.' Thiophene and its benzo derivatives represent abundant sulfur-containing impurities in coal and petroleum feedstocks

  6. Demonstrating Allotropic Modifications of Sulfur.

    ERIC Educational Resources Information Center

    McCarty, Jillian L.; Dragojlovic, Veljko

    2002-01-01

    Shows how a common demonstration that consists of slowly heating sulfur powder in a test tube to illustrate sulfur's allotropic modifications can convince students of conclusions about the moon Io which they often find surprising. Describes the demonstration in full. (Author/MM)

  7. SULFUR RETENTION IN COAL ASH

    EPA Science Inventory

    The report gives results of an analytical study to assess the potential for sulfur retention in various types of coal-fired boilers. Results of a field test of 10 industrial coal-fired boilers were used to evaluate the impact on sulfur retention of the operating variables (load a...

  8. A soft approach to encapsulate sulfur: polyaniline nanotubes for lithium-sulfur batteries with long cycle life.

    PubMed

    Xiao, Lifen; Cao, Yuliang; Xiao, Jie; Schwenzer, Birgit; Engelhard, Mark H; Saraf, Laxmikant V; Nie, Zimin; Exarhos, Gregory J; Liu, Jun

    2012-03-01

    A novel vulcanized polyaniline nanotube/sulfur composite was prepared successfully via an in situ vulcanization process by heating a mixture of polyaniline nanotube and sulfur at 280 °C. The electrode could retain a discharge capacity of 837 mAh g(-1) after 100 cycles at a 0.1 C rate and manifested 76% capacity retention up to 500 cycles at a 1 C rate. PMID:22278978

  9. Cycling of sulfur in subduction zones: The geochemistry of sulfur in the Mariana Island Arc and back-arc trough

    USGS Publications Warehouse

    Alt, J.C.; Shanks, Wayne C., III; Jackson, M.C.

    1993-01-01

    The sulfur contents and sulfur isotopic compositions of 24 glassy submarine volcanics from the Mariana Island Arc and back-arc Mariana Trough were determined in order to investigate the hypothesis that subducted seawater sulfur (??34S = 21???) is recycled through arc volcanism. Our results for sulfur are similar to those for subaerial arc volcanics: Mariana Arc glasses are enriched in 34S (??34S = up to 10.3???, mean = 3.8???) and depleted in S (20-290 ppm, mean = 100 ppm) relative to MORB (850 ppm S, ??34S = 0.1 ?? 0.5???). The back-arc trough basalts contain 200-930 ppm S and have ??34S values of 1.1 ?? 0.5???, which overlap those for the arc and MORB. The low sulfur contents of the arc and some of the trough glasses are attributed to (1) early loss of small amounts of sulfur through separation of immiscible sulfide and (2) later vapor-melt equilibrium control of sulfur contents and loss of sulfur in a vapor phase from sulfide-undersaturated melts near the minimum in sulfur solubility at f{hook}O2 ??? NNO (nickel-nickel oxide). Although these processes removed sulfur from the melts their effects on the sulfur isotopic compositions of the melts were minimal. Positive trends of ??34S with 87Sr 86Sr, LILE and LREE contents of the arc volcanics are consistent with a metasomatic seawater sulfur component in the depleted sub-arc mantle source. The lack of a 34S-rich slab signature in the trough lavas may be attributed to equilibration of metasomatic fluid with mantle material along the longer pathway from the slab to the source of the trough volcanics. Sulfur is likely to have been transported into the mantle wedge by metasomatic fluid derived from subducted sediments and pore fluids. Gases extracted from vesicles in arc and back-arc samples are predominantly H2O, with minor CO2 and traces of H2S and SO2. CO2 in the arc and back-arc rocks has ??13C values of -2.1 to -13.1???, similar to MORB. These data suggest that degassing of CO2 could explain the slightly lower ??13C values for some Mariana Trough volcanic glasses, and that incorporation of subduction-derived organic carbon into the Mariana Trough mantle source may not be necessary. More analyses are required to resolve this question, however. ?? 1993.

  10. Sulfur speciation in hard coal by means of a thermal decomposition method.

    PubMed

    Spiewok, W; Ciba, J; Trojanowska, J

    2002-02-01

    A new method for the determination of organic and pyritic sulfur in hard coal is presented. The method is based on controlled thermal decomposition of coal sample in oxygen-free and oxygen atmospheres. The results for sulfur liberated in an argon atmosphere at temperatures up to 773 K were close to organic sulfur contents (Sorg), although owing to the definition of 'organic sulfur' the values were not directly comparable. Sorg contents are calculated from the difference between total sulfur content in coal and contents of this element in the form of sulfides, sulfates and pyrites. Sulfur contents, found in the second stage of analysis, were close to pyritic sulfur contents. The difference between total sulfur content and the sum of sulfur values obtained in stages I and II corresponded to sulfur contents in those samples which were neither decomposed nor oxidized at temperatures up to 1173 K. Although not comparable with such conventional concepts for industrial purposes these data are attractive due to the ease and rapidity of the new method for the control of sulfur streams in industrial processes. PMID:11939541

  11. Petroleum and diesel sulfur degradation under gamma radiation

    NASA Astrophysics Data System (ADS)

    Andrade, Luana dos Santos; Calvo, Wilson Aparecido Parejo; Sato, Ivone Mulako; Duarte, Celina Lopes

    2015-10-01

    Hydrodesulfurization (HDS) is currently the most common method used by refineries to remove sulfur compounds from petroleum fractions. However, it is not highly effective for removing thiophene compounds such as benzothiophene. Additionally, this process generates high costs for the oil industry. In the present work, ionizing radiation was used in order to study the effect on the degradation of petroleum and diesel sulfur compounds. Crude oil and diesel fuel samples were studied, without any pretreatment, and irradiated using a cobalt-60 gamma cell in a batch system at absorbed doses of 30 kGy and 50 kGy. The sulfur compounds were extracted and then analyzed by gas chromatography associated with mass spectrometry (GCMS). A high efficiency of ionizing radiation was observed regarding the degradation of sulfur compounds such as benzothiophene and benzenethiol and the formation of fragments, for example 1.2-dimethylbenzene and toluene.

  12. Sulfur in the Apollo 17 basalts and their source regions

    NASA Technical Reports Server (NTRS)

    Gibson, E. K., Jr.; Morris, R. V.; Usselman, T. M.

    1976-01-01

    Thirty-two Apollo 17 mare basalts have been analyzed for their total sulfur and metallic iron abundances. Sulfur abundances range from 1580 to 2770 microgram S/g with a median value of 1860 microgram S/g. Metallic iron abundances ranged from 0.033 to 0.21 wt.% Fe, with a mean value of 0.13 wt% Fe. The coarse-grained basalts contain more metallic iron than the fine-grained basalts. The metallic iron and sulfur abundances are not apparently related to the cooling rates of the basalts. A slight negative correlation exists between the concentrations of metallic iron and total sulfur for the Apollo 17 basalts. Sulfur content of the mare basalts increases with increasing degrees of fractionation whereas the metallic iron content decreases. Metallic iron in mare basalts may be ascribed to a variety of processes; at present the dominant process is unknown. The source regions for the Apollo 17 and 11 basalts were saturated with sulfur as compared to the Apollo 12 and 15 low titanium basalts which were not saturated.

  13. Sulfur abundances and distributions in mare basalts and their source magmas

    NASA Technical Reports Server (NTRS)

    Gibson, E. K., Jr.; Chang, S.; Lennon, K.; Moore, G. W.; Pearce, G. W.

    1975-01-01

    An inverse correlation between metallic iron content and total sulfur abundances was observed by Gibson and Moore (1974) for five Apollo 17 and six Apollo 15 basalts. An investigation was conducted with the objective to distinguish between two processes leading to the inverse metallic iron and total sulfur correlation. The investigation included analyses of ten Apollo 15 and five Apollo 17 basalts for their sulfur and metallic iron abundances along with carbon and hydrogen. The sulfur isotopic compositions were measured for a possible identification of the fractionation processes which might have occurred during volatilization of the basalts.

  14. PILOT PLANT STUDY OF CONVERSION OF COAL TO LOW SULFUR FUEL

    EPA Science Inventory

    The report gives results of a program to develop, on bench and pilot scales, operating conditions for the key step in the IGT process to desulfurize coal by thermal and chemical treatment. This process, to date, uses the 'sulfur-getter' concept. (A sulfur-getter is a material tha...

  15. Selective catalytic reduction system and process for control of NO.sub.x emissions in a sulfur-containing gas stream

    DOEpatents

    Sobolevskiy, Anatoly

    2015-08-11

    An exhaust gas treatment process, apparatus, and system for reducing the concentration of NOx, CO and hydrocarbons in a gas stream, such as an exhaust stream (29), via selective catalytic reduction with ammonia is provided. The process, apparatus and system include a catalytic bed (32) having a reducing only catalyst portion (34) and a downstream reducing-plus-oxidizing portion (36). Each portion (34, 36) includes an amount of tungsten. The reducing-plus-oxidizing catalyst portion (36) advantageously includes a greater amount of tungsten than the reducing catalyst portion (36) to markedly limit ammonia salt formation.

  16. Numerical Study of Sulfur Outgassing in Response to Decompression and Crystallization

    NASA Astrophysics Data System (ADS)

    Bachmann, O.; Su, Y.; Huber, C.; Zajacz, Z.

    2013-12-01

    Volcanic sulfur emissions impact climate over regional and sometimes global scales. In most explosive eruptions, sulfur emissions are greatly in excess of estimates based on sulfur content in melt at magma chamber pressure; it is commonly referred to as excess sulfur degassing. One of the possible explanations for this phenomenon is that sulfur is stored in an exsolved gas phase in the upper crustal reservoir. In order to test this hypothesis, we implemented a model for the growth of volatile bubbles from a silicate melt based on the work of Lensky et al. (2004) and Forestier-Coste et al. (2012). Our model includes the diffusion and partitioning of sulfur from the melt to bubbles. Basically, there are two processes for bubbles to grow, and retain sulfur, from the melt: (1) degassing during magmas ascent in conduits (first boiling) and (2) bubble nucleation and growth as magma cools and crystallizes (second boiling). We present calculations of diffusion under different decompression rates to simulate first boiling. Our results suggest that the sulfur uptake by bubbles during decompression driven degassing in volcanic conduits is typically not efficient. For most decompression rates, a much smaller amount of sulfur than predicted from equilibrium partitioning is found in bubbles. Thus, a balanced sulfur budget requires sulfur enrichment in bubbles prior to eruption. To test the efficiency of sulfur uptake by bubbles during the thermal maturation of magmas in shallow reservoirs, we have also developed a model for bubble growth and sulfur uptake during second boiling. Results show that efficient sulfur extraction into the magmatic volatile phase requires a crystallization-driven exsolution stage.

  17. Novel Sulfur-Tolerant Anodes for Solid Oxide Fuel Cells

    SciTech Connect

    Lei Yang; Meilin Liu

    2008-12-31

    One of the unique advantages of SOFCs over other types of fuel cells is the potential for direct utilization of hydrocarbon fuels (it may involve internal reforming). Unfortunately, most hydrocarbon fuels contain sulfur, which would dramatically degrade SOFC performance at parts-per-million (ppm) levels. Low concentration of sulfur (ppm or below) is difficult to remove efficiently and cost-effectively. Therefore, knowing the exact poisoning process for state-of-the-art anode-supported SOFCs with Ni-YSZ cermet anodes, understanding the detailed anode poisoning mechanism, and developing new sulfur-tolerant anodes are essential to the promotion of SOFCs that run on hydrocarbon fuels. The effect of cell operating conditions (including temperature, H{sub 2}S concentration, cell voltage/current density, etc.) on sulfur poisoning and recovery of nickel-based anode in SOFCs was investigated. It was found that sulfur poisoning is more severe at lower temperature, higher H{sub 2}S concentration or lower cell current density (higher cell voltage). In-situ Raman spectroscopy identified the nickel sulfide formation process on the surface of a Ni-YSZ electrode and the corresponding morphology change as the sample was cooled in H{sub 2}S-containing fuel. Quantum chemical calculations predicted a new S-Ni phase diagram with a region of sulfur adsorption on Ni surfaces, corresponding to sulfur poisoning of Ni-YSZ anodes under typical SOFC operating conditions. Further, quantum chemical calculations were used to predict the adsorption energy and bond length for sulfur and hydrogen atoms on various metal surfaces. Surface modification of Ni-YSZ anode by thin Nb{sub 2}O{sub 5} coating was utilized to enhance the sulfur tolerance. A multi-cell testing system was designed and constructed which is capable of simultaneously performing electrochemical tests of 12 button cells in fuels with four different concentrations of H{sub 2}S. Through systematical study of state-of-the-art anode-supported SOFC button cells, it is seen that the long-term sulfur poisoning behavior of those cells indicate that there might be a second-stage slower degradation due to sulfur poisoning, which would last for a thousand hour or even longer. However, when using G-18 sealant from PNNL, the 2nd stage poisoning was effectively prohibited.

  18. Discovery of practical production processes for arylsulfur pentafluorides and their higher homologues, bis- and tris(sulfur pentafluorides): Beginning of a new era of “super-trifluoromethyl” arene chemistry and its industry

    PubMed Central

    Garrick, Lloyd M; Saito, Norimichi

    2012-01-01

    Summary Various arylsulfur pentafluorides, ArSF5, have long been desired in both academic and industrial areas, and ArSF5 compounds have attracted considerable interest in many areas such as medicines, agrochemicals, and other new materials, since the highly stable SF5 group is considered a “super-trifluoromethyl group” due to its significantly higher electronegativity and lipophilicity. This article describes the first practical method for the production of various arylsulfur pentafluorides and their higher homologues, bis- and tris(sulfur pentafluorides), from the corresponding diaryl disulfides or aryl thiols. The method consists of two steps: (Step 1) treatment of a diaryl disulfide or an aryl thiol with chlorine in the presence of an alkali metal fluoride, and (step 2) treatment of the resulting arylsulfur chlorotetrafluoride with a fluoride source, such as ZnF2, HF, and Sb(III/V) fluorides. The intermediate arylsulfur chlorotetrafluorides were isolated by distillation or recrystallization and characterized. The aspects of these new reactions are revealed and reaction mechanisms are discussed. As the method offers considerable improvement over previous methods in cost, yield, practicality, applicability, and large-scale production, the new processes described here can be employed as the first practical methods for the economical production of various arylsulfur pentafluorides and their higher homologues, which could then open up a new era of “super-trifluoromethyl” arene chemistry and its applications in many areas. PMID:22509218

  19. Enhancement of cycle performance of Li-S batteries by redistribution of sulfur.

    PubMed

    Kim, Kwi Ryong; Yu, Seung-Ho; Sung, Yung-Eun

    2016-01-01

    A practically available strategy is employed to improve the cycle life of lithium-sulfur batteries. The simple process of activation cycling at the polysulfide dissolution region leads to the partial dissolution of polysulfides and the redistribution of sulfur on the electrode. After 50 cycles, the modified activation-cycled sulfur cathode exhibits a capacity that is roughly double that of a cathode without activation cycling. PMID:26608356

  20. Method of preparing graphene-sulfur nanocomposites for rechargeable lithium-sulfur battery electrodes

    DOEpatents

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

    2015-04-07

    A method of preparing a graphene-sulfur nanocomposite for a cathode in a rechargeable lithium-sulfur battery comprising thermally expanding graphite oxide to yield graphene layers, mixing the graphene layers with a first solution comprising sulfur and carbon disulfide, evaporating the carbon disulfide to yield a solid nanocomposite, and grinding the solid nanocomposite to yield the graphene-sulfur nanocomposite. 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 of less than 50 nm.

  1. 46 CFR 148.04-20 - Sulfur.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Sulfur. 148.04-20 Section 148.04-20 Shipping COAST GUARD... Special Additional Requirements for Certain Material § 148.04-20 Sulfur. (a) When sulfur is loaded in a deep hold with general cargo in the 'tween deck hold above the sulfur, a dust proof wooden...

  2. A description of the global sulfur cycle and its controlling processes in the National Center for Atmospheric Research Community Climate Model, Version 3

    NASA Astrophysics Data System (ADS)

    Rasch, Philip J.; Barth, Mary C.; Kiehl, Jeffrey T.; Schwartz, Stephen E.; Benkovitz, Carmen M.

    2000-01-01

    We examine the balance between processes that contribute to the global and regional distributions of sulfate aerosol in the Earth's atmosphere using a set of simulations from the National Center for Atmospheric Research Community Climate Model, Version 3. The analysis suggests that the seasonal cycle of SO2 and SO42- are controlled by a complex interplay between transport, chemistry and deposition processes. The seasonal cycle of these species is not strongly controlled by temporal variations in emissions but by seasonal variations in volume of air processed by clouds, mass of liquid water serving as a site for aqueous chemistry, amount of oxidant available for the conversion from SO2 to SO42-, vertical transport processes, and deposition. A tagging of the sulfate by emission region (Europe, North America, Asia, and rest of world [ROW]), chemical pathway (gaseous versus in-cloud), and type of emissions (anthropogenic versus biogenic) is used to differentiate the balance of processes controlling the production and loading from this material. Significant differences exist in the destiny of SO2 molecules emitted from the several regions. An SO2 molecule emitted from the ROW source region has a much greater potential to form sulfate than one emitted from, for example, Europe. A greater fraction of the SO2 molecules is oxidized that originate from ROW compared with other areas, and once formed, the sulfate has a longer residence time (that is, it is not readily scavenged). The yield of sulfate from ROW sources of SO2 is a factor of 4 higher than that of Europe. A substantially higher fraction of the SO2 emitted over Europe is oxidized to sulfate through the ozone pathway compared to other regions. The analysis suggests that there are significant differences in the vertical distribution, and horizontal extent, of the propagation of sulfate emitted from the several source regions. Sulfate from Asian source regions reaches the farthest from its point of origin and makes a significant contribution to burdens in both hemispheres, primarily from plumes reaching out in the upper troposphere. Sulfate from other source regions tends to remain trapped in their hemisphere of origin.

  3. 40 CFR 50.17 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.17 Section 50.17 Protection of Environment ENVIRONMENTAL....17 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level of the national primary 1-hour annual ambient air quality standard for oxides of sulfur is 75...

  4. Graphene-sulfur nanocomposites for rechargeable lithium-sulfur battery electrodes

    SciTech Connect

    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..

  5. Sulfur Dioxide Crossover during the Production of Hydrogen and Sulfuric Acid in a PEM Electrolyzer

    E-print Network

    Weidner, John W.

    Sulfur Dioxide Crossover during the Production of Hydrogen and Sulfuric Acid in a PEM Electrolyzer in the thermochemical conversion of sulfur dioxide to sulfuric acid for the large-scale production of hydrogen. Unfortunately, during operation, sulfur dioxide can diffuse from the anode to the cathode. This has several

  6. 40 CFR 50.5 - National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... standard for sulfur oxides (sulfur dioxide). 50.5 Section 50.5 Protection of Environment ENVIRONMENTAL....5 National secondary ambient air quality standard for sulfur oxides (sulfur dioxide). (a) The level... than 0.05 ppm shall be rounded up). (b) Sulfur oxides shall be measured in the ambient air as...

  7. 40 CFR 50.5 - National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... standard for sulfur oxides (sulfur dioxide). 50.5 Section 50.5 Protection of Environment ENVIRONMENTAL....5 National secondary ambient air quality standard for sulfur oxides (sulfur dioxide). (a) The level... than 0.05 ppm shall be rounded up). (b) Sulfur oxides shall be measured in the ambient air as...

  8. 40 CFR 50.17 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.17 Section 50.17 Protection of Environment ENVIRONMENTAL....17 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level of the national primary 1-hour annual ambient air quality standard for oxides of sulfur is 75...

  9. 40 CFR 50.17 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.17 Section 50.17 Protection of Environment ENVIRONMENTAL....17 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level of the national primary 1-hour annual ambient air quality standard for oxides of sulfur is 75...

  10. 40 CFR 50.5 - National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... standard for sulfur oxides (sulfur dioxide). 50.5 Section 50.5 Protection of Environment ENVIRONMENTAL....5 National secondary ambient air quality standard for sulfur oxides (sulfur dioxide). (a) The level... than 0.05 ppm shall be rounded up). (b) Sulfur oxides shall be measured in the ambient air as...

  11. 40 CFR 50.5 - National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... standard for sulfur oxides (sulfur dioxide). 50.5 Section 50.5 Protection of Environment ENVIRONMENTAL....5 National secondary ambient air quality standard for sulfur oxides (sulfur dioxide). (a) The level... than 0.05 ppm shall be rounded up). (b) Sulfur oxides shall be measured in the ambient air as...

  12. 40 CFR 50.17 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.17 Section 50.17 Protection of Environment ENVIRONMENTAL....17 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level of the national primary 1-hour annual ambient air quality standard for oxides of sulfur is 75...

  13. 40 CFR 50.5 - National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... standard for sulfur oxides (sulfur dioxide). 50.5 Section 50.5 Protection of Environment ENVIRONMENTAL....5 National secondary ambient air quality standard for sulfur oxides (sulfur dioxide). (a) The level... than 0.05 ppm shall be rounded up). (b) Sulfur oxides shall be measured in the ambient air as...

  14. 40 CFR 50.4 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.4 Section 50.4 Protection of Environment ENVIRONMENTAL....4 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). Link to an... to or greater than 0.005 ppm shall be rounded up). (c) Sulfur oxides shall be measured in the...

  15. 40 CFR 50.17 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.17 Section 50.17 Protection of Environment ENVIRONMENTAL....17 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level of the national primary 1-hour annual ambient air quality standard for oxides of sulfur is 75...

  16. Coal Liquefaction desulfurization process

    DOEpatents

    Givens, Edwin N. (Bethlehem, PA)

    1983-01-01

    In a solvent refined coal liquefaction process, more effective desulfurization of the high boiling point components is effected by first stripping the solvent-coal reacted slurry of lower boiling point components, particularly including hydrogen sulfide and low molecular weight sulfur compounds, and then reacting the slurry with a solid sulfur getter material, such as iron. The sulfur getter compound, with reacted sulfur included, is then removed with other solids in the slurry.

  17. Toxicology of sulfur in ruminants: review

    SciTech Connect

    Kandylis, K.

    1984-10-01

    This review deals with the toxicology of sulfur in ruminants including toxicity, neurotoxic effects, and mechanism of toxic action of hydrogen sulfide, clinical signs, and treatment. It will report effects of excessive intake of sulfur by ruminants on feed intake, animal performance, ruminal digestion and motility, rumination, and other physiological functions. Poisoning of animals with sulfur from industrial emissions (sulfur dioxide) also is discussed. Excessive quantities of dietary sulfur (above .3 to .4%) as sulfate or elemental sulfur may cause toxic effects and in extreme cases can be fatal. The means is discussed whereby consumption of excessive amounts of sulfur leads to toxic effects. 53 references, 1 table.

  18. Sulfur Dioxide variability in the Venus Atmosphere

    NASA Astrophysics Data System (ADS)

    Vandaele, Ann C.; Esposito, Larry W.; Lefevre, Franck; Mills, Franklin; Limaye, Sanjay; Mahieux, Arnaud; Belyaev, Denis; Encrenaz, Therese; Marcq, Emmanuel; Korablev, Oleg; Parkinson, Christopher; Wilson, Colin; Wilquet, Valérie; Chamberlain, Sarah; Jessup, Kandis Lea; Stolzenbach, Aurelien

    The recent observations of SO _{2} by SOIR and SPICAV-UV on board Venus Express and ground-based observations of SO _{2} and SO have provoked much reaction in the scientific community. SO _{2} is strongly related to the formation of the clouds and haze on Venus, which are composed of sulfuric acid combined to water complexes. Presence and variations of SO _{2} could be the proof of a possible volcanism on Venus. The most intriguing are discrepancies among different observations, and the suspected long-term variations of the SO _{2} abundance observed on the scales of several years, in particular during Pioneer Venus Orbiter and Venus Express missions. Similar trends are also observed in the super-rotation period and circulation patterns, which suggest that these aspects may be more strongly coupled than expected. An ISSI international team has been built in view of considering different aspects of sulfur chemistry on Venus. This includes comparison and validation of observations, from past missions, from Venus Express, from the Earth, and from Hubble Space Telescope, modeling of photochemistry and of other processes in which the sulfur family is involved. We will consider not only SO _{2}, but also SO and other constituents involved in its cycle. Reference density and vmr fields will be constructed from the detailed analysis and comparison of data. These will be included into the next generation of the VIRA references atmosphere.

  19. METHOD TO PREVENT SULFUR ACCUMULATION INSIDE MEMBRANE ELECTRODE ASSEMBLY

    SciTech Connect

    Steimke, J.; Steeper, T.; Herman, D.; Colon-Mercado, H.; Elvington, M.

    2009-06-22

    HyS is conceptually the simplest of the thermochemical cycles and involves only sulfur chemistry. In the HyS Cycle hydrogen gas (H{sub 2}) is produced at the cathode of the electrochemical cell (or electrolyzer). Sulfur dioxide (SO{sub 2}) is oxidized at the anode to form sulfuric acid (H{sub 2}SO{sub 4}) and protons (H{sup +}) as illustrated below. A separate high temperature reaction decomposes the sulfuric acid to water and sulfur dioxide which are recycled to the electrolyzers, and oxygen which is separated out as a secondary product. The electrolyzer includes a membrane that will allow hydrogen ions to pass through but block the flow of hydrogen gas. The membrane is also intended to prevent other chemical species from migrating between electrodes and undergoing undesired reactions that could poison the cathode or reduce overall process efficiency. In conventional water electrolysis, water is oxidized at the anode to produce protons and oxygen. The standard cell potential for conventional water electrolysis is 1.23 volts at 25 C. However, commercial electrolyzers typically require higher voltages ranging from 1.8 V to 2.6 V [Kirk-Othmer, 1991]. The oxidation of sulfur dioxide instead of water in the HyS electrolyzer occurs at a much lower potential. For example, the standard cell potential for sulfur dioxide oxidation at 25 C in 50 wt % sulfuric acid is 0.29 V [Westinghouse, 1980]. Since power consumption by the electrolyzers is equal to voltage times current, and current is proportional to hydrogen production, a large reduction in voltage results in a large reduction in electrical power cost per unit of hydrogen generated.

  20. ENGINEERING EVALUATION OF HOT-GAS DESULFURIZATION WITH SULFUR RECOVERY

    SciTech Connect

    G.W. ROBERTS; J.W. PORTZER; S.C. KOZUP; S.K. GANGWAL

    1998-05-31

    Engineering evaluations and economic comparisons of two hot-gas desulfurization (HGD) processes with elemental sulfur recovery, being developed by Research Triangle Institute, are presented. In the first process, known as the Direct Sulfur Recovery Process (DSRP), the SO{sub 2} tail gas from air regeneration of zinc-based HGD sorbent is catalytically reduced to elemental sulfur with high selectivity using a small slipstream of coal gas. DSRP is a highly efficient first-generation process, promising sulfur recoveries as high as 99% in a single reaction stage. In the second process, known as the Advanced Hot Gas Process (AHGP), the zinc-based HGD sorbent is modified with iron so that the iron portion of the sorbent can be regenerated using SO{sub 2} . This is followed by air regeneration to fully regenerate the sorbent and provide the required SO{sub 2} for iron regeneration. This second-generation process uses less coal gas than DSRP. Commercial embodiments of both processes were developed. Process simulations with mass and energy balances were conducted using ASPEN Plus. Results show that AHGP is a more complex process to operate and may require more labor cost than the DSRP. Also capital costs for the AHGP are higher than those for the DSRP. However, annual operating costs for the AHGP appear to be considerably less than those for the DSRP with a potential break-even point between the two processes after just 2 years of operation for an integrated gasification combined cycle (IGCC) power plant using 3 to 5 wt% sulfur coal. Thus, despite its complexity, the potential savings with the AHGP encourage further development and scaleup of this advanced process.

  1. RECOVERY OF CALCIUM CARBONATE AND SULFUR FROM FGD SCRUBBER WASTE

    EPA Science Inventory

    The report gives results of a demonstration of key process steps in the proprietary Kel-S process for recovering calcium carbonate and sulfur from lime/limestone flue gas desulfurization (FGD) scrubber waste. The steps are: reduction of the waste to calcium sulfide (using coal as...

  2. Efficient regulation of elemental sulfur recovery through optimizing working height of upflow anaerobic sludge blanket reactor during denitrifying sulfide removal process.

    PubMed

    Huang, Cong; Li, Zhi-Ling; Chen, Fan; Liu, Qian; Zhao, You-Kang; Gao, Ling-Fang; Chen, Chuan; Zhou, Ji-Zhong; Wang, Ai-Jie

    2016-01-01

    In this study, two lab-scale UASB reactors were established to testify S(0) recovery efficiency, and one of which (M-UASB) was improved from the previous T-UASB by shortening reactor height once S(2-) over oxidation was observed. After the height was shortened from 60 to 30cm, S(0) recovery rate was improved from 7.4% to 78.8%, and while, complete removal of acetate, nitrate and S(2-) was simultaneously maintained. Meanwhile, bacterial community distribution was homogenous throughout the reactor, with denitrifying sulfide oxidization bacteria predominant, such as Thauera and Azoarcus spp., indicating the optimized condition for S(0) recovery. The effective control of working height/volume in reactors plays important roles for the efficient regulation of S(0) recovery during DSR process. PMID:26497112

  3. Nitrogen-Doped Mesoporous Carbon: A Top-Down Strategy to Promote Sulfur Immobilization for Lithium-Sulfur Batteries.

    PubMed

    Zhao, Xiaohui; Liu, Ying; Manuel, James; Chauhan, Ghanshyam S; Ahn, Hyo-Jun; Kim, Ki-Won; Cho, Kwon-Koo; Ahn, Jou-Hyeon

    2015-10-01

    The loss of active sulfur material is a challenge in the application of lithium-sulfur (Li-S) batteries. To immobilize sulfur, a nitrogen-doped mesoporous carbon (PMC) was synthesized with polyaniline (PANi) as the carbon source, which was used for development of Li-S batteries. The nitrogen content and pore system of the PMCs were modulated by varying the pyrolysis temperature to impart good electrochemical properties to the Li-S cells. As a result, the optimal capacity reversibility was obtained with the PMC synthesized at 700?°C that consisted of 12.8?% nitrogen. The enhanced cycle performance of Li-S cells was also validated at high sulfur contents up to 70?% and high C-rates up to 2?C. Furthermore, such sulfur/PMC cathodes could alleviate volume expansion during the discharge process. The results suggest that our synthesized nitrogen-doped PMCs prepared by this top-down strategy are promising materials to immobilize active sulfur in Li-S batteries. PMID:26336933

  4. Biotic and abiotic carbon to sulfur bond cleavage. Technical report, July 1, 1991--September 30, 1991

    SciTech Connect

    Frost, J.W.

    1991-12-31

    Cleavage of aliphatic organosulfonate carbon to sulfur (C-S) bonds, a critical link in the global biogeochemical sulfur cycle, has been identified in Escherichia coli K-12. Enormous quantities of inorganic sulfate are continuously converted (Scheme I) into methanesulfonic acid 1 and acylated 3-(6-sulfo-{alpha}-D-quinovopyranosyl)-L-glycerol 2. Biocatalytic desulfurization (Scheme I) of 1 and 2, which share the structural feature of an aliphatic carbon bonded to a sulfonic acid sulfur, completes the cycle, Discovery of this desulfurization in E. coli provides an invaluable paradigm for study of a biotic process which, via the biogeochemical cycle, significantly influences the atmospheric concentration of sulfur-containing molecules.

  5. Hydrogen and sulfur recovery from hydrogen sulfide wastes

    DOEpatents

    Harkness, J.B.L.; Gorski, A.J.; Daniels, E.J.

    1993-05-18

    A process is described for generating hydrogen and elemental sulfur from hydrogen sulfide waste in which the hydrogen sulfide is [dis]associated under plasma conditions and a portion of the hydrogen output is used in a catalytic reduction unit to convert sulfur-containing impurities to hydrogen sulfide for recycle, the process also including the addition of an ionizing gas such as argon to initiate the plasma reaction at lower energy, a preheater for the input to the reactor and an internal adjustable choke in the reactor for enhanced coupling with the microwave energy input.

  6. Hydrogen and sulfur recovery from hydrogen sulfide wastes

    DOEpatents

    Harkness, John B. L. (Naperville, IL); Gorski, Anthony J. (Woodridge, IL); Daniels, Edward J. (Oak Lawn, IL)

    1993-01-01

    A process for generating hydrogen and elemental sulfur from hydrogen sulfide waste in which the hydrogen sulfide is associated under plasma conditions and a portion of the hydrogen output is used in a catalytic reduction unit to convert sulfur-containing impurities to hydrogen sulfide for recycle, the process also including the addition of an ionizing gas such as argon to initiate the plasma reaction at lower energy, a preheater for the input to the reactor and an internal adjustable choke in the reactor for enhanced coupling with the microwave energy input.

  7. Optimizing stratospheric sulfur geoengineering by seasonally changing sulfur injections

    NASA Astrophysics Data System (ADS)

    Laakso, Anton; Partanen, Antti-Ilari; Kokkola, Harri; Lehtinen, Kari; Korhonen, Hannele

    2015-04-01

    Solar radiation management (SRM) by stratospheric sulfur injection has been shown to have potential in counteracting global warming if reducing of greenhouse gases has not been achieved fast enough and if climate warming will continue. Injecting large amounts of sulfate particles to the stratosphere would increase the reflectivity of the atmosphere and less sunlight would reach the surface. However, the effectivity (per injected sulphur mass unit) of this kind of geoengineering would decrease when amount of injected sulfur is increased. When sulfur concentration increases, stratospheric particles would grow to larger sizes which have larger gravitational settling velocity and which do not reflect radiation as efficiently as smaller particles. In many previous studies, sulfur has been assumed to be injected along the equator where yearly mean solar intensity is the highest and from where sulfur is spread equally to both hemispheres. However, the solar intensity will change locally during the year and sulfate has been assumed to be injected and spread to the hemisphere also during winter time, when the solar intensity is low. Thus sulfate injection could be expected to be more effective, if sulfur injection area is changed seasonally. Here we study effects of the different SRM injection scenarios by using two versions of the MPI climate models. First, aerosol spatial and temporal distributions as well as the resulting radiative properties from the SRM are defined by using the global aerosol-climate model ECHAM6.1-HAM2.2-SALSA. After that, the global and regional climate effects from different injection scenarios are predicted by using the Max Planck Institute's Earth System Model (MPI-ESM). We carried out simulations, where 8 Tg of sulfur is injected as SO2 to the stratosphere at height of 20-22 km in an area ranging over a 20 degree wide latitude band. Results show that changing the sulfur injection area seasonally would lead to similar global mean shortwave radiative forcing (-4.41 W/m2 at top of atmosphere) as if sulfur is injected only to the equator (-4.40 W/m2). However zonal mean distribution would be different and forcing is concentrated relatively more to the midlatitudes and less to the equator. Cooling effect from the geoengineering and warming effect from the increased greenhouse gas has been shown in many studies to lead to cooling in the equator and warming in the poles compared the preindustrial conditions. Changing the injection area seasonally might prevent this from happening and lead globally to more homogeneous temperature change.

  8. Production of elemental sulfur from H{sub 2}S and CO{sub 2} derived from a coal desulfurization process. Quarterly technical process report, April 1, 1994--June 30, 1994

    SciTech Connect

    Hu, Longsheng; Jiang, Xueyu; Khang, Soon-Jai

    1994-08-01

    During the third quarter of this project, by using the apparatus previously setup for preparation of catalysts, the CoO-MoO{sub 3}-Al{sub 2}O{sub 3} catalyst was prepared and the thermal stability of the catalyst was tested. Efforts were made on the calibration and the programming of the two column GC of a Perkin Elmer Gas Chromatograph. Column A was used for detecting sulfur related substances such as H{sub 2}S, COS and CS{sub 2}, and column B was for CO, CH{sub 4} and H{sub 2}. All of the GC standard curves were obtained. Non-catalytic experiments were carried out by using the packed bed reactor system with blank, filled only with quartz wool and Al{sub 2}O{sub 3} support for future reference. A modified new reactor was designed to quickly quench the reaction and to prohibit the occurrence of re-equilibration of reaction products. Further thermodynamic analyses for the reaction of H{sub 2}S and CO, were performed using the Stanjan method.

  9. A novel coal feeder for production of low sulfur fuel

    SciTech Connect

    Khang, S.J.; Keener, T.C.; Line, L.

    1992-01-01

    The following tasks have been performed (1) Change of the single-ended driving mechanism of the inner screw shaft to a double-ended driving mechanism, (2) Study of the total sulfur balance on the feeder reactor system, (3) Analytical measurements of the organic sulfur contents in the feed coal and the product char, (4) Study of the organic sulfur removal efficiency in the feeder reactor, (5) Designing and setting up a combustor which is physically attached to the feeder system, (6) Study of the combustion characteristics of char and volatiles produced from the pyrolysis process in the feeder system, and (7) Modeling the pyrolysis process in the inner screw tube to estimate the heat transfer coefficient. Some preliminary conclusions have been obtained: (1) Double-ended driving mechanism of the inner screw feeder is useful for a uniform stress on the shaft and to raise the reaction temperature without an additional metal torque on the shaft. (2) The total sulfur balance shows that the sulfur removal efficiency of CaO in this reactor is higher than 90%. (3) The organic sulfur in Ohio [number sign]8 coal is 1.72% which amounts to 45.4% of the total sulfur content. (4) A 73.1% of the organic sulfur is removed in the dual-screw feeder reactor at a temperature of 475[degree]C with the residence time of 6 min., (5) The S[sub 2]O emission from the combustor stack reduces as the coal feeder temperature rises, corresponding to the level of H S release from the dual-screw feeder. (6) The total heating value of the coal does not significantly decrease during the pyrolysis and desulfurization processes in the coal feeder. The decrease is mainly due to the loss of sulfur from coal. (7) The heat transfer step is the main resistance to the pyrolysis process in this system. The heat transfer coefficient is estimated to be about 331.7 W/m-K.

  10. The electrochemical properties of lithium/sulfur cell using sulfur-carbon nanotubes composite.

    PubMed

    Kim, Dong-Ju; Park, Jin-Woo; Kim, Jong-Seon; Cho, Kweon-Koo; Kim, Ki-Won; Ahn, Jou-Hyeon; Jo, Min-Kyung; Choi, Hyun-Joo; Bae, Dong-Hyun; Ahn, Hyo-Jun

    2011-01-01

    Sulfur electrode was prepared using sulfur-CNT composite powder. The sulfur electrode showed homogenous mixture of sulfur and the CNTs with a network structure. We investigated on the discharge behavior and cycling property of lithium/sulfur cell using sulfur electrodes with CNTs as unique conducting agents. The discharge capacity of the Li/TEGDME/S cell was about 1227 mAh/g-sulfur for the first cycle and decreased to 155 mAh/g-sulfur after 14 cycles. PMID:21446481

  11. ADVANCED SULFUR CONTROL CONCEPTS FOR HOT-GAS DESULFURIZATION TECHNOLOGY

    SciTech Connect

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

    1998-10-31

    This research project examined the feasibility of a second generation high-temperature coal gas desulfurization process in which elemental sulfur is produced directly during the sorbent regeneration phase. Two concepts were evaluated experimentally. In the first, FeS was regenerated in a H2O-O2 mixture. Large fractions of the sulfur were liberated in elemental form when the H2O-O2 ratio was large. However, the mole percent of elemental sulfur in the product was always quite small (<<1%) and a process based on this concept was judged to be impractical because of the low temperature and high energy requirements associated with condensing the sulfur. The second concept involved desulfurization using CeO2 and regeneration of the sulfided sorbent, Ce2O2S, using SO2 to produce elemental sulfur directly. No significant side reactions were observed and the reaction was found to be quite rapid over the temperature range of 500°C to 700°C. Elemental sulfur concentrations (as S2) as large as 20 mol% were produced. Limitations associated with the cerium sorbent process are concentrated in the desulfurization phase. High temperature and highly reducing coal gas such as produced in the Shell gasification process are required if high sulfur removal efficiencies are to be achieved. For example, the equilibrium H2S concentration at 800°C from a Shell gas in contact with CeO2 is about 300 ppmv, well above the allowable IGCC specification. In this case, a two-stage desulfurization process using CeO2 for bulk H2S removal following by a zinc sorbent polishing step would be required. Under appropriate conditions, however, CeO2 can be reduced to non-stoichiometric CeOn (n<2) which has significantly greater affinity for H2S. Pre-breakthrough H2S concentrations in the range of 1 ppmv to 5 ppmv were measured in sulfidation tests using CeOn at 700°C in highly reducing gases, as measured by equilibrium O2 concentration, comparable to the Shell gas. Good sorbent durability was indicated in 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.

  12. Specific gravity and API gravity of biodiesel and ultra-low sulfur diesel (ULSD) blends

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biodiesel is an alternative fuel made from vegetable oils and animal fats. In 2006, the U. S. Environmental Protection Agency mandated a maximum sulfur content of 15 ppm in on-road diesel fuels. Processing to produce the new ultra-low sulfur petrodiesel (ULSD) alters specific gravity (SG) and othe...

  13. Denitrification of groundwater with elemental sulfur.

    PubMed

    Soares, M I M

    2002-03-01

    Autotrophic denitrification was studied in laboratory columns packed with granular elemental sulfur only and operated in an upflow mode. Soluble inorganic carbon, sodium bicarbonate, was supplied as source of carbon for microbial growth. Denitrification rates of up to 0.20 kg N removed m(-3) d(-1) were obtained at a hydraulic retention time of I h, and a nitrate loading of 0.24 kg N m(-3) d(-1). The process is extremely simple, stable and easy to maintain. PMID:11905445

  14. Sulfur dioxide removal from gas streams

    SciTech Connect

    Urban, P.; Ginger, E.A.

    1986-11-11

    A process is described for removal of sulfur dioxide pollutant gas from gas stream which comprises contacting the gas stream with pretreated shale in the form of an aqueous solution of aluminum sulfate including from about 0.1 to about 2.0% by weight of the pretreated shale. The pretreatment of the shale comprises the heating of the shale in the presence of a gas unable to support combustion at a temperature in a range of from about 340/sup 0/C. to about 480/sup 0/C.

  15. Sulfur Chemistry in the Early and Present Atmosphere of Mars

    NASA Technical Reports Server (NTRS)

    Levine, Joel S.; Summers, M. E.

    2011-01-01

    Atmospheric sulfur species resulting from volcanic emissions impact the composition and chemistry of the atmosphere, impact the climate, and hence, the habitability of Mars and impact the mineralogy and composition of the surface of Mars. The geochemical/ photochemical cycling of sulfur species between the interior (via volcanism), the atmosphere (atmospheric photochemical and chemical processes) and the deposition of sulfuric acid on the surface of Mars is an important, but as yet poorly understood geochemical/ photochemical cycle on Mars. There is no observational evidence to indicate that Mars is volcanically active at the present time, however, there is strong evidence that volcanism was an important and widespread process on early Mars. The chemistry and photochemistry of sulfur species in the early and present atmosphere of Mars will be assessed using a one-dimensional photochemical model. Since it is generally assumed that the atmosphere of early Mars was significantly denser than the present 6-millibar atmosphere, photochemical calculations were performed for the present atmosphere and for the atmosphere of early Mars with assumed surface pressures of 60 and 350-millibars, where higher surface pressure resulted from enhanced atmospheric concentrations of carbon dioxide (CO2). The following sections include the results of earlier modeling studies, a summary of the one-dimensional photochemical model used in this study, a summary of the photochemistry and chemistry of sulfur species in the atmosphere of Mars and some of the results of the calculations.

  16. Volcanogenic Sulfur on Earth and Io: Composition and Spectroscopy

    USGS Publications Warehouse

    Kargel, J.S.; Delmelle, P.; Nash, D.B.

    1999-01-01

    The causes of Io's variegated surface, especially the roles of sulfur, and the geochemical history of sulfur compounds on Io are not well understood. Suspecting that minor impurities in sulfur might be important, we have investigated the major and trace element chemistry and spectroscopic reflectance of natural sulfur from a variety of terrestrial volcanic-hydrothermal environments. Evidence suggests that Io may be substantially coated with impure sulfur. On Earth, a few tenths of a percent to a few percent of chalcophile trace elements (e.g., As and Se) comonly occur in sulfur and appear to stabilize material of yellow, brown, orange, and red hues, which may persist even at low temperatures. Percentage levels of chalcophile impurities are reasonably expected to occur on Io in vapor sublimate deposits and flows derived from such deposits. Such impurities join a host of other mechanisms that might explain Io's reds and yellows. Two-tenths to two percent opaque crystalline impurities, particularly pyrite (FeS2), commonly produces green, gray, and black volcanic sulfur on Earth and might explain areas of Io having deposits of these colors. Pyrite produces a broad absorption near 1 ??m that gradually diminishes out to 1.6 ??m - similar but not identical to the spectrum of Io seen in Galileo NIMS data. Percentage amounts of carbonaceous impurities and tens of percent SiO2 (as silicates) also strongly affect the spectral properties of Earth's sulfur. Io's broad absorption between 0.52 and 0.64 ??m remains unexplained by these data but could be due to sodium sulfides, as suggested previously by others, or to As, Se, or other impurities. These impurities and others, such as P and Cl (which could exist on Io's surface in amounts over 1% that of sulfur), greatly alter the molecular structure of molten and solid sulfur. Minor impurities could impact Io's geology, such as the morphology of sulfur lava flows and the ability of sulfur to sustain high relief. We have not found any natural sulfur containing significant Na beyond that attributable to silicate inclusions. In sum, the unique physical-chemical properties of S-rich systems and the strong affinity of certain elements for S may have broad implications for the appearance, spectroscopic interpretation, and geologic processes of Io. Identification of impurities in sulfur may be helpful in tracing the geochemical evolution of surface deposits on Io. Perhaps foretelling of new areas of investigation, Cl has recently been reported in the Io torus (M. Kueppers and N. M. Schneider 1999, Eos Trans.80, 5207), suggesting the presence on Io of either salts, such as halite, or sulfur chlorides. Further evidence of minor iogenic impurities should be sought in Io's neutral cloud and plasma torus as well as in further scrutiny of Io's reflectance spectra. ?? 1999 Academic Press.

  17. Volcanogenic Sulfur on Earth and Io: Composition and Spectroscopy

    NASA Astrophysics Data System (ADS)

    Kargel, Jeffrey S.; Delmelle, Pierre; Nash, Douglas B.

    1999-11-01

    The causes of Io's variegated surface, especially the roles of sulfur, and the geochemical history of sulfur compounds on Io are not well understood. Suspecting that minor impurities in sulfur might be important, we have investigated the major and trace element chemistry and spectroscopic reflectance of natural sulfur from a variety of terrestrial volcanic-hydrothermal environments. Evidence suggests that Io may be substantially coated with impure sulfur. On Earth, a few tenths of a percent to a few percent of chalcophile trace elements (e.g., As and Se) comonly occur in sulfur and appear to stabilize material of yellow, brown, orange, and red hues, which may persist even at low temperatures. Percentage levels of chalcophile impurities are reasonably expected to occur on Io in vapor sublimate deposits and flows derived from such deposits. Such impurities join a host of other mechanisms that might explain Io's reds and yellows. Two-tenths to two percent opaque crystalline impurities, particularly pyrite (FeS 2), commonly produces green, gray, and black volcanic sulfur on Earth and might explain areas of Io having deposits of these colors. Pyrite produces a broad absorption near 1 ?m that gradually diminishes out to 1.6 ?m—similar but not identical to the spectrum of Io seen in Galileo NIMS data. Percentage amounts of carbonaceous impurities and tens of percent SiO 2 (as silicates) also strongly affect the spectral properties of Earth's sulfur. Io's broad absorption between 0.52 and 0.64 ?m remains unexplained by these data but could be due to sodium sulfides, as suggested previously by others, or to As, Se, or other impurities. These impurities and others, such as P and Cl (which could exist on Io's surface in amounts over 1% that of sulfur), greatly alter the molecular structure of molten and solid sulfur. Minor impurities could impact Io's geology, such as the morphology of sulfur lava flows and the ability of sulfur to sustain high relief. We have not found any natural sulfur containing significant Na beyond that attributable to silicate inclusions. In sum, the unique physical-chemical properties of S-rich systems and the strong affinity of certain elements for S may have broad implications for the appearance, spectroscopic interpretation, and geologic processes of Io. Identification of impurities in sulfur may be helpful in tracing the geochemical evolution of surface deposits on Io. Perhaps foretelling of new areas of investigation, Cl has recently been reported in the Io torus (M. Kueppers and N. M. Schneider 1999, Eos Trans.80, 5207), suggesting the presence on Io of either salts, such as halite, or sulfur chlorides. Further evidence of minor iogenic impurities should be sought in Io's neutral cloud and plasma torus as well as in further scrutiny of Io's reflectance spectra.

  18. Sulfur capture in combination bark boilers

    SciTech Connect

    Someshwar, A.V.; Jain, A.K. )

    1993-07-01

    A review of sulfur dioxide emission data for eight combination bark boilers in conjunction with the sulfur contents of the fuels reveals significant sulfur capture ranging from 10% to over 80% within the solid ash phase. Wood ash characteristics similar to activated carbon as well as the significant wood ash alkali oxide and carbonate fractions are believed responsible for the sulfur capture. Sulfur emissions from combination bark-fossil fuel firing are correlated to the sulfur input per ton of bark or wood residue fired.

  19. Production of elemental sulfur from H{sub 2}S and CO{sub 2} derived from a coal desulfurization process. Quarterly technical process report, December 1, 1993--March 31, 1994

    SciTech Connect

    Hu, L.; Jiang, X.; Khang, S.J.

    1994-05-01

    During the second quarter of the project, an experimental apparatus was setup for catalyst screening studies. Sulfided Co-Mo-Al{sub 2}O{sub 3} catalyst was prepared and a thermodynamic study for the reaction of H{sub 2}S and CO{sub 2} was performed. A packed bed reactor made of quartz tube was setup for catalyst screening studies. This reactor was also used for the H{sub 2} reduction of catalyst. Temperature profile in the reactor was measured and results indicated that in the middle of the reactor (5 to 6 inches in length) the temperature profile may be regarded as isothermal. Sulfided Co-Mo catalyst was prepared by first reducing (using H{sub 2}) and sulfiding (using H{sub 2}S) a commercially available CoO-MoO{sub 3}-Al{sub 2}O{sub 3} catalyst. Thermodynamic analysis for the reaction of H{sub 2}S and CO{sub 2} was performed by using the JANAF thermochemic table and the STANJAN method. The results indicated that the following reaction mechanism might be suitable for the reaction of H{sub 2}S and CO{sub 2} to produce elemental sulfur and methane: (1) 2H{sub 2}S = 2H{sub 2}+S{sub 2}, (2) CO{sub 2}+H{sub 2}=CO+H{sub 2}O, (3) CO{sub 2}+4H{sub 2}=CH{sub 4}+2H{sub 2}O, and (4) CO+3H{sub 2}=CH{sub 4}+2H{sub 2}O.

  20. Commercial Alloys for Sulfuric Acid Vaporization in Thermochemical Hydrogen Cycles

    SciTech Connect

    Thomas M. Lillo; Karen M. Delezene-Briggs

    2005-10-01

    Most thermochemical cycles being considered for producing hydrogen include a processing stream in which dilute sulfuric acid is concentrated, vaporized and then decomposed over a catalyst. The sulfuric acid vaporizer is exposed to highly aggressive conditions. Liquid sulfuric acid will be present at a concentration of >96 wt% (>90 mol %) H2SO4 and temperatures exceeding 400oC [Brown, et. al, 2003]. The system will also be pressurized, 0.7-3.5 MPa, to keep the sulfuric acid in the liquid state at this temperature and acid concentration. These conditions far exceed those found in the commercial sulfuric acid generation, regeneration and handling industries. Exotic materials, e.g. ceramics, precious metals, clad materials, etc., have been proposed for this application [Wong, et. al., 2005]. However, development time, costs, reliability, safety concerns and/or certification issues plague such solutions and should be considered as relatively long-term, optimum solutions. A more cost-effective (and relatively near-term) solution would be to use commercially-available metallic alloys to demonstrate the cycle and study process variables. However, the corrosion behavior of commercial alloys in sulfuric acid is rarely characterized above the natural boiling point of concentrated sulfuric acid (~250oC at 1 atm). Therefore a screening study was undertaken to evaluate the suitability of various commercial alloys for concentration and vaporization of high-temperature sulfuric acid. Initially alloys were subjected to static corrosion tests in concentrated sulfuric acid (~95-97% H2SO4) at temperatures and exposure times up to 200oC and 480 hours, respectively. Alloys with a corrosion rate of less than 5 mm/year were then subjected to static corrosion tests at a pressure of 1.4 MPa and temperatures up to 375oC. Exposure times were shorter due to safety concerns and ranged from as short as 5 hours up to 144 hours. The materials evaluated included nickel-, iron- and cobalt-based commercial alloys. The corrosion rates in these tests are reported and how they may or may not relate to the corrosion behavior in an operating thermochemical cycle is discussed.

  1. Fluidized bed sulfur dioxide removal

    SciTech Connect

    Nguyen, X.T.

    1982-01-05

    A system is disclosed for reducing the emission of sulfur particularly for high sulfur coal combustion in a fluidized bed by injecting limestone into the bed and calcining the limestone in the bed to form lime. A portion of the lime so formed is reacted with a portion of the SO2 generated in the bed, removing the excess of material containing lime so generated from the bed. Excess lime is slaked in water, then contacted with the flue gases leaving the fluid bed and containing SO2 with the lime slurry so formed thereby removing a further significant portion of the generated SO2 from the flue gas.

  2. Modulation of the Midpoint Potential of the [2Fe-2S] Rieske Iron Sulfur Center by Qo Occupants in the bc1 Complex

    E-print Network

    Crofts, Antony R.

    Modulation of the Midpoint Potential of the [2Fe-2S] Rieske Iron Sulfur Center by Qo Occupants the immediate donor to c1, the Rieske iron-sulfur protein (ISP). Because the effect was seen only over, and an iron-sulfur center, ISP1) and two quinone-processing sites, for oxidation of ubiquinol (Qo site

  3. Sulfur Hexafluoride Tracer Dispersion within Cherry Orchard

    E-print Network

    Collins, Gary S.

    Sulfur Hexafluoride Tracer Dispersion within Cherry Orchard Zeyuan Chen, S. Edburg, and B. Lamb-GAPS to measure sulfur hexafluoride: an inert gas that is not commonly found in ambient air and is easily

  4. Three-Zone Catalyst Resists Sulfur Poisoning

    NASA Technical Reports Server (NTRS)

    Voecks, G. E.; Stephanopoulos, M. F.; Houseman, J.

    1984-01-01

    Three-zone catalyst bed uses different types of nickel catalysts to convert sulfur-containing hydrocarbon fuels to hydrogen and carbon monoxide. Zones designed to achieve conversion with minimal residue of unconverted hydrocarbon, no soot and mimimal sulfur contamination.

  5. Origin of the {lambda} Transition in Liquid Sulfur

    SciTech Connect

    Scopigno, T.; Yannopoulos, S. N.; Andrikopoulos, K. S.; Fioretto, D.; Ruocco, G.

    2007-07-13

    Developing a novel experimental technique, we applied photon correlation spectroscopy using infrared radiation in liquid sulfur around T{sub {lambda}}, i.e., in the temperature range where an abrupt increase in viscosity by 4 orders of magnitude is observed upon heating within few degrees. This allowed us--overcoming photoinduced and absorption effects at visible wavelengths--to reveal a chain relaxation process with characteristic time in the millisecond range. These results do rehabilitate the validity of the Maxwell relation in sulfur from an apparent failure, allowing rationalizing of the mechanical and thermodynamic behavior of this system within a viscoelastic scenario.

  6. Slipstream testing of hot-gas desulfurization with sulfur recovery

    SciTech Connect

    Gangwal, S.K.; Porter, J.W.

    1995-11-01

    The objective of this work is to further the development of zinc titanate fluidized-bed desulfurization (ZTFBD), and the Direct Sulfur Recovery Process (DSRP) for hot gas cleanup of coal gas used in integrated gasification combined-cycle (IGCC) power generation systems. Results are described.

  7. CONTROL OF SULFUR EMISSIONS FROM OIL SHALE RETORTS

    EPA Science Inventory

    The objectives of this study were to determine the best available control technology (BACT) for control of sulfur emissions from oil shale processing facilities and then to develop a design for a mobile slipstream pilot plant that could be used to test and demonstrate that techno...

  8. LIGNOSULFONATE-MODIFIED CALCIUM HYDROXIDE FOR SULFUR DIOXIDE CONTROL

    EPA Science Inventory

    The article discusses the use of lignosulfonate-modified calcium hydroxide Ca(OH)2 for sulfur dioxide (SO2) control. The limestone injection multistage burner (LIMB) process is currently being developed at the U.S. EPA as a low cost retrofittable technology for controlling oxides...

  9. Polarographic analysis of sulfur species in marine porewaters

    SciTech Connect

    Not Available

    1985-07-01

    A schematic is described to determine the major sulfur species found in marine porewaters. With polarographic techniques, it is possible to measure thiosulfate, sulfite, bisulfide, and polysulfide ions at a mercury electrode. Polysulfide ions, S/sub x//sup 2 -/, can be considered to be composed of one sulfur in the 2- oxidation state, S(2-), and the remaining (x-1) sulfurs in the zero-valent oxidation state, S(0). The number of sulfur atoms in each is measurable. Tetrathionate and other polythionates can be measured as well but have not been detected in porewaters studied to date. Salt marsh and subtidal porewater profiles contain significant concentrations of thiosulfate, bisulfide, and polysulfide. The ratio of S(2-) to S(0) is higher in subtidal porewaters than in salt marsh porewaters and indicates the importance of zero-valent sulfur to the biogeochemical processes prevalent in the salt marsh ecosystem. The S(0) concentrations in porewaters from salt marsh sediments are greater than those predicted from equilibrium calculations.

  10. Removal of sulfur and nitrogen containing pollutants from discharge gases

    SciTech Connect

    Joubert, J.I.

    1986-05-06

    A process is described for the removal of sulfur oxide-containing pollutants from a gas flow including entrained ash which consists of: entraining finely divided, unsupported oxide of copper powder in the gas flow to react with the sulfur oxide containing pollutants and form a sulfate of copper in mixture within the powder. The finely divided oxide of copper powder has an average particle size of less than 30 microns; separating the powder and ash from the gas. The powder and ash are contracted with oxide of sulfur gas to sulfate substantially all of the oxide of copper in the powder. The sulfated powder and ash are contacted with aqueous solvent to dissolve the sulfate of copper into solution while ash remains as solid. The liquid solution containing sulfate of copper is separated from the solid ash. The liquid solution is spray dried to form fine particles including a sulfate of copper. The sulfate of copper particles is heated to a sufficient temperature to decompose the sulfate of copper to a finely divided oxide of copper powder and an oxide of sulfur gas. The finely divided oxide of copper powder is returned into contact with the gas flow; and a portion of the oxide of sulfur gas is recycled into contact with the powder and ash.

  11. New insights into Archean sulfur cycle from mass-independent sulfur isotope records from the

    E-print Network

    New insights into Archean sulfur cycle from mass-independent sulfur isotope records from in revised form 9 May 2003; accepted 9 May 2003 Abstract We have measured multiple sulfur isotope ratios (34 S/33 S/32 S) for sulfide sulfur in shale and carbonate lithofacies from the Hamersley Basin, Western

  12. Sulfur Economy and Cell Wall Biosynthesis during Sulfur Limitation of Chlamydomonas reinhardtii1

    E-print Network

    Sulfur Economy and Cell Wall Biosynthesis during Sulfur Limitation of Chlamydomonas reinhardtii1 that specifically accumulate during sulfur limitation of Chlamydomonas reinhardtii. These polypeptides, present at high levels in the extracellular polypeptide fraction from a sulfur-deprived, cell wall-minus C

  13. 40 CFR 52.1881 - Control strategy: Sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Control strategy: Sulfur oxides (sulfur... Control strategy: Sulfur oxides (sulfur dioxide). (a) USEPA is approving, disapproving or taking no...

  14. Chemistry of Sulfur Oxides on Transition Metals. II. Thermodynamics of Sulfur Oxides on Platinum(111)

    E-print Network

    Lin, Xi

    Chemistry of Sulfur Oxides on Transition Metals. II. Thermodynamics of Sulfur Oxides on Platinum at the highest coverages and sulfur oxidation states. Calculated vibrational spectra are used to assign observed the preferred SOx species on Pt(111), consistent with observation. I. Introduction The chemistry of sulfur

  15. Sulfur Isotope Effects of Dissimilatory Sulfite Reductase

    PubMed Central

    Leavitt, William D.; Bradley, Alexander S.; Santos, André A.; Pereira, Inês A. C.; Johnston, David T.

    2015-01-01

    The precise interpretation of environmental sulfur isotope records requires a quantitative understanding of the biochemical controls on sulfur isotope fractionation by the principle isotope-fractionating process within the S cycle, microbial sulfate reduction (MSR). Here we provide the only direct observation of the major (34S/32S) and minor (33S/32S, 36S/32S) sulfur isotope fractionations imparted by a central enzyme in the energy metabolism of sulfate reducers, dissimilatory sulfite reductase (DsrAB). Results from in vitro sulfite reduction experiments allow us to calculate the in vitro DsrAB isotope effect in 34S/32S (hereafter, 34?DsrAB) to be 15.3 ± 2‰, 2?. The accompanying minor isotope effect in 33S, described as 33?DsrAB, is calculated to be 0.5150 ± 0.0012, 2?. These observations facilitate a rigorous evaluation of the isotopic fractionation associated with the dissimilatory MSR pathway, as well as of the environmental variables that govern the overall magnitude of fractionation by natural communities of sulfate reducers. The isotope effect induced by DsrAB upon sulfite reduction is a factor of 0.3–0.6 times prior indirect estimates, which have ranged from 25 to 53‰ in 34?DsrAB. The minor isotope fractionation observed from DsrAB is consistent with a kinetic or equilibrium effect. Our in vitro constraints on the magnitude of 34?DsrAB is similar to the median value of experimental observations compiled from all known published work, where 34?r?p = 16.1‰ (r–p indicates reactant vs. product, n = 648). This value closely matches those of MSR operating at high sulfate reduction rates in both laboratory chemostat experiments (34?SO4?H2S =  17.3 ± 1.5‰, 2?) and in modern marine sediments (34?SO4?H2S =  17.3 ± 3.8‰). Targeting the direct isotopic consequences of a specific enzymatic processes is a fundamental step toward a biochemical foundation for reinterpreting the biogeochemical and geobiological sulfur isotope records in modern and ancient environments.

  16. Reduction mechanism of sulfur in lithium-sulfur battery: From elemental sulfur to polysulfide

    NASA Astrophysics Data System (ADS)

    Zheng, Dong; Zhang, Xuran; Wang, Jiankun; Qu, Deyu; Yang, Xiaoqing; Qu, Deyang

    2016-01-01

    The polysulfide ions formed during the first reduction wave of sulfur in Li-S battery were determined through both in-situ and ex-situ derivatization of polysulfides. By comparing the cyclic voltammetric results with and without the derivatization reagent (methyl triflate) as well as the in-situ and ex-situ derivatization results under potentiostatic condition, in-situ derivatization was found to be more appropriate than its ex-situ counterpart, since subsequent fast chemical reactions between the polysulfides and sulfur may occur during the timeframe of ex-situ procedures. It was found that the major polysulfide ions formed at the first reduction wave of elemental sulfur were the S4 2 - and S5 2 - species, while the widely accepted reduction products of S8 2 - and S6 2 - for the first reduction wave were in low abundance.

  17. Behavior of sulfur during coal pyrolysis

    USGS Publications Warehouse

    Shao, D.; Hutchinson, E.J.; Heidbrink, J.; Pan, W.-P.; Chou, C.-L.

    1994-01-01

    The behavior of sulfur in Illinois coals during pyrolysis was evaluated by thermogravimetry/ Fourier transform-infrared spectroscopy (TG/FT-IR) techniques. SO2, COS, and H2S were major gaseous sulfur-containing products observed during coal pyrolysis. The release rates of the gaseous sulfur species showed several peaks within the temperature ranges, which were due to the emission of different forms of sulfur in coal. ?? 1994.

  18. Sulfur recovery from low-quality natural gas

    SciTech Connect

    Gangwal, S.K.; McMichael, W.J.

    1992-05-01

    The objectives of this work are to (1) demonstrate on a bench-scale the Direct Sulfur Recovery Process (DSRP) for up to 99% or higher recovery of sulfur (as elemental sulfur) from SO{sub 2}-containing regeneration off-gases produced in integrated gasification combined cycle (IGCC) power generating systems employing hot-gas cleanup and (2) promote DSRP technology transfer to industry. Technology transfer activities have involved meetings with several industrial organizations, presentations at national scientific conferences, and experiments to evaluate DSRP`s potential for treating various H{sub 2}S-containing gases such as low-quality natural gas (LQNG) and amine regeneration gas. This paper will discuss the results of DSRP experiments with H{sub 2}S-containing gases.

  19. Sulfur recovery from low-quality natural gas

    SciTech Connect

    Ganwal, S.K.; McMichael, W.J.

    1992-06-01

    The objectives of this work are to (1) demonstrate on a bench-scale the Direct Sulfur Recovery Process (DSRP) for up to 99% or higher recovery of sulfur (as elemental sulfur) from SO{sub 2}-containing regeneration off-gases produced in integrated gasification combined cycle (IGCC) power generating systems employing hot-gas cleanup and (2) promote DSRP technology transfer to industry. The treatment of SO{sub 2}-containing regeneration off-previously (Gangwal and McMichael, 1991). Technology transfer activities have involved meetings with several industrial organizations, presentations at national scientific conferences, and experiments to evaluate DSRP`s potential for treating various H{sub 2}S-containing gases such as low-quality natural gas (LQNG) and amine regeneration gas. This paper will discuss the results of DSRP experiments with H{sub 2}S-containing gases.

  20. Sulfur recovery from low-quality natural gas

    SciTech Connect

    Ganwal, S.K.; McMichael, W.J.

    1992-01-01

    The objectives of this work are to (1) demonstrate on a bench-scale the Direct Sulfur Recovery Process (DSRP) for up to 99% or higher recovery of sulfur (as elemental sulfur) from SO{sub 2}-containing regeneration off-gases produced in integrated gasification combined cycle (IGCC) power generating systems employing hot-gas cleanup and (2) promote DSRP technology transfer to industry. The treatment of SO{sub 2}-containing regeneration off-previously (Gangwal and McMichael, 1991). Technology transfer activities have involved meetings with several industrial organizations, presentations at national scientific conferences, and experiments to evaluate DSRP's potential for treating various H{sub 2}S-containing gases such as low-quality natural gas (LQNG) and amine regeneration gas. This paper will discuss the results of DSRP experiments with H{sub 2}S-containing gases.

  1. Historical Sulfur Dioxide Emissions 1850-2000: Methods and Results

    SciTech Connect

    Smith, Steven J.; Andres, Robert; Conception , Elvira; Lurz, Joshua

    2004-01-25

    A global, self-consistent estimate of sulfur dioxide emissions over the last one and a half century were estimated by using a combination of bottom-up and best available inventory methods including all anthropogenic sources. We find that global sulfur dioxide emissions peaked about 1980 and have generally declined since this time. Emissions were extrapolated to a 1{sup o} x 1{sup o} grid for the time period 1850-2000 at annual resolution with two emission height levels and by season. Emissions are somewhat higher in the recent past in this new work as compared with some comprehensive estimates. This difference is largely due to our use of emissions factors that vary with time to account for sulfur removals from fossil fuels and industrial smelting processes.

  2. HYBRID SULFUR ELECTROLYZER DEVELOPMENT FY09 SECOND QUARTER REPORT

    SciTech Connect

    Herman, D; David Hobbs, D; Hector Colon-Mercado, H; Timothy Steeper, T; John Steimke, J; Mark Elvington, M

    2009-04-15

    The primary objective of the DOE-NE Nuclear Hydrogen Initiative (NHI) is to develop the nuclear hydrogen production technologies necessary to produce hydrogen at a cost competitive with other alternative transportation fuels. The focus of the NHI is on thermochemical cycles and high temperature electrolysis that can be powered by heat from high temperature gas reactors. The Savannah River National Laboratory (SRNL) has been tasked with the primary responsibility to perform research and development in order to characterize, evaluate and develop the Hybrid Sulfur (HyS) thermochemical process. This report documents work during the first quarter of Fiscal Year 2009, for the period between January 1, 2009 and March 31, 2009. The HyS Process is a two-step hybrid thermochemical cycle that is part of the 'Sulfur Family' of cycles. As a sulfur cycle, it uses high temperature thermal decomposition of sulfuric acid to produce oxygen and to regenerate the sulfur dioxide reactant. The second step of the process uses a sulfur dioxide depolarized electrolyzer (SDE) to split water and produce hydrogen by electrochemically reacting sulfur dioxide with H{sub 2}O. The SDE produces sulfuric acid, which is then sent to the acid decomposer to complete the cycle. The DOE NHI program is developing the acid decomposer at Sandia National Laboratory for application to both the HyS Process and the Sulfur Iodine Cycle. The SDE is being developed at SRNL. During FY05 and FY06, SRNL designed and conducted proof-of-concept testing for a SDE using a low temperature, PEM fuel cell-type design concept. The advantages of this design concept include high electrochemical efficiency, small footprint and potential for low capital cost, characteristics that are crucial for successful implementation on a commercial scale. During FY07, SRNL extended the range of testing of the SDE to higher temperature and pressure, conducted a 100-hour longevity test with a 60-cm{sup 2} single cell electrolyzer, and designed and built a larger, multi-cell stack electrolyzer. During FY08, SRNL continued SDE development, including development and successful testing of a three-cell electrolyzer stack with a rated capacity of 100 liters per hour. The HyS program for FY09 program will address improving SDE performance by focusing on preventing or minimizing sulfur deposition inside the cell caused by SO{sub 2} crossover, reduction of cell voltage for improved efficiency, an extension of cell operating lifetime. During FY09 a baseline technology development program is being conducted to address each of these issues. Button-cell (2-cm{sup 2}) and single cell (60-cm{sup 2}) SDEs will be fabricated and tested. A pressurized button-cell test facility will be designed and constructed to facilitate addition testing. The single cell test facility will be upgraded for unattended operation, and later for operation at higher temperature and pressure. Work will continue on development of the Gas Diffusion Electrode (GDE), or Gap Cell, as an alternative electrolyzer design approach that is being developed under subcontract with industry partner Giner Electrochemical Systems. If successful, it could provide an alternative means of preventing sulfur crossover through the proton exchange membrane, as well as the possibility for higher current density operation based on more rapid mass transfer in a gas-phase anode. Promising cell components will be assembled into membrane electrode assemblies (MEAs) and tested in the single cell test facility. Upon modification for unattended operation, test will be conducted for 200 hours or more. Both the button-cell and modified single cell facility will be utilized to demonstrate electrolyzer operation without sulfur build-up limitations, which is a Level 1 Milestone.

  3. Dynamics of a Novel Class of Polymers: Polymerized Sulfur

    NASA Astrophysics Data System (ADS)

    Masser, Kevin; Kim, Jenny; Oleshko, Vladimir; Griebel, Jared; Chung, Woo; Simmons, Adam; Pyun, Jeff; Soles, Christopher

    2013-03-01

    In this study we investigate the dynamics of a new type of polymer, consisting mainly of sulfur. Room-temperature stable polymerized sulfur samples were prepared by crosslinking the well-known living sulfur polymers formed at elevated temperatures by the addition of a crosslinking agent. This reverse vulcanization process was used to create a series of samples with different amounts of crosslinking agent. These polymers show great promise for use in advanced batteries as cathode materials. Each system exhibits a glassy-state beta relaxation, with the intensity of this relaxation proportional to the crosslinking content. A dynamic glass transition is also observed for each system, and the glass transition temperature/segmental relaxation moves to higher temperatures with increased crosslink content as is typically observed in crosslinked systems. As is typical of polymers, ion motion in these systems is closely coupled to the backbone motion of the host polymer. National Research Council Postdoctoral Fellowship

  4. 46 CFR 153.1046 - Sulfuric acid.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Sulfuric acid. 153.1046 Section 153.1046 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK....1046 Sulfuric acid. No person may liquefy frozen or congealed sulfuric acid other than by external...

  5. 21 CFR 582.1095 - Sulfuric acid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Sulfuric acid. 582.1095 Section 582.1095 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1095 Sulfuric acid. (a) Product. Sulfuric acid. (b) Conditions of use. This substance is...

  6. 46 CFR 153.1046 - Sulfuric acid.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Sulfuric acid. 153.1046 Section 153.1046 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK....1046 Sulfuric acid. No person may liquefy frozen or congealed sulfuric acid other than by external...

  7. 21 CFR 184.1095 - Sulfuric acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sulfuric acid. 184.1095 Section 184.1095 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1095 Sulfuric acid. (a) Sulfuric acid (H2SO4, CAS Reg. No. 7664-93-9),...

  8. 21 CFR 184.1095 - Sulfuric acid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sulfuric acid. 184.1095 Section 184.1095 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DIRECT FOOD....1095 Sulfuric acid. (a) Sulfuric acid (H2SO4, CAS Reg. No. 7664-93-9), also known as oil of vitriol,...

  9. 46 CFR 153.1046 - Sulfuric acid.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Sulfuric acid. 153.1046 Section 153.1046 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK....1046 Sulfuric acid. No person may liquefy frozen or congealed sulfuric acid other than by external...

  10. 21 CFR 582.1095 - Sulfuric acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Sulfuric acid. 582.1095 Section 582.1095 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1095 Sulfuric acid. (a) Product. Sulfuric acid. (b) Conditions of use. This substance is...

  11. 46 CFR 153.1046 - Sulfuric acid.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Sulfuric acid. 153.1046 Section 153.1046 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK....1046 Sulfuric acid. No person may liquefy frozen or congealed sulfuric acid other than by external...

  12. 21 CFR 582.1095 - Sulfuric acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Sulfuric acid. 582.1095 Section 582.1095 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1095 Sulfuric acid. (a) Product. Sulfuric acid. (b) Conditions of use. This substance is...

  13. 21 CFR 184.1095 - Sulfuric acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sulfuric acid. 184.1095 Section 184.1095 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1095 Sulfuric acid. (a) Sulfuric acid (H2SO4, CAS Reg. No. 7664-93-9),...

  14. 21 CFR 582.1095 - Sulfuric acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sulfuric acid. 582.1095 Section 582.1095 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1095 Sulfuric acid. (a) Product. Sulfuric acid. (b) Conditions of use. This substance is...

  15. 21 CFR 184.1095 - Sulfuric acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sulfuric acid. 184.1095 Section 184.1095 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1095 Sulfuric acid. (a) Sulfuric acid (H2SO4, CAS Reg. No. 7664-93-9),...

  16. 21 CFR 582.1095 - Sulfuric acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Sulfuric acid. 582.1095 Section 582.1095 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1095 Sulfuric acid. (a) Product. Sulfuric acid. (b) Conditions of use. This substance is...

  17. 46 CFR 153.1046 - Sulfuric acid.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Sulfuric acid. 153.1046 Section 153.1046 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK....1046 Sulfuric acid. No person may liquefy frozen or congealed sulfuric acid other than by external...

  18. 21 CFR 184.1095 - Sulfuric acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sulfuric acid. 184.1095 Section 184.1095 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1095 Sulfuric acid. (a) Sulfuric acid (H2SO4, CAS Reg. No. 7664-93-9),...

  19. 21 CFR 582.3862 - Sulfur dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Sulfur dioxide. 582.3862 Section 582.3862 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... Sulfur dioxide. (a) Product. Sulfur dioxide. (b) (c) Limitations, restrictions, or explanation....

  20. 21 CFR 182.3862 - Sulfur dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sulfur dioxide. 182.3862 Section 182.3862 Food and... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 182.3862 Sulfur dioxide. (a) Product. Sulfur dioxide. (b) (c) Limitations, restrictions, or explanation. This substance...

  1. 21 CFR 582.3862 - Sulfur dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Sulfur dioxide. 582.3862 Section 582.3862 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... Sulfur dioxide. (a) Product. Sulfur dioxide. (b) (c) Limitations, restrictions, or explanation....

  2. Policy Analysis Changing Trends in Sulfur Emissions

    E-print Network

    Jacobson, Mark

    Policy Analysis Changing Trends in Sulfur Emissions in Asia: Implications for Acid Deposition, Air result in sulfur emissions lower than any IPCC forecasts. Estimatingpast change are intimately linked to sulfur (1). Over the last 25 years the primary energy demand in Asia has

  3. 21 CFR 182.3862 - Sulfur dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sulfur dioxide. 182.3862 Section 182.3862 Food and... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 182.3862 Sulfur dioxide. (a) Product. Sulfur dioxide. (b) (c) Limitations, restrictions, or explanation. This substance...

  4. Two stage sorption of sulfur compounds

    DOEpatents

    Moore, William E. (Manassas, VA)

    1992-01-01

    A two stage method for reducing the sulfur content of exhaust gases is disclosed. Alkali- or alkaline-earth-based sorbent is totally or partially vaporized and introduced into a sulfur-containing gas stream. The activated sorbent can be introduced in the reaction zone or the exhaust gases of a combustor or a gasifier. High efficiencies of sulfur removal can be achieved.

  5. Air Quality Criteria for Sulfur Oxides.

    ERIC Educational Resources Information Center

    National Air Pollution Control Administration (DHEW), Washington, DC.

    Included is a literature review which comprehensively discusses knowledge of the sulfur oxides commonly found in the atmosphere. The subject content is represented by the 10 chapter titles: Physical and Chemical Properties and the Atmospheric Reactions of the Oxides of Sulfur; Sources and Methods of Measurements of Sulfur Oxides in the Atmosphere;…

  6. 21 CFR 182.3862 - Sulfur dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sulfur dioxide. 182.3862 Section 182.3862 Food and... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 182.3862 Sulfur dioxide. (a) Product. Sulfur dioxide. (b) (c) Limitations, restrictions, or explanation. This substance...

  7. 21 CFR 582.3862 - Sulfur dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sulfur dioxide. 582.3862 Section 582.3862 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... Sulfur dioxide. (a) Product. Sulfur dioxide. (b) (c) Limitations, restrictions, or explanation....

  8. 21 CFR 582.3862 - Sulfur dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Sulfur dioxide. 582.3862 Section 582.3862 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... Sulfur dioxide. (a) Product. Sulfur dioxide. (b) (c) Limitations, restrictions, or explanation....

  9. 21 CFR 182.3862 - Sulfur dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sulfur dioxide. 182.3862 Section 182.3862 Food and... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 182.3862 Sulfur dioxide. (a) Product. Sulfur dioxide. (b) (c) Limitations, restrictions, or explanation. This substance...

  10. 21 CFR 582.3862 - Sulfur dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Sulfur dioxide. 582.3862 Section 582.3862 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... Sulfur dioxide. (a) Product. Sulfur dioxide. (b) (c) Limitations, restrictions, or explanation....

  11. Module: Material Structure Focus: Allotropes of Sulfur

    E-print Network

    Rowley, Clarence W.

    Module: Material Structure Focus: Allotropes of Sulfur Duration: 43 minute period Contact: Daniel to define the term "allotrope." 4. Students will be able to compare and contrast the 3 allotropes of sulfur. Materials: Vegetable Oil Safety Goggles Powdered Sulfur Bunsen Burner Filter Paper Test Tube Cold Distilled

  12. 21 CFR 182.3862 - Sulfur dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sulfur dioxide. 182.3862 Section 182.3862 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 182.3862 Sulfur dioxide. (a) Product. Sulfur...

  13. Two stage sorption of sulfur compounds

    SciTech Connect

    Moore, W.E.

    1991-12-31

    A two stage method for reducing the sulfur content of exhaust gases is disclosed. Alkali- or alkaline-earth-based sorbent is totally or partially vaporized 10 and introduced into a sulfur-containing gas stream. The activated sorbent can be introduced in the reaction zone or the exhaust gases of a combustor or a gasifier. High efficiencies of sulfur removal can be achieved.

  14. 46 CFR 148.315 - Sulfur.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Sulfur. 148.315 Section 148.315 Shipping...for Certain Materials § 148.315 Sulfur. (a) This part applies to lump or coarse grain powder sulfur only. Fine-grained powder...

  15. 46 CFR 148.315 - Sulfur.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Sulfur. 148.315 Section 148.315 Shipping...for Certain Materials § 148.315 Sulfur. (a) This part applies to lump or coarse grain powder sulfur only. Fine-grained powder...

  16. 46 CFR 148.04-20 - Sulfur.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Shipping 5 2010-10-01 2010-10-01 false Sulfur. 148.04-20 Section 148.04-20 Shipping...Requirements for Certain Material § 148.04-20 Sulfur. (a) When sulfur is loaded in a deep hold with general cargo in the...

  17. 46 CFR 148.315 - Sulfur.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Sulfur. 148.315 Section 148.315 Shipping...for Certain Materials § 148.315 Sulfur. (a) This part applies to lump or coarse grain powder sulfur only. Fine-grained powder...

  18. 46 CFR 148.315 - Sulfur.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Sulfur. 148.315 Section 148.315 Shipping...for Certain Materials § 148.315 Sulfur. (a) This part applies to lump or coarse grain powder sulfur only. Fine-grained powder...

  19. Seal for sodium sulfur battery

    DOEpatents

    Topouzian, Armenag (Birmingham, MI); Minck, Robert W. (Lathrup Village, MI); Williams, William J. (Northville, MI)

    1980-01-01

    This invention is directed to a seal for a sodium sulfur battery in which the sealing is accomplished by a radial compression seal made on a ceramic component of the battery which separates an anode compartment from a cathode compartment of the battery.

  20. TRENDS IN RURAL SULFUR CONCENTRATIONS

    EPA Science Inventory

    This paper presents an analysis of regional trends in atmospheric concentrations in sulfur dioxide (502) and particulate sulfate (50~- ) at rural monitoring sites in the Clean Air Act Status and Trends Monitoring Network (CAsTNet) from 1990 to 1999. A two-stage approach is used t...

  1. Sulfur Dioxide and Material Damage

    ERIC Educational Resources Information Center

    Gillette, Donald G.

    1975-01-01

    This study relates sulfur dioxide levels with material damage in heavily populated or polluted areas. Estimates of loss were determined from increased maintenance and replacement costs. The data indicate a decrease in losses during the past five years probably due to decline in pollution levels established by air quality standards. (MR)

  2. Nutrient cyling in soils: Sulfur

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sulfur (S) is an essential element required for normal plant growth, a fact that has been recognized since the nineteenth century. It is considered a secondary macronutrient, following the primary macronutrients nitrogen (N), phosphorus (P), and potassium (K), but is needed by plants at levels compa...

  3. SULFUR DIOXIDE SOURCES IN AK

    EPA Science Inventory

    This map shows industrial plants which emit 100 tons/year or more of sulfur dioxide (SO2) in Alaska. The SO2 sources are plotted on a background map of cities and county boundaries. Data Sources: SO2 Sites: U.S. EPA AIRS System, County Outlines: 1990 Census Tiger Line Files 1:1...

  4. High pressure sulfuric acid decomposition experiments for the sulfur-iodine thermochemical cycle.

    SciTech Connect

    Velasquez, Carlos E; Reay, Andrew R.; Andazola, James C.; Naranjo, Gerald E.; Gelbard, Fred

    2005-09-01

    A series of three pressurized sulfuric acid decomposition tests were performed to (1) obtain data on the fraction of sulfuric acid catalytically converted to sulfur dioxide, oxygen, and water as a function of temperature and pressure, (2) demonstrate real-time measurements of acid conversion for use as process control, (3) obtain multiple measurements of conversion as a function of temperature within a single experiment, and (4) assess rapid quenching to minimize corrosion of metallic components by undecomposed acid. All four of these objectives were successfully accomplished. This report documents the completion of the NHI milestone on high pressure H{sub 2}SO{sub 4} decomposition tests for the Sulfur-Iodine (SI) thermochemical cycle project. All heated sections of the apparatus, (i.e. the boiler, decomposer, and condenser) were fabricated from Hastelloy C276. A ceramic acid injection tube and a ceramic-sheathed thermocouple were used to minimize corrosion of hot liquid acid on the boiler surfaces. Negligible fracturing of the platinum on zirconia catalyst was observed in the high temperature decomposer. Temperature measurements at the exit of the decomposer and at the entry of the condenser indicated that the hot acid vapors were rapidly quenched from about 400 C to less than 20 C within a 14 cm length of the flow path. Real-time gas flow rate measurements of the decomposition products provided a direct measurement of acid conversion. Pressure in the apparatus was preset by a pressure-relief valve that worked well at controlling the system pressure. However, these valves sometimes underwent abrupt transitions that resulted in rapidly varying gas flow rates with concomitant variations in the acid conversion fraction.

  5. Sulfur capture with limestone injection in cyclone combustion flow. Final report, 17 September 1982-15 April 1983

    SciTech Connect

    Zauderer, B.

    1983-04-01

    An analytical study was performed to identify the phenomena responsible for the observed 25-35% sulfur capture with limestone injection in a laboratory-scale cyclone coal combustor. The study's primary objective was to determine the feasibility of using this sulfur-control process in a commercial-scale cyclone, suitable for oil-fired-boiler conversion to coal. The methodology used consisted in separately analyzing the processes occurring during heatup, devolatilization, and char burnup of coal particles, and in the calcination, sulfur capture, and sulfur re-evolution reactions of the limestone in the gas and slag covered wall of the cyclone.

  6. The removal of sulfur dioxide from flue gases

    PubMed Central

    Kettner, Helmut

    1965-01-01

    The growth of industrialization makes it imperative to reduce the amounts of sulfur dioxide emitted into the atmosphere. This article describes various processes for cleaning flue gases, and gives details of new methods being investigated. Wet scrubbing with water, though widely practised, has many disadvantages. Scrubbing with zinc oxide, feasible in zinc works, is more satisfactory. Dry methods use a solid absorbent; they have the advantage of a high emission temperature. Other methods are based on the addition to the fuel or the flue gases of substances such as activated metal oxides, which react with the sulfur to form compounds less harmful than sulfur dioxide. Also being investigated are a two-stage combustion system, in which the sulfur dioxide is removed in the first stage, and the injection of activated powdered dolomite into burning fuel; the resulting sulfates being removed by electrostatic precipitation. A wet catalysis process has recently been developed. Most of the cleaning processes are not yet technically mature, but first results show good efficiency and relatively low cost. PMID:14315714

  7. CLOSEOUT REPORT FOR HYBRID SULFUR PRESSURIZED BUTTON CELL TEST FACILITY

    SciTech Connect

    Steeper, T.

    2010-09-15

    This document is the Close-Out Report for design and partial fabrication of the Pressurized Button Cell Test Facility at Savannah River National Laboratory (SRNL). This facility was planned to help develop the sulfur dioxide depolarized electrolyzer (SDE) that is a key component of the Hybrid Sulfur Cycle for generating hydrogen. The purpose of this report is to provide as much information as possible in case the decision is made to resume research. This report satisfies DOE Milestone M3GSR10VH030107.0. The HyS Cycle is a hybrid thermochemical cycle that may be used in conjunction with advanced nuclear reactors or centralized solar receivers to produce hydrogen by watersplitting. The HyS Cycle utilizes the high temperature (>800 C) thermal decomposition of sulfuric acid to produce oxygen and regenerate sulfur dioxide. The unique aspect of HyS is the generation of hydrogen in a water electrolyzer that is operated under conditions where dissolved sulfur dioxide depolarizes the anodic reaction, resulting in substantial voltage reduction. Low cell voltage is essential for both high thermodynamic efficiency and low hydrogen cost. Sulfur dioxide is oxidized at the anode, producing sulfuric acid that is sent to the high temperature acid decomposition portion of the cycle. Sulfur dioxide from the decomposer is cycled back to electrolyzers. The electrolyzer cell uses the membrane electrode assembly (MEA) concept. Anode and cathode are formed by spraying a catalyst, typically platinized carbon, on both sides of a Proton Exchange Membrane (PEM). SRNL has been testing SDEs for several years including an atmospheric pressure Button Cell electrolyzer (2 cm{sup 2} active area) and an elevated temperature/pressure Single Cell electrolyzer (54.8 cm{sup 2} active area). SRNL tested 37 MEAs in the Single Cell electrolyzer facility from June 2005 until June 2009, when funding was discontinued. An important result of the final months of testing was the development of a method that prevents the formation of a sulfur layer previously observed in MEAs used in the Hybrid Sulfur Cycle electrolyzer. This result is very important because the sulfur layer increased cell voltage and eventually destroyed the MEA that is the heart of the cell. Steimke and Steeper [2005, 2006, 2007, 2008] reported on testing in the Single Cell Electrolyzer test facility in several periodic reports. Steimke et. al [2010] issued a final facility close-out report summarizing all the testing in the Single Cell Electrolyzer test facility. During early tests, significant deterioration of the membrane occurred in 10 hours or less; the latest tests ran for at least 200 hours with no sign of deterioration. Ironically, the success with the Single Cell electrolyzer meant that it became dedicated to long runs and not available for quick membrane evaluations. Early in this research period, the ambient pressure Button Cell Electrolyzer test facility was constructed to quickly evaluate membrane materials. Its small size allowed testing of newly developed membranes that typically were not available in sizes large enough to test in the Single Cell electrolyzer. The most promising membranes were tested in the Single Cell Electrolyzer as soon as sufficient large membranes could be obtained. However, since the concentration of SO{sub 2} gas in sulfuric acid decreases rapidly with increasing temperature, the ambient pressure Button Cell was no longer able to achieve the operating conditions needed to evaluate the newer improved high temperature membranes. Significantly higher pressure operation was required to force SO{sub 2} into the sulfuric acid to obtain meaningful concentrations at increased temperatures. A high pressure (200 psig), high temperature (120 C) Button Cell was designed and partially fabricated just before funding was discontinued in June 2009. SRNL completed the majority of the design of the test facility, including preparation of a process and instrument drawing (P&ID) and preliminary designs for the major components. SRNL intended to complete the designs and procu

  8. Molecular-Confinement of Polysulfide within Mesoscale Electrodes for the Practical Application of Lithium Sulfur Batteries

    SciTech Connect

    Chen, Junzheng; Wu, Dangxin; Walter, Eric D.; Engelhard, Mark H.; Bhattacharya, Priyanka; Pan, Huilin; Shao, Yuyan; Gao, Fei; Xiao, Jie; Liu, Jun

    2015-04-01

    Nitrogen-doped porous carbon (NPC) and multi-wall carbon nanotube (MWCNT) have been frequently studied to immobilize sulfur in lithium-sulfur (Li-S) batteries. However, neither NPC nor MWCNT itself can effectively confine the soluble polysufides if cathode thickness e.g. sulfur loading is increased. In this work, NPC was combined with MWCNT to construct an integrated host structure to immobilize sulfur at a relevant scale. The function of doped nitrogen atoms was revisited and found to effectively attract sulfur radicals generated during the electrochemical process. The addition of MWCNT facilitated the uniform coating of sulfur nanocomposites to a practically usable thickness and homogenized the distribution of sulfur particles in the pristine electrodes, while NPC provided sufficient pore volume to trap dissolved species. More importantly, the wetting issue, the critical challenge for thick sulfur cathodes, is also mitigated after the adoption of MWCNT, leading to a high areal capacity of ca. 2.5 mAh/cm2 with capacity retention of 81.6% over 100 cycles

  9. Development of Efficient Flowsheet and Transient Modeling for Nuclear Heat Coupled Sulfur Iodine Cyclefor Hydrogen Production

    SciTech Connect

    Shripad T. Revankar; Nicholas R. Brown; Cheikhou Kane; Seungmin Oh

    2010-05-01

    The realization of the hydrogen as an energy carrier for future power sources relies on a practical method of producing hydrogen in large scale with no emission of green house gases. Hydrogen is an energy carrier which can be produced by a thermochemical water splitting process. The Sulfur-Iodine (SI) process is an example of a water splitting method using iodine and sulfur as recycling agents.

  10. Advanced sulfur control concepts for hot gas desulfurization technology

    SciTech Connect

    1998-09-01

    The objective of this project is to develop a hot-gas desulfurization process scheme for control of H{sub 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.

  11. Transporters in plant sulfur metabolism

    PubMed Central

    Gigolashvili, Tamara; Kopriva, Stanislav

    2014-01-01

    Sulfur is an essential nutrient, necessary for synthesis of many metabolites. The uptake of sulfate, primary and secondary assimilation, the biosynthesis, storage, and final utilization of sulfur (S) containing compounds requires a lot of movement between organs, cells, and organelles. Efficient transport systems of S-containing compounds across the internal barriers or the plasma membrane and organellar membranes are therefore required. Here, we review a current state of knowledge of the transport of a range of S-containing metabolites within and between the cells as well as of their long distance transport. An improved understanding of mechanisms and regulation of transport will facilitate successful engineering of the respective pathways, to improve the plant yield, biotic interaction and nutritional properties of crops. PMID:25250037

  12. Flash pyrolysis of coal, coal maceral, and coal-derived pyrite with on-line characterization of volatile sulfur compounds

    USGS Publications Warehouse

    Chou, I.-Ming; Lake, M.A.; Griffin, R.A.

    1988-01-01

    A Pyroprobe flash pyrolysis-gas chromatograph equipped with a flame photometric detector was used to study volatile sulfur compounds produced during the thermal decomposition of Illinois coal, coal macerals and coal-derived pyrite. Maximum evolution of volatile organic sulfur compounds from all coal samples occurred at a temperature of approximately 700??C. At this temperature, the evolution of thiophene, its alkyl isomers, and short-chain dialkyl sulfide compounds relative to the evolution of benzothiophene and dibenzothiophene compounds was greater from coal high in organic sulfur than from coal low in organic sulfur. The variation in the evolution of sulfur compounds observed for three separate coal macerals (exinite, vitrinite, and inertinite) was similar to that observed for whole coal samples. However, the variation trend for the macerals was much more pronounced. Decomposition of coal-derived pyrite with the evolution of elemental sulfur was detected at a temperature greater than 700??C. The results of this study indicated that the gas chromotographic profile of the volatile sulfur compounds produced during flash pyrolysis of coals and coal macerals varied as a function of the amount of organic sulfur that occurred in the samples. Characterization of these volatile sulfur compounds provides a better understanding of the behavior of sulfur in coal during the thermolysis process, which could be incorporated in the design for coal cleaning using flash pyrolysis techniques. ?? 1988.

  13. Recovery and separation of sulfuric acid and iron from dilute acidic sulfate effluent and waste sulfuric acid by solvent extraction and stripping.

    PubMed

    Qifeng, Wei; Xiulian, Ren; Jingjing, Guo; Yongxing, Chen

    2016-03-01

    The recovery and simultaneous separation of sulfuric acid and iron from dilute acidic sulfate effluent (DASE) and waste sulfuric acid (WSA) have been an earnest wish for researchers and the entire sulfate process-based titanium pigment industry. To reduce the pollution of the waste acid and make a comprehensive use of the iron and sulfuric acid in it, a new environmentally friendly recovery and separation process for the DASE and the WSA is proposed. This process is based on the reactive extraction of sulfuric acid and Fe(III) from the DASE. Simultaneously, stripping of Fe(III) is carried out in the loaded organic phase with the WSA. Compared to the conventional ways, this innovative method allows the effective extraction of sulfuric acid and iron from the DASE, and the stripping of Fe(III) from the loaded organic phase with the WSA. Trioctylamine (TOA) and tributyl phosphate (TBP) in kerosene (10-50%) were used as organic phases for solvent extraction. Under the optimal conditions, about 98% of Fe(III) and sulfuric acid were removed from the DASE, and about 99.9% of Fe(III) in the organic phase was stripped with the WSA. PMID:26546698

  14. Metabolism of sulfur amino acids in Saccharomyces cerevisiae.

    PubMed Central

    Thomas, D; Surdin-Kerjan, Y

    1997-01-01

    Sulfur amino acid biosynthesis in Saccharomyces cerevisiae involves a large number of enzymes required for the de novo biosynthesis of methionine and cysteine and the recycling of organic sulfur metabolites. This review summarizes the details of these processes and analyzes the molecular data which have been acquired in this metabolic area. Sulfur biochemistry appears not to be unique through terrestrial life, and S. cerevisiae is one of the species of sulfate-assimilatory organisms possessing a larger set of enzymes for sulfur metabolism. The review also deals with several enzyme deficiencies that lead to a nutritional requirement for organic sulfur, although they do not correspond to defects within the biosynthetic pathway. In S. cerevisiae, the sulfur amino acid biosynthetic pathway is tightly controlled: in response to an increase in the amount of intracellular S-adenosylmethionine (AdoMet), transcription of the coregulated genes is turned off. The second part of the review is devoted to the molecular mechanisms underlying this regulation. The coordinated response to AdoMet requires two cis-acting promoter elements. One centers on the sequence TCACGTG, which also constitutes a component of all S. cerevisiae centromeres. Situated upstream of the sulfur genes, this element is the binding site of a transcription activation complex consisting of a basic helix-loop-helix factor, Cbf1p, and two basic leucine zipper factors, Met4p and Met28p. Molecular studies have unraveled the specific functions for each subunit of the Cbf1p-Met4p-Met28p complex as well as the modalities of its assembly on the DNA. The Cbf1p-Met4p-Met28p complex contains only one transcription activation module, the Met4p subunit. Detailed mutational analysis of Met4p has elucidated its functional organization. In addition to its activation and bZIP domains, Met4p contains two regulatory domains, called the inhibitory region and the auxiliary domain. When the level of intracellular AdoMet increases, the transcription activation function of Met4 is prevented by Met30p, which binds to the Met4 inhibitory region. In addition to the Cbf1p-Met4p-Met28p complex, transcriptional regulation involves two zinc finger-containing proteins, Met31p and Met32p. The AdoMet-mediated control of the sulfur amino acid pathway illustrates the molecular strategies used by eucaryotic cells to couple gene expression to metabolic changes. PMID:9409150

  15. A Combined Proteomic and Transcriptomic Analysis on Sulfur Metabolism Pathways of Arabidopsis thaliana under Simulated Acid Rain

    PubMed Central

    Wang, Wenhua; Simon, Martin; Wu, Feihua; Hu, Wenjun; Chen, Juan B.; Zheng, Hailei

    2014-01-01

    With rapid economic development, most regions in southern China have suffered acid rain (AR) pollution. In our study, we analyzed the changes in sulfur metabolism in Arabidopsis under simulated AR stress which provide one of the first case studies, in which the systematic responses in sulfur metabolism were characterized by high-throughput methods at different levels including proteomic, genomic and physiological approaches. Generally, we found that all of the processes related to sulfur metabolism responded to AR stress, including sulfur uptake, activation and also synthesis of sulfur-containing amino acid and other secondary metabolites. Finally, we provided a catalogue of the detected sulfur metabolic changes and reconstructed the coordinating network of their mutual influences. This study can help us to understand the mechanisms of plants to adapt to AR stress. PMID:24595051

  16. Oxygen and sulfur interactions with a clean iron surface and the effect of rubbing contact on these interactions

    NASA Technical Reports Server (NTRS)

    Buckley, D. H.

    1973-01-01

    An investigation was conducted to determine the nature of the chemical interactions of oxygen and sulfur with iron when surfaces are stationary and also during sliding in a vacuum environment. Various gases that contained sulfur, oxygen, or both were adsorbed to iron at 23 C. The gases included oxygen, hydrogen sulfide, methyl mercaptan, and sulfur dioxide. Friction experiments were conducted with a hemispherical rider sliding on a rotating disk. An Auger cylindrical mirror analyzer was used to monitor the iron surface chemistry. The results of this study indicate that oxygen will completely displace sulfide films from iron surfaces. Organic thiols containing sulfur, such as methyl mercaptan, adsorb to an iron surface dissociatively. Only sulfur is detected on the iron surface. Sliding inhibits the formation of sulfide films on iron with the adsorption of hydrogen sulfide and methyl mercaptan. With oxygen and sulfur dioxide, the sliding process does not affect adsorption behavior.

  17. Sulfur dioxide residue in sulfur-fumigated edible herbs: The fewer, the safer?

    PubMed

    Duan, Su-Min; Xu, Jun; Bai, Ying-Jia; Ding, Yan; Kong, Ming; Liu, Huan-Huan; Li, Xiu-Yang; Zhang, Qing-Shan; Chen, Hu-Biao; Liu, Li-Fang; Li, Song-Lin

    2016-02-01

    The residual content of sulfur dioxide is frequently regarded as the exclusive indicator in the safety evaluation of sulfur-fumigated edible herbs. To examine the feasibility of such assessment criteria, here the variations in residual sulfur dioxide content during sulfur-fumigation and the potential mechanisms involved were investigated, using Angelicae Sinensis Radix (ASR) as a model herb. The residual sulfur dioxide content and ten major bioactive components in sulfur-fumigated ASR samples were dynamically examined at 13 successive time points within 72 h sulfur-fumigation. The relationship between the content variation tendency of sulfur dioxide and the ten chemicals was discussed. The results suggested that sulfur dioxide-involved chemical transformation of the original components in ASR might cause large consumption of residual sulfur dioxide during sulfur-fumigation. It implies that without considering the induced chemical transformation of bioactive components, the residual sulfur dioxide content alone might be inadequate to comprehensively evaluate the safety of sulfur-fumigated herbs. PMID:26304328

  18. Nitrogen-sulfur compounds in stratospheric aerosols

    NASA Technical Reports Server (NTRS)

    Farlow, N. H.; Snetsinger, K. G.; Hayes, D. M.; Lem, H. Y.; Tooper, B. M.

    1978-01-01

    Two forms of nitrosyl sulfuric acid (NOHSO4 and NOHS2O7) have been tentatively identified in stratospheric aerosols. The first of these can be formed either directly from gas reactions of NO2 with SO2 or by gas-particle interactions between NO2 and H2SO4. The second product may form when SO3 is involved. Estimates based on these reactions suggest that the maximum quantity of NO that might be absorbed in stratospheric aerosols could vary from one-third to twice the amount of NO in the surrounding air. If these reactions occur in the stratosphere, then a mechanism exists for removing nitrogen oxides from that region by aerosol particle fallout. This process may typify another natural means that helps cleanse the lower stratosphere of excessive pollutants.

  19. Project for laboratory study for removal of organic sulfur from coal

    SciTech Connect

    Not Available

    1981-01-15

    Major accomplishments are listed: 1. It was found that molten sodium hydroxide (in place of mixed sodium and potassium hydroxides) followed by dilute sulfuric acid wash gave Gravimelt coal with the usual amount of sulfur and mineral matter removal but there was no MAF heat content loss over the small amount required for replacement of sulfur atoms by oxygen atoms in the coal structure - e.g., these samples had both measured heat content and MAF heat content in excess of 1400 Btu/lb. Therefore, the selectivity of the Gravimelt Process appears to be very high. 2. It was found that demineralized and desulfurizd Gravimelt coal has significantly less alkali metals content than the input coal. 3. Kentucky No. 11 coal was reduced in sulfur content to a level of 0.10 lbs of sulfur (0.20 lbs of sulfur dioxide)/10/sup 6/ Btu with an ash content of 0.21% in a cumulative reaction time of 60 minutes. This represents a 96% reduction in sulfur and a 97% reduction in ash. This product is significantly lower in sulfur content and ash than are typical synthetic or conventional liquid boiler fuels. 4. The Gravimelt Process was tested on Illinois No. 6 coal giving essentially identical results to those previously obtained for the Kentucky No. 11 coal under the same conditions (89% reduction in sulfur and 97% reduction in ash). 5. A technology for the regeneration of spent caustic has been identified within the tanning industry which corresponds to most of our Gravimelt Process requirements.

  20. Control of Sulfur Dioxide Emissions from Pulverized Coal-Fired Boilers by Dry Removal with Lime and Limestone Sorbants 

    E-print Network

    Schwartz, M. H.

    1979-01-01

    pulverized coal-fired boiler equipment. These are: (1) coal cleaning to remove pyritic sulfur, (2) conventional wet, nonregenerable scrubbing with alkaline slurry and solution processes, and (3) dry processes which involve direct introduction of lime...

  1. Optical properties of sulfur copolymers for infrared applications

    NASA Astrophysics Data System (ADS)

    Namnabat, Soha; Gabriel, Jared J.; Pyun, Jeffrey; Norwood, Robert A.

    2014-03-01

    The development of organic polymers with high refractive indices has been widely investigated, as a possible alternative to inorganic metal oxide, semiconductor, or chalcogenide-based materials for a variety of optical devices and components, such as waveguides, anti-reflective coatings, charge-coupled devices and fiber optic cables. In principle, organic-based polymers are attractive for these applications because of their low weight, ease of processing, mechanical toughness, and facile chemical variation using commercially available precursors. However, one of the fundamental challenges associated with organic polymers is their generally low refractive indices in comparison to their inorganic counterparts. Herein we report on the optical characterization of a new class of sulfur copolymers that are readily moldable, transparent above 500nm, possess high refractive index (n < 1.8) and take advantage of the low infrared absorption of S?S bonds for potential use in the mid-infrared at 3-5 microns. These materials are largely made from elemental sulfur by an inverse vulcanization process; in the current study we focus on the properties of a chemically stable, branched copolymer of poly(sulfur-random-1,3-diisopropenylbenzene) (poly(S-r-DIB). Copolymers with elemental sulfur content ranging from 50% to 80% by weight were studied by UV-VIS spectroscopy, FTIR, and prism coupling for refractive index measurement. Clear correlation between material composition and the optical properties was established, confirming that the high polarizability of the sulfur atom leads to high refractive index while also maintaining low optical loss. Applications of the materials for bulk optics, high-density photonic circuits, and infrared components will also be discussed.

  2. Contribution of isotopologue self-shielding to sulfur mass-independent fractionation during sulfur dioxide photolysis

    E-print Network

    Lyons, J. R.

    Signatures of sulfur mass-independent fractionation (S-MIF) are observed for sulfur minerals in Archean rocks, and for modern stratospheric sulfate aerosols (SSA) deposited in polar ice. Ultraviolet light photolysis of ...

  3. Ceramic-metal seals for advanced battery systems. [sodium sulfur and lithium sulfur batteries

    NASA Technical Reports Server (NTRS)

    Reed, L.

    1978-01-01

    The search for materials which are electrochemically compatible with the lithium sulfur and sodium sulfur systems is discussed. The use liquid or braze alloys, titanium hydrite coatings, and tungsten yttria for bonding beryllium with ceramic is examined.

  4. THE SOLAR FLARE SULFUR ABUNDANCE FROM RESIK OBSERVATIONS

    SciTech Connect

    Sylwester, J.; Sylwester, B.; Phillips, K. J. H.; Kuznetsov, V. D. E-mail: bs@cbk.pan.wroc.pl E-mail: kvd@izmiran.ru

    2012-06-01

    The RESIK instrument on CORONAS-F spacecraft observed several sulfur X-ray lines in three of its four channels covering the wavelength range 3.8-6.1 A during solar flares. The fluxes are analyzed to give the sulfur abundance. Data are chosen for when the instrument parameters were optimized. The measured fluxes of the S XV 1s{sup 2}-1s4p (w4) line at 4.089 A gives A(S) = 7.16 {+-} 0.17 (abundances on a logarithmic scale with A(H) = 12) which we consider to be the most reliable. Estimates from other lines range from 7.13 to 7.24. The preferred S abundance estimate is very close to recent photospheric abundance estimates and to quiet-Sun solar wind and meteoritic abundances. This implies no fractionation of sulfur by processes tending to enhance the coronal abundance from the photospheric that depend on the first ionization potential (FIP), or that sulfur, though its FIP has an intermediate value of 10.36 eV, acts like a 'high-FIP' element.

  5. HYDROCARBON AND SULFUR SENSORS FOR SOFC SYSTEMS

    SciTech Connect

    A.M. Azad; Chris Holt; Todd Lesousky; Scott Swartz

    2003-11-01

    The following report summarizes work conducted during the Phase I program Hydrocarbon and Sulfur Sensors for SOFC Systems under contract No. DE-FC26-02NT41576. For the SOFC application, sensors are required to monitor hydrocarbons and sulfur in order to increase the operation life of SOFC components. This report discusses the development of two such sensors, one based on thick film approach for sulfur monitoring and the second galvanic based for hydrocarbon monitoring.

  6. Influences of clouds and rain on the large-scale transport and deposition of sulfur

    SciTech Connect

    Luecken, D.J.; Berkowitz, C.M.; Easter, R.C.

    1991-07-01

    This paper describes the application of a three-dimensional, global-scale Eulerian model with an explicit description of cloud and chemical processes. Simulation results describing the transport of sulfur from North America and Europe across the north Atlantic Ocean during a climatological July are presented. Wet deposition was found to contribute slightly more to total sulfur deposition than dry deposition, a feature explained by the large amounts of precipitation during this month. The wet deposition patterns did not always correspond to the emissions patterns. The precipitation rate and spatial distribution had a large effect on the calculated concentrations of soluble sulfur species. 10 refs., 7 figs., 1 tab.

  7. Sulfur in lunar mare basalts as a function of bulk composition

    NASA Technical Reports Server (NTRS)

    Gibson, E. K., Jr.; Brett, R.; Andrawes, F.

    1977-01-01

    Sulfur abundances and metallic iron abundances in 18 Apollo 12 mare basalts were determined. No correlation between sulfur abundance and metallic iron content was detected; metallic iron abundances are not primarily caused by S loss. Sulfur abundances, directly related to the bulk composition of the rocks and especially to the TiO2 content, increase with increasing degrees of fractionation and appear to result from S concentration in the melts during fractionation. Unlike the Apollo 17 melts, the Apollo 12 melts were unsaturated with respect to sulfide. Composition appears to control S content for Apollo 17 basalts, and cumulus processes may cause Fe-FeS enrichment.

  8. ECONOMICS OF NITROGEN OXIDES, SULFUR OXIDES, AND ASH CONTROL SYSTEMS FOR COAL-FIRED UTILITY POWER PLANTS

    EPA Science Inventory

    The report gives results of an EPA-sponsored economic evaluation of three processes to reduce NOx, SO2, and ash emissions from coal-fired utility power plants: one based on 3.5% sulfur eastern bituminous coal; and the other, on 0.7% sulfur western subbituminous coal. NOx control ...

  9. Are the clouds of Venus sulfuric acid.

    NASA Technical Reports Server (NTRS)

    Young, A. T.

    1973-01-01

    It is shown that strong aqueous sulfuric acid solutions have the right refractive index and freeze at Venusian cloud temperature, explain the dryness of the Venusian stratosphere, are consistent with some features of the Venusian IR spectrum, and do not absorb in highly reflecting areas of Venus. It is also indicated that such solutions should be produced by reactions between known atmospheric constituents and most sulfur-bearing rock at the Venusian surface temperature, and require only small amounts of sulfur consistent with its cosmic abundance and with the amounts of other volatile elements present in the atmosphere. It is believed therefore that the clouds of Venus consist of sulfuric acid solutions.

  10. The Microbial Karst Sulfuric Acid Dynamo

    NASA Astrophysics Data System (ADS)

    Lyon, E.; Meyer, K.; Koffman, B.; Galdenzi, S.; Macalady, J.

    2004-12-01

    The original model for sulfuric acid speleogenesis attributes limestone dissolution to the oxidation of gaseous H2S to sulfuric acid on limestone cave walls (Egemeier 1981). This model has recently been reexamined in Lower Kane Cave, Wyoming (USA), where the most intense limestone dissolution appears to be the result of microbial colonization of limestone surfaces below the water table (Engel et al. 2004). In contrast, sulfuric acid speleogenesis in the Frasassi Caves (Italy) is equally intense above and below the water table, and is mediated not only by sulfur-oxidizing bacteria but by a complex community of sulfur cycling microorganisms including diverse sulfate-reducing bacteria. The sulfate-reducing bacteria were identified in 16S rDNA clone libraries from both cave walls and cave stream biofilms. These findings suggest a new model for sulfuric acid speleogenesis in which a full range of oxidants and reductants available to indigenous sulfur-cycling microbial communities control the extent of sulfur recycling and sulfuric acid production at limestone surfaces.

  11. UHPLC UHD Q-TOF MS/MS analysis of the impact of sulfur fumigation on the chemical profile of Codonopsis Radix (Dangshen).

    PubMed

    Ma, Xiao-qing; Leung, Alexander Kai Man; Chan, Chi Leung; Su, Tao; Li, Wei-dong; Li, Su-mei; Fong, David Wang Fun; Yu, Zhi-Ling

    2014-01-21

    Over recent decades sulfur fumigation has been becoming abused in processing some freshly harvested Chinese medicinal herbs, although it is questioned whether sulfur fumigation can result in changes in efficacy and safety of the herbs. One of the herbs commonly processed by sulfur fumigation is Codonopsis Radix (Dangshen). A report showed that lobetyolin content in sulfur-fumigated Dangshen was lower than in air-dried Dangshen. Whereas there is no investigation designed to compare the chemical profiles of the sulfur-fumigated Dangshen and the air-dried Dangshen. In the present study, a rapid and versatile ultra-high-performance liquid chromatography coupled with ultra-high resolution quadrupole time-of-flight mass spectrometry (UHPLC UHD Q-TOF MS/MS) method was developed for comprehensive analysis of the chemical profiles of sulfur-fumigated and air-dried Dangshen samples. Principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) demonstrated that there were significant chemical differences between sulfur-fumigated and air-dried Dangshen samples. Among the changed components, 57 compounds were identified, in which 15 sulfur-containing compounds were detected only in sulfur-fumigated samples. The established methods were successfully applied to discriminate sulfur-fumigated Dangshen among commercial samples. Whether the chemical changes caused by sulfur fumigation affect the clinical efficacy and safety of Dangshen needs to be further investigated. PMID:24286102

  12. Characterization of Sulfur Compounds in Coffee Beans by Sulfur K-XANES Spectroscopy

    SciTech Connect

    Lichtenberg, H.; Hormes, J.; Prange, A.; Modrow, H.

    2007-02-02

    In this 'feasibility study' the influence of roasting on the sulfur speciation in Mexican coffee beans was investigated by sulfur K-XANES Spectroscopy. Spectra of green and slightly roasted beans could be fitted to a linear combination of 'standard' reference spectra for biological samples, whereas longer roasting obviously involves formation of additional sulfur compounds in considerable amounts.

  13. Characterization of Sulfur Compounds in Coffee Beans by Sulfur K-XANES Spectroscopy

    NASA Astrophysics Data System (ADS)

    Lichtenberg, H.; Prange, A.; Modrow, H.; Hormes, J.

    2007-02-01

    In this `feasibility study' the influence of roasting on the sulfur speciation in Mexican coffee beans was investigated by sulfur K-XANES Spectroscopy. Spectra of green and slightly roasted beans could be fitted to a linear combination of `standard' reference spectra for biological samples, whereas longer roasting obviously involves formation of additional sulfur compounds in considerable amounts.

  14. Advanced Byproduct Recovery: Direct Catalytic Reduction of Sulfur Dioxide to Elemental Sulfur. Sixth quarterly technical progress report, January - March 1997

    SciTech Connect

    1997-03-01

    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}.

  15. Apparatus for measurements of transport properties of thin films under sulfur atmosphere at moderate temperatures

    NASA Astrophysics Data System (ADS)

    Clamagirand, J. M.; Ares, J. R.; Diaz-Chao, P.; Pascual, A.; Ferrer, I. J.; Sánchez, C.

    2015-04-01

    An experimental system able to simultaneously measure the electrical resistance and the thermopower of metallic and semiconducting thin films (with thicknesses from ~nm to ~µm) under sulfur atmosphere from room temperature up to 400?°C and total pressures >0.5-1?mbar is designed and implemented. Calibration tests of the system were performed with palladium foils and films as well as p-type and n-type sulfide semiconducting films: iron disulfide and palladium monosulfide. Uncertainties of measured thermopower and resistance values are less than 10% and 5%, respectively. To check the capability of the system under sulfur atmosphere, in situ measurements of transport properties during sulfuration of palladium films were carried out. During the process, sulfur partial pressure and film temperature are accurately controlled. Apparatus may be used to determine the evolution of transport properties of different metal sulfides during their formation/decomposition processes, opening new pathways to investigate the thermoelectric properties of more complex thin film sulfides.

  16. Producing vapor grown carbon fibers with high sulfur coal without SO{sub 2} emissions

    SciTech Connect

    Alig, R.L.; Lake, M.L.; Guth, J.R.; Burton, D.J.

    1995-12-01

    This paper describes the development of a unique process that produces a highly graphitic, vapor grown carbon fiber (VGCF) from the gas phase in pound quantities. Past vapor grown carbon fiber progress has stagnated because the iron catalyst did not grow filaments profusely enough to make a practical continuous reactor. It has been found that by adding H{sub 2}S at an equimolar level with the iron catalyst, the filament formation vastly increases. Coal is desirable as a sulfur source, for it eliminates the need for handling toxic H{sub 2}S, and it is a very low cost hydrocarbon supply for the process. We show that Ohio, high-sulfur coal containing 2.5 to 4.6% sulfur accomplishes both tasks. Furthermore, there is evidence that the sulfur from the coal remains with the carbon fiber catalyst during the reaction and does not exhaust as SO{sub 2} into the atmosphere.

  17. Toward understanding the effect of low-activity waste glass composition on sulfur solubility

    DOE PAGESBeta

    Vienna, John D.; Kim, Dong -Sang; Muller, Isabelle S.; Piepel, Greg F.; Kruger, Albert A.; Jantzen, C.

    2014-07-24

    The concentration of sulfur in nuclear waste glass melter feed must be maintained below the point where salt accumulates on the melt surface. The allowable concentrations may range from 0.37 to over 2.05 weight percent (of SO3 on a calcined oxide basis) depending on the composition of the melter feed and processing conditions. If the amount of sulfur exceeds the melt tolerance level, a molten salt will accumulate, which may upset melter operations and potentially shorten the useful life of the melter. At the Hanford site, relatively conservative limits have been placed on sulfur loading in melter feed, which inmore »turn significantly increases the amount of glass that will be produced. Crucible-scale sulfur solubility data and scaled melter sulfur tolerance data have been collected on simulated Hanford waste glasses over the last 15 years. These data were compiled and analyzed. A model was developed to predict the solubility of SO3 in glass based on 252 simulated Hanford low-activity waste (LAW) glass compositions. This model represents the data well, accounting for over 85% of the variation in data, and was well validated. The model was also found to accurately predict the tolerance for sulfur in melter feed for 13 scaled melter tests of simulated LAW glasses. The model can be used to help estimate glass volumes and make informed decisions on process options. The model also gives quantitative estimates of component concentration effects on sulfur solubility. The components that most increase sulfur solubility are Li2O > V2O5> CaO ? P2O5 > Na2O ? B2O3 > K2O. The components that most decrease sulfur solubility are Cl > Cr2O3 > Al2O3 > ZrO2 ? SnO2 > Others ? SiO2. As a result, the order of component effects is similar to previous literature data, in most cases.« less

  18. NONEQUILIBRIUM SULFUR CAPTURE & RETENTION IN AN AIR COOLED SLAGGING COAL COMBUSTOR

    SciTech Connect

    Bert Zauderer

    2003-04-21

    Calcium oxide injected in a slagging combustor reacts with the sulfur from coal combustion to form sulfur-bearing particles. The reacted particles impact and melt in the liquid slag layer on the combustor wall by the centrifugal force of the swirling combustion gases. Due to the low solubility of sulfur in slag, it must be rapidly drained from the combustor to limit sulfur gas re-evolution. Prior analyses and laboratory scale data indicated that for Coal Tech's 20 MMBtu/hour, air-cooled, slagging coal combustor slag mass flow rates in excess of 400 lb/hr should limit sulfur re-evolution. The objective of this 42-month project was to validate this sulfur-in-slag model in a group of combustor tests. A total of 36 days of testing on the combustor were completed during the period of performance of this project. This was more that double the 16 test days that were required in the original work statement. The extra tests were made possible by cost saving innovations that were made in the operation of the combustor test facility and in additional investment of Coal Tech resources in the test effort. The original project plan called for two groups of tests. The first group of tests involved the injection of calcium sulfate particles in the form of gypsum or plaster of Paris with the coal into the 20 MMBtu/hour-combustor. The second group of tests consisted of the entire two-step process, in which lime or limestone is co-injected with coal and reacts with the sulfur gas released during combustion to form calcium sulfate particles that impact and dissolve in the slag layer. Since this sulfur capture process has been validated in numerous prior tests in this combustor, the primary effort in the present project was on achieving the high slag flow rates needed to retain the sulfur in the slag.

  19. Coal gasification cogeneration process

    SciTech Connect

    Marten, J.H.

    1990-10-16

    This patent describes a process for the coproduction of a combustible first gas stream usable as an energy source, a sulfur-dioxide-containing second gas stream usable as a source for oxidant in the gasification of coal and a sulfur-dioxide-containing third gas stream usable as a feedstock for the production of sulfuric acid. It comprises: reacting coal in a coal gasification zone in the presence of an oxidant under partial coal-gasifying conditions to produce carbonaceous char and a crude gas stream; separating sulfur-containing compounds from the crude gas stream in a sulfur recovery zone to produce a combustible first gas stream and elemental sulfur; reacting the carbonaceous char and gypsum in a reaction zone in proportions such that the non-gypsum portion of the carbonaceous char and gypsum mixture contains sufficient reducing potential to reduce sulfur in the gypsum to gaseous compounds of sulfur in a +4 or lower oxidation state under reducing conditions to produce first a sulfur-dioxide-containing second gas stream which contains weaker SO{sub 2} produced in an early stage of the reaction zone and removed from the reaction zone, and then a sulfur-dioxide-containing third gas stream which contains concentrated SO{sub 2} recovered from a later stage of the reaction zone.

  20. The first laboratory measurements of sulfur ions sputtering water ice

    NASA Astrophysics Data System (ADS)

    Galli, André; Pommerol, Antoine; Vorburger, Audrey; Wurz, Peter; Tulej, Marek; Scheer, Jürgen; Thomas, Nicolas; Wieser, Martin; Barabash, Stas

    2015-04-01

    The upcoming JUpiter ICy moons Explorer mission to Europa, Ganymede, and Callisto has renewed the interest in the interaction of plasma with an icy surface. In particular, the surface release processes on which exosphere models of icy moons rely should be tested with realistic laboratory experiments. We therefore use an existing laboratory facility for space hardware calibration in vacuum to measure the sputtering of water ice due to hydrogen, oxygen, and sulfur ions at energies from 1 keV to 100 keV. Pressure and temperature are comparable to surface conditions encountered on Jupiter's icy moons. The sputter target is a 1cm deep layer of porous, salty water ice. Our results confirm theoretical predictions that the sputter yield from oxygen and sulfur ions should be similar. Thanks to the modular set-up of our experiment we can add further surface processes relevant for icy moons, such as electron sputtering, sublimation, and photodesorption due to UV light.

  1. Isotopic inferences of ancient biochemistries - Carbon, sulfur, hydrogen, and nitrogen

    NASA Technical Reports Server (NTRS)

    Schidlowski, M.; Hayes, J. M.; Kaplan, I. R.

    1983-01-01

    In processes of biological incorporation and subsequent biochemical processing sizable isotope effects occur as a result of both thermodynamic and kinetic fractionations which take place during metabolic and biosynthetic reactions. In this chapter a review is provided of earlier work and recent studies on isotope fractionations in the biogeochemical cycles of carbon, sulfur, hydrogen, and nitrogen. Attention is given to the biochemistry of carbon isotope fractionation, carbon isotope fractionation in extant plants and microorganisms, isotope fractionation in the terrestrial carbon cycle, the effects of diagenesis and metamorphism on the isotopic composition of sedimentary carbon, the isotopic composition of sedimentary carbon through time, implications of the sedimentary carbon isotope record, the biochemistry of sulfur isotope fractionation, pathways of the biogeochemical cycle of nitrogen, and the D/H ratio in naturally occurring materials.

  2. Sulfate- and Sulfur-Reducing Bacteria as Terrestrial Analogs for Microbial Life on Jupiter's Satellite Io

    NASA Technical Reports Server (NTRS)

    Pikuta, Elena V.; Hoover, Richard B.; Six, N. Frank (Technical Monitor)

    2001-01-01

    Observations from the Voyager and Galileo spacecraft have revealed Jupiter's moon Io to be the most volcanically active body of our Solar System. The Galileo Near Infrared Imaging Spectrometer (NIMS) detected extensive deposits of sulfur compounds, elemental sulfur and SO2 frost on the surface of Io. There are extreme temperature variations on Io's surface, ranging from -130 C to over 2000 C at the Pillan Patera volcanic vent. The active volcanoes, fumaroles, calderas, and lava lakes and vast sulfur deposits on this frozen moon indicate that analogs of sulfur- and sulfate-reducing bacteria might inhabit Io. Hence Io may have great significance to Astrobiology. Earth's life forms that depend on sulfur respiration are members of two domains: Bacteria and Archaea. Two basic links of the biogeochemical sulfur cycle of Earth have been studied: 1) the sulfur oxidizing process (occurring at aerobic conditions) and 2) the process of sulfur-reduction to hydrogen sulfide (anaerobic conditions). Sulfate-reducing bacteria (StRB) and sulfur-reducing bacteria (SrRB) are responsible for anaerobic reducing processes. At the present time the systematics of StRB include over 112 species distributed into 35 genera of Bacteria and Archaea. Moderately thermophilic and mesophilic SrRB belong to the Bacteria. The hyperthermophilic SrRB predominately belong to the domain Archaea and are included in the genera: Pyrodictium, Thermoproteus, Pyrobaculum, Thermophilum, Desulfurococcus, and Thermodiscus. The StRB and SrRB use a wide spectrum of substrates as electron donors for lithotrophic and heterotrophic type nutrition. The electron acceptors for the StRB include: sulfate, thiosulfate, sulfite, sulfur, arsenate, dithionite, tetrathionate, sulfur monoxide, iron, nitrite, selenite, fumarate, oxygen, carbon dioxide, and chlorine-containing phenol compounds. The Sulfate- and Sulfur-reducing bacteria are widely distributed in anaerobic ecosystems, including extreme environments like hot springs, deepsea hydrothermal vents, soda and high salinity lakes, and cryo-environments. Furthermore, the StRB and SrRB have Astrobiological significance as these anaerobic extremophiles may represent the dominant relic life forms that inhabited our planet during the extensive volcanic activity in the Earth's early evolutionary period.

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

    NASA Astrophysics Data System (ADS)

    Liu, Ya; Guo, Jinxin; Zhang, Jun; Su, Qingmei; Du, Gaohui

    2015-01-01

    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-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.

  4. Device for the removal of sulfur dioxide from exhaust gas by pulsed energization of free electrons

    SciTech Connect

    Mizuno, A.; Clements, J.S.; Davis, R.H.

    1984-01-01

    The performance of a new device using pulsed streamer corona for the removal of sulfur dioxide from humid air has been evaluated. The pulsed streamer corona produced free electrons which enhance gas-phase chemical reactions, and convert SO/sub 2/ to sulfuric acid mist. The SO/sub 2/ removal efficiency was compared with that of the electron-beam flue-gas treatment process. The comparison demonstrates the advantage of the novel device.

  5. 40 CFR 180.444 - Sulfur dioxide; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Sulfur dioxide; tolerances for residues. ...Specific Tolerances § 180.444 Sulfur dioxide; tolerances for residues. ...follows for sulfite residues of the fungicide sulfur dioxide (determined as (SO2 ))...

  6. 40 CFR 52.2575 - Control strategy: Sulfur dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Control strategy: Sulfur dioxide. 52.2575 Section 52.2575...Wisconsin § 52.2575 Control strategy: Sulfur dioxide. (a) Part D—Approval...the Administrator approved the Wisconsin sulfur dioxide control plan. (1) Part...

  7. 40 CFR 52.2575 - Control strategy: Sulfur dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Control strategy: Sulfur dioxide. 52.2575 Section 52.2575...Wisconsin § 52.2575 Control strategy: Sulfur dioxide. (a) Part D—Approval...the Administrator approved the Wisconsin sulfur dioxide control plan. (1) Part...

  8. 40 CFR 52.795 - Control strategy: Sulfur dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Control strategy: Sulfur dioxide. 52.795 Section 52.795...Indiana § 52.795 Control strategy: Sulfur dioxide. (a) Revised APC-13...Indiana's Air Pollution Control regulations (sulfur dioxide emission limitation) is...

  9. 40 CFR 52.1030 - Control strategy: Sulfur oxides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Control strategy: Sulfur oxides. 52.1030 Section 52... § 52.1030 Control strategy: Sulfur oxides. (a) The revision to Regulation 100.6 (Chapter 106) “Low Sulfur Fuel Regulation” for the...

  10. 40 CFR 180.444 - Sulfur dioxide; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Sulfur dioxide; tolerances for residues. ...Specific Tolerances § 180.444 Sulfur dioxide; tolerances for residues. ...follows for sulfite residues of the fungicide sulfur dioxide (determined as (SO2 ))...

  11. 40 CFR 180.444 - Sulfur dioxide; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Sulfur dioxide; tolerances for residues. ...Specific Tolerances § 180.444 Sulfur dioxide; tolerances for residues. ...follows for sulfite residues of the fungicide sulfur dioxide (determined as (SO2 ))...

  12. 46 CFR 153.545 - Special requirements for liquid sulfur.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... false Special requirements for liquid sulfur. 153.545 Section 153.545 Shipping...153.545 Special requirements for liquid sulfur. (a) A containment system carrying liquid sulfur must have: (1) A cargo tank...

  13. 40 CFR 52.724 - Control strategy: Sulfur dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Control strategy: Sulfur dioxide. 52.724 Section 52.724...Illinois> § 52.724 Control strategy: Sulfur dioxide. (a) Part D—Conditional...insure attainment and maintenance of the sulfur dioxide standard, and the...

  14. 40 CFR 52.1030 - Control strategy: Sulfur oxides.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Control strategy: Sulfur oxides. 52.1030 Section 52... § 52.1030 Control strategy: Sulfur oxides. (a) The revision to Regulation 100.6 (Chapter 106) “Low Sulfur Fuel Regulation” for the...

  15. 40 CFR 52.1117 - Control strategy: Sulfur oxides.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Control strategy: Sulfur oxides. 52.1117 Section 52.1117...Maryland § 52.1117 Control strategy: Sulfur oxides. (a) [Reserved] ...attainment and maintenance of the national sulfur dioxide standards. [40 FR...

  16. 40 CFR 52.231 - Regulations: Sulfur oxides.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Regulations: Sulfur oxides. 52.231 Section 52.231...California § 52.231 Regulations: Sulfur oxides. (a) [Reserved...National Ambient Air Quality Standard for Sulfur Oxides. (1) Lake County...

  17. 40 CFR 52.795 - Control strategy: Sulfur dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Control strategy: Sulfur dioxide. 52.795 Section 52.795...Indiana § 52.795 Control strategy: Sulfur dioxide. (a) Revised APC-13...Indiana's Air Pollution Control regulations (sulfur dioxide emission limitation) is...

  18. 46 CFR 153.545 - Special requirements for liquid sulfur.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... false Special requirements for liquid sulfur. 153.545 Section 153.545 Shipping...153.545 Special requirements for liquid sulfur. (a) A containment system carrying liquid sulfur must have: (1) A cargo tank...

  19. 40 CFR 52.2575 - Control strategy: Sulfur dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Control strategy: Sulfur dioxide. 52.2575 Section 52.2575...Wisconsin § 52.2575 Control strategy: Sulfur dioxide. (a) Part D—Approval...the Administrator approved the Wisconsin sulfur dioxide control plan. (1) Part...

  20. 40 CFR 52.795 - Control strategy: Sulfur dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Control strategy: Sulfur dioxide. 52.795 Section 52.795...Indiana § 52.795 Control strategy: Sulfur dioxide. (a) Revised APC-13...Indiana's Air Pollution Control regulations (sulfur dioxide emission limitation) is...

  1. 40 CFR 52.1126 - Control strategy: Sulfur oxides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Control strategy: Sulfur oxides. 52.1126 Section 52.1126...Massachusetts § 52.1126 Control strategy: Sulfur oxides. (a) The revisions...District, which allows a relaxation of sulfur in fuel limitations under...

  2. 40 CFR 52.1030 - Control strategy: Sulfur oxides.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Control strategy: Sulfur oxides. 52.1030 Section 52... § 52.1030 Control strategy: Sulfur oxides. (a) The revision to Regulation 100.6 (Chapter 106) “Low Sulfur Fuel Regulation” for the...

  3. 40 CFR 52.231 - Regulations: Sulfur oxides.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Regulations: Sulfur oxides. 52.231 Section 52.231...California § 52.231 Regulations: Sulfur oxides. (a) [Reserved...National Ambient Air Quality Standard for Sulfur Oxides. (1) Lake County...

  4. 40 CFR 52.795 - Control strategy: Sulfur dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Control strategy: Sulfur dioxide. 52.795 Section 52.795...Indiana § 52.795 Control strategy: Sulfur dioxide. (a) Revised APC-13...Indiana's Air Pollution Control regulations (sulfur dioxide emission limitation) is...

  5. 46 CFR 153.545 - Special requirements for liquid sulfur.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... false Special requirements for liquid sulfur. 153.545 Section 153.545 Shipping...153.545 Special requirements for liquid sulfur. (a) A containment system carrying liquid sulfur must have: (1) A cargo tank...

  6. 40 CFR 52.2575 - Control strategy: Sulfur dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Control strategy: Sulfur dioxide. 52.2575 Section 52.2575...Wisconsin § 52.2575 Control strategy: Sulfur dioxide. (a) Part D—Approval...the Administrator approved the Wisconsin sulfur dioxide control plan. (1) Part...

  7. 46 CFR 153.545 - Special requirements for liquid sulfur.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... false Special requirements for liquid sulfur. 153.545 Section 153.545 Shipping...153.545 Special requirements for liquid sulfur. (a) A containment system carrying liquid sulfur must have: (1) A cargo tank...

  8. 40 CFR 52.795 - Control strategy: Sulfur dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Control strategy: Sulfur dioxide. 52.795 Section 52.795...Indiana § 52.795 Control strategy: Sulfur dioxide. (a) Revised APC-13...Indiana's Air Pollution Control regulations (sulfur dioxide emission limitation) is...

  9. 40 CFR 52.1126 - Control strategy: Sulfur oxides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Control strategy: Sulfur oxides. 52.1126 Section 52.1126...Massachusetts § 52.1126 Control strategy: Sulfur oxides. (a) The revisions...District, which allows a relaxation of sulfur in fuel limitations under...

  10. 40 CFR 180.444 - Sulfur dioxide; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Sulfur dioxide; tolerances for residues. ...Specific Tolerances § 180.444 Sulfur dioxide; tolerances for residues. ...follows for sulfite residues of the fungicide sulfur dioxide (determined as (SO2 ))...

  11. 40 CFR 52.1126 - Control strategy: Sulfur oxides.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Control strategy: Sulfur oxides. 52.1126 Section 52.1126...Massachusetts § 52.1126 Control strategy: Sulfur oxides. (a) The revisions...District, which allows a relaxation of sulfur in fuel limitations under...

  12. 40 CFR 52.724 - Control strategy: Sulfur dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Control strategy: Sulfur dioxide. 52.724 Section 52.724...Illinois> § 52.724 Control strategy: Sulfur dioxide. (a) Part D—Conditional...insure attainment and maintenance of the sulfur dioxide standard, and the...

  13. 46 CFR 153.545 - Special requirements for liquid sulfur.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... false Special requirements for liquid sulfur. 153.545 Section 153.545 Shipping...153.545 Special requirements for liquid sulfur. (a) A containment system carrying liquid sulfur must have: (1) A cargo tank...

  14. 40 CFR 52.1126 - Control strategy: Sulfur oxides.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Control strategy: Sulfur oxides. 52.1126 Section 52.1126...Massachusetts § 52.1126 Control strategy: Sulfur oxides. (a) The revisions...District, which allows a relaxation of sulfur in fuel limitations under...

  15. 40 CFR 180.444 - Sulfur dioxide; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Sulfur dioxide; tolerances for residues. ...Specific Tolerances § 180.444 Sulfur dioxide; tolerances for residues. ...follows for sulfite residues of the fungicide sulfur dioxide (determined as (SO2 ))...

  16. 40 CFR 52.724 - Control strategy: Sulfur dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Control strategy: Sulfur dioxide. 52.724 Section 52.724...Illinois> § 52.724 Control strategy: Sulfur dioxide. (a) Part D—Conditional...insure attainment and maintenance of the sulfur dioxide standard, and the...

  17. 40 CFR 52.231 - Regulations: Sulfur oxides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Regulations: Sulfur oxides. 52.231 Section 52.231...California § 52.231 Regulations: Sulfur oxides. (a) [Reserved...National Ambient Air Quality Standard for Sulfur Oxides. (1) Lake County...

  18. 40 CFR 52.231 - Regulations: Sulfur oxides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Regulations: Sulfur oxides. 52.231 Section 52.231...California § 52.231 Regulations: Sulfur oxides. (a) [Reserved...National Ambient Air Quality Standard for Sulfur Oxides. (1) Lake County...

  19. 40 CFR 52.2575 - Control strategy: Sulfur dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Control strategy: Sulfur dioxide. 52.2575 Section 52.2575...Wisconsin § 52.2575 Control strategy: Sulfur dioxide. (a) Part D—Approval...the Administrator approved the Wisconsin sulfur dioxide control plan. (1) Part...

  20. 40 CFR 52.724 - Control strategy: Sulfur dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Control strategy: Sulfur dioxide. 52.724 Section 52.724...Illinois> § 52.724 Control strategy: Sulfur dioxide. (a) Part D—Conditional...insure attainment and maintenance of the sulfur dioxide standard, and the...