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1

Sulfur recovery process  

SciTech Connect

This paper describes a method for recovering sulfur from a process feed stream mixture of gases comprising sulfur-containing compounds including hydrogen sulfide using the Claus reaction to convert sulfur-containing compounds to elemental sulfur and crystallization to separate sulfur-containing compounds from a tail gas of the Claus reaction for further processing as a recycle stream. It comprises: providing a Claus feed stream containing a stoichiometric excess of hydrogen sulfide, the Claus feed stream including the process feed stream and the recycles stream; introducing the Claus feed stream and an oxidizing agent into a sulfur recovery unit for converting sulfur-containing compounds in the Claus feed stream to elemental sulfur; withdrawing the tail gas from the sulfur recovery unit; separating water from the tail gas to producing a dehydrated tail gas; separating sulfur-containing compounds including carbonyl sulfide from the dehydrated tail gas as an excluded material by crystallization and withdrawing an excluded material-enriched output from the crystallization to produce the recycle stream; and combining the recycle stream with the process feed stream to produce the Claus feed stream.

Hise, R.E.; Cook, W.J.

1991-06-04

2

Processing high sulfur coal  

SciTech Connect

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

Sooter, M.C.

1981-09-29

3

Process for removing sulfur compounds  

SciTech Connect

A process for removing sulfur compounds including at least hydrogen sulfide and sulfur dioxide from a sulfur contaminated fluid stream having a concentration of said sulfur compounds is described comprising the step of: contacting said sulfur contaminated fluid stream with an absorption composition comprising: zinc oxide in an amount between about 60 and about 90 weight percent; zinc phosphate in an amount between about 10 and about 40 weight percent; and alumina in an amount up to about 30 weight percent to produce a treated effluent stream having a substantially reduced concentration of said sulfur compounds.

Lowery, R.E.; Engelbert, D.R.

1993-06-15

4

Advanced Sulfur Control Processing  

Microsoft Academic Search

The primary objective of this project is to determine the feasibility of an alternate concept for the regeneration of high temperature desulfurization sorbents in which elemental sulfur, instead of SO, is produced. If successful, this concept will eliminate or alleviate problems caused by the highly exothermic nature of the regeneration reaction, the tendency for metal sulfate formation, and the need

S. K. Gangwal; J. W. Portzer; B. S. Turk; R. Gupta

1996-01-01

5

Sulfur-Oxygen Processes on Io.  

National Technical Information Service (NTIS)

Laboratory studies of irradiated sulfur dioxide frost have found that sulfur trioxide should be formed as a consequence of the irradiation process. The spectral reflectance of solid sulfur trioxide was measured in the laboratory and it was found that the ...

R. M. Nelson W. D. Smythe

1987-01-01

6

Process for removing sulfur from sulfur-containing gases  

DOEpatents

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

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

1989-01-01

7

Improved sulfur removal processes evaluated for IGCC  

SciTech Connect

An inherent advantage of Integrated Coal Gasification Combined Cycle (IGCC) electric power generation is the ability to easily remove and recover sulfur. During the last several years, a number of new, improved sulfur removal and recovery processes have been commercialized. An assessment is given of alternative sulfur removal processes for IGCC based on the Texaco coal gasifier. The Selexol acid gas removal system, Claus sulfur recovery, and SCOT tail gas treating are currently used in Texaco-based IGCC. Other processes considered are: Purisol, Sulfinol-M, Selefning, 50% MDEA, Sulften, and LO-CAT. 2 tables.

Not Available

1986-12-01

8

Process for removing sulfur from coal  

DOEpatents

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

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

1983-08-11

9

Development of enhanced sulfur rejection processes  

SciTech Connect

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

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

1993-03-23

10

Development of enhanced sulfur rejection processes  

SciTech Connect

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

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

1996-03-01

11

INDUSTRIAL PROCESS PROFILES FOR ENVIRONMENTAL USE: CHAPTER 23. SULFUR, SULFUR OXIDES AND SULFURIC ACID  

EPA Science Inventory

The catalog of Industrial Process Profiles for Environmental Use was developed as an aid in defining the environmental impacts of industrial activity in the United States. Entries for each industry are in consistent format and form separate chapters of the study. The sulfur indus...

12

Assessment of sulfur removal processes for advanced fuel cell systems  

NASA Astrophysics Data System (ADS)

The performance characteristics of potential sulfur removal processes were evaluated and four of these processes, the Selexol process, the Benfield process, the Sulfinol process, and the Rectisol process, were selected for detailed technical and economic comparison. The process designs were based on a consistent set of technical criteria for a grass roots facility with a capacity of 10,000 tons per day of Illinois No. 6 coal. Two raw gas compositions, based on oxygen blown and air blown Texaco gasification, were used. The bulk of the sulfur was removed in the sulfur removal unit, leaving a small amount of sulfur compounds in the gas. The remaining sulfur compounds were removed by reaction with zinc oxide in the sulfur polishing unit. The impact of COS hydrolysis pretreatment on sulfur removal was evaluated. Comprehensive capital and O and M cost estimates for each of the process schemes were developed.

Lorton, G. A.

1980-01-01

13

Assessment of Sulfur Removal Processes for Advanced Fuel Cell Systems.  

National Technical Information Service (NTIS)

This study consisted of a technical evaluation and economic comparison of sulfur removal processes for integration into a coal gasification-molten carbonate (CGMC) fuel cell power plant. Initially, the performance characteristics of potential sulfur remov...

G. A. Lorton

1980-01-01

14

Investigation of sulfur removal using direct oxidation processes  

SciTech Connect

Refinery fuel gas streams typically contain sulfur compounds. The principle such compound is hydrogen sulfide: minor constituents are carbonyl sulfide and mercaptan sulfur. These sulfur species must be removed in order that refinery combustion processes meet emission limitations imposed by regulatory authorities. Usually these fuel gas streams are low pressure. Choices for sulfur removal technology are constrained by the low pressure and the relatively low concentration of the sulfur species in the gas. The primary objective of this work is to identify applicable process technologies that might be employed to remove sulfur compounds and produce elemental sulfur directly. The methodology to investigate applicable processes consisted of the following steps: identify applicable technologies that are advanced beyond the research stage; review literature; query licensors to provide information on capital costs, utility requirements, chemical requirements, waste streams, and experience; and interview operators to ascertain actual experience with the process.

Pack, G.E.

1985-01-01

15

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

SciTech Connect

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

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

1980-12-23

16

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

DOEpatents

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.

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

1991-01-01

17

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

NASA Astrophysics Data System (ADS)

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

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

2000-10-01

18

Process for production of synthesis gas with reduced sulfur content  

DOEpatents

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

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

1989-01-01

19

Process for Producing Sulfurous Acid Treated Alumina.  

National Technical Information Service (NTIS)

The activated alumina is effective for bleaching refined cottonseed oil. It is prepared by soaking ground activated alumina with an aqueous solution of sulfurous acid until a specific saturation is reached. The alumina is then removed from the solution an...

W. A. Pons J. C. Kuck V. L. Frampton

1964-01-01

20

Assessment of sulfur removal processes for advanced fuel cell systems  

Microsoft Academic Search

The performance characteristics of potential sulfur removal processes were evaluated and four of these processes, the Selexol process, the Benfield process, the Sulfinol process, and the Rectisol process, were selected for detailed technical and economic comparison. The process designs were based on a consistent set of technical criteria for a grass roots facility with a capacity of 10,000 tons per

G. A. Lorton

1980-01-01

21

Process of Making a Granulated, Homogeneous Phosphate Rock Sulfur Fertilizer.  

National Technical Information Service (NTIS)

The product has a defined and critical particle size range which increases the effectiveness of the product as a fertilizer. The process includes blending together a mixture of pulverized phosphate rock and elemental sulfur, subsequently granulating same,...

T. P. Hignett G. Hoffmeister

1965-01-01

22

Process for the removal of sulfur oxides  

Microsoft Academic Search

Sulfur oxides are removed from waste gases containing the same by scrubbing the waste gas with an aqueous scrubbing solution containing the aluminate of sodium, potassium or ammonium, and an additional compound selected from the group consisting of aluminum sulfate and alum.

T. Takeyama; A. Takahashi; K. Matsumura; K. Kitagawa

1979-01-01

23

Process for removal of sulfur compounds from conjugated diolefins  

Microsoft Academic Search

This patent describes a process for reducing the level of sulfur compounds selected from hydrogen sulfide and carbon disulfide in a sulfur compound-containing liquid conjugated diolefin hydrocarbon having an atmospheric boiling point in the range from about -5° to about 45°C. The process consists of contacting the liquid diolefin at a temperature up to about the boiling point of the

Slaugh

1986-01-01

24

Assessment of sulfur removal processes for advanced fuel cell systems  

SciTech Connect

This study consisted of a technical evaluation and economic comparison of sulfur removal processes for integration into a coal gasification-molten carbonate (CGMC) fuel cell power plant. Initially, the performance characteristics of potential sulfur removal processes were evaluated and screened for conformance to the conditions and requirements expected in commercial CGMC power plants. Four of these processes, the Selexol process, the Benfield process, the Sulfinol process, and the Rectisol process, were selected for detailed technical and economic comparison. The process designs were based on a consistent set of technical criteria for a grass roots facility with a capacity of 10,000 tons per day of Illinois No. 6 coal. Two raw gas compositions, based on oxygen-blown and air-blown Texaco gasification, were used. The bulk of the sulfur was removed in the sulfur removal unit, leaving a small amount of sulfur compounds in the gas (1 ppMv or 25 ppMv). The remaining sulfur compounds were removed by reaction with zinc oxide in the sulfur polishing unit. The impact of COS hydrolysis pretreatment on sulfur removal was evaluated. Comprehensive capital and O and M cost estimates for each of the process schemes were developed for the essentially complete removal of sulfur compounds. The impact on the overall plant performance was also determined. The total capital requirement for sulfur removal schemes ranged from $59.4/kW to $84.8/kW for the oxygen-blown cases and from $89.5/kW to $133/kW for the air-blown cases. The O and M costs for sulfur removal for 70% plant capacity factor ranged from 0.82 mills/kWh to 2.76 mills/kWh for the oxygen-blown cases and from 1.77 mills/kWh to 4.88 mills/kWh for the air-blown cases. The Selexol process benefitted the most from the addition of COS hydrolysis pretreatment.

Lorton, G.A.

1980-01-01

25

Integrated process for converting sulfur-containing fuels to low sulfur combustible gas  

SciTech Connect

Sulfur-containing fuels are converted to substantially sulfurfree combustible gas in an integrated process involving part combustion in a dense phase fluidized conversion bed of particles comprising alkaline earth metal oxides. An oxygen-containing gas is passed into the base of the bed to maintain a relatively high fuel/air ratio. Sulfur is chemically fixed in the particles by reaction to form alkaline earth metal sulfide. Particles containing alkaline earth metal sulfide are circulated from one region of the conversion bed to one region of a dense phase fluidized regeneration bed operated at a higher temperature and fluidized by passing into the base thereof an oxygen-containing gas which exothermically regenerates chemically active alkaline earth metal oxide from the sulfide liberating gases which have a low oxygen content and a relatively high content of sulfur moieties (e.g. SO2). Hot particles are circulated from a second region of the regeneration bed to a second region of the conversion bed for use in fixing further quantities of sulfur from sulfur-containing fuel. Both beds contain a high molar proportion of unreacted alkaline earth metal oxide thereby imparting high sulfur-retaining capability to the conversion bed, and the beds interact cooperatively with each other at least in that particles entering the regeneration bed moderate temperatures therein and particles entering the conversion bed add heat thereto thereby reducing the fuel requirement for maintaining the conversion bed temperature.

Moss, G.

1981-03-10

26

The Fate of Sulfur in Late-Stage Magmatic Processes: Insights From Quadruple Sulfur Isotopes  

NASA Astrophysics Data System (ADS)

Multiple sulfur isotopes (32S, 33S, 34S and 36S) have recently been shown to be useful tracers of fluid-rock interaction in seafloor hydrothermal systems [1]. Here we present the application of multiple sulfur isotopes to subaerial volcanoes with the aim of unraveling the various processes fractionating sulfur in the upper volcanic system. We take advantage of the fact that the ascent of volcanic gases through a hydrothermal system causes complex isotopic fractionation between the quaduple sulfur isotopes. ?34S is thought to trace the source of sulfur as well as magma degassing; at equilibrium, ?33S follows a mass-dependent fractionation relationship such that two phases in equilibrium with each other have equal ?33S values (?33S ? ln(?33S+1) - 0.515ln(?34S+1)). Disequilibrium ?33S values can indicate isotope mixing and other fluid-rock interactions. The ultimate aim of this study is to assess the use of quadruple sulfur isotopes to obtain quantitative information on the sulfur cycle at convergent plate margins. The sulfur mass balance at convergent margins is poorly constrained, partly because late-stage processes are challenging to quantify and lead to large uncertainties in the global output fluxes. Quadruple sulfur isotopes provide a powerful tool to untangle the convoluted history of volcanic systems. Here we report the first quadruple sulfur isotopic values for H2S, SO2 and native sulfur from arc volcanoes. Fumarolic gases (100C) and sulfur sublimates were collected from Poas and Turrialba, two actively degassing volcanoes in Costa Rica. The gases were bubbled in situ through chemical traps to separate H2S from SO2: H2S was reacted to form ZnS, and SO2 to form BaSO4. Sulfur was chemically extracted from the solid phases and precipitated as Ag2S, which was fluorinated to SF6 and analysed by IRMS. Poas and Turrialba have H2S/SO2 1 and 0.01, respectively. ?34SH2S and ?34SSO2 are similar to gases measured at other arcs [2], - 7.9 and 0.6 for Poas, and -8.5 and +9 for Turrialba, likely reflecting a mixture of mantle (?34S = 0) and slab sources which have been degassed to variable degrees. Sulfur sublimate values are similar to those for H2S. ?33S values are different within each H2S/SO2 pair (?33SH2S and ?33SSO2 are -0.01 and -0.02 for Poas, 0 and -0.07 for Turrialba), indicating that at Turrialba, the two gas species are not in isotopic equilibrium. Reaction of the gases with mineral phases, such as sulfur-bearing alteration products in the volcanic edifice (e.g., alunite, anhydrite, sulfides) may explain these differences. [1] Ono et al. (2007), GCA 70 1170-1182, [2] Taylor (1986), RiM 16 185-225

Keller, N. S.; Ono, S.; Shaw, A. M.

2009-05-01

27

HYBRID SULFUR RECOVERY PROCESS FOR NATURAL GAS UPGRADING  

SciTech Connect

This first quarter report of 2001 describes progress on a project funded by the U.S. Department of Energy (DOE) to test a hybrid sulfur recovery process for natural gas upgrading. The process concept represents a low cost option for direct treatment of natural gas streams to remove H{sub 2}S in quantities equivalent to 0.2-25 metric tons (LT) of sulfur per day. This process is projected to have lower capital and operating costs than the competing technologies, amine/aqueous iron liquid redox and amine/Claus/tail gas treating, and have a smaller plant footprint, making it well suited to both on-shore and offshore applications. CrystaSulf{trademark} (service mark of Gas Research Institute) is a new nonaqueous sulfur recovery process that removes hydrogen sulfide (H{sub 2}S) from gas streams and converts it into elemental sulfur. CrystaSulf features high sulfur recovery similar to aqueous-iron liquid redox sulfur recovery processes, but differs from the aqueous processes in that CrystaSulf controls the location where elemental sulfur particles are formed. In the hybrid process, approximately 1/3 of the total H{sub 2}S in the natural gas is first oxidized to SO{sub 2} at low temperatures over a heterogeneous catalyst. Low temperature oxidation is done so that the H{sub 2}S can be oxidized in the presence of methane and other hydrocarbons without oxidation of the hydrocarbons. The project involves the development of a catalyst using laboratory/bench-scale catalyst testing, and then demonstration of the catalyst at CrystaTech's pilot plant in west Texas. During this reporting periods new catalyst formulations were tested. The experiments showed that the newest catalyst has slightly better performance, but catalyst TDA No.2 is still superior overall for use with the hybrid CrystaSulf process due to lower costs. Plans for catalyst pelletization and continued testing are described.

Girish Srinivas; Steven C. Gebhard; David W. DeBerry

2001-05-01

28

Durability Testing of the Direct Sulfur Recovery Process  

Microsoft Academic Search

Designs for advanced integrated gasification combined cycle (IGCC) power systems call for desulfurization of coal gasifier gas at high-temperature, high-pressure (HTHP) conditions using highly efficient, regenerable metal oxides such as zinc titanate. Regeneration of the sulfided sorbent using an oxygen-containing gas stream results in a sulfur dioxide (SO)-containing off-gas at HTHP conditions. The patented Direct Sulfur Recovery Process (DSRP) developed

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

1996-01-01

29

Biological sulfuric acid transformation: Reactor design and process optimization  

Microsoft Academic Search

As an alternative to the current disposal technologies for waste sulfuric acid, a new combination of recycling processes was developed. The strong acid (H[sub 2]SO[sub 4]) is biologically converted with the weak acid (CH[sub 3]COOH) into two volatile weak acids (H[sub 2]S, H[sub 2]CO[sub 3]) by sulfate-reducing bacteria. The transformation is possible without prior neutralization of the sulfuric acid. The

Gerhard Stucki; R. A. Huerzeler; K. W. Hanselmann

1993-01-01

30

HYBRID SULFUR RECOVERY PROCESS FOR NATURAL GAS UPGRADING  

SciTech Connect

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

Dennis Dalrymple

2004-04-01

31

HYBRID SULFUR RECOVERY PROCESS FOR NATURAL GAS UPGRADING  

SciTech Connect

This third quarter report of 2003 describes progress on a project funded by the U.S. Department of Energy (DOE) to test a hybrid sulfur recovery process for natural gas upgrading. The process concept represents a low-cost option for direct treatment of natural gas streams to remove H{sub 2}S in quantities equivalent to 0.2-25 metric tons (LT) of sulfur per day. This process is projected to have lower capital and operating costs than the competing technologies, amine/aqueous iron liquid redox and amine/Claus/tail gas treating, and have a smaller plant footprint, making it well suited to both on-shore and off-shore applications. CrystaSulf{reg_sign} (service mark of CrystaTech, Inc.) is a new nonaqueous sulfur recovery process that removes hydrogen sulfide (H{sub 2}S) from gas streams and converts it into elemental sulfur. CrystaSulf features high sulfur recovery similar to aqueous-iron liquid redox sulfur recovery processes, but differs from the aqueous processes in that CrystaSulf controls the location where elemental sulfur particles are formed. In the hybrid process, approximately 1/3 of the total H{sub 2}S in the natural gas is first oxidized to SO{sub 2} at low temperatures over a heterogeneous catalyst. Low temperature oxidation is done so that the H{sub 2}S can be oxidized in the presence of methane and other hydrocarbons without oxidation of the hydrocarbons. The project involves the development of a catalyst using laboratory/bench-scale catalyst testing, and then demonstration of the catalyst at CrystaTech's pilot plant site in west Texas.

Dennis Dalrymple

2003-10-01

32

HYBRID SULFUR RECOVERY PROCESS FOR NATURAL GAS UPGRADING  

SciTech Connect

This fourth quarter report of 2002 describes progress on a project funded by the U.S. Department of Energy (DOE) to test a hybrid sulfur recovery process for natural gas upgrading. The process concept represents a low cost option for direct treatment of natural gas streams to remove H{sub 2}S in quantities equivalent to 0.2-25 metric tons (LT) of sulfur per day. This process is projected to have lower capital and operating costs than the competing technologies, amine/aqueous iron liquid redox and amine/Claus/tail gas treating, and have a smaller plant footprint, making it well suited to both on-shore and offshore applications. CrystaSulf (service mark of CrystaTech, Inc.) is a new nonaqueous sulfur recovery process that removes hydrogen sulfide (H{sub 2}S) from gas streams and converts it into elemental sulfur. CrystaSulf features high sulfur recovery similar to aqueous-iron liquid redox sulfur recovery processes, but differs from the aqueous processes in that CrystaSulf controls the location where elemental sulfur particles are formed. In the hybrid process, approximately 1/3 of the total H{sub 2}S in the natural gas is first oxidized to SO{sub 2} at low temperatures over a heterogeneous catalyst. Low temperature oxidation is done so that the H{sub 2}S can be oxidized in the presence of methane and other hydrocarbons without oxidation of the hydrocarbons. The project involves the development of a catalyst using laboratory/bench-scale catalyst testing, and then demonstration of the catalyst at CrystaTech's pilot plant in west Texas. Previous reports described development of a catalyst with the required selectivity and efficiency for producing sulfur dioxide from H{sub 2}S. In the laboratory, the catalyst was shown to be robust and stable in the presence of several intentionally added contaminants, including condensate from the pilot plant site. Bench-scale catalyst testing at the CrystaSulf pilot plant using the actual pilot plant gas was successful and a skid-mounted, catalyst pilot unit has been designed for fabrication and testing at the CrystaSulf pilot site.

Joe Lundeen; Girish Srinivas; David W. DeBerry

2003-01-01

33

HYBRID SULFUR RECOVERY PROCESS FOR NATURAL GAS UPGRADING  

SciTech Connect

This first quarter report of 2003 describes progress on a project funded by the U.S. Department of Energy (DOE) to test a hybrid sulfur recovery process for natural gas upgrading. The process concept represents a low cost option for direct treatment of natural gas streams to remove H{sub 2}S in quantities equivalent to 0.2-25 metric tons (LT) of sulfur per day. This process is projected to have lower capital and operating costs than the competing technologies, amine/aqueous iron liquid redox and amine/Claus/tail gas treating, and have a smaller plant footprint, making it well suited to both on-shore and off-shore applications. CrystaSulf{reg_sign} (service mark of CrystaTech, Inc.) is a new nonaqueous sulfur recovery process that removes hydrogen sulfide (H{sub 2}S) from gas streams and converts it into elemental sulfur. CrystaSulf features high sulfur recovery similar to aqueous-iron liquid redox sulfur recovery processes, but differs from the aqueous processes in that CrystaSulf controls the location where elemental sulfur particles are formed. In the hybrid process, approximately 1/3 of the total H{sub 2}S in the natural gas is first oxidized to SO{sub 2} at low temperatures over a heterogeneous catalyst. Low temperature oxidation is done so that the H{sub 2}S can be oxidized in the presence of methane and other hydrocarbons without oxidation of the hydrocarbons. The project involves the development of a catalyst using laboratory/bench-scale catalyst testing, and then demonstration of the catalyst at CrystaTech's pilot plant in west Texas. Previous reports described development of a catalyst with the required selectivity and efficiency for producing sulfur dioxide from H{sub 2}S. In the laboratory, the catalyst was shown to be robust and stable in the presence of several intentionally added contaminants, including condensate from the pilot plant site. Bench-scale catalyst testing at the CrystaSulf pilot plant using the actual pilot plant gas was successful, and a skid-mounted catalyst pilot unit has been designed for fabrication and testing at the CrystaSulf pilot site.

Dennis Dalrymple

2003-04-01

34

HYBRID SULFUR RECOVERY PROCESS FOR NATURAL GAS UPGRADING  

SciTech Connect

This second quarter report of 2003 describes progress on a project funded by the U.S. Department of Energy (DOE) to test a hybrid sulfur recovery process for natural gas upgrading. The process concept represents a low cost option for direct treatment of natural gas streams to remove H{sub 2}S in quantities equivalent to 0.2-25 metric tons (LT) of sulfur per day. This process is projected to have lower capital and operating costs than the competing technologies, amine/aqueous iron liquid redox and amine/Claus/tail gas treating, and have a smaller plant footprint, making it well suited to both on-shore and off-shore applications. CrystaSulf{reg_sign} (service mark of CrystaTech, Inc.) is a new nonaqueous sulfur recovery process that removes hydrogen sulfide (H{sub 2}S) from gas streams and converts it into elemental sulfur. CrystaSulf features high sulfur recovery similar to aqueous-iron liquid redox sulfur recovery processes, but differs from the aqueous processes in that CrystaSulf controls the location where elemental sulfur particles are formed. In the hybrid process, approximately 1/3 of the total H{sub 2}S in the natural gas is first oxidized to SO{sub 2} at low temperatures over a heterogeneous catalyst. Low temperature oxidation is done so that the H{sub 2}S can be oxidized in the presence of methane and other hydrocarbons without oxidation of the hydrocarbons. The project involves the development of a catalyst using laboratory/bench-scale catalyst testing, and then demonstration of the catalyst at CrystaTech's pilot plant in west Texas. Previous reports described development of a catalyst with the required selectivity and efficiency for producing sulfur dioxide from H{sub 2}S. In the laboratory, the catalyst was shown to be robust and stable in the presence of several intentionally added contaminants, including condensate from the pilot plant site. Bench-scale catalyst testing at the CrystaSulf pilot plant using the actual pilot plant gas was successful, and a skid-mounted catalyst pilot unit has been designed for fabrication and testing at the CrystaSulf pilot site.

Dennis Dalrymple

2003-07-01

35

Reduction of produced elementary sulfur in denitrifying sulfide removal process.  

PubMed

Denitrifying sulfide removal (DSR) processes simultaneously convert sulfide, nitrate, and chemical oxygen demand from industrial wastewater into elemental sulfur, dinitrogen gas, and carbon dioxide, respectively. The failure of a DSR process is signaled by high concentrations of sulfide in reactor effluent. Conventionally, DSR reactor failure is blamed for overcompetition for heterotroph to autotroph communities. This study indicates that the elementary sulfur produced by oxidizing sulfide that is a recoverable resource from sulfide-laden wastewaters can be reduced back to sulfide by sulfur-reducing Methanobacterium sp. The Methanobacterium sp. was stimulated with excess organic carbon (acetate) when nitrite was completely consumed by heterotrophic denitrifiers. Adjusting hydraulic retention time of a DSR reactor when nitrite is completely consumed provides an additional control variable for maximizing DSR performance. PMID:21286712

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

2011-02-01

36

Nuclear Hydrogen Production Based on the Hybrid Sulfur Thermochemical Process  

SciTech Connect

Two Sulfur cycles - the Sulfur-Iodine (SI) and the Hybrid Sulfur (HyS) - have emerged as the leading thermochemical processes for making hydrogen using heat provided by advanced nuclear reactors. Numerous international efforts have been underway for several years to develop the SI cycle, but development of the HyS has lagged behind. Savannah River National Laboratory (SRNL) has been tasked by the U.S. Department of Energy Office of Nuclear Energy, Science and Technology with development of the HyS cycle since 2004. This paper discusses the background, current status, recent development results, and the future potential for the HyS process. Process design studies suggest that a net thermal efficiency of over 50% (higher heating value basis) is possible with HyS. Economic studies indicate that a nuclear hydrogen plant based on this process can be economically competitive, assuming that the sulfur dioxide-depolarized electrolyzer can be successfully developed. SRNL has demonstrated the use of a proton exchange membrane cell to perform this function, thus holding promise for economic and efficient hydrogen production. (authors)

Summers, William A.; Gorensek, Maximilian B. [Savannah River National Laboratory, 773-42A, Aiken, SC 29808 (United States)

2006-07-01

37

Process for removing pyritic sulfur from bituminous coals  

Microsoft Academic Search

This patent describes a process for reducing sulfur and ash content of bituminous coal. It comprises: grinding the bituminous feed coal to particle size of less than or equal to 600 micrometers to form a fine coal; mixing the fine coal with water and less than 10% by weight of dry coal of a bridging oil to form a coal-water-oil

W. Pawlak; J. S. Janiak; A. A. Turak; B. L. Ignasiak

1990-01-01

38

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

SciTech Connect

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

Frey, H.C. [North Carolina State Univ., Raleigh, NC (United States); Williams, R.B. [Carneigie Mellon Univ., Pittsburgh, PA (United States)

1995-09-01

39

Nitrate removal with sulfur-limestone autotrophic denitrification processes  

Microsoft Academic Search

Nitrate removal using sulfur and limestone autotrophic denitrification (SLAD) processes was evaluated with four laboratory-scale fixed-bed column reactors. The research objectives were (1) to determine the optimum design criteria of the fixed-bed SLAD columns; and (2) to evaluate the effects of biofouling on the SLAD column performance. A maximum denitrification rate of 384 g NO⁻-N(m³·day) was achieved at a loading

Joel M. Flere; Tian C. Zhang

1999-01-01

40

Process for removing sulfur oxide and nitrogen oxide  

SciTech Connect

This patent describes a process for reducing at least one of (1) the sulfur oxide content of a sulfur oxide-containing gas and (2) the nitrogen oxide content of a nitrogen oxide-containing gs which includes contacting the gas with a material at conditions to reduce at least one of (1) the sulfur oxide content of the gas and (2) the nitrogen oxide of the gas, the improvement comprising utilizing as at least a portion of the material the spinel/clay composition produced in accordance with the process comprising: (a) combining (1) an acidic, aluminum-containing composition in which the aluminum is present in a positively charged species, and (2) a basic alkaline earth metal-containing composition to form a gel mixture; and (b) mixing the gel with kaolin clay to form a co-gel mixture; and (c) calcinating the co-gel mixture to form the alkaline earth metal, aluminum-containing spinel composition, in a kaolin clay matrix.

Bhattacharyya, A

1989-05-16

41

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

SciTech Connect

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

Hiroshi Fukui; Isao Minatsuki [Mitsubishi Heavy Industries, LTD. (Japan); Kazuo Ishino [Pacific Rundum Co., Ltd. (Japan)

2006-07-01

42

Development of spent fuel reprocessing process based on selective sulfurization: Study on the Pu, Np and Am sulfurization  

NASA Astrophysics Data System (ADS)

For the recovery of fissile materials from spent nuclear fuel, we have proposed a novel reprocessing process based on selective sulfurization of fission products (FPs). The key concept of this process is utilization of unique chemical property of carbon disulfide (CS2), i.e., it works as a reductant for U3O8 but works as a sulfurizing agent for minor actinides and lanthanides. Sulfurized FPs and minor actinides (MA) are highly soluble to dilute nitric acid while UO2 and PuO2 are hardly soluble, therefore, FPs and MA can be removed from Uranium and Plutonium matrix by selective dissolution. As a feasibility study of this new concept, the sulfurization behaviours of U, Pu, Np, Am and Eu are investigated in this paper by the thermodynamical calculation, phase analysis of chemical analogue elements and tracer experiments.

Kirishima, Akira; Amano, Yuuki; Nihei, Toshifumi; Mitsugashira, Toshiaki; Sato, Nobuaki

2010-03-01

43

Development of a Process for Producing an Ashless, Low-Sulfur Fuel from Coal. Volume IV. Product Studies. Part 4. Sulfur Removal from Coal Minerals.  

National Technical Information Service (NTIS)

Sulfur removal from residual solids of the Solvent Refined Coal (SRC) Process is investigated. The residue, called coal minerals, contains various amounts of ferrous oxide, silica, carbon, and alumina. The preferential oxidation technique for sulfur remov...

1974-01-01

44

Processing of heavy high-sulfur crude oil  

SciTech Connect

Heavy high-sulfur crude oil is subjected to distillation to produce gas and liquid hydrocarbon products and a residuum. The gas and liquid products are desulfurized. Part of the residuum is coked in a delayed coker, and sulfur in the coke is removed by high temperature calcination. The remainder of the residuum is air-blown to produce an asphalt product, and sulfur recovered from the other products is added to the asphalt to produce a sulfur-enriched asphalt product.

Boyer, L.D.

1982-06-01

45

SULFURIC ACID REMOVAL PROCESS EVALUATION: SHORT-TERM RESULTS  

SciTech Connect

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

Gary M. Blythe; Richard McMillan

2002-02-04

46

SULFURIC ACID REMOVAL PROCESS EVALUATION: SHORT-TERM RESULTS  

SciTech Connect

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

Gary M. Blythe; Richard McMillan

2002-03-04

47

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

SciTech Connect

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

Hobbs, D.

2010-07-22

48

Effect of sulfur concentration on sludge acidification during the SSDML process  

Microsoft Academic Search

Heavy metals present in sewage sludges can be leached out, among other processes, by a process using a consortium of sulfur oxidizing bacteria. The metal leaching could be combined with aerobic sludge digestion to result in the Simultaneous Sludge Digestion and Metal Leaching (SSDML) process. A detailed knowledge of the effect of sulfur concentration on the pH variations of the

T. R. Sreekrishnan; R. D. Tyagi; J. F. Blais; N. Meunier; P. G. C. Campbell

1996-01-01

49

Method of removing sulfur oxides and nitrogen oxides by dry process  

SciTech Connect

This invention relates to a method of removing sulfur and nitrogen oxides by a dry process comprising passing a waste gas through a bed of a carbonaceous adsorbent to remove sulfur oxides and adding ammonia to remove nitrogen oxides, characterized in that at least two carbonaceous adsorbent beds are used and the carbonaceous adsorbent used mainly for removal of sulfur oxides is further used for treatment of the waste gas leaving the final carbonaceous adsorbent bed to remove the ammonia.

Hamada, T.; Komatsubara, V.

1984-09-04

50

Process for the hydrodesulfurization of natural gas containing organic sulfur compounds and oxygen  

SciTech Connect

Process is claimed for hydrodesulfurizing a gas comprising together methane, at least one organic sulfur compound and oxygen, characterized by the step of passing a mixture of said gas with a hydrogen containing gas on a palladium catalyst at a temperature of 300/sup 0/ to 450/sup 0/ C. The gas usually comprises at least 2 mg/Nm/sup 3/ of sulfur as organic sulfur and 0.05 to 2% by volume of oxygen.

Deschamps, A.; Cosyns, J.; Le Page, J.F.

1984-07-17

51

Preparation of sulfurized powdered activated carbon from waste tires using an innovative compositive impregnation process.  

PubMed

The objective of this study is to develop an innovative compositive impregnation process for preparing sulfurized powdered activated carbon (PAC) from waste tires. An experimental apparatus, including a pyrolysis and activation system and a sulfur (S) impregnation system, was designed and applied to produce sulfurized PAC with a high specific surface area. Experimental tests involved the pyrolysis, activation, and sulfurization of waste tires. Waste-tire-derived PAC (WPAC) was initially produced in the pyrolysis and activation system. Experimental results indicated that the Brunauer-Emmett-Teller (BET) surface area of WPAC increased, and the average pore radius of WPAC decreased, as water feed rate and activation time increased. In this study, a conventional direct impregnation process was used to prepare the sulfurized PAC by impregnating WPAC with sodium sulfide (Na2S) solution. Furthermore, an innovative compositive impregnation process was developed and then compared with the conventional direct impregnation process. Experimental results showed that the compositive impregnation process produced the sulfurized WPAC with high BET surface area and a high S content. A maximum BET surface area of 886 m2/g and the S content of 2.61% by mass were obtained at 900 degrees C and at the S feed ratio of 2160 mg Na2S/g C. However, the direct impregnation process led to a BET surface area of sulfurized WPAC that decreased significantly as the S content increased. PMID:15303299

Yuan, Chung-Shin; Lin, Hsun-Yu; Wu, Chun-Hsin; Liu, Ming-Han; Hung, Chung-Hsuang

2004-07-01

52

Sulfur tolerant molten carbonate fuel cell anode and process  

DOEpatents

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

Remick, Robert J. (Naperville, IL)

1990-01-01

53

HYBRID SULFUR PROCESS REFERENCE DESIGN AND COST ANALYSIS  

SciTech Connect

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

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

2009-05-12

54

Sulfur:limestone autotrophic denitrification processes for treatment of nitrate-contaminated water: batch experiments  

Microsoft Academic Search

In this study, an innovative process of using sulfur:limestone autotrophic denitrification (SLAD) for treatment of nitrate-contaminated surface or wastewater was put forward. The feasibility of this SLAD process was evaluated using lab-scale batch reactors operated under both aerobic and anaerobic conditions. Autotrophic denitrification occurred in batch reactors spiked with sulfur:limestone (S:L) under either aerobic or anaerobic conditions at both high

Tian C Zhang; David G Lampe

1999-01-01

55

Sulfur Recovery from Acid Gas Using the Claus Process and High Temperature Air Combustion (HiTAC) Technology  

Microsoft Academic Search

Sulfur-bearing compounds are very detrimental to the environment and to industrial process equipment. They are often obtained or formed as a by-product of separation and thermal processing of fuels containing sulfur, such as coal, crude oil and natural gas. The two sulfur compounds, which need special attention, are: hydrogen sulfide (H2S) and sulfur dioxide (SO2). H2S is a highly corrosive

Mohamed Sassi; Ashwani K. Gupta

56

Process for recovery of sulfur from acid gases  

DOEpatents

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.

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

1995-01-01

57

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

SciTech Connect

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

Benjamin Russ

2009-06-01

58

Use of the Stauffer Chemical Co. phosphate process to combine sulfur recovery with SO abatement  

Microsoft Academic Search

Use of the Stauffer Chemical Co. phosphate process to combine sulfur recovery with SO abatement at the 30,000 bbl\\/day USA Petrochem Corp. refinery in Ventura, Calif., to abate 12 tons\\/day of hydrogen sulfide from a hydrogen sulfide stream off an amine unit and meet low sulfur dioxide emissions standards will require an installed capital cost of about $1,200,000, a $22,000\\/yr

L. P. van Brocklin; H. L. Hill

1980-01-01

59

Instrumental methods of analysis of sulfur compounds in synfuel process streams. Quarterly technical progress report, October-December 1982  

Microsoft Academic Search

The general objective is to develop dependable and accurate instrumental analysis methods for the determination of sulfur moieties. These will include polysulfides, dithionite and polythionates. Calorimetric procedures (thermometric titrations, injection enthalpimetry) and electroanalytical techniques (voltammetry, coulometric analysis, etc.) will be used. The complete speciation of sulfur will be undertaken in representative synfuel process stream samples. Total sulfidic sulfur has been

J. Jordan; J. Stahl; J. Yakupkovic

1983-01-01

60

Sulfur Fumigation Processing of Traditional Chinese Medicinal Herbs: Beneficial or Detrimental?  

PubMed Central

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

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

2011-01-01

61

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

PubMed

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

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

2011-12-27

62

SULFURIC ACID REMOVAL PROCESS EVALUATION: LONG-TERM RESULTS  

SciTech Connect

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

Gary M. Blythe; Richard McMillan

2002-07-03

63

Hydrogen production by the GA sulfur-iodine process: a progress report  

SciTech Connect

The progress of the overall total development effort of the General Atomic (GA) sulfur-iodine thermochemical water-splitting cycle over the last two years is summarized. The major accomplishments have been: significant improvements in the chemistry of the process; development, review, and revision of an engineering flowsheet, resulting in a thermal process efficiency of 47%; screening, identification, and testing of potential materials-of-construction for the corrosive process fluids; small-scale demonstration of the cycle in a closed loop under recycle conditions; installation of bench-scale equipment and demonstration of parts of the process in this system; and development of a conceptual, preliminary flowsheet for the GA sulfur-iodine cycle driven by solar energy. The results of the work carried out during the last two years have demonstrated that thermochemical water splitting by the sulfur-iodine cycle is a feasible process and have provided confidence that thermal efficiencies in the range of 50% are achievable.

Besenbruch, G.E.; McCorkle, K.H.; Norman, J.H.; O'Keefe, D.R.; Schuster, J.R.; Trester, P.W.; Yoshimoto, M.

1980-05-01

64

Investigation of the diffusion process for the extraction of sulfur dioxide from gaseous mixtures  

SciTech Connect

The removal of sulfur-containing compounds from industrial gases is a most urgent problem. Most of the existing methods for removal of SO/sub 2/ from exhaust gases are based on the use of various chemical processes. However, all these methods, such as the sulfite-bisulfite method, ozone catalysis, ammonia-sulfuric acid method and others, have a number of shortcomings: high cost and high consumption of reagents, in many cases irreversible absorption of SO/sub 2/, low economic efficiency. The present study deals with an analysis of the possibilities of practical application of the diffusion method for purification of exhaust gases using selective gas-permeable membranes. This method assures that the purification process will be continuous, eliminates the use of chemical reagents, and makes it possible to enrich the gaseous mixture to SO/sub 2/ concentrations sufficient for further processing of the sulfur dioxide to sulfuric acid. The work consisted of two basic stages: selection of material for fabrication of separative membranes and investigation of the process of extraction of sulfur dioxide from gaseous mixtures. The investigation revealed the theoretical possibility of the extraction of SO/sub 2/ from exhaust gases using membranes made from polydimethylsiloxane. Optimum process conditions were found: a gaseous mixture containing 1.5% SO/sub 2/ can be enriched to 6% sulfur dioxide with a coefficient of extraction of 70%. The data obtained were used to design a pilot plant facility for removal of sulfur-containing compounds from exhaust gases. 1 reference, 2 figures, 2 tables.

Beyyakov, V.P.; Chekalov, L.N.; Talakin, O.G.; Chanina, I.E.; Sviridova, V.I

1980-04-01

65

Hybrid Sulfur Recovery Process for Natural Gas Upgrading. Final Report (January 1, 2001-June 30, 2004).  

National Technical Information Service (NTIS)

This final report describes the objectives, technical approach, results and conclusions for a project funded by the U.S. Department of Energy to test a hybrid sulfur recovery process for natural gas upgrading. The process concept is a configuration of Cry...

A. Zammerilli D. Dalrymple

2004-01-01

66

Electrochemical studies of gold ore processing wastewater containing cyanide, copper, and sulfur compounds  

Microsoft Academic Search

The electrochemistry of real gold ore processing wastewater solutions from copper sulfide containing gold ore has been investigated. Analysis shows that the wastewater contains a range of sulfur compounds in various oxidation states from sulfide to sulfate. The electrochemical characteristics of the gold ore processing wastewater were evaluated using rotating disk, cyclic voltammetric, polarization and preparative electrolysis studies. The solutions

S. C. Cheng; M. Gattrell; T. Guena; B. MacDougall

2006-01-01

67

Catalytic process for removing SO from sulfuric acid plant off gases  

Microsoft Academic Search

The invention is directed to an integrated process for reducing the SO content of sulfuric acid plant off gases by (1) passing the SO-containing feed gas to the process over a specially defined multistage oxidation catalyst to convert SO to SO, (2) absorbing the SO in water to form HSO and (3) scrubbing the off gases with aqueous hydrogen peroxide

1976-01-01

68

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

DOEpatents

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

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

1995-01-01

69

Project on sulfur dioxide removal and waste products utilization process. Final report  

SciTech Connect

The report describes the pilot plant evaluation for a unique process designed for effectively removing sulfur dioxide from stack gas and converting it into useful product as construction materials, chemical for water and wastewater treatment. The product can also be recycled for further SO/sub x/ removal. The product are particles having a core of lime surrounded by a shell of anhydrous calcium sulfate, which has a plurality of cracks. The product has been given a coined name Linfan. The process evaluation has shown that it is very efficient in sulfur oxide (SO/sub 2/ and SO/sub 3/) removal, 100% or near 100% removal efficiency has been attained.

Lin, P.W.

1984-06-01

70

Sulfur Iodine Process Summary for the Hydrogen Technology Down-Selection  

SciTech Connect

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

Benjamin Russ

2009-05-01

71

Use of nonionic surfactant to reduce sulfuric acid mist in the copper electrowinning process  

Microsoft Academic Search

During the copper electrowinning process, sulfuric acid mist is released into the air above the electrowinning tanks. This mist causes health problems for the operators in the electrowinning plant. Therefore, the Occupational Safety and Health Administration (OSHA) has mandated that electrowinning tanks comply with new stringent regulations. This has sparked an interest by copper mines to develop new techniques to

Jennifer L. Sigley; Paul C. Johnson; Stephen P. Beaudoin

2003-01-01

72

DEVELOPMENT OF THE WESTVACO ACTIVATED CARBON PROCESS FOR SOX RECOVERY AS ELEMENTAL SULFUR. VOLUME II. APPENDIX  

EPA Science Inventory

The report gives results of a demonstration (in a 20,000-cfh integral pilot plant) of an all-dry, fluidized-bed process, using activated carbon for recovering SO2 as elemental sulfur. Granular carbon was recycled continuously more than 20 times between contact with flue gas from ...

73

DEVELOPMENT OF THE WESTVACO ACTIVATED CARBON PROCESS FOR SOX RECOVERY AS ELEMENTAL SULFUR. VOLUME I  

EPA Science Inventory

The report gives results of a demonstration (in a 20,000-cfh integral pilot plant) of an all-dry, fluidized-bed process, using activated carbon for recovering SO2 as elemental sulfur. Granular carbon was recycled continuously more than 20 times between contact with flue gas from ...

74

Early evaluation of potential worker exposure problems associated with the Claus-type sulfur recovery process.  

PubMed

Early evaluation of process plants, such as the Claus-type SRU (sulfur recovery unit), in the design stage not only minimizes worker exposure to toxic chemicals and noise, but also reduces costs for retrofit engineering controls. The Claus-type SRU converts the hydrogen sulfide in refinery acid gas into elemental sulfur. In the process, the SRU handles toxic gases containing high concentrations of H2S, SO2, and other sulfur compounds. These gases can be emitted into the worker's breathing zone during start-ups, shutdowns, routine operations, emergencies, and turnarounds. This paper describes the Claus-type sulfur recovery process, the potential sources of worker exposure to toxic chemicals and noise, and the engineering controls that should be adopted at the plant design stage to minimize the risks of worker exposure. Engineering controls include improved pump seals and a choice of sample configurations based on the physical form and concentration of H2S in the process lines. PMID:7055085

Amarnani, S H; Powell, R W

1982-01-01

75

Configuring the thermochemical hydrogen sulfuric acid process step for the Tandem Mirror Reactor  

SciTech Connect

This paper identifies the sulfuric acid step as the critical part of the thermochemical cycle in dictating the thermal demands and temperature requirements of the heat source. The General Atomic Sulfur-Iodine Cycle is coupled to a Tandem Mirror. The sulfuric acid decomposition process step is focused on specifically since this step can use the high efficiency electrical power of the direct converter together with the other thermal-produced electricity to Joule-heat a non-catalytic SO/sub 3/ decomposer to approximately 1250/sup 0/K. This approach uses concepts originally suggested by Dick Werner and Oscar Krikorian. The blanket temperature can be lowered to about 900/sup 0/K, greatly alleviating materials problems, the level of technology required, safety problems, and costs. A moderate degree of heat has been integrated to keep the cycle efficiency around 48%, but the number of heat exchangers has been limited in order to keep hydrogen production costs within reasonable bounds.

Galloway, T.R.

1981-05-01

76

Configuring the thermochemical hydrogen sulfuric acid process step for the Tandem Mirror reactor  

NASA Astrophysics Data System (ADS)

The sulfuric acid step was identified as the critical part of the thermochemical cycle in dictating the thermal demands and temperature requirements of the heat source. The general atomic sulfur-iodine cycle was coupled to a tandem mirror. The sulfuric acid decomposition process step was focused on specifically since this step can use the high efficiency electrical power of the direct converter together with the other thermal-produced electricity to Joule-heat a noncatalytic SO3 decomposer to approximately 1250 K. The blanket temperature was lowered to about 900 K, greatly alleviating materials problems, the level of technology required safety problems, and costs. A moderate degree of heat was integrated to keep the cycle efficiency around 48%, but the number of heat exchangers was limited in order to keep hydrogen production costs within reasonable bounds.

Galloway, T. R.

1981-05-01

77

Responses to the Environmental Health and Safety (EH and S) questionnaire on liquid redox sulfur-recovery processes. Final report  

Microsoft Academic Search

Liquid redox sulfur recovery processes represent an important category of methods currently in use for removing H2S and recovering elemental sulfur from gaseous streams. The Gas Research Institute has been funding research on the complex chemistry of these processes in order to improve their performance and reliability and to evaluate the environmental effects of discharge streams. Since little information is

Rueter

1990-01-01

78

Modeling the gas and liquid-phase resistances in the dry scrubbing process for sulfur dioxide removal  

SciTech Connect

A spray of tiny droplets containing water and calcium hydroxide is used to absorb and react with sulfur dioxide. Simultaneously, water evaporates from the droplets, and solid particles are formed. These particles contain calcium sulfite (the reaction product), unreacted calcium hydroxide, and a small amount of equilibrium moisture. The process is modeled as a spray of isolated droplets that undergo no internal circulation. Sulfur dioxide mass transfer is treated as a series of resistance in the gas and liquid. In the liquid, dissolved sulfur dioxide diffuses through a stagnant film to react with calcium hydroxide. A monodisperse spray is considered first, followed by a polydisperse spray. The effects of important process variables on the conversion of sulfur dioxide are explored in both systems. For instance, as more water is sprayed into the gas, the conversion of sulfur dioxide increases, because the liquid surface area is greater and the droplets take longer to dry. The conversion also increases as more calcium hydroxide is added to the liquid, because the liquid-phase resistance decreases. The conversion decreases substantially at high sulfur dioxide concentration, because less sulfurous acid ionizes. Backmixing the gas often increases the conversion of sulfur dioxide, because the droplets dry more slowly. Reducing the size of the monodispersion, or the mean size of the polydispersion, also increases the conversion, because the equilibrium moisture has greater surface area. The conversion of sulfur dioxide in a monodispersion is compared with the conversion of sulfur dioxide in a polydispersion having the same volume to surface ratio.

Kinzey, M.K. Jr.

1988-01-01

79

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

Microsoft Academic Search

A long-term performance of a packed-bed bioreactor containing sulfur and limestone was evaluated for the denitrification of drinking water. Autotrophic denitrification rate was limited by the slow dissolution rate of sulfur and limestone. Dissolution of limestone for alkalinity supplementation increased hardness due to release of Ca2+. Sulfate production is the main disadvantage of the sulfur autotrophic denitrification process. The effluent

Erkan Sahinkaya; Nesrin Dursun; Adem K?l?c; Sevgi Demirel; Sinan Uyanik; Ozer Cinar

80

Process screening study of alternative gas treating and sulfur removal systems for IGCC (Integrated Gasification Combined Cycle) power plant applications: Final report  

Microsoft Academic Search

One of the inherent advantages of the Integrated Gasification Combined Cycle plant (IGCC) over other coal-based electric generation technologies is that the sulfur in the coal is converted into a form which can be removed and recovered. Extremely low sulfur oxide emissions can result. Gas treating and sulfur recovery processes for the control of sulfur emissions are an integral part

F. E. Biasca; N. Korens; B. L. Schulman; D. R. Simbeck

1987-01-01

81

Abatement of Sulfur Hexafluoride Emissions from the Semiconductor Manufacturing Process by Atmospheric-Pressure Plasmas  

Microsoft Academic Search

Sulfur hexafluoride (SF6) is an important gas for plasma etching processes in the semiconductor industry. SF6 intensely absorbs infrared radiation and, consequently, aggravates global warming. This study investigates SF6 abatement by nonthermal plasma technologies under atmospheric pressure. Two kinds of nonthermal plasma processesdielectric barrier discharge (DBD) and combined plasma catalysis (CPC)were employed and evaluated. Experimental results indicated that as much

How Ming Lee; Moo Been Chang; Kuan Yu Wu

2004-01-01

82

High temperature solar thermochemical processing - Hydrogen and sulfur from hydrogen sulfide  

NASA Astrophysics Data System (ADS)

Sunlight, concentrated to high intensities, has a rarely recognized potential for adding process heat to reactors at high temperatures. Hydrogen sulfide is a by-product of the sweetening of fossil fuels. In this paper, by way of example, the production of hydrogen and sulfur from hydrogen sulfide is used as a device for showing how solar processing might be considered as a successor to a currently used industrial process, the Claus process. It is concluded that this and other processes should be explored as means of using as well as storing solar energy.

Noring, J. E.; Fletcher, E. A.

1982-08-01

83

Low strength wastewater treatment under low temperature conditions by a novel sulfur redox action process.  

PubMed

The objective of this research is to make a novel wastewater treatment process activated by a sulfur-redox cycle action of microbes in low temperature conditions. This action is carried out by sulfate-reducing bacteria (SRB) and sulfur-oxidizing bacteria (SOB). The process was comprised of a UASB reactor as pre-treatment and an aerobic downflow hanging sponge (DHS) reactor as post-treatment. As the results of reactor operation, the whole process achieved that over 90% of CODcr removal efficiency, less than 30 mgCODcr/L (less than 15 mgBOD/L) of final effluent, at 12 h of HRT and at 8 degrees C of UASB reactor temperature. Acetobacterium sp. was detected as the predominant species by PCR-DGGE method targeting 16SrDNA with band excision and sequence analysis. In the UASB reactor, various species of sulfate-reducing bacterium, Desulfobulbus sp., Desulfovibrio sp., and Desulfomicrobium sp., were found by cloning analysis. In the DHS reactor, Tetracoccus sp. presented as dominant. The proposed sulfur-redox action process was considered as an applicable process for low strength wastewater treatment in low temperature conditions. PMID:16749445

Yamaguchi, T; Bungo, Y; Takahashi, M; Sumino, H; Nagano, A; Araki, N; Imai, T; Yamazaki, S; Harada, H

2006-01-01

84

Hydrogen production by the GA sulfur-iodine process: a progress report  

SciTech Connect

A summary of the progress of the overall total development effort of the General Atomic (GA) sulfur-iodine thermochemical water-splitting cycle over the last two years is reported. The major accomplishments have been the following: (1) Significant improvements in the chemistry of the process. (2) Development, review, and revision of an engineering flowsheet, resulting in a thermal process efficiency of 47%. (3) Screening, identification, and testing of potential materials-of-construction for the corrosive process fluids. (4) Small-scale demonstration of the cycle in a closed loop under recycle conditions. (5) Installation of bench-scale equipment and demonstration of parts of the process in this system. (6) Development of a conceptual, preliminary flowsheet for the GA sulfur-iodine cycle driven by solar energy. The results of the work carried out during the last two years have demonstrated that thermochemical water splitting by the sulfur-iodine cycle is a feasible process and have provided confidence that thermal efficiencies in the range of 50% are achievable.

Besenbruch, G.E.; McCorkle, K.H.; Norman, J.H.; O'Keefe, D.R.; Schuster, J.R.; Yoshimoto, M.

1980-03-01

85

Gasoline from natural gas by sulfur processing. Final technical report, June 1993--July 1996  

SciTech Connect

The overall objective of this research project was 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 use catalysts and sulfur-containing intermediates: (1) to convert natural gas to CS{sub 2} and (2) to convert CS{sub 2} to gasoline-range liquids. Experimental data generated in this project were for use in evaluating the commercial potential of the process.

Erekson, E.J.

1996-07-01

86

Sulfate-reduction, sulfide-oxidation and elemental sulfur bioreduction process: Modeling and experimental validation.  

PubMed

This study describes the sulfate-reducing (SR) and sulfide-oxidizing (SO) process using Monod-type model with best-fit model parameters both being reported and estimated. The molar ratio of oxygen to sulfide (ROS) significantly affects the kinetics of the SR+SO process. The S(0) is produced by SO step but is later consumed by sulfur-reducing bacteria to lead to "rebound" in sulfide concentration. The model correlated well all experimental data in the present SR+SO tests and the validity of this approach was confirmed by independent sulfur bioreduction tests in four denitrifying sulfide removal (DSR) systems. Modeling results confirm that the ratio of oxygen to sulfide is a key factor for controlling S(0) formation and its bioreduction. Overlooking S(0) bioreduction step would overestimate the yield of S(0). PMID:23994962

Xu, Xijun; Chen, Chuan; Lee, Duu-Jong; Wang, Aijie; Guo, Wanqian; Zhou, Xu; Guo, Hongliang; Yuan, Ye; Ren, Nanqi; Chang, Jo-Shu

2013-07-30

87

Process for producing dry, sulfur-free, CH[sub 4]-enriched synthesis or fuel gas  

Microsoft Academic Search

A process is described for the production of a dry, sulfur-free methane enriched synthesis gas or fuel gas stream comprising: (1) cooling a particulate-free raw synthesis or fuel gas feed stream comprising H[sub 2], CO, CO[sub 2], H[sub 2]O, N[sub 2], H[sub 2]S, COS and with or without methane to a temperature in the range of about 60 F to

E. T. Child; W. L. Jr. Lafferty; R. M. Suggitt; F. C. Jahnke

1993-01-01

88

Temperature dependence of vibrational relaxation processes in sulfur crystals: Effect of isotopic impurities  

Microsoft Academic Search

We have studied phonon relaxation processes in orthorhombic sulfur crystals, for several lattice and internal vibrations. Bandwidths were measured as a function of temperature using a tandem FabryPerot spectrometer instrument with a limiting resolution of 0.001 cm?1. In order to obtain a basis for the study of the effect of isotopic impurities, we have grown single crystals of isotopically pure

Maurizio Becucci; Emilio Castellucci; Paolo Foggi; Salvatore Califano; David A. Dows

1992-01-01

89

A pilot test plan of the thermochemical water-splitting iodinesulfur process  

Microsoft Academic Search

Research and development (R&D) of hydrogen production systems using high-temperature gas-cooled reactors (HTGR) are being conducted by the Japan Atomic Research Institute (JAERI). To develop the systems, superior hydrogen production methods are essential. The thermochemical hydrogen production cycle, the IS (iodinesulfur) process, is a prospective candidate, in which heat supplied by HTGR can be consumed for the thermal driving load.

Shinji Kubo; Seiji Kasahara; Hiroyuki Okuda; Atsuhiko Terada; Nobuyuki Tanaka; Yoshitomo Inaba; Hirofumi Ohashi; Yoshiyuki Inagaki; Kaoru Onuki; Ryutaro Hino

2004-01-01

90

Gasoline from natural gas by sulfur processing. Quarterly progress report, June--September 1993  

SciTech Connect

The overall objective of this research project is to develop a catalytic process to convert natural gas to liquid transportation fuels. The process consists of two steps that each utilize catalysts and sulfur containing intermediates: (1) to convert natural gas to CS{sub 2}, and (2) to convert CS{sub 2} to gasoline range liquids. Experimental data will be generated to demonstrate the potential of catalysts and the overall process. During this first quarter, progress in the following areas has been made. One high surface area molybdenum catalyst has been prepared. An existing unit at IGT is being modified to accommodate the sulfur feedstocks and the higher temperatures(> 1300{degrees}K) required for studying the reactions of hydrogen sulfide and methane as proposed in Tasks 2 through 5. An HP 5890 gas chromatograph with a TCD(thermal conductivity detector) for detecting fixed gases including hydrogen and an FPD(flame photometric detector) for detecting sulfur compounds was purchased using SMP funds and has been received.

Erekson, E.J.; Miao, F.Q.

1993-10-01

91

Process for improving a gas containing a minor amount of sulfur dioxide impurity and producing a hydrogen sulfide-rich gas  

Microsoft Academic Search

A process is provided for adsorbing sulfur dioxide impurity from an impure gas and producing a hydrogen sulfide-rich gas. In the process, a first adsorbate containing oxidized sulfur is produced by contacting the impure gas with an adsorbent comprising a composite of an alumina support and sodium and vanadium oxides. A second adsorbate containing reduced sulfur is produced by contacting

Blanton

1980-01-01

92

Fabrication and characterization of thermomechanically processed sulfur and boron doped amorphous carbon films  

NASA Astrophysics Data System (ADS)

Small scale, high power density, reliable, and long-life power supplies would be useful or even critical for space missions or the growing number of microdetectors, microsensors, and miniature vehicles. Alpha or beta particle voltaic devices could satisfy these requirements but have been shown to degrade quickly due to radiation damage. Amorphous carbon (a-C) PN junctions or PIN devices could provide radiation hardness and sufficiently high efficiency. As the range of alpha and beta particles in a-C is 20-120microm, much thicker films than are typical are needed to maximize collection of the particle energy. In this work, the fabrication of thermomechanically processed p- and n-type doped a-C films were investigated as a first step in the future development of radiation hard voltaic devices. Boron carbide (B4C) powder was mixed with a-C nanopowders as a possible p-type dopant with sulfur powder utilized as a possible n-type dopant. Doping levels of 2.5at%, 5.0at%, and 10.0at% were investigated for both dopants with films pressed at 109C over a pressure range of 0.3-5.0GPa. Initial attempts to fabricate rectifying PN junctions and PIN devices was unsuccessful. Bonding properties were characterized using Raman spectroscopy with electronic properties primarily assessed using the van der Pauw method. Undoped a-C and boron-doped films were found to be slightly p-type with sulfur-doped films converting to n-type. All films were found to consist almost entirely of nano-graphitic sp2 rings with only slight changes in disorder at different pressures. Sulfur doped films were less brittle which is indicative of crosslinking. Boron doping did not significantly change the film electronic properties and is not an effective dopant at these temperatures and pressures. Sulfur doping had a greater effect and could likely be utilized as basis for an n-type material in a device. Initial irradiation studies using alpha particles showed that boron and undoped films became more p-type with sulfur films converting to p-type. The sulfur doped films returned to n-type after isothermal annealing.

Carlson, Lonnie

93

Process for producing dry, sulfur-free, CH[sub 4]-enriched synthesis or fuel gas  

SciTech Connect

A process is described for the production of a dry, sulfur-free methane enriched synthesis gas or fuel gas stream comprising: (1) cooling a particulate-free raw synthesis or fuel gas feed stream comprising H[sub 2], CO, CO[sub 2], H[sub 2]O, N[sub 2], H[sub 2]S, COS and with or without methane to a temperature in the range of about 60 F to 130 F and separating out at least a portion of water condensate; (2) mixing together said cooled raw synthesis or fuel gas from (1) and a portion of cryogenic liquefied natural gas (LNG) thereby further cooling the new synthesis or fuel gas to a temperature in the range of about [minus]75 F to 60 F; (3) directly contacting the mixture from (2) in an acid-gas removal zone with liquid acid-gas absorbent solvent thereby absorbing sulfur-containing compounds, water, and at least a portion of the CO[sub 2], and thereby producing acid-gas rich liquid absorbent solvent containing dissolved water and a dry stream of methane enriched synthesis or fuel gas; (4) separating said acid-gas rich liquid absorbent from said dry stream of methane enriched synthesis or fuel gas comprising H[sub 2], CO, CH[sub 4], and substantially no sulfur-containing gas or moisture; (5) regenerating the separated acid-gas rich liquid absorbent solvent to remove the sulfur-containing gas and the dissolved water; and (6) introducing regenerated liquid acid-gas absorbent solvent into said acid gas removal zone.

Child, E.T.; Lafferty, W.L. Jr.; Suggitt, R.M.; Jahnke, F.C.

1993-08-03

94

Sulfuric acid on Europa and the radiolytic sulfur cycle.  

PubMed

A comparison of laboratory spectra with Galileo data indicates that hydrated sulfuric acid is present and is a major component of Europa's surface. In addition, this moon's visually dark surface material, which spatially correlates with the sulfuric acid concentration, is identified as radiolytically altered sulfur polymers. Radiolysis of the surface by magnetospheric plasma bombardment continuously cycles sulfur between three forms: sulfuric acid, sulfur dioxide, and sulfur polymers, with sulfuric acid being about 50 times as abundant as the other forms. Enhanced sulfuric acid concentrations are found in Europa's geologically young terrains, suggesting that low-temperature, liquid sulfuric acid may influence geological processes. PMID:10506568

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

1999-10-01

95

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

Microsoft Academic Search

This work investigates the interactions between gas-phase carbonyl compounds and sulfuric acid aerosols. It focuses on understanding the chemical processes, giving a first estimate of their importance in the atmosphere, and suggesting directions for further investigations. The solubility and reactivity of a compound with a large enolization constant, 2,4-pentanedione, in water\\/sulfuric acid solutions 096wt% have been investigated at room temperature

Barbara Nozire; Daniel D Riemer

2003-01-01

96

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

SciTech Connect

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

Parks, II, James E [ORNL; Ponnusamy, Senthil [ORNL

2006-01-01

97

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

SciTech Connect

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

Lynn, S.; Cairns, E.J.

1992-11-01

98

Sequences of the iron-sulfur protein precursor necessary for its import and two-step processing in yeast mitochondria.  

PubMed

Gene fusion techniques were used to examine whether the presequence of the iron-sulfur protein contains sufficient information for the import of attached mouse cytosolic enzyme dihydrofolate reductase into isolated yeast mitochondria and its subsequent two-step processing. Genes encoding amino-terminal segments of the iron-sulfur precursor protein including the proposed first presequence (residues 1-21), the complete presequence (residues 1-30), and various lengths of the precursor protein from 31 to 160 residues were fused, in frame, to dihydrofolate reductase. All of the fusion proteins, after synthesis in an in vitro transcription-translation system, were imported into a protease-resistant compartment of mitochondria where a single proteolytic cleavage was observed at the first processing site. The second cleavage, however, was not observed after import of any of the chimeric proteins, suggesting that the second cleavage may be strongly influenced by the presence of the passenger protein. A deletion mutant of the iron-sulfur protein precursor lacking residues 161-180 underwent two proteolytic cleavages similar to those observed for the wild-type iron-sulfur protein after import into mitochondria. These results suggest that the complete sequence of the mature form of the iron-sulfur protein including the amino acid residues involved in binding the iron sulfur clusters is not necessary for the second cleavage to occur. In addition, the hydrophobic sequence present in residues 55-66 of the precursor protein which has been suggested to anchor the iron-sulfur protein to the inner membrane, was not necessary for the import and two-step processing of the protein, since a deletion mutant lacking residues 55-66 was processed correctly. PMID:8037454

Japa, S; Beattie, D S

1994-08-01

99

Coupled sulfur isotopic and chemical mass transfer modeling: Approach and application to dynamic hydrothermal processes  

SciTech Connect

A computational modeling code (EQPSreverse arrowS) has been developed to examine sulfur isotopic distribution pathways coupled with calculations of chemical mass transfer pathways. A post processor approach to EQ6 calculations was chosen so that a variety of isotopic pathways could be examined for each reaction pathway. Two types of major bounding conditions were implemented: (1) equilibrium isotopic exchange between sulfate and sulfide species or exchange only accompanying chemical reduction and oxidation events, and (2) existence or lack of isotopic exchange between solution species and precipitated minerals, parallel to the open and closed chemical system formulations of chemical mass transfer modeling codes. All of the chemical data necessary to explicitly calculate isotopic distribution pathways is generated by most mass transfer modeling codes and can be input to the EQPS code. Routines are built in to directly handle EQ6 tabular files. Chemical reaction models of seafloor hydrothermal vent processes and accompanying sulfur isotopic distribution pathways illustrate the capabilities of coupling EQPSreverse arrowS with EQ6 calculations, including the extent of differences that can exist due to the isotopic bounding condition assumptions described above. 11 refs., 2 figs.

Janecky, D.R.

1988-09-21

100

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

SciTech Connect

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

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

1993-03-23

101

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

NASA Astrophysics Data System (ADS)

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.

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

2012-08-01

102

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

SciTech Connect

In this invention, a process is disclosed characterized by heating a slurry of coal in the presence of a process-derived recycle solvent and passing same to a dissolver zone, separating the resultant gases and liquid/solid products therefrom, vacuum distilling the liquid/solids products, separating the portions of the liquid/solids vacuum distillation effluent into a solid ash, unconverted coal particles and SRC material having a boiling point above 850/sup 0/ F. and subjecting same to a critical solvent deashing step to provide an ash-free SRC product. The lighter liquid products from the vacuum distillation possess a boiling point below 850/sup 0/ F. and are passed through a distillation tower, from which recycled solvent is recovered in addition to light distillate boiling below 400/sup 0/ F. (overhead). The ash-free SRC product in accompanyment with at least a portion of the process derived solvent is passed in combination to a hydrotreating zone containing a hydrogenation catalyst and in the presence of hydrogen is hydroprocessed to produce a desulfurized and denitrogenized low-sulfur, low-ash boiler fuel and a process derived recycle solvent which is recycled to slurry the coal in the beginning of the process before heating.

Roberts, G.W.; Tao, J.C.

1985-08-13

103

Gasoline from natural gas by sulfur processing. Quarterly report No. 11, January--March 1996  

SciTech Connect

The overall objective of this research project is to develop a catalytic process to convert natural gas to liquid transportation fuels. The process consists of two steps that each use catalysts and sulfur-containing intermediates: (1) converting natural has to CS{sub 2} and (2) converting CS{sub 2} to gasoline-range liquids. Experimental data will be generated to demonstrate the potential of catalysts and the overall process. During this quarter, progress in the following areas has been made: Hydrogenation of CS{sub 2} to liquid hydrocarbons was accomplished on two sets of catalyst a cobalt exchanged ZSM-5 and a mixture containing MoS{sub 2} hydrogenation catalyst and HZSM-5. CS{sub 2} conversions of up to 100% were achieved. The highest selectivity to C{sub 4}{sup +} hydrocarbons was 52%. There is interest within the oil companies we contacted for a process that converts natural gas to liquid hydrocarbons. In addition there is also interest in a process that produces hydrogen for a refinery, while at the same time it removes hydrogen sulfide.

Erekson, E.J.

1996-05-01

104

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

DOEpatents

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

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

1985-01-01

105

Process screening study of alternative gas treating and sulfur removal systems for IGCC (Integrated Gasification Combined Cycle) power plant applications: Final report  

SciTech Connect

One of the inherent advantages of the Integrated Gasification Combined Cycle plant (IGCC) over other coal-based electric generation technologies is that the sulfur in the coal is converted into a form which can be removed and recovered. Extremely low sulfur oxide emissions can result. Gas treating and sulfur recovery processes for the control of sulfur emissions are an integral part of the overall IGCC plant design. There is a wide range of commercially proven technologies which are highly efficient for sulfur control. In addition, there are many developing technologies and new concepts for applying established technologies which offer potential improvements in both technical and economic performance. SFA Pacific, Inc. has completed a screening study to compare several alternative methods of removing sulfur from the gas streams generated by the Texaco coal gasification process for use in an IGCC plant. The study considered cleaning the gas made from high and low sulfur coals to produce a low sulfur fuel gas and a severely desulfurized synthesis gas (suitable for methanol synthesis), while maintaining a range of low levels of total sulfur emissions. The general approach was to compare the technical performance of the various processes in meeting the desulfurization specifications laid out in EPRI's design basis for the study. The processing scheme being tested at the Cool Water IGCC facility incorporates the Selexol acid gas removal process which is used in combination with a Claus sulfur plant and a SCOT tailgas treating unit. The study has identified several commercial systems, as well as some unusual applications, which can provide efficient removal of sulfur from the fuel gas and also produce extremely low sulfur emissions - so as to meet very stringent sulfur emissions standards. 29 refs., 8 figs., 8 tabs.

Biasca, F.E.; Korens, N.; Schulman, B.L.; Simbeck, D.R.

1987-12-01

106

Sulfuric acid-sulfur heat storage cycle  

DOEpatents

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

Norman, John H. (LaJolla, CA)

1983-12-20

107

Sulfur barrier for use with in situ processes for treating formations  

DOEpatents

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

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

2009-12-15

108

Process for preparing a sulfurized molybdenum-containing composition and lubricating oil containing said composition  

SciTech Connect

Antioxidant additives for lubricating oil are prepared by combining a polar promoter, ammonium tetrathiomolybdate, and a basic nitrogen compound complex to form a sulfur- and molybdenumcontaining composition.

Devries, L.; King, J.M.

1981-08-11

109

Understanding volcanic processes using UV camera measurements of sulfur dioxide and coincident infrasound and seismicity  

NASA Astrophysics Data System (ADS)

The exsolution of volatiles from magma maintains an important control on volcanic eruption styles. The nucleation, growth, and connectivity of bubbles during magma ascent provide the driving force behind eruptions, and the rate, volume, and ease of gas exsolution can affect eruptive activity. Volcanic plumes are the observable consequence of this magmatic degassing, and remote sensing techniques allow us to quantify changes in gas exsolution. However, until recently the methods used to measure volcanic plumes did not have the capability of detecting rapid changes in degassing on the scale of standard geophysical observations. The advent of the UV camera now makes high sample rate gas measurements possible. This type of dataset can then be compared to other volcanic observations to provide an in depth picture of degassing mechanisms in the shallow conduit. The goals of this research are to develop a robust methodology for UV camera field measurements of volcanic plumes, and utilize this data in conjunction with seismoacoustic records to illuminate degassing processes. Field and laboratory experiments were conducted to determine the effects of imaging conditions, vignetting, exposure time, calibration technique, and filter usage on the UV camera sulfur dioxide measurements. Using the best practices determined from these studies, a field campaign was undertaken at Volcan de Pacaya, Guatemala. Coincident plume sulfur dioxide measurements, acoustic recordings, and seismic observations were collected and analyzed jointly. The results provide insight into the small explosive features, variations in degassing rate, and plumbing system of this complex volcanic system. This research provides useful information for determining volcanic hazard at Pacaya, and demonstrates the potential of the UV camera in multiparameter studies.

Dalton, Marika Piirak

110

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

Microsoft Academic Search

The overall objective of this round robin project was to select the most efficient, as determined by the efficiency index, cost effective, as determined by the annual cost per ton of SO removed, advanced flotation device available. This machine was to process ultra fine coal, maximize Btu recovery and maximize pyritic sulfur rejection. The device will first be installed as

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

1990-01-01

111

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

PubMed

Chemical conditioners are often used to enhance sewage sludge dewaterability through altering sludge properties and flocs structure, both affect odorous compounds emissions not only during sludge conditioning but also in subsequent sludge disposal. This study was to investigate emission characteristics of ammonia (NH(3)), sulfur dioxide (SO(2)), hydrogen sulfide (H(2)S) and carbonyl sulfide (COS) generated from sewage sludge conditioned by three representative conditioners, i.e., organic polymers, iron salts and skeleton builders, F-S (Fenton's reagent and skeleton builders) composite conditioner. The results demonstrate that polyacrylamide (PAM) has an insignificant effect on emission characteristics of nitrogen- and sulfur-containing odorous compounds, because the properties, sulfur and nitrogen speciations are similar in PAM-conditioned sludge and raw sludge (RS). Significant increases of SO(2) and H(2)S emissions in the H(2)SO(4) conditioning process were observed due to the accelerated decomposition of sulfur-containing amino acids in acidic environment. Fenton peroxidation facilitates the formation of COS. CaO can reduce sulfur-containing gases emission via generation of calcium sulfate. However, under strong alkaline conditions, free ammonia or protonated amine in sludge can be easily converted to volatile ammonia, resulting in a significant release of NH(3). PMID:22902143

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

2012-08-07

112

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

Code of Federal Regulations, 2010 CFR

...is the process for approval of a test method for determining the sulfur content...is the process for approval of a test method for determining the sulfur content...by each test facility for each test method that it wishes to have...

2010-07-01

113

Advanced sulfur control concepts  

Microsoft Academic Search

Regenerable metal oxide sorbents, such as zinc titanate, are being developed to efficiently remove hydrogen sulfide (HS) from coal gas in advanced power systems. Dilute air regeneration of the sorbents produces a tailgas containing a few percent sulfur dioxide (SO). Catalytic reduction of the SO to elemental sulfur with a coal gas slipstream using the Direct Sulfur Recovery Process (DSRP)

S. K. Gangwal; B. S. Turk; R. P. Gupta

1995-01-01

114

Sulfur dioxide: A versatile reagent for the processing of cobaltic oxide minerals  

NASA Astrophysics Data System (ADS)

Cobaltic oxide minerals are readily dissolved in mildly acidic sulfuric solutions provided a reducing agent is also present. Sulfur dioxide is the most common reductant recommended for this purpose, but its addition during the leaching step could lead to significant environmental problems and could affect the recovery of copper if present in large amounts. This paper presents a novel approach whereby the reductant used during the leach is ferrous sulfate and sulfur dioxide is added at a later stage in a controlled manner to regenerate the reductant after any copper present has been recovered. Sulfur dioxide can also be used during purification of the cobalt bleed, where, blended with oxygen, it constitutes a powerful oxidant capable of selectively oxidizing and precipitating manganese away from the cobalt. This paper will present several applications of the use of sulfur dioxide as a primary reductant, a regenerant for ferrous sulfate, and a selective oxidant for manganese.

Ferron, C. Joe

2008-10-01

115

A fuel-cell-assisted iron redox process for simultaneous sulfur recovery and electricity production from synthetic sulfide wastewater.  

PubMed

Sulfide present in wastewaters and waste gases should be removed due to its toxicity, corrosivity, and malodorous property. Development of effective, stable, and feasible methods for sulfur recovery from sulfide attains a double objective of waste minimization and resource recovery. Here we report a novel fuel-cell-assisted iron redox (FC-IR) process for simultaneously recovering sulfur and electricity from synthetic sulfide wastewater. The FC-IR system consists of an oxidizing reactor where sulfide is oxidized to elemental sulfur by Fe(III), and a fuel cell where Fe(III) is regenerated from Fe(II) concomitantly with electricity producing. The oxidation of sulfide by Fe(III) is significantly dependent on solution pH. Increasing the pH from 0.88 to 1.96 accelerates the oxidation of sulfide, however, lowers the purity of the produced elemental sulfur. The performance of fuel cell is also a strong function of solution pH. Fe(II) is completely oxidized to Fe(III) when the fuel cell is operated at a pH above 6.0, whereas only partially oxidized below pH 6.0. At pH 6.0, the highest columbic efficiency of 75.7% is achieved and electricity production maintains for the longest time of 106 h. Coupling operation of the FC-IR system obtains sulfide removal efficiency of 99.90%, sulfur recovery efficiency of 78.6 8.3%, and columbic efficiency of 58.6 1.6%, respectively. These results suggest that the FC-IR process is a promising tool to recover sulfur and energy from sulfide. PMID:23149300

Zhai, Lin-Feng; Song, Wei; Tong, Zhong-Hua; Sun, Min

2012-11-02

116

Development of a zero-emissions sulfur-recovery process: 2. Sulfur-recovery process based on the reactions of H[sub 2]S and CO[sub 2] at high temperature  

SciTech Connect

When H[sub 2]S is heated above 600 C in the presence of CO[sub 2], elemental sulfur and synthesis gas are formed. A sulfur-recovery process using this chemistry is as follows: H[sub 2]S is heated in a high-temperature reactor in the presence Of CO[sub 2] and a suitable catalyst. The primary products of the overall reaction are S[sub 2], CO, H[sub 2], and H[sub 2]O. Small amounts of COS, SO[sub 2], and CS[sub 2] also form. Rapid quenching of the reaction mixture to roughly 600 C prevents loss Of S[sub 2] during cooling. Carbonyl sulfide is removed from the product gas by hydrolysis back to CO[sub 2] and H[sub 2]S. Unreacted CO[sub 2] and H[sub 2]S are removed from the product gas and recycled to the reactor, leaving a gas consisting chiefly of H[sub 2] and CO, which recovers the hydrogen value from the H[sub 2]S. This process is economically favorable compared to the existing sulfur-recovery technology and allows emissions of sulfur-containing gases to be controlled to very low levels.

Towler, G.P.; Lynn, S. (Univ. of California, Berkeley, CA (United States). Dept. of Chemical Engineering)

1993-11-01

117

Hydration of aircraft engine soot particles under plume conditions: Effect of sulfuric and nitric acid processing  

NASA Astrophysics Data System (ADS)

Hydration properties of original engine soot produced by burning TC1 aviation kerosene in aircraft engine combustor are studied under simulated plume conditions. Engine-generated soot demonstrates a high level of water uptake due to the existence of fraction of impurities originating within an engine. It contains 13.5 wt% water soluble compounds including 3.5 wt% organic and inorganic sulfates. Total amount of water vapor absorbed by engine soot particles increases with the temperature decrease in the exhaust plume and reaches 18 wt% at threshold contrail formation conditions. Chemical processing of soot particles in the young plume through the coagulation with sulfate aerosols and H2SO4/H2O heterogeneous nucleation leads to 0.2 wt% of H2SO4 accumulating at high fuel sulfur content. Such a small amount of additional H2SO4 cannot result in the increase of water uptake by the fraction of impurities of engine-generated soot particles but may activate the hydrophobic fraction that originally contains a negligible amount of water soluble compounds. HNO3 processing may compete with H2SO4 in respect to increase of water uptake. It is inferred that the fraction of impurities of engine-generated soot plays a key role in the CCN formation in the aircraft plume.

Shonija, N. K.; Popovicheva, O. B.; Persiantseva, N. M.; Savel'Ev, A. M.; Starik, A. M.

2007-01-01

118

Mixing of sulfur between pyritic and organic phases during coal conversion processes: Annual final report, March 1, 1986-February 28, 1987  

SciTech Connect

In preparation for using /sup 33/S NMR for characterization of organic sulfur types in coal, previously prepared substituted dibenzothiophene model compounds were converted to their corresponding sulfones and their sulfur-33 nmr recorded. The sulfur-33 NMR spectra of dibenzothiophene-5,5-dioxide (2), 2-(p-methylphenylsulfonyl) dibenzothiophene-5,5-dioxide (4), and 2-(methylsulfonyl) dibenzothiophene-5,5-dioxide (6) are reported. The chemical shifts were in the +2 to -21 ppM range. The line widths ranged 70 to 200 Hz. The changes in /sup 13/C chemical shift experienced by aromatic carbons upon oxidizing the sulfide to its sulfone were also studied and the data used to identify which sulfone was formed in multiple thioether-containing aromatics after partial oxidation. Continuing results on the use of the substituted dibenzothiophenes to monitor mixing of sulfur between pyritic and organic phases are also reported. Non-isothermal hydrodesulfurization of model organic sulfur compounds was carried out in a cola-like environment. The model sulfur compounds represented different types of carbon-sulfur bonds commonly encountered in coal. Similar experiments were carried out in the presence of troilite (iron sulfide) to investigate the possibility of sulfur migration from the organic compound to the iron sulfide. Next, iron pyrite was hydrodesulfurized in the presence of some organic molecules to see if sulfur could be incorporated into the organic molecules during the process. Results show that sulfur from organic compounds can be absorbed by troilite, and, similarly, sulfur from pyrite can form new carbon-sulfur bonds during hydrodesulfurization. Based on these observations, it is suggested that during coal conversion reactions it is possible to have intermigration of sulfur between the organic and the inorganic phases.

Dunkerton, L.V.; Nigam, A.; Mitra, S.; Phillips, J.B.; Smith, G.V.; Wiltowska, T.

1987-05-01

119

Permanganate oxidation of sulfur compounds to prevent poisoning of Pd catalysts in water treatment processes.  

PubMed

The practical application of Pd-catalyzed water treatment processes is impeded by catalyst poisoning by reduced sulfur compounds (RSCs). In this study, the potential of permanganate as a selective oxidant for the removal of microbially generated RSCs in water and as a regeneration agent for S-poisoned catalysts was evaluated. Hydrodechlorination using Pd/Al2O3 was carried out as a probe reaction in permanganate-pretreated water. The activity of the Pd catalysts in the successfully pretreated reaction medium was similar to that in deionized water. The catalyst showed no deactivation behavior in the presence of permanganate at a concentration level < or = 0.07 mM. With a residual oxidant concentration of > or = 0.08 mM, a significant but temporary inhibition of the catalytic dechlorination was observed. Unprotected Pd/Al2O3, which had been completely poisoned by sulfide, was reactivated by a combined treatment with permanganate and hydrazine. However, the anthropogenic water pollutants thiophene and carbon disulfide were resistant against permanganate. Together with the preoxidation of catalyst poisons, hydrophobic protection of the catalysts was studied. Pd/zeolite and various hydrophobically coated catalysts showed a higher stability against ionic poisons and permanganate than the uncoated catalyst. By means of a combination of oxidative water pretreatment and hydrophobic catalyst protection, we provide a new tool to harness the potential of Pd-catalyzed hydrodehalogenation for the treatment of real waters. PMID:18754501

Angeles-Wedler, Dalia; Mackenzie, Katrin; Kopinke, Frank-Dieter

2008-08-01

120

[Microbial processes of the carbon and sulfur cycles in the White Sea].  

PubMed

The present paper contains the results of our microbiological and biogeochemical investigations carried out during a series of expeditions to the White Sea in 2002-2006. The studies were conducted in the open part of the White Sea, as well as in the Onega, Dvina, and Kandalaksha bays. In August 2006, the photosynthetic productivity in the surface water layer was low (47-145 mg C m(-2) day(-1)). Quantitative characteristics of microbial numbers and activity of the the key microbial processes occurring in the water column of the White Sea were explored. Over the 5-year period of observations, the total number of bacterial cells in the surface layer of the water column varied from 50 to 600 thousand cells ml(-1). In August 2006, bacterioplankton production (BP) was estimated to be 0.26-3.3 microg C l(-1) day(-1); the P/B coefficient varied from 0.22 to 0.93. The suspended organic matter had a lighter isotope composition (from -28.0 to -30.5 per thousand) due to the predominance of terrigenous organic matter delivered by the Northern Dvina waters. The interseasonal and interannual variation coefficients for phytoplankton production and BP numbers are compared. The bacterioplankton community of the White Sea's deep water was found to be more stable than that of the surface layer. In the surface layer of bottom sediments, methane concentration was 0.2-5.2 microl dm(-3); the rate of bacterial sulfate reduction was 18-260 microg S dm(-3) day(-1); and the rates of methane production and oxidation were 24-123 and 6-13 nl CH4 dm(-3) day(-1) respectively. We demonstrated that the rates of microbial processes of the carbon and sulfur cycles occurring in the sediments of the White Sea basin were low. PMID:19137722

Savvichev, A S; Rusanov, I I; Zakharova, E E; Veslopolova, E F; Mitskevich, I N; Kravchishina, M D; Lein, A Iu; Ivanov, M V

121

A demonstration study on a closed-cycle hydrogen production by the thermochemical water-splitting iodinesulfur process  

Microsoft Academic Search

Japan Atomic Energy Research Institute (JAERI) has been conducting R&D on thermochemical hydrogen production using the water-splitting iodinesulfur process, as part of the research programs striving to utilize heat from a high temperature gas-cooled reactor (HTGR). The R&D is currently at the bench-scale stage and covers several fields including the evaluation of structural materials in corrosion environments, the improvement in

Shinji Kubo; Hayato Nakajima; Seiji Kasahara; Syunichi Higashi; Tomoo Masaki; Hiroyoshi Abe; Kaoru Onuki

2004-01-01

122

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

SciTech Connect

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.

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

1997-12-01

123

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

SciTech Connect

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

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

1980-05-01

124

An Improved Process in the Finishing of Cellulose-Containing Materials by Use of Magnesium Sulfate with N-Methylol Amide Crosslinking Agents and Sulfuric Acid.  

National Technical Information Service (NTIS)

The patent application relates to an improved process for obtaining finished fabrics which have higher strength than normally encountered in fabrics treated for durable press properties with an N-methylol amide crosslinking agent and sulfuric acid. Specif...

R. M. Reinhardt R. M. H. Kullman

1974-01-01

125

Dry Sorbent Process for the Simultaneous Removal of Sulfur and Nitrogen Oxides.  

National Technical Information Service (NTIS)

The patent application concerns the removal of nitrogen oxides and sulfur oxides, in the concentrations found in fossil-fuel flue gases, by treatment with a dry sorbent such as a molecular sieve or anhydrous calcium sulfate. At low concentrations of NO, r...

E. E. Berkau D. W. Pershing

1974-01-01

126

Process for preparing a sulfurized molybdenum-containing composition and lubricating oil containing the composition  

SciTech Connect

Antioxidant additives for lubricating oil are prepared by (1) combining a polar solvent, an acidic molybdenum compound and an oil-soluble basic nitrogen compound to form molybdenum-containing complex and (2) contacting said complex with carbon disulfide to form a sulfur-and molybdenum-containing composition.

Devries, L.; King, J.M.

1981-08-25

127

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

SciTech Connect

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

Huffman, G.P.; Huggins, F.E.; Shah, N. [Kentucky Univ., Lexington, KY (United States). Consortium for Fossil Fuel Science

1992-11-01

128

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

SciTech Connect

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

Huffman, G.P.; Huggins, F.E.; Shah, N. (Kentucky Univ., Lexington, KY (United States). Consortium for Fossil Fuel Science)

1992-11-01

129

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

SciTech Connect

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

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

2010-01-10

130

Sulfuric Acid on Europa's Surface and the Radiolytic Sulfur Cycle  

NASA Astrophysics Data System (ADS)

Galileo infrared spectra of Europa's surface show distorted water bands that have been attributed to hydrated evaporite salts (McCord et al., J. Geophys. Res. 104, 11827, 1999) or to the scattering properties of ice (Dalton and Clark, Bull. Am. Astron. Soc. 30, 1081, 1998). Using new laboratory spectra, we show that hydrated sulfuric acid can explain Europa's spectra and further show that this species is a product of radiolysis. Sulfuric acid on Europa occurs as the radiolytically stable octahydrate and hemihexahydrate and is a major surface component, along with water ice. The sulfuric acid concentration correlates spatially with Europa's visually dark material, which we identify as radiolytically altered sulfur polymers. Radiolysis by incident jovian plasma continuously cycles sulfur between three chemical reservoirs: sulfuric acid, polymerized sulfur, and sulfur dioxide, with the acid being about 50 times more abundant than the other forms because of the stability of the sulfate anion under irradiation. The original source of sulfur may be incident iogenic sulfur ions or endogenic sulfur compounds that are altered by radiolysis. Geological processes can bury and redistribute the sulfurous material, producing a sulfur-rich crust and a non-uniform surface distribution. The low melting point of sulfuric acid and its ability to supercool may facilitate geological processes. Europa's magnetic response may be influenced by the electrical conductivity of sulfuric acid.

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

1999-09-01

131

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

SciTech Connect

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

Harrison, K.E.; Ferris, D.D. (ICF Kaiser Engineers, Inc., Pittsburgh, PA (USA)); Kosky, R.M. (Consolidation Coal Co., Pittsburgh, PA (USA)); Warchol, J.J.; Musiol, W.F.; Shiao, S.Y. (Babcock and Wilcox Co., New Orleans, LA (USA)); Luttrell, G.H.; Adel, G.T.; Yoon, R.H. (Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (USA))

1990-01-01

132

ADVANCED SULFUR CONTROL CONCEPTS  

Microsoft Academic Search

Conventional sulfur removal in integrated gasification combined cycle (IGCC) power plants involves numerous steps: COS (carbonyl sulfide) hydrolysis, amine scrubbing\\/regeneration, Claus process, and tail-gas treatment. Advanced sulfur removal in IGCC systems involves typically the use of zinc oxide-based sorbents. The sulfides sorbent is regenerated using dilute air to produce a dilute SO (sulfur dioxide) tail gas. Under previous contracts the

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

2003-01-01

133

Gasoline from natural gas by sulfur processing. Quarterly technical progress report No. 2, October 1, 1993--December 31, 1993  

SciTech Connect

This report presents the work performed at the Institute of Gas Technology (IGT) during the second program quarter from October 1, 1993 to December 31, 1993, under Department of Energy (DOE) Contract No. DE-AC22-93PC92114. This program has co-ordinated funding for Task 1 from IGT`s Sustaining Membership Program (SMP), while DOE is funding Tasks 2--8. Progress in all tasks are reported. The overall objective of this research project is to develop a catalytic process to convert natural gas to liquid transportation fuels. The process consists of two steps that each utilize catalysts and sulfur containing intermediates: (1) to convert natural gas to CS{sub 2} and (2) to convert CS{sub 2} to gasoline range liquids. Experimental data will be generated to demonstrate the potential of catalysts and the overall process. During this quarter, progress in the following areas has been made. An existing unit at IGT was modified to accommodate the sulfur feedstocks and the higher temperatures (>1300{degree}K) required for studying the reactions of hydrogen sulfide and methane as proposed in Tasks 2--5. An HP 5890 gas chromatograph with a TCD (thermal conductivity detector) for detecting fixed gases including hydrogen and an FPD (flame photometric detector) for detecting sulfur compounds was purchased using SMP funds and has been installed and calibrated. A total of seventy runs on MoS{sub 2}, WS{sub 2}, ZrS{sub 2} catalysts as well as quartz wool were performed. As high as 61% H{sub 2}S conversion was observed.

Erekson, E.J.; Miao, F.Q.

1994-02-01

134

Advanced sulfur control concepts  

SciTech Connect

Regenerable metal oxide sorbents, such as zinc titanate, are being developed to efficiently remove hydrogen sulfide (H{sub 2}S) from coal gas in advanced power systems. Dilute air regeneration of the sorbents produces a tailgas containing a few percent sulfur dioxide (SO{sub 2}). Catalytic reduction of the SO{sub 2} to elemental sulfur with a coal gas slipstream using the Direct Sulfur Recovery Process (DSRP) is a leading first-generation technology. Currently the DSRP is undergoing field testing at gasifier sites. The objective of this study is to develop second-generation processes that produce elemental sulfur without coal gas or with limited use. Novel approaches that were evaluated to produce elemental sulfur from sulfided sorbents include (1) sulfur dioxide (SO{sub 2}) regeneration, (2) substoichiometric (partial) oxidation, (3) steam regeneration followed by H{sub 2}S oxidation, and (4) steam-air regeneration. Preliminary assessment of these approaches indicated that developing SO{sub 2} regeneration faced the fewest technical and economic problems among the four process options. Elemental sulfur is the only likely product of SO{sub 2} regeneration and the SO{sub 2} required for the regeneration can be obtained by burning a portion of the sulfur produced. Experimental efforts have thus been concentrated on SO{sub 2}-based regeneration processes. Results from laboratory investigations are presented and discussed.

Gangwal, S.K.; Turk, B.S.; Gupta, R.P.

1995-11-01

135

Reduce claus sulfur emission  

Microsoft Academic Search

Operating efficiency of the world's more than 400 sulfur recovery plants must be increased to reduce sulfur emission. Unusually strict controls are being proclaimed by many governmental bodies which require careful design of new plants and improved operation of all plants to minimize side reactions and develop maximum recoveries. The Claus Process must be augmented with more reactors or other

1972-01-01

136

Bacteria morphology and diversity of the combined autotrophic nitritation and sulfur-carbon three-dimensional-electrode denitrification process.  

PubMed

The bacterial morphology and diversity in the reactors of a combined autotrophic nitritation and sulfur-carbon three-dimensional-electrode denitrification (CANSCTED) process operating under steady-state conditions were investigated by scanning electron microscopy and partial 16S rDNA cloning and sequencing. The CANSCTED process consisted of two parts, i.e., the nitritation membrane bioreactor (NMBR) and the sulfur-carbon three-dimensional-electrode denitrification reactor (SCTED). When the influent NH(+) 4 concentration of NMBR ranged from 854 to 1086mg N L(-1), with about 50% NH(+) 4 removal efficiency and NO(-) 2 accumulation rate, the spherical and spheroidal ammonia-oxidizing bacteria were predominant, with community successions of ?-Proteobacteria (60.0%), Bacteroidetes (28.3%) and Chloroflexi (11.7%). The NMBR effluent with 429?543mg N L(-1) NH(+) 4 and 519?578mg N L(-1) NO(-) 2 was continuously supplied to SCTED for sulfur denitrification, bioelectrochemical hydrogen denitrification, and anaerobic ammonium oxidation. The predominant bacterial community successions were ?-Proteobacteria (78.3%) and ?-Proteobacteria (21.7%). When the SCTED influent was supplied with only NO(-) 2 (412-525mg N L(-1)) as nitrogen substrate, the predominant bacteria in SCTED were short-bacilliform and spheroidal denitrification bacteria, ?-Proteobacteria (82.0%), ?-Proteobacteria (16.4%) and ?-Proteobacteria (1.6%). Although the predominant bacterial communities were both ?-Proteobacteria and ?-Proteobacteria in SCTED, the species and quantity of each community varied with the change of SCTED influent composition, which indicated that the composition influence the bacterial morphology and diversity in SCTED. PMID:24117082

Wang, Haiyan; Zhou, Yuexi; Yuan, Quan; Zhao, Hua; Dai, Xin

2014-01-01

137

Fractionation of sulfur isotopes during atmospheric processes: SO2 oxidation and photolysis  

NASA Astrophysics Data System (ADS)

Measurements of stable sulfur isotopes can be used to investigate the chemistry of SO2 in the environment. The oxidation pathway of SO2 plays an important role in determining its environmental effect: gaseous oxidation by OH radicals produces gas-phase sulfuric acid that can nucleate to produce new particles and CCN, while heterogeneous oxidation can change the surface properties of existing particles. Stable isotopes have been used in the investigation of these oxidation pathways, but a major limitation is the lack of laboratory studies of the isotopic fractionation factor for the gaseous reaction (Castleman et al., 1974; Leung et al., 2001; Tanaka et al., 1994). An experimental set-up to investigate the kinetic fractionation of 34S/32S (? = k34/k32) during this reaction has been developed. OH radicals are generated by flowing humidified nitrogen past a mercury lamp producing high-energy UV light. SO2 gas with a known isotopic composition reacts with the OH radicals to produce sulfuric acid gas. Collection methods for both H2SO4 and SO2 gases have been characterised. H2SO4 gas is collected in a glass condenser system and washed out with MilliQ water. This collection method introduces no significant isotopic fractionation. SO2 gas is collected in two bubblers containing 6% H2O2 solution at 273 K, which introduces fractionation of 13 2 (? = 1.013 0.002) at 273 K, agreeing with aqueous uptake and oxidation (Saltzman et al., 1983). Following collection, BaCl2 is added to precipitate the sulfur as BaSO4 and the solutions are filtered to collect the BaSO4 grains for analysis in the NanoSIMS. Photolytic and aqueous oxidation of SO2 are the main interfering reactions occurring in the system, and were investigated by running the reaction set-up without generating OH radicals. High humidity conditions produce fractionation of 11 7 (? = 1.011 0.007) at 293 K, which corresponds well with previous results for the SO2(g)-HSO3-(aq) system (Eriksen, 1972). Comparison with SO2 collection fractionation gives a temperature dependency of 0.1/K. At lower humidity the mass-independent signature of the photolytic reaction (Farquhar et al., 2001) is clearly seen, with little interference from the aqueous reaction. After consideration of these interferences, the fractionation during oxidation of SO2 by OH radicals was measured to be 9.8 2.9 (? = 1.098 0.0029) at 273 K, with a temperature dependency of 0.09 0.12 /K.

Harris, E. J.; Sinha, B.; Hoppe, P.; Crowley, J.; Foley, S. F.

2010-12-01

138

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

SciTech Connect

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

Robert S. Cherry

2006-09-01

139

Solvent-refined-coal (SRC) process. Determination of trace hydrocarbon, sulfur, and nitrogen compounds in SRC-II process development Unit P-99 gas streams. [Impure hydrogen in recycle gas and low pressure gas processing  

Microsoft Academic Search

A knowledge of the identity and concentration of trace hydrocarbon, sulfur, and nitrogen compounds in the various gas streams of the SRC-II Coal Liquefaction Process is needed in order to design the recycle gas purification and low pressure gas processing systems in large-scale plants. This report discusses the results of an experimental study to identify and quantify trace compounds in

J. A. Gray; R. D. Galli; J. H. McCracken

1982-01-01

140

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

NASA Astrophysics Data System (ADS)

This work investigates the interactions between gas-phase carbonyl compounds and sulfuric acid aerosols. It focuses on understanding the chemical processes, giving a first estimate of their importance in the atmosphere, and suggesting directions for further investigations. The solubility and reactivity of a compound with a large enolization constant, 2,4-pentanedione, in water/sulfuric acid solutions 0-96 wt% have been investigated at room temperature using the bubble column/GC-FID technique. 2,4-pentanedione was found to undergo aldol condensation at acidities as low as 20 wt% H 2SO 4, that is, well in the tropospheric range of aerosol composition. In agreement with well-established organic chemical knowledge, this reaction resulted in changes of color of the solutions of potential importance for the optical properties of the aerosols. 2,4-pentanedione was also found to undergo retroaldol reaction, specific to dicarbonyl compounds, producing acetone and acetaldehyde. The Henry's law coefficient for 2,4-pentanedione was found to be a factor 5 larger than the one of acetone over the whole range of acidity, with a value in water of H (297 K)=(15527) M atm -1. A chemical system is proposed to describe the transformations of carbonyl compounds in sulfuric acid aerosols. Aldol condensation is likely to be the most common reaction for these compounds, probably involving a large number of the ones present in the atmosphere and a wide range of aerosol compositions. The enolization constant contributes as a proportional factor to the rate constant for aldol condensation, and is shown in this work to contribute as an additive constant to the Henry's law coefficient. In addition to the many important aspects of these reactions illustrated in this work, the rate of aldol condensation was estimated to be potentially fast enough for the losses of some compounds in acidic aerosols to compete with their gas-phase chemistry in the atmosphere.

Nozire, Barbara; Riemer, Daniel D.

141

Sulfur-emission-control technology for coal-conversion plants. [List of 60 processes with uses, brief description and flowsheet; 63 references  

SciTech Connect

The degree of commercialization and the industrial applications of each control technology are summarized in Table 2. The technologies which have been used or planned for coal conversion facilities are listed in Table 3. The Chiyoda Thoroughbred 101 was the most used process for flue gas SO/sub 2/ control, followed by the Citrate process. Both are recovery processes. However, throwaway processes are much more common for flue gas desulfurization. Therefore, both the dual alkali process and a conventional lime/limestone process should be included when evaluating control technology options. Thus, the SO/sub x/ removal processes recommended for further study are: (1) Chiyoda Thoroughbred 101; (2) Citrate; (3) generalized dual-alkali (e.g., CEA-ADL); and (4) conventional lime/limestone scrubbing. From Table 3, the Rectisol, Stretford, Benfield, Selexol, Claus and Amoco sulfur recovery processes were most often chosen for acid gas removal and sulfur recovery. These processes are all widely commercialized. For tail gas clean-up from sulfur recovery plants, the SCOT, IFP, Beavon and W-L SO/sub 2/ recovery processes were most often specified for coal conversion facilities, as shown in Table 3. They are all fully commercialized and applicable technologies, as shown in Table 2. The control technologies selected for further detailed examination cover the general types of sulfur control schemes potentially applicable to coal conversion facilities. Further, they are all commercially available.

Weber, R.C.; Herman, D.R.; Smock, M.E.

1981-10-01

142

Sulfur emissions  

Microsoft Academic Search

The Environmental Defense Fund challenges a recent conclusion of the Advisory Committee on Oceans and International Environmental and Scientific Affairs ''that nitrogen oxides were the limiting factor in the formation of acids, including sulfuric acid, in acid rain.'' Acceptance of this would mean shifting strategies to reduce acidic sulfur deposition by reducing regional sulfur dioxide SO emissions in eastern North

1985-01-01

143

Iron Dissolution of Dust Source Materials during Simulated Acidic Processing: The Effect of Sulfuric, Acetic, and Oxalic Acids.  

PubMed

Atmospheric organic acids potentially display different capacities in iron (Fe) mobilization from atmospheric dust compared with inorganic acids, but few measurements have been made on this comparison. We report here a laboratory investigation of Fe mobilization of coal fly ash, a representative Fe-containing anthropogenic aerosol, and Arizona test dust, a reference source material for mineral dust, in pH 2 sulfuric acid, acetic acid, and oxalic acid, respectively. The effects of pH and solar radiation on Fe dissolution have also been explored. The relative capacities of these three acids in Fe dissolution are in the order of oxalic acid > sulfuric acid > acetic acid. Oxalate forms mononuclear bidentate ligand with surface Fe and promotes Fe dissolution to the greatest extent. Photolysis of Fe-oxalate complexes further enhances Fe dissolution with the concomitant degradation of oxalate. These results suggest that ligand-promoted dissolution of Fe may play a more significant role in mobilizing Fe from atmospheric dust compared with proton-assisted processing. The role of atmospheric organic acids should be taken into account in global-biogeochemical modeling to better access dissolved atmospheric Fe deposition flux at the ocean surface. PMID:23883276

Chen, Haihan; Grassian, Vicki H

2013-08-29

144

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

SciTech Connect

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

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

1999-01-22

145

Sulfur capture mechanisms.  

National Technical Information Service (NTIS)

The Morgantown Energy Technology Center is currently involved in developing high-temperature cleanup for the integrated gasification combined cycle process. Solid sorbents are being employed to remove sulfur-bearing gases. Therefore, it is important to kn...

R. V. Siriwardane J. A. Poston S. D. Woodruff

1992-01-01

146

Ferrous iron oxidation by sulfur-oxidizing Acidithiobacillus ferrooxidans and analysis of the process at the levels of transcription and protein synthesis.  

PubMed

In contrast to iron-oxidizing Acidithiobacillus ferrooxidans, A. ferrooxidans from a stationary phase elemental sulfur-oxidizing culture exhibited a lag phase in pyrite oxidation, which is similar to its behaviour during ferrous iron oxidation. The ability of elemental sulfur-oxidizing A. ferrooxidans to immediately oxidize ferrous iron or pyrite without a lag phase was only observed in bacteria obtained from growing cultures with elemental sulfur. However, these cultures that shifted to ferrous iron oxidation showed a low rate of ferrous iron oxidation while no growth was observed. Two-dimensional gel electrophoresis was used for a quantitative proteomic analysis of the adaptation process when bacteria were switched from elemental sulfur to ferrous iron. A comparison of total cell lysates revealed 39 proteins whose increase or decrease in abundance was related to this phenotypic switching. However, only a few proteins were closely related to iron and sulfur metabolism. Reverse-transcription quantitative PCR was used to further characterize the bacterial adaptation process. The expression profiles of selected genes primarily involved in the ferrous iron oxidation indicated that phenotypic switching is a complex process that includes the activation of genes encoding a membrane protein, maturation proteins, electron transport proteins and their regulators. PMID:23291738

Kucera, Jiri; Bouchal, Pavel; Lochman, Jan; Potesil, David; Janiczek, Oldrich; Zdrahal, Zbynek; Mandl, Martin

2013-01-05

147

Process for producing benzene by hydrodealkylation of a hydrocarbon fraction comprising alkylaromatic hydrocarbons, olefinic hydrocarbons and sulfur compound  

SciTech Connect

A stabilized hydrocarbon fraction comprising toluene, xylene, sulfur and olefinic hydrocarbons is converted to benzene by catalytic hydrodesulfurization, hydrodealkylation and catalytic hydrogenation.

Derrien, M.; Cosyns, J.

1984-07-31

148

Hydrogen generation process. Quarterly technical progress report, May 17, 1976August 16, 1976. [Hybrid electrolytic-thermochemical process based on electrolysis of sulfurous acid  

Microsoft Academic Search

During the first quarter, considerable progress was made in each of the major program areas. Significant gains were achieved in increasing the voltage efficiency of the sulfur dioxide-depolarized electrolyzer. Permeability and resistivity measurements were completed on a microporous rubber separator. A commercial platinum catalyst for thermal-catalytically decomposing sulfur trioxide into sulfur dioxide and oxygen was evaluated at space velocities of

G. H. Farbman; L. E. Brecher

1976-01-01

149

Pilot Scale Up of Processes to Demonstrate Utilization of Pulverized Coal Flyash Modified by the Addition of Limestone-Dolomite Sulfur Dioxide Removal Additives.  

National Technical Information Service (NTIS)

Bench-scale experiments to examine methods for potential use of modified flyash indicate that this ash, the solid by-product resulting from the limestone/dolomite process for fixing gaseous sulfur oxides as solid sulfates, can be considered a suitable raw...

1971-01-01

150

Thermodynamic characterization of metal dissolution and inhibitor adsorption processes in the low carbon steel\\/mimosa tannin\\/sulfuric acid system  

Microsoft Academic Search

The corrosion rates in the presence of mimosa tannin as a low carbon steel corrosion inhibitor in sulfuric acid media, were measured by the weight loss method, in the range of temperatures from 20 to 60C. The Temkin, Frumkin and Freundlich isotherms were tested for their fit to the experimental data. The free energies and enthalpies for the adsorption process

Sanja Martinez; Ivica Stern

2002-01-01

151

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

Microsoft Academic Search

Battelle Pacific Northwest Laboratories has begun to develop a project for removing sulfur compounds from fuel gases at elevated temperature (> 700°C) based on the use of molten mixtures of alkali metal carbonates and calcium carbonate as the active reactants. The sulfur removal capacity of the molten salt mixture may be regenerated by stripping with CO and steam, usually at

G. E. Stegen; K. M. Olson

1980-01-01

152

Sulfur capture mechanisms  

Microsoft Academic Search

The Morgantown Energy Technology Center is currently involved in developing high-temperature cleanup for the integrated gasification combined cycle process. Solid sorbents are being employed to remove sulfur-bearing gases. Therefore, it is important to know the reaction mechanisms and kinetics of the interactions of the sulfur-bearing gases with sorbent materials, and the changes in elemental composition during reactions in order to

R. V. Siriwardane; J. A. Poston; S. D. Woodruff

1992-01-01

153

Linking Food Webs and Biogeochemical Processes in Wetlands: Insights From Sulfur Isotopes  

Microsoft Academic Search

To better understand the transfer of nutrients into prairie wetland food webs we have investigated the cycling of S (via S isotope systematics and geochemistry) in a prairie wetland landscape by characterizing sources (ground water, interstitial water, surface water) and processes in a small catchment comprised of four wetlands in eastern South Dakota. We focused on S to derive process

C. A. Stricker; G. R. Guntenspergen; R. O. Rye

2005-01-01

154

Processes for converting methane to higher molecular weight hydrocarbons via sulfur-containing intermediates  

SciTech Connect

This patent describes a process for converting methane to higher molecular weight hydrocarbons. The process comprising the steps of contacting methane with carbonyl sulfide in the presence of UV light under conditions sufficient to generate Ch/sub 3/SH; and contacting CH/sub 3/SH with a catalyst under conditions sufficient to produce hydrogen sulfide and a mixture of hydrocarbons having at least two carbon atoms.

Han, S.; Palermo, R.E.

1989-09-05

155

Solvent refined coal (SRC) process. Research and development report No. 53. Interim report No. 23, 1976--1977. Development of a process for producing an ashless, low-sulfur fuel from coal. Volume IV. Product studies. Part 11. Processing of solvent refined coal minerals  

Microsoft Academic Search

The solvent refining process of Pittsburgh and Midway Coal Mining Company for coal cleaning results in a residue termed coal mineral. This residue contains essentially all the ash and inorganic sulfur of the original coal plus some organic sulfur and undissolved carbon. The carbon content varies from 20% to 60% depending on the severity of treatment in the refining process.

Biswas

1979-01-01

156

The Impact of Sulfur Dioxide on a Processing Tomato Stressed with Chronic Ambient Ozone.  

National Technical Information Service (NTIS)

This study was designed to identify growth and yield responses of VF 145B-7879 processing tomato plants from ambient ozone and varying SO2 exposures. The definition of possible interactions between the two gases was of greatest interest. A 3 x 3 factorial...

R. J. Oshima

1979-01-01

157

Effects of Ozone and Sulfur Dioxide on Processing Tomato Yields and Quality.  

National Technical Information Service (NTIS)

The object of the experiment was to study the effects of SO2 and/or ozone on tomato vegetative growth, fruit yields, and fruit quality. Two varieties of processing tomatoes, UC-204-B and E-6203, were exposed to four levels of ozone and two levels of SO2. ...

R. F. Brewer

1986-01-01

158

Lunar sulfur  

NASA Astrophysics Data System (ADS)

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

Kuck, David L.

159

Effects of ozone and sulfur dioxide on processing tomato yields and quality. Final report  

SciTech Connect

The object of the experiment was to study the effects of SO/sub 2/ and/or ozone on tomato vegetative growth, fruit yields, and fruit quality. Two varieties of processing tomatoes, UC-204-B and E-6203, were exposed to four levels of ozone and two levels of SO/sub 2/. Exposure to ambient ozone caused a 20% reduction in vine weights and 27% reduction in weight of red fruit compared to filtered air. Exposure to 0.1 ppm SO/sub 2/ produced 7% fewer vines and approximately 8% less fruit as compared with no SO/sub 2/ exposure. Fruit quality tests indicated that increasing ozone levels reduce soluble solids (Brix), and they reduce viscosity, an important indicator of processing behavior. Exposure to SO/sub 2/ in the concentrations used increased total solids but had no measurable effect on viscosity or consistency.

Brewer, R.F.

1986-03-01

160

Recovery of vanadium in deep processing of medium- and high-sulfur crude oils and bitumens  

Microsoft Academic Search

Recovery of vanadium from the products of crude oil and hit=men processing has become an active issue because of the shortage of vanadium, the rarity of vanadium ore deposits, and the low concentrations of vanadium in the richest ores (1000-1500 g\\/tonne [ppm by weight]). The vanadium concentration in many crude oils and bitumens is comparable to that in ores. For

D. M. Soskind; V. V. Gribkov; N. P. Slatvinskii-Sidak; M. I. Popov; V. A. Bryukvin; A. G. Vorontnikov

1988-01-01

161

Application of the active soda process for removing sulfur dioxide from flue gases  

SciTech Connect

The active soda process was applied for desulfurization of flue gases emitted by a plant burning heavy fuel oil in a rotary drum drier for stone aggregate. The flue gas capacity of the plant was about 6.7 m{sup 3}/s at normal conditions. The SO{sub 2} concentration varied between 400-500 ppm. The solid, dry and fine-grained NaHCO{sub 3} of good quality was fed directly into the hot gas stream at the outlet of the rotary drier in two variants-with and without grinding. The mean particle size was 0.180 m{sup {minus}3} or 0.070 m{sup {minus}3}, respectively. The achieved desulfurization degree was shown to be directly dependent on the flue gas temperature and on the grinding effect, as well as on the normalized stoichiometric ratio. The highest achieved desulfurization degree amounted up to 74 percent. During the design of the desulfurization process no pilot plant installations and tests were necessary, and for the final process no special chemical reactor was used.

Erdoes, E.; Mocek, K.; Lippert, E.; Uchytilova, V. (The J. Heyrovsky Institute of Physical Chemistry and Electrochemistry, Prague (Czechoslovakia)); Neuzil, L.; Bejcek, V. (Institute of Chemical Technology, Prague (Czechoslovakia))

1989-09-01

162

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

NASA Astrophysics Data System (ADS)

We have simulated different models of CaS-FeS-MgS sulfide formation and determine the solubility of sulfur in silicate melts at high pressure and high temperatures. We will present their implications for planetary differentiation and Mercury.

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

2012-03-01

163

Formation and Decomposition of Sulfur Compounds in Dispenser Cathodes.  

National Technical Information Service (NTIS)

Formation of sulfur compounds during cathode processing and generation of sulfur during cathode operation were examined using thermodynamic data. Sulfur compounds can be formed in dispenser cathodes exposed to a source of hydrogen sulfide (such as stainle...

R. A. Lipeles

1987-01-01

164

[Microbial processes of the carbon and sulfur cycles in the Chukchi Sea].  

PubMed

The research performed in August 2004 within the framework of the Russian-American Long-term Census of the Arctic (RUSALCA) resulted in the first data concerning the rates of the key microbial processes in the water column and bottom sediments of the Bering strait and the Chukchi Sea. The total bacterial counts in the water column varied from 30 x 10(3) cells ml(-1) in the northern and eastern parts to 245 x 10(3) cells ml(-1) in the southern part. The methane content in the water column of the Chukchi sea varied from 8 nmol CH4 l(-1) in the eastern part of the sea to 31 nmol CH4 l(-1) in the northern part of the Herald Canyon. Active microbial processes occurred in the upper 0-3 cm of the bottom sediments; the methane formation rate varied from 0.25 to 16 nmol CH4 dm(-3) day(-1). The rates of methane oxidation varied from 1.61 to 14.7 nmol CH4 dm(-3) day(-1). The rates of sulfate reduction varied from 1.35 to 16.2 micromol SO4(2-) dm(-3) day(-1). The rate of methane formation in the sediments increased with depth, while sulfate reduction rates decreased (less than 1 micromol SO4(2-) dm(-3) day(-1)). These high concentrations of biogenic elements and high rates of microbial processes in the upper sediment layers suggest a specific type of trophic chain in the Chukchi Sea. The approximate calculated balance of methane emission from the water column into the atmosphere is from 5.4 to 57.3 micromol CH4 m(-2) day(-1). PMID:18069330

Savvichev, A S; Rusanov, I I; Pimenov, N V; Zakharova, E E; Veslopolova, E F; Lein, A Iu; Crane, K; Ivanov, M V

165

Electrochemical processes on a platinum anode and electrochemiluminescence of the uranyl ion in concentrated sulfuric acid  

SciTech Connect

This article describes the results of an investigation of the electrochemiluminescence (EChL) arising on an electrode subjected to preliminary treatment. Electrochemical processes on a platinum anode depend on the degree of oxidation of the electrode surface and on the nature of the particles adsorbed on it. The luminescence resulting from electrolysis was recorded on a photometric setup, including a photoelectronic multiplier, fed by a VS-22 high-voltage rectifier, and an EPPV-60 electronic potentiometer, which records the current of the photoelectronic multiplier. The kinetics of EChL greatly depend on the state of the electrode surface. Changes in the EChL are determined by the change in the composition of the adsorbed layer on the oxide film of the electrode. The results indicate a comparatively low rate of desorption of active particles from the surface of the platinum electrode even after cessation of electrolysis. It is concluded that EChL can serve as a test for the presence of active particles on the electrode surface.

Kazakov, V.P.; Lotnik, S.V.; Parshin, G.S.; Zagidullin, S.N.

1984-05-01

166

Experimental study of an extractive coking process to produce low-sulfur liquid fuels from bituminous coal. Quarterly report, May 1, 1976July 31, 1976  

Microsoft Academic Search

The feasibility of a coal liquefaction process using hydrogenated solvent to produce gas, low-sulfur, low-ash coal liquid and high-ash coke from bituminous coal is being investigated. After some initial difficulties were resolved, conversions of moisture-and-ash-free coal to coal liquid with efficiencies of 39 to 49 percent have been attained. If this efficiency can be improved, the potential for coal liquefaction

E. Interess; S. A. Reber; R. M. Nadkarni; R. W. Hyde

1976-01-01

167

Effects of high salinity and constituent organic compounds on treatment of photo-processing waste by a sulfur-oxidizing bacteria\\/granular activated carbon sludge system  

Microsoft Academic Search

To achieve practical treatment of photo-processing waste (PW) using our previously proposed sulfur-oxidizing bacteria (SOB)\\/granular activated carbon (GAC) sludge system, this paper elucidates why 3- to 5-X dilution of PW was required. That is, a series of experiments were carried out to show the effects of high salinity and constituent organic compounds in PW, respectively. Both an inorganic salts system

Bin-Le Lin; Masaaki Hosomi; Akihiko Murakami

2002-01-01

168

Study on the destructive effect to inherent quality of Fritillaria thunbergii Miq. (Zhebeimu) by sulfur-fumigated process using chromatographic fingerprinting analysis.  

PubMed

The after-harvesting sun-dried processing of Fritillariae thunbergii bulbus (Zhebeimu) was the traditional treatment for commodity. Over recent decades the natural drying process for bulbus of Fritillariae has been replaced by sulfur-fumigation for reducing the drying duration and pest control. We used ultra-performance liquid chromatography coupled with evaporative light scattering detection (UPLC-ELSD) fingerprinting analysis and major alkaloids determination to investigate the potential damaging effect of the sulfur-fumigating process. The experimental conditions were as follows: Chromatography was proceeded on Waters Acquity UPLC BEH C(18) column; the linear gradient elution was conducted with mobile phase prepared from acetonitrile-0.02% triethylamine; the drift tube temperature was set at 40C with a nitrogen flow-rate of 30psi, and the spray parameter was set 40%. All calibration curves showed good linear regression (R>0.9991) within the tested range. The method was validated for precision, accuracy, limit of detection and quantification. The study also has shown that sulfur-fumigated samples had significant loss of the main active compounds and a more destructive fingerprint profile when compared to the sun-dried samples. PMID:22326548

Duan, Baozhong; Huang, Linfang; Chen, Shilin

2012-02-10

169

Solvent refined coal (SRC) process: development of a process for producing an ashless, low-sulfur fuel from coal. Research and development report No. 53, interim report No. 20. Volume IV. Product studies. Part II. Processing of coal minerals for the period 1975--1976  

Microsoft Academic Search

The solvent refined process for coal liquefaction results in a residue, termed coal minerals, containing approximately 50% carbon and the remainder mineral material. Silica, alumina, iron, and sulfur (pyrites) make up the majority of the minerals. The gasification of the carbon as fuel and the recovery of iron and sulfur are the main concern of this study. Pulverized coal minerals

Moh; T. T. L

1978-01-01

170

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

SciTech Connect

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

Towler, G.P.; Lynn, S.

1993-05-01

171

Sulfur Oxide Removal from Power Plant Stack Gas: Conceptual Design and Cost Study. Sorption by Limestone or Lime: Dry Process.  

National Technical Information Service (NTIS)

Previous studies have found that the injection of limestone or lime into a boiler will greatly reduce the amount of sulfur oxides in the stack gases. A scrubber may be used at the end of the system to enhance the degree of reaction; if such a device is no...

1968-01-01

172

Genetic engineering of sulfur-degrading Sulfolobus  

SciTech Connect

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

Ho, N.W.Y.

1991-01-01

173

Chemical removal of pyritic sulfur from coal  

Microsoft Academic Search

A new approach for the chemical removal of pyritic sulfur from coal is described. The process is based on the discovery that aqueous ferric salt selectively oxidizes the pyritic sulfur in coal to chemical forms which can be removed by vaporization, steam, or solvent extraction. Data for removal of the pyritic sulfur from four major coals (Lower Kittanning, Illinois No.

J. W. Hamersma; M. L. Kraft; E. P. Koutsoukos; R. A. Meyers

1976-01-01

174

Method for removing sulfur oxide from waste gases and recovering elemental sulfur  

DOEpatents

A continuous catalytic fused salt extraction process is described for removing sulfur oxides from gaseous streams. The gaseous stream is contacted with a molten potassium sulfate salt mixture having a dissolved catalyst to oxidize sulfur dioxide to sulfur trioxide and molten potassium normal sulfate to solvate the sulfur trioxide to remove the sulfur trioxide from the gaseous stream. A portion of the sulfur trioxide loaded salt mixture is then dissociated to produce sulfur trioxide gas and thereby regenerate potassium normal sulfate. The evolved sulfur trioxide is reacted with hydrogen sulfide as in a Claus reactor to produce elemental sulfur. The process may be advantageously used to clean waste stack gas from industrial plants, such as copper smelters, where a supply of hydrogen sulfide is readily available.

Moore, Raymond H. (Richland, WA)

1977-01-01

175

Instrumental methods of analysis of sulfur compounds in synfuel process streams. Quarterly technical progress report for April-June 1984. [Sulfidic, polysulfidic, thiosulfate, sulfite, sulfate, thiocyanate  

SciTech Connect

Task 1: methods development for the speciation of the polysulfides. Work on this task has been completed in December 1983 and reported accordingly in DOE/PC/40783-T13. Task 2: methods development for the speciation of dithionite and polythionates. Electrochemical reduction of tetrathionate and pentathionate at the dropping mercury electrode (DME) proceeds through a mechanism involving specific adsorption of the reactant at the DME surface and yielding polarographic waves at -0.2 volt (versus the saturated calomel electrode) in aqueous solution. Ethanol interferes with the specific adsorption of tetrathionate and pentathionate in a range of potentials between 0.0 and -1.1 volt, because EtOH is preferentially adsorbed. This results in a shift of the polarographic half-wave potentials of tetrathionate and pentathionate, which facilitates their determination in polythionate mixtures. On the other hand, the polarographic reduction of trithionate is unaffected by ethanol, because it occurs at -1.5 volt where ethanol is not adsorbed at the surface of the DME. Task 3: total accounting of the sulfur balance in representative samples of synfuel process streams. Analyses of two aqueous gasifier effluents from Grand Forks, ND, were performed. An untreated specimen contained sulfidic and polysulfidic sulfur, thiosulfate and thiocyanate. On the other hand, sulfite, sulfate, and thiocyanate were the only sulfur moieties observed in the Grand Forks sample which had been stripped at PETC. 7 references, 1 figure, 3 tables.

Jordan, J.; Sexton, E.; Talbott, J.; Yakupkovic, J.

1984-07-01

176

Novel separation process of gaseous mixture of SO and O with ionic liquid for hydrogen production in thermochemical sulfur-iodine water splitting cycle  

Microsoft Academic Search

Sulfur-Iodine cycle is the most promising thermochemical cycle for water splitting to produce hydrogen which can replace the fossil fuels in the future. As a sub-cycle in the thermochemical Sulfur-Iodine water splitting cycle, sulfuric acid (HSO) decomposes into oxygen (O) and sulfur dioxide (SO) which should be separated for the recycle of SO into the sulfuric acid generation reaction (Bunsen

Chang Soo Kim; Gyeong Taek Gong; Kye Sang Yoo; Honggon Kim; Byoung Gwon Lee; Byoung Sung Ahn; Kwang Deog Jung; Ki Yong Lee; Kwang Ho Song

2007-01-01

177

Elucidating microbial processes in nitrate- and sulfate-reducing systems using sulfur and oxygen isotope ratios: The example of oil reservoir souring control  

NASA Astrophysics Data System (ADS)

Sulfate-reducing bacteria (SRB) are ubiquitous in anoxic environments where they couple the oxidation of organic compounds to the production of hydrogen sulfide. This can be problematic for various industries including oil production where reservoir "souring" (the generation of H 2S) requires corrective actions. Nitrate or nitrite injection into sour oil fields can promote SRB control by stimulating organotrophic nitrate- or nitrite-reducing bacteria (O-NRB) that out-compete SRB for electron donors (biocompetitive exclusion), and/or by lithotrophic nitrate- or nitrite-reducing sulfide oxidizing bacteria (NR-SOB) that remove H 2S directly. Sulfur and oxygen isotope ratios of sulfide and sulfate were monitored in batch cultures and sulfidic bioreactors to evaluate mitigation of SRB activities by nitrate or nitrite injection. Sulfate reduction in batch cultures of Desulfovibrio sp. strain Lac15 indicated typical Rayleigh-type fractionation of sulfur isotopes during bacterial sulfate reduction (BSR) with lactate, whereas oxygen isotope ratios in unreacted sulfate remained constant. Sulfur isotope fractionation in batch cultures of the NR-SOB Thiomicrospira sp. strain CVO was minimal during the oxidation of sulfide to sulfate, which had ?18O SO4 values similar to that of the water-oxygen. Treating an up-flow bioreactor with increasing doses of nitrate to eliminate sulfide resulted in changes in sulfur isotope ratios of sulfate and sulfide but very little variation in oxygen isotope ratios of sulfate. These observations were similar to results obtained from SRB-only, but different from those of NR-SOB-only pure culture control experiments. This suggests that biocompetitive exclusion of SRB took place in the nitrate-injected bioreactor. In two replicate bioreactors treated with nitrite, less pronounced sulfur isotope fractionation and a slight decrease in ?18O SO4 were observed. This indicated that NR-SOB played a minor role during dosing with low nitrite and that biocompetitive exclusion was the major process. The results demonstrate that stable isotope data can contribute unique information for understanding complex microbial processes in nitrate- and sulfate-reducing systems, and offer important information for the management of H 2S problems in oil reservoirs and elsewhere.

Hubert, Casey; Voordouw, Gerrit; Mayer, Bernhard

2009-07-01

178

Options for small-scale sulfur recovery  

SciTech Connect

With the issuance by the Alberta Energy Resources Conservation Board and Alberta Environment of their report entitled Sulphur Recovery Guidelines for Sour Gas Plants in Alberta in August of 1988, the requirement in Alberta to recover sulfur was broadened to a sulfur content of 1 ton/D or greater in the inlet gas to a new sour-gas treating plant. This paper reviews the processes in use for recovering sulfur from sour-natural-gas streams that have a total sulfur content of 5 ton/D or less. These processes are the modified Claus process, the recycle Selectox process, and the reduction/oxidation processes LO-CAT and SulFerox. While the modified Claus process is used in large sulfur-recovery plants, the other processes may be more economical for sulfur recovery on a small scale. A description of the sour-gas treating and sulfur-recovery processes is given, and a comparison of estimated capital and operating costs for typical sour-gas streams is provided. All of the above processes are in operation in North America. Operating experiences with these processes in Alberta are discussed. The quality of the end-product sulfur varies among these processes, and the options for sulfur disposal are reviewed.

Royan, T. [Tartan Engineering Corp. Ltd. (Canada); Wichert, E. [Gascan Resources Ltd., Calgary, Alberta (Canada)

1997-11-01

179

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

PubMed

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

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

2013-07-11

180

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

Code of Federal Regulations, 2013 CFR

...sulfur subcategory. The provisions of this subpart are applicable to the processing of sulfur on shore and in marshes and estuaries by the Frasch process. Not covered are sulfur refining operations that are not performed at the mining and collection...

2013-07-01

181

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

SciTech Connect

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

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

1993-10-12

182

High pressure sulfuric acid decomposition experiments for the sulfur-iodine thermochemical cycle  

Microsoft Academic Search

A series of three pressurized sulfuric acid decomposition tests were performed to (1) obtain data on the fraction of sulfuric acid catalytically converted to sulfur dioxide, oxygen, and water as a function of temperature and pressure, (2) demonstrate real-time measurements of acid conversion for use as process control, (3) obtain multiple measurements of conversion as a function of temperature within

Carlos E Velasquez; Andrew R. Reay; James C. Andazola; Gerald E. Naranjo; Fred Gelbard

2005-01-01

183

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

Code of Federal Regulations, 2013 CFR

...test method for determining the sulfur content of diesel or ECA marine fuel? ...approved by voluntary consensus-based standards bodies. For such...method for determining the sulfur content of diesel fuel if it meets...

2013-07-01

184

Sulfurization of a carbon surface for vapor phase mercury removal II: Sulfur forms and mercury uptake  

Microsoft Academic Search

Sulfur forms deposited on carbonaceous surfaces after exposure to hydrogen sulfide were analyzed using XPS and XANES. Higher temperatures promote the formation of organic sulfur and the presence of H2S during the cooling process increased elemental sulfur content. Temperatures between 400600C were found to be optimal for producing effective mercury uptake sorbents. The increased amount of sulfur deposited during the

Wenguo Feng; Eric Borguet; Radisav D. Vidic

2006-01-01

185

Uses of Lunar Sulfur.  

National Technical Information Service (NTIS)

Sulfur and sulfur compounds have a wide range of applications for their fluid, electrical, chemical and biochemical properties. Although low in abundance on the Moon (/approximately/0.1% in mare soils), sulfur is surface-correlated and relatively extracta...

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

1988-01-01

186

Uses of lunar sulfur  

SciTech Connect

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

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

1988-01-01

187

Sulfur Extended Asphalt Availability of Sulfur.  

National Technical Information Service (NTIS)

This report assesses the availability and pricing of sulfur with respect to sulfur extended asphalt paving mixtures. The assessment includes a review of past and current trends as well as sulfur estimates up to the year 2000 for the United States and spec...

J. P. Mahoney M. K. Loose J. A. Larry

1982-01-01

188

Coal gasification pilot plant support studies. Subtask 3-3. Improved methods of removal, recovery, or conversion of sulfur and nitrogen compounds in raw product gases from coal gasification processes  

SciTech Connect

Results are reported from three exploratory programs to improve the processing techniques for the removal, conversion, or recovery of sulfur and nitrogen compounds without gas quenching in coal gasification processes. The areas of investigation were the following: (1) fuel gas desulfurization, (2) catalytic ammonia decomposition in fuel gas streams, and (3) catalytic hydrolysis of carbonyl sulfide in fuel gas streams.

Not Available

1980-12-01

189

Effects of sulfur forms on heavy metals bioleaching from contaminated sediments  

Microsoft Academic Search

The use of recyclable forms of sulfur will exclude the risk of sediment reacidification and reduce the cost of bioleaching process. Three different forms of sulfur (namely sulfur powder, prills and pieces) were used to examine the utilization and recycle of sulfur, used as energy substrate for sulfur-oxidizing bacteria (SOB) in the bioleaching of heavy metal-contaminated sediments. The results showed

D. Fang; L. Zhao; L. X. Zhou; H. X. Shan

2009-01-01

190

Production of sulfur from sulfur dioxide obtained from flue gas  

SciTech Connect

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

Miller, R.

1989-06-06

191

Production of elemental sulfur and methane from H{sub 2}S and CO{sub 2} derived from a coal desulfurization process. First quarterly report, 1996  

SciTech Connect

During the tenth quarter of the project, bench scale experiments were performed to investigate the adsorption ability of different kinds of materials within sulfur vapor environment. Four kinds of adsorbents have been tested. The experimental results indicated that activated carbon was the beet of four adsorbents tested. In addition to the baseline tests, several designs of activated carbon feed system have been tested. Under an inert environment, bench scale experiments were performed to investigate the characteristics and efficiency of activated carbon passing through the Co-Mo-Alumina catalyst bed. The results showed that activated carbon powder could easily be transported through the catalytic bed. The adsorption process may be applicable to promote conversion of H{sub 2}S in the H{sub 2}S and CO{sub 2} rea system.

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

1997-09-01

192

Introduction to Sulfur Metabolism in Phototrophic Organisms  

Microsoft Academic Search

Sulfur is one of the most versatile elements in life due to its reactivity in different oxidation and reduction states. In\\u000a phototrophic organisms, the redox properties of sulfur in proteins and of sulfur-containing metabolites are particularly important\\u000a for the mediation between the reductive assimilation processes of photosynthesis and reactive oxygen species that arise as\\u000a by-products of electron transport chains in

Christiane Dahl; Rdiger Hell; Thomas Leustek; David Knaff

193

Volcanic sulfur  

NASA Astrophysics Data System (ADS)

Although I may be overly demanding in expecting a member of the Eos staff to be familiar with recent articles in AGU journals, I am moved to make a mild protest concerning attribution in the Volcanic Sulfur Dynamics news item by Mario E. Godinez (Eos, June 14, 1983, p. 411).Since the news story stated that an important result of the RAVE experiment was to estimate the SO2 flux from Mount St. Helens on just one day, I must point out that both my research group and USGS scientists have monitored the emissions from Mount St. Helens and estimated SO2 (and other) fluxes over extended periods of time. Our results, which were based on in situ airborne measurements carried out over a period of a year, include estimates of the flux rates of SO2, H2S, H2O, sulfates, halides, and various other particles, prior to, during, and after the explosive eruption of Mount St. Helens on May 18, 1980 [Hobbs et al., 1983]. The USGS measurements, which are made remotely through use of an airborne correlation spectrometer, also commenced in 1980 a n d have provided data several times a week since that time [Casadevall et al., 1981]. We have also estimated the fluxes of various materials (including SO2) from eight other volcanos [Radke et al.., 1976; Stith et al.., 1978; Radke, 1982].

Hobbs, Peter V.

194

Combined bioelectrochemical and sulfur autotrophic denitrification for drinking water treatment  

Microsoft Academic Search

A combined bioelectrochemical and sulfur autotrophic denitrification process for drinking water treatment was put forward and investigated extensively in this paper. In this new process, the bioelectrochemical denitrification was carried out in the upper part of the reactor while sulfur denitrification in the lower part. The H+ produced in Sulfur Part could be consumed by hydrogen denitrification in Bioelectrochemical Part.

Haiyan Wang; Jiuhui Qu

2003-01-01

195

EFFECT OF PYRITIC SULFUR AND MINERAL HATTER ON ORGANIC SULFUR REMOVAL FROM COAL  

Microsoft Academic Search

The perchloroethylene coal cleaning process uses perchloroethylene as the solvent to remove both organic and inorganic forms of sulfur without any significant loss to its calorific value. The process removes these forms of sulfur in two sequential unit steps. The objective of this investigation was to determine the exact sequence of operations in the Process. Hence, organosulfur was removed before

Padmakar Vishnubhatt; Theodore Thome; Sunggyu Lee

1993-01-01

196

How to cope with your sulfur problems. [COPE process; use of oxygen enriched air to increase capacity  

Microsoft Academic Search

COPE (Claus Oxygen-based Process Expansion) technology presents an improvement to the modified Claus process that replaces air with up to 100% oxygen to debottleneck Claus Sulphur Recovery Unit's (SRU's). The major equipment requirements of the COPE process are the installation of an acid gas recycle blower and a proprietary burner. The recycle stream acts as a coolant to moderate reaction

B. G. Goar; W. P. Hegarty; T. W. Thew

1986-01-01

197

World petroleum-derived sulfur production  

SciTech Connect

Research efforts in new uses for sulfur, among them those of the Sulfur Development Institute of Canada, have resulted in the development of several new product markets. Petroleum and natural gas derived sulfurs are finding use as asphalt extenders in road construction throughout North America and as concrete extenders and substitutes for Portland cement in the construction industries of Mexico and the Middle East. Their use in masonry blocks is now being commercialized. Canada is the world's largest producer of commercial sulfur; 80% of it is used as a processing chemical in the form of sulfuric acid. Saudi Arabia, recently having begun to commercialize its vast resources, is constructing plants for the extraction of sulfur from natural gas and plans to export between 6 and 7 x 10/sup 5/ tons annually, much of it for fertilizer manufacture to India, Tunisia, Italy, Pakistan, Greece, Morocco, and Thailand.

Cantrell, A.

1982-08-02

198

Development of instrumental methods of analysis of sulfur compounds in coal process streams. Eleventh quarterly technical progress report, April-June 1980  

Microsoft Academic Search

Full implementation of an algorithm for calculating thermodynamic estimates of sulfur moiety concentrations is reported. The scope of the algorithm is unrestricted, including mononuclear and polynuclear sulfur species. Implementation is achieved through the use of substantiated numerical approximation. In Voltammetric Method Development, equations describing the analytic geometry of differential pulse voltammograms are reviewed critically. Work on appropriate refinements has been

1980-01-01

199

Process for Cleaning and Removal of Sulfur Compounds from Low Btu Fuel Gases. Interim Report, January--March 1976.  

National Technical Information Service (NTIS)

It is proposed to remodel the PDU by incorporation of appropriate sub-systems to permit operation in continuous process mode. The PDU will be operated for a period of time sufficient to demonstrate process viability. It has been relocated to an inproved s...

R. H. Moore D. C. Ham G. E. Stegen

1976-01-01

200

Process for cleaning and removal of sulfur compounds from low Btu fuel gases. Interim report, January--March 1976  

Microsoft Academic Search

It is proposed to remodel the PDU by incorporation of appropriate sub-systems to permit operation in continuous process mode. The PDU will be operated for a period of time sufficient to demonstrate process viability. It has been relocated to an inproved support facility and repaired to a state of near readiness for operation. During early pilot plant operation relatively high

R. H. Moore; D. C. Ham; G. E. Stegen

1976-01-01

201

Energy Harvesting, Electrode Processes and the Partitioning and Speciation of Solid Phase Iron and Sulfur in Marine Sediments.  

National Technical Information Service (NTIS)

Fuel cells that facilitate electrochemical reactions in the marine environment are under development as future long-term power sources for marine instrumentation. This research focused on anode processes and small-scale environmental impacts of fuel cells...

C. E. Reimers

2003-01-01

202

How to cope with your sulfur problems. [COPE process; use of oxygen enriched air to increase capacity  

SciTech Connect

COPE (Claus Oxygen-based Process Expansion) technology presents an improvement to the modified Claus process that replaces air with up to 100% oxygen to debottleneck Claus Sulphur Recovery Unit's (SRU's). The major equipment requirements of the COPE process are the installation of an acid gas recycle blower and a proprietary burner. The recycle stream acts as a coolant to moderate reaction furnace temperature, effectively replacing nitrogen as a diluent. The specially designed burner allows for the safe and effective handling of the four feed streams: air, oxygen, acid gas, and recycle gas. Co-licensed by Goar, Arrington and Associates, Inc. (GAA) and Air Products and Chemicals, Inc., the COPE process presents an economically attractive means of expanding the capacity of an SRU. The first two COPE units are in commercial operation at a major gulf Coast refinery in the USA and have demonstrated an 85% increase in capacity by enriching to the 55% O/sub 2/ level.

Goar, B.G.; Hegarty, W.P.; Thew, T.W.

1986-01-01

203

Effects of high salinity and constituent organic compounds on treatment of photo-processing waste by a sulfur-oxidizing bacteria/granular activated carbon sludge system.  

PubMed

To achieve practical treatment of photo-processing waste (PW) using our previously proposed sulfur-oxidizing bacteria (SOB)/granular activated carbon (GAC) sludge system, this paper elucidates why 3- to 5-X dilution of PW was required. That is, a series of experiments were carried out to show the effects of high salinity and constituent organic compounds in PW, respectively. Both an inorganic salts system and calcination PW system showed that SOB completely oxidizes S2O(3)2- -S to SO(4)2- -S even at 12.3 or 13.6% salinity, respectively; hence the dilution requirement is not attributable to high salinity. In experiments employing SOB and SOB/GAC systems to investigate the effects of 23 constituent compounds in PW, compounds were classified into Groups I, II, IIIa, and IIIb. Even with 10 g/l GAC, the nine compounds in Group IIIb still exhibited a toxic effect on SOB activity at 1- and 3-X dilutions; thus it is these compounds that are responsible for requiring dilution of PW. Accordingly, a reduction in their use within the photodeveloping and fix-stabilizing industry, and/or use of > 10g/l GAC, are new considerations for establishing a more practical PW treatment process. PMID:11848345

Lin, Bin-Le; Hosomi, Masaaki; Murakami, Akihiko

2002-02-01

204

Elemental sulfur recovery from desulfurization sorbents in advanced power systems  

Microsoft Academic Search

Regenerable metal oxide sorbents, such as zinc titanate, are being developed to efficiently remove hydrogen sulfide (HS) from coal gas in advanced power systems. Dilute air regeneration of the sorbents produces a tailgas containing a few percent sulfur dioxide (SO). Catalytic reduction of the SO to elemental sulfur with a coal gas slipstream using the Direct Sulfur Recovery Process (DSRP)

T. P. Dorchak; S. K. Gangwal; B. S. Turk

1995-01-01

205

Filamentous Chloroflexi (green non-sulfur bacteria) are abundant in wastewater treatment processes with biological nutrient removal  

Microsoft Academic Search

Most filamentous bacteria in biological nutrient removal (BNR) processes have not been identified beyond their morphotype and simple staining reactions. Furthermore, the majority of sludge filaments observed under the microscope do not hybridize to commonly used phylogenetic probes for well characterized bacterial phyla such as the Proteobacteria, Actinobacteria, Firmicutes and Bacteroidetes. Specific 16S rRNA-targeted oligonucleotide probes were designed for the

L. Bjrnsson; Philip Hugenholtz; Gene W. Tyson; Linda L. Blackall

2002-01-01

206

A novel three phase fluidized bed process for simultaneous selective flocculation and microbial desulfurization of high sulfur coal  

Microsoft Academic Search

The purpose of this work was to investigate the feasibility of recovery and reclamation of ultrafine coal particles generated during the processing of coal. 10--35% of the total annual tonnage of coal in atypical coal preparation plant is estimated to be lost in forms of ultrafine particles during the mining, shipping, handling, and preparation of the coal. The technical feasibility

Liang-Shih Fan; F. Bavarian; Y. A. Attia; M. Elzeky

1990-01-01

207

A novel three phase fluidized bed process for simultaneous selective flocculation and microbial desulfurization of high sulfur coal. Final report  

Microsoft Academic Search

The purpose of this work was to investigate the feasibility of recovery and reclamation of ultrafine coal particles generated during the processing of coal. 10--35% of the total annual tonnage of coal in atypical coal preparation plant is estimated to be lost in forms of ultrafine particles during the mining, shipping, handling, and preparation of the coal. The technical feasibility

Liang-Shih Fan; F. Bavarian; Y. A. Attia; M. Elzeky

1990-01-01

208

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

SciTech Connect

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

Tanaka, Nobuyuki; Yoshida, Mitsunori; Okuda, Hiroyuki; Sato, Hiroyuki; Kubo, Shinji; Onuki, Kaoru [Japan Atomic Energy Agency, 4002 Narita-cho, Oarai-machi, Higash-iibaraki-gun Ibaraki 311-1393 (Japan)

2007-07-01

209

[Determination and distribution of sulfur compounds in coked gasoline by gas chromatography-sulfur chemiluminescence detection].  

PubMed

The method for the separation and determination of sulfur compounds in coked gasoline by gas chromatography-sulfur chemiluminescence detection (GC-SCD) was established. Seventy-four sulfur compounds including hydrogen sulfide, mercaptans, sulfides, disulfides, thiophene, alkyl thiophenes, benzothiophene, alkyl benzothiophenes in a coked gasoline sample were identified by standard samples and past identified results. The retention indexes of different sulfur compounds in coked gasoline under programmed temperature condition were calculated based on the retention times of hydrosulfide, ethyl mercaptan, n-propyl mercaptan, thiophene, 2-methyl thiophene, 2-ethylthiophene, 2-propylthiophene, C4-thiophene (t(R) = 40.28 min), benzothiophene, and methylbenzothiophene (t(R) = 58.13 min). The relative standard deviations of the determination results of main sulfur compounds (isopropyl mercaptan, n-propyl mercaptan, n-butyl mercaptan, 2-methylthiophene, 3-methylthiophene, 2, 4-dimethylthiophene, 2,3,4-trimethylthiophene) in coked gasoline were less than 5%, and the detection limit for sulfur was 0.05 mg/L. The linear range of sulfur was 0.2 - 400 mg/L for each sulfur compounds (r2 = 0. 999). The contents of sulfur compounds, especially the content of mercaptan, are much more than those in the catalytic gasoline. There is also a big difference in the sulfur contents between 2-methylthiophene and 3-methylthiophene. The data can be useful for the study of hydrodesulfurizing catalyst and industrial process planning. PMID:17679435

Yang, Yongtan; Wang, Zheng

2007-05-01

210

Sulfur isotopic systematics of granitoids from southwestern New Brunswick, Canada: implications for magmatic-hydrothermal processes, redox conditions, and gold mineralization  

Microsoft Academic Search

Bulk ?\\u000a 34Srock values, sulfur contents, and magnetic susceptibility were determined for 12 gold-related granitoid intrusions in southwestern\\u000a New Brunswick, the Canadian Appalachians. The sulfur isotope compositions of sulfide minerals in some of the granitoid samples\\u000a were also analyzed. This new dataset was used to characterize two distinctive groups of granitoids: (1) a Late Devonian granitic\\u000a series (GS) and (2)

Xue-Ming Yang; David R. Lentz

2010-01-01

211

Sulfur tolerant anode materials  

SciTech Connect

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

Not Available

1988-02-01

212

Biochemistry of sulfur  

SciTech Connect

This book presents information on the following topics: the chemistry of sulfur; the oxidation states of sulfur; the reduction of sulfate and the oxidation of sulfide; the sulfur cycle; oxidation of inorganic sulfide; the metabolism and functions of methionine; taurine and the oxidative metabolism of cysteine; thiols, disulfides, and thioesters; thioethers; thiamine; biotin; sulfates; inherited disorders of sulfur metabolism; cystinuria; sulfur and the metabolism of xenobiotics; general aspects of xenobiotic metabolism; glutathione and sulfation of xenobiotics; and metabolic activation as a result of sulfate conjugation.

Huxtable, R.J.; LaFranconi, W.M.

1986-01-01

213

Investigation of the thermal decomposition of sulfuric acid containing inorganic impurities  

SciTech Connect

Oleum is recovered by thermal decomposition of sulfuric acid wastes to sulfur dioxide with conversion of the sulfur dioxide to oleum. The organic substances in sulfuric acid wastes can affect the thermal-decomposition indexes of sulfuric acid wastes. They studied the effect of toluene, nitrotoluene, benzoic acid, and carbon on the yield of sulfur dioxide and also the possibility of reduction of acid vapors by products of pyrolysis and incomplete combustion of hydrocarbons. It is shown that the yield of sulfur dioxide in thermal decomposition of hydrocarbon-containing sulfuric acid wastes can be increased if the process assumes the nature of reductive decomposition.

Kogtev, S.E.; Nikandrov, I.S.; Borisenko, A.S.; Peretrutov, A.A.

1986-09-20

214

An integrated biodesulfurization process, including inoculum preparation, desulfurization and sulfate removal in a single step, for removing sulfur from oils.  

SciTech Connect

BACKGROUND: A single-stage reactor, in which the growth of bacterial culture, induction of desulfurizing enzymes, and desulfurization reaction are carried out in a single step, was adopted to investigate desulfurization of DBT at high cell densities. IGTS8 was used as the biocatalyst. Optimal condition for the bacterial growth and DBT desulfurization were also investigated. RESULTS: Optimization of fermentation conditions was necessary to obtain high cell densities including controlling accumulation of acetate. Under optimal operating conditions, the maximum OD600 was measured to be 26.6 at 118 h of cultivation. When biodesulfurization of DBT in model oil with a high cell density culture of IGTS8 was investigated, accumulation of sulfate was found to limit the extent of desulfurization. A sulfate removal step was added to obtain a single-stage integrated biodesulfurization process. Sulfate removal was achieved via an aqueous bleed stream and use of a separation unit to recycle the organic phase. CONCLUSION : A proof of principle of a complete system capable of biocatalyst growth, induction, desulfurization and by-product separation was demonstrated. This system enables simplification of the biodesulfurization process and has potential to lower the operating cost of the bioprocess.

Tangaromsuk, Jantana [ORNL; Borole, Abhijeet P [ORNL; Kruatrachue, Maleeya [Mahidol University; Pokethitiyook, Prayad [PTT Research and Technical Institute

2008-01-01

215

Low-Sulfur Fuel Oil from Coal.  

National Technical Information Service (NTIS)

A high-sulfur bituminous coal suspended in coal tar was hydrodesulfurized by continuous processing through a fixed bed of pelletized cobalt molybdate on alumina catalyst, under conditions of highly turbulent flow of hydrogen to prevent obstruction of the ...

P. M. Yavorsky S. Akhtar S. Friedman

1971-01-01

216

Neutralization and Biodegradation of Sulfur Mustard.  

National Technical Information Service (NTIS)

The chemical warfare agent sulfur mustard was hydrolyzed to products that were biologically mineralized in sequencing batch reactors seeded with activated sludge. Greater than 90% carbon removal was achieved using laboratory scale bioreactors processing h...

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

1997-01-01

217

Sulfur Cycling in Constructed Wetlands  

Microsoft Academic Search

Constructed wetlands (CWs) have been successfully employed in both mining and domestic wastewater applications, yet the fundamental\\u000a processes responsible for treatment are poorly quantified. Sulfur is common in CW influent streams and is highly reactive,\\u000a redox-sensitive, and microbially active; therefore, it plays an important role in both desirable and deleterious processes\\u000a in CWs. In this chapter we review the major

Paul J. Sturman; Otto R. Stein; Jan Vymazal; Lenka Krpfelov

218

Biologically produced sulfur particles and polysulfide ions  

Microsoft Academic Search

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

W. E. Kleinjan

2005-01-01

219

Fate of excess sulfur in higher plants  

SciTech Connect

The mechanisms which have evolved in higher plants to cope with excess sulfur in their environments are reviewed. Survival in a sulfur-rich environment is seldom achieved through avoidance of the intake of sulfur. The presence of excess sulfur in the soil or in the air usually results in an intake of excess sulfur into plants. An immediate injury by the excess sulfur taken up is, however, prevented by a series of metabolic processes. Storage of excess sulfur in a metabolically inactive compartment, i.e. the vacuole, appears to occur in most plants. The finding of a storage of glutathione is several investigations suggests that with increasing accumulation of sulfate its reduction also increases. Under these conditions the cysteine concentration in different compartments of the cell may still be maintained at a low level by the incorporation of the excess cysteine synthesized into glutathione. This peptide appears to be the storage form of reduced sulfur in higher plants. 167 references, 2 figures.

Rennenberg, H.

1984-01-01

220

Unsteady diagenetic processes and sulfur biogeochemistry in tropical deltaic muds: Implications for oceanic isotope cycles and the sedimentary record  

NASA Astrophysics Data System (ADS)

Sedimentary S cycling is usually conceptualized and interpreted within the context of steadily accreting (1-D) transport-reaction regimes. Unsteady processes, however, are common in many sedimentary systems and can result in dramatically different S reaction balances and diagenetic products than steady conditions. Globally important common examples include tropical deltaic topset and inner shelf muds such as those extending from the Amazon River 1600 km along the Guianas coast of South America. These deposits are characterized by episodic reworking of the surface seabed over vertical depths of 0.1-3 m. Reworked surface sediments act as unsteady, suboxic batch reactors, unconformably overlying relict anoxic, often methanic deposits, and have diagenetic properties largely decoupled from net accumulation of sediment. Despite well-oxygenated water and an abundant reactive organic matter supply, physical disturbance inhibits macrofauna, and benthic communities are dominated by microbial biomass across immense areas. In the surficial suboxic layer, molecular biological analyses, tracer experiments, sediment C/S/Fe compositions, and ? 34S, ? 18O of pore water SO42- indicate close coupling of anaerobic C, S, and Fe cycles. ? 18O- SO42- can increase by 2-3 during anaerobic recycling without net change in ? 34S- SO42-, demonstrating SO42- reduction coupled to complete anaerobic reoxidation to SO42- and a ? 18O- SO42- reduction + reoxidation fractionation factor?12 (summed magnitudes). S reoxidation must be coupled to Fe-oxide reduction, contributing to high dissolved Fe 2+ (1 mM) and Fe mobilization-export. The reworking of Amazon-Guianas shelf muds alone may isotopically alter ? 18O- SO42- equivalent in mass to?25% of the annual riverine delivery of SO42- to the global ocean. Unsteady conditions result in preservation of unusually heavy ? 34S isotopic compositions of residual Cr reducible S, ranging from 0 to >30 in physically reworked deposits. In contrast, bioturbated facies adjacent to physically reworked regions accumulate isotopically light S (? 34S to -20) in otherwise similar decomposition regimes. The isotopic patterns of both physically and biologically reworked regions can be simulated with simple diagenetic models. Heavy S isotopic signatures are largely a consequence of unsteady diffusion and progressive anaerobic burndown into underlying deposits, whereas isotopically depleted bioturbated deposits predominantly reflect biogenic diffusive scaling and isotopic distillation/diffusive pumping associated with reoxidation in burrow walls immediately adjacent to reduced zones. The S isotopic transition from unsteady physically controlled regions of the Amazon delta moving laterally into bioturbated facies mimics the transition of S isotopic patterns temporally in the geologic record during the rise of bioturbation. No special role for S disproportionation is required to explain these differences. The potential role of unsteady, suboxic diagenesis and dynamic reworking of sediments has been largely ignored in models of the evolution of surficial elemental cycling and interpretations of the geologic record.

Aller, Robert C.; Madrid, Vanessa; Chistoserdov, Andrei; Aller, Josephine Y.; Heilbrun, Christina

2010-08-01

221

Production of elemental sulfur and methane from H{sub 2}S and CO{sub 2} derived from a coal desulfurization process. Quarterly technical progress report, October 1, 1995--December 31, 1995  

SciTech Connect

During the ninth quarter of the project, bench scale experiments were performed to investigate the adsorption ability of different kinds of materials within sulfur vapor environment. Four kinds of adsorbents have been tested. The experiment results indicated that activated carbon was the best of four adsorbents tested. The adsorption process may be applicable to promote conversion of H{sub 2}S in the H{sub 2}S and SO{sub 2} reaction system.

Gong, S.-Y.; Jiang, X.; Khang, S.-J.; Keener, T.C.

1995-12-31

222

Reconstruction of changes in global sulfur cycling from marine sulfate isotopes  

Microsoft Academic Search

Stable isotope ratios of sulfur (?34S) and oxygen (?18O) in marine sulfate respond to changes in fluxes and processes in the global sulfur cycle. The two isotope systems respond on different time scales to different factors affecting the global sulfur cycle. Sulfur isotopes respond primarily to the relative fluxes of weathering-derived sulfate to the oceans versus the net flux of

Simon H. Bottrell; Robert J. Newton

2006-01-01

223

Tribological behavior of near-frictionless carbon coatings in high- and low-sulfur diesel fuels  

Microsoft Academic Search

The sulfur content in diesel fuel has a significant effect on diesel engine emissions, which are currently subject to environmental regulations. It has been observed that engine particulate and gaseous emissions are directly proportional to fuel sulfur content. With the introduction of low-sulfur fuels, significant reductions in emissions are expected. The process of sulfur reduction in petroleum-based diesel fuels also

M. F. Alzoubi; O. O. Ajayi; O. L. Eryilmaz; O. Ozturk; A. Erdemir; G. Fenske

2000-01-01

224

AN EXAMINATION OF ASTM PROCEDURES FOR DETERMINING SULFUR FORMS IN COAL  

Microsoft Academic Search

Several raw coals of various ranks were used to examine the effects of some of the variations in ASTM procedures on analytical results obtained for total sulfur and sulfur forms. ASTM procedures were also used to determine pyritic sulfur in two coals cleaned by selective agglomeration processes.In addition, organic sulfur values obtained by the indirect ASTM procedure were compared to

Glenn A. Norton; Rachel E. Peters; Colin D. Chriswell

1994-01-01

225

H2S(g) removal using a modified, low-ph liquid redox sulfur recovery (LRSR) process with electrochemical regeneration of the Fe catalyst couple.  

PubMed

A modified pH 1.0 liquid redox sulfur recovery (LRSR) process, based on reactive absorption of H(2)S((g)) in an acidic (pH 1.0) iron solution ([Fe(III)] = 9-8 g L(-1), [Fe(II)] = 1-2 g L(-1)) and electrochemical regeneration of the Fe(III)/Fe(II) catalyst couple, is introduced. Fe(II) was oxidized in a flow-through electrolytic cell by Cl(2(aq)) formed on a Ti/RuO(2) anode. pH 1.0 was applied to retard the potential precipitation of predominantly jarosite group Fe(III) species. At pH 1.0, the presence of chloride ions at [Cl(-)] = 30 g L(-1) allows for both efficient (indirect) electrochemical oxidation of Fe(II) and efficient H(2)S((g)) reactive absorption. The latter observation was hypothesized to be associated with higher concentrations of Fe(III)-Cl complexes that are more highly reactive toward H(2)S((aq)) than are free Fe(III) ions and Fe-SO(4) complexes that otherwise dominate pH 1.0 Fe(III) solutions in the absence of a significant Cl(-) concentration. At the described operational conditions the rate of Fe(II) oxidation in the experimental system was 0.793 kg Fe h(-1) per m(2) anode surface area, at a current efficiency of 58%. Electricity cost within the electrochemical step was approximated at $0.9 per kg H(2)S((g)) removed. PMID:19924962

Gendel, Youri; Levi, No'omi; Lahav, Ori

2009-11-01

226

Apparatus for recovery of sulfur  

SciTech Connect

This patent describes an apparatus for the recovery of sulfur from an underground sulfur formation. It comprises means for the injection of hot water into contact with the underground sulfur formation; means to permit the water and elemental sulfur to remain in contact, so as to melt at least a portion of the sulfur and form a mixture of molten sulfur and water; means for removing the mixture of molten sulfur and heated water to the surface; means for separating the water and sulfur mixture to recover molten sulfur and water; and means to recycle the water to the underground formation.

Peters, J.R.; Ramey, M.E.; Seyffert, A.E.; Canon, J.L.; Robinson, M.W.; Abercrombie, W.T.

1989-09-26

227

Relationship between corrosion and the biological sulfur cycle: A review  

SciTech Connect

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

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

2000-04-01

228

Sulfurization of a Carbon Surface for Vapor Phase Mercury Removal-II: Sulfur Forms and Mercury Uptake  

SciTech Connect

Sulfur forms deposited on carbonaceous surfaces after exposure to hydrogen sulfide were analyzed using XPS and XANES. Higher temperatures promote the formation of organic sulfur and the presence of H{sub 2}S during the cooling process increased elemental sulfur content. Temperatures between 400-600 C were found to be optimal for producing effective mercury uptake sorbents. The increased amount of sulfur deposited during the cooling process in the presence of H2S was very effective towards Hg uptake in nitrogen. Correlation of mercury uptake capacity and the content of each sulfur form indicated that elemental sulfur, thiophene, and sulfate are likely responsible for mercury uptake, with elemental sulfur species being the most effective.

Feng,W.; Borguet, E.; Vidic, R.

2006-01-01

229

Sulfur and olefin management in the gasoline  

SciTech Connect

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

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

1995-09-01

230

Plasma-chemical conversion of hydrogen sulfide into hydrogen and sulfur.  

National Technical Information Service (NTIS)

A waste-treatment process that recovers both hydrogen and sulfur from hydrogen-sulfide-contaminated industrial wastes is being developed to replace the Claus technology, which recovers only sulfur. The proposed process is based on research reported in the...

J. B. L. Harkness R. D. Doctor E. J. Daniels

1993-01-01

231

Optimization of wastewater feeding for single-cell protein production in an anaerobic wastewater treatment process utilizing purple non-sulfur bacteria in mixed culture condition  

Microsoft Academic Search

Impacts of operation timing of feeding and withdrawal on anaerobic wastewater treatment utilizing purple non-sulfur bacteria have been investigated in mixed culture condition with acidogenic bacteria. Simulated wastewater containing glucose was treated in a laboratory-scale chemostat reactor, changing the timing of wastewater feeding and withdrawal. Rhodopseudomonas palustris, which does not utilize glucose as a substrate, was inoculated in the reactor.

Ryo Honda; Kensuke Fukushi; Kazuo Yamamoto

2006-01-01

232

The Role of Malate Dehydrogenase Isoforms in the Regulation of Anabolic and Catabolic Processes in the Colorless Sulfur Bacterium Beggiatoa leptomitiformis D-402  

Microsoft Academic Search

The functional role of tetrameric and dimeric isoforms of malate dehydrogenase in the carbon metabolism of the colorless sulfur bacterium Beggiatoa leptomitiformis, strain D-402, was studied. This strain can grow both lithotrophically and organotrophically. By use of inhibition analysis, the tetrameric isoenzyme was shown to operate in the glyoxylate cycle and the dimeric form was found to be involved in

A. T. Eprintsev; M. I. Falaleeva; M. Yu. Grabovich; N. V. Parfenova; N. N. Kashirskaya; G. A. Dubinina

2004-01-01

233

Elusive pyrite sulfur  

Microsoft Academic Search

Methods to analyze coal and coal refuse for pyrite sulfur and ash quickly and accurately is presented. ASTM, x-ray diffracton methods, an innovative new method which combines thermogravimetric analysis with ferromagnetism, and direct measurement by reduction of the sulfur to hydrogen sulfide are discussed.

Heunisch

2009-01-01

234

Io's Sulfur: Surface Distribution and Chemical Nature of Impurities  

NASA Astrophysics Data System (ADS)

Galileo SSI and NIMS data have returned a wealth of information on the surface composition of Io. Our analysis suggests that elemental sulfur and sulfur dioxide are nearly ubiquitous but that the ratio of these two materials varies widely. Some of the most spectacular concentrations of elemental sulfur occur near major volcanoes and hotspots. In these areas the color and spectral signature of sulfur and any other materials present varies widely, in some cases forming concentrically zoned deposits around calderas. The spectral variability of sulfur may be due to many mechanisms; inclusion of minor impurities is among the possible controls. We have made some tentative identifications of possible impurities-- iron (as opaque inclusions of FeS disseminated in sulfur) appears to cause the green coloration of some deposits on Io-- including Io's so-called "golf courses." Arsenic, selenium, and tellurium (dissolved in quenched sulfur polymers and/or bonded in stoichiometric compounds with sulfur) may contribute to reddish coloration of other deposits. As little as one percent of these impurities may produce marked changes in the spectral reflectance and color of sulfur. However, other mechanisms can account for Io's reds; Io's green deposits are harder to explain in the absence of pyrite or other metallic sulfide inclusions in elemental sulfur; the logical alternative, ultramafic silicates, has fallen out of favor with the Galileo team due to absence of a diagnostic band near 0.9 microns. These colored forms of impure sulfur have been observed both in nature (in terrestrial volcanogenic native sulfur) and in recent lab specimens quenched from the molten state and containing controlled quantities of impurities (cf abstract by MacIntyre et al., this volume). Evidence for impurities in Io's sulfur will be presented, and we will offer a glimpse into possible geological process implications of the distribution of sulfur on Io and the impurities that may be present in Io's sulfur.

Kargel, J. S.; MacIntyre, T.; Dalton, B.; Clark, R.

2000-10-01

235

Regional river sulfur runoff  

SciTech Connect

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

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

1985-01-20

236

Sulfur Recovery in a Coal Gasification Plant.  

National Technical Information Service (NTIS)

For the western coal feed, the combination of a non-selective Selexol process for acid gas removal, FMC Double Alkali process for flue gas cleanup, and a Stretford process for sulfur recovery, was the most economical among the cases studied. For the easte...

W. S. Chia F. A. Todd

1978-01-01

237

Sulfur recovery in a coal gasification plant  

Microsoft Academic Search

To determine the most economical combination of processes for removing sulfur compounds from a coal gasification plant's gasifier raw gas and boiler flue gas, C. F. Braun and Co. examined alternatives for a 250 million cu ft\\/day plant using the Bituminous Coal Research Inc. Bi-Gas gasification process. For a western coal feed, the combination of a nonselective Selexol process for

W. S. Chia; F. A. Todd; W. J. Stupin

1978-01-01

238

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

NASA Astrophysics Data System (ADS)

The sulfur geochemistry of the lacustrine Paleogene Green River Formation (Colorado, Utah, and Wyoming, USA) is unlike that of most marine and other lacustrine rocks. Distinctive chemical, isotopic, and mineralogical characteristics of the formation are pyrrhotite and marcasite, high contents of iron mineral sulfides strikingly enriched in34S, cyclical trends in sulfur abundance and ?34S values, and long-term evolutionary trends in ?34S values. Analyses that identified and quantified these characteristics include carbonate-free abundance of organic carbon (0.13 47 wt%), total iron (0.31 13 wt%), reactive iron (>70% of total iron), total sulfur (0.02 16 wt%), acid-volatile monosulfide (SAv), disulfide (SDi > 70% of total sulfur), sulfate (SSO4) and organosulfur (SOrg); isotopic composition of separated sulfur phases (?34SDi,Av up to +49); and mineralogy, morphology and paragenesis of sulfide minerals. Mineralogy, morphology, ?34SDi,Av, and ?34SOrg have a distinctive relation, reflecting variable and unique depositional and early diagenetic conditions in the Green River lakes. When the lakes were brackish, dissimilatory sulfate-reducing bacteria in the sediment produced H2S, which initially reacted with labile iron to form pyrite framboids and more gradually with organic matter to form organosulfur compounds. During a long-lived stage of saline lake water, the amount of sulfate supplied by inflow decreased and alkalinity and pH of lake waters increased substantially. Extensive bacterial sulfate reduction in the water column kept lake waters undersaturated with sulfate minerals. A very high H2S:SO4 ratio developed in stagnant bottom water aided by the high pH that kinetically inhibited iron sulfidization. Progressive removal of H2S by coeval formation of iron sulfides and organosulfur compounds caused the isotopic composition of the entire dissolved sulfur reservoir to evolve to ?34S values much greater than that of inflow sulfate, which is estimated to have been +20 A six-million-year interval within Lake Uinta cores records this evolution as well as smaller systematic changes in ?34S, interpreted to reflect ~ 100,000-year lake-level cycles. When porewater was exceptionally reducing, unstable FeS phases eventually recrystallized to pyrrhotite during diagenesis. A much later reaction related to weathering altered pyrrhotite to marcasite.

Tuttle, Michele L.; Goldhaber, Martin B.

1993-07-01

239

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

USGS Publications Warehouse

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

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

1993-01-01

240

Oxygen and sulfur isotope fractionation during anaerobic bacterial disproportionation of elemental sulfur  

Microsoft Academic Search

Bacterial disproportionation of elemental sulfur is an important process in the sulfur cycle of natural sediments and leads to the formation of hydrogen sulfide and sulfate. The oxygen atoms in sulfate during this anaerobic process are completely derived from water according to the overall reaction: 4H2O + 4S0 ? 3H2S + SO42? + 2H+In the present study, stable oxygen isotope

M. E. Bttcher; B. Thamdrup; T. W. Vennemann

2001-01-01

241

Sulfur removal from high-sulfur Illinois coal by low-temperature perchloroethylene (PCE) extraction  

SciTech Connect

A pre-combustion coal desulfurization process at 120{degree}C using perchloroethylene (PCE) to remove up to 70% of the organic sulfur has been developed by the Midwest Ore Processing Co. (MWOPC). However, this process has not yet proven to be as successful with Illinois coals as it has for Ohio and Indiana coals. The organic sulfur removal has been achieved only with highly oxidized Illinois coals containing high sulfatic sulfur. A logical explanation for this observation is vital to successful process optimization for the use of Illinois coals. In addition, the high levels of organic sulfur removals observed by the MWOPC may be due to certain errors involved in the ASTM data interpretation; this needs verification. For example, elemental sulfur extracted by the PCE may be derived from pyrite oxidation during coal pre-oxidation, but it may be interpreted as organic sulfur removed by the PCE using ASTM analysis. The goals of this research are: (1) to independently confirm and possibly to improve the organic sulfur removal from Illinois coals with the PCE desulfurization process reported by the MWOPC, (2) to verify the forms-of-sulfur determination using the ASTM method for the PCE process evaluation, and (3) to determine the suitability of Illinois coals for use in the PCE desulfurization process. This project involves the Illinois State Geological Survey (ISGS), Eastern Illinois University (EIU), the University of Illinois-Urbana/Champaign (UI-UC), and the University of Kentucky, Lexington (UK). This is the first year of a two-year project.

Chou, M.I.M.

1991-01-01

242

Kinetics of decomposition of manganese slimes by sulfur dioxide  

SciTech Connect

Lean manganese ores, and slimes obtained during mechanical beneficiation of Chiatura manganese ores, have been treated by the sulfite process, by saturation of suspensions with sulfur dioxide. The kinetics of saturation of the suspensions with sulfur dioxide, and transfer of manganese into solution was studied. Manganese was leached out by passing sulfur dioxide through the slime suspension. The sulfur dioxide dissolved in water to form the weakly dissociated sulfurous acid in equilibrium with its anhydrides. The leaching was conducted without access of air at room temperature. An equation for determination of the rate of sulfur dioxide adsorption by a manganese-containing slurry and for calculation of the degree of manganese extraction into solution was developed from the experimental results. The reaction order and the control regime of the processes were determined.

Dzhaparidze, P.I.; Kelbakiani, N.V.

1982-02-20

243

Are we getting enough sulfur in our diet?  

PubMed Central

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

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

2007-01-01

244

Sulfur geochemistry of Jurassic high-sulfur coals from Egypt  

Microsoft Academic Search

Jurassic high-sulfur coals from the Maghara area in Egypt were analyzed for the abundance and isotopic composition of different forms of sulfur. Analyses indicated that the sulfur occurs in the form of organic, pyrite, and sulfate forms. Pyrite sulfur represents the major fraction, while sulfate sulfur is minor and could be formed during sample preparation for the analyses.The ?34S CDT

Hassan Baioumy

2010-01-01

245

Radiolysis of sulfuric acid, sulfuric acid monohydrate, and sulfuric acid tetrahydrate and its relevance to Europa  

NASA Astrophysics Data System (ADS)

We report laboratory studies on the 0.8 MeV proton irradiation of ices composed of sulfuric acid (H 2SO 4), sulfuric acid monohydrate (H 2SO 4H 2O), and sulfuric acid tetrahydrate (H 2SO 44H 2O) between 10 and 180 K. Using infrared spectroscopy, we identify the main radiation products as H 2O, SO 2, (S 2O 3) x, H 3O +, HSO4-, and SO42-. At high radiation doses, we find that H 2SO 4 molecules are destroyed completely and that H 2SO 4H 2O is formed on subsequent warming. This hydrate is significantly more stable to radiolytic destruction than pure H 2SO 4, falling to an equilibrium relative abundance of 50% of its original value on prolonged irradiation. Unlike either pure H 2SO 4 or H 2SO 4H 2O, the loss of H 2SO 44H 2O exhibits a strong temperature dependence, as the tetrahydrate is essentially unchanged at the highest irradiation temperatures and completely destroyed at the lowest ones, which we speculate is due to a combination of radiolytic destruction and amorphization. Furthermore, at the lower temperatures it is clear that irradiation causes the tetrahydrate spectrum to transition to one that closely resembles the monohydrate spectrum. Extrapolating our results to Europa's surface, we speculate that the variations in SO 2 concentrations observed in the chaotic terrains are a result of radiation processing of lower hydration states of sulfuric acid and that the monohydrate will remain stable on the surface over geological times, while the tetrahydrate will remain stable in the warmer regions but be destroyed in the colder regions, unless it can be reformed by other processes, such as thermal reactions induced by diurnal cycling.

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

2011-09-01

246

Parametric study of sulfuric acid decomposer for hydrogen production  

Microsoft Academic Search

It is proposed to use a ceramic high-temperature heat exchanger as a sulfuric acid decomposer for hydrogen production within the sulfuriodine thermo-chemical cycle portion of the hydrogen production process. In this cycle, hot helium from a nuclear reactor is used to heat the SI (sulfuric acid) feed components (H2O, H2SO4, SO3) to obtain appropriate conditions for the SI decomposition reaction.

Valery Ponyavin; Yitung Chen; Taha Mohamed; Mohamed Trabia; Anthony E. Hechanova; Merrill Wilson

2008-01-01

247

Separation of sulfur isotopes  

DOEpatents

Sulfur isotopes are continuously separated and enriched using a closed loop reflux system wherein sulfur dioxide (SO.sub.2) is reacted with sodium hydroxide (NaOH) or the like to form sodium hydrogen sulfite (NaHSO.sub.3). Heavier sulfur isotopes are preferentially attracted to the NaHSO.sub.3, and subsequently reacted with sulfuric acid (H.sub.2 SO.sub.4) forming sodium hydrogen sulfate (NaHSO.sub.4) and SO.sub.2 gas which contains increased concentrations of the heavier sulfur isotopes. This heavy isotope enriched SO.sub.2 gas is subsequently separated and the NaHSO.sub.4 is reacted with NaOH to form sodium sulfate (Na.sub.2 SO.sub.4) which is subsequently decomposed in an electrodialysis unit to form the NaOH and H.sub.2 SO.sub.4 components which are used in the aforesaid reactions thereby effecting sulfur isotope separation and enrichment without objectionable loss of feed materials.

DeWitt, Robert (Centerville, OH); Jepson, Bernhart E. (Dayton, OH); Schwind, Roger A. (Centerville, OH)

1976-06-22

248

INTERNATIONAL SULFUR DEPOSITION MODEL EVALUATION - 1980 STANDARD MODEL INPUT DATA SET  

EPA Science Inventory

North American meteorological and sulfur emissions data for 1980 have been processed to serve as input data to regional acid deposition models participating in the International Sulfur Deposition Model Evaluation (ISDME) Project. Using these data sets, 15 regional acid deposition...

249

Alternative method for the removal of oxides of nitrogen and sulfur from combustion processes. Second quarterly technical status report, September 17-March 31, 1986  

SciTech Connect

The program is on schedule. The current program has clearly demonstrated that SO/sub x/ and NO/sub x/ can be decomposed to elemental sulfur and nitrogen by a zirconia solid electrolyte cell. The Ceramatec and VSM team have also carried out design system modeling which suggests that a cell design is feasible that can meet system integration and economic requirements. The achievement of these major milestones verifies that the proposed program approach is feasible and provides a strong incentive to continue the program into Phase II.

Joshi, A.V.

1986-01-01

250

Quantitative proteomics of Chlorobaculum tepidum: insights into the sulfur metabolism of a phototrophic green sulfur bacterium.  

PubMed

Chlorobaculum (Cba.) tepidum is a green sulfur bacterium that oxidizes sulfide, elemental sulfur, and thiosulfate for photosynthetic growth. To gain insight into the sulfur metabolism, the proteome of Cba. tepidum cells sampled under different growth conditions has been quantified using a rapid gel-free, filter-aided sample preparation (FASP) protocol with an in-solution isotopic labeling strategy. Among the 2245 proteins predicted from the Cba. tepidum genome, approximately 970 proteins were detected in unlabeled samples, whereas approximately 630-640 proteins were detected in labeled samples comparing two different growth conditions. Wild-type cells growing on thiosulfate had an increased abundance of periplasmic cytochrome c-555 and proteins of the periplasmic thiosulfate-oxidizing SOX enzyme system when compared with cells growing on sulfide. A dsrM mutant of Cba. tepidum, which lacks the dissimilatory sulfite reductase DsrM protein and therefore is unable to oxidize sulfur globules to sulfite, was also investigated. When compared with wild type, the dsrM cells exhibited an increased abundance of DSR enzymes involved in the initial steps of sulfur globule oxidation (DsrABCL) and a decreased abundance of enzymes putatively involved in sulfite oxidation (Sat-AprAB-QmoABC). The results show that Cba. tepidum regulates the cellular levels of enzymes involved in sulfur metabolism and other electron-transferring processes in response to the availability of reduced sulfur compounds. PMID:22092713

Falkenby, Lasse G; Szymanska, Monika; Holkenbrink, Carina; Habicht, Kirsten S; Andersen, Jens S; Miller, Mette; Frigaard, Niels-Ulrik

2011-08-25

251

Geochemistry of sulfur in the Florida Everglades; 1994 through 1999  

USGS Publications Warehouse

In this report, we present data on the geochemistry of sulfur in sediments and in surface water, groundwater, and rainwater in the Everglades region in south Florida. The results presented here are part of a larger study intended to determine the roles played by the cycling of carbon, nitrogen, phosphorus, and sulfur in the ecology of the south Florida wetlands. The geochemistry of sulfur in the region is particularly important because of its link to the production of toxic methylmercury through processes mediated by sulfate reducing bacteria. Sediment cores were collected from the Everglades Agricultural Area (EAA), Water Conservation Areas (WCAs) 1A and 2A, from Lake Okeechobee, and from Taylor Slough in the southern Everglades. Water collection was more widespread and includes surface water from WCAs 1A, 2A, 3A, 2B, the EAA, Taylor Slough, Lake Okeechobee, and the Kissimmee River. Groundwater was collected from The Everglades Nutrient Removal Area (ENR) and from WCA 2A. Rainwater was collected at two month intervals over a period of one year from the ENR and from WCA 2A. Water was analyzed for sulfate concentration and sulfate sulfur stable isotopic ratio (34S/32S). Sediment cores were analyzed for total sulfur concentration and/or for concentrations of sulfur species (sulfate, organic sulfur, disulfides, and acid volatile sulfides (AVS)) and for their stable sulfur isotopic ratio. Results show a decrease in total sulfur content (1.57 to 0.61 percent dry weight) with depth in two sediment cores collected in WCA 2A, indicating that there has been an increase in total sulfur content in recent times. A sediment core from the center of Lake Okeechobee shows a decrease in total sulfur content with depth (0.28 to 0.08 percent dry weight). A core from the periphery of the lake (South Bay) likewise shows a decrease in total sulfur content with depth (1.00 to 0.69 percent dry weight), however, the overall sulfur content is greater than that near the center at all depths. This suggests input of sulfur in recent times, especially near the lake margins. Sediments show a general decrease in sulfur concentration with depth, probably because of increases in sulfur input to the marshes in recent times. Regional differences in the concentrations and stable isotopic ratios of sulfate sulfur in surface water show that sulfur contamination to the northern Everglades likely originates from canals draining the EAA.

Bates, Anne L.; Orem, W. H.; Harvey, J. W.; Spiker, E. C.

2000-01-01

252

Microbial stabilization of sulfur-landen sorbents; Technical report, September 1--November 30, 1993  

SciTech Connect

Clean coal technologies that involve limestone for sulfur capture generate lime/limestone products laden with sulfur at various oxidation states. If sulfur is completely stabilized as sulfate, the spent sorbent is ready for commercial utilization as gypsum. However, the presence of reduced sulfur species requires additional processing. Thermal oxidation of reduced sulfur can result in undesirable release of SO{sub 2}. Microbial oxidation might provide an inexpensive and effective alternative. Sorbents laden with reduced forms of sulfur such as sulfide, sulfite, or various polythionate species serve as growth substrates for sulfur-oxidizing bacteria, which have the potential to convert all sulfur to sulfate. This quarter, efforts focused on determining the combined effects of dibasic acids (DBA) and Ca{sup +2} concentration on several strains of neutrophilic thiobacilli, including Thiobacillus neapolitanus ATCC 23639 and ATCC 23641, and an isolate, TQ1, which was obtained from a commercial sulfur dioxide scrubber that utilizes DBA.

Miller, K.W. [Illinois State Univ., Normal, IL (United States)

1993-12-31

253

Comparative Aspects of Sulfur Mineralization in Sediments of a Eutrophic Lake Basin  

PubMed Central

The net mineralization of organic sulfur compounds in surface sediments of Wintergreen Lake was estimated from a mass-balance budget of sulfur inputs and sediment sulfur concentrations. The net mineralization of organic sulfur inputs is <50% complete, which is consistent with the dominance of organic sulfur (>80% of total sulfur) in sediment. Although sediment sulfur is predominantly organic, sulfate reduction is the most significant process in terms of the quantities of sulfur transformed in surface sediments. Rates of sulfate reduction in these sediments average 7 mmol/m2 per day. On an annual basis, this rate is 19-fold greater than net rates of organic sulfur mineralization and 65-fold greater than sulfate ester hydrolysis.

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

1982-01-01

254

Sulfur: the key for filling carbon nanotubes with metals  

Microsoft Academic Search

It is shown, using combined structural and chemical analysis modes of transmission electron microscopy, that various filled nanotubes can be produced by arcing a graphite cathode and a graphite anode doped with the filling element and a small quantity of sulfur. A growth mechanism based on a catalytic process involving carbon, a metal and sulfur is proposed.

N. Demoncy; O. Stphan; N. Bran; C. Colliex; A. Loiseau; H. Pascard

1999-01-01

255

Sulfur: the key for filling carbon nanotubes with metals  

Microsoft Academic Search

It is shown, using combined structural and chemical analysis modes of transmission electron microscopy, that various filled elements can be produced by arcing a graphite cathode and a graphite anode doped with the filling element and a small quantity of sulfur. A growth mechanism based on a catalytic process involving carbon, a metal and sulfur is proposed.

A. Loiseau; N. Demoncy; O. Stphan; C. Colliex; H. Pascard

1999-01-01

256

Designing an alkalized alumina pilot plant for sulfur oxides removal  

Microsoft Academic Search

A continuous pilot plant has been designed and constructed to obtain operational data that can be used to scale-up the process of removing sulfur oxides from flue gases in a dilute phase contactor by a dry absorbent. Known as ''alkalized alumina,'' this absorbent is a coprecipitate of sodium and aluminum oxides which react chemically with the sulfur oxides to form

R. C. Kurtzrock; D. H. McCrea; G. J. Cinquegrane

1967-01-01

257

Trafficking in persulfides: delivering sulfur in biosynthetic pathways  

Microsoft Academic Search

The presence of sulfur in cofactors has been appreciated for over a century, but the trafficking and delivery of sulfur to cofactors and nucleosides is still not fully understood. In the last decade, great strides have been made toward understanding those processes and the enzymes that conduct them, including cysteine desulfurases and rhodanese homology domain proteins. The persulfide group (RSSH)

Eugene G Mueller

2006-01-01

258

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

SciTech Connect

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

Attar, A.

1983-05-01

259

Sulfur Chemiluminescence Detection Compared to Sulfur Flame Photometric Detection.  

National Technical Information Service (NTIS)

Detection of compounds containing sulfur heteratom is traditionally accomplished using flame photometric detection (FPD). Sulfur chemiluminescence detection (SCD) is an alternative to FPD. This report compares the FPD with two SCD configurations using var...

M. W. Elizy L. G. Janes

1998-01-01

260

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

SciTech Connect

Laboratory investigations have been conducted on the effects of variations in sulfur sample histories on their solid-state transformation rate and the corresponding spectral variation of freshly frozen sulfur. The temporal variations in question may be due to differences in the amount and type of metastable allotropes present in the sulfur after solidification, as well as to the physics of the phase-transformation process itself. The results obtained are pertinent to the physical behavior and spectral variation of such freshly solidified sulfur as may exist on the Jupiter moon Io; this would initially solidify into a glassy solid or monoclinic crystalline lattice, then approach ambient dayside temperatures. Laboratory results imply that the monoclinic or polymeric allotropes can in these circumstances be maintained, and will take years to convert to the stable orthorhombic crystalline form. 114 refs.

Moses, J.I.; Nash, D.B. (California Institute of Technology, Pasadena (USA) San Juan Capistrano Research Institute, CA (USA))

1991-02-01

261

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

NASA Astrophysics Data System (ADS)

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

Moses, J. I.; Nash, D. B.

1991-02-01

262

Sodium sulfur battery seal  

DOEpatents

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

Mikkor, Mati (Ann Arbor, MI)

1981-01-01

263

Standard reference materials: sampling, materials handling, processing, and packaging of NBS (National Bureau of Standards) sulfur in coal standard reference materials  

SciTech Connect

This publication describes in detail the performance of a grant given to Valley Forge Laboratories, Inc., by the National Bureau of Standards, to obtain and prepare four standard reference coals, with nominal sulfur contents of 0.5, 2.0, 3.0, and 4.5 percent to be issued as SRM's 2682, 2683, 2684, and 2685, respectively. All activities pertaining to the sampling, preparation, packaging, and homogeneity testing of the coal SRM's are documented in this report, including a separate description of each of the four coal sampling activities. Protocols used in the development of these Standard Reference Materials are similar to those used in other NBS SRM preparation procedures to ensure that materials used for SRM's have the highest possible homogeneity and stability.

Gills, T.E.; Seward, R.W.; Collins, R.J.; Webster, W.C.

1983-08-01

264

Hydrate sulfuric acid after sulfur implantation in water ice  

Microsoft Academic Search

For many years an ongoing research program performed at our laboratory has had the aim to investigate the implantation of reactive ions in ices relevant to planetology by using IR spectroscopy. We present new results obtained by implanting 200 keV sulfur ions into water ice at 80 K. We have looked at the formation of sulfur-bearing molecules such as sulfuric

G. Strazzulla; G. A. Baratta; G. Leto; O. Gomis

2007-01-01

265

Development of Specialized Sulfur Concretes.  

National Technical Information Service (NTIS)

Specialized sulfur concretes were developed by the Federal Bureau of Mines as a result of research for the beneficial utilization of sulfur in construction materials. Materials were developed for use in acid and salt corrosive environments where portland ...

T. A. Sullivan W. C. McBee

1979-01-01

266

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

SciTech Connect

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

Miller, K.W. [Illinois State Univ., Normal, IL (United States); Hillyer, D.

1993-12-31

267

Sulfur Dioxide Measurements Near Point Sources Using Ultraviolet Spectroscopy From Aircraft During ICARTT-2004  

Microsoft Academic Search

Accurate measurements of sulfur dioxide are important in urban air pollution studies due to the role sulfur dioxide plays in atmospheric processes such as acid rain and particle formation. We will show slant column sulfur dioxide abundances that were derived using the differential optical absorption spectroscopy (DOAS) technique with ultraviolet spectrograph measurements taken aboard the NOAA WP-3D aircraft during ICARTT-2004.

M. L. Melamed; A. O. Langford; J. S. Daniel; H. L. Miller; R. W. Portmann; R. Schofield; S. Solomon

2005-01-01

268

Coal slagging burner for producing clean low-sulfur fuel gas  

Microsoft Academic Search

The process is described for combusting coal containing about 2% to 8% sulfur by weight to release and recover the heat content thereof while producing a low-sulfur off-gas which comprises: combusting finely divided coal in a slagging cyclone burner under conditions of incomplete combustion to convert the sulfur content of the coal to hydrogen sulfide, carrying out the incomplete combustion

M. T. Hepworth; G. R. Wicker

1986-01-01

269

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

SciTech Connect

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

Ho, N.W.Y.

1991-12-31

270

Service properties of jet fuels in relation to group composition of sulfur compounds in fuel  

Microsoft Academic Search

Most middle-distillate fuels are produced from medium- and high-sulfur crude oils. Even with the increasing use of hydrotreating processes, jet fuels still contain sulfur compounds that may vary in group composition. Numerous studies [1, 2] have been devoted to the matter of how sulfur compounds influence the service properties of fuels. The compounds that have been studied in the most

Ya. B. Chertkov; E. P. Seregin; T. I. Kirsanova; A. N. Romanov; T. A. Lifanova; G. B. Skovorodin

1976-01-01

271

Sulfur removal at high temperature during coal combustion in furnaces: a review  

Microsoft Academic Search

This paper focuses on sulfur removal technologies in industrial grate furnaces (IGF) and pulverized coal fired boilers (PCFB) with high flame temperature of 12001600 C. The SO2 reduction without sorbents during coal combustion, thermal stabilities of sulfation products, kinetics of sulfur retention reactions of sorbents, desulfurization processes, and sulfur removal under unconventional atmospheres at high temperature are reviewed. It is

Jun Cheng; Junhu Zhou; Jianzhong Liu; Zhijun Zhou; Zhenyu Huang; Xinyu Cao; Xiang Zhao; Kefa Cen

2003-01-01

272

Genetic and Proteomic Studies of Sulfur Oxidation in Chlorobium tepidum (syn. Chlorobaculum tepidum)  

Microsoft Academic Search

The oxidation of reduced sulfur compounds is perhaps the most poorly understood physiological process carried out by the green\\u000a sulfur bacteria (the Chlorobiaceae). My laboratory is testing models of sulfur oxidation pathways in the model system Chlorobium tepidum (ATCC 49652 syn. Chlorobaculum tepidum (Imhoff, 2003) ) by the creation and analysis of mutant strains lacking specific gene products. The availability

Leong-Keat Chan; Rachael Morgan-Kiss; Thomas E. Hanson

273

Formation of insoluble, nonhydrolyzable, sulfur-rich macromolecules via incorporation of inorganic sulfur species into algal carbohydrates  

NASA Astrophysics Data System (ADS)

The process of sulfur incorporation into organic matter was simulated in the laboratory by sulfurization of cell material of the prymnesiophyte alga Phaeocystis in sea water with inorganic polysulfides at 50C. Flash pyrolysis of the residue, obtained after extraction and several hydrolysis steps, yielded mainly C 1-C 4 alkylbenzenes and C 1-C 4 alkylphenols and, in contrast to control and blank experiments, relatively high amounts of C 0-C 4 alkylthiophenes. The distribution of the thiophenes is very similar to that in pyrolysates of type II-S kerogens. The formation of high-molecular-weight sulfur-rich macromolecules co-occurs with a marked drop in the content of hydrolyzable carbohydrates. This indicates that sulfurization results in the preservation of algal carbohydrate carbon in a macromolecular structure composed of (poly)sulfidic cross-linked carbohydrate skeletons, which upon pyrolysis yields alkylthiophenes. Sulfurization of glucose under similar conditions resulted in the formation of a nonhydrolyzable, solid material, which yielded high amounts of organic sulfur compounds upon pyrolysis, mainly short-chain alkylthiophenes, although with a different distribution than that in the pyrolysate of the sulfurized algal material. The carbon numbers of these organic sulfur compounds extend beyond six, indicating that the length of the carbon skeleton of the pyrolysis products is not limited by the length of the carbon skeleton of the substrate. These results suggest that the sulfurization of carbohydrates may be an important pathway in the preservation of organic matter in euxinic depositional environments.

Kok, Marika D.; Schouten, Stefan; Sinninghe Damst, Jaap S.

2000-08-01

274

Thermophilic Carbon-Sulfur-Bond-Targeted Biodesulfurization  

PubMed Central

Petroleum contains many heterocyclic organosulfur compounds refractory to conventional hydrodesulfurization carried out with chemical catalysts. Among these, dibenzothiophene (DBT) and DBTs bearing alkyl substitutions are representative compounds. Two bacterial strains, which have been identified as Paenibacillus strains and which are capable of efficiently cleaving carbon-sulfur (C--S) bonds in DBT at high temperatures, have been isolated for the first time. Upon attacking DBT and its various methylated derivatives at temperatures up to 60(deg)C, both growing and resting cells of these bacteria can release sulfur atoms as sulfate ions and leave the monohydroxylated hydrocarbon moieties intact. Moreover, when either of these paenibacilli was incubated at 50(deg)C with light gas oil previously processed through hydrodesulfurization, the total sulfur content in the oil phase clearly decreased.

Konishi, J.; Ishii, Y.; Onaka, T.; Okumura, K.; Suzuki, M.

1997-01-01

275

Adventures in Organic Sulfur Chemistry  

Microsoft Academic Search

On several occasions, SULFUR REPORTS has invited persons who have done outstanding work in sulfur chemistry to summarize highlights of their research career in a semiautobiographical review. The present account is from a distinguished chemist who has contributed importantly for nearly 50 years to medicinal and organic aspects of sulfur chemistry. Ernest E. Campaigne (who prefers simply E. Campaigne) was

E. Campaigne

1990-01-01

276

Method of capturing sulfur  

Microsoft Academic Search

A fluidized bed boiler, and a method of operating same in which air is passed through a grate to fluidize a bed of particulate material containing fossil fuel disposed on the grate. A raw acceptor for the sulfur produced as a result of the combustion of the fuel is introduced into the housing and confined within an area of the

R. D. Stewart; R. L. Gamble

1984-01-01

277

For sale: Sulfur emissions  

Microsoft Academic Search

The allowance trading market has started a slow march to maturity. Competitive developers should understand the risks and opportunities now presented. The marketplace for sulfur dioxide (SO) emissions allowances - the centerpiece of Title 4's acid rain reduction program - remains enigmatic 19 months after the Clean Air Act amendments of 1990 were passed. Yet it is increasingly clear that

Heiderscheit

2009-01-01

278

Sodium sulfur battery seal  

DOEpatents

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

Topouzian, Armenag (Birmingham, MI)

1980-01-01

279

CONTROLLING SULFUR OXIDES  

EPA Science Inventory

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

280

Metagenomic assessment of a sulfur-oxidizing enrichment culture derived from marine sediment  

Microsoft Academic Search

The biological oxidation of reduced sulfur compounds is a critically important process in global sulfur biogeochemistry. In\\u000a this study, we enriched from marine sediments under denitrifying conditions, chemolithotrophic sulfur oxidizers that could\\u000a oxidize a variety of reduced sulfur compounds: thiosulfate, tetrathionate, sulfide, and polysulfide. Two major phylotypes\\u000a of 16S rRNA gene (>99% identity in each phylotype) were detected in this

Man-Young Jung; VinhHoa Pham; Soo-Je Park; So-Jeong Kim; Jong-Chan Chae; Yul Roh; Sung-Keun Rhee

2010-01-01

281

Sulfur Impregnation on Activated Carbon Fibers through H 2 S Oxidation for Vapor Phase Mercury Removal  

Microsoft Academic Search

Sulfur was impregnated onto activated carbon fibers ACFs through H2S oxidation catalyzed by the sorbent surface in a fixed-bed reactor. By changing the temperature and duration of the sulfur impregnation process, ACFs with different sulfur contents were developed. Characterization of ACFs before and after sulfur impregnation was conducted by surface area analysis, energy dispersive X-ray analysis, thermogravimetric analysis, X-ray photoelectron

Wenguo Feng; Seokjoon Kwon; Xue Feng; Eric Borguet; Radisav D. Vidic

2009-01-01

282

Sulfur removal from high-sulfur Illinois coal by low-temperature perchloroethylene (PCE) extraction. Technical report, December 1, 1991--February 29, 1992  

SciTech Connect

A pre-combustion coal desulfurization process at 120{degree}C using perchloroethylene (PCE) to remove up to 70% of the organic sulfur has been developed by the Midwest Ore Processing Co. (MWOPC). However, this process has not yet proven to be as successful with Illinois coals as it has for Ohio and Indiana coals. In addition, the high levels of organic sulfur removals observed by the MWOPC may be due to certain errors involved in the ASTM data interpretation; this needs verification. For example, elemental sulfur extracted by the PCE may be derived from pyrite oxidation during coal preoxidation, but it may be interpreted as organic sulfur removed by the PCE using ASTM analysis. The purposes of this research are to independently confirm and possibly to improve the organic sulfur removal from Illinois coals with the PCE desulfurization process reported by the MWOPC and to verify the forms-of-sulfur determination using the ASTM method for the PCE process evaluation.

Chou, M.I.M; Lytle, J.M.; Ruch, R.R.; Kruse, C.W.; Chaven, C.; Hackley, K.C.; Hughes, R.E.; Harvey, R.D.; Frost, J.K. [Illinois State Geological Survey, Champaign, IL (United States); Buchanan, D.H. [Eastern Illinois Univ., Charleston, IL (United States); Stucki, J.W. [Illinois Univ., Urbana, IL (United States); Huffman, G.; Huggins, F.E. [Kentucky Univ., Lexington, KY (United States)

1992-09-01

283

Analyze trace sulfur compounds in hydrocarbon gas streams  

SciTech Connect

Measuring trace sulfur compounds in fuel gases has been an industry requirement for many years and now plays a role in a variety of processing areas. One such area involves controlling hydrogen sulfide (H{sub 2}S) and other sulfur compounds in natural gas and fuel gas to prevent corrosion of pipelines and other equipment. Further, using sulfur compounds as odorants makes natural gas safer. In addition, the presence of sulfur compounds in fuel gases used to fire boilers and incinerators contributes to overall facility SO{sub 2} emissions. In all cases, the ability to accurately identify and quantify sulfur compounds is playing an increasingly important role. Despite improvements in analytical technology, little attention has been given to proper sampling of gas streams for trace sulfur. Most existing sample stations and equipment in refineries are inadequate for these purposes. While the hydrocarbon background gases are relatively stable, sulfur compounds found in these process streams are very reactive. Improper collection and storage of the gas sample results in a nonrepresentative sample and a poor result, regardless of the quality of the analytical method. Specific sampling and analytical techniques are successfully used to measure sulfur content of hydrocarbon gas streams as shown here.

Anderson, M.; Dimmer, R.C. [Brimstone Engineering Services, Inc., Englewood, CO (United States)

1997-04-01

284

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

SciTech Connect

During the tenth quarter of the project, bench scale experiments were performed to investigate the adsorption ability of different kinds of materials within sulfur vapor environment. Four kinds of adsorbents have been tested. The experimental results indicated that activated carbon was the best of four adsorbents tested. In addition to the baseline tests, several designs of activated carbon feed system have been tested. Under an inert environment, bench scale experiments were performed to investigate the characteristics and efficiency of activated carbon passing through the Co-Mo-Alumina catalyst bed. The results showed that activated carbon powder could easily be transported through the catalytic bed. The adsorption process may be applicable to promote conversion of H{sub 2}S in the H{sub 2}S and CO{sub 2} reaction system.

Gong, S.Y.; Jiang, X.; Khang, S.J.; Keener, T.C.

1996-12-31

285

Sulfur-emission-control technology for coal-conversion plants. [List of 60 processes with uses, brief description and flowsheet; 63 references  

Microsoft Academic Search

The degree of commercialization and the industrial applications of each control technology are summarized in Table 2. The technologies which have been used or planned for coal conversion facilities are listed in Table 3. The Chiyoda Thoroughbred 101 was the most used process for flue gas SO control, followed by the Citrate process. Both are recovery processes. However, throwaway processes

R. C. Weber; D. R. Herman; M. E. Smock

1981-01-01

286

Enhanced sulfur removal from fuels  

SciTech Connect

This patent describes a process for hydrotreating a petroleum distillate feedstock in a plurality of hydrotreating zones. It comprises splitting the feedstock by fractionation into at least two different boiling point fractions, including a first distillate stream relatively depleted in sulfur and a second distillate stream relatively concentrated in sulfur, wherein the first distillate stream boils in the range of 350{degrees} to 575{degrees} F and the second distillate stream boils in the range of 575{degrees} to 700{degrees} F; hydrotreating in a first hydrotreating zone the first distillate stream in admixture with an excess of hydrogen to obtain a first effluent; and hydrotreating in a second hydrotreating zone, the second distillate stream in admixture with an excess of hydrogen to obtain a second effluent; wherein the first hydrotreating zone is at a total pressure of 100 wherein the first hydrotreating zone is at a total pressure of 100 to 250 psia and the second hydrotreating zone is at a total pressure of 100 to 800 psia and the ratio of total pressure in the first hydrotreating zone to the total pressure in the second hydrotreating zone is in the range of about 1:2 to 1:8 and whereby a greater hydrogen consumption per barrel occurs in the second hydrotreating zone than in the first hydrotreating zone.

Kingswood, S.L.; Markley, G.E.

1991-02-05

287

Sulfur removal from high-sulfur Illinois coal by low-temperature perchloroethylene (PCE) extraction. Annual report, September 1, 1991August 31, 1992  

Microsoft Academic Search

The Midwest Ore Processing Co. (MWOPC) has reported a precombustion coal desulfurization process using perchloroethylene (PCE) at 120°C to remove up to 70% of the organic sulfur. However, this process has not been proven to be as successful with Illinois coals as it has been for Ohio and Indiana coals. Also, the high levels of organic sulfur removals observed by

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

1992-01-01

288

Process for removing sulfur from sulfur-containing gases  

DOEpatents

The present disclosure relates to i The government may own certain rights in the present invention pursuant to EPA Cooperative Agreement CR 81-1531. This is a continuation of U.S. Ser. No. 928,337, filed Nov. 7, 1986, now U.S. Pat. No. 4,804,521.

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

1990-01-01

289

Soluble Sulfur Species Extracted from Coal by Chemical Leaching.  

National Technical Information Service (NTIS)

The nature of the soluble sulfur-containing reaction products from the desulfurization of pyrite was studied. The rate of oxydesulfurization of the two varieties of pyrite was studied under the leaching conditions of the Ames process. Concentrations of so...

M. D. Stephenson

1982-01-01

290

Chemical Composition of Microimpurities in Jet Fuels from Sulfurous Petroleum.  

National Technical Information Service (NTIS)

The microimpurities of the jet fuels from sulfurous petroleums consist of ash elements, tars, and 'structural' water. In the process of transportation, settling, and filtration of the fuels there occurs a separation of the microimpurities in accordance wi...

V. N. Zrelov N. I. Marinchenko

1964-01-01

291

Method for removal of sulfur compounds from a gas  

SciTech Connect

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

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

1981-08-11

292

Atmospheric sulfur in Archean komatiite-hosted nickel deposits.  

PubMed

Some of Earth's largest iron-nickel (Fe-Ni) sulfide ore deposits formed during the Archean and early Proterozoic. Establishing the origin of the metals and sulfur in these deposits is critical for understanding their genesis. Here, we present multiple sulfur isotope data implying that the sulfur in Archean komatiite-hosted Fe-Ni sulfide deposits was previously processed through the atmosphere and then accumulated on the ocean floor. High-temperature, mantle-derived komatiite magmas were then able to incorporate the sulfur from seafloor hydrothermal sulfide accumulations and sulfidic shales to form Neoarchean komatiite-hosted Fe-Ni sulfide deposits at a time when the oceans were sulfur-poor. PMID:19965423

Bekker, Andrey; Barley, Mark E; Fiorentini, Marco L; Rouxel, Olivier J; Rumble, Douglas; Beresford, Stephen W

2009-11-20

293

Sulfur-substituted tetrahedranes.  

PubMed

The stable sulfur-substituted tetrahedrane derivatives 2-4 were synthesized by the reaction of tris(trimethylsilyl)tetrahedranyllithium 1 with diphenyl disulfide, bis(4-nitrophenyl) disulfide, and bis(2,4-dinitrophenyl) disulfide, respectively, and characterized by both NMR spectroscopy and X-ray crystallography. Phenylsulfonyltetrahedrane 5 was prepared by the reaction of 2 and m-chloroperbenzoic acid. The UV-vis absorption spectra of 2-4 suggested an interaction of the ? orbital of the tetrahedrane core and the lone-pair electrons on the sulfur atom, whereas no interaction for 5 was found. Thermal reactions of 2 and 5 are also reported; 2 underwent fragmentation into two acetylene molecules, whereas 5 gave the corresponding cyclobutadiene. PMID:21728313

Ochiai, Tatsumi; Nakamoto, Masaaki; Inagaki, Yusuke; Sekiguchi, Akira

2011-07-07

294

Sulfur in the atmosphere  

Microsoft Academic Search

In unpolluted areas sulfur occurs primarily in three compounds, SO\\/sup 2 -\\/ in aerosols and SO and HS in gas. Sources of SO\\/sup 2 -\\/ are the ocean, the soil, and the oxidation of the gaseous compounds. A considerable fraction of the SO is of anthropogenic origin. As measurements in polluted and unpolluted areas indicate, most of the HS seems

C. E. Junge

1960-01-01

295

Ultrasonic coal-wash for de-sulfurization.  

PubMed

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

Ambedkar, B; Nagarajan, R; Jayanti, S

2010-09-17

296

Beyond the sulfur effect  

SciTech Connect

The addition of reactive elements (REs) is known to increase the adherence of Al{sub 2}O{sub 3} scales and the underlying alloys. A widely accepted mechanism is that the REs getter the sulfur impurity in the alloy, thus preventing it from segregating to the scale-alloy interface to weaken the interfacial bonding. This paper provides evidence showing that not all S-free interfaces are strong. Although eliminating the sulfur in the alloy can greatly improve scale adhesion, the presence of RE clearly has additional beneficial effects that make the scale-alloy interface even stronger. Fe{sub 3}Al-base alloys, with or without Zr additions or a desulfurization H{sub 2}-anneal were oxidized at 1000 C in O{sub 2}. The amount of sulfur at the Al{sub 2}O{sub 3}-alloy interface was studied after the scales were removed by scratching with a diamond stylus in ultra-high vacuum using Auger spectroscopy. The interface composition was related to the spallation resistance of the scale.

Hou, P.Y. [Lawrence Berkeley National Lab., CA (United States). Materials Science Div.

1999-10-01

297

Microbial Metabolism of Inorganic Sulfur Compounds  

Microsoft Academic Search

Inorganic sulfur compounds are used by microorganisms (bacteria, fungi, algae) and plants for assimilation, i.e. biosynthesis of sulfur-containing cell constituents.Quantitatively, within the biogeochemical cycle of sulfur the utilization of inorganic sulfur compounds in bacterial energy metabolism, i.e. dissimilatory sulfur utilization, is of far higher importance. Reduced sulfur compounds serve as electron donors for photosynthesis and respiration, whereas inorganic sulfur compounds

Hans G. Trper

1985-01-01

298

ADVANCED SULFUR CONTROL CONCEPTS FOR HOT GAS DESULFURIZATION TECHNOLOGY  

SciTech Connect

The objective of this project is to develop a hot-gas desulfurization process scheme for control of H2S in HTHP coal gas that can be more simply and economically integrated with known regenerable sorbents in DOE/METC-sponsored work than current leading hot-gas desulfurization technologies. In addition to being more economical, the process scheme to be developed must yield an elemental sulfur byproduct. The Direct Sulfur Recovery Process (DSRP), a leading process for producing an elemental sulfur byproduct in hot-gas desulfurization systems, incurs a coal gas use penalty, because coal gas is required to reduce the SO2 in regeneration off-gas to elemental sulfur. Alternative regeneration schemes, which avoid coal gas use and produce elemental sulfur, will be evaluated. These include (i) regeneration of sulfided sorbent using SO2 ; (ii) partial oxidation of sulfided sorbent in an O2 starved environment; and (iii) regeneration of sulfided sorbent using steam to produce H2S followed by direct oxidation of H2S to elemental sulfur. Known regenerable sorbents will be modified to improve the feasibility of the above alternative regeneration approaches. Performance characteristics of the modified sorbents and processes will be obtained through lab- and bench-scale testing. Technical and economic evaluation of the most promising processes concept(s) will be carried out.

NONE

1998-09-30

299

Mssbauer study of the inorganic sulfur removal from coals  

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

300

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

NASA Astrophysics Data System (ADS)

The lower Ediacaran Doushantuo Formation in the Yangtze Gorges area contains exceptionally preserved microfossils, including the earliest known animal resting eggs and embryos. These fossils are preserved in cm-sized chert nodules, which typically have a microbial mat fragment in the center, a silica cortex, a pyrite rim, and an outer rim of blocky calcite. Petrographic analysis indicates that the formation of the blocky calcite rim postdates that of the pyrite rim and silica cortex. The pyrite rim grew centripetally during early diagenesis, representing a reaction front that was determined by the dynamics between ambient Fe2+ and H2S, the latter of which was derived from bacterial sulfate reduction (BSR) of mat fragment in nodule center. The silica cortex was formed pervasively through replacement of carbonate sediments prior to compaction.Secondary ion mass spectroscopy (SIMS) sulfur isotopes of individual pyrite crystals (?34Spy - SIMS) in pyrite rims and matrices show highly positive values (15.2-39.8). The pyrite rims do not show an isotopic gradient between small crystals formed in outer rim during early diagenesis and large crystals formed in inner rim during subsequent overgrowth. Although rim pyrite in the same chert nodule has consistent ?34Spy - SIMS values, there are significant spatial and stratigraphic variations in ?34Spy - SIMS values of both matrix and rim pyrite. Overall, isotopic fractionation between pyrite and carbonate associated sulfate (CAS) is small (< 22). The isotopic and petrographic data can be interpreted as evidence for rapid BSR of highly metabolizable organic matter in a diagenetic environment with limited sulfate availability, local anoxia, high Fe2+ concentration, and low sedimentation rate. The embryonic nodules nucleated on microbial mat fragments and stayed in the BSR zone during early diagenesis, when rapid BSR in the nodule center generated outward-diffusing H2S that was confined by readily available Fe2+ to precipitate the pyrite rim. The precipitation of the silica cortex was facilitated by localized pH change related to BSR and pyrite precipitation, with silica sourced from silica-rich Precambrian seawater and from microbially mediated clay diagenesis. Like the pyrite rim, the silica cortex was also formed rapidly during early diagenesis, leading to the exceptional preservation of microfossils within these nodules.

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

2010-09-01

301

Development of the Hybrid Sulfur Thermochemical Cycle  

SciTech Connect

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

Summers, William A.; Steimke, John L

2005-09-23

302

Analysis of oil shale retort production stream gases for sulfur species  

SciTech Connect

Analysis of the sulfur species in the production gas stream of oil shale retorts is important for environmental and process development needs. Combined gas chromatography/mass spectrometry and gas chromatography with flame photometric detection have been applied to the qualitative and quantitative analysis of sulfur species in the production gas stream from six oil shale retorting experiments. Hydrogen sulfide was determined to be the most abundant species and represented approximately 95 percent (wt.) of the sulfur present. Minor sulfur species identified and quantitated include carbonyl sulfide, carbon disulfide, methylmercaptan, ethylmercaptan, propylmercaptan, and thiophene. Sulfur dioxide was not identified during any of the retorting experiments studied. The distribution of these sulfur species from the six retorting experiments is important because it provides a baseline for the design of process control technologies. The importance of the liquid product collection train for control of sulfur emissions was also demonstrated.

Guffey, F.D.; Barbour, F.A.; Cummings, R.E.

1983-01-01

303

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

Code of Federal Regulations, 2013 CFR

... false National primary ambient air quality standards for sulfur oxides (sulfur dioxide...NATIONAL PRIMARY AND SECONDARY AMBIENT AIR QUALITY STANDARDS § 50.17 National primary ambient air quality standards for sulfur oxides (sulfur...

2013-07-01

304

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

Code of Federal Regulations, 2013 CFR

... false National primary ambient air quality standards for sulfur oxides (sulfur dioxide...NATIONAL PRIMARY AND SECONDARY AMBIENT AIR QUALITY STANDARDS § 50.4 National primary ambient air quality standards for sulfur oxides (sulfur...

2013-07-01

305

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

NASA Astrophysics Data System (ADS)

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

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

2013-11-01

306

Experimental study of an extractive coking process to produce low-sulfur liquid fuels from bituminous coal. Final report, January 1975July 1977. [Delayed coking  

Microsoft Academic Search

The delayed coking process is technically feasible. The following specific results of those detailed in the previous section contribute to this conclusion: coal conversions at near optimal conditions are greater than 50% of the M.A.F. coal; simulated process solvent is readily hydrotreated to a material with improved hydrogen-donor properties; the solvent properties can be modified by distillation; lower extraction temperatures

W. Interess; R. M. Nadkarni; R. W. Hyde; S. A. Reber

1977-01-01

307

Biotic and abiotic carbon to sulfur bond cleavage. Final report  

SciTech Connect

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

Frost, J.W.

1994-05-01

308

Potential change during intercalation of sulfuric acid in host carbons with different textures  

Microsoft Academic Search

From the electric potential changes, the intercalation reaction of sulfuric acid in graphite was divided into two elemental processes: the charging process of the interface between graphite layer and intercalated sulfuric acid in pure stages, which corresponded to a steep increase in potential, and the stage transformation process caused by further intercalation, which showed a plateau on the potential change

Norio Iwashita; Hiroshi Shioyama; Michio Inagaki

1995-01-01

309

Scrubbing gas from high-sulfur coal  

Microsoft Academic Search

A magnesium-sulfate-promoted limestone-scrubbing system designed for Associated Electric Co-op's Thomas Hill (Mo) Unit 3, removes 91% of flue-gas SO produced from burning 5.75%-sulfur coal. The system represents the first commerical use of promoted limestone as a reagent. A description of the processing steps is given, including sludge dewatering and recovery of soluble magnesium sulfate. Its economics is included to highlight

J. C. Yarze; H. Hurwitz

1978-01-01

310

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

SciTech Connect

We propose a process that uses sulfur dioxide from coal combustion as a raw material to synthesize polymeric ferric sulfate (PFS), a water treatment agent. The process uses sodium chlorate as an oxidant and ferrous sulfate as an absorbent. The major chemical mechanisms in this reaction system include oxidation, hydrolysis, and polymerization. Oxidation determines sulfur conversion efficiency while hydrolysis and polymerization control the quality of product. Many factors, including SO{sub 2} inlet concentration, flow rate of simulated flue gas, reaction temperature, addition rate of oxidant and stirring rate, may affect the efficiencies of SO{sub 2} removal. Currently, the effects of SO{sub 2} inlet concentration, the flow rate of simulated flue gas and addition rate of flue gas on removal efficiencies of SO{sub 2}, are being investigated. Experiments shown in this report have demonstrated that the conversion efficiencies of sulfur dioxide with ferrous sulfate as an absorbent are in the range of 60-80% under the adopted process conditions. However, the conversion efficiency of sulfur dioxide may be improved by optimizing reaction conditions to be investigated. Partial quality indices of the synthesized products, including Fe{sup 2+} concentration and total iron concentration, have been evaluated.

Robert C. Brown; Maohong Fan

2001-12-01

311

High temperature gas desulfurization with elemental sulfur production  

Microsoft Academic Search

Preliminary results on the use of cerium oxide as a high-temperature desulfurization sorbent are presented. The primary advantage of cerium over current zinc-based sorbents is the potential to produce elemental sulfur during the regeneration phase of the process. Although CeO2 is less effective for H2S removal during sulfidation, the sulfided product, Ce2O2S, will react with SO2 to produce elemental sulfur

Y. Zeng; S. Zhang; F. R. Groves; D. P. Harrison

1999-01-01

312

ADVANCED SULFUR CONTROL CONCEPTS FOR HOT-GAS DESULFURIZATION TECHNOLOGY  

Microsoft Academic Search

This research project examined the feasibility of a second generation high-temperature coal gas desulfurization process in which elemental sulfur is produced directly during the sorbent regeneration phase. Two concepts were evaluated experimentally. In the first, FeS was regenerated in a H2O-O2 mixture. Large fractions of the sulfur were liberated in elemental form when the H2O-O2 ratio was large. However, the

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

1998-01-01

313

Plasma-chemical conversion of hydrogen sulfide into hydrogen and sulfur  

Microsoft Academic Search

A waste-treatment process that recovers both hydrogen and sulfur from hydrogen-sulfide-contaminated industrial wastes is being developed to replace the Claus technology, which recovers only sulfur. The proposed process is based on research reported in the Soviet technical literature and uses microwave (or radio-frequency) energy to initiate plasma-chemical reactions that dissociate hydrogen sulfide into elemental hydrogen and sulfur. In the plasma-chemical

J. B. L. Harkness; R. D; E. J. Daniels

1993-01-01

314

Membranes for the Sulfur-Iodine Integrated Laboratory Scale Demonstration  

SciTech Connect

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

Frederick F. Stewart

2007-08-01

315

Experimental study of an extractive coking process to produce low-sulfur liquid fuels from bituminous coal. Quarterly report, October 25, 1975January 30, 1976  

Microsoft Academic Search

The major objective is to demonstrate the technical and economic feasibility of the delayed coking process for the extractive coking of bituminous coals. The first two pilot plant runs using hydrotreated solvent have been completed at Foster Wheeler. For both, the slurrying mode of operation was used. The first run gave a conversion of 45 percent of the moisture-and-ash-free coal,

S. A. Reber; R. M. Nadkarni; R. W. Hyde

1976-01-01

316

Demonstrating Allotropic Modifications of Sulfur.  

ERIC Educational Resources Information Center

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

McCarty, Jillian L.; Dragojlovic, Veljko

2002-01-01

317

Volume efficient sodium sulfur battery  

DOEpatents

In accordance with the teachings of this specification, a sodium sulfur battery is formed as follows. A plurality of box shaped sulfur electrodes are provided, the outer surfaces of which are defined by an electrolyte material. Each of the electrodes have length and width dimensions substantially greater than the thicknesses thereof as well as upwardly facing surface and a downwardly facing surface. An electrode structure is contained in each of the sulfur electrodes. A holding structure is provided for holding the plurality of sulfur electrodes in a stacked condition with the upwardly facing surface of one sulfur electrode in facing relationship to the downwardly facing surface of another sulfur electrode thereabove. A small thickness dimension separates each of the stacked electrodes thereby defining between each pair of sulfur electrodes a volume which receives the sodium reactant. A reservoir is provided for containing sodium. A manifold structure interconnects the volumes between the sulfur electrodes and the reservoir. A metering structure controls the flow of sodium between the reservoir and the manifold structure.

Mikkor, Mati (Ann Arbor, MI)

1980-01-01

318

Sulfur removal from high-sulfur Illinois coal by low-temperature perchloroethylene (PCE) extraction. Annual report, September 1, 1991--August 31, 1992  

SciTech Connect

The Midwest Ore Processing Co. (MWOPC) has reported a precombustion coal desulfurization process using perchloroethylene (PCE) at 120{degree}C to remove up to 70% of the organic sulfur. However, this process has not been proven to be as successful with Illinois coals as it has been for Ohio and Indiana coals. Also, the high levels of organic sulfur removals observed by the MWOPC may be due to certain errors involved in interpreting data from the American Society For Testing and Materials (ASTM) method for forms-of-sulfur analysis. The purposes of this research are to independently confirm and possibly to improve the organic sulfur removal from Illinois coals with the PCE desulfurization process and to verify the forms-of-sulfur determination using the ASTM method for evaluation of the PCE process. One problem that limits commercial application of the PCE process is the high chlorine content in the PCE-treated coals. Hence, an additional goal of this investigation is to develop a dechlorination procedure to remove excess PCE from the PCE-treated coal. MWOPC`s results have been repeated on our tests for the fresh IBC-104 coal. Oxidation of coals was found to affect subsequent PCE desulfurization. Elemental sulfur is more amenable than organic sulfur to removal by PCE. Ohio 5/6 coal appears to produce elemental sulfur more readily than Illinois coal during oxidation.

Chou, M.I.M.; Lytle, J.M.; Ruch, R.R.; Kruse, C.W.; Chaven, C.; Hackley, K.C.; Hughes, R.E.; Harvey, R.D.; Frost, J.K. [Illinois Dept. of Energy and Natural Resources, Springfield, IL (United States). Geological Survey; Buchanan, D.H. [Eastern Illinois Univ., Charleston, IL (United States); Stucki, J.W. [Illinois Univ., Urbana, IL (United States); Huffman, G.P.; Huggins, F.E. [Kentucky Univ., Lexington, KY (United States); Banerjee, D.D. [Center for Research on Sulfur in Coal, Carterville, IL (United States)

1992-12-31

319

Sulfur specific chromatography using hydrogenalysis  

SciTech Connect

A totally sulfur specific chromatographic detector is described based on the differential colorimetry of lead acetate tape. Its output is linear with concentration, and has no response to compounds other than sulfur compounds. These characteristics are particularly advantageous when analyzing hydrocarbon gases and light hydrocarbon liquids for low part per million and part per billion concentrations of sulfur compounds. As each particular sulfur species is eluted from a chromatograph column it is mixed with hydrogen and swept into a tube furnace. In the furnace, this sulfur peak is changed into a corresponding hydrogen sulfide peak. The corresponding hydrogen sulfide peak is detected by a lead acetate tape based hydrogen sulfide analyzer. Theory of operation, performance characteristics, and applicability of this type of detector are discussed.

Szinyei, W.J. (Tracor Atlas, Inc., 9441 Baythorne Dr., Houston, TX (US))

1988-01-01

320

Current efficiency studies of the zinc electrowinning process on aluminum rotating cylinder electrode (RCE) in sulfuric acid medium: Influence of different additives  

Microsoft Academic Search

This work studies the effect of three additives, sodium lauryl sulfate (SLS), cetyltrimethylammonium bromide (CTABr) and arabic gum (AG) on zinc electrowinning on aluminum in a solution of 85gL?1 Zn(II) (1.3M) in 108gL?1 H2SO4 (1.1M). The influence of these three additives is analyzed during the different stages of the reduction process using chronopotentiometric techniques on an aluminum rotating disk electrode

Alejandro Recndiz; Ignacio Gonzlez; Jos L. Nava

2007-01-01

321

Soluble sulfur species extracted from coal by chemical leaching. [MS thesis; mineral and coal-derived pyrite; 114 references  

Microsoft Academic Search

The nature of the soluble sulfur-containing reaction products from the desulfurization of pyrite was studied. The rate of oxydesulfurization of the two varieties of pyrite was studied under the leaching conditions of the Ames process. Concentrations of soluble sulfur species were determined for oxydesulfurization using leach solutions of sodium carbonate, sodium bicarbonate, distilled water, and dilute sulfuric acid and for

1982-01-01

322

Production of elemental sulfur and methane from H{sub 2}S and CO{sub 2} derived from a coal desulfurization process. Quarterly technical progress report, January 1, 1995--March 31, 1995  

SciTech Connect

During the sixth quarter of the project, simulations were carried out to investigate the feasibility of producing elemental sulfur and methane from hydrogen sulfide and carbon dioxide by using the overall reaction of H{sub 2}S and CO{sub 2} based on the following equation: 4 H{sub 2}S + CO{sub 2} {l_equilibrium} 2 S{sub 2} + CH{sub 4}+2 H{sub 2}O. The results indicate that two reaction zones are required to realize the above reaction. The first reaction zone should be composed of multiple stages to recover the elemental sulfur without the equilibrium limitations. With optimum temperatures in each zone, the conversion can be increased significantly. The simulation also indicates less amounts of by-products, such as COS, CS{sub 2} and SO{sub 2}. The limitation on the extraction of sulfur is directly related to the sulfur vapor pressure.

Jiang, X.; Khang, S.J.

1995-08-01

323

Coal Liquefaction desulfurization process  

DOEpatents

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

Givens, Edwin N. (Bethlehem, PA)

1983-01-01

324

Sulfur: The plankton/climate connection  

SciTech Connect

A key process in the global sulfur cycle is the transfer of volatile forms of the element from sea to land via the atmosphere. Early budgets calculated the amount of sulfur required to balance the cycle and generally assumed that this flux was achieved by formation of hydrogen sulfide (H[sub 2]S) in coastal waters, mud flats, etc. However, Lovelock et al. (1972) made the first field measurements of dimethylsulfide (DMS) in seawater and suggested that it represented the missing link in the S cycle. Other sulfur gases, such as carbonylsulfide (COS), carbon disulfide (CS[sub 2]), methylmercaptan (CH[sub 3]SH), and dimethyldisulfide (CH[sub 3]SSCH[sub 3]), are also often observed, but DMS is usually dominant (Andreae et al. 1983, Cline and Bates 1983, Turner and Liss 1985). Over the past decade or so thousands of analyses have been made covering coastal, shelf, and open ocean environments, which show that DMS is ubiquitous in seawater but that considerable spatial and temporal variability occurs (see Cooper and Matrai 1989). In this review the authors consider processes leading to the formation of DMS in seawater, its emission to the atmosphere, and transformations therein, the possible role of DMS oxidation products in climate regulation as proposed by Charlson et al. (1987), and how global changes might affect DMS production. 80 refs., 2 figs.

Malin, G.; Turner, S.M.; Liss, P.S. (Univ. of East Anglia, Norwich (United Kingdom))

1992-10-01

325

Quaternary Marine Sulfur Cycle Dynamics  

NASA Astrophysics Data System (ADS)

Published data show a -0.8% change in marine sulfate ?34S ratios in the past 2 Ma. Prior to this period it was stable at ~ 22% for ~ 50Ma since the Eocene. Compared to the residence time of sulfate (>10 Ma) the observed change is large and implies a major disturbance of the marine sulfur cycle. However, the cause of the disturbance, as well as the timing of its onset are poorly constrained. Here we present a new set of ?34S ratios of marine sulfate for the last 3 Ma with a temporal resolution of ~300ka, which shows a linear decline from 22 to ~21% in the past 1.75Ma. This may represent a change in volcanic and hydrothermal activity, pyrite burial or erosion and weathering of exposed evaporites and sulfides, which are the main processes affecting sulfate ?34S. However, during this period there is no geological evidence for exceptional volcanic and hydrothermal activity and consequently, the observed negative shift reflects either a change in isotopic composition and volume of erosional input of sulfate to the ocean, or a decrease in pyrite burial. The isotopic composition of the input flux depends on the relative proportion of sulfide vs. sulfate weathering. Sedimentary sulfides are mostly concentrated in organic rich sediments on continental shelves. Existing sea level records suggest periodic sea level drops during glacial stages related to the formation of ice sheets. This could affect sulfur cycling in two ways: a) exposure to surface weathering and erosion agents of large parts of continental shelves increased global sulfide oxidation and thus the input flux of sulfate to the ocean and/or b) the reduction of shelf areas resulted in decreased pyrite burial. We explore the effects of these changes with a simple box model. The modeling results indicate that the observed isotopic shift requires a 150% increase of pyrite weathering or a 90% reduction of pyrite burial over the past 1.75Ma. When both of these processes change in concert the same effect is produced with the doubling of pyrite weathering and 50% decrease of pyrite burial. As pyrite burial and organic matter burial are intimately linked, a drastic decrease in pyrite burial should leave its mark in the carbon isotopic record which shows no evidence of a major change in carbon cycling. We thus propose that increased sulfide weathering, either from subaerial exposure, or as a result of increased winnowing might be the principal cause of the negative ?34S shift in the Quaternary.

Markovic, S.; Paytan, A.; Wortmann, U. G.

2011-12-01

326

Sulfur passivation techniques for III-V wafer bonding  

NASA Astrophysics Data System (ADS)

The use of direct wafer bonding in a multijunction III-V solar cell structure requires the formation of a low resistance bonded interface with minimal thermal treatment. A wafer bonded interface behaves as two independent surfaces in close proximity, hence a major source of resistance is Fermi level pinning common in III-V surfaces. This study demonstrates the use of sulfur passivation in III-V wafer bonding to reduce the energy barrier at the interface. Two different sulfur passivation processes are addressed. A dry sulfur passivation method that utilizes elemental sulfur vapor activated by ultraviolet light in vacuum is compared with aqueous sulfide and native oxide etch treatments. Through the addition of a sulfur desorption step in vacuum, the UV-S treatment achieves bondable surfaces free of particles contamination or surface roughening. X-ray photoelectron spectroscopy measurements of the sulfur treated GaAs surfaces find lower levels of oxide and the appearance of sulfide species. After 4 hrs of air exposure, the UV-S treated GaAs actually showed an increase in the amount of sulfide bonded to the semiconductor, resulting in less oxidation compared to the aqueous sulfide treatment. Large area bonding is achieved for sulfur treated GaAs / GaAs and InP / InP with bulk fracture strength achieved after annealing at 400 C and 300 C respectively, without large compressive forces. The electrical conductivity across a sulfur treated 400 C bonded n-GaAs/n-GaAs interface significantly increased with a short anneal (1-2 minutes) at elevated temperatures (50--600 C). Interfaces treated with the NH4OH oxide etch, on the other hand, exhibited only mild improvement in accordance with previously published studies in this area. TEM and STEM images revealed similar interfacial microstructure changes with annealing for both sulfur treated and NH4OH interfaces, whereby some areas have direct semiconductor-semiconductor contact without any interfacial layer. Fitting the observed temperature dependence of zero bias conductance using a model for tunneling through a grain boundary reveals that the addition of sulfur at the interface lowered the interfacial energy barrier by 0.2 eV. The interface resistance for these sulfur-treated structures is less than 0.03 Ocm 2 at room temperature. These results emphasize that sulfur passivation techniques reduce interface states that otherwise limit the implementation of wafer bonding for high efficiency solar cells and other devices.

Jackson, Michael James

327

PILOT PLANT STUDY OF CONVERSION OF COAL TO LOW SULFUR FUEL  

EPA Science Inventory

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

328

In-situ Raman Spectroscopic Investigation of Sulfur, Sulfur-Water, and Sulfur-Methane-Water Systems Between 22 and 450 C  

NASA Astrophysics Data System (ADS)

Previous investigations have used native sulfur as a catalyst for thermochemical sulfate reduction (TSR) experiments, but the mechanisms for the TSR processes are still not clear. In order to establish possible mechanisms, we investigated the sulfur, sulfur-water, and sulfur-water-methane systems in the fused silica capillary capsules (FSCC) by using the USGS-type heating-cooling stage and in-situ Raman spectroscopy between 22 and 450 C. Samples were loaded in the FSCC (0.3 mm OD, 0.1 mm ID, and 10 to 25 mm long) using the method of Chou et al. (2008, Geochim. Cosmochim. Acta, 72, 5217). Raman spectra were collected with a JY/Horiba LabRam HR Raman system using 532.06 nm laser excitation. In the sulfur system, we observed (1) the melting of native sulfur at 115.5 C; (2) the breaking of S8 rings during heating as indicated by the gradual reduction in intensity of Raman signals near 219 and 473 cm-1; (3) the formation of new sulfur-bearing species indicated by the presence of Raman bands near 1440, 1250 cm-1, and other signals between 200 and 550 cm-1; and (4) the reappearance of S8 bands and the reduction of the signals near 1440 and 1250 cm-1 at room temperature (RT). In the sulfur-water system, we observed (1) the Raman bands near 1440 and 1250 cm-1 in the aqueous, vapor, and liquid sulfur phases during heating; (2) the presence of H2S (~2592 cm-1) and HS- (~2575 cm-1) in the aqueous phase above about 260 C; (3) the disproportionation reaction of S to H2S and SO2/bisulfate, which occurred after L-V homogenization at about 369 C, and was indicated by the presence of HSO4- (~1045 cm-1) and SO2 (~1149 cm-1); (4) the presence of intermediate species indicated by the Raman signals between 200 and 720 cm-1 during heating; (5) the reduction of Raman band intensities of SO2 and H2S during cooling and the disappearance of SO2 below 310 C; and (6) the detection of SO42- (~980 cm-1) and H2S (~2590 cm-1) in the aqueous phase and H2S (~2611 cm-1) in vapor phase one day after cooling to RT. Our results indicate the reversibility of the disproportionation reaction. In the sulfur-water-methane system, we observed (1) the Raman bands of sulfur-bearing species near 1440 and 1250 cm-1 in the aqueous, vapor, and liquid sulfur phases during heating; (2) the generation of H2S and CO2 in both aqueous and vapor phases, and the increase of the intensities of their Raman signals with increasing temperature; and (3) the presence of solid sulfur together with CO2 and H2S in both aqueous and vapor phases after cooling to RT. However, we did not observe the formation of any high-valence sulfur species (e.g., SO2, HSO4-, and SO42-) in this system, indicating the disproportionation reaction of sulfur did not occur in the presence of methane. Our in-situ observation method has the potential of providing important information for the TSR processes, which is difficult to obtain from the conventional quenching method.

Yuan, S.; Chou, I.; Li, J.; Burruss, R. C.

2009-12-01

329

The purification of elemental sulfur  

SciTech Connect

Sulfur has been purified by a dynamic pyrolysis procedure that takes into account the unique viscosity-temperature relationship of the liquid. An apparatus is described that incorporates gas-bubbling and rocking to overcome diffusion-limited kinetics. For the first time, a mechanism is proposed for the pyrolytic purification of sulfur based upon Carsul formation and the H{sub 2}S{leftrightarrow}H{sub 2}S{sub {ital x}} equilibrium. Infrared methods are delineated for qualitative analysis and quantitative estimates of anion contaminants, including the omnipresent hydrocarbon impurities. Our purified sulfur has a total carbon, oxygen, and hydrogen impurity level of {lt}10 {mu}g/g.

Susman, S.; Rowland, S.C.; Volin, K.J. (Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States))

1992-06-01

330

Recovery of elemental sulfur during the oxidative ammoniacal leaching of chalcopyrite  

SciTech Connect

The discovery of elemental sulfur as a principal product in the oxidation of copper sulfides during ammoniacal leaching is relatively new. Reilly and Scott have reported the recovery of up to 60 pct of the sulfur content of synthetic covellite during an ammoniacal leaching study carried out in the presence of an immiscible organic sulfur solvent. Filmer et al. have reported the development of a low temperature oxidative ammonia leach process in which part of the sulfur content of the sulfides (upwards of 76 pct) reports as elemental sulfur and can be recovered from the leach residues by solvent extraction. Prior to this point it was generally believed that elemental sulfur was not formed during an ammoniacal leaching process.

Reilly, I.G.; Scott, D.S.

1984-12-01

331

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

PubMed

The detection of sulfur compounds in different hydrocarbon matrices, from light hydrocarbon feedstocks to medium synthetic crude oil feeds provides meaningful information for optimization of refining processes as well as demonstration of compliance with petroleum product specifications. With the incorporation of planar microfluidic devices in a novel chromatographic configuration, sulfur compounds from hydrogen sulfide to alkyl dibenzothiophenes and heavier distributions of sulfur compounds over a wide range of matrices spanning across a boiling point range of more than 650C can be characterized, using one single analytical configuration in less than 25min. In tandem with a sulfur chemiluminescence detector for sulfur analysis is a flame ionization detector. The flame ionization detector can be used to establish the boiling point range of the sulfur compounds in various hydrocarbon fractions for elemental specific simulated distillation analysis as well as profiling the hydrocarbon matrices for process optimization. Repeatability of less than 3% RSD (n=20) over a range of 0.5-1000 parts per million (v/v) was obtained with a limit of detection of 50 parts per billion and a linear range of 0.5-1000 parts per million with a correlation co-efficient of 0.998. PMID:23726084

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

2013-05-02

332

Colourless sulfur bacteria and their role in the sulfur cycle  

Microsoft Academic Search

SummaryThe bacteria belonging to the families of the Thiobacteriaceae, Beggiatoaceae and Achromatiaceae are commonly called the colourless\\u000a sulfur bacteria. While their ability to oxidize reduced inorganic sulfur compounds has clearly been established, it is still\\u000a not known whether all these organisms can derive metabolically useful energy from these oxidations.\\u000a \\u000a During the last decades research has mainly focussed on the genus

J. Gijs Kuenen

1975-01-01

333

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

SciTech Connect

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

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

1994-08-01

334

Novel Sulfur-Tolerant Anodes for Solid Oxide Fuel Cells  

SciTech Connect

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

Lei Yang; Meilin Liu

2008-12-31

335

New Limits on Sulfur in Combustion.  

National Technical Information Service (NTIS)

New regulation concerning the emission of sulfur from combustion plants are suggested in this report. The emission limits would be 0.05 g sulfur/MJ of fuel for plants emitting more than 400 tons of sulfur/year, and 0.10 g sulfur/MJ of fuel for plants emit...

1987-01-01

336

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

SciTech Connect

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}.

NONE

1997-06-01

337

Desulfurization of HS containing gas streams with production of elemental sulfur  

Microsoft Academic Search

A process is disclosed for desulfurization of gas streams by which reduced sulfur compound, such as HS, is reacted with solid sulfur removal metal oxide compound which is an oxide of chromium, combination of zinc and chromium, combination of zinc and aluminum and mixtures thereof at about 400 to 1600°F producing sulfided sulfur removal compound followed by regeneration of the

G. L. Anderson; F. O. Berry; H. A. Borders

1982-01-01

338

Sulfurization of carbon surface for vapor phase mercury removal I: Effect of temperature and sulfurization protocol  

Microsoft Academic Search

The uptake of hydrogen sulfide by carbon materials (ACFs and BPL) under dry and anoxic conditions was tested using a fixed bed reactor system to determine the effects of sorbent properties, temperature (200800C) and sulfurization protocols on the sulfur content, sulfur stability, sulfur distribution, and to elucidate possible reaction mechanisms for the formation of sulfur species. Sorbents with higher surface

Wenguo Feng; Eric Borguet; Radisav D. Vidic

2006-01-01

339

Alkali metal/sulfur battery  

DOEpatents

Alkali metal/sulfur batteries in which the electrolyte-separator is a relatively fragile membrane are improved by providing means for separating the molten sulfur/sulfide catholyte from contact with the membrane prior to cooling the cell to temperatures at which the catholyte will solidify. If the catholyte is permitted to solidify while in contact with the membrane, the latter may be damaged. The improvement permits such batteries to be prefilled with catholyte and shipped, at ordinary temperatures.

Anand, Joginder N. (Clayton, CA)

1978-01-01

340

Disproportionation of elemental sulfur by haloalkaliphilic bacteria from soda lakes.  

PubMed

Microbial disproportionation of elemental sulfur to sulfide and sulfate is a poorly characterized part of the anoxic sulfur cycle. So far, only a few bacterial strains have been described that can couple this reaction to cell growth. Continuous removal of the produced sulfide, for instance by oxidation and/or precipitation with metal ions such as iron, is essential to keep the reaction exergonic. Hitherto, the process has exclusively been reported for neutrophilic anaerobic bacteria. Here, we report for the first time disproportionation of elemental sulfur by three pure cultures of haloalkaliphilic bacteria isolated from soda lakes: the Deltaproteobacteria Desulfurivibrio alkaliphilus and Desulfurivibrio sp. AMeS2, and a member of the Clostridia, Dethiobacter alkaliphilus. All cultures grew in saline media at pH 10 by sulfur disproportionation in the absence of metals as sulfide scavengers. Our data indicate that polysulfides are the dominant sulfur species under highly alkaline conditions and that they might be disproportionated. Furthermore, we report the first organism (Dt. alkaliphilus) from the class Clostridia that is able to grow by sulfur disproportionation. PMID:24030483

Poser, Alexander; Lohmayer, Regina; Vogt, Carsten; Knoeller, Kay; Planer-Friedrich, Britta; Sorokin, Dimitry; Richnow, Hans-H; Finster, Kai

2013-09-13

341

Sulfur-induced greenhouse warming on early Mars  

NASA Astrophysics Data System (ADS)

Mineralogical, geological, geophysical, and isotopic data recently returned from Mars suggest that the delivery of sulfur gases to the atmosphere may have played a significant role in the planet's early evolution. Using the Gusev Crater basalt composition and a batch melting model, we obtain a high sulfur solubility, approximately 1400 ppm, in Martian mantle melts. We proceed to explore different scenarios for the pulsed degassing of sulfur volatiles associated with the emplacement of near-surface dikes during the late Noachian or early Hesperian, when surface pressures are thought to be substantially higher than present. We investigate background Martian atmospheres of 50 and 500 mbar CO2 with varying abundances of H2O and sulfur volatiles (H2S and SO2 mixing ratios of 10-3 to 10-6). Results suggest that these sulfur volatile influxes, alone, could have been responsible for greenhouse warming up to 25 K above that caused by CO2. Including additional water vapor feedback, this process could have raised the early surface temperature above the freezing point for brines and possibly allowed transient liquid water on the Martian surface. Each temperature rise was likely to have been short-lived, however, due to brief residence times for sulfur volatiles in an optically thin atmosphere.

Johnson, Sarah Stewart; Mischna, Michael A.; Grove, Timothy L.; Zuber, Maria T.

2008-08-01

342

Emission of sulfur from Lake Ontario sediments  

Microsoft Academic Search

Calculations indicate that about 6.0 x 10⁵ kg of sulfur is released annually from Lake Ontario sediments. This constitutes about 1% of the annual sulfur input into the sediments and is insignificant compared to the total sulfur that cycles annually through the lake. The sulfur released from the sediments is enriched in ³²S with the result that the sulfur in

J. O. Nriagu; R. D. Coker

1976-01-01

343

ENGINEERING EVALUATION OF HOT-GAS DESULFURIZATION WITH SULFUR RECOVERY  

SciTech Connect

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

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

1998-05-31

344

METHOD TO PREVENT SULFUR ACCUMULATION INSIDE MEMBRANE ELECTRODE ASSEMBLY  

SciTech Connect

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

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

2009-06-22

345

Study of a combined heterotrophic and sulfur autotrophic denitrification technology for removal of nitrate in water  

Microsoft Academic Search

A combined two-step process of heterotrophic denitrification in a fluidized reactor and sulfur autotrophic denitrification processes (CHSAD) was developed for the removal of nitrate in drinking water. In this process, the advantage of high efficiency of heterotrophic denitrification with non-excessive methanol and the advantage of non-pollution of sulfur autotriphic denitrification were integrated in this CHSAD process. And, this CHSAD process

Huijuan Liu; Wei Jiang; Dongjin Wan; Jiuhui Qu

2009-01-01

346

Recovery of Calcium Carbonate and Sulfur from FGD Scrubber Waste.  

National Technical Information Service (NTIS)

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

R. P. Arganbright P. Huang G. S. Benner B. G. Mandelik T. S. Roche

1982-01-01

347

Sulfur, coke, and crude quality -- Conclusion: US crude slate continues to get heavier, higher in sulfur  

SciTech Connect

A review of the API gravity and sulfur content of crudes input to US refinery stills indicates a continuing trend toward processing poorer-quality crudes. Over the past 10 years, gravity has declined by 0.17[degree]/year, and sulfur content has increased 0.029 wt %/year. Additionally, as the production of US crudes continues to decrease, foreign crude oils will be imported in greater quantities to fill the needs of US refineries. A review of the historical data on foreign crude oils indicates that, in the coming years, foreign crudes imported into the US will become heavier. Refiners on the East Coast and Gulf Coast need to modify their heavy-end processing units--as many already are doing--to accept these heavier crudes and produce light, clean transportation fuels. The paper discusses crude quality in the five PAD districts and for imported crude.

Swain, E.J. (Swain (Edward J.), Houston, TX (United States))

1995-01-09

348

Smaller sulfur molecules promise better lithium-sulfur batteries.  

PubMed

The lithium-sulfur battery holds a high theoretical energy density, 4-5 times that of today's lithium-ion batteries, yet its applications have been hindered by poor electronic conductivity of the sulfur cathode and, most importantly, the rapid fading of its capacity due to the formation of soluble polysulfide intermediates (Li(2)S(n), n = 4-8). Despite numerous efforts concerning this issue, combatting sulfur loss remains one of the greatest challenges. Here we show that this problem can be effectively diminished by controlling the sulfur as smaller allotropes. Metastable small sulfur molecules of S(2-4) were synthesized in the confined space of a conductive microporous carbon matrix. The confined S(2-4) as a new cathode material can totally avoid the unfavorable transition between the commonly used large S(8) and S(4)(2-). Li-S batteries based on this concept exhibit unprecedented electrochemical behavior with high specific capacity, good cycling stability, and superior rate capability, which promise a practicable battery with high energy density for applications in portable electronics, electric vehicles, and large-scale energy storage systems. PMID:23101502

Xin, Sen; Gu, Lin; Zhao, Na-Hong; Yin, Ya-Xia; Zhou, Long-Jie; Guo, Yu-Guo; Wan, Li-Jun

2012-10-31

349

Hydration of pure and base-Containing sulfuric acid clusters studied by computational chemistry methods  

NASA Astrophysics Data System (ADS)

The formation of hydrates of small molecular sulfuric acid clusters and cluster containing both sulfuric acid and base (ammonia or dimethylamine) has been studied by means of computational chemistry. Using a combined ab initio/density functional approach, formation energies of clusters with up to four sulfuric acid molecules, and up to two base molecules, have been calculated. Consequences for the hydration level of the corresponding clusters have been modelled. While the majority of pure sulfuric acid cluster are comparatively strongly hydrated, base containing cluster were found to be less hydrophilic. Dimethylamine is particularly effective in lowering the hydrophilicity of the cluster. Implications of the hydration profiles on atmospheric processes are discussed.

Henschel, Henning; Ortega, Ismael K.; Kupiainen, Oona; Olenius, Tinja; Kurtn, Theo; Vehkamki, Hanna

2013-05-01

350

A new test procedure for biogenic sulfuric acid corrosion of concrete  

PubMed

A new test method is described for biogenic sulfuric acid corrosion of concrete, more specifically in sewer conditions. The aim of the new test method is the development of an accelerated and reproducible procedure for monitoring the resistance of different types of concrete with regard to biogenic sulfuric acid corrosion. This experimental procedure reflects worst case conditions by providing besides H2S, also an enrichment of thiobacilli and biologically produced sulfur. By simulating the cyclic processes occurring in sewer pipes, significant differences between concrete mixtures could be detected after 51 days. Concrete modified by a styrene-acrylic ester polymer demonstrated a higher resistance against biogenic sulfuric acid attack. PMID:11068828

Vincke; Verstichel; Monteny; Verstraete

1999-01-01

351

Control of Sulfur Dioxide Emissions from Copper Smelters: Volume II. Hydrogen Sulfide Production from Copper Concentrates.  

National Technical Information Service (NTIS)

A laboratory investigation has been made of a modified copper smelting process which provides a solution to the sulfur dioxide air pollution problem. Preliminary economic evaluation of the process appears favorable with good prospects for further improvem...

C. A. Rohrmann H. T. Fullam

1974-01-01

352

Microbial stabilization of sulfur-laden sorbents. Technical report, December 1, 1992--February 29, 1993  

SciTech Connect

Clean coal technologies that involve limestone for in situ sulfur capture generate lime/limestone products laden with sulfur at various oxidation states. If sulfur is completely stabilized as sulfate, the spent sorbent is ready for commercial utilization as gypsum. However, the presence of reduced sulfur species requires additional processing. Thermal oxidation of reduced sulfur frequently results in undesirable release of SO{sub 2}. Microbial oxidation may provide an inexpensive and effective alternative. Sorbents laden with reduced forms of sulfur such as sulfide or sulfite can serve as growth substrates for sulfur-oxidizing bacteria, which convert all sulfur to sulfate. The goals of this project are to optimize conditions for sulfate generation from sulfide and sulfite on prepared lime/limestone mixtures; to test and optimize the effectiveness of microbial processing on spent sorbents from coal gasification, in-duct sorbent injection, and fluidized bed combustion; and to search for hyperalkalinophilic thiobacilli, which would be effective up to pH 11. We report here progress toward controlling the pH of culture media, and determining the highest pH at which several environmental isolates and named strains could initiate sulfur oxidation.

Miller, K.W. [Illinois State Univ., Normal, IL (United States); Banerjee, D. [Illinois Clean Coal Inst., Carterville, IL (United States)

1993-05-01

353

Correlation of Sulfuric Acid Hydrate Abundance with Charged Particle Flux at the Surface of Europa  

NASA Astrophysics Data System (ADS)

The trailing hemisphere of Jupiter's moon Europa is bombarded by charged particles trapped within Jupiter's magnetosphere. Sulfur ion implantation and impacting energetic electrons strongly affect the surface chemistry of Europa. Understanding these processes is important for disentangling the extrinsic and intrinsic components of Europa's surface chemistry. In the sulfur cycle model of Carlson et al. (Science 286, 97, 1999), hydrated sulfuric acid represents the dominant reaction product of radiolytic surface modification processes on Europa. In recent compositional investigations employing linear mixture modeling, Dalton et al. (LPSC XV, #2511, 2009) and Shirley et al. (Icarus, in press, 2010) document a well-defined gradient of hydrated sulfuric acid abundance for a study area spanning the leading side - trailing side boundary in Argadnel Regio. Sulfuric acid hydrate abundance in this region increases toward the trailing side apex. Here we compare the derived sulfuric acid hydrate abundances at 41 locations on Europa's surface with independent model results describing 1) the sulfur ion flux (Hendrix et al., 2010, in preparation), and 2) the energetic electron flux, at the same locations. We improve upon the prior calculation of electron energy into the surface of Paranicas et al. (2009, in Europa, U. Arizona, p529; Pappalardo, McKinnon, & Khurana eds.) by incorporating a realistic pitch angle dependence of the distribution. While the sulfur ion implantation and electron energy deposition model distributions differ in important details, both show trailing side gradients similar to that found for the sulfuric acid hydrate. Correlation coefficients exceed 0.9 in comparisons of each of these models with the sulfuric acid hydrate distribution. Our results support models in which the electron energy flux drives reactions that utilize implanted sulfur to produce sulfuric acid hydrate. This work was performed at the California Institute of Technology-Jet Propulsion Laboratory under contract with NASA's Outer Planets Research Program.

Dalton, James B.; Paranicas, C. P.; Cassidy, T. A.; Shirley, J. H.

2010-10-01

354

ADVANCED SULFUR CONTROL CONCEPTS FOR HOT-GAS DESULFURIZATION TECHNOLOGY  

SciTech Connect

This research project examined the feasibility of a second generation high-temperature coal gas desulfurization process in which elemental sulfur is produced directly during the sorbent regeneration phase. Two concepts were evaluated experimentally. In the first, FeS was regenerated in a H2O-O2 mixture. Large fractions of the sulfur were liberated in elemental form when the H2O-O2 ratio was large. However, the mole percent of elemental sulfur in the product was always quite small (<<1%) and a process based on this concept was judged to be impractical because of the low temperature and high energy requirements associated with condensing the sulfur. The second concept involved desulfurization using CeO2 and regeneration of the sulfided sorbent, Ce2O2S, using SO2 to produce elemental sulfur directly. No significant side reactions were observed and the reaction was found to be quite rapid over the temperature range of 500C to 700C. Elemental sulfur concentrations (as S2) as large as 20 mol% were produced. Limitations associated with the cerium sorbent process are concentrated in the desulfurization phase. High temperature and highly reducing coal gas such as produced in the Shell gasification process are required if high sulfur removal efficiencies are to be achieved. For example, the equilibrium H2S concentration at 800C from a Shell gas in contact with CeO2 is about 300 ppmv, well above the allowable IGCC specification. In this case, a two-stage desulfurization process using CeO2 for bulk H2S removal following by a zinc sorbent polishing step would be required. Under appropriate conditions, however, CeO2 can be reduced to non-stoichiometric CeOn (n<2) which has significantly greater affinity for H2S. Pre-breakthrough H2S concentrations in the range of 1 ppmv to 5 ppmv were measured in sulfidation tests using CeOn at 700C in highly reducing gases, as measured by equilibrium O2 concentration, comparable to the Shell gas. Good sorbent durability was indicated in a twenty-five-cycle test. The sorbent was exposed for 58 consecutive days to temperatures between 600C and 800C and gas atmospheres from highly reducing to highly oxidizing without measurable loss of sulfur capacity or reactivity. In the process analysis phase of this study, a two-stage desulfurization process using cerium sorbent with SO2 regeneration followed by zinc sorbent with dilute O2 regeneration was compared to a single-stage process using zinc sorbent and O2 regeneration with SO2 in the regeneration product gas converted to elemental sulfur using the direct sulfur recovery process (DSRP). Material and energy balances were calculated using the process simulation package PRO/II. Major process equipment was sized and a preliminary economic analysis completed. Sorbent replacement rate, which is determined by the multicycle sorbent durability, was found to be the most significant factor in both processes. For large replacement rates corresponding to average sorbent lifetimes of 250 cycles or less, the single-stage zinc sorbent process with DSRP was estimated to be less costly. However, the cost of the two-stage cerium sorbent process was more sensitive to sorbent replacement rate, and, as the required replacement rate decreased, the economics of the two-stage process improved. For small sorbent replacement rates corresponding to average sorbent lifetimes of 1000 cycles or more, the two-stage cerium process was estimated to be less costly. In the relatively wide middle range of sorbent replacement rates, the relative economics of the two processes depends on other factors such as the unit cost of sorbents, oxygen, nitrogen, and the relative capital costs.

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

1998-10-31

355

Sulfur dioxide removal from gas streams  

SciTech Connect

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

Urban, P.; Ginger, E.A.

1986-11-11

356

Determining the sulfur concentration of refractory materials with the AS7012 rapid analyzer  

Microsoft Academic Search

Attempts have been made to develop a rapid and precise method for the determination of sulfur in refractory materials, raw materials, and slags with an automatic coulometric AS-7012 rapid analyzer designed by the VNIIAchermet Institute. The apparatus is designed for the determination of sulfur in steels and alloys during their production processes and their treatment, and also for grading analyses

Aizenberg

1986-01-01

357

Discrimination between 34S and 32S during bacterial metabolism of inorganic sulfur compounds.  

PubMed Central

Sulfur isotope effects during the oxidation of thiosulfate by Thiobacillus versutus were found to be negligible. This result is considered in relation to other oxidative and reductive processes to assess which reactions are most likely to control the isotopic compositions of sulfur compounds in microbial sulfureta.

Fry, B; Cox, J; Gest, H; Hayes, J M

1986-01-01

358

Studies on the Removal of Sulfur Dioxide from Hot Flue Gases to Prevent Air Pollution  

Microsoft Academic Search

The pollution of the atmosphere by sulfur dioxide is one of the gravest of all in public nuisance problems, especially in the industrial regions. A practically applicable method in industry for the removal of sulfur dioxide has been studied. The Kiyoura-T .I .T. process utilizes the oxidation method to convert S02 of the flue gas to S03 in the presence

Raisaku Kiyoura

1966-01-01

359

ANALYSIS OF OIL SHALE RETORT PRODUCTION STREAM GASES FOR SULFUR SPECIES  

Microsoft Academic Search

Analysis of the sulfur species in the production gas stream of oil shale retorts is important for environmental and process development needs. Combined gas chromatography\\/mass spectrometry and gas chromatography with flame photometric detection have been applied to the qualitative and quantitative analysis of sulfur species in the production gas stream from six oil shale retorting experiments. Hydrogen sulfide was determined

F. D. Guffey; F. A. Barbour; R. E. Cummings

1983-01-01

360

Sulfur polymer cement as a low-level waste glass matrix encapsulant.  

National Technical Information Service (NTIS)

Sulfur polymer cement (SPC) is being considered as a matrix encapsulant for the Hanford low-level (activity) waste glass. SPC is an elemental sulfur polymer-stabilized thermoplastic that is fluid at 120 (degrees)C to 140(degrees)C. The candidate process w...

P. Sliva Y. B. Peng D. K. Peeler

1996-01-01

361

Volcanogenic Sulfur on Earth and Io: Composition and Spectroscopy  

USGS Publications Warehouse

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

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

1999-01-01

362

Biochemistry of Dissimilatory Sulfur Oxidation  

SciTech Connect

The long term goals of this research were to define the substrate oxidation pathways, the electron transport mechanisms, and the modes of energy conservation employed during the dissimilatory oxidation of sulfur practiced by various species of the thiobacilli. Specific adhesion of the thiobacilli to elemental sulfur was studied by electrical impedance, dynamic light scattering, laser Doppler velocimetry, and optical trapping methods. The conclusion is that the thiobacilli appear to express specific receptors that enable the bacteria to recognize and adhere to insoluble sulfur. The enzyme tetrathionate oxidase was purified from two species of the thiobacilli. Extensive structural and functional studies were conducted on adenosine 5'-phosphosulfate reductase purified from cell-free extracts of Thiobacillus denitrificans. The kinetic mechanism of rhodanese was studied.

Blake II, R.

2003-05-30

363

Advanced byproduct recovery: Direct catalytic reduction of sulfur dioxide to elemental sulfur. Fourth quarterly technical progress report  

SciTech Connect

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.

NONE

1997-01-01

364

Speciation of sulfur in the insoluble organic matter from carbonaceous chondrites by XANES spectroscopy  

NASA Astrophysics Data System (ADS)

Sulfur speciation in a comprehensive set of insoluble organic matter (IOM) samples extracted from 3 CI (Orgueil, Alais, Ivuna), 5 CM (QUE97990, Murchison, Murray, QUE99355, Cold Bokkeveld), 1 CR (Renazzo) and ungrouped C2 Tagish Lake chondrites has been studied by K-edge XANES micro-spectroscopy. Five main sulfur groups were identified: (1) sulfides, (2) aliphatic sulfur, (3) heterocyclic organic sulfur, (4) oxidized organic sulfur and (5) sulfates. The IOM of the 3 CIs and the extensively altered Cold Bokkeveld CM exhibit a higher abundance of heterocyclic versus aliphatic organic sulfur compared to the other CMs and compared to the Renazzo and Tagish Lake chondrites. This suggests greater thermal heating on the parent body of CIs, consistent with the higher temperatures experienced by these chondrites (~ 70 C for the most altered clasts of Cold Bokkeveld; 100-150 C for CIs). Alais may have experienced more heating than Ivuna and Orgueil. The IOM of CIs contains oxidized organic sulfur, suggesting the presence of a mild-temperature oxidation process on the parent body. Among type 2 chondrites other than Cold Bokkeveld, no significant variation of the sulfur speciation was detected. This suggests tenuous oxidation processes and a low-temperature aqueous alteration (< ~ 35 C) on the parent body. The global chemical variations between the CR and CM groups (e.g. H/C elemental ratio, alkyl groups concentration) reported in earlier studies appear to be more the result of chemical variations among the accreted precursors than of post-accretional processes.

Orthous-Daunay, F.-R.; Quirico, E.; Lemelle, L.; Beck, P.; Deandrade, V.; Simionovici, A.; Derenne, S.

2010-12-01

365

Kinetics of Sulfur Oxide, Sulfur Fluoride, and Sulfur Oxyfluoride Anions with Atomic Species at 298 and 500 K.  

National Technical Information Service (NTIS)

The rate constants and product-ion branching ratios for the reactions of sulfur dioxide (SO2(-)), sulfur fluoride (SF(n)-), and sulfur oxyfluoride anions (SO(x)F(y)) with H, H2, N, N2, NO, and 0 have been measured in a selected-ion flow tube (SIFT). H ato...

A. A. Viggiano A. J. Midey

2007-01-01

366

Standard test method for trace quantities of total sulfur (Wickbold and Beckman combustion apparatus)  

SciTech Connect

This method covers the determination of total sulfur primarily in the range from 2 to 25 ppM in volatile, normally liquid organic materials. The method may be extended to liquid materials with higher sulfur concentration and to viscous liquids and solids by using appropriate solvents. Samples should not contain more than 100 ppM of halogens, 2 ppM of barium, or 0.1 ppM of lead or appreciable ashforming substances. For the determination of total sulfur in liquefied petroleum gases see ASTM Method D 2784, Test for Sulfur in Liquefied Petroleum Gases (Oxy-Hydrogen Burner or Lamp). The sample is burned in an oxy-hydrogen atomizer burner. The oxides of sulfur are absorbed and oxidized to sulfuric acid in a hydrogen peroxide solution. The sulfate ions are determined then by either of the following finishes: barium perchlorate titration - the sulfate is titrated with barium perchlorate using a thorin-methylene blue mixed indicator; turbidimetric - the sulfate is precipitated as barium sulfate and the turbidity of a suspension of the precipitate is measured with a photometer. It is important to have the sulfur content of light liquid petroleum products at low enough concentrations to meet any applicable government regulations. The presence of sulfur may result in corrosion of metal surfaces. Sulfur may be poisonous to catalysts in subsequent processing.

Not Available

1980-01-01

367

CE IGCC Repowering plant sulfuric acid plant. Topical report, June 1993  

SciTech Connect

A goal of the CE IGCC Repowering project is to demonstrate a hot gas clean-up system (HGCU), for the removal of sulfur from the product gas stream exiting the gasifier island. Combustion Engineering, Inc. (ABB CE) intends to use a HGCU developed by General Electric Environmental Services (GEESI). The original design of this system called for the installation of the HGCU, with a conventional cold gas clean-up system included as a full-load operational back-up. Each of these systems removes sulfur compounds and converts them into an acid off-gas. This report deals with the investigation of equipment to treat this off-gas, recovering these sulfur compounds as elemental sulfur, sulfuric acid or some other form. ABB CE contracted ABB Lummus Crest Inc. (ABB LCI) to perform an engineering evaluation to compare several such process options. This study concluded that the installation of a sulfuric acid plant represented the best option from both a technical and economic point of view. Based on this evaluation, ABB CE specified that a sulfuric acid plant be installed to remove sulfur from off-gas exiling the gas clean-up system. ABB LCI prepared a request for quotation (RFQ) for the construction of a sulfuric acid production plant. Monsanto Enviro-Chem Inc. presented the only proposal, and was eventually selected as the EPC contractor for this system.

Chester, A.M.

1993-12-01

368

Methanation process  

SciTech Connect

A process comprises contacting a sulfur-containing feedstream comprising carbon monoxide and hydrogen with a catalytically effective amount of a supported catalyst consisting of at least one of iridium and rhodium under methanation conditions and in the presence of a finite, effective, small amount of steam sufficient to increase methanation activity when said activity is affected by sulfur poisoning so that a predominant amount of carbon monoxide and hydrogen in the feedstream is converted to methane. In a process comprising contacting a sulfur-containing feedstream of carbon monoxide and hydrogen with a supported catalyst consisting of at least one of iridium and rhodium under methanation conditions such that said carbon monoxide and hydrogen in said feedstream are converted to methane, and in which there is a loss of methanation activity caused by entry of sulfur into the feed and poisoning of said catalyst, the improvement for restoring methanation activity in situ of the sulfur-poisoned catalyst which comprises contacting said sulfur-poisoned catalyst under methanation conditions with a sulfur-free feed of carbon monoxide and hydrogen in the presence of steam in an amount ranging from about 1 to about 30 mole percent of the synthesis feed for a period of time sufficient to substantially restore the activity of said catalyst and continuing methanation by contacting said catalyst having restored methanation catalytic activity with carbon monoxide and hydrogen under methanation conditions such that a predominant amount of said carbon monoxide and hydrogen is converted to methane.

Finch, J.; Poska, F.

1980-07-08

369

Contemporaneous early diagenetic formation of organic and inorganic sulfur in estuarine sediments from St. Andrew Bay, Florida, USA  

NASA Astrophysics Data System (ADS)

Estuarine sediment samples were collected from nine stations in St. Andrew Bay near Panama City, Florida, USA. Contrasting grain size and varying concentration of organic carbon allowed a comparative study of the relationships among organic degradation processes, sulfur cycling, and diagenetic removal of dissolved sulfide produced by bacterial sulfate reduction. Abundance and sulfur isotopic composition were determined for dissolved sulfide, dissolved sulfate, pyrite, humic-acid sulfur, fulvic-acid sulfur, and elemental sulfur. Presence of free dissolved sulfide and enrichment in 34S of porewater sulfate in samples from organic-rich, muddy sediments of St. Andrew Bay indicate high rates of sulfate reduction and anoxic conditions below 5 mm depth. Such conditions are not reflected in samples from organic-poor, sandy, near-shore sediments collected from highly productive areas occupied by seagrass beds. In this estuarine system, pyrite and fulvic-acid sulfur are the largest sinks for sulfide produced by bacterial sulfate reduction. Strong correlation between abundances of pyrite and fulvic-acid sulfur suggests coincident formation in the uppermost 10 cm of sediment. Large differences in isotopic composition between these two species and consistent enrichment in 34S of the fulvic-acid fraction, however, indicate two different reaction pathways. Abundance and sulfur isotopic composition of humic-acid and fulvic-acid sulfur suggest that organic sulfur is derived from mixing between (1) 34S-depleted sulfur with an unknown oxidation state that was recycled from bacterial hydrogen sulfide and (2) 34S-enriched sulfur interpreted as primary biosynthetic sulfur originally assimilated from dissolved sulfate. Samples taken from sandy sediment localities where aquatic vascular plants are rooted in the anoxic zone show a strong depletion in 34S in the fulvic-acid sulfur fraction suggesting recycled hydrogen sulfide as the dominant source of organic sulfur.

Brchert, Volker; Pratt, Lisa M.

1996-07-01

370

Sulfur Volatiles in the Early Martian Atmosphere  

NASA Astrophysics Data System (ADS)

Our modeling indicates a high sulfur solubility in martian mantle melts and suggests that sulfur volatile pulses associated with large, discreet volcanic events during the late Noachian may have significantly warmed the atmosphere.

Johnson, S. S.; Zuber, M. T.; Grove, T. L.; Pavlov, A. A.; Mischna, M. A.

2007-03-01

371

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

PubMed

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

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

2011-11-15

372

Grapevine & Sulfur: Old Partners, New Achievements  

Microsoft Academic Search

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

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

373

The Hybrid Sulfur Cycle for Nuclear Hydrogen Production  

SciTech Connect

Two Sulfur-based cycles--the Sulfur-Iodine (SI) and the Hybrid Sulfur (HyS)--have emerged as the leading thermochemical water-splitting processes for producing hydrogen utilizing the heat from advanced nuclear reactors. Numerous international efforts have been underway for several years to develop the SI Cycle, but development of the HyS Cycle has lagged. The purpose of this paper is to discuss the background, current status, recent development results, and the future potential for this thermochemical process. Savannah River National Laboratory (SRNL) has been supported by the U.S. Department of Energy Office of Nuclear Energy, Science, and Technology since 2004 to evaluate and to conduct research and development for the HyS Cycle. Process design studies and flowsheet optimization have shown that an overall plant efficiency (based on nuclear heat converted to hydrogen product, higher heating value basis) of over 50% is possible with this cycle. Economic studies indicate that a nuclear hydrogen plant based on this process can be economically competitive, assuming that the key component, the sulfur dioxide-depolarized electrolyzer, can be successfully developed. SRNL has recently demonstrated the use of a proton-exchange-membrane electrochemical cell to perform this function, thus holding promise for economical and efficient hydrogen production.

Summers, William A.; Gorensek, Maximilian B.; Buckner, Melvin R.

2005-09-08

374

LIGNOSULFONATE-MODIFIED CALCIUM HYDROXIDE FOR SULFUR DIOXIDE CONTROL  

EPA Science Inventory

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

375

Hydrogen peroxide in sulfuric acid extraction of uranium ores  

Microsoft Academic Search

Uranium can be extracted from its ores at a pH of 2.5 to 5.5 using sulfuric acid, hydrogen peroxide, trace of iron and a sulfate. The extraction process is applicable to both tank leaching of conventionally mined ores and in situ leaching.

DeVries

1984-01-01

376

Elemental sulfur dynamics in acid sulfate soil landscapes  

Microsoft Academic Search

The precipitation and dissolution of iron and sulfur minerals has a primary influence on water quality of acid sulfate affected landscapes (Fanning et al. 2002; Nordstrom 2000). The two key processes involved are the microbially mediated reduction and oxidation of sulfate and iron (Peine et al. 2000), which drive the geochemical store and flux of acidity. Iron sulfide minerals are

Richard T Bush; Edward D Burton; Leigh A Sullivan; Salirian R Claff

2006-01-01

377

Dynamic simulation of sulfur-removal systems. Final report  

Microsoft Academic Search

A generalized computer simulation has been developed to predict the dynamic response of alternate gas absorption systems for selective removal of sulfur compounds or ammonia from fuel gas or synthesis gas produced from coal or other fossil fuels. The models use numerical methods based upon finite difference techniques to determine the spatial distribution of process variables within both the absorption

J. H. Alexander; T. R. Blake; D. H. Jr. Brownell; W. D. Henline; D. E. Wilkins

1982-01-01

378

Closing the loop for the sulfur-iodine cycle  

Microsoft Academic Search

The current status of a program to develop the sulfur-iodine thermochemical water-splitting cycle for hydrogen production is reviewed, with emphasis on the operation of the closed loop cycle demonstrator. The advantages of the proposed process include: (1) well characterized chemical reactions involving only fluids; (2) heat utilization within a temperature range accessible to heat sources utilizing existing materials technology (specifically,

G. Caprioglio; K. McCorkle; R. Sharp

1980-01-01

379

Hydrogen peroxide in sulfuric acid extraction of uranium ores  

SciTech Connect

Uranium can be extracted from its ores at a pH of 2.5 to 5.5 using sulfuric acid, hydrogen peroxide, trace of iron and a sulfate. The extraction process is applicable to both tank leaching of conventionally mined ores and in situ leaching.

DeVries, F.W.

1984-01-10

380

Limits to Sulfur Accumulation in Transgenic Lupin Seeds Expressing a Foreign Sulfur-Rich Protein  

PubMed Central

The low sulfur amino acid content of legume seeds restricts their nutritive value for animals. We have investigated the limitations to the accumulation of sulfur amino acids in the storage proteins of narrow leaf lupin (Lupinus angustifolius) seeds. Variation in sulfur supply to lupin plants affected the sulfur amino acid accumulation in the mature seed. However, when sulfur was in abundant supply, it accumulated to a large extent in oxidized form, rather than reduced form, in the seeds. At all but severely limiting sulfur supply, addition of a transgenic (Tg) sink for organic sulfur resulted in an increase in seed sulfur amino acid content. We hypothesize that demand, or sink strength for organic sulfur, which is itself responsive to environmental sulfur supply, was the first limit to the methionine (Met) and cysteine (Cys) content of wild-type lupin seed protein under most growing conditions. In Tg, soil-grown seeds expressing a foreign Met- and Cys-rich protein, decreased pools of free Met, free Cys, and glutathione indicated that the rate of synthesis of sulfur amino acids in the cotyledon had become limiting. Homeostatic mechanisms similar to those mediating the responses of plants to environmental sulfur stress resulted in an adjustment of endogenous protein composition in Tg seeds, even when grown at adequate sulfur supply. Uptake of sulfur by lupin cotyledons, as indicated by total seed sulfur at maturity, responded positively to increased sulfur supply, but not to increased demand in the Tg seeds.

Tabe, Linda M.; Droux, Michel

2002-01-01

381

Sulfur removal from high-sulfur Illinois coal by low-temperature perchloroethylene (PCE) extraction. Technical report, September 1, 1991--November 30, 1991  

SciTech Connect

A pre-combustion coal desulfurization process at 120{degree}C using perchloroethylene (PCE) to remove up to 70% of the organic sulfur has been developed by the Midwest Ore Processing Co. (MWOPC). However, this process has not yet proven to be as successful with Illinois coals as it has for Ohio and Indiana coals. The organic sulfur removal has been achieved only with highly oxidized Illinois coals containing high sulfatic sulfur. A logical explanation for this observation is vital to successful process optimization for the use of Illinois coals. In addition, the high levels of organic sulfur removals observed by the MWOPC may be due to certain errors involved in the ASTM data interpretation; this needs verification. For example, elemental sulfur extracted by the PCE may be derived from pyrite oxidation during coal pre-oxidation, but it may be interpreted as organic sulfur removed by the PCE using ASTM analysis. The goals of this research are: (1) to independently confirm and possibly to improve the organic sulfur removal from Illinois coals with the PCE desulfurization process reported by the MWOPC, (2) to verify the forms-of-sulfur determination using the ASTM method for the PCE process evaluation, and (3) to determine the suitability of Illinois coals for use in the PCE desulfurization process. This project involves the Illinois State Geological Survey (ISGS), Eastern Illinois University (EIU), the University of Illinois-Urbana/Champaign (UI-UC), and the University of Kentucky, Lexington (UK). This is the first year of a two-year project.

Chou, M.I.M.

1991-12-31

382

Gas phase reaction of sulfur trioxide with water vapor  

SciTech Connect

Sulfur trioxide (SO3) has long been known to react with water to produce sulfuric acid (H2S04). It has been commonly assumed that the gas phase reaction in the Earth`s atmosphere between SO3 and water vapor to produce sulfuric acid vapor is an important step in the production of sulfuric acid aerosol particles. The kinetics of the gas phase reaction of SO3 with water vapor have previously been studied by Castleman and co-workers, Wang et al and Reiner and Arnold. Each of these studies was carried out in a flow reactor, with the first two studies performed at low pressure (1-10 Torr) and the latter from approx. 30 to 260 Torr. Each of these studies measured SO3 decays over a range of H2O vapor levels, obtaining data consistent with interpreting the reaction of gaseous SO3 and H2O as a bimolecular process. It is not clear why previous experimental studies failed to observe a nonlinear dependence of SO3 consumption on water vapor concentration. It is probable that sufficient water dimer exists in much of the Earth`s atmosphere to allow dimer reactions to participate in sulfuric acid vapor formation.

Kolb, C.E.; Molina, M.J.; Jayne, J.T.; Meads, R.F.; Worsnop, D.R.

1994-12-31

383

Synthesis of sulfur nanoparticles in aqueous surfactant solutions.  

PubMed

Sulfur is a widely used element in different applications such as fertilizers, pharmaceuticals, rubber, fiber industries, bioleaching processes, anti microbial agents, insecticides, and fumigants, etc. Nanosize sulfur particles are useful for pharmaceuticals, modification of carbon nano tubes, and synthesis of nano composites for lithium batteries. In this study we report a surfactant assisted route for the synthesis of sulfur nanoparticles by an acid catalyzed precipitation of sodium thiosulphate. We use both the inorganic and organic acids, and find that organic acid gives lower size sulfur particles. The size of the particles also depends on the reactant concentration and acid to reactant ratio. The effect of different surfactants (TX-100, CTAB, SDBS, and SDS) on particle size shows that the surfactant can significantly reduce the particle size without changing the shape. The size reducing ability is not same for all the surfactants, depending on the type of surfactant. The anionic surfactant SDBS is more effective for obtaining a uniform size in both the acid media. Whereas, the lowest size (30 nm) particles were obtained in a certain reactant concentration range using CTAB surfactant. The objective of this study is to synthesize sulfur nanoparticles in aqueous media and also study the effect of different surfactants on particle size. PMID:20038467

Chaudhuri, Rajib Ghosh; Paria, Santanu

2009-12-06

384

HYBRID SULFUR ELECTROLYZER DEVELOPMENT FY09 SECOND QUARTER REPORT  

SciTech Connect

The primary objective of the DOE-NE Nuclear Hydrogen Initiative (NHI) is to develop the nuclear hydrogen production technologies necessary to produce hydrogen at a cost competitive with other alternative transportation fuels. The focus of the NHI is on thermochemical cycles and high temperature electrolysis that can be powered by heat from high temperature gas reactors. The Savannah River National Laboratory (SRNL) has been tasked with the primary responsibility to perform research and development in order to characterize, evaluate and develop the Hybrid Sulfur (HyS) thermochemical process. This report documents work during the first quarter of Fiscal Year 2009, for the period between January 1, 2009 and March 31, 2009. The HyS Process is a two-step hybrid thermochemical cycle that is part of the 'Sulfur Family' of cycles. As a sulfur cycle, it uses high temperature thermal decomposition of sulfuric acid to produce oxygen and to regenerate the sulfur dioxide reactant. The second step of the process uses a sulfur dioxide depolarized electrolyzer (SDE) to split water and produce hydrogen by electrochemically reacting sulfur dioxide with H{sub 2}O. The SDE produces sulfuric acid, which is then sent to the acid decomposer to complete the cycle. The DOE NHI program is developing the acid decomposer at Sandia National Laboratory for application to both the HyS Process and the Sulfur Iodine Cycle. The SDE is being developed at SRNL. During FY05 and FY06, SRNL designed and conducted proof-of-concept testing for a SDE using a low temperature, PEM fuel cell-type design concept. The advantages of this design concept include high electrochemical efficiency, small footprint and potential for low capital cost, characteristics that are crucial for successful implementation on a commercial scale. During FY07, SRNL extended the range of testing of the SDE to higher temperature and pressure, conducted a 100-hour longevity test with a 60-cm{sup 2} single cell electrolyzer, and designed and built a larger, multi-cell stack electrolyzer. During FY08, SRNL continued SDE development, including development and successful testing of a three-cell electrolyzer stack with a rated capacity of 100 liters per hour. The HyS program for FY09 program will address improving SDE performance by focusing on preventing or minimizing sulfur deposition inside the cell caused by SO{sub 2} crossover, reduction of cell voltage for improved efficiency, an extension of cell operating lifetime. During FY09 a baseline technology development program is being conducted to address each of these issues. Button-cell (2-cm{sup 2}) and single cell (60-cm{sup 2}) SDEs will be fabricated and tested. A pressurized button-cell test facility will be designed and constructed to facilitate addition testing. The single cell test facility will be upgraded for unattended operation, and later for operation at higher temperature and pressure. Work will continue on development of the Gas Diffusion Electrode (GDE), or Gap Cell, as an alternative electrolyzer design approach that is being developed under subcontract with industry partner Giner Electrochemical Systems. If successful, it could provide an alternative means of preventing sulfur crossover through the proton exchange membrane, as well as the possibility for higher current density operation based on more rapid mass transfer in a gas-phase anode. Promising cell components will be assembled into membrane electrode assemblies (MEAs) and tested in the single cell test facility. Upon modification for unattended operation, test will be conducted for 200 hours or more. Both the button-cell and modified single cell facility will be utilized to demonstrate electrolyzer operation without sulfur build-up limitations, which is a Level 1 Milestone.

Herman, D; David Hobbs, D; Hector Colon-Mercado, H; Timothy Steeper, T; John Steimke, J; Mark Elvington, M

2009-04-15

385

Preliminary Investigation of Sulfur Loading in Hanford LAW Glass  

SciTech Connect

A preliminary estimate was developed for loading limits for high-sulfur low-activity waste (LAW) feeds that will be vitrified into borosilicate glass at the Hanford Site in the waste-cleanup effort. Previous studies reported in the literature were consulted to provide a basis for the estimate. The examination of previous studies led to questions about sulfur loading in Hanford LAW glass, and scoping tests were performed to help answer these questions. These results of these tests indicated that a formulation approach developed by Vienna and colleagues shows promise for maximizing LAW loading in glass. However, there is a clear need for follow-on work. The potential for significantly lowering the amount of LAW glass produced at Hanford (after the initial phase of processing) because of higher sulfur tolerances may outweigh the cost and effort required to perform the necessary testing.

Vienna, John D.; Hrma, Pavel R.; Buchmiller, William C.; Ricklefs, Joel S.

2004-04-01

386

Historical Sulfur Dioxide Emissions 1850-2000: Methods and Results  

SciTech Connect

A global, self-consistent estimate of sulfur dioxide emissions over the last one and a half century were estimated by using a combination of bottom-up and best available inventory methods including all anthropogenic sources. We find that global sulfur dioxide emissions peaked about 1980 and have generally declined since this time. Emissions were extrapolated to a 1{sup o} x 1{sup o} grid for the time period 1850-2000 at annual resolution with two emission height levels and by season. Emissions are somewhat higher in the recent past in this new work as compared with some comprehensive estimates. This difference is largely due to our use of emissions factors that vary with time to account for sulfur removals from fossil fuels and industrial smelting processes.

Smith, Steven J.; Andres, Robert; Conception , Elvira; Lurz, Joshua

2004-01-25

387

Influence of alkaline earth metals on the activity and sulfur stability of zeolites in the No x ?C 3 ?C 4 hydrocarbon selective reduction of no to nitrogen (SKV) process  

Microsoft Academic Search

The results of the influence of alkaline earth metal and magnesium cations on the activity and sulfur stability of catalysts\\u000a based on synthetic mordenites and high-silicon zeolites with pentasil structures on the selective reduction of nitrogen oxides\\u000a with C3?C4 hydrocarbons are presented. Doping the H-form of mordenite and pentasils with Ca, Sr, Ba, and Mg cations increased their\\u000a activity and

M. G. Martsenyuk-Kukharuk; V. L. Struzhko; V. P. Stasevich; S. N. Orlik

1999-01-01

388

Physiology of Haloalkaliphilic Sulfur-oxidizing Bacteria  

Microsoft Academic Search

The inorganic sulfur oxidation by obligate haloalkaliphilic chemolithoautotrophs was only recently discovered and investigated. These autotrophic sulfur oxidizing bacteria (SOB), capable of oxidation of inorganic sulfur compounds at moderate to high salt concentration and at high pH, can be divided into three genera belonging to the γ subdivision of the Proteobacteria: Thioalkalimicrobium, Thioalkalivibrio and Thioalkalispira. Their taxonomy, metabolic diversity and

H. L. Banciu

2004-01-01

389

46 CFR 153.1046 - Sulfuric acid.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Sulfuric acid. 153.1046 Section 153.1046 Shipping...Cargo Procedures § 153.1046 Sulfuric acid. No person may liquefy frozen or congealed sulfuric acid other than by external tank heating...

2011-10-01

390

46 CFR 153.1046 - Sulfuric acid.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Sulfuric acid. 153.1046 Section 153.1046 Shipping...Cargo Procedures § 153.1046 Sulfuric acid. No person may liquefy frozen or congealed sulfuric acid other than by external tank heating...

2012-10-01

391

Air Quality Criteria for Sulfur Oxides.  

ERIC Educational Resources Information Center

|Included is a literature review which comprehensively discusses knowledge of the sulfur oxides commonly found in the atmosphere. The subject content is represented by the 10 chapter titles: Physical and Chemical Properties and the Atmospheric Reactions of the Oxides of Sulfur; Sources and Methods of Measurements of Sulfur Oxides in the

National Air Pollution Control Administration (DHEW), Washington, DC.

392

Two stage sorption of sulfur compounds  

DOEpatents

A two stage method for reducing the sulfur content of exhaust gases is disclosed. Alkali- or alkaline-earth-based sorbent is totally or partially vaporized 10 and introduced into a sulfur-containing gas stream. The activated sorbent can be introduced in the reaction zone or the exhaust gases of a combustor or a gasifier. High efficiencies of sulfur removal can be achieved.

Moore, W.E.

1991-12-31

393

TRENDS IN RURAL SULFUR CONCENTRATIONS  

EPA Science Inventory

This paper presents an analysis of regional trends in atmospheric concentrations in sulfur dioxide (502) and particulate sulfate (50~- ) at rural monitoring sites in the Clean Air Act Status and Trends Monitoring Network (CAsTNet) from 1990 to 1999. A two-stage approach is used t...

394

Sulfur Dioxide and Material Damage  

ERIC Educational Resources Information Center

|This study relates sulfur dioxide levels with material damage in heavily populated or polluted areas. Estimates of loss were determined from increased maintenance and replacement costs. The data indicate a decrease in losses during the past five years probably due to decline in pollution levels established by air quality standards. (MR)|

Gillette, Donald G.

1975-01-01

395

Seal for sodium sulfur battery  

DOEpatents

This invention is directed to a seal for a sodium sulfur battery in which the sealing is accomplished by a radial compression seal made on a ceramic component of the battery which separates an anode compartment from a cathode compartment of the battery.

Topouzian, Armenag (Birmingham, MI); Minck, Robert W. (Lathrup Village, MI); Williams, William J. (Northville, MI)

1980-01-01

396

SULFUR DIOXIDE SOURCES IN AK  

EPA Science Inventory

This map shows industrial plants which emit 100 tons/year or more of sulfur dioxide (SO2) in Alaska. The SO2 sources are plotted on a background map of cities and county boundaries. Data Sources: SO2 Sites: U.S. EPA AIRS System, County Outlines: 1990 Census Tiger Line Files 1:1...

397

Effects on plants of sulfur pollutants from coal combustion  

Microsoft Academic Search

Sulfur dioxide, the most widely known form of sulfur pollution, is highly toxic to plant life, even at levels lower than the current Federal Ambient Air Quality Standard. Sulfur dioxide can also form sulfates, sulfites, and liquids such as sulfurous acid and sulfuric acid, all of which can be toxic to plant and animal life. Most sulfur compounds also acidify

1978-01-01

398

Alkylation and distillation: reaction conditions, sulfuric acid usage, experiences in distillation, difficulties with excessive content of propane and sulfur  

Microsoft Academic Search

This report discussed results of experiments on several topics of operational detail of the alkylation process. One problem which had arisen in industrial-scale production was that the dehydrogenation step produced small amounts of butadiene among the normal butylene. the presence of these small amounts caused a great increase (more than a doubling) in the amount of usage of sulfuric acid

Straetz

2008-01-01

399

High pressure sulfuric acid decomposition experiments for the sulfur-iodine thermochemical cycle.  

SciTech Connect

A series of three pressurized sulfuric acid decomposition tests were performed to (1) obtain data on the fraction of sulfuric acid catalytically converted to sulfur dioxide, oxygen, and water as a function of temperature and pressure, (2) demonstrate real-time measurements of acid conversion for use as process control, (3) obtain multiple measurements of conversion as a function of temperature within a single experiment, and (4) assess rapid quenching to minimize corrosion of metallic components by undecomposed acid. All four of these objectives were successfully accomplished. This report documents the completion of the NHI milestone on high pressure H{sub 2}SO{sub 4} decomposition tests for the Sulfur-Iodine (SI) thermochemical cycle project. All heated sections of the apparatus, (i.e. the boiler, decomposer, and condenser) were fabricated from Hastelloy C276. A ceramic acid injection tube and a ceramic-sheathed thermocouple were used to minimize corrosion of hot liquid acid on the boiler surfaces. Negligible fracturing of the platinum on zirconia catalyst was observed in the high temperature decomposer. Temperature measurements at the exit of the decomposer and at the entry of the condenser indicated that the hot acid vapors were rapidly quenched from about 400 C to less than 20 C within a 14 cm length of the flow path. Real-time gas flow rate measurements of the decomposition products provided a direct measurement of acid conversion. Pressure in the apparatus was preset by a pressure-relief valve that worked well at controlling the system pressure. However, these valves sometimes underwent abrupt transitions that resulted in rapidly varying gas flow rates with concomitant variations in the acid conversion fraction.

Velasquez, Carlos E; Reay, Andrew R.; Andazola, James C.; Naranjo, Gerald E.; Gelbard, Fred

2005-09-01

400

Metal and sulfur cycling in a highly dynamic sedimentary system  

NASA Astrophysics Data System (ADS)

Variable depositional conditions in marine sediments can have a strong impact on the associated biogeochemical cycles. In areas with high sedimentation rates, including mass flow-related deposition, (highly-) reactive mineral phases can be buried rapidly. This situation leads to appreciable availability of reactive compounds for microorganisms in deep-subsurface anoxic environments. To unravel the influence of these dynamic conditions on the biogeochemical cycling of metals and sulfur we investigated sediments from the western Argentine Basin. The samples were taken during the RV Meteor Expedition M78/3 in May - July 2009. The sedimentary environments of the continental margin off Argentina and Uruguay are particularly well suited to study non-steady state processes. Here we present results of metal and sulfur geochemistry of sediments from cores retrieved from different water depths. The investigated sediments are characterized by high amounts of terrigenous material and show striking enrichments of reactive metals. Concentrations of calcium carbonate are low (<15 wt%), and organic carbon amounts are generally below 1.5 wt% with slightly higher values in the uppermost sediment layer. The concentrations of acid volatile sulfur as well as chromium reducible sulfur reflect the alteration of iron oxides and their primary signals. Analysis of elemental sulfur indicates ongoing alteration of metal oxides via reaction with hydrogen sulfide, with elevated concentrations of up to 60 mol/g. Data of sequential metal extraction show the enrichment of highly reactive metal oxides not only at the sediments surface but also below the sulfidic zone. Likewise, pore water data show elevated values of dissolved metals in these zones. Overall, our data show that the fast burial of reactive mineral phases not only strongly influences the metal and sulfur coupled geochemistry but also has an impact on biogeochemical processes in the deeper sediments.

Riedinger, N.; Formolo, M.; Henkel, S.; Tomasini, J.; Vossmeyer, A.; Arnold, G. L.; Sawicka, J.; Lyons, T. W.; Kasten, S.

2010-12-01

401

Selective catalytic reduction of sulfur dioxide to elemental sulfur. Quarterly technical progress report No. 6, October--December 1993  

SciTech Connect

Elemental sulfur recovery from SO{sub 2}-containing gas stream is highly attractive as it produces a salable product and no waste to dispose of. However, commercially available schemes are complex and involve multi-stage reactors, such as, most notably in the Resox (reduction of SO{sub 2} with coke) and Claus plant (reaction of SO{sub 2} with H{sub 2}S over catalyst). This project will investigate a cerium oxide catalyst for the single stage selective reduction of SO{sub 2} to elemental sulfur by a reductant, such as carbon monoxide. Cerium oxide has been identified in recent work at MIT as a superior catalyst for SO{sub 2} reduction by CO to elemental sulfur because its high activity and high selectivity to sulfur over COS over a wide temperature range (400--650{degree}C). The detailed kinetic and parametric studies of SO{sub 2} reduction planned in this work over various CeO{sub 2} formulations will provide the necessary basis for development of a very simplified process, namely that of a single-stage elemental sulfur recovery scheme from variable concentration gas streams. The potential cost- and energy-efficiency benefits from this approach can not be overstated. A first apparent application is treatment of a regenerator off-gases in power plants using regenerative flue gas desulfurization. Such a simple catalytic converter may offer the long-sought ``Claus-alternative`` for coal-fired power plant applications.

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

1993-12-31

402

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

Microsoft Academic Search

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

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

403

Microbial stabilization of sulfur-laden sorbents. [Quarterly] technical report, March 1, 1993--May 31, 1993  

SciTech Connect

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

Miller, K.W. [Illinois State Univ., Normal, IL (United States)

1993-09-01

404

Rhodanese Functions as Sulfur Supplier for Key Enzymes in Sulfur Energy Metabolism  

PubMed Central

How microorganisms obtain energy is a challenging topic, and there have been numerous studies on the mechanisms involved. Here, we focus on the energy substrate traffic in the hyperthermophilic bacterium Aquifex aeolicus. This bacterium can use insoluble sulfur as an energy substrate and has an intricate sulfur energy metabolism involving several sulfur-reducing and -oxidizing supercomplexes and enzymes. We demonstrate that the cytoplasmic rhodanese SbdP participates in this sulfur energy metabolism. Rhodaneses are a widespread family of proteins known to transfer sulfur atoms. We show that SbdP has also some unusual characteristics compared with other rhodaneses; it can load a long sulfur chain, and it can interact with more than one partner. Its partners (sulfur reductase and sulfur oxygenase reductase) are key enzymes of the sulfur energy metabolism of A. aeolicus and share the capacity to use long sulfur chains as substrate. We demonstrate a positive effect of SbdP, once loaded with sulfur chains, on sulfur reductase activity, most likely by optimizing substrate uptake. Taken together, these results lead us to propose a physiological role for SbdP as a carrier and sulfur chain donor to these key enzymes, therefore enabling channeling of sulfur substrate in the cell as well as greater efficiency of the sulfur energy metabolism of A. aeolicus.

Aussignargues, Clement; Giuliani, Marie-Cecile; Infossi, Pascale; Lojou, Elisabeth; Guiral, Marianne; Giudici-Orticoni, Marie-Therese; Ilbert, Marianne

2012-01-01

405

The removal of sulfur dioxide from flue gases  

PubMed Central

The growth of industrialization makes it imperative to reduce the amounts of sulfur dioxide emitted into the atmosphere. This article describes various processes for cleaning flue gases, and gives details of new methods being investigated. Wet scrubbing with water, though widely practised, has many disadvantages. Scrubbing with zinc oxide, feasible in zinc works, is more satisfactory. Dry methods use a solid absorbent; they have the advantage of a high emission temperature. Other methods are based on the addition to the fuel or the flue gases of substances such as activated metal oxides, which react with the sulfur to form compounds less harmful than sulfur dioxide. Also being investigated are a two-stage combustion system, in which the sulfur dioxide is removed in the first stage, and the injection of activated powdered dolomite into burning fuel; the resulting sulfates being removed by electrostatic precipitation. A wet catalysis process has recently been developed. Most of the cleaning processes are not yet technically mature, but first results show good efficiency and relatively low cost.

Kettner, Helmut

1965-01-01

406

Determination of sulfur trioxide in engine exhaust.  

PubMed Central

Sulfur trioxide in the exhaust gas of an internal combustion engine is removed and concentrated by absorption in a solution of 80% isopropyl alcohol, which quantitatively absorbs it and inhibits the oxidation of any sulfur dioxide which may be absorbed. The absorbed sulfur trioxide (sulfuric acid) is determined by an absorption titration by using barium chloride as the titrant and thorin as the indicator. The sulfur dioxide content of the exhaust is measured continuously by means of a DuPont Model 411 ultraviolet photoanalyzer.

Arnold, D R

1975-01-01

407

Antibotulinal efficacy of sulfur dioxide in meat.  

PubMed Central

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.

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

1980-01-01

408

Sulfur accumulation in the timbers of King Henry VIII's warship Mary Rose: A pathway in the sulfur cycle of conservation concern  

PubMed Central

In marine-archaeological oak timbers of the Mary Rose large amounts of reduced sulfur compounds abound in lignin-rich parts such as the middle lamella between the cell walls, mostly as thiols and disulfides, whereas iron sulfides and elemental sulfur occur in separate particles. Synchrotron-based x-ray microspectroscopy was used to reveal this environmentally significant accumulation of organosulfur compounds in waterlogged wood. The total concentration of sulfur in reduced forms is ?1 mass % throughout the timbers, whereas iron fluctuates up to several mass %. Conservation methods are being developed aiming to control acid-forming oxidation processes by removing the reactive iron sulfides and stabilizing the organosulfur compounds.

Sandstrom, Magnus; Jalilehvand, Farideh; Damian, Emiliana; Fors, Yvonne; Gelius, Ulrik; Jones, Mark; Salome, Murielle

2005-01-01

409

CLOSEOUT REPORT FOR HYBRID SULFUR PRESSURIZED BUTTON CELL TEST FACILITY  

SciTech Connect

This document is the Close-Out Report for design and partial fabrication of the Pressurized Button Cell Test Facility at Savannah River National Laboratory (SRNL). This facility was planned to help develop the sulfur dioxide depolarized electrolyzer (SDE) that is a key component of the Hybrid Sulfur Cycle for generating hydrogen. The purpose of this report is to provide as much information as possible in case the decision is made to resume research. This report satisfies DOE Milestone M3GSR10VH030107.0. The HyS Cycle is a hybrid thermochemical cycle that may be used in conjunction with advanced nuclear reactors or centralized solar receivers to produce hydrogen by watersplitting. The HyS Cycle utilizes the high temperature (>800 C) thermal decomposition of sulfuric acid to produce oxygen and regenerate sulfur dioxide. The unique aspect of HyS is the generation of hydrogen in a water electrolyzer that is operated under conditions where dissolved sulfur dioxide depolarizes the anodic reaction, resulting in substantial voltage reduction. Low cell voltage is essential for both high thermodynamic efficiency and low hydrogen cost. Sulfur dioxide is oxidized at the anode, producing sulfuric acid that is sent to the high temperature acid decomposition portion of the cycle. Sulfur dioxide from the decomposer is cycled back to electrolyzers. The electrolyzer cell uses the membrane electrode assembly (MEA) concept. Anode and cathode are formed by spraying a catalyst, typically platinized carbon, on both sides of a Proton Exchange Membrane (PEM). SRNL has been testing SDEs for several years including an atmospheric pressure Button Cell electrolyzer (2 cm{sup 2} active area) and an elevated temperature/pressure Single Cell electrolyzer (54.8 cm{sup 2} active area). SRNL tested 37 MEAs in the Single Cell electrolyzer facility from June 2005 until June 2009, when funding was discontinued. An important result of the final months of testing was the development of a method that prevents the formation of a sulfur layer previously observed in MEAs used in the Hybrid Sulfur Cycle electrolyzer. This result is very important because the sulfur layer increased cell voltage and eventually destroyed the MEA that is the heart of the cell. Steimke and Steeper [2005, 2006, 2007, 2008] reported on testing in the Single Cell Electrolyzer test facility in several periodic reports. Steimke et. al [2010] issued a final facility close-out report summarizing all the testing in the Single Cell Electrolyzer test facility. During early tests, significant deterioration of the membrane occurred in 10 hours or less; the latest tests ran for at least 200 hours with no sign of deterioration. Ironically, the success with the Single Cell electrolyzer meant that it became dedicated to long runs and not available for quick membrane evaluations. Early in this research period, the ambient pressure Button Cell Electrolyzer test facility was constructed to quickly evaluate membrane materials. Its small size allowed testing of newly developed membranes that typically were not available in sizes large enough to test in the Single Cell electrolyzer. The most promising membranes were tested in the Single Cell Electrolyzer as soon as sufficient large membranes could be obtained. However, since the concentration of SO{sub 2} gas in sulfuric acid decreases rapidly with increasing temperature, the ambient pressure Button Cell was no longer able to achieve the operating conditions needed to evaluate the newer improved high temperature membranes. Significantly higher pressure operation was required to force SO{sub 2} into the sulfuric acid to obtain meaningful concentrations at increased temperatures. A high pressure (200 psig), high temperature (120 C) Button Cell was designed and partially fabricated just before funding was discontinued in June 2009. SRNL completed the majority of the design of the test facility, including preparation of a process and instrument drawing (P&ID) and preliminary designs for the major components. SRNL intended to complete the designs and procu

Steeper, T.

2010-09-15

410

The origin of sulfur-bearing species on the surfaces of icy satellites  

NASA Astrophysics Data System (ADS)

Observations of icy satellites of Jupiter and Saturn at ultraviolet, visible, and infrared wavelengths reveals that their surfaces consist mainly of water ice and hydrated materials along with minor amounts of some volatiles. In particular on Europa, Ganymede, and Callisto the presence of sulfur-bearing minor species such as elemental sulfur, SO2, H2S, and hydrated sulfuric acid has been evidenced or suggested. A still open question is whether those minor species are endogenic i.e. native from the satellite or are produced by exogenic processes. The exogenic sources are implantation of sulfur ions coming from the Io torus, neutrals from Io, and bombardment by micrometeorites. To give a contribution to answer those questions a series of experiments have been performed at the laboratory in Catania: - Implantation of sulfur ions into water ice. It has been found that hydrated sulfuric acid is formed with high yield (0.65 0.1 molecules/ion). An upper limit to the production yield of SO2 (Y? 0.025 molelcules/ion) has been estimated (Strazzulla et al. 2007). - Ion irradiation of water ice deposited on sulfurous materials looking to the formation of new species at the interface (ion mixing). The results show that there is not evidence for the efficient synthesis of SO2 after irradiation (Gomis and Strazzulla 2008) The experimental results are here presented and discussed in the light of the relevance they have to understand the origin of sulfur bearing species on the surface of icy satellites in the external Solar System. References: G. Strazzulla, G.A. Baratta, G. Leto, O. Gomis, Hydrate sulfuric acid after sulfur implantation in water ice, Icarus 192 (2007) 623-628 O.Gomis, G. Strazzulla, Ion irradiation of H2O ice on top of sulfurous solid residues and its relevance to the Galilean satellites, Icarus in press (2008) doi:10.1016/j.icarus.2007.09.015

Strazzulla, Giovanni

411

Sulfur gas emissions from stored flue gas desulfurization solids. Final report  

SciTech Connect

The emissions of volatile, sulfur-containing compounds from the surfaces of 13 flue gas desulfurization (FGD) solids field storage sites have been characterized. The sulfur gas emissions from these storage surfaces were determined by measuring the sulfur gas enhancement of sulfur-free sweep air passing through a dynamic emission flux chamber placed over selected sampling areas. Samples of the enclosure sweep air were cryogenically concentrated in surface-deactivated Pyrex U traps. Analyses were conducted by wall-coated, open-tubular, capillary column, cryogenic, temperature-programmed gas chromatography using a sulfur-selective flame photometric detector. Several major variables associated with FGD sludge production processes were examined in relation to the measured range and variations in sulfur fluxes including: the sulfur dioxide scrubbing reagent used, sludge sulfite oxidation, unfixed or stabilized (fixed) FGD solids, and ponding or landfill storage. The composition and concentration of the measured sulfur gas emissions were found to vary with the type of solids, the effectiveness of rainwater drainage from the landfill surface, the method of impoundment, and the sulfate/sulfite ratio of the solids. The FGD solids emissions may contain hydrogen sulfide, carbonyl sulfide, dimethyl sulfide, carbon disulfide, and dimethyl disulfide in varying concentrations and ratios. In addition, up to four unidentified organo-sulfur compounds were found in the emissions from four different FGD solids. The measured, total sulfur emissions ranged from less than 0.01 to nearly 0.3 kg of sulfur per day for an equivalent 40.5 hectare (100 acre) FGD solids impoundment surface.

Adams, D.F.; Farwell, S.O.

1981-10-01

412

Sulfur removal from high-sulfur Illinois coal by low-temperature perchloroethylene (PCE) extraction. Technical report, December 1, 1992--February 28, 1993  

SciTech Connect

The purpose of this project are to independently confirm and possibly to improve the organic sulfur removal from Illinois coals with the PCE process developed by the Midwest Ore Processing Co.(MWOPC), to verify the forms-of-sulfur determination using the ASTM method for evaluation of the PCE process, and to develop a dechlorination procedure to remove excess PCE from the PCE-treated coal. The objectives for year-2 study are to verify the possible effect of PCE treatment on coal-derived FeS{sub 2}, FeSO{sub 4}, and Fe{sub 2}(SO{sub 4}){sub 3} on ASTM coal analysis, to investigate the behavior of sulfur during oxidation and PCE desulfurization using the isotopically signatured coal sample to investigate the proprietary reagent on the oxidation of the organic sulfur model compounds with and without additives, to evaluate this new oxidation on the organic sulfur removal by PCE desulfurization, and to study other innovative pretreatment processes for the removal of organic sulfur from coal under mild conditions. Oxidation study on the organosulfur model compounds alone was completed in first quarter. The oxidation reactions were repeated on the organosulfur model compounds with the presence of hydrocarbon additives. These additives are known to easily produce hydroperoxides during air oxidation. Analysis of the reaction products is in progress.

Chou, M.I.M.; Lytle, J.M.; Ruch, R.R.; Kruse, C.W.; Chaven, C.; Hackley, K.C.; Hughes, R.E.; Harvey, R.D. [Illinois Dept. of Energy and Natural Resources, Springfield, IL (United States). Geological Survey; Buchanan, D.H. [Eastern Illinois Univ., Charleston, IL (United States); Stucki, J.W. [Illinois Univ., Urbana, IL (United States); Huffman, G.; Huggins, F.E. [Kentucky Univ., Lexington, KY (United States); Ho, K.K. [Institute of Gas Technology, Chicago, IL (United States)

1993-05-01

413

Sulfur removal from high-sulfur Illinois coal by low-temperature perchloroethylene (PCE) extraction. [Quarterly] technical report, March 1, 1993--May 31, 1993  

SciTech Connect

The purposes of this project are: to independently confirm and possibly to improve the organic sulfur removal from Illinois coals with the PCE process developed by the Midwest Ore Processing Co. (MWOPC), to verify the forms-of-sulfur determination using the ASTM method for evaluation of the PCE process, and to develop a dechlorination procedure to remove excess PCE from the PCE-treated coal. The objectives for the second year are: to verify the possible effects of PCE treatment on coal-derived FeS{sub 2}, FeSO{sub 4}, and Fe{sub 2}(SO{sub 4}){sub 3} on ASTM coal analysis, to investigate the behavior of sulfur during oxidation and PCE desulfurization using the isotopically signatured coal sample, to investigate the effects of conditions and/or reagents on the oxidation of the organic-sulfur-model compounds, to evaluate the extended oxidation condition on the organic sulfur removal by PCE desulfurization, and to study other innovative pretreatment processes for the removal of organic sulfur from coal under mild conditions.

Chou, M.I.M. [Illinois State Geological Survey, Champaign, IL (United States); Buchanan, D.H. [Eastern Illinois Univ., Charleston, IL (United States); Stucki, J.W. [Illinois Univ., Urbana, IL (United States)

1993-09-01

414

Polysulfide Sealant Compositions. 2. Interactions between Elemental Sulfur and Organosulfur Compounds. (Reannouncement with New Availability Information).  

National Technical Information Service (NTIS)

Added sulfur in polysulfide aircraft sealants can become chemically bound to the polymer backbone. The chemical processes involved, and their effect on thermal performance of the resulting sealants, have been examined. Reactions of aliphatic thiols with s...

P. J. Hanhela R. J. Hook D. B. Paul

1994-01-01

415

Sulfur Polymer Stabilization/Solidification (SPSS) Treatability of Los Alamos National Laboratory Mercury Waste.  

National Technical Information Service (NTIS)

Brookhaven National Laboratory's Sulfur Polymer Stabilization/Solidification (SPSS) process was used to treat approximately 90kg of elemental mercury mixed waste from Los Alamos National Laboratory. Treatment was carried out in a series of eight batches u...

J. W. Adams P. D. Kalb

2001-01-01

416

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

NASA Astrophysics Data System (ADS)

The sulfur contents and sulfur isotopic compositions of 24 glassy submarine volcanics from the Mariana Island Arc and back-arc Mariana Trough were determined in order to investigate the hypothesis that subducted seawater sulfur (delta S-34 = 21 parts per thousand) is recycled through arc volcanism. Our results for sulfur are similar to those for subaerial arc volcanics: Mariana Arc glasses are enriched in S-34(delta S-34 = up to 10.3 parts per thousand, mean = 3.8 parts per thousand) and depleted in S(20-290 ppm, mean = 100 ppm) relative to mid ocean ridge basalt (MORB)(850 ppm S, delta S-34 = 0.1 +/- 0.5 parts per thousand). The bac-arc trough basalts contain 200-930 ppm S and have delta S-34 values of 1.1 +/- 0.5 parts per thousand, which overlap those for the arc and MORB. The low sulfur contents of the arc and some of the trough glasses are attributed to (1) early loss of small amounts of sulfur through separation of immiscible sulfide and (2) later vapor-melt equilibrium control of sulfur contents and loss of sulfur in a vapor phase from sulfide-undersaturated melts near the minimum in sulfur solubility at fO2 is approximately equal to NNO (nickel-nickel oxide). Although these processes removed sulfur from the melts their effects on the sulfur isotopic compositions of the melts were minimal. Positive trends of delta S-34 with Sr-87/Sr-86 large ion lithophile element (LILE) and Light rare earth elements (LREE) contents of the arc volcanics are consistent with a metasomatic seawater sulfur component in the depleted sub-arc mantle source. The lack of a S-34-rich slab signature in the trough lavas may be attributed to equilibration of metasomatic fluid with mantle material along the longer pathway from the slab to the source of the trough volcanics. Sulfur is likely to have been transported into the mantle wedge by metasomatic fluid derived from subducted sediments and pore fluids. Gases extracted from vesicles in arc and back-arc samples are predominantly H2O, with minor CO2 and traces of H2S and SO2.CO2 in the arc and back-arc rocks has delta C-13 values of -2.1 to 13.1 parts per thousand, similar to MORB. These data suggest that degassing of CO2 could explain the slightly lower delta C-13 values for some Mariana Trough volcanic glasses, and that incorporation of subduction-derived organic carbon into the Mariana trough mantle source may not be necessary. More analyses are required to resolve this question, however.

Alt, Jeffrey C.; Shanks, Wayne C., III; Jackson, Michael C.

1993-10-01

417

Amphiphilic surface modification of hollow carbon nanofibers for improved cycle life of lithium sulfur batteries.  

PubMed

Tremendous effort has been put into developing viable lithium sulfur batteries, due to their high specific energy and relatively low cost. Despite recent progress in addressing the various problems of sulfur cathodes, lithium sulfur batteries still exhibit significant capacity decay over cycling. Herein, we identify a new capacity fading mechanism of the sulfur cathodes, relating to Li(x)S detachment from the carbon surface during the discharge process. This observation is confirmed by ex-situ transmission electron microscopy study and first-principles calculations. We demonstrate that this capacity fading mechanism can be overcome by introducing amphiphilic polymers to modify the carbon surface, rendering strong interactions between the nonpolar carbon and the polar Li(x)S clusters. The modified sulfur cathode show excellent cycling performance with specific capacity close to 1180 mAh/g at C/5 current rate. Capacity retention of 80% is achieved over 300 cycles at C/2. PMID:23394300

Zheng, Guangyuan; Zhang, Qianfan; Cha, Judy J; Yang, Yuan; Li, Weiyang; Seh, Zhi Wei; Cui, Yi

2013-02-14

418

Task 4.4 - development of supercritical fluid extraction methods for the quantitation of sulfur forms in coal  

SciTech Connect

Development of advanced fuel forms depends on having reliable quantitative methods for their analysis. Determination of the true chemical forms of sulfur in coal is necessary to develop more effective methods to reduce sulfur content. Past work at the Energy & Environmental Research Center (EERC) indicates that sulfur chemistry has broad implications in combustion, gasification, pyrolysis, liquefaction, and coal-cleaning processes. Current analytical methods are inadequate for accurately measuring sulfur forms in coal. This task was concerned with developing methods to quantitate and identify major sulfur forms in coal based on direct measurement (as opposed to present techniques based on indirect measurement and difference values). The focus was on the forms that were least understood and for which the analytical methods have been the poorest, i.e., organic and elemental sulfur. Improved measurement techniques for sulfatic and pyritic sulfur also need to be developed. A secondary goal was to understand the interconversion of sulfur forms in coal during thermal processing. EERC has developed the first reliable analytical method for extracting and quantitating elemental sulfur from coal (1). This method has demonstrated that elemental sulfur can account for very little or as much as one-third of the so-called organic sulfur fraction. This method has disproved the generally accepted idea that elemental sulfur is associated with the organic fraction. A paper reporting the results obtained on this subject entitled {open_quote}Determination of Elemental Sulfur in Coal by Supercritical Fluid Extraction and Gas Chromatography with Atomic Emission Detection{close_quote} was published in Fuel (A).

Timpe, R.C.

1995-04-01

419

ADVANCED SULFUR CONTROL CONCEPTS FOR HOT GAS DESULFURIZATION TECHNOLOGY  

SciTech Connect

The objective of this project is to develop a hot-gas desulfurization process scheme for control of H{sub 2}S in HTHP coal gas that can be more simply and economically integrated with known regenerable sorbents in DOE/METC-sponsored work than current leading hot-gas desulfurization technologies. In addition to being more economical, the process scheme to be developed must yield an elemental sulfur byproduct.

Unknown

1999-04-01

420

ADVANCED SULFUR CONTROL CONCEPTS FOR HOT GAS DESULFURIZATION TECHNOLOGY  

SciTech Connect

The objective of this project is to develop a hot-gas desulfurization process scheme for control of H{sub 2}S in HTHP coal gas that can be more simply and economically integrated with known regenerable sorbents in DOE/METC-sponsored work than current leading hot-gas desulfurization technologies. In addition to being more economical, the process scheme to be developed must yield an elemental sulfur byproduct.

None

1998-12-31

421

A two-dimensional model of sulfur species and aerosols  

Microsoft Academic Search

A two-dimensional model of sulfate aerosols has been developed. The model includes the sulfate precursor species H2S, CS2, DMS, OCS, and S02. Microphysical processes simulated are homogeneous nucleation, condensation and evaporation, coagulation, and sedimentation. Tropospheric aerosols are removed by washout processes and by surface deposition. We assume that all aerosols are strictly binary water-sulfuric acid solutions without solid cores. The

Debra K. Weisenstein; Glenn K. Yue; Malcolm K. W. Ko; Nien-Dak Sze; Jose M. Rodriguez; Courtney J. Scott

1997-01-01

422

ADVANCED SULFUR CONTROL CONCEPTS FOR HOT GAS DESULFURIZATION TECHNOLOGY  

SciTech Connect

The objective of this project is to develop a hot-gas desulfurization process scheme for control of H{sub 2}S in HTHP coal gas that can be more simply and economically integrated with known regenerable sorbents in DOE/METC-sponsored work than current leading hot-gas desulfurization technologies. In addition to being more economical, the process scheme to be developed must yield an elemental sulfur byproduct.

Unknown

1999-07-01

423

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

SciTech Connect

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.

NONE

1997-12-31

424

U. S. crude slate gets heavier, higher in sulfur  

SciTech Connect

This paper reports that historical records of API gravities and sulfur contents of crude oil runs to U.S. refineries show that the quality of the U.S. crude oil pool is worsening. This trend has, of course, been influenced by the increasing capability of U.S. refiners to process heavier and higher-sulfur crudes, the availability of such crudes, and, at times, attractive differentials between them and lighter crudes. Ten years ago, the U.S. Department of Energy (DOE) started to report monthly and yearly composite values of API gravity and sulfur content for crude oils processed in refinery districts and Petroleum Administration for Defense (PAD) districts. The 10-year history of annual composite values for API gravity and sulfur content is shown in Table 1, for the U.S. in total, and by PAD district (PADD). A simple regression analysis was conducted on each set of data and plotted to see how well actual data matched straight-line calculated data. If the calculated trend line tracks the actual data, then it is reasonable to extrapolate the trend for the next 3-5 years.

Swain, E.J. (Bechtel Corp., Houston, TX (US))

1991-09-09

425

Nutritional essentiality of sulfur in health and disease.  

PubMed

Sulfur is the seventh most abundant element measurable in the human body and is supplied mainly by the intake of methionine (Met), an indispensable amino acid found in plant and animal proteins. Met controls the initiation of protein synthesis, governs major metabolic and catalytic activities, and may undergo reversible redox processes safeguarding protein integrity. Withdrawal of Met from customary diets causes the greatest downsizing of lean body mass following either unachieved replenishment (malnutrition) or excessive losses (inflammation). These physiopathologically unrelated morbidities nevertheless stimulate comparable remethylation reactions from homocysteine, indicating that Met homeostasis benefits from high metabolic priority. Inhibition of cystathionine-?-synthase activity causes the upstream sequestration of homocysteine and the downstream drop in cysteine and glutathione. Consequently, the enzymatic production of hydrogen sulfide and the nonenzymatic reduction of elemental sulfur to hydrogen sulfide are impaired. Sulfur operates as cofactor of several enzymes critically involved in the regulation of oxidative processes. A combination of malnutrition and nutritional deprivation of sulfur maximizes the risk of cardiovascular disorders and stroke, constituting a novel clinical entity that threatens plant-eating population groups. PMID:23815141

Ingenbleek, Yves; Kimura, Hideo

2013-05-24

426

Influence of sulfur in coals on char morphology and combustion  

SciTech Connect

During coal carbonization (pyrolysis), as during the combustion process of pulverized coal in a combustor, not all of the sulfur is released. Significant proportions become pat of the structure of the resultant coke and char. The combustion process of the char within the flames of the combustor in influenced dominantly by char morphology. This, in turn, controls the accessibility of oxidizing gases to the surfaces of the carbonaceous substance of the char. Mineral matter content, its extent and state of distribution, also exerts an influence on char morphology created during pyrolysis/carbonization. This complexity of coal renders it a very difficult material to study, systematically, to distinguish and separate out the contributing factors which influence combustion characteristics. Therefore, in such circumstances, it is necessary to simplify the systems by making use of model chars/cokes/carbons which can be made progressively more complex, but in a controlled way. In this way complicating influence in chars from coals can be eliminated, so enabling specific influences to be studied independently. It is important to note that preliminary work by Marsh and Gryglewicz (1990) indicated that levels of sulfur of about 3 to 5 wt % can reduce reactivities by 10 to 25%. The overall purpose of the study is to provide meaningful kinetic data to establish, quantitatively, the influence of organically-bound sulfur on the reactivity of carbons, and to ascertain if gasification catalysts are effective in the preferential removal of sulfur from the chars.

Marsh, H.

1991-01-01

427

Aerosol Nucleation Rates of Sulfuric Acid and Water Measured Under the Lower Tropospheric Conditions  

NASA Astrophysics Data System (ADS)

Nucleation is a gas to particle conversion process in which solid or liquid aerosol particles form directly from the gas phase species and thus is an important step in the chain of reactions that lead to cloud formation. However, the nucleation mechanisms are poorly understood. There are presently large discrepancies amongst the measured nucleation rates by different laboratory studies; nucleation rates taken under the atmospheric conditions are very rare. We perform laboratory experiments of aerosol nucleation under the atmospheric conditions with a novel chemical ionization mass spectrometer (CIMS) and nano-particle differential mobility analyzer (Nano-DMA) and water condensation nuclei counter (WCPC). Our CIMS measures low concentrations of sulfuric acid (down to 1e-6 cm-3). Measurements of Nano-DMA and WCPC provide aerosol nucleation rates. An atmospheric pressure flow reactor is used to photochemically produce sulfuric acid particles from the reactions of OH and sulfur dioxide. Sulfur dioxide is also detected by CIMS. OH forms from the photo-dissociation of water vapor using a mercury lamp and the OH concentrations are calculated based on the known photochemical reaction rates and measured photon fluxes. This OH generation method also allows for sulfuric acid calibration. We will present nucleation rates of sulfuric acid and water as a function of sulfuric acid concentration, RH and temperature under the conditions of lower troposphere. We also compare these results with those by Berndt et al. (2005) that show relatively high concentrations of sulfuric acid and water nucleation rates comparable to the atmospheric observations.