Exposure experiments of trees to sulfur dioxide gas. Part I

Energy Technology Data Exchange (ETDEWEB)

Otani, A.

1974-12-01

The effects of gaseous sulfur dioxide on trees were studied. Twenty species of plant seedlings (70 cm in height) including Cedrus deodara, Metasequoia glyptostroboides, Ginkgo biloba, Celmus parvifolia var. albo-marginata, Pinus thumbergii, P. densiflora, Cryptomeria japonica, and Quercus myrsinaefolia, were exposed in a room to gaseous sulfur dioxide at 0.8 ppm for 7.5 hr/day (from 9 am to 4:30 pm) for 24 days at a temperature of 20-35 deg C and RH of 55-75%. Visible damage to plants was lighter in C.j. and Chamae cyparis obtusa, more severe in P.t., G.b., and C.d. The damage appeared earlier in G.b., Cinnamomum camphona, and Ilex rotunda, and the change of early symptoms was smaller in P.t., C.j., and C.o. The leaves of the 4-5th positions from the sprout were apt to be damaged. Although the sulfur content of exposed leaves increased markedly, that in other parts did not increase. Because of the high concentration of the gas and the short period of exposure, the absorption of sulfur into leaves should have differed from the situation in fields where longer exposure to lower concentrations of the gas would be expected. 6 references.

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

International Nuclear Information System (INIS)

K.C. Kwon

2002-01-01

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

Formation and Control of Sulfur Oxides in Sour Gas Oxy-Combustion: Prediction Using a Reactor Network Model

KAUST Repository

Bongartz, Dominik

2015-11-19

© 2015 American Chemical Society. Sour natural gas currently requires expensive gas cleanup before it can be used in power generation because it contains large amounts of hydrogen sulfide (H2S) and carbon dioxide (CO2) that entail a low heating value and highly corrosive combustion products. A potential alternative is to use the gas directly in a gas turbine process employing oxy-fuel combustion, which could eliminate the need for gas cleanup while also enabling the application of carbon capture and sequestration, possibly combined with enhanced oil recovery (EOR). However, the exact influence of an oxy-fuel environment on the combustion products of sour gas has not been quantified yet. In this work, we used a reactor network model for the combustor and the gas turbine together with our recently assembled and validated detailed chemical reaction mechanism for sour gas combustion to investigate the influence of some basic design parameters on the combustion products of natural gas and sour gas in CO2 or H2O diluted oxy-fuel combustion as well as in conventional air combustion. Our calculations show that oxy-fuel combustion produces up to 2 orders of magnitude less of the highly corrosive product sulfur trioxide (SO3) than air combustion, which clearly demonstrates its potential in handling sulfur containing fuels. Unlike in air combustion, in oxy-fuel combustion, SO3 is mainly formed in the flame zone of the combustor and is then consumed as the combustion products are cooled in the dilution zone of the combustor and the turbine. In oxy-fuel combustion, H2O dilution leads to a higher combustion efficiency than CO2 dilution. However, if the process is to be combined with EOR, CO2 dilution makes it easier to comply with the very low levels of oxygen (O2) required in the EOR stream. Our calculations also show that it might even be beneficial to operate slightly fuel-rich because this simultaneously decreases the O2 and SO3 concentration further. The flame zone

Process for removal of sulfur oxides from hot gases

International Nuclear Information System (INIS)

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

1984-01-01

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

The diversity of the effects of sulfur mustard gas inhalation on respiratory system 10 years after a single, heavy exposure: analysis of 197 cases.

Science.gov (United States)

Emad, A; Rezaian, G R

1997-09-01

To find out the late pulmonary sequelae of sulfur mustard gas inhalation in 197 veterans, 10 years after their exposure. Cross-sectional clinical study. University hospital. One hundred ninety-seven veterans with a single, heavy exposure to sulfur mustard gas in 1986 and 86 nonexposed veterans as their control group. Pulmonary function tests, carbon monoxide diffusion capacity, bronchoscopy, and high-resolution CT of the chest were performed in all patients. Transbronchial lung biopsy was done in 24 suspected cases of pulmonary fibrosis. Asthma was diagnosed in 21 (10.65%), chronic bronchitis in 116 (58.88%), bronchiectasis in 17 (8.62%), airway narrowing due to searing or granulation tissue in 19 (9.64%), and pulmonary fibrosis in 24 (12.18%) cases. None of these were found among the control group except for a single case of chronic bronchitis. Although the respiratory symptoms of an acute sulfur mustard gas inhalation are usually transient and nonspecific, it can lead to the development of a series of chronic destructive pulmonary sequelae in such cases.

Oxidation-sulfidation behavior of Ni aluminide in oxygen-sulfur mixed-gas atmospheres

International Nuclear Information System (INIS)

Natesan, K.

1988-01-01

Oxidation-sulfidation studies were conducted with sheet samples of nickel aluminide, containing 23.5 at. % Al, 0.5 at. % Hf, and 0.2 at. % B, in an annealed condition and after preoxidation treatments. Continuous weight-change measurements were made by a thermogravimetric technique in exposure atmospheres of air, a low-pO/sub 2/ gas mixture, and low-pO/sub 2/ gas mixtures with several levels of sulfur. The air-exposed specimens developed predominantly nickel oxide; the specimen exposed to a low-pO/sub 2/ environment developed an aluminum oxide scale. As the sulfur content of the gas mixture increased, the alumina scale exhibited spallation and the alloy tended to form nickel sulfide as the reaction phase. The results indicated that the sulfidation reaction of nickel aluminide specimens (both bare and preoxidized) was determined by the rate of transport of nickel from the substrate through the scale to the gas/alumina scale interface, the mechanical integrity of the oxide scale, and the H/sub 2/S concentration in the exposure environment

Removal of sulfur from process streams

International Nuclear Information System (INIS)

Brignac, D.G.

1984-01-01

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

Experimental study for the use of sulfur hexafluoride as dielectric gas in particle accelerators

International Nuclear Information System (INIS)

Candanedo y Bernabe, C.

1993-01-01

The sulfur hexafluoride is the better dielectric gas in the world. It is used in particle accelerator, power stations and high voltage transformators. This is a high stable gas, but when is used as dielectric is degraded in toxic and corrosive fluorides this degradation of sulfur hexafluoride is a function of the voltaic arc, crown effect, pressure, temperature and radiation. The purification of the sulfur fluoride permitted to work in safe form and without the risks as contaminant. The objective of the work is the development of a process for the separation of the wastes from the fabrication of sulphur fluoride and the products of degradation. This process used adsorbents when this gas is used as dielectric. The methodology employed was bibliography research, experimental design of the equipment, construction of the experimental equipment, selection and use of adsorbents, installation of the adsorption columns for the experimentation, flow of the sulfur hexafluoride through the adsorbents, searching of the fluoride hexafluoride before and after of the step through the adsorption columns and writing of the results. In base to the results we conclude that the process is good. The work could be advantage using chromatographic techniques with adequate standards. Is possible to extend the study using an additional number of adsorbents. (Author). 34 refs, 7 graphs, 3 tabs

Determination of sulfur dioxide in wine using headspace gas chromatography and electron capture detection.

Science.gov (United States)

Aberl, A; Coelhan, M

2013-01-01

Sulfites are routinely added as preservatives and antioxidants in wine production. By law, the total sulfur dioxide content in wine is restricted and therefore must be monitored. Currently, the method of choice for determining the total content of sulfur dioxide in wine is the optimised Monier-Williams method, which is time consuming and laborious. The headspace gas chromatographic method described in this study offers a fast and reliable alternative method for the detection and quantification of the sulfur dioxide content in wine. The analysis was performed using an automatic headspace injection sampler, coupled with a gas chromatograph and an electron capture detector. The method is based on the formation of gaseous sulfur dioxide subsequent to acidification and heating of the sample. In addition to free sulfur dioxide, reversibly bound sulfur dioxide in carbonyl compounds, such as acetaldehyde, was also measured with this method. A total of 20 wine samples produced using diverse grape varieties and vintages of varied provenance were analysed using the new method. For reference and comparison purposes, 10 of the results obtained by the proposed method were compared with those acquired by the optimised Monier-Williams method. Overall, the results from the headspace analysis showed good correlation (R = 0.9985) when compared with the conventional method. This new method requires minimal sample preparation and is simple to perform, and the analysis can also be completed within a short period of time.

40 CFR 52.724 - Control strategy: Sulfur dioxide.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy: Sulfur dioxide. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Illinois> § 52.724 Control strategy: Sulfur... Energy Incorporated. This disapproval does not in and of itself result in the growth restrictions of...

Environmental and economic benefits of natural gas use for pollution control

International Nuclear Information System (INIS)

Dey, P.R.; Berkau, E.E.; Schnelle, K.B.

1993-01-01

One of the primary goals of this research effort was to document and compare the economic and environment benefits of using natural gas for pollution control in boilers, furnaces and internal combustion engines, with conventional control technologies. The study indicated that replacement of 15% of the coal used in coal-fired boilers employed in the generation of electric power in the US, with natural gas, would considerably reduce the emissions of acid rain precursors such as sulfur and nitrogen oxides, and do so in a cost-effect manner. The reductions achieved were also in concordance with the reductions in sulfur dioxide emissions mandated by the new Clean Air Act (CAA) Amendments of 1990. The combustion of natural gas would also produce less carbon dioxide as compared to the combustion of coal with an equivalent amount of heat content. Carbon dioxide is a greenhouse gas, i.e., it is believed to play a major role in global warming. Natural gas technology therefore presents a cost-effective step in the eventual mitigation of two of the main environmental problems presently facing us, acid rain, and global warming

Effect of dimethylamine on the gas phase sulfuric acid concentration measured by Chemical Ionization Mass Spectrometry

CERN Document Server

Rondo, L.; Kürten, A.; Adamov, A.; Bianchi, F.; Breitenlechner, M.; Duplissy, J.; Franchin, A.; Dommen, J.; Donahue, N. M.; Dunne, E. M.; Flagan, R. C.; Hakala, J.; Hansel, A.; Keskinen, H.; Kim, J.; Jokinen, T.; Lehtipalo, K.; Leiminger, M.; Praplan, A.; Riccobono, F.; Rissanen, M. P.; Sarnela, N.; Schobesberger, S.; Simon, M.; Sipilä, M.; Smith, J. N.; Tomé, A.; Tröstl, J.; Tsagkogeorgas, G.; Vaattovaara, P.; Winkler, P. M.; Williamson, C.; Wimmer, D.; Baltensperger, U.; Kirkby, J.; Kulmala, M.; Petäjä, T.; Worsnop, D. R.; Curtius, J.

2016-01-01

Sulfuric acid is widely recognized as a very important substance driving atmospheric aerosolnucleation. Based on quantum chemical calculations it has been suggested that the quantitative detectionof gas phase sulfuric acid (H2SO4) by use of Chemical Ionization Mass Spectrometry (CIMS) could be biased inthe presence of gas phase amines such as dimethylamine (DMA). An experiment (CLOUD7 campaign) was setup at the CLOUD (Cosmics Leaving OUtdoor Droplets) chamber to investigate the quantitative detection ofH2SO4in the presence of dimethylamine by CIMS at atmospherically relevant concentrations. For the first time inthe CLOUD experiment, the monomer sulfuric acid concentration was measured by a CIMS and by two CI-APi-TOF(Chemical Ionization-Atmospheric Pressure interface-Time Of Flight) mass spectrometers. In addition, neutralsulfuric acid clusters were measured with the CI-APi-TOFs. The CLOUD7 measurements show that in the presenceof dimethylamine (<5 to 70 pptv) the sulfuric acid monomer measured by the CIMS...

Aqueous process for recovering sulfur from hydrogen sulfide-bearing gas

Science.gov (United States)

Basu, Arunabha

2015-05-05

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

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

Science.gov (United States)

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

2006-10-01

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

Gasoline from natural gas by sulfur processing

Energy Technology Data Exchange (ETDEWEB)

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

1995-12-31

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

Sulfur transformations related to revegetation of flue gas desulfurization sludge disposal sites

Energy Technology Data Exchange (ETDEWEB)

Barlas, S.A.; Artiola, J.F.; Salo, L.F.; Goodrich-Mahoney, J.W. [University of Arizona, Tucson, AZ (United States). Dept. of Soil, Water and Environmental Sciences

1999-10-01

This study investigated factors controlling redox conditions in flue gas desulfurization (FGD) sludge and identified ways to minimize the production of phytotoxic reduced sulfur species at FGD sludge disposal sites. The oxidation of reduced FGD sludge (Eh-385 mV) appears to be a two-step process mostly controlled by water content. Eighty percent of total sulfide in reduced sludge was oxidized within 20 h of exposure to air with constant water evaporation. When organic carbon (OC) was added to saturated oxidized sludge, the Eh dropped exponentially. Sulfate reduction began at an Eh of about -75 mV and reached a maximum at -265 to -320 mV. Water content, degree of mixing, concentration of OC, and temperature control the rate and extent of reduction of FGD sludge. This suggests that water saturation and OC inputs to revegetated disposal sites should be controlled, especially during warm temperatures, to prevent production of phytotoxic levels of sulfides.

Measurements of sulfur compounds in CO2 by diode laser atomic absorption spectrometry

International Nuclear Information System (INIS)

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

2003-01-01

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

Application of microturbines to control emissions from associated gas

Science.gov (United States)

Schmidt, Darren D.

2013-04-16

A system for controlling the emission of associated gas produced from a reservoir. In an embodiment, the system comprises a gas compressor including a gas inlet in fluid communication with an associated gas source and a gas outlet. The gas compressor adjusts the pressure of the associated gas to produce a pressure-regulated associated gas. In addition, the system comprises a gas cleaner including a gas inlet in fluid communication with the outlet of the gas compressor, a fuel gas outlet, and a waste product outlet. The gas cleaner separates at least a portion of the sulfur and the water from the associated gas to produce a fuel gas. Further, the system comprises a gas turbine including a fuel gas inlet in fluid communication with the fuel gas outlet of the gas cleaner and an air inlet. Still further, the system comprises a choke in fluid communication with the air inlet.

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

Science.gov (United States)

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))...

Sulfur Nanoparticles Synthesis and Characterization from H2S Gas, Using Novel Biodegradable Iron Chelates in W/O Microemulsion

Directory of Open Access Journals (Sweden)

Harle Arti

2008-01-01

Full Text Available AbstractSulfur nanoparticles were synthesized from hazardous H2S gas using novel biodegradable iron chelates in w/o microemulsion system. Fe3+–malic acid chelate (0.05 M aqueous solution was studied in w/o microemulsion containing cyclohexane, Triton X-100 andn-hexanol as oil phase, surfactant, co-surfactant, respectively, for catalytic oxidation of H2S gas at ambient conditions of temperature, pressure, and neutral pH. The structural features of sulfur nanoparticles have been characterized by X-ray diffraction (XRD, transmission electron microscope (TEM, energy dispersive spectroscopy (EDS, diffused reflectance infra-red Fourier transform technique, and BET surface area measurements. XRD analysis indicates the presence of α-sulfur. TEM analysis shows that the morphology of sulfur nanoparticles synthesized in w/o microemulsion system is nearly uniform in size (average particle size 10 nm and narrow particle size distribution (in range of 5–15 nm as compared to that in aqueous surfactant systems. The EDS analysis indicated high purity of sulfur (>99%. Moreover, sulfur nanoparticles synthesized in w/o microemulsion system exhibit higher antimicrobial activity (against bacteria, yeast, and fungi than that of colloidal sulfur.

Gas chromatographic studies of the relative retention of the sulfur isotopes in carbonyl sulfide, carbon disulfide, and sulfur dioxide

International Nuclear Information System (INIS)

Fetzer, J.C.; Rogers, L.B.

1980-01-01

A precision gas chromatograph, coupled to a quadrupole mass spectrometer and an on-line computer, was used to study the fractionation on Porasil A of the 32 S/ 34 S isotopic pair in a variety of sulfur-containing molecules. Carbonyl sulfide (COS) yielded an average α value of 1.00074 +- 0.00017 (standard deviation) for the temperature range 25 0 C to 75 0 C. The carbon disulfide (CS 2 ) value was 1.00069 +- 0.00023 for the range 53 0 C to 103 0 C, and that for sulfur dioxide (SO 2 ) was 1.00090 +- 0.00018 for the range 62 0 C to 112 0 C. Differential thermodynamic data have been reported. A Porapak Q column showed no fractionation of this isotopic pair in these three molecules

Biologically removing sulfur from dilute gas flows

Science.gov (United States)

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

1999-05-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1997-12-01

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

Impurity of Sulfur Layers and Magmatic Gas Scrubbing: Implications for Gas Monitoring

Science.gov (United States)

Scolamacchia, T.

2017-12-01

The evidence of bodies of elemental sulfur (Se) beneath acid crater lakes at the summit of composite active volcanoes has been recognized several decades ago (Oppenheimer and Stevenson, 1989; Christenson and Woods, 1993). But Se accumulation was already hypothesized a century ago at Kusatzu Shirane (Japan) based on the observation of sulfur spherules floating on its crater-lake (Ohashi, 1919). Since these pioneering works, other studies have focused on understanding key aspects of molten sulfur bodies, considered a feature unique of volcanic lakes. Instead, it is reasonable to assume that Se bodies occur in several volcanic settings because a) several reactions may lead to Se deposition from S-bearing gases, and b) crater-lakes, surface expressions of hydrothermal systems, are transient features. The scrubbing of several magmatic gases, some of which critical for volcano monitoring, has been attributed to ground/surface waters (Symonds et al. 2001). Nevertheless, gas scrubbing could reflect viscosity variations of impure Se within hydrothermal systems. Industrial experiments indicated that impurities (organics, H2S, ammonia, HCl, HF, HBr, HI) hinder Se polymerization at T ≥ 160ºC, allowing viscosity to remain low for long time depending on the maximum T achieved and heating rates (Bacon and Fanelli, 1943). However, a prolonged heating destroys the viscosity-modifying substances (e.g. H2Sx formed by reactions with organics, H2S, or ammonia) and dramatic Se viscosity increases occur after a certain number of heating and cooling cycles. A prolonged boiling of Se with organics was observed to release H2S, following H2Sx disruption. Some gases (e.g. SO2) do not affect Se viscosity. In volcanic environments gases such as SO2, CO2 could escape under Selow viscosity regimes. Also, halogens absence in gas emissions could be caused by their participation in reactions within S-layers causing its viscosity to remain low. More data are needed to validate the hypothesis

Possibilities of analyzing dump and sewage gas, and determination of halogen and sulfur compounds

Energy Technology Data Exchange (ETDEWEB)

Eisenmann, R

1985-01-01

In connection with the utilization of refuse and sewage gas efficacions analytical methods are gaining increasing importance especially with regard to halogen and sulfur compounds. The paper describes various possibilities to determine those substances. Besides gas chromatography it takes into account classic analytical methods which can be superior in biogas analytics to modern physical processes. The advantages and disadvantages of each method are discussed and practical experiences obtained by their application reported.

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

Science.gov (United States)

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

1991-01-01

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

Control Room Habitability for Accidental Sulfuric Acid Release

International Nuclear Information System (INIS)

Cho, Sungmin; Lee, Heedo; Song, Dongsoo

2006-01-01

The 10 CFR 50 Appendix A Criterion 19, 'Control Room', requires that a control room be provided from which actions can be taken to operate the nuclear power unit safely under normal conditions and to maintain it in a safe condition under accident conditions. For compliance with the requirement, the control room of a nuclear power plant should be appropriately protected from hazardous chemicals that may be discharged as a result of equipment failures, operator errors, or events and conditions outside the control of the nuclear power plant. We have excluded sulfuric acid from a target of estimation for control room habitability merely because its boiling point is too high; qualitative analysis in this paper shows that we can exclude sulfuric acid from the target of habitability estimation

Diesel Emission Control -- Sulfur Effects (DECSE) Program; Phase I Interim Date Report No. 3: Diesel Fuel Sulfur Effects on Particulate Matter Emissions

Energy Technology Data Exchange (ETDEWEB)

DOE; ORNL; NREL; EMA; MECA

1999-11-15

The Diesel Emission Control-Sulfur Effects (DECSE) is a joint government/industry program to determine the impact of diesel fuel sulfur levels on emission control systems whose use could lower emissions of nitrogen oxides (NO{sub x}) and particulate matter (PM) from on-highway trucks in the 2002--2004 model years. Phase 1 of the program was developed with the following objectives in mind: (1) evaluate the effects of varying the level of sulfur content in the fuel on the emission reduction performance of four emission control technologies; and (2) measure and compare the effects of up to 250 hours of aging on selected devices for multiple levels of fuel sulfur content. This interim report covers the effects of diesel fuel sulfur level on particulate matter emissions for four technologies.

Influence of liquid and gas flow rates on sulfuric acid mist removal from air by packed bed tower

Directory of Open Access Journals (Sweden)

Jafari Mohammad Javad

2012-12-01

Full Text Available Abstract The possible emission of sulfuric acid mists from a laboratory scale, counter-current packed bed tower operated with a caustic scrubbing solution was studied. Acid mists were applied through a local exhaust hood. The emissions from the packed bed tower were monitored in three different categories of gas flow rate as well as three liquid flow rates, while other influencing parameters were kept almost constant. Air sampling and sulfuric acid measurement were carried out iso-kinetically using USEPA method 8. The acid mists were measured by the barium-thorin titration method. According to the results when the gas flow rate increased from 10 L/s to 30 L/s, the average removal efficiency increased significantly (p 3, respectively. L/G of 2–3 was recommended for designing purposes of a packed tower for sulfuric acid mists and vapors removal from contaminated air stream.

Membrane Assisted Simultaneous Extraction and Derivatization with Triphenylphosphine of Elemental Sulfur in Arabian Crude Samples by Gas Chromatography/Mass Spectrometry

Directory of Open Access Journals (Sweden)

Ibrahim Al-Zahrani

2015-01-01

Full Text Available Determination of trace level elemental sulfur from crude oil samples is a tedious task. Recently, several gas chromatographic methods were reported in which selective triphenylphosphine derivatization of sulfur was used to form triphenylphosphine sulfide. Direct quantitation of elemental sulfur from crude oil requires an efficient sample preparation method. This paper describes how simultaneous extraction derivatization of elemental sulfur was performed for the first time using porous hollow fiber membrane. A thick (0.25 um pore size; 1550 μm wall thickness; and 5500 μm inner diameter hollow fiber membrane filled with triphenylphosphine (dissolved N-methylpyrrolidone is used as a solvent bar. The solvent bar is tumbled freely in the crude oil sample; the elemental sulfur was extracted and derivatized. Finally, the derivatized sulfur was analyzed by gas chromatography/mass spectrometry. Various experimental conditions of solvent bar microextraction (SBME were optimized to achieve higher extraction. The linear range was established between 1 and 50 μg/mL, while a squared regression coefficient was found to be 0.9959 μg/mL. Relative standard deviation (RSD was below 10%. Relative recoveries were calculated for SBME in crude oil samples and were in the range between 98.2% and 101.2%.

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

Science.gov (United States)

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

2014-02-04

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

Process for removal of sulfur compounds from fuel gases

Science.gov (United States)

Moore, Raymond H.; Stegen, Gary E.

1978-01-01

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

New method for reduction of burning sulfur of coal

International Nuclear Information System (INIS)

Lyutskanov, L.; Dushanov, D.

1998-01-01

The coal pyrolysis is key phase in the the pyrolysis-combustion cycle as it provides char for combustor. The behaviour of sulfur compounds during coal pyrolysis depends on factors as rank of coal, quantity of sulfur and sulfur forms distribution in the coal, quantity and kind of mineral matter and the process conditions. The mineral content of coal may inhibit or catalyze the formation of volatile sulfur compounds. The pyrolysis itself is a mean of removing inorganic and organic sulfur but anyway a portion of it remains in the char while the other moves into the tar and gas. The aim of this study was to determine an optimal reduction of burning sulfur at the coal pyrolysis by varying parametric conditions. The pyrolysis of different kinds of coal has been studied. The samples with size particles o C at atmospheric pressure and with a heating rate of 6-50 o C min -1 . They were treated with exhaust gas and nitrogen at an addition of steam and air. The char obtained remains up to 10 min at the final temperature. The char samples cool without a contact with air. Two methods of desulfurization-pyrolysis were studied - using 9-vertical tubular reactor and 9-horizontal turning reactor. The results obtained show that at all samples there is a decrease of burning sulfur with maximal removal efficiency 83%. For example at a pyrolysis of Maritsa Iztok lignite coal the burning sulfur is only 16% in comparison with the control sample. The remained is 90% sulfate, 10% organic and pyrite traces when a mixture 'exhaust gas-water stream-air' was used. The method of desulfurization by pyrolysis could be applied at different kinds of coal and different conditions. Char obtained as a clean product can be used for generating electric power. This innovation is in a stage of patenting

Fast-regenerable sulfur dioxide adsorbents for diesel engine emission control

Science.gov (United States)

Li, Liyu [Richland, WA; King, David L [Richland, WA

2011-03-15

Disclosed herein are sorbents and devices for controlling sulfur oxides emissions as well as systems including such sorbents and devices. Also disclosed are methods for making and using the disclosed sorbents, devices and systems. In one embodiment the disclosed sorbents can be conveniently regenerated, such as under normal exhaust stream from a combustion engine, particularly a diesel engine. Accordingly, also disclosed are combustion vehicles equipped with sulfur dioxide emission control devices.

Ultra Low Sulfur Home Heating Oil Demonstration Project

Energy Technology Data Exchange (ETDEWEB)

Batey, John E. [Energy Research Center, Inc., Easton, CT (United States); McDonald, Roger [Brookhaven National Lab. (BNL), Upton, NY (United States)

2015-09-30

This Ultra Low Sulfur (ULS) Home Heating Oil Demonstration Project was funded by the New York State Energy Research and Development Authority (NYSERDA) and has successfully quantified the environmental and economic benefits of switching to ULS (15 PPM sulfur) heating oil. It advances a prior field study of Low Sulfur (500 ppm sulfur) heating oil funded by NYSERDA and laboratory research conducted by Brookhaven National Laboratory (BNL) and Canadian researchers. The sulfur oxide and particulate matter (PM) emissions are greatly reduced as are boiler cleaning costs through extending cleaning intervals. Both the sulfur oxide and PM emission rates are directly related to the fuel oil sulfur content. The sulfur oxide and PM emission rates approach near-zero levels by switching heating equipment to ULS fuel oil, and these emissions become comparable to heating equipment fired by natural gas. This demonstration project included an in-depth review and analysis of service records for both the ULS and control groups to determine any difference in the service needs for the two groups. The detailed service records for both groups were collected and analyzed and the results were entered into two spreadsheets that enabled a quantitative side-by-side comparison of equipment service for the entire duration of the ULS test project. The service frequency for the ULS and control group were very similar and did indicate increased service frequency for the ULS group. In fact, the service frequency with the ULS group was slightly less (7.5 percent) than the control group. The only exception was that three burner fuel pump required replacement for the ULS group and none were required for the control group.

Research on Frequency Control of Grid Connected Sodium-Sulfur Battery

Directory of Open Access Journals (Sweden)

Zhang Fenglin

2018-01-01

Full Text Available Sodium sulfur battery is the only energy storage battery with large capacity and high energy density. It has a great application prospect in the peak load shifting of power grid, due to the lack of domestic research on it, it is urgent to evaluate the effect of grid-connection of sodium sulfur battery scientifically. According to the experimental data of the sodium sulfur battery project, the battery model is built. Compared with the real discharge curve, the error of the model simulation curve is small, so the battery model is effective. The AC / DC power grid model is built, and the rectifier and inverter control circuits are designed to simulate the scenario that the wind turbine and the battery are supplied to the passive load. The simulation results show that the grid-connected model of the sodium sulfur battery under the two control strategies can stabilize the larger frequency fluctuation.

Environment-Friendly Control of Pear Scab and Rust Using Lime Sulfur

Directory of Open Access Journals (Sweden)

Ju Hoon Cha

2018-03-01

Full Text Available Pear scab and rust are the major diseases causing severe epidemics in organic cultivation of pear trees. Incidences of pear scab and rust were compared in organically managed plots and conventionally managed plots to obtain optimum application schedule of environment-friendly control agents in organically managed plots. Organically cultural practice with 10 time-applications of lime sulfur and Bordeaux mixture showed higher than 40% of control efficacies of pear scab and rust compared to conventionally cultural practice. Organically cultural practice with 8 time-applications of lime sulfur considering weather condition showed higher than 30% of control efficacies of pear scab compared to conventionally cultural practice. The results suggest that proper application of environment-friendly control agents such as lime sulfur considering weather condition will enable effective control of the major diseases for organic cultivation of pear.

Two-step rapid sulfur capture. Final report

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-04-01

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

Sulfur isotope fractionation during oxidation of sulfur dioxide: gas-phase oxidation by OH radicals and aqueous oxidation by H2O2, O3 and iron catalysis

Directory of Open Access Journals (Sweden)

J. N. Crowley

2012-01-01

Full Text Available The oxidation of SO2 to sulfate is a key reaction in determining the role of sulfate in the environment through its effect on aerosol size distribution and composition. Sulfur isotope analysis has been used to investigate sources and chemical processes of sulfur dioxide and sulfate in the atmosphere, however interpretation of measured sulfur isotope ratios is challenging due to a lack of reliable information on the isotopic fractionation involved in major transformation pathways. This paper presents laboratory measurements of the fractionation factors for the major atmospheric oxidation reactions for SO2: Gas-phase oxidation by OH radicals, and aqueous oxidation by H2O2, O3 and a radical chain reaction initiated by iron. The measured fractionation factor for 34S/32S during the gas-phase reaction is αOH = (1.0089±0.0007−((4±5×10−5 T(°C. The measured fractionation factor for 34S/32S during aqueous oxidation by H2O2 or O3 is αaq = (1.0167±0.0019−((8.7±3.5 ×10−5T(°C. The observed fractionation during oxidation by H2O2 and O3 appeared to be controlled primarily by protonation and acid-base equilibria of S(IV in solution, which is the reason that there is no significant difference between the fractionation produced by the two oxidants within the experimental error. The isotopic fractionation factor from a radical chain reaction in solution catalysed by iron is αFe = (0.9894±0.0043 at 19 °C for 34S/32S. Fractionation was mass-dependent with regards to 33S/32S for all the reactions investigated. The radical chain reaction mechanism was the only measured reaction that had a faster rate for the light isotopes. The results presented in this study will be particularly useful to determine the importance of the transition metal-catalysed oxidation pathway compared to other oxidation pathways, but other main oxidation pathways can not be distinguished based on stable sulfur isotope measurements alone.

40 CFR 52.1126 - Control strategy: Sulfur oxides.

Science.gov (United States)

2010-07-01

... Department of Environmental Quality Engineering.). Gardner State Hospital, Gardner. Grafton State Hospital... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Sulfur oxides. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Massachusetts § 52.1126 Control...

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

International Nuclear Information System (INIS)

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

1991-01-01

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

Sulfur-doped graphene via thermal exfoliation of graphite oxide in H2S, SO2, or CS2 gas.

Science.gov (United States)

Poh, Hwee Ling; Šimek, Petr; Sofer, Zdeněk; Pumera, Martin

2013-06-25

Doping of graphene with heteroatoms is an effective way to tailor its properties. Here we describe a simple and scalable method of doping graphene lattice with sulfur atoms during the thermal exfoliation process of graphite oxides. The graphite oxides were first prepared by Staudenmaier, Hofmann, and Hummers methods followed by treatments in hydrogen sulfide, sulfur dioxide, or carbon disulfide. The doped materials were characterized by scanning electron microscopy, high-resolution X-ray photoelectron spectroscopy, combustible elemental analysis, and Raman spectroscopy. The ζ-potential and conductivity of sulfur-doped graphenes were also investigated in this paper. It was found that the level of doping is more dramatically influenced by the type of graphite oxide used rather than the type of sulfur-containing gas used during exfoliation. Resulting sulfur-doped graphenes act as metal-free electrocatalysts for an oxygen reduction reaction.

Ancient wood of the Acqualadrone rostrum: materials history through gas chromatography/mass spectrometry and sulfur X-ray absorption spectroscopy.

Science.gov (United States)

Frank, Patrick; Caruso, Francesco; Caponetti, Eugenio

2012-05-15

In 2008 the rostrum from an ancient warship was recovered from the Mediterranean near Acqualadrone, Sicily. To establish its provenance and condition, samples of black and brown rostrum wood were examined using sulfur K-edge X-ray absorption spectroscopy (XAS) and gas chromatography/mass spectrometry (GC/MS). GC/MS of pyrolytic volatiles yielded only guaiacyl derivatives, indicating construction from pinewood. A derivatized extract of black wood yielded forms of abietic acid and sandaracopimaric acid consistent with pine pitch waterproofing. Numerical fits to the sulfur K-edge XAS spectra showed that about 65% of the endogenous sulfur consisted of thiols and disulfides. Elemental sulfur was about 2% and 7% in black and brown wood, respectively, while pyritic sulfur was about 12% and 6%. About 2% of the sulfur in both wood types was modeled as trimethylsulfonium, possibly reflecting biogenic (dimethylsulfonio)propionate. High-valent sulfur was exclusively represented by sulfate esters, consistent with bacterial sulfotransferase activity. Traces of chloride were detected, but no free sulfate ion. In summary, the rostrum was manufactured of pine wood and subsequently waterproofed with pine pitch. The subsequent 2300 years included battle, foundering, and marine burial followed by anoxia, bacterial colonization, sulfate reduction, and mobilization of transition metals, which produced pyrite and copious appended sulfur functionality.

Mercury adsorption properties of sulfur-impregnated adsorbents

Science.gov (United States)

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.

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

DEFF Research Database (Denmark)

Konttinen, Jukka T.; Johnsson, Jan Erik

1999-01-01

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

New treating processes for sulfur-containing natural gases

Energy Technology Data Exchange (ETDEWEB)

Kislenko, N.; Aphanasiev, A.; Nabokov, S.; Ismailova, H. [VNIIGAS, Moscow (Russian Federation)

1996-12-31

The traditional method of removing H{sub 2}S from sour natural gases is first to treat the gas with a solvent and then to recover the H{sub 2}S from the sour stream in a Claus plant. This method recovers up to 97% of the sulfur when a three-stage Claus unit is employed. Amine/Claus units have operating difficulties for small sulfur capacities (up to 5 tons/day) because the operation of the fired equipment (reaction furnace) is much more difficult. Therefore, for small scale sulfur recovery plants redox processes which exhibit a significant reduction in investment and operating costs are normally used. Many different factors influence the choice of gas desulfurization technology--composition and gas flow, environmental sulfur recovery requirements and CO{sub 2}/H{sub 2}S ratio.

Experimental and numerical modeling of sulfur plugging in carbonate reservoirs

Energy Technology Data Exchange (ETDEWEB)

Abou-Kassem, J.H. [Chemical and Petroleum Engineering Department, UAE University, PO Box 17555, Al-Ain (United Arab Emirates)

2000-05-01

Sour gas, mainly in the form of hydrogen sulfide, is produced in large amounts from many oil and gas reservoirs in the United Arab Emirates. In addition to creating problems in production lines, the precipitation of elemental sulfur in vicinity of the wellbore is often reported to cause wellbore damage. While there have been several studies performed on the role of solid deposition in gas reservoirs, the role of sulfur deposition in oil reservoirs has not been investigated. This paper presents experimental results along with a comprehensive wellbore model that predicts sulfur precipitation as well as plugging. Two separate sets of experiments, one for a gas phase system and another for a crude oil system, were conducted to investigate the deposition of elemental sulfur in (linear) carbonate cores. The gas flow tests were conducted with elemental sulfur being carried with nitrogen through limestone cores. Changes in gas flow rate were monitored while the injection pressure was held constant. A series of experiments generated valuable data for plugging with elemental sulfur. X-ray diffraction tests provided evidence of sulfur deposition along the cores. The oil flow tests were carried out to observe sulfur precipitation and plugging in a carbonate core. The crude oil was de-asphalted before conducting these tests in order to isolate the effect of asphaltene plugging. Significant plugging was observed and was found to be dependent on flow rate and initial sulfur concentration. This information was used in a phenomenological model that was incorporated in the wellbore numerical model. The data for the numerical model were obtained from both test tube and oil flow experiments. By using a phenomenological model, the wellbore plugging was modeled with an excellent match (with experimental results)

Sensing sulfur oxides and other sulfur bearing pollutants with solid electrolyte pellets. I. Gas concentration cells

Energy Technology Data Exchange (ETDEWEB)

Chamberland, A M; Gauthier, J M

1977-01-01

A new sensing technique using a solid electrolyte has been demonstrated for sulfur-bearing pollutants. Based on potentiometric measurements across a pellet of potassium sulfate, this sensor allows concentrations of sulfur dioxides, sulfur trioxide, hydrogen sulfide, methyl mercaptan and carbonyl sulfide in air to be measured with accuracy. Its operational concentration range at the present time is 0.1 ppM up to at least 10,000 ppM. The presence of other common pollutants such as carbon dioxide, methane, nitric oxide and nitrogen dioxide does not interfere with the measurement of air samples containing sulfur-bearing pollutants.

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

Science.gov (United States)

2010-07-01

....0 pounds of sulfur dioxide per million BTU actual heat input for the coal-fired boiler and 0.4... BTU actual heat input for coal-fired boiler C exiting through stack 5. (3) 2.24 pounds of sulfur dioxide per million BTU acutal heat input for coal-fired boiler D exiting through stack 6. (E) In lieu of...

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

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-06-01

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

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

Energy Technology Data Exchange (ETDEWEB)

1977-01-01

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

The performance of oil-fired boilers: The influence of fuel sulfur on emissions and appliance integrity

International Nuclear Information System (INIS)

Lee, S.W.

1997-01-01

ASHRAE research project RP-757 examined the impact of distillate fuel sulfur content on the energy and emission performance of oil-fired boilers. The project involved construction of a combustion test rig housed in a constant-temperature test room; installation of a 102.5 kW (350,000 Btu/h) capacity, steel hot water boiler equipped with a special test section to simulate boiler heat exchanger surfaces; introduction of continuous emission analyzers and data-acquisition/control systems; and preparation of specific test fuel oils in the 0.01% to 1.2% sulfur range. The combustion experiments provided comprehensive data including flue gas composition, total deposit weight on test heat exchanger surfaces, pH, sulfite and sulfate in the flue gas condensate and soluble deposits, and iron and sulfur in soluble and insoluble deposits. Controlled combustion experiments using the experimental boiler and fuels have provided the following observations for a systematic increase of boiler fuel sulfur: the flue gas SO 2 increased linearly; the acidity and concentrations of sulfite and sulfate in flue gas condensate and the soluble deposits increased; total surface deposits, which are made up of the soluble and insoluble portions, increased linearly; higher amounts of soluble iron sulfates formed with apparent increased corrosion potential of metal surfaces; and the boiler efficiency remained unchanged during the short-term combustion experiments

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-09-15

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

Simultaneous removal of sulfur dioxide and polycyclic aromatic hydrocarbons from incineration flue gas using activated carbon fibers.

Science.gov (United States)

Liu, Zhen-Shu; Li, Wen-Kai; Hung, Ming-Jui

2014-09-01

Incineration flue gas contains polycyclic aromatic hydrocarbons (PAHs) and sulfur dioxide (SO2). The effects of SO2 concentration (0, 350, 750, and 1000 ppm), reaction temperature (160, 200, and 280 degrees C), and the type of activated carbon fibers (ACFs) on the removal of SO2 and PAHs by ACFs were examined in this study. A fluidized bed incinerator was used to simulate practical incineration flue gas. It was found that the presence of SO2 in the incineration flue gas could drastically decrease removal of PAHs because of competitive adsorption. The effect of rise in the reaction temperature from 160 to 280 degrees C on removal of PAHs was greater than that on SO2 removal at an SO2 concentration of 750 ppm. Among the three ACFs studied, ACF-B, with the highest microporous volume, highest O content, and the tightest structure, was the best adsorbent for removing SO2 and PAHs when these gases coexisted in the incineration flue gas. Implications: Simultaneous adsorption of sulfur dioxide (SO2) and polycyclic aromatic hydrocarbons (PAHs) emitted from incineration flue gas onto activated carbon fibers (ACFs) meant to devise a new technique showed that the presence of SO2 in the incineration flue gas leads to a drastic decrease in removal of PAHs because of competitive adsorption. Reaction temperature had a greater influence on PAHs removal than on SO2 removal. ACF-B, with the highest microporous volume, highest O content, and tightest structure among the three studied ACFs, was found to be the best adsorbent for removing SO2 and PAHs.

Sulfur gained from flue gas, a demonstration unit of the Wellman-Lord process annexed to a black coal power plant

Energy Technology Data Exchange (ETDEWEB)

Schulte, H

1977-12-16

Details of reducing air pollution by desulfurization of flue gases are presented. The demonstration unit is annexed to a 115 MW block at the Gary power plant in Indiana, USA. A second unit is being installed at the larger coal power plant in San Juan, New Mexico. The Wellman-Lord technology achieves a higher than 90% desulfurization of industrial waste gases. The technology is based on washing the gases with sodium sulfide. The resulting concentrated sulfur dioxide gas is used for pure sulfur and sulfuric acid production. Sodium sulfate is another commercial by-product obtained from the sodium sulfide regeneration cycle. Chemical details and the technological flow sheet are discussed. Electricity production costs in the power plants due to desulfurization of waste gases will increase by an estimated 15%. Advantages, in addition to reducing air pollution and marketing sulfur products, are also seen in the absence of sulfur containing wastes for disposal. (In German)

Sulfur-Bearing Phases Detected by Evolved Gas Analysis of the Rocknest Aeolian Deposit, Gale Crater, Mars

Science.gov (United States)

Mcadam, Amy Catherine; Franz, Heather Bryant

2014-01-01

The Sample Analysis at Mars (SAM) instrument suite detected SO2, H2S, OCS, and CS2 from approx.450 to 800 C during evolved gas analysis (EGA) of materials from the Rocknest aeolian deposit in Gale Crater, Mars. This was the first detection of evolved sulfur species from a Martian surface sample during in situ EGA. SO2(approx. 3-22 micro-mol) is consistent with the thermal decomposition of Fe sulfates or Ca sulfites, or evolution/desorption from sulfur-bearing amorphous phases. Reactions between reduced sulfur phases such as sulfides and evolved O2 or H2O in the SAM oven are another candidate SO2 source. H2S (approx.41-109 nmol) is consistent with interactions of H2O, H2 and/or HCl with reduced sulfur phases and/or SO2 in the SAM oven. OCS (approx.1-5 nmol) and CS2(approx.0.2-1 nmol) are likely derived from reactions between carbon-bearing compounds and reduced sulfur. Sulfates and sulfites indicate some aqueous interactions, although not necessarily at the Rocknest site; Fe sulfates imply interaction with acid solutions whereas Ca sulfites can form from acidic to near-neutral solutions. Sulfides in the Rocknest materials suggest input from materials originally deposited in a reducing environment or from detrital sulfides from an igneous source. The presence of sulfides also suggests that the materials have not been extensively altered by oxidative aqueous weathering. The possibility of both reduced and oxidized sulfur compounds in the deposit indicates a nonequilibrium assemblage. Understanding the sulfur mineralogy in Rocknest materials, which exhibit chemical similarities to basaltic fines analyzed elsewhere on Mars, can provide insight in to the origin and alteration history of Martian surface materials.

Volcanic sulfur degassing and the role of sulfides in controlling volcanic metal emissions

Science.gov (United States)

Edmonds, M.; Liu, E.

2017-12-01

Volcanoes emit prodigious quantities of sulfur and metals, their behaviour inextricably linked through pre-eruptive sulfide systematics and through degassing and speciation in the volcanic plume. Fundamental differences exist in the metal output of ocean island versus arc volcanoes, with volcanoes in Hawaii and Iceland outgassing large fluxes of gaseous and particulate chalcophiles; and arc volcanoes' plumes, in contrast, enriched in Zn, Cu, Tl and Pb. Metals and metalloids partition into a magmatic vapor phase from silicate melt at crustal pressures. Their abundance in magmatic vapor is influenced strongly by sulfide saturation and by the composition of the magmatic vapor phase, particularly with respect to chloride. These factors are highly dependent on tectonic setting. Metal outgassing is controlled by magma water content and redox: deep saturation in vapor and minimal sulfide in arc basalts yields metal-rich vapor; shallow degassing and resorption of sulfides feeds the metal content of volcanic gas in ocean islands. We present a detailed study of the sulfide systematics of the products of the 2014-2015 Holuhraun basaltic fissure eruption (Bárðarbunga volcanic system, Iceland) to illustrate the interplay between late water and sulfur outgassing; sulfide saturation and breakdown; and metal partitioning into a vapor phase. Sulfide globules, representing quenched droplets of an immiscible sulfide liquid, are preserved within erupted tephra. Sulfide globules in rapidly quenched tephra are preserved within both matrix glass and as inclusions in crystals. The stereologically-corrected 3D size distribution of sulfide globules ranges from importance in supplying sulfur and metals to the atmosphere during eruption.

Hydrogen production system based on high temperature gas cooled reactor energy using the sulfur-iodine (SI) thermochemical water splitting cycle

International Nuclear Information System (INIS)

Garcia, L.; Gonzalez, D.

2011-01-01

Hydrogen production from water using nuclear energy offers one of the most attractive zero-emission energy strategies and the only one that is practical on a substantial scale. Recently, strong interest is seen in hydrogen production using heat of a high-temperature gas-cooled reactor. The high-temperature characteristics of the modular helium reactor (MHR) make it a strong candidate for producing hydrogen using thermochemical or high-temperature electrolysis (HTE) processes. Eventually it could be also employ a high-temperature gas-cooled reactor (HTGR), which is particularly attractive because it has unique capability, among potential future generation nuclear power options, to produce high-temperature heat ideally suited for nuclear-heated hydrogen production. Using heat from nuclear reactors to drive a sulfur-iodine (SI) thermochemical hydrogen production process has been interest of many laboratories in the world. One of the promising approaches to produce large quantity of hydrogen in an efficient way using the nuclear energy is the sulfur-iodine (SI) thermochemical water splitting cycle. Among the thermochemical cycles, the sulfur iodine process remains a very promising solution in matter of efficiency and cost. This work provides a pre-conceptual design description of a SI-Based H2-Nuclear Reactor plant. Software based on chemical process simulation (CPS) was used to simulate the thermochemical water splitting cycle Sulfur-Iodine for hydrogen production. (Author)

Natural gas and the environment

International Nuclear Information System (INIS)

DeCarufel, A.

1991-01-01

The role of various atmospheric pollutants in environmental changes and the global water cycle, carbon cycle, and energy balance is explained. The role of sulfur dioxide and nitrogen oxides in acid deposition is also outlined. The pollutants that contribute to environmental problems include nitrogen oxides and volatile organic compounds, carbon dioxide, and other greenhouse gases. The potential for natural gas utilization to mitigate some of these pollution problems is explored. Natural gas combustion emits less carbon dioxide and nitrogen oxides than combustion of other fossil fuel, and also does not produce sulfur dioxide, particulates, or volatile organics. Other pollution controlling opportunities offered by natural gas include the use of low-polluting burners, natural gas vehicles, and cogeneration systems. 18 figs., 4 tabs

Diesel Emission Control -- Sulfur Effects (DECSE) Program; Phase I Interim Data Report No. 1

Energy Technology Data Exchange (ETDEWEB)

DOE; ORNL; NREL; EMA; MECA

1999-08-15

The Diesel Emission Control-Sulfur Effects (DECSE) is a joint government/industry program to determine the impact of diesel fuel sulfur levels on emission control systems whose use could lower emissions of nitrogen oxides (NO{sub x}) and particulate matter (PM) from on-highway trucks in the 2002--2004 model years. Phase 1 of the program was developed with the following objectives in mind: (1) evaluate the effects of varying the level of sulfur content in the fuel on the emission reduction performance of four emission control technologies; and (2) measure and compare the effects of up to 250 hours of aging on selected devices for multiple levels of fuel sulfur content. This interim data report summarizes results as of August, 1999, on the status of the test programs being conducted on three technologies: lean-NO{sub x} catalysts, diesel particulate filters and diesel oxidation catalysts.

LIFAC flue gas desulfurization process an alternative SO{sub 2} control strategy

Energy Technology Data Exchange (ETDEWEB)

Patel, J.G. [Tampella Power Corp., Atlanta, GA (United States); Vilala, J. [Tampella Power Inc., Tampere (Finland)

1995-12-01

This paper discusses the results from two recently completed LIFAC flue gas desulfurization plants - 300 MW Shand lignite powered station owned by Saskatchewan Power Corporation and 60 MW Whitewater Valley high sulfur coal fired station owned by Richmond Powerand Light. LIFACis a dry FGD process in which limestone is injected into the upper regions of the boiler furnace and an activation reactor is used to humidify the unreacted limestone to achieve additional sulfur capture. The performance in both plants indicates that 70 to 80% sulfur is removed at a Ca/S ratio of 2. Cost performance data from these plants has shown that LI FAC both on construction cost and $/ton SO{sub 2} removed basis is very cost competitive compared to other SO{sub 2} control technologies. The Richmond plant has been realized under the auspices of the U.S. Department of Energy`s Clean Coal Technology program. The Shand plant is the first commercial installation in North America. The paper also discusses highlights of operating and maintenance experience, availability and handling of the solid waste product.

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

International Nuclear Information System (INIS)

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

2007-01-01

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

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

Science.gov (United States)

2016-01-01

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

FURNACE INJECTION OF ALKALINE SORBENTS FOR SULFURIC ACID CONTROL; SEMIANNUAL

International Nuclear Information System (INIS)

Gary M. Blythe

2002-01-01

This document summarizes progress on Cooperative Agreement DE-FC26-99FT40718, Furnace Injection of Alkaline Sorbents for Sulfuric Acid Control, during the time period October 1, 2001 through March 31, 2002. The objective of this project is to demonstrate the use of alkaline reagents injected into the furnace of coal-fired boilers as a means of controlling sulfuric acid emissions. The coincident removal of hydrochloric acid and hydrofluoric acid is also being determined, as is the removal of arsenic, a known poison for NO(sub X) selective catalytic reduction (SCR) catalysts. EPRI, the Tennessee Valley Authority (TVA), FirstEnergy Corporation, American Electric Power (AEP) and the Dravo Lime Company are project co-funders. URS Corporation is the prime contractor. This is the fifth reporting period for the subject Cooperative Agreement. During the previous (fourth) period, two long-term sorbent injection tests were conducted, one on Unit 3 at FirstEnergy's Bruce Mansfield Plant (BMP) and one on Unit 1 at AEP's Gavin Plant. Those tests determined the effectiveness of injecting alkaline slurries into the upper furnace of the boiler as a means of controlling sulfuric acid emissions from these units. The alkaline slurries tested included commercially available magnesium hydroxide slurry (Gavin Plant) and a byproduct magnesium hydroxide slurry (at both Gavin and BMP). The tests showed that injecting either the commercial or the byproduct magnesium hydroxide slurry could achieve up to 70-75% overall sulfuric acid removal. At BMP, the overall removal was limited by the need to maintain acceptable electrostatic precipitator (ESP) particulate control performance. At Gavin Plant, the overall sulfuric acid removal was limited because the furnace injected sorbent was less effective at removing SO(sub 3) formed across the SCR system installed on the unit for NO(sub X) control than at removing SO(sub 3) formed in the furnace. The SO(sub 3) removal results were presented in the

Effects of sulfur on lead partitioning during sludge incineration based on experiments and thermodynamic calculations

Energy Technology Data Exchange (ETDEWEB)

Liu, Jing-yong, E-mail: www053991@126.com [School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006 (China); Huang, Shu-jie; Sun, Shui-yu; Ning, Xun-an; He, Rui-zhe [School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006 (China); Li, Xiao-ming [Guangdong Testing Institute of Product Quality Supervision, Guangzhou 510330 (China); Chen, Tao [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Luo, Guang-qian [State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074 (China); Xie, Wu-ming; Wang, Yu-jie; Zhuo, Zhong-xu; Fu, Jie-wen [School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006 (China)

2015-04-15

Highlights: • A thermodynamic equilibrium calculation was carried out. • Effects of three types of sulfurs on Pb distribution were investigated. • The mechanism for three types of sulfurs acting on Pb partitioning were proposed. • Lead partitioning and species in bottom ash and fly ash were identified. - Abstract: Experiments in a tubular furnace reactor and thermodynamic equilibrium calculations were conducted to investigate the impact of sulfur compounds on the migration of lead (Pb) during sludge incineration. Representative samples of typical sludge with and without the addition of sulfur compounds were combusted at 850 °C, and the partitioning of Pb in the solid phase (bottom ash) and gas phase (fly ash and flue gas) was quantified. The results indicate that three types of sulfur compounds (S, Na{sub 2}S and Na{sub 2}SO{sub 4}) added to the sludge could facilitate the volatilization of Pb in the gas phase (fly ash and flue gas) into metal sulfates displacing its sulfides and some of its oxides. The effect of promoting Pb volatilization by adding Na{sub 2}SO{sub 4} and Na{sub 2}S was superior to that of the addition of S. In bottom ash, different metallic sulfides were found in the forms of lead sulfide, aluminosilicate minerals, and polymetallic-sulfides, which were minimally volatilized. The chemical equilibrium calculations indicated that sulfur stabilizes Pb in the form of PbSO{sub 4}(s) at low temperatures (<1000 K). The equilibrium calculation prediction also suggested that SiO{sub 2}, CaO, TiO{sub 2}, and Al{sub 2}O{sub 3} containing materials function as condensed phase solids in the temperature range of 800–1100 K as sorbents to stabilize Pb. However, in the presence of sulfur or chlorine or the co-existence of sulfur and chlorine, these sorbents were inactive. The effect of sulfur on Pb partitioning in the sludge incineration process mainly depended on the gas phase reaction, the surface reaction, the volatilization of products, and the

Reduction of produced elementary sulfur in denitrifying sulfide removal process.

Science.gov (United States)

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

2011-05-01

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

Performance of the 0.3-meter transonic cryogenic tunnel with air, nitrogen, and sulfur hexafluoride media under closed loop automatic control

Science.gov (United States)

Balakrishna, S.; Kilgore, W. Allen

1995-01-01

The NASA Langley 0.3-m Transonic Cryogenic Tunnel was modified in 1994, to operate with any one of the three test gas media viz., air, cryogenic nitrogen gas, or sulfur hexafluoride gas. This document provides the initial test results with respect to the tunnel performance and tunnel control, as a part of the commissioning activities on the microcomputer based controller. The tunnel can provide precise and stable control of temperature to less than or equal to +/- 0.3 K in the range 80-320 K in cyro mode or 300-320 K in air/SF6 mode, pressure to +/- 0.01 psia in the range 15-88 psia and Mach number to +/- O.0015 in the range 0.150 to transonic Mach numbers up to 1.000. A new heat exchanger has been included in the tunnel circuit and is performing adequately. The tunnel airfoil testing benefits considerably by precise control of tunnel states and helps in generating high quality aerodynamic test data from the 0.3-m TCT.

Transformation of sulfur during pyrolysis and hydropyrolysis of coal

Energy Technology Data Exchange (ETDEWEB)

Chen, H.; Li, B.; Yang, J.; Zhang, B. [Chinese Academy of Sciences, Taiyuan (China). Inst. of Coal Chemistry

1998-05-01

It is reported that the transformation of sulfur during pyrolysis (Py) under nitrogen and hydropyrolysis (HyPy) of Chinese Yanzhou high sulfur bituminous coal and Hongmiao lignite was studied in a fixed-bed reactor. The volatile sulfur-containing products were determined by gas chromatography with flame photometric detection. The sulfur in initial coal and char (mainly aliphatic and thiophenic sulfur forms) was quantitatively analyzed using X-ray photoelectron spectroscopy (XPS). The desulfurization yield was calculated by elemental analysis. The main volatile sulfur-containing gas was H{sub 2}S in both Py and HyPy. Both the elemental analysis and XPS results indicated that more sulfur was removed in HyPy than in Py under nitrogen. Thiophenic sulfur can be partially hydrogenated and removed in HyPy. Pyrite can be reduced to a ferrous sulfide completely even as low as 400{degree}C in HyPy while in Py the reduction reaction continues up to 650{degree}C. Mineral matter can not only fix H{sub 2}S produced in Py and HyPy to form higher sulfur content chars but also catalyses the desulfurization reactions to form lower sulfur content tars in HyPy. 24 refs., 8 figs., 4 tabs.

Analysis of hydrogen, carbon, sulfur and volatile compounds in (U3Si2 - Al) nuclear fuel

International Nuclear Information System (INIS)

Moura, Sergio C.; Redigolo, Marcelo M.; Amaral, Priscila O.; Leao, Claudio; Oliveira, Glaucia A.C. de; Bustillos, Oscar V.

2015-01-01

Uranium silicide U 3 Si 2 is used as nuclear fuel in the research nuclear reactor IEA-R1 at IPEN/CNEN, Sao Paulo, Brazil. The U 3 Si 2 is dispersed in aluminum reaching high densities of uranium in the nucleus of the fuel, up to 4.8 gU cm -3 . This nuclear fuel must comply with a quality control, which includes analysis of hydrogen, carbon and sulfur for the U 3 Si 2 and volatile compound for the aluminum. Hydrogen, carbon and sulfur are analyzed by the method of Radio Frequency gas extraction combustion coupled with Infrared detector. Volatile compounds are analyzed by the method of heated gas extraction coupled with gravimetric measurement. These methods are recommended by the American Society for Testing Materials (ASTM) for nuclear materials. The average carbon and sulfur measurements are 30 μg g -1 and 3 μg g -1 , respectively, and 40 μg g -1 for volatile compounds. The hydrogen analyzer is a TCHEN 600 LECO, carbon and sulfur analyzer is a CS 244 LECO and the volatile compounds analyzer is a home-made apparatus that use a resistant furnace, a gas pipe measurement and a glove-box with controlled atmosphere where an analytical balance has been installed, this analyzer was made at IPEN laboratory. (author)

Effects of sulfur on lead partitioning during sludge incineration based on experiments and thermodynamic calculations.

Science.gov (United States)

Liu, Jing-yong; Huang, Shu-jie; Sun, Shui-yu; Ning, Xun-an; He, Rui-zhe; Li, Xiao-ming; Chen, Tao; Luo, Guang-qian; Xie, Wu-ming; Wang, Yu-Jie; Zhuo, Zhong-xu; Fu, Jie-wen

2015-04-01

Experiments in a tubular furnace reactor and thermodynamic equilibrium calculations were conducted to investigate the impact of sulfur compounds on the migration of lead (Pb) during sludge incineration. Representative samples of typical sludge with and without the addition of sulfur compounds were combusted at 850 °C, and the partitioning of Pb in the solid phase (bottom ash) and gas phase (fly ash and flue gas) was quantified. The results indicate that three types of sulfur compounds (S, Na2S and Na2SO4) added to the sludge could facilitate the volatilization of Pb in the gas phase (fly ash and flue gas) into metal sulfates displacing its sulfides and some of its oxides. The effect of promoting Pb volatilization by adding Na2SO4 and Na2S was superior to that of the addition of S. In bottom ash, different metallic sulfides were found in the forms of lead sulfide, aluminosilicate minerals, and polymetallic-sulfides, which were minimally volatilized. The chemical equilibrium calculations indicated that sulfur stabilizes Pb in the form of PbSO4(s) at low temperatures (incineration process mainly depended on the gas phase reaction, the surface reaction, the volatilization of products, and the concentration of Si, Ca and Al-containing compounds in the sludge. These findings provide useful information for understanding the partitioning behavior of Pb, facilitating the development of strategies to control the volatilization of Pb during sludge incineration. Copyright © 2014 Elsevier Ltd. All rights reserved.

A Sulfur Trigger for the 2017 Phreatomagmatic Eruption of Poás Volcano, Costa Rica? Insights from MultiGAS and Drone-based Gas Monitoring

Science.gov (United States)

de Moor, M. J.; Aiuppa, A.; Avard, G.; Diaz, J. A.; Corrales, E.; Rüdiger, J.; D´Arcy, F.; Fischer, T. P.; Stix, J.; Alan, A.

2017-12-01

In April 2017 Poás volcano entered its first magmatic eruption period of the 21st century. The initial explosive blasts produced eruption columns up to 4 km in height, destroyed the pre-existing dome that was emplaced during the last magmatic eruption in the 1950s, and showered the tourist observation deck with bombs. Over the following months, the hyperacid crater lake dried out and a transition from phreatomagmatic to strombolian activity was observed. Two vents now dominate the activity. The main vent (old dome site) produces gas, ash, and scoria. A second vent is located in the dried-out lake bed and produces a peculiar canary-yellow gas plume. A fixed MultiGAS instrument installed in the crater bottom recorded large changes in gas composition prior to the explosive eruptions. The station recorded a dramatic increase in SO2/CO2 from an average of 0.04 for March 2017 to an average of 7.4 the day before the first explosive eruption that occurred at 18:30 on 12 April. A simultaneous rapid decrease in H2S/SO2 from 2.7 to drones, allowing continued gas monitoring despite dangerous conditions. Extremely high SO2/CO2 of 33 was measured with drone-based miniaturized MultiGAS ("miniGAS") in May 2017, and the ratio has since dropped to 3, which are more typical values of high temperature magmatic gases at Poás. The SO2 flux from Poás was at record low levels (Drone-based SO2 DOAS ("DROAS") measurements indicate high SO2 fluxes from Poas of >2000 T/d since the explosive eruptions, indicating a strong magmatic source and open conduits. We attribute the unusually S-rich gas compositions observed at Poás prior to and during the initial eruptions to combustion of previously deposited hydrothermal sulfur. The very low gas flux from the system prior to the explosive eruptions suggests that this sulfur may have played a role in hydrothermal sealing, leading to pressurization of the magmatic-hydrothermal system and ultimately triggering phreatomagmatic eruptions and "top down

Methane oxidation in presence of sulfur dioxide

International Nuclear Information System (INIS)

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

2006-01-01

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

Composite harm to plants by sulfurous acid gas and oxidant

Energy Technology Data Exchange (ETDEWEB)

Matsushima, J

1971-01-01

The composite effects on plants of sulfur dioxide and ozone, SO/sub 2/ and PAN, SO/sub 2/ and nitrogen dioxide, and NO/sub 2/ and ozone were studied. Pinto bean plants were exposed to SO/sub 2/ or O/sub 3/ only, to each gas alternately, and to a mixture of the two. The degree of injury by the gas or gases was indicated in percentage by area of the leaves damaged. In cases where no geometric effect occurred the damage to the plant by the individual gas had been great; damage from the individual gas had been slight in these cases where such an effect was observed. The geometric effect is produced when the density of SO/sub 2/ is rather low, generally 0.05-0.25 ppm. A mixture of SO/sub 2/ and O/sub 3/ was applied to a tabacco plant; it affected fully grown leaves. In experiments on the composite effects of SO/sub 2/ and PAN on bean, tomato and pepper plants, PAN affected mainly young leaves while SO/sub 2/ affected mature ones. These effects were arithmetric rather then geometric. The SO/sub 2/ and NO/sub 2/ were also studied in the same manner. When SO/sub 2/ and NO/sub 2/ were mixed, a geometric effect was conspicuous in damage to vegetables, the symptoms of damage by either of the two appeared about the same, younger leaves being affected less. When treated with the two gases alternately, the damage was greater if the plants were first treated with NO/sub 2/; possible causes for this effect are discussed. No significant composite effect of NO/sub 2/ and O/sub 3/ was observed.

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

Energy Technology Data Exchange (ETDEWEB)

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

2010-02-15

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

Childhood physical abnormalities following paternal exposure to sulfur mustard gas in Iran: a case-control study

Directory of Open Access Journals (Sweden)

Khademolhosseini Seyyed M

2010-07-01

Full Text Available Abstract Background Mustard gas, a known chemical weapon, was used during the Iran-Iraq war of 1980-1988. We aimed to determine if exposure to mustard gas among men was significantly associated with abnormalities and disorders among progenies. Methods Using a case-control design, we identified all progenies of Sardasht men (exposed group, n = 498, who were born at least nine months after the exposure, compared to age-matched controls in Rabat, a nearby city (non-exposed group, n = 689. We conducted a thorough medical history, physical examination, and appropriate paraclinical studies to detect any physical abnormality and/or disorder. Given the presence of correlated data, we applied Generalized Estimating Equation (GEE multivariable models to determine associations. Results The overall frequency of detected physical abnormalities and disorders was significantly higher in the exposed group (19% vs. 11%, Odds Ratio [OR] 1.93, 95% Confidence Interval [CI], 1.37-2.72, P = 0.0002. This was consistent across sexes. Congenital anomalies (OR 3.54, 95% CI, 1.58-7.93, P = 0.002 and asthma (OR, 3.12, 95% CI, 1.43-6.80, P = 0.004 were most commonly associated with exposure. No single abnormality was associated with paternal exposure to mustard gas. Conclusion Our study demonstrates a generational effect of exposure to mustard gas. The lasting effects of mustard gas exposure in parents effects fertility and may impact child health and development in the long-term.

Potential of electrical gas discharges for pollution control of large gas volumes

International Nuclear Information System (INIS)

Kogelschatz, U.

1997-01-01

Non-equilibrium gas discharges in many cases offer an innovative approach to the solution cf industrial air pollution problems. Negative corona discharges are used in electrostatic precipitators to collect dust and fly ash particles. Pulsed positive streamer coronas, dielectric-barrier discharges and possibly also flow-stabilised high pressure glow discharges are emerging technologies for the destruction of air pollutants like nitrogen oxides and sulfur dioxide in flue gases and volatile organic compounds (VOCs) in industrial effluents. The different discharge types are discussed with special emphasis on their potential for upscaling. Major applications are expected particularly in the removal of dilute concentrations of air pollutants, in odour control and in the simultaneous removal of different pollutants. Dielectric-barrier discharges exhibit disposal efficiencies similar to those of pulsed positive streamer coronas and require less sophisticated feeding circuits in large-scale industrial applications. (author)

Metal-free reduction of the greenhouse gas sulfur hexafluoride, formation of SF5 containing ion pairs and the application in fluorinations

KAUST Repository

Rueping, Magnus; Nikolaienko, Pavlo; Lebedev, Yury; Adams, Alina

2017-01-01

A protocol for the fast and selective two-electron reduction of the potent greenhouse gas sulfur hexafluoride (SF6) by organic electron donors at ambient temperature has been developed. The reaction yields solid ion pairs consisting of donor

Plutonium oxides analysis. Sulfur potentiometric analysis

International Nuclear Information System (INIS)

Anon.

Total sulfur determination (sulfur, sulfates, sulfides ...) in plutonium oxides, suitable for sulfate ion content between 0.003 percent to 0.2 percent, by dissolution in nitric hydrofluoric acid, nitrates elimination, addition of hydrochloric acid and reduction in hydrogen sulfide which is carried by an inert gas and neutralized by sodium hydroxide. Sodium sulfide is titrated with mercuric acetate by constant intensity potentiometry [fr

Sulfur dioxide emissions and market effects under the Clean Air Act Acid Rain Program

International Nuclear Information System (INIS)

Zipper, C.E.; Gilroy, L.

1998-01-01

The Clean Air Act Amendments of 1990 (CAAA90) established a national program to control sulfur dioxide (SO 2 ) emissions from electricity generation. CAAA90's market-based approach includes trading and banking of SO 2 -emissions allowances. The paper presents an analysis of data describing electric utility SO 2 emissions in 1995, the first year of the program's Phase I, and market effects over the 1990-95 period. Fuel switching and flue-gas desulfurization were the dominant means used in 1995 by targeted generators to reduce emissions to 51% of 1990 levels. Flue-gas desulfurization costs, emissions allowance prices, low-sulfur coal prices, and average sulfur contents of coals shipped to electric utilities declined over the 1990-95 period. Projections indicate that 13-15 million allowances will have been banked during the programs' Phase I, which ends in 1999, a quantity expected to last through the first decade of the program's stricter Phase II controls. In 1995, both allowance prices and SO 2 emissions were below pre-CAAA90 expectations. The reduction of SO 2 emissions beyond pre-CAAA90 expectations, combined with lower-than-expected allowance prices and declining compliance costs, can be viewed as a success for market-based environmental controls. 21 refs., 6 figs., 3 tabs

New uses of sulfur - update

Energy Technology Data Exchange (ETDEWEB)

Almond, K.P.

1995-07-01

An update to an extensive bibliography on alternate uses of sulfur was presented. Alberta Sulphur Research Ltd., previously compiled a bibliography in volume 24 of this quarterly bulletin. This update provides an additional 44 new publications. The information regarding current research focusses on topics regarding the use of sulfur in oil and gas applications, mining and metallurgy, concretes and other structural materials, waste management, rubber and textile products, asphalts and other paving and highway applications.

Sulfur dimers adsorbed on Au(111) as building blocks for sulfur octomers formation: A density functional study

International Nuclear Information System (INIS)

Hernandez-Tamargo, Carlos E.; Montero-Alejo, Ana Lilian; Pujals, Daniel Codorniu; Mikosch, Hans; Hernández, Mayra P.

2014-01-01

Experimental scanning tunneling microscopy (STM) studies have shown for more than two decades rectangular formations when sulfur atoms are deposited on Au(111) surfaces. The precursors have ranged from simple molecules or ions, such as SO 2 gas or sulfide anions, to more complex organosulfur compounds. We investigated, within the framework of the Density Functional Theory, the structure of these rectangular patterns assuming them entirely composed of sulfur atoms as the experimental evidence suggests. The sulfur coverage at which the simulations were carried out (0.67 ML or higher) provoked that the sulfur-sulfur association had to be taken into account for achieving a good agreement between the sets of simulated and experimental STM images. A combination of four sulfur dimers per rectangular formation properly explained the trends obtained by the experimental STM analysis which were related with the rectangles' size and shape fluctuations together with sulfur-sulfur distances within these rectangles. Finally, a projected density of states analysis showed that the dimers were capable of altering the Au(5d) electronic states at the same level as atomic sulfur adsorbed at low coverage. Besides, sulfur dimers states were perfectly distinguished, whose presence near and above the Fermi level can explain both: sulfur-sulfur bond elongation and dimers stability when they stayed adsorbed on the surface at high coverage

Sulfur dimers adsorbed on Au(111) as building blocks for sulfur octomers formation: A density functional study

Energy Technology Data Exchange (ETDEWEB)

Hernandez-Tamargo, Carlos E.; Montero-Alejo, Ana Lilian [Laboratory of Computational and Theoretical Chemistry (LQCT), Faculty of Chemistry, Havana University, Havana 10400 (Cuba); Pujals, Daniel Codorniu [Higher Institute of Technologies and Applied Sciences (InSTEC), Havana 10400 (Cuba); Mikosch, Hans [Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/E164-EC, 1060 Vienna (Austria); Hernández, Mayra P., E-mail: mayrap@imre.oc.uh.cu [Instituto de Ciencias y Tecnologías de Materiales (IMRE), Havana 10400 (Cuba)

2014-07-28

Experimental scanning tunneling microscopy (STM) studies have shown for more than two decades rectangular formations when sulfur atoms are deposited on Au(111) surfaces. The precursors have ranged from simple molecules or ions, such as SO{sub 2} gas or sulfide anions, to more complex organosulfur compounds. We investigated, within the framework of the Density Functional Theory, the structure of these rectangular patterns assuming them entirely composed of sulfur atoms as the experimental evidence suggests. The sulfur coverage at which the simulations were carried out (0.67 ML or higher) provoked that the sulfur-sulfur association had to be taken into account for achieving a good agreement between the sets of simulated and experimental STM images. A combination of four sulfur dimers per rectangular formation properly explained the trends obtained by the experimental STM analysis which were related with the rectangles' size and shape fluctuations together with sulfur-sulfur distances within these rectangles. Finally, a projected density of states analysis showed that the dimers were capable of altering the Au(5d) electronic states at the same level as atomic sulfur adsorbed at low coverage. Besides, sulfur dimers states were perfectly distinguished, whose presence near and above the Fermi level can explain both: sulfur-sulfur bond elongation and dimers stability when they stayed adsorbed on the surface at high coverage.

Characteristics of Sulfuric Acid Condensation on Cylinder Liners of Large Two-Stroke Marine Engines

DEFF Research Database (Denmark)

Cordtz, Rasmus Lage; Mayer, Stefan; Schramm, Jesper

. Formation of corrosive sulfuric acid in the cylinder gas is modeled with a cali-brated engine model that incorporates a detailed sulfur reaction mechanism. Condensation of sulfuric acid follows the analogy between heat and mass transfer. Average bulk gas acid dew points are calculated by applying two......-phase thermochemistry of the binary H2O-H2SO4 system. Max dew points of typically more than 200 °C are modeled close to max pressure and variations in terms of operating conditions are not large. However small increments of the dew point provided by e.g. the residual gas fraction, operating pressure, sulfur content...

78 FR 5303 - Approval and Promulgation of Implementation Plans; State of Missouri; Control of Sulfur Emissions...

Science.gov (United States)

2013-01-25

... stringency of the SIP. Missouri's revision adds 10 CSR 10- 5.570 Control of Sulfur Emissions from Stationary... approving the State's request to add 10 CSR 10-5.570 Control of Sulfur Emissions from Stationary Boilers to... Management and Budget under Executive Order 12866 (58 FR 51735, October 4, 1993); Does not impose an...

40 CFR 52.125 - Control strategy and regulations: Sulfur oxides.

Science.gov (United States)

2010-07-01

... to existing fuel burning equipment producing electrical energy will provide for the attainment and...: Sulfur oxides. 52.125 Section 52.125 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... since the control strategy does not analyze the impact of smelter fugitive emissions on ambient air...

Contribution to the study of sulfur trioxide formation and determination of the sulfuric acid dew point in boiler plants

Energy Technology Data Exchange (ETDEWEB)

Mueller, H.

1983-11-01

This paper analyzes chemical reaction kinetics of the formation of sulfur trioxide and sulfuric acid in combustion air and flue gas of steam generators. Formulae for sulfuric acid equilibrium reactions according to Wahnschaffe (W. Grimm, 1972) and R. Hasse, H.W. Borgmann (1962) are presented. Theoretical acid dew point, combustion parameters with influence on the dew point temperature and formation of sulfates are further discussed. Sulfur trioxide formation at temperatures above 1,000 C as a non-equilibrium reaction is outlined as another variant of chemical reactions. A graphic evaluation is made of dew point conditions in brown coal dust fired, and heating oil fired steam generators. (11 refs.)

Use of sulfur concrete for radioecological problems solution in Kazakhstan

International Nuclear Information System (INIS)

Takibaev, Zh.; Belyashov, D.; Vagin, S.

2001-01-01

At present during intensive development of oil and gas fields in Kazakhstan a lot amount of sulfur is extracting. The problem of sulfur utilization demands its immediate solution. One of the perspective trends of sulfur utilization is use it in production of sulfur polymer concrete. It is well known, that encapsulation of low level radioactive and toxic wastes in sulfur polymer concrete and design from it radiation protection facilities have good perspectives for solution of radioecological problems. Sulfur concrete has high corrosion and radiation stability, improved mechanical and chemical properties. Unique properties of sulfur concrete allow to use it in materials ensuring protection from external irradiation

Quantitative on-line analysis of sulfur compounds in complex hydrocarbon matrices.

Science.gov (United States)

Djokic, Marko R; Ristic, Nenad D; Olahova, Natalia; Marin, Guy B; Van Geem, Kevin M

2017-08-04

An improved method for on-line measurement of sulfur containing compounds in complex matrices is presented. The on-line system consists of a specifically designed sampling system connected to a comprehensive two-dimensional gas chromatograph (GC×GC) equipped with two capillary columns (Rtx ® -1 PONA×SGE BPX50), a flame ionization detector (FID) and a sulfur chemiluminescence detector (SCD). The result is an unprecedented sensitivity down to ppm level (1 ppm-w) for various sulfur containing compounds in very complex hydrocarbon matrices. In addition to the GC×GC-SCD, the low molecular weight sulfur containing compounds such as hydrogen sulfide (H 2 S) and carbonyl sulfide (COS) can be analyzed using a thermal conductivity detector of a so-called refinery gas analyzer (RGA). The methodology was extensively tested on a continuous flow pilot plant for steam cracking, in which quantification of sulfur containing compounds in the reactor effluent was carried out using 3-chlorothiophene as internal standard. The GC×GC-FID/-SCD settings were optimized for ppm analysis of sulfur compounds in olefin-rich (ethylene- and propylene-rich) hydrocarbon matrices produced by steam cracking of petroleum feedstocks. Besides that is primarily used for analysis of the hydrocarbon matrix, FID of the GC×GC-FID/-SCD set-up serves to double check the amount of added sulfur internal standard which is crucial for a proper quantification of sulfur compounds. When vacuum gas oil containing 780 ppm-w of elemental sulfur in the form of benzothiophenes and dibenzothiophenes is subjected to steam cracking, the sulfur balance was closed, with 75% of the sulfur contained in the feed is converted to hydrogen sulfide, 13% to alkyl homologues of thiophene while the remaining 12% is present in the form of alkyl homologues of benzothiophenes. The methodology can be applied for many other conversion processes which use sulfur containing feeds such as hydrocracking, catalytic cracking, kerogen

Selective catalytic oxidation: a new catalytic approach to the desulfurization of natural gas and liquid petroleum gas for fuel cell reformer applications

Science.gov (United States)

Lampert, J.

In both natural gas and liquid petroleum gas (LPG), sulfur degrades the performance of the catalysts used in fuel reformers and fuel cells. In order to improve system performance, the sulfur must be removed to concentrations of less than 200 ppbv (in many applications to less than 20 ppbv) before the fuel reforming operation. Engelhard Corporation presents a unique approach to the desulfurization of natural gas and LPG. This new method catalytically converts the organic and inorganic sulfur species to sulfur oxides. The sulfur oxides are then adsorbed on a high capacity adsorbent. The sulfur compounds in the fuel are converted to sulfur oxides by combining the fuel with a small amount of air. The mixture is then heated from 250 to 270 °C, and contacted with a monolith supported sulfur tolerant catalyst at atmospheric pressure. When Engelhard Corporation demonstrated this catalytic approach in the laboratory, the result showed sulfur breakthrough to be less than 10 ppbv in the case of natural gas, and less than 150 ppbv for LPG. We used a simulated natural gas and LPG mixture, doped with a 50-170 ppmv sulfur compound containing equal concentrations of COS, ethylmercaptan, dimethylsulfide, methylethylsulfide and tetrahydrothiophene. There is no need for recycled H 2 as in the case for hydrodesulfurization.

Sodium lauryl sulfate - a biocide for controlling acidity development in bulk commercially formed solid elemental sulfur

Energy Technology Data Exchange (ETDEWEB)

Hyne, J. B. [Calgary Univ., AB (Canada). Dept. of Biological Sciences

1996-04-01

Acidification of bulk elemental sulfur caused by Thiobacillus species which consume elemental sulfur by converting it into oxidized sulfur forms, was studied. Contributory factors, such as length of time in transit or in storage, warm temperatures, the presence of air and moisture, particle size and form of sulfur, and the presence of sources of carbon, nitrogen and phosphorus nutrients, were reviewed. Laboratory experiments with adding sodium lauryl sulfate (SLS), a known biocide, to sulfur inoculated with Thiobacillus, proved to be an efficient method for controlling acidity development. At the concentration required for effectiveness SLS did not interfere with purity specifications, had negligible effect on moisture, and appeared to be compatible with current dust suppression application practices. 2 tabs., 3 figs.

Air Versus Sulfur Hexafluoride Gas Tamponade in Descemet Membrane Endothelial Keratoplasty: A Fellow Eye Comparison.

Science.gov (United States)

von Marchtaler, Philipp V; Weller, Julia M; Kruse, Friedrich E; Tourtas, Theofilos

2018-01-01

To perform a fellow eye comparison of outcomes and complications when using air or sulfur hexafluoride (SF6) gas as a tamponade in Descemet membrane endothelial keratoplasty (DMEK). One hundred thirty-six eyes of 68 consecutive patients who underwent uneventful DMEK in both eyes for Fuchs endothelial corneal dystrophy were included in this retrospective study. Inclusion criteria were air tamponade (80% of the anterior chamber volume) in the first eye and 20% SF6 gas tamponade (80% of the anterior chamber volume) in the second eye; and same donor tissue culture condition in both eyes. All eyes received laser iridotomy on the day before DMEK. Main outcome measures included preoperative and postoperative best-corrected visual acuity, endothelial cell density, corneal volume, rebubbling rate, and rate of postoperative pupillary block caused by the air/gas bubble. Thirteen of 68 eyes (19.1%) with an air tamponade needed rebubbling compared with 4 of 68 eyes (5.9%) with an SF6 gas tamponade (P = 0.036). Postoperative pupillary block necessitating partial release of air/gas occurred in 1 eye (1.5%) with an air tamponade and 3 eyes (4.4%) with an SF6 gas tamponade (P = 0.301). There were no significant differences in preoperative and postoperative best-corrected visual acuity, endothelial cell density, and corneal volume within 3-month follow-up. Our results confirm the previously reported better graft adhesion when using an SF6 gas tamponade in DMEK without increased endothelial cell toxicity. The rate of pupillary block in eyes with an SF6 gas tamponade was comparable to that with an air tamponade. As a consequence, we recommend using SF6 gas as the tamponade in DMEK.

Metal-free reduction of the greenhouse gas sulfur hexafluoride, formation of SF5 containing ion pairs and the application in fluorinations

KAUST Repository

Rueping, Magnus

2017-05-04

A protocol for the fast and selective two-electron reduction of the potent greenhouse gas sulfur hexafluoride (SF6) by organic electron donors at ambient temperature has been developed. The reaction yields solid ion pairs consisting of donor dications and SF5-anions which can be effectively used in fluorination reactions.

Demonstration of Selective Catalytic Reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Technical progress report, first and second quarters 1994

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-11-01

The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from U.S., Japanese and European catalyst suppliers on a high-sulfur U.S. coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involve injecting ammonia into the flue gas generated from coal combustion in a boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to form nitrogen and water vapor. Although SCR is widely practiced in Japan and Europe on gas-, oil-, and low-sulfur coal-fired boilers, there are several technical uncertainties associated with applying SCR to U.S. coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in U.S. coals that are not present in other fuels; (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO{sub 2} and SO{sub 3}; and (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties are being explored by operating a series of small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur U.S. coal. The project is being conducted in the following three phases: permitting, environmental monitoring plan and preliminary engineering; detailed design engineering and construction; and operation, testing, disposition and final report. The project was in the operation and testing phase during this reporting period. Accomplishments for this period are described.

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

Science.gov (United States)

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

2012-08-14

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

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

International Nuclear Information System (INIS)

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

2008-01-01

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

Sulfur recirculation for increased electricity production in Waste-to-Energy plants.

Science.gov (United States)

Andersson, Sven; Blomqvist, Evalena W; Bäfver, Linda; Jones, Frida; Davidsson, Kent; Froitzheim, Jan; Karlsson, Martin; Larsson, Erik; Liske, Jesper

2014-01-01

Sulfur recirculation is a new technology for reducing boiler corrosion and dioxin formation. It was demonstrated in full-scale tests at a Waste to Energy plant in Göteborg (Sweden) during nearly two months of operation. Sulfur was recirculated as sulfuric acid from the flue gas cleaning back to the boiler, thus creating a sulfur loop. The new technology was evaluated by extensive measurement campaigns during operation under normal conditions (reference case) and operation with sulfur recirculation. The chlorine content of both fly ash and boiler ash decreased and the sulfur content increased during the sulfur recirculation tests. The deposit growth and the particle concentration decreased with sulfur recirculation and the dioxin concentration (I-TEQ) of the flue gas was reduced by approximately 25%. Sulfuric acid dew point measurements showed that the sulfuric acid dosage did not lead to elevated SO3 concentrations, which may otherwise induce low temperature corrosion. In the sulfur recirculation corrosion probe exposures, the corrosion rate decreased for all tested materials (16Mo3, Sanicro 28 and Inconel 625) and material temperatures (450 °C and 525 °C) compared to the reference exposure. The corrosion rates were reduced by 60-90%. Sulfur recirculation prevented the formation of transition metal chlorides at the metal/oxide interface, formation of chromate and reduced the presence of zinc in the corrosion products. Furthermore, measured corrosion rates at 525 °C with sulfur recirculation in operation were similar or lower compared to those measured at 450 °C material temperature in reference conditions, which corresponds to normal operation at normal steam temperatures. This implies that sulfur recirculation allows for higher steam data and electricity production without increasing corrosion. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

40 CFR 80.500 - What are the implementation dates for the motor vehicle diesel fuel sulfur control program?

Science.gov (United States)

2010-07-01

... Information § 80.500 What are the implementation dates for the motor vehicle diesel fuel sulfur control... 40 Protection of Environment 16 2010-07-01 2010-07-01 false What are the implementation dates for the motor vehicle diesel fuel sulfur control program? 80.500 Section 80.500 Protection of Environment...

FURNACE INJECTION OF ALKALINE SORBENTS FOR SULFURIC ACID REMOVAL

Energy Technology Data Exchange (ETDEWEB)

Gary M. Blythe

2004-01-01

The objective of this project has been to demonstrate the use of alkaline reagents injected into the furnace of coal-fired boilers as a means of controlling sulfuric acid emissions. The project was co-funded by the U.S. DOE National Energy Technology Laboratory under Cooperative Agreement DE-FC26-99FT40718, along with EPRI, the American Electric Power Company (AEP), FirstEnergy Corporation, the Tennessee Valley Authority, and Carmeuse North America. Sulfuric acid controls are becoming of increased interest for coal-fired power generating units for a number of reasons. In particular, sulfuric acid can cause plant operation problems such as air heater plugging and fouling, back-end corrosion, and plume opacity. These issues will likely be exacerbated with the retrofit of selective catalytic reduction (SCR) for NOX control, as SCR catalysts are known to further oxidize a portion of the flue gas SO{sub 2} to SO{sub 3}. The project tested the effectiveness of furnace injection of four different magnesium-based or dolomitic alkaline sorbents on full-scale utility boilers. These reagents were tested during one- to two-week tests conducted on two FirstEnergy Bruce Mansfield Plant (BMP) units. One of the sorbents tested was a magnesium hydroxide slurry byproduct from a modified Thiosorbic{reg_sign} Lime wet flue gas desulfurization process. The other three sorbents are available commercially and include dolomite, pressure-hydrated dolomitic lime, and commercially available magnesium hydroxide. The dolomite reagent was injected as a dry powder through out-of-service burners. The other three reagents were injected as slurries through air-atomizing nozzles inserted through the front wall of the upper furnace. After completing the four one- to two-week tests, the most promising sorbents were selected for longer-term (approximately 25-day) full-scale tests on two different units. The longer-term tests were conducted to confirm sorbent effectiveness over extended operation on two

The Quantitation of Sulfur Mustard By-Products, Sulfur-Containing Herbicides, and Organophosphonates in Soil and Concrete

Energy Technology Data Exchange (ETDEWEB)

Tomkins, B.A., Sega, G.A. [Oak Ridge National Lab., TN (United States)], Macnaughton, S.J. [Microbial Insights, Inc., Rockford, TN (United States)

1997-12-31

Over the past fifty years, the facilities at Rocky Mountain Arsenal have been used for the manufacturing, bottling, and shipping sulfur- containing herbicides, sulfur mustard, and Sarin. There is a need for analytical methods capable of determining these constituents quickly to determine exactly how specific waste structural materials should be handled, treated, and landfilled.These species are extracted rapidly from heated samples of soil or crushed concrete using acetonitrile at elevated pressure, then analyzed using a gas chromatograph equipped with a flame photometric detector. Thiodiglycol, the major hydrolysis product of sulfur mustard, must be converted to a silylated derivative prior to quantitation. Detection limits, calculated using two statistically-unbiased protocols, ranged between 2-13 micrograms analyte/g soil or concrete.

Sensitivity analysis of a light gas oil deep hydrodesulfurization process via catalytic distillation

Energy Technology Data Exchange (ETDEWEB)

Rosales-Quintero, A.; Vargas-Villamil, F.D. [Prog. de Matematicas Aplicadas y Computacion, Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152, Mexico, D.F. 07330 (Mexico); Arce-Medina, E. [Instituto Politecnico Nacional, ESIQIE, Ed. 8 Col. Lindavista, Mexico, D.F. 07738 (Mexico)

2008-01-30

In this work, a sensitivity analysis of a light gas oil deep hydrodesulfurization catalytic distillation column is presented. The aim is to evaluate the effects of various parameters and operating conditions on the organic sulfur compound elimination by using a realistic light gas oil fraction. The hydrocarbons are modeled using pseudocompounds, while the organic sulfur compounds are modeled using model compounds, i.e., dibenzothiophene (DBT) and 4,6-dimethyl dibenzothiophene (4,6-DMDBT). These are among the most refractive sulfur compounds present in the oil fractions. A sensitivity analysis is discussed for the reflux ratio, bottom flow rate, condenser temperature, hydrogen and gas oil feed stages, catalyst loading, the reactive, stripping, and rectifying stages, feed disturbances, and multiple feeds. The results give insight into the qualitative effect of some of the operating variables and disturbances on organic sulfur elimination. In addition, they show that special attention must be given to the bottom flow rate and LGO feed rate control. (author)

Sulfur Poisoning of Ni/stabilized-zirconia Anodes – Effect on Long-Term Durability

DEFF Research Database (Denmark)

Hauch, Anne; Hagen, Anke; Hjelm, Johan

2013-01-01

Sulfur impurities in carbon containing fuels for solid oxide fuel cells (SOFC), e.g. natural gas and biogas, can lead to significant losses in performance due to the sulfur sensitivity of Ni/YSZ SOFC anodes. Full cells having Ni/YSZ and Ni/ScYSZ anodes have been characterized during long-term gal...... to focus on the long-term effect over a few hundred of hours. This work describes and correlates the observed evolution of anode performance, over hundreds of hours, with sulfur poisoning with the different operating conditions.......Sulfur impurities in carbon containing fuels for solid oxide fuel cells (SOFC), e.g. natural gas and biogas, can lead to significant losses in performance due to the sulfur sensitivity of Ni/YSZ SOFC anodes. Full cells having Ni/YSZ and Ni/ScYSZ anodes have been characterized during long...

Gas dusulfurization

International Nuclear Information System (INIS)

Powell, B.E.; Bakhshi, V.S.; Randolph, D.A.

1984-01-01

A process for adsorbing sulfur dioxide from a gas comprising contacting a gas containing SO 2 , such as a flue gas, with about stoichiometric amounts of a specially prepared calcium oxide so that substantially all of the sulfur dioxide content is reacted throughout the calcium oxide particle to form a calcium sulfate reaction product. The useful calcium oxide particles comprise a highly voided skeletal structure of very large surface area and large pore volume with numerous macro pores. Such particles are obtained by flash calcining sand-size grains of calcium carbonate, such as aragonite, calcite or dolomite

Reduced sulfur compounds in gas from construction and demolition debris landfills.

Science.gov (United States)

Lee, Sue; Xu, Qiyong; Booth, Matthew; Townsend, Timothy G; Chadik, Paul; Bitton, Gabriel

2006-01-01

The biological conversion of sulfate from disposed gypsum drywall to hydrogen sulfide (H(2)S) in the anaerobic environment of a landfill results in odor problems and possible health concerns at many disposal facilities. To examine the extent and magnitude of such emissions, landfill gas samples from wells, soil vapor samples from the interface of the waste and cover soil, and ambient air samples, were collected from 10 construction and demolition (C&D) debris landfills in Florida and analyzed for H(2)S and other reduced sulfur compounds (RSC). H(2)S was detected in the well gas and soil vapor at all 10 sites. The concentrations in the ambient air above the surface of the landfill were much lower than those observed in the soil vapor, and no direct correlation was observed between the two sampling locations. Methyl mercaptan and carbonyl sulfide were the most frequently observed other RSC, though they occurred at smaller concentrations than H(2)S. This research confirmed the presence of H(2)S at C&D debris landfills. High concentrations of H(2)S may be a concern for employees working on the landfill site. These results indicate that workers should use proper personal protection at C&D debris landfills when involved in excavation, landfill gas collection, or confined spaces. The results indicate that H(2)S is sufficiently diluted in the atmosphere to not commonly pose acute health impacts for these landfill workers in normal working conditions. H(2)S concentrations were extremely variable with measurements occurring over a very large range (from less than 3 ppbv to 12,000 ppmv in the soil vapor and from less than 3 ppbv to 50 ppmv in ambient air). Possible reasons for the large intra- and inter-site variability observed include waste and soil heterogeneities, impact of weather conditions, and different site management practices.

Gas-phase advanced oxidation as an integrated air pollution control technique

Directory of Open Access Journals (Sweden)

Getachew A. Adnew

2016-03-01

Full Text Available Gas-phase advanced oxidation (GPAO is an emerging air cleaning technology based on the natural self-cleaning processes that occur in the Earth’s atmosphere. The technology uses ozone, UV-C lamps and water vapor to generate gas-phase hydroxyl radicals that initiate oxidation of a wide range of pollutants. In this study four types of GPAO systems are presented: a laboratory scale prototype, a shipping container prototype, a modular prototype, and commercial scale GPAO installations. The GPAO systems treat volatile organic compounds, reduced sulfur compounds, amines, ozone, nitrogen oxides, particles and odor. While the method covers a wide range of pollutants, effective treatment becomes difficult when temperature is outside the range of 0 to 80 °C, for anoxic gas streams and for pollution loads exceeding ca. 1000 ppm. Air residence time in the system and the rate of reaction of a given pollutant with hydroxyl radicals determine the removal efficiency of GPAO. For gas phase compounds and odors including VOCs (e.g. C6H6 and C3H8 and reduced sulfur compounds (e.g. H2S and CH3SH, removal efficiencies exceed 80%. The method is energy efficient relative to many established technologies and is applicable to pollutants emitted from diverse sources including food processing, foundries, water treatment, biofuel generation, and petrochemical industries.

An experimental study: Role of different ambient on sulfurization of MoO{sub 3} into MoS{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Kumar, Prabhat, E-mail: prabhat89k@gmail.com; Singh, Megha; Sharma, Rabindar K.; Reddy, G.B.

2016-06-25

Molybdenum disulfide (MoS{sub 2}) nanostructured thin films (NTFs) were synthesised by sulfurizing MoO{sub 3} NTFs using three different non-conventional methods (named methods 1–3). Method 1 uses sulfur vapors, second employs H{sub 2}S/Ar gas and third adopts plasma of H{sub 2}S/Ar gas. HRTEM revealed formation of core–shell nanostructures with maximum shell thickness obtained in method 3. The samples showed uniform nanoflakes (NFs) throughout substrate, revealed by SEM, same as their precursor MoO{sub 3.} XRD and Raman analysis disclosed crystalline MoS{sub 2} and degree of crystallinity was greatest in case of sulfurization in plasma ambient. Quantitative analysis of sulfurized films carried out by XPS shows presence of MoS{sub 2} in all three methods with percentage found to be 18%, 87% and ∼100% respectively. The effect of sulfurizing ambient on its efficiency to convert MoO{sub 3} into MoS{sub 2} has been studied and it was found out that plasma ambient has resulted in high quality of MoS{sub 2} NTFs based on parameters as crystallinity, purity, uniformity and stoichiometry control. - Highlights: • Comparison of three non-conventional methods of sulfurization. • Parameters used for comparison are crystallinity, purity, sulfurized thickness, uniformity and stoichiometry. • H{sub 2}S/Ar plasma based method came out to be best among other techniques. • A soft template reactions for sulfurization of MoO{sub 3} nanoflake is proposed.

Mineralogical controls on surface colonization by sulfur-metabolizing microbial communities

Science.gov (United States)

Jones, A. A.; Bennett, P.

2012-12-01

When characterizing microbial diversity and the microbial ecosystem of the shallow subsurface the mineral matrix is generally assumed to be homogenous and unreactive. We report here experimental evidence that microorganisms colonize rock surfaces according to the rock's chemistry and the organism's metabolic requirements and tolerances. We investigated this phenomenon using laboratory biofilm reactors with both a pure culture of sulfur-oxidizing Thiothrix unzii and a mixed environmental sulfur-metabolizing community from Lower Kane, Cave, WY, USA. Reactors contained rock and mineral chips (calcite, albite, microcline, quartz, chert, Madison Limestone (ML), Madison Dolostone (MD), and basalt) amended with one of the two inoculants. Biomass of attached microorganisms on each mineral surface was quantified. The 16S rRNA of attached microbial communities were compared using Roche FLX and Titanium 454 next generation pyrosequencing. A primary controlling factor on taxonomy of attached microorganisms in both pure and mixed culture experiments was mineral buffering capacity. In mixed culture experiments acid-buffering carbonates were preferentially colonized by neutrophilic sulfur-oxidizing microorganisms (~18% to ~27% of microorganisms), while acidophilic sulfur-oxidizing microorganisms colonized non-buffering quartz exclusively (~46% of microorganisms). The nutrient content of the rock was a controlling factor on biomass accumulation, with neutrophilic organisms selecting between carbonate surfaces of equivalent buffer capacities according to the availability of phosphate. Dry biomass on ML was 17.8 ± 2.3 mg/cm2 and MD was 20.6 ± 6.8 mg/cm2; while nutrient poor calcite accumulated 2.4 ± 0.3 mg/cm2. Biomass accumulation was minimal on non-buffering nutrient-limited surfaces. These factors are countered by the competitive exclusion of some populations. A pure culture of T. unzii preferentially colonizes carbonates while a very closely related Thiothrix spp is excluded

Catalysts for the reduction of SO{sub 2} to elemental sulfur

Energy Technology Data Exchange (ETDEWEB)

Jin, Y.; Yu, Q.Q.; Chang, S.G. [Lawrence Berkeley Lab., Berkeley, CA (United States)

1995-11-01

Catalysts have been prepared for the reduction of SO{sub 2} to elemental sulfur by synthesis gas. A catalyst allows to obtain more than 97% yield of elemental sulfur with a single-stage reactor at 540{degrees}C. A lifetime test has been successfully performed. The mass balance of sulfur and carbon has been checked. The effect of H{sub 2}S, COS, and H{sub 2}O has been studied.

Gas-controlled dynamic vacuum insulation with gas gate

Science.gov (United States)

Benson, D.K.; Potter, T.F.

1994-06-07

Disclosed is a dynamic vacuum insulation comprising sidewalls enclosing an evacuated chamber and gas control means for releasing hydrogen gas into a chamber to increase gas molecule conduction of heat across the chamber and retrieving hydrogen gas from the chamber. The gas control means includes a metal hydride that absorbs and retains hydrogen gas at cooler temperatures and releases hydrogen gas at hotter temperatures; a hydride heating means for selectively heating the metal hydride to temperatures high enough to release hydrogen gas from the metal hydride; and gate means positioned between the metal hydride and the chamber for selectively allowing hydrogen to flow or not to flow between said metal hydride and said chamber. 25 figs.

Sulfur transformation during rapid hydropyrolysis of coal under high pressure by using a continuous free fall pyrolyzer

Energy Technology Data Exchange (ETDEWEB)

W.-C. Xu; M. Kumagai

2003-02-01

The behavior of sulfur transformation during rapid hydropyrolysis of coal was investigated using a pressurized, continuous free fall pyrolyzer under the conditions of temperature ranging from 923 to 1123 K and hydrogen pressure up to 5 MPa. The yields of sulfur converted to gas, tar and char were determined, together with the analyses of sulfur form distributions in coals and chars. The results showed that the decomposition of inorganic sulfur species was affected only by the temperature, while the increases in temperature and hydrogen pressure obviously enhanced the removal of organic sulfur from coal. The extent of organic sulfur removal was proportional to the coal conversion, depending on coal type. A significant retention of gaseous sulfur products by the organic matrix of the char was observed during hydropyrolysis of a Chinese coal above 1023 K, even under the pressurized hydrogen atmosphere. The kinetic analysis indicates that the rate of organic sulfur removal from coal was 0.2th-order with respect to the hydrogen pressure, and the activation energy for total sulfur removal and organic sulfur removal is 17 26 and 13 55 kJ/mol, respectively. The low activation energies suggest that the transformation and removal of sulfur from coal might be controlled by the diffusion and/or thermodynamic equilibrium during hydropyrolysis under the pressurized conditions. 29 refs., 10 figs., 3 tabs.

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

Science.gov (United States)

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

1997-11-01

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

Sulfur metabolism in phototrophic sulfur bacteria

DEFF Research Database (Denmark)

Frigaard, Niels-Ulrik; Dahl, Christiane

2008-01-01

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

Removal of Sulfur Dioxide from Flue Gas Using the Sludge Sodium Humate

Directory of Open Access Journals (Sweden)

Yu Zhao

2013-01-01

Full Text Available This study shows the ability of sodium humate from alkaline treatment sludge on removing sulfur dioxide (SO2 in the simulated flue gas. Experiments were conducted to examine the effect of various operating parameters, like the inlet SO2 concentration or temperature or O2, on the SO2 absorption efficiency and desulfurization time in a lab-scale bubbling reactor. The sludge sodium humate in the supernatant after alkaline sludge treatment shows great performance in SO2 absorption, and such efficiency can be maintained above 98% with 100 mL of this absorption solution at 298 K (flue gas rate of 0.12 m3/h. The highest SO2 absorption by 1.63 g SHA-Na is 0.946 mmol in the process, which is translated to 0.037 g SO2 g−1 SHA-Na. The experimental results indicate that the inlet SO2 concentration slightly influences the SO2 absorption efficiency and significantly influences the desulfurization time. The pH of the absorption solution should be above 3.5 in this process in order to make an effective desulfurization. The products of this process were characterized by Fourier transform infrared spectroscopy and X-ray diffraction. It can be seen that the desulfurization products mainly contain sludge humic acid sediment, which can be used as fertilizer components.

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

International Nuclear Information System (INIS)

Naman, S.A.; Veziroglu, A.

2009-01-01

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

Mustard gas or sulfur mustard: an old chemical agent as a new terrorist threat.

Science.gov (United States)

Wattana, Monica; Bey, Tareg

2009-01-01

Sulfur mustard is a member of the vesicant class of chemical warfare agents that causes blistering to the skin and mucous membranes. There is no specific antidote, and treatment consists of systematically alleviating symptoms. Historically, sulfur mustard was used extensively in inter-governmental conflicts within the trenches of Belgium and France during World War I and during the Iran-Iraq conflict. Longitudinal studies of exposed victims show that sulfur mustard causes long-term effects leading to high morbidity. Given that only a small amount of sulfur mustard is necessary to potentially cause an enormous number of casualties, disaster-planning protocol necessitates the education and training of first-line healthcare responders in the recognition, decontamination, triage, and treatment of sulfur mustard-exposed victims in a large-scale scenario.

Demonstration of Selective Catalytic Reduction Technology to Control Nitrogen Oxide Emissions From High-Sulfur, Coal-Fired Boilers: A DOE Assessment

International Nuclear Information System (INIS)

Federal Energy Technology Center

1999-01-01

The goal of the U.S. Department of Energy (DOE) Clean Coal Technology (CCT) program is to furnish the energy marketplace with a number of advanced, more efficient, and environmentally responsible coal utilization technologies through demonstration projects. These projects seek to establish the commercial feasibility of the most promising advanced coal technologies that have developed beyond the proof-of-concept stage. This document serves as a DOE post-project assessment of a project selected in CCT Round 2. The project is described in the report ''Demonstration of Selective Catalytic Reduction (SCR) Technology for the Control of Nitrogen Oxide (NO(sub x)) Emissions from High-Sulfur, Coal-Fired Boilers'' (Southern Company Services 1990). In June 1990, Southern Company Services (Southern) entered into a cooperative agreement to conduct the study. Southern was a cofunder and served as the host at Gulf Power Company's Plant Crist. Other participants and cofunders were EPRI (formerly the Electric Power Research Institute) and Ontario Hydro. DOE provided 40 percent of the total project cost of$23 million. The long-term operation phase of the demonstration was started in July 1993 and was completed in July 1995. This independent evaluation is based primarily on information from Southern's Final Report (Southern Company Services 1996). The SCR process consists of injecting ammonia (NH(sub 3)) into boiler flue gas and passing the 3 flue gas through a catalyst bed where the NO(sub x) and NH(sub 3) react to form nitrogen and water vapor. The objectives of the demonstration project were to investigate: Performance of a wide variety of SCR catalyst compositions, geometries, and manufacturing methods at typical U.S. high-sulfur coal-fired utility operating conditions; Catalyst resistance to poisoning by trace metal species present in U.S. coals but not present, or present at much lower concentrations, in fuels from other countries; and Effects on the balance-of-plant equipment

Microbial Desulfurization of a Crude Oil Middle-Distillate Fraction: Analysis of the Extent of Sulfur Removal and the Effect of Removal on Remaining Sulfur

Science.gov (United States)

Grossman, M. J.; Lee, M. K.; Prince, R. C.; Garrett, K. K.; George, G. N.; Pickering, I. J.

1999-01-01

Rhodococcus sp. strain ECRD-1 was evaluated for its ability to desulfurize a 232 to 343°C middle-distillate (diesel range) fraction of Oregon basin (OB) crude oil. OB oil was provided as the sole source of sulfur in batch cultures, and the extent of desulfurization and the chemical fate of the residual sulfur in the oil after treatment were determined. Gas chromatography (GC), flame ionization detection, and GC sulfur chemiluminesce detection analysis were used to qualitatively evaluate the effect of Rhodococcus sp. strain ECRD-1 treatment on the hydrocarbon and sulfur content of the oil, respectively. Total sulfur was determined by combustion of samples and measurement of released sulfur dioxide by infrared absorption. Up to 30% of the total sulfur in the middle distillate cut was removed, and compounds across the entire boiling range of the oil were affected. Sulfur K-edge X-ray absorption-edge spectroscopy was used to examine the chemical state of the sulfur remaining in the treated OB oil. Approximately equal amounts of thiophenic and sulfidic sulfur compounds were removed by ECRD-1 treatment, and over 50% of the sulfur remaining after treatment was in an oxidized form. The presence of partially oxidized sulfur compounds indicates that these compounds were en route to desulfurization. Overall, more than two-thirds of the sulfur had been removed or oxidized by the microbial treatment. PMID:9872778

Effect of Elemental Sulfur and Sulfide on the Corrosion Behavior of Cr-Mo Low Alloy Steel for Tubing and Tubular Components in Oil and Gas Industry.

Science.gov (United States)

Khaksar, Ladan; Shirokoff, John

2017-04-20

The chemical degradation of alloy components in sulfur-containing environments is a major concern in oil and gas production. This paper discusses the effect of elemental sulfur and its simplest anion, sulfide, on the corrosion of Cr-Mo alloy steel at pH 2 and 5 during 10, 20 and 30 h immersion in two different solutions. 4130 Cr-Mo alloy steel is widely used as tubing and tubular components in sour services. According to the previous research in aqueous conditions, contact of solid sulfur with alloy steel can initiate catastrophic corrosion problems. The corrosion behavior was monitored by the potentiodynamic polarization technique during the experiments. Energy dispersive X-ray spectroscopy (EDS) and scanning electron microscopy (SEM) have been applied to characterize the corrosion product layers after each experiment. The results show that under the same experimental conditions, the corrosion resistance of Cr-Mo alloy in the presence of elemental sulfur is significantly lower than its resistance in the presence of sulfide ions.

Deregulated gas in 1985 seen costly

Energy Technology Data Exchange (ETDEWEB)

Schaffer, P.

1980-05-05

Deregulation of natural gas wellhead prices will mean higher prices for nonboiler industrial users, according to an Energy and Environmental Analysis Inc. (EEA) study. The price increases of high-sulfur residual fuel oil will exceed inflation rates, but low-sulfur residual oil and distillate oil will have smaller increases because of upgraded refineries. Te economc imact analysis is broken down by region and includes estimates of gas, high-sulfur coal, and low-sulfur coal prices thrugh 1995. Free copies of the report are available from the Federal Energy Regulatory Commission's Office of Public Information. (DCK)

Recovery of sulfur from residue gases of low H/sub 2/S concentration

Energy Technology Data Exchange (ETDEWEB)

Bratzler, K; Doerges, A; Schlauer, J

1976-01-01

The Lucas process is intended for reduction of SO/sub 2/ and H/sub 2/S in Claus tail gas or other low-sulfur residue gases to levels below 200 ppm (H/sub 2/S only in traces). In the first stage, all sulfur compounds are burned to SO/sub 2/; in the second stage, a coke reactor reduces SO/sub 3/ and O/sub 2/; and in the third stage, the SO/sub 2/ is absorbed in an aqueous alkali phosphate solution. Concentrated SO/sub 2/ from regeneration of the solution is returned to the Claus plant, or can be catalystically reduced to elemental sulfur. The process was proven out in a semitechnical pilot plant, with satisfactory results as follows: sulfur recovery, 97 to 99.8%; energy consumption per 1,000 cu m feed gas, 2.6 to 3.7 kw-hr plus 860 to 930 MJ heating gas (however, 300 to 350 kg steam was generated); 0.15 kg chemicals; 0.7 to 1.5 kg coke; and a minimal amount of catalyst if sulfur is produced. Investment is only 60 to 80% of that in a 2-stage Claus process, with which the Lucas process is competitive.

Experimental and numerical modeling of sulfur plugging in a carbonate oil reservoir

Energy Technology Data Exchange (ETDEWEB)

Al-Awadhy, F. [ADMA-OPCO, Abudhabi (United Arab Emirates); Kocabas, I.; Abou-Kassem, J.H. [UAE University, Al Ain (United Arab Emirates); Islam, M.R. [Dalhousie University, Halifax, NS (United States)

2005-01-15

Many oil and gas reservoirs in the United Arab Emirates produce large amounts of sour gas, mainly in the form of hydrogen sulfide. In addition to creating problems in the production line, wellbore damage is often reported due to the precipitation of elemental sulfur in the vicinity of the wellbore. While there have been several studies performed on the role of solid deposition in a gas reservoir, the role of sulfur deposition in oil reservoirs has not been investigated. This article presents experimental results along with a comprehensive wellbore model that predicts sulfur precipitation as well as plugging. The experiments were conducted in a core (linear) system. Both analytical and numerical modelings were performed in a linear coordinate system. Data for the numerical model was obtained from both test tube and coreflood experiments. By using a phenomenological model, the wellbore plugging was modeled with an excellent match (with experimental results). The crude oil was de-asphalted prior to conducting the experiment in order to isolate the effect of asphaltene plugging. A series of coreflood tests was carried out to observe sulfur precipitation and plugging in a carbonate rock. Significant plugging was observed and was found to be dependent on flow rate and initial sulfur concentration. This information was used in the phenomenological model and can be incorporated in the wellbore numerical model. (author)

One-step hydrothermal synthesis of three-dimensional porous graphene aerogels/sulfur nanocrystals for lithium–sulfur batteries

International Nuclear Information System (INIS)

Jiang, Yong; Lu, Mengna; Ling, Xuetao; Jiao, Zheng; Chen, Lingli; Chen, Lu; Hu, Pengfei; Zhao, Bing

2015-01-01

Highlights: • 3D porous GA/S nanocrystals are prepared by a one-step hydrothermal method. • The structure is affected by hydrothermal temperature and liquid sulfur’s viscosity. • The hybrid delivers a capacity of 716.2 mA h g −1 after 50 cycles at 100 mA g −1 . • The nanosized S, strong adsorbability and intimate contact of GNS are main factors. - Abstract: Lithium–sulfur (Li–S) batteries are receiving significant attention as a new energy source because of its high theoretical capacity and specific energy. However, the low sulfur loading and large particles (usually in submicron dimension) in the cathode greatly offset its advantage in high energy density and lead to the instability of the cathode and rapid capacity decay. Herein, we introduce a one-step hydrothermal synthesis of three-dimensional porous graphene aerogels/sulfur nanocrystals to suppress the rapid fading of sulfur electrode. It is found that the hydrothermal temperature and viscosity of liquid sulfur have significant effects on particle size and loading mass of sulfur nanocrystals, graphitization degree of graphene and chemical bonding between sulfur and oxygen-containing groups of graphene. The hybrid could deliver a specific capacity of 716.2 mA h g −1 after 50 cycles at a current density of 100 mA g −1 and reversible capacity of 517.9 mA h g −1 at 1 A g −1 . The performance we demonstrate herein suggests that Li–S battery may provide an opportunity for development of rechargeable battery systems

Calculating the flue gas dew point for raw brown coal fired steam generators

Energy Technology Data Exchange (ETDEWEB)

Schinkel, W.

1977-01-01

The paper analyzes parameters influencing the sulfuric acid dew point in flue gas of steam generators. Sulfur content and alkaline earths content in the fuel air ratio during combustion, fly ash content in the flue gas (which absorbs sulfur dioxide and sulfur trioxide) and combustion conditions in steam generators are relevant parameters in the combustion process. A thermodynamic and reaction kinetic calculation of the sulfuric acid dew point is, however, not yet possible. A statistical evaluation of dew point measurements in steam generators is, therefore, employed. Various diagrams show results of dew point measurements carried out at generators with steam capacities ranging from 40 to 660 t/h, which demonstrate relations of these parameters to flue gas dew points, in particular the relative sulfur content (sulfur content in the raw brown coal compared to coal ash content and alkaline earths content). A function is derived for the conversion of fuel sulfur to sulfur trioxide. A diagram presents the relation of the flue gas dew point to partial pressures of sulfuric acid and steam. Direct calculation of the flue gas dew point was achieved by the proposed method. It is applied in steam generator design. (17 refs.)

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

Science.gov (United States)

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

2018-02-01

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

Demonstration of SCR technology for the control of NOx emissions from high-sulfur coal-fired utility boilers

Energy Technology Data Exchange (ETDEWEB)

Hinton, W.S. [W.S. Hinton and Associates, Cantonment, FL (United States); Maxwell, J.D.; Healy, E.C.; Hardman, R.R. [Southern Company Services, Inc., Birmingham, AL (United States); Baldwin, A.L. [Dept. of Energy, Pittsburgh, PA (United States)

1997-12-31

This paper describes the completed Innovative Clean Coal Technology project which demonstrated SCR technology for reduction of flue gas NO{sub x} emissions from a utility boiler burning US high-sulfur coal. The project was sponsored by the US Department of Energy, managed and co-funded by Southern Company Services, Inc. on behalf of the Southern Company, and also co-funded by the Electric Power Research Institute and Ontario Hydro. The project was located at Gulf Power Company`s Plant Crist Unit 5 (a 75 MW tangentially-fired boiler burning US coals that had a sulfur content ranging from 2.5--2.9%), near Pensacola, Florida. The test program was conducted for approximately two years to evaluate catalyst deactivation and other SCR operational effects. The SCR test facility had nine reactors: three 2.5 MW (5,000 scfm), and operated on low-dust flue gas. The reactors operated in parallel with commercially available SCR catalysts obtained from suppliers throughout the world. Long-term performance testing began in July 1993 and was completed in July 1995. A brief test facility description and the results of the project are presented in this paper.

Peatland Acidobacteria with a dissimilatory sulfur metabolism.

Science.gov (United States)

Hausmann, Bela; Pelikan, Claus; Herbold, Craig W; Köstlbacher, Stephan; Albertsen, Mads; Eichorst, Stephanie A; Glavina Del Rio, Tijana; Huemer, Martin; Nielsen, Per H; Rattei, Thomas; Stingl, Ulrich; Tringe, Susannah G; Trojan, Daniela; Wentrup, Cecilia; Woebken, Dagmar; Pester, Michael; Loy, Alexander

2018-02-23

Sulfur-cycling microorganisms impact organic matter decomposition in wetlands and consequently greenhouse gas emissions from these globally relevant environments. However, their identities and physiological properties are largely unknown. By applying a functional metagenomics approach to an acidic peatland, we recovered draft genomes of seven novel Acidobacteria species with the potential for dissimilatory sulfite (dsrAB, dsrC, dsrD, dsrN, dsrT, dsrMKJOP) or sulfate respiration (sat, aprBA, qmoABC plus dsr genes). Surprisingly, the genomes also encoded DsrL, which so far was only found in sulfur-oxidizing microorganisms. Metatranscriptome analysis demonstrated expression of acidobacterial sulfur-metabolism genes in native peat soil and their upregulation in diverse anoxic microcosms. This indicated an active sulfate respiration pathway, which, however, might also operate in reverse for dissimilatory sulfur oxidation or disproportionation as proposed for the sulfur-oxidizing Desulfurivibrio alkaliphilus. Acidobacteria that only harbored genes for sulfite reduction additionally encoded enzymes that liberate sulfite from organosulfonates, which suggested organic sulfur compounds as complementary energy sources. Further metabolic potentials included polysaccharide hydrolysis and sugar utilization, aerobic respiration, several fermentative capabilities, and hydrogen oxidation. Our findings extend both, the known physiological and genetic properties of Acidobacteria and the known taxonomic diversity of microorganisms with a DsrAB-based sulfur metabolism, and highlight new fundamental niches for facultative anaerobic Acidobacteria in wetlands based on exploitation of inorganic and organic sulfur molecules for energy conservation.

Sulfur and Hydrogen Isotope Anomalies in Meteorite Sulfonic Acids

Science.gov (United States)

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.

Development of a gas-to-particle conversion model for use in three-dimensional global sulfur budget studies

International Nuclear Information System (INIS)

Kreidenweis, S.M.

1993-08-01

A fully-parameterized model for the formation and growth of aerosols via gas-to-particle conversion has been developed and tested. A particularly significant contribution is a new method for the prediction of numbers of particles nucleated using information on the vapor source rate, relative humidity, and preexisting aerosol alone, thus eliminating the need to solve a system of coupled ODEs. Preliminary tests indicate substantial reduction in computational costs, but it is recommended that the BIMODAM model be incorporated into a large-scale model of the sulfur cycle in order to more fully test its computational feasibility

Carbon nanotube-like materials in the exhaust from a diesel engine using gas oil/ethanol mixing fuel with catalysts and sulfur.

Science.gov (United States)

Suzuki, Shunsuke; Mori, Shinsuke

2017-08-01

Particulate matter from a diesel engine, including soot and carbon nanomaterials, was collected on a sampling holder and the structure of the materials was studied by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). As a result of employing gas oil/ethanol mixing fuel with sulfur and ferrocene/molybdenum as catalyst sources, formation of carbon nanotubes (CNT)-like materials in addition to soot was observed in the exhaust gas from a diesel engine. It was revealed that CNT-like materials were included among soot in our system only when the following three conditions were satisfied simultaneously: high ethanol fraction in fuel, high sulfur loading, and presence of catalyst sources in fuel. This study confirmed that if at least one of these three conditions was not satisfied, CNT-like materials were not observed in the exhaust from a diesel engine. These experimental results shown in this work provide insights into understanding CNT-like material formation mechanism in a diesel engine. Recent papers reported that carbon nanotube-like materials were included in the exhaust gas from engines, but conditions for carbon nanotube-like material formation have not been well studied. This work provides the required conditions for carbon nanotube-like material growth in a diesel engine, and this will be helpful for understanding the carbon nanotube-like material formation mechanism and taking countermeasures to preventing carbon nanotube-like material formation in a diesel engine.

Innovative Clean Coal Technology (ICCT): Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Technical progress report, third and fourth quarters 1994

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-11-01

The objective of this project is to demonstrate and evaluate commercially available selective catalytic reduction (SCR) catalysts from U.S., Japanese, and European catalyst suppliers on a high-sulfur U.S. Coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to form nitrogen and water vapor. Although SCR is widely practiced in Japan and European gas-, oil-, and low-sulfur coal-fired boilers, there are several technical uncertainties associated with applying SCR to U.S. coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in U.S. coals that are not present in other fuels; (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO{sub 2} and SO{sub 3}; performance of a wide variety of SCR catalyst compositions, geometries, and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties are being explored by operating a series of small- scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur U.S. coal. The demonstration is being performed at Gulf Power Company`s Plant Crist Unit No. 5 (75 MW capacity) near Pensacola, Florida. The project is funded by the U.S. Department of Energy (DOE), Southern Company Services, Inc. (SCS on behalf of the entire Southern electric system), the Electric Power Research Institute (EPRI), and Ontario Hydro. SCS is the participant responsible for managing al aspects of this project. 1 ref., 69 figs., 45 tabs.

Influence of the temperature of superheating surfaces in a gas flow on the formation of sulfur trioxide

Energy Technology Data Exchange (ETDEWEB)

Vnukov, A K; Taran, O E

1977-05-01

In supercritical steam generators fired with sulfur-rich heating fuel oil, catalytic after-oxidation of SO/sub 2/ takes place in amounts which correspond to the formation of SO/sub 3/ in the furnaces. The amount of SO/sub 3/ produced depends directly on the dirt accumulation in the convection stack. Corrosion-free operation of heating surfaces and flue gas stacks cannot be achieved by a mere reduction of the excess pressure; this is proved by operational experience for this type of steam generator. An investigation of the mechanism of catalytic SO/sub 3/ formation will help to find further measures to be taken, e.g., cleaning of the convection heating surfaces, introduction of additives to poison the catalysts, etc. It should thus be possible, in the long run, to reduce the low-temperature corrosion of heating surfaces and gas stacks and to improve the operational performance of the boilers.

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

Science.gov (United States)

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

2016-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1995-06-01

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

Sulfur impacts on forest health in west-central Alberta

International Nuclear Information System (INIS)

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

1994-01-01

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

Technical note: A simple back-mounted harness for grazing dairy cows to facilitate the sulfur hexafluoride tracer gas technique.

Science.gov (United States)

van Wyngaard, Josef D V; Meeske, Robin; Erasmus, Lourens J

2018-03-01

We describe here a cattle harness to attach a gas collection vessel to facilitate the sulfur hexafluoride (SF 6 ) tracer gas technique. The harness consists of 2 major components: (1) a lightweight, robust body fabricated from an equine surcingle or lunge roller with padded thoracic trapezius pressure points, a bespoke shaping shaft for spine support, and adjustable buckles on both sides; and (2) an elastic flank-strap to prevent the harness from dislodging. The spine support consists of stainless steel laminated with carbon fiber. This support minimizes the contact area with the animal's skin, relieves the spine area of pressure, and creates free flow of ambient air below the platform, reducing sweat accumulation and hence preventing skin lesions. The harness weighs approximately 1.2 kg, allows for attachment of 2 gas collection vessels (animal and background sample), and is cost effective. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

One-step hydrothermal synthesis of three-dimensional porous graphene aerogels/sulfur nanocrystals for lithium–sulfur batteries

Energy Technology Data Exchange (ETDEWEB)

Jiang, Yong; Lu, Mengna; Ling, Xuetao; Jiao, Zheng; Chen, Lingli; Chen, Lu [School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444 (China); Hu, Pengfei [Instrumental Analysis and Research Center, Shanghai University, Shanghai 200444 (China); Zhao, Bing, E-mail: bzhao@shu.edu.cn [School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444 (China)

2015-10-05

Highlights: • 3D porous GA/S nanocrystals are prepared by a one-step hydrothermal method. • The structure is affected by hydrothermal temperature and liquid sulfur’s viscosity. • The hybrid delivers a capacity of 716.2 mA h g{sup −1} after 50 cycles at 100 mA g{sup −1}. • The nanosized S, strong adsorbability and intimate contact of GNS are main factors. - Abstract: Lithium–sulfur (Li–S) batteries are receiving significant attention as a new energy source because of its high theoretical capacity and specific energy. However, the low sulfur loading and large particles (usually in submicron dimension) in the cathode greatly offset its advantage in high energy density and lead to the instability of the cathode and rapid capacity decay. Herein, we introduce a one-step hydrothermal synthesis of three-dimensional porous graphene aerogels/sulfur nanocrystals to suppress the rapid fading of sulfur electrode. It is found that the hydrothermal temperature and viscosity of liquid sulfur have significant effects on particle size and loading mass of sulfur nanocrystals, graphitization degree of graphene and chemical bonding between sulfur and oxygen-containing groups of graphene. The hybrid could deliver a specific capacity of 716.2 mA h g{sup −1} after 50 cycles at a current density of 100 mA g{sup −1} and reversible capacity of 517.9 mA h g{sup −1} at 1 A g{sup −1}. The performance we demonstrate herein suggests that Li–S battery may provide an opportunity for development of rechargeable battery systems.

Stability of sulfur slopes on Io

Science.gov (United States)

Clow, G. D.; Carr, M. H.

1980-01-01

The mechanical properties of elemental sulfur are such that the upper crust of Io cannot be primarily sulfur. For heat flows in the range 100-1000 ergs/sq cm sec sulfur becomes ductile within several hundred meters of the surface and would prevent the formation of calderas with depths greater than this. However, the one caldera for which precise depth data are available is 2 km deep, and this value may be typical. A study of the mechanical equilibrium of simple slopes shows that the depth to the zone of rapid ductile flow strongly controls the maximum heights for sulfur slopes. Sulfur scarps with heights greater than 1 km will fail for all heat flows greater than 180 ergs/sq cm sec and slope angles greater than 22.5 deg. The observed relief on Io is inconsistent with that anticipated for a predominantly sulfur crust. However, a silicate crust with several percent sulfur included satisfies both the mechanical constraints and the observed presence of sulfur on Io.

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

Energy Technology Data Exchange (ETDEWEB)

Robert S. Weber

1999-05-01

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

Sulfur emission from Victorian brown coal under pyrolysis, oxy-fuel combustion and gasification conditions.

Science.gov (United States)

Chen, Luguang; Bhattacharya, Sankar

2013-02-05

Sulfur emission from a Victorian brown coal was quantitatively determined through controlled experiments in a continuously fed drop-tube furnace under three different atmospheres: pyrolysis, oxy-fuel combustion, and carbon dioxide gasification conditions. The species measured were H(2)S, SO(2), COS, CS(2), and more importantly SO(3). The temperature (873-1273 K) and gas environment effects on the sulfur species emission were investigated. The effect of residence time on the emission of those species was also assessed under oxy-fuel condition. The emission of the sulfur species depended on the reaction environment. H(2)S, SO(2), and CS(2) are the major species during pyrolysis, oxy-fuel, and gasification. Up to 10% of coal sulfur was found to be converted to SO(3) under oxy-fuel combustion, whereas SO(3) was undetectable during pyrolysis and gasification. The trend of the experimental results was qualitatively matched by thermodynamic predictions. The residence time had little effect on the release of those species. The release of sulfur oxides, in particular both SO(2) and SO(3), is considerably high during oxy-fuel combustion even though the sulfur content in Morwell coal is only 0.80%. Therefore, for Morwell coal utilization during oxy-fuel combustion, additional sulfur removal, or polishing systems will be required in order to avoid corrosion in the boiler and in the CO(2) separation units of the CO(2) capture systems.

Sulfur degassing due to contact metamorphism during flood basalt eruptions

Science.gov (United States)

Yallup, Christine; Edmonds, Marie; Turchyn, Alexandra V.

2013-11-01

We present a study aimed at quantifying the potential for generating sulfur-rich gas emissions from the devolatilization of sediments accompanying sill emplacement during flood basalt eruptions. The potential contribution of sulfur-rich gases from sediments might augment substantially the magma-derived sulfur gases and hence impact regional and global climate. We demonstrate, from a detailed outcrop-scale study, that sulfur and total organic carbon have been devolatilized from shales immediately surrounding a 3-m thick dolerite sill on the Isle of Skye, Scotland. Localized partial melting occurred within a few centimetres of the contact in the shale, generating melt-filled cracks. Pyrite decomposed on heating within 80 cm of the contact, generating sulfur-rich gases (a mixture of H2S and SO2) and pyrrhotite. The pyrrhotite shows 32S enrichment, due to loss of 34S-enriched SO2. Further decomposition and oxidation of pyrrhotite resulted in hematite and/or magnetite within a few cm of the contact. Iron sulfates were produced during retrogressive cooling and oxidation within 20 cm of the contact. Decarbonation of the sediments due to heating is also observed, particularly along the upper contact of the sill, where increasing δ13C is consistent with loss of methane gas. The geochemical and mineralogical features observed in the shales are consistent with a short-lived intrusion, emplaced in desulfurization, as well as decarbonation, of shales adjacent to an igneous intrusion. The liberated fluids, rich in sulfur and carbon, are likely to be focused along regions of low pore fluid pressure along the margins of the sill. The sulfur gases liberated from the sediments would have augmented the sulfur dioxide (and hydrogen sulfide) yield of the eruption substantially, had they reached the surface. This enhancement of the magmatic sulfur budget has important implications for the climate impact of large flood basalt eruptions that erupt through thick, volatile-rich sedimentary

Advanced byproduct recovery: Direct catalytic reduction of sulfur dioxide to elemental sulfur. Quarterly report, April 1--June 30, 1997

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-31

The team of Arthur D. Little, Tufts University and Engelhard Corporation are conducting Phase 1 of a four and a half year, two-phase effort to develop and scale-up an advanced byproduct recovery technology that is a direct, single-stage, catalytic process for converting sulfur dioxide to elemental sulfur. This catalytic process reduces SO{sub 2} over a fluorite-type oxide (such as ceria and zirconia). The catalytic activity can be significantly promoted by active transition metals, such as copper. More than 95% elemental sulfur yield, corresponding to almost complete sulfur dioxide conversion, was obtained over a Cu-Ce-O oxide catalyst as part of an on-going DOE-sponsored, University Coal Research Program. This type of mixed metal oxide catalyst has stable activity, high selectivity for sulfur production, and is resistant to water and carbon dioxide poisoning. Tests with CO and CH{sub 4} reducing gases indicate that the catalyst has the potential for flexibility with regard to the composition of the reducing gas, making it attractive for utility use. The performance of the catalyst is consistently good over a range of SO{sub 2} inlet concentration (0.1 to 10%) indicating its flexibility in treating SO{sub 2} tail gases as well as high concentration streams. The principal objective of the Phase 1 program is to identify and evaluate the performance of a catalyst which is robust and flexible with regard to choice of reducing gas. In order to achieve this goal, the authors have planned a structured program including: Market/process/cost/evaluation; Lab-scale catalyst preparation/optimization studies; Lab-scale, bulk/supported catalyst kinetic studies; Bench-scale catalyst/process studies; and Utility review. Progress is reported from all three organizations.

The partitioning of sulfur between multicomponent aqueous fluids and felsic melts

Science.gov (United States)

Binder, Bernd; Wenzel, Thomas; Keppler, Hans

2018-02-01

Sulfur partitioning between melt and fluid phase largely controls the environmental impact of volcanic eruptions. Fluid/melt partitioning data also provide the physical basis for interpreting changes in volcanic gas compositions that are used in eruption forecasts. To better constrain some variables that control the behavior of sulfur in felsic systems, in particular the interaction between different volatiles, we studied the partitioning of sulfur between aqueous fluids and haplogranitic melts at 200 MPa and 750-850 °C as a function of oxygen fugacity (Ni-NiO or Re-ReO2 buffer), melt composition (Al/(Na + K) ratio), and fluid composition (NaCl and CO2 content). The data confirm a first-order influence of oxygen fugacity on the partitioning of sulfur. Under "reducing conditions" (Ni-NiO buffer), D fluid/melt is nearly one order of magnitude larger (323 ± 14 for a metaluminous melt) than under "oxidizing conditions" (Re-ReO2 buffer; 74 ± 5 for a metaluminous melt). This effect is likely related to a major change in sulfur speciation in both melt and fluid. Raman spectra of the quenched fluids show the presence of H2S and HS- under reducing conditions and of SO4 2- and HSO4 - under oxidizing conditions, while SO2 is undetectable. The latter observation suggests that already at the Re-ReO2 buffer, sulfur in the fluid is almost completely in the S6+ state and, therefore, more oxidized than expected according to current models. CO2 in the fluid (up to x CO2 = 0.3) has no effect on the fluid/melt partitioning of sulfur, neither under oxidizing nor under reducing conditions. However, the effect of NaCl depends on redox state. While at oxidizing conditions, D fluid/melt is independent of x NaCl, the fluid/melt partition coefficient strongly decreases with NaCl content under reducing conditions, probably due to a change from H2S to NaSH as dominant sulfur species in the fluid. A decrease of D fluid/melt with alkali content in the melt is observed over the entire

Innovation-driven efficient development of the Longwangmiao Fm large-scale sulfur gas reservoir in Moxi block, Sichuan Basin

Directory of Open Access Journals (Sweden)

Xinhua Ma

2016-03-01

Full Text Available The Lower Cambrian Longwangmiao Fm gas reservoir in Moxi block of the Anyue Gas field, Sichuan Basin, is the largest single-sandbody integrated carbonate gas reservoir proved so far in China. Notwithstanding this reservoir's advantages like large-scale reserves and high single-well productivity, there are multiple complicated factors restricting its efficient development, such as a median content of hydrogen sulfide, low porosity and strong heterogeneity of fracture–cave formation, various modes of gas–water occurrences, and close relation between overpressure and stress sensitivity. Up till now, since only a few Cambrian large-scale carbonate gas reservoirs have ever been developed in the world, there still exists some blind spots especially about its exploration and production rules. Besides, as for large-scale sulfur gas reservoirs, the exploration and construction is costly, and production test in the early evaluation stage is severely limited, all of which will bring about great challenges in productivity construction and high potential risks. In this regard, combining with Chinese strategic demand of strengthening clean energy supply security, the PetroChina Southwest Oil & Gas Field Company has carried out researches and field tests for the purpose of providing high-production wells, optimizing development design, rapidly constructing high-quality productivity and upgrading HSE security in the Longwangmiao Fm gas reservoir in Moxi block. Through the innovations of technology and management mode within 3 years, this gas reservoir has been built into a modern large-scale gas field with high quality, high efficiency and high benefit, and its annual capacity is now up to over 100 × 108 m3, with a desirable production capacity and development indexes gained as originally anticipated. It has become a new model of large-scale gas reservoirs with efficient development, providing a reference for other types of gas reservoirs in China.

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

Energy Technology Data Exchange (ETDEWEB)

Baxter, Larry L.

2008-06-09

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

Th17/Treg immunoregulation and implications in treatment of sulfur mustard gas-induced lung diseases.

Science.gov (United States)

Iman, Maryam; Rezaei, Ramazan; Azimzadeh Jamalkandi, Sadegh; Shariati, Parvin; Kheradmand, Farrah; Salimian, Jafar

2017-12-01

Sulfur mustard (SM) is an extremely toxic gas used in chemical warfare to cause massive lung injury and death. Victims exposed to SM gas acutely present with inhalational lung injury, but among those who survive, some develop obstructive airway diseases referred to as SM-lung syndrome. Pathophysiologically, SM-lung shares many characteristics with smoking-induced chronic obstructive pulmonary disease (COPD), including airway remodeling, goblet cell metaplasia, and obstructive ventilation defect. Some of the hallmarks of COPD pathogenesis, which include dysregulated lung inflammation, neutrophilia, recruitment of interleukin 17A (IL -17A) expressing CD4 + T cells (Th17), and the paucity of lung regulatory T cells (Tregs), have also been described in SM-lung. Areas covered: A literature search was performed using the MEDLINE, EMBASE, and Web of Science databases inclusive of all literature prior to and including May 2017. Expert commentary: Here we review some of the recent findings that suggest a role for Th17 cell-mediated inflammatory changes associated with pulmonary complications in SM-lung and suggest new therapeutic approaches that could potentially alter disease progression with immune modulating biologics that can restore the lung Th17/Treg balance.

Antibotulinal efficacy of sulfur dioxide in meat.

Science.gov (United States)

Tompkin, R B; Christiansen, L N; Shaparis, A B

1980-01-01

The addition of sodium metabisulfite as a source of sulfur dioxide delayed botulinal outgrowth in perishable canned comminuted pork when it was temperature abused at 27 degree C. The degree of inhibition was directly related to the level of sulfur dioxide. Levels greater than 100 microgram of sulfur dioxide per g were necessary to achieve significant inhibition when a target level of 100 botulinal spores per g was used. Sodium nitrite partially reduced the efficacy of the sulfur dioxide. Sulfur dioxide offers a new option for the control of botulinal outgrowth in cured or noncured meat and poultry products. PMID:6996613

Process for recovery of sulfur from acid gases

Science.gov (United States)

Towler, Gavin P.; Lynn, Scott

1995-01-01

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

Transport-Induced Spatial Patterns of Sulfur Isotopes (δ34S) as Biosignatures

Science.gov (United States)

Mansor, Muammar; Harouaka, Khadouja; Gonzales, Matthew S.; Macalady, Jennifer L.; Fantle, Matthew S.

2018-01-01

Cave minerals deposited in the presence of microbes may host geochemical biosignatures that can be utilized to detect subsurface life on Earth, Mars, or other habitable worlds. The sulfur isotopic composition of gypsum (CaSO4·2H2O) formed in the presence of sulfur-oxidizing microbes in the Frasassi cave system, Italy, was evaluated as a biosignature. Sulfur isotopic compositions (δ34SV-CDT) of gypsum sampled from cave rooms with sulfidic air varied from -11 to -24‰, with minor deposits of elemental sulfur having δ34S values between -17 and -19‰. Over centimeter-length scales, the δ34S values of gypsum varied by up to 8.5‰. Complementary laboratory experiments showed negligible fractionation during the oxidation of elemental sulfur to sulfate by Acidithiobacillus thiooxidans isolated from the caves. Additionally, gypsum precipitated in the presence and absence of microbes at acidic pH characteristic of the sulfidic cave walls has δ34S values that are on average 1‰ higher than sulfate. We therefore interpret the 8.5‰ variation in cave gypsum δ34S (toward more negative values) to reflect the isotopic effect of microbial sulfide oxidation directly to sulfate or via elemental sulfur intermediate. This range is similar to that expected by abiotic sulfide oxidation with oxygen, thus complicating the use of sulfur isotopes as a biosignature at centimeter-length scales. However, at the cave room (meter-length) scale, reactive transport modeling suggests that the overall ˜13‰ variability in gypsum δ34S reflects isotopic distillation of circulating H2S gas due to microbial sulfide oxidation occurring along the cave wall-atmosphere interface. Systematic variations of gypsum δ34S along gas flow paths can thus be interpreted as biogenic given that slow, abiotic oxidation cannot produce the same spatial patterns over similar length scales. The expression and preservation potential of this biosignature is dependent on gas flow parameters and diagenetic

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

International Nuclear Information System (INIS)

Robert S. Weber

1999-01-01

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

Stabilization of sulfuric acid dimers by ammonia, methylamine, dimethylamine, and trimethylamine

Science.gov (United States)

Jen, Coty N.; McMurry, Peter H.; Hanson, David R.

2014-06-01

This study experimentally explores how ammonia (NH3), methylamine (MA), dimethylamine (DMA), and trimethylamine (TMA) affect the chemical formation mechanisms of electrically neutral clusters that contain two sulfuric acid molecules (dimers). Dimers may also contain undetectable compounds, such as water or bases, that evaporate upon ionization and sampling. Measurements were conducted using a glass flow reactor which contained a steady flow of humidified nitrogen with sulfuric acid concentrations of 107 to 109 cm-3. A known molar flow rate of a basic gas was injected into the flow reactor. The University of Minnesota Cluster Chemical Ionization Mass Spectrometer was used to measure the resulting sulfuric acid vapor and cluster concentrations. It was found that, for a given concentration of sulfuric acid vapor, the dimer concentration increases with increasing concentration of the basic gas, eventually reaching a plateau. The base concentrations at which the dimer concentrations saturate suggest NH3 heuristic models for cluster formation by acid-base reactions are developed to interpret the data. The models provide ranges of evaporation rate constants that are consistent with observations and leads to an analytic expression for nucleation rates that is consistent with atmospheric observations.

Biologically produced sulfur particles and polysulfide ions

NARCIS (Netherlands)

Kleinjan, W.E.

2005-01-01

This thesis deals with the effects of particles of biologically produced sulfur (or 'biosulfur') on a biotechnological process for the removal of hydrogen sulfide from gas streams. Particular emphasis is given to the role of polysulfide ions in such a process. These

Measurement of sulfur dioxide oxidation rates in wintertime orographic clouds

International Nuclear Information System (INIS)

Snider, J.R.

1990-01-01

SO2-reaction studies in the clouds are examined and summarized to experimentally confirm model predictions and previous field studies regarding dominant SO2-reaction pathways. Controlled amounts of SO2 were released into nonprecipitating orographic clouds, and sulfate yields are compared to oxidant depletions. The sulfate yields were taken from cloud-water samples and liquid-water-concentration measurements, and oxidant-depletion data were generated from continuous gas-phase measurements. Comparisons of Y sub SO4 and D sub H2O2 suggest that H2O2 is the dominant oxidant, and the in-cloud reaction between H2O2 and the bisulfite ion can be expressed by a simple rate that agrees with predictions and laboratory results. The rate measurements are found to be inconsistent with the rate law proposed by Hegg and Hobbs (1982) and with some observational data. The present conclusions are of interest to evaluating the effects of sulfur dioxide emissions on sulfuric acid deposition. 30 refs

CD4/CD8 ratio and cytokine levels of the BAL fluid in patients with bronchiectasis caused by sulfur mustard gas inhalation

Directory of Open Access Journals (Sweden)

Emad Yasaman

2007-01-01

Full Text Available Abstract Objective To analyze cytokine levels in BAL fluid of patients with bronchiectasis due to mustard gas inhalation. Patients 29 victims with mustard gas-induced bronchiectasis and 25 normal veterans as control group. Intervention PFTs,, high-resolution CT scans of the chest, analyses of BAL fluids for five cytokines (IL-8, IL-1β, IL-6, TNF-α, IL-12 and analyses of BAL fluids for cellular and flow-cytometric analysis of the phenotype of bronchoalveolar cells were performed in all cases. Results CD4 lymphocytes expressed as percentage or absolute number were significantly higher in patients with bronchiectasis than in controls (32.17 ± 16.00 vs 23.40 ± 6.97%, respectively; p = 0.01; and 3.31 ± 2.03 vs 1.88 ± 0.83 × 103 cells/ml, respectively; p = 0.001. The CD4/CD8 ratio was significantly higher in patients with bronchiectasis than in controls (3.08 ± 2.05 vs 1.68 ± 0.78; p = 0.002. There were significant differences in cytokine (IL-8, IL-1β, IL-6, TNF-α, IL-12 levels of BAL fluid between patients with bronchiectasis and healthy controls. A significant correlation was observed between the HRCT scores and both the percentage and the absolute number of CD4 lymphocytes in BAL fluid in patients with bronchiectasis (r = -0.49, p = 0.009; r = -0.50, p = 0.008; respectively. HRCT scores showed a significant correlation with CD4/CD8 ratios (r = 0.54, p = 0.004 too. Of measured BAL cytokines, only IL-8 (r = -0.52, p = 0.005 and TNF-aα (r = 0.44, p = 0.01 showed significant correlations with the HRCT scores. Conclusion The increased levels of cytokines CD4 lymphocytes in the BAL fluid suggest the possible causative mechanism in the lung in sulfur mustard gas-induced bronchiectasis by the recruitment of neutrophils into the lung.

NONEQUILIBRIUM SULFUR CAPTURE & RETENTION IN AN AIR COOLED SLAGGING COAL COMBUSTOR

Energy Technology Data Exchange (ETDEWEB)

Bert Zauderer

2003-04-21

Calcium oxide injected in a slagging combustor reacts with the sulfur from coal combustion to form sulfur-bearing particles. The reacted particles impact and melt in the liquid slag layer on the combustor wall by the centrifugal force of the swirling combustion gases. Due to the low solubility of sulfur in slag, it must be rapidly drained from the combustor to limit sulfur gas re-evolution. Prior analyses and laboratory scale data indicated that for Coal Tech's 20 MMBtu/hour, air-cooled, slagging coal combustor slag mass flow rates in excess of 400 lb/hr should limit sulfur re-evolution. The objective of this 42-month project was to validate this sulfur-in-slag model in a group of combustor tests. A total of 36 days of testing on the combustor were completed during the period of performance of this project. This was more that double the 16 test days that were required in the original work statement. The extra tests were made possible by cost saving innovations that were made in the operation of the combustor test facility and in additional investment of Coal Tech resources in the test effort. The original project plan called for two groups of tests. The first group of tests involved the injection of calcium sulfate particles in the form of gypsum or plaster of Paris with the coal into the 20 MMBtu/hour-combustor. The second group of tests consisted of the entire two-step process, in which lime or limestone is co-injected with coal and reacts with the sulfur gas released during combustion to form calcium sulfate particles that impact and dissolve in the slag layer. Since this sulfur capture process has been validated in numerous prior tests in this combustor, the primary effort in the present project was on achieving the high slag flow rates needed to retain the sulfur in the slag.

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

Science.gov (United States)

Simson, Amanda

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

Effect of aircraft exhaust sulfur emissions on near field plume aerosols

Energy Technology Data Exchange (ETDEWEB)

Brown, R.C.; Miake-Lye, R.C.; Anderson, M.R.; Kolb, C.E. [Aerodyne Research, Inc., Billerica, MA (United States). Center for Chemical and Environmental Physics

1997-12-31

Based on estimated exit plane sulfur speciation, a two dimensional, axisymmetric flow field model with coupled gas phase oxidation kinetics and aerosol nucleation and growth dynamics is used to evaluate the effect of fuel sulfur oxidation in the engine on the formation and growth of volatile H{sub 2}SO{sub 4}/H{sub 2}O aerosols in the near field plume. The conversion of fuel sulfur to sulfur trioxide and sulfuric acid in the engine is predicted to significantly increase the number density and surface area density of volatile H{sub 2}SO{sub 4}/H{sub 2}O aerosols and the chemical activation of exhaust soot particulates. This analysis indicates the need for experimental measurements of exhaust SO{sub x} emissions to fully assess the atmospheric impact of aircraft emissions. (author) 18 refs.; Submitted to Geophysical Research Letters

Effect of aircraft exhaust sulfur emissions on near field plume aerosols

Energy Technology Data Exchange (ETDEWEB)

Brown, R C; Miake-Lye, R C; Anderson, M R; Kolb, C E [Aerodyne Research, Inc., Billerica, MA (United States). Center for Chemical and Environmental Physics

1998-12-31

Based on estimated exit plane sulfur speciation, a two dimensional, axisymmetric flow field model with coupled gas phase oxidation kinetics and aerosol nucleation and growth dynamics is used to evaluate the effect of fuel sulfur oxidation in the engine on the formation and growth of volatile H{sub 2}SO{sub 4}/H{sub 2}O aerosols in the near field plume. The conversion of fuel sulfur to sulfur trioxide and sulfuric acid in the engine is predicted to significantly increase the number density and surface area density of volatile H{sub 2}SO{sub 4}/H{sub 2}O aerosols and the chemical activation of exhaust soot particulates. This analysis indicates the need for experimental measurements of exhaust SO{sub x} emissions to fully assess the atmospheric impact of aircraft emissions. (author) 18 refs.; Submitted to Geophysical Research Letters

Operating experience with unit for sulfuric acid alkylation of isobutane by butylenes

Energy Technology Data Exchange (ETDEWEB)

Tagavov, I.T.; Sumanov, V.T.; Khadzhiev, S.N.

1988-09-01

The operation of units for the sulfuric acid alkylation of isobutanes by butylenes have been performed. The reaction was carried out in a KSG-3 horizontal sulfuric acid contractor. A butane-butylene fraction from catalytic cracking and an isobutane fraction from the central gas fractionating unit were used as a feedstock. The studies have shown that the unit will give a high-quality product under various conditions of operation. The specific consumption of sulfuric acid in processing different types of feed remains within acceptable limits.

Oceanic emissions of sulfur: Application of new techniques

Science.gov (United States)

Jodwalis, Clara Mary

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 budgets of natural sulfur emissions are uncertain because of (1) the uncertainty in the traditional method used to estimate DMS sea-to-air flux, and (2) the spatial and temporal variability of DMS sea-to-air flux. We have worked to lessen the uncertainty on both fronts. The commonly used method for estimating DMS sea-to-air flux is certain to a factor of two, at best. We used a novel instrumental technique to measure, for the first time, sulfur gas concentration fluctuations in the marine boundary layer. The measured concentration fluctuations were then used with two established micrometeorological techniques to estimate sea-to-air flux of sulfur. Both methods appear to be more accurate than the commonly used one. The analytical instrument we used in our studies shows potential as a direct flux measurement device. High primary productivity in high-latitude oceans suggests a potentially large DMS source from northern oceans. To begin to investigate this hypothesis, we have measured DMS in the air over northern oceans around Alaska. For integrating and extrapolating field measurements over larger areas and longer time periods, we have developed a model of DMS ocean mixing, biological production, and sea-to-air flux of DMS. The model's main utility is in gaining intuition on which parameters are most important to DMS sea-to-air flux. This information, along with a direct flux measurement capability, are crucial steps toward the long-term goal of remotely sensing DMS flux. A remote sensing approach will mitigate the problems of spatial and temporal

Dew point of gases with low sulfuric acid content

Energy Technology Data Exchange (ETDEWEB)

Fieg, J.

1981-07-01

Discusses control of air pollution caused by sulfur compounds in solid fuels during combustion. Excessive amount of oxygen during combustion leads to formation of sulfur trioxide. Sulfur trioxide reacts with water vapor and forms sulfuric acid. Chemical reactions which lead to formation of sulfuric acid are described. Conditions for sulfuric acid condensation are analyzed. Several methods for determining dew point of flue gases with low sulfuric acid content are reviewed: methods based on determination of electric conductivity of condensed sulfuric acid (Francis, Cheney, Kiyoure), method based on determination of sulfuric acid concentration in the gaseous phase and in the liquid phase after cooling (Lee, Lisle and Sensenbaugh, Ross and Goksoyr). (26 refs.) (In Polish)

The benefits of combining elemental sulfur with a DMI fungicide to control Monilinia fructicola isolates resistant to propiconazole.

Science.gov (United States)

Holb, Imre J; Schnabel, Guido

2008-02-01

Management of demethylation inhibitor (DMI) fungicide resistance in Monilinia fructicola (G. Winter) Honey is a priority in peach orchards of the southeastern United States, but DMI fungicides are still an important component of antiresistance strategies in view of the few effective alternatives. The goal of this study was to investigate potential benefits of a sulfur/propiconazole mixture for the control of propiconazole-resistant isolates. The mixture provided the best control for propiconazole-resistant isolates, regardless of protective or curative application timings, or the presence or absence of fruit injury. Propiconazole-resistant isolates developed disease on detached fruit after protective or curative applications of propiconazole or its mixture with sulfur, but protective applications of the mixture significantly reduced (P = 0.05) disease symptoms compared with the individual compounds. Additive to slightly synergistic effects were observed for the mixture in protective treatments of peaches inoculated with propiconazole-resistant isolates. The results suggest that the addition of elemental sulfur to a DMI fungicide is likely to be a relatively inexpensive means to improve brown rot control in peach production areas where reduced sensitivity to DMI fungicides is suspected but has not led to noticeable control failure.

Graphene-sulfur nanocomposites for rechargeable lithium-sulfur battery electrodes

Science.gov (United States)

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

2014-06-17

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

Cryogenic treatment of gas

Science.gov (United States)

Bravo, Jose Luis [Houston, TX; Harvey, III, Albert Destrehan; Vinegar, Harold J [Bellaire, TX

2012-04-03

Systems and methods of treating a gas stream are described. A method of treating a gas stream includes cryogenically separating a first gas stream to form a second gas stream and a third stream. The third stream is cryogenically contacted with a carbon dioxide stream to form a fourth and fifth stream. A majority of the second gas stream includes methane and/or molecular hydrogen. A majority of the third stream includes one or more carbon oxides, hydrocarbons having a carbon number of at least 2, one or more sulfur compounds, or mixtures thereof. A majority of the fourth stream includes one or more of the carbon oxides and hydrocarbons having a carbon number of at least 2. A majority of the fifth stream includes hydrocarbons having a carbon number of at least 3 and one or more of the sulfur compounds.

Exhaust gas clean up process

Science.gov (United States)

Walker, R.J.

1988-06-16

A method of cleaning an exhaust gas containing particulates, SO/sub 2/ and NO/sub x/ is described. The method involves prescrubbing with water to remove HCl and most of the particulates, scrubbing with an aqueous absorbent containing a metal chelate and dissolved sulfite salt to remove NO/sub x/ and SO/sub 2/, and regenerating the absorbent solution by controlled heating, electrodialysis and carbonate salt addition. The NO/sub x/ is removed as N/sub 2/ gas or nitrogen sulfonate ions and the oxides of sulfur are removed as a valuable sulfate salt. 4 figs.

Characterization of hydrogen, nitrogen, oxygen, carbon and sulfur in nuclear fuel (UO2) and cladding nuclear rod materials

International Nuclear Information System (INIS)

Crewe, Maria Teresa I.; Lopes, Paula Corain; Moura, Sergio C.; Sampaio, Jessica A.G.; Bustillos, Oscar V.

2011-01-01

The importance of Hydrogen, Nitrogen, Oxygen, Carbon and Sulfur gases analysis in nuclear fuels such as UO 2 , U 3 O 8 , U 3 Si 2 and in the fuel cladding such as Zircaloy, is a well known as a quality control in nuclear industry. In UO 2 pellets, the Hydrogen molecule fragilizes the metal lattice causing the material cracking. In Zircaloy material the H2 molecules cause the boiling of the cladding. Other gases like Nitrogen, Oxygen, Carbon and Sulfur affect in the lattice structure change. In this way these chemical compounds have to be measure within specify parameters, these measurement are part of the quality control of the nuclear industry. The analytical procedure has to be well established by a convention of the quality assurance. Therefore, the Oxygen, Carbon, Sulfur and Hydrogen are measured by infrared absorption (IR) and the nitrogen will be measured by thermal conductivity (TC). The gas/metal analyzer made by LECO Co. model TCHEN-600 is Hydrogen, Oxygen and Nitrogen analyzer in a variety of metals, refractory and other inorganic materials, using the principle of fusion by inert gas, infrared and thermo-coupled detector. The Carbon and Sulfur compounds are measure by LECO Co. model CS-400. A sample is first weighed and placed in a high purity graphite crucible and is casted on a stream of helium gas, enough to release the oxygen, nitrogen and hydrogen. During the fusion, the oxygen present in the sample combines with the carbon crucible to form carbon monoxide. Then, the nitrogen present in the sample is analyzed and released as molecular nitrogen and the hydrogen is released as gas. The hydrogen gas is measured by infrared absorption, and the sample gases pass through a trap of copper oxide which converts CO to CO 2 and hydrogen into water. The gases enter the cell where infrared water content is then converted making the measurement of total hydrogen present in the sample. The Hydrogen detection limits for the nuclear fuel is 1 μg/g for the Nitrogen

Desulfurization kinetics of molten copper by gas bubbling

Science.gov (United States)

Fukunaka, Y.; Nishikawa, K.; Sohn, H. S.; Asaki, Z.

1991-02-01

Molten copper with 0.74 wt pct sulfur content was desulfurized at 1523 K by bubbling Ar-O2 gas through a submerged nozzle. The reaction rate was significantly influenced not only by the oxygen partial pressure but also by the gas flow rate. Little evolution of SO2 gas was observed in the initial 10 seconds of the oxidation; however, this was followed by a period of high evolution rate of SO2 gas. The partial pressure of SO2 gas decreased with further progress of the desulfurization. The effect of the immersion depth of the submerged nozzle was negligible. The overall reaction is decomposed to two elementary reactions: the desulfurization and the dissolution rate of oxygen. The assumptions were made that these reactions are at equilibrium and that the reaction rates are controlled by mass transfer rates within and around the gas bubble. The time variations of sulfur and oxygen contents in the melt and the SO2 partial pressure in the off-gas under various bubbling conditions were well explained by the mathematical model combined with the reported thermodynamic data of these reactions. Based on the present model, it was anticipated that the oxidation rate around a single gas bubble was mainly determined by the rate of gas-phase mass transfer, but all oxygen gas blown into the melt was virtually consumed to the desulfurization and dissolution reactions before it escaped from the melt surface.

HYBRID SULFUR CYCLE FLOWSHEETS FOR HYDROGEN PRODUCTION USING HIGH-TEMPERATURE GAS-COOLED REACTORS

Energy Technology Data Exchange (ETDEWEB)

Gorensek, M.

2011-07-06

Two hybrid sulfur (HyS) cycle process flowsheets intended for use with high-temperature gas-cooled reactors (HTGRs) are presented. The flowsheets were developed for the Next Generation Nuclear Plant (NGNP) program, and couple a proton exchange membrane (PEM) electrolyzer for the SO2-depolarized electrolysis step with a silicon carbide bayonet reactor for the high-temperature decomposition step. One presumes an HTGR reactor outlet temperature (ROT) of 950 C, the other 750 C. Performance was improved (over earlier flowsheets) by assuming that use of a more acid-tolerant PEM, like acid-doped poly[2,2'-(m-phenylene)-5,5'-bibenzimidazole] (PBI), instead of Nafion{reg_sign}, would allow higher anolyte acid concentrations. Lower ROT was accommodated by adding a direct contact exchange/quench column upstream from the bayonet reactor and dropping the decomposition pressure. Aspen Plus was used to develop material and energy balances. A net thermal efficiency of 44.0% to 47.6%, higher heating value basis is projected for the 950 C case, dropping to 39.9% for the 750 C case.

Gas Sensing Analysis of Ag-Decorated Graphene for Sulfur Hexafluoride Decomposition Products Based on the Density Functional Theory

Directory of Open Access Journals (Sweden)

Xiaoxing Zhang

2016-11-01

Full Text Available Detection of decomposition products of sulfur hexafluoride (SF6 is one of the best ways to diagnose early latent insulation faults in gas-insulated equipment, and the occurrence of sudden accidents can be avoided effectively by finding early latent faults. Recently, functionalized graphene, a kind of gas sensing material, has been reported to show good application prospects in the gas sensor field. Therefore, calculations were performed to analyze the gas sensing properties of intrinsic graphene (Int-graphene and functionalized graphene-based material, Ag-decorated graphene (Ag-graphene, for decomposition products of SF6, including SO2F2, SOF2, and SO2, based on density functional theory (DFT. We thoroughly investigated a series of parameters presenting gas-sensing properties of adsorbing process about gas molecule (SO2F2, SOF2, SO2 and double gas molecules (2SO2F2, 2SOF2, 2SO2 on Ag-graphene, including adsorption energy, net charge transfer, electronic state density, and the highest and lowest unoccupied molecular orbital. The results showed that the Ag atom significantly enhances the electrochemical reactivity of graphene, reflected in the change of conductivity during the adsorption process. SO2F2 and SO2 gas molecules on Ag-graphene presented chemisorption, and the adsorption strength was SO2F2 > SO2, while SOF2 absorption on Ag-graphene was physical adsorption. Thus, we concluded that Ag-graphene showed good selectivity and high sensitivity to SO2F2. The results can provide a helpful guide in exploring Ag-graphene material in experiments for monitoring the insulation status of SF6-insulated equipment based on detecting decomposition products of SF6.

Refractories for exhaust gas scrubbers

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-07-01

Primary metal smelters are recovering a greater percentage of their stack emissions because of increased global environmental pressures. Copper and nickel producers processing sulfide ore are under particular scrutiny for sulfur dioxide emissions. The use of various acid plant designs and associated scrubbers to capture the gas is commonplace. Failure of acid plant or sulfur dioxide control devices can be very expensive, both in terms of repair costs and lost production. Close attention should be paid to ensure smooth, long term and proper operation of these vessels. With INCO flash furnace shops smelter gases are treated immediately upon leaving the furnace in a particulate scrubber where the gases are cooled and de-dusted in a water spray chamber. The amount of chlorine and fluorine in the waste gas can vary widely, ranging from non-existent to being a major source of concern for refractory wear. Developed specifically for use in hazardous waste incinerators burning fluorine-containing materials, spall-resistant, high-purity alimina bricks were installed in various gas cleaning units in copper smelting plants. Because of the materials's combination of abrasion resistance, thermal cycling resistance, and chemical durability under conditions of variable SO(3) and fluorine attack, the material has proven to be more than adequate for the challenges of gas cleaning equipment. 2 refs.

Partial oxidation process for producing a stream of hot purified gas

Science.gov (United States)

Leininger, T.F.; Robin, A.M.; Wolfenbarger, J.K.; Suggitt, R.M.

1995-03-28

A partial oxidation process is described for the production of a stream of hot clean gas substantially free from particulate matter, ammonia, alkali metal compounds, halides and sulfur-containing gas for use as synthesis gas, reducing gas, or fuel gas. A hydrocarbonaceous fuel comprising a solid carbonaceous fuel with or without liquid hydrocarbonaceous fuel or gaseous hydrocarbon fuel, wherein said hydrocarbonaceous fuel contains halides, alkali metal compounds, sulfur, nitrogen and inorganic ash containing components, is reacted in a gasifier by partial oxidation to produce a hot raw gas stream comprising H{sub 2}, CO, CO{sub 2}, H{sub 2}O, CH{sub 4}, NH{sub 3}, HCl, HF, H{sub 2}S, COS, N{sub 2}, Ar, particulate matter, vapor phase alkali metal compounds, and molten slag. The hot raw gas stream from the gasifier is split into two streams which are separately deslagged, cleaned and recombined. Ammonia in the gas mixture is catalytically disproportionated into N{sub 2} and H{sub 2}. The ammonia-free gas stream is then cooled and halides in the gas stream are reacted with a supplementary alkali metal compound to remove HCl and HF. Alkali metal halides, vaporized alkali metal compounds and residual fine particulate matter are removed from the gas stream by further cooling and filtering. The sulfur-containing gases in the process gas stream are then reacted at high temperature with a regenerable sulfur-reactive mixed metal oxide sulfur sorbent material to produce a sulfided sorbent material which is then separated from the hot clean purified gas stream having a temperature of at least 1000 F. 1 figure.

Emissions of biogenic sulfur gases from Alaskan tundra

Science.gov (United States)

Hines, Mark E.; Morrison, Michael C.

1992-01-01

Results of sulfur emission measurements made in freshwater and marine wetlands in Alaskan tundra during the Arctic Boundary Layer Expedition 2A (ABLE 3A) in July 1988 are presented. The data indicate that this type of tundra emits very small amounts of gaseous sulfur and, when extrapolated globally, accounts for a very small percentage of the global flux of biogenic sulfur to the atmosphere. Sulfur emissions from marine sites are up to 20-fold greater than fluxes from freshwater habitats and are dominated by dimethyl sulfide (DMS). Highest emissions, with a mean of 6.0 nmol/sq m/h, occurred in water-saturated wet meadow areas. In drier upland tundra sites, highest fluxes occurred in areas inhabited by mixed vegetation and labrador tea at 3.0 nmol/sq m/h and lowest fluxes were from lichen-dominated areas at 0.9 nmol/sq m/h. DMS was the dominant gas emitted from all these sites. Emissions of DMS were highest from intertidal soils inhabited by Carex subspathacea.

Health Endpoint Attributed to Sulfur Dioxide Air Pollutants

Directory of Open Access Journals (Sweden)

Geravandi

2015-07-01

Full Text Available Background Sulfur dioxide is a colorless gas, released from burning of coal, high-sulfur coal,s and diesel fuel. Sulfur dioxide harms human health by reacting with the moisture in the nose, nasal cavity and throat and this is the way by which it destroys the nerves in the respiratory system. Objectives The aim of this study was to focus on identifying the effects associated with sulfur dioxide on health in Ahvaz, Iran. Materials and Methods Data collections were performed by Ahvaz meteorological organization and the department of environment. Sampling was performed for 24 hours in four stations. Methods of sampling and analysis were according to US environmental protection agency (EPA guideline. Afterwards, we processed the raw data including instruction set correction of averaging, coding and filtering by Excel software and then, the impact of meteorological parameters were converted as the input file to the AirQ model. Finally, we calculated the health effects of exposure to sulfur dioxide. Results According to the findings, the concentration of sulfur dioxide in Ahvaz had an annual average of 51 μg/m3. Sum of the numbers of hospital admissions for respiratory diseases attributed to sulfur dioxide was 25 cases in 2012. Approximately, 5% of the total hospital admissions for respiratory disease and respiratory mortality happened when sulfur dioxide concentration was more than 10 mg/m3. Conclusions According to the results of this study, this increase could be due to higher fuel consumption, usage of gasoline in vehicles, oil industry, and steel and heavy industries in Ahwaz. The risk of mortality and morbidity were detected at the current concentrations of air pollutants.

Control of Copper Resistance and Inorganic Sulfur Metabolism by Paralogous Regulators in Staphylococcus aureus*

Science.gov (United States)

Grossoehme, Nicholas; Kehl-Fie, Thomas E.; Ma, Zhen; Adams, Keith W.; Cowart, Darin M.; Scott, Robert A.; Skaar, Eric P.; Giedroc, David P.

2011-01-01

All strains of Staphylococcus aureus encode a putative copper-sensitive operon repressor (CsoR) and one other CsoR-like protein of unknown function. We show here that NWMN_1991 encodes a bona fide Cu(I)-inducible CsoR of a genetically unlinked copA-copZ copper resistance operon in S. aureus strain Newman. In contrast, an unannotated open reading frame found between NWMN_0027 and NWMN_0026 (denoted NWMN_0026.5) encodes a CsoR-like regulator that represses expression of adjacent genes by binding specifically to a pair of canonical operator sites positioned in the NWMN_0027–0026.5 intergenic region. Inspection of these regulated genes suggests a role in assimilation of inorganic sulfur from thiosulfate and vectorial sulfur transfer, and we designate NWMN_0026.5 as CstR (CsoR-like sulfur transferase repressor). Expression analysis demonstrates that CsoR and CstR control their respective regulons in response to distinct stimuli with no overlap in vivo. Unlike CsoR, CstR does not form a stable complex with Cu(I); operator binding is instead inhibited by oxidation of the intersubunit cysteine pair to a mixture of disulfide and trisulfide linkages by a likely metabolite of thiosulfate assimilation, sulfite. CsoR is unreactive toward sulfite under the same conditions. We conclude that CsoR and CstR are paralogs in S. aureus that function in the same cytoplasm to control distinct physiological processes. PMID:21339296

Control of copper resistance and inorganic sulfur metabolism by paralogous regulators in Staphylococcus aureus.

Science.gov (United States)

Grossoehme, Nicholas; Kehl-Fie, Thomas E; Ma, Zhen; Adams, Keith W; Cowart, Darin M; Scott, Robert A; Skaar, Eric P; Giedroc, David P

2011-04-15

All strains of Staphylococcus aureus encode a putative copper-sensitive operon repressor (CsoR) and one other CsoR-like protein of unknown function. We show here that NWMN_1991 encodes a bona fide Cu(I)-inducible CsoR of a genetically unlinked copA-copZ copper resistance operon in S. aureus strain Newman. In contrast, an unannotated open reading frame found between NWMN_0027 and NWMN_0026 (denoted NWMN_0026.5) encodes a CsoR-like regulator that represses expression of adjacent genes by binding specifically to a pair of canonical operator sites positioned in the NWMN_0027-0026.5 intergenic region. Inspection of these regulated genes suggests a role in assimilation of inorganic sulfur from thiosulfate and vectorial sulfur transfer, and we designate NWMN_0026.5 as CstR (CsoR-like sulfur transferase repressor). Expression analysis demonstrates that CsoR and CstR control their respective regulons in response to distinct stimuli with no overlap in vivo. Unlike CsoR, CstR does not form a stable complex with Cu(I); operator binding is instead inhibited by oxidation of the intersubunit cysteine pair to a mixture of disulfide and trisulfide linkages by a likely metabolite of thiosulfate assimilation, sulfite. CsoR is unreactive toward sulfite under the same conditions. We conclude that CsoR and CstR are paralogs in S. aureus that function in the same cytoplasm to control distinct physiological processes.

Mechanistic modeling of sulfur-deprived photosynthesis and hydrogen production in suspensions of Chlamydomonas reinhardtii.

Science.gov (United States)

Williams, C R; Bees, M A

2014-02-01

The ability of unicellular green algal species such as Chlamydomonas reinhardtii to produce hydrogen gas via iron-hydrogenase is well known. However, the oxygen-sensitive hydrogenase is closely linked to the photosynthetic chain in such a way that hydrogen and oxygen production need to be separated temporally for sustained photo-production. Under illumination, sulfur-deprivation has been shown to accommodate the production of hydrogen gas by partially-deactivating O2 evolution activity, leading to anaerobiosis in a sealed culture. As these facets are coupled, and the system complex, mathematical approaches potentially are of significant value since they may reveal improved or even optimal schemes for maximizing hydrogen production. Here, a mechanistic model of the system is constructed from consideration of the essential pathways and processes. The role of sulfur in photosynthesis (via PSII) and the storage and catabolism of endogenous substrate, and thus growth and decay of culture density, are explicitly modeled in order to describe and explore the complex interactions that lead to H2 production during sulfur-deprivation. As far as possible, functional forms and parameter values are determined or estimated from experimental data. The model is compared with published experimental studies and, encouragingly, qualitative agreement for trends in hydrogen yield and initiation time are found. It is then employed to probe optimal external sulfur and illumination conditions for hydrogen production, which are found to differ depending on whether a maximum yield of gas or initial production rate is required. The model constitutes a powerful theoretical tool for investigating novel sulfur cycling regimes that may ultimately be used to improve the commercial viability of hydrogen gas production from microorganisms. © 2013 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc.

a Real-Time GIS Platform for High Sour Gas Leakage Simulation, Evaluation and Visualization

Science.gov (United States)

Li, M.; Liu, H.; Yang, C.

2015-07-01

The development of high-sulfur gas fields, also known as sour gas field, is faced with a series of safety control and emergency management problems. The GIS-based emergency response system is placed high expectations under the consideration of high pressure, high content, complex terrain and highly density population in Sichuan Basin, southwest China. The most researches on high hydrogen sulphide gas dispersion simulation and evaluation are used for environmental impact assessment (EIA) or emergency preparedness planning. This paper introduces a real-time GIS platform for high-sulfur gas emergency response. Combining with real-time data from the leak detection systems and the meteorological monitoring stations, GIS platform provides the functions of simulating, evaluating and displaying of the different spatial-temporal toxic gas distribution patterns and evaluation results. This paper firstly proposes the architecture of Emergency Response/Management System, secondly explains EPA's Gaussian dispersion model CALPUFF simulation workflow under high complex terrain and real-time data, thirdly explains the emergency workflow and spatial analysis functions of computing the accident influencing areas, population and the optimal evacuation routes. Finally, a well blow scenarios is used for verify the system. The study shows that GIS platform which integrates the real-time data and CALPUFF models will be one of the essential operational platforms for high-sulfur gas fields emergency management.

Gas Control System for HEAO-B

Science.gov (United States)

Taylor, B.; Brissette, R.; Humphrey, A.; Morris, J.; Luger, J.; Swift, W.

1978-01-01

The HEAO-B Gas Control System consists of a high pressure gas storage supply together with distribution and regulation assemblies and their associated electronics for management of gas required for HEAO-B X-ray counter experiments. The Gas Control System replenishes a gas mixture (82 percent argon, 12.3 percent carbon dioxide, 5.7 percent xenon) in the counter volumes which is lost by: diffusion through controlled leakage plugs, diffusion through counter windows, and consumption resulting from periodic purges. The gas density in each counter volume is maintained constant to within 0.25 percent by comparison with a sealed reference volume. The system is fully redundant, capable of operating at atmospheric pressure as well as in a vacuum, contains interlocks which shut down gas flow in the event of either leakage or excessive pressure, and is able to shut down counter high voltage if counter pressure is abnormally low. The system is electronically controlled by ground command and self-sustaining in orbit for a period of at least one year.

Gas cleaning and hydrogen sulfide removal for COREX coal gas by sorption enhanced catalytic oxidation over recyclable activated carbon desulfurizer.

Science.gov (United States)

Sun, Tonghua; Shen, Yafei; Jia, Jinping

2014-02-18

This paper proposes a novel self-developed JTS-01 desulfurizer and JZC-80 alkaline adsorbent for H2S removal and gas cleaning of the COREX coal gas in small-scale and commercial desulfurizing devices. JTS-01 desulfurizer was loaded with metal oxide (i.e., ferric oxides) catalysts on the surface of activated carbons (AC), and the catalyst capacity was improved dramatically by means of ultrasonically assisted impregnation. Consequently, the sulfur saturation capacity and sulfur capacity breakthrough increased by 30.3% and 27.9%, respectively. The whole desulfurizing process combined selective adsorption with catalytic oxidation. Moreover, JZC-80 adsorbent can effectively remove impurities such as HCl, HF, HCN, and ash in the COREX coal gas, stabilizing the system pressure drop. The JTS-01 desulfurizer and JZC-80 adsorbent have been successfully applied for the COREX coal gas cleaning in the commercial plant at Baosteel, Shanghai. The sulfur capacity of JTS-01 desulfurizer can reach more than 50% in industrial applications. Compared with the conventional dry desulfurization process, the modified AC desulfurizers have more merit, especially in terms of the JTS-01 desulfurizer with higher sulfur capacity and low pressure drop. Thus, this sorption enhanced catalytic desulfurization has promising prospects for H2S removal and other gas cleaning.

Sulfur dioxide: foe or friend for life?

Science.gov (United States)

Wang, Xin-Bao; Cui, Hong; Liu, Xiaohong; Du, Jun-Bao

2017-12-01

Sulfur dioxide (SO₂) is a toxic gas and air pollutant. The toxic effects of SO₂ have been extensively studied. Oxidative damage due to SO₂ can occur in multiple organs. Inhaled SO₂ can also cause chromosomal aberrations, DNA damage and gene mutations in mammals. However, SO₂ can also be generated from the sulfur-containing amino acid, L-cysteine. Recent studies have shown that SO₂ has a vasorelaxant effect, and ameliorates pulmonary hypertension and vascular remodeling. SO₂ can also reduce lung injury and myocardial injury in rats. In addition, SO₂ reduces myocardial ischemia-reperfusion injury and atherosclerotic lesions. Therefore, SO₂ exerts both detrimental and protective effects in mammals. Is SO₂ a foe or friend for life?.

Retrofit acid gas emission control for municipal waste incineration application of dry sorbent injection

International Nuclear Information System (INIS)

Zmuda, J.T.; Smith, P.V.

1991-01-01

Dry sorbent injection (DSI) has been successfully demonstrated on coal fired boiler applications as a means of reducing sulfur dioxide emissions. More recently, the dry sorbent injection process was applied to an existing municipal waste incinerator to provide acid gas emission controls. The results obtained from the successful demonstration of the sorbent injection system on an existing municipal incinerator are presented. Removal efficiencies of compounds such as HCl, SO 2 , SO 3 , mercury, and others by the use of sorbent injection are shown. Effects of the DSI system on downstream equipment, such as electrostatic precipitators, fabric filters, ash handling systems, and waste management is included. The impacts of the DSI system on the furnace is also discussed. In this paper a discussion of dry sorbent injection as a means of reducing acid gas and other emissions from existing municipal waste incinerators which may be affected by the regulations is presented. An application case study will outline typical exhaust conditions, expected pollution reductions, capital and operating costs, and type of available sorbents and their costs

Identifying parameter windows for sulfur removal by direct limestone injection in the rich zone of staged heat engine combustors

International Nuclear Information System (INIS)

Colaluca, M.A.

1990-01-01

Recent experimental evidence suggests the possibility of sulfur cleanup by direct injection at gas temperatures that do not thermodynamically favor the absorption of sulfur by the limestone. The purpose of this paper is to analytically investigate possible mechanistic explanations of this observed sulfur capture with the goal of evaluating the potential for limestone injection sulfur capture in direct coal fired gas turbine and diesel engine (heat engines) combustion applications. The method was to use current available data on the physical properties of limestone, and the rates of the pertinent reactions, and to develop mathematical models of the processes experienced by the sorbent particles. The models were then used to predict extent of capture at the high-pressure, high-temperature, short residence time conditions of interest. The goal was to first investigate capture in a single-pulse reactor (combustion bomb) and then to extrapolate these results to advanced coal-fired heat engine combustion environments. Model predictions were in good agreement with observed sulfur capture in cold wall combustion bomb studies and suggest that efficient sulfur capture (in excess of 80 percent calcium utilization) may b e possible when limestone sorbents are injected into high-temperature combustion products, even when the gas temperatures exceed the thermodynamically favored temperature window by several hundred kelvins. This behavior is possible because particle temperatures are moderated and held at levels that favor sulfur capture due to the strongly endothermic calcination reaction

Sulfur compounds and species in Russian residues by XPS and PY-GC-PFPO

Energy Technology Data Exchange (ETDEWEB)

Quan, S.; Suoqi, Z.; Chunming, X. [University of Petroleum, State Key Laboraory of Heavy Oil Processing, Beijing (China); Kotlyar, L.; Kung, J. [National Research Council of Canada, Institute for Chemical processand Environmental Technology, Ottawa, ON (Canada); Chung, K. H. [Syncrude Canada Limited, Edmonton, AB (Canada)

2004-07-01

Distribution and structure of sulfur components of Russian crude oil were investigated by separating vacuum residues from the oil into 17 narrow cuts and one end-cut using the supercritical fluid extraction and fractionation technique (SFEF). The cuts were analyzed by gas chromatography, with conditions optimized from 600 degrees C to 1,000 degrees C, and between two and twenty seconds. In general, the total amount of of the sulfur compounds in pyrolizates was found to be proportional to the sulfur content in the vacuum residues. Thiophenes, benzothiophenes and dibenzothiophene content varied from vacuum residue to vacuum residue. Benzothiophens were identified as the dominant sulfur compounds in the pyrolizate of Russian crude oil.

Effect of sulfur dioxide on proteins of the vegetable organism

Energy Technology Data Exchange (ETDEWEB)

Reckendorfer, P; Beran, F

1931-01-01

Experiments were performed to determine the effects of sulfur dioxide on red clover in a controlled environment. An increase in the concentration of sulfur dioxide caused a significant decrease in the digestible protein. However, after the sulfur dioxide was discontinued, there was a decrease in the indigestible protein. The leaves showed an increase in spotting with an increase in sulfur dioxide concentration. Chemical analysis of the soil revealed a higher sulfur content in these experiments.

Measurements to determine the sulfuric acid dew point and the SO sub 3 concentration in flue gas of power plant vessels. Messungen zur Bestimmung des Saeuretaupunktes und der SO sub 3 -Konzentration im Rauchgas von Kraftwerkskesseln

Energy Technology Data Exchange (ETDEWEB)

Derichs, W.; Menden, W. (RWE Energie AG, Bergheim (Germany)); Ebel, P.K. (Apparatebau Hundsbach GmbH, Baden-Baden (Germany))

1990-01-01

Among the customary methods of dew point determination, the technique of recording the increase in conductivity between two electrodes at the moment of acid condensing onto them, and measuring at the same time the temperature of the sensor, is appropriate to determine the sulfuric acid dew point in dust-laden flue gas. By means of the sensitivity of a newly developed sensor, the accuracy of the measurement method could be improved to such an extent that also low acid dew points and rapid changes can be recorded reliably. Measurements have shown that the acid dew point primarily depends on the SO{sub 3} content which is substantially determined by the sulfur content of the fuel and the type of flue gas ducts. Further influential quantities include flue gas humidity, air surplus, other gaseous flue gas components such as HCl and HF, as well as the quantity, composition and temperature-dependent adsorption capability of the flue dusts. (orig./BBR).

Hot and Dry Cleaning of Biomass-Gasified Gas Using Activated Carbons with Simultaneous Removal of Tar, Particles, and Sulfur Compounds

Directory of Open Access Journals (Sweden)

Kinya Sakanishi

2012-05-01

Full Text Available This study proposes a gas-cleaning process for the simultaneous removal of sulfur compounds, tar, and particles from biomass-gasified gas using Fe-supported activated carbon and a water-gas shift reaction. On a laboratory scale, the simultaneous removal of H2S and COS was performed under a mixture of gases (H2/CO/CO2/CH4/C2H4/N2/H2S/COS/steam. The reactions such as COS + H2 → H2S + CO and COS + H2O → H2S + CO2 and the water-gas shift reaction were promoted on the Fe-supported activated carbon. The adsorption capacity with steam was higher than that without steam. On a bench scale, the removal of impurities from a gas derived from biomass gasification was investigated using two activated filters packed with Fe-supported activated carbon. H2S and COS, three- and four-ring polycyclic aromatic hydrocarbons (PAHs, and particles were removed and a water-gas shift reaction was promoted through the first filter at 320–350 °C. The concentrations of H2S and COS decreased to less than 0.1 ppmv. Particles and the one- and two-ring PAHs, except for benzene, were then removed through the second filter at 60–170 °C. The concentration of tar and particles decreased from 2428 to 102 mg Nm−3 and from 2244 to 181 mg Nm−3, respectively.

Biologically produced sulfur

NARCIS (Netherlands)

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

2003-01-01

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

Defected and Functionalized Germanene based Nanosensors under Sulfur Comprising Gas Exposure

KAUST Repository

Hussain, Tanveer

2018-03-27

Efficient sensing of sulfur containing toxic gases like H2S and SO2 is of outmost importance due to the adverse effects of these noxious gases. Absence of an efficient 2D based nanosensors capable of anchoring H2S and SO2 with feasible binding and an apparent variation in electronic properties upon the exposure of gas molecules has motivated us to explore the promise of germanene nano sheet (Ge-NS) for this purpose. In the present study, we have performed a comprehensive computational investigation by means of DFT based first principles calculations to envisage the structural, electronic and gas sensing properties of pristine, defected and metal substituted Ge-NS. Our initial screening has revealed that although interaction of SO2 on pristine Ge-NS is within the desirable range, however H2S binding is falling below the required values to guarantee an effective sensing. To improve the binding characteristics, we have considered the interactions between H2S and SO2 with defected and metal substituted Ge-NS. The systematic removals of Ge atoms from a reasonably large super cell lead to mono-vacancy, di-vacancies and tri-vacancies in Ge-NS. Similarly, different transition metals like As, Co, Cu, Fe, Ga, Ge Ni and Zn have been substituted into the monolayer to realize substituted Ge-NS. Our van der Waals corrected DFT calculations have concluded that the vacancy and substitution defects not only improve the binding characteristics but also enhance the sensing propensity of both H2S and SO2. The total and projected density of states show significant variations in electronic properties of pristine and defected Ge-NS before and after the exposure to the gases, which are essential in constituting a signal to be detected by the external circuit of the sensor. We strongly believe that out present work would not only advance the knowledge towards the application of Ge-NS based sensing, but also provide the motivation for the synthesis of an efficient nanosensors for H2S and SO

A primer on sulfur for the planetary geologist

Science.gov (United States)

Theilig, E.

1982-01-01

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

submitter Unexpectedly acidic nanoparticles formed in dimethylamine–ammonia–sulfuric-acid nucleation experiments at CLOUD

CERN Document Server

Lawler, Michael J; Kim, Jaeseok; Ahlm, Lars; Tröstl, Jasmin; Praplan, Arnaud P; Schobesberger, Siegfried; Kürten, Andreas; Kirkby, Jasper; Bianchi, Federico; Duplissy, Jonathan; Hansel, Armin; Jokinen, Tuija; Keskinen, Helmi; Lehtipalo, Katrianne; Leiminger, Markus; Petäjä, Tuukka; Rissanen, Matti; Rondo, Linda; Simon, Mario; Sipilä, Mikko; Williamson, Christina; Wimmer, Daniela; Riipinen, Ilona; Virtanen, Annele; Smith, James N

2016-01-01

New particle formation driven by acid–base chemistry was initiated in the CLOUD chamber at CERN by introducing atmospherically relevant levels of gas-phase sulfuric acid and dimethylamine (DMA). Ammonia was also present in the chamber as a gas-phase contaminant from earlier experiments. The composition of particles with volume median diameters (VMDs) as small as 10 nm was measured by the Thermal Desorption Chemical Ionization Mass Spectrometer (TDCIMS). Particulate ammonium-to-dimethylaminium ratios were higher than the gas-phase ammonia-to-DMA ratios, suggesting preferential uptake of ammonia over DMA for the collected 10–30 nm VMD particles. This behavior is not consistent with present nanoparticle physicochemical models, which predict a higher dimethylaminium fraction when NH3 and DMA are present at similar gas-phase concentrations. Despite the presence in the gas phase of at least 100 times higher base concentrations than sulfuric acid, the recently formed particles always had measured base : ...

Distillers by-product cattle diets enhance reduced sulfur gas fluxes from feedlot soils and manures

Science.gov (United States)

Total reduced sulfur (TRS) emissions from animal feeding operations are a concern with increased feeding of high-sulfur distillers by-products. Three feeding trials were conducted to evaluate feeding wet distillers grain plus solubles (WDGS) on TRS fluxes. Fresh manure was collected three times duri...

Sulfur oxides and nitrogen oxides gas treating process

International Nuclear Information System (INIS)

Forbes, J. T.

1985-01-01

A process is disclosed for treating particle-containing gas streams by removing particles and gaseous atmospheric pollutants. Parallel passage contactors are utilized to remove the gaseous pollutants. The minimum required gas flow rate for effective operation of these contactors is maintained by recycling a variable amount of low temperature gas which has been passed through a particle removal zone. The recycled gas is reheated by heat exchange against a portion of the treated gas

SYNTHESIS OF SULFUR-BASED WATER TREATMENT AGENT FROM SULFUR DIOXIDE WASTE STREAMS

Energy Technology Data Exchange (ETDEWEB)

Robert C. Brown; Maohong Fan; Adrienne Cooper

2004-11-01

Absorption of sulfur dioxide from a simulated flue gas was investigated for the production of polymeric ferric sulfate (PFS), a highly effective coagulant useful in treatment of drinking water and wastewater. The reaction for PFS synthesis took place near atmospheric pressure and at temperatures of 30-80 C. SO{sub 2} removal efficiencies greater than 90% were achieved, with ferrous iron concentrations in the product less than 0.1%. A factorial analysis of the effect of temperature, oxidant dosage, SO{sub 2} concentration, and gas flow rate on SO{sub 2} removal efficiency was carried out, and statistical analyses are conducted. The solid PFS was also characterized with different methods. Characterization results have shown that PFS possesses both crystalline and non-crystalline structure. The kinetics of reactions among FeSO{sub 4} {center_dot} 7H{sub 2}O, NaHSO{sub 3} and NaClO{sub 3} was investigated. Characterizations of dry PFS synthesized from SO{sub 2} show the PFS possesses amorphous structure, which is desired for it to be a good coagulant in water and wastewater treatment. A series of lab-scale experiments were conducted to evaluate the performance of PFS synthesized from waste sulfur dioxide, ferrous sulfate and sodium chlorate. The performance assessments were based on the comparison of PFS and other conventional and new coagulants for the removal of turbidity and arsenic under different laboratory coagulant conditions. Pilot plant studies were conducted at Des Moines Water Works in Iowa and at the City of Savannah Industrial and Domestic (I&D) Water Treatment Plant in Port Wentworth, Georgia. PFS performances were compared with those of conventional coagulants. The tests in both water treatment plants have shown that PFS is, in general, comparable or better than other coagulants in removal of turbidity and organic substances. The corrosion behavior of polymeric ferric sulfate (PFS) prepared from SO{sub 2} and ferric chloride (FC) were compared. Results

Acid Gas Removal from Natural Gas with Alkanolamines

DEFF Research Database (Denmark)

Sadegh, Negar

commercially for the removal of acid gas impurities from natural gas. Alkanolamines, simple combinations of alcohols and ammonia, are the most commonly used category of chemical solvents for acid gas capture. This Ph.D. project is aboutthermodynamics of natural gas cleaning process with alkanolamines......Some 40 % of the world’s remaining gas reserves are sour or acid, containing large quantities of CO2 and H2S and other sulfur compounds. Many large oil and gas fields have more than 10 mole % CO2 and H2S content. In the gas processing industry absorption with chemical solvents has been used...... pressure on acid gas solubility was also quantitatively investigated through both experimental and modeling approaches....

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

International Nuclear Information System (INIS)

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

2016-01-01

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

Non-mass-dependent fractionation of sulfur and oxygen isotopes during UV photolysis of sulfur dioxide

Science.gov (United States)

Pen, Aranh

Since the discovery of anomalous sulfur isotope abundance in the geological record in sulfate and sulfide minerals (Farquhar et al., 2000), much effort has been put into understanding their origin to provide new insights into the environmental conditions on the early Earth (Farquhar et al., 2001; Pavlov and Kasting, 2002; Ono et al., 2003; Zahnle et al., 2006; Farquhar et al., 2007; Lyons, 2007; Lyons, 2008). This discovery gained immense interest because of its implications for both the lack of oxygen in the atmosphere during the Archean era 2.5-3.8 Gya (billion years ago), and for rise of oxygen, or the "Great Oxidation Event", that occurred 2.2-2.4 Gya (Holland, 2002). These signatures are believed to be produced in an anticorrelation to oxygen abundance in the early atmosphere, which will aid in quantifying the rate of oxygenation during the "Great Oxidation Event". According to Farquhar et al. (2000), the non-mass-dependent (NMD), or anomalous, fractionation signatures were produced by photochemical reactions of volcanic sulfur species in Earth's early atmosphere (> 2.3 Gya) due to the lack of an oxygen and ozone shield, resulting in an atmosphere transparent to solar ultraviolet (UV) radiation (Farquhar et al., 2001). Interpretation of the anomalous rock records, though, depends on the identification of (1) chemical reactions that can produce the NMD signature (Farquhar and Wing, 2003); and (2) conditions necessary for conversion of the gas-phase products into solid minerals (Pavlov and Kasting, 2002). The focus of my research addresses the first step, which is to determine whether the chemical reactions that occurred in Earth's early atmosphere, resulting in NMD fractionation of sulfur isotopes, were due to broadband UV photochemistry, and to test isotopic self-shielding as the possible underlying mechanism. In this project, our goals were to test isotopic self-shielding during UV photolysis as a possible underlying mechanism for anomalous sulfur isotopic

Elemental sulfur identified in urine of cheetah, Acinonyx jubatus.

Science.gov (United States)

Burger, Ben V; Visser, Runine; Moses, Alvira; Le Roux, Maritha

2006-06-01

The urine of the cheetah, Acinonyx jubatus, is almost odorless, and probably for this reason, it has not attracted much attention from scientists. Using gas chromatography-mass spectrometry, we identified 27 and 37 constituents in the headspace vapor of the urine of male and female cheetah, respectively. These constituents, composed of hydrocarbons, short-chain ethers, aldehydes, saturated and unsaturated cyclic and acyclic ketones, 2-acetylfuran, dimethyl disulfide, dimethyl sulfone, phenol, myristic acid (tetradecanoic acid), urea, and elemental sulfur, are all present in the headspace vapor in very small quantities; dimethyl disulfide is present in such a low concentration that it cannot be detected by the human nose. This is only the second example of elemental sulfur being secreted or excreted by an animal. It is hypothesized that the conversion of sulfur-containing compounds in the cheetah's diet to elemental sulfur and to practically odorless dimethyl sulfone enables this carnivore to operate as if "invisible" to the olfactory world of its predators as well as its prey, which would increase its chances of survival.

Mobil positioning itself to become Canada's premier oil and gas company

International Nuclear Information System (INIS)

Thomas, A.

1994-01-01

To achieve its goal of becoming Canada's premier oil and gas company by the year 2000, Mobil Oil Canada is empowering its employees and applying appropriate technology to unlock resources and create value. Mobil produces 4.1 million m 3 of oil and natural gas liquids, 5.6 million m 3 /y of natural gas and 438,000 tonnes/y of sulfur. It also operates over 3,000 wells in western Canada and eleven gas processing plants, manages 1,700 km of pipeline, and has 33% interest in the Hibernia project on the Grand Banks. Oil lifting costs have decreased over the past three years from $3.40/bbl to $2.80/bbl and development costs are under $2/bbl. Innovative technology used to achieve high production and low costs include the use of three dimensional seismic surveys and horizontal drilling. Other techniques used at particular sites include installation of downhole injection regulators to control problems of segregation and metering between different water injection zones at the Carson Creek field, use of artificial lifts in gas wells, and a dual gas lift at the Rainbow Lake oil field. At the Lone Pine gas plant, the first Superclaus-99 sulfur recovery process was installed, reducing sulfur emissions by 60% and increasing recovery efficiency from 95% to 98%. Mobil has operated in Canada since 1940 and has made significant discoveries, including Canada's largest producing oil field, the Pembina. In 1971, Mobil discovered gas of commercial significance off the east coast and helped discover the Hibernia and Venture fields. The Hibernia project is scheduled to come on stream in 1997 and Mobil expects the economics of the project to be favorable, with a $12-13/bbl oil price needed to break even. 7 figs

Natural gas

Energy Technology Data Exchange (ETDEWEB)

Fraser, J W

1967-08-01

This report on the natural gas industry of Canada includes: composition and uses of natural gas, production statistics, exploration and development, reserve estimates, natural gas processing, transportation, and marketing. For the Canadian natural gas industry, 1966 was a year of moderate expansion in all phases, with a strong demand continuing for sulfur and liquid hydrocarbons produced as by-products of gas processing. Value of natural gas production increased to $199 million and ranked sixth in terms of value of mineral ouput in Canada. Currently, natural gas provides over 70% of Canada's energy requirements. Proved remaining marketable reserves are estimated to be in excess of a 29-yr supply.

Action of sulfurous oxide on plants

Energy Technology Data Exchange (ETDEWEB)

Schroeder, J

1873-01-01

In order to ascertain which trees best withstand the action of sulfurous oxide, and are, therefore, best suited for planting in neighborhoods where this gas is given off, young trees of various kinds growing in the open ground, were exposed under glass shades to air containing quantities of sulfurous oxide, varying from 1/10,000 to 1/70,000, under circumstances most favorable to its action, viz., in direct sunlight and after having been watered. The sensitiveness of the leaves was carefully noticed, and also the power which the trees possessed of compensating for injury by the reproduction of leaves; this was found to vary considerably in different trees, as did also the resisting power in the first case. Alder, sycamore, ash, and especially maple, are recommended for growth where exposed to smoke containing sulfurous oxide; next follow birch, hornbeam, and oak, and last, beech. The pines did not give constant results, but in nature they suffer more than other trees, and this is owing to the fact that, although their sensitiveness at first is less than that of other trees, their power of restoring lost leaves is much less.

Simultaneous removal of nitrogen oxide/nitrogen dioxide/sulfur dioxide from gas streams by combined plasma scrubbing technology.

Science.gov (United States)

Chang, Moo Been; Lee, How Ming; Wu, Feeling; Lai, Chi Ren

2004-08-01

Oxides of nitrogen (NOx) [nitrogen oxide (NO) + nitrogen dioxide (NO2)] and sulfur dioxide (SO2) are removed individually in traditional air pollution control technologies. This study proposes a combined plasma scrubbing (CPS) system for simultaneous removal of SO2 and NOx. CPS consists of a dielectric barrier discharge (DBD) and wet scrubbing in series. DBD is used to generate nonthermal plasmas for converting NO to NO2. The water-soluble NO2 then can be removed by wet scrubbing accompanied with SO2 removal. In this work, CPS was tested with simulated exhausts in the laboratory and with diesel-generator exhausts in the field. Experimental results indicate that DBD is very efficient in converting NO to NO2. More than 90% removal of NO, NOx, and SO2 can be simultaneously achieved with CPS. Both sodium sulfide (Na2S) and sodium sulfite (Na2SO3) scrubbing solutions are good for NO2 and SO2 absorption. Energy efficiencies for NOx and SO2 removal are 17 and 18 g/kWh, respectively. The technical feasibility of CPS for simultaneous removal of NO, NO2, and SO2 from gas streams is successfully demonstrated in this study. However, production of carbon monoxide as a side-product (approximately 100 ppm) is found and should be considered.

Hysteresis Phenomena in Sulfur Dioxide Oxidation over Supported Vanadium Catalysts

DEFF Research Database (Denmark)

Masters, Stephen G.; Eriksen, Kim Michael; Fehrmann, Rasmus

1997-01-01

Catalyst deactivation and hysteresis behavior in industrial SO2-oxidation catalysts have been studied in the temperature region 350-480 C by combined in situ EPR spectroscopy and catalytic activity measurements. The feed gas composition simulated sulfuric acid synthesis gas and wet/dry de......NOx'ed flue gas. The vanadium (IV) compound K4(VO)3(SO4)5 precipitated during all the investigated conditions hence causing catalyst deactivation. Hysteresis behavior of both the catalytic activity and the V(IV) content was observed during reheating....

Conversion of sulfur and nitrogen oxides in air under exposure to microsecond electron beams

International Nuclear Information System (INIS)

Denisov, G.V.; Kuznetsov, D.L.; Novoselov, Yu.N.; Tkachenko, R.M.

2002-01-01

Flue gases of power plants realizing sulfur and nitrogen oxides into the atmosphere represent one of the environmental pollution sources. Paper presents the results of experimental investigations of conversion of sulfur and nitrogen oxides in the ionized gas mixture simulating composition of off-gases of thermal power stations. Pulse beam of microsecond duration electrons was used as a source of ionization. Mutual influence of both types of oxides on process of their conversion is shown. One studied possible kinetic mechanisms to remove sulfur and nitrogen oxides from gaseous mixture [ru

Modeling the condensation of sulfuric acid and water on the cylinder liner of a large two-stroke marine diesel engine

DEFF Research Database (Denmark)

Cordtz, Rasmus Faurskov; Mayer, Stefan; Eskildsen, Svend S.

2018-01-01

Corrosive wear of cylinder liners in large two-stroke marine diesel engines that burn heavy fuel oil containing sulfur is coupled to the formation of gaseous sulfur trioxide (SO3) and subsequent combined condensation of sulfuric acid (H2SO4) and water (H2O) vapor. The present work seeks to address...... vapor liquid equilibrium. By assuming homogenous cylinder gas mixtures condensation is modeled using a convective heat and mass transfer analogy combined with realistic liner temperature profiles. Condensation of water is significantly altered by the liner temperature and charge air humidity while...... how fuel sulfur content, charge air humidity and liner temperature variations affects the deposition of water and sulfuric acid at low load operation. A phenomenological engine model is applied to simulate the formation of cylinder/bulk gas combustion products and dew points comply with H2O–H2SO4...

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

International Nuclear Information System (INIS)

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

1986-01-01

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

Sulfur biogeochemistry of oil sands composite tailings

Energy Technology Data Exchange (ETDEWEB)

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

2011-07-01

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

Lagrangian measurements of sulfur dioxide to sulfate conversion rates

Energy Technology Data Exchange (ETDEWEB)

Zak, B D

1981-12-01

On the basis of Project MISTT data and proposed homogenous gas phase oxidation mechanisms for sulfur dioxide, it has been suggested that the degree of mixing with background air, the chemical composition of the background air, and the intensity of the sunlight available are key factors determining the rate of sulfur dioxide to sulfate conversion. These hypotheses are examined in light of Lagrangian measrements of conversion rates in power plant plumes made during the Tennessee Plume Study and Project Da Vinci. It is found that the Lagrangian conversion rate measurements are consistent with these hypotheses. It has also been suggested that the concentration of ozone may serve as a workable surrogate for the concentrations of the free radicals involved in the homogeneous gas phase mechanism. The night-time Lagrangian data remind one that the gross difference in mean lifetime of ozone and free radicals can lead to situations in which the ozone concentration is not a good surrogate for the free radical concentrations.

NONEQUILIBRIUM SULFUR CAPTURE AND RETENTION IN AN AIR COOLED SLAGGING COAL COMBUSTOR

International Nuclear Information System (INIS)

Dr. Bert Zauderer

1999-01-01

Calcium oxide injected in a slagging combustor reacts with the sulfur from coal combustion to form sulfur-bearing particles. They are deposited on the liquid slag layer on the combustor wall. Due to the low solubility of sulfur in slag, slag must be rapidly drained from the combustor to limit sulfur gas re-evolution. Analysis indicated that slag mass flow rates in excess of 400 lb/hr should limit sulfur re-evolution. The objective of this 42-month project was to perform a series of tests to determine the factors that control the retention of the sulfur in the slag. 36 days of testing on the combustor were completed prior to the end of this reporting period, 12/31/98. This compares with 16 tests required in the original project plan. Combustor tests in early 1997 with high (37%) ash, Indian coal confirmed that high slag mass flow rates of about 500 lb/hr resulted in retention in the slag of up to 20% of the injected sulfur content mineral matter. To further increase the slag flow rate, rice husks, which contain 20% ash, and rice husk char, which contain 70% ash, were co-fired with coal in the combustor. A series of 13 combustor tests were performed in fourth quarter of 1997 and a further 6 tests were performed in January 1998 and in the summer of 1998. The test objective was to achieve slag flow rates between 500 and 1,000 lb/hr. Due to the very low bulk density of rice husk, compared to pulverized coal, almost the entire test effort focused on developing methods for feeding the rice husks into combustor. In the last test of December 1997, a peak mineral matter, injection rate of 592 lb/hr was briefly achieved by injection of coal, rice husk char, gypsum, and limestone into the combustor. However, no significant sulfur concentration was measured in the slag removed from the combustor. The peak injection rate reached with biomass in the 1997 tests was 310 lb/hr with rice husk, and 584 lb/hr with rice husk char

Degradation of solid oxide fuel cell metallic interconnects in fuels containing sulfur

Energy Technology Data Exchange (ETDEWEB)

Ziomek-Moroz, M.; Hawk, Jeffrey A.

2005-01-01

Hydrogen is the main fuel for all types of fuel cells except direct methanol fuel cells. Hydrogen can be generated from all manner of fossil fuels, including coal, natural gas, diesel, gasoline, other hydrocarbons, and oxygenates (e.g., methanol, ethanol, butanol, etc.). Impurities in the fuel can cause significant performance problems and sulfur, in particular, can decrease the cell performance of fuel cells, including solid oxide fuel cells (SOFC). In the SOFC, the high (800-1000°C) operating temperature yields advantages (e.g., internal fuel reforming) and disadvantages (e.g., material selection and degradation problems). Significant progress in reducing the operating temperature of the SOFC from ~1000 ºC to ~750 ºC may allow less expensive metallic materials to be used for interconnects and as balance of plant (BOP) materials. This paper provides insight on the material performance of nickel, ferritic steels, and nickel-based alloys in fuels containing sulfur, primarily in the form of H2S, and seeks to quantify the extent of possible degradation due to sulfur in the gas stream.

Effects of sulfur dioxide on vegetation

Energy Technology Data Exchange (ETDEWEB)

Whitby, G S

1939-11-11

A discussion is presented on the effects of sulfur dioxide on vegetation as observed at Trail, British Columbia. The investigation was carried out over a period of eight years, 1929 to 1937. The concentration of sulfur dioxide at the United States border was carefully determined throughout the crop season at a point 16 miles from the source of sulfur dioxide. Maximum and average concentrations in part per million are given. The sulfur content of vegetation was determined and was found to diminish as the distance from the smelter increased. It was determined that the sulfur content may rise to four times the normal amount without injurious effect. This is particularly so with prolonged low concentration. The effect on the soil was determined by measuring soluble sulfate, pH and exchangeable bases. The soil near the plant was affected, but this fell off rapidly with increase in distance so that eight miles from the smelter the soil was substantially normal. No effect on water supplies was found. An appreciable retardation in growth, as determined by annular rings, was noted for trees exposed to the sulfur dioxide. This effect was lost following installation of sulfur dioxide control at Trail. Conifers were found more susceptible during periods of active growth than when dormant. Also, transplanted conifers were more severly affected than native trees. Seedlings were less resistant that older trees.

The future of airborne sulfur-containing particles in the absence of fossil fuel sulfur dioxide emissions.

Science.gov (United States)

Perraud, Véronique; Horne, Jeremy R; Martinez, Andrew S; Kalinowski, Jaroslaw; Meinardi, Simone; Dawson, Matthew L; Wingen, Lisa M; Dabdub, Donald; Blake, Donald R; Gerber, R Benny; Finlayson-Pitts, Barbara J

2015-11-03

Sulfuric acid (H2SO4), formed from oxidation of sulfur dioxide (SO2) emitted during fossil fuel combustion, is a major precursor of new airborne particles, which have well-documented detrimental effects on health, air quality, and climate. Another precursor is methanesulfonic acid (MSA), produced simultaneously with SO2 during the atmospheric oxidation of organosulfur compounds (OSCs), such as dimethyl sulfide. In the present work, a multidisciplinary approach is used to examine how contributions of H2SO4 and MSA to particle formation will change in a large coastal urban area as anthropogenic fossil fuel emissions of SO2 decline. The 3-dimensional University of California Irvine-California Institute of Technology airshed model is used to compare atmospheric concentrations of gas phase MSA, H2SO4, and SO2 under current emissions of fossil fuel-associated SO2 and a best-case futuristic scenario with zero fossil fuel sulfur emissions. Model additions include results from (i) quantum chemical calculations that clarify the previously uncertain gas phase mechanism of formation of MSA and (ii) a combination of published and experimental estimates of OSC emissions, such as those from marine, agricultural, and urban processes, which include pet waste and human breath. Results show that in the zero anthropogenic SO2 emissions case, particle formation potential from H2SO4 will drop by about two orders of magnitude compared with the current situation. However, particles will continue to be generated from the oxidation of natural and anthropogenic sources of OSCs, with contributions from MSA and H2SO4 of a similar order of magnitude. This could be particularly important in agricultural areas where there are significant sources of OSCs.

On-line optimal control improves gas processing

International Nuclear Information System (INIS)

Berkowitz, P.N.; Papadopoulos, M.N.

1992-01-01

This paper reports that the authors' companies jointly funded the first phase of a gas processing liquids optimization project that has the specific purposes to: Improve the return of processing natural gas liquids, Develop sets of control algorithms, Make available a low-cost solution suitable for small to medium-sized gas processing plants, Test and demonstrate the feasibility of line control. The ARCO Willard CO 2 gas recovery processing plant was chosen as the initial test site to demonstrate the application of multivariable on-line optimal control. One objective of this project is to support an R ampersand D effort to provide a standardized solution to the various types of gas processing plants in the U.S. Processes involved in these gas plants include cryogenic separations, demethanization, lean oil absorption, fractionation and gas treating. Next, the proposed solutions had to be simple yet comprehensive enough to allow an operator to maintain product specifications while operating over a wide range of gas input flow and composition. This had to be a supervisors system that remained on-line more than 95% of the time, and achieved reduced plant operating variability and improved variable cost control. It took more than a year to study various gas processes and to develop a control approach before a real application was finally exercised. An initial process for C 2 and CO 2 recoveries was chosen

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-01-01

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

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

International Nuclear Information System (INIS)

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

1990-01-01

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

Fluorine and sulfur simultaneously co-doped suspended graphene

Science.gov (United States)

Struzzi, C.; Sezen, H.; Amati, M.; Gregoratti, L.; Reckinger, N.; Colomer, J.-F.; Snyders, R.; Bittencourt, C.; Scardamaglia, M.

2017-11-01

Suspended graphene flakes are exposed simultaneously to fluorine and sulfur ions produced by the μ-wave plasma discharge of the SF6 precursor gas. The microscopic and spectroscopic analyses, performed by Raman spectroscopy, scanning electron microscopy and photoelectron spectromicroscopy, show the homogeneity in functionalization yield over the graphene flakes with F and S atoms covalently bonded to the carbon lattice. This promising surface shows potential for several applications ranging from biomolecule immobilization to lithium battery and hydrogen storage devices. The present co-doping process is an optimal strategy to engineer the graphene surface with a concurrent hydrophobic character, thanks to the fluorine atoms, and a high affinity with metal nanoparticles due to the presence of sulfur atoms.

Study of the reduction of sulfur dioxide to elemental sulfur by carbon monoxide on a La/sub 0/ /sub 5/ Sr/sub 0/ /sub 5/ CoO/sub 3/ catalyst

Energy Technology Data Exchange (ETDEWEB)

Hibbert, D B; Tseung, A C.C.

1979-12-01

A study of the reduction of sulfur dioxide to elemental sulfur by carbon monoxide on a La/sub 0/ /sub 5/ Sr/sub 0/ /sub 5/ CoO/sub 3/ catalyst a perovskite oxide, to determine the effects of oxygen and water on SO2 reduction showed that in the presence of 5 to 16% oxygen, the reaction between sulfur dioxide and carbon monoxide still occurred if there was sufficient carbon monoxide in the gas to react with all the oxygen. At 600C, all the sulfur dioxide was removed at 5 to 16% oxygen levels. Water vapor at 2% did not adversely affect the reaction. The unwanted by-products, hydrogen disulfide and carbonyl sulfide, were reduced at contact times below 0.25 sec. During the reaction, the catalyst itself reacted with sulfur to give metal sulfides. When reagent grade CO/sub 2/O/sub 3/ was substituted for perovskite oxide, the maximum conversion of 98% of sulfur dioxide was attained at 550C, but an unacceptably high concentration of carbonyl sulfide was formed; within 1 hr, the sulfur dioxide conversion fell to 60%. The perovskite oxide reaction may be useful in removing sulfur dioxide from fosill fuel stack gases.

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

International Nuclear Information System (INIS)

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

2015-01-01

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

Removal and recovery of nitrogen and sulfur oxides from gaseous mixtures containing them

International Nuclear Information System (INIS)

Cooper, H.B.H.

1984-01-01

A cyclic process for removing lower valence nitrogen oxides from gaseous mixtures includes treating the mixtures with an aqueous media including alkali metal carbonate and alkali metal bicarbonate and a preoxygen oxidant to form higher valence nitrogen oxides and to capture these oxides as alkali metal salts, expecially nitrites and nitrates, in a carbonate/bicarbonate-containing product aqueous media. Highly selective recovery of nitrates in high purity and yield may then follow, as by crystallization, with the carbonate and bicarbonate alkali metal salts strongly increasing the selectivity and yield of nitrates. The product nitrites are converted to nitrates by oxidation after lowering the product aqueous media pH to below about 9. A cyclic process for removing sulfur oxides from gas mixtures includes treating these mixtures includes treating these mixtures with aqueous media including alkali metal carbonate and alkali metal bicarbonate where the ratio of alkali metal to sulfur dioxide is not less than 2. The sulfur values may be recovered from the resulting carbonate/bicarbonate/-sulfite containing product aqueous media as alkali metal sulfate or sulfite salts which are removed by crystallization from the carbonate-containing product aqueous media. As with the nitrates, the carbonate/bicarbonate system strongly increases yield of sulfate or sulfite during crystallization. Where the gas mixtures include both sulfur dioxide and lower valence nitrogen oxides, the processes for removing lower valence nitrogen oxides and sulfur dioxide may be combined into a single removal/recovery system, or may be effected in sequence

Biological (flue) gas desulfurization

Energy Technology Data Exchange (ETDEWEB)

Buisman, C.J.N.; Dijkman, H. [PAQUES, Balk (Netherlands); Prins, W.L.; Verbraak, P. [Biostar CV, Balk (Netherlands); Den Hartog, A.J. [Hoogovens Groep BV, IJmuiden (Netherlands)

1995-12-31

Biotechnological research has been carried out to find new micro-organisms and processes to make useful products, and to reveal new ways and biotechnological mechanisms to produce elemental sulfur in waste water treatment. Biotechnological development work has been carried out and the first commercial installation (on 300 m{sup 3}/hr scale) to produce sulfur from polluted waste water was started up in 1992. The importance of this recent research and development in the area of waste water treatment was recognized. In an intensive cooperation between Hoogovens Technical Services and PACQUES the concept for a totally new Biological Flue Gas Desulfurization process (BIO-FGD), producing sulfur as by-product, was invented. It consists of the combination of a sodium scrubber with two biological reactors resulting in a very attractive new concept for a gas cleaning process. A description of the process is given and the pilot plant results are outlined. 4 figs., 5 refs.

Isotope dilution ICP-MS with laser-assisted sample introduction for direct determination of sulfur in petroleum products.

Science.gov (United States)

Boulyga, Sergei F; Heilmann, Jens; Heumann, Klaus G

2005-08-01

Inductively coupled plasma isotope dilution mass spectrometry (ICP-IDMS) with direct laser-assisted introduction of isotope-diluted samples into the plasma, using a laser ablation system with high ablation rates, was developed for accurate sulfur determinations in different petroleum products such as 'sulfur-free' premium gasoline, diesel fuel, and heating oil. Two certified gas oil reference materials were analyzed for method validation. Two different 34S-enriched spike compounds, namely, elementary sulfur dissolved in xylene and dibenzothiophene in hexane, were synthesized and tested for their usefulness in this isotope dilution technique. The isotope-diluted sample was adsorbed on a filter-paper-like material, which was fixed in a special holder for irradiation by the laser beam. Under these conditions no time-dependent spike/analyte fractionation was only observed for the dibenzothiophene spike during the laser ablation process, which means that the measured 34S/32S isotope ratio of the isotope-diluted sample remained constant-a necessary precondition for accurate results with the isotope dilution technique. A comparison of LA-ICP-IDMS results with the certified values of the gas oil reference materials and with results obtained from ICP-IDMS analyses with wet sample digestion demonstrated the accuracy of the new LA-ICP-IDMS method in the concentration range of 9.2 microg g(-1) ('sulfur-free' premium gasoline) to 10.4 mg g(-1) (gas oil reference material BCR 107). The detection limit for sulfur by LA-ICP-IDMS is 0.04 microg g(-1) and the analysis time is only about 10 min, which therefore also qualifies this method for accurate determinations of low sulfur contents in petroleum products on a routine level.

Comparison of Xe single bubble sonoluminescence in water and sulfuric acid

International Nuclear Information System (INIS)

An Yu

2008-01-01

Using the equations of fluid mechanics with proper boundary conditions and taking account of the gas properties, we can numerically simulate the process of single bubble sonoluminescence, in which electron–neutral atom bremsstrahlung, electron—ion bremsstrahlung and recombination radiation, and the radiative attachment of electrons to atoms and molecules contribute to the light emission. The calculation can quantitatively or qualitatively interpret the experimental results. We find that the accumulated heat energy inside the compressed gas bubble is mostly consumed by the chemical reaction, therefore, the maximum degree of ionization inside Xe bubble in water is much lower than that in sulfuric acid, of which the vapour pressure is very low. In addition, in sulfuric acid much larger p a and R 0 are allowed which makes the bubbles in it much brighter than that in water. (classical areas of phenomenology)

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

International Nuclear Information System (INIS)

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

1978-03-01

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

Thermal stress analysis of sulfur deactivated solid oxide fuel cells

Science.gov (United States)

Zeng, Shumao; Parbey, Joseph; Yu, Guangsen; Xu, Min; Li, Tingshuai; Andersson, Martin

2018-03-01

Hydrogen sulfide in fuels can deactivate catalyst for solid oxide fuel cells, which has become one of the most critical challenges to stability. The reactions between sulfur and catalyst will cause phase changes, leading to increase in cell polarization and mechanical mismatch. A three-dimensional computational fluid dynamics (CFD) approach based on the finite element method (FEM) is thus used to investigate the polarization, temperature and thermal stress in a sulfur deactivated SOFC by coupling equations for gas-phase species, heat, momentum, ion and electron transport. The results indicate that sulfur in fuels can strongly affect the cell polarization and thermal stresses, which shows a sharp decrease in the vicinity of electrolyte when 10% nickel in the functional layer is poisoned, but they remain almost unchanged even when the poisoned Ni content was increased to 90%. This investigation is helpful to deeply understand the sulfur poisoning effects and also benefit the material design and optimization of electrode structure to enhance cell performance and lifetimes in various hydrocarbon fuels containing impurities.

Power control system for a hot gas engine

Science.gov (United States)

Berntell, John O.

1986-01-01

A power control system for a hot gas engine of the type in which the power output is controlled by varying the mean pressure of the working gas charge in the engine has according to the present invention been provided with two working gas reservoirs at substantially different pressure levels. At working gas pressures below the lower of said levels the high pressure gas reservoir is cut out from the control system, and at higher pressures the low pressure gas reservoir is cut out from the system, thereby enabling a single one-stage compressor to handle gas within a wide pressure range at a low compression ratio.

Sixth annual coal preparation, utilization, and environmental control contractors conference

Energy Technology Data Exchange (ETDEWEB)

1990-01-01

A conference was held on coal preparation, utilization and environmental control. Topics included: combustion of fuel slurries; combustor performance; desulfurization chemically and by biodegradation; coal cleaning; pollution control of sulfur oxides and nitrogen oxides; particulate control; and flue gas desulfurization. Individual projects are processed separately for the databases. (CBS).

Sulfur-Containing Agrochemicals.

Science.gov (United States)

Devendar, Ponnam; Yang, Guang-Fu

2017-10-09

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

Pyrite sulfur isotopes reveal glacial-interglacial environmental changes

Science.gov (United States)

Pasquier, Virgil; Sansjofre, Pierre; Rabineau, Marina; Revillon, Sidonie; Houghton, Jennifer; Fike, David A.

2017-06-01

The sulfur biogeochemical cycle plays a key role in regulating Earth’s surface redox through diverse abiotic and biological reactions that have distinctive stable isotopic fractionations. As such, variations in the sulfur isotopic composition (δ34S) of sedimentary sulfate and sulfide phases over Earth history can be used to infer substantive changes to the Earth’s surface environment, including the rise of atmospheric oxygen. Such inferences assume that individual δ34S records reflect temporal changes in the global sulfur cycle; this assumption may be well grounded for sulfate-bearing minerals but is less well established for pyrite-based records. Here, we investigate alternative controls on the sedimentary sulfur isotopic composition of marine pyrite by examining a 300-m drill core of Mediterranean sediments deposited over the past 500,000 y and spanning the last five glacial-interglacial periods. Because this interval is far shorter than the residence time of marine sulfate, any change in the sulfur isotopic record preserved in pyrite (δ34Spyr) necessarily corresponds to local environmental changes. The stratigraphic variations (>76‰) in the isotopic data reported here are among the largest ever observed in pyrite, and are in phase with glacial-interglacial sea level and temperature changes. In this case, the dominant control appears to be glacial-interglacial variations in sedimentation rates. These results suggest that there exist important but previously overlooked depositional controls on sedimentary sulfur isotope records, especially associated with intervals of substantial sea level change. This work provides an important perspective on the origin of variability in such records and suggests meaningful paleoenvironmental information can be derived from pyrite δ34S records.

Occurrence and abatement of volatile sulfur compounds during biogas production.

Science.gov (United States)

Andersson, Fräs Annika T; Karlsson, Anna; Svensson, Bo H; Ejlertsson, Jörgen

2004-07-01

Volatile sulfur compounds (VSCs) in biogas originating from a biogas production plant and from a municipal sewage water treatment plant were identified. Samples were taken at various stages of the biogas-producing process, including upgrading the gas to vehicle-fuel quality. Solid-phase microextraction was used for preconcentration of the VSCs, which were subsequently analyzed using gas chromatography in combination with mass spectrometry. Other volatile organic compounds present also were identified. The most commonly occurring VSCs in the biogas were hydrogen sulfide, carbonyl sulfide, methanethiol, dimethyl sulfide, and dimethyl disulfide, and hydrogen sulfide was not always the most abundant sulfur (S) compound. Besides VSCs, oxygenated organic compounds were commonly present (e.g., ketones, alcohols, and esters). The effect of adding iron chloride to the biogas reactor on the occurrence of VSCs also was investigated. It was found that additions of 500-g/m3 substrate gave an optimal removal of VSCs. Also, the use of a prefermentation step could reduce the amount of VSCs formed in the biogas process. Moreover, in the carbon dioxide scrubber used for upgrading the gas, VSCs were removed efficiently, leaving traces (ppbv levels). The scrubber also removed other organic compounds.

Adsorption and dissociation of sulfur-based toxic gas molecules on silicene nanoribbons: a quest for high-performance gas sensors and catalysts.

Science.gov (United States)

Walia, Gurleen Kaur; Randhawa, Deep Kamal Kaur

2018-03-16

The adsorption behavior of sulfur-based toxic gases (H 2 S and SO 2 ) on armchair silicene nanoribbons (ASiNRs) was investigated using first-principles density functional theory (DFT). Being a zero band gap material, application of bulk silicene is limited in nanoelectronics, despite its high carrier mobility. By restricting its dimensions into one dimension, construction of nanoribbons, and by introduction of a defect, its band gap can be tuned. Pristine armchair silicene nanoribbons (P-ASiNRs) have a very low sensitivity to gas molecules. Therefore, a defect was introduced by removal of one Si atom, leading to increased sensitivity. To deeply understand the impact of the aforementioned gases on silicene nanoribbons, electronic band structures, density of states, charge transfers, adsorption energies, electron densities, current-voltage characteristics and most stable adsorption configurations were calculated. H 2 S is dissociated completely into HS and H species when adsorbed onto defective armchair silicene nanoribbons (D-ASiNRs). Thus, D-ASiNR is a likely catalyst for dissociation of the H 2 S gas molecule. Conversely, upon SO 2 adsorption, P-ASiNR acts as a suitable sensor, whereas D-ASiNR provides enhanced sensitivity compared with P-ASiNR. On the basis of these results, D-ASiNR can be expected to be a disposable sensor for SO 2 detection as well as a catalyst for H 2 S reduction. Graphical abstract Comparison of I-V characteristics of pristine and defective armchair silicene nanoribbons with H 2 S and SO 2 adsorbed on them.

Degradation and dielectric properties of sulfur hexafluoride

International Nuclear Information System (INIS)

Fluck, Eric

1985-01-01

Sparking potential of sulfur hexafluoride is studied as a function of its decomposition by electrical discharges. The analysis of the gas is performed by mass spectrometry. The quantity of products resulting from spark discharges as a function of charge transported is plotted for SO_2F_2, SiF_4, SOF_4; it shows a linear increase with charge transported. Production rates of fluoride gases strongly increase with quantity of water vapor present at the beginning of the spark discharges. Decomposition of the gas, even at high levels (20%) does not exhibit measurable variations of sparking potential (at constant pressure). Production of SiF_4 by degradation of glass walls by hydrofluoric acid produced by discharges shows the important role played by this acid in the decomposition of the gas. It is necessary to use a gas containing water impurities at a level as small as possible. (author)

Controlled humidity gas circulators

International Nuclear Information System (INIS)

Gruner, S.M.

1981-01-01

A programmable circulator capable of regulating the humidity of a gas stream over a wide range of humidity is described. An optical dew-point hygrometer is used as a feedback element to control the addition or removal of water vapor. Typical regulation of the gas is to a dew-point temperature of +- 0.2 0 C and to an accuracy limited by the dew-point hygrometer

The source and longevity of sulfur in an Icelandic flood basalt eruption plume

Science.gov (United States)

Ilyinskaya, Evgenia; Edmonds, Marie; Mather, Tamsin; Schmidt, Anja; Hartley, Margaret; Oppenheimer, Clive; Pope, Francis; Donovan, Amy; Sigmarsson, Olgeir; Maclennan, John; Shorttle, Oliver; Francis, Peter; Bergsson, Baldur; Barsotti, Sara; Thordarson, Thorvaldur; Bali, Eniko; Keller, Nicole; Stefansson, Andri

2015-04-01

The Holuhraun fissure eruption (Bárðarbunga volcanic system, central Iceland) has been ongoing since 31 August 2014 and is now the largest in Europe since the 1783-84 Laki event. For the first time in the modern age we have the opportunity to study at first hand the environmental impact of a flood basalt fissure eruption (>1 km3 lava). Flood basalt eruptions are one of the most hazardous volcanic scenarios in Iceland and have had enormous societal and economic consequences across the northern hemisphere in the past. The Laki eruption caused the deaths of >20% of the Icelandic population by environmental pollution and famine and potentially also increased European levels of mortality through air pollution by sulphur-bearing gas and aerosol. A flood basalt eruption was included in the UK National Risk Register in 2012 as one of the highest priority risks. The gas emissions from Holuhraun have been sustained since its beginning, repeatedly causing severe air pollution in populated areas in Iceland. During 18-22 September, SO2 fluxes reached 45 kt/day, a rate of outgassing rarely observed during sustained eruptions, suggesting that the sulfur loading per kg of erupted magma exceeds both that of other recent eruptions in Iceland and perhaps also other historic basaltic eruptions globally. This raises key questions regarding the origin of these prodigious quantities of sulphur. A lack of understanding of the source of this sulfur, the conversion rates of SO2 gas into aerosol, the residence times of aerosol in the plume and the dependence of these on meteorological factors is limiting our confidence in the ability of atmospheric models to forecast gas and aerosol concentrations in the near- and far-field from Icelandic flood basalt eruptions. In 2015 our group is undertaking a project funded by UK NERC urgency scheme to investigate several aspects of the sulfur budget at Holuhraun using a novel and powerful approach involving simultaneous tracking of sulfur and

21 CFR 870.4300 - Cardiopulmonary bypass gas control unit.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass gas control unit. 870.4300... bypass gas control unit. (a) Identification. A cardiopulmonary bypass gas control unit is a device used to control and measure the flow of gas into the oxygenator. The device is calibrated for a specific...

Irradiation of FeS: Implications for the Lifecycle of Sulfur in the Interstellar Medium and Presolar FeS Grains

Science.gov (United States)

Keller, Lindsay P.; Loeffler, M. J.; Christoffersen, R.; Dukes, C.; Rahman, Z.; Baragiola, R.

2010-01-01

Fe(Ni) sulfides are ubiquitous in chondritic meteorites and cometary samples where they are the dominant host of sulfur. Despite their abundance in these early solar system materials, their presence in interstellar and circumstellar environments is poorly understood. Fe-sulfides have been reported from astronomical observations of pre- and post-main sequence stars [1, 2] and occur as inclusions in bonafide circumstellar silicate grains [3, 4]. In cold, dense molecular cloud (MC) environments, sulfur is highly depleted from the gas phase [e.g. 5], yet observations of sulfur-bearing molecules in dense cores find a total abundance that is only a small fraction of the sulfur seen in diffuse regions [6], therefore the bulk of the depletion must reside in an abundant unobserved phase. In stark contrast, sulfur is essentially undepleted from the gas phase in the diffuse interstellar medium (ISM) [7-9], indicating that little sulfur is incorporated into solid grains in this environment. This is a rather puzzling observation unless Fe-sulfides are not produced in significant quantities in stellar outflows, or their lifetime in the ISM is very short due to rapid destruction. The main destruction mechanism is sputtering due to supernova shocks in the warm, diffuse ISM [10]. This process involves the reduction of Fe-sulfide with the production of Fe metal as a by-product and returning S to the gas phase. In order to test this hypothesis, we irradiated FeS and analyzed the resulting material using X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM).

Argon cover gas purity control on LMFBR

Energy Technology Data Exchange (ETDEWEB)

Maeda, Hiroshi; Kobayashi, Takayoshi [PNC (Japan); Ishiyama, Satoshi [Toshiba (Japan); Motonaga, Tetsuji [Hitachi (Japan)

1987-07-01

Various control methods on chemical impurities and radioactive materials (fission products) in the primary argon gas of LMFBRs' have been studied based on experiences in Joyo and results of research and development. These results are reflected on MONJU design. On-line gas chromatographs are installed both in the Primary and in the Secondary Argon Gas Systems in JOYO. Also, chemical analysis has been done by batch sampling in JOYO. Though the rise of impurity concentration had been measured after periodical fuel exchange operation, impurity concentration has been controlled sufficiently under target control limits. In MONJU detailed design, the Rare Gas Removal and Recovery System which consisted of cryogenic distillation equipment had been eliminated and the capacity of Charcoal Beds in the Primary Argon Gas System has been improved to keep the concentration of radioactive materials sufficient low levels. The necessity to control the impurities in fresh argon gas which is supplied to the Primary Argon Gas System is now considered to keep the concentration of Kr and Xe isotopes in specified level, because their isotopes may make background rise for the Tagging Gas Failed Fuel Detection and Location System. Based on various investigations performed on sodium vapor trapping to obtain its detailed characteristics, design specifications and operating conditions of MONJU's Vapor Traps have been decided. To keep the level of radioactivity in gaseous effluents to the environment as low as reasonably achievable, the following means are now adopted in MONJU: the Primary Argon Gas System is composed of a closed recirculating path, but the exhaust gas discharged has different path after the Charcoal Beds; fresh argon gas is blown down to prevent Primary Argon Gas from releasing to the circumference during opening of the primary argon gas boundary, such as fuel exchange operations. (author)

Exhaust circulation into dry gas desulfurization process to prevent carbon deposition in an Oxy-fuel IGCC power generation

International Nuclear Information System (INIS)

Kobayashi, Makoto; Nakao, Yoshinobu; Oki, Yuso

2014-01-01

Highlights: • Power plant with semi-closed gas turbine and O 2 –CO 2 coal gasifier was studied. • We adopt dry gas sulfur removal process to establish the system. • The exhaust gas circulation remarkably prevented carbon deposition. • Efficiency loss for exhaust gas circulation is quite small. • Appropriate operating condition of sulfur removal process is revealed. - Abstract: Semi-closed cycle operation of gas turbine fueled by oxygen–CO 2 blown coal gasification provides efficient power generation with CO 2 separation feature by excluding pre-combustion type CO 2 capture that usually brings large efficiency loss. The plant efficiency at transmission end is estimated as 44% at lower heating value (LHV) providing compressed CO 2 with concentration of 93 vol%. This power generation system will solve the contradiction between economical resource utilization and reduction of CO 2 emission from coal-fired power plant. The system requires appropriate sulfur reduction process to protect gas turbine from corrosion and environment from sulfur emission. We adopt dry gas sulfur removal process to establish the system where apprehension about the detrimental carbon deposition from coal gas. The effect of circulation of a portion of exhaust gas to the process on the retardation of carbon deposition was examined at various gas compositions. The circulation remarkably prevented carbon deposition in the sulfur removal sorbent. The impact of the circulation on the thermal efficiency is smaller than the other auxiliary power consumption. Thus, the circulation is appropriate operation for the power generation

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

Energy Technology Data Exchange (ETDEWEB)

Gorensek, M.; Edwards, T.

2009-06-11

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

Foliar injury responses of eleven plant species to ozone/sulfur dioxide mixtures

Energy Technology Data Exchange (ETDEWEB)

Tingey, D T; Reinert, R A; Dunning, J A; Heck, W W

1973-01-01

Eleven plant species were exposed to ozone and/or sulfur dioxide to determine if a mixture of the two gases enhanced foliar injury. Tobacco, radish, and alfalfa developed more injury that the additive injury of the single gases. In other species, such as cabbage, broccoli, and tomato, the foliar injury from mixed-gas exposures was additive or less than additive. Leaf injury from the ozone/sulfur dioxide mixture appeared as upper surface flecking, stipple, bifacial necrosis, and lower surface glazing and, in general, appeared similar to injury from oxidant or ozone. The concentrations of ozone and sulfur dioxide that caused plant injury were similar to those found in urban areas. These concentrations may result in yield losses to plants grown under field conditions.

Isotope dilution ICP-MS with laser-assisted sample introduction for direct determination of sulfur in petroleum products

Energy Technology Data Exchange (ETDEWEB)

Boulyga, Sergei F.; Heilmann, Jens; Heumann, Klaus G. [Johannes Gutenberg-University Mainz (Germany). Institute of Inorganic Chemistry and Analytical Chemistry

2005-08-01

Inductively coupled plasma isotope dilution mass spectrometry (ICP-IDMS) with direct laser-assisted introduction of isotope-diluted samples into the plasma, using a laser ablation system with high ablation rates, was developed for accurate sulfur determinations in different petroleum products such as 'sulfur-free' premium gasoline, diesel fuel, and heating oil. Two certified gas oil reference materials were analyzed for method validation. Two different {sup 34}S-enriched spike compounds, namely, elementary sulfur dissolved in xylene and dibenzothiophene in hexane, were synthesized and tested for their usefulness in this isotope dilution technique. The isotope-diluted sample was adsorbed on a filter-paper-like material, which was fixed in a special holder for irradiation by the laser beam. Under these conditions no time-dependent spike/analyte fractionation was only observed for the dibenzothiophene spike during the laser ablation process, which means that the measured {sup 34}S/{sup 32}S isotope ratio of the isotope-diluted sample remained constant - a necessary precondition for accurate results with the isotope dilution technique. A comparison of LA-ICP-IDMS results with the certified values of the gas oil reference materials and with results obtained from ICP-IDMS analyses with wet sample digestion demonstrated the accuracy of the new LA-ICP-IDMS method in the concentration range of 9.2 {mu}g g{sup -1} ('sulfur-free' premium gasoline) to 10.4 mg g{sup -1} (gas oil reference material BCR 107). The detection limit for sulfur by LA-ICP-IDMS is 0.04 {mu}g g{sup -1} and the analysis time is only about 10 min, which therefore also qualifies this method for accurate determinations of low sulfur contents in petroleum products on a routine level. (orig.)

Effect of sulfur removal on scale adhesion to PWA 1480

International Nuclear Information System (INIS)

Smialek, J.L.; Tubbs, B.K.

1995-01-01

A commercial superalloy, PWA 1480, was annealed in hydrogen at 1,000 C to 1,300 C in order to remove a 10 ppmw sulfur impurity. This treatment was very successful above 1,200 C, resulting in residual sulfur contents below 0.1 ppmw. The degree of scale adhesion in subsequent 1,100 C cyclic oxidation tests was inversely related to residual sulfur content. Control of adhesion by desulfurization in the absence of reactive elements supports an adhesion mechanism based on oxide-metal bonding weakened by sulfur segregation. Attempts at sulfur purging and improving adhesion by repeated oxidation/polishing were not successful, in contrast to previous studies on NiCrAl

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

International Nuclear Information System (INIS)

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

2007-07-01

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

Modelling of Rotor-gas bearings for Feedback Controller Design

DEFF Research Database (Denmark)

Theisen, Lukas Roy Svane; Niemann, Hans Henrik

2014-01-01

Controllable rotor-gas bearings are popular oering adaptability, high speed operation, low friction and clean operation. Rotor-gas bearings are however highly sensitive to disturbances due to the low friction of the injected gas. These undesirable damping properties call for controllers, which ca...... and are shown to accurately describe the dynamical behaviour of the rotor-gas bearing. Design of a controller using the identied models is treated and experiments verify the improvement of the damping properties of the rotor-gas bearing.......Controllable rotor-gas bearings are popular oering adaptability, high speed operation, low friction and clean operation. Rotor-gas bearings are however highly sensitive to disturbances due to the low friction of the injected gas. These undesirable damping properties call for controllers, which can...... be designed from suitable models describing the relation from actuator input to measured shaft position. Current state of the art models of controllable gas bearings however do not provide such relation, which calls for alternative strategies. The present contribution discusses the challenges for feedback...

Understanding the effects of sulfur on mercury capture from coal-fired utility flue gases

Energy Technology Data Exchange (ETDEWEB)

Morris, E.A.; Morita, K.; Jia, C.Q. [University of Toronto, Toronto, ON (Canada)

2010-07-01

Coal combustion continues to be a major source of energy throughout the world and is the leading contributor to anthropogenic mercury emissions. Effective control of these emissions requires a good understanding of how other flue gas constituents such as sulfur dioxide (SO{sub 2}) and sulfur trioxide (SO{sub 3}) may interfere in the removal process. Most of the current literature suggests that SO{sub 2} hinders elemental mercury (Hg{sup 0}) oxidation by scavenging oxidizing species such as chlorine (Cl2) and reduces the overall efficiency of mercury capture, while there is evidence to suggest that SO{sub 2} with oxygen (O{sub 2}) enhances Hg{sup 0} oxidation by promoting Cl2 formation below 100{sup o}C. However, studies in which SO{sub 2} was shown to have a positive correlation with Hg{sup 0} oxidation in full-scale utilities indicate that these interactions may be heavily dependent on operating conditions, particularly chlorine content of the coal and temperature. While bench-scale studies explicitly targeting SO{sub 3} are scarce, the general consensus among full-scale coal-fired utilities is that its presence in flue gas has a strong negative correlation with mercury capture efficiency. The exact reason behind this observed correlation is not completely clear, however. While SO{sub 3} is an inevitable product of SO{sub 2} oxidation by O{sub 2}, a reaction that hinders Hg{sup 0} oxidation, it readily reacts with water vapor, forms sulfuric acid (H{sub 2 }SO{sub 4}) at the surface of carbon, and physically blocks active sites of carbon. On the other hand, H{sub 2}SO{sub 4} on carbon surfaces may increase mercury capacity either through the creation of oxidation sites on the carbon surface or through a direct reaction of mercury with the acid. However, neither of these beneficial impacts is expected to be of practical significance for an activated carbon injection system in a real coal-fired utility flue gas.

Atomic charges of sulfur in ionic liquids: experiments and calculations.

Science.gov (United States)

Fogarty, Richard M; Rowe, Rebecca; Matthews, Richard P; Clough, Matthew T; Ashworth, Claire R; Brandt, Agnieszka; Corbett, Paul J; Palgrave, Robert G; Smith, Emily F; Bourne, Richard A; Chamberlain, Thomas W; Thompson, Paul B J; Hunt, Patricia A; Lovelock, Kevin R J

2017-12-14

Experimental near edge X-ray absorption fine structure (NEXAFS) spectra, X-ray photoelectron (XP) spectra and Auger electron spectra are reported for sulfur in ionic liquids (ILs) with a range of chemical structures. These values provide experimental measures of the atomic charge in each IL and enable the evaluation of the suitability of NEXAFS spectroscopy and XPS for probing the relative atomic charge of sulfur. In addition, we use Auger electron spectroscopy to show that when XPS binding energies differ by less than 0.5 eV, conclusions on atomic charge should be treated with caution. Our experimental data provides a benchmark for calculations of the atomic charge of sulfur obtained using different methods. Atomic charges were computed for lone ions and ion pairs, both in the gas phase (GP) and in a solvation model (SMD), with a wide range of ion pair conformers considered. Three methods were used to compute the atomic charges: charges from the electrostatic potential using a grid based method (ChelpG), natural bond orbital (NBO) population analysis and Bader's atoms in molecules (AIM) approach. By comparing the experimental and calculated measures of the atomic charge of sulfur, we provide an order for the sulfur atoms, ranging from the most negative to the most positive atomic charge. Furthermore, we show that both ChelpG and NBO are reasonable methods for calculating the atomic charge of sulfur in ILs, based on the agreement with both the XPS and NEXAFS spectroscopy results. However, the atomic charges of sulfur derived from ChelpG are found to display significant, non-physical conformational dependence. Only small differences in individual atomic charge of sulfur were observed between lone ion (GP) and ion pair IL(SMD) model systems, indicating that ion-ion interactions do not strongly influence individual atomic charges.

Adsorption of sulfur dioxide on ammonia-treated activated carbon fibers

Science.gov (United States)

Mangun, C.L.; DeBarr, J.A.; Economy, J.

2001-01-01

A series of activated carbon fibers (ACFs) and ammonia-treated ACFs prepared from phenolic fiber precursors have been studied to elucidate the role of pore size, pore volume, and pore surface chemistry on adsorption of sulfur dioxide and its catalytic conversion to sulfuric acid. As expected, the incorporation of basic functional groups into the ACFs was shown as an effective method for increasing adsorption of sulfur dioxide. The adsorption capacity for dry SO2 did not follow specific trends; however the adsorption energies calculated from the DR equation were found to increase linearly with nitrogen content for each series of ACFs. Much higher adsorption capacities were achieved for SO2 in the presence of oxygen and water due to its catalytic conversion to H2SO4. The dominant factor for increasing adsorption of SO2 from simulated flue gas for each series of fibers studied was the weight percent of basic nitrogen groups present. In addition, the adsorption energies calculated for dry SO2 were shown to be linearly related to the adsorption capacity of H2SO4 from this flue gas for all fibers. It was shown that optimization of this parameter along with the pore volume results in higher adsorption capacities for removal of SO2 from flue gases. ?? 2001 Elsevier Science Ltd. All rights reserved.

Catalyst for the reduction of sulfur dioxide to elemental sulfur

Science.gov (United States)

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

1996-02-27

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

Feedforward Nonlinear Control Using Neural Gas Network

Directory of Open Access Journals (Sweden)

Iván Machón-González

2017-01-01

Full Text Available Nonlinear systems control is a main issue in control theory. Many developed applications suffer from a mathematical foundation not as general as the theory of linear systems. This paper proposes a control strategy of nonlinear systems with unknown dynamics by means of a set of local linear models obtained by a supervised neural gas network. The proposed approach takes advantage of the neural gas feature by which the algorithm yields a very robust clustering procedure. The direct model of the plant constitutes a piece-wise linear approximation of the nonlinear system and each neuron represents a local linear model for which a linear controller is designed. The neural gas model works as an observer and a controller at the same time. A state feedback control is implemented by estimation of the state variables based on the local transfer function that was provided by the local linear model. The gradient vectors obtained by the supervised neural gas algorithm provide a robust procedure for feedforward nonlinear control, that is, supposing the inexistence of disturbances.

Durability of solid oxide fuel cells using sulfur containing fuels

DEFF Research Database (Denmark)

Hagen, Anke; Rasmussen, Jens Foldager Bregnballe; Thydén, Karl Tor Sune

2011-01-01

The usability of hydrogen and also carbon containing fuels is one of the important advantages of solid oxide fuel cells (SOFCs), which opens the possibility to use fuels derived from conventional sources such as natural gas and from renewable sources such as biogas. Impurities like sulfur compounds...... are critical in this respect. State-of-the-art Ni/YSZ SOFC anodes suffer from being rather sensitive towards sulfur impurities. In the current study, anode supported SOFCs with Ni/YSZ or Ni/ScYSZ anodes were exposed to H2S in the ppm range both for short periods of 24h and for a few hundred hours. In a fuel...

Device provides controlled gas leaks

Science.gov (United States)

Kami, S. K.; King, H. J.

1968-01-01

Modified palladium leak device provides a controlled release /leak/ of very small quantities of gas at low or medium pressures. It has no moving parts, requires less than 5 watts to operate, and is capable of releasing the gas either continuously or in pulses at adjustable flow rates.

Heat pipe air preheater for gas-/oil-fired power plants

International Nuclear Information System (INIS)

Teixeira, D.P.

1993-02-01

With the rising costs of fuel, utilities are constantly looking for ways to improve the net plant heat rate of new and existing units. Significant heat rate improvements can be obtained by reducing the exit stack flue gas temperature. This project evaluated two technologies to reduce flue gas temperatures: heat pipes and liquid-coupled heat exchangers. The specific unit chosen for evaluating these systems was Pacific Gas ampersand Electric's 750 MW Moss Landing Power Plant, Unit 7. Both natural gas and low sulfur (0.5%) fuel oil are fired at this plant. Accordingly, the heat exchangers were required to operate on both fuels. This study investigated the heat recovery installation through the preliminary engineering level of detail. At the conclusion of this effort, the results indicated that neither concept was economically attractive for the retrofit situation involved. In addition, several major technical questions remained unresolved concerning the design of a single heat-exchange device capable of operating on gas (sulfur-free) and oil (sulfur-containing) environments over the full normal operating load range. While the technologies this study reviewed have been installed in actual power plant applications, the site-specific aspects of Moss Landing Unit 7 significantly influenced the estimated costs and performance of each alternative. Using more cost-effective and corrosion-resistant materials may help reduce costs. The following conditions would further enhance the viability of lowering exit gas temperatures: Higher capacity factors; rising fuel costs; greater use of sulfur-free fuels, such as natural gas; lower manufacturing costs for heat exchanger technologies; or new unit application

Sulfur status in long distance runners

International Nuclear Information System (INIS)

Kovacs, L; Zamboni, C; Lourenço, T; Macedo, D

2015-01-01

In sports medicine, sulfur plays an important role and its deficiency can cause muscle injury affecting the performance of the athletes. However, its evaluation is unusual in conventional clinical practice. In this study the sulfur levels were determined in Brazilian amateur athlete's blood using Neutron Activation Analyses (NAA) technique. Twenty six male amateur runners, age 18 to 36 years, participated of this study. The athletes had a balanced diet, without multivitamin/mineral supplements. The blood collection was performed at LABEX (Laboratoriode Bioquimica do Exercicio, UNICAMP-SP) and the samples were irradiated for 300 seconds in a pneumatic station in the nuclear reactor (IEA-R1, 3-4.5MW, pool type) at IPEN/CNEN-SP. The results were compared with the control group (subjects of same age but not involved with physical activities) and showed that the sulfur concentration was 44% higher in amateurs athletes than control group. These data can be considered for preparation of balanced diet, as well as contributing for proposing new protocols of clinical evaluation. (paper)

Sulfur status in long distance runners

Science.gov (United States)

Kovacs, L.; Zamboni, C.; Lourenço, T.; Macedo, D.

2015-07-01

In sports medicine, sulfur plays an important role and its deficiency can cause muscle injury affecting the performance of the athletes. However, its evaluation is unusual in conventional clinical practice. In this study the sulfur levels were determined in Brazilian amateur athlete's blood using Neutron Activation Analyses (NAA) technique. Twenty six male amateur runners, age 18 to 36 years, participated of this study. The athletes had a balanced diet, without multivitamin/mineral supplements. The blood collection was performed at LABEX (Laboratoriode Bioquimica do Exercicio, UNICAMP-SP) and the samples were irradiated for 300 seconds in a pneumatic station in the nuclear reactor (IEA-R1, 3-4.5MW, pool type) at IPEN/CNEN-SP. The results were compared with the control group (subjects of same age but not involved with physical activities) and showed that the sulfur concentration was 44% higher in amateurs athletes than control group. These data can be considered for preparation of balanced diet, as well as contributing for proposing new protocols of clinical evaluation.

Absorption of ozone, sulfur dioxide, and nitrogen dioxide by petunia plants

Energy Technology Data Exchange (ETDEWEB)

Elkiey, T.; Ormrod, D.P.

1981-01-01

Petunia plants (Petunia hybrida Vilm.) of three varieties with differing air pollutant sensitivities were grown in controlled environments and the absorption rates of ozone (O/sub 3/), sulfur dioxide (SO/sub 2/) and nitrogen dioxide (NO/sub 2/) determined during single gas and mixed gas exposures. Additional experiments were conducted to evaluate effects of duration of exposure, leaf age, and plant growth stage on absorption of O/sub 3/. Absorption of all pollutants from single gases or the mixture was generally greater for the more sensitive varieties. Absorption from single gases was generally greater than from the mixed gases. Absorption rates tended to decrease gradually throughout the day and from day to day with continuous exposure. Absorption of O/sub 3/ was proportional to exposure concentration and decreased with time at differing rates for each variety. More O/sub 3/ was absorbed by older than younger leaves and by plants at the early vegetative stage compared with those in the prefloral stage.

Hydrate Control for Gas Storage Operations

Energy Technology Data Exchange (ETDEWEB)

Jeffrey Savidge

2008-10-31

The overall objective of this project was to identify low cost hydrate control options to help mitigate and solve hydrate problems that occur in moderate and high pressure natural gas storage field operations. The study includes data on a number of flow configurations, fluids and control options that are common in natural gas storage field flow lines. The final phase of this work brings together data and experience from the hydrate flow test facility and multiple field and operator sources. It includes a compilation of basic information on operating conditions as well as candidate field separation options. Lastly the work is integrated with the work with the initial work to provide a comprehensive view of gas storage field hydrate control for field operations and storage field personnel.

Fabrication of SO/sub 2/preparation system and calibration of PINSTECH sulfur standard for /sup 34/S/sup 32/S mass spectrometric analysis

International Nuclear Information System (INIS)

Sajjad, M.I.; Latif, Z.; Ali, M.; Qureshi, R.M.; Tasneem, M.A.; Khan, I.H.; Ahmed, M.; Ahmed, I.

1994-05-01

This report describes the fabrication and standardization of operation procedures of a SO/sub 2/ preparation system used for the extraction of sulfur dioxide gas from sulfur minerals (aqueous sulfate, elemental sulfur, and sulfides) for sulfur isotope ratio measurements on a gas source mass spectrometer for hydrological, geological and environmental applications. SO/sub 2/ preparation procedure as described by Fumitaka Yanagisawa and Hitoshi Sakai (1983) is adopted with some modifications. A chemically pure BaSO/sub 4/ powder is chosen as PINSTECH Sulfur Standard PSS-I for routine laboratory /sup 34/S analysis. PSS-1 is calibrated against the International Atomic Energy Agency (IAEA) standard Cannon Diablo Troilite (CDT) using the NBS-127 sulfur standard Sigma /sup 34/S values of PSS-1 as analyzed at PINSTECH and Institute fur Hydorlogie, Munich are found to be 14.58 +-0.07 % CDT (n=6) and 14.59+-0.15% CDT (n=2) respectively. NBS-127 is BaSO/sub 4/ powder from the National Bureau of Standards, USA and has been calibrated against CDT. Interlaboratory comparison of various standards is also documented. Using this system, the reproducibility of sulfur isotope ratio measurements is better than +-0.2 % (n=10). (author)

Fabrication of SO/sub 2/preparation system and calibration of PINSTECH sulfur standard for /sup 34/S/sup 32/S mass spectrometric analysis

Energy Technology Data Exchange (ETDEWEB)

Sajjad, M I; Latif, Z; Ali, M; Qureshi, R M; Tasneem, M A; Khan, I H; Ahmed, M; Ahmed, I

1994-05-01

This report describes the fabrication and standardization of operation procedures of a SO/sub 2/ preparation system used for the extraction of sulfur dioxide gas from sulfur minerals (aqueous sulfate, elemental sulfur, and sulfides) for sulfur isotope ratio measurements on a gas source mass spectrometer for hydrological, geological and environmental applications. SO/sub 2/ preparation procedure as described by Fumitaka Yanagisawa and Hitoshi Sakai (1983) is adopted with some modifications. A chemically pure BaSO/sub 4/ powder is chosen as PINSTECH Sulfur Standard PSS-I for routine laboratory /sup 34/S analysis. PSS-1 is calibrated against the International Atomic Energy Agency (IAEA) standard Cannon Diablo Troilite (CDT) using the NBS-127 sulfur standard Sigma /sup 34/S values of PSS-1 as analyzed at PINSTECH and Institute fur Hydorlogie, Munich are found to be 14.58 +-0.07 % CDT (n=6) and 14.59+-0.15% CDT (n=2) respectively. NBS-127 is BaSO/sub 4/ powder from the National Bureau of Standards, USA and has been calibrated against CDT. Interlaboratory comparison of various standards is also documented. Using this system, the reproducibility of sulfur isotope ratio measurements is better than +-0.2 % (n=10). (author).

Fabrication Of Control Rod System Of The RSG-GAS

International Nuclear Information System (INIS)

Sudirdjo, Hari; Setyono; Prasetya, Hendra

2001-01-01

Eight units of control rod mechanical system of RSG-GAS has been fabricated. The control rod mechanical system of RSG-GAS consist of guide tube and lifting rod. Complete construction of the control rod mechanical system of RSG-GAS are guide tube, lifting rod, absorber, and absorber casing. The eight units of the control rod mechanical system of RSG-GAS has been fabricated according to the mechanical engineering design

Lithium sulfur batteries and electrolytes and sulfur cathodes thereof

Science.gov (United States)

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

2017-05-23

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

Hydrogen production by Chlamydomonas reinhardtii under light driven sulfur deprived condition

Energy Technology Data Exchange (ETDEWEB)

Vijayaraghavan, Krishnan; Karthik, Rajendran [Biotechnology Research Division, Department of Biotechnology, Prathyusha Institute of Technology and Management, Aranvoyalkuppam, Thiruvallur District 602025, Tamil Nadu (India); Kamala Nalini, S.P. [Department of Biotechnology, Vel Group of Educational Institutions, Avadi, Alamadhi Road, Chennai 600062, Tamil Nadu (India)

2009-10-15

This article explores the possibility of demonstrating sustainable photohydrogen production using Chlamydomonas reinhardtii when grown in sulfur deprived photoautotrophic condition. The hydrogen evolving capability of the algal species was monitored based on alternating light and dark period. Investigation was carried out during the day time in order to exploit the solar energy for meeting the demand of the light period. The results showed that when the reactor was operated at varying photoperiod namely 2, 3 and 4 h of alternating light and dark period, the gas generation was found to be 32 {+-} 4, 63 {+-} 7 and 52 {+-} 5 mL/h, while the corresponding hydrogen content was 47, 86 and 87% respectively. Functional components of hydrogen generation reaction centers were also analyzed, which showed that the PS(I) reaction centers were involved in hydrogen production pathway, as the light absorption by PS(I) was prerequisite for hydrogen generation under sulfur deprived photoautotrophic condition. The findings showed a higher gas yield and hydrogen content under dark period, whereas under light period the gas content was below detectable level for hydrogen due to the reversible hydrogenase reaction. (author)

Control apparatus for hot gas engine

Science.gov (United States)

Stotts, Robert E.

1986-01-01

A mean pressure power control system for a hot gas (Stirling) engine utilizing a plurality of supply tanks for storing a working gas at different pressures. During pump down operations gas is bled from the engine by a compressor having a plurality of independent pumping volumes. In one embodiment of the invention, a bypass control valve system allows one or more of the compressor volumes to be connected to the storage tanks. By selectively sequencing the bypass valves, a capacity range can be developed over the compressor that allows for lower engine idle pressures and more rapid pump down rates.

Use of zeolites for the removal of volatile sulfur compounds from industrial waste gases and from natural gases

Energy Technology Data Exchange (ETDEWEB)

Dudzik,; Z,; Bilska, M

1974-12-01

The use of zeolites for the removal of sulfur dioxide from industrial waste gases and for the removal of hydrogen sulfide and volatile mercaptans from the natural gas or synthetic gas manufactured from coal is discussed. The effectiveness and cost of zeolite methods are superior to that of other methods. The best sorption properties with respect to sulfur dioxide are observed in faujasites and erionites. The molecular sieve 13X (a sodium form of low-silicon faujasite) is the most effective sorbent of hydrogen sulfide, produced commercially on a large scale. This zeolite is also a very effective catalyst for simultaneous oxygenation of hydrogen sulfide. The reaction with oxygen can begin at temperatures as low as -80/sup 0/C. The effectiveness of zeolite reactors is enhanced by the presence of oxygen in the gas being purified, and is hindered by the presence of water or water vapor. The extraordinary catalytic activity of sodium faujasites is due to free donors, and sulfur and oxygen ion donors at their surface. A zeolite reactor is also economical.

Process using sorbents for the removal of SOx from flue gas

International Nuclear Information System (INIS)

Pinnavaia, T.J.; Amareskera, J.; Polansky, C.A.

1992-01-01

This patent describes a process for removing the SO x components from a flue gas stream containing oxygen, sulfur dioxide and sulfur trioxide from the combustion of coal from a coal-fired boiler which comprises combusting the coal in the boiler to provide the flue gas stream and contacting the the gas stream with a heated sorbent composition at 400 degrees to 1000 degrees C wherein the the sorbent before being heated is selected from the group consisting of a layered double hydroxide composition of formula: [M 1-x II M x III (OH) 2 ](A n- ) x/n · yH 2 O wherein M II is a divalent metal cation and M III is a trivalent metal cation selected from the group consisting of Group IIA. IIB and IIIA metals as the cation which form metal oxides and which are capable of reacting with SO 2 to form metal sulfites and SO 3 to form metal sulfates, A is an interlayer anion of charge n- which comprises at least one metal atoms selected from the group consisting of main group metals and transition metals which provide oxidation of sulfur dioxide to sulfur trioxide in an amount sufficient that the layered double hydroxide structure promotes the oxidation of the sulfur dioxide to the sulfur trioxide at the combustion conditions within the coal-fired boiler, wherein y is moles of water

Identification of organic sulfur compounds in coal bitumen obtained by different extraction techniques using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometric detection

Energy Technology Data Exchange (ETDEWEB)

Machado, Maria Elisabete; Cappelli Fontanive, Fernando; Bastos Caramao, Elina; Alcaraz Zini, Claudia [Universidade Federal do Rio Grande do Sul, Instituto de Quimica, Porto Alegre, RS (Brazil); Oliveira, Jose Vladimir de [URI, Universidade Regional Integrada do Alto Uruguai e das Missoes, Erechim, RS (Brazil)

2011-11-15

The determination of organic sulfur compounds (OSC) in coal is of great interest. Technically and operationally these compounds are not easily removed and promote corrosion of equipment. Environmentally, the burning of sulfur compounds leads to the emission of SO{sub x} gases, which are major contributors to acid rain. Health-wise, it is well known that these compounds have mutagenic and carcinogenic properties. Bitumen can be extracted from coal by different techniques, and use of gas chromatography coupled to mass spectrometric detection enables identification of compounds present in coal extracts. The OSC from three different bitumens were tentatively identified by use of three different extraction techniques: accelerated solvent extraction (ASE), ultrasonic extraction (UE), and supercritical-fluid extraction (SFE). Results obtained from one-dimensional gas chromatography (1D GC) coupled to quadrupole mass spectrometric detection (GC-qMS) and from two-dimensional gas chromatography with time-of-flight mass spectrometric detection (GC x GC-TOFMS) were compared. By use of 2D GC, a greater number of OSC were found in ASE bitumen than in SFE and UE bitumens. No OSC were identified with 1D GC-qMS, although some benzothiophenes and dibenzothiophenes were detected by use of EIM and SIM modes. GC x GC-TOFMS applied to investigation of OSC in bitumens resulted in analytical improvement, as more OSC classes and compounds were identified (thiols, sulfides, thiophenes, naphthothiophenes, benzothiophenes, and benzonaphthothiophenes). The roof-tile effect was observed for OSC and PAH in all bitumens. Several co-elutions among analytes and with matrix interferents were solved by use of GC x GC. (orig.)

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

Science.gov (United States)

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

2017-06-06

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-12-26

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

Iron and Sulfur Species and Sulfur Isotopic Compositions of Authigenic Pyrite in Gas Hydrate-Bearing Sediments from Hydrate Ridge, Cascadia Margin (ODP Leg 204): A Proposal of Conceptual Models to Indicate the Non-Steady State Depositional and Diagenetic Processes

Science.gov (United States)

Liu, C.; Jiang, S. Y.; Su, X.

2017-12-01

Two accretionary sediment sequences from Sites 1245 and 1252 recovered during Ocean Drilling Program (ODP) Leg 204 at Hydrate Ridge, Cascadia Margin were investigated to explore the non-steady state depositional and diagenetic history. Five iron species and three sulfur species were chemically extracted, and their concentrations and the sulfur isotopic compositions of pyrite were determined. After the mineral recognitions of these species and detailed comparative analyses, the aerobic history of bottom seawater has been determined. The formation of pyrite is thought to be controlled by the limited production of hydrogen sulfide relative to the supply of reactive iron. Also, the intrusion of oxygen by bioturbation would oxidize the reduced sulfur species and further suppress pyritization. To explain the geochemical relationship between pyrite and siderite and the sulfur isotope characteristics of pyrite, we propose seven conceptual models based on the variations in depositional rate and methane flux, and the models succeed in explaining the geochemical results and are validated by the observed non-steady state events. These models may contribute to the reconstruction of the non-steady state processes in other research areas in the future.

Catalytic processing of high-sulfur fuels for distributed hydrogen production

Energy Technology Data Exchange (ETDEWEB)

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

2010-07-01

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

Transfer characterization of sulfur from coal-burning emission to plant leaves by PIXE and XANES

Energy Technology Data Exchange (ETDEWEB)

Bao, L.M.; Zhang, G.L.; Zhang, Y.X.; Li, Y.; Lin, J.; Liu, W.; Cao, Q.C.; Zhao, Y.D.; Ma, C.Y.; Han, Y. [Chinese Academy of Sciences, Shanghai (China). Shanghai Institute of Applied Physics

2009-11-15

The impact of coal-burning emission on sulfur in camphor leaves was investigated using Proton Induced X-ray Emission (PIXE) and synchrotron radiation technique X-ray Absorption Near-Edge Structure (XANES) spectroscopy. The PIXE results show that the sulfur concentrations in the leaves collected at the polluted site are significantly higher than those in controls. The sulfur XANES spectra show the presence of organic (disulfides, thiols, thioethers, sulfonates and sulfoxides) and inorganic sulfur (sulfates) in the leaves. The inorganic sulfur in the leaves of camphor tree polluted by coal combustion is 15% more than that of the control site. The results suggest that the long-term coal-burning pollution resulted in an enhanced content of the total sulfur and sulfate in the leaves, and the uptake of sulfur by leaves had exceeded the metabolic requirement of plants and the excess of sulfur was stored as SO{sub 4}2{sup -}. It can monitor the sulfur pollution in atmosphere.

Moderate temperature gas purification system: Application to high calorific coal-derived fuel

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, M.; Shirai, H.; Nunokawa, M. [Central Research Institute of Electric Power Industry, Kanagawa (Japan)

2008-01-15

Simultaneous removal of dust, alkaline and alkaline-earth metals, halides and sulfur compounds is required to enlarge application of coal-derived gas to the high-temperature fuel cells and the fuel synthesis through chemical processing. Because high calorific fuel gas, such as oxygen-blown coal gas, has high carbon monoxide content, high-temperature (above 450{sup o}C) gas purification system is always subjected to the carbon deposition. We suggest moderate temperature (around 300{sup o}C) operation of the gas purification system to avoid the harmful disproportionation reaction and efficient removal of the various contaminants. Because the reaction rate is predominant to the performance of contaminant removal in the moderate temperature gas purification system, we evaluated the chemical removal processes; performance of the removal processes for halides and sulfur compounds was experimentally evaluated. The halide removal process with sodium aluminate sorbent had potential performance at around 300{sup o}C. The sulfur removal process with zinc ferrite sorbent was also applicable to the temperature range, though the reaction kinetics of the sorbent is essential to be approved.

ENHANCED CONTROL OF MERCURY BY WET FLUE GAS DESULFURIZATION SYSTEMS; FINAL

International Nuclear Information System (INIS)

Unknown

2001-01-01

The U.S. Department of Energy and EPRI co-funded this project to improve the control of mercury emissions from coal-fired power plants equipped with wet flue gas desulfurization (FGD) systems. The project has investigated catalytic oxidation of vapor-phase elemental mercury to a form that is more effectively captured in wet FGD systems. If successfully developed, the process could be applicable to over 90,000 MW of utility generating capacity with existing FGD systems, and to future FGD installations. Field tests were conducted to determine whether candidate catalyst materials remain active towards mercury oxidation after extended flue gas exposure. Catalyst life will have a large impact on the cost effectiveness of this potential process. A mobile catalyst test unit was used to test the activity of four different catalyst materials for a period of up to six months each at three utility sites. Catalyst testing was completed at the first site, which fires Texas lignite, in December 1998; at the second test site, which fires a Powder River Basin subbituminous coal, in November 1999; and at the third site, which fires a medium- to high-sulfur bituminous coal, in January 2001. Results of testing at each of the three sites were reported in previous technical notes. At Site 1, catalysts were tested only as powders dispersed in sand bed reactors. At Sites 2 and 3, catalysts were tested in two forms, including powders dispersed in sand and in commercially available forms such as extruded pellets and coated honeycomb structures. This final report summarizes and presents results from all three sites, for the various catalyst forms tested. Field testing was supported by laboratory tests to screen catalysts for activity at specific flue gas compositions, to investigate catalyst deactivation mechanisms and methods for regenerating spent catalysts. Laboratory results are also summarized and discussed in this report

To control and to be controlled – understanding the Arabidopsis SLIM1 function in sulfur deficiency through comprehensive investigation of the EIL protein family.

Directory of Open Access Journals (Sweden)

Anna eWawrzyńska

2014-10-01

Full Text Available SSLIM1, a member of the EIN3-like (EIL family of transcription factors in Arabidopsis, is the regulator of many sulfur-deficiency responsive genes. Among the five other proteins of the family, three regulate ethylene responses and two have unassigned functions. Contrary to the well-defined ethylene signaling, the pathway leading from sensing sulfate status to the activation of its acquisition via SLIM1 is completely unknown. SLIM1 binds to the 20 nt-long specific UPE-box sequence; however, it also recognizes the shorter TEIL sequence, unique for the whole EIL family. SLIM1 takes part in the upregulation and downregulation of various sulfur metabolism genes, but also it controls the degradation of glucosinolates under sulfur deficient conditions. Besides facilitating the increased flux through the sulfate assimilation pathway, SLIM1 induces microRNA395, specifically targeting ATP sulfurylases and a low-affinity sulfate transporter, SULTR2;1, thus affecting sulfate translocation to the shoot. Here, we briefly review the identification, structural characteristics and molecular function of SLIM1 from the perspective of the whole EIL protein family.

Emissions of toxic pollutants from compressed natural gas and low sulfur diesel-fueled heavy-duty transit buses tested over multiple driving cycles.

Science.gov (United States)

Kado, Norman Y; Okamoto, Robert A; Kuzmicky, Paul A; Kobayashi, Reiko; Ayala, Alberto; Gebel, Michael E; Rieger, Paul L; Maddox, Christine; Zafonte, Leo

2005-10-01

The number of heavy-duty vehicles using alternative fuels such as compressed natural gas (CNG) and new low-sulfur diesel fuel formulations and equipped with after-treatment devices are projected to increase. However, few peer-reviewed studies have characterized the emissions of particulate matter (PM) and other toxic compounds from these vehicles. In this study, chemical and biological analyses were used to characterize the identifiable toxic air pollutants emitted from both CNG and low-sulfur-diesel-fueled heavy-duty transit buses tested on a chassis dynamometer over three transient driving cycles and a steady-state cruise condition. The CNG bus had no after-treatment, and the diesel bus was tested first equipped with an oxidation catalyst (OC) and then with a catalyzed diesel particulate filter (DPF). Emissions were analyzed for PM, volatile organic compounds (VOCs; determined on-site), polycyclic aromatic hydrocarbons (PAHs), and mutagenic activity. The 2000 model year CNG-fueled vehicle had the highest emissions of 1,3-butadiene, benzene, and carbonyls (e.g., formaldehyde) of the three vehicle configurations tested in this study. The 1998 model year diesel bus equipped with an OC and fueled with low-sulfur diesel had the highest emission rates of PM and PAHs. The highest specific mutagenic activities (revertants/microg PM, or potency) and the highest mutagen emission rates (revertants/mi) were from the CNG bus in strain TA98 tested over the New York Bus (NYB) driving cycle. The 1998 model year diesel bus with DPF had the lowest VOCs, PAH, and mutagenic activity emission. In general, the NYB driving cycle had the highest emission rates (g/mi), and the Urban Dynamometer Driving Schedule (UDDS) had the lowest emission rates for all toxics tested over the three transient test cycles investigated. Also, transient emissions were, in general, higher than steady-state emissions. The emissions of toxic compounds from an in-use CNG transit bus (without an oxidation

Modelling and Identification for Control of Gas Bearings

DEFF Research Database (Denmark)

Theisen, Lukas Roy Svane; Niemann, Hans Henrik; Santos, Ilmar

2015-01-01

Gas bearings are popular for their high speed capabilities, low friction and clean operation, but suffer from poor damping, which poses challenges for safe operation in presence of disturbances. Enhanced damping can be achieved through active lubrication techniques using feedback control laws....... Such control design requires models with low complexity, able to describe the dominant dynamics from actuator input to sensor output over the relevant range of operation. The mathematical models based on first principles are not easy to obtain, and in many cases, they cannot be directly used for control design...... to industrial rotating machinery with gas bearings and to allow for subsequent control design. The paper shows how piezoelectric actuators in a gas bearing are efficiently used to perturb the gas film for identification over relevant ranges of rotational speed and gas injection pressure. Parameter...

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

Science.gov (United States)

Wasmund, Kenneth; Mußmann, Marc; Loy, Alexander

2017-08-01

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

Formation and Control of Sulfur Oxides in Sour Gas Oxy-Combustion: Prediction Using a Reactor Network Model

KAUST Repository

Bongartz, Dominik; Shanbhogue, Santosh J.; Ghoniem, Ahmed F.

2015-01-01

© 2015 American Chemical Society. Sour natural gas currently requires expensive gas cleanup before it can be used in power generation because it contains large amounts of hydrogen sulfide (H2S) and carbon dioxide (CO2) that entail a low heating

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

Science.gov (United States)

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

2018-04-01

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

Nanostructured sulfur cathodes

KAUST Repository

Yang, Yuan

2013-01-01

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

Control characteristics of inert gas recovery plant

International Nuclear Information System (INIS)

Mikawa, Hiroji; Kato, Yomei; Kamiya, Kunio

1980-01-01

This paper presents a dynamic simulator and the control characteristics for a radioactive inert gas recovery plant which uses a cryogenic liquefying process. The simulator was developed to analyze the operational characteristics and is applicable to gas streams which contain nitrogen, argon, oxygen and krypton. The characteristics analysis of the pilot plant was performed after the accuracy of the simulator was checked using data obtained in fundamental experiments. The relationship between the reflux ratio and krypton concentration in the effluent gas was obtained. The decontamination factor is larger than 10 9 when the reflux ratio is more than 2. 0. The control characteristics of the plant were examined by changing its various parameters. These included the amount of gas to be treated, the heater power inside the evaporator and the liquid nitrogen level in the condenser. These characteristics agreed well with the values obtained in the pilot plant. The results show that the krypton concentration in the effluent gas increases when the liquid nitrogen level is decreased. However, in this case, the krypton concentration can be minimized by applying a feed forward control to the evaporator liquid level controller. (author)

Determining total sulfur content in coal by MSC radiometric sulfur meter

Energy Technology Data Exchange (ETDEWEB)

Czerw, B; Sikora, T; Golebiowski, W

1976-01-01

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

Synergistic capture mechanisms for alkali and sulfur species from combustion. Final report

Energy Technology Data Exchange (ETDEWEB)

Peterson, T.W.; Shadman, F.; Wendt, J.O.L.; Mwabe, P.O.

1994-02-01

Experimental work was carried out on a 17 kW, 600 cm long, gas laboratory combustor, to investigate the post flame reactive capture of alkali species by kaolinite. Emphasis was on alkali/sorbent interactions occurring in flue gas at temperatures above the alkali dewpoint and on the formation of water insoluble reaction products. Time-temperature studies were carried out by injecting kaolinite at different axial points along the combustor. The effect of chlorine and sulfur on alkali capture was investigated by doping the flame with SO{sub 2} and Cl{sub 2} gases to simulate coal flame environments. Particle time and temperature history was kept as close as possible to that which would ordinarily be found in a practical boiler. Experiments designed to extract apparent initial reaction rates were carried using a narrow range, 1-2 {mu}m modal size sorbent, while, a coarse, multi size sorbent was used to investigate the governing transport mechanisms. The capture reaction has been proposed to be between alkali hydroxide and activated kaolinite, and remains so in the presence of sulfur and chlorine. The presence of sulfur reduces sodium capture by under 10% at 1300{degree}C. Larger reductions at lower temperatures are attributed to the elevated dewpoint of sodium ({approximately}850{degree}C) with subsequent reduction in sorbent residence time in the alkali gas phase domain. Chlorine reduces sodium capture by 30% across the temperature range covered by the present experiments. This result has been linked to thermodynamic equilibria between sodium hydroxide, sodium chloride and water.

Multi-component removal in flue gas by aqua ammonia

Science.gov (United States)

Yeh, James T [Bethel Park, PA; Pennline, Henry W [Bethel Park, PA

2007-08-14

A new method for the removal of environmental compounds from gaseous streams, in particular, flue gas streams. The new method involves first oxidizing some or all of the acid anhydrides contained in the gas stream such as sulfur dioxide (SO.sub.2) and nitric oxide (NO) and nitrous oxide (N.sub.2O) to sulfur trioxide (SO.sub.3) and nitrogen dioxide (NO.sub.2). The gas stream is subsequently treated with aqua ammonia or ammonium hydroxide which captures the compounds via chemical absorption through acid-base or neutralization reactions. The products of the reactions can be collected as slurries, dewatered, and dried for use as fertilizers, or once the slurries have been dewatered, used directly as fertilizers. The ammonium hydroxide can be regenerated and recycled for use via thermal decomposition of ammonium bicarbonate, one of the products formed. There are alternative embodiments which entail stoichiometric scrubbing of nitrogen oxides and sulfur oxides with subsequent separate scrubbing of carbon dioxide.

Technologies options for acid-rain control. Book chapter

International Nuclear Information System (INIS)

Princiotta, F.T.

1992-01-01

The report discusses acid rain control options available to the electric utility industry. They include coal switching, flue gas desulfurization, and such emerging lower cost technologies as Limestone Injection Multistage Burners (LIMB) and Advanced Silicate (ADVACATE), both developed by EPA, selective use of gas to reduce nitrogen oxides (NOx) and sulfur dioxide (SO2) in coal-fired boilers, and the use of Integrated Coal Gasification Combined Cycle (IGCC) technology

Process and device for liquid organic waste processing by sulfuric mineralization

International Nuclear Information System (INIS)

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

1990-01-01

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

Modeling the condensation of sulfuric acid and water on the cylinder liner of a large two-stroke marine diesel engine

DEFF Research Database (Denmark)

Cordtz, Rasmus Faurskov; Mayer, Stefan; Eskildsen, Svend S.

2018-01-01

how fuel sulfur content, charge air humidity and liner temperature variations affects the deposition of water and sulfuric acid at low load operation. A phenomenological engine model is applied to simulate the formation of cylinder/bulk gas combustion products and dew points comply with H2O–H2SO4...

Standard practice for preparing sulfur prints for macrostructural evaluation

CERN Document Server

American Society for Testing and Materials. Philadelphia

2008-01-01

1.1 This practice provides information required to prepare sulfur prints (also referred to as Baumann Prints) of most ferrous alloys to reveal the distribution of sulfide inclusions. 1.2 The sulfur print reveals the distribution of sulfides in steels with bulk sulfur contents between about 0.010 and 0.40 weight percent. 1.3 Certain steels contain complex sulfides that do not respond to the test solutions, for example, steels containing titanium sulfides or chromium sulfides. 1.4 The sulfur print test is a qualitative test. The density of the print image should not be used to assess the sulfur content of a steel. Under carefully controlled conditions, it is possible to compare print image intensities if the images are formed only by manganese sulfides. 1.5 The sulfur print image will reveal details of the solidification pattern or metal flow from hot or cold working on appropriately chosen and prepared test specimens. 1.6 This practice does not address acceptance criteria based on the use of the method. ...

Intensification of oxidative desulfurization of gas oil by ultrasound irradiation: Optimization using Box–Behnken design (BBD)

International Nuclear Information System (INIS)

Jalali, Mohammad Reza; Sobati, Mohammad Amin

2017-01-01

Highlights: • Ultrasound-assisted oxidative desulfurization (UAOD) of gas oil was studied. • The influences of the different operating parameters were investigated. • Response surface methodology (RSM) was used to find the best operating parameters. • An accurate correlation was developed for the sulfur removal. • Ultrasound-assisted desulfurization process was compared with conventional process. - Abstract: In the present work, ultrasound assisted oxidative desulfurization (UAOD) of gas oil as the feedstock with sulfur content of 2210 ppmw was investigated using a mixture of hydrogen peroxide and formic acid as the oxidant and catalyst, respectively. The influences of main process variables such as sonication time (2–30 min), oxidation temperature (40–70 °C), hydrogen peroxide to sulfur molar ratio (10–50), formic acid to oxidant molar ratio (2–4), ultrasound power per gas oil volume (5.56–8.89 W/mL), and number of extraction stages (1–4) on the sulfur removal of gas oil were investigated. Response surface methodology (RSM) based on Box–Behnken design (BBD) and single-factor experiments were employed. The best performance of UAOD process for gas oil was achieved at 50 °C of reaction temperature, oxidant to sulfur molar ratio of 46.36, formic acid to oxidant molar ratio of 3.22, sonication time of 19.81 min, and 7.78 W/mL as the ultrasound power per gas oil volume. The sulfur removal of UAOD process was evaluated after oxidation under the abovementioned conditions followed by (a) one stage extraction and (b) four stages extraction using acetonitrile as solvent. The observed sulfur removal was 87 for case (a) and 96.2% for case (b). The UAOD process was also compared with conventional ODS process. Considerable improvement on the sulfur removal was observed specially in lower reaction time in the case of using ultrasound irradiation in comparison with conventional mixing.

ELECTROCHEMICAL SEPARATION AND CONCENTRATION OF HYDROGEN SULFIDE FROM GAS MIXTURES

Science.gov (United States)

Winnick, Jack; Sather, Norman F.; Huang, Hann S.

1984-10-30

A method of removing sulfur oxides of H.sub.2 S from high temperature gas mixtures (150.degree.-1000.degree. C.) is the subject of the present invention. An electrochemical cell is employed. The cell is provided with inert electrodes and an electrolyte which will provide anions compatible with the sulfur containing anions formed at the anode. The electrolyte is also selected to provide inert stable cations at the temperatures encountered. The gas mixture is passed by the cathode where the sulfur gases are converted to SO.sub.4 -- or, in the case of H.sub.2 S, to S--. The anions migrate to the anode where they are converted to a stable gaseous form at much greater concentration levels (>10X). Current flow may be effected by utilizing an external source of electrical energy or by passing a reducing gas such as hydrogen past the anode.

Sulfur dioxide initiates global climate change in four ways

International Nuclear Information System (INIS)

Ward, Peter L.

2009-01-01

1980 anthropogenic sulfur emissions peaked and began to decrease because of major efforts especially in Japan, Europe, and the United States to reduce acid rain. Atmospheric concentrations of methane began decreasing in 1990 and have remained nearly constant since 2000, demonstrating an increase in oxidizing capacity. Global temperatures became roughly constant around 2000 and even decreased beginning in late 2007. Meanwhile atmospheric concentrations of carbon dioxide have continued to increase at the same rate that they have increased since 1970. Thus SO 2 is playing a far more active role in initiating and controlling global warming than recognized by the Intergovernmental Panel on Climate Change. Massive reduction of SO 2 should be a top priority in order to reduce both global warming and acid rain. But man is also adding two to three orders of magnitude more CO 2 per year to the climate than one 'large' volcanic eruption added in the past. Thus CO 2 , a greenhouse gas, is contributing to global warming and should be reduced. We have already significantly reduced SO 2 emissions in order to reduce acid rain. We know how to do it both technically and politically. In the past, sudden climate change was typically triggered by sudden increases in volcanic activity. Slow increases in greenhouse gases, therefore, do not appear as likely as currently thought to trigger tipping points where the climate suddenly changes. However we do need to start planning an appropriate human response to future major increases in volcanic activity.

Joint project final report, Task II: Sulfur chemistry, Task III: Nitrogen Chemistry[Straw fired power plants

Energy Technology Data Exchange (ETDEWEB)

Glarborg, P.; Lans, R. van der; Weigang, L.; Arendt Jensen, P.; Degn Jensen, A.; Dam-Johansen, K.

2001-09-01

It is the aim of the project to promote the use of biomass in the production of power and heat in Denmark as well as enhancing the technology base of the Danish industry within this area. The project involves, the following task areas: 1) Deposit Build-up; 2) Sulfur Chemistry; 3) Nitrogen Chemistry; and 4) Furnace Modeling. The present report covers the activities in task 2 and 3, which are carried out at Department of Chemical Engineering, DTU. Task 2: Sulfur chemistry: The lab-scale results show that the amount of sulfur released into the gas-phase increases at high temperatures. Other process parameters such as oxygen concentration have less impact. Little sulfur is apparently released during char oxidation. The experiments show that about 40% of the sulfur is released during pyrolysis at 400 {sup d}eg{sup .}C. At combustion conditions it was found that about 50% of the sulfur is released at 500{sup d}eg.{sup C}; above this temperature an almost linear correlation is found beteen sulfur release and combustion temperature up to 80-85% release at 950{sup d}eg.{sup C}. The experiments are in agreement with results from full scale straw fired grate boilers, indicating that only a small amount of fuel-sulfur is fixed in the bottom ash under typical operating conditions. The results are important in order to understand the varying emission levels observed in full-scala systems and provide guidelines for low SO{sub 2} operation. Task 3: Nitrogen chemistry: In the nitgrogen chemistry submodel volatile-N is released as NH{sub 3} and N{sub 2}. The ammonia can react further to N{sub 2} or NO. Char nitrogen is oxidized to NO, and the char bed acts as a catalyst for the reduction of NO to N{sub 2}. Predictions with the bed-model including the NO submodel indicate that when all volatile nitrogen is converted to NH{sub 3}, the concentrations og NH{sub 3} are significantly overpredicted. This means that either the NH{sub 3} reaction rates are underpredicted or that a smaller

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

Science.gov (United States)

Ramkumar, Shwetha; Fan, Liang-Shih

2013-07-30

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

Genomic Insights into the Sulfur Metabolism of Phototrophic Green Sulfur Bacteria

DEFF Research Database (Denmark)

Frigaard, Niels-Ulrik; Bryant, Donald A.

2008-01-01

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

Shell launches its Claus off-gas desulfurization process

Energy Technology Data Exchange (ETDEWEB)

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

1972-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1997-12-31

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

Acidophilic sulfur disproportionation

Science.gov (United States)

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

2013-07-01

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

Origin of electrolyte-dopant dependent sulfur poisoning of SOFC anodes.

Science.gov (United States)

Zeng, ZhenHua; Björketun, Mårten E; Ebbesen, Sune; Mogensen, Mogens B; Rossmeisl, Jan

2013-05-14

The mechanisms governing the sulfur poisoning of the triple phase boundary (TPB) of Ni-XSZ (X2O3 stabilized zirconia) anodes have been investigated using density functional theory. The calculated sulfur adsorption energies reveal a clear correlation between the size of the cation dopant X(3+) and the sulfur tolerance of the Ni-XSZ anode; the smaller the ionic radius, the higher the sulfur tolerance. The mechanistic study shows that the size of X(3+) strongly influences XSZ's surface energy, which in turn determines the adhesion of Ni to XSZ. The Ni-XSZ interaction has a direct impact on the Ni-S interaction and on the relative stability of reconstructed and pristine Ni(100) facets at the TPB. Together, these two effects control the sulfur adsorption on the Ni atoms at the TPB. The established relationships explain experimentally observed dopant-dependent anode performances and provide a blueprint for the future search for and preparation of highly sulfur tolerant anodes.

Quantitative analysis of sulfur forms of coal and the pyrolysis behavior of sulfur compounds; Sekitanchu no io kagobutsu no keitaibetsu gan`yuryo no teiryo to sono netsubunkai kyodo

Energy Technology Data Exchange (ETDEWEB)

Mae, K.; Miura, K.; Shimada, M. [Kyoto University, Kyoto (Japan). Faculty of Engineering

1996-10-28

As part of the studies on coal utilization basics, considerations were given on quantification of sulfur forms of coal and the pyrolysis behavior of sulfur compounds. With the temperature raising oxidation method, a thermo-balance was connected directly to a mass analyzer, and the coal temperature was raised at a rate of 5{degree}C per minute and gasified. Peak division was performed on SO2 and COS production to derive sulfur forms of coal. Using the slow-speed pyrolysis method, production rates of H2S, COS, SO2 and mercaptans were measured at a temperature raising rate of 20{degree}C per minute. Sulfur content in char was also measured. With the quick pyrolysis method, a Curie point pyrolyzer was connected directly to a gas chromatograph, by which secondary reaction is suppressed, and initial pyrolytic behavior can be tracked. All kinds of coals produce a considerable amount of SO2 in the slow-speed pyrolysis, but very little in the quick pyrolysis. Instead, H2S and mercaptans are produced. Sulfur compound producing mechanisms vary depending on the temperature raising rates. By using a parallel primary reaction model, analysis was made on reactions of H2S production based on different activation energies, such as those generated from pyrite decomposition and organic sulfur decomposition. The analytic result agreed also with that from the temperature raising oxidation method. 4 refs., 6 figs., 1 tab.

A dynamic study on the sulfuric acid distillation column for VHTR-assisted hydrogen production systems

International Nuclear Information System (INIS)

Youngjoon, Shin; Heesung, Shin; Jiwoon, Jang; Kiyoung, Lee; Jonghwa, Chang

2007-01-01

The sulfur-iodine (SI) cycle and the Westinghouse sulfur hybrid cycle coupled to a very high temperature gas-cooled reactor (VHTR) are well known as a feasible technology to produce hydrogen. The concentration of the sulfuric acid solution and its decomposition are essential parts in both cycles. In this paper, the thermophysical properties which are the boiling point, latent heat, and the partial pressures of water, sulfuric acid, and sulfur trioxide have been correlated as a function of the sulfuric acid concentration for the H 2 SO 4 and H 2 O binary chemical system, based on the data in Perry's chemical engineers' hand-book and other experimental data. By using these thermophysical correlations, a dynamic analysis of a sulfuric acid distillation column has been performed to establish the column design requirements and its optimum operation condition. From the results of the dynamic analysis, an optimized column system is anticipated for a distillation column equipped with 2 ideal plates and a second plate feeding system from the bottom plate. The effects of the hold-up of the re-boiler and the reflux ratio from the top product stream on the elapsing time when the system progresses toward a steady state have been analyzed. (authors)

Desulfurized gas production from vertical kiln pyrolysis

Science.gov (United States)

Harris, Harry A.; Jones, Jr., John B.

1978-05-30

A gas, formed as a product of a pyrolysis of oil shale, is passed through hot, retorted shale (containing at least partially decomposed calcium or magnesium carbonate) to essentially eliminate sulfur contaminants in the gas. Specifically, a single chambered pyrolysis vessel, having a pyrolysis zone and a retorted shale gas into the bottom of the retorted shale zone and cleaned product gas is withdrawn as hot product gas near the top of such zone.

Development and industrial application of catalyzer for low-temperature hydrogenation hydrolysis of Claus tail gas

Directory of Open Access Journals (Sweden)

Honggang Chang

2015-10-01

Full Text Available With the implementation of more strict national environmental protection laws, energy conservation, emission reduction and clean production will present higher requirements for sulfur recovery tail gas processing techniques and catalyzers. As for Claus tail gas, conventional hydrogenation catalyzers are gradually being replaced by low-temperature hydrogenation catalyzers. This paper concentrates on the development of technologies for low-temperature hydrogenation hydrolysis catalyzers, preparation of such catalyzers and their industrial application. In view of the specific features of SO2 hydrogenation and organic sulfur hydrolysis during low-temperature hydrogenation, a new technical process involving joint application of hydrogenation catalyzers and hydrolysis catalyzers was proposed. In addition, low-temperature hydrogenation catalyzers and low-temperature hydrolysis catalyzers suitable for low-temperature conditions were developed. Joint application of these two kinds of catalyzers may reduce the inlet temperatures in the conventional hydrogenation reactors from 280 °C to 220 °C, at the same time, hydrogenation conversion rates of SO2 can be enhanced to over 99%. To further accelerate the hydrolysis rate of organic sulfur, the catalyzers for hydrolysis of low-temperature organic sulfur were developed. In lab tests, the volume ratio of the total sulfur content in tail gas can be as low as 131 × 10−6 when these two kinds of catalyzers were used in a proportion of 5:5 in volumes. Industrial application of these catalyzers was implemented in 17 sulfur recovery tail gas processing facilities of 15 companies. As a result, Sinopec Jinling Petrochemical Company had outstanding application performances with a tail gas discharging rate lower than 77.9 mg/m3 and a total sulfur recovery of 99.97%.

Metrological aspects to quality control for natural gas analyses

Energy Technology Data Exchange (ETDEWEB)

Ribeiro, Claudia Cipriano; Borges, Cleber Nogueira; Cunha, Valnei S. [Instituto Nacional de Metrologia, Normalizacao e Qualidade Industrial (INMETRO), Rio de Janeiro, RJ (Brazil); Augusto, Cristiane R. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil); Augusto, Marco Ignazio [Companhia Estadual de Gas do Rio de Janeiro (CEG), RJ (Brazil)

2008-07-01

The Product's Quality and Services are fundamental topics in the globalized commercial relationship inclusive concern the measurements in natural gas. Considerable investments were necessary for industry especially about the quality control in the commercialized gas with an inclusion of the natural gas in Brazilian energetic resources The Brazilian Regulatory Agency, ANP - Agencia Nacional de Petroleo, Gas Natural e Biocombustiveis - created the Resolution ANP no.16. This Resolution defines the natural gas specification, either national or international source, for commercialization in Brazil and list the tolerance concentration for some components. Between of this components are the inert compounds like the CO{sub 2} and N{sub 2}. The presence of this compounds reduce the calorific power, apart from increase the resistance concern the detonation in the case of vehicular application, and occasion the reduction in the methane concentration in the gas. Controls charts can be useful to verify if the process are or not under Statistical Control. The process can be considerate under statistical control if the measurements have it values between in lower and upper limits stated previously The controls charts can be approach several characteristics in each subgroup: means, standard deviations, amplitude or proportion of defects. The charts are draws for a specific characteristic and to detect some deviate in the process under specific environment conditions. The CEG - Companhia de Distribuicao de Gas do Rio de Janeiro and the DQUIM - Chemical Metrology Division has an agreement for technical cooperation in research and development of gas natural composition Concern the importance of the natural gas in the Nation development, as well as the question approaching the custody transference, the objective of this work is demonstrate the control quality of the natural gas composition between the CEG laboratory and the DQUIM laboratory aiming the quality increase of the

Influence of sulfur and nitrogen supply on the susceptibility of Pisum sativum to SO/sub 2/

Energy Technology Data Exchange (ETDEWEB)

Klein, H; Jaeger, H J; Steubing, L

1974-01-01

The susceptibility of Pisum to SO/sub 2/ injury was examined in relation to the sulfur and nitrogen nutrition. The injury was measured by comparing the dry matter yield to control and treated plants. SO/sub 2/ effects on metabolism were established by determining the content of organic and inorganic sulfur and, indirectly, by measuring total nitrogen, amino acid nitrogen, and protein nitrogen. The plants grown in nutrient solutions deficient in sulfur or nitrogen showed a decreased sensitivity to SO/sub 2/ pollution compared to the control. The higher content of amino acid nitrogen and organic sulfur of the plants grown in a nitrogen-deficient solution suggests that an increased synthesis of sulfur containing amino acids occurs. The slighter injury of the plants deficient in sulfur may be explained by the delayed sulfur supply.

Prebiotics mitigate in vitro sulfur-containing odour generation in caecal content of pigs

Directory of Open Access Journals (Sweden)

Yuan Fan Deng

2015-03-01

Full Text Available The objective of this study was to examine the effects and role of prebiotics, such as inulin, fructo-oligosaccharides (FOS and galactooligosaccharides (GAS, to mitigate sulfur-containing odour gases, hydrogen sulfide (H2S and methyl mercaptan (CH3SH using pigs as in vitro study model. Inocula obtained from pigs were incubated at 39°C for 24 h using 550 mg sterilised substrate (caecal contents supplemented with or without 50 mg prebiotics. Production of total gas, H2S and CH3SH were determined. The results showed that total gas production for the caecal content of pigs was 57.3 mL, and that for H2S and CH3SH was 220.2 and 15.2 μL, respectively. The total gas production increased (P<0.05, whereas concentrations of H2S and CH3SH decreased (P<0.05 with supplementation of prebiotics. Among the prebiotics, inulin was the most effective in mitigating H2S and CH3SH productions, reducing the two malodorous gases by 14.7 and 19.8%, respectively. The reduction of the above two sulfur- containing gases was supported by lower sulfate-reducing bacteria population and higher sulfate radical concentrations in the prebiotics, particularly that of inulin supplementation group.

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

NARCIS (Netherlands)

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

2017-01-01

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

A batch assay to measure microbial hydrogen sulfide production from sulfur-containing solid wastes

International Nuclear Information System (INIS)

Sun, Mei; Sun, Wenjie; Barlaz, Morton A.

2016-01-01

Large volumes of sulfur-containing wastes enter municipal solid waste landfills each year. Under the anaerobic conditions that prevail in landfills, oxidized forms of sulfur, primarily sulfate, are converted to sulfide. Hydrogen sulfide (H 2 S) is corrosive to landfill gas collection and treatment systems, and its presence in landfill gas often necessitates the installation of expensive removal systems. For landfill operators to understand the cost of managing sulfur-containing wastes, an estimate of the H 2 S production potential is needed. The objective of this study was to develop and demonstrate a biochemical sulfide potential (BSP) test to measure the amount of H 2 S produced by different types of sulfur-containing wastes in a relatively fast (30 days) and inexpensive (125 mL serum bottles) batch assay. This study confirmed the toxic effect of H 2 S on both sulfate reduction and methane production in batch systems, and demonstrated that removing accumulated H 2 S by base adsorption was effective for mitigating inhibition. H 2 S production potentials of coal combustion fly ash, flue gas desulfurization residual, municipal solid waste combustion ash, and construction and demolition waste were determined in BSP assays. After 30 days of incubation, most of the sulfate in the wastes was converted to gaseous or aqueous phase sulfide, with BSPs ranging from 0.8 to 58.8 mL H 2 S/g waste, depending on the chemical composition of the samples. Selected samples contained solid phase sulfide which contributed to the measured H 2 S yield. A 60 day incubation in selected samples resulted in 39–86% additional sulfide production. H 2 S production measured in BSP assays was compared with that measured in simulated landfill reactors and that calculated from chemical analyses. H 2 S production in BSP assays and in reactors was lower than the stoichiometric values calculated from chemical composition for all wastes tested, demonstrating the importance of assays to estimate the

Biological conversion of coal synthesis gas to methane

Energy Technology Data Exchange (ETDEWEB)

Barik, S; Corder, R E; Clausen, E C; Gaddy, J L

1987-09-01

High temperatures and pressures are required, and therefore, high costs incurred during catalytic upgrading of coal synthesis gas to methane. Thus, the feasibility of biological reactions in converting synthesis gas to methane has been demonstrated in mixed and pure cultures. Complete conversion has been achieved in 2 hours with a mixed culture, and 45 minutes to 1.5 hours in pure cultures of P. productus and Methanothrix sp.. Typical sulfur levels involved during the process are found not to inhibit the bacteria and so sulfur does not have to be removed prior to biomethanation. Preliminary economic analyses indicate that coal gas may be biologically methanated for 50-60 cents/million Btu. Further studies with pure culture bacteria and increased pressure are expected to enhance biomethanation economics.

Accidents with sulfuric acid

Directory of Open Access Journals (Sweden)

Rajković Miloš B.

2006-01-01

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

Moderate temperature gas purification system: application to high calorific coal derived fuel

Energy Technology Data Exchange (ETDEWEB)

M. Kobayashi; H. Shirai; M. Nunokawa [Central Research Institute of Electric Power Industry (CRIEPI), Kanagawa (Japan)

2005-07-01

Simultaneous removal of dust, alkaline and alkaline-earth metals, halides and sulfur compounds is required to enlarge application of coal-derived gas to the high temperature fuel cells and the fuel synthesis through chemical processing. Because high calorific fuel gas, such as oxygen-blown coal gas, has high carbon monoxide content, high temperature gas purification system is always subjected to the carbon deposition and slippage of contaminant of high vapor pressure. It was suggested that moderate temperature operation of the gas purification system is applied to avoid the harmful disproportionation reaction and efficient removal of the various contaminants. To establish the moderate temperature gas purification system, the chemical-removal processes where the reaction rate is predominant to the performance of contaminant removal should be evaluated. Performance of the removal processes for halides and sulfur compounds were experimentally evaluated. The halide removal process with sodium based sorbent had potential good performance at around 300{sup o}C. The sulfur removal process was also applicable to the temperature range, although the improvement of the sulfidation reaction rate is considered to be essential. 11 refs., 8 figs., 1 tab.

Radiation induced sulfur dioxide removal

International Nuclear Information System (INIS)

Chmielewski, A.G.

2000-01-01

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

(18)O(2) label mechanism of sulfur generation and characterization in properties over mesoporous Sm-based sorbents for hot coal gas desulfurization.

Science.gov (United States)

Liu, B S; Wan, Z Y; Wang, F; Zhan, Y P; Tian, M; Cheung, A S C

2014-02-28

Using a sol-gel method, SmMeOx/MCM-41 or SBA-15 (Me=Fe, Co and Zn) and corresponding unsupported sorbents were prepared. The desulfurization performance of these sorbents was evaluated over a fixed-bed reactor and the effects of reaction temperature, feed and sorbent composition on desulfurization performance were studied. Samarium-based sorbents used to remove H2S from hot coal gas were reported for the first time. The results of successive sulfidation/regeneration cycles revealed that SmFeO3/SBA-15 sorbent was suitable for desulfurization of hot coal gas in the chemical industry. The formation of elemental sulfur during both sulfidation and regeneration processes depended strongly on the catalytic action of Sm2O2S species, which was confirmed for the first time via high sensitive time of flight mass spectrometer (TOF-MS) using 6%vol(18)O2/Ar regeneration gas and can reduce markedly procedural complexity. The sorbents were characterized using N2-adsorption, high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), temperature-programmed reduction of H2 (H2-TPR), thermogravimetry (TG) and time-of-flight mass spectrometry (TOF-MS) techniques. Copyright © 2014 Elsevier B.V. All rights reserved.

Modeling and Simulation of the Sulfur-Iodine Process Coupled to a Very High-Temperature Gas-Cooled Nuclear Reactor

International Nuclear Information System (INIS)

Shin, Youngjoon; Lee, Taehoon; Lee, Kiyoung; Kim, Minhwan

2015-01-01

Hydrogen produced from water using nuclear energy will avoid both the use of fossil fuel and CO 2 emission presumed to be the dominant reason for global warming. A thermo-chemical sulfur-iodine (SI) process coupled to a Very High Temperature Gas-Cooled Reactor(VHTR) is one of the most prospective hydrogen production methods that split water using nuclear energy because the SI process is suitable for large-scale hydrogen production without CO 2 emission. The dynamic simulation code to evaluate the start-up behavior of the chemical reactors placed on the secondary helium loop of the SI process has been developed and partially verified using the steady state values obtained from the Aspen Plus TM Code simulation. As the start-up dynamic simulation results of the SI process coupled to the IHX, which is one of components in the VHTR system, it is expected that the integrated secondary helium loop of the SI process can be successfully and safely approach the steady state condition

The Provenance of Sulfur that Becomes Non-Seasalt Sulfate (NSS)

Science.gov (United States)

Huebert, B. J.; Simpson, R. M.; Howell, S. G.

2012-12-01

As a part of the Pacific Atmospheric Sulfur Experiment (PASE), we measured sulfur gases and aerosol chemistry (vs size) from the NCAR C-130 near Christmas Island. Monthly (project) average concentrations in the Marine Boundary Layer (MBL, the lowest mixed layer) and Buffer Layer (BuL, a more stable layer atop the MBL, with clouds) are used to evaluate the formation, loss, and exchange rates for DMS, SO2, and NSS in each layer. We evaluate entrainment, divergence, vertical mixing, chemical formation and loss for each to make a self-consistent budget of oxidized sulfur in the remote marine atmosphere. We find that long-range transport of sulfur from continental sources can be larger than the sulfur source from biogenic dimethyl sulfide, DMS. DMS does not appear to control either the number of NSS particles or NSS mass.

A Universal Strategy To Prepare Sulfur-Containing Polymer Composites with Desired Morphologies for Lithium-Sulfur Batteries.

Science.gov (United States)

Zeng, Shao-Zhong; Zeng, Xierong; Tu, Wenxuan; Huang, Haitao; Yu, Liang; Yao, Yuechao; Jin, Nengzhi; Zhang, Qi; Zou, Jizhao

2018-06-19

Lithium-sulfur (Li-S) batteries are probably the most promising candidates for the next-generation batteries owing to their high energy density. However, Li-S batteries face severe technical problems where the dissolution of intermediate polysulfides is the biggest problem because it leads to the degradation of the cathode and the lithium anode, and finally the fast capacity decay. Compared with the composites of elemental sulfur and other matrices, sulfur-containing polymers (SCPs) have strong chemical bonds to sulfur and therefore show low dissolution of polysulfides. Unfortunately, most SCPs have very low electron conductivity and their morphologies can hardly be controlled, which undoubtedly depress the battery performances of SCPs. To overcome these two weaknesses of SCPs, a new strategy was developed for preparing SCP composites with enhanced conductivity and desired morphologies. With this strategy, macroporous SCP composites were successfully prepared from hierarchical porous carbon. The composites displayed discharge/charge capacities up to 1218/1139, 949/922, and 796/785 mA h g -1 at the current rates of 5, 10, and 15 C, respectively. Considering the universality of this strategy and the numerous morphologies of carbon materials, this strategy opens many opportunities for making carbon/SCP composites with novel morphologies.

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

International Nuclear Information System (INIS)

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

2016-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-08-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-11-09

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

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

Directory of Open Access Journals (Sweden)

Sheng S. Zhang

2013-12-01

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

Idiosyncrasies of volcanic sulfur viscosity and the triggering of unheralded volcanic eruptions

Directory of Open Access Journals (Sweden)

Teresa eScolamacchia

2016-03-01

Full Text Available Unheralded blue-sky eruptions from dormant volcanoes cause serious fatalities, such as at Mt. Ontake (Japan on 27 September 2014. Could these events result from magmatic gas being trapped within hydrothermal system aquifers by elemental sulfur (Se clogging pores, due to sharp increases in its viscosity when heated above 159oC? This mechanism was thought to prime unheralded eruptions at Mt. Ruapehu in New Zealand. Impurities in sulfur (As, Te, Se are known to modify S-viscosity and industry experiments showed that organic compounds, H2S, and halogens dramatically influence Se viscosity under typical hydrothermal heating/cooling rates and temperature thresholds. However, the effects of complex sulfur compositions are currently ignored at volcanoes, despite its near ubiquity in long-lived volcano-hydrothermal systems. Models of impure S behavior must be urgently formulated to detect pre-eruptive warning signs before the next blue-sky eruption

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

International Nuclear Information System (INIS)

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

2012-01-01

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

Sulfur nanocrystals anchored graphene composite with highly improved electrochemical performance for lithium-sulfur batteries

Science.gov (United States)

Zhang, Jun; Dong, Zimin; Wang, Xiuli; Zhao, Xuyang; Tu, Jiangping; Su, Qingmei; Du, Gaohui

2014-12-01

Two kinds of graphene-sulfur composites with 50 wt% of sulfur are prepared using hydrothermal method and thermal mixing, respectively. Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray Spectra mapping show that sulfur nanocrystals with size of ∼5 nm dispersed on graphene sheets homogeneously for the sample prepared by hydrothermal method (NanoS@G). While for the thermal mixed graphene-sulfur composite (S-G mixture), sulfur shows larger and uneven size (50-200 nm). X-ray Photoelectron Spectra (XPS) reveals the strong chemical bonding between the sulfur nanocrystals and graphene. Comparing with the S-G mixture, the NanoS@G composite shows highly improved electrochemical performance as cathode for lithium-sulfur (Li-S) battery. The NanoS@G composite delivers an initial capacity of 1400 mAh g-1 with the sulfur utilization of 83.7% at a current density of 335 mA g-1. The capacity keeps above 720 mAh g-1 over 100 cycles. The strong adherence of the sulfur nanocrystals on graphene immobilizes sulfur and polysulfides species and suppressed the "shuttle effect", resulting higher coulombic efficiency and better capacity retention. Electrochemical impedance also suggests that the strong bonding enabled rapid electronic/ionic transport and improved electrochemical kinetics, therefore good rate capability is obtained. These results demonstrate that the NanoS@G composite is a very promising candidate for high-performance Li-S batteries.

Coal fired flue gas mercury emission controls

International Nuclear Information System (INIS)

Wu, Jiang; Pan, Weiguo; Cao, Yan; Pan, Weiping

2015-01-01

Mercury (Hg) is one of the most toxic heavy metals, harmful to both the environment and human health. Hg is released into the atmosphere from natural and anthropogenic sources and its emission control has caused much concern. This book introduces readers to Hg pollution from natural and anthropogenic sources and systematically describes coal-fired flue gas mercury emission control in industry, especially from coal-fired power stations. Mercury emission control theory and experimental research are demonstrated, including how elemental mercury is oxidized into oxidized mercury and the effect of flue gas contents on the mercury speciation transformation process. Mercury emission control methods, such as existing APCDs (air pollution control devices) at power stations, sorbent injection, additives in coal combustion and photo-catalytic methods are introduced in detail. Lab-scale, pilot-scale and full-scale experimental studies of sorbent injection conducted by the authors are presented systematically, helping researchers and engineers to understand how this approach reduces the mercury emissions in flue gas and to apply the methods in mercury emission control at coal-fired power stations.

Coal fired flue gas mercury emission controls

Energy Technology Data Exchange (ETDEWEB)

Wu, Jiang; Pan, Weiguo [Shanghai Univ. of Electric Power (China); Cao, Yan; Pan, Weiping [Western Kentucky Univ., Bowling Green, KY (United States)

2015-05-01

Mercury (Hg) is one of the most toxic heavy metals, harmful to both the environment and human health. Hg is released into the atmosphere from natural and anthropogenic sources and its emission control has caused much concern. This book introduces readers to Hg pollution from natural and anthropogenic sources and systematically describes coal-fired flue gas mercury emission control in industry, especially from coal-fired power stations. Mercury emission control theory and experimental research are demonstrated, including how elemental mercury is oxidized into oxidized mercury and the effect of flue gas contents on the mercury speciation transformation process. Mercury emission control methods, such as existing APCDs (air pollution control devices) at power stations, sorbent injection, additives in coal combustion and photo-catalytic methods are introduced in detail. Lab-scale, pilot-scale and full-scale experimental studies of sorbent injection conducted by the authors are presented systematically, helping researchers and engineers to understand how this approach reduces the mercury emissions in flue gas and to apply the methods in mercury emission control at coal-fired power stations.

Irradiation technologies used for combustion gases and diluted sulfurous gases decontamination

International Nuclear Information System (INIS)

Villanueva Z, Loreto

1998-01-01

A brief description of irradiation technology used for ambient decontamination is presented here. The system is adequate fort gas and liquid effluents and solid wastes. In particular, the characteristics and applications of the irradiation done with an electron beam to gas effluent is described, mainly to clean combustion gases and other industrial gases containing sulfur and nitrogen oxides, S O x and N O x , respectively. This technology permits the remove of these contaminants and the acquisition of a solid byproduct, an ammonia sulfate-nitrate, apt for fertilizer applications. (author)

Feedforward Nonlinear Control Using Neural Gas Network

OpenAIRE

Machón-González, Iván; López-García, Hilario

2017-01-01

Nonlinear systems control is a main issue in control theory. Many developed applications suffer from a mathematical foundation not as general as the theory of linear systems. This paper proposes a control strategy of nonlinear systems with unknown dynamics by means of a set of local linear models obtained by a supervised neural gas network. The proposed approach takes advantage of the neural gas feature by which the algorithm yields a very robust clustering procedure. The direct model of the ...

Degradation of the blister agent sulfur mustard, bis(2-chloroethyl) sulfide, on concrete

International Nuclear Information System (INIS)

Brevett, Carol A.S.; Sumpter, Kenneth B.; Wagner, George W.; Rice, Jeffrey S.

2007-01-01

The products formed from the degradation of the blister agent sulfur mustard [bis(2-chloroethyl) sulfide] on concrete were identified using gas chromatography with mass spectrometry detection (GC/MSD), 1 H NMR, 2D 1 H- 13 C NMR and 13 C solid state magic angle spinning (SSMAS) NMR. In situ and extraction experiments were performed. Sulfur mustard was detected in the in situ 13 C SSMAS samples for 12 weeks, whereas less than 5% of the sulfur mustard was detected in extracts from the concrete monoliths after 8 days. Sulfonium ions and (2-chloroethylthio)ethyl ether (T) were observed on the in situ samples after a period of 12 weeks, whereas vinyl species and bis(2-chloroethyl) sulfoxide were observed in the extracts of the concrete monoliths within 24 h. The differences between the extraction and the SSMAS data indicated that the sulfur mustard existed in the concrete in a non-extractable form prior to its degradation. Extraction methods alone were not sufficient to identify the products; methods to identify the presence of non-extractable degradation products were also required

Gas-Jet Meniscus Control in Ribbon Growth

Science.gov (United States)

Zoutendyk, J. A.; Vonroos, O.

1983-01-01

Gas jet used to control shape of meniscus and thus to regulate ribbon thickness in vertical silicon-ribbon growth. Gas jet also cools ribbon, increasing maximum possible pull speed for silicon, contact angle of 11 degrees plus or minus 1 degree required for constant thickness ribbon growth. Cooling effect of gas jet increases maximum possible pull speed.

SYNTHESIS OF SULFUR-BASED WATER TREATMENT AGENT FROM SULFUR DIOXIDE WASTE STREAMS

Energy Technology Data Exchange (ETDEWEB)

Robert C. Brown; Maohong Fan; Adrienne Cooper

2002-10-01

Absorption of sulfur dioxide from a simulated flue gas was investigated for the production of polymeric ferric sulfate (PFS), a highly effective coagulant useful in treatment of drinking water and wastewater. The reaction for PFS synthesis took place near atmospheric pressure and at temperatures of 30-80 C. SO{sub 2} removal efficiencies greater than 90% were achieved, with ferrous iron concentrations in the product less than 0.1%. A factorial analysis of the effect of temperature, oxidant dosage, SO{sub 2} concentration, and gas flow rate on SO{sub 2} removal efficiency was carried out, and statistical analyses are conducted. The solid PFS was also characterized with different methods. Characterization results have shown that PFS possesses both crystalline and non-crystalline structure. The kinetics of reactions among FeSO{sub 4} {center_dot} 7H{sub 2}O, NaHSO{sub 3} and NaClO{sub 3} was investigated. The PFS product was used in pilot-scale tests at a municipal water treatment facility and gave good results in removal of turbidity and superior results in removal of disinfection byproduct precursors (TOC, DOC, UV-254) when compared with equal doses of ferric chloride.

A screening method for the isolation of polyhydroxyalkanoate-producing purple non-sulfur photosynthetic bacteria from natural seawater

Directory of Open Access Journals (Sweden)

Mieko Higuchi-Takeuchi

2016-09-01

Full Text Available Polyhydroxyalkanoates (PHAs are a family of biopolyesters accumulated by a variety of microorganisms as carbon and energy storage under starvation conditions. We focused on marine purple non-sulfur photosynthetic bacteria as host microorganisms for PHA production and developed a method for their isolation from natural seawater. To identify novel PHA-producing marine purple non-sulfur photosynthetic bacteria, natural seawaters were cultured in nutrient-rich medium for purple non-sulfur photosynthetic bacteria, and twelve pink- or red-pigmented colonies were picked up. Gas chromatography mass spectrometry analysis revealed that four isolates synthesized PHA at levels ranging from 0.5 to 24.4 wt% of cell dry weight. The 16S ribosomal RNA sequence analysis revealed that one isolate (HM2 showed 100% identity to marine purple non-sulfur photosynthetic bacteria. In conclusion, we have demonstrated in this study that PHA-producing marine purple non-sulfur photosynthetic bacteria can be isolated from natural seawater under nutrient-rich conditions.

Sulfur driven nucleation mode formation in diesel exhaust under transient driving conditions.

Science.gov (United States)

Karjalainen, Panu; Rönkkö, Topi; Pirjola, Liisa; Heikkilä, Juha; Happonen, Matti; Arnold, Frank; Rothe, Dieter; Bielaczyc, Piotr; Keskinen, Jorma

2014-02-18

Sulfur driven diesel exhaust nucleation particle formation processes were studied in an aerosol laboratory, on engine dynamometers, and on the road. All test engines were equipped with a combination of a diesel oxidation catalyst (DOC) and a partial diesel particulate filter (pDPF). At steady operating conditions, the formation of semivolatile nucleation particles directly depended on SO2 conversion in the catalyst. The nucleation particle emission was most significant after a rapid increase in engine load and exhaust gas temperature. Results indicate that the nucleation particle formation at transient driving conditions does not require compounds such as hydrocarbons or sulfated hydrocarbons, however, it cannot be explained only by the nucleation of sulfuric acid. A real-world exhaust study with a heavy duty diesel truck showed that the nucleation particle formation occurs even with ultralow sulfur diesel fuel, even at downhill driving conditions, and that nucleation particles can contribute 60% of total particle number emissions. In general, due to sulfur storage and release within the exhaust aftertreatment systems and transients in driving, emissions of nucleation particles can even be the dominant part of modern diesel vehicle exhaust particulate number emissions.

Anthropogenic emissions of oxidized sulfur and nitrogen into the atmosphere of the former Soviet Union in 1985 and 1990

Energy Technology Data Exchange (ETDEWEB)

Ryaboshapko, A.G.; Brukhanov, P.A.; Gromov, S.A.; Proshina, Yu.V; Afinogenova, O.G. [Institute of Global Climate and Ecology, Moscow (Russian Federation)

1996-09-01

Anthropogenic emissions of oxidized sulfur and nitrogen over the former Soviet Union for 1985 and 1990 were calculated on the basis of a combination of `bottom-up` and `top-down` approaches. Sulfur dioxide emissions from combustion of hard coal, brown coal, oil products, natural gas, shale oil, peat, wood as well as from metallurgy, sulfuric acid production, and cement production were estimated. Nitrogen oxides emissions were considered separately for large power plants, small power plants, industrial boilers, residential combustion units, and for transport. The sulfur and nitrogen emissions were spatially distributed over the former Soviet Union with 1 x 1 degree resolution. Data on 721 point sources of sulfur dioxide emissions and on the 242 largest power stations as nitrogen oxides sources were used. The area sources of both sulfur dioxide and nitrogen oxides were distributed according to the population density separately for about 150 administrative units of the former Soviet Union. 63 refs., 19 tabs.

Gas solubilities widespread applications

CERN Document Server

Gerrard, William

1980-01-01

Gas Solubilities: Widespread Applications discusses several topics concerning the various applications of gas solubilities. The first chapter of the book reviews Henr's law, while the second chapter covers the effect of temperature on gas solubility. The third chapter discusses the various gases used by Horiuti, and the following chapters evaluate the data on sulfur dioxide, chlorine data, and solubility data for hydrogen sulfide. Chapter 7 concerns itself with solubility of radon, thoron, and actinon. Chapter 8 tackles the solubilities of diborane and the gaseous hydrides of groups IV, V, and

Lime sulfur toxicity to broad mite, to its host plants and to natural enemies.

Science.gov (United States)

Venzon, Madelaine; Oliveira, Rafael M; Perez, André L; Rodríguez-Cruz, Fredy A; Martins Filho, Sebastião

2013-06-01

An acaricidal effect of lime sulfur has not been demonstrated for Polyphagotarsonemus latus. However, lime sulfur can cause toxicity to natural enemies and to host plants. In this study, the toxicity of different concentrations of lime sulfur to P. latus, to the predatory mite Amblyseius herbicolus and to the predatory insect Chrysoperla externa was evaluated. Additionally, the phytotoxicity of lime sulfur to two P. latus hosts, chili pepper and physic nut plants, was determined. Lime sulfur at a concentration of 9.5 mL L(-1) restrained P. latus population growth. However, this concentration was deleterious to natural enemies. The predatory mite A. herbicolus showed a negative value of instantaneous growth rate, and only 50% of the tested larvae of C. externa reached adulthood when exposed to 10 mL L(-1) . Physic nut had severe injury symptoms when sprayed with all tested lime sulfur concentrations. For chili pepper plants, no phytoxicity was observed at any tested concentration. Lime sulfur might be used for P. latus control on chili pepper but not on physic nut owing to phytotoxicity. Care should be taken when using lime sulfur in view of negative effects on natural enemies. Selective lime sulfur concentration integrated with other management tactics may provide an effective and sustainable P. latus control on chili pepper. © 2012 Society of Chemical Industry.

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

International Nuclear Information System (INIS)

Jung, Yong Hun

2010-02-01

Humanity has been facing major energy challenges such as the severe climate change, threat of energy security and global energy shortage especially for the developing world. Particularly, growing awareness of the global warming has led to efforts to develop the sustainable energy technologies for the harmony of the economy, social welfare and environment. Water-splitting nuclear hydrogen production is expected to help to resolve those challenges, when high energy efficiency and low cost for hydrogen production become possible. Once-through Hybrid Sulfur process (Ot-HyS), proposed in this work, produces hydrogen using the same SO 2 Depolarized water Electrolysis (SDE) process found in the original Hybrid Sulfur cycle (HyS) proposed by Westinghouse, which has the sulfuric acid decomposition (SAD) process using high temperature heat source in order to recover sulfur dioxide for the SDE process. But Ot-HyS eliminated this technical hurdle by replacing it with well-established sulfur combustion process to feed sulfur dioxide to the SDE process. Because Ot-HyS has less technical challenges, Ot-HyS is expected to advance the realization of the large-scale nuclear hydrogen production by feeding an initial nuclear hydrogen stock. Most of the elemental sulfur, at present, is supplied by desulfurization process for environmental reasons during the processing of natural gas and petroleum refining and expected to increase significantly. This recovered sulfur will be burned with oxygen in the sulfur combustion process so that produced sulfur dioxide could be supplied to the SDE process to produce hydrogen. Because the sulfur combustion is a highly exothermic reaction releasing 297 kJ/mol of combustion heat resulting in a large temperature rise, efficiency of the Ot-HyS is expected to be high by recovering this great amount of high grade excess heat with nuclear energy. Sulfuric acid, which is a byproduct of the SDE process, could be sent to the neighboring consumers with or even

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

International Nuclear Information System (INIS)

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

2014-01-01

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

Conductive framework of inverse opal structure for sulfur cathode in lithium-sulfur batteries.

Science.gov (United States)

Jin, Lu; Huang, Xiaopeng; Zeng, Guobo; Wu, Hua; Morbidelli, Massimo

2016-09-07

As a promising cathode inheritor for lithium-ion batteries, the sulfur cathode exhibits very high theoretical volumetric capacity and energy density. In its practical applications, one has to solve the insulating properties of sulfur and the shuttle effect that deteriorates cycling stability. The state-of-the-art approaches are to confine sulfur in a conductive matrix. In this work, we utilize monodisperse polystyrene nanoparticles as sacrificial templates to build polypyrrole (PPy) framework of an inverse opal structure to accommodate (encapsulate) sulfur through a combined in situ polymerization and melting infiltration approach. In the design, the interconnected conductive PPy provides open channels for sulfur infiltration, improves electrical and ionic conductivity of the embedded sulfur, and reduces polysulfide dissolution in the electrolyte through physical and chemical adsorption. The flexibility of PPy and partial filling of the inverse opal structure endure possible expansion and deformation during long-term cycling. It is found that the long cycling stability of the cells using the prepared material as the cathode can be substantially improved. The result demonstrates the possibility of constructing a pure conductive polymer framework to accommodate insulate sulfur in ion battery applications.

The Influence of Fuel Sulfur on the Operation of Large Two-Stroke Marine Diesel Engines

DEFF Research Database (Denmark)

Cordtz, Rasmus Faurskov

The present work focusses on SO3/H2SO4 formation and sulfuric acid (H2SO4) condensation in a large low speed 2-stroke marine diesel engine. SO3 formation is treated theoretically from a formulated multizone engine model described in this work that includes a detailed and validated sulfur reaction...... mechanism. Model results show that for a large marine engine generally about 3 % - 6 % of the fuel sulfur converts to SO3 while the remainder leaves the engine as SO2 from which the SO3 is formed during the expansion stroke. SO3 formation scales with the cylinder pressure and inversely with the engine speed...... as also demonstrated by a number of SO3 experiments described in this work. The experiments are carried out with a heavy duty medium speed 4 stroke diesel engine operating on heavy fuel oil including ≈ 2 wt. % sulfur. SO3 was measured successfully in the exhaust gas with the PENTOL SO3 analyzer...

Overview of Gas Research Institute environmental research programs

International Nuclear Information System (INIS)

Evans, J.M.

1991-01-01

The Gas Research Institute (GRI) is a private not-for-profit membership organization of natural gas pipelines, distribution companies and natural gas producers. GRI's purpose is to plan, to manage and to develop financing for a gas-related research and development (R and D) program on behalf of its members and their customers. GRI does not do any research itself. GRI's R and D program is designed to provide advanced technologies for natural gas supply, transport, storage, distribution and end-use applications in all markets. In addition, basic research is conducted for GRI in these areas to build a foundation for future technology breakthroughs. Work in the Environment and Safety Research Department includes sections interested in: supply related research, air quality research, end use equipment safety research, gas operations safety research, and gas operations environmental research. The Natural Gas Supply Program has research ongoing in such areas as: restoration of pipeline right-of-ways; cleaning up town gas manufacturing sites; the development of methanogenic bacteria for soil and groundwater cleanup; development of biological fluidized carbon units for rapid destruction of carbonaceous compounds; research on liquid redox sulfur recovery for sulfur removal from natural gas; research on produced water and production wastes generated by the natural gas industry; environmental effects of coalbed methane production; and subsurface effects of natural gas operations. The western coalbed methane and ground water programs are described

Selective adsorption of refractory sulfur species on active carbons and carbon based CoMo catalyst.

Science.gov (United States)

Farag, Hamdy

2007-03-01

Adsorption technique could be a reliable alternative in removing to a certain remarkable extent the sulfur species from the feedstock of petroleum oil. The performance of various carbons on adsorption of model sulfur compounds in a simulated feed solution and the sulfur containing compounds in the real gas oil was evaluated. The adsorption experiments have been carried out in a batch scale at ambient temperature and under the atmospheric pressure. In general, the most refractory sulfur compounds in the hydrotreatment reactions were selectively removed and adsorbed. It was found that the adsorbents affinities to dibenzothiophene and 4,6-dimethyldibenzothiophene were much more favored and pronounced than the aromatic matrices like fluorene, 1-methylnaphthalene and 9-methylanthracene. Among the sulfur species, 4,6-dimethyldibenzothiophene was the highest to be removed in terms of both selectivity and capacity over all the present adsorbents. The studied adsorbents showed significant capacities for the polyaromatic thiophenes. The electronic characteristics seem to play a certain role in such behavior. Regeneration of the used adsorbent was successfully attained either by washing it with toluene or by the release of the adsorbates through heat treatment. A suggested adsorptive removal process of sulfur compounds from petroleum distillate over carbon supported CoMo catalyst was discussed.

Status of the INERI sulfur-iodine integrated-loop experiment

International Nuclear Information System (INIS)

Pickard, P.; Carles, Ph.; Buckingham, R.; Russ, B.; Besenbruch, G.

2007-01-01

The Sulfur-Iodine (S-I) thermochemical water-splitting cycle has been studied as a potential source of hydrogen on a large scale. Coupled to a nuclear reactor, an S-I hydrogen plant could efficiently produce hydrogen without greenhouse gas emissions. In the S-I cycle, iodine and sulfur dioxide are combined with water to create two immiscible acid phases - a light sulfuric acid phase, and a heavy hydriodic acid phase. The sulfuric acid phase is decomposed at temperatures near 850 C degrees, and the resulting sulfur dioxide is recycled back into the process. The hydriodic acid in the lower phase is separated from excess water and iodine, and is then decomposed into the product hydrogen and iodine. The water and iodine from these steps are also recycled. In an International Nuclear Energy Research Initiative (INERI) project supported by the US DOE Office of Nuclear Energy, Sandia National Labs (SNL) has teamed with Cea in France, and industrial partner General Atomics (GA) to construct and operate a closed-loop device for demonstration of hydrogen production by the S-I process. Previous work in Japan has demonstrated continuous closed-loop operation of the S-I cycle for up to one week using glass components at atmospheric pressure. This work will aim for operation under process conditions expected at the pilot plant-level and beyond pressures up to 20 bar using engineering materials of construction. Staff at Cea is responsible for the acid-generation step, known as the Bunsen reaction. SNL is handling the sulfuric acid decomposition step, and GA is providing equipment for decomposing hydriodic acid into the product hydrogen. All parties are assembling equipment at the GA site in San Diego, California. Operation of the closed-loop device is expected to commence in the second half of calendar year 2007. This paper will summarize project goals, work done to date, current status, and scheduled future work on the INERI S-I Integrated-Loop Experiment. (authors)

Sulfur poisoning in cattle

Energy Technology Data Exchange (ETDEWEB)

Julian, R J; Harrison, K B

1975-01-01

A case of sulfur poisoning is described in which 12 of 20 cattle died following the feeding of sulfur. Respiratory distress and abdominal pain were the prominent signs. Examination of one animal revealed vasculitis and necrosis of the rumen and abomasal wall. The possible toxic effects of sulfur are discussed.

NIM gas controlled sodium heat pipe

Science.gov (United States)

Yan, X.; Zhang, J. T.; Merlone, A.; Duan, Y.; Wang, W.

2013-09-01

Gas controlled heat pipes (GCHPs) provide a uniform, stable and reproducible temperature zone to calibrate thermometers and thermocouples, and to realize defining fixed points using a calorimetric method. Therefore, to perform such investigations, a GCHP furnace using sodium as its working fluid was constructed at the National Institute of Metrology (NIM), China. Also, investigations into the thermal characteristics of the NIM gas controlled sodium heat pipe were carried out. The temperature stability over 5 hours was better than ±0.25 mK while controlling the pressure at 111250 Pa. The temperature uniformity within 14 cm from the bottom of the thermometer well was within 0.3 mK. While keeping the pressure stable at the same value, 17 temperature determinations were performed over 14 days, obtaining a temperature reproducibility of 1.27 mK. Additionally, the NIM gas controlled sodium heat pipe was compared with the sodium heat pipe produced by INRiM. The temperature in the INRiM sodium heat pipe operating at 111250 Pa was determined, obtaining a difference of 21 mK with respect to the NIM GCHP. This difference was attributed to sodium impurities, pressure controller capabilities and reproducibility, and instabilities of high temperature standard platinum resistance thermometers (HTSPRTs). Further investigations will be carried out on extending the pressure/temperature range and connecting both GCHPs to the same pressure line.

Sulfur Earth

Science.gov (United States)

de Jong, B. H.

2007-12-01

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

The Clean Coal Technology Program 100 MWe demonstration of gas suspension absorption for flue gas desulfurization

Energy Technology Data Exchange (ETDEWEB)

Hsu, F.E.; Hedenhag, J.G. [AirPol Inc., Teterboro, NJ (United States); Marchant, S.K.; Pukanic, G.W. [Dept. of Energy, Pittsburgh, PA (United States). Pittsburgh Energy Technology Center; Norwood, V.M.; Burnett, T.A. [Tennessee Valley Authority, Chattanooga, TN (United States)

1997-12-31

AirPol Inc., with the cooperation of the Tennessee Valley Authority (TVA) under a Cooperative Agreement with the United States Department of Energy, installed and tested a 10 MWe Gas Suspension Absorption (GSA) Demonstration system at TVA`s Shawnee Fossil Plant near Paducah, Kentucky. This low-cost retrofit project demonstrated that the GSA system can remove more than 90% of the sulfur dioxide from high-sulfur coal-fired flue gas, while achieving a relatively high utilization of reagent lime. This paper presents a detailed technical description of the Clean Coal Technology demonstration project. Test results and data analysis from the preliminary testing, factorial tests, air toxics texts, 28-day continuous demonstration run of GSA/electrostatic precipitator (ESP), and 14-day continuous demonstration run of GSA/pulse jet baghouse (PJBH) are also discussed within this paper.

Etching radical controlled gas chopped deep reactive ion etching

Science.gov (United States)

Olynick, Deidre; Rangelow, Ivo; Chao, Weilun

2013-10-01

A method for silicon micromachining techniques based on high aspect ratio reactive ion etching with gas chopping has been developed capable of producing essentially scallop-free, smooth, sidewall surfaces. The method uses precisely controlled, alternated (or chopped) gas flow of the etching and deposition gas precursors to produce a controllable sidewall passivation capable of high anisotropy. The dynamic control of sidewall passivation is achieved by carefully controlling fluorine radical presence with moderator gasses, such as CH.sub.4 and controlling the passivation rate and stoichiometry using a CF.sub.2 source. In this manner, sidewall polymer deposition thicknesses are very well controlled, reducing sidewall ripples to very small levels. By combining inductively coupled plasmas with controlled fluorocarbon chemistry, good control of vertical structures with very low sidewall roughness may be produced. Results show silicon features with an aspect ratio of 20:1 for 10 nm features with applicability to nano-applications in the sub-50 nm regime. By comparison, previous traditional gas chopping techniques have produced rippled or scalloped sidewalls in a range of 50 to 100 nm roughness.

Method of removing oxides of sulfur and oxides of nitrogen from exhaust gases

Science.gov (United States)

Walker, Richard J.

1986-01-01

A continuous method is presented for removing both oxides of sulfur and oxides of nitrogen from combustion or exhaust gases with the regeneration of the absorbent. Exhaust gas is cleaned of particulates and HCl by a water scrub prior to contact with a liquid absorbent that includes an aqueous solution of bisulfite and sulfite ions along with a metal chelate, such as, an iron or zinc aminopolycarboxylic acid. Following contact with the combustion gases the spent absorbent is subjected to electrodialysis to transfer bisulfite ions into a sulfuric acid solution while splitting water with hydroxide and hydrogen ion migration to equalize electrical charge. The electrodialysis stack includes alternate layers of anion selective and bipolar membranes. Oxides of nitrogen are removed from the liquid absorbent by air stripping at an elevated temperature and the regenerated liquid absorbent is returned to contact with exhaust gases for removal of sulfur oxides and nitrogen oxides.

Sulfur problems in Swedish agriculture

Energy Technology Data Exchange (ETDEWEB)

Johansson, O

1959-01-01

The present paper deals with some aspects of the sulfur situation in Swedish agriculture with special emphasis on the importance of and relationships among various sources of sulfur supply. An inventory of the sulfur content of Swedish soils and hay crops includes 649 soil samples and a corresponding number of hay samples from 59 locations. In a special investigation the samples were found to be representative of normal Swedish farm land. It is concluded that the amount of sulfur compounds in the air is the primary factor which determines the amount of sulfur added to the soil from the atmosphere. Compared with values obtained in other countries, the amount of sulfur added by the precipitation in Sweden is very low. The distribution in air and precipitation of sulfur from an industrial source was studied in a special investigation. An initial reason for the present study was the damage to vegetation caused by smoke from an industrial source. It was concluded that the average conditions in the vicinity of the industrial source with respect to smoke constituents in the air and precipitation were unfavorable only to the plants directly within a very narrow region. Relationships among the sulfur contents of air, of precipitation, of soils and of plants have been subject to special investigations. In the final general discussion and conclusions it is pointed out that the results from these investigations indicate evident differences in the sulfur status of Swedish soils. The present trend toward the use of more highly concentrated fertilizers poor in sulfur may be expected to cause a considerable change in the sulfur situation in Swedish agriculture. 167 references, 40 figures, 44 tables.

Opportunities in the United States' gas processing industry

International Nuclear Information System (INIS)

Meyer, H.S.; Leppin, D.

1997-01-01

To keep up with the increasing amount of natural gas that will be required by the market and with the decreasing quality of the gas at the well-head, the gas processing industry must look to new technologies to stay competitive. The Gas Research Institute (GR); is managing a research, development, design and deployment program that is projected to save the industry US dollar 230 million/year in operating and capital costs from gas processing related activities in NGL extraction and recovery, dehydration, acid gas removal/sulfur recovery, and nitrogen rejection. Three technologies are addressed here. Multivariable Control (MVC) technology for predictive process control and optimization is installed or in design at fourteen facilities treating a combined total of over 30x10 9 normal cubic meter per year (BN m 3 /y) [1.1x10 12 standard cubic feet per year (Tcf/y)]. Simple pay backs are typically under 6 months. A new acid gas removal process based on n-formyl morpholine (NFM) is being field tested that offers 40-50% savings in operating costs and 15-30% savings in capital costs relative to a commercially available physical solvent. The GRI-MemCalc TM Computer Program for Membrane Separations and the GRI-Scavenger CalcBase TM Computer Program for Scavenging Technologies are screening tools that engineers can use to determine the best practice for treating their gas. (au) 19 refs

EFFECT OF SOLE AND ASSOCIATIVE ACTIONS OF ELEMENTAL SULFUR AND INOCULATION SULFUR OXIDIZING BACTERIA ON GROWTH AND NUTRIENTS CONTENTS OF PEPPER PLANTS AND THE USED SOILS

Directory of Open Access Journals (Sweden)

S. A. Ibrahim

2011-12-01

Full Text Available A pot experiment was conducted to study the effect of elemental sulfur (E.S rate (2.5 g/kg soil and sulfur oxidizing bacteria on pepper plant and some chemical properties of two representative soil samples varying in their texture and CaCO3 content. Pepper was grown in Shobrakheet clay loam and Nobaria sandy loam soils for 50 days. Each soil was treated with elemental sulfur (2.5 g kg-1 soil and inoculated with two sulfur oxidizing bacteria (S.O.B. No.8 and S.O.B. ATCC 8158. Elemental sulfur with or without sulfur oxidizing bacteria increased shoot dry weights of pepper plants as compared with control. The highest effect was observed with E.S + ATCC 8158 treatment which resulted in increasing the pepper shoot dry weights from 1.36 to 2.08 g pot-1 with the clay loam soil and from 0.77 to 1.37 g pot-1 with the sandy loam soil. The same treatment resulted in the highest plant content of S, N, P, K and micronutrients.

A batch assay to measure microbial hydrogen sulfide production from sulfur-containing solid wastes

Energy Technology Data Exchange (ETDEWEB)

Sun, Mei, E-mail: msun8@uncc.edu [Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Campus Box 7908, Raleigh, NC (United States); Sun, Wenjie, E-mail: wsun@smu.edu [Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Campus Box 7908, Raleigh, NC (United States); Department of Civil and Environmental Engineering, Southern Methodist University, PO Box 750340, Dallas, TX (United States); Barlaz, Morton A., E-mail: barlaz@ncsu.edu [Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Campus Box 7908, Raleigh, NC (United States)

2016-05-01

Large volumes of sulfur-containing wastes enter municipal solid waste landfills each year. Under the anaerobic conditions that prevail in landfills, oxidized forms of sulfur, primarily sulfate, are converted to sulfide. Hydrogen sulfide (H{sub 2}S) is corrosive to landfill gas collection and treatment systems, and its presence in landfill gas often necessitates the installation of expensive removal systems. For landfill operators to understand the cost of managing sulfur-containing wastes, an estimate of the H{sub 2}S production potential is needed. The objective of this study was to develop and demonstrate a biochemical sulfide potential (BSP) test to measure the amount of H{sub 2}S produced by different types of sulfur-containing wastes in a relatively fast (30 days) and inexpensive (125 mL serum bottles) batch assay. This study confirmed the toxic effect of H{sub 2}S on both sulfate reduction and methane production in batch systems, and demonstrated that removing accumulated H{sub 2}S by base adsorption was effective for mitigating inhibition. H{sub 2}S production potentials of coal combustion fly ash, flue gas desulfurization residual, municipal solid waste combustion ash, and construction and demolition waste were determined in BSP assays. After 30 days of incubation, most of the sulfate in the wastes was converted to gaseous or aqueous phase sulfide, with BSPs ranging from 0.8 to 58.8 mL H{sub 2}S/g waste, depending on the chemical composition of the samples. Selected samples contained solid phase sulfide which contributed to the measured H{sub 2}S yield. A 60 day incubation in selected samples resulted in 39–86% additional sulfide production. H{sub 2}S production measured in BSP assays was compared with that measured in simulated landfill reactors and that calculated from chemical analyses. H{sub 2}S production in BSP assays and in reactors was lower than the stoichiometric values calculated from chemical composition for all wastes tested, demonstrating

Biogenic sulfur compounds and the global sulfur cycle

International Nuclear Information System (INIS)

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

1982-01-01

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

Synergistic interaction and controllable active sites of nitrogen and sulfur co-doping into mesoporous carbon sphere for high performance oxygen reduction electrocatalysts

Science.gov (United States)

Oh, Taeseob; Kim, Myeongjin; Park, Dabin; Kim, Jooheon

2018-05-01

Nitrogen and sulfur co-doped mesoporous carbon sphere (NSMCS) was prepared as a metal-free catalyst by an economical and facile pyrolysis process. The mesoporous carbon spheres were derived from sodium carboxymethyl cellulose as the carbon source and the nitrogen and sulfur dopants were derived from urea and p-benzenedithiol, respectively. The doping level and chemical states of nitrogen and sulfur in the prepared NSMCS can be easily adjusted by controlling the pyrolysis temperature. The NSMCS pyrolyzed at 900 °C (NSMCS-900) exhibited higher oxygen reduction reaction activity than the mesoporous carbon sphere doped solely with nitrogen or sulfur, due to the synergistic effect of co-doping. Among all the NSMCS samples, NSMCS-900 exhibited excellent ORR catalytic activity owing to the presence of a highly active site, consisting of pyridinic N, graphitic N, and thiophene S. Remarkably, the NSMCS-900 catalyst was comparable with commercial Pt/C, in terms of the onset and the half-wave potentials and showed better durability than Pt/C for ORR in an alkaline electrolyte. The approach demonstrated in this work could be used to prepare promising metal-free electrocatalysts for application in energy conversion and storage.

Effluents of toxic and corrosion-active components at coke-oven gas combustion

International Nuclear Information System (INIS)

Mikhajlov, G.S.; Afanas'ev, Yu.O.; Plotnikov, V.A.; Iskhakov, Kh.A.; Tikhov, S.D.; Gaus, A.I.; Nagibin, P.D.

1996-01-01

Various modes of coke-coal gas combustion are studied and dependence of concentration of nitrogen sulfur oxides and carbon monoxides originating in smoke gases on the air excess delivered to the combustion chamber is determined. The lowest summary releases of hazardous substances are achieved by the excess air coefficients α > 1.2 relative to modes of coke-coal gas combustion with smoke gases recirculation. The quantity of sulfur does not depend on the mode of fuel combustion and is determined by the total sulfur content in the fuel. To prevent the corrosion of low-temperature heat exchange surfaces it is necessary to heat up the feed-water up to the temperature exceeding the temperature of the coal gases dew point by 10-15 deg C. 10 refs

Modeling and Simulation of the Sulfur-Iodine Process Coupled to a Very High-Temperature Gas-Cooled Nuclear Reactor

Energy Technology Data Exchange (ETDEWEB)

Shin, Youngjoon; Lee, Taehoon; Lee, Kiyoung; Kim, Minhwan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-10-15

Hydrogen produced from water using nuclear energy will avoid both the use of fossil fuel and CO{sub 2} emission presumed to be the dominant reason for global warming. A thermo-chemical sulfur-iodine (SI) process coupled to a Very High Temperature Gas-Cooled Reactor(VHTR) is one of the most prospective hydrogen production methods that split water using nuclear energy because the SI process is suitable for large-scale hydrogen production without CO{sub 2} emission. The dynamic simulation code to evaluate the start-up behavior of the chemical reactors placed on the secondary helium loop of the SI process has been developed and partially verified using the steady state values obtained from the Aspen Plus{sup TM} Code simulation. As the start-up dynamic simulation results of the SI process coupled to the IHX, which is one of components in the VHTR system, it is expected that the integrated secondary helium loop of the SI process can be successfully and safely approach the steady state condition.

Ultra High Efficiency ESP for Fine Particulate and Air Toxics Control

International Nuclear Information System (INIS)

Srinivasachar, Srivats; Pease, Benjamin R.; Porle, Kjell; Mauritzson, Christer; Haythornthwaite, Sheila

1997-01-01

Nearly ninety percent of U.S. coal-fired utility boilers are equipped with electrostatic precipitators (ESP). Cost effective retrofittable ESP technologies are the only means to accomplish Department of Energy's (DOE) goal of a major reduction in fine particulate and air toxic emissions from coal-fired power plants. Particles in the size range of 0.1 to 5 (micro)m typically escape ESPs. Metals, such as arsenic, cadmium, lead, molybdenum and antimony, concentrate on these particles. This is the main driver for improved fine particulate control. Vapor phase emissions of mercury, selenium and arsenic are also of major concern. Current dry ESPs, which operate at temperatures greater than 280 F, provide little control for vapor phase toxics. The need for inherent improvement to ESPs has to be considered keeping in perspective the current trend towards the use of low sulfur coals. Switching to low sulfur coals is the dominant approach for SO 2 emission reduction in the utility industry. Low sulfur coals generate high resistivity ash, which can cause an undesirable phenomenon called ''back corona.'' Higher particulate emissions occur if there is back corona in the ESP. Results of the pilot-scale testing identified the ''low temperature ESP'' concept to have the biggest impact for the two low sulfur coals investigated. Lowering the flue gas temperature to 220 F provided the maximum impact in terms of decreased emissions. Intermediate operating temperatures (reduction from 340 to 270 F) also gave significant ESP performance improvement. A significant reduction in particulate emissions was also noted when the flue gas humidity was increased (temperature held constant) from the baseline condition for these moderately high resistivity ash coals. Independent control of flue gas humidity and temperature was an important and a notable element in this project. Mercury emissions were also measured as a function of flue gas temperature. Mercury emissions decreased as the flue gas

SELECTED YIELD COMPONENTS IN WHITE MUSTARD (SINAPIS ALBA VERSUS SULFUR FERTILIZATION

Directory of Open Access Journals (Sweden)

Bożena BARCZAK

2011-10-01

Full Text Available As shown by the research made based on the four-year field experiment, sulfur fertilization, in general, significantly differentiated the white mustard yield components. Of all the factors (sulfur application method, its form and dose, the greatest effect on the yield structure components was demonstrated for the sulfur dose. The use of 40 kg S·ha-1, regardless of the form applied and the sulfur application method, resulted in significant increases in most of the characters, as compared with the control. The application of sulfur into soil showed a significantly more favorable effect on the seed weigh and number per silique and on the weight of seeds of the entire plant than the foliar application of this nutrient. The white mustard seed yield size was most correlated with the number of siliques per plant, and successively less with the thousand seed weight.

Gas box control system for Tandem Mirror Experiment-Upgrade

International Nuclear Information System (INIS)

Bell, H.H. Jr.; Hunt, A.L.; Clower, C.A. Jr.

1983-01-01

The Tandem Mirror Experiment-Upgrade (TMX-U) uses several methods to feed gas (usually deuterium) at different energies into the plasma region of the machine. One is an arrangement of eight high-speed piezo-electric valves mounted on special manifolds (gas box) that feed cold gas directly to the plasma. This paper describes the electronic valve control and data acquisition portions of the gas box, which are controlled by a desk-top computer. Various flow profiles have been developed and stored in the control computer for ready access by the operator. The system uses two modes of operation, one that exercises and characterizes the valves and one that operates the valves with the rest of the experiment. Both the valve control signals and the pressure transducers data are recorded on the diagnostics computer so that they are available for experiment analysis

Steep spatial gradients of volcanic and marine sulfur in Hawaiian rainfall and ecosystems

Energy Technology Data Exchange (ETDEWEB)

Bern, Carleton R., E-mail: cbern@usgs.gov [U.S. Geological Survey, Denver Federal Center, Denver, CO 80225 (United States); Department of Geography University of California, Santa Barbara, CA 93106-4060 (United States); Chadwick, Oliver A. [Department of Geography University of California, Santa Barbara, CA 93106-4060 (United States); Kendall, Carol [U.S. Geological Survey, Menlo Park, CA (United States); Pribil, Michael J. [U.S. Geological Survey, Denver Federal Center, Denver, CO 80225 (United States)

2015-05-01

Sulfur, a nutrient required by terrestrial ecosystems, is likely to be regulated by atmospheric processes in well-drained, upland settings because of its low concentration in most bedrock and generally poor retention by inorganic reactions within soils. Environmental controls on sulfur sources in unpolluted ecosystems have seldom been investigated in detail, even though the possibility of sulfur limiting primary production is much greater where atmospheric deposition of anthropogenic sulfur is low. Here we measure sulfur isotopic compositions of soils, vegetation and bulk atmospheric deposition from the Hawaiian Islands for the purpose of tracing sources of ecosystem sulfur. Hawaiian lava has a mantle-derived sulfur isotopic composition (δ{sup 34}S VCDT) of − 0.8‰. Bulk deposition on the island of Maui had a δ{sup 34}S VCDT that varied temporally, spanned a range from + 8.2 to + 19.7‰, and reflected isotopic mixing from three sources: sea-salt (+ 21.1‰), marine biogenic emissions (+ 15.6‰), and volcanic emissions from active vents on Kilauea Volcano (+ 0.8‰). A straightforward, weathering-driven transition in ecosystem sulfur sources could be interpreted in the shift from relatively low (0.0 to + 2.7‰) to relatively high (+ 17.8 to + 19.3‰) soil δ{sup 34}S values along a 0.3 to 4100 ka soil age-gradient, and similar patterns in associated vegetation. However, sub-kilometer scale spatial variation in soil sulfur isotopic composition was found along soil transects assumed by age and mass balance to be dominated by atmospheric sulfur inputs. Soil sulfur isotopic compositions ranged from + 8.1 to + 20.3‰ and generally decreased with increasing elevation (0–2000 m), distance from the coast (0–12 km), and annual rainfall (180–5000 mm). Such trends reflect the spatial variation in marine versus volcanic inputs from atmospheric deposition. Broadly, these results illustrate how the sources and magnitude of atmospheric deposition can exert controls

Steep spatial gradients of volcanic and marine sulfur in Hawaiian rainfall and ecosystems

International Nuclear Information System (INIS)

Bern, Carleton R.; Chadwick, Oliver A.; Kendall, Carol; Pribil, Michael J.

2015-01-01

Sulfur, a nutrient required by terrestrial ecosystems, is likely to be regulated by atmospheric processes in well-drained, upland settings because of its low concentration in most bedrock and generally poor retention by inorganic reactions within soils. Environmental controls on sulfur sources in unpolluted ecosystems have seldom been investigated in detail, even though the possibility of sulfur limiting primary production is much greater where atmospheric deposition of anthropogenic sulfur is low. Here we measure sulfur isotopic compositions of soils, vegetation and bulk atmospheric deposition from the Hawaiian Islands for the purpose of tracing sources of ecosystem sulfur. Hawaiian lava has a mantle-derived sulfur isotopic composition (δ 34 S VCDT) of − 0.8‰. Bulk deposition on the island of Maui had a δ 34 S VCDT that varied temporally, spanned a range from + 8.2 to + 19.7‰, and reflected isotopic mixing from three sources: sea-salt (+ 21.1‰), marine biogenic emissions (+ 15.6‰), and volcanic emissions from active vents on Kilauea Volcano (+ 0.8‰). A straightforward, weathering-driven transition in ecosystem sulfur sources could be interpreted in the shift from relatively low (0.0 to + 2.7‰) to relatively high (+ 17.8 to + 19.3‰) soil δ 34 S values along a 0.3 to 4100 ka soil age-gradient, and similar patterns in associated vegetation. However, sub-kilometer scale spatial variation in soil sulfur isotopic composition was found along soil transects assumed by age and mass balance to be dominated by atmospheric sulfur inputs. Soil sulfur isotopic compositions ranged from + 8.1 to + 20.3‰ and generally decreased with increasing elevation (0–2000 m), distance from the coast (0–12 km), and annual rainfall (180–5000 mm). Such trends reflect the spatial variation in marine versus volcanic inputs from atmospheric deposition. Broadly, these results illustrate how the sources and magnitude of atmospheric deposition can exert controls over

Genomic and Evolutionary Perspectives on Sulfur Metabolism in Green Sulfur Bacteria

DEFF Research Database (Denmark)

Frigaard, Niels-Ulrik; Bryant, Donald A.

2008-01-01

Green sulfur bacteria (GSB) are anaerobic photoautotrophs that oxidize sulfide, elemental sulfur, thiosulfate, ferrous iron, and hydrogen for growth. We present here an analysis of the distribution and evolution of enzymes involved in oxidation of sulfur compounds in GSB based on genome sequence......, in combination with phylogenetic analyses, suggests that the Dsr system in GSB could be a recent acquisition, which was obtained by lateral gene transfer in part from sulfideoxidizing bacteria and in part from sulfate-reducing bacteria. All thiosulfate-utilizing GSB strains have an identical sox gene cluster...

Acidithiobacillus caldus sulfur oxidation model based on transcriptome analysis between the wild type and sulfur oxygenase reductase defective mutant.

Directory of Open Access Journals (Sweden)

Linxu Chen

Full Text Available Acidithiobacillus caldus (A. caldus is widely used in bio-leaching. It gains energy and electrons from oxidation of elemental sulfur and reduced inorganic sulfur compounds (RISCs for carbon dioxide fixation and growth. Genomic analyses suggest that its sulfur oxidation system involves a truncated sulfur oxidation (Sox system (omitting SoxCD, non-Sox sulfur oxidation system similar to the sulfur oxidation in A. ferrooxidans, and sulfur oxygenase reductase (SOR. The complexity of the sulfur oxidation system of A. caldus generates a big obstacle on the research of its sulfur oxidation mechanism. However, the development of genetic manipulation method for A. caldus in recent years provides powerful tools for constructing genetic mutants to study the sulfur oxidation system.An A. caldus mutant lacking the sulfur oxygenase reductase gene (sor was created and its growth abilities were measured in media using elemental sulfur (S(0 and tetrathionate (K(2S(4O(6 as the substrates, respectively. Then, comparative transcriptome analysis (microarrays and real-time quantitative PCR of the wild type and the Δsor mutant in S(0 and K(2S(4O(6 media were employed to detect the differentially expressed genes involved in sulfur oxidation. SOR was concluded to oxidize the cytoplasmic elemental sulfur, but could not couple the sulfur oxidation with the electron transfer chain or substrate-level phosphorylation. Other elemental sulfur oxidation pathways including sulfur diooxygenase (SDO and heterodisulfide reductase (HDR, the truncated Sox pathway, and the S(4I pathway for hydrolysis of tetrathionate and oxidation of thiosulfate in A. caldus are proposed according to expression patterns of sulfur oxidation genes and growth abilities of the wild type and the mutant in different substrates media.An integrated sulfur oxidation model with various sulfur oxidation pathways of A. caldus is proposed and the features of this model are summarized.

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

International Nuclear Information System (INIS)

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

2009-01-01

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

Combustible gas concentration control facility and operation method therefor

International Nuclear Information System (INIS)

Yoshikawa, Kazuhiro; Ando, Koji; Kinoshita, Shoichiro; Yamanari, Shozo; Moriya, Kimiaki; Karasawa, Hidetoshi

1998-01-01

The present invention provides a hydrogen gas-control facility by using a fuel battery-type combustible gas concentration reducing device as a countermeasure for controlling a hydrogen gas in a reactor container. Namely, a hydrogen electrode adsorb hydrogen by using an ion exchange membrane comprising hydrogen ions as a charge carrier. An air electrode adsorb oxygen in the air. A fuel battery converts recombining energy of hydrogen and oxygen to electric energy. Hydrogen in this case is supplied from an atmosphere in the container. Oxygen in this case is supplied from the air outside of the container. If hydrogen gas should be generated in the reactor, power generation of is performed by the fuel battery by using hydrogen gas, as a fuel, on the side of the hydrogen electrode of the fuel battery and using oxygen, as a fuel, in the air outside of the container on the side of the air electrode. Then, the hydrogen gas is consumed thereby controlling the hydrogen gas concentration in the container. Electric current generated in the fuel battery is used as an emergency power source for the countermeasure for a severe accident. (I.S.)

Combustible gas concentration control facility and operation method therefor

Energy Technology Data Exchange (ETDEWEB)

Yoshikawa, Kazuhiro; Ando, Koji; Kinoshita, Shoichiro; Yamanari, Shozo; Moriya, Kimiaki; Karasawa, Hidetoshi

1998-09-25

The present invention provides a hydrogen gas-control facility by using a fuel battery-type combustible gas concentration reducing device as a countermeasure for controlling a hydrogen gas in a reactor container. Namely, a hydrogen electrode adsorb hydrogen by using an ion exchange membrane comprising hydrogen ions as a charge carrier. An air electrode adsorb oxygen in the air. A fuel battery converts recombining energy of hydrogen and oxygen to electric energy. Hydrogen in this case is supplied from an atmosphere in the container. Oxygen in this case is supplied from the air outside of the container. If hydrogen gas should be generated in the reactor, power generation of is performed by the fuel battery by using hydrogen gas, as a fuel, on the side of the hydrogen electrode of the fuel battery and using oxygen, as a fuel, in the air outside of the container on the side of the air electrode. Then, the hydrogen gas is consumed thereby controlling the hydrogen gas concentration in the container. Electric current generated in the fuel battery is used as an emergency power source for the countermeasure for a severe accident. (I.S.)

75 FR 7426 - Tier 2 Light-Duty Vehicle and Light-Duty Truck Emission Standards and Gasoline Sulfur Control...

Science.gov (United States)

2010-02-19

... 2060-AI23; 2060-AQ12 Tier 2 Light-Duty Vehicle and Light-Duty Truck Emission Standards and Gasoline.... The rulemaking also required oil refiners to limit the sulfur content of the gasoline they produce. Sulfur in gasoline has a detrimental impact on catalyst performance and the sulfur requirements have...

Control and treatment of sulfur oxides emissions; Prevention et traitement des emissions d`oxydes de soufre

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-01

The conference on the control and treatment of sulfur oxides emissions has held in Le Havre the 4. and 5. december, 1997. The aim of this conference was to promote the information on the different treatment technologies and to contribute on the one hand to the supporting and revival of the environmental protection and on the other hand to the desulfurization programs. It has allowed to recall too the technical and financial support of the Ademe to the manufacturers. (O.M.)

Biomimetic Ant-Nest Electrode Structures for High Sulfur Ratio Lithium-Sulfur Batteries.

Science.gov (United States)

Ai, Guo; Dai, Yiling; Mao, Wenfeng; Zhao, Hui; Fu, Yanbao; Song, Xiangyun; En, Yunfei; Battaglia, Vincent S; Srinivasan, Venkat; Liu, Gao

2016-09-14

The lithium-sulfur (Li-S) rechargeable battery has the benefit of high gravimetric energy density and low cost. Significant research currently focuses on increasing the sulfur loading and sulfur/inactive-materials ratio, to improve life and capacity. Inspired by nature's ant-nest structure, this research results in a novel Li-S electrode that is designed to meet both goals. With only three simple manufacturing-friendly steps, which include slurry ball-milling, doctor-blade-based laminate casting, and the use of the sacrificial method with water to dissolve away table salt, the ant-nest design has been successfully recreated in an Li-S electrode. The efficient capabilities of the ant-nest structure are adopted to facilitate fast ion transportation, sustain polysulfide dissolution, and assist efficient precipitation. High cycling stability in the Li-S batteries, for practical applications, has been achieved with up to 3 mg·cm(-2) sulfur loading. Li-S electrodes with up to a 85% sulfur ratio have also been achieved for the efficient design of this novel ant-nest structure.

Emissions of biogenic sulfur gases from northern bogs and fens

Science.gov (United States)

Demello, William Zamboni; Hines, Mark E.; Bayley, Suzanne E.

1992-01-01

Sulfur gases are important components of the global cycle of S. They contribute to the acidity of precipitation and they influence global radiation balance and climate. The role of terrestrial sources of biogenic S and their effect on atmospheric chemistry remain as major unanswered questions in our understanding of the natural S cycle. The role of northern wetlands as sources and sinks of gaseous S by measuring rates of S gas exchange as a function of season, hydrologic conditions, and gradients in tropic status was investigated. Experiments were conducted in wetlands in New Hampshire, particularly a poor fen, and in Mire 239, a poor fen at the Experimental Lakes Area (ELA) in Ontario. Emissions were determined using Teflon enclosures, gas cryotrapping methods and gas chromatography (GC) with flame photometric detection. Dynamic (sweep flow) and static enclosures were employed which yielded similar results. Dissolved S gases and methane were determined by gas stripping followed by GC.

Capacity Fade Analysis of Sulfur Cathodes in Lithium–Sulfur Batteries

Science.gov (United States)

Yan, Jianhua; Liu, Xingbo

2016-01-01

Rechargeable lithium–sulfur (Li–S) batteries are receiving ever‐increasing attention due to their high theoretical energy density and inexpensive raw sulfur materials. However, their rapid capacity fade has been one of the key barriers for their further improvement. It is well accepted that the major degradation mechanisms of S‐cathodes include low electrical conductivity of S and sulfides, precipitation of nonconductive Li2S2 and Li2S, and poly‐shuttle effects. To determine these degradation factors, a comprehensive study of sulfur cathodes with different amounts of electrolytes is presented here. A survey of the fundamentals of Li–S chemistry with respect to capacity fade is first conducted; then, the parameters obtained through electrochemical performance and characterization are used to determine the key causes of capacity fade in Li–S batteries. It is confirmed that the formation and accumulation of nonconductive Li2S2/Li2S films on sulfur cathode surfaces are the major parameters contributing to the rapid capacity fade of Li–S batteries. PMID:27981001

Acclimation of green algae to sulfur deficiency: underlying mechanisms and application for hydrogen production.

Science.gov (United States)

Antal, Taras K; Krendeleva, Tatyana E; Rubin, Andrew B

2011-01-01

Hydrogen is definitely one of the most acceptable fuels in the future. Some photosynthetic microorganisms, such as green algae and cyanobacteria, can produce hydrogen gas from water by using solar energy. In green algae, hydrogen evolution is coupled to the photosynthetic electron transport in thylakoid membranes via reaction catalyzed by the specific enzyme, (FeFe)-hydrogenase. However, this enzyme is highly sensitive to oxygen and can be quickly inhibited when water splitting is active. A problem of incompatibility between the water splitting and hydrogenase reaction can be overcome by depletion of algal cells of sulfur which is essential element for life. In this review the mechanisms underlying sustained hydrogen photoproduction in sulfur deprived C. reinhardtii and the recent achievements in studying of this process are discussed. The attention is focused on the biophysical and physiological aspects of photosynthetic response to sulfur deficiency in green algae.

Sulfur contents and sulfur-isotope compositions of thiotrophic symbioses in bivalve molluscs and vestimentiferan worms

Science.gov (United States)

Vetter, R.D.; Fry, B.

1998-01-01

Total sulfur (S(TOT)), elemental sulfur (S??) and sulfur-isotope compositions (??34S) of marine animals were analyzed to determine whether these chemical characteristics could help distinguish animals with a sulfur-based, thiotrophic nutrition from animals whose nutrition is based on methanotrophy or on more normal consumption of phytoplankton-derived organic matter. The presence of S??was almost entirely confined to the symbiont-containing tissues of thiotrophs, but was sometimes undetectable in thiotrophic species where sulfide availability was probably low. When S??contents were subtracted, the remaining tissue-sulfur concentrations were similar for all nutritional groups. ??34S values were typically lower for thiotrophs than for other groups, although there was overlap in methanotroph and thiotroph values at some sites. Field evidence supported the existence of small to moderate (1 to 10???)34S fractionations in the uptake of sulfides and metabolism of thiosulfate. In general, a total sulfur content of >3% dry weight, the presence of elemental sulfur, and ??34S values less than + 5??? can be used to infer a thiotrophic mode of nutrition.

Process and equipment for the detection of impurities like salted water and sulfur contained in a multiphase fluid by nuclear techniques

International Nuclear Information System (INIS)

Arnold, D.M.; Paap, H.J.

1981-01-01

A technique for detecting impurities, like sulfur and salted water, in petroleum refineries is described. The fluid is bombarded with fast neutrons which are showed down and then captured producing gamma spectra. Analysis of the spectra indicates the relative presence of sulfur, hydrogen and chlorine. The gas/liquid ratio of the fluid can also be calculated. An apparatus making use of this technique is also described [fr

Diesel Emission Control- Sulfur Effects (DECSE) Program- Phase II Summary Report: NOx Adsorber Catalysts; FINAL

International Nuclear Information System (INIS)

None

2000-01-01

The investigations performed in this project demonstrated the ability to develop a NO(sub x) regeneration strategy including both an improved lean/rich modulation cycle and rich engine calibration, which resulted in a high NO(sub x) conversion efficiency over a range of operating temperatures. A high-temperature cycle was developed to desulfurize the NO(sub x) absorber catalyst. The effectiveness of the desulfurization process was demonstrated on catalysts aged using two different sulfur level fuels. The major findings of this project are as follows: (1) The improved lean/rich engine calibration achieved as a part of this test project resulted in NO(sub x) conversion efficiencies exceeding 90% over a catalyst inlet operating temperature window of 300 C-450 C. This performance level was achieved while staying within the 4% fuel economy penalty target defined for the regeneration calibration. (2) The desulfurization procedure developed showed that six catalysts, which had been exposed to fuel sulfur levels of 3-, 16-, and 30-ppm for as long as 250 hours, could be recovered to greater than 85% NO(sub x) conversion efficiency over a catalyst inlet operating temperature window of 300 C-450 C, after a single desulfurization event. This performance level was achieved while staying within the 4% fuel economy penalty target defined for the regeneration calibration. (3) The desulfurization procedure developed has the potential to meet in-service engine operating conditions and provide acceptable driveability conditions. (4) Although aging with 78-ppm sulfur fuel reduced NO(sub x) conversion efficiency more than aging with 3-ppm sulfur fuel as a result of sulfur contamination, the desulfurization events restored the conversion efficiency to nearly the same level of performance. However, repeatedly exposing the catalyst to the desulfurization procedure developed in this program caused a continued decline in the catalyst's desulfurized performance. Additional work will be

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

Science.gov (United States)

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

2018-06-01

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

Demand outlook for sulfur and high-sulfur petroleum coke

Energy Technology Data Exchange (ETDEWEB)

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

1980-01-01

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

SULFUR POLYMER ENCAPSULATION

International Nuclear Information System (INIS)

KALB, P.

2001-01-01

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

Experimental data on compressive strength and durability of sulfur concrete modified by styrene and bitumen.

Science.gov (United States)

Dehestani, M; Teimortashlu, E; Molaei, M; Ghomian, M; Firoozi, S; Aghili, S

2017-08-01

In this data article experimental data on the compressive strength, and the durability of styrene and bitumen modified sulfur concrete against acidic water and ignition are presented. The percent of the sulfur cement and the gradation of the aggregates used are according to the ACI 548.2R-93 and ASTM 3515 respectively. For the styrene modified sulfur concrete different percentages of styrene are used. Also for the bitumen modified sulfur concrete, different percentages of bitumen and the emulsifying agent (triton X-100) are utilized. From each batch three 10×10×10 cm cubic samples were casted. One of the samples was used for the compressive strength on the second day of casting, and one on the twenty-eighth day. Then the two samples were put under the high pressure flame of the burning liquid gas for thirty seconds and their ignition resistances were observed. The third sample was put into the acidic water and after twenty eight days immersion in water was dried in the ambient temperature. After drying its compressive strength has been evaluated.

Confine sulfur in mesoporous metal–organic framework @ reduced graphene oxide for lithium sulfur battery

International Nuclear Information System (INIS)

Bao, Weizhai; Zhang, Zhian; Qu, Yaohui; Zhou, Chengkun; Wang, Xiwen; Li, Jie

2014-01-01

Highlights: • Metal organic framework @ reduced graphene oxide was applied for sulfur cathode. • MIL-101(Cr)@rGO/S composites are synthesized by a facile two-step liquid method. • Cycling stability of MIL-101(Cr)@rGO/S sulfur cathode was improved. -- Abstract: Mesoporous metal organic framework @ reduced graphene oxide (MIL-101(Cr)@rGO) materials have been used as a host material to prepare the multi-composite sulfur cathode through a facile and effective two-step liquid phase method successfully, which is different from the simple MIL-101(Cr)/S mixed preparation method. The successful reduced graphene oxide coating in the MIL-101(Cr)@rGO improve the electronic conductivity of meso-MOFs effectively. The discharge capacity and capacity retention rate of MIL-101(Cr)@rGO/S composite sulfur cathode are as high as 650 mAh g −1 and 66.6% at the 50th cycle at the current density of 335 mA g −1 . While the discharge capacity and capacity retention rate of MIL-101(Cr)/S mixed sulfur cathode is 458 mAh g −1 and 37.3%. Test results indicate that the MIL-101(Cr)@rGO is a promising host material for the sulfur cathode in the lithium–sulfur battery applications

Volatile earliest Triassic sulfur cycle

DEFF Research Database (Denmark)

Schobben, Martin; Stebbins, Alan; Algeo, Thomas J.

2017-01-01

model experiment. Exposure of evaporite deposits having a high δ 34S may account for the source change, with a possible role for the Siberian Traps volcanism by magmatic remobilization of Cambrian rock salt. A high sulfur cycle turnover rate would have left the ocean system vulnerable to development......Marine biodiversity decreases and ecosystem destruction during the end-Permian mass extinction (EPME) have been linked to widespread marine euxinic conditions. Changes in the biogeochemical sulfur cycle, microbial sulfate reduction (MSR), and marine dissolved sulfate concentrations during...... fractionation and point to a more universal control, i.e., contemporaneous seawater sulfate concentration.The MSR-trend transfer function yielded estimates of seawater sulfate of 0.6-2.8mM for the latest Permian to earliest Triassic, suggesting a balanced oceanic S-cycle with equal S inputs and outputs...

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

Science.gov (United States)

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

2012-08-01

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

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

Science.gov (United States)

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.

Device for controlling gas recovery

International Nuclear Information System (INIS)

Ichioka, Atsushi.

1976-01-01

Purpose: To provide a controlling device for UF 6 gas recovery device, which can increase working efficiency and to discriminate normality and abnormality of the recovery device. Constitution: The gas recovery device comprises a plurality of traps, which are connected in series. The UF 6 gas is introduced into the first trap where adsorbing work is taken place to accumulate UF 6 gases, and the UF 6 gases partly flow into the succeeding trap. Even in this trap, when the adsorbing work begins, the succeeding trap is operated in series fashion. In this manner, two traps are continuously operated to recover the gases while performing the steps of adsorbing, waiting and regenerating in that order. The switching operation of the aforesaid steps is accomplished on the basis of concentration of the UF 6 detected between two traps, which are continuously driven. (Kamimura, M.)

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-09-03

Thionyl chloride is often used to convert alcohols into more reactive alkyl chloride, which can be easily converted to many compounds that are not possible from alcohols directly. One important reaction of alkyl chloride is nucleophilic substitution, which is typically conducted under basic conditions. Sulfur dioxide, the by-product from alcohol-thionyl chloride reactions, often reacts with alkyl chloride to form a sulfonyl acid impurity, resulting in yield loss. Therefore, the alkyl chloride is typically isolated to remove the by-products including sulfur dioxide. However, in our laboratory, the alkyl chloride formed from alcohol and thionyl chloride was found to be a potential mutagenic impurity, and isolation of this compound would require extensive safety measures. As a result, a flow-through process was developed, and the sulfur dioxide was purged using a combination of vacuum degassing and nitrogen gas sweeping. An analytical method that can quickly and accurately quantitate residual levels of sulfur dioxide in the reaction mixture is desired for in-process monitoring. We report here a simple ultraviolet (UV) spectrophotometry method for this measurement. This method takes advantage of the dramatic change in the UV absorbance of sulfur dioxide with respect to pH, which allows for accurate quantitation of sulfur dioxide in the presence of the strong UV-absorbing matrix. Each sample solution was prepared using 2 different diluents: 1) 50 mM ammonium acetate in methanol +1% v/v hydrochloric acid, pH 1.3, and 2) 50 mM ammonium acetate in methanol +1% glacial acetic acid, pH 4.0. The buffer solutions were carefully selected so that the UV absorbance of the sample matrix (excluding sulfur dioxide) at 276 nm remains constant. In the pH 1.3 buffer system, sulfur dioxide shows strong UV absorbance at 276 nm. Therefore, the UV absorbance of sample solution is the sum of sulfur dioxide and sample matrix. While in the pH 4.0 buffer system, sulfur dioxide has

Development of alternative sulfur dioxide control strategies for a metropolitan area and its environs, utilizing a modified climatological dispersion model

Science.gov (United States)

K. J. Skipka; D. B. Smith

1977-01-01

Alternative control strategies were developed for achieving compliance with ambient air quality standards in Portland, Maine, and its environs, using a modified climatological dispersion model (CDM) and manipulating the sulfur content of the fuel oil consumed in four concentric zones. Strategies were evaluated for their impact on ambient air quality, economics, and...

Corrosion by concentrated sulfuric acid in carbon steel pipes and tanks: state of the art

Energy Technology Data Exchange (ETDEWEB)

Panossian, Zehbour; Almeida, Neusvaldo Lira de; Sousa, Raquel Maria Ferreira de [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil); Pimenta, Gutemberg de Souza [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas e Desenvolvimento (CENPES); Marques, Leandro Bordalo Schmidt [PETROBRAS Engenharia, Rio de Janeiro, RJ (Brazil)

2009-07-01

PETROBRAS, allied to the policy of reduction of emission of pollutants, has been adjusting the processes of the new refineries to obtain products with lower sulfur content. Thus, the sulfur dioxide, extracted from the process gases of a new refinery to be built in the Northeast, will be used to produce sulfuric acid with concentration between (94-96) %. This acid will be stored in carbon steel tanks and transported through a buried 8-km carbon steel pipe from the refinery to a pier, where it will be loaded onto ships and sent to the consumer markets. Therefore, the corrosion resistance of carbon steel by concentrated acid will become a great concern for the mentioned storage and transportation. When the carbon steel comes into contact with concentrated sulfuric acid, there is an immediate acid attack with the formation of hydrogen gas and ferrous ions which, in turn, forms a protective layer of FeSO{sub 4} on the metallic surface. The durability of the tanks and pipes made of carbon steel will depend on the preservation of this protective layer. This work presents a review of the carbon steel corrosion in concentrated sulfuric acid and discusses the preventive methods against this corrosion, including anodic protection. (author)

Sulfur isotopic analysis of carbonyl sulfide and its application for biogeochemical cycles

Science.gov (United States)

Hattori, Shohei; Kamezaki, Kazuki; Ogawa, Takahiro; Toyoda, Sakae; Katayama, Yoko; Yoshida, Naohiro

2016-04-01

Carbonyl sulfide (OCS or COS) is the most abundant gas containing sulfur in the atmosphere, with an average mixing ratio of 500 p.p.t.v. in the troposphere. OCS is suggested as a sulfur source of the stratospheric sulfate aerosols (SSA) which plays an important role in Earth's radiation budget and ozone depletion. Therefore, OCS budget should be validated for prediction of climate change, but the global OCS budget is imbalance. Recently we developed a promising new analytical method for measuring the stable sulfur isotopic compositions of OCS using nanomole level samples: the direct isotopic analytical technique of on-line gas chromatography-isotope ratio mass spectrometry (GC-IRMS) using fragmentation ions S+ (Hattori et al., 2015). The first measurement of the δ34S value for atmospheric OCS coupled with isotopic fractionation for OCS sink reactions in the stratosphere (Hattori et al., 2011; Schmidt et al., 2012; Hattori et al., 2012) explains the reported δ34S value for background stratospheric sulfate, suggesting that OCS is a potentially important source for background (nonepisodic or nonvolcanic) stratospheric sulfate aerosols. This new method measuring δ34S values of OCS can be used to investigate OCS sources and sinks in the troposphere to better understand its cycle. It is known that some microorganisms in soil can degrade OCS, but the mechanism and the contribution to the OCS in the air are still uncertain. In order to determine sulfur isotopic enrichment factor of OCS during degradation via microorganisms, incubation experiments were conducted using strains belonging to the genera Mycobacterium, Williamsia and Cupriavidus, isolated from natural soil environments (Kato et al., 2008). As a result, sulfur isotope ratios of OCS were increased during degradation of OCS, indicating that reaction for OC32S is faster than that for OC33S and OC34S. OCS degradation via microorganisms is not mass-independent fractionation (MIF) process, suggesting that this

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

Energy Technology Data Exchange (ETDEWEB)

Hackley, K.C.; Buchanan, D.H.; Coombs, K.; Chaven, C.; Kruse, C.W. (Eastern Illinois University, Charleston, IL (USA). Chemistry Dept.)

1990-01-01

Hot tetrachloroethene (perchloroethylen PCE) extracts significant amounts of elemental sulfur (S{sup o}) from weathered coals but not from pristine coals. The objective of this study was to determine whether S{sup o} 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 S{sup o} was compared to the isotopic compositions of the pyritic and the organic sulfur in a coal. The S{sup o} was shown to have an isotopic signature similar to the pyritic sulfur. Additionally, the isotopic differences observed between the pyritic, S{sup o} and sulfatic sulfur were consistent with bacterial mediated oxidation of sulfide sulfur (pyrite) as the source of both the sulfatic and elemental sulfur. 21 refs., 2 tabs.

Energy generation and the sulfur-carbon cycles: Final technical report for period March 1981 thru February 1985

International Nuclear Information System (INIS)

Zeikus, J.G.

1987-05-01

The aim of this research was to understand the role of anaerobic bacteria in natural and man-influenced carbon cycles in nature. The major goal was to elucidate how sulfur metabolism influenced organic decomposition in aquatic sediments. The research compared these processes in two different anaerobic ecosystems: the sulfate-depleted sediments of Lake Mendota, Wisconsin and the sulfate-saturated sediments of Great Salt Lake, Utah. The approach was both ecological and physiological, and employed both in situ characterization of carbon and sulfur metabolism with radiotracers and laboratory species isolation-characterization studies with pure and defined mixed cultures to demonstrate the prevalent environmental paths of carbon electrons, and sulfur during the anaerobic decomposition of organic matter. The significance of this research encompassed fundamental knowledge of the carbon sulfur cycles, applied knowledge on the microbial genesis of flammable gas and oil and extended knowledge on the diversity and metabolic activity of obligately anaerobic bacteria in nature. 13 refs

Solubility of flue gas components in NaOH based scrubber solutions