Sample records for sulfur compounds sulfur

  1. 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.

  2. Thiophenic Sulfur Compounds Released During Coal Pyrolysis.

    PubMed

    Xing, Mengwen; Kong, Jiao; Dong, Jie; Jiao, Haili; Li, Fan

    2013-06-01

    Thiophenic sulfur compounds are released during coal gasification, carbonization, and combustion. Previous studies indicate that thiophenic sulfur compounds degrade very slowly in the environment, and are more carcinogenic than polycyclic aromatic hydrocarbons and nitrogenous compounds. Therefore, it is very important to study the principle of thiophenic sulfur compounds during coal conversion, in order to control their emission and promote clean coal utilization. To realize this goal and understand the formation mechanism of thiophenic sulfur compounds, this study focused on the release behavior of thiophenic sulfur compounds during coal pyrolysis, which is an important phase for all coal thermal conversion processes. The pyrolyzer (CDS-5250) and gas chromatography-mass spectrometry (Focus GC-DSQII) were used to analyze thiophenic sulfur compounds in situ. Several coals with different coal ranks and sulfur contents were chosen as experimental samples, and thiophenic sulfur compounds of the gas produced during pyrolysis under different temperatures and heating rates were investigated. Levels of benzothiophene and dibenzothiophene were obtained during pyrolysis at temperatures ranging from 200°C to 1300°C, and heating rates ranging from 6°C/ms to 14°C/ms and 6°C/s to 14°C/s. Moreover, the relationship between the total amount of benzothiophene and dibenzothiophene released during coal pyrolysis and the organic sulfur content in coal was also discussed. This study is beneficial for understanding the formation and control of thiophenic sulfur compounds, since it provides a series of significant results that show the impact that operation conditions and organic sulfur content in coal have on the amount and species of thiophenic sulfur compounds produced during coal pyrolysis. PMID:23781126

  3. Thiophenic Sulfur Compounds Released During Coal Pyrolysis

    PubMed Central

    Xing, Mengwen; Kong, Jiao; Dong, Jie; Jiao, Haili; Li, Fan

    2013-01-01

    Abstract Thiophenic sulfur compounds are released during coal gasification, carbonization, and combustion. Previous studies indicate that thiophenic sulfur compounds degrade very slowly in the environment, and are more carcinogenic than polycyclic aromatic hydrocarbons and nitrogenous compounds. Therefore, it is very important to study the principle of thiophenic sulfur compounds during coal conversion, in order to control their emission and promote clean coal utilization. To realize this goal and understand the formation mechanism of thiophenic sulfur compounds, this study focused on the release behavior of thiophenic sulfur compounds during coal pyrolysis, which is an important phase for all coal thermal conversion processes. The pyrolyzer (CDS-5250) and gas chromatography–mass spectrometry (Focus GC-DSQII) were used to analyze thiophenic sulfur compounds in situ. Several coals with different coal ranks and sulfur contents were chosen as experimental samples, and thiophenic sulfur compounds of the gas produced during pyrolysis under different temperatures and heating rates were investigated. Levels of benzothiophene and dibenzothiophene were obtained during pyrolysis at temperatures ranging from 200°C to 1300°C, and heating rates ranging from 6°C/ms to 14°C/ms and 6°C/s to 14°C/s. Moreover, the relationship between the total amount of benzothiophene and dibenzothiophene released during coal pyrolysis and the organic sulfur content in coal was also discussed. This study is beneficial for understanding the formation and control of thiophenic sulfur compounds, since it provides a series of significant results that show the impact that operation conditions and organic sulfur content in coal have on the amount and species of thiophenic sulfur compounds produced during coal pyrolysis. PMID:23781126

  4. Changes in organic sulfur compounds in coal macerals during liquefaction

    SciTech Connect

    Winans, R.E. [Argonne National Lab., IL (United States); Joseph, J.T.; Fisher, R.B. [Amoco Oil Co., Naperville, IL (United States). Research and Development Dept.

    1994-02-01

    Several general trends were observed in reactivity patterns of sulfur compounds in macerals. Sulfur is reduced in the asphaltene fraction compared to initial maceral. Aliphatics are removed and polycyclic aromatic compounds are both stable and probably formed under these conditions. Molecules containing two sulfur atoms are formed. The preasphaltenes are now being analyzed by DEIHRMS.

  5. MANUAL METHOD FOR MEASUREMENT OF REDUCED SULFUR COMPOUNDS

    EPA Science Inventory

    A manual method for measuring reduced sulfur compounds in Kraft pulp mill and sulfur recovery plant emissions was evaluated. The method involves removing SO2 from the gas stream (if present) with a citric acid-potassium citrate buffer, that passes reduced sulfur compounds; therma...

  6. The reaction kinetics of gasoline sulfur compounds: Catalytic mechanisms for sulfur reduction

    SciTech Connect

    Harding, R.H.; Gatte, R.R.; Albro, T.G.; Wormsbecher, R.F. [W.R. Grace & Co. Conn, Columbia, MD (United States)

    1993-12-31

    One of the key elements of reformulated gasoline is the reduction of the sulfur compounds produced by fluid catalytic cracking. This paper probes the reaction kinetics of refractory gasoline-range thiophene derivatives (thiophene, tetrahydrothiophene, and alkylthiophenes) in an effort to determine the mechanisms of sulfur compound cracking in the FCC unit. The gasoline-range sulfur compounds were analyzed using gas chromatography with an atomic emission detector. The authors` results show that the FCC catalysts affects the cracking of sulfur compounds through both hydrogen transfer and zeolite pore restriction mechanisms. An experimental FCC catalyst is shown to reduce gasoline sulfur content in the Davidson Circulating Riser (DCR{sup TM}) pilot unit. Model compound tests show that the activity of the catalyst is due to both its catalytic and adsorptive properties. Tetrahydrothiophene, which is produced from thiophenes by hydrogen transfer, is completely removed by the experimental catalyst.

  7. Diversity of Sulfur Compound Production in Lactic Acid Bacteria1

    Microsoft Academic Search

    K. E. Seefeldt; B. C. Weimer

    2000-01-01

    Volatile sulfur compounds such as methanethiol, di- methyl disulfide, dimethyl trisulfide, and hydrogen sul- fide constitute an important fraction of Cheddar cheese flavor. These compounds are products of the catabolism of methionine and cysteine by bacteria in the cheese matrix. The objectives of this study were to examine the levels and types of volatile sulfur compounds produced from methionine by

  8. Correlation of heat of formation data for organic sulfur compounds

    Microsoft Academic Search

    J. P. McCullough; W. D. Good

    1961-01-01

    The method of Allen was used to correlate unpublished and recently published Bureau of Mines results for the heats of formation of organic sulfur compounds. Six parameters were evaluated from data for 25 acyclic alkane thiols, sulfides and disulfides. With the inclusion of appropriate strain energies, the results for seven cyclic sulfur compounds also were correlated. For all 32 compounds,

  9. Reduced Sulfur Compound Oxidation byThiobacillus caldus

    Microsoft Academic Search

    KEVIN B. HALLBERG; MARK DOPSON

    1996-01-01

    The oxidation of reduced inorganic sulfur compounds was studied by using resting cells of the moderate thermophile Thiobacillus caldus strain KU. The oxygen consumption rate and total oxygen consumed were determined for the reduced sulfur compounds thiosulfate, tetrathionate, sulfur, sulfide, and sulfite in the absence and in the presence of inhibitors and uncouplers. The uncouplers 2,4-dinitrophenol and carbonyl cyanidem-chlorophenyl-hydrazone had

  10. Formation of volatile sulfur compounds and metabolism of methionine and other sulfur compounds in fermented food.

    PubMed

    Landaud, Sophie; Helinck, Sandra; Bonnarme, Pascal

    2008-01-01

    The formation of volatile sulfur compounds (VSC) in fermented food is a subject of interest. Such compounds are essential for the aroma of many food products like cheeses or fermented beverages, in which they can play an attractive or a repulsive role, depending on their identity and their concentration. VSC essentially arise from common sulfur-bearing precursors, methionine being the most commonly found. In the first section of this paper, the main VSC found in cheese, wine, and beer are reviewed. It is shown that a wide variety of VSC has been evidenced in these food products. Because of their low odor threshold and flavor notes, these compounds impart essential sensorial properties to the final product. In the second section of this review, the main (bio)chemical pathways leading to VSC synthesis are presented. Attention is focused on the microbial/enzymatic phenomena-which initiate sulfur bearing precursors degradation-leading to VSC production. Although chemical reactions could also play an important role in this process, this aspect is not fully developed in our review. The main catabolic pathways leading to VSC from the precursor methionine are presented. PMID:18064452

  11. Method for removal of sulfur compounds from a gas stream

    SciTech Connect

    Frech, K.J.; Tazuma, J.J.

    1982-01-19

    This invention relates to a process for the removal of sulfur compounds from a gas stream. More specifically, this invention relates to an improvement in the iron oxide method of sulfur removal from a gas stream through the use of hydrogen peroxide.

  12. Selective determination of volatile sulfur compounds in wine by gas chromatography with sulfur chemiluminescence detection.

    PubMed

    Siebert, Tracey E; Solomon, Mark R; Pollnitz, Alan P; Jeffery, David W

    2010-09-01

    Volatile sulfur compounds can be formed at various stages during wine production and storage, and some may impart unpleasant "reduced" aromas to wine when present at sensorially significant concentrations. Quantitative data are necessary to understand factors that influence the formation of volatile sulfur compounds, but their analysis is not a trivial undertaking. A rapid and selective method for determining 10 volatile sulfur-containing aroma compounds in wine that have been linked to "off-odors" has been developed. The method utilizes static headspace injection and cool-on-column gas chromatography coupled with sulfur chemiluminescence detection (GC-SCD). Validation demonstrated that the method is accurate, precise, robust, and sensitive, with limits of quantitation around 1 microg/L or better, which is below the aroma detection thresholds for the analytes. Importantly, the method does not form artifacts, such as disulfides, during sample preparation or analysis. To study the contribution of volatile sulfur compounds, the GC-SCD method was applied to 68 commercial wines that had reductive sensory evaluations. The analytes implicated as contributors to reductive characters were hydrogen sulfide, methanethiol, and dimethyl sulfide, whereas carbon disulfide played an uncertain role. PMID:20707415

  13. The sulfur fixing characteristics on calcium-compounds

    SciTech Connect

    Dongyao, X.; Qiaowen, Y.; Jinghua, C.; Qiwen, F.; Peiling, X.

    1999-07-01

    On the basis of a three factor and four level orthogonal experiment, the sulfur fixing characteristic on calcium-compounds has been studied. Three factors include burning temperature, the ratio of calcium versus sulfur and calcium-compounds. The sulfur fixing efficiency of sample was calculated through measuring the sulfur content of slag by means of X-ray fluorescent analysis, and it was found that influence of calcium-compounds on the efficiency is more important than the burning temperature or the ratio, and that Ca(OH){sub 2} has a better efficiency than CaO or CaCO{sub 3}. As the burning temperature is increased, the efficiency is decreased; when the ratio is increased, the efficiency will increase. Sulfur fixing agent and coal powder were mixed, then the mixture obtained was burned, the best efficiency of fixing sulfur was only 33%. As a result, some measures must be adopted to increase the efficiency to a extent that the sulfur fixing agent on the basis of calcium-compounds can be used practically.

  14. Method for removal of sulfur compounds from a gas

    SciTech Connect

    Frech, K.J.; Tazuma, J.J.

    1981-08-11

    This invention relates to a process for the removal of sulfur compounds from a gas stream which consists of contacting said gas stream with alkali metal salts of sulfonamides or resins containing sulfonamide functionalities.

  15. Organosulfur compounds in sulfur-rich Rasa Coal

    Microsoft Academic Search

    Jaap S. Sinninghe Damsté; Curt M. White; John B. Green; Jan W. de Leeuw

    1999-01-01

    The organosulfur compounds in the extract and pyrolysate of the unusually organic sulfur-rich (11.4 wt %) Upper Palaeocene Raa coal have been identified by gas chromatography-high-resolution mass spectrometry. The major organosulfur compounds (OSC) present in the extract are alkylated benzo[b]- and dibenzothiophenes and in the pyrolysates alkylated thiophenes and benzo[b]thiophenes. In addition, a large suite of sulfur-containing polyaromatics were identified,

  16. Infrared absorption of sulfur bearing compounds

    NASA Technical Reports Server (NTRS)

    Maki, A.

    1982-01-01

    The sulfur bearing molecules of most interest in studies of planetary atmospheres are the simple, stable hydrides and oxides, H2S, H2SO4, SO2, and SO3, and the carbon containing species OCS and CO2. For interpreting spectroscopic observations, the properties that must be known are: transition frequencies, transition intensities, transition assignments in terms of quantum number assignments and lower state energy levels, and pressure broadening constants (including their temperature dependence).

  17. Antioxidant properties of organic sulfur compounds and criteria for evaluating these properties

    Microsoft Academic Search

    I. A. Rubinshtein; E. P. Sobolev

    1965-01-01

    1.The antioxidant properties of organic sulfur compounds are well characterized by the proposed criteria for inhibitor evaluation. These criteria reflect the features of chemical structure of the organic sulfur compounds.2.All of the organic sulfur compounds that were investigated do possess antioxidant properties.3.The antioxidant properties of organic sulfur compounds depend mainly on the nature of the bonds of the sulfur atoms;

  18. Modulation of volatile sulfur compounds by wine yeast.

    PubMed

    Swiegers, J H; Pretorius, I S

    2007-04-01

    Sulfur compounds in wine can be a 'double-edged sword'. On the one hand, certain sulfur-containing volatile compounds such as hydrogen sulfide, imparting a rotten egg-like aroma, can have a negative impact on the perceived quality of the wine, and on the other hand, some sulfur compounds such as 3-mercaptohexanol, imparting fruitiness, can have a positive impact on wine flavor and aroma. Furthermore, these compounds can become less or more attractive or repulsive depending on their absolute and relative concentrations. This presents an interesting challenge to the winemaker to modulate the concentrations of these quality-determining compounds in wine in accordance with consumer preferences. The wine yeast Saccharomyces cerevisiae plays a central role in the production of volatile sulfur compounds. Through the sulfate reduction sequence pathway, the HS(-) is formed, which can lead to the formation of hydrogen sulfide and various mercaptan compounds. Therefore, limiting the formation of the HS(-) ion is an important target in metabolic engineering of wine yeast. The wine yeast is also responsible for the transformation of non-volatile sulfur precursors, present in the grape, to volatile, flavor-active thiol compounds. In particular, 4-mercapto-4-methylpentan-2-one, 3-mercaptohexanol, and 3-mercaptohexyl acetate are the most important volatile thiols adding fruitiness to wine. This paper briefly reviews the metabolic processes involved in the production of important volatile sulfur compounds and the latest strategies in the pursuit of developing wine yeast strains as tools to adjust wine aroma to market specifications. PMID:17262212

  19. Improving rubber concrete by waste organic sulfur compounds.

    PubMed

    Chou, Liang-Hisng; Lin, Chun-Nan; Lu, Chun-Ku; Lee, Cheng-Haw; Lee, Maw-Tien

    2010-01-01

    In this study, the use of crumb tyres as additives to concrete was investigated. For some time, researchers have been studying the physical properties of concrete to determine why the inclusion of rubber particles causes the concrete to degrade. Several methods have been developed to improve the bonding between rubber particles and cement hydration products (C-S-H) with the hope of creating a product with an improvement in mechanical strength. In this study, the crumb tyres were treated with waste organic sulfur compounds from a petroleum refining factory in order to modify their surface properties. Organic sulfur compounds with amphiphilic properties can enhance the hydrophilic properties of the rubber and increase the intermolecular interaction forces between rubber and C-S-H. In the present study, a colloid probe of C-S-H was prepared to measure these intermolecular interaction forces by utilizing an atomic force microscope. Experimental results showed that rubber particles treated with waste organic sulfur compounds became more hydrophilic. In addition, the intermolecular interaction forces increased with the adsorption of waste organic sulfur compounds on the surface of the rubber particles. The compressive, tensile and flexural strengths of concrete samples that included rubber particles treated with organic sulfur compound also increased significantly. PMID:19710121

  20. 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.

  1. MEASUREMENT OF VOLATILE SULFUR COMPOUNDS ASSOCIATED WITH ANIMAL FEEDING OPERATIONS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Volatile sulfur compounds (VSC) are a major class of chemicals associated with odor from animal feeding operations. Identifying and quantifying VSC in air is challenging due to their volatility, reactivity, and low concentrations. In this study, a canister based method is presented that allowed fo...

  2. Hydrous pyrolysis transformation of organic sulfur compounds: Part 1. Reactivity and chemical changes

    Microsoft Academic Search

    Zhiguang Song; Maochun Wang; B. D. Batts; Xianming Xiao

    2005-01-01

    The geochemical transformations of a number of individual model sulfur compounds were investigated using laboratory hydrous pyrolysis under conditions of constant temperature between 200 and 330°C and in the presence of low-sulfur brown coal. The results show that most of the compounds were reactive and could eventually be transformed largely into secondary sulfur species, whereas only aryl sulphides and condensed

  3. Emission of volatile sulfur compounds from spruce trees

    SciTech Connect

    Rennenberg, H.; Huber, B.; Schroeder, P.; Stahl, K.; Haunold, W.; Georgil, H.W.; Slovik, S.; Pfanz, H. (Fraunhofer Institut fuer Atmosphaerische Umweltforschung, Garmisch-Partenkirchen (West Germany))

    1990-03-01

    Spruce (Picea abies L.) trees from the same clone were supplied with different, but low, amounts of plant available sulfate in the soil (9.7-18.1 milligrams per 100 grams of soil). Branches attached to the trees were enclosed in a dynamic gas exchange cuvette and analyzed for the emission of volatile sulfur compounds. Independent of the sulfate supply in the soil, H{sub 2}S was the predominant reduced sulfur compound continuously emitted from the branches with high rates during the day and low rates in the night. In the light, as well as in the dark, the rates of H{sub 2}S emission increased exponentially with increasing water vapor flux from the needles. Approximately 1 nanomole of H{sub 2}S was found to be emitted per mole of water. When stomata were closed completely, only minute emission of H{sub 2}S was observed. Apparently, H{sub 2}S emission from the needles is highly dependent on stromatal aperture, and permeation through the cuticle is negligible. In several experiments, small amounts of dimethylsulfide and carbonylsulfide were also detected in a portion of the samples. However, SO{sub 2} was the only sulfur compound consistently emitted from branches of spruce trees in addition to H{sub 2}S. Emission of SO{sub 2} mainly proceeded via an outburst starting before the beginning of the light period. The total amount of SO{sub 2} emitted from the needles during this outburst was correlated with the plant available sulfate in the soil. The diurnal changes in sulfur metabolism that may result in an outburst of SO{sub 2} are discussed.

  4. Sulfur isotope fractionation during incorporation of sulfur nucleophiles into organic compounds.

    PubMed

    Amrani, Alon; Ma, Qisheng; Ahmad, Ward Said; Aizenshtat, Zeev; Tang, Yongchun

    2008-03-21

    (34)S enrichment is shown to occur during sulfurization reactions and for the first time conclusively attributed to an isotope equilibrium effect rather than selective addition of (34)S enriched nucleophiles. PMID:18389132

  5. Catalytic hydrodesulfurization of an organic sulfur compound contained in gasoline

    SciTech Connect

    Johnson, M.M.; Nowack, G.P.

    1982-02-09

    The catalytic hydrodesulfurization of an organic sulfur compound contained in gasoline is carried out in the presence of a catalyst composition comprising catalytic grade alumina and a catalytic component at least one member of which is selected from the group consisting of molybdenum and tungsten. A catalytic promoter may also be present in the catalyst composition with at least one member of the catalytic promoter being selected from the group consisting of iron, cobalt and nickel. A suitable nitrogen compound is also contacted with the catalyst composition to at least partially suppress the saturation of olefins in the gasoline during the hydrodesulfurization process.

  6. Identification and origin of odorous sulfur compounds in cooked ham.

    PubMed

    Thomas, Caroline; Mercier, Frédéric; Tournayre, Pascal; Martin, Jean-Luc; Berdagué, Jean-Louis

    2014-07-15

    The aim of this work was to identify and gain further knowledge on the origin of sulfur compounds present in the volatile fraction of cooked ham, and on their role in the aroma of this product. To this end, we performed analyses by one- and two-dimensional gas chromatography coupled with mass spectrometry, and olfactometry. Among the odorant sulfur compounds identified, three furans present in trace amounts proved to have very intense odours responsible for the "meaty, cooked ham" notes of this pork product. They were 2-methyl-3-furanthiol, 2-methyl-3-(methyldithio)furan and bis(2-methyl-3-furyl) disulphide. Addition of thiamine or cysteine also enabled us to study the effect of these odour precursors on the formation of odorant furans during the cooking of ham. The results revealed a direct link between the thermal degradation of thiamine and the formation of these compounds. By contrast, addition of cysteine in the presence of fructose or xylose did not appreciably increase their production. PMID:24594176

  7. Portable instrument and method for detecting reduced sulfur compounds in a gas

    DOEpatents

    Gaffney, J.S.; Kelly, T.J.; Tanner, R.L.

    1983-06-01

    A portable real time instrument for detecting concentrations in the part per billion range of reduced sulfur compounds in a sample gas. Ozonized air or oxygen and reduced sulfur compounds in a sample gas stream react to produce chemiluminescence in a reaction chamber and the emitted light is filtered and observed by a photomultiplier to detect reduced sulfur compounds. Selective response to individual sulfur compounds is achieved by varying reaction chamber temperature and ozone and sample gas flows, and by the use of either air or oxygen as the ozone source gas.

  8. Scalping of light volatile sulfur compounds by wine closures.

    PubMed

    Silva, Maria A; Jourdes, Michaël; Darriet, Philippe; Teissedre, Pierre-Louis

    2012-11-01

    Closures have an important influence on wine quality during aging in a bottle. Closures have a direct impact on oxygen exposure and on volatiles scavenging in wine. Model wine solution soaking assays of several types of closures (i.e., natural and technical cork stoppers, synthetic closures, screw caps) with two important wine volatile sulfur compounds led to a considerable reduction in their levels. After 25 days, cork closures and synthetic closures, to a lesser extent, have significantly scavenged hydrogen sulfide and dimethyl sulfide. These compounds have a determinant impact on wine aging bouquet, being largely responsible for "reduced off-flavors". Hydrogen sulfide levels are often not well correlated with the exposure of wine to oxygen or with the permeability of the closure. Its preferential sorption by some types of closures may explain that behavior. Scalping phenomenon should be taken into account when studying wine post-bottling development. PMID:23072649

  9. Characterizing reduced sulfur compounds emissions from a swine concentrated animal feeding operation

    E-print Network

    Aneja, Viney P.

    Characterizing reduced sulfur compounds emissions from a swine concentrated animal feeding emissions from swine CAFOs. This article provides a comprehensive analysis of RSCs emissions from a swine sulfide CAFO emissions Swine a b s t r a c t Reduced sulfur compounds (RSCs) emissions from concentrated

  10. Influence of different sulfur compounds on corrosion due to naphthenic acid

    Microsoft Academic Search

    Omar Yépez

    2005-01-01

    The influence of different sulfur compounds on corrosion due to naphthenic acid was studied by means of the new method FeNCOR™. It was found that such influence occurs after the reduction of the given sulfur compound by the cathodic reaction of the overall process of naphthenic acid corrosion. When the reduction product is H2S the formation of a potentially protective

  11. Organo-sulfur compounds in sediments of the Puget Sound basin

    Microsoft Academic Search

    Timothy S. Bates; Roy Carpenter

    1979-01-01

    Sediment samples from a variety of different environments were analyzed for organo-sulfur compounds (OSC) to provide the first characterization of the amounts and types of these compounds in sediments of the greater Puget Sound basin. A gas Chromatograph equipped with a sulfur specific flame photometric detector was used to quantify individual OSC. Compositions of OSC mixtures were essentially constant throughout

  12. On a Negative-Ion Concept of EP Action of Organo-Sulfur Compounds

    Microsoft Academic Search

    Cz. Kajdas

    1985-01-01

    To understand the chemical behavior of EP additives in sliding contacts, the concept of an anionic mechanism of the elementary sulfur and organo-sulfur compounds has been proposed. The model is based upon the ionization of these compounds by the action of exoelectrons. It has been shown that disulfides exhibit more efficient EP performance than monosulfides because lower energy is needed

  13. Catalytic oxidation of gaseous reduced sulfur compounds using coal fly ash

    Microsoft Academic Search

    James R Kastner; K. C Das; Nathan D Melear

    2002-01-01

    Activated carbon has been shown to oxidize reduced sulfur compounds, but in many cases it is too costly for large-scale environmental remediation applications. Alternatively, we theorized that coal fly ash, given its high metal content and the presence of carbon could act as an inexpensive catalytic oxidizer of reduced sulfur compounds for “odor” removal. Initial results indicate that coal fly

  14. ATP-sulfurylase, sulfur-compounds, and plant stress tolerance

    PubMed Central

    Anjum, Naser A.; Gill, Ritu; Kaushik, Manjeri; Hasanuzzaman, Mirza; Pereira, Eduarda; Ahmad, Iqbal; Tuteja, Narendra; Gill, Sarvajeet S.

    2015-01-01

    Sulfur (S) stands fourth in the list of major plant nutrients after N, P, and K. Sulfate (SO42-), a form of soil-S taken up by plant roots is metabolically inert. As the first committed step of S-assimilation, ATP-sulfurylase (ATP-S) catalyzes SO42--activation and yields activated high-energy compound adenosine-5?-phosphosulfate that is reduced to sulfide (S2-) and incorporated into cysteine (Cys). In turn, Cys acts as a precursor or donor of reduced S for a range of S-compounds such as methionine (Met), glutathione (GSH), homo-GSH (h-GSH), and phytochelatins (PCs). Among S-compounds, GSH, h-GSH, and PCs are known for their involvement in plant tolerance to varied abiotic stresses, Cys is a major component of GSH, h-GSH, and PCs; whereas, several key stress-metabolites such as ethylene, are controlled by Met through its first metabolite S-adenosylmethionine. With the major aim of briefly highlighting S-compound-mediated role of ATP-S in plant stress tolerance, this paper: (a) overviews ATP-S structure/chemistry and occurrence, (b) appraises recent literature available on ATP-S roles and regulations, and underlying mechanisms in plant abiotic and biotic stress tolerance, (c) summarizes ATP-S-intrinsic regulation by major S-compounds, and (d) highlights major open-questions in the present context. Future research in the current direction can be devised based on the discussion outcomes. PMID:25904923

  15. 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.

  16. Lunar sulfur

    NASA Astrophysics Data System (ADS)

    Kuck, David L.

    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.

  17. Method to enhance removal of sulfur compounds by slag

    SciTech Connect

    Breen, B.P.; Gabrielson, J.E.; Pohl, J.H.

    1989-07-18

    This patent describes a method for burning carbonaceous material containing sulfur and ash in a slagging combustor so that the sulfur is captured and rejected with the slag without interrupting slag flow and without accelerating corrosion. It comprises the steps of: injecting a carbonaceous material containing sulfur and ash into a slagging combustor; causing the carbonaceous material to burn and form a slag; maintaining the slag at a temperature within the range of 2000{sup 0} to 2500{sup 0} and at a stoichiometry less than oxidizing; maintaining a percentage of air available for combustion within the range of 80% to 120%; and adding up to 20 percent auxiliary fuel to control and establish combustion conditions necessary for operation.

  18. Measurements of sulfur compounds in CO 2 by diode laser atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Franzke, J.; Stancu, D. G.; Niemax, K.

    2003-07-01

    Two simple methods for the analysis of the total concentration of sulfur in CO 2 by diode laser atomic absorption spectrometry of excited, metastable sulfur atoms in a direct current discharge are presented. In the first method, the CO 2 sample gas is mixed with the plasma gas (Ar or He) while the second is based on reproducible measurements of the sulfur released from the walls in a helium discharge after being deposited as a result of operating the discharge in pure CO 2 sample gas. The detection limits obtained satisfy the requirements for the control of sulfur compounds in CO 2 used in the food and beverage industry.

  19. A STUDY TO IMPROVE EPA METHODS 15 AND 16 FOR REDUCED SULFUR COMPOUNDS

    EPA Science Inventory

    EPA source test methods for reduced sulfur compounds, Method 15 for Claus sulfur recovery plants and Method 16 for Kraft pulp mills have been evaluated, and information is provided for the user. Techniques and procedures for the gas chromatographic measurement of hydrogen sulfide...

  20. BIOGENIC SULFUR COMPOUNDS IN COASTAL ATMOSPHERES OF NORTH CAROLINA

    EPA Science Inventory

    Atmospheric H2S, SO2, and particulate SO4(-2), Na(+), C1(-), NH4(-), and NO3(-) were measured in two experiments on the North Carolina coast to determine the levels of biogenic sulfur species at marsh and estuarine locations where dissimilatory bacterial sulfate reduction produce...

  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. Volatile Sulfur Compounds as a Predictor for Esophagogastroduodenal Mucosal Injury

    PubMed Central

    Yoo, Seung Hee; Jung, Hyeon Sik; Sohn, Wee Sik; Kim, Bong Hwan; Ku, Bon Ho; Kim, Young Saeng; Park, Sang Woon

    2008-01-01

    Background/Aims Halitosis is a symptom that bothers patients more socially than medically and its pathogenic mechanisms are unclear and treatment armamenterium is limited. Clinicians generally ignored active interventions. Since halitosis is closely associated with volatile sulfur compounds (VSCs), we used a Halimeter and gas chromatography to measure VSCs in patients with Helicobacter-pylori (H. pylori)-associated gastric diseases. Methods We categorized 72 patients with H. pylori infection into two groups based on their endoscopic findings: a non-erosive mucosal group (NE, n=24) and an erosive mucosal group (E, n=48). Halitosis was objectively assessed by applying either a Halimeter to breath air or gas chromatography to gastric juice. Simultaneously, the expression of VSC-generating enzyme was measured with reverse-transcriptase PCR using mRNA isolated from biopsy tissues. Results The levels of VSCs in exhaled breaths or aspirated gastric juices differed significantly between the NE and E groups (p<0.00001), suggesting that VSCs might reflect eroded epithelial damage induced by H. pylori infection. The expressions of cystathionine ?-synthase (CBS) and cystathionine ?-lyase (CSE) were broadly consistent with the degree of mucosal injury. Conclusions Erosive changes in esophagogastroduodenal mucosa were strongly correlated with increased VSC levels, suggesting that halitosis might result from H. pylori-associated erosive lesions. PMID:20485620

  3. Metal phosphate reduction in the presence of gaseous sulfur compounds

    SciTech Connect

    Kriklivyi, D.I.; Klimovich, M.A.; Petrovskaya, N.A.

    1992-05-20

    The phosphorus used for combining with calcium oxide is usually obtained by means of thermally stable acidic or amphoteric oxide additives, i.e., almost only silicon dioxide, aluminum oxide, and aluminum silicate. The reduction of tricalcium phosphate and natural calcium phosphate ores by natural gas in the presence of such additives at an acidity coefficient (C{sub a}) of 1 may be brought to completion in 1-3 h. Increasing the C{sub a} of a charge to 1.5-3 facilitates solid-phase reduction of low-melting phosphate ores and raises the phosphorus vaporization rate. However solid-phase additives in the phosphate and their high consumption increase charge preparation cost and lower equipment efficiency. The purpose of this paper is to study a replacement of solid-phase fluxes by volatiles that can combine with basic oxides. This approach was examined theoretically as to the possibility of replacing solid-phase fluxes by hydrogen chloride and volatile sulfur compounds. The latter is often found in natural gases that could be used in the phosphorus industry without prior purification. 15 refs., 3 figs., 3 tabs.

  4. Antimicrobial activity of sulfur compounds derived from cabbage.

    PubMed

    Kyung, K H; Fleming, H P

    1997-01-01

    Selected sulfur compounds found in cabbage and its fermentation product, sauerkraut, were tested for minimum inhibitory concentration (MIC) against growth of 15 species of bacteria and 4 species of yeasts. S-Methyl-L-cysteine sulfoxide, sinigrin, and dimethyl sulfide at 500 ppm were not inhibitory to any of the bacteria and yeasts tested. Dimethyl disulfide at 500 ppm retarded some, but did not prevent growth of any of the test microorganisms. Dimethyl trisulfide had an MIC to bacteria of 200 ppm and to yeast of 20 ppm. Methyl methanethiosulfinate had an MIC between 50 and 200 ppm for all bacteria, and between 6 and 10 ppm for all yeasts tested. Methyl methanethiosulfonate had an MIC between 20 and 100 ppm for bacteria and between 50 and 500 ppm for yeasts. Allyl isothiocyanate had an MIC between 50 and 500 ppm for bacteria and between 1 and 4 ppm for yeasts. Methyl methanethiosulfinate was 10 to 100 times more inhibitory against Listeria monocytogenes at pH values of 5, 6, and 7 and was much less influenced by pH than was sodium benzoate. PMID:10465044

  5. DSRP, Direct Sulfur Production

    SciTech Connect

    Gangwal, S.K.; McMichael, W.J.; Agarwal, S.K.; Jang, B.L.; Howe, G.B. [Research Triangle Inst., Research Triangle Park, NC (United States); Chen, D.H.; Hopper, J.R. [Lamar Univ., Beaumont, TX (United States)

    1993-08-01

    Hot-gas desulfurization processes for IGCC and other advanced power applications utilize regenerable mixed-metal oxide sorbents to remove hydrogen sulfide (H{sub 2}S) from raw coal gas. Regeneration of these sorbents produces an off-gas typically containing I to 3 percent sulfur dioxide (SO{sub 2}). Production of elemental sulfur is a highly desirable option for the ultimate disposal of the SO{sub 2} content of this off-gas. Elemental sulfur, an essential industrial commodity, is easily stored and transported. As shown in Figure 1, the DSRP consists of two catalytic reactors, each followed by a sulfur condenser. Hot regenerator off-gas is mixed with a hot coal-gas slip stream and fed to the first DSRP reactor. Approximately 95 percent of the sulfur gas in the inlet stream of the first reactor is converted to elemental sulfur. The outlet gas of the first DSRP reactor is cooled, condensing out sulfur. The gas could be recycled after the Stage I condenser. Alteratively, by adjusting the proportion of coal gas to regenerator off-gas, the effluent composition of the first reactor can be controlled to produce an H{sub 2}S-to-SO{sub 2} ratio of 2 to 1 at 95 percent sulfur conversion. The cooled gas stream is then passed to the second DSRP reactor where 80 to 90 percent of the remaining sulfur compounds are converted to elemental sulfur via the modified Claus reaction at high pressure. The total efficiency of the two reactors for the conversion of sulfur compounds to elemental sulfur is projected to be about 99.5 percent.

  6. [Metabolism and gene regulation of important volatile sulfur compounds in wine--a review].

    PubMed

    Ma, Jie; Liu, Yanlin

    2011-01-01

    Wine microbes can produce volatile sulfur compounds during wine fermentation. The main volatile sulfur compounds found in wine are hydrogen sulfide, sulfides, thiol, thiolesters, sulful-containing fusel alcohols, sulful-containing heterocycles and "fruity volatile thiols". They can affect the wine flavor dramatically. Metabolism pathways and related gene regulations of these compounds are discussed in this review. This review also proposes that research on wine microbes is an effective way to increase concentrations of flavor compounds in wine and inhibit undesirable off-flavor compounds at the same time. PMID:21465784

  7. Immersed effects of Ta and Zr compounds on activity of oxygen reduction reaction in sulfuric acid

    NASA Astrophysics Data System (ADS)

    Matsuzawa, Koichi; Nozawa, Kazuhiro; Yamauchi, Kyosuke; Ishihara, Akimitsu; Mitsushima, Shigenori; Ota, Ken-ichiro

    2013-03-01

    The immersed effects of Ta and Zr compounds (Ta-CNO and Zr-CNO) on the activity of oxygen reduction reaction (ORR) have been investigated in the sulfuric acid. The concentration of Zr on Zr-CNO was higher than that of Pt on Pt black. The concentration of Ta on Ta-CNO was almost the same as that of Pt on Pt black in sulfuric acid. The catalytic activity of Zr-CNO for the ORR decreased with time. In contrast, the catalytic activity of Ta-CNO for the ORR was maintained up to 1050 h in the sulfuric acid.

  8. Ab initio study of hypervalent sulfur hydrides as model intermediates in the interconversion reactions of compounds containing sulfur-sulfur bonds

    SciTech Connect

    Laitinen, R.S.; Pakkanen, T.A.; Steudel, R.

    1987-02-04

    Ab initio MO calculations involving the 4-31G* basis set have been used to predict the equilibrium geometries of the hypervalent sulfur hydrides H/sub 2/SS, (HS)/sub 2/SS, H/sub 2/S(SH)/sub 2/, H/sub 2/S(SSH)/sub 2/, and the cyclic H/sub 4/S/sub 4/. The energy changes in their formation from appropriate sulfanes H/sub 2/S/sub n/ (n = 1-4) have been studied with the 6-31G* basis set including the correction for the electron correlation by the second- and third-order Moeller-Plesset perturbation theory. The results are used to discuss the possible pathways in the interconversion reactions between various sulfur compounds containing cumulated SS bonds, for example, the formation of S/sub 7/ from S/sub 8/ for which hypervalent intermediates have been proposed recently. Comparison with experimental evidence is made whenever possible.

  9. Anti-Inflammatory Activity of Sulfur-Containing Compounds from Garlic

    PubMed Central

    Lee, Da Yeon; Li, Hua; Lim, Hyo Jin; Lee, Hwa Jin; Jeon, Raok

    2012-01-01

    Abstract We identified four anti-inflammatory sulfur-containing compounds from garlic, and their chemical structures were identified as Z- and E-ajoene and oxidized sulfonyl derivatives of ajoene. The sulfur compounds inhibited the production of nitric oxide (NO) and prostaglandin E2 (PGE2) and the expression of the pro-inflammatory cytokines tumor necrosis factor-?, interleukin-1?, and interleukin-6 in lipopolysaccharide (LPS)-activated macrophages. Western blotting and reverse transcription–polymerase chain reaction analysis demonstrated that these sulfur compounds attenuated the LPS-induced expression of the inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins and mRNA. Moreover, these sulfur-containing compounds suppressed the nuclear factor-?B (NF-?B) transcriptional activity and the degradation of inhibitory-?B? in LPS-activated macrophages. Furthermore, we observed that they markedly inhibited the LPS-induced phosphorylations of p38 mitogen-activated protein kinases and extracellular signal-regulated kinases (ERK) at 20??M. These data demonstrate that the sulfur compounds from garlic, (Z, E)-ajoene and their sulfonyl analogs, can suppress the LPS-induced production of NO/PGE2 and the expression of iNOS/COX-2 genes by inhibiting the NF-?B activation and the phosphorylations of p38 and ERK. Taken together, these data show that Z- and E-ajoene and their sulfonyl analogs from garlic might have anti-inflammatory therapeutic potential. PMID:23057778

  10. High-Pressure Iron-Sulfur Compounds and their Implications for the Mineralogy of the Sulfur-Bearing Iron Cores

    NASA Astrophysics Data System (ADS)

    Koch-Müller, M.; Fei, Y.; Wirth, R.; Bertka, C. M.

    2003-04-01

    Sulfur is considered to be the possible light element that alloys with iron in the terrestrial planetary cores. Prior to 1997, end-members Fe and FeS are used to model the cores because no intermediate compounds between Fe and FeS were found. Recent high-pressure experiments revealed that at least three new iron-sulfur compounds, Fe3S2, Fe2S, and Fe3S, were formed at high pressures [Fei et al. Science 275, 1621-1623, 1997; Fei et al. Am. Mineral. 85, 1830-1833, 2000]. Because the physical properties of a planetary core are governed by its mineralogy, it is essential to fully characterize these compounds. We synthesized Fe3S,Fe3S2 and Fe2S iron-sulfur compounds at 22 GPa and 950 to 1050 oC and characterized them by X-ray powder diffraction, electron microprobe analyses and transmission electron microscopy. Fe3S is a quenchable phase in the Fe-S system. It is isostructural with Cr3P. The X-ray diffraction patterns for the Fe3S2 and Fe2S samples are complicated and cannot be indexed with a single phase. TEM and X-ray diffraction measurements show that the samples are extremely fine grained and multi phase products. Fe2S exists as a phase in the Fe-S system, but it is unstable at ambient condition. The TEM measurements revealed that it decomposes to Fe3S and FeS. However, the Fe2S phase was partially survived during quenching. X-ray diffraction data indicated that Fe2S exists in two polymorphs. Both polymorphs have the hexagonal cell. Their possible structure analogs are Ti2P and Fe2P. The Fe3S2 phase is of non-stoichiometric nature. The exact composition of the Fe3S2 phase synthesized in this study is close to Fe3.2S2. It is isostructural with TiP0.63 (=Ti3.18P2). During quenching it partially decomposes to FeS and Fe2S. The stability fields and the structures of the Fe2S and Fe3.2S2 phases need to be further investigated by in-situ measurements. From the TEM measurements, we also found single crystals of cubic Fe2S3 in the quenched Fe3.2S2 sample. However, the quantity of this phase is very small (1 wt% based on the quantitative phase analysis).

  11. Air/water oxidative desulfurization of coal and sulfur-containing compounds

    NASA Astrophysics Data System (ADS)

    Warzinski, R. P.; Freidman, S.; LaCount, R. B.

    1981-02-01

    Air/water Oxydesulfurization has been demonstrated in autoclave experiments at the Pittsburgh Energy Technology Center for various coals representative of the major U. S. coal basins. The applicability at present of this treatment for producing an environmentally acceptable coal has been restricted by recently proposed SO2 emission standards for utility boilers. The product would, however, be attractive to the many smaller industrial coal users who cannot afford to operate and maintain flue gas desulfurization systems. It is also possible that the utility industry could realize a benefit by using chemically cleaned coal with partial flue gas scrubbing. The higher cost of the cleaned coal would be offset by the reduction in capital and operating costs resulting from decreased FGD requirements. The susceptibility of sulfur in coal to oxidative removal varies with the nature of the sulfur-containing species. The inorganic sulfur compounds, primarily pyrite, marcasite, and iron sulfate, are more amenable to treatment than the organically bound sulfur which exhibits varying degrees of resistance depending on its chemical environment. Air/water Oxydesulfurization consistently removes in excess of 90 percent of the pyritic sulfur; the extent and efficiency of organic sulfur removal however, depends on the type of coal and severity of treatment used. In general, the organic sulfur of the higher rank coals exhibits more resistance to treatment than that of the lower rank coals; however, the accompanying heating value is greater for the latter. Similar treatment of sulfur-containing model compounds further illustrates the relative susceptibilities of different chemical species to oxidation. Application of these data to the understanding of the complex chemistry involved in the treatment of coal is a preliminary step toward improving the efficiency of Oxydesulfurization.

  12. Sulfur/lithium-insertion compound composite cathodes for Li-S batteries

    NASA Astrophysics Data System (ADS)

    Su, Yu-Sheng; Manthiram, Arumugam

    2014-12-01

    A part of carbon additives in sulfur cathodes is replaced by lithium-insertion compounds as they can contribute extra capacity and increase the overall energy density. Accordingly, VO2(B) and TiS2 were incorporated into sulfur cathodes as they can work within the same voltage window as that of sulfur. However, VO2(B) was found to be incompatible with the glyme-based electrolytes that are usually used in Li-S cells, but TiS2 performs well while coupled with sulfur. The S/C/TiS2 composite cathode delivers 252 mAh g-1 more than that of pristine sulfur cathode (1334 mAh g-1 vs. 1082 mAh g-1). The increased capacity is not only due to the contribution by TiS2 itself but also due to a better active-material dispersion and utilization. Serving as active reaction sites during cycling, TiS2 suppresses agglomeration of sulfur and facilitates better ionic/electronic transport within the cathode structure. This composite cathode design provides another direction for Li-S batteries to improve the overall energy density.

  13. Low Temperature Sorbents for removal of Sulfur Compounds from fluid feed Streams

    SciTech Connect

    Siriwardane, Ranjan

    1999-09-30

    A sorbent material is provided comprising a material reactive with sulfur, a binder unreactive with sulfur and an inert material, wherein the sorbent absorbs the sulfur at temperatures between 30 and 200 C. Sulfur absorption capacity as high as 22 weight percent has been observed with these materials.

  14. Uptake of Small Organic Compounds by Sulfuric Acid Aerosols: Dissolution and Reaction

    NASA Technical Reports Server (NTRS)

    Iraci, L. T.; Michelsen, R. R.; Ashbourn, S. F. M.; Staton, S. J. R.

    2003-01-01

    To assess the role of oxygenated volatile organic compounds in the upper troposphere and lower stratosphere, the interactions of a series of small organic compounds with low-temperature aqueous sulfuric acid will be evaluated. The total amount of organic material which may be taken up from the gas phase by dissolution, surface layer formation, and reaction during the particle lifetime will be quantified. Our current results for acetaldehyde uptake on 40 - 80 wt% sulfuric acid solutions will be compared to those of methanol, formaldehyde, and acetone to investigate the relationships between chemical functionality and heterogeneous activity. Where possible, equilibrium uptake will be ascribed to component pathways (hydration, protonation, etc.) to facilitate evaluation of other species not yet studied in low temperature aqueous sulfuric acid.

  15. Contribution of sulfuric acid and oxidized organic compounds to particle formation and growth

    NASA Astrophysics Data System (ADS)

    Riccobono, F.; Rondo, L.; Sipilä, M.; Barmet, P.; Curtius, J.; Dommen, J.; Ehn, M.; Ehrhart, S.; Kulmala, M.; Kürten, A.; Mikkilä, J.; Petäjä, T.; Weingartner, E.; Baltensperger, U.

    2012-05-01

    Lack of knowledge about the mechanisms underlying new particle formation and their subsequent growth is one of the main causes for the large uncertainty in estimating the radiative forcing of atmospheric aerosols in global models. We performed chamber experiments designed to study the contributions of sulfuric acid and organic vapors to formation and to the early growth of nucleated particles, respectively. Distinct experiments in the presence of two different organic precursors (1,3,5-trimethylbenzene and ?-pinene) showed the ability of these compounds to reproduce the formation rates observed in the low troposphere. These results were obtained measuring the sulfuric acid concentrations with two Chemical Ionization Mass Spectrometers confirming the results of a previous study which modeled the sulfuric acid concentrations in presence of 1,3,5-trimethylbenzene. New analysis methods were applied to the data collected with a Condensation Particle Counter battery and a Scanning Mobility Particle Sizer, allowing the assessment of the size resolved growth rates of freshly nucleated particles. The effect of organic vapors on particle growth was investigated by means of the growth rate enhancement factor (?), defined as the ratio between the measured growth rate in the presence of ?-pinene and the kinetically limited growth rate of the sulfuric acid and water system. The observed ? values indicate that the growth is dominated by organic compounds already at particle diameters of 2 nm. Both the absolute growth rates and ? showed a strong dependence on particle size supporting the nano-Köhler theory. Moreover, the separation of the contributions from sulfuric acid and organic compounds to particles growth reveals that the organic contribution seems to be enhanced by the sulfuric acid concentration. The size resolved growth analysis finally indicates that both condensation of oxidized organic compounds and reactive uptake contribute to particle growth.

  16. Contribution of sulfuric acid and oxidized organic compounds to particle formation and growth

    NASA Astrophysics Data System (ADS)

    Riccobono, F.; Rondo, L.; Sipilä, M.; Barmet, P.; Curtius, J.; Dommen, J.; Ehn, M.; Ehrhart, S.; Kulmala, M.; Kürten, A.; Mikkilä, J.; Paasonen, P.; Petäjä, T.; Weingartner, E.; Baltensperger, U.

    2012-10-01

    Lack of knowledge about the mechanisms underlying new particle formation and their subsequent growth is one of the main causes for the large uncertainty in estimating the radiative forcing of atmospheric aerosols in global models. We performed chamber experiments designed to study the contributions of sulfuric acid and organic vapors to the formation and early growth of nucleated particles. Distinct experiments in the presence of two different organic precursors (1,3,5-trimethylbenzene and ?-pinene) showed the ability of these compounds to reproduce the formation rates observed in the low troposphere. These results were obtained measuring the sulfuric acid concentrations with two chemical ionization mass spectrometers confirming the results of a previous study which modeled the sulfuric acid concentrations in presence of 1,3,5-trimethylbenzene. New analysis methods were applied to the data collected with a condensation particle counter battery and a scanning mobility particle sizer, allowing the assessment of the size resolved growth rates of freshly nucleated particles. The effect of organic vapors on particle growth was investigated by means of the growth rate enhancement factor (?), defined as the ratio between the measured growth rate in the presence of ?-pinene and the kinetically limited growth rate of the sulfuric acid and water system. The observed ? values indicate that the growth is already dominated by organic compounds at particle diameters of 2 nm. Both the absolute growth rates and ? showed a strong dependence on particle size, supporting the nano-Köhler theory. Moreover, the separation of the contributions from sulfuric acid and organic compounds to particle growth reveals that the organic contribution seems to be enhanced by the sulfuric acid concentration. Finally, the size resolved growth analysis indicates that both condensation of oxidized organic compounds and reactive uptake contribute to particle growth.

  17. Abatement of volatile organic sulfur compounds in odorous emissions from the bio-industry.

    PubMed

    Smet, E; Van Langenhove, H

    1998-01-01

    Compounds of interest in this work are methanethiol (MeSH), dimethyl sulfide (Me2S), dimethyl polysulfides (Me2Sx) and carbon disulfide (CS2) since these volatiles have been identified as predominant odorants in the emission of a wide range of activities in the bio-industry (e.g. aerobic waste water treatment plants, composting plants, rendering plants). In these processes, the occurrence of volatile organic sulfur compounds is mainly related to the presence of anaerobic microsites with consecutive fermentation of sulfur containing organic material and/or to the breakdown of the latter due to thermal heating. Due to the chemical complexity of these low-concentrated waste gas streams and the high flow rates to be handled, mainly biotechnological techniques and scrubbers can be used to control the odour emission. When using biofilters or trickling filters, inoculation with specific microorganisms and pH-control strategies should be implemented to optimise the removal of volatile organic sulfur compounds. In scrubbers, chemical oxidation of the volatile organic sulfur compounds can be obtained by dosing hypochlorite, ozone or hydrogen peroxide to the scrubbing liquid. However, optimal operational conditions for each of these abatement techniques requires a further research in order to guarantee a long-term and efficient overall odour abatement. PMID:10022070

  18. Extraction of odorizing sulfur compounds from natural gas and reodorization therewith

    Microsoft Academic Search

    A. Kruis; H. Karwat

    1975-01-01

    Linde AG's new approach permits natural gas odorants to be removed from natural gas before it is liquefied by peakshaving plants and to be saved for reinjection when the natural gas is vaporized. The odorants, mainly organic sulfur compounds, are removed by scrubbing natural gas prior to natural gas liquefaction and then freed of other impurities such as COâ, HâO,

  19. Finishing process for the removal of sulfur compounds from a gas steam

    SciTech Connect

    Tazuma, J.J.; Frech, K.J.

    1984-07-31

    The invention relates to a finishing process for the removal of low level concentrations of mercaptans, sulfides and disulfides from a gas stream, especially a natural gas stream. The sulfur compounds are washed from the gas stream with a solution containing hydrogen peroxide, sodium carbonate or sodium hydroxide, and ammonia or an amine.

  20. Preparation of the Modified Y Zeolite for Removal of Organic Sulfur Compounds from FCC Gasoline

    Microsoft Academic Search

    H. Zhu; L. Song; D. Liu; Z. Sun

    2011-01-01

    Ce(IV)-loaded modified NaY (NH4Y) zeolite was prepared for selective adsorptive desulfurization from fluid catalytic cracked (FCC) gasoline. Ce(?)Y was obtained from NH4Y using a liquid-phase ion-exchange method. Ce(IV)Y was obtained from calcining Ce(?)Y at 550°C. The structures of the Ce(IV)Y and NaY samples, selective adsorption of organic sulfur compounds on Ce(IV)Y and NaY zeolite, sulfur content of FCC gasoline, and

  1. Reaction of hydroxy and carbonyl compounds with sulfur tetrafluoride. XVI. Reactions of vicinal dihydric alcohols with sulfur tetrafluoride

    SciTech Connect

    Burmakov, A.I.; Hassanein, S.M.; Kunshenko, B.V.; Alekseeva, L.A.; Yagupol'skii, L.M.

    1986-11-20

    During the action of sulfur tetrafluoride on ethanediol, d,l-1,2-propanediol, d,l-3,3,3-trifluoro-1,2-propanediol regioselective substitution of one of the hydroxyl groups by a fluorine atom occurs, depending on the electronic nature of the groups present in the molecule. The second hydroxy group in converted into a fluorosulfite group.

  2. Determination of sulfur compounds in coal by mass spectrometry, correlated with XANES and XPS

    SciTech Connect

    Winans, R.E.; Melnikov, P.E.; Dyrkacz, G.R.; Bloomquist, C.A.A. [Argonne National Lab., IL (United States); Gorbaty, M.L.; Kelemen, S.R.; George, G.N. [Exxon Research and Engineering Co., Annandale, NJ (United States)

    1993-03-01

    The objective of this study is to identify important organic sulfur-containing compounds in the Argonne Premium Coals and in selected, separated coal macerals. In-source, desorption/pyrolysis high resolution mass spectrometry is being used to characterize the volatile species of whole coals, macerals, and their extracts. To examine the possibility of secondary reactions and undesirable selectivity, the MS data is compared to data from direct techniques, XANES and XPS. The MS results con-elate very well which supports the suggestion that the species seen are indigenous to the original sample. Therefore, specific structural assignments to the sulfur species can be made. Quantitative speciation of organic sulfur in coals has been accomplished by both XANES and XPS with what appears to be good reliability. Mass spectrometry approaches provide more detailed molecular information, but suffer from problems with sampling. In the past we have found it difficult to isolate aliphatic sulfur compounds by thermal desorption or pyrolysis due to their thermal transformation to aromatic species. However, recently we have found that with in-source pyrolysis the occurrence of secondary reactions is reduced significantly. Results from both a selected setof the Argonne Premium Coal Samples and a set of three macerals from the Listen-Stockton coal (APCS 7) are discussed.

  3. Determination of sulfur compounds in coal by mass spectrometry, correlated with XANES and XPS

    SciTech Connect

    Winans, R.E.; Melnikov, P.E.; Dyrkacz, G.R.; Bloomquist, C.A.A. (Argonne National Lab., IL (United States)); Gorbaty, M.L.; Kelemen, S.R.; George, G.N. (Exxon Research and Engineering Co., Annandale, NJ (United States))

    1993-01-01

    The objective of this study is to identify important organic sulfur-containing compounds in the Argonne Premium Coals and in selected, separated coal macerals. In-source, desorption/pyrolysis high resolution mass spectrometry is being used to characterize the volatile species of whole coals, macerals, and their extracts. To examine the possibility of secondary reactions and undesirable selectivity, the MS data is compared to data from direct techniques, XANES and XPS. The MS results con-elate very well which supports the suggestion that the species seen are indigenous to the original sample. Therefore, specific structural assignments to the sulfur species can be made. Quantitative speciation of organic sulfur in coals has been accomplished by both XANES and XPS with what appears to be good reliability. Mass spectrometry approaches provide more detailed molecular information, but suffer from problems with sampling. In the past we have found it difficult to isolate aliphatic sulfur compounds by thermal desorption or pyrolysis due to their thermal transformation to aromatic species. However, recently we have found that with in-source pyrolysis the occurrence of secondary reactions is reduced significantly. Results from both a selected setof the Argonne Premium Coal Samples and a set of three macerals from the Listen-Stockton coal (APCS 7) are discussed.

  4. EVALUATION OF TECHNIQUES FOR MEASURING BIOGENIC AIRBORNE SULFUR COMPOUNDS, CEDAR ISLAND FIELD STUDY, 1977

    EPA Science Inventory

    Sulfur in both gaseous and particulate form has been measured near biogenic sources using new measurement techniques. The preconcentration of gaseous sulfur on gold-coated glass beads followed by desorption into a flame photometric detection for sulfur is shown to have a detectio...

  5. Defluorination of organofluorine sulfur compounds by Pseudomonas sp. strain D2

    SciTech Connect

    Key, B.D.; Criddle, C.S. [Michigan State Univ., East Lansing, MI (United States)] [Michigan State Univ., East Lansing, MI (United States); Howell, R.D. [3M Environmental Technology and Safety Services, St. Paul, MN (United States)] [3M Environmental Technology and Safety Services, St. Paul, MN (United States)

    1998-08-01

    Little is known of the potential for biodegradation of fluorinated sulfonates. Because of the apparent stability of fluorinated organics, their bioactivity, and their potential for accumulation in the environment, it is important to understand their environmental fate and the mechanisms by which they might be degraded. To evaluate this potential, the following model compounds were selected: difluoromethane sulfonate (DFMS), trifluoromethane sulfonate (TFMS), 2,2,2-trifluoroethane sulfonate (TES), perfluorooctane sulfonate (PFOS), and 1H,1H,2H,2H-perfluorooctane sulfonate (H-PFOS). A laboratory isolate designated Pseudomonas sp. strain D2 completely defluorinated DFMS under aerobic sulfur-limiting conditions in a defined mineral medium. Strain D2 utilized DFMS as the sole source of sulfur, but not as a source of carbon or energy. DFMS utilization was inhibited by other forms of sulfur, and noncompetitive inhibition kinetics were observed, with K{sub i}-values of 3--4 {micro}M for sulfate, sulfite, methane sulfonate, and cystine. Strain D2 was subsequently used to evaluate degradation of other fluorinated sulfonates. Growth and defluorination were only observed for those compounds containing hydrogen (TES and H-PFOS). TFMS and PFOS were not degraded. TES was completely defluorinated, and H-PFOS was partially defluorinated. No volatile transformation products were detected for TES or DFMS, but six volatile products were detected for H-PFOS. All of the volatile products contained oxygen and fluorine, but not sulfur. This is the first report of defluorination of fluorinated sulfonates, a linkage between sulfur assimilation and defluorination, and generation of volatile fluorinated biotransformation products.

  6. Removal of sulfur compounds from petroleum re?nery wastewater through adsorption on modified activated carbon.

    PubMed

    Ben Hariz, Ichrak; Al Ayni, Foued; Monser, Lotfi

    2014-01-01

    The adsorption of sulfur compounds from petroleum refinery wastewater on a chemically modified activated carbon (MAC) was investigated. The modification technique (nitric acid, hydrogen peroxide and thermal modification) enhanced the removal capacity of carbon and therefore decreases cost-effective removal of sulfide from refinery wastewater. Adsorption equilibrium and kinetics data were determined for sulfur removal from real re?nery wastewater. The data were evaluated according to several adsorption isotherm and kinetics models. The Freundlich isotherm fitted well with the equilibrium data of sulfur on different adsorbents, whereas the kinetics data were best fitted by the pseudo-second-order model. Insights of sulfide removal mechanisms indicated that the sorption was controlled through the intraparticle diffusion mechanism with a significant contribution of film diffusion. The MAC adsorbent was found to have an effective removal capacity of approximately 2.5 times that of non-modified carbon. Using different MAC, sulfides were eliminated with a removal capacity of 52 mg g(-1). Therefore, MAC can be utilized as an effective and less expensive adsorbent for the reduction of sulfur in refinery wastewater. PMID:25353943

  7. Removal of sulfur compounds from diesel using ArF laser and oxygen.

    PubMed

    Gondal, M A; Siddiqui, M N; Al-Hooshani, K

    2013-01-01

    A laser-based technique for deep desulfurization of diesel and other hydrocarbon fuels by removal of dimethyldibenzothiophene (DMDBT), a persistent sulfur contaminant in fuel oils has been developed. We report a selective laser excitation of DMDBT in diesel and model compounds such as n-hexane in a reaction chamber under oxygen environment where oxidative reactions can take place. ArF laser emitting at 193 nm was employed for excitation of oxygen and DMDBT, while for process optimization, the laser energy was varied from 50 to 200 mJ/cm(2). The laser-irradiated DMDBT solution under continuous oxygen flow was analyzed by UV absorption spectrometer to determine the photochemical oxidative degradation of DMDBT. In just 5 min of laser irradiation time, almost 95% DMDBT was depleted in a diesel containing 200 ppm of DMDBT. This article provides a new method for the removal of sulfur compounds from diesel by laser based photochemical process. PMID:23947704

  8. Molecular Structure of sulfur

    NSDL National Science Digital Library

    2002-08-26

    The discoverer of sulfur remains anonymous because of lack of records. However, one can trace back to the discovery of R.W. Wood when he used ultra-violet rays to find a sulfur deposit near the crater of Aristarchus on the moon. Sulfur is also found in meteorites. In the United States, Sulfur can be found along the Gulf Coast in wells sunk along salt domes. It is brought to the surface using the Frasch Process in which heated water is forced into the wells and melts the surface. Sulfur may also be found in volcanos or hot springs. Other uses of Sulfur include making phosphatic fertilizers, matches, and medicine. The mineral is a good insulator and takes part in bleaching dried fruit. Sulfur is a minor constitute of body fluids, fats, and skeletal minerals. It can be said that Sulfur is essential to life.

  9. Regional characteristics of dry deposition of sulfur and nitrogen compounds at EANET sites in Japan from 2003 to 2008

    NASA Astrophysics Data System (ADS)

    Endo, Tomomi; Yagoh, Hiroaki; Sato, Keiichi; Matsuda, Kazuhide; Hayashi, Kentaro; Noguchi, Izumi; Sawada, Kiyoshi

    2011-02-01

    The regional characteristics of estimated dry deposition and total atmospheric deposition, including dry and wet deposition, at 10 EANET sites in Japan from April 2003 to March 2008 are discussed. The components examined for dry deposition were sulfur compounds (SO 2 and particulate SO 42-) and nitrogen compounds (HNO 3, NH 3, particulate NO 3-, and NH 4+). Dry deposition was calculated by the product of the deposition velocity estimated by the inferential method for forest and grass surfaces and the air concentration of each compound. The 5-year mean annual dry deposition amounts for sulfur and nitrogen compounds were in the range of 5-37 and 7-50 mmol m -2 year -1, respectively. The regional characteristics of dry deposition amounts were similar between sulfur and nitrogen compounds, which showed higher deposition in the Sea of Japan side and in the Western Japan. The 5-year mean annual total deposition amounts for sulfur and nitrogen compounds were in the range of 28-77 and 22-130 mmol m -2 year -1, respectively. The contribution of dry deposition to the total deposition amounts was 10-55% and 13-56% for sulfur and nitrogen compounds, respectively. The regional characteristic of total deposition was different between sulfur and nitrogen compounds. Total deposition amounts in Japan were larger than those in CASTNET and EMEP because of high wet deposition, which implied that the increasing emissions of air pollutants in East Asia caused high atmospheric depositions.

  10. Formation of Unusual Valent Organic Sulfur and Selenium Compounds via Transannular Interaction

    Microsoft Academic Search

    Naomichi Furukawa

    1993-01-01

    1,5-Dithia- and diselenacyclooctane [1,5-DTCO and 1,5-DSeCO] were prepared and converted to the dication salts using NOPF6 or conc. H2SO4. The structures of the salts were determined by the x-ray crystallographic analysis revealing that ?-bond is formed between the two sulfur or selenium atoms. Several other sterically congested dications derived from dibenzothiocin, 1,9-disubstituted dibenzothiophenes and the corresponding selenium compounds were synthesized

  11. Removal of sulfur compounds from utility pipelined synthetic natural gas using modified activated carbons

    Microsoft Academic Search

    Hong Cui; Scott Q. Turn; Mark A. Reese

    2009-01-01

    Synthetic natural gas (SNG), which is produced from petroleum and distributed via pipeline in Honolulu by The Gas Company, was analyzed using a gas chromatograph equipped with a sulfur chemiluminescence detector (GC\\/SCD). Hydrogen sulfide (H2S), methyl mercaptan (MM), ethyl mercaptan (EM), dimethylsulfide (DMS), dimethyl disulfide (DMDS), tetrahydrothiophene (THT), ethyl disulfide (EDS), and one unidentified compound (UN1) were detected. Among these

  12. Quantification of Trace Volatile Sulfur Compounds in Milk by SolidPhase Microextraction and Gas Chromatography–Pulsed Flame Photometric Detection

    Microsoft Academic Search

    P. A. Vazquez-Landaverde; J. A. Torres; M. C. Qian

    2006-01-01

    Volatile sulfur compounds have been reported to be responsible for the sulfurous off-flavors generated dur- ing the thermal processing of milk; however, their anal- ysis has been a challenge due to their high reactivity, highvolatility,andlowsensorythreshold.Inthisstudy, reactive thiols were stabilized and the volatile sulfur compounds in milk were extracted by headspace solid- phase microextraction, and analyzed by gas chromatog- raphyandpulsed-flamephotometricdetection.Calibra- tioncurvesfor7sulfur-containingcompoundswerecon-

  13. Sulfur-containing Compounds in Lemna perpusilla 6746 Grown at a Range of Sulfate Concentrations

    PubMed Central

    Datko, Anne H.; Mudd, S. Harvey; Giovanelli, John; Macnicol, Peter K.

    1978-01-01

    Lemna perpusilla 6746, grown photoautotrophically at a series of sulfate concentrations ranging from 0.32 to 1,000 ?m, was labeled to radioisotopic equilibrium with 35SO42?. Sulfur-containing compounds were isolated and purified from the colonies. Radioactivity in each compound was a measure of the amount of that compound present in the tissue. The following compounds were identified and quantitated: inorganic sulfate, glutathione, homocyst(e)ine, cyst(e)ine, methionine, S-methylmethionine sulfonium, S-adenosylmethionine, S-adenosylhomocysteine, cystathionine, chloroformsoluble (presumed to be sulfolipid), protein cyst(e)ine, and protein methionine. ?-Glutamylcyst(e)ine, erythro- and threo-thiothreonine, and S-methylcysteine were not detected. No volatile 35S compounds were formed during plant growth at 1,000 ?m sulfate, nor were significant amounts of 35S compounds excreted into the medium. The amount of each component present in colonies grown over the 3,000-fold range of medium sulfate was relatively constant except for inorganic sulfate. This increased about 30-fold from the lowest to the highest medium sulfate concentration. The total soluble sulfur amino acids increased about 1.5- to 2-fold, due primarily to an increased amount of glutathione. Protein cyst(e)ine and protein methionine were the major organic sulfur compounds in Lemna, and the amounts of these compounds remained virtually constant despite the variation in external sulfate concentration. Procedures for the analysis of S-adenosylmethionine, S-methylmethionine sulfonium, and S-adenosylhomocysteine are presented. PMID:16660573

  14. 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.

  15. Sulfur 1s near edge x-ray absorption fine structure spectroscopy of thiophenic and aromatic thioether compounds.

    PubMed

    Behyan, Shirin; Hu, Yongfeng; Urquhart, Stephen G

    2013-06-01

    Thiophenic compounds are major constituents of fossil fuels and pose problems for fuel refinement. The quantification and speciation of these compounds is of great interest in different areas such as biology, fossil fuels studies, geology, and archaeology. Sulfur 1s Near-Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy has emerged as a qualitative and quantitative method for sulfur speciation. A firm understanding of the sulfur 1s NEXAFS spectra of organosulfur species is required for these analytical studies. To support this development, the sulfur 1s NEXAFS spectra of simple thiols and thioethers were previously examined, and are now extended to studies of thiophenic and aromatic thioether compounds, in the gas and condensed phases. High-resolution spectra have been further analyzed with the aid of Improved Virtual Orbital (IVO) and ?(self-consistent field) ab initio calculations. Experimental sulfur 1s NEXAFS spectra show fine features predicted by calculation, and the combination of experiment and calculation has been used to improve the assignment of spectroscopic features important for the speciation and quantification of sulfur compounds. Systematic differences between gas and condensed phases are also explored; these differences suggest a significant role for conformational effects in the NEXAFS spectra of condensed species. PMID:23758366

  16. Sulfur 1s near edge x-ray absorption fine structure spectroscopy of thiophenic and aromatic thioether compounds

    NASA Astrophysics Data System (ADS)

    Behyan, Shirin; Hu, Yongfeng; Urquhart, Stephen G.

    2013-06-01

    Thiophenic compounds are major constituents of fossil fuels and pose problems for fuel refinement. The quantification and speciation of these compounds is of great interest in different areas such as biology, fossil fuels studies, geology, and archaeology. Sulfur 1s Near-Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy has emerged as a qualitative and quantitative method for sulfur speciation. A firm understanding of the sulfur 1s NEXAFS spectra of organosulfur species is required for these analytical studies. To support this development, the sulfur 1s NEXAFS spectra of simple thiols and thioethers were previously examined, and are now extended to studies of thiophenic and aromatic thioether compounds, in the gas and condensed phases. High-resolution spectra have been further analyzed with the aid of Improved Virtual Orbital (IVO) and ?(self-consistent field) ab initio calculations. Experimental sulfur 1s NEXAFS spectra show fine features predicted by calculation, and the combination of experiment and calculation has been used to improve the assignment of spectroscopic features important for the speciation and quantification of sulfur compounds. Systematic differences between gas and condensed phases are also explored; these differences suggest a significant role for conformational effects in the NEXAFS spectra of condensed species.

  17. [Corrosion of pipe steel samples and conjugated conversion of sulfur compounds by thiobacteria Halothiobacillus neapolitanus DSM 15147].

    PubMed

    Vatsurina, A V; Esikova, T Z; Kholodenko, V P; Va?nshte?n, M B; Dubkova, V I

    2005-01-01

    The kinetics of conversion of sulfur compounds by Halothiobacillus neapolitanus DSM 15147 bacteria was studied in the presence of steel samples. It was shown that the presence of steel altered the known pathway of sulfur compound oxidation by thiobacteria. Production of atomic hydrogen via the interaction between biogenic sulfuric acid and steel enhanced secondary production of intermediates and decreased the content of sulfate produced previously. The process was accompanied by pH elevation and continuation of intense growth of the thiobacterium culture. Thiobacteria formed a corrosive medium, which caused metal destruction. The protective properties of anticorrosive coatings 225 LS and 640 mk were tested. It was shown that these coatings protected steel from the destructive effect of biogenic sulfuric acid. PMID:16240657

  18. On-line sulfur analysis

    SciTech Connect

    Not Available

    1988-02-01

    Field gas processing plants take great care to remove sulfur compounds from the gas coming in through the gathering system to reduce the toxicity and corrosivity of the gas. Then, at key points along the transportation and distribution networks, sulfur-based odorant compounds are added to the gas for safety and to comply with governmental regulations. As a result, a wide range of sulfides may be present in the gas stream, presenting a difficult measurement and separation task for even well-equipped laboratories. Field requirements are even more demanding of time and instrument reliability. Specificity in sulfur compound analysis is becoming more and more important, transcending the traditional ''grains of sulfur per cubit ft'' and, in some instances, regulatory requirements.

  19. Determination of total sulfur content via sulfur-specific chemiluminescence detection

    SciTech Connect

    Kubala, S.W.; Campbell, D.N. [Fluid Data, Inc., Angleton, TX (United States); DiSanzo, F.P. [Paulsboro Research Lab., NJ (United States)

    1995-12-31

    A specially designed system, based upon sulfur-specific chemiluminescence detection (SSCD), was developed to permit the determination of total sulfur content in a variety of samples. This type of detection system possesses several advantages such as excellent linearity and selectivity, low minimum detectable levels, and an equimolar response to various sulfur compounds. This paper will focus on the design and application of a sulfur-specific chemiluminescence detection system for use in determining total sulfur content in gasoline.

  20. Formation of Volatile Sulfur-Containing Compounds by Saccharomyces cerevisiae in Soymilk Supplemented with L-methionine

    Microsoft Academic Search

    Jasmine Mei Bei Quek; Yi-Xin Seow; Peter K. C. Ong; Shao-Quan Liu

    2011-01-01

    The formation of volatile sulfur-containing flavor compounds from L-methionine catabolism by Saccharomyces cerevisiae EC-1118 was investigated in soymilk supplemented with this sulfur-containing amino acid with a focus on methionol (3-methylthio-1-propanol). Methionol produced from L-methionine metabolism of yeast in soymilk was extracted by solid-phase microextraction (SPME) and analyzed by gas chromatography-mass spectrometry (GC-MS). The effects of time (0 – 72 h),

  1. Investigation on a new liquid redox method for H 2S removal and sulfur recovery with heteropoly compound

    Microsoft Academic Search

    Rui Wang

    2003-01-01

    An innovative approach to H2S removal and sulfur recovery involving the use of heteropoly compounds was investigated systematically in this study. The favorable redox potential of sodium phosphomolybdate (HPAS) makes it thermodynamically feasible for it to oxidate H2S to elemental sulfur and to be regenerated by air. The presence of Na2CO3 in HPAS system can improve the absorption rate of

  2. Direct night-time ejection of particle-phase reduced biogenic sulfur compounds from the ocean to the atmosphere.

    PubMed

    Gaston, Cassandra J; Furutani, Hiroshi; Guazzotti, Sergio A; Coffee, Keith R; Jung, Jinyoung; Uematsu, Mitsuo; Prather, Kimberly A

    2015-04-21

    The influence of oceanic biological activity on sea spray aerosol composition, clouds, and climate remains poorly understood. The emission of organic material and gaseous dimethyl sulfide (DMS) from the ocean represents well-documented biogenic processes that influence particle chemistry in marine environments. However, the direct emission of particle-phase biogenic sulfur from the ocean remains largely unexplored. Here we present measurements of ocean-derived particles containing reduced sulfur, detected as elemental sulfur ions (e.g., (32)S(+), (64)S2(+)), in seven different marine environments using real-time, single particle mass spectrometry; these particles have not been detected outside of the marine environment. These reduced sulfur compounds were associated with primary marine particle types and wind speeds typically between 5 and 10 m/s suggesting that these particles themselves are a primary emission. In studies with measurements of seawater properties, chlorophyll-a and atmospheric DMS concentrations were typically elevated in these same locations suggesting a biogenic source for these sulfur-containing particles. Interestingly, these sulfur-containing particles only appeared at night, likely due to rapid photochemical destruction during the daytime, and comprised up to ?67% of the aerosol number fraction, particularly in the supermicrometer size range. These sulfur-containing particles were detected along the California coast, across the Pacific Ocean, and in the southern Indian Ocean suggesting that these particles represent a globally significant biogenic contribution to the marine aerosol burden. PMID:25835033

  3. 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.

  4. Genome-Wide Transcriptional Profiling of the Purple Sulfur Bacterium Allochromatium vinosum DSM 180T during Growth on Different Reduced Sulfur Compounds

    PubMed Central

    Weissgerber, Thomas; Dobler, Nadine; Polen, Tino; Latus, Jeanette; Stockdreher, Yvonne

    2013-01-01

    The purple sulfur bacterium Allochromatium vinosum DSM 180T is one of the best-studied sulfur-oxidizing anoxygenic phototrophic bacteria, and it has been developed into a model organism for laboratory-based studies of oxidative sulfur metabolism. Here, we took advantage of the organism's high metabolic versatility and performed whole-genome transcriptional profiling to investigate the response of A. vinosum cells upon exposure to sulfide, thiosulfate, elemental sulfur, or sulfite compared to photoorganoheterotrophic growth on malate. Differential expression of 1,178 genes was observed, corresponding to 30% of the A. vinosum genome. Relative transcription of 551 genes increased significantly during growth on one of the different sulfur sources, while the relative transcript abundance of 627 genes decreased. A significant number of genes that revealed strongly enhanced relative transcription levels have documented sulfur metabolism-related functions. Among these are the dsr genes, including dsrAB for dissimilatory sulfite reductase, and the sgp genes for the proteins of the sulfur globule envelope, thus confirming former results. In addition, we identified new genes encoding proteins with appropriate subcellular localization and properties to participate in oxidative dissimilatory sulfur metabolism. Those four genes for hypothetical proteins that exhibited the strongest increases of mRNA levels on sulfide and elemental sulfur, respectively, were chosen for inactivation and phenotypic analyses of the respective mutant strains. This approach verified the importance of the encoded proteins for sulfur globule formation during the oxidation of sulfide and thiosulfate and thereby also documented the suitability of comparative transcriptomics for the identification of new sulfur-related genes in anoxygenic phototrophic sulfur bacteria. PMID:23873913

  5. Genome-wide transcriptional profiling of the purple sulfur bacterium Allochromatium vinosum DSM 180T during growth on different reduced sulfur compounds.

    PubMed

    Weissgerber, Thomas; Dobler, Nadine; Polen, Tino; Latus, Jeanette; Stockdreher, Yvonne; Dahl, Christiane

    2013-09-01

    The purple sulfur bacterium Allochromatium vinosum DSM 180(T) is one of the best-studied sulfur-oxidizing anoxygenic phototrophic bacteria, and it has been developed into a model organism for laboratory-based studies of oxidative sulfur metabolism. Here, we took advantage of the organism's high metabolic versatility and performed whole-genome transcriptional profiling to investigate the response of A. vinosum cells upon exposure to sulfide, thiosulfate, elemental sulfur, or sulfite compared to photoorganoheterotrophic growth on malate. Differential expression of 1,178 genes was observed, corresponding to 30% of the A. vinosum genome. Relative transcription of 551 genes increased significantly during growth on one of the different sulfur sources, while the relative transcript abundance of 627 genes decreased. A significant number of genes that revealed strongly enhanced relative transcription levels have documented sulfur metabolism-related functions. Among these are the dsr genes, including dsrAB for dissimilatory sulfite reductase, and the sgp genes for the proteins of the sulfur globule envelope, thus confirming former results. In addition, we identified new genes encoding proteins with appropriate subcellular localization and properties to participate in oxidative dissimilatory sulfur metabolism. Those four genes for hypothetical proteins that exhibited the strongest increases of mRNA levels on sulfide and elemental sulfur, respectively, were chosen for inactivation and phenotypic analyses of the respective mutant strains. This approach verified the importance of the encoded proteins for sulfur globule formation during the oxidation of sulfide and thiosulfate and thereby also documented the suitability of comparative transcriptomics for the identification of new sulfur-related genes in anoxygenic phototrophic sulfur bacteria. PMID:23873913

  6. Detection and classification of gaseous sulfur compounds by solid electrolyte cyclic voltammetry of cermet sensor array.

    PubMed

    Kramer, Kirsten E; Rose-Pehrsson, Susan L; Hammond, Mark H; Tillett, Duane; Streckert, Holger H

    2007-02-12

    Electrochemical sensors composed of a ceramic-metallic (cermet) solid electrolyte are used for the detection of gaseous sulfur compounds SO(2), H(2)S, and CS(2) in a study involving 11 toxic industrial chemical (TIC) compounds. The study examines a sensor array containing four cermet sensors varying in electrode-electrolyte composition, designed to offer selectivity for multiple compounds. The sensors are driven by cyclic voltammetry to produce a current-voltage profile for each analyte. Raw voltammograms are processed by background subtraction of clean air, and the four sensor signals are concatenated to form one vector of points. The high-resolution signal is compressed by wavelet transformation and a probabilistic neural network is used for classification. In this study, training data from one sensor array was used to formulate models which were validated with data from a second sensor array. Of the 11 gases studied, 3 that contained sulfur produced the strongest responses and were successfully analyzed when the remaining compounds were treated as interferents. Analytes were measured from 10 to 200% of their threshold-limited value (TLV) according to the 8-h time weighted average (TWA) exposure limits defined by the National Institute of Occupational Safety and Health (NIOSH). True positive classification rates of 93.3, 96.7, and 76.7% for SO(2), H(2)S, and CS(2), respectively, were achieved for prediction of one sensor unit when a second sensor was used for modeling. True positive rates of 83.3, 90.0, and 90.0% for SO(2), H(2)S, and CS(2), respectively, were achieved for the second sensor unit when the first sensor unit was used for modeling. Most of the misclassifications were for low concentration levels (such 10-25% TLV) in which case the compound was classified as clean air. Between the two sensors, the false positive rates were 2.2% or lower for the three sulfur compounds, 0.9% or lower for the interferents (eight remaining analytes), and 5.8% or lower for clean air. The cermet sensor arrays used in this analysis are rugged, low cost, reusable, and show promise for multiple compound detection at parts-per-million (ppm) levels. PMID:17386588

  7. 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).

  8. Synthesis and characterization of porous metal oxides and desulfurization studies of sulfur containing compounds

    NASA Astrophysics Data System (ADS)

    Garces Trujillo, Hector Fabian

    This thesis contains two parts: 1) synthesis and characterization of porous metal oxides that include zinc oxide and a porous mixed-valent manganese oxide with an amorphous structure (AMO) 2) the desulfurization studies for the removal of sulfur compounds. Zinc oxide with different nano-scale morphologies may result in various porosities with different adsorption capabilities. A tunable shape microwave synthesis of ZnO nano-spheres in a co-solvent mixture is presented. The ZnO nano-sphere material is investigated as a desulfurizing sorbent in a fixed bed reactor in the temperature range 200 to 400 °C and compared with ZnO nanorods and platelet-like morphologies. Fresh and sulfided materials were characterized by X-ray diffraction (XRD), BET specific surface area, pore volume, scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (SEM/EDX), Raman spectroscopy, and thermogravimetric analysis (TGA). The tunable shape microwave synthesis of ZnO presents a high sulfur sorption capacity at temperatures as low as 200 °C which accounts for a three and four fold enhancement over the other preparations presented in this work, and reached 76 % of the theoretical sulfur capacity (TSC) at 300 °C. Another ZnO material with a bimodal micro- and mesopore size distribution investigated as a desulfurizing sorbent presents a sorption capacity that reaches 87% of the theoretical value for desulfurization at 400 °C at breakthrough time. A deactivation model that considers the activity of the solid reactant was used to fit the experimental data. Good agreement between the experimental breakthrough curves and the model predictions are obtained. Manganese oxides are a type of metal oxide materials commonly used in catalytic applications. Little is known about the adsorption capabilities for the removal of sulfur compounds. One of these manganese oxides; amorphous manganese oxide (AMO) is highly promising material for low temperature sorption processes. Amorphous manganese oxide (AMO) has been used in catalytic processes such as for the catalytic oxidation of benzyl alcohol, the preferential oxidation of CO, and for the capture of formate species. This chapter explores the possibility of using AMO in sorption processes for the removal of two contaminants; H 2S and COS in the temperature range 200 - 400 °C.

  9. Sulfur recovery system

    Microsoft Academic Search

    1977-01-01

    Recovery of chemicals from a sodium sulfide containing pulping liquor which is cycled from a digester through a recovery system is effected by separating hydrogen sulfide gas, either from the cooking liquor or from various points in the recovery system, to provide a source of sulfide sulfur which is oxidized to sulfur. When separated from the cooking liquor, it is

  10. Field sampling method for quantifying volatile sulfur compounds from animal feeding operations

    NASA Astrophysics Data System (ADS)

    Trabue, Steven; Scoggin, Kenwood; Mitloehner, Frank; Li, Hong; Burns, Robert; Xin, Hongwei

    Volatile sulfur compounds (VSCs) are a major class of chemicals associated with odor from animal feeding operations (AFOs). Identifying and quantifying VSCs in air is challenging due to their volatility, reactivity, and low concentrations. In the present study, a canister-based method collected whole air in fused silica-lined (FSL) mini-canister (1.4 L) following passage through a calcium chloride drying tube. Sampled air from the canisters was removed (10-600 mL), dried, pre-concentrated, and cryofocused into a GC system with parallel detectors (mass spectrometer (MS) and pulsed flame photometric detector (PFPD)). The column effluent was split 20:1 between the MS and PFPD. The PFPD equimolar sulfur response enhanced quantitation and the location of sulfur peaks for mass spectral identity and quantitation. Limit of quantitation for the PFPD and MSD was set at the least sensitive VSC (hydrogen sulfide) and determined to be 177 and 28 pg S, respectively, or 0.300 and 0.048 ?g m -3 air, respectively. Storage stability of hydrogen sulfide and methanethiol was problematic in warm humid air (25 °C, 96% relative humidity (RH)) without being dried first, however, stability in canisters dried was still only 65% after 24 h of storage. Storage stability of hydrogen sulfide sampled in the field at a swine facility was over 2 days. The greater stability of field samples compared to laboratory samples was due to the lower temperature and RH of field samples compared to laboratory generated samples. Hydrogen sulfide was the dominant odorous VSCs detected at all swine facilities with methanethiol and dimethyl sulfide detected notably above their odor threshold values. The main odorous VSC detected in aged poultry litter was dimethyl trisulfide. Other VSCs above odor threshold values for poultry facilities were methanethiol and dimethyl sulfide.

  11. Thermophilic biodesulfurization of various heterocyclic sulfur compounds and crude straight-run light gas oil fraction by a newly isolated strain Mycobacterium phlei WU-0103.

    PubMed

    Ishii, Yoshitaka; Kozaki, Shinya; Furuya, Toshiki; Kino, Kuniki; Kirimura, Kohtaro

    2005-02-01

    Various heterocyclic sulfur compounds such as naphtho[2,1-b]thiophene (NTH) and benzo[b]thiophene (BTH) derivatives can be detected in diesel oil, in addition to dibenzothiophene (DBT) derivatives. Mycobacterium phlei WU-0103 was newly isolated as a bacterial strain capable of growing in a medium with NTH as the sulfur source at 50 degrees C. M. phlei WU-0103 could degrade various heterocyclic sulfur compounds, not only NTH and its derivatives but also DBT, BTH, and their derivatives at 45 degrees C. When M. phlei WU-0103 was cultivated with the heterocyclic sulfur compounds such as NTH, NTH 3,3-dioxide, DBT, BTH, and 4,6-dialkylDBTs as sulfur sources, monohydroxy compounds and sulfone compounds corresponding to starting heterocyclic sulfur compounds were detected by gas chromatography-mass spectrometry analysis, suggesting the sulfur-specific desulfurization pathways for heterocyclic sulfur compounds. Moreover, total sulfur content in 12-fold-diluted crude straight-run light gas oil fraction was reduced from 1000 to 475 ppm S, with 52% reduction, by the biodesulfurization treatment at 45 degrees C with growing cells of M. phlei WU-0103. Gas chromatography analysis with a flame photometric detector revealed that most of the resolvable peaks, such as those corresponding to alkylated derivatives of NTH, DBT, and BTH, disappeared after the biodesulfurization treatment. These results indicated that M. phlei WU-0103 may have a good potential as a biocatalyst for practical biodesulfurization of diesel oil. PMID:15702256

  12. Aircraft exhaust sulfur emissions

    NASA Astrophysics Data System (ADS)

    Brown, R. C.; Anderson, M. R.; Miake-Lye, R. C.; Kolb, C. E.; Sorokin, A. A.; Buriko, Y. Y.

    The conversion of fuel sulfur to S(VI) (SO3 + H2SO4) in supersonic and subsonic aircraft engines is estimated numerically. Model results indicate between 2% and 10% of the fuel sulfur is emitted as S(VI). It is also shown that, for a high sulfur mass loading, conversion in the turbine is kinetically limited by the level of atomic oxygen. This results in a higher oxidation efficiency at lower sulfur loadings. SO3 is the primary S(VI) oxidation product and calculated H2SO4 emission levels were less than 1% of the total fuel sulfur. This source of S(VI) can exceed the S(VI) source due to gas phase oxidation in the exhaust wake.

  13. Catalytic sulfur degassing

    SciTech Connect

    Baker, D.C.

    1988-07-05

    A process is described for the preparation of (1) synthesis gas reduced in solids and acidic gases and (2) elemental sulfur which comprises (a) treating coal, shale or tar sands with oxygen to produce a synthesis gas stream containing inorganic sulfide; (b) recovering slag particles from the treatment of coal in step (a) and selecting particles thereof suitable for use as a catalyst carrier; (c) treating the slag from step (b) with the synthesis gas substantially free of slag particles to deposit on the surface slag particles a catalytic amount of at least one metal sulfide; (d) treating the synthesis gas from step (c) to remove acidic gases suitable for sulfur production; (e) converting the acid gases from step (d) to liquid sulfur; and (f) contacting the liquid sulfur with the catalytic slag particles from step (c) to reduce the hydrogen sulfide and hydrogen polysulfide content of the sulfur.

  14. Regional river sulfur runoff

    SciTech Connect

    Husar, R.B.; Husar, J.D.

    1985-01-20

    The water and sulfur runoff data for 54 large river basins were assembled, covering 65% of the nondesert land area of the world. The sulfur concentration ranges from 0.5 mg S/L for the West African rivers Niger and Volta to 100 mg S/L in the Colorado River; the world average is 3.2 mg S/L. The concentrations in central and eastern Europe as well as central and eastern North America exceed 8 mg S/L. The sulfur runoff density is also highest in the river basins over these industrialized regions, exceeding 2 g S/m/sup 2//yr. However, high sulfur runoff density in excess of 3 g S/m/sup 2//yr is also measured over the Pacific islands New Zealand and New Guinea and the archipelagos of Indonesia and the Philippines. The natural background sulfur runoff was estimated by assuming that South America, Africa, Australia, and the Pacific Islands are unperturbed by man and that the average river sulfur concentration is in the range 1--3 mg S/L. Taking these background concentration values, the man-induced sulfur runoff for Europe ranges between 2 and 8 times the natural flow, and over North America, man's contribution ranges between 1 and 5 times the natural runoff. The global sulfur flow from nondesert land to the oceans and the Caspian Sea is estimated as 131 Tg S/yr, of which 46--85 Tg S/yr is attributed to natural causes. The regional river sulfur runoff pattern discussed in this paper does not have enough spatial resolution to be directly applicable to studies of the environmental effects of man-induced sulfur flows. However, it points to the continental-size regions where those perturbations are most evident and to the magnitude of the perturbations as expressed in units of the natural flows.

  15. Combined removal of sulfur compounds and nitrate by autotrophic denitrification in bioaugmented activated sludge system.

    PubMed

    Manconi, I; Carucci, A; Lens, P

    2007-10-15

    An autotrophic denitrification process using reduced sulfur compounds (thiosulfate and sulfide) as electron donor in an activated sludge system is proposed as an efficient and cost effective alternative to conventional heterotrophic denitrification for inorganic (or with low C/N ratio) wastewaters and for simultaneous removal of sulfide or thiosulfate and nitrate. A suspended culture of sulfur-utilizing denitrifying bacteria was fast and efficiently established by bio-augmentation of activated sludge with Thiobacillus denitrificans. The stoichiometry of the process and the key factors, i.e. N/S ratio, that enable combined sulfide and nitrogen removal, were determined. An optimum N/S ratio of 1 (100% nitrate removal without nitrite formation and low thiosulfate concentrations in the effluent) has been obtained during reactor operation with thiosulfate at a nitrate loading rate (NLR) of 17.18 mmol N L(-1) d(-1). Complete nitrate and sulfide removal was achieved during reactor operation with sulfide at a NLR of 7.96 mmol N L(-1) d(-1) and at N/S ratio between 0.8 and 0.9, with oxidation of sulfide to sulfate. Complete nitrate removal while working at nitrate limiting conditions could be achieved by sulfide oxidation with low amounts of oxygen present in the influent, which kept the sulfide concentration below inhibitory levels. PMID:17724757

  16. The influence of hydroxyl volatile organic compounds on the oxidation of aqueous sulfur dioxide by oxygen.

    PubMed

    Dhayal, Yogpal; Chandel, C P S; Gupta, K S

    2014-01-01

    Although the effect of volatile organic compounds (VOCs) on the oxidation of dissolved sulfur dioxide by oxygen has been the subject of many investigations, this is the first study which examines the effect of a large number of precisely 16 hydroxy compounds. The kinetics both in the absence and the presence of VOCs was defined by rate laws (A and B): -d[S(IV)]dt = R? = k?[S(IV)] (A) -d[S(IV)]dt = R(i) = k(i)[S(IV)] (B) where R? and k? are the initial rate and first-order rate constant, respectively, in the absence of VOCs, R(i), and k(i) are the initial rate and the first-order rate constant, respectively, in the presence of VOCs, and [S(IV)] is the concentration of dissolved sulfur dioxide, sulfur(IV). The nature of the dependence of k(i) on the concentration of inhibitor, [Inh], was defined by Eq. (C). [k(i) = k?/(1 + B[Inh]) (C) where B is an empirical inhibition parameter. The values of B have been determined from the plots of 1/k(i) versus [Inh]. Among aliphatic and aromatic hydroxy compounds studied, t-butyl alcohol and pinacol were without any inhibition effect due to the absence of secondary or tertiary hydrogen. The values of inhibition parameter, B, were related to k(inh), the rate constant for the reaction of SO?(-) radical with the inhibitor, by Eq. (D). B = (9 ± 2) x 10?? x k(inh) (D) Equation (D) may be used to calculate the values of either of B or k(inh) provided that the other is known. The extent of inhibition depends on the value of the composite term, B[Inh]. However, in accordance with Eq. (C), the extent of inhibition would be sizeable and measurable when B[Inh]?> 0.1 and oxidation of S(IV) would be almost completely stopped when B[Inh]???10. B[Inh] value can be used as a guide whether the reaction step: SO4 (-)?+ organics???SO?(2-)?+ non-chain products: should be included in the multiphase models or not. PMID:24638831

  17. 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.

  18. 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

  19. Quantitative structure-property relationship study of normal boiling points for halogen-\\/ oxygen-\\/ sulfur-containing organic compounds using the CODESSA program

    Microsoft Academic Search

    Ovidiu Ivanciuc; Teodora Ivanciuc; Alexandru T. Balaban

    1998-01-01

    QSPR (Quantitative Structure-Property Relationship) models for the estimation of boiling points of organic compounds containing halogens, oxygen, or sulfur without hydrogen bonding were established with the CODESSA (Comprehensive Descriptors for Structural and Statistical Analysis) program developed by Katritzky and coworkers. The boiling points of 185 compounds containing oxygen or sulfur can be accurately computed with a MLR (Multi-Linear Regression) equation

  20. Quantification of volatile sulfur compounds in complex gaseous matrices by solid-phase microextraction.

    PubMed

    Nielsen, Annika T; Jonsson, Susanne

    2002-07-19

    Procedures were assessed for quantifying nine volatile sulfur compounds found in complex gaseous samples collected at a biogas-production plant and a sewage treatment plant. The target compounds were extracted by solid-phase microextraction (using the 75-microm Carboxen-polydimethylsiloxane fiber coating) at 22 degrees C for 20 min, and analyzed by GC-MS. Detection limits ranged between 1 pptv (v/v) for carbon disulfide and 470 pptv (v/v) for hydrogen sulfide. High amounts of organic compounds were found during full-scan analysis of the samples and standard additions to individual sub-samples revealed that the analysis was subject to matrix effects. However, the functions obtained by standard additions were still linear and quantification was possible for all the compounds tested except hydrogen sulfide. No detectable losses were observed during storage in the sampling containers, made of Tedlar film, over a storage period of 20 h. However, water permeated through the walls and the relative humidity in the bag increased during storage until it reached the ambient level. Finally, it was shown that the drying agent, CaCl2, caused no detectable losses of any of the compounds. PMID:12188001

  1. PTR-MS measurement of partition coefficients of reduced volatile sulfur compounds in liquids from biotrickling filters.

    PubMed

    Liu, Dezhao; Feilberg, Anders; Nielsen, Anders Michael; Adamsen, Anders Peter S

    2013-01-01

    Biological air filtration for reduction of emissions of volatile sulfur compounds (e.g., hydrogen sulfide, methanethiol and dimethyl sulfide) from livestock production facilities is challenged by poor partitioning of these compounds into the aqueous biofilm or filter trickling water. In this study, Henry's law constants of reduced volatile sulfur compounds were measured for deionized water, biotrickling filter liquids (from the first and second stages of a two-stage biotrickling filter), and NaCl solutions by a dynamic method using Proton-Transfer-Reaction Mass Spectrometry (PTR-MS) at a temperature range of 3-45°C. NaCl solutions were used to estimate salting-out constants up to an ionic strength of 0.7 M in order to evaluate the effect of ionic strength on partitioning between air and biofilter liquids. Thermodynamic parameters (enthalpy and entropy of phase exchange) were obtained from the measured partition coefficients as a function of temperature. The results show that the partition coefficients of organic sulfur compounds in the biotrickling filter liquids were generally very close to the corresponding partition coefficients in deionized water. Based on the estimated ionic strength of biofilter liquids, it is assessed that salting-out effects are of no importance for these compounds. For H(2)S, a higher enthalpy of air-liquid partitioning was observed for 2nd stage filter liquid, but not for 1st stage filter liquid. In general, the results show that co-solute effects for sulfur compounds can be neglected in numerical biofilter models and that the uptake of volatile sulfur compounds in biotrickling filter liquids cannot be increased by decreasing ionic strength. PMID:22960062

  2. The effect of a mouthrinse containing chlorine dioxide in the clinical reduction of volatile sulfur compounds.

    PubMed

    Soares, Leo Guimaraes; Guaitolini, Roberto Luiz; Weyne, Sergio de Carvalho; Falabella, Marcio Eduardo Vieira; Tinoco, Eduardo Muniz Barretto; da Silva, Denise Gomes

    2013-07-01

    This study sought to evaluate the clinical effect of a mouthrinse containing 0.3% chlorine dioxide (ClO2) in reducing oral volatile sulfur compounds (VSC). Halitosis was induced by L-cysteine in 11 volunteers, and 4 solutions were compared: a test solution containing 0.3% ClO2, 0.07% cetylpyridinium chloride (CPC), and 0.05% sodium fluoride; a placebo; a solution containing 0.05% CPC; and a control solution of 0.2% chlorhexidine gluconate (CHX). VSC levels were assessed using a Halimeter, and 6 measurements were made from baseline to 3 hours postrinse. The VSC reduction rate of the test mouthrinse was superior to the placebo and the CPC solution. There was no difference between the test solution and the CHX solution in VSC reduction rates immediately postrinse, or at 2 and 3 hours postrinse; both solutions were statistically superior to the placebo and the CPC solution. PMID:23823344

  3. Comparison of volatile sulfur compound concentrations measured with a sulfide detector vs. gas chromatography.

    PubMed

    Furne, J; Majerus, G; Lenton, P; Springfield, J; Levitt, D G; Levitt, M D

    2002-02-01

    The accuracy of the Halimeter, an inexpensive, simple instrument that measures total breath volatile sulfur compounds (VSCs), has not been adequately tested. We compared Halimeter measurements with those obtained with a specific and sensitive gas chromatographic (GC) technique. The Halimeter gave different, biexponential responses to a constant concentration of different VSCs: The relative response rate and sensitivity were hydrogen sulfide > methyl mercaptan > dimethylsulfide. The transient peak VSC concentration of oral samples was reached long before the sulfide detector fully responded. The GC measurement of initial total VSCs in breath samples was 2.7+/-0.48 times greater than the peak concentration of the Halimeter. However, the plateau phase measurement of the Halimeter was 25% greater than that of GC. While GC and Halimeter measurements positively correlated, appreciable differences were observed. In studies where relatively precise VSC measurements are required, GC is the preferable technique. PMID:11827259

  4. Effects of oil drops containing Lactobacillus salivarius WB21 on periodontal health and oral microbiota producing volatile sulfur compounds

    Microsoft Academic Search

    Nao Suzuki; Kazunari Tanabe; Toru Takeshita; Masahiro Yoneda; Tomoyuki Iwamoto; Sueko Oshiro; Yoshihisa Yamashita; Takao Hirofuji

    2012-01-01

    The objective of this paper is to evaluate the effects of oil drops containing Lactobacillus salivarius WB21 on periodontal health and oral microbiota producing volatile sulfur compounds (VSCs). For this study, 42 subjects were randomly assigned to receive oil samples containing L. salivarius WB21 or a placebo for two weeks. Oral assessment and saliva collection were performed on days 1

  5. Cure Characteristics and Thermal Properties of Sulfur-Cured EPDM-Based Composites by Compounding with Layered Nano-Organoclays

    Microsoft Academic Search

    Ahmad Mousa

    2006-01-01

    Organoclay was compounded with ethylene-propylene-diene-monomer (EPDM) using a two roll mill and cured by conventional sulfur curing system. The organoclay content was progressively increased from 0 to 10 parts per hundred of rubber (phr) of the EPDM rubber. Cure characteristics were carried out on an Ekktron moving die rheometer. It has been found that cure and scorch time were decreased

  6. Release of sulfur dioxide and nitric oxide and characteristic of coal combustion under the effect of calcium based organic compounds

    Microsoft Academic Search

    Shengli Niu; Kuihua Han; Chunmei Lu

    2011-01-01

    The influences of calcium based organic compounds of calcium propionate (CP), the product of the modified calcium hydroxide by propionic acid (named as MCP) and the product of the modified calcium hydroxide and magnesium oxide by propionic acid (named as MCMP) on the release of sulfur dioxide (SO2) and nitric oxide (NO) and on the characteristic of coal combustion have

  7. Variation of some fermentative sulfur compounds in Italian "millesime" classic sparkling wines during aging and storage on lees.

    PubMed

    Fedrizzi, Bruno; Magno, Franco; Finato, Fabio; Versini, Giuseppe

    2010-09-01

    Fermentative sulfur compounds are recognized as strongly affecting wine aroma, mainly as off-flavors, but recently also as possible positive contributors to wine quality and typicity in still wines. Nevertheless, no evidence has been provided for the influence of these molecules on sparkling wine aroma, except for peculiar volatile thiols found in French Champagne. According to the traditional method, the second fermentation, occurring in sealed bottles, is the essence of the procedure. After this fermentation, sparkling wine is aged on yeast lees for a period ranging from a few months to several years so that yeast autolysis can take place. So far, no evidence is provided for the effect of yeast contact duration on the level of sulfur compounds. Following a HS-SPME/GC-MS method, 13 sulfur compounds, that is, ethylmercaptan, dimethyl sulfide, diethyl sulfide, dimethyl disulfide, diethyl disulfide, methyl thioacetate, ethyl thioacetate, 2-mercaptoethanol, 2-(methylthio)-1-ethanol, 3-(methylthio)-1-propanol, 4-(methylthio)-1-butanol, benzothiazole, and 5-(2-hydroxyethyl)-4-methylthiazole, were quantified in several Italian sparkling wines, produced according to the traditional method in two wineries from Trentino-South Tyrol, region. Additionally, the influence of winemaking technology differences and vintage effects on the evolution of the quoted sulfur compounds was considered. This investigation was carried out by coupling the HS-SPME data with those obtained by SPE method and relevant to other volatile compounds, which are considered as winemaking markers. This work furnished the first evidence of the effect of aging and lees contact at different storage temperatures on the levels of these analytes in sparkling wines. Significant increments were observed for dimethyl sulfide, diethyl sulfide, 2-(methylthio)-1-ethanol, 3-(methylthio)-1-propanol, and 4-(methylthio)-1-butanol during aging with a different variation slope possibly due to the remarkably different storage temperatures. No clear influence of lees contact duration was found for the majority of the sulfur compounds considered. PMID:20806972

  8. Sulfur removal from a gas stream

    SciTech Connect

    Frech, K.J.; Tazuma, J.J.

    1984-03-06

    There is disclosed a process for removing sulfur compounds from a gas stream. The process involves passing the gas stream containing the sulfur compounds through a mass of porous material that has deposited upon it a metal oxide, the improvement comprises the continuous or intermittent addition of an oxidizing agent and an amine.

  9. Process for converting sulfur in hydrocarbon to water soluble form

    Microsoft Academic Search

    1980-01-01

    A desulfurization process is disclosed wherein a sulfur-containing hydrocarbon material is contacted with a sulfur oxide compound and an amine, a salt of an amine, or mixtures thereof. The contacting converts the sulfur component of the hydrocarbon material to water soluble form thereby allowing the sulfur components to be readily separated by water washing.

  10. Determination of sulfur heterocycles in coal liquids and shale oils

    Microsoft Academic Search

    Cherylyn. Willey; Masatomo. Iwao; Raymond N. Castle; Milton L. Lee

    1981-01-01

    Sulfur heterocycles are found in low concentrations in most coal-derived liquids and shale oils, and therefore, isolation of the heterocyclic sulfur fraction is necessary for individual compound identification. A new methodology for the isolation and subsequent separation and identification of sulfur heterocycles is described and applied to selected coal liquids and shale oils. Identification was accomplished by sulfur-selective flame photometric

  11. Bacterial ethane formation from reduced, ethylated sulfur compounds in anoxic sediments

    USGS Publications Warehouse

    Oremland, R.S.; Whiticar, Michael J.; Strohmaier, F.E.; Kiene, R.P.

    1988-01-01

    Trace levels of ethane were produced biologically in anoxic sediment slurries from five chemically different aquatic environments. Gases from these locations displayed biogenic characteristics, having 12C-enriched values of ??13CH4 (-62 to -86%.), ??13C2H6 (-35 to -55%.) and high ratios (720 to 140,000) of CH4 [C2H6 + C3H8]. Endogenous production of ethane by slurries was inhibited by autoclaving or by addition of the inhibitor of methanogenic bacteria, 2-bromoethanesulfonic acid (BES). Ethane formation was stimulated markedly by ethanethiol (ESH), and, to a lesser extent, by diethylsulfide (DES). Formation of methane and ethane in ESH- or DES-amended slurries was blocked by BES. Experiments showed that ethionine (or an analogous compound) could be a precursor of ESH. Ethylamine or ethanol additions to slurries caused only a minor stimulation of ethane formation. Similarly, propanethiol additions resulted in only a minor enhancement of propane formation. Cell suspensions of a methyltrophic methanogen produced traces of ethane when incubated in the presence of DES, although the organism did not grow on this compound. These results indicate that methanogenic bacteria produce ethane from the traces of ethylated sulfur compounds present in recent sediments. Preliminary estimates of stable carbon isotope fractionation associated with sediment methane formation from dimethylsulfide was about 40%., while ethane formation from DES and ESH was only 4. 6 and 6.5%., respectively. ?? 1988.

  12. [Influence of transition metal compounds on superoxide dismutase activity of sulfur reducing Desulfuromonas acetoxidans bacteria].

    PubMed

    Vasyliv, O M; Hnatush, S O

    2013-01-01

    Superoxide dismutase, as one of the enzymes of cells' antioxidant defensive system, catalyzes superoxide anion-radical (O2-) dismutation with O2 and H2O2 forming. The influence of such transition metal compounds, as FeSO4, FeCl3, MnCl2, NiCl2, and CoCl2 on superoxide dismutase activity of sulfur-reducing Desulfuromonas acetoxidans bacteria has been investigated. Maximal activity of the investigated enzyme has been observed accordingly under the influence of 1.0 mM of NiCl2, 2.0 mM of CoCl2 and MnCl2 on the second day and under the influence of 1.0 mM of FeCl3 and FeSO4 respectively, on the third day of growth in comparison with control samples. An increase of incubation time and concentration of metal compound in the medium caused the inhibition of superoxide dismutase activity. PMID:23720962

  13. Reversible formation of ammonium persulfate/sulfuric acid graphite intercalation compounds and their peculiar Raman spectra.

    PubMed

    Dimiev, Ayrat M; Bachilo, Sergei M; Saito, Riichiro; Tour, James M

    2012-09-25

    Graphite intercalation compounds (GICs) can be considered stacks of individual doped graphene layers. Here we demonstrate a reversible formation of sulfuric acid-based GICs using ammonium persulfate as the chemical oxidizing agent. No covalent chemical oxidation leading to the formation of graphite oxide occurs, which inevitably happens when other compounds such as potassium permanganate are used to charge carbon layers. The resulting acid/persulfate-induced stage-1 and stage-2 GICs are characterized by suppression of the 2D band in the Raman spectra and by unusually strong enhancement of the G band. The G band is selectively enhanced at different doping levels with different excitations. These observations are in line with recent reports for chemically doped and gate-modulated graphene and support newly proposed theories of Raman processes. At the same time GICs have some advantageous differences over graphene, which are demonstrated in this report. Our experimental observations, along with earlier reported data, suggest that at high doping levels the G band cannot be used as the reference peak for normalizing Raman spectra, which is a commonly used practice today. A Fermi energy shift of 1.20-1.25 eV and ?1.0 eV was estimated for the stage-1 and stage-2 GICs, respectively, from the Raman and optical spectroscopy data. PMID:22880798

  14. REGIONAL AIR POLLUTION STUDY: SULFUR COMPOUNDS AND PARTICULATE SIZE DISTRIBUTION INVENTORY

    EPA Science Inventory

    In conjunction with the Regional Air Pollution Study being conducted in the St. Louis Air Quality Control Region (AQCR), a methodology for estimating the amount of sulfur trioxide (SO3) emitted by combustion sources was developed. It is based on SO2/SO3 ratios determined both exp...

  15. The relationship between oral malodor and volatile sulfur compounds producing bacteria

    Microsoft Academic Search

    Yosef P. Krespi; Mel Rosenberg

    2004-01-01

    Objectives: Halitosis can be a crippling social problem where the standard dental treatments and mouthwashes often recommended provide only temporary relief. Oral malodor is primarily the result of microbial metabolism. The mouth is home to hundreds of bacterial species with various nutritional preferences. These organisms enjoy proteins, as they digest proteins several fetid substances arise. The role of volatile sulfur

  16. Need total sulfur content? Use chemiluminescence

    SciTech Connect

    Kubala, S.W.; Campbell, D.N. [Fluid Data, Inc., Angleton, TX (United States); DiSanzo, F.P. [Mobil Technology Co., Paulsboro, NJ (United States)

    1996-09-01

    Regulations issued by the United States Environmental Protection Agency require petroleum refineries to reduce or control the amount of total sulfur present in their refined products. These legislative requirements have led many refineries to search for online instrumentation that can produce accurate and repeatable total sulfur measurements within allowed levels. Several analytical methods currently exist to measure total sulfur content. They include X-ray fluorescence (XRF), microcoulometry, lead acetate tape, and pyrofluorescence techniques. Sulfur-specific chemiluminescence detection (SSCD) has recently received much attention due to its linearity, selectivity, sensitivity, and equimolar response. However, its use has been largely confined to the area of gas chromatography. This article focuses on the special design considerations and analytical utility of an SSCD system developed to determine total sulfur content in gasoline. The system exhibits excellent linearity and selectivity, the ability to detect low minimum levels, and an equimolar response to various sulfur compounds. 2 figs., 2 tabs.

  17. Sulfur distribution within coal pyrolysis products

    Microsoft Academic Search

    Andrzej Czaplicki; Wojciech Smo?ka

    1998-01-01

    The pyrolysis of coal leads to distribution of sulfur compounds in pyrolysis gas, char and tar generated during the process. The effect of the process parameters of autothermal coal pyrolysis in the circulating fluidized bed reactor on total sulfur distribution has been investigated. Several experimental tests were performed at the temperature of 920°C. Non-coking coal from the Wieczorek Mine (Upper

  18. Biocatalytic sulfur removal from fuels: applicability for producing low sulfur gasoline.

    PubMed

    McFarland, B L; Boron, D J; Deever, W; Meyer, J A; Johnson, A R; Atlas, R M

    1998-01-01

    Environmental regulations are driving R&D efforts to produce low sulfur fuels, including diesel fuel and gasoline for motor vehicles. Biocatalytic sulfur removal from fuels has potential applicability for producing low sulfur gasoline. Microbial biocatalysts have been identified that can biotransform sulfur compounds found in fuels, including ones that selectively remove sulfur from dibenzothiophene heterocyclic compounds. Most attention is give to the 4S pathway of Rhodococcus, which can remove sulfur from substituted and unsubstituted dibenzothiophenes, including sulfur compounds that hinder chemical catalysis and that resist removal by mild hydrotreatment. Various bioreactor and bioprocess designs are being tested for use with biocatalysts, including recombinant biocatalysts, for use in removing sulfur from fuels and feedstocks within the petroleum refinery stream. With bioprocess improvements that enhance biocatalyst stability, achieve faster kinetics, improve mass transfer limitations, temperature and solvent tolerance, as well as broaden substrate specificity to attack a greater range of heterocyclic compounds, biocatalysis may be a cost-effective approach to achieve the production of low sulfur gasoline. The challenge will be to accomplish these improvements by the time the regulations for low sulfur gasoline and other vehicle fuels go into effect in order to be competitive with emerging nonbiological desulfurization technologies. PMID:9675512

  19. Molecular Spectra of Sulfur Molecules and Solid Sulfur Allotropes

    Microsoft Academic Search

    Bodo Eckert; Ralf Steudel

    Molecular spectroscopy is one of the most important means to characterize the various species in solid, liquid and gaseous elemental sulfur. In this chapter the vibrational, UV-Vis and mass spectra of sulfur molecules with between 2 and 20 atoms are critically reviewed together with the spectra of liquid sulfur and of solid allotropes including polymeric and high-pressure phases. In particular,

  20. Multidimensional gas chromatography in combination with accurate mass, tandem mass spectrometry, and element-specific detection for identification of sulfur compounds in tobacco smoke.

    PubMed

    Ochiai, Nobuo; Mitsui, Kazuhisa; Sasamoto, Kikuo; Yoshimura, Yuta; David, Frank; Sandra, Pat

    2014-09-01

    A method is developed for identification of sulfur compounds in tobacco smoke extract. The method is based on large volume injection (LVI) of 10?L of tobacco smoke extract followed by selectable one-dimensional ((1)D) or two-dimensional ((2)D) gas chromatography (GC) coupled to a hybrid quadrupole time-of-flight mass spectrometer (Q-TOF-MS) using electron ionization (EI) and positive chemical ionization (PCI), with parallel sulfur chemiluminescence detection (SCD). In order to identify each individual sulfur compound, sequential heart-cuts of 28 sulfur fractions from (1)D GC to (2)D GC were performed with the three MS detection modes (SCD/EI-TOF-MS, SCD/PCI-TOF-MS, and SCD/PCI-Q-TOF-MS). Thirty sulfur compounds were positively identified by MS library search, linear retention indices (LRI), molecular mass determination using PCI accurate mass spectra, formula calculation using EI and PCI accurate mass spectra, and structure elucidation using collision activated dissociation (CAD) of the protonated molecule. Additionally, 11 molecular formulas were obtained for unknown sulfur compounds. The determined values of the identified and unknown sulfur compounds were in the range of 10-740ngmg total particulate matter (TPM) (RSD: 1.2-12%, n=3). PMID:25087743

  1. Isolation and characterization of a facultative methanotroph degrading malodor-causing volatile sulfur compounds.

    PubMed

    Lee, Jung-Hee; Kim, Tae Gwan; Cho, Kyung-Suk

    2012-10-15

    Simultaneous removal of methane and malodor-causing volatile sulfur compounds (MVSCs), both emitted from landfills, is a desirable characteristic for methane-mitigation approaches. A methanotrophic bacterium was isolated from a microbial consortium, enriched with methane and dimethyl sulfide (DMS). It grew in the complex nutrient medium R2A without methane, and stably exhibited methanotrophic activity after facultative growth. It was identified as Sphingopyxis sp. MD2 by comparison of the 16S rRNA gene. It belongs to Sphingomonadales, whose members have not shown methanotrophic activity, phylogenetically distinct from orders of known methanotrophs. The MD2 biomass increased at a growth rate of 1.18d(-1) when methane was used as the sole growth substrate. An inhibition test with allylthiourea and PCR/sequencing confirmed the presence of particulate methane monooxygenase in MD2. DMS decreased the methane oxidation rate (2634±146 ?mole g DCW(-1) h(-1)) by 12%, while H(2)S had no effect on the methane oxidation rate. Interestingly, methanethiol (MT) enhanced the methane oxidation rate by more than 50%. MD2 degraded H(2)S and MT, regardless of the presence of methane. MD2 also degraded DMS in the presence of methane, indicating co-metabolism. These combined results indicate that MD2 may be a promising biological resource for simultaneous removal of methane and MVSCs. PMID:22884733

  2. Assessment of reduced sulfur compounds in ambient air as malodor components in an urban area

    NASA Astrophysics Data System (ADS)

    Susaya, Janice; Kim, Ki-Hyun; Phan, Nhu-Thuc; Kim, Jo-Chun

    2011-07-01

    Long-term monitoring of reduced sulfur compounds (RSCs: hydrogen sulfide (H 2S), methanethiol (CH 3SH), dimethyl sulfide (DMS), and dimethyl disulfide (DMDS)) in ambient air was made using an on-line GC system at an odor monitoring station in the city of Ansan, South Korea (August 2005-December 2007). The results were examined to assess the status of RSC pollution, its relative contribution to malodor, and the controlling factors of its occurrence. H 2S (mean of 0.27 ppb) was eminent in terms of both magnitude and occurrence frequency, while others were not with mean values of 0.11 (DMDS), 0.10 (DMS), and 0.07 ppb (CH 3SH). Unlike others, the temporal trends of H 2S were best represented by the combined effects of its source processes and meteorological conditions. The results of correlation analysis indicate strong correlations between RSCs and water-related parameters (e.g., rainfall, dew point, and relative humidity). The role of RSCs as malodor component appears to be pronounced during nighttime, especially in summer. If the relative contribution of RSCs to malodor is assessed by means of the sum of odor intensity (SOI), its impact is relatively low, with an SOI value of 1.22 (weak odor strength). Consequently, a more deliberate approach may be needed to effectively assess odor occurrence patterns in ambient air.

  3. Kinetics of aerobic oxidation of volatile sulfur compounds in wastewater and biofilm from sewers.

    PubMed

    Rudelle, E A; Vollertsen, J; Hvitved-Jacobsen, T; Nielsen, A H

    2013-01-01

    Laboratory experiments were conducted to investigate the kinetics of aerobic chemical and biological oxidation of selected odorous volatile sulfur compounds (VSCs) by wastewater and biofilm from sewers. The VSCs included methyl mercaptan (MeSH), ethyl mercaptan (EtSH), dimethyl sulfide (DMS) and total inorganic sulfide, which have all been reported as the main constituents of foul sewer gas. Samples of wastewater and biofilm for the experiments were obtained from two locations that differed significantly with respect to the occurrence of VSCs. One location represented an odor hot-spot downstream of a force main and the other was a gravity sewer transporting young aerobic wastewater. The kinetics of VSC oxidation for both wastewater and suspended biofilm samples followed a first-order rate equation. The average values of the reaction rate constants demonstrated the following order of reactivity: total inorganic sulfide > EtSH ? MeSH > DMS. Except for total inorganic sulfide oxidation in wastewater, kinetic parameters for each VSC were of similar magnitude for the two locations. In the wastewater from the odor hot-spot, sulfide inorganic oxidation rates were approximately 12 times faster than in the aerobic wastewater. PMID:24334879

  4. Computational Studies of CO2 Activation via Photochemical Reactions with Reduced Sulfur Compounds

    PubMed Central

    Baltrusaitis, Jonas; Patterson, Eric; Hatch, Courtney

    2012-01-01

    Reactions between CO2 and reduced sulfur compounds (RSC) - H2S and CH3SH - were investigated using ground and excited state density functional theory (DFT) and coupled cluster (CC) methods to explore possible RSC oxidation mechanisms and CO2 activation mechanisms in the atmospheric environment. Ground electronic state calculations at the CR-CC(2,3)/6-311+G(2df,2p)//CAM-B3LYP/6-311+G(2df,2p) level show proton transfer as a limiting step in the reduction of CO2 with activation energies of 49.64 and 47.70 kcal/mol, respectively, for H2S and CH3SH. On the first excited state surface, CR-EOMCC(2,3)/6-311+G(2df,2p)//CAM-B3LYP/6-311+G(2df,2p) calculations reveal that energies of <250 nm are needed to form H2S-CO2 and CH3SH-CO2 complexes allowing facile hydrogen atom transfer. Once excited, all reaction intermediates and transition states are downhill energetically showing either C-H or C-S bond formation in the excited state whereas only C-S bond formation was found in the ground state. Environmental implications of these data are discussed with a focus on tropospheric reactions between CO2 and RSC, as well as potential for carbon sequestration using photocatalysis. PMID:22920727

  5. Origins of sulfur compounds in the atmosphere of a zone of high productivity (Gulf of Guinea)

    SciTech Connect

    Delmas, R.; Servant, J.

    1982-12-20

    Recent observations have suggested substantial emission of sulfur compounds by oceanic water which could explain the presence of SO/sub 2/ and SO/sup +//sub 4/ in the air above these waters. The emission is thought to increase with the productivity of the oceanic zones. This point is discussed in relation to the Gulf of Guinea, a zone of high productivity. During the first two campaigns between Dakar, Abidjan, and the Gulf of Guinea SO/sup +//sub 4/ concentrations were measured in the air. Between Abidjan and the Gulf of Guinea the atmospheric SO= /sub 4/ concentrations decreased from 800 to 400 ng m/sup -3/. During the third campaign, between Abidjan and the South Equatorial Current (latitude 1/sup 0/S), the H/sub 2/S and SO/sub 2/ concentrations were measured. The mean H/sub 2/S concentration was 20 ng m/sup -3/, and that of SO/sub 2/ varied between 120 and under 50 ng m/sup -3/. The origins of SO/sub 2/ and SO/sup +//sub 4/ in the air of this area are discussed through the daily variations of the H/sub 2/S content of the air and a contribution from the forested zones of West Africa.

  6. Measurements of Volatile Organic Compounds and Gaseous Sulfuric Acid During the 2008 CAREBEIJING Campaign

    NASA Astrophysics Data System (ADS)

    Zhang, R.; Zheng, J.; Hu, M.; Zhu, T.

    2009-05-01

    Air quality in Beijing has been a hot topic recently, because Beijing hosted the 2008 summer Olympics. To combat the problem, China ordered numerous factories shut down or used only sporadically during the games to limit air pollution in the area. Another major step involved ordering about one-half of the city's 3.3 million vehicles off the road during the games, allowing only cars on roads with odd or even-numbered license plates on alternate days until the games were over. In addition, China has implemented new auto emission standards since March 2009 with regulations that are similar to those used throughout Europe. Our team at the Texas A&M participated in the 2008 CAREBEIJING campaign, with the objectives of studying the complex chemistry of the air in Beijing, looking at emission controls and their effectiveness, studying the surrounding air from other regions and how it can affect Beijing's air, and comparing all of our findings with air quality in other cities we have examined, such as Mexico City and Houston. In this talk, preliminary results of measurements of volatile organic compounds (VOCs) and gaseous sulfuric acid will be presented to discuss the trends of VOCs and new particle formation associated with the traffic control.

  7. Effects of Streptococcus thermophilus on volatile sulfur compounds produced by Porphyromonas gingivalis.

    PubMed

    Lee, Sung-Hoon; Baek, Dong-Heon

    2014-11-01

    Halitosis as oral malodour is an unpleasant odour caused by volatile sulfur compounds (VSCs). VSCs are produced primarily by anaerobic bacteria that abundantly produce proteinase as trypsin-like enzyme. General therapies, such as mouthwash and plaque control, do not provide a continuous effect on oral halitosis. Streptococcus thermophilus is a probiotic bacterium that is beneficial for human health. The aim of this study was to evaluate the effect of S. thermophilus on Porphyromonas gingivalis-producing VSCs and to analyze the inhibitory mechanism of halitosis. P. gingivalis was cultured with or without S. thermophilus, and the emission of VSCs from the spent culture medium was measured by gas chromatography. In order to analyze the inhibitory effect, the antibacterial activity of S. thermophilus against P. gingivalis was assessed. After the spent culture medium or whole bacterial of S. thermophilus was mixed with the spent culture medium of P. gingivalis, VSCs were again measured by gas chromatograph. When S. thermophilus and P. gingivalis were co-cultivated, VSCs were present at a lower level than those of single-cultured P. gingivalis. S. thermophilus inhibited growth of P. gingivalis, and the whole bacteria and the spent culture medium of S. thermophilus reduced emission of VSCs gas. S. thermophilus may reduce oral malodour by inhibition of P. gingivalis growth and neutralizing VSCs with their metabolites or themselves. PMID:25105253

  8. Cryogenic trapping of reduced sulfur compounds using a nafion drier and cotton wadding as an oxidant scavenger

    NASA Astrophysics Data System (ADS)

    Hofmann, U.; Hofmann, R.; Kesselmeier, J.

    A commercially available Nafion drier (Perma-Pure) was tested under laboratory and field conditions and shown to be suitable for measurements of reduced sulfur compounds such as H 2S, COS, CH 3SH, CH 3SCH 3 (DMS) and CS 2 in dry and humid air in the pptv-range. For the scavenging of oxidants we combined the Nafion drier technique with a cotton oxidant scrubber. Results obtained under laboratory conditions with humidified samples and in the course of a small field experiment confirm the oxidant scrubber qualities of cotton and indicate that the cotton oxidant scrubber in combination with a Nafion drier is suitable for measurements of nearly all reduced sulfur compounds except CH 3SH.

  9. Methods for removing malodorous sulfur compounds from pulp mill flue gases and the like by using green liquor

    SciTech Connect

    Farin, W.G.

    1984-02-14

    This is an improved method for removing malodorous sulfur compounds from flue gases generated in kraft or sodium sulfite pulping operations and the like by the absorption process using green liquor, an aqueous solution containing sodium sulfide and sodium carbonate. The malodorous gas compounds, including hydrogen sulfide, methyl mercaptan, and dimethyl sulfide are preferentially absorbed by the sodium sulfide forming sodium hydrosulfide and methanol. Any sulfur dioxide in the gas is absorbed and neutralized by sodium carbonate. In this method carbon dioxide absorption is minimized and the formation of sodium bicarbonate is limited. Sodium bicarbonate formation is minimized in order to avoid its reaction with sodium hydrosulfide which would then release undesirable hydrogen sulfide during absorption, as well as to forestall the need to increase chemical and lime kiln capacity requirements when the green liquor returned to the kraft recovery process contains excess amounts of sodium bicarbonate.

  10. Alkali metal-sulfur cells

    SciTech Connect

    Auborn, J.J.; Granstaff, S.M.

    1982-11-02

    An alkali metal, such as sodium, sulfur cell having an alkali metal anode, a solid ionic electrolyte, such as sodium beta alumina, and a liquid catholyte formed by sulfur, a halosulfane, such as sulfur monochloride and a haloacid, such as aluminum chloride, is described.

  11. CONTROLLING SULFUR OXIDES

    EPA Science Inventory

    This Research Summary describes EPA's program to develop new and improve existing technologies for sulfur oxides control. As we increasingly turn to coal as the primary utility and industrial fuel, while trying to deal with the problems of acid precipitation, visibility degradati...

  12. Sulfur in basaltic magmas

    Microsoft Academic Search

    Paul Wallace; Ian S. E. Carmichael

    1992-01-01

    The concentration of S in basaltic magmas at 1 atm pressure is strongly dependent on temperature, the fugacities of oxygen ( f O 2 ) and sulfur ( f S 2 ), and bulk composition. Microprobe analyses of total S in rapidly quenched, submarine basalt glasses, used in conjunction with wet chemical analyses of Fe 2 O 3 \\/ FeO

  13. Transformation of Sulfur Compounds by an Abundant Lineage of Marine Bacteria in the ?-Subclass of the Class Proteobacteria

    PubMed Central

    González, José M.; Kiene, Ronald P.; Moran, Mary Ann

    1999-01-01

    Members of a group of marine bacteria that is numerically important in coastal seawater and sediments were characterized with respect to their ability to transform organic and inorganic sulfur compounds. Fifteen strains representing the Roseobacter group (a phylogenetic cluster of marine bacteria in the ?-subclass of the class Proteobacteria) were isolated from seawater, primarily from the southeastern United States. Although more than one-half of the isolates were obtained without any selection for sulfur metabolism, all of the isolates were able to degrade the sulfur-containing osmolyte dimethyl sulfoniopropionate (DMSP) with production of dimethyl sulfide (DMS). Five isolates also degraded DMSP with production of methanethiol, indicating that both cleavage and demethylation pathways for DMSP occurred in the same organism, which is unusual. Five isolates were able to reduce dimethyl sulfoxide to DMS, and several isolates also degraded DMS and methanethiol. Sulfite oxygenase activity and methanesulfonic acid oxygenase activity were also present in some of the isolates. The ability to incorporate the reduced sulfur in DMSP and methanethiol into cellular material was studied with one of the isolates. A group-specific 16S rRNA probe indicated that the relative abundance of uncultured bacteria in the Roseobacter group increased in seawater enriched with DMSP or DMS. Because this group typically accounts for >10% of the 16S ribosomal DNA pool in coastal seawater and sediments of the southern United States, clues about its potential biogeochemical role are of particular interest. Studies of culturable representatives suggested that the group could mediate a number of steps in the cycling of both organic and inorganic forms of sulfur in marine environments. PMID:10473380

  14. Combined chemical and microbiological removal of organic sulfur from coal

    SciTech Connect

    Raphaelian, L.A.

    1991-01-01

    The objective of this work is to investigate techniques for chemically converting the sulfur containing organic compounds in coal to compounds that can be treated microbiologically to remove the organically bound sulfur. The goal is to achieve an economically feasible mild chemical oxidation of the organic sulfur in a representative Illinois Basin coal by converting the sulfur to sulfoxides and sulfones; the carbon sulfur bond in the sulfoxides and sulfones would then be broken microbiologically and the sulfur removed from the coal as sulfate.

  15. 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.

  16. Spatial distributions of volatile sulfur compounds in surface seawater and overlying atmosphere in the northwestern Pacific Ocean, eastern Indian Ocean, and Southern Ocean

    Microsoft Academic Search

    Yayoi Inomata; Masahiko Hayashi; Kazuo Osada; Yasunobu Iwasaka

    2006-01-01

    Distributions of volatile sulfur compounds (carbonyl sulfide (COS), carbon disulfide (CS2), hydrogen sulfide (H2S), dimethyl sulfide (DMS)) in surface seawater and overlying atmosphere were measured in the northwestern Pacific, eastern Indian, and Southern Oceans (40°N–66°S, 40°E–140°E) in November–December 1996 during the 38th Japanese Antarctic Research Expedition cruise. Seawater measurements revealed that DMS was the dominant sulfur compound, with concentrations of

  17. Sulfur emissions from Mt. Etna

    Microsoft Academic Search

    Wolfgang Jaeschke; Harald Berresheim; Hans-W. Georgii

    1982-01-01

    In the course of three measuring trips to the Mt. Etna volcano (Sicily), field measurements and measurements by aircraft were carried out in the plume of the volcano to determine the concentration distributions and emission rates for the sulfur compounds H2S, SO2, and SO42-. Furthermore, the removal of H2S and SO2 and the production of SO42- in the dispersing plume

  18. Allyl isothiocyanate from mustard seed is effective in reducing the levels of volatile sulfur compounds responsible for intrinsic oral malodor.

    PubMed

    Tian, Minmin; Hanley, A Bryan; Dodds, Michael W J

    2013-06-01

    Oral malodor is a major social and psychological issue that affects general populations. Volatile sulfur compounds (VSCs), particularly hydrogen sulfide (H?S) and methyl mercaptan (CH?SH), are responsible for most oral malodor. The objectives for this study were to determine whether allyl isothiocyanate (AITC) at an organoleptically acceptable level can eliminate VSCs containing a free thiol moiety and further to elucidate the mechanism of action and reaction kinetics. The study revealed that gas chromatograph with a sulfur detector demonstrated a good linearity, high accuracy and sensitivity on analysis of VSCs. Zinc salts eliminate the headspace level of H?S but not CH?SH. AITC eliminates both H?S and CH?SH via a nucleophilic addition reaction. In addition, a chemical structure-activity relationship study revealed that the presence of unsaturated group on the side chain of the isothiocyanate accelerates the elimination of VSCs. PMID:23470258

  19. Stability of volatile sulfur compounds (VSCs) in sampling bags - impact of temperature.

    PubMed

    Le, H; Sivret, E C; Parcsi, G; Stuetz, R M

    2013-01-01

    Volatile sulfur compounds (VSCs) are a major component of odorous emissions that can cause annoyance to local populations surrounding wastewater, waste management and agricultural practices. Odour collection and storage using sample bags can result in VSC losses due to sorption and leakage. Stability within 72 hour storage of VSC samples in three sampling bag materials (Tedlar, Mylar, Nalophan) was studied at three temperatures: 5, 20, and 30 °C. The VSC samples consisted of hydrogen sulfide (H2S), methanethiol (MeSH), ethanethiol (EtSH), dimethyl sulfide (DMS), tert-butanethiol (t-BuSH), ethylmethyl sulfide (EMS), 1-butanethiol (1-BuSH), dimethyl disulfide (DMDS), diethyl disulfide (DEDS), and dimethyl trisulfide (DMTS). The results for H2S showed that higher loss trend was clearly observed (46-50% at 24 hours) at 30 °C compared to the loss at 5 °C or 20 °C (of up to 27% at 24 hours) in all three bag materials. The same phenomenon was obtained for other thiols with the relative recoveries after a 24 hour period of 76-78% at 30 °C and 80-93% at 5 and 20 °C for MeSH; 77-80% at 30 °C and 79-95% at 5 and 20 °C for EtSH; 87-89% at 30 °C and 82-98% at 5 and 20 °C for t-BuSH; 61-73% at 30 °C and 76-98% at 5 and 20 °C for 1-BuSH. Results for other sulfides and disulfides (DMS, EMS, DMDS, DEDS) indicated stable relative recoveries with little dependency on temperature (83-103% after 24 hours). DMTS had clear loss trends (with relative recoveries of 74-87% in the three bag types after 24 hours) but showed minor differences in relative recoveries at 5, 20, and 30 °C. PMID:24185074

  20. The chemical processing of gas-phase carbonyl compounds by sulfuric acid aerosols: 2,4-pentanedione

    NASA Astrophysics Data System (ADS)

    Nozière, Barbara; Riemer, Daniel D.

    This work investigates the interactions between gas-phase carbonyl compounds and sulfuric acid aerosols. It focuses on understanding the chemical processes, giving a first estimate of their importance in the atmosphere, and suggesting directions for further investigations. The solubility and reactivity of a compound with a large enolization constant, 2,4-pentanedione, in water/sulfuric acid solutions 0-96 wt% have been investigated at room temperature using the bubble column/GC-FID technique. 2,4-pentanedione was found to undergo aldol condensation at acidities as low as 20 wt% H 2SO 4, that is, well in the tropospheric range of aerosol composition. In agreement with well-established organic chemical knowledge, this reaction resulted in changes of color of the solutions of potential importance for the optical properties of the aerosols. 2,4-pentanedione was also found to undergo retroaldol reaction, specific to dicarbonyl compounds, producing acetone and acetaldehyde. The Henry's law coefficient for 2,4-pentanedione was found to be a factor 5 larger than the one of acetone over the whole range of acidity, with a value in water of H (297 K)=(155±27) M atm -1. A chemical system is proposed to describe the transformations of carbonyl compounds in sulfuric acid aerosols. Aldol condensation is likely to be the most common reaction for these compounds, probably involving a large number of the ones present in the atmosphere and a wide range of aerosol compositions. The enolization constant contributes as a proportional factor to the rate constant for aldol condensation, and is shown in this work to contribute as an additive constant to the Henry's law coefficient. In addition to the many important aspects of these reactions illustrated in this work, the rate of aldol condensation was estimated to be potentially fast enough for the losses of some compounds in acidic aerosols to compete with their gas-phase chemistry in the atmosphere.

  1. New sulfur-containing corrosion inhibitor

    SciTech Connect

    Prince, P.

    2000-04-01

    No corrosion inhibitor available today is ideal in every way, but a new class of sulfur-containing compounds promises to address many field requirements. This article describes the performance characteristics of these compounds and discusses possible inhibition mechanisms. The emphasis in this work was on better understanding corrosion inhibition by sulfur-containing inhibitors under high shear-stress conditions, with special focus on localized (pitting) corrosion. The results indicate that the new sulfur-containing inhibitors (e.g., mercaptoalcohol [MA]) could be more effective in the field than currently available inhibitors.

  2. X-ray absorption spectroscopic investigation of sulfur sites in coal: organic sulfur identification

    Microsoft Academic Search

    C. L. Spiro; J. Wong; F. W. Lytle; R. B. Greegor; D. H. Maylotte; S. H. Lamson

    1984-01-01

    High-resolution x-ray absorption spectroscopy was used to probe the chemical and structural environments of sulfur in coal. Measurement of the sulfur K-edge spectra down to 2472.0 electron volts under nonvacuum conditions was made possible in an all-helium path, and a Stern-Heald type ion chamber was used for fluorescence detection. For a number of selected sulfur-containing minerals and organic model compounds,

  3. Sulfur dichloride, SCl2

    NSDL National Science Digital Library

    This month's molecule is sulfur dichloride, SCl2. This and other small inorganic molecules are discussed in the article by Matta and Gillespie. They describe electron density in molecules and how to analyze it to obtain information about molecular bonding and structure. Different depictions of electron density in SCl2 and other small molecules emphasize different aspects of their electron density and of the structures of the molecules.

  4. Stratospheric sulfur oxidation kinetics

    SciTech Connect

    Jayne, J.T.; Worsnop, D.R.; Kolb, C.E. [Aerodyne Research, Inc., Billerica, MA (United States)] [and others

    1995-12-31

    Oxidation of SO2 to H2SO4 in the atmosphere is believed to involve the reaction of SO3 with water. It is commonly assumed that this is an important step leading to homogeneous nucleation of H2SO4 aerosol particles. Heterogeneous chemistry on sulfuric acid aerosols regulate much of the ozone photochemistry in the lower stratosphere and are also believed to have significant effect on the climate. Understanding aerosol loading requires a detailed knowledge of the stratospheric sulfur budget, including its oxidation kinetics. Here we present results of a laboratory project studying a key step in the oxidation process, the homogeneous reaction between SO3 and H2O vapor. Kinetic measurements are performed in a high-pressure turbulent fast-flow reactor (fabricated at MIT) which minimizes heterogeneous loss of SO3 on reactorwalls. The rate of decay of SO3 and the appearance of H2SO4 is monitored in the presence of excess water vapor. Gas phase reactants and products are detected via an atmospheric pressure chemical ionization mass spectrometer which is coupled to the exit of the flow reactor. Sulfuric acid nucleation studies can also be performed using the turbulent flow reactor. Initial measurements using a particle detector (based on Mie scattering) showed that aerosol formation and particle size distribution are controlled by varying the SO3/H2O gas ratio and the reactor temperature. Results for the reaction SO3J+ H2O show a second order dependence in water vapor density and a strong negative temperature dependence. The results, measured in the range -30C to +95C, imply that an SO3.H2O adduct and/or a water dimer species is likely involved in the reaction mechanism. Results of recent theoretical calculations on the SO3 + H2O system also support the finding that two water molecules are involved. Implications for the gas phase production of sulfuric acid in the atmosphere will be discussed.

  5. Sulfur mobility in peat

    Microsoft Academic Search

    Martin Novák; Marie Adamová; R. Kelman Wieder; Simon H. Bottrell

    2005-01-01

    Lead-210 chronologies, vertical S concentration gradients and ?34S values are presented for 5 Sphagnum-dominated peat bogs located in Central Europe (Rybarenska slat and Ocean Bog; Czech Republic) and the British Isles (Thorne Moors, England; Connemara, Ireland; and Mull, Scotland). Sulfur concentrations were measured in three 40-cm deep peat cores per site, sectioned into 2-cm segments. The coefficient of variation in

  6. Inhibition of heterocyclic aromatic amine formation in fried ground beef patties by garlic and selected garlic-related sulfur compounds.

    PubMed

    Shin, Inn-Seung; Rodgers, W John; Gomaa, Enayat A; Strasburg, Gale M; Gray, J Ian

    2002-11-01

    The effects of garlic and selected organosulfur compounds (diallyl disulfide, dipropyl disulfide, diallyl sulfide, allyl methyl sulfide, allyl mercaptan, cysteine, and cystine) on the formation of heterocyclic aromatic amines (HAAs) in fried ground beef patties were evaluated. Minced garlic cloves (ca. 4.8 to 16.7%, wt/wt) or organosulfur compounds (0.67 mmol) were added directly to ground beef. Patties (100 g) were fried at 225 degrees C (surface temperature) for 10 min per side. Two patties were fried for each replication, and five replicates were analyzed for each treatment. For each replicate, four subsamples were analyzed (two unspiked subsamples for concentration and two spiked subsamples for the recovery of HAA standards). The volatile sulfur compounds significantly (P < 0.05) reduced concentrations of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine by reductions of 46 to 81%, while average reductions of 35, 22, and 71%, were achieved with cystine, cysteine, and whole garlic, respectively. The volatile sulfur compounds reduced concentrations of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline by 34 to 67%, while reductions of 25, 19, and 63% (P < 0.05) were achieved with cystine, cysteine, and whole garlic, respectively. These studies confirm that garlic and some organosulfur compounds have the potential to reduce HAA formation incooked beef patties. PMID:12430700

  7. Method for reducing the sulfur content of a sulfur-containing hydrocarbon stream

    DOEpatents

    Mahajan, Devinder

    2004-12-28

    The sulfur content of a liquid hydrocarbon stream is reduced under mild conditions by contracting a sulfur-containing liquid hydrocarbon stream with transition metal particles containing the transition metal in a zero oxidation state under conditions sufficient to provide a hydrocarbon product having a reduced sulfur content and metal sulfide particles. The transition metal particles can be produced in situ by adding a transition metal precursor, e.g., a transition metal carbonyl compound, to the sulfur-containing liquid feed stream and sonicating the feed steam/transition metal precursor combination under conditions sufficient to produce the transition metal particles.

  8. Use of a novel fluorinated organosulfur compound to isolate bacteria capable of carbon-sulfur bond cleavage.

    PubMed

    Van Hamme, Jonathan D; Fedorak, Phillip M; Foght, Julia M; Gray, Murray R; Dettman, Heather D

    2004-03-01

    The vacuum residue fraction of heavy crudes contributes to the viscosity of these oils. Specific microbial cleavage of C-S bonds in alkylsulfide bridges that form linkages in this fraction may result in dramatic viscosity reduction. To date, no bacterial strains have been shown conclusively to cleave C-S bonds within alkyl chains. Screening for microbes that can perform this activity was greatly facilitated by the use of a newly synthesized compound, bis-(3-pentafluorophenylpropyl)-sulfide (PFPS), as a novel sulfur source. The terminal pentafluorinated aromatic rings of PFPS preclude growth of aromatic ring-degrading bacteria but allow for selective enrichment of strains capable of cleaving C-S bonds. A unique bacterial strain, Rhodococcus sp. strain JVH1, that used PFPS as a sole sulfur source was isolated from an oil-contaminated environment. Gas chromatography-mass spectrometry analysis revealed that JVH1 oxidized PFPS to a sulfoxide and then a sulfone prior to cleaving the C-S bond to form an alcohol and, presumably, a sulfinate from which sulfur could be extracted for growth. Four known dibenzothiophene-desulfurizing strains, including Rhodococcus sp. strain IGTS8, were all unable to cleave the C-S bond in PFPS but could oxidize PFPS to the sulfone via the sulfoxide. Conversely, JVH1 was unable to oxidize dibenzothiophene but was able to use a variety of alkyl sulfides, in addition to PFPS, as sole sulfur sources. Overall, PFPS is an excellent tool for isolating bacteria capable of cleaving subterminal C-S bonds within alkyl chains. The type of desulfurization displayed by JVH1 differs significantly from previously described reaction results. PMID:15006770

  9. Use of a Novel Fluorinated Organosulfur Compound To Isolate Bacteria Capable of Carbon-Sulfur Bond Cleavage

    PubMed Central

    Van Hamme, Jonathan D.; Fedorak, Phillip M.; Foght, Julia M.; Gray, Murray R.; Dettman, Heather D.

    2004-01-01

    The vacuum residue fraction of heavy crudes contributes to the viscosity of these oils. Specific microbial cleavage of C—S bonds in alkylsulfide bridges that form linkages in this fraction may result in dramatic viscosity reduction. To date, no bacterial strains have been shown conclusively to cleave C—S bonds within alkyl chains. Screening for microbes that can perform this activity was greatly facilitated by the use of a newly synthesized compound, bis-(3-pentafluorophenylpropyl)-sulfide (PFPS), as a novel sulfur source. The terminal pentafluorinated aromatic rings of PFPS preclude growth of aromatic ring-degrading bacteria but allow for selective enrichment of strains capable of cleaving C—S bonds. A unique bacterial strain, Rhodococcus sp. strain JVH1, that used PFPS as a sole sulfur source was isolated from an oil-contaminated environment. Gas chromatography-mass spectrometry analysis revealed that JVH1 oxidized PFPS to a sulfoxide and then a sulfone prior to cleaving the C—S bond to form an alcohol and, presumably, a sulfinate from which sulfur could be extracted for growth. Four known dibenzothiophene-desulfurizing strains, including Rhodococcus sp. strain IGTS8, were all unable to cleave the C—S bond in PFPS but could oxidize PFPS to the sulfone via the sulfoxide. Conversely, JVH1 was unable to oxidize dibenzothiophene but was able to use a variety of alkyl sulfides, in addition to PFPS, as sole sulfur sources. Overall, PFPS is an excellent tool for isolating bacteria capable of cleaving subterminal C—S bonds within alkyl chains. The type of desulfurization displayed by JVH1 differs significantly from previously described reaction results. PMID:15006770

  10. Microbial populations analysis and field application of biofilter for the removal of volatile-sulfur compounds from swine wastewater treatment system

    Microsoft Academic Search

    Kuo-Ling Ho; Ying-Chien Chung; Yueh-Hsien Lin; Ching-Ping Tseng

    2008-01-01

    A biofilter packed with granular activated carbon (GAC) was applied to eliminate volatile-sulfur compounds (VSC) emitted from solid–liquid separation tank in swine wastewater treatment system. Hydrogen sulfide, methanethiol, dimethyl disulfide, and dimethyl sulfide were effectively reduced to 96–100% at gas residence times of 13–30s. Elemental sulfur and sulfate are their primary oxidation metabolites. Regarding odor, an average of 86% reduction

  11. Fluorine-Induced Chemiluminescence Detection of Biologically Methylated Tellurium, Selenium, and Sulfur Compounds and Methyldithiocarbhydrazide as a Formaldehyde Derivatization Reagent

    NASA Astrophysics Data System (ADS)

    Chasteen, Thomas Girard

    1990-01-01

    The first part of this dissertation describes capillary chromatography coupled to a fluorine-induced chemiluminescence detector as a sensitive method by which biologically methylated metalloids can be determined in the presence of high concentrations of potentially interfering molecules. With a wide linear range and excellent sensitivity, this method was applied to the detection of dimethyl selenide (DMSe), dimethyl diselenide (DMDSe), and dimethyl telluride (DMTe), often found in biological environments in the presence of interfering methylated sulfur gases, such as methanethiol, dimethyl sulfide, dimethyl disulfide, and dimethyl trisulfide. Detection limits for DMSe, DMDSe, and DMTe were 30, 9, and 7 picograms, respectively. This DMTe detection limit is the lowest reported to date for a volatile tellurium gas. A variety of selenium-resistant bacteria emitted mixtures of methylated sulfur/selenium gases when dosed with inorganic selenium salts in the presence of sulfur containing growth media. One of the gases detected was dimethyl selenenyl sulfide, CH_3SeSCH _3, reported here for the first time in headspace above microorganisms. In addition, this detector responded to reduced phosphorus compounds such as phosphine. The detection limit for this compound was 2.8 picograms. Detection limits for alkylated phosphines trimethyl and triethyl phosphine were 0.5 and 17 picograms respectively, based on the relative response of these compounds compared to dimethyl sulfide. This method can be used for the simultaneous determination of methylated sulfur, selenium, tellurium compounds found in biological systems. Part II of this dissertation describes work with methyldithiocarbhydrazide, a compound that has been synthesized for use as a derivatization reagent to capture formaldehyde in the gas phase. Chosen for its ability to react in a manner similar to 2,4-dinitrophenylhydrazine, this molecule was selected based on two structural characteristics: a hydrazine tag to react with and thereby capture carbonyls and a methyl sulfide group to allow for sensitive detection by fluorine-induced chemiluminescence. Although in the final analysis methyldithiocarbohydrazide failed as a successful means by which formaldehyde can be determined using gas chromatography in conjunction with fluorine-induced chemiluminescence, it did successfully derivatize formaldehyde in both solution and the gas phase without the need for low pH conditions.

  12. Phanerozoic cycles of sedimentary carbon and sulfur

    PubMed Central

    Garrels, Robert M.; Lerman, Abraham

    1981-01-01

    A reservoir model of a Recent steady-state sedimentary system in which the reduced sulfur and oxidized sulfur reservoirs were coupled with the oxidized carbon and reduced carbon reservoirs was constructed. The time curve of the sulfur isotope ratios of the sedimentary sulfate reservoir was used to drive the model back to the beginning of Cambrian time (600 million years ago), producing the reservoir sizes and isotope values and material fluxes of the carbon-sulfur system. The predicted values of carbon isotope ratios of the carbonate reservoir agree well with observed values, showing that the model is basically sound. Some general conclusions from this success are (i) material flux rates in the carbon-oxygen-sulfur system of the geologic past (averaged over tens of millions of years) lie within about a factor of 2 of Recent rates. (ii) The oxidation-reduction balances of Phanerozoic time were dominated by reciprocal relationships between carbon and sulfur compounds. (iii) The rate of production of atmospheric oxygen by storage in sediments of organic carbon of photosynthetic origin increased from the Cambrian Period to the Permian Period and declined somewhat from the Permian Period to the Present. (iv) The storage of oxygen in oxidized sulfur compounds kept pace (within the limits of the data) with oxygen production. (v) Transfer of oxygen from CO2 to SO4 from the Cambrian to the Permian Period was several times the Recent free oxygen content of the atmosphere. PMID:16593066

  13. Sulfurized limonite as material for fast decomposition of organic compounds by heterogeneous Fenton reaction.

    PubMed

    Toda, Kei; Tanaka, Toshinori; Tsuda, Yutaka; Ban, Masahiro; Koveke, Edwin P; Koinuma, Michio; Ohira, Shin-Ichi

    2014-08-15

    Rapid decomposition of wastewater contaminants using sulfurized limonite (S-limonite) was investigated. Limonite is used for desulfurization of biogases, and S-limonite is obtained from desulfurization plants as solid waste. In this work, the profitable use of S-limonite in water treatment was examined. The divalent Fe in S-limonite was expected to produce OH radicals, as Fe(2+) ions and limonite thermally treated with H2 do. Methylene blue was used for batch-wise monitoring of the decomposition performance. The decomposition rate was fast and the methylene blue solution color disappeared in only 10s when a small amount of H2O2 was added (1mM in the sample solution) in the presence of S-limonite. The OH radicals were formed by a heterogeneous reaction on the S-limonite surface and Fenton reaction with dissolved Fe(2+). The decomposition of pentachlorophenol was also examined; it was successfully decomposed in batch-wise tests. The surfaces of limonite before sulfurization, S-limonite, and S-limonite after use for water treatment were performed using scanning electron microscopy and X-ray photoelectron spectroscopy. The results show that S-limonite reverted to limonite after being used for water treatment. PMID:24997258

  14. Influence of Sulfur for Oxygen Substitution in the Solvolytic Reactions of Chloroformate Esters and Related Compounds

    PubMed Central

    D’Souza, Malcolm J.; Kevill, Dennis N.

    2014-01-01

    The replacement of oxygen within a chloroformate ester (ROCOCl) by sulfur can lead to a chlorothioformate (RSCOCl), a chlorothionoformate (ROCSCl), or a chlorodithioformate (RSCSCl). Phenyl chloroformate (PhOCOCl) reacts over the full range of solvents usually included in Grunwald-Winstein equation studies of solvolysis by an addition-elimination (A-E) pathway. At the other extreme, phenyl chlorodithioformate (PhSCSCl) reacts across the range by an ionization pathway. The phenyl chlorothioformate (PhSCOCl) and phenyl chlorothionoformate (PhOCSCl) react at remarkably similar rates in a given solvent and there is a dichotomy of behavior with the A-E pathway favored in solvents such as ethanol-water and the ionization mechanism favored in aqueous solvents rich in fluoroalcohol. Alkyl esters behave similarly but with increased tendency to ionization as the alkyl group goes from 1° to 2° to 3°. N,N-Disubstituted carbamoyl halides favor the ionization pathway as do also the considerably faster reacting thiocarbamoyl chlorides. The tendency towards ionization increases as, within the three contributing structures of the resonance hybrid for the formed cation, the atoms carrying positive charge (other than the central carbon) change from oxygen to sulfur to nitrogen, consistent with the relative stabilities of species with positive charge on these atoms. PMID:25310653

  15. Facilitated and selective oxidation of thiophenic sulfur compounds using MoOx/Al?O?-H?O? system under ultrasonic irradiation.

    PubMed

    Akbari, Azam; Omidkhah, Mohammadreza; Towfighi Darian, Jafar

    2015-03-01

    Oxidative desulfurization of thiophenic sulfur compounds of benzothiophene (BT), dibenzothiophene (DBT) and 4,6-dimethyl dibenzothiophene (4,6-DMDBT) with MoOx/Al?O? catalyst and H?O? oxidant has been facilitated and more selective under ultrasonic irradiation. The catalyst with the optimum 10% of Mo loading consisted of isolated tetrahedral molybdenum oxide species based on FTIR analysis. The increase of Mo loading to 15% and 20% caused to generation of polymolybdate and MoO? crystals which decreased desulfurization activity. Sonication enhanced the apparent reaction rate constants in oxidation of all three sulfur compounds. An increase in the Arrhenius factor (A0), which is the total number of collisions per second, could explain the acceleration in the rate constants by sonication. The apparent activated energy (Ea) of BT oxidation was reduced from 96.6 to 75.3 kJ/mol by using ultrasound. This indicated that ultrasound had also a chemical effect, like a catalytic influence, in the acceleration of BT removal. DBT oxidation was reduced when investigated in the presence of tetralin, naphthalene and 2-methyl naphthalene as the model aromatic compounds of actual light oils. A higher selectivity toward DBT elimination in the presence of aromatics was obtained by sonication when compared with the silent treatment. Ultrasound cleaned the catalyst surface from adsorbed aromatics. On the basis of the obtained results, a mechanistic proposal for this desulfurization was explained. Oxidation was performed by nucleophilic attack of sulfur atom to the molybdenum peroxide species of tetrahedral molybdates, which was more advanced by sonication. PMID:25258211

  16. Relationship Between Corrosion and the Biological Sulfur Cycle: A Review

    Microsoft Academic Search

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

    2000-01-01

    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

  17. Current emission trends for nitrogen oxides, sulfur dioxide, and volatile organic compounds by month and state: Methodology and results

    SciTech Connect

    Kohout, E.J.; Miller, D.J.; Nieves, L.A.; Rothman, D.S.; Saricks, C.L.; Stodolsky, F.; Hanson, D.A.

    1990-08-01

    This report presents estimates of monthly sulfur dioxide (SO{sub 2}), nitrogen oxides (NO{sub x}), and nonmethane voltatile organic compound (VOC) emissions by sector, region, and state in the contiguous United States for the years 1975 through 1988. This work has been funded as part of the National Acid Precipitation Assessment Program's Emissions and Controls Task Group by the US Department of Energy (DOE) Office of Fossil Energy (FE). The DOE project officer is Edward C. Trexler, DOE/FE Office of Planning and Environment.

  18. Current emission trends for nitrogen oxides, sulfur dioxide, and volatile organic compounds by month and state: Methodology and results

    SciTech Connect

    Kohout, E.J.; Miller, D.J.; Nieves, L.A.; Rothman, D.S.; Saricks, C.L.; Stodolsky, F.; Hanson, D.A.

    1990-08-01

    This report presents estimates of monthly sulfur dioxide (SO{sub 2}), nitrogen oxides (NO{sub x}), and nonmethane voltatile organic compound (VOC) emissions by sector, region, and state in the contiguous United States for the years 1975 through 1988. This work has been funded as part of the National Acid Precipitation Assessment Program`s Emissions and Controls Task Group by the US Department of Energy (DOE) Office of Fossil Energy (FE). The DOE project officer is Edward C. Trexler, DOE/FE Office of Planning and Environment.

  19. 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.

  20. Corrosivity of sulfur-bearing diesel fuels

    Microsoft Academic Search

    E. P. Sobolev; E. S. Churshukov; I. V. Rozhkov; I. A. Rubinshtein

    1966-01-01

    1.The corrosivity of sulfur-bearing diesel fuels is directly dependent on the chemical structure of the organic sulfur compounds present in the fuels.2.Mercaptans, especially aromatic mercaptans, exhibit the greatest effect on the process of steel corrosion. Fuels containing mercaptans give three to four times the amount of corrosion shown by fuels containing sulfides or thiophenes in concentrations 80 times the mercaptan

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

    SciTech Connect

    Najjar, M.S.; Corbeels, R.J.; Kokturk, U.

    1989-07-25

    This patent describes a process for the partial oxidation of a sulfur- and silicate-containing carbonaceous fuel to produce a synthesis gas with reduced sulfur content. It comprises partial oxidizing fuel at a temperature in the range of 1800{sup 0}-2200{sup 0}F. in the presence of a temperature moderator, an oxygen-containing gas and a sulfur capture additive which comprises 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 a sulfur-containing sodium-iron silicate phase and a sodium-iron sulfide phase. This patent describes a process for the partial oxidation of a sulfur- and silicate-containing carbonaceous fuel to produce a synthesis gas with reduced sulfur content. It comprises partially oxidizing a sulfur- and silicate-containing carbonaceous fuel at a temperature in the range of 1800{sup 0}-2200{sup 0}F in the presence of a temperature moderator, an oxygen-containing gas and a sulfur capture additive which comprises an iron-containing compound, a sodium-containing compound portion, and a copper-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 a sulfur-containing sodium-iron silicate phase and a sodium-copper-iron sulfide phase.

  2. Sodium sulfur storage battery

    SciTech Connect

    Kagawa, H.; Matsui, K.

    1985-04-09

    The present invention discloses a sodium-sulfur storage battery utilizing an inside of a sodium-ion conductive solid electrolyte tube as a negative chamber, comprising an a-alumina ring jointed with solder glass to an open end of said electrolyte tube, a flange aluminum housing having a fine hole at its bottom incorporated in said solid electrolyte tube, a negative auxiliary cover thermo-compressively jointed through a flange of said aluminum housing to an upper surface of said a-aluminum ring, and a negative cover provided with a negative current collector terminal welded to said negative auxiliary cover.

  3. Expand sulfur plant capacity

    SciTech Connect

    Hull, R. [BOC Gases, Murray Hill, NJ (United States); Watson, R. [BOC Gases, Guildford (United Kingdom); Chow, T.K. [Ralph M Parsons Co., Pasadena, CA (United States)] [and others

    1995-09-01

    Interest in oxygen use to expand existing Claus sulfur plants in refineries has been building ever since high oxygen concentrations were successfully used at the Conoco, Lake Charles La., refinery, and the KOA, Kawasaki refinery in Japan. This interest increased recently due to the demand created by numerous refinery hydrotreater projects, driven by more stringent fuel quality and sulfur emission standards, as well as the economic incentive to process low-cost heavy, sour crudes. Various approaches that introduce low oxygen levels have resulted in moderate capacity increases. Oxygen can be added to the air supply stream for concentrations up to 30% oxygen. Beyond the 30% oxygen level, oxygen must be introduced into the reaction furnace through a burner specifically designed to accommodate oxygen, or through a separate oxygen lance. However, higher oxygen concentrations result in higher temperatures, which rapidly approach the furnace refractory design limits. Methods must be employed to mitigate the reaction furnace temperature whenever high oxygen levels are necessary to coincide with significant capacity increases in refinery operations. Three proprietary technologies are in commercial operation that successfully address this issue.

  4. 21 CFR 184.1095 - Sulfuric acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...colorless, oily liquid. It is prepared by reacting sulfur dioxide (SO2 ) with oxygen and mixing the resultant sulfur trioxide (SO3 ) with water, or by reacting nitric oxide (NO) with sulfur dioxide and water. (b) The ingredient meets the...

  5. 21 CFR 184.1095 - Sulfuric acid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...colorless, oily liquid. It is prepared by reacting sulfur dioxide (SO2 ) with oxygen and mixing the resultant sulfur trioxide (SO3 ) with water, or by reacting nitric oxide (NO) with sulfur dioxide and water. (b) The ingredient meets the...

  6. 21 CFR 184.1095 - Sulfuric acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...colorless, oily liquid. It is prepared by reacting sulfur dioxide (SO2 ) with oxygen and mixing the resultant sulfur trioxide (SO3 ) with water, or by reacting nitric oxide (NO) with sulfur dioxide and water. (b) The ingredient meets the...

  7. 21 CFR 184.1095 - Sulfuric acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...colorless, oily liquid. It is prepared by reacting sulfur dioxide (SO2 ) with oxygen and mixing the resultant sulfur trioxide (SO3 ) with water, or by reacting nitric oxide (NO) with sulfur dioxide and water. (b) The ingredient meets the...

  8. 21 CFR 184.1095 - Sulfuric acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...colorless, oily liquid. It is prepared by reacting sulfur dioxide (SO2 ) with oxygen and mixing the resultant sulfur trioxide (SO3 ) with water, or by reacting nitric oxide (NO) with sulfur dioxide and water. (b) The ingredient meets the...

  9. Characterizing reduced sulfur compounds emissions from a swine concentrated animal feeding operation

    NASA Astrophysics Data System (ADS)

    Rumsey, Ian C.; Aneja, Viney P.; Lonneman, William A.

    2014-09-01

    Reduced sulfur compounds (RSCs) emissions from concentrated animal feeding operations (CAFOs) have become a potential environmental and human health concern, as a result of changes in livestock production methods. RSC emissions were determined from a swine CAFO in North Carolina. RSC measurements were made over a period of ?1 week from both the barn and lagoon during each of the four seasonal periods from June 2007 to April 2008. During sampling, meteorological and other environmental parameters were measured continuously. Seasonal hydrogen sulfide (H2S) barn concentrations ranged from 72 to 631 ppb. Seasonal dimethyl sulfide (DMS; CH3SCH3) and dimethyl disulfide (DMDS; CH3S2CH3) concentrations were 2-3 orders of magnitude lower, ranging from 0.18 to 0.89 ppb and 0.47 to 1.02 ppb, respectively. The overall average barn emission rate was 3.3 g day-1 AU-1 (AU (animal unit) = 500 kg of live animal weight) for H2S, which was approximately two orders of magnitude higher than the DMS and DMDS overall average emissions rates, determined as 0.017 g day-1 AU-1 and 0.036 g day-1 AU-1, respectively. The overall average lagoon flux was 1.33 ?g m-2 min-1 for H2S, which was approximately an order of magnitude higher than the overall average DMS (0.12 ?g m-2 min-1) and DMDS (0.09 ?g m-2 min-1) lagoon fluxes. The overall average lagoon emission for H2S (0.038 g day-1 AU-1) was also approximately an order of magnitude higher than the overall average DMS (0.0034 g day-1 AU-1) and DMDS (0.0028 g day-1 AU-1) emissions. H2S, DMS and DMDS have offensive odors and low odor thresholds. Over all four sampling seasons, 77% of 15 min averaged H2S barn concentrations were an order of magnitude above the average odor threshold. During these sampling periods, however, DMS and DMDS concentrations did not exceed their odor thresholds. The overall average barn and lagoon emissions from this study were used to help estimate barn, lagoon and total (barn + lagoon) RSC emissions from swine CAFOs in North Carolina. Total (barn + lagoon) H2S emissions from swine CAFOs in North Carolina were estimated to be 1.22*106 kg yr-1. The barns had significantly higher H2S emissions than the lagoons, contributing ?98% of total North Carolina H2S swine CAFO emissions. Total (barn + lagoon) emissions for DMS and DMDS were 1-2 orders of magnitude lower, with barns contributing ?86% and ?93% of total emissions, respectively. H2S swine CAFO emissions were estimated to contribute ?18% of North Carolina H2S emissions.

  10. Clinical comparison of a new manual toothbrush on breath volatile sulfur compounds.

    PubMed

    Williams, Malcolm I; Vazquez, Joe; Cummins, Diane

    2004-10-01

    The objective of this randomized, crossover study was to compare the effectiveness of a newly designed manual toothbrush (Colgate 360 degrees) to two commercially available manual toothbrushes (Oral-B Indicator and Oral-B CrossAction) and a battery-powered toothbrush (Crest SpinBrush PRO) for their ability to reduce overnight volatile sulfur compounds (VSC) associated with oral malodor. The study followed a four-period crossover design. Following a washout period, prospective subjects arrived at the testing facility without eating, drinking, or performing oral hygiene for baseline evaluation of breath VSC levels. For each phase of the study, subjects were given one of the test tooth-brushes and a tube of regular toothpaste to take home, and they were instructed to brush their teeth in their customary manner for 1 minute. When using the Colgate 360 degrees toothbrush, subjects were instructed to clean their tongue with the implement on the back of the brush head for 10 seconds. The following morning, subjects reported to the testing facility, again without performing oral hygiene, eating, or drinking, for the overnight evaluation. After a minimum 2-day washout period, subjects repeated the same regimen using the other toothbrushes. The levels of breath VSC were evaluated instrumentally using a gas chromatograph equipped with a flame photometric detector. Measurements were taken in duplicate and then averaged. The levels of VSC were expressed as parts per billion (ppb) in mouth air. Sixteen men and women completed the study. At baseline, the mean levels of VSC in mouth air for the 4 toothbrushes were 719.8 ppb+/-318.4 ppb, 592.8 ppb+/-264.6 ppb, 673.8 ppb+/-405.9 ppb, and 656.2 ppb+/-310.2 ppb for the Colgate 360 degrees, Oral-B Indicator, Crest SpinBrush PRO, and Oral-B CrossAction, respectively. Overnight, the mean breath VSC levels after using the four toothbrushes were lower than those observed at baseline. The respective mean levels of breath VSC were 266.5 ppb+/-269.9 ppb, 545.2 ppb+/-346.1 ppb, 567 ppb+/-335.7 ppb, and 554.6 ppb+/-398.4 ppb. Only the Colgate 360 degrees toothbrush provided a statistically significant reduction (P < .05) in breath VSC vs baseline. Additionally, the Colgate 360 degrees toothbrush was statistically significantly better (P < .05) than the three commercial toothbrushes in reducing breath VSC. Therefore, the results of this randomized, crossover clinical study indicate that a newly designed manual toothbrush with a tongue-cleaning implement on the back of the brush head was significantly more effective than three commercially available toothbrushes in reducing morning breath VSC associated with oral malodor. PMID:15789979

  11. Sulfur removal from natural gas

    Microsoft Academic Search

    Hakka

    1974-01-01

    Elemental sulfur entrained in natural gas at the well is removed by first contacting the natural gas with an aqueous solution of 5 to 50 wt % of monoethanolamine and then separating the sulfur-containing aqueous solution from the natural gas.

  12. 21 CFR 582.3862 - Sulfur dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 582.3862 Sulfur dioxide. (a) Product. Sulfur dioxide. (b) [Reserved] (c) Limitations,...

  13. 21 CFR 582.3862 - Sulfur dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 582.3862 Sulfur dioxide. (a) Product. Sulfur dioxide. (b) [Reserved] (c) Limitations,...

  14. 21 CFR 582.3862 - Sulfur dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 582.3862 Sulfur dioxide. (a) Product. Sulfur dioxide. (b) [Reserved] (c) Limitations,...

  15. 21 CFR 582.3862 - Sulfur dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 582.3862 Sulfur dioxide. (a) Product. Sulfur dioxide. (b) [Reserved] (c) Limitations,...

  16. An investigation of sulfur distribution during thermal plasma pyrolysis of used tires

    Microsoft Academic Search

    L. Tang; H. Huang

    2004-01-01

    Plasma pyrolysis of used tires leads to the distribution of sulfur compounds in gas and char generated during the process. Sulfur transformation and distribution were investigated by analyzing the gas and char at different conditions. Sulfides in the gaseous product were analyzed using photometric method. It was found that hydrogen sulfide was the main compound containing sulfur. The sulfur content

  17. Reactions of SIV species with organic compounds: formation mechanisms of organo-sulfur derivatives in atmospheric aerosols

    NASA Astrophysics Data System (ADS)

    Passananti, Monica; Shang, Jing; Dupart, Yoan; Perrier, Sébastien; George, Christian

    2015-04-01

    Secondary organic aerosol (SOA) have an important impact on climate, air quality and human health. However the chemical reactions involved in their formation and growth are not fully understood or well-constrained in climate models. It is well known that inorganic sulfur (mainly in oxidation states (+IV) and (+VI)) plays a key role in aerosol formation, for instance sulfuric acid is known to be a good nucleating gas. In addition, acid-catalyzed heterogeneous reactions of organic compounds has shown to produce new particles, with a clear enhancement in the presence of ozone (Iinuma 2013). Organosulfates have been detected in tropospheric particles and aqueous phases, which suggests they are products of secondary organic aerosol formation process (Tolocka 2012). Originally, the production of organosulfates was explained by the esterification reaction of alcohols, but this reaction in atmosphere is kinetically negligible. Other formation pathways have been suggested such as hydrolysis of peroxides and reaction of organic matter with sulfite and sulfate radical anions (SO3-, SO4-) (Nozière 2010), but it remains unclear if these can completely explain atmospheric organo-sulfur aerosol loading. To better understand the formation of organo-sulfur compounds, we started to investigate the reactivity of SIV species (SO2 and SO32-) with respect to specific functional groups (organic acids and double bonds) on atmospherically relevant carboxylic acids and alkenes. The experiments were carried out in the homogeneous aqueous phase and at the solid-gas interface. A custom built coated-wall flow tube reactor was developed to control relativity humidity, SO2 concentration, temperature and gas flow rate. Homogeneous and heterogeneous reaction kinetics were measured and resulting products were identified using liquid chromatography coupled with an orbitrap mass spectrometer (LC-HR-MS). The experiments were performed with and without the presence of ozone in order to evaluate any impact on the SIV oxidation and product formation. Preliminary results reveal that oxidation of SIV species can occur under a variety of atmospherically relevant conditions. Furthermore, LC-HR-MS analysis confirms the formation of organo-sulfur compounds that could derive from sulfate and/or the sulfite radical anion. These results elucidate the role of organo-sulfates aqueous and interfacial chemistry, important for our scientific understanding of atmospheric SOA formation. Iinuma Y., Kahnt A., Mutzel A., Böge O., Herrmann H., Environ. Sci. Technol., 2013, (47), 3639-3647, DOI: 10.1021/es305156z. Mauldin III R. L., Berndt T., Sipilä M., Paasonen P., Petäjä T., Kim S., Kurtén T., Stratmann F., Kerminen V.-M., Kulmala M., Nature, 2012, (488), 193-196, DOI: 10.1038/nature11278. Nozière B., Ekström S., AlsbergT., Holmström S., Geophys. Res. Lett., 2010, (37), 1-6, DOI: 10.1029/2009GL041683. Tolocka M.P., Turpin B., Environ. Sci. Technol., 2012, (46), 7978-7983, DOI: 10.1021/es300651v.

  18. Bacterial reworking and the abundance of organo-sulfur compounds in cretaceous kerogens from Sergipe Basin, Brazil

    SciTech Connect

    Carmo, A.M.; Pratt, L.M. [Indiana Univ., Bloomington, IN (United States); Stankiewicz, B.A. [Univ. of Bristol (United Kingdom)] [and others

    1996-10-01

    Immature kerogens of Upper Cretaceous marine strata from Sergipe Basin, Brazil are composed of variable amounts of reddish-fluorescing amorphous organic matter (rAOM) and algal remains (alginite). Pyrolysates of the alginite-dominated kerogens have prominent n-alk-1-ene/n-alkane pairs, and {alpha},{omega} alkadienes. Concentration of organo-sulfur compounds (OSC) are low but dominate the non-aliphatic components. In contrast, pyrolysates of the rAOM-dominated kerogens have high concentrations of OSC (mainly C{sub 1}C{sub 5} alkylthiophenes) and alkyl-benzenes in addition to abundant n-alk-1-ene/n-alkane pairs. Microprobe analysis of individual macerals revealed that S/C ratios of the alginites; are 50 to 30% lower than S/C ratios of the rAOM, indicating preferential concentration of OSC in the latter. Low preservation of algal remains and presence of relatively pronounced hopenes/hopanes and isoprenoids in pyrolysates of rAOM-dominated kerogens indicate substantial bacterial processing of primary organic matter. Therefore, it is suggested that the rAOM-dominated kerogens are enriched in OSC due to increased bacterial reworking and efficient sulfur incorporation into rAOM.

  19. Biological production and spatial variation of dimethylated sulfur compounds and their relation with plankton in the North Yellow Sea

    NASA Astrophysics Data System (ADS)

    Li, Cheng-Xuan; Yang, Gui-Peng; Wang, Bao-Dong

    2015-07-01

    The concentrations of dimethylated sulfur compounds and chlorophyll a, as well as biological production and consumption rates of dimethylsulfide (DMS), were measured in the surface water of the North Yellow Sea (NYS, 37-40°N to 121-124°E) in winter 2007. Surface DMS, dissolved and particulate dimethylsulfoniopropionate (DMSPd and DMSPp) concentrations in the study area increased significantly from offshore to inshore sites, with the average values of 2.00, 4.52 and 7.21 nM, respectively. The biological production and consumption rates of DMS were estimated, with the average values of 5.41 and 3.84 nM d-1, respectively. The spatial variation of chlorophyll a was consistent with that of DMS and DMSP, as well as with that of DMS biological production, suggesting that phytoplankton biomass might play an important role in controlling the distribution of DMS and DMSP in the study area. According to the collective data of dimethylated sulfur compounds and DMS biological conversion in China Seas, the dimethylated sulfur compounds concentrations in the NYS during winter were a factor of 2 and 1.3 higher than those in the East China Sea and South China Sea, respectively. Less DMS (DMSP) in NYS was released in winter than that in spring and summer, which could be attributed to the shift in phytoplankton community composition dominated by diatoms to non-diatoms from winter to summer. Quantitative comparison analysis pointed to DMSPp rather than DMSPd as an important precursor of DMS in the surface water. The estimated sea-to-air fluxes of DMS using Liss and Merlivat (LM86), Wanninkhof (W92) and Nightingale (N2000) formulae were 2.72, 5.12 and 4.28 ?mol m-2 d-1, respectively. In the surface water, the biological turnover time of DMS varied from 0.21 to 1.73 d with an average of 0.83 d, which was about 5.43-fold faster than the mean DMS sea-air turnover time (3.12 d), implying that microbial consumption was a main sink of DMS in the surface water.

  20. The significance of glucosinolates for sulfur storage in Brassicaceae seedlings

    PubMed Central

    Aghajanzadeh, Tahereh; Hawkesford, Malcolm J.; De Kok, Luit J.

    2014-01-01

    Brassica juncea seedlings contained a twofold higher glucosinolate content than B. rapa and these secondary sulfur compounds accounted for up to 30% of the organic sulfur fraction. The glucosinolate content was not affected by H2S and SO2 exposure, demonstrating that these sulfur compounds did not form a sink for excessive atmospheric supplied sulfur. Upon sulfate deprivation, the foliarly absorbed H2S and SO2 replaced sulfate as the sulfur source for growth of B. juncea and B. rapa seedlings. The glucosinolate content was decreased in sulfate-deprived plants, though its proportion of organic sulfur fraction was higher than that of sulfate-sufficient plants, both in absence and presence of H2S and SO2. The significance of myrosinase in the in situ turnover in these secondary sulfur compounds needs to be questioned, since there was no direct co-regulation between the content of glucosinolates and the transcript level and activity of myrosinase. Evidently, glucosinolates cannot be considered as sulfur storage compounds upon exposure to excessive atmospheric sulfur and are unlikely to be involved in the re-distribution of sulfur in B. juncea and B. rapa seedlings upon sulfate deprivation. PMID:25566279

  1. 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.

  2. 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.

  3. Evaluated Chemical Kinetic Data for the Reactions of Atomic Oxygen O(3P) with Sulfur Containing Compounds

    NASA Astrophysics Data System (ADS)

    Singleton, D. L.; Cvetanovi?, R. J.

    1988-10-01

    Chemical kinetic data for reactions of O(3P) atoms with sulfur containing compounds are compiled and critically evaluated. Specifically, the reactions considered include the interactions of the ground electronic state of oxygen atoms, O(3P), with S2, SF2, SF5, SOF, S2O, SO, SO2, SO3, SH, H2S, D2S, H2SO4, CS, CS2, COS, CH3SH, C2H5SH, C4H9SH, C5H11SH, CH3SCH3, cy-CH2SCH2, cy-CHCHSCHCH, CH3SSCH3, SCF2, SCCl2, and cy-CF2SCF2S. With one exception, the liquid phase reaction O(3P)+H2SO4?products, all the data considered were for gas phase reactions. Where possible, ``Recommended'' values of the rate parameters have been assessed and conservative uncertainty limits assigned to them.

  4. [An evaluation of acute effects of sulfur compounds for the human organism in natural gas fields emergencies (review)].

    PubMed

    Salikhova, L R; Zebseev, V V; Karpov, A I; Eremin, M N; Gorlov, A V

    2003-01-01

    A trend towards a growing number of emergency situations at industrial enterprises has been recently traced throughout the world. The main reasons of such phenomenon are: a comprehensive use of highly dangerous technologies and materials; large-scale violations of the operational rules and norms; and an inadmissibly high wear-and-tear of the main production funds in economic branches with extra risk. The world experience is indicative of a high degree of danger related with exploiting the natural-gas fields with a high content of sulfur compounds. The occurrence of emergency situations in the mentioned fields is accompanied by development of acute and sub-acute toxic effects in the workers and population. It necessitated, recently, an elaboration of a concept of a relative safety, in view of an unfavorable impact produced by chemical substances in emergencies, and an elaboration of methods applicable to the evaluation of emergency regulations. PMID:12852038

  5. 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.

  6. 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.

  7. Sulfur-Free Selective Pulping

    E-print Network

    Dimmel, D. R.; Bozell, J. J.

    an increase in pulping rate and yields, which translates to less energy required per ton of product. Less sulfur means a simplified process, lower odor emissions, and a decrease requirement for bleaching chemicals, meaning less organics being discharged...

  8. Photometric properties of powdered sulfur

    NASA Astrophysics Data System (ADS)

    Gradie, J.; Veverka, J.

    1984-05-01

    Particle size, temperature, thermal history, and scattering geometry are shown by the present laboratory investigation of the spectrophotometric properties of three particle-size fractions of sulfur to influence the spectral reflectance of both normal and quenched molten samples of sulfur. A scattering law that consists of a linear combination of lunar-like and Lambertian terms adequately describes the data for all particle sizes. Near opposition, sulfur particles closely follow a Minnaert limb darkening law except where the reflectance is low, as in the strong UV absorption band of the larger particle size fractions. The present data indicate that quantitative comparisons between disk-integrated observations of Io and laboratory measurements of flat sulfur samples are inadequate unless temperature effects and scattering geometry changes are included.

  9. Zirconium in sulfuric acid applications

    SciTech Connect

    Webster, R.T.; Yau, T.L.

    1986-02-01

    Zirconium is one of the few metals that resists attack by sulfuric acid at concentrations up to 75% and temperatures to boiling and above. This capability makes zirconium a good structural metal for use in 40 to 65% H/sub 2/SO/sub 4/ up to boiling temperatures and for weak acid concentrations at elevated temperatures. Zirconium's corrosion properties in sulfuric acid solutions are compared with nickel base alloys. Examples of applications and limitations in the use of zirconium are presented.

  10. TECHNIQUE FOR MEASURING REDUCED FORMS OF SULFUR IN AMBIENT AIR

    EPA Science Inventory

    A new technique for measuring low concentrations of volatile sulfur compounds in ambient air is discussed. The technique consists of preconcentration of sulfur compounds by chemisorption on gold metal coated sand or gold foil surface followed by thermal desorption, separation, an...

  11. The fate of sulfur during rapid pyrolysis of scrap tires.

    PubMed

    Hu, Hongyun; Fang, Yuan; Liu, Huan; Yu, Ren; Luo, Guangqian; Liu, Wenqiang; Li, Aijun; Yao, Hong

    2014-02-01

    The fate of sulfur during rapid pyrolysis of scrap tires at temperatures from 673 to 1073K was investigated. Sulfur was predominant in the forms of thiophenic and inorganic sulfides in raw scrap tires. In the pyrolysis process, sulfur in organic forms was unstable and decomposed, leading to the sulfur release into tar and gases. At 673 and 773K, a considerable amount of sulfur was distributed in tar. Temperature increasing from 773 to 973K promoted tar decomposition and facilitated sulfur release into gases. At 1073K, the interactions between volatiles and char stimulated the formation of high-molecular-weight sulfur-containing compounds. After pyrolysis, almost half of the total content of sulfur in raw scrap tires still remained in the char and was mostly in the form of sulfides. Moreover, at temperatures higher than 873K, part of sulfur in the char was immobilized in the sulfates. In the pyrolysis gases, H2S was the main sulfur-containing gas. Increasing temperature stimulated the decomposition of organic polymers in scrap tires and more H2S was formed. Besides H2S, other sulfur-containing gases such as CH3SH, COS and SO2 were produced during the rapid pyrolysis of scrap tires. PMID:24238304

  12. Production of ultra-low-sulfur gasoline: an equilibrium and kinetic analysis on adsorption of sulfur compounds over Ni/MMS sorbents.

    PubMed

    Subhan, Fazle; Liu, B S; Zhang, Q L; Wang, W S

    2012-11-15

    High performance nickel-based micro-mesoporous silica (Ni/MMS) sorbent was prepared by incipient wetness impregnation with ultrasonic aid (IWI-u) for adsorptive desulfurization (ADS) of commercial gasoline and simulated fuels. The sorbents were characterized with BET, XRD, TPR, SEM, HRTEM and TG/DTG. These results show that 20 wt%Ni/MMS (IWI-u) can still retain the framework of MMS and nickel particles were homogeneously distributed in the MMS channels without any aggregation, which improved significantly the ADS performance of the sorbents. The studies on the ADS kinetics indicate that the adsorption behavior of thiophene (T), benzothiophene (BT) and dibenzothiophene (DBT) over 20 wt%Ni/MMS (IWI-u) can be described appropriately by pseudo second-order kinetic model. The intraparticle diffusion model verified that the steric hindrance and intraparticle diffusion were the rate controlling step of the adsorption process of DBT molecules. Langmuir model can be used to describe the adsorption isotherms for T, BT and DBT due to low coverage. The regeneration sorbent maintains the sulfur removal efficiency of 85.9% for 6 cycles. PMID:23022413

  13. Characterization and quantification of the oxides of sulfur and nitrogen and associated compounds in their gaseous, aerosol, and dissolved states

    SciTech Connect

    Newman, L

    1980-05-01

    The needs and problems associated with the characterization and quantification of the oxides of sulfur and nitrogen and associated compounds in their gaseous, aerosol, and dissolved states are discussed. Illustrations are given of the techniques in present usage for the determination of the substances of interest to investigators concerned with the effects of air pollutants on the terrestrial ecosystem. The value and utility of the newer techniques employing real time continuous instrumentation are presented and compared with the more traditional approaches utilizing sampling collection. A plea is made to provide resources for data reduction especially in order to obtain constructive utilization of continuous instrumentation. It is asserted that real time instrumentation is best utilized during campaign measurement programs where short time resolution is required and that collection techniques still have a place, especially in long term monitoring efforts. Special attention was directed at, and the problems highlighted that are associated with, the utilization of the real time instruments available for the flame photometric determination of the oxides of sulfur and the chemiluminescent measurement of the oxides of nitrogen. The newer methods proposed for their use in the determination of sulfate and nitric acid respectively are presented. The difficulties associated with the determination of nitrate are enunciated and attention focused on the problems of obtaining a sample due to the variation of the vapor pressure of gaseous nitric acid and ammonia above solid ammonium nitrate which is in association with an acidic aerosol containing sulfate. The utility of measurements of the composition of rainwater is discussed in light of its application to determine the mechanisms through which rain derives its chemical composition.

  14. Photochemical oxidation and dispersion of gaseous sulfur compounds from natural and anthropogenic sources around a coastal location

    NASA Astrophysics Data System (ADS)

    Song, Sang-Keun; Shon, Zang-Ho; Kim, Ki-Hyun

    The photochemical oxidation and dispersion of reduced sulfur compounds (RSCs: H 2S, CH 3SH, DMS, CS 2, and DMDS) emitted from anthropogenic (A) and natural (N) sources were evaluated based on a numerical modeling approach. The anthropogenic emission concentrations of RSCs were measured from several sampling sites at the Donghae landfill (D-LF) (i.e., source type A) in South Korea during a series of field campaigns (May through December 2004). The emissions of natural RSCs in a coastal study area near the D-LF (i.e., source type N) were estimated from sea surface DMS concentrations and transfer velocity during the same study period. These emission data were then used as input to the CALPUFF dispersion model, revised with 34 chemical reactions for RSCs. A significant fraction of sulfur dioxide (SO 2) was produced photochemically during the summer (about 34% of total SO 2 concentrations) followed by fall (21%), spring (15%), and winter (5%). Photochemical production of SO 2 was dominated by H 2S (about 55% of total contributions) and DMS (24%). The largest impact of RSCs from source type A on SO 2 concentrations occurred around the D-LF during summer. The total SO 2 concentrations produced from source type N around the D-LF during the summer (a mean SO 2 concentration of 7.4 ppbv) were significantly higher than those (?0.3 ppbv) during the other seasons. This may be because of the high RSC and SO 2 emissions and their photochemistry along with the wind convergence.

  15. 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.

  16. 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

  17. Selective catalytic reduction of sulfur dioxide to elemental sulfur

    SciTech Connect

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

    1992-01-01

    Elemental sulfur recovery from SO[sub 2]-containing gas streams is highly attractive as it produces a saleable. Product and no waste to dispose of. However, commercially available schemes are complex and involve multi-stage reactors, such as, most notably in the Resox (reduction of SO[sub 2] with coke) and Claus plants(reaction of SO[sub 2] with H[sub 2]S over catalyst). This project win investigate a cerium oxide catalyst for the single-stage selective reduction SO[sub 2] to elemental sulfur by a reductant, such as carbon monoxide. Cerium oxide has been identified as a superior catalyst for SO[sub 2] reduction by CO to elemental sulfur because of its high activity and high selectivity to sulfur over COS over a wide temperature range(400--650C). Kinetic and parametric studies of SO[sub 2] reduction planned over various CeO[sub 2]-formulations will provide the necessary basis for development of a simplified process, a single-stage elemental sulfur recovery scheme from variable concentration gas streams. A first apparent application is treatment of regenerator off-gases in power plants using regenerative flue gas desulfurization. Such a simple catalytic converter may offer the long-sought Claus-alternative'' for coal-fired power plant applications.

  18. Gaseous Sulfur Pollutants from Urban and Natural Sources

    Microsoft Academic Search

    Elmer Robinson; Robert C. Robbins

    1970-01-01

    Major aspects of the circulation through the atmospheric environment of sulfur pollutants have been estimated, including source magnitudes, residual atmospheric concentrations, and scavenging processes. The compounds considered include SO2 and H2S, as well as sulfates. One-third of the sulfur reaching the atmosphere comes from pollutant sources, mainly as SO2. Within the atmosphere there is a net transfer of sulfur from

  19. Intermediate sulfur oxidation state compounds in the euxinic surface sediments of the Dvurechenskii mud volcano (Black Sea)

    NASA Astrophysics Data System (ADS)

    Lichtschlag, Anna; Kamyshny, Alexey; Ferdelman, Timothy G.; deBeer, Dirk

    2013-03-01

    The deep Black Sea is known to be depleted in electron-acceptors for sulfide oxidation. This study on depth distributions of sulfur species (S(II), S(0), Sn2-, SO32-, SO32-, SO42-) in the Dvurechenskii mud volcano, a cold seep situated in the permanently anoxic eastern Black Sea basin (Sorokin Trough, 2060 m water depth), showed remarkable concentrations of sulfide oxidation products. Sulfite concentrations of up to 11 ?mol L-1, thiosulfate concentrations of up to 22 ?mol L-1, zero-valent sulfur concentrations of up to 150 ?mol L-1 and up to five polysulfide species were measured in the upper 20 cm of the sediment. Electron-acceptors found to be available in the Dvurechenskii mud volcano (DMV) for the oxidation of hydrogen sulfide to sulfide oxidation intermediates are iron-minerals, and probably also reactive manganese phases. Up to 60 ?mol g-1 of reactive iron-minerals and up to 170 ?mol L-1 dissolved iron was present in the central summit with the highest fluid upflow and fresh mud outflow. Thus, the source for the oxidative power in the DMV are reactive iron phases extruded with the mud from an ancient source in the deeply buried sediments, leading to the formation of various sulfur intermediates in comparably high concentrations. Another possible source of sulfide oxidation intermediates in DMV sediments could be the formation of zero-valent sulfur by sulfate dependent anaerobic microbial oxidation of methane followed by disproportionation of zero-valent sulfur. Sulfide oxidation intermediates, which are produced by these processes, do not reach thermodynamic equilibrium with rhombic sulfur, especially close to the active center of the DMV due to a short equilibration time. Thus, mud volcano sediments, such as in the DMV, can provide oxidizing niches even in a highly reduced environment like the abyssal part of the Black Sea.

  20. 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.

  1. Control of oxidative sulfur metabolism in Chlorobium

    SciTech Connect

    Maka, A.

    1986-01-01

    The photosynthetic, anaerobic microorganism Chlorobium limicola forma sp. thiosulfatophilum is being investigated as a possible biocatalyst for the removal of acid gases (primarily H/sub 2/S) generated by the hydroprocessing of fossil fuels. The organism was grown in an anaerobic, fed-batch photobioreactor which was continuously supplied with N/sub 2/, CO/sub 2/ and H/sub 2/S. The effect of light intensity, surface area of illuminated bioreactor, H/sub 2/S flow rate and various wavelength regions of light on oxidative sulfur metabolism by Chlorobium was examined. Light intensity, surface area of illuminated bioreactor, and H/sub 2/S flow rate regulated oxidative sulfur metabolism. The H/sub 2/S utilization rate increased with a corresponding increase in light intensity. The photoautotroph grew in any selected wavelength region with production of the various sulfur compounds, i.e., thiosulfate, sulfate, and sulfur. However, the rate of H/sub 2/S oxidation was wavelength dependent. The photosynthetic quantum efficiency (which is the molecules of sulfur (S/sup 0/) produced per photon utilized) was determined for this system. It is possible that the quantum efficiency can be used as a sufficiency factor for a photobioreactor. The sufficiency factor would be a unique characteristic of the reactor and demonstrate the relationship between light intensity and the rate of the light driven reaction. This sufficiency factor could be used for the determination of a light efficient photobioreactor.

  2. Sulfur in human nutrition and applications in medicine.

    PubMed

    Parcell, Stephen

    2002-02-01

    Because the role of elemental sulfur in human nutrition has not been studied extensively, it is the purpose of this article to emphasize the importance of this element in humans and discuss the therapeutic applications of sulfur compounds in medicine. Sulfur is the sixth most abundant macromineral in breast milk and the third most abundant mineral based on percentage of total body weight. The sulfur-containing amino acids (SAAs) are methionine, cysteine, cystine, homocysteine, homocystine, and taurine. Dietary SAA analysis and protein supplementation may be indicated for vegan athletes, children, or patients with HIV, because of an increased risk for SAA deficiency in these groups. Methylsulfonylmethane (MSM), a volatile component in the sulfur cycle, is another source of sulfur found in the human diet. Increases in serum sulfate may explain some of the therapeutic effects of MSM, DMSO, and glucosamine sulfate. Organic sulfur, as SAAs, can be used to increase synthesis of S-adenosylmethionine (SAMe), glutathione (GSH), taurine, and N-acetylcysteine (NAC). MSM may be effective for the treatment of allergy, pain syndromes, athletic injuries, and bladder disorders. Other sulfur compounds such as SAMe, dimethylsulfoxide (DMSO), taurine, glucosamine or chondroitin sulfate, and reduced glutathione may also have clinical applications in the treatment of a number of conditions such as depression, fibromyalgia, arthritis, interstitial cystitis, athletic injuries, congestive heart failure, diabetes, cancer, and AIDS. Dosages, mechanisms of action, and rationales for use are discussed. The low toxicological profiles of these sulfur compounds, combined with promising therapeutic effects, warrant continued human clinical trails. PMID:11896744

  3. Interactions between natural organic matter, sulfur, arsenic and iron oxides in re-oxidation compounds within riparian wetlands: nanoSIMS and X-ray adsorption spectroscopy evidences.

    PubMed

    Al-Sid-Cheikh, Maya; Pédrot, Mathieu; Dia, Aline; Guenet, Hélène; Vantelon, Delphine; Davranche, Mélanie; Gruau, Gérard; Delhaye, Thomas

    2015-05-15

    Arsenic (As) is a toxic and ubiquitous element which can be responsible for severe health problems. Recently, Nano-scale Secondary Ions Mass Spectrometry (nanoSIMS) analysis has been used to map organomineral assemblages. Here, we present a method adapted from Belzile et al. (1989) to collect freshly precipitated compounds of the re-oxidation period in a natural wetland environment using a polytetrafluoroethylene (PTFE) sheet scavenger. This method provides information on the bulk samples and on the specific interactions between metals (i.e. As) and the natural organic matter (NOM). Our method allows producing nanoSIMS imaging on natural colloid precipitates, including (75)As(-), (56)Fe(16)O(-), sulfur ((32)S(-)) and organic matter ((12)C(14)N) and to measure X-ray adsorption of sulfur (S) K-edge. A first statistical treatment on the nanoSIMS images highlights two main colocalizations: (1) (12)C(14)N(-), (32)S(-), (56)Fe(16)O(-) and (75)As(-), and (2) (12)C(14)N(-), (32)S(-) and (75)As(-). Principal component analyses (PCAs) support the importance of sulfur in the two main colocalizations firstly evidenced. The first component explains 70% of the variance in the distribution of the elements and is highly correlated with the presence of (32)S(-). The second component explains 20% of the variance and is highly correlated with the presence of (12)C(14)N(-). The X-ray adsorption near edge spectroscopy (XANES) on sulfur speciation provides a quantification of the organic (55%) and inorganic (45%) sulfur compositions. The co-existence of reduced and oxidized S forms might be attributed to a slow NOM kinetic oxidation process. Thus, a direct interaction between As and NOM through sulfur groups might be possible. PMID:25704268

  4. MICROBIAL DEGRADATION OF NITROGEN, OXYGEN, AND SULFUR HETEROCYCLIC COMPOUNDS UNDER ANAEROBIC CONDITIONS: STUDIES WITH AQUIFER SAMPLES

    EPA Science Inventory

    The potential for anaerobic biodegradation of 12 heterocyclic model compounds was studied. ine of the model compounds were biotransformed in aquifer slurries under sulfate-reducing or methanogenic conditions. he nitrogen and oxygen heterocyclic compounds were more susceptible to ...

  5. MICROBIAL DEGRADATION OF NITROGEN, OXYGEN AND SULFUR HETEROCYCLIC COMPOUNDS UNDER ANAEROBIC CONDITIONS: STUDIES WITH AQUIFER SAMPLES

    EPA Science Inventory

    The potential for anaerobic biodegradation of 12 heterocyclic model compounds was studied. Nine of the model compounds were biotransformed in aquifer slurries under sulfate-reducing or methanogenic conditions. The nitrogen and oxygen heterocyclic compounds were more susceptible t...

  6. Identification, synthesis, and characterization of novel sulfur-containing volatile compounds from the in-depth analysis of Lisbon lemon peels (Citrus limon L. Burm. f. cv. Lisbon).

    PubMed

    Cannon, Robert J; Kazimierski, Arkadiusz; Curto, Nicole L; Li, Jing; Trinnaman, Laurence; Ja?czuk, Adam J; Agyemang, David; Da Costa, Neil C; Chen, Michael Z

    2015-02-25

    Lemons (Citrus limon) are a desirable citrus fruit grown and used globally in a wide range of applications. The main constituents of this sour-tasting fruit have been well quantitated and characterized. However, additional research is still necessary to better understand the trace volatile compounds that may contribute to the overall aroma of the fruit. In this study, Lisbon lemons (C. limon L. Burm. f. cv. Lisbon) were purchased from a grove in California, USA, and extracted by liquid-liquid extraction. Fractionation and multidimensional gas chromatography-mass spectrometry were utilized to separate, focus, and enhance unidentified compounds. In addition, these methods were employed to more accurately assign flavor dilution factors by aroma extract dilution analysis. Numerous compounds were identified for the first time in lemons, including a series of branched aliphatic aldehydes and several novel sulfur-containing structures. Rarely reported in citrus peels, sulfur compounds are known to contribute significantly to the aroma profile of the fruit and were found to be aroma-active in this particular study on lemons. This paper discusses the identification, synthesis, and organoleptic properties of these novel volatile sulfur compounds. PMID:25639384

  7. PROTOTYPE CORRELATION MASK FLAME PHOTOMETRIC DETECTOR FOR MEASURING SULFUR DIOXIDE

    EPA Science Inventory

    A prototype flame photometric detector system (FPD) to measure gaseous sulfur compounds was fabricated using a previously developed correlation mask optical system and a new flame housing. Also, a new burner for the FPD system was optimized to view the excited molecular sulfur em...

  8. Basic sulfur recovery research. Annual technical report, January 31, 1991

    Microsoft Academic Search

    DeBerry

    1991-01-01

    The fundamentals of chemical interactions between chemical reagents and reduced sulfur compounds in the liquid redox and other sulfur recovery processes are explored in order to use the information to target the most effective options in processing steps for the gas industry. Methods for following concentration of an intermediate chemical species in the reaction of iron chelates and hydrogen sulfide

  9. Oceanic emissions of sulfur: Application of new techniques

    Microsoft Academic Search

    Clara Mary Jodwalis

    1998-01-01

    Sulfur gases and aerosols are important in the atmosphere because they play major roles in acid rain, arctic haze, air pollution, and climate. Globally, man-made and natural sulfur emissions are comparable in magnitude. The major natural source is dimethyl sulfide (DMS) from the oceans, where it originates from the degradation of dimethysulfonioproprionate (DMSP), a compound produced by marine phytoplankton. Global

  10. 46 CFR 153.1046 - Sulfuric acid.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations Special Cargo Procedures § 153.1046 Sulfuric acid. No person may liquefy frozen or congealed sulfuric acid other than by external tank heating...

  11. 46 CFR 153.1046 - Sulfuric acid.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations Special Cargo Procedures § 153.1046 Sulfuric acid. No person may liquefy frozen or congealed sulfuric acid other than by external tank heating...

  12. 46 CFR 153.1046 - Sulfuric acid.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations Special Cargo Procedures § 153.1046 Sulfuric acid. No person may liquefy frozen or congealed sulfuric acid other than by external tank heating...

  13. 46 CFR 153.1046 - Sulfuric acid.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations Special Cargo Procedures § 153.1046 Sulfuric acid. No person may liquefy frozen or congealed sulfuric acid other than by external tank heating...

  14. 46 CFR 153.1046 - Sulfuric acid.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations Special Cargo Procedures § 153.1046 Sulfuric acid. No person may liquefy frozen or congealed sulfuric acid other than by external tank heating...

  15. Dispersion and photochemical oxidation of reduced sulfur compounds in and around a large industrial complex in Korea

    NASA Astrophysics Data System (ADS)

    Song, Sang-Keun; Shon, Zang-Ho; Kim, Ki-Hyun; Kim, Yoo-Keun; Pal, Raktim

    In this study, the environmental behavior of reduced sulfur compounds (RSCs: H 2S, DMS, CS 2, DMDS, and CH 3SH) was investigated in an area influenced by strong anthropogenic processes based on a numerical modeling approach. The RSC emission concentrations were measured from multiple locations around the Ban-Wall industrial complex (BWIC) in the city of An San (AS), Korea, during a series of field campaigns held between August 2004 and September 2005. These emissions were then used as input for a CALPUFF dispersion model with the 34 dominant chemical reactions for RSCs. The impact of RSC emission on SO 2 concentrations was assessed further in the study areas. The model study indicated the possibility that RSCs emitted in and around the BWIC can exert a direct impact on the ambient SO 2 concentration levels in its surrounding areas with the most prominent effect observed during summer. Our prediction indicated that a significant fraction of SO 2 was produced photochemically in and around the BWIC during the summer (about 30% of total SO 2 concentrations) and fall events (˜20%). These photochemical productions of SO 2 were mainly ascribable to H 2S (˜60% of total contributions) and DMDS (˜25%) out of all five target RSCs. Meteorological contribution (dispersion) to SO 2 concentration level was also highest during summer.

  16. Effect of nitrogen supplementation and Saccharomyces species on hydrogen sulfide and other volatile sulfur compounds in shiraz fermentation and wine.

    PubMed

    Ugliano, Maurizio; Fedrizzi, Bruno; Siebert, Tracey; Travis, Brooke; Magno, Franco; Versini, Giuseppe; Henschke, Paul A

    2009-06-10

    A Shiraz must with low yeast assimilable nitrogen (YAN) was supplemented with two increasing concentrations of diammonium phosphate (DAP) and fermented with one Saccharomyces cerevisiae and one Saccharomyces bayanus strain, with maceration on grape skins. Hydrogen sulfide (H(2)S) was monitored throughout fermentation, and a total of 16 volatile sulfur compounds (VSCs) were quantified in the finished wines. For the S. cerevisiae yeast strain, addition of DAP to a final YAN of 250 or 400 mg/L resulted in an increased formation of H(2)S compared to nonsupplemented fermentations (100 mg/L YAN). For this yeast, DAP-supplemented fermentations also showed prolonged formation of H(2)S into the later stage of fermentation, which was associated with increased H(2)S in the final wines. The S. bayanus strain showed a different H(2)S production profile, in which production was inversely correlated to initial YAN. No correlation was found between total H(2)S produced by either yeast during fermentation and H(2)S concentration in the final wines. For both yeasts, DAP supplementation yielded higher concentrations of organic VSCs in the finished wines, including sulfides, disulfides, mercaptans, and mercaptoesters. PCA analysis indicated that nitrogen supplementation before fermentation determined a much clearer distinction between the VSC profiles of the two yeasts compared to nonsupplemented fermentations. These results raise questions concerning the widespread use of DAP in the management of low YAN fermentations with respect to the formation of reductive characters in wine. PMID:19391591

  17. Grapevine & Sulfur: Old Partners, New Achievements

    Microsoft Academic Search

    S. Amâncio; S. Tavares; J. C. Fernandes; C. Sousa

    The central role of sulfur in biological functions Sulfur (S) is the 14th more abundant element on earth crust (Charlson et\\u000a al. 1992), the 9th and least abundant essential macronutrient in plants (Saito 2004) and the 6th element in the cytoplasm\\u000a (Xavier and LeGall 2007). The interconversion of oxidized and reduced sulfur states, the biogeochemical sulfur cycle, depends\\u000a mainly on

  18. Transition metal-catalyzed oxidation of atmospheric sulfur: Global implications for the sulfur budget

    E-print Network

    Alexander, Becky

    Transition metal-catalyzed oxidation of atmospheric sulfur: Global implications for the sulfur(IV)) oxidation by O2 catalyzed by transition metals. Due to the lack of photochemically produced OH and H2O2), Transition metal-catalyzed oxidation of atmospheric sulfur: Global implications for the sulfur budget, J

  19. Six new tin-sulfur containing compounds obtained under solvothermal conditions

    NASA Astrophysics Data System (ADS)

    Pienack, Nicole; Lühmann, Henning; Seidlhofer, Beatrix; Ammermann, Janina; Zeisler, Christoph; Danker, Felix; Näther, Christian; Bensch, Wolfgang

    2014-07-01

    During explorative solvothermal syntheses six new compounds containing either the [Sn2S6]4- or the [SnS4]4- anion were obtained and structurally characterized: [Ni(1,2-dach)3]2Sn2S6·4H2O (1) (1,2-dach = trans-1,2-diaminocyclohexane), o-{[Ni(tepa)]2Sn2S6} (2) (tepa = tetraethylenepentamine), [Ni(peha)]2Sn2S6·H2O (3) (peha = pentaethylenehexamine), [Ni(aepa)]2Sn2S6 (4) (aepa = N-2-aminoethyl-1,3-propandiamine), [Co(dien)]2Sn2S6 (5) (dien = diethylenetriamine), and {[Mn(trien)]2SnS4} (trien = triethylenetetramine). In all compounds in-situ formed transition metal amine complexes act as charge compensating ligands or are bound to the thiostannate anions. Compound 2 is an orthorhombic polymorph of a recently published monoclinic compound. In compound 6 the very rare [Mn2N8S2] bi-octahedron is observed as main structural motif. This compound contains a one-dimensional chain which was also observed in a pseudo-polymorphic compound. The structures of all compounds are characterized by an extended hydrogen bonding network between S atoms of the anions and the H atoms of the amine ligands and/or water molecules.

  20. Gas chromatographic and capillary gas chromatographic/mass spectrometric determination of organic sulfur compounds (OSCs) in sediment from ports: Significance of these compounds as an oil pollution index

    SciTech Connect

    Ogata, Masana; Fujisawa, Kuniyasu (Okayama Univ. Medical School (Japan))

    1990-06-01

    Oil pollution arises in waters near petroleum industrial districts. In oily odor fish caught in the coast near petroleum industries, toluene, other aromatic hydrocarbons and olefinic hydrocarbons have been detected. The authors also reported the presence of organic sulfur compounds (OSCs), probably originating from polluting oil, in fish caught in the Seto Inland Sea after an accidental oil spilling from a tank. In a previous study, the authors detected OSCs in the oyster and mussel caught in the Seto Inland Sea. However, the presence of OSCs and polyaromatic hydrocarbons (PAHs) in sea sediments has not been described. In the present report, OSCs and PAHs in the sea sediments collected in several ports facing Seto Inland Sea were analyzed by a gas chromatographic/mass spectrometric (GC-MS) system.

  1. 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...

  2. Recovery of sulfur from native ores

    SciTech Connect

    Womack, J.T.; Wiewiorowski, T.K.; Astley, V.C.; Perez, J.W.; Headington, T.A.

    1992-03-17

    This patent describes a process for removing elemental sulfur from ores containing elemental sulfur. It comprises crushing a sulfur-containing ore to a coarse particle size wherein ore particles produced during crushing enable substantially all of the sulfur to be liberated during a heating step and to produce an ore gangue that is substantially not susceptible to flotation: forming an aqueous ore slurry containing about 50-80% by weight of solids from the crushed ore and adjusting the pH to at least a pH of about 8.0; heating the aqueous ore slurry formed in step (b) under elevated pressure to a temperature of about 240{degrees} - 315{degrees} F. for sufficient time to melt and liberate elemental sulfur contained in the ore to produce liberated molten sulfur and ore gangue, wherein the slurry is heated while agitating the slurry at sufficient velocity to substantially maintain the ore, ore gangue and liberated molten sulfur in suspension; cooling the heated slurry sufficiently to resolidify the liberated molten sulfur; conditioning the aqueous slurry of step (d) with a flotation aid; separating the condition aqueous slurry of ore gangue and resolidified sulfur in a flotation unit to produce a sulfur-rich flotation concentrate overstream; and recovering the sulfur-rich flotation concentrate and separating the sulfur therefrom.

  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. The evolution of infalling sulfur species in Titan's atmosphere

    NASA Astrophysics Data System (ADS)

    Hickson, K. M.; Loison, J. C.; Cavalié, T.; Hébrard, E.; Dobrijevic, M.

    2014-12-01

    Aims: We studied the hypothesis that micrometeorites and Enceladus' plume activity could carry sulfur-bearing species into the upper atmosphere of Titan, in a manner similar to oxygen-bearing species. Methods: We have developed a detailed photochemical model of sulfur compounds in the atmosphere of Titan that couples hydrocarbon, nitrogen, oxygen, and sulfur chemistries. Results: Photochemical processes produce mainly CS and H2CS in the upper atmosphere of Titan and C3S, H2S and CH3SH in the lower atmosphere. Mole fractions of these compounds depend significantly on the source of sulfur species. Conclusions: A possible future detection of CS (or the determination of a low upper limit) could be used to distinguish the two scenarios for the origin of sulfur species, which then could help to differentiate the various scenarios for the origin of H2O, CO, and CO2 in the stratosphere of Titan.

  5. Theoretical investigation of the interaction between aromatic sulfur compounds and [BMIM](+)[FeCl4](-) ionic liquid in desulfurization: A novel charge transfer mechanism.

    PubMed

    Li, Hongping; Zhu, Wenshuai; Chang, Yonghui; Jiang, Wei; Zhang, Ming; Yin, Sheng; Xia, Jiexiang; Li, Huaming

    2015-06-01

    In this work, interaction nature between a group of aromatic sulfur compounds and [BMIM](+)[FeCl4](-) have been investigated by density functional theory (DFT). A coordination structure is found to be critical to the mechanism of extractive desulfurization. Interaction energy and extractive selectivity follow the order: thiophene (TH)sulfur compounds transfer into the Lewis part of ionic liquid, namely, [FeCl4](-). Furthermore, it is better to consider the Lewis acidity of Fe-containing ionic liquid by the whole unit (such as [FeCl4](-) and aromatic sulfur compounds (X)) rather than only Fe or S atom. PMID:25900860

  6. Model aging and oxidation effects on varietal, fermentative, and sulfur compounds in a dry botrytized red wine.

    PubMed

    Fedrizzi, Bruno; Zapparoli, Giacomo; Finato, Fabio; Tosi, Emanuele; Turri, Arianna; Azzolini, Michela; Versini, Giuseppe

    2011-03-01

    From harvest until wine arrives to the consumer, oxygen plays a crucial role in the definition of the final aroma. In the present research, the effect of the model oxidative aging on a dry red Botrytis wine, such as Italian Amarone, was considered. Amarone wine was submitted to model oxidative aging and then analyzed with two different approaches (SPE-GC-MS and HS-SPME/GC-MS). The same sampling plan was adopted to study the model aging of the same Amarone wine in anaerobic conditions. The HS-SPME/GC-MS method was applied to investigate for the first time the effect of the oxidative aging on a vast number of fermentative sulfur compounds. This research highlighted peculiar evolutions for several volatile compounds. In particular, benzaldehyde showed a sensitive increment during the oxidative aging, with a rate much higher than that reported for non-Botrytis red wines. On the other hand, several sulfides (dimethyl sulfide, 3-(methylthio)-1-propanol, etc.) disappeared after just 15 days of oxidative aging. A wine oxidation marker such as 3-(methylthio)-propanal was not found in any of the oxidized wines; conversely methionol-S-oxide was tentatively identified. This evidence has not been mentioned in the literature. A possible involvement of grape withering process and Botrytis in these mechanisms was supposed: a dry red wine, produced from the same but without any grape withering process and Botrytis infection (e.g., Bardolino wine), was submitted to oxidative aging and analysis. This red wine showed an evolution similar to those reported in the literature for dry red wines but significantly different from the Amarone wine. PMID:21314124

  7. The interaction of atmospheric and soil sulfur on the sulfur and selenium concentration of range plants

    Microsoft Academic Search

    D. G. Milchunas; W. K. Lauenroth; J. L. Dodd

    1983-01-01

    Summary A native northern mixed prairie, Montana, U.S.A., was exposed to three controlled levels of sulfur dioxide and subplots fertilized with sulfur and\\/or selenium. Plant species that accumulated relatively greater quantities of soil sulfur did not necessarily accumulate relatively greater quantities of atmospheric sulfur, andvisa versa. Plant-sulfur concentrations increased with increasing time and level of exposure, but the rate of

  8. Sulfur-oxidizing Bacteria: A Novel Bioinoculant for Sulfur Nutrition and Crop Production

    Microsoft Academic Search

    R. Anandham; P. Indira Gandhi; M. SenthilKumar; R. Sridar; P. Nalayini; Tong-Min Sa

    \\u000a Sulfur is an essential nutrient for plant growth as sulfur-deficient conditions cause severe losses in crop yield. Sulfur\\u000a nutrition has received little attention for many years, since fertilizers and atmospheric inputs have provided adequate amounts.\\u000a However, recent reductions in sulfur inputs from atmospheric depositions have resulted in a negative sulfur balance in agricultural\\u000a soils, making crop plants increasingly dependent on

  9. A design strategy applied to sulfur resistant lean NOx̳ automotive catalysts

    E-print Network

    Tang, Hairong

    2005-01-01

    Catalyst poisoning due to sulfur compounds derived from fuel sulfur presents a major challenge, intractable thus far, to development of many advanced technologies for automotive catalysts such as the lean NOx, trap. Under ...

  10. Additive for lubricants and hydrocarbon fuels comprising reaction products of olefins, sulfur, hydrogen sulfide and polymeric succinimide compounds

    SciTech Connect

    Horodysky, A.G.; Law, D.A.

    1988-11-22

    This patent describes a process for making an additive for lubricants comprising co-reacting: (a) an olefin; (b) sulfur; (c) hydrogen sulfide; and (d) a polymeric succinimide selected from the group consisting of the reaction products of polymeric succinic anhydride with one or more reactants selected from the group consisting of: (a) polyethylene amines selected from the group consisting of diethylene triamines, treithylenetetramine, and tetraethylenepentamine; (b) hydroxyl containing amines, and; (c) polyols in conjunction with (a) or (b) selected from the group consisting of pentaerythritol, and trimethylol propane; at a temperature between about 130/sup 0/C and about 200/sup 0/C and a pressure of about 0 psig to about 900 psig, the reactants being reacted in a molar ratio of olefin, polymeric succinimide, and hydrogen sulfide to sulfur of about 3 to about 0.5, about 0.001, to about 0.4, and about 0.5 to about 0.7, respectively.

  11. Emission of sulfur-bearing compounds from motor vehicle and aircraft engines. A report to congress

    Microsoft Academic Search

    Kawecki

    1978-01-01

    This report was generated in response to section 403(g) of The Clean Air Act as amended August, 1977. The report covers (1) a review of emission factors for HâSOâ, SOâ, sulfate, HâS, and carbonyl sulfide from motor vehicles, motor vehicle engines and aircraft engines; (2) a review of the known effects on health and welfare of these compounds; (3) the

  12. ROLE OF SULFUR IN REDUCING PCDD AND PCDF FORMATION

    EPA Science Inventory

    Past research has suggested that the presence of sulfur (S) in municipal waste combustors (MWCs) can decrease downstream formation of chlorinated organic compounds, particularly polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Thus, co-firing a...

  13. New cysteine-S-conjugate precursors of volatile sulfur compounds in bell peppers (Capsicum annuum L. cultivar).

    PubMed

    Starkenmann, Christian; Niclass, Yvan

    2011-04-13

    The objective of this study was to verify whether the volatile organic sulfur compounds recently discovered in bell pepper (Capsicum annuum, L. cultivars), such as the mercapto-ketones: 4-sulfanyl-2-heptanone and 2-sulfanyl-4-heptanone, the mercapto-alcohols: 4-sulfanyl-2-heptanol and 2-sulfanyl-4-heptanol, and heptane-2,4-dithiol, originate from their corresponding cysteine-S-conjugates. Analysis of aqueous extracts of red and green bell pepper by ultraperformance liquid chromatography-mass spectrometry with electrospray ionization in the positive mode (UPLC-MS ESI(+)) displayed masses corresponding to the expected cysteine-S-conjugates. To confirm this observation, four cysteine-S-conjugates were prepared as authentic samples: S-(3-hydroxy-1-methylhexyl)-L-cysteine, S-(3-hydroxy-1-propylbutyl)-L-cysteine, S-(3-oxo-1-propylbutyl)-L-cysteine, and (2R,2'R)-3,3'-(4-hydroxyheptane-2,6-diyl)bis(sulfanediyl) bis(2-aminopropanoic acid). By comparison with the fragmentation patterns and retention times of synthetic mixtures of cysteine-S-conjugate diastereoisomers, the natural occurrence of cysteine conjugates was confirmed in bell peppers. In addition, the cysteine-S-conjugates from red and green bell pepper extracts were concentrated by ion exchange chromatography and the fractions incubated with a ?-lyase (apotryptophanase). The liberated thiols were concentrated by affinity chromatography, and their occurrence, detected by gas chromatography-mass spectrometry, confirmed our predictions. Moreover, 3-sulfanyl-1-hexanol was also detected and the occurrence of S-(1(2-hydroxyethyl)butyl)-L-cysteine confirmed. A quantitative estimation based on external calibration curves, established by UPLC-MS ESI(+) in selected reaction monitoring mode, showed that cysteine-S-conjugates were present at concentrations in the range of 1 to 100 ?g/kg (±20%). PMID:21375341

  14. Crystalline structure of sulfur nanowires.

    NASA Astrophysics Data System (ADS)

    Carvajal, Eliel; Santiago, Patricia; Mendoza, Doroteo

    2001-03-01

    Sulfur nanowires have been synthesized by a nanoporous alumina template approach. Two types of wires were obtained, some of them straight and very long but the most of them curly. The diameter was 15nm, typically more than 1000nm of length and the longest of these wires seems to be almost monocrystalline.A first sight on them by electron microscopy showed differences, on the crystalline structure, compared to the most stable bulk allotrope. Studying carefully the wires' structure by X-ray diffraction on the confined wires, and by high resolution electron microscopy and electron diffraction, on the released ones, we found that the cell parameters are near the ones for ? bulk sulfur.

  15. Comparative Aspects of Sulfur Mineralization in Sediments of a Eutrophic Lake Basin †

    PubMed Central

    King, Gary M.; Klug, M. J.

    1982-01-01

    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/m2 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

  16. 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.

  17. Sodium Sulfur Technology Program Nastec

    NASA Technical Reports Server (NTRS)

    Highley, Bob; Somerville, W. Andrew

    1992-01-01

    The NaSTEC program focuses on developing currently available sodium sulfur cells for use in space applications and investigating the operational parameters of the cells. The specific goals of the program are to determine the operational parameters and verify safety limits of Na/S technology battery cells; test long term zero-g operation; and create a life test database. The program approach and ground and flight test objectives are described in textual and graphic form.

  18. 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.

  19. 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.

  20. 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.

  1. Regeneration of Sulfur Deactivated Ni-based Biomass Syngas Cleaning Catalysts

    Microsoft Academic Search

    Liyu Li; Christopher J. Howard; David L. King; Mark A. Gerber; Robert A. Dagle; Don J. Stevens

    2010-01-01

    Nickel-based catalysts have been widely tested in decomposing tar and methane in hot biomass syngas cleanup researches. However these catalysts can be easily deactivated by the sulfur compounds in syngas due to the strong sulfur adsorption effect on the Ni surface. Here we report on a new regeneration process, which can effectively and efficiently regenerate the sulfur-poisoned Ni reforming catalysts.

  2. Refining a complex nickel alloy to remove a sulfur impurity during vacuum induction melting: Part II

    NASA Astrophysics Data System (ADS)

    Sidorov, V. V.; Min, P. G.

    2014-12-01

    The results of studying the refining of complexly alloyed nickel melts from sulfur during melting in a vacuum induction furnace or with the use of an oxide calcium crucible, metallic calcium added to a melt, or rare-earth metals additions (which form thermodynamically stable refractory compounds with sulfur and, thus, eliminate the harmful effect of sulfur in the alloys) are reported.

  3. Limestone Corrosion by Neutrophilic Sulfur-Oxidizing Bacteria: A Coupled Microbe-Mineral System

    Microsoft Academic Search

    Elspeth S. Steinhauer; Christopher R. Omelon; Philip C. Bennett

    2010-01-01

    Subsurface karst aquifers receiving sulfidic water can host complex chemolithotrophic microbial communities that are capable of dissolving limestone, forming new karstic habitat. Neutrophilic sulfur-oxidizing bacteria use reduced sulfur compounds as energy rich substrate, potentially producing sulfuric acid as a geochemically reactive byproduct. The physicochemical relationship between a biofilm forming on a limestone surface and the extent of microbial influence on

  4. Glutathione levels in phloem sap of rice plants under sulfur deficient conditions

    Microsoft Academic Search

    Yusuke Kuzuhara; Amiko Isobe; Motoko Awazuhara; Toru Fujiwara; Hiroaki Hayashi

    2000-01-01

    Glutathione which is an abundant reduced sulfur compound in plants is considered to play important roles in the transmission of the sulfur nutrient status between organs within the plant body and in the long-distance transport of reduced sulfur. We determined the concentrations of glutathione, ?-glutamylcysteine (?-EC), sulfate in the rice phloem sap collected by the insect laser technique. Phloem sap

  5. Prebiotic Synthesis of Methionine and Other Sulfur-Containing Organic Compounds on the Primitive Earth: A Contemporary Reassessment Based on an Unpublished 1958 Stanley Miller Experiment

    NASA Astrophysics Data System (ADS)

    Parker, Eric T.; Cleaves, H. James; Callahan, Michael P.; Dworkin, Jason P.; Glavin, Daniel P.; Lazcano, Antonio; Bada, Jeffrey L.

    2011-06-01

    Original extracts from an unpublished 1958 experiment conducted by the late Stanley L. Miller were recently found and analyzed using modern state-of-the-art analytical methods. The extracts were produced by the action of an electric discharge on a mixture of methane (CH4), hydrogen sulfide (H2S), ammonia (NH3), and carbon dioxide (CO2). Racemic methionine was formed in significant yields, together with other sulfur-bearing organic compounds. The formation of methionine and other compounds from a model prebiotic atmosphere that contained H2S suggests that this type of synthesis is robust under reducing conditions, which may have existed either in the global primitive atmosphere or in localized volcanic environments on the early Earth. The presence of a wide array of sulfur-containing organic compounds produced by the decomposition of methionine and cysteine indicates that in addition to abiotic synthetic processes, degradation of organic compounds on the primordial Earth could have been important in diversifying the inventory of molecules of biochemical significance not readily formed from other abiotic reactions, or derived from extraterrestrial delivery.

  6. Effects of rehydration nutrients on H2S metabolism and formation of volatile sulfur compounds by the wine yeast VL3

    PubMed Central

    2011-01-01

    In winemaking, nutrient supplementation is a common practice for optimising fermentation and producing quality wine. Nutritionally suboptimal grape juices are often enriched with nutrients in order to manipulate the production of yeast aroma compounds. Nutrients are also added to active dry yeast (ADY) rehydration media to enhance subsequent fermentation performance. In this study we demonstrate that nutrient supplementation at rehydration also has a significant effect on the formation of volatile sulfur compounds during wine fermentations. The concentration of the 'fruity' aroma compounds, the polyfunctional thiols 3-mercaptohexan-1-ol (3MH) and 3-mercaptohexyl acetate (3MHA), was increased while the concentration of the 'rotten egg' aroma compound, hydrogen sulfide (H2S), was decreased. Nutrient supplementation of the rehydration media also changed the kinetics of H2S production during fermentation by advancing onset of H2S production. Microarray analysis revealed that this was not due to expression changes within the sulfate assimilation pathway, which is known to be a major contributor to H2S production. To gain insight into possible mechanisms responsible for this effect, a component of the rehydration nutrient mix, the tri-peptide glutathione (GSH) was added at rehydration and studied for its subsequent effects on H2S formation. GSH was found to be taken up during rehydration and to act as a source for H2S during the following fermentation. These findings represent a potential approach for managing sulfur aroma production through the use of rehydration nutrients. PMID:22044590

  7. Effects of rehydration nutrients on H2S metabolism and formation of volatile sulfur compounds by the wine yeast VL3.

    PubMed

    Winter, Gal; Henschke, Paul A; Higgins, Vincent J; Ugliano, Maurizio; Curtin, Chris D

    2011-01-01

    In winemaking, nutrient supplementation is a common practice for optimising fermentation and producing quality wine. Nutritionally suboptimal grape juices are often enriched with nutrients in order to manipulate the production of yeast aroma compounds. Nutrients are also added to active dry yeast (ADY) rehydration media to enhance subsequent fermentation performance. In this study we demonstrate that nutrient supplementation at rehydration also has a significant effect on the formation of volatile sulfur compounds during wine fermentations. The concentration of the 'fruity' aroma compounds, the polyfunctional thiols 3-mercaptohexan-1-ol (3MH) and 3-mercaptohexyl acetate (3MHA), was increased while the concentration of the 'rotten egg' aroma compound, hydrogen sulfide (H2S), was decreased. Nutrient supplementation of the rehydration media also changed the kinetics of H2S production during fermentation by advancing onset of H2S production. Microarray analysis revealed that this was not due to expression changes within the sulfate assimilation pathway, which is known to be a major contributor to H2S production. To gain insight into possible mechanisms responsible for this effect, a component of the rehydration nutrient mix, the tri-peptide glutathione (GSH) was added at rehydration and studied for its subsequent effects on H2S formation. GSH was found to be taken up during rehydration and to act as a source for H2S during the following fermentation. These findings represent a potential approach for managing sulfur aroma production through the use of rehydration nutrients. PMID:22044590

  8. Ectothiorhodospira mobilis Pelsh, a Photosynthetic Sulfur Bacterium Depositing Sulfur Outside the Cells1

    PubMed Central

    Trüper, Hans G.

    1968-01-01

    From salt flats on the Galapagos Islands, two strains of a red photosynthetic bacterium were isolated and identified as Ectothiorhodospira mobilis, an organism first described by Pelsh in 1937. The cells are curved in a short spiral, 0.7 to 1.0 ? wide and 2.0 to 4.8 ? long. They are motile by a polar tuft of flagella. Cells contain several large stacks of lamellar membranes, carrying the pigments bacteriochlorophyll a and carotenoids of the spirillo xanthin series. Cell division occurs by binary fission, not budding. The organism is strictly anaerobic and obligately photosynthetic. Its ability to grow well with sulfide, sulfur, thiosulfate, or sulfite as photosynthetic H donors puts it taxonomically in the Thiorhodaceae. During growth with sulfide, elementary sulfur is deposited outside the cells in the medium and disappears during further growth. A limited number of organic carbon compounds can be utilized as hydrogen donors in place of inorganic sulfur compounds. Under these conditions, sulfate can serve as the sulfur source. The enzymes catalase and hydrogenase are present. The newly isolated strains require vitamin B12. They also require a salinity of 2 to 3% NaCl, but they are not extreme halophiles. The organism is not identical with any of the species listed in Bergey's Manual. Images PMID:5650091

  9. Reduction of sulfuric acid by natural gas

    SciTech Connect

    Kogtev, S.E.; Nikandrov, I.S.

    1987-12-01

    The reduction of sulfuric acid to sulfur dioxide was studied to obtain a higher yield of sulfur dioxide. The reactions which take place in the presence of excess methane were listed. Gibbs energy reactions were presented showing the thermodynamic probability for the occurrence of the reactions within a wide temperature range. Gas analysis for the content of sulfur and carbon dioxides, methane hydrogen, hydrogen sulfate, and carbon monoxide was performed chromatographically using a katharometer and sequential columns packed with Polysorb 1 and NaX zeolite. It was shown that through high-temperature reduction of sulfuric acid by natural gas, the yield of sulfur dioxide could be raised to 100% at 1173 K.

  10. Sulfur and Hydrogen Isotope Anomalies in Meteorite Sulfonic Acids

    NASA Technical Reports Server (NTRS)

    Cooper, George W.; Thiemens, Mark H.; Jackson, Teresa L.; Chang, Sherwood

    1997-01-01

    Intramolecular carbon, hydrogen, and sulfur isotope ratios were measured on a homologous series of organic sulfonic acids discovered in the Murchison meteorite. Mass-independent sulfur isotope fractionations were observed along with high deuterium/hydrogen ratios. The deuterium enrichments indicate formation of the hydrocarbon portion of these compounds in a low-temperature environment that is consistent with that of interstellar clouds. Sulfur-33 enrichments observed in methanesulfonic acid could have resulted from gas-phase ultraviolet irradiation of a precursor, carbon disulfide. The source of the sulfonic acid precursors may have been the reactive interstellar molecule carbon monosulfide.

  11. 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.

  12. 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.

  13. An overview of liquid redox sulfur recovery

    Microsoft Academic Search

    D. A. Dalrymple; T. W. Trofe; J. M. Evans

    1989-01-01

    Liquid redox sulfur recovery processes absorb HâS from gas streams and produce elemental sulfur for sale or disposal. These processes, which involve the overall reaction of HâS with oxygen to form elemental sulfur and water can be used in a wide variety of applications where HâS removal and recovery are required. They can be used to desulfurize natural gas, either

  14. Pyrolysis of high sulfur Indian coals

    Microsoft Academic Search

    B. P. Baruah; Puja Khare

    2007-01-01

    Pyrolysis experiments under laboratory conditions for five numbers of high sulfur coal samples from the states of Meghalaya and Nagaland, India, were carried out at temperatures of 450, 600, 850, and 1000{sup o}C, respectively. The yield of products and thermal release of sulfur from these coals are investigated. The distribution of sulfur in the pyrolyzed products, i.e., char\\/coke, gas, and

  15. The use of sulfur in dermatology.

    PubMed

    Gupta, Aditya K; Nicol, Karyn

    2004-01-01

    Sulfur has antifungal, antibacterial, and keratolytic activity. In the past, its use was widespread in dermatological disorders such as acne vulgaris, rosacea, seborrheic dermatitis, dandruff, pityriasis versicolor, scabies, and warts. Adverse events associated with topically applied sulfur are rare and mainly involve mild application site reactions. Sulfur, used alone or in combination with agents such as sodium sulfacetamide or salicylic acid, has demonstrated efficacy in the treatment of many dermatological conditions. PMID:15303787

  16. New correlations predict physical properties of elemental sulfur

    SciTech Connect

    Shuai, X.; Meisen, A. [Univ. of British Columbia, Vancouver, British Columbia (Canada)

    1995-10-16

    Until now, elemental sulfur`s physical properties have not been systematically correlated. Simple tools for predicting these properties are necessary, especially for engineering calculations, because sulfur is widely used industrially. Newly developed correlations use temperature to estimate sulfur`s density, specific heat, vapor pressure, viscosity, and thermal conductivity.

  17. Bioleaching of metals from sewage sludge: Elemental sulfur recovery

    Microsoft Academic Search

    B. R. Ravishankar; J. F. Blais; H. Benmoussa; R. D. Tyagi

    2009-01-01

    Heavy metal leaching by sulfur-oxidizing bacteria, one of the most promising sludge detoxification methods, uses elemental sulfur as a microbial energy substrate. The addition of elemental sulfur in a powdered form makes it impossible to recover unused sulfur and can promote microbial reacidification of disposed sludge. Hence, recoverable forms of sulfur are preferred. The purpose of the present study was

  18. SELECTIVE REMOVAL OF ORGANIC SULFUR FROM COAL BY PERCHLOROETHYLENE EXTRACTION

    Microsoft Academic Search

    Sunggyu Lee; Sunil K. Kesavan; Byung G. Lee; Amit Ghosh; Conrad J. Kulik

    1989-01-01

    Desulfurization of coal involves the removal of both the inorganic and organic forms of sulfur. Several physical methods are available for the removal of inorganic sulfur which is normally represented by pyritic and sulfatic sulfur. Removal of organic sulfur requires the use of chemical cleaning methods. This paper presents the results of an organic sulfur removal technique which employs an

  19. Sulfur metabolism in higher plants: potential for phytoremediation

    Microsoft Academic Search

    Wilfried H. O. Ernst

    1998-01-01

    Sulfur is a major nutrient for all organisms. Plant species have a high biodiversity in uptake, metabolization and accumulation of sulfur so that there are potentials to use plants for phytoremediation of sulfur-enriched sites. A survey of soils enriched with sulfur either naturally or by human activities shows that a surplus of sulfur is mostly accompanied with a surplus of

  20. Missing SO2 oxidant in the coastal atmosphere? - observations from high-resolution measurements of OH and atmospheric sulfur compounds

    NASA Astrophysics Data System (ADS)

    Berresheim, H.; Adam, M.; Monahan, C.; O'Dowd, C.; Plane, J. M. C.; Bohn, B.; Rohrer, F.

    2014-11-01

    Diurnal and seasonal variations of gaseous sulfuric acid (H2SO4) and methane sulfonic acid (MSA) were measured in NE Atlantic air at the Mace Head atmospheric research station during the years 2010 and 2011. The measurements utilized selected-ion chemical ionization mass spectrometry (SI/CIMS) with a detection limit for both compounds of 4.3 × 104 cm-3 at 5 min signal integration. The H2SO4 and MSA gas-phase concentrations were analyzed in conjunction with the condensational sink for both compounds derived from 3 nm to 10 ?m (aerodynamic diameter) aerosol size distributions. Accommodation coefficients of 1.0 for H2SO4 and 0.12 for MSA were assumed, leading to estimated atmospheric lifetimes on the order of 7 and 25 min, respectively. With the SI/CIMS instrument in OH measurement mode alternating between OH signal and background (non-OH) signal, evidence was obtained for the presence of one or more unknown oxidants of SO2 in addition to OH. Depending on the nature of the oxidant(s), its ambient concentration may be enhanced in the CIMS inlet system by additional production. The apparent unknown SO2 oxidant was additionally confirmed by direct measurements of SO2 in conjunction with calculated H2SO4 concentrations. The calculated H2SO4 concentrations were consistently lower than the measured concentrations by a factor of 4.7 ± 2.4 when considering the oxidation of SO2 by OH as the only source of H2SO4. Both the OH and the background signal were also observed to increase significantly during daytime aerosol nucleation events, independent of the ozone photolysis frequency, J(O1D), and were followed by peaks in both H2SO4 and MSA concentrations. This suggests a strong relation between the unknown oxidant(s), OH chemistry, and the atmospheric photolysis and photooxidation of biogenic iodine compounds. As to the identity of the atmospheric SO2 oxidant(s), we have been able to exclude ClO, BrO, IO, and OIO as possible candidates based on {ab initio} calculations. Nevertheless, IO could contribute significantly to the observed CIMS background signal. A detailed analysis of this CIMS background signal in context with recently published kinetic data currently suggests that Criegee intermediates (CIs) produced from ozonolysis of alkenes play no significant role for SO2 oxidation in the marine atmosphere at Mace Head. On the other hand, SO2 oxidation by small CIs such as CH2OO produced photolytically or possibly in the photochemical degradation of methane is consistent with our observations. In addition, H2SO4 formation from dimethyl sulfide oxidation via SO3 as an intermediate instead of SO2 also appears to be a viable explanation. Both pathways need to be further explored.

  1. Occurrence and identification of series of organic sulfur compounds in oils and sediment extracts. I. A study of Rozel Point Oil (USA)

    SciTech Connect

    Damste, J.S.S.; De Leeuw, J.W.; Dalen, A.C.K.; De Zeeuw, M.A.; Lange, F.; Rijstra, W.I.C.; Schenck, P.A.

    1987-09-01

    A number of novel series of organic sulfur compounds (OSC) have been identified in several oils and sediment extracts including Rozel Point Oil (Bos Elder County, Utah, U.S.A.; Miocene). This oil contains these series in abundance, and the OSC were therefore studied in detail. The aromatic fraction was fractionated using column chromatography, and the fractions obtained were analyzed by GC with simultaneous flame ionization and flame photometric detection (PFD) and by Gas Chromatography/Ma (GC-MS). Series of isoprenoid thiophenes, isoprenoid thiolanes, isoprenoid bithiophenes, isoprenoid thienylthiolanes, isoprenoid benzothiophenes, thiophene and thiolane steranes, 2,5-di-n-alkylthiolanes, 2,6-di-n-alkylthianes and 2,4-di-n-alkylbenzo(b)thiophenes have been identified. The identifications were based on chromatographic and mass spectral data, response on the FPD, carbon skeleton determination by desulfurization and in some cases on mass spectral data from, and coinjections with, synthetic compounds. Together, almost 1000 OSC have been identified in the aromatic fraction of this oil. Because the carbon skeletons of the OSC identified have the same structures as the well know hydrocarbons from geological materials (isoprenoid hydrocarbons, steranes, n-alkanes) these compounds are thought to be products of sulfur incorporation reactions into specific precursors.

  2. New aromatic biomarkers in sulfur-rich coal

    Microsoft Academic Search

    R. Gorchs; M. A. Olivella; F. X. C. de las Heras

    2003-01-01

    A molecular study of linear, branched and isoprenyl alkylbenzene skeletons and alkenylbenzenes in the soluble fraction extracted from a sulfur-rich Utrillas coal was carried out using gas chromatography–mass spectrometry (GC–MS). The presence of C24–C28 diaromatic compounds, not previously reported in coals, suggests that photosynthetic green sulfur bacteria may have made an input of organic matter to these coals. The unsaturated

  3. Partial oxidation of sulfur-containing solid carbonaceous fuel

    Microsoft Academic Search

    M. S. Najjar; R. J. Corbeels

    1988-01-01

    This patent describes a process for the simultaneous partial oxidation and desulfurization of a sulfur and silicate-containing comminuted solid carbonaceous fuel comprising (basis solid fuel) 0.2 to 0.6 wt. % sulfur and 0.1 to 30 wt. % of silicate compounds including iron silicate the improvement comprising: (1) reacting in the reaction zone of a partial oxidation gas generator a feed

  4. 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-containing molecules on transition metal catalysts has been of interest to scientists for more than 2 decades.1. How- ever, sulfur chemistry on transition metal surfaces is so complicated that it remains far from

  5. In situ desulfurization during combustion of high-sulfur coals added with sulfur capture sorbents

    Microsoft Academic Search

    Lian Zhang; Atsushi Sato; Yoshihiko Ninomiya; Eiji Sasaoka

    2003-01-01

    Two Chinese coals, added with two types of sulfur capture sorbents, were combusted in a drop tube furnace to investigate effect of reaction temperature on sulfur removal during coal combustion. Limestone was used as sorbent and mixed with coal physically for sulfur removal. In addition, another sorbent, calcium acetate, synthesized from natural limestone, was also used for in situ removal

  6. Stable Sulfur Isotopic Evidence for Historical Changes of Sulfur Cycling in Estuarine Sediments from Northern Florida

    Microsoft Academic Search

    Volker Brüchert; Lisa M. Pratt

    1999-01-01

    Data on abundance and isotopic composition of porewater and sedimentary sulfur species are reported for relatively uncontaminated and highly contaminated fine-grained anoxic sediments of St. Andrew Bay, Florida. A strong contrast in amount and composition of sedimentary organic matter at the two sites allows a comparative study of the historical effects of increased organic loading on sulfur cycling and sulfur

  7. A study of volatile organic sulfur emissions causing urban odors

    Microsoft Academic Search

    Aysen Muezzinoglu

    2003-01-01

    Levels of hydrogen sulfide and sulfur containing organic compounds were studied in the air at the deltas of the polluted creeks in the city of Izmir, Turkey in summer 2001. High concentrations of these malodorous compounds were measured in the air samples. Presence of these compounds in the air was connected with the dark appearance and rising gas bubbles in

  8. Comparison of the UCB sulfur recovery process with conventional sulfur recovery technology for treating recycle gas from a crude oil residuum hydrotreater. [UCBSRP sulfur recovery process

    SciTech Connect

    Lynn, S.; Neumann, D.W.; Sciamanna, S.F.; Vorhis, F.H.

    1986-03-31

    The University of California, Berkeley, Sulfur Recovery Process (UCBSRP) is being developed as an alternative to conventional sulfur recovery technology for removing hydrogen sulfide from gas streams and converting it to elemental sulfur. In the UCBSRP the hydrogen sulfide is absorbed by a physical solvent and the resulting solution of H/sub 2/S is mixed with a stoichiometrically equivalent amount of slulfur dioxide dissolved in the same solvent. The reaction between the two sulfur compounds forms water, which is miscible with the solvent, and elemental sulfur, which crystallizes from solution when its solubility is exceeded. Part of the sulfur formed in the reaction is burned to make the SO/sub 2/ needed in the process, and the heat of combustion is recovered in a waste-heat boiler. Sulfur is recovered by cooling the solution, settling the additional crystals that form, and centrifuging the slurry pumped from the bottom of the crystallizer-surge tank. In this report the UCBSRP is compared to conventional technology for the case of the removal of H/sub 2/S from the recycle gas of a high-pressure petroleum residuum hydrotreater. The conventional technology selected for this comparison consists of an absorber/stripper operation using diethanol amine as the absorbent, a Claus sulfur plant, and a SCOT tail-gas treating unit. From this comparison it is estimated that the DFC for the UCBSRP would be about 61% of that for the conventional technology. The utility costs for this application of the UCBSRP are estimated to be less than the credit for the high-pressure steam produced whereas the utility costs for the conventional process are substantially more. 6 refs., 3 figs., 9 tabs.

  9. Sulfuric Acid and Water: Paradoxes of Dilution

    ERIC Educational Resources Information Center

    Leenson, I. A.

    2004-01-01

    On equilibrium properties of aqueous solutions of sulfuric acid, Julius Thomsen has marked that the heat evolved on diluting liquid sulfuric acid with water is a continuous function of the water used, and excluded absolutely the acceptance of definite hydrates as existing in the solution. Information about thermochemical measurement, a discussion…

  10. Sulfur in Distillers Grains for Dairy Cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sulfur is an essential element needed by animals for many functions. About 0.15% of the body weight is sulfur. It is found in the amino acids methionine, cysteine, cystine, homocysteine, and taurine; in chondroitin sulfate of cartilage; and in the B-vitamins, thiamin and biotin. Methionine, thiam...

  11. Phosphine-catalyzed construction of sulfur heterocycles.

    PubMed

    Gabillet, Sandra; Lecerclé, Delphine; Loreau, Olivier; Carboni, Michael; Dézard, Sophie; Gomis, Jean-Marie; Taran, Frédéric

    2007-09-27

    A simple and efficient method for constructing sulfur heterocycles was developed using a phosphine-catalyzed tandem umpolung addition and intramolecular cyclization of bifunctional sulfur pronucleophiles on arylpropiolates. The reaction offers a promising route to synthetically useful as well as biologically active heterocycles under neutral conditions. PMID:17803312

  12. Production of Low-Sulfur Converter Steel

    Microsoft Academic Search

    É. N. Shebanits; A. A. Larionov; B. V. Neboga; A. V. Pobegailo; M. N. Yakin; S. A. Ovsyannikov

    2000-01-01

    The production of low-sulfur (sulfur content of 0.005% or less) tube steel for pipelines, which has been successfully introduced at the Mariupol’ Metallurgical Combine, requires desulfurization of the pig iron and steel at the corresponding stages of the production process. The decision on an efficient method of desulfurization must be made on the basis of economic as well as technical

  13. Pyrolysis of high sulfur Indian coals

    SciTech Connect

    B.P. Baruah; Puja Khare [RRL Jorhat, Assam (India). Coal Chemistry Division

    2007-12-15

    Pyrolysis experiments under laboratory conditions for five numbers of high sulfur coal samples from the states of Meghalaya and Nagaland, India, were carried out at temperatures of 450, 600, 850, and 1000{sup o}C, respectively. The yield of products and thermal release of sulfur from these coals are investigated. The distribution of sulfur in the pyrolyzed products, i.e., char/coke, gas, and tar, is also reported. Hydrocarbon and sulfurous gases released at different temperatures were analyzed by a gas chromatograph (GC) with an FID (flame ionized detector) and an FPD (flame photometric detector), respectively. H{sub 2}S evolution during coal pyrolysis was found to be a function of temperature up to 850{sup o}C. The low concentration of SO{sub 2} detected for some of the samples is due to decomposition of inorganic sulphates present. Evolution of methane for the coals tested increases with the increase of temperature. Maximum sulfur release was found in the range of 600-850{sup o}C and has a decreasing tendency from 850-1000{sup o}C, which might be due to the incorporation of sulfur released into the coal matrix. Activation energies for sulfur release were found in the range of 38-228 kJ mol{sup -1}, which were higher than the reported activation energies for lignites and bituminous coals mainly due to highly stable organic sulfur functionalities. 52 refs., 9 figs., 6 tabs.

  14. Novel aqueous aluminum/sulfur batteries

    SciTech Connect

    Licht, S.; Peramunage, D. (Clark Univ., Worcester, MA (United States))

    1993-01-01

    Aluminum sulfur batteries based on concentrated polysulfide catholytes and an alkaline aluminum anode are introduced and investigated. The new battery is expressed by aluminum oxidation and aqueous sulfur reduction for an overall battery discharge consisting of 2Al + S[sub 4][sup 2[minus

  15. A solid sulfur cathode for aqueous batteries.

    PubMed

    Peramunage, D; Licht, S

    1993-08-20

    Because of its high resistivity and subsequent low electroactivity, sulfur is not normally considered a room-temperature battery cathode. An elemental sulfur cathode has been made with a measured capacity of over 900 ampere.hours per kilogram, more than 90 percent of the theoretical storage capacity of solid sulfur at room temperature, accessed by means of a lightweight, highly conductive, aqueous polysulfide interface through the electrocatalyzed reaction S + H(2)O + 2e(-) --> HS(-) + OH(-). This solid sulfur cathode was first used in a battery with an aluminum anode for an overall discharge reaction 2Al + 3S + 3OH(-) + 3H(2)O --> 2Al(OH)(3) + 3HS(-), giving a cell potential of 1.3 volts. The theoretical specific energy of the aluminum-sulfur battery (based on potassium salts) is 910 watt.hours per kilogram with an experimental specific energy of up to 220 watt.hours per kilogram. PMID:17739624

  16. Combined chemical and microbiological removal of organic sulfur from coal. Technical report, September 1, 1990--August 31, 1991

    SciTech Connect

    Raphaelian, L.A.

    1991-12-31

    The objective of this work is to investigate techniques for chemically converting the sulfur containing organic compounds in coal to compounds that can be treated microbiologically to remove the organically bound sulfur. The goal is to achieve an economically feasible mild chemical oxidation of the organic sulfur in a representative Illinois Basin coal by converting the sulfur to sulfoxides and sulfones; the carbon sulfur bond in the sulfoxides and sulfones would then be broken microbiologically and the sulfur removed from the coal as sulfate.

  17. Electrolyte for lithium-sulfur dioxide electrochemical cell

    SciTech Connect

    Faulkner, L.R.; Davidson, I.J.

    1988-06-21

    A nonaqueous conductive liquid is described which comprises a solution of aluminium chloride and at least one lithium salt in a mixture of liquid sulfur dioxide with at least one polar organic compound wherein the polar organic compound has a Donor Number in the range from about 10 to about 25.

  18. Sodium sulfur battery flight experiment definition study

    NASA Technical Reports Server (NTRS)

    Chang, Rebecca R.; Minck, Robert

    1989-01-01

    Sodium-sulfur batteries were identified as the most likely successor to nickel-hydrogen batteries for space applications. One advantage of the Na/S battery system is that the usable specific energy is two to three times that of nickel-hydrogen batteries. This represents a significant launch cost savings or increased payload mass capabilities. Sodium-sulfur batteries support NASA OAST's proposed Civil Space Technology Initiative goal of a factor of two improvement in spacecraft power system performance, as well as the proposed Spacecraft 2000 initiative. The sodium-sulfur battery operates at between 300 and 400 C, using liquid sodium and sulfur/polysulfide electrodes and solid ceramic electrolyte. The transport of the electrode materials to the surface of the electrolyte is through wicking/capillary forces. These critical transport functions must be demonstrated under actual microgravity conditions before sodium-sulfur batteries can be confidently utilized in space. Ford Aerospace Corporation, under contract to NASA Lewis Research Center, is currently working on the sodium-sulfur battery space flight experiment definition study. The objective is to design the experiment that will demonstrate operation of the sodium-sulfur battery/cell in the space environment with particular emphasis on evaluation of microgravity effects. Experimental payload definitions were completed and preliminary designs of the experiment were defined.

  19. Simple and Excellent Selective Chemiluminescence-Based CS2 On-Line Detection System for Rapid Analysis of Sulfur-Containing Compounds in Complex Samples.

    PubMed

    Zhang, Runkun; Li, Gongke; Hu, Yufei

    2015-06-01

    To study the interesting chemical reaction phenomenon can greatly contribute to the development of an innovative analytical method. In this paper, a simple CL reaction cell was constructed to study the chemiluminescence (CL) emission from the thermal oxidation of carbon disulfide (CS2). We found that the CL detection of CS2 exhibits unique characteristics of excellent selectivity and rapid response capacity. Experimental investigations together with theoretical calculation were performed to study the mechanism behind the CL reaction. The results revealed that the main luminous intermediates generated during the thermal degradation of CS2 are SO2* and CO2*. Significantly, this CL emission phenomenon has a wide application due to many sulfur-containing compounds that can convert to CS2 under special conditions. On the basis of this scheme, a CS2-generating and detection system was developed for rapid measurement of CS2 or other compounds that can convert to CS2. The usefulness of the system was demonstrated by measuring dithiocarbamate (DTC) pesticides (selected mancozeb as a representative analyte) based on the evolution of CS2 in spiked agricultural products. Results showed that the system allows online and large volume detection of CS2 under nonequilibrium condition, which greatly reduces the analytical time. The concentrations of mancozeb in the spiked samples were well-quantified with satisfied recoveries of 76.9-97.3%. The system not only addresses the urgent need for rapid in-field screening of DTC residues in foodstuffs but also opens a new opportunity for the fast, convenient, and cost-effective detection of CS2 and some other sulfur-containing compounds in complex samples. PMID:25913203

  20. Sulfuric acid/hydrogen peroxide rinsing study

    SciTech Connect

    Clews, P.J.; Nelson, G.C.; Matlock, C.A. [and others

    1995-12-01

    Sulfuric acid hydrogen peroxide mixtures (SPM) are commonly used in the semiconductor industry to remove organic contaminants from wafer surfaces. This viscous solution is very difficult to rinse off water surfaces. Various rinsing conditions were tested and the resulting residual acid left on the water surface was measured. Particle growth resulting from incomplete rinse is correlated with the amount of sulfur on the wafer surface measured by Time of Flight Secondary Ion Mass Spectroscopy (TOF-SIMS). The amount of sulfur on the wafer structure after the rinse step is strongly affected by the wafer film type and contact angle prior to the SPM clean.

  1. Sulfur and olefin management in the gasoline

    SciTech Connect

    Nocca, J.L.; Gialella, R.M. [IFP Enterprises, Inc., Houston, TX (United States); Cosyns, J.; Burzynski, J.P. [IFP, Rueil Malmaison (France)

    1995-09-01

    As transportation fuel composition is fine-tuned, sulfur and olefin concentration in the gasoline will come under increased scrutiny. This paper presents various options to limit sulfur and olefins with special emphasis on FCC Gasoline Desulfurization and C{sub 5} Skeletal Isomerization. Hydrodesulfurization of the C{sub 6} + FCC gasoline and processing of the FCC C{sub 5} cut in a Tame/Skeletal Isomerization complex is shown to meet the most stringent olefin and sulfur specifications while substantially reducing RVP and increasing refinery based oxygenates production.

  2. The evaluation of recovery rate associated with the use of thermal desorption systems for the analysis of atmospheric reduced sulfur compounds (RSC) using the GC/PFPD method.

    PubMed

    Kim, Ki-Hyun; Ju, Do-Weon; Joo, Sang-Woo

    2005-10-31

    In this work, the recovery rate (RR) of preconcentration technique was examined using a combination of the Peltier cooling (PC) and thermal desorption (TD) system for the gas chromatographic (GC) analysis of reduced sulfur compounds (RSC) in air. The possible loss or gain of analytes resulting from the use of the PC/TD system was estimated by analyzing equimolar standards (10ppm) of four S compounds including H(2)S, CH(3)SH, DMS, and DMDS in two different manners: (1) by injecting directly the four S compounds into the GC via injector and (2) by introducing them through the PC/TD system. When a series of tests were conducted on different types of gas media (ultrapure air versus N(2)) and across varying relative humidity (RH), it was found that the RR values for the four S compounds vary from 80 to 110% range. The overall results of our study thus indicate that the RR for the PC/TD system is fairly good and that subtle differences in their RR values may reflect the combined effects of different factors investigated in this study such as types of gas media, RH change, and properties of target analytes (e.g., recovery rate of the least (H(2)S) versus the highest compound (DMDS)). PMID:18970264

  3. CONSTRUCTION OF A PROTOTYPE SULFURIC ACID MIST MONITOR

    EPA Science Inventory

    A prototype sulfuric acid mist monitor has been constructed for the purpose of detecting sulfuric acid-sulfur trioxide. The monitor utilized the selective condensation method with subsequent determination of sulfuric acid by measuring the conductivity of an aqueous isopropanol so...

  4. Sulfur Flow Analysis for New Generation Steel Manufacturing Process

    Microsoft Academic Search

    Chang-Qing HU; Chun-Xia ZHANG; Xiao-Wei HAN; Rui-Yu YIN

    2008-01-01

    Sulfur flow for new generation steel manufacturing process is analyzed by the method of material flow analysis, and measures for SO2 emission reduction are put forward as assessment and target intervention of the results. The results of sulfur flow analysis indicate that 90% of sulfur comes from fuels. Sulfur finally discharges from the steel manufacturing route in various steps, and

  5. Sulfur transformations during pyrolysis of a high sulfur Polish coking coal

    Microsoft Academic Search

    Gra?yna Gryglewicz

    1995-01-01

    A coking coal containing 4.9 wt%, db, of sulfur was subjected to pyrolysis at 330–1700°C in an atmosphere of evolved gases. The changes in the forms of sulfur were determined by wet chemical analysis. Scanning electron microscopy (SEM) combined with X-ray microanalysis were used to monitor the reduction of pyrite during coal pyrolysis and the retention of sulfur by the

  6. Heterogeneous Photochemical Oxidation of Sulfur Dioxide

    NASA Astrophysics Data System (ADS)

    El-Zanan, H. S.; Stockwell, W. R.

    2007-12-01

    The gas phase oxidation of sulfur dioxide by the hydroxyl radical is a significant source of sulfate aerosol in the troposphere and stratosphere. Stockwell and Calvert (1983) performed fifteen chamber experiments where mixtures of HONO, NO, NO2, H2O, SO2 and CO were photolyzed in synthetic air or in nitrogen containing approximately 50 ppm oxygen. They found that the atmospheric oxidation of SO2 by hydroxyl radical was a chain process that occurs through the production of an HO2 radical followed by reaction with NO to reproduce HO. We have reanalyzed this dataset and we have found that a very large amount of the observed SO2 oxidation (70.0 ± 9.1 %) is not explained through the HO + SO2 reaction alone. The Regional Atmospheric Chemistry Mechanism (RACM2) was used to investigate additional chemical pathways for the oxidation of SO2. A mechanism consisting of photochemical heterogeneous reactions is proposed to account for the observed additional sulfur dioxide oxidation not accounted for by gas phase oxidation. The analysis showed that the measured time dependent SO2, CO2 and nitrogenous compound concentrations could be simulated by the photochemical heterogeneous mechanism in conjunction with the RACM2 mechanism.

  7. Sodium-sulfur batteries for satellite applications

    NASA Astrophysics Data System (ADS)

    Wolanczyk, Stephan M.; Vukson, Stephen P.

    1990-04-01

    A development status evaluation is presented for the USAF's various efforts to advance sodium-sulfur battery technology as a basis for GEO and LEO satellite energy storage systems. These efforts encompass the High Energy Density Rechargeable Battery program, the LEO Sodium-Sulfur Cell Development program, the Improved Sodium-Sulfur Electrolyte program, and the Lightweight Aerospace Battery (LAB) program. An especially taxing requirement for batteries of this type is the substantial number of charge/discharge cycles typical of LEO satellite applications. The LAB program, which will extend to 1993, is intended to develop a bipolar, flat-plate sodium-sulfur satellite battery with 7-10 year service life in LEO and 15 years in GEO.

  8. 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 the correspondence between tracer gas concentration and atmospheric stability. Within the Tukey Cherry Orchard, we

  9. Dual protection of sulfur by carbon nanospheres and graphene sheets for lithium-sulfur batteries.

    PubMed

    Wang, Bei; Wen, Yanfen; Ye, Delai; Yu, Hua; Sun, Bing; Wang, Guoxiu; Hulicova-Jurcakova, Denisa; Wang, Lianzhou

    2014-04-25

    Well-confined elemental sulfur was implanted into a stacked block of carbon nanospheres and graphene sheets through a simple solution process to create a new type of composite cathode material for lithium-sulfur batteries. Transmission electron microscopy and elemental mapping analysis confirm that the as-prepared composite material consists of graphene-wrapped carbon nanospheres with sulfur uniformly distributed in between, where the carbon nanospheres act as the sulfur carriers. With this structural design, the graphene contributes to direct coverage of sulfur to inhibit the mobility of polysulfides, whereas the carbon nanospheres undertake the role of carrying the sulfur into the carbon network. This composite achieves a high loading of sulfur (64.2?wt?%) and gives a stable electrochemical performance with a maximum discharge capacity of 1394?mAh?g(-1) at a current rate of 0.1?C as well as excellent rate capability at 1?C and 2?C. The improved electrochemical properties of this composite material are attributed to the dual functions of the carbon components, which effectively restrain the sulfur inside the carbon nano-network for use in lithium-sulfur rechargeable batteries. PMID:24692070

  10. Effects of variation of dietary sulfur on movement of sulfur in sheep rumen

    SciTech Connect

    Kandylis, K.; Bray, A.C.

    1987-01-01

    Effects of variations in dietary sulfur on rumen sulfur dynamics were studied under steady state conditions. In the first experimental period, three sheep were given 33.3 g of a pelleted diet hourly containing 1.59 g sulfur/kg (low) and in the second period the sulfur content was increased to 3.21 g/kg (high) by the addition of sodium sulfate. The daily sulfur intake was 1.158 g on the low sulfur diet and .545 g of this passed from the rumen in protein, .614 g was calculated to be absorbed from the rumen as sulfide, and .052 g was estimated to be recycled to the rumen. For sheep with daily intakes of 2.317 g sulfur, 1.212 g passed from the rumen in protein, 1.078 g was absorbed from the rumen, and .093 g was estimated to be recycled. It was estimated that 127 and 165 g microbial protein were synthesized/kg organic matter truly digested in the rumen for low and high sulfur diets, respectively. A simple model using simultaneous equations was proposed to describe rumen sulfur metabolism.

  11. Definition of Non-Conventional Sulfur Utilization in Western Kazakhstan for Sulfur Concrete (Phase 1)

    SciTech Connect

    Kalb, Paul

    2007-05-31

    Battelle received a contract from Agip-KCO, on behalf a consortium of international oil and gas companies with exploration rights in the North Caspian Sea, Kazakhstan. The objective of the work was to identify and help develop new techniques for sulfur concrete products from waste, by-product sulfur that will be generated in large quantitites as drilling operations begin in the near future. BNL has significant expertise in the development and use of sulfur concrete products and has direct experience collaborating with the Russian and Kazakh partners that participated. Feasibility testing was successfully conducted for a new process to produce cost-effective sulfur polymer cement that has broad commerical applications.

  12. Isotopic composition and speciation of sulfur in the Miocene Monterey Formation: Reevaluation of sulfur reactions during early diagenesis in marine environments

    Microsoft Academic Search

    Doreen A. Zaback; Lisa M. Pratt

    1992-01-01

    The timing and pathways of early diagenetic sulfur transfer from dissolved species in pore waters to solid inorganic and organic compounds in sediments have been studied in the Miocene Monterey Formation, Santa Maria Basin (onshore), California. Correlation between concentrations of total organic carbon (TOC) and total sulfur (TS), in addition to concentrations of titanium, aluminum, total iron, and reactive iron,

  13. Biologically produced sulfur particles and polysulfide ions

    Microsoft Academic Search

    W. E. Kleinjan

    2005-01-01

    This thesis deals with the effects of particles of biologically produced sulfur (or 'biosulfur<\\/span>') on a biotechnological process for the removal of hydrogen sulfide from gas streams. Particular emphasis is given to the role of polysulfide ions in such a process. These polysulfide ions are formed from reaction of sulfide with biologically produced sulfur. The basic concepts of this

  14. Sulfur Nutrition and Assimilation in Crop Plants

    Microsoft Academic Search

    Avtar Singh Bimbraw

    Sulfur (S) deficiency has become common in agricultural soils and has resulted in crop yield loss. Agricultural soils are\\u000a further at risk from S-deficiency in cereals and oilseed crops. The present paper discusses the effects of sulfur on plant\\u000a growth and crop quality in various crops associated with S-deficiency and increase in the environment (Air pollution). Plant\\u000a responses to S-supply

  15. Polymer Electrolytes for Lithium/Sulfur Batteries

    PubMed Central

    Zhao, Yan; Zhang, Yongguang; Gosselink, Denise; Doan, The Nam Long; Sadhu, Mikhail; Cheang, Ho-Jae; Chen, Pu

    2012-01-01

    This review evaluates the characteristics and advantages of employing polymer electrolytes in lithium/sulfur (Li/S) batteries. The main highlights of this study constitute detailed information on the advanced developments for solid polymer electrolytes and gel polymer electrolytes, used in the lithium/sulfur battery. This includes an in-depth analysis conducted on the preparation and electrochemical characteristics of the Li/S batteries based on these polymer electrolytes. PMID:24958296

  16. Effect of feeding distiller’s grains on reduced sulfur emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Odorous reduced sulfur compounds are produced during manure decomposition and emitted from confined animal feeding operations. Feeding high-sulfur distiller’s byproducts may increase the emission of these compounds. The objectives of a series of feedlot pen studies was to (i) determine if emission...

  17. Identification of control parameters for the sulfur gas storability with bag sampling methods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Air samples containing sulfur compounds are often collected and stored in sample bags prior to analyses. The storage stability of six gaseous sulfur compounds (H2S, CH3SH, DMS, CS2, DMDS and SO2) was compared between two different bag materials (polyvinyl fluoride (PVF) and polyester aluminum (PEA))...

  18. Synthesis and structure of bismuth compounds bearing a sulfur-bridged bis(phenolato) ligand and their catalytic application to the solvent-free synthesis of propylene carbonate from CO2 and propylene oxide.

    PubMed

    Yin, Shuang-Feng; Shimada, Shigeru

    2009-03-01

    Two bismuth compounds bearing a sulfur-bridged bis(phenolato) ligand were synthesized and found to show high catalytic activity and selectivity for solvent-free synthesis of propylene carbonate from CO(2) and propylene oxide in the presence of iodide salts as co-catalysts at room temperature under 1 atm CO(2). PMID:19225661

  19. Sulfur nutrition of deciduous trees

    NASA Astrophysics Data System (ADS)

    Herschbach, Cornelia; Rennenberg, Heinz

    2001-01-01

    Sulfur in its reduced form (-II) is an essential nutrient for growth and development, but is mainly available to plants in its oxidised form as sulfate. Deciduous trees take up sulfate by the roots from the soil solution and reduce sulfate to sulfide via assimilatory sulfate reduction in both roots and leaves. For reduction in the leaves, sulfate is loaded into the xylem and transported to the shoot. The surplus of sulfate not reduced in the chloroplast or stored in the vacuole and the surplus of reduced S not used for protein synthesis in the leaves is loaded into the phloem and transported back to the roots. Along the transport path, sulfate and glutathione (GSH) is unloaded from the phloem for storage in xylem and phloem parenchyma as well as in pit and ray cells. Re-mobilised S from storage tissues is loaded into the xylem during spring, but a phloem to xylem exchange does not appear to exist later in the season. As a consequence, a cycling pool of S was only found during the change of the seasons. The sulfate:glutathione ratio in the phloem seems to be involved in the regulation of S nutrition. This picture of S nutrition is discussed in relation to the different growth patterns of deciduous trees from the temperate climate zone, i.e. (1) terminated, (2) periodic and (3) indeterminate growth patterns, and in relation to environmental changes.

  20. Novel Cysteine-Centered Sulfur Metabolic Pathway in the Thermotolerant Methylotrophic Yeast Hansenula polymorpha

    PubMed Central

    Oh, Doo-Byoung; Kwon, Ohsuk; Lee, Sang Yup; Sibirny, Andriy A.; Kang, Hyun Ah

    2014-01-01

    In yeast and filamentous fungi, sulfide can be condensed either with O-acetylhomoserine to generate homocysteine, the precursor of methionine, or with O-acetylserine to directly generate cysteine. The resulting homocysteine and cysteine can be interconverted through transsulfuration pathway. Here, we systematically analyzed the sulfur metabolic pathway of the thermotolerant methylotrophic yeast Hansenula polymorpha, which has attracted much attention as an industrial yeast strain for various biotechnological applications. Quite interestingly, the detailed sulfur metabolic pathway of H. polymorpha, which was reconstructed based on combined analyses of the genome sequences and validation by systematic gene deletion experiments, revealed the absence of de novo synthesis of homocysteine from inorganic sulfur in this yeast. Thus, the direct biosynthesis of cysteine from sulfide is the only pathway of synthesizing sulfur amino acids from inorganic sulfur in H. polymorpha, despite the presence of both directions of transsulfuration pathway Moreover, only cysteine, but no other sulfur amino acid, was able to repress the expression of a subset of sulfur genes, suggesting its central and exclusive role in the control of H. polymorpha sulfur metabolism. 35S-Cys was more efficiently incorporated into intracellular sulfur compounds such as glutathione than 35S-Met in H. polymorpha, further supporting the cysteine-centered sulfur pathway. This is the first report on the novel features of H. polymorpha sulfur metabolic pathway, which are noticeably distinct from those of other yeast and filamentous fungal species. PMID:24959887

  1. Sulfur "Concrete" for Lunar Applications - Sublimation Concerns

    NASA Technical Reports Server (NTRS)

    Grugel, Richard N.; Toutanji, Houssam

    2006-01-01

    Melting sulfur and mixing it with an aggregate to form "concrete" is commercially well established and constitutes a material that is particularly well-suited for use in corrosive environments. Discovery of the mineral troilite (FeS) on the moon poses the question of extracting the sulfur for use as a lunar construction material. This would be an attractive alternative to conventional concrete as it does not require water. However, the viability of sulfur concrete in a lunar environment, which is characterized by lack of an atmosphere and extreme temperatures, is not well understood. Here it is assumed that the lunar ore can be mined, refined, and the raw sulfur melded with appropriate lunar regolith to form, for example, bricks. This study evaluates pure sulfur and two sets of small sulfur concrete samples that have been prepared using JSC-1 lunar stimulant and SiO2 powder as aggregate additions. Each set was subjected to extended periods in a vacuum environment to evaluate sublimation issues. Results from these experiments are presented and discussed within the context of the lunar environment.

  2. Improved Chromatographic Techniques for Sulfur Pollutants

    NASA Technical Reports Server (NTRS)

    Hartmann, C. H.

    1971-01-01

    This paper describes several improvements in instrumental techniques for the analysis of low ppb concentrations of sulfur gases using gas chromatography (G.C.). This work has focused on the analytical problem of ambient air monitoring of the two main sulfur gas pollutants, hydrogen sulfide and sulfur dioxide. The most significant technical improvement that will be reported here is the newly developed silica gel column for ppb concentrations of the light sulfur gases (COS, H2S, CS2, SO2, CH3SH). A simplified inlet system will be described which improves reliability of the GC system. The flame photometric detector is used as the means of selectively and sensitively detecting the low concentrations of sulfur gases. Improvements will be described which have yielded better performance than previously reported for this application of the detector. Also included in this paper will be a report of field monitoring using this improved GC system. Reliability and repeatability of performance at the low ppb concentrations of sulfur gases will be demonstrated.

  3. Homolytic bond dissociation energies for C-H bonds adjacent to sulfur and aromatic moieties: The effects of substituents of C-H bond strengths of the benzylic positions in coal model compounds

    SciTech Connect

    Alnajjar, M.S.; Franz, J.A. [Pacific Northwest Lab., Richland, WA (United States); Gleicher, G.J.; Truksa, S. [Oregon State Univ., Corvallis, OR (United States). Dept. of Chemistry; Bordwell, F.; Zhang, Xian-Man [Northwestern Univ., Evanston, IL (United States). Dept. of Chemistry

    1993-09-01

    Sulfur-containing compounds are precursors for thiyl radicals at coal liquefaction temperatures due to the weakness of The and S-S bonds. Thiyl radicals play important roles in hydrogen atom shuttling between benzylic positions and catalyze the cleavage and the formation of strong C-C bonds. Although many reactions of thiyl and other sulfur-containing radicals are qualitatively understood, the homolytic bond dissociation energies (EDE`s) and the thermochemistry associated with many key high molecular weight hydrocarbon and sulfur-containing organic structures important to coal is lacking because they are inappropriate for gas-phase techniques. The measurement of BDE`s has been proven to be difficult even in the simplest of molecules.

  4. Ab initio studies of tropospheric sulfur chemistry

    SciTech Connect

    Wilson, C. [Univ. of Warwick, West Midlands (United Kingdom)

    1996-10-01

    For a detailed understanding of tropospheric chemistry, one requires accurate kinetic data for all of the reactions thought to be important. In some cases, it is difficult to obtain this information experimentally. Ab initio quantum chemical methods can make a significant contribution to the understanding of reaction mechanisms. Structures of transition states and reaction intermediates can be determined. Calculations can predict kinetic and energetic data for reactions. Reduce sulfur compounds which are present in the troposphere include H{sub 2}S, OCS, CS{sub 2}, CH{sub 3}SH and CH{sub 3}SCH{sub 3}. Each of these can be oxidised by OH radicals. We have studied these oxidation reactions using ab initio methods in order to elucidate some details of the mechanisms and possible products.

  5. Behavior of sulfur and chlorine in coal during combustion and boiler corrosion. Technical report, December 1, 1992February 28, 1993

    Microsoft Academic Search

    C. L. Chou; K. C. Hackley; J. Cao; R. R. Frost; R. R. Ruch; W. P. Pan; M. L. Upchurch; H. B. Cao; D. Shao; H. H. Ho

    1993-01-01

    The goals of this project is to investigate the behavior of sulfur and chlorine during pyrolysis and combustion of Illinois coals, the chemistry of boiler deposits and the process of ash formation, and remedial measures to reduce the sulfur and chlorine compounds in combustion gases. The chemistry of boiler deposits provides information about the behavior of sulfur, chlorine, and ash

  6. Novel aromatic carotenoid derivatives from sulfur photosynthetic bacteria in sediments

    Microsoft Academic Search

    Philippe Schaeffer; Pierre Adam; Patrick Wehrung; Pierre Albrecht

    1997-01-01

    Novel aromatic carotenoid derivatives 7 and 8 have been identified by synthesis of reference compounds in a H2\\/PtO2-hydrogenated fraction from the organic extract of a lake sediment (lake Cadagno, Switzerland). They derive from unreported carotenoids presumably biosynthesized by purple sulfur photosynthetic bacteria (Chromatiaceae) and represent potential biomarkers to establish the occurrence of photic zone anoxia in ancient ecosystems.

  7. Workshop on sulfur chemistry in flue gas desulfurization

    SciTech Connect

    Wallace, W.E. Jr.

    1980-05-01

    The Flue Gas Desulfurization Workshop was held at Morgantown, West Virginia, June 7-8, 1979. The presentations dealt with the chemistry of sulfur and calcium compounds in scrubbers. DOE and EPRI programs in this area are described. Ten papers have been entered individually into EDB and ERA. (LTN)

  8. Coal gasification: molten salt processes for sulfur emission control

    Microsoft Academic Search

    Glueck

    1973-01-01

    Two molten salt desulfurization processes are illustrated. ; Precombustion desulfurization of coal takes place in a single vessel. Pulverized ; coal, slurried with molten salt, is allowed to react with a melt that contains an ; agent with an affinity for the sulfurous compounds. The coal collects at the ; top, being less dense than the melt, and is drawn

  9. Ring cleavage of sulfur heterocycles: how does it happen?

    Microsoft Academic Search

    David C. Bressler; Jason A. Norman; Phillip M. Fedorak

    1998-01-01

    Sulfur heterocycles are common constituents ofpetroleum and liquids derived from coal, and they arefound in some secondary metabolites of microorganismsand plants. They exist primarily as saturated ringsand thiophenes. There are two major objectives drivinginvestigations of the microbial metabolism oforganosulfur compounds. One is the quest to develop aprocess for biodesulfurization of fossil fuels, andthe other is to understand the fates of

  10. Modern applications for a total sulfur reduction distillation method - what’s old is new again

    PubMed Central

    2014-01-01

    Background The use of a boiling mixture of hydriodic acid, hypophosphorous acid, and hydrochloric acid to reduce any variety of sulfur compounds has been in use in various applications since the first appearance of this method in the literature in the 1920’s. In the realm of sulfur geochemistry, this method remains a useful, but under-utilized technique. Presented here is a detailed description of the distillation set-up and procedure, as well as an overview of potential applications of this method for marine sulfur biogeochemistry/isotope studies. The presented applications include the sulfur isotope analysis of extremely low amounts of sulfate from saline water, the conversion of radiolabeled sulfate into sulfide, the extraction of refractory sulfur from marine sediments, and the use of this method to assess sulfur cycling in Aarhus Bay sediments. Results The STrongly Reducing hydrIodic/hypoPhosphorous/hydrochloric acid (STRIP) reagent is capable of rapidly reducing a wide range of sulfur compounds, including the most oxidized form, sulfate, to hydrogen sulfide. Conversion of as little as approximately 5 micromole sulfate is possible, with a sulfur isotope composition reproducibility of 0.3 permil. Conclusions Although developed many decades ago, this distillation method remains relevant for many modern applications. The STRIP distillation quickly and quantitatively converts sulfur compounds to hydrogen sulfide which can be readily collected in a silver nitrate trap for further use. An application of this method to a study of sulfur cycling in Aarhus Bay demonstrates that we account for all of the sulfur compounds in pore-water, effectively closing the mass balance of sulfur cycling. PMID:24808759

  11. Basic sulfur recovery research. Annual technical report, January 31, 1991

    SciTech Connect

    DeBerry, D.W.

    1991-01-31

    The fundamentals of chemical interactions between chemical reagents and reduced sulfur compounds in the liquid redox and other sulfur recovery processes are explored in order to use the information to target the most effective options in processing steps for the gas industry. Methods for following concentration of an intermediate chemical species in the reaction of iron chelates and hydrogen sulfide were developed. Additional kinetic methods involving ultraviolet spectroscopy and sulfide ion selective electrode measurements were developed for following the chemical reactants during key stages of the reactions.

  12. Extraction, separation, and analysis of high sulfur coal

    SciTech Connect

    Olesik, S.V.; Pekay, L.A.; Larkins, W. Jr. (comps.)

    1992-05-31

    The work described in this report studies the removal of sulfur by oxidative interaction of various cupric salts with coal and also considers the possibility of removing organic sulfur by the selective interaction of supercritical ethanol with the organic coal matrix. Either one of these methods could potentially be used to pretreat coals before burning. The primary purpose of these studies is to ascertain the nature of the chemical reactions occurring, the chemical composition of the resultant products, and information on possible reaction mechanisms. This information should allow prediction of reasonable reaction conditions for the removal of organosulfur compound from coal.

  13. Extraction, separation, and analysis of high sulfur coal. Final report

    SciTech Connect

    Olesik, S.V.; Pekay, L.A.; Larkins, W. Jr. [comps.

    1992-05-31

    The work described in this report studies the removal of sulfur by oxidative interaction of various cupric salts with coal and also considers the possibility of removing organic sulfur by the selective interaction of supercritical ethanol with the organic coal matrix. Either one of these methods could potentially be used to pretreat coals before burning. The primary purpose of these studies is to ascertain the nature of the chemical reactions occurring, the chemical composition of the resultant products, and information on possible reaction mechanisms. This information should allow prediction of reasonable reaction conditions for the removal of organosulfur compound from coal.

  14. Porous Hollow Carbon@Sulfur Composites for High-Power Lithium–Sulfur Batteries

    SciTech Connect

    Navaneedhakrishnan, Jayaprakash [School of Chemical and Biomolecular Engineering, Cornell Univ., Ithaca, NY (United States); Shen, Jingguo [School of Chemical and Biomolecular Engineering, Cornell Univ., Ithaca, NY (United States); Moganty, Surya S. [School of Chemical and Biomolecular Engineering, Cornell Univ., Ithaca, NY (United States); Corona, Alexandra [School of Chemical and Biomolecular Engineering, Cornell Univ., Ithaca, NY (United States); Archer, Lynden A. [School of Chemical and Biomolecular Engineering, Cornell Univ., Ithaca, NY (United States)

    2011-06-20

    C @ S nanocomposites based on mesoporous hollow carbon capsules were prepared by a template approach. Their excellent properties as a cathode material in a lithium secondary battery of S-sequestration of elemental sulfur in the carbon capsules, a restricted polysulfide shuttling and an improved electron transport on sulfur are attributed.

  15. COULOMETRIC DETERMINATION OF TOTAL SULFUR AND REDUCED INORGANIC SULFUR FRACTIONS IN ENVIRONMENTAL SAMPLES

    EPA Science Inventory

    Evaluation of the solid-phase partitioning of sulfur is frequently an important analytical component of risk assessments at hazardous waste sites because minerals containing reduced-sulfur can significantly affect the transport and fate of organic and inorganic contaminants in na...

  16. Modification of Sulfur Dioxide Injury to Tobacco and Tomato by Varying Nitrogen and Sulfur Nutrition

    Microsoft Academic Search

    Ida A. Leone; Eileen Brennan

    1972-01-01

    The body of information presented in this paper is directed to plant scientists who are concerned with factors which modify the susceptibility of plants to air pollutants.Tobacco and tomato plants grown in sand-solution culture with varying levels of nitrogen or sulfur were exposed to injurious levels of sulfur dioxide. Plants of both species which were deficient in either nutrient exhibited

  17. Sugar yields from dilute sulfuric acid and sulfur dioxide pretreatments and subsequent enzymatic hydrolysis of switchgrass

    E-print Network

    California at Riverside, University of

    Sugar yields from dilute sulfuric acid and sulfur dioxide pretreatments and subsequent enzymatic%, and 10% wt.% of dry biomass were also tested at 180 °C for 10 min. Sugar yields were tracked for pretreatment and subsequent enzymatic hydrolysis to identify conditions for the highest total sugar yields

  18. Sulfur isotope fractionation during the reduction of elemental sulfur and thiosulfate by Dethiosulfovibrio spp.

    NASA Astrophysics Data System (ADS)

    Surkov, A. V.; Böttcher, M. E.; Kuever, J.

    2009-04-01

    Thiosulfate and elemental sulfur are typical by-products of the oxidation of dissolved sulfide and important sulfur intermediates in the biogeochemical sulfur cycle of natural sediments where they can be further transformed by microbial or chemical oxidation, reduction, or disproportionation. Due to the often superimposing reaction pathways of the sulfur intermediates in natural environments specific tracers are needed to better resolve the complex microbial and biogeochemical reactions. An important fingerprint for sulfur cycling is provided by the microbial fractionation of the stable sulfur isotopes S-34 and S-32. Proper interpretation of isotope signals in nature, however, is only possible by the calibration with results obtained with pure cultures under defined experimental conditions. In addition, sulfur isotope discrimination may provide informations about specific encymatic biochemical pathways within the bacterial cells. In this study, we report the results for the discrimination of stable sulfur isotopes S-32 and S-34 during reduction of thiosulfate and elemental sulfur by non-sulfate, but sulfur- and thiosulfate-reducing bacteria which are phylogenetically not related to sulfate-reducing bacteria. Experiments with were conducted at known cell-specific thiosulfate reduction rates. Stable sulfur isotope fractionation was investigated during reduction of thiosulfate and elemental sulfur at 28°C by growing batch cultures of Dethiosulfovibrio marinus WS100 (type strain DSM 12537) and Dethiosulfovibrio russensis (type strain DSM 12538) using citrate as carbon and energy source. The cell-specific reduction rates were 0.3 to 2.4 fmol cell-1 d-1 (thiosulfate) and 31 to 38 fmol cell-1 d-1 (elemental sulphur), respectively. The sulfide produced was depleted in S-34 by 12 per mil compared to total thiosulfate sulfur, close to previous results observed for sulfate-reducing bacteria, indicating that the thiosulfate-reducing mechanism of sulfate reducers is similar to that of the investigated thiosulfate-reducing strains. Elemental sulfur reduction yields sulfide depleted in S-34 and isotope fractionation effects between 1.3 and 5.2 per mil for Dethiosulfovibrio russensis and 1.7 and 5.1 per mil Dethiosulfovibrio marinus, with the smaller fractionation effects observed in the exponential growth phase and enhanced discrimination under conditions of citrate depletion and cell lysis.

  19. Ametryne and Prometryne as Sulfur Sources for Bacteria

    PubMed Central

    Cook, Alasdair M.; Hütter, Ralf

    1982-01-01

    Bacteria were isolated that could utilize quantitatively the s-triazine herbicide prometryne [N,N? -bis(1-methylethyl)-6-(methylthio)-1,3,5-triazine-2,4-diamine] or ametryne [N-ethyl-N?-(1-methylethyl)-6-(methylthio)-1,3,5-triazine- 2,4-diamine], or both, as a sole source of sulfur for growth. The success of enrichments depended on previous exposure of the soil inoculum to s-triazine herbicides. Deaminoethylametryne [4-(1-methylethyl)amino-6-(methylthio)-1,3,5-triazine-2-(1H)-one], methylsulfonic acid, and sodium sulfate could also be used as sulfur sources. Utilization of a compound was quantified as the growth yield per mole of sulfur supplied. Yields were about 6 kg of protein per mol of sulfur. The product of the desulfuration of an s-triazine was identified as the corresponding hydroxy-derivative. This is the first substantiated report of the utilization of these s-triazines as sulfur sources by bacteria. PMID:16345988

  20. Examination of sulfur forms in coal by direct pyrolysis and flameless ozone-sulfur chemiluminescence detection

    SciTech Connect

    Glinski, R.J.; Xu, Xiaoyang; McGowan, C.W. [Tennessee Technological Univ., Cookeville, TN (United States)

    1995-12-31

    The extremely high selectivity of the newly developed ozone-sulfur chemiluminescence detector (SCD) has been coupled with controlled-temperature pyrolysis to allow qualitative and semiquantitative determination of sulfur forms in coal. Pyrolysis products from the heating of a sulfur containing solid sample were swept directly through a high-temperature conversion tube and into the SCD to yield a strong signal. Upon heating the pyrolysis tube from room temperature to 700 degrees C, several distinct peaks were observed by the SCD, identified as being due to aliphatic sulfides and thiols, elemental sulfur, simple thiophenes, pyrite, and complex thiophenes. Standard addition of the pure inorganic substances provided semiquantitative determinations. Three coals were examined and could be quickly and easily distinguished by their sulfur forms. The results are compared with those of other pyrolysis methods.

  1. 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

    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 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

  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. Comparison of the UCB sulfur recovery process with conventional sulfur recovery technology for treating recycle gas from a crude oil residuum hydrotreater. [UCBSRP sulfur recovery process

    Microsoft Academic Search

    S. Lynn; D. W. Neumann; S. F. Sciamanna; F. H. Vorhis

    1986-01-01

    The University of California, Berkeley, Sulfur Recovery Process (UCBSRP) is being developed as an alternative to conventional sulfur recovery technology for removing hydrogen sulfide from gas streams and converting it to elemental sulfur. In the UCBSRP the hydrogen sulfide is absorbed by a physical solvent and the resulting solution of HâS is mixed with a stoichiometrically equivalent amount of slulfur

  4. The effecting factors of sulfur evolution during coal combustion

    SciTech Connect

    Liu Zechang; Yu Hongguan; Wang Li [Shandong Inst. of Mining and Technology, Ji`nan (China). Dept. of Coal Chemical Engineering

    1997-12-31

    Three kinds of bituminous coal and one kind of anthracite have been used to investigate the factors affecting sulfur evolution during coal combustion by means of improved automatic sulfur analyzer. In this paper the sulfur evolution index, that is, the relative quantity of sulfur evolution (Vs), the final quantity of sulfur evolution (Va), the rate of sulfur evolution and delay time, are selected to describe the sulfur evolution. The results show that the rate and quantity of sulfur evolution is affected by the temperature, retention time, type of coal, sulfur forms, calcium-based content in coal, oxygen concentration and flow velocity of air. The study can provide some knowledge for selecting sorbent for coal combustion.

  5. 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.

  6. 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

  7. 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

  8. Variation of organic sulfur in macerals of selected Illinois Basin coals

    USGS Publications Warehouse

    Demir, I.; Harvey, R.D.

    1991-01-01

    An electron microbeam technique was used to determine the distribution of organic sulfur in the main macerals of five Illinois Basin coals. On average, sporinites are the highest, inertinites the lowest, and vitrinites intermediate in organic sulfur for each coal. The observed differences are likely due to varying affinities of the different pre-maceral materials for sulfur and/or local variation in the production of H2S primarily during the peat stage. Investigation of molecular structures of individual macerals in relation to the findings of this study may delineate the relative abundance of organic sulfur in various organic compounds and thus lead to the development of efficient desulfurization processes. ?? 1991.

  9. Application of a sodium sulfur cell with dynamic sulfur electrode to a battery system

    NASA Astrophysics Data System (ADS)

    Tokoi, H.; Takahashi, K.; Shimoyashiki, S.

    1992-01-01

    The construction and performance of a sodium sulfur battery system with dynamic sulfur electrodes are described. Three cells were first connected in parallel, then two such groups were connected in series. Each cell included a liquid sodium-filled beta-double-prime-alumina tube and a system to feed liquid sulfur into the annular cathode. Low-resistance graphite felt was tightly packed around the beta-double-prime-alumina tube. Sodium pentasulfide was removed from the sulfur electrode. The battery was operated automatically and stably charged and discharged in the two-phase region. The discharged energy was 4372 Wh (capacity 1170 Ah) during a continuous operation of 19.5 h. The discharge/charge energy efficiency of the battery was 82 percent at an averaged current density of 100 mA/sq cm and operating temperature of 350 C. The deviation of the cell current in a parallel chain was less than 7 percent, and this was induced by the difference in internal resistance. In the daily charge/discharge cycle, cell capacity with the dynamic sulfur electrode was 1.5 times higher than that with the static sulfur electrode using the same active surface of beta-double-prime-alumina, because the internal resistance of the former cell was constant regardless of cell capacity. This battery system with a dynamic sulfur electrode can be applied to energy storage systems,such as large scale load leveling systems, electric vehicle batteries, and solar energy systems.

  10. Production of Lunar Concrete Using Molten Sulfur

    NASA Technical Reports Server (NTRS)

    Omar, Husam A.

    1993-01-01

    The United States has made a commitment to go back to the moon to stay in the early part of the next century. In order to achieve this objective it became evident to NASA that a Lunar Outpost will be needed to house scientists and astronauts who will be living on the moon for extended periods of time. A study has been undertaken by the authors and supported by NASA to study the feasibility of using lunar regolith with different binders such as molten sulfur, epoxy or hydraulic cement as a construction material for different lunar structures. The basic premise of this study is that it will be more logical and cost effective to manufacture lunar construction materials utilizing indigenous resources rather than transporting needed materials from earth. Lunar concrete (made from Hydraulic Cement and lunar soil) has been studied and suggested as the construction material of choice for some of the lunar projects. Unfortunately, its hydration requires water which is going to be a precious commodity on the moon. Therefore this study explores the feasibility of using binders other than hydraulic cement such as sulfur or epoxy with lunar regolith as a construction material. This report describes findings of this study which deals specifically with using molten sulfur as a binder for Lunar concrete. It describes laboratory experiments in which the sulfur to lunar soil simulant ratios by weight were varied to study the minimum amount of sulfur required to produce a particular strength. The compressive and tensile strengths of these mixes were evaluated. Metal and fiber glass fibers were added to some of the mixes to study their effects on the compressive and tensile strengths. This report also describes experiments where the sulfur is melted and mixed with the lunar regolith in a specially designed vacuum chamber. The properties of the produced concrete were compared to those of concrete produced under normal pressure.

  11. An overview of liquid redox sulfur recovery

    SciTech Connect

    Dalrymple, D.A.; Trofe, T.W.; Evans, J.M.

    1989-03-01

    Liquid redox sulfur recovery processes absorb H/sub 2/S from gas streams and produce elemental sulfur for sale or disposal. These processes, which involve the overall reaction of H/sub 2/S with oxygen to form elemental sulfur and water can be used in a wide variety of applications where H/sub 2/S removal and recovery are required. They can be used to desulfurize natural gas, either directly or by desulfurizing acid gas removal process off gas; refinery and chemical plant fuel gases and sour off gases; process and off-gas streams in coal gasification plants; geothermal vent gas; shale oil plant and underground coal gasification plant gases; Claus tail gas; and enhanced oil recovery vent gas. For many applications, liquid redox processes offer: excellent sulfur removal, often reducing H/sub 2/S levels to 10 ppm or less; one-step conversion of H/sub 2/S gas to elemental sulfur; ambient temperature and pressure operation; the ability to handle fluctuating inlet gas flow rates and H/sub 2/S concentrations; the capability of treating both low- and high-H/sub 2/S gas streams; and regenerating catalysts. This article summarizes information on six liquid redox sulfur recovery processes that are offered commercially today, and it gives an overview of research sponsored by the Gas Research Institute (GRI) in this area. To date, this research has focused primarily on the original technology - the Stretford process. Stretford has the greatest number of plants and the widest variety of applications experience.

  12. Feed and process effects on the in situ reduction of sulfur in FCC gasoline

    Microsoft Academic Search

    J. A. Valla; A. A. Lappas; I. A. Vasalos; C. W. Kuehler; N. J. Gudde

    2004-01-01

    In this study we investigated the effects of various types of fluid catalytic cracking (FCC) feedstocks (VGO, FCC gasoline and FCC gasoline cuts) on sulfur compound distribution in the gasoline produced from FCC process. A bench scale short contact time microactivity test unit (SCT-MAT) and an FCC pilot plant unit were found to be satisfactory for the gasoline sulfur studies.

  13. The sulfur budget of the troposphere

    NASA Technical Reports Server (NTRS)

    Tiwari, S. N.; Augustsson, T. R.

    1981-01-01

    A one dimensional photochemical tropospheric model was used to calculate the vertical profiles of tropospheric species. Particular attention is focused on the recent inclusion of the chemistry of the sulfur group, which consists of 13 species involving a total of 45 chemical reactions. It is found that the chemistry of the sulfur species, because it is largely anthropogenic, plays an increasingly important role in the distribution of tropospheric gases. The calculated vertical profiles were compared to available measurements and generally found to be in good agreement.

  14. Method of making a sodium sulfur battery

    DOEpatents

    Elkins, P. E.

    1981-09-22

    A method of making a portion of a sodium sulfur battery is disclosed. The battery portion made is a portion of the container which defines the volume for the cathodic reactant materials which are sulfur and sodium polysulfide materials. The container portion is defined by an outer metal casing with a graphite liner contained therein, the graphite liner having a coating on its internal diameter for sealing off the porosity thereof. The steel outer container and graphite pipe are united by a method which insures that at the operating temperature of the battery, relatively low electrical resistance exists between the two materials because they are in intimate contact with one another. 3 figs.

  15. Atmospheric Sulfur Cycle Effects of Carbonyl Sulfide (OCS)

    NASA Technical Reports Server (NTRS)

    McBee, Joshua

    1996-01-01

    Carbonyl Sulfide(OCS) is considered to be one of the major sources of sulfur appearing in the stratosphere due to its relative inertness, about I to 10 yearsl. However, the roles of OCS as well as other reduced sulfur compounds such as carbon disulfide (CS2), hydrogen sulfide (H2S), and dimethyl disulfide(CH3)2S2, are not completely understood in the atmosphenc sulfur cycle. Consequently vely little information is available about the effect of sulfur compounds in the stratosphere. The ability of OCS to penetrate into the stratosphere makes it an excellent tracer for study of the role of the sulfi r cycle in stratospheric chemistry. Previously techniques such as gas chromatography and whole air sampling have been used to measure OCS analytically. Each technique had its drawbacks however, with both being quite slow, and whole air sampling being somewhat unreliable. With molecular spectroscopy, however, it has been found in recent years that the tunable diode laser absorption spectrometer (TDL) provides a very rapid and accurate method of measuring OCS and other trace gases

  16. The determination of hydrogen sulfide and total sulfur

    SciTech Connect

    Vincent, A. [ITT Barton, City of Industry, CA (United States)

    1995-12-01

    Producers, processors, pipelines and distribution companies measure both hydrogen sulfide (H2S) and total sulfur for compliance with purchase contracts, which generally contain sulfur quality clauses relating to those two parameters. A quarter grain of H2S per one hundred standard cubic feet (0.25 gr H2S/100 SCF) and one grain of total sulfur (1 gr S/100 SCF) are common contract limits. To ensure that both buyer and seller are dealing with gas within these limits, it is common to monitor both parameters, as well as others, on both sides of the custody transfer point. More often, sulfur monitoring entails measuring total sulfur, mercaptans, and sulfides to assure the gas is odorized at the desired level. Odorant is a combination of mercaptans and sulfides added to the gas to alert users of any leaks. Odorization at the proper level is important since over-odorization is an waste of costly chemicals resulting in excess leak calls, and under-odorization is a safety hazard for the customer which in the worst case could result in an explosion with great personal injury and property damage. Odorant monitoring should also be used in conjunction with olfactory readings as an archival record in the event of litigation. There are several means of measuring these parameters, using either manual methods or instrument techniques. The manual methods involve wet chemistry, including collecting the desired sulfur compounds in an absorbing solution and then titrating the solution with a second reactive solution of known concentration. These methods are described in detail in ASTM and the Gas Processors. In this treatment we will discuss only the instrumental means, the most common of which are gas chromatography, lead acetate tape methods. and electrolytic titration.

  17. 46 CFR 153.556 - Special requirements for sulfuric acid and oleum.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...false Special requirements for sulfuric acid and oleum. 153.556 Section 153...556 Special requirements for sulfuric acid and oleum. (a) Except as prescribed...containment systems carrying sulfuric acid, oleum, or contaminated sulfuric...

  18. 46 CFR 153.556 - Special requirements for sulfuric acid and oleum.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...false Special requirements for sulfuric acid and oleum. 153.556 Section 153...556 Special requirements for sulfuric acid and oleum. (a) Except as prescribed...containment systems carrying sulfuric acid, oleum, or contaminated sulfuric...

  19. 46 CFR 153.556 - Special requirements for sulfuric acid and oleum.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...false Special requirements for sulfuric acid and oleum. 153.556 Section 153...556 Special requirements for sulfuric acid and oleum. (a) Except as prescribed...containment systems carrying sulfuric acid, oleum, or contaminated sulfuric...

  20. 46 CFR 153.556 - Special requirements for sulfuric acid and oleum.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...false Special requirements for sulfuric acid and oleum. 153.556 Section 153...556 Special requirements for sulfuric acid and oleum. (a) Except as prescribed...containment systems carrying sulfuric acid, oleum, or contaminated sulfuric...

  1. 46 CFR 153.556 - Special requirements for sulfuric acid and oleum.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...false Special requirements for sulfuric acid and oleum. 153.556 Section 153...556 Special requirements for sulfuric acid and oleum. (a) Except as prescribed...containment systems carrying sulfuric acid, oleum, or contaminated sulfuric...

  2. 40 CFR 52.928 - Control strategy: Sulfur oxides.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Control strategy: Sulfur oxides. 52.928 Section 52.928...Kentucky § 52.928 Control strategy: Sulfur oxides. The revised SO2 emission limit for large coal-fired boilers in Bell, Clark,...

  3. Developments for the precombustion removal of inorganic sulfur from coal

    Microsoft Academic Search

    Travis Thoms

    1995-01-01

    As precombustion sulfur removal becomes an attractive alternative to flue gas scrubbers, scientists have explored several methods of removing inorganic sulfur from coal and coal chars. Microbial desulfurization, halogenation, pyrolysis, electrochemical oxidation, and irradiation are all avenues now under investigation.

  4. 40 CFR 52.928 - Control strategy: Sulfur oxides.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Control strategy: Sulfur oxides. 52.928 Section 52.928...Kentucky § 52.928 Control strategy: Sulfur oxides. The revised SO2 emission limit for large coal-fired boilers in Bell, Clark,...

  5. 40 CFR 52.928 - Control strategy: Sulfur oxides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Control strategy: Sulfur oxides. 52.928 Section 52.928...Kentucky § 52.928 Control strategy: Sulfur oxides. The revised SO2 emission limit for large coal-fired boilers in Bell, Clark,...

  6. 40 CFR 52.928 - Control strategy: Sulfur oxides.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Control strategy: Sulfur oxides. 52.928 Section 52.928...Kentucky § 52.928 Control strategy: Sulfur oxides. The revised SO2 emission limit for large coal-fired boilers in Bell, Clark,...

  7. 40 CFR 52.928 - Control strategy: Sulfur oxides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Control strategy: Sulfur oxides. 52.928 Section 52.928...Kentucky § 52.928 Control strategy: Sulfur oxides. The revised SO2 emission limit for large coal-fired boilers in Bell, Clark,...

  8. Choline as a fuel sweetener and sulfur antagonist

    SciTech Connect

    Roof, G.L.; Porlier, B.W.; Cravey, W.E.

    1986-06-10

    A method is described of sweetening petroleum hydrocarbon fuels and, at the same time, reducing the sulfur content thereof which comprises treating such fuels with a sweetening and sulfur-removing amount of choline.

  9. Effects of Reduced Sulfur Compounds on Pd-catalytic Hydrodechlorination of TCE in Groundwater by Cathodic H2 under Electrochemically-induced Oxidizing Conditions

    PubMed Central

    Yuan, Songhu; Chen, Mingjie; Mao, Xuhui; Alshawabkeh, Akram N.

    2014-01-01

    Reduced sulfur compounds (RSCs) poison Pd catalysts for catalytic hydrodechlorination of contaminants in anoxic groundwater. This study investigates the effects of RSCs on Pd-catalytic hydrodechlorination of trichloroethylene (TCE) in oxic groundwater. Water electrolysis in an undivided electrolytic cell is used to produce H2 for TCE hydrodechlorination under oxidizing conditions. TCE is efficiently hydrodechlorinated to ethane, with significant accumulation of H2O2 under acidic conditions. Presence of sulfide at concentrations less than 93.8 ?M moderately inhibits TCE hydrodechlorination and H2O2 production. Presence of sulfite at low concentrations (? 1 mM) significantly enhances TCE decay, while at high concentration (3 mM) inhibits initially and enhances afterwards when sulfite concentration declines to less than 1 mM. Using radical scavenging experiments and electron spin resonance assay, SO3•? which is generated from sulfite under oxidizing conditions is validated as the new reactive species contributing to the enhancement. This study reveals a distinct mechanism of effect of sulfite on TCE hydrodechlorination by Pd and H2 in oxic groundwater and presents an alternative approach to increasing resistance of Pd to RSCs poisoning. PMID:23962132

  10. Effects of reduced sulfur compounds on Pd-catalytic hydrodechlorination of trichloroethylene in groundwater by cathodic H2 under electrochemically induced oxidizing conditions.

    PubMed

    Yuan, Songhu; Chen, Mingjie; Mao, Xuhui; Alshawabkeh, Akram N

    2013-09-17

    Reduced sulfur compounds (RSCs) poison Pd catalysts for catalytic hydrodechlorination of contaminants in anoxic groundwater. This study investigates the effects of RSCs on Pd-catalytic hydrodechlorination of trichloroethylene (TCE) in oxic groundwater. Water electrolysis in an undivided electrolytic cell is used to produce H2 for TCE hydrodechlorination under oxidizing conditions. TCE is efficiently hydrodechlorinated to ethane, with significant accumulation of H2O2 under acidic conditions. The presence of sulfide at concentrations less than 93.8 ?M moderately inhibits TCE hydrodechlorination and H2O2 production. The presence of sulfite at low concentrations (?1 mM) significantly enhances TCE decay, while at high concentration (3 mM) inhibits initially and enhances afterward when sulfite concentration declines to less than 1 mM. Using radical scavenging experiments and an electron spin resonance assay, SO3(•-), which is generated from sulfite under oxidizing conditions, is validated as the new reactive species contributing to the enhancement. This study reveals a distinct mechanism of effect of sulfite on TCE hydrodechlorination by Pd and H2 in oxic groundwater and presents an alternative approach to increasing resistance of Pd to RSCs poisoning. PMID:23962132

  11. An Approach for Measuring the Sorptive Behavior of Odorants Using a Multifunction Thermal Desorber Unit: Preliminary Tests on Reduced Sulfur Compounds

    PubMed Central

    Kim, Ki-Hyun; Choi, Ye-Jin; Yang, Hye-Soon; Joo, Sang-Woo

    2008-01-01

    In this study, the sorptive behavior of reduced sulfur compounds (RSC) was investigated using a combination of thermal desorber (TD) unit and gas chromatography (GC). To examine the sorptive properties of RSC on textile materials, two types of experiments were conducted under experimental conditions favorable for sorptive processes. In all the experiments, gaseous standards of hydrogen sulfide, methanethiol, dimethyl sulfide, and dimethyl disulfide were supplied to initiate the adsorption processes on textile pieces. The textile pieces were then forced to release those adsorbed RSC under a fixed condition. It was found that the extent of adsorption, if evaluated quantitatively, occurred at approximately 1/1000 to 1/100 of the level of RSC standards supplied originally to induce adsorption. It also indicated that RSC adsorption was affected very sensitively by the initial exposure durations to induce RSC adsorption with an exponential decrease in relative recovery (RR) values with increasing exposure time. The relative sorptive patterns, when compared between different RSCs, were affected most sensitively by such factors as molecular weight and/or physical contact conditions.

  12. Oxygen consumption and development of volatile sulfur compounds during bottle aging of two Shiraz wines. Influence of pre- and postbottling controlled oxygen exposure.

    PubMed

    Ugliano, Maurizio; Dieval, Jean-Baptiste; Siebert, Tracey E; Kwiatkowski, Mariola; Aagaard, Olav; Vidal, Stéphane; Waters, Elizabeth J

    2012-09-01

    The evolution of different volatile sulfur compounds (VSCs) during bottle maturation of two Shiraz wines submitted to controlled oxygen exposure prior to bottling (through micro-oxygenation, MOX) and postbottling (through the closure) was investigated. H(2)S, methyl mercaptan (MeSH), and dimethyl sulfide (DMS) were found to increase during aging. Lower postbottling oxygen exposure, as obtained by different degrees of oxygen ingress through the closure, resulted in increased H(2)S and methyl mercaptan. In one wine MOX increased the concentration of H(2)S and methyl mercaptan during maturation. Dimethyl disulfide and DMS were not affected by any form of oxygen exposure. Overall, postbottling oxygen had a stronger influence than MOX on the evolution of VSCs. Data suggest that dimethyl disulfide was not a precursor to methyl mercaptan during bottle maturation. For the two wines studied, a consumption of oxygen of 5 mg/L over 12 months was the most effective oxygen exposure regimen to decrease accumulation of MeSH and H(2)S during bottle aging. PMID:22900817

  13. X-ray absorption spectroscopy of bacterial sulfur globules

    Microsoft Academic Search

    Graham N

    2002-01-01

    Sulfur K-edge X-ray absorption spectroscopy is a powerful in situ probe of sulfur biochemistry in intact cells and tissues. Under favorable circumstances the technique can provide quantitative information on the chemical identify of the sulfur species that are present in a sample. Prange et al. have recently reported an X-ray absorption spectroscopic study of bacterial sulfur storage globules. Unfortunately there

  14. Iron-sulfur proteins: ancient structures, still full of surprises

    Microsoft Academic Search

    H. Beinert

    2000-01-01

    This article is a survey of the properties and functions of Fe-S proteins under the following headings: sulfur and iron; iron-sulfur clusters; evolution of cofactor use; early observations; complex and extended clusters; sulfur exchange and core interconversions; synthesis and biosynthesis of Fe-S clusters; functions of Fe-S clusters: electron transfer, electron delocalization, spin states and magnetism, covalency of sulfur bonds; non-electron

  15. The problem of sulfur content in calcined petroleum coke

    NASA Astrophysics Data System (ADS)

    Vogt, M. Franz; Waller, James H.; Zabreznik, Rodney D.

    1990-07-01

    The sulfur content of petroleum coke has steadily increased in recent years, and forecasts show levels will rise even further. This increase in sulfur content comes at a time when environmental awareness is at a peak, and regulatory restrictions are likely to place limits on the amount of sulfur permitted. Fortunately for aluminum smelters, several methods of reducing the sulfur content in petroleum coke appear to be viable.

  16. Discovery of self-combusting volcanic sulfur flows

    Microsoft Academic Search

    Andrew J. L. Harris; Sarah B. Sherman; Robert Wright

    2000-01-01

    Hitherto sulfur flows have been recognized as lobate features similar in form to basaltic lava flows. However, we have discovered a self-combusting sulfur-flow mode that leaves an entirely different and unexpected deposit. In this mode, the flow is emplaced in a combusting state, so that all sulfur is burned away to leave a sulfur-free, thermally eroded trough. During the 4-hr-long

  17. ReaxFF molecular dynamics simulations on lithiated sulfur cathode materials.

    PubMed

    Islam, Md Mahbubul; Ostadhossein, Alireza; Borodin, Oleg; Yeates, A Todd; Tipton, William W; Hennig, Richard G; Kumar, Nitin; van Duin, Adri C T

    2015-02-01

    Sulfur is a very promising cathode material for rechargeable energy storage devices. However, sulfur cathodes undergo a noticeable volume variation upon cycling, which induces mechanical stress. In spite of intensive investigation of the electrochemical behavior of the lithiated sulfur compounds, their mechanical properties are not very well understood. In order to fill this gap, we developed a ReaxFF interatomic potential to describe Li-S interactions and performed molecular dynamics (MD) simulations to study the structural, mechanical, and kinetic behavior of the amorphous lithiated sulfur (a-LixS) compounds. We examined the effect of lithiation on material properties such as ultimate strength, yield strength, and Young's modulus. Our results suggest that with increasing lithium content, the strength of lithiated sulfur compounds improves, although this increment is not linear with lithiation. The diffusion coefficients of both lithium and sulfur were computed for the a-LixS system at various stages of Li-loading. A grand canonical Monte Carlo (GCMC) scheme was used to calculate the open circuit voltage profile during cell discharge. The Li-S binary phase diagram was constructed using genetic algorithm based tools. Overall, these simulation results provide insight into the behavior of sulfur based cathode materials that are needed for developing lithium-sulfur batteries. PMID:25529209

  18. [Determination of the content of sulfur of coal by the infrared absorption method with high acccuracy].

    PubMed

    Wang, Hai-Feng; Lu, Hai; Li, Jia; Sun, Guo-Hua; Wang, Jun; Dai, Xin-Hua

    2014-02-01

    The present paper reported the differential scanning calorimetry-thermogravimetry curves and the infrared (IR) absorption spectrometry under the temperature program analyzed by the combined simultaneous thermal analysis-IR spectrometer. The gas products of coal were identified by the IR spectrometry. This paper emphasized on the combustion at high temperature-IR absorption method, a convenient and accurate method, which measures the content of sulfur in coal indirectly through the determination of the content of sulfur dioxide in the mixed gas products by IR absorption. It was demonstrated, when the instrument was calibrated by varied pure compounds containing sulfur and certified reference materials (CRMs) for coal, that there was a large deviation in the measured sulfur contents. It indicates that the difference in chemical speciations of sulfur between CRMs and the analyte results in a systematic error. The time-IR absorption curve was utilized to analyze the composition of sulfur at low temperatures and high temperatures and then the sulfur content of coal sample was determined by using a CRM for coal with a close composition of sulfur. Therefore, the systematic error due to the difference in chemical speciations of sulfur between the CRM and analyte was eliminated. On the other hand, in this combustion at high temperature-IR absorption method, the mass of CRM and analyte were adjusted to assure the sulfur mass equal and then the CRM and the analyte were measured alternately. This single-point calibration method reduced the effect of the drift of the IR detector and improved the repeatability of results, compared with the conventional multi-point calibration method using the calibration curves of signal intensity vs sulfur mass. The sulfur content results and their standard deviations of an anthracite coal and a bituminous coal with a low sulfur content determined by this modified method were 0.345% (0.004%) and 0.372% (0.008%), respectively. The uncertainty (U, k =2) of sulfur contents of two coal samples was evaluated to be 0.019% and 0.021%, respectively. Two main modifications, namely the calibration using the coal CRM with a similar composition of low-temperature sulfur and high temperature sulfur, and the single-point calibration alternating CRM and analyte, endow the combustion at high temperature-IR absorption method with an accuracy obviously better than that of the ASTM method. Therefore, this modified method has a well potential in the analysis of sulfur content. PMID:24822403

  19. Magnetic and electrical properties of novel compounds in the alkaline earth-transition metal-sulfur and selenium systems

    Microsoft Academic Search

    H. Steinfink

    1974-01-01

    The interrelationship between crystal structure and electrical and magnetic compounds has been investigated. It has been shown that the physical behavior of Ba-Fe-S compounds can be predicted from a knowledge of the crystal structure and the presence of mobile or localized electrons. An unusually large range of temperature independent electrical conductivity has been observed for BaCu4S3.

  20. Inhibitory effect of sulfur dioxide and other stress compounds in wine on the ATPase activity of Oenococcus oeni

    Microsoft Academic Search

    Ramon Carreté; M. Teresa Vidal; Albert Bordons; Magda Constant??

    2002-01-01

    Malolactic fermentation (MLF) is carried out by Oenococcus oeni under very harsh conditions. This paper shows that stress compounds in wine such as SO2, fatty acids and copper have an inhibitory effect on cell growth and MLF duration, and relates this effect to an inhibition of ATPase activity. Of the stress compounds, SO2 and dodecanoic acid had the strongest effect,

  1. Assessing Potential Acidification of Marine Archaeological Wood Based on Concentration of Sulfur Species

    SciTech Connect

    Not Available

    2011-06-22

    The presence of sulfur in marine archaeological wood presents a challenge to conservation. Upon exposure to oxygen, sulfur compounds in waterlogged wooden artifacts are being oxidized, producing sulfuric acid. This speeds the degradation of the wood, potentially damaging specimens beyond repair. Sulfur K-edge x-ray absorption spectroscopy was used to identify the species of sulfur present in samples from the timbers of the Mary Rose, a preserved 16th century warship known to undergo degradation through acidification. The results presented here show that sulfur content varied significantly on a local scale. Only certain species of sulfur have the potential to produce sulfuric acid by contact with oxygen and seawater in situ, such as iron sulfides and elemental sulfur. Organic sulfurs, such as the amino acids cysteine and methionine, may produce acid but are integral parts of the wood's structure and may not be released from the organic matrix. The sulfur species contained in the sample reflect the exposure to oxygen while submerged, and this exposure can differ greatly over time and position. A better understanding of the species pathway to acidifications required, along with its location, in order to suggest a more customized and effective preservation strategy. Waterlogged archaeological wood, frequently in the form of shipwrecks, is being excavated for historical purposes in many countries around the world. Even after extensive efforts towards preservation, scientists are discovering that accumulation of sulfate salts results in acidic conditions on the surfaces of the artifacts. Sulfuric acid degrades structural fibers in the wood by acid hydrolysis of cellulose, accelerating the decomposition of the ship timbers. Determining the sulfur content of waterlogged wood is now of great importance in maritime archaeology. Artifact preservation is often more time consuming and expensive than the original excavation; but it is key to the availability of objects for future study as well as maintaining the integrity of historical data and preserving the value of museum pieces. Sulfur occurs in a wide number of oxidation states from -2 to +6, and appears in numerous organic and inorganic compounds in nature. However, it is a very minor component of wood. Sulfur K-edge x-ray absorption spectroscopy (XAS) is a valuable technique because it has the ability to detect very low concentrations of sulfur in the specimen. XAS is also sensitive to differences in oxidation states, as well as long and short range order in molecules.

  2. World sulfur production: As of Jan. 1, 1994

    SciTech Connect

    Not Available

    1994-06-13

    The article consists of a table which lists company and location, source of sulfur, type of process used, design capacity, and sulfur production for 42 countries. Sources of sulfur include refinery gases, natural gas, acid gases, crude oil, shale gas, oil sands, coke oven gas, and hydrogen sulfide.

  3. FEASIBILITY OF PRODUCING ELEMENTAL SULFUR FROM MAGNESIUM SULFITE

    EPA Science Inventory

    The report gives results of a study to extend potential applications of MgO flue gas desulfurization processes by allowing the sulfur to be recovered as elemental sulfur as well as sulfuric acid. The study considered the feasibility of combining the exothermic SO2 reduction react...

  4. Historical Sulfur Dioxide Emissions 1850-2000: Methods and Results

    E-print Network

    Hultman, Nathan E.

    due to our use of emissions factors that vary with time to account for sulfur removals from fossil fuels and industrial smelting processes. 1. INTRODUCTION Sulfur is ubiquitous in the biosphere and often increased sulfur deposition and atmospheric sulfate loadings near most industrialized areas. Sulfate acid

  5. Heterogeneous interaction of peroxyacetyl nitrate with liquid sulfuric acid

    Microsoft Academic Search

    Renyi Zhang; Ming-Taun Leu

    1997-01-01

    The uptake of peroxyacetyl nitrate (PAN) on liquid sulfuric acid surfaces has been investigated using a fast-flow reactor coupled to a chemical ionization mass spectrometer. PAN was observed to be reversibly adsorbed on sulfuric acid. From the time-dependent uptake, Henry's law solubility constant of PAN in sulfuric acid was obtained. The measured solubility constant was found to depend strongly on

  6. SOLID SORBENT FOR COLLECTING ATMOSPHERIC SULFUR DIOXIDE

    EPA Science Inventory

    A solid sorbent for collecting atmospheric SO2 was evaluated as part of an overall effort to develop a replacement method for the West-Gaeke method presently used to measure 24-hour ambient sulfur dioxide concentrations in ambient air. Research showed that a solid sorbent, consis...

  7. LABORATORY MEASUREMENT OF SULFUR DIOXIDE DEPOSITION VELOCITIES

    EPA Science Inventory

    Measurements of sulfur dioxide deposition velocities have been carried out in the laboratory with the use of a cylindrical flow reaction. Analysis of data from these experiments was performed with models that specifically account for diffusive transport in the system. Consequentl...

  8. Sulfuric acid thermoelectrochemical system and method

    DOEpatents

    Ludwig, Frank A. (Rancho Palos Verdes, CA)

    1989-01-01

    A thermoelectrochemical system in which an electrical current is generated between a cathode immersed in a concentrated sulfuric acid solution and an anode immersed in an aqueous buffer solution of sodium bisulfate and sodium sulfate. Reactants consumed at the electrodes during the electrochemical reaction are thermochemically regenerated and recycled to the electrodes to provide continuous operation of the system.

  9. SULFUR DIOXIDE OXIDATION REACTIONS IN AQUEOUS SOLUTIONS

    EPA Science Inventory

    This is the final report on a three year project to study the kinetics and mechanisms of some 105 reactions involving the aqueous oxidation of sulfur dioxide and nitrogen oxides in mixed catalyst-oxidant systems at low pH (0-3). The 105 systems involve six redox reaction types: S...

  10. REGIONAL TRENDS IN RURAL SULFUR CONCENTRATIONS

    EPA Science Inventory

    This paper presents an analysis of trends in atmospheric concentrations of sulfur dioxide (SO,) and particulate sulfate (SO42-) 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 to estimat...

  11. Wound Healing of Cutaneous Sulfur Mustard Injuries

    PubMed Central

    Graham, John S.; Chilcott, Robert P.; Rice, Paul; Milner, Stephen M.; Hurst, Charles G.; Maliner, Beverly I.

    2005-01-01

    Sulfur mustard is an alkylating chemical warfare agent that primarily affects the eyes, skin, and airways. Sulfur mustard injuries can take several months to heal, necessitate lengthy hospitalizations, and result in significant cosmetic and/or functional deficits. Historically, blister aspiration and/or deroofing (epidermal removal), physical debridement, irrigation, topical antibiotics, and sterile dressings have been the main courses of action in the medical management of cutaneous sulfur mustard injuries. Current treatment strategy consists of symptomatic management and is designed to relieve symptoms, prevent infections, and promote healing. There are currently no standardized or optimized methods of casualty management that prevent or minimize deficits and provide for speedy wound healing. Several laboratories are actively searching for improved therapies for cutaneous vesicant injury, with the aim of returning damaged skin to optimal appearance and normal function in the shortest time. Improved treatment will result in a better cosmetic and functional outcome for the patient, and will enable the casualty to return to normal activities sooner. This editorial gives brief overviews of sulfur mustard use, its toxicity, concepts for medical countermeasures, current treatments, and strategies for the development of improved therapies. PMID:16921406

  12. EFFECTS OF SULFURIC ACID AEROSOLS ON VEGETATION

    EPA Science Inventory

    A continuous flow system for exposing plants to submicron aerosols of sulfuric acid has been developed and an operational model has been constructed. Exposure chambers have been designed to allow simultaneous exposures of the same plant to aerosol and control environments. All su...

  13. Mass-independent sulfur isotope fractionation during photochemistry of sulfur dioxide

    E-print Network

    Whitehill, Andrew (Andrew Richard)

    2015-01-01

    Mass-independent sulfur isotope signatures are observed in Archean and early Paleoproterozoic sedimentary sulfate and sulfide minerals, and provide the most robust constraints on early atmospheric oxygen levels. Smaller ...

  14. Low sulfur depletion in the Horsehead PDR

    NASA Astrophysics Data System (ADS)

    Goicoechea, J. R.; Pety, J.; Gerin, M.; Teyssier, D.; Roueff, E.; Hily-Blant, P.; Baek, S.

    2006-09-01

    Aims.We present 3.65'' × 3.34'' angular-resolution IRAM Plateau de Bure Interferometer (PdBI) observations of the CS J = 2-1 line toward the Horsehead Photodissociation Region (PDR), complemented with IRAM-30m single-dish observations of several rotational lines of CS, C34S and HCS^+. We analyse the CS and HCS+ photochemistry, excitation and radiative transfer to obtain their abundances and the physical conditions prevailing in the cloud edge. Since the CS abundance scales to that of sulfur, we determine the gas phase sulfur abundance in the PDR, an interesting intermediate medium between translucent clouds (where sulfur remains in the gas phase) and dark clouds (where large depletions have been invoked). Methods: .A nonlocal non-LTE radiative transfer code including dust and cosmic background illumination adapted to the Horsehead geometry has been developed to carefuly analyse the CS, C34S, HCS+ and C18O rotational line emission. We use this model to consistently link the line observations with photochemical models to determine the CS/HCS^+/S/S+ structure of the PDR. Results: .Densities of n(H_2)?(0.5{-}1.0) × 105 cm-3 are required to reproduce the CS and C34S J = 2-1 and 3-2 line emission. CS J = 5-4 lines show narrower line widths than the CS low-J lines and require higher density gas components not resolved by the 10'' IRAM-30m beam. These values are larger than previous estimates based in CO observations. We found ?(CS) = (7 ± 3) × 10-9 and ?(HCS+) = (4 ± 2) × 10-11 as the averaged abundances in the PDR. According to photochemical models, the gas phase sulfur abundance required to reproduce these values is S/H = (3.5 ± 1.5) × 10-6, only a factor ?4 less abundant than the solar sulfur elemental abundance. Since only lower limits to the gas temperature are constrained, even lower sulfur depletion values are possible if the gas is significantly warmer. Conclusions: .The combination of CS, C34S and HCS+ observations together with the inclusion of the most recent CS collisional and chemical rates in our models implies that sulfur depletion invoked to account for CS and HCS+ abundances is much smaller than in previous studies.

  15. Heat Transfer Characteristics of Sulfur and Sulfur Diluted with Hydrogen Sulfide Flowing Through Circular Tubes 

    E-print Network

    Stone, Porter Walwyn

    1960-01-01

    disadvantages, it has characteristics which favor its use as a reactor coolant. These characteristics may be classified as nuclear, physical and chemical. Nuclear. Sulfur has a relatively low tendency to absorb neutrons, its absorption cross...-section for thermal neutrons being 0. 130 barns. For comparison, water has an absorption cross-section of 0. 58 barns for thermal neutrons (2) . Sulfur is not activated by exposure to neutron flux in such a way as to produce a radioactive isotope which...

  16. Gasoline sulfur control may be required. Gasoline production and sulfur content

    Microsoft Academic Search

    Motte

    1979-01-01

    An analysis of the comparative costs for reducing the sulfur content of current unleaded gasoline supplies in the U.S. to avoid sulfate pollution in use with three-way exhaust-gas catalysts, indicates that hydrodesulfurization of the fluid catalytic cracker (FCC) feed, which is mainly 316°⁻⁵³⁸sup 0\\/C straight-run gas oil containing 1000-4000 ppm sulfur, would cost a total of $3-$5 billion and would

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

    SciTech Connect

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

    2013-06-01

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

  18. Control of Oxidative Sulfur Metabolism of Chlorobium limicola forma thiosulfatophilum.

    PubMed

    Cork, D; Mathers, J; Maka, A; Srnak, A

    1985-02-01

    A metered blend of anaerobic-grade N(2), CO(2), and H(2)S gases was introduced into an illuminated, 800-ml liquid volume, continuously stirred tank reactor. The system, described as an anaerobic gas-to-liquid phase fed-batch reactor, was used to investigate the effects of H(2)S flow rate and light energy on the accumulation of oxidized sulfur compounds formed by the photoautotroph Chlorobium limicola forma thiosulfatophilum during growth. Elemental sulfur was formed and accumulated in stoichiometric quantities when light energy and H(2)S molar flow rate levels were optimally adjusted in the presence of nonlimiting CO(2). Deviation from the optimal H(2)S and light energy levels resulted in either oxidation of sulfur or complete inhibition of sulfide oxidation. Based on these observations, a model of sulfide and sulfur oxidases electrochemically coupled to the photosynthetic reaction center of Chlorobium spp. is presented. The dynamic deregulation of oxidative pathways may be a mechanism for supplying the photosynthetic reaction center with a continuous source of electrons during periods of varying light and substrate availability, as in pond ecosystems where Chlorobium spp. are found. Possible applications for a sulfide gas removal process are discussed. PMID:16346713

  19. The effect of sulfur loading on the electrochemical performance of a sulfur-polymer composite cathode coated on aluminium foil.

    PubMed

    Doan, The Nam Long; Gosselink, Denise; Hoang, Tuan K A; Chen, P

    2014-07-21

    A scaling-up investigation of a sulfur-polymer cathode for rechargeable lithium-sulfur batteries is reported. The proposed procedure uses a low cost aluminium current collector and is suitable for mass production of a composite cathode, with sulfur loading levels of up to 5.9 mg cm(-2), and good electrochemical performance. PMID:24910180

  20. Inhibition of copper corrosion by bis-(1,1?-benzotriazoly)-?,?-diamide compounds in aerated sulfuric acid solution

    NASA Astrophysics Data System (ADS)

    Zhang, Da-Quan; Gao, Li-Xin; Zhou, Guo-Ding

    2006-05-01

    Three kinds of novel corrosion inhibitors, bis-(1,1'-benzotriazoly)-?,?-succinyldiamide (BSU), bis-(1,1'-benzotriazoly)-?,?-adipoyldiamide (BAD), and bis-(1,1'-benzotriazoly)-?,?-azelayldiamide (BAZ) were synthesized and certified by IR and 1H NMR. Their corrosion inhibition effects for copper in 0.5 M H 2SO 4 were evaluated by weight-loss method. It shows that among the three compounds, only BSU behaves better compared with BTA. The inhibition efficiency (IE) increased with increasing BSU concentration to 85.2% at the 5 × 10 -4 M level. Polarization studies showed that BSU suppressed both anodic and cathodic corrosion reactions. The minimum energy conformation of these compounds was obtained by MM2 force field program. The two benzotriazoly moieties in BSU molecule are more parallel than in other compounds. This is benefit to increase the inhibition effects of BSU.

  1. Volatile compounds of sulfur in the Fe-C-S system at 5.3 GPa and 1300°C

    NASA Astrophysics Data System (ADS)

    Zhimulev, E. I.; Sonin, V. M.; Bul'bak, T. A.; Chepurov, A. I.; Tomilenko, A. A.; Pokhilenko, N. P.

    2015-05-01

    This report presents the results of experimental studies of the fluid phase in the Fe-C-S system at high P and T values (5.3 GPa and 1300°C) conforming to diamond synthesis. The samples for experiments were mounted on air; therefore, the volatile compounds detected after the experiments are characterized by a wide variety and complicated composition involving both inorganic and organic components. Among the inorganic compounds, CO2, H2O, N2, SO2, CS2, and COS were detected. The GC/MS analysis revealed hydrocarbons (paraffins, olefins, and arenes), including high-molecular compounds. The formation of heavy hydrocarbons confirms their thermodynamic stability under high pressure. Oxygenated hydrocarbons (alcohols, aldehydes, ketones, carboxylic acids, and ethers) were also detected.

  2. Method to prevent sulfur accumulation in membrane electrode assembly

    DOEpatents

    Steimke, John L; Steeper, Timothy J; Herman, David T

    2014-04-29

    A method of operating a hybrid sulfur electrolyzer to generate hydrogen is provided that includes the steps of providing an anolyte with a concentration of sulfur dioxide, and applying a current. During steady state generation of hydrogen a plot of applied current density versus concentration of sulfur dioxide is below a boundary line. The boundary line may be linear and extend through the origin of the graph with a slope of 0.001 in which the current density is measured in mA/cm2 and the concentration of sulfur dioxide is measured in moles of sulfur dioxide per liter of anolyte.

  3. Cysteine S -conjugate ?-lyases: important roles in the metabolism of naturally occurring sulfur and selenium-containing compounds, xenobiotics and anticancer agents

    Microsoft Academic Search

    Arthur J. L. Cooper; Boris F. Krasnikov; Zoya V. Niatsetskaya; John T. Pinto; Patrick S. Callery; Maria T. Villar; Antonio Artigues; Sam A. Bruschi

    2011-01-01

    Cysteine S-conjugate ?-lyases are pyridoxal 5?-phosphate-containing enzymes that catalyze ?-elimination reactions with cysteine S-conjugates that possess a good leaving group in the ?-position. The end products are aminoacrylate and a sulfur-containing\\u000a fragment. The aminoacrylate tautomerizes and hydrolyzes to pyruvate and ammonia. The mammalian cysteine S-conjugate ?-lyases thus far identified are enzymes involved in amino acid metabolism that catalyze ?-lyase reactions

  4. Transient Studies of a Sodium Sulfur Cell

    NASA Astrophysics Data System (ADS)

    Caprio, Sarah

    Modern grids will include input from fossil-fueled power generation facilities as well as renewable energy sources, and these are expected to work together actively. One major problem with this integrated power production is that most renewable energy sources are intermittent and variable, and thus introduce a very challenging situation with regard to grid stability and reliability. Also, fossil-fueled power generation facilities have load cycles based on expected usage. A non-reliable power source cannot feasibly be used to supply the grid with proper amounts of energy needed in peak times. A solution to this dilemma is power storage. The sodium-sulfur battery has high potential for electrical storage at the grid level due to its high energy density, low cost of the reactants, and high open-circuit voltage. However, the use of sodium-sulfur batteries at the grid level requires high current density operation that can cause cell deterioration, leading to lower sulfur utilization and lower energy efficiency. In addition, it can result in undesired thermal runaway leading to potentially hazardous situations. A rigorous, dynamic model of a sodium-sulfur battery can be used to study these phenomena, design the battery for optimal transient performance, and develop mitigation strategies. Most literature on sodium-sulfur batteries is concerned the dynamics of the sulfur electrode (a sodium-polysulfide melt). There is limited data in the open literature for dynamics of an entire cell. With this motivation, a first-principles dynamic model of a sodium-sulfur cell (with beta"-alumina electrolyte) has been developed. The state of discharge (SOD) of a sodium-sulfur cell significantly affects the heat generation rate, rates of electrochemical reactions, and internal resistance. To capture these phenomena correctly, a fully coupled thermal-electrochemical model has been developed. The thermal model considers heat generation due to Ohmic loss, Peltier heat, and heat due to the entropy change. Species conservation equations are written in the sulfur electrode by considering the phase transition and change in the composition depending on the SOD. The electrochemical reactions are modeled by using Arrhenius-type rate equations with temperature-dependent terms and varying species concentration depending on the SOD. Species conservation equations are written in the beta"-alumina electrolyte for the ionic species by considering the change in composition due to diffusion and migration. In addition, the potential distribution, and the cell resistance for this spatially distributed system has been modeled. The physicochemical properties are considered to be temperature-dependent. The model is used to study both charging and discharging characteristics of the cell at varying current densities. The PDE-based model is solved in Aspen Custom Modeler by using method of lines. Our work shows that an appropriate thermal management strategy is necessary for high current-density operation, especially in the case of high penetration of the renewable energy into the grid.

  5. Reactivity of elemental sulfur nanoparticles and their role on the formation of sulfur intermediates

    NASA Astrophysics Data System (ADS)

    Kafantaris, F. C. A.; Druschel, G.

    2014-12-01

    Sulfur biogeochemical cycling involves a vast network of chemical reactions including oxidation, reduction and disproportionation, polymerization (S-S bonding), and aggregation that leads to nanoparticulate elemental sulfur (S8(nano)) and eventually the most stable bulk mineral form, a-S8. These reactions can occur in aqueous systems inorganically, intracellularly as assimilatory or dissimilatory reactions in microbial cells, or in presence of microbial organic exudates (e.g. surfactants). Elemental sulfur participates in nucleophilic and hydrolysis reactions to form sulfur intermediates, such as polysulfide ions. The nucleophilic reaction with sulfide (as H2S or HS-, reaction 1), is a key process in the dissolution of elemental sulfur: xS8 + H2S = Sx2- + 2 H+ (1) Polysulfides are inherently unstable in acidic conditions, experiencing a series of chain elongation reactions to form the S8 ring form of molecular elemental sulfur (overall this is the reverse of reaction 1). S8 rings are also inherently insoluble in water and undergo a very rapid coarsening process to form S8nano that then coarsens more slowly via an Ostwald ripening process to form colloidal particles of a-S8. Coarsening kinetics are influenced by temperature, and the presence/absence and type of surfactants [1]. The amount of polysulfide at any point is thus a balance between the forward and reverse overall reactions represented in reaction 1, and influenced by microbial generation of reduced sulfide and/or microbial production of organic surfactants, and the size of the elemental sulfur particles. Here we present some preliminary data on the kinetics of elemental sulfur consumption (reaction 1) that have been tested in various sizes and surface properties of the sulfur nanoparticles. The surface area and presence (or absence) of surfactant molecules influences the kinetics of polysulfide formation. The cycling of that reaction may play a significant role to the element's bioavailability to microorganisms, which incorporate the nanoparticulate (rather than the bulk a-S8) form of elemental sulfur or polysulfides in their specific metabolisms [2]. 1. Garcia and Druschel (2014) Submitted Manuscript 2. Boyd and Druschel (2013) Appl. Environ. Microbiol. 79 (6) 2061-2068

  6. Measurement of biogenic sulfur emissions from soils and vegetation using dynamic enclosure methods: Total sulfur gas emissions via MFC\\/FD\\/FPD determinations

    Microsoft Academic Search

    D. L. MacTaggart; D. F. Adams; S. O. Farwell

    1987-01-01

    Metal foil collection\\/flash desorption\\/flame photometric detection (MFC\\/FD\\/FPD) was one of the analytical methods used to measure emissions of gaseous, sulfur-containing compounds from several terrestrial natural sources during a cooperative field program in the summer of 1985. Nonspeciated, total sulfur gas emissions were determined by using the MFC\\/FD\\/FPD technique in combination with a Nafion Perma-Pure drying device to sample air from

  7. Optimization of ultrasound assisted-emulsification-dispersive liquid-liquid microextraction by experimental design methodologies for the determination of sulfur compounds in wines by gas chromatography-mass spectrometry.

    PubMed

    Jofré, Viviana P; Assof, Mariela V; Fanzone, Martín L; Goicoechea, Héctor C; Martínez, Luis D; Silva, María F

    2010-12-17

    A new method was developed for analyzing sulfur compounds in the aroma of white wines using ultrasound assisted-emulsification-dispersive liquid-liquid microextraction coupled with gas chromatography-mass spectrometry detection. In the present work, the analytical method for simultaneous determination of seven sulfur compounds (methylmercaptoacetate, methyl(methylthio)acetate, 2-methylthioethanol, 3-methylthiopropanol, 3-methylthiohexanol, 4-methylthio-4-methyl-2-pentanone and hexanethiol) is reported. Parameters that affect the efficiency of the methodology such as extracting and dispersing solvents, sample volume, ion strength, cavitation time and centrifugation time were investigated using a fractionated factorial 2(6-1) (R=V) screening design. Then, the factors presenting significant positive effects on the analytical response (extracting volume, ion strength, cavitation time and centrifugation time) were considered in a further central composite design to optimize the operational conditions for the ultrasound assisted-emulsification-dispersive liquid-liquid microextraction procedure. Additionally, multiple response simultaneous optimization by using the desirability function was used to find the optimum experimental conditions. The best results were obtained using pH sample 4.25, extractant volume 150?L, ionic strength 8.75% NaCl, cavitation time 20s and centrifugation time 50s. The use of the optimized ultrasound assisted-emulsification-dispersive liquid-liquid microextraction technique allowed to obtain the best extraction results with the minimum interference from other substances from the matrix, and it allowed to quantify the analytes in white wine samples by calibration graphs. Recoveries ranging from 91.99% to 125.87% for all sulfur compounds proved the accuracy of the proposed method in white wine samples. Method detection limits were in the range of 0.36-1.67ngmL(-1) and limits of quantitation were between 0.63 and 3.02ngmL(-1) for sulfur compounds in white wine samples. The proposed methodology was successfully applied for the determination concentrations of sulfur compounds in different commercial Chardonnay wine samples from Mendoza, Argentine. PMID:21094391

  8. System for recovering sulfur from gases, especially natural gas

    SciTech Connect

    Gryka, G.E.

    1992-09-01

    The objective of this project is to design, construct and operate a laboratory reactor to convert hydrogen sulfide into liquid sulfur, using a patented PIPco process as a basis. Reaction conditions will be studied, continuous regenerative operation demonstrated, and data necessary to design a field test system will be collected. The subject process is a regenerative buffered water circulating system with two primary steps: (1) loading of the solution with SO[sub 2] (which can be generated by buming sulfur or H[sub 2]S), and (2) H[sub 2]S separation - reaction to form sulfur - and sulfur separation. Many regenerative liquid redox sulfur recovery systems offer potential for combining H[sub 2]S separation and sulfur formation into one step. PIPco's data and engineering study suggest the process may have advantages over other liquid systems: Use of potassiurti citrate buffer increases sulfur dioxide (oxidizing agent) loading by a factor of 8 or more, up to 160 grams SO[sub 2]/liter of solution can be carried to the separator - reactor, thereby reducing liquid circulating rates and equipment size. The separator - reactor is operated at a temperature above 120[degrees]C (the melting point of elemental sulfur). Therefore, sulfur is produced and separated in liquid form. This eliminates sulfur plugging and separation problems by avoiding the production of solid sulfur.

  9. Large Sulfur Isotope Fractionation Does Not Require Disproportionation

    NASA Astrophysics Data System (ADS)

    Sim, Min Sub; Bosak, Tanja; Ono, Shuhei

    2011-07-01

    The composition of sulfur isotopes in sedimentary sulfides and sulfates traces the sulfur cycle throughout Earth’s history. In particular, depletions of sulfur-34 (34S) in sulfide relative to sulfate exceeding 47 per mil (‰) often serve as a proxy for the disproportionation of intermediate sulfur species in addition to sulfate reduction. Here, we demonstrate that a pure, actively growing culture of a marine sulfate-reducing bacterium can deplete 34S by up to 66‰ during sulfate reduction alone and in the absence of an extracellular oxidative sulfur cycle. Therefore, similar magnitudes of sulfur isotope fractionation in sedimentary rocks do not unambiguously record the presence of other sulfur-based metabolisms or the stepwise oxygenation of Earth’s surface environment during the Proterozoic.

  10. The oxidation state of sulfur in magmatic fluids

    NASA Astrophysics Data System (ADS)

    Binder, Bernd; Keppler, Hans

    2011-01-01

    Sulfur compounds in volcanic gases are responsible for the global cooling after explosive eruptions and they probably controlled the early evolution of the Earth's atmosphere. We have therefore studied the oxidation state of sulfur in aqueous fluids under the pressure and temperature conditions and oxygen fugacities typical for magma chambers (0.5-3 kbar, 650-950 °C, Ni-NiO to Re-ReO2 buffer conditions). Sulfur speciation was determined by Raman spectroscopy of quenched fluids trapped as inclusions in quartz. Our results show that sulfur in hydrothermal fluids and volcanic gases is much more oxidized than previously thought and in particular, some explosive eruptions may release a significant fraction of sulfur as SO3 or its hydrated forms. In the pressure range from 500 to 2000 bar, the equilibrium constant K1 of the reaction 2H2S + 3O2 = 2SO2 + 2H2O in aqueous fluids can be described by lnK1 = -(57.1 ± 7.1) + (173,480 ± 7592)T- 1, where T is temperature in Kelvin. The equilibrium constant K2 for the reaction SO2 + ½O2 = SO3 in aqueous fluids, where SO3 may include hydrated forms, such as H2SO4, was found to be strongly pressure dependent, with lnK2 = -(5.2 ± 5.7) + (19,243 ± 5993)T- 1 at 1500 bar; lnK2 = -(11.1 ± 1.3) + (25,383 ± 1371)T- 1 at 2000 bar and lnK2 = -(22.1 ± 2.2) + (37,082 ± 2248)T- 1 at 2500 bar. Our data imply that volcanoes may directly inject hexavalent sulfur in the form of H2SO4 into the atmosphere, not only on Earth, but possibly also on Venus and on Mars, when it was still tectonically active. Remote measurements from satellites may have underestimated the sulfur yield of some recent eruptions. Moreover, the mechanisms of the interaction of volcanic gases with the stratosphere need to be reconsidered.

  11. Accumulation of atmospheric sulfur in some Costa Rican soils

    USGS Publications Warehouse

    Bern, Carleton R.; Townsend, Alan R.

    2013-01-01

    Sulfur is one of the macronutrient elements whose sources to terrestrial ecosystems should shift from dominance by rock-weathering to atmospheric deposition as soils and underlying substrate undergo progressive weathering and leaching. However, the nature and timing of this transition is not well known. We investigated sources of sulfur to tropical rain forests growing on basalt-derived soils in the Osa Peninsula region of Costa Rica. Sulfur sources were examined using stable isotope ratios (?34S) and compared to chemical indices of soil development. The most weathered soils, and the forests they supported, are dominated by atmospheric sulfur, while a less weathered soil type contains both rock-derived and atmospheric sulfur. Patterns of increasing ?34S with increasing soil sulfur concentration across the landscape suggest atmospheric sulfur is accumulating, and little rock-derived sulfur has been retained. Soil sulfur, minus adsorbed sulfate, is correlated with carbon and nitrogen, implying that sulfur accumulation occurs as plants and microbes incorporate sulfur into organic matter. Only the lower depth increments of the more weathered soils contained significant adsorbed sulfate. The evidence suggests a pattern of soil development in which sulfur-bearing minerals in rock, such as sulfides, weather early relative to other minerals, and the released sulfate is leached away. Sulfur added via atmospheric deposition is retained as organic matter accumulates in the soil profile. Adsorbed sulfate accumulates later, driven by changes in soil chemistry and mineralogy. These aspects of sulfur behavior during pedogenesis in this environment may hasten the transition to dominance by atmospheric sources.

  12. Characterization of the Fe Site in Iron-Sulfur-Cluster-Free Hydrogenase (Hmd) and of a Model Compound via Nuclear Resonance Vibrational Spectroscopy (NRVS)

    PubMed Central

    Guo, Yisong; Wang, Hongxin; Xiao, Yuming; vogt, Sonja; Shima, Seigo; Volkers, Phillip I.; Pelmentschikov, Vladimir; Alp, Ercan E.; Sturhahn, Wolfgang; Yada, Yoshitaka

    2009-01-01

    We have used 57Fe nuclear resonance vibrational spectroscopy (NRVS) to study the iron site in the iron-sulfur-cluster-free hydrogenase Hmd from the methanogenic archaeon Methanothermobacter marburgensis. The spectra have been interpreted by comparison with a cis-(CO)2-ligated Fe model compound, Fe(S2C2H4)(CO)2(PMe3)2, as well as by normal mode simulations of plausible active site structures. For this model complex, normal mode analyses both from an optimized Urey-Bradley force field and from complementary density functional theory (DFT) calculations produced consistent results. Previous IR spectroscopic studies found strong CO stretching modes at 1944 and 2011 cm?1, interpreted as evidence for cis-Fe(CO)2 ligation. The NRVS data provide further insight into the dynamics of the Fe site, revealing Fe-CO stretch and Fe-CO bend modes at 494, 562, 590, and 648 cm?1, consistent with the proposed cis-Fe(CO)2 ligation. The NRVS also reveals a band assigned to Fe-S stretching motion at ~311 cm?1, and another reproducible feature at ~380 cm?1. The 57Fe partial vibrational densities of states (PVDOS) for Hmd can be reasonably well simulated by a normal mode analysis based on a Urey-Bradley force field for a 5-coordinate cis-(CO)2-ligated Fe site with additional cysteine, water, and pyridone cofactor ligands. A final interpretation of the Hmd NRVS data, including DFT analysis, awaits a 3-dimensional structure for the active site. PMID:18407624

  13. Isotopic composition and speciation of sulfur in the Miocene Monterey Formation: Reevaluation of sulfur reactions during early diagenesis in marine environments

    SciTech Connect

    Zaback, D.A.; Pratt, L.M. (Indiana Univ., Bloomington (United States))

    1992-02-01

    The timing and pathways of early diagenetic sulfur transfer from dissolved species in pore waters to solid inorganic and organic compounds in sediments have been studied in the Miocene Monterey Formation, Santa Maria Basin (onshore), California. Correlation between concentrations of total organic carbon (TOC) and total sulfur (TS), in addition to concentrations of titanium, aluminum, total iron, and reactive iron, have been used to infer organic matter reactivity, redox conditions, and relative rates of clastic and biogenic input for each lithofacies. Isotopic compositions of six sulfur species (acid-volatile, disulfide, kerogen, bitumen, sulfate, and elemental) have provided information regarding relative timing of sulfur incorporation, sulfate diffusivity in the upper centimeters of the sediments, and the sources of sulfur for individual species. Consistent ordering of isotopic values for sulfur species (disulfide < acid-volatile sulfide {le} kerogen) indicates that pyrite precipitated nearest to the sediment-water interface under mildly reducing conditions and with little or no decrease in sulfate concentration relative to seawater. Enrichment of {sup 34}S in acid-volatile sulfide and kerogen sulfur resulted from formation of these species at greater depths or in restricted micro-environments under more reducing conditions and with low concentrations of porewater sulfate. The formation of acid-volatile sulfide after pyrite but during early diagenesis is significant because it implies more strongly reducing conditions than are generally recognized in deep-water marine sediments.

  14. Chemistry of ascorbic acid and sulfur dioxide as an antioxidant system relevant to white wine.

    PubMed

    Barril, Célia; Clark, Andrew C; Scollary, Geoffrey R

    2012-06-30

    The impact of the combined ascorbic acid and sulfur dioxide antioxidants on white wine oxidation processes was investigated using a range of analytical techniques, including flow injection analysis for free and total sulfur dioxide and two chromatographic methods for ascorbic acid, its oxidative degradation products and phenolic compounds. The combination of different analytical techniques provided a fast and simultaneous means for the monitoring of oxidation processes in a model wine system. In addition, the initial mole ratio of sulfur dioxide to ascorbic acid was varied and the model wine complexity was increased by the inclusion of metal ions (copper(II) and iron(II)). Sulfur dioxide was found not to be a significant binder of ascorbic acid oxidative degradation products and could not prevent the formation of certain phenolic pigment precursors. The results provide a detailed insight into the ascorbic acid/sulfur dioxide antioxidant system in wine conditions. PMID:22688051

  15. Solvent extraction of elemental sulfur from coal and a determination of its source using stable sulfur isotopes

    USGS Publications Warehouse

    Hackley, Keith C.; Buchanan, D.H.; Coombs, K.; Chaven, C.; Kruse, C.W.

    1990-01-01

    Hot tetrachloroethene (perchloroethylene, PCE) extracts significant amounts of elemental sulfur (So) from weathered coals but not from pristine coals. The objective of this study was to determine whether So extracted by PCE is an oxidation product of pyrite or whether it originates in some way from unstable, organically-bound sulfur. The isotopic composition of the PCE-extracted So was compared to the isotopic compositions of the pyritic and the organic sulfur in a coal. The So was shown to have an isotopic signature similar to the pyritic sulfur. Additionally, the isotopic differences observed between the pyritic, So and sulfatic sulfur were consistent with bacterial mediated oxidation of sulfide sulfur (pyrite) as the source of both the sulfatic and elemental sulfur. ?? 1990.

  16. Sulfuric acid thermoelectrochemical system and method

    SciTech Connect

    Ludwig, F.A.

    1989-03-07

    This patent describes a thermoelectrochemical system for generating an electrical current including: an electrochemical cell having a cathode compartment and an anode compartment, the compartments having a common ion permeable separation wall; a cathode comprising lead oxide and an anode comprising lead sulfate located within their respective compartments, the cathode and anode being connectable externally of the cell for generation of the electrical current therebetween; a cathode solution comprising concentrated sulfuric acid located in the cathode compartment and in contract with the cathode wherein water is generated or collected and sulfuric acid is consumed at the cathode during generation of the electrical current; an anode solution comprising an aqueous buffer solution of sodium sulfate and sodium bisulfate located in the anode compartment and in contact with the anode wherein sodium bisulfate is generated and sodium sulfate is consumed at the anode during generation of the electrical current.

  17. Novel Fluorinated Phosphorus-Sulfur Heteroatom Compounds: Synthesis and Characterization of Ferrocenyl- and Aryl-Phosphonofluorodithioic Salts, Adducts, and Esters.

    PubMed

    Hua, Guoxiong; Du, Junyi; Surgenor, Brian A; Slawin, Alexandra M Z; Woollins, J Derek

    2015-01-01

    A series of novel ferrocenyl- and aryl-phosphonofluorodithioic salts, adducts, and esters has been prepared. The reaction of 2,4-diferrocenyl-1,3,2,4-diathiadiphosphetane 2,4-disulfide {[FcP(?-S)S]2, FcLR} with dry KF or tetrabutylammonium fluoride (TBAF) led to the corresponding potassium and tetrabutylammonium salts of ferrocenyldithiofluorophosphinic acids. Treating potassium ferrocenyldithiofluorophosphinic acid with an equimolar amount of tetraphenylphosphonium chloride readily yielded the corresponding organic adducts, and with mono- and di-halogenated alkanes generated a series of the corresponding esters of ferrocenylphosphonofluoridodithioates. Similarly, using 1,3-epithionaphtho[1,8-cd][1,2,6] oxadiphosphinine 1,3-disulfide or Belleau's Reagent in place of FcLR resulted in the corresponding novel salts, adducts, and ester derivatives. All new compounds have been characterized by means of multi-NMR (1H, 13C, 31P, 19F) spectroscopy and accurate mass measurement in conjunction with single crystal X-ray crystallography of four structures. PMID:26151115

  18. Molecular Structure of sulfur oxide tetrafluoride

    NSDL National Science Digital Library

    2002-09-11

    SOF4 is also know as sulfur flouride oxide and better known as Thionyl tetraflouride. It has a bipyramidal shape and a strong odor. Thionyl tetraflouride is dangerous to all living tissue and is also flamable. Thionyl tetraflouride reacts with moisture and water to form hydrofluoric acid and thionyl fluoride. SOF4 has many double bonds that cause distortion and the single bonds are pushed away.

  19. Sulfur Oxidation and Contrail Precursor Chemistry

    NASA Technical Reports Server (NTRS)

    DeWitt, Kenneth J.

    2003-01-01

    Sulfuric acid (H2SO4), formed in commercial aircraft operations via fuel-S (goes to) SO2 (goes to) SO3 (goes to) H2SO4 plays an important role in the formation of contrails. It is believed that the first step occurs inside the combustor, the second step in the engine exit nozzle, and the third step in the exhaust plume. Thus, measurements of the sulfur oxidation rates are critical to the understanding of contrail formation. Field measurements of contrails formed behind commercial aircraft indicate that significantly greater conversion of fuel-bound sulfur to sulfate aerosol occurs than can be explained by our current knowledge of contrail physics and chemistry. The conversion of sulfur from S(IV) to S(VI) oxidation state, required for sulfate aerosol formation, is thermodynamically favored for the conditions that exist within jet engines but is kinetically disfavored. The principal reaction pathway is O+SO2+M (goes to) SO3+M. The rates of this reaction have never been measured in the temperature and pressure regimes available to aircraft operation. In the first year (FY02) of this project, we performed a series of experiments to elucidate the rate information for the O+SO2+M (goes to) SO3+M reaction. The work performed is described following the proposed work plan. Because we used the H2/O2 system for an O-atom source and rate coefficients were obtained via computer simulation, construction of a reaction mechanism and either recalculation or estimation of thermodynamic properties of H(x)SO(y) species are described first.

  20. Sulfur-containing additives based on polythiodiglycol

    Microsoft Academic Search

    A. I. Balin; T. N. Veretenova; L. M. Kashtan; V. B. Tarasevich

    1986-01-01

    l) was obtained by the interaction of ethylene ch!orohydrin and sodium polysulfide in the presence of 1-2% oxyethylated alkylphenols (emulsifiers OP-7 and OP-10), while heating the reaction mixture to I08-I09~ The resulting polythiodiglycol is an oily, light-brown liquid, with a faint, specific odor; the viscosity at 50~ is 0.35 mm2\\/sec, density at 20~ 1400 kg\\/m 3, and sulfur content 56-58%

  1. Sulfur unit control in a DCS

    SciTech Connect

    Reif, D.R. (Rosemount, Inc., Eden Prairie, MN (USA))

    1989-08-01

    Sulfur Recovery Units (SRUs) traditionally have been operated with basic regulatory control strategies implemented through a process control system. Many modern DCSs have enough calculation power to execute advanced control strategies at the controller level without the need for a process computer. Included in this article is a discussion of some control schemes that can be implemented at the controller level in a DCS resulting in tighter control and increased operating margins.

  2. The structure of iron–sulfur proteins

    Microsoft Academic Search

    Heinrich Sticht; Paul Rösch

    1998-01-01

    Ferredoxins are a group of iron–sulfur proteins for which a wealth of structural and mutational data have recently become available. Previously unknown structures of ferredoxins which are adapted to halophilic, acidophilic or hyperthermophilic environments and new cysteine patterns for cluster ligation and non-cysteine cluster ligation have been described. Site-directed mutagenesis experiments have given insight into factors that influence the geometry,

  3. Sulfur, selenium and tellurium pseudopeptides: synthesis and biological evaluation.

    PubMed

    Shaaban, Saad; Sasse, Florenz; Burkholz, Torsten; Jacob, Claus

    2014-07-15

    A new series of sulfur, selenium and tellurium peptidomimetic compounds was prepared employing the Passerini and Ugi isocyanide based multicomponent reactions (IMCRs). These reactions were clearly superior to conventional methods traditionally used for organoselenium and organotellurium synthesis, such as classical nucleophilic substitution and coupling methods. From the biological point of view, these compounds are of considerable interest because of suspected anticancer and antimicrobial activities. While the sulfur and selenium containing compounds generally did not show either anticancer or antimicrobial activities, their tellurium based counterparts frequently exhibited antimicrobial activity and were also cytotoxic. Some of the compounds synthesized even showed selective activity against certain cancer cells in cell culture. These compounds induced a cell cycle delay in the G0/G1 phase. At closer inspection, the ER and the actin cytoskeleton appeared to be the primary cellular targets of these tellurium compounds, in line with some of our previous studies. As most of these peptidomimetic compounds also comply with Lipinski's Rule of Five, they promise good bioavailability, which needs to be studied as part of future investigations. PMID:24890655

  4. Sodium-sulfur batteries for naval applications

    SciTech Connect

    Posthumus, K.J.C.M. [Royal Netherlands Navy, The Hague (Netherlands). Directorate Material; Schillemans, R.A.A.; Kluiters, E.C. [TNO Inst. of Environmental Sciences, Delft (Netherlands)

    1996-11-01

    Since 1981 the Electrochemistry Group of TNO carries out a research program for the Royal Netherlands Navy (RNLN) with respect to batteries and fuel cells. Part of this Advanced Batteries program was the evaluation of possible alternatives for the nowadays applied batteries in conventional diesel electric submarines and ships. From this evaluation the high temperature sodium-sulfur battery proved to be the most promising candidate. To investigate the feasibility of the sodium-sulfur battery for naval application, calculations have been made on the expected performance within the two envisaged applications. To validated the calculation experimental testing was carried out on the submarine application. During operational missions the application hardly requires any supply of heating energy. Within the submarine application there is no need for installing a cooling system for the battery. Shock and vibration tests on a 10 kWh module did not lead to any measurable decrease in performance. Calculations show that the operational characteristics of a submarine equipped with sodium sulfur batteries outperform a submarine equipped with the traditional lead acid batteries. The short lifetime is the most important limitation in all applications.

  5. 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.

  6. Sulfur: The plankton/climate connection

    SciTech Connect

    Malin, G.; Turner, S.M.; Liss, P.S. (Univ. of East Anglia, Norwich (United Kingdom))

    1992-10-01

    A key process in the global sulfur cycle is the transfer of volatile forms of the element from sea to land via the atmosphere. Early budgets calculated the amount of sulfur required to balance the cycle and generally assumed that this flux was achieved by formation of hydrogen sulfide (H[sub 2]S) in coastal waters, mud flats, etc. However, Lovelock et al. (1972) made the first field measurements of dimethylsulfide (DMS) in seawater and suggested that it represented the missing link in the S cycle. Other sulfur gases, such as carbonylsulfide (COS), carbon disulfide (CS[sub 2]), methylmercaptan (CH[sub 3]SH), and dimethyldisulfide (CH[sub 3]SSCH[sub 3]), are also often observed, but DMS is usually dominant (Andreae et al. 1983, Cline and Bates 1983, Turner and Liss 1985). Over the past decade or so thousands of analyses have been made covering coastal, shelf, and open ocean environments, which show that DMS is ubiquitous in seawater but that considerable spatial and temporal variability occurs (see Cooper and Matrai 1989). In this review the authors consider processes leading to the formation of DMS in seawater, its emission to the atmosphere, and transformations therein, the possible role of DMS oxidation products in climate regulation as proposed by Charlson et al. (1987), and how global changes might affect DMS production. 80 refs., 2 figs.

  7. Assessment of the stoichiometry and efficiency of CO2 fixation coupled to reduced sulfur oxidation

    PubMed Central

    Klatt, Judith M.; Polerecky, Lubos

    2015-01-01

    Chemolithoautotrophic sulfur oxidizing bacteria (SOB) couple the oxidation of reduced sulfur compounds to the production of biomass. Their role in the cycling of carbon, sulfur, oxygen, and nitrogen is, however, difficult to quantify due to the complexity of sulfur oxidation pathways. We describe a generic theoretical framework for linking the stoichiometry and energy conservation efficiency of autotrophic sulfur oxidation while accounting for the partitioning of the reduced sulfur pool between the energy generating and energy conserving steps as well as between the main possible products (sulfate vs. zero-valent sulfur). Using this framework, we show that the energy conservation efficiency varies widely among SOB with no apparent relationship to their phylogeny. Aerobic SOB equipped with reverse dissimilatory sulfite reductase tend to have higher efficiency than those relying on the complete Sox pathway, whereas for anaerobic SOB the presence of membrane-bound, as opposed to periplasmic, nitrate reductase systems appears to be linked to higher efficiency. We employ the framework to also show how limited rate measurements can be used to estimate the primary productivity of SOB without the knowledge of the sulfate-to-zero-valent-sulfur production ratio. Finally, we discuss how the framework can help researchers gain new insights into the activity of SOB and their niches.

  8. Isotopic composition and speciation of sulfur in the Miocene Monterey Formation: Reevaluation of sulfur reactions during early diagenesis in marine environments

    NASA Astrophysics Data System (ADS)

    Zaback, Doreen A.; Pratt, Lisa M.

    1992-02-01

    The timing and pathways of early diagenetic sulfur transfer from dissolved species in pore waters to solid inorganic and organic compounds in sediments have been studied in the Miocene Monterey Formation, Santa Maria Basin (onshore), California. Correlation between concentrations of total organic carbon (TOC) and total sulfur (TS), in addition to concentrations of titanium, aluminum, total iron, and reactive iron, have been used to infer organic matter reactivity, redox conditions, and relative rates of clastic and biogenic input for each lithofacies. Isotopic compositions of six sulfur species (acid-volatile, disulfide, kerogen, bitumen, sulfate and elemental) have provided information regarding relative timing of sulfur incorporation, sulfate diffusivity in the upper centimeters of the sediments, and the sources of sulfur for individual species. Isotopically, the disulfide species expresses the greatest fractionation relative to estimated values of Miocene seawater sulfate (~ +22‰ CDT). On average, disulfide is depleted in 34S by 10.4%. relative to kerogen and by 9.9‰ relative to acid-volatile sulfide. The ? 34S of bitumen shows no systematic change relative to ? 34S keregon, suggesting the presence of migrated bitumen. Isotopic similarity of sulfate and elemental sulfur to sulfides and bitumen indicates that sulfate and elemental sulfur are chemical and/or biological oxidation products derived from sulfides and bitumen. Consistent ordering of isotopic values for sulfur species (disulfide < acid-volatile sulfide ? kerogen) indicates that pyrite precipitated nearest to the sediment-water interface under mildly reducing conditions and with little or no decrease in sulfate concentration relative to seawater. Enrichment of 34S in acid-volatile sulfide and kerogen sulfur resulted from formation of these species at greater depths or in restricted micro-environments under more reducing conditions and with low concentrations of porewater sulfate. The formation of acid-volatile sulfide after pyrite but during early diagenesis is significant because it implies more strongly reducing conditions than are generally recognized in deep-water marine sediments.

  9. Dimethylsulfoniopropionate and Methanethiol Are Important Precursors of Methionine and Protein-Sulfur in Marine Bacterioplankton

    PubMed Central

    Kiene, Ronald P.; Linn, Laura J.; González, José; Moran, Mary Ann; Bruton, Jody A.

    1999-01-01

    Organic sulfur compounds are present in all aquatic systems, but their use as sources of sulfur for bacteria is generally not considered important because of the high sulfate concentrations in natural waters. This study investigated whether dimethylsulfoniopropionate (DMSP), an algal osmolyte that is abundant and rapidly cycled in seawater, is used as a source of sulfur by bacterioplankton. Natural populations of bacterioplankton from subtropical and temperate marine waters rapidly incorporated 15 to 40% of the sulfur from tracer-level additions of [35S]DMSP into a macromolecule fraction. Tests with proteinase K and chloramphenicol showed that the sulfur from DMSP was incorporated into proteins, and analysis of protein hydrolysis products by high-pressure liquid chromatography showed that methionine was the major labeled amino acid produced from [35S]DMSP. Bacterial strains isolated from coastal seawater and belonging to the ?-subdivision of the division Proteobacteria incorporated DMSP sulfur into protein only if they were capable of degrading DMSP to methanethiol (MeSH), whereas MeSH was rapidly incorporated into macromolecules by all tested strains and by natural bacterioplankton. These findings indicate that the demethylation/demethiolation pathway of DMSP degradation is important for sulfur assimilation and that MeSH is a key intermediate in the pathway leading to protein sulfur. Incorporation of sulfur from DMSP and MeSH by natural populations was inhibited by nanomolar levels of other reduced sulfur compounds including sulfide, methionine, homocysteine, cysteine, and cystathionine. In addition, propargylglycine and vinylglycine were potent inhibitors of incorporation of sulfur from DMSP and MeSH, suggesting involvement of the enzyme cystathionine ?-synthetase in sulfur assimilation by natural populations. Experiments with [methyl-3H]MeSH and [35S]MeSH showed that the entire methiol group of MeSH was efficiently incorporated into methionine, a reaction consistent with activity of cystathionine ?-synthetase. Field data from the Gulf of Mexico indicated that natural turnover of DMSP supplied a major fraction of the sulfur required for bacterial growth in surface waters. Our study highlights a remarkable adaptation by marine bacteria: they exploit nanomolar levels of reduced sulfur in apparent preference to sulfate, which is present at 106- to 107-fold higher concentrations. PMID:10508088

  10. Milestones in plant sulfur research on sulfur-induced-resistance (SIR) in Europe.

    PubMed

    Bloem, Elke; Haneklaus, Silvia; Schnug, Ewald

    2014-01-01

    Until the 1970's of the last century sulfur (S) was mainly regarded as a pollutant being the main contributor of acid rain, causing forest dieback in central Europe. When Clean Air Acts came into force at the start of the 1980's SO2 contaminations in the air were consequently reduced within the next years. S changed from an unwanted pollutant into a lacking plant nutrient in agriculture since agricultural fields were no longer "fertilized" indirectly by industrial pollution. S deficiency was first noticed in Brassica crops that display an especially high S demand because of its content of S-containing secondary metabolites, the glucosinolates. In Scotland, where S depositions decreased even faster than in continental Europe, an increasing disease incidence with Pyrenopeziza brassicae was observed in oilseed rape in the beginning 1990's and the concept of sulfur-induced-resistance (SIR) was developed after a relationship between the S status and the disease incidence was uncovered. Since then a lot of research was carried out to unravel the background of SIR in the metabolism of agricultural crops and to identify metabolites, enzymes and reactions, which are potentially activated by the S metabolism to combat fungal pathogens. The S status of the crop is affecting many different plant features such as color and scent of flowers, pigments in leaves, metabolite concentrations and the release of gaseous S compounds which are directly influencing the desirability of a crop for a variety of different organisms from microorganisms, over insects and slugs to the point of grazing animals. The present paper is an attempt to sum up the knowledge about the effect of the S nutritional status of agricultural crops on parameters that are directly related to their health status and by this to SIR. Milestones in SIR research are compiled, open questions are addressed and future projections were developed. PMID:25642233

  11. Role of Sulfur for Plant Production in Agricultural and Natural Ecosystems

    Microsoft Academic Search

    Fang-jie Zhao; Michael Tausz; Luit J. De Kok

    Sulfur is essential for plant growth and functioning. Sulfate taken up by the roots is the primary sulfur source for growth,\\u000a but additionally plants are able to utilize absorbed sulfur gases by the shoot. Prior to its assimilation sulfur needs to\\u000a be reduced and cysteine is the primary precursor or sulfur donor for other plant sulfur metabolites. Sulfur is of

  12. Quantitative determination of wine highly volatile sulfur compounds by using automated headspace solid-phase microextraction and gas chromatography-pulsed flame photometric detection. Critical study and optimization of a new procedure.

    PubMed

    López, Ricardo; Lapeña, Ana Cristina; Cacho, Juan; Ferreira, Vicente

    2007-03-01

    The quantitative determination of wine volatile sulfur compounds by automated headspace solid-phase microextraction (HS-SPME) with a carboxen-polydimethylsiloxane (CAR-PDMS) fiber and subsequent gas chromatography-pulsed flame photometric detection (GC-PFPD) has been evaluated. The direct extraction of the sulfur compounds in 5 ml of wine has been found to suffer from matrix effects and short linear ranges, problems which could not be solved by the use of different internal standards or by multiple headspace SPME. These problems were attributed to saturation of the fiber and to competitive effects between analytes, internal standards and other wine volatiles. Another problem was the oxidation of analytes during the procedure. The reduction in sample volume by a factor 50 (0.1 ml diluted with water or brine) brought about a reduction in the amount of sulfur compounds taken in the fiber by a factor just 3.3. Consequently, a new procedure has been proposed. In a sealed vial containing 4.9 ml of saturated NaCl brine, the air is thoroughly displaced with nitrogen, and the wine (0.1 ml) and the internal standards (0.02 ml) are further introduced with a syringe through the vial septum. This sample is extracted at 35 degrees C for 20 min. This procedure makes a satisfactory determination possible of hydrogen sulfide, methanethiol, ethanethiol, dimethyl sulfide, diethyl sulfide and dimethyl disulfide. The linear dynamic ranges cover the normal ranges of occurrence of these analytes in wine with typical r2 between 0.9823 and 0.9980. Reproducibility in real samples ranges from 10 to 20% and repeatability is better than 10% in most cases. The method accuracy is satisfactory, with errors below 20% for hydrogen sulfide and mostly below 10% for the other compounds. The proposed method has been applied to the analysis of 34 Spanish wines. PMID:17207804

  13. Biogeochemistry of sulfur in the Vienna Woods: Study of sulfur stable isotope ratios by MC-ICP-MS as indicator of biogeochemical S cycling

    NASA Astrophysics Data System (ADS)

    Hanousek, Ondrej; Berger, Torsten W.; Prohaska, Thomas

    2014-05-01

    Sulfur entering forest ecosystems originates mainly from combustion of fossil fuels. This source of sulfur has been strongly (by more than 95 %) reduced in last decades and recently, higher sulfur output (in soil solution or stream water) than sulfur input (in rain water) in an ecosystem was registered in many monitored forest ecosystems. This unbalance may be caused by weathering of sulfur-bearing rocks, desorption of sulfur adsorbed in soil in the past or (re)mineralization of organic sulfur compounds. This 'negative' balance leads to mobilization of base cations along with SO42- and as such to an acidification of soils. As hypothesis, ?34S/32S depletion in stream water will be observed if a considerable proportion of atmospherically deposited sulfate is cycled through the organic S pool. Rain water and soil solutions samples were collected for this study at 3 sites (beech stands) in the Vienna Woods, Austria twice a month from May 2010 to April 2012. Due to the expected sulfate concentration gradient with respect to the distance from a tree, sampling was carried out at 5 intervals from a stem. The sulfur concentration in the samples was determined by ion chromatography. Sulfur isotope ratios (?34S/32SV CDT) were analyzed by multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) in edge-resolution mode. The method was validated using IAEA-S-1 and IAEA-S-2 isotopic certified reference materials. The combined standard uncertainty of the measurement (uc = 0.10 %, k = 1) proves the suitability of the developed method. The concentration of sulfur in rain water showed expected behavior, with a seasonal maximum in winter months, in contrast to the corresponding ?34S/32SV CDT isotope ratios, where no or low seasonal trends were observed. The sulfur isotope ratios in soil solution samples show a dependence on the distance from a tree stem and the sampling depth with lower ?34S/32SV CDT ratios as compared to the precipitation. The measured isotopic fractionation in soil solution samples might be ascribed to aforementioned biogeochemical redistribution of organic sulfur.

  14. Method of detecting sulfur dioxide

    Microsoft Academic Search

    Leonard D. Spicer; Dennis W. Bennett; Jon F. Davis

    1985-01-01

    (CH.sub.3).sub.3 SiNSO is produced by the reaction of ((CH.sub.3).sub.3 Si).sub.2 NH with SO.sub.2. Also produced in the reaction are ((CH.sub.3).sub.3 Si).sub.2 O and a new solid compound [NH.sub.4 ][(CH.sub.3).sub.3 SiOSO.sub.2 ]. Both (CH.sub.3).sub.3 SiNSO and [NH.sub.4 ][(CH.sub.3).sub.3 SiOSO.sub.2 ] have fluorescent properties. The reaction of the subject invention is used in a method of measuring the concentration of SO.sub.2 pollutants

  15. Behavior of sulfur and chlorine in coal during combustion and boiler corrosion. Final technical report, 1 September, 1992--31 August, 1993

    Microsoft Academic Search

    C. L. Chou; K. C. Hackley; J. Cao; D. M. Moore; J. Xu; R. R. Ruch; W. P. Pan; M. L. Upchurch; H. B. Cao

    1993-01-01

    The goals of this project are to investigate the behavior of sulfur and chlorine during pyrolysis and combustion of Illinois coals, the chemistry and mineralogy of boiler deposits, the effects of combustion gases on boiler materials, and remedial measures to reduce the sulfur and chlorine compounds in combustion gases. Replicate determinations of chlorine and sulfur evolution during coal pyrolysis-gas combustion

  16. Reduction of gap states of ternary IIIV semiconductor surfaces by sulfur passivation: Comparative studies of AlGaAs and InGaP

    E-print Network

    Kim, Sehun

    of compound semiconductor surfaces. Since Massies, Dezaly, and Linh first used sulfur to treat the GaAsReduction of gap states of ternary III­V semiconductor surfaces by sulfur passivation: Comparative-cleaned surface--a result similar to that for GaAs. © 1996 American Vacuum Society. I. INTRODUCTION Sulfur

  17. SULFUR CHEMISTRY. Gas phase observation and microwave spectroscopic characterization of formic sulfuric anhydride.

    PubMed

    Mackenzie, Rebecca B; Dewberry, Christopher T; Leopold, Kenneth R

    2015-07-01

    We report the observation of a covalently bound species, formic sulfuric anhydride (FSA), that is produced from formic acid and sulfur trioxide under supersonic jet conditions. FSA has been structurally characterized by means of microwave spectroscopy and further investigated by using density functional theory and ab initio calculations. Theory indicates that a ?2 + ?2 + ?2 cycloaddition reaction between SO3 and HCOOH is a plausible pathway to FSA formation and that such a mechanism would be effectively barrierless. We speculate on the possible role that FSA may play in the Earth's atmosphere. PMID:26138972

  18. Chemiluminescence sulfur detection in capillary supercritical fluid chromatography

    SciTech Connect

    Bornhop, D.J.; Murphy, B.J.; Krieger-Jones, L.

    1989-04-01

    The need for selective detectors in supercritical fluid chromatography (SFC) is particularly evident for the sensitive analysis of sulfur-containing species. These sulfur species are of interest to the environmental community, for the analysis of pesticides and atmospheric pollutants, as well as to the petroleum industry. Various detectors have been employed for the analysis of sulfur. The authors describe the use of a chemiluminescence sulfur detector (SCD) for the analysis of sulfur-containing organic analytes as separated by supercritical fluid chromatography. Detection limits of 35 and 115 pg of isopropylthiol and dodecanethiol, respectively, have been obtained for the SFC-SCD system with the linear dynamic range of about 10/sup 3/. Sulfur detectability appears to be independent of chromatographic pressure and the utility of the system is illustrated by the presentation of several real world analyses.

  19. SULFUR CONTENT OF THE COAL RESOURCES OF THE UNITED STATES: CURRENT STATUS.

    USGS Publications Warehouse

    Cecil, C.B.; Dulong, F.T.

    1986-01-01

    The sulfur content of United States coal can be assessed using a variety of approaches. The sulfur content may be expressed in terms of total sulfur in the coal, pounds of sulfur per million Btu, or sulfur remaining after reduction by coal preparation. In addition, sulfur content may be applied to the demonstrated reserve base or to coal resource estimates. Unfortunately, current data bases do not allow for an integrated assessment at the national level. Although classification of coal resources and reserves according to sulfur content is arbitrary, preferential production of low-sulfur reserves will positively skew the total sulfur of the remaining coal resource.

  20. Sensitivity of ginseng to ozone and sulfur dioxide

    SciTech Connect

    Proctor, J.T.A.; Ormrod, D.P.

    1981-10-01

    American ginseng (Panax quinquefolius L.), was injured by exposure to 20 pphm ozone and/or 50 pphm (v/v) sulfur dioxide for 6 hr daily for 4 days. Ozone induced upper surface leaflet stippling along the veins and interveinally, and sulfur dioxide induced mild chlorosis to irregular necrotic areas. Ginseng was less sensitive to ozone and as sensitive to sulfur dioxide as 'Cherry Belle' radish (Raphanus sativus L.) and 'Bel W-3' tobacco (Nicotiana tabacum L.).

  1. Sulfide catalysts for reducing SO2 to elemental sulfur

    DOEpatents

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

    2001-01-01

    A highly efficient sulfide catalyst for reducing sulfur dioxide to elemental sulfur, which maximizes the selectivity of elemental sulfur over byproducts and has a high conversion efficiency. Various feed stream contaminants, such as water vapor are well tolerated. Additionally, hydrogen, carbon monoxide, or hydrogen sulfides can be employed as the reducing gases while maintaining high conversion efficiency. This allows a much wider range of uses and higher level of feed stream contaminants than prior art catalysts.

  2. Role of Sulfur in Cadmium Accumulation of Tagetes erecta L

    Microsoft Academic Search

    Qian Feng; Peidong Tai; Peijun Li; Yanli Guo; Shasha Fu

    2009-01-01

    The role of sulfur in cadmium (Cd) accumulation was investigated in Tagetes erecta L. Shoot Cd concentrations were significantly increased with increasing of sulfur levels in the culture solution. In another experiment, leaf application of sodium sulfate (Na2SO4) or cysteine to sulfur (S)-starved plants significantly increased Cd accumulation in shoots up to three folds or twice that of those S-starved

  3. Regulation of Nitrogen Assimilation by Sulfur in Bean

    Microsoft Academic Search

    Juan M. Ruiz; Rosa M. Rivero; Luis Romero

    2005-01-01

    The objective of the present work was to determine the impact of sulfur(s) deficiency or toxicity on NO3 metabolism in bean plants (Phaseolus vulgaris cv. ‘Strike’). Sulfur was applied to the nutrient solution for 30 d at three dosages: 0 mM (S0), considered deficient; 1.875 mM (S1), considered optimal; and 18.75 mM (S2), considered toxic. The results indicated that the

  4. Effects of sulfur forms on heavy metals bioleaching from contaminated sediments

    Microsoft Academic Search

    D. Fang; L. Zhao; L. X. Zhou; H. X. Shan

    2009-01-01

    The use of recyclable forms of sulfur will exclude the risk of sediment reacidification and reduce the cost of bioleaching process. Three different forms of sulfur (namely sulfur powder, prills and pieces) were used to examine the utilization and recycle of sulfur, used as energy substrate for sulfur-oxidizing bacteria (SOB) in the bioleaching of heavy metal-contaminated sediments. The results showed

  5. Microbial stabilization of sulfur-laden sorbents. [Quarterly] technical report, March 1, 1993May 31, 1993

    Microsoft Academic Search

    1993-01-01

    Clean coal technologies that involve limestone for in situ 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 frequently results in undesirable release of SOâ.

  6. Origins of Sulfur in Coal: Importance of the Ester Sulfate Content of Peat

    Microsoft Academic Search

    Daniel Casagrande; Kristine Siefert

    1977-01-01

    The sulfur found in coal stems in large part from sulfur incorporation at the peat-forming stage. Ester sulfate (a carbon-oxygen-sulfur linkage) is a major contributor to the sulfur in peat and thus is an important determiner of the quantity and forms of sulfur eventually found in coal.

  7. Partial oxidation of sulfur-containing solid carbonaceous fuel

    SciTech Connect

    Najjar, M.S.; Corbeels, R.J.

    1989-01-31

    This patent describes a process for the simultaneous partial oxidation and desulfurization of a sulfur and silicate-containing comminuted solid carbonaceous fuel comprising, basis solid fuel, 0.2 to 6.0 wt. % sulfur and 0.1 to 30 wt. % of silicate compounds including iron silicate. The improvements consist of (1) reacting in the free-flow unobstructed down-flowing vertical refractory lined reaction zone of a partial oxidation gas generator a feed mixture comprising the solid carbonaceous fuel and first and second types of supplemental calcium-containing material with a controlled amount of free-oxygen containing gas and a temperature moderator so that an equilibrium oxygen concentration is provided in the gas phase in the reaction zone with a partial pressure which is less than about 10/sup -9/ atmospheres; (2) cooling and cleaning the hot raw effluent gas mixture from (1) by contacting the effluent gas mixture with a liquid hydrocarbonaceous fuel cooling and scrubbing agent, thereby producing a slurry comprising slag and calcium sulfide in liquid hydrocarbonaceous fuel, (3) steam stripping the slurry and separating a gaseous mixture comprising steam and H/sub 2/S; and (4) recycling the sulfur-depleted slurry to the front end of the process for use in preparation of fresh feed mixture to the partial oxidation gas generator.

  8. Helium Droplets Doped with Sulfur and C60

    PubMed Central

    2014-01-01

    Clusters of sulfur are grown by passing superfluid helium nanodroplets through a pickup cell filled with sulfur vapor. In some experiments the droplets are codoped with C60. The doped droplets are collided with energetic electrons and the abundance distributions of positively and negatively charged cluster ions are recorded. We report, specifically, distributions of Sm+, Sm–, and C60Sm– containing up to 41 sulfur atoms. We also observe complexes of sulfur cluster anions with helium; distributions are presented for HenSm– with n ? 31 and m ? 3. The similarity between anionic and cationic C60Sm± spectra is in striking contrast to the large differences between spectra of Sm+ and Sm–.

  9. Accidental Sulfur Poisoning in a Group of Holstein Heifers

    PubMed Central

    Gunn, Moira F.; Baird, John D.; Wilkie, Judith S. Nimmo

    1987-01-01

    Fourteen animals died or were euthanized after toxic levels of elemental sulfur were accidentally fed to a group of 120 Holstein heifers. Dehydration, rumen stasis, tachycardia, and diarrhea were seen along with metabolic acidosis, hypokalemia, and hypochloremia. The majority of deaths occurred from 3 to 10 days after the sulfur was fed to the heifers. Postmortem examination showed rumenitis, acute alveolitis, and renal tubular necrosis. The toxicity of ingested sulfur was attributed to the conversion of sulfur to hydrogen sulfide in the rumen. ImagesFigure 5.Figure 6.Figure 7.Figure 8.Figure 9.Figure 10. PMID:17422758

  10. Mercury adsorption properties of sulfur-impregnated adsorbents

    USGS Publications Warehouse

    Hsi, N.-C.; Rood, M.J.; Rostam-Abadi, M.; Chen, S.; Chang, R.

    2002-01-01

    Carbonaceous and noncarbonaceous adsorbents were impregnated with elemental sulfur to evaluate the chemical and physical properties of the adsorbents and their equilibrium mercury adsorption capacities. Simulated coal combustion flue gas conditions were used to determine the equilibrium adsorption capacities for Hg0 and HgCl2 gases to better understand how to remove mercury from gas streams generated by coal-fired utility power plants. Sulfur was deposited onto the adsorbents by monolayer surface deposition or volume pore filling. Sulfur impregnation increased the total sulfur content and decreased the total and micropore surface areas and pore volumes for all of the adsorbents tested. Adsorbents with sufficient amounts of active adsorption sites and sufficient microporous structure had mercury adsorption capacities up to 4,509 ??g Hg/g adsorbent. Elemental sulfur, organic sulfur, and sulfate were formed on the adsorbents during sulfur impregnation. Correlations were established with R2>0.92 between the equilibrium Hg0/HgCl2 adsorption capacities and the mass concentrations of elemental and organic sulfur. This result indicates that elemental and organic sulfur are important active adsorption sites for Hg0 and HgCl2.

  11. Sulfur speciation in natural hydrothermal waters, Iceland

    NASA Astrophysics Data System (ADS)

    Kaasalainen, Hanna; Stefánsson, Andri

    2011-05-01

    The speciation of aqueous dissolved sulfur was determined in hydrothermal waters in Iceland. The waters sampled included hot springs, acid-sulfate pools and mud pots, sub-boiling well discharges and two-phase wells. The water temperatures ranged from 4 to 210 °C, the pH T was between 2.20 and 9.30 at the discharge temperature and the SO 4 and Cl concentrations were 0.020-52.7 and <0.01-10.0 mmol kg -1, respectively. The analyses were carried out on-site within ˜10 min of sampling using ion chromatography (IC) for sulfate (SO 42-), thiosulfate (S 2O 32-) and polythionates (S xO 62-) and titration and/or colorimetry for total dissolved sulfide (S 2-). Sulfite (SO 32-) could also be determined in a few cases using IC. Alternatively, for few samples in remote locations the sulfur oxyanions were stabilized on a resin on site following elution and analysis by IC in the laboratory. Dissolved sulfate and with few exceptions also S 2- were detected in all samples with concentrations of 0.02-52.7 mmol kg -1 and <1-4100 ?mol kg -1, respectively. Thiosulfate was detected in 49 samples of the 73 analyzed with concentrations in the range of <1-394 ?mol kg -1 (S-equivalents). Sulfite was detected in few samples with concentrations in the range of <1-3 ?mol kg -1. Thiosulfate and SO 32- were not detected in <100 °C well waters and S 2O 32- was observed only at low concentrations (<1-8 ?mol kg -1) in ˜200 °C well waters. In alkaline and neutral pH hot springs, S 2O 32- was present in significant concentrations sometimes corresponding to up to 23% of total dissolved sulfur (S TOT). In steam-heated acid-sulfate waters, S 2O 32- was not a significant sulfur species. The results demonstrate that S 2O 32- and SO 32- do not occur in the deeper parts of <150 °C hydrothermal systems and only in trace concentrations in ˜200-300 °C systems. Upon ascent to the surface and mixing with oxygenated ground and surface waters and/or dissolution of atmospheric O 2, S 2- is degassed and oxidized to SO 32- and S 2O 32- and eventually to SO 42- at pH >8. In near-neutral hydrothermal waters the oxidation of S 2- and the interaction of S 2- and S 0 resulting in the formation of S x2- are considered important. At lower pH values the reactions seemed to proceed relatively rapidly to SO 42- and the sulfur chemistry of acid-sulfate pools was dominated by SO 42-, which corresponded to >99% of S TOT. The results suggest that the aqueous speciation of sulfur in natural hydrothermal waters is dynamic and both kinetically and source-controlled and cannot be estimated from thermodynamic speciation calculations.

  12. Sonic enhanced ash agglomeration and sulfur capture

    SciTech Connect

    Not Available

    1991-01-01

    The major objective of the Phase 1 test program is to confirm the feasibility of the Manufacturing and Technology Conversion International, Inc. bimodal particle size approach to enhance particulate control by acoustic ash agglomeration. An ancillary objective of the Phase 1 effort is to demonstrate and confirm the feasibility of an acoustic field to enhance sulfur capture by increasing sorbent reactivity. Phase 1 tests are designed to cover the frequency range between 50 and 1400 Hz, establish monomodal baseline performance as a benchmark from which to measure the degree of enhancement expected from the bimodal approach, and, finally, to confirm the effectiveness of low-frequency fields over high-frequency fields for realistic particulate streams. The program will demonstrate the effectiveness of a unique approach which uses a bimodal distribution composed of large sorbent particles and fine fly ash particles to enhance ash agglomeration and sulfur capture at conditions found in direct coal-fired turbines. Under the impact of high-intensity sound waves, sorbent reactivity and utilization, it is theorized, will increase while agglomerates of fly ash and sorbents are formed which are readily collected in commercial cyclones. The work will extend the concept from the demonstration of feasibility (Phase 1), through proof-of-concept (Phase 2) to the construction (Phase 3) of a coal-fired pulsed combustor with in-furnace sorbent injection. For Phase 1, Pennsylvania State University will conduct studies for enhanced sulfur capture in The Combustion Laboratory and agglomeration tests in the High Intensity Acoustic Laboratory. 2 refs., 43 figs., 7 tabs.

  13. Sulfur in Degassing Volcanoes: Thermochemistry and Experiments

    NASA Astrophysics Data System (ADS)

    Wykes, J. L.; Henley, R. W.; King, P. L.

    2014-12-01

    Very high temperature fumaroles unambiguously represent samples of magmatic gas expanding to the surface from sub-volcanic magma bodies. Here we present the results of thermochemical modelling of measured fumarole gas compositions that confirm that magmatic gases are SO2-dominant when redox is controlled by homogeneous gas reactions involving SO2, H2S and other species, i.e. the 'gas buffer'. In subsurface volcanic environments, SO2 also dominates when oxygen fugacity, fO2, is greater than the value imposed by the Ni-NiO buffer; a common situation in arc environments. These results indicate that to understand the systematics of arc magma degassing, it is necessary to investigate how SO2, the principle sulfur gas, reacts directly with magmatic materials. Thermochemical modelling of the interaction between SO2-bearing gas mixtures and common rock-forming minerals such as anorthite and calcite indicates that SO2 spontaneously disproportionates to form anhydrite and a reduced sulfur species. Experimental investigation of these reactions in a gas-mixing tube furnace at 600-800 °C, 1 bar, demonstrates extremely rapid anhydrite formation on the surface of crystalline anorthite through chemisorption. In the presence of H2O, the reduced sulfur species is H2S, which may subsequently react with co-transported metals such as Fe and Cu in the magmatic gas to form metal sulfides. It is proposed that this mechanism provides a straightforward explanation for the massive amounts of coexisting sulfate and sulfide cogenerated at depths of 1 to 4 km inside volcanic systems and now exposed as porphyry copper deposits. Anhydrite dissolution may contribute to the fragility of volcanic structures.

  14. Synthesis of three-dimensionally interconnected sulfur-rich polymers for cathode materials of high-rate lithium-sulfur batteries.

    PubMed

    Kim, Hoon; Lee, Joungphil; Ahn, Hyungmin; Kim, Onnuri; Park, Moon Jeong

    2015-01-01

    Elemental sulfur is one of the most attractive cathode active materials in lithium batteries because of its high theoretical specific capacity. Despite the positive aspect, lithium-sulfur batteries have suffered from severe capacity fading and limited rate capability. Here we report facile large-scale synthesis of a class of organosulfur compounds that could open a new chapter in designing cathode materials to advance lithium-sulfur battery technologies. Porous trithiocyanuric acid crystals are synthesized for use as a soft template, where the ring-opening polymerization of elemental sulfur takes place along the thiol surfaces to create three-dimensionally interconnected sulfur-rich phases. Our lithium-sulfur cells display discharge capacity of 945?mAh?g(-1) after 100 cycles at 0.2?C with high-capacity retention of 92%, as well as lifetimes of 450 cycles. Particularly, the organized amine groups in the crystals increase Li(+)-ion transfer rate, affording a rate performance of 1210, mAh?g(-1) at 0.1?C and 730?mAh?g(-1) at 5?C. PMID:26065407

  15. Sulfur-containing particles emitted by concealed sulfide ore deposits: an unknown source of sulfur-containing particles in the atmosphere

    NASA Astrophysics Data System (ADS)

    Cao, J. J.; Li, Y. K.; Jiang, T.; Hu, G.

    2015-06-01

    Sources of sulfur dioxide, sulfates, and organic sulfur compounds, such as fossil fuels, volcanic eruptions, and animal feeding operations, have attracted considerable attention. In this study, we collected particles carried by geogas flows ascending through soil, geogas flows above the soil that had passed through the soil, and geogas flows ascending through deep faults of concealed sulfide ore deposits, and analysed them using transmission electron microscopy. Numerous crystalline and amorphous sulfur-containing particles or particle aggregations were found in the ascending geogas flows. In addition to S, the particles contained O, Ca, K, Mg, Fe, Na, Pb, Hg, Cu, Zn, As, Ti, Sr, Ba, Si, etc. Such particles are usually a few to several hundred nanometres in diameter with either regular or irregular morphology. The sulfur-containing particles originated from deep-seated weathering or faulting products of concealed sulfide ore deposits. The particles suspended in the ascending geogas flow migrated through faults from deep-seated sources to the atmosphere. This is a previously unknown source of the atmospheric particles. This paper reports, for the first time, the emission of sulfur-containing particles into the atmosphere from concealed sulfide ore deposits. The climatic and ecological influences of these sulfur-containing particles and particle aggregations should be assessed.

  16. Synthesis of three-dimensionally interconnected sulfur-rich polymers for cathode materials of high-rate lithium–sulfur batteries

    PubMed Central

    Kim, Hoon; Lee, Joungphil; Ahn, Hyungmin; Kim, Onnuri; Park, Moon Jeong

    2015-01-01

    Elemental sulfur is one of the most attractive cathode active materials in lithium batteries because of its high theoretical specific capacity. Despite the positive aspect, lithium–sulfur batteries have suffered from severe capacity fading and limited rate capability. Here we report facile large-scale synthesis of a class of organosulfur compounds that could open a new chapter in designing cathode materials to advance lithium–sulfur battery technologies. Porous trithiocyanuric acid crystals are synthesized for use as a soft template, where the ring-opening polymerization of elemental sulfur takes place along the thiol surfaces to create three-dimensionally interconnected sulfur-rich phases. Our lithium–sulfur cells display discharge capacity of 945?mAh?g?1 after 100 cycles at 0.2?C with high-capacity retention of 92%, as well as lifetimes of 450 cycles. Particularly, the organized amine groups in the crystals increase Li+-ion transfer rate, affording a rate performance of 1210, mAh?g?1 at 0.1?C and 730?mAh?g?1 at 5?C. PMID:26065407

  17. Recent trends in the chemistry of sulfur-containing reducing agents

    NASA Astrophysics Data System (ADS)

    Makarov, Sergei V.

    2001-10-01

    Data on the structure, synthesis, stability and reactivity of sulfur-containing reducing agents with C-S or S-S bonds — sodium dithionite, sodium hydroxymethanesulfinate and thiourea oxides — are surveyed. Reactions of anaerobic and aerobic decomposition of sulfur-containing reducing agents are discussed. The applications of these compounds in the studies of non-linear phenomena in chemical kinetics and in guanidine syntheses are considered. The bibliography includes 165 references.

  18. Diatomic sulfur (S/sub 2/)

    SciTech Connect

    Steliou, K.; Salama, P.; Brodeur, D.; Gareau, Y.

    1987-02-04

    Recently, they described a group 14 metal assisted procedure for the preparation and Diels-Alder trapping of S/sub 2/, a highly reactive diatomic form of elemental sulfur. Their continuing efforts in this area have led us to develop an alternate synthetic method that affords this reactive dienophile by, to their knowledge, an unprecedented intramolecular carbon-carbon bond-forming reaction. The ability to generate S/sub 2/ conveniently, and at temperatures more conductive to Diels-Alder trapping, makes it synthetically attractive to use. The present procedure should therefore, find widespread application in the synthesis of 1,2-dithiins.

  19. Zirconium in a sulfuric acid pickling application

    SciTech Connect

    Yau, T.L.

    1988-01-01

    In 1972, Goodyear discovered that zirconium was an ideal material to construct heating coils for sulfuric acid picking tanks. Recently, localized corrosion and high uniform corrosion were reported with certain zirconium coils. The problems could be attributed to the contamination of chloride and/or fluoride ions. Results of electrochemical and immersion tests are used to discuss the effects of acid concentration and acid impurities, such as iron, chloride and fluoride ions, on zirconium's corrosion properties in H/sub 2/SO/sub 4/. Possible sources for acid impurities are identified. Recommendations are made for steel picking when zirconium equipment is used.

  20. Status of sulfur oxides control technology

    SciTech Connect

    Sedman, C.B.; Gooch, J.P.

    1996-12-31

    The paper discusses the status of sulfur oxides (SOx) control technology, as outlined at the 1995 SOx Control Symposium. The status of key commercial-scale flue gas desulfurization (FGD) applications in the U.S., Japan, and Europe was documented, with emphasis on wet limestone scrubbing. Dry FGD, furnace sorbent injection, and combined SOx/nitrogen oxides (NOx) applications were also described. Special sessions were devoted to FGD materials, component selection, chemical additives, and chemistry. Research programs to improve existing concepts and develop new approaches were described. The paper summarizes highlights of the papers and presentations which have implications toward the Eastern European market for SOx control.

  1. Sulfur speciation in natural hydrothermal waters, Iceland

    Microsoft Academic Search

    Hanna Kaasalainen; Andri Stefánsson

    2011-01-01

    The speciation of aqueous dissolved sulfur was determined in hydrothermal waters in Iceland. The waters sampled included hot springs, acid-sulfate pools and mud pots, sub-boiling well discharges and two-phase wells. The water temperatures ranged from 4 to 210°C, the pHT was between 2.20 and 9.30 at the discharge temperature and the SO4 and Cl concentrations were 0.020–52.7 and <0.01–10.0mmolkg?1, respectively.

  2. Sulfur-containing catalysts for water electrolysis

    SciTech Connect

    Burshtein, R.Kh.; Kazarinov, V.E.; Pshenichnikov, A.G.; Barbasheva, I.E.; Gafarova, O.A.; Obrushnikova, I.V.

    1987-11-01

    A catalyst which is made by reaction of nickel and cobalt salts with sodium dithionite has been developed in order to obtain active electrodes for water electrolysis. In acidic solutions of pH between 2.7 and 4.0 the dithionite decomposes to sulfur, hydrogen sulfide, and sulfite. This reaction was used by us to activate electrodes in the presence of nickel and cobalt salts. The electrodes obtained were used in alkaline water electrolysis, both as cathodes and as anodes. The tests were performed in 6 N KOH at a temperature of 70/sup 0/C. The potentials were measured relative to a mercury-mercuric oxide reference electrode.

  3. Sulfur removal and comminution of carbonaceous material

    DOEpatents

    Narain, N.K.; Ruether, J.A.; Smith, D.N.

    1987-10-07

    Finely divided, clean coal or other carbonaceous material is provided by forming a slurry of coarse coal in aqueous alkali solution and heating the slurry under pressure to above the critical conditions of steam. The supercritical fluid penetrates and is trapped in the porosity of the coal as it swells in a thermoplastic condition at elevated temperature. By a sudden, explosive release of pressure the coal is fractured into finely divided particles with release of sulfur-containing gases and minerals. The finely divided coal is recovered from the minerals for use as a clean coal product. 2 figs.

  4. Sulfur removal and comminution of carbonaceous material

    DOEpatents

    Narain, Nand K. (Bethel Park, PA); Ruether, John A. (McMurray, PA); Smith, Dennis N. (Herminie, PA)

    1988-01-01

    Finely divided, clean coal or other carbonaceous material is provided by forming a slurry of coarse coal in aqueous alkali solution and heating the slurry under pressure to above the critical conditions of steam. The supercritical fluid penetrates and is trapped in the porosity of the coal as it swells in a thermoplastic condition at elevated temperature. By a sudden, explosive release of pressure the coal is fractured into finely divided particles with release of sulfur-containing gases and minerals. The finely divided coal is recovered from the minerals for use as a clean coal product.

  5. SYNTHESIS OF SULFUR-BASED WATER TREATMENT AGENT FROM SULFUR DIOXIDE WASTE STREAMS

    SciTech Connect

    Robert C. Brown; Maohong Fan

    2001-12-01

    We propose a process that uses sulfur dioxide from coal combustion as a raw material to synthesize polymeric ferric sulfate (PFS), a water treatment agent. The process uses sodium chlorate as an oxidant and ferrous sulfate as an absorbent. The major chemical mechanisms in this reaction system include oxidation, hydrolysis, and polymerization. Oxidation determines sulfur conversion efficiency while hydrolysis and polymerization control the quality of product. Many factors, including SO{sub 2} inlet concentration, flow rate of simulated flue gas, reaction temperature, addition rate of oxidant and stirring rate, may affect the efficiencies of SO{sub 2} removal. Currently, the effects of SO{sub 2} inlet concentration, the flow rate of simulated flue gas and addition rate of flue gas on removal efficiencies of SO{sub 2}, are being investigated. Experiments shown in this report have demonstrated that the conversion efficiencies of sulfur dioxide with ferrous sulfate as an absorbent are in the range of 60-80% under the adopted process conditions. However, the conversion efficiency of sulfur dioxide may be improved by optimizing reaction conditions to be investigated. Partial quality indices of the synthesized products, including Fe{sup 2+} concentration and total iron concentration, have been evaluated.

  6. ACCUMULATION OF ATMOSPHERIC SULFUR BY PLANTS AND SULFUR-SUPPLYING CAPACITY OF SOILS

    EPA Science Inventory

    The Tennessee Valley Authority conducted studies to measure the amount of sulfur (S) that is transferred from the atmosphere to agro-ecosystems and to determine the S-supplying capacity of soils in the Tennessee Valley. Three techniques were tested for determining the fractional ...

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

    SciTech Connect

    NONE

    1997-06-01

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

  8. Toxicologic Appraisal of Particulate Matter, Oxides of Sulfur, and Sulfuric Acid

    Microsoft Academic Search

    Mary O. Amdur

    1969-01-01

    An examination of the available toxicological literature indicates that sulfur dioxide itself would be properly classified as a mild respiratory irritant, the main portion of which is absorbed in the upper respiratory tract. The reported industrial experience of symptoms of mild chronic respiratory irritation from exposures at or above 5 ppm is compatible with what would have been predicted on

  9. The influence of bottom water oxygenation and reactive iron content on sulfur incorporation into bitumens from Jurassic marine shales

    SciTech Connect

    Raiswell, R.; Bottrell, S.H.; Al-Biatty, H.J.; Tan, M.MD. (Leeds Univ. (United Kingdom))

    1993-06-01

    Sulfur isotope studies of bitumens (dichloromethane- extractable) from jurassic marine shales indicate that most sulfur is derived, at least initially, from diagenetic sulfate reduction. Under euxinic or semi-euxinic conditions sulfur incorporation in the Jet Rock and Posidonienschiefer bitumens appears to post-date formation of most reactive syngenetic pyrite but occurs contemporaneously with the formation small concentrations of later pyrite, relatively depleted in [sup 32]S. The most reactive iron minerals were mainly pyritized before any significant incorporation of sulfur occurred, and subsequent solidification reactions only occurred in response to prolonged contact between dissolved sulfide and residual, poorly reactive iron minerals (forming in the later pyrite) and organic matter (incorporating sulfur into bitumen). In these circumstances, which are typical of most euxinic or semi-euxinic sediments, the abundance of reactive iron is not the main control on the incorporation of sulfur (0.8 wt percent in the Jet Rock, 1.5 wt percent in the Posidonienschiefer) into bitumen. Consistent with this, variable concentrations of bitumen S occur in the Alum Shales (2.48 and 0.86 wt percent) which have uniform reactive iron contents. In the Alum Shales, the weakly bioturbated and more oxygenated depositional environments appear to favor sulfur incorporation into bitumens, which may occur here via partially oxidized sulfur species. Bitumen compositions suggest that oxygen is eliminated as sulfur is incorporated, possibly due to the dehydration of polar compounds followed by nucleophilic addition of sulfur. 64 refs., 6 figs., 4 tabs.

  10. Sulfur Distribution in Bacteriorhodopsin from Multiple Wavelength Anomalous Diffraction Near the Sulfur KEdge with Synchrotron X-Ray Radiation

    Microsoft Academic Search

    Wolfgang Behrens; Harald Otto; Heinrich B. Stuhrmann; Maarten P. Heyn

    1998-01-01

    Bacteriorhodopsin contains nine sulfur atoms from the nine methionine residues. The distribution of these sulfur atoms in the projected density map was determined from x-ray diffraction experiments using multiple wavelength anomalous diffraction (MAD) at the sulfur K-edge (5.02Å) with synchrotron radiation. The experiments were performed with uniaxial samples of oriented purple membranes at room temperature and 86% relative humidity. For

  11. A comparative study of leaching kinetics of limonitic laterite and synthetic iron oxides in sulfuric acid containing sulfur dioxide

    Microsoft Academic Search

    G Senanayake; G. K Das

    2004-01-01

    Limonitic laterite ore of particle size 90–125 ?m containing goethite, magnetite and hematite was leached for 6 h at a pulp density of 10% (wt\\/vol) in sulfuric acid in the absence or presence of sulfur dioxide at atmospheric pressure and 90 °C in a glass reactor vessel. The sulfur dioxide flow rate was kept at 0.6 L min?1 L?1 of

  12. Synthesis and structures of cadmium carboxylate and thiocarboxylate compounds with a sulfur-rich coordination environment: carboxylate exchange kinetics involving tris(2-mercapto-1-t-butylimidazolyl)hydroborato cadmium complexes, [Tm(Bu(t))]Cd(O2CR).

    PubMed

    Kreider-Mueller, Ava; Quinlivan, Patrick J; Owen, Jonathan S; Parkin, Gerard

    2015-04-20

    A series of cadmium carboxylate compounds in a sulfur-rich environment provided by the tris(2-tert-butylmercaptoimidazolyl)hydroborato ligand, namely, [Tm(Bu(t))]CdO2CR, has been synthesized via the reactions of the cadmium methyl derivative [Tm(Bu(t))]CdMe with RCO2H. Such compounds mimic aspects of cadmium-substituted zinc enzymes and also the surface atoms of cadmium chalcogenide crystals, and have therefore been employed to model relevant ligand exchange processes. Significantly, both (1)H and (19)F NMR spectroscopy demonstrate that the exchange of carboxylate groups between [Tm(Bu(t))]Cd(?(2)-O2CR) and the carboxylic acid RCO2H is facile on the NMR time scale, even at low temperature. Analysis of the rate of exchange as a function of concentration of RCO2H indicates that reaction occurs via an associative rather than dissociative pathway. In addition to carboxylate compounds, the thiocarboxylate derivative [Tm(Bu(t))]Cd[?(1)-SC(O)Ph] has also been synthesized via the reaction of [Tm(Bu(t))]CdMe with thiobenzoic acid. The molecular structure of [Tm(Bu(t))]Cd[?(1)-SC(O)Ph] has been determined by X-ray diffraction, and an interesting feature is that, in contrast to the carboxylate derivatives [Tm(Bu(t))]Cd(?(2)-O2CR), the thiocarboxylate ligand binds in a ?(1) manner via only the sulfur atom. PMID:25826184

  13. Cysteine Is Not the Sulfur Source for Iron-Sulfur Cluster and Methionine Biosynthesis in the Methanogenic Archaeon Methanococcus maripaludis*

    PubMed Central

    Liu, Yuchen; Sieprawska-Lupa, Magdalena; Whitman, William B.; White, Robert H.

    2010-01-01

    Three multiprotein systems are known for iron-sulfur (Fe-S) cluster biogenesis in prokaryotes and eukaryotes as follows: the NIF (nitrogen fixation), the ISC (iron-sulfur cluster), and the SUF (mobilization of sulfur) systems. In all three, cysteine is the physiological sulfur source, and the sulfur is transferred from cysteine desulfurase through a persulfidic intermediate to a scaffold protein. However, the biochemical nature of the sulfur source for Fe-S cluster assembly in archaea is unknown, and many archaea lack homologs of cysteine desulfurases. Methanococcus maripaludis is a methanogenic archaeon that contains a high amount of protein-bound Fe-S clusters (45 nmol/mg protein). Cysteine in this archaeon is synthesized primarily via the tRNA-dependent SepRS/SepCysS pathway. When a ?sepS mutant (a cysteine auxotroph) was grown with 34S-labeled sulfide and unlabeled cysteine, <8% of the cysteine, >92% of the methionine, and >87% of the sulfur in the Fe-S clusters in proteins were labeled, suggesting that the sulfur in methionine and Fe-S clusters was derived predominantly from exogenous sulfide instead of cysteine. Therefore, this investigation challenges the concept that cysteine is always the sulfur source for Fe-S cluster biosynthesis in vivo and suggests that Fe-S clusters are derived from sulfide in those organisms, which live in sulfide-rich habitats. PMID:20709756

  14. Photon and Water Mediated Sulfur Oxide and Acid Chemistry in the Atmosphere of Venus

    NASA Astrophysics Data System (ADS)

    Kroll, Jay A.; Vaida, Veronica

    2014-06-01

    Sulfur compounds have been observed in the atmospheres of a number of planetary bodies in our solar system including Venus, Earth, Mars, Io, Europa, and Callisto. The global cloud cover on Venus located at an altitude between 50 and 80 kilometers is composed primarily of sulfuric acid (H_2SO_4) and water. Planetary photochemical models have attempted to explain observations of sulfuric acid and sulfur oxides with significant discrepancies remaining between models and observation. In particular, high SO_2 mixing ratios are observed above 90 km which exceed model predictions by orders of magnitude. Work recently done in the Vaida lab has shown red light can drive photochemistry through overtone pumping for acids like H_2SO_4 and has been successful in explaining much of the sulfur chemistry in Earth's atmosphere. Water can have a number of interesting effects such as catalysis, suppression, and anti-catalysis of thermal and photochemical processes. We investigate the role of water complexes in the hydration of sulfur oxides and dehydration of sulfur acids and present spectroscopic studies to document such effects. We investigate these reactions using FTIR and UV/Vis spectroscopy and will report on our findings.

  15. Total sulfate vs. sulfuric acid monomer concenterations in nucleation studies

    NASA Astrophysics Data System (ADS)

    Neitola, K.; Brus, D.; Makkonen, U.; Sipilä, M.; Mauldin, R. L., III; Sarnela, N.; Jokinen, T.; Lihavainen, H.; Kulmala, M.

    2015-03-01

    Sulfuric acid is known to be a key component for atmospheric nucleation. Precise determination of sulfuric-acid concentration is a crucial factor for prediction of nucleation rates and subsequent growth. In our study, we have noticed a substantial discrepancy between sulfuric-acid monomer concentrations and total-sulfate concentrations measured from the same source of sulfuric-acid vapor. The discrepancy of about 1-2 orders of magnitude was found with similar particle-formation rates. To investigate this discrepancy, and its effect on nucleation, a method of thermally controlled saturator filled with pure sulfuric acid (97% wt.) for production of sulfuric-acid vapor is applied and rigorously tested. The saturator provided an independent vapor-production method, compared to our previous method of the furnace (Brus et al., 2010, 2011), to find out if the discrepancy is caused by the production method itself. The saturator was used in a H2SO4-H2O nucleation experiment, using a laminar flow tube to check reproducibility of the nucleation results with the saturator method, compared to the furnace. Two independent methods of mass spectrometry and online ion chromatography were used for detecting sulfuric-acid or sulfate concentrations. Measured sulfuric-acid or total-sulfate concentrations are compared to theoretical predictions calculated using vapor pressure and a mixing law. The calculated prediction of sulfuric-acid concentrations agrees very well with the measured values when total sulfate is considered. Sulfuric-acid monomer concentration was found to be about 2 orders of magnitude lower than theoretical predictions, but with a temperature dependency similar to the predictions and the results obtained with the ion-chromatograph method. Formation rates are reproducible when compared to our previous results with both sulfuric-acid or total-sulfate detection and sulfuric-acid production methods separately, removing any doubts that the vapor-production method would cause the discrepancy. Possible reasons for the discrepancy are discussed and some suggestions include that the missing sulfuric acid is in clusters, formed with contaminants found in most laboratory experiments. One-to-two-order-of-magnitude higher sulfuric-acid concentrations (measured as total sulfate in this study) would contribute to a higher fraction of particle growth rate than assumed from the measurements by mass spectrometers (i.e. sulfuric-acid monomer). However, the observed growth rates by sulfate-containing vapor in this study does not directly imply a similar situation in the field, where sources of sulfate are much more diverse.

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

    SciTech Connect

    Vasilije Manovic; Borislav Grubor [University of Belgrade, Belgrade (Serbia & Montenegro)

    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.

  17. A comparison of the UCB sulfur recovery process with conventional sulfur recovery technology for treating recycle gas from a crude oil residuum hydrotreater

    Microsoft Academic Search

    S. Lynn; D. W. Neumann; S. F. Sciamanna; F. H. Vorhis

    1986-01-01

    The University of California, Berkeley, Sulfur Recovery Process (UCBSRP) is being developed as an alternative to conventional sulfur recovery technology for removing hydrogen sulfide from gas streams and converting it to elemental sulfur. In the UCBSRP the hydrogen sulfide is absorbed by a physical solvent and the resulting solution of HâS is mixed with a stoichiometrically equivalent amount of sulfur

  18. Structural insight into the mode of interactions of SoxL from Allochromatium vinosum in the global sulfur oxidation cycle.

    PubMed

    Bagchi, Angshuman

    2012-12-01

    Microbial redox reactions of inorganic sulfur compounds are one of the important reactions for the recycling of sulfur to maintain the environmental sulfur balance. These reactions are carried out by phylogenetically diverse microorganisms. The sulfur oxidizing gene cluster (sox) of ?-proteobacteria, Allochromatium vinosum comprises two divergently transcribed units. The central players of this process are SoxY, SoxZ and SoxL. SoxY is sulfur compound binder which binds to sulfur anions with the help of SoxZ. SoxL is a rhodanese like protein, which then cleaves off the sulfur substrate from the SoxYZ complex to recycle the SoxY and SoxZ. In the present work, homology modeling has been employed to build the three dimensional structures of SoxY, SoxZ and SoxL. With the help of docking simulations the amino acid residues of these proteins involved in the interactions have been identified. The interactions between the SoxY, SoxZ and SoxL proteins are mediated mainly through hydrogen bonding. Strong positive fields created by the SoxZ and SoxL proteins are found to be responsible for the binding and removal of the sulfur anion. The probable biochemical mechanism of sulfur anion oxidation process has been identified. PMID:23053932

  19. Sulfur Mustard Toxicity Following Dermal Exposure

    PubMed Central

    Paromov, Victor; Suntres, Zacharias; Smith, Milton; Stone, William L.

    2007-01-01

    Objective: Sulfur mustard (bis-2-(chloroethyl) sulfide) is a chemical warfare agent (military code: HD) causing extensive skin injury. The mechanisms underlying HD-induced skin damage are not fully elucidated. This review will critically evaluate the evidence showing that oxidative stress is an important factor in HD skin toxicity. Oxidative stress results when the production of reactive oxygen (ROS) and/or reactive nitrogen oxide species (RNOS) exceeds the capacity of antioxidant defense mechanisms. Methods: This review will discuss the role of oxidative stress in the pathophysiology of HD skin toxicity in both in vivo and in vitro model systems with emphasis on the limitations of the various model systems. Evidence supporting the therapeutic potential of antioxidants and antioxidant liposomes will be evaluated. Antioxidant liposomes are effective vehicles for delivering both lipophilic (incorporated into the lipid bilayers) and water-soluble (encapsulated in the aqueous inner-spaces) antioxidants to skin. The molecular mechanisms interconnecting oxidative stress to HD skin toxicity are also detailed. Results: DNA repair and inflammation, in association with oxidative stress, induce intracellular events leading to apoptosis or to a programmable form of necrosis. The free radical, nitric oxide (NO), is of considerable interest with respect to the mechanisms of HD toxicity. NO signaling pathways are important in modulating inflammation, cell death, and wound healing in skin cells. Conclusions: Potential future directions are summarized with emphasis on a systems biology approach to studying sulfur mustard toxicity to skin as well as the newly emerging area of redox proteomics. PMID:18091984

  20. 40 CFR 721.7770 - Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...sulfuric acid ester, substituted amine salt. 721.7770 Section 721.7770 ...sulfuric acid ester, substituted amine salt. (a) Chemical substance and significant...sulfuric acid ester, substituted amine salt (PMN P-92-396) is subject to...

  1. 40 CFR 721.7770 - Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...sulfuric acid ester, substituted amine salt. 721.7770 Section 721.7770 ...sulfuric acid ester, substituted amine salt. (a) Chemical substance and significant...sulfuric acid ester, substituted amine salt (PMN P-92-396) is subject to...

  2. Using ISC & GIS to predict sulfur deposition from coal-fired power plants 

    E-print Network

    Lopez, Jose Ignacio

    1993-01-01

    The goal of this research project was to determine if atmospheric sources have the potential of contributing significantly to the sulfur content of grazed forage. Sulfur deposition resulting from sulfur dioxide emissions from coal- fired power...

  3. 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, the equilibrium isotopic fractionation of sulfur during adsorption is investigated using a similar 1-dimensional-independent isotopic fractionation Adsorption Sulfur Morse potential Adsorption processes of gaseous molecules

  4. Using ISC & GIS to predict sulfur deposition from coal-fired power plants

    E-print Network

    Lopez, Jose Ignacio

    1993-01-01

    The goal of this research project was to determine if atmospheric sources have the potential of contributing significantly to the sulfur content of grazed forage. Sulfur deposition resulting from sulfur dioxide emissions from coal- fired power...

  5. 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.

  6. Effect of Environmental Factors on Sulfur Gas Emissions from Drywall

    SciTech Connect

    Maddalena, Randy

    2011-08-20

    Problem drywall installed in U.S. homes is suspected of being a source of odorous and potentially corrosive indoor pollutants. The U.S. Consumer Product Safety Commission's (CPSC) investigation of problem drywall incorporates three parallel tracks: (1) evaluating the relationship between the drywall and reported health symptoms; (2) evaluating the relationship between the drywall and electrical and fire safety issues in affected homes; and (3) tracing the origin and the distribution of the drywall. To assess the potential impact on human health and to support testing for electrical and fire safety, the CPSC has initiated a series of laboratory tests that provide elemental characterization of drywall, characterization of chemical emissions, and in-home air sampling. The chemical emission testing was conducted at Lawrence Berkeley National Laboratory (LBNL). The LBNL study consisted of two phases. In Phase 1 of this study, LBNL tested thirty drywall samples provided by CPSC and reported standard emission factors for volatile organic compounds (VOCs), aldehydes, reactive sulfur gases (RSGs) and volatile sulfur compounds (VSCs). The standard emission factors were determined using small (10.75 liter) dynamic test chambers housed in a constant temperature environmental chamber. The tests were all run at 25 C, 50% relative humidity (RH) and with an area-specific ventilation rate of {approx}1.5 cubic meters per square meter of emitting surface per hour [m{sup 3}/m{sup 2}/h]. The thirty samples that were tested in Phase 1 included seventeen that were manufactured in China in 2005, 2006 and 2009, and thirteen that were manufactured in North America in 2009. The measured emission factors for VOCs and aldehydes were generally low and did not differ significantly between the Chinese and North American drywall. Eight of the samples tested had elevated emissions of volatile sulfur-containing compounds with total RSG emission factors between 32 and 258 micrograms per square meter per hour [{micro}g/m{sup 2}/h]. The dominant sulfur containing compounds in the RSG emission stream were hydrogen sulfide with emission factors between 17-201 {micro}g/m{sup 2}/h, and sulfur dioxide with emission factors between 8-64 {micro}g/m{sup 2}/h. The four highest emitting samples also had a unique signature of VSC emissions including > 40 higher molecular weight sulfur-containing compounds although the emission rate for the VSCs was several orders of magnitude lower than that of the RSGs. All of the high emitting drywall samples were manufactured in China in 2005-2006. Results from Phase 1 provided baseline emission factors for drywall samples manufactured in China and in North America but the results exclude variations in environmental conditions that may exist in homes or other built structures, including various combinations of temperature, RH, ventilation rate and the influence of coatings such as texture and paints. The objective of Phase 2 was to quantify the effect of temperature and RH on the RSG emission factors for uncoated drywall, and to measure the effect of plaster and paint coatings on RSG emission factors from drywall. Additional experiments were also performed to assess the influence of ventilation rate on measured emission factors for drywall.

  7. The structure of the first stable monosubstituted sulfur diimide.

    PubMed

    Jones, Ray

    2015-06-01

    The title compound, 4-(4-methylphenyl)-1,3-diaza-2,4-dithiabuta-1,2-diene, C7H8N2S2, was the first example of a stable monosubstituted sulfur diimide to be documented [Jones (1988). PhD thesis, Imperial College, University of London, England]. Although a partial description of this structure was published previously, the full details are presented here. This allows a detailed comparison against the only other example of this system published to date, highlighting differences in bonding, conformation and packing. PMID:26044326

  8. Synthesis of sulfur-35-labeled glycyrrhizic acid glycopeptide with methionine

    SciTech Connect

    Baltina, L.A.; Kondratenko, R.M.; Kuvatov, Yu.G.; Murinov, Yu.I.; Tolstikov, G.A.

    1988-11-01

    To carry out pharmacokinetic investigations, we prepared sulfur-35-labeled protected glycyrrhizic acid glycopeptide with methionine by the reaction of pentaacetylglycyrrhizic trichloride with a small excess of (/sup 35/S)-methionine methyl ester hydrochloride. Melting points were determined on a Boetius microscopic stage. The IR spectra were recorded with a UR-20 spectrograph in mineral oil. The UV spectra were measured with a Specord UV-vis spectrophotometer in ethanol. The specific rotation was determined with a Perkin-Elmer 141 M polarimeter in a 1-dm-long tube. The radioactivity of the /sup 35/S-labeled compounds was measured by a scintillation method with an Izokan-300 counter.

  9. Influence of sulfur and cadmium on antioxidants, phytochelatins and growth in Indian mustard.

    PubMed

    Bashir, Humayra; Ibrahim, Mohamed M; Bagheri, Rita; Ahmad, Javed; Arif, Ibrahim A; Baig, M Affan; Qureshi, M Irfan

    2015-01-01

    Soils in many parts of the world are contaminated with heavy metals, leading to multiple, deleterious effects on plants and threats to world food production efficiency. Cadmium (Cd) is one such metal, being toxic at relatively low concentrations as it is readily absorbed and translocated in plants. Sulfur-rich compounds are critical to the impact of Cd toxicity, enabling plants to increase their cellular defence and/or sequester Cd into vacuoles mediated by phytochelatins (PCs). The influence of sulfur on Cd-induced stress was studied in the hyperaccumulator plant Indian mustard (Brassica juncea) using two sulfur concentrations (+S, 300 µM [Formula: see text] and S-deficient -S, [Formula: see text]) with and without the addition of Cd (100 µM CdCl2) at two different time intervals (7 and 14 days after treatment). Compared with control plants (+S/-Cd), levels of oxidative stress were higher in S-deficient (-S/-Cd) plants, and greatest in S-deficient Cd-treated (-S/+Cd) plants. However, additional S (+S/+Cd) helped plants cope with oxidative stress. Superoxide dismutase emerged as a key player against Cd stress under both -S and +S conditions. The activity of ascorbate peroxidase, glutathione reductase and catalase declined in Cd-treated and S-deficient plants, but was up-regulated in the presence of sulfur. Sulfur deficiency mediated a decrease in ascorbate and glutathione (GSH) content but changes in ascorbate (reduced : oxidized) and GSH (reduced : oxidized) ratios were alleviated by sulfur. Our data clearly indicate that a sulfur pool is needed for synthesis of GSH, non-protein thiols and PCs and is also important for growth. Sulfur-based defence mechanisms and the cellular antioxidant pathway, which are critical for tolerance and growth, collapsed as a result of a decline in the sulfur pool. PMID:25587194

  10. Sodium sulfur container with chromium/chromium oxide coating

    DOEpatents

    Ludwig, Frank A. (Irvine, CA); Higley, Lin R. (Santa Ana, CA)

    1981-01-01

    A coating of chromium/chromium oxide is disclosed for coating the surfaces of electrically conducting components of a sodium sulfur battery. This chromium/chromium oxide coating is placed on the surfaces of the electrically conducting components of the battery which are in contact with molten polysulfide and sulfur reactants during battery operation.

  11. Solubility of HCL in sulfuric acid at stratospheric temperatures

    SciTech Connect

    Williams, L.R.; Golden, D.M.

    1993-10-22

    The solubility of HCl in sulfuric acid was measured using a Knudsen cell technique. Effective Henry's law constants are reported for sulfuric acid concentrations between 50 and 60 weight percent and for temperatures between 220 and 230 K. The measured values indicate that very little HCl will be dissolved in the stratospheric sulfate aerosol particles.

  12. Sulfur-induced greenhouse warming on early Mars

    Microsoft Academic Search

    Sarah Stewart Johnson; Michael A. Mischna; Timothy L. Grove; Maria T. Zuber

    2008-01-01

    Mineralogical, geological, geophysical, and isotopic data recently returned from Mars suggest that the delivery of sulfur gases to the atmosphere may have played a significant role in the planet's early evolution. Using the Gusev Crater basalt composition and a batch melting model, we obtain a high sulfur solubility, approximately 1400 ppm, in Martian mantle melts. We proceed to explore different

  13. Sulfur dioxide initiates global climate change in four ways

    Microsoft Academic Search

    Peter L. Ward

    2009-01-01

    Global climate change, prior to the 20th century, appears to have been initiated primarily by major changes in volcanic activity. Sulfur dioxide (SO2) is the most voluminous chemically active gas emitted by volcanoes and is readily oxidized to sulfuric acid normally within weeks. But trace amounts of SO2 exert significant influence on climate. All major historic volcanic eruptions have formed

  14. Method of desulfurizing and deodorizing sulfur bearing hydrocarbon feedstocks

    SciTech Connect

    Kutty, K.K.; James, V.A.

    1988-11-22

    This patent describes a process for producing a substantially sulfur-free liquid hydrocarbon having a boiling range of about 150/sup 0/-200/sup 0/C, an aromatic content between about 15-18 percent by weight, and a flash point of 38/sup 0/-43/sup 0/C, from sulfur-bearing hydrocarbon liquid boiling in the kerosene range, which comprises the steps of: (a) contacting the sulfur-bearing liquid hydrocarbon with sodium hydride in an amount ranging from about 0.01 to about 5 percent by weight based on the weight of the sulfur-bearing liquid hydrocarbon, in the liquid phase and in a hydrogen free environment at normal atmospheric pressure, and heating the mixture to boiling to form an insoluble sulfide sludge and a hydrocarbon liquid having a reduced sulfur content; (b) distilling the hydrocarbon liquid formed in step (a) and collecting a fraction boiling in the range of about 150/sup 0/-200/sup 0/C; (c) contacting the hydrocarbon fraction from step (b) with sulfuric acid and permitting the mixture of the hydrocarbon and the acid to separate into an acid fraction and hydrocarbon fraction, the contacting being conducted at normal atmospheric pressure; (d) contacting the hydrocarbon fraction from step (c) sequentially with an alkaline oxidizing agent, a strong alkaline neutralizing agent, and a hot wash water to form a substantially sulfur-free hydrocarbon fraction and an aqueous fraction; and, (e) recovering the sulfur-free hydrocarbon fraction.

  15. Arsenite Elicits Anomalous Sulfur Starvation Responses in Barley1[W

    PubMed Central

    Reid, Rob; Gridley, Kate; Kawamata, Yuta; Zhu, Yongguan

    2013-01-01

    Treatment of barley (Hordeum vulgare) seedlings with arsenite (AsIII) rapidly induced physiological and transcriptional changes characteristic of sulfur deficiency, even in plants replete with sulfur. AsIII and sulfur deficiency induced 5- to 20-fold increases in the three genes responsible for sulfate reduction. Both treatments also caused up-regulation of a sulfate transporter, but only in the case of sulfur deficiency was there an increase in sulfate influx. Longer-term changes included reduction in transfer of sulfur from roots to shoots and an increase in root growth relative to shoot growth. Genes involved in complexation and compartmentation of arsenic were up-regulated by AsIII, but not by sulfur deficiency. The rate at which arsenic accumulated appeared to be controlled by the rate of thiol synthesis. Over a range of AsIII concentrations and growth periods, the ratio of thiols to arsenic was always close to 3:1, which is consistent with the formation of a stable complex between three glutathione molecules per AsIII. The greater toxicity of arsenic under sulfur-limiting conditions is likely to be due to an intensification of sulfur deficiency as a result of thiol synthesis, rather than to a direct toxicity to metabolism. Because influx of AsIII was nearly 20-fold faster than the rate of synthesis of thiols, it is questionable whether this complexation strategy can be effective in preventing arsenic toxicity, unless arsenic uptake becomes limited by diffusive resistances in the rhizosphere. PMID:23482871

  16. COMPARISON OF AUTOMATED AND MANUAL SULFURIC ACID SAMPLING SYSTEMS

    EPA Science Inventory

    The purpose of this program was to evaluate the performance of three sulfuric acid vapor sampling systems consisting of (1) a commercially available continuous monitor (SSL) manufactured by Severn Science Limited of Great Britain, (2) an automated prototype sulfuric acid mist mon...

  17. RESISTANCE OF FLY ASH BASED GEOPOLYMER MORTARS IN SULFURIC ACID

    Microsoft Academic Search

    Suresh Thokchom; Partha Ghosh; Somnath Ghosh

    The present paper reports the experimental results of a study conducted to assess the resistance of fly ash based Geopolymer mortar specimens in sulfuric acid. The program consisted immersion of geopolymer mortar samples having percentage Na2O ranging from 5% to 8% of fly ash in a 10% Sulfuric acid solution up to a period of 18 weeks and evaluation of

  18. EMISSIONS OF SULFUR TRIOXIDE FROM COAL-FIRED POWER PLANTS

    EPA Science Inventory

    Emissions of sulfur trioxide (SO3) are a key component of plume opacity and acid deposition. Consequently, these emissions need to be low enough not to cause opacity violations and acid deposition. Generally, a small fraction of sulfur in coal is converted to SO3 in coal-fired co...

  19. Solubility of HCL in sulfuric acid at stratospheric temperatures

    NASA Technical Reports Server (NTRS)

    Williams, Leah R.; Golden, David M.

    1993-01-01

    The solubility of HCl in sulfuric acid was measured using a Knudsen cell technique. Effective Henry's law constants are reported for sulfuric acid concentrations between 50 and 60 weight percent and for temperatures between 220 and 230 K. The measured values indicate that very little HCl will be dissolved in the stratospheric sulfate aerosol particles.

  20. Sulfuric acid deposition from stratospheric geoengineering with sulfate aerosols

    E-print Network

    Robock, Alan

    aerosols can potentially result in an increase in acid deposition. [4] Acid rain has been studiedSulfuric acid deposition from stratospheric geoengineering with sulfate aerosols Ben Kravitz,1 Alan limit of hydration of all sulfate aerosols into sulfuric acid. For annual injection of 5 Tg of SO2

  1. Pressure leaching of synthetic zinc silicate in sulfuric acid medium

    Microsoft Academic Search

    Shanming He; Jikun Wang; Jiangfeng Yan

    2011-01-01

    The pressure leaching of synthetic zinc silicate is studied in the present paper. Five key parameters were explored, namely, sulfuric acid concentration, the final pH of leaching pulp, leaching temperature, water content and iron addition. The experimental results obtained show that sulfuric acid concentration, the final pH, iron addition, water content and leaching temperature have significant effect on the leaching

  2. 40 CFR 52.2033 - Control strategy: Sulfur oxides.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Control strategy: Sulfur oxides. 52.2033 Section 52.2033...Pennsylvania § 52.2033 Control strategy: Sulfur oxides. (a) The revision to... Date of submittal Clairton Coke and Coal Works (U.S. Steel) Allegheny...

  3. Paleoenvironments and Distribution of Low-Sulfur Coal in Illinois

    Microsoft Academic Search

    Colin G. Treworgy; Russell J. Jacobson

    1986-01-01

    Previous studies have shown that coal over- lain by a thick sequence of nonmarine strata is generally lower in sulfur content than adjacent areas of the same seam overlain by marine strata. These nonmarine sedi- ments are interpreted to be of fluvial origin and consist primarily of crevasse-splay deposits. Two patterns of occurrence of crevasse-splay deposits associated with low- sulfur

  4. Supplementary Material Sulfur Dioxide and Primary Carbonaceous Aerosol Emissions

    E-print Network

    Meskhidze, Nicholas

    society currently depends greatly on fossil fuels (40% oil, 24% gas, 22% coal) with smaller contributions and technical objectives of each of the three areas are as follows: 2.1.1 Sulfur cycle management. Rationale the quality of gas stored in subsurface reservoirs, because the H2S must be removed Sulfur Cycle Management

  5. 40 CFR 52.2033 - Control strategy: Sulfur oxides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Control strategy: Sulfur oxides. 52.2033 Section 52.2033...Pennsylvania § 52.2033 Control strategy: Sulfur oxides. (a) The revision to... Date of submittal Clairton Coke and Coal Works (U.S. Steel) Allegheny...

  6. 40 CFR 52.2033 - Control strategy: Sulfur oxides.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Control strategy: Sulfur oxides. 52.2033 Section 52.2033...Pennsylvania § 52.2033 Control strategy: Sulfur oxides. (a) The revision to... Date of submittal Clairton Coke and Coal Works (U.S. Steel) Allegheny...

  7. 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.

  8. 40 CFR 52.2033 - Control strategy: Sulfur oxides.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Control strategy: Sulfur oxides. 52.2033 Section 52.2033...Pennsylvania § 52.2033 Control strategy: Sulfur oxides. (a) The revision to... Date of submittal Clairton Coke and Coal Works (U.S. Steel) Allegheny...

  9. RESPONSE OF MAIZE AND WHEAT TO SULFUR DIOXIDE

    EPA Science Inventory

    Four hybrids of maize and seven cultivars of wheat were exposed to relatively low concentrations of sulfur dioxide (0.1 to 0.6 ppm) for up to 100 hours. Maize was found to be tolerant to sulfur dioxide and only minor differences were observed in dry mass, foliar injury, and total...

  10. Sulfur dioxide oxidation and plume formation at cement kilns

    Microsoft Academic Search

    Barry Dellinger; Gary Grotecloss; Christopher R. Fortune; James L. Cheney; James B. Homolya

    1980-01-01

    Results of source sampling at the Glens Falls cement kiln in Glens Falls, N.Y., are reported for sulfur oxides, ammonia, hydrochloric acid, oxygen, and moisture content. The origin of a detached, high-opacity, persistent plume originating from the cement kiln stack is investigated. It is proposed that this plume is due to ammonium salts of SOx and sulfuric acid that have

  11. Modeling of Sodium Sulfur Battery for Power System Applications

    Microsoft Academic Search

    Zahrul F. Hussien; Lee W. Cheung; Mohd F. M. Siam; Amir B. Ismail

    2007-01-01

    Sodium sulfur battery is an advanced secondary battery that is relatively new in power system applications. This paper presents the modeling and simulation of sodium sulfur battery used in power system applications such as for battery energy storage system and power quality custom devices. Several electrical battery models are reviewed and important factors to be considered in modeling the battery

  12. Two-step rapid sulfur capture. Final report

    SciTech Connect

    NONE

    1994-04-01

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

  13. Diminishing the role of sulfur oxides in air pollution

    Microsoft Academic Search

    P. H. Abelson

    1967-01-01

    Each year, in the US, more than 20 million tons of sulfur are discharged into the atmosphere, most of it in the form of SOâ. This gas is slowly converted into sulfuric acid, which is corrosive to many materials, including metals, building stones, and clothing. The toxicity of SOâ and HâSOâ to plants and animals is controversial, as is the

  14. Chapter 2 Soil Sulfur Cycling in Temperate Agricultural Systems

    Microsoft Academic Search

    Jørgen Eriksen

    2009-01-01

    Despite the essential role of sulfur for plant growth, it has historically received little attention because of an ample supply from the atmosphere and commercial fertilizers. However, during the last 20–30 years the situation has changed dramatically and today we face the challenge of optimizing sulfur availability in cropping systems in synchrony with plant demand and in the required form

  15. FUEL RICH SULFUR CAPTURE IN A COMBUSTION ENVIRONMENT

    EPA Science Inventory

    A refractory-lined, natural gas furnace was used to study fuel rich sulfur capture reactions of calcium sorbents under typical combustion conditions. The fuel rich sulfur species H2S and COS were monitored in a near-continuous fashion using a gas chromatograph equipped with a fl...

  16. Research Articles The Formation of Sulfate and Elemental Sulfur

    E-print Network

    Jimenez, Jose-Luis

    Conditions: Implications for Early Earth H. Langley DeWitt,1,2 Christa A. Hasenkopf,2,3 Melissa G. Trainer,4 years old is thought to be evidence for an early anoxic atmosphere. Photolysis of sulfur dioxide (SO2 aerosols on early Earth are discussed. Key Words: S-MIF--Archean atmosphere--Early Earth--Sulfur aerosols

  17. SUSCEPTIBILIT MAGNTIQUE DE QUELQUES SULFURES ET OXYDES DE PLUTONIUM

    E-print Network

    Paris-Sud XI, Université de

    261. SUSCEPTIBILITÉ MAGNÉTIQUE DE QUELQUES SULFURES ET OXYDES DE PLUTONIUM Par GEORGES RAPHAEL et CHARLES DE NOVION, S.E.C.P.E.R., Section d'Études des Céramiques à base de Plutonium, Centre d susceptibilite magnétique des sulfures de plutonium : PuS, Pu3S4, PU2S3CXI PuS2. Ces composes non conduc- teurs

  18. Emerging technology for the reduction of sulfur in FCC fuels

    SciTech Connect

    Wormsbecher, R.F.; Weatherbee, G.D.; Kim, G.; Dougan, T.J. (Grace Davison, Baltimore, MD (United States))

    1993-01-01

    Passage of the Clean Air Act of 1990 and new regulations issued in California will set new limits on the sulfur content of gasoline. Because most of the sulfur in the gasoline pool comes from FCC naphtha, there is a strong incentive to reduce the sulfur content of this stream in the most cost efficient manner. This work introduces emerging catalytic technology for the direct reduction of the sulfur content of FCC gasolines, called the GSR[trademark] (Gasoline Sulfur Reduction) technology. Studies of this new technology were carried out using the Davison Circulating Riser pilot unit. The GSR technology is shown to reduce the sulfur in FCC naphtha by 15%, with two feedstocks. It is shown that this technology is selective to sulfur species in the middle of the gasoline boiling range, and converts these species to H[sub 2]S, while preserving most of the base catalyst selectivities. Various other catalytic scenarios for minimizing the gasoline sulfur content are also given.

  19. Sulfur in coal and its environmental impact from Yanzhou mining district, China

    Microsoft Academic Search

    Guijian Liu; Zicheng Peng; Pingyue Yang; Guiliang Wang

    2001-01-01

    Sulfur is one of the hazardous elements in coal. The concentrations of sulfur are relatively high in coal. The major forms\\u000a of sulfur in coal are pyritic, organic and sulfate. Pyritic and organic sulfur generally account for the bulk of sulfur in\\u000a coal. Elemental sulfur also occurs in coal, but only in trace to minor amounts. When coals are burned,

  20. Electrochemical oxidation of wine polyphenols in the presence of sulfur dioxide.

    PubMed

    Makhotkina, Olga; Kilmartin, Paul A

    2013-06-12

    Electrochemical oxidation of three representative wine polyphenols (catechin, caffeic acid, and quercetin) in the presence of sulfur dioxide in a model wine solution (pH = 3.3) was investigated. The oxidation was undertaken using chronoamperometry at a rotating glassy carbon rod electrode, and the reaction products were characterized by HPLC-MS. The mechanism of electrochemical oxidation of polyphenols in the presence of sulfur dioxide was proposed to be an ECEC mechanism. The polyphenols first underwent a one-electron oxidation to a semiquinone radical, which can be reduced back to the original polyphenol by sulfur dioxide, or further oxidized to the quinone form. In the cases of caffeic acid and catechin, the quinone combined with sulfur dioxide and produced new derivatives. The quercetin quinone underwent further chemical transformations, producing several new compounds. The proposed mechanisms were confirmed by digital simulation of cyclic voltammograms. PMID:23692398