Hydrogen sulfide, from sulfides

Commercial-scale processes have been developed for the production of hydrogen sulfide from heavy fuel oils and sulfur as well as from methane, water vapor, and sulfur. The latter process can be carried out in two steps reaction of methane with sulfur to form carbon disulfide and hydrogen sulfide followed by hydrolysis of carbon disulfide (116). 

Conversion Processes. Most of the adsorption and absorption processes remove hydrogen sulfide from sour gas streams thus producing both a sweetened product stream and an enriched hydrogen sulfide stream. In addition to the hydrogen sulfide, this latter stream can contain other co-absorbed species, potentially including carbon dioxide, hydrocarbons, and other sulfur compounds. Conversion processes treat the hydrogen sulfide stream to recover the sulfur as a salable product. 

NKK s Bio-SR process is another iron-based redox process which instead of chelates, uses Thiobacillusferroidans )2iQ. - 2i to regenerate the solution (9). This process absorbs hydrogen sulfide from a gas stream into a ferric sulfate solution. The solution reacts with the hydrogen sulfide to produce elemental sulfur and ferrous sulfate. The sulfur is separated via mechanical means, such as filtering. The solution is regenerated to the active ferric form by the bacteria. 

Black Liquor Soap Acidulation. Only two-thirds of a typical black Hquor soap consists of the sodium salts of fatty acids and resin acids (rosin). These acids are layered in a Hquid crystal fashion. In between these layers is black Hquor at the concentration of the soap skimmer, with various impurities, such as sodium carbonate, sodium sulfide, sodium sulfate, sodium hydroxide, sodium Hgnate, and calcium salts. This makes up the remaining one-third of the soap. Cmde tall oil is generated by acidifying the black Hquor soap with 30% sulfuric acid to a pH of 3. This is usually done in a vessel at 95°C with 20—30 minutes of vigorous agitation. Caution should be taken to scmb the hydrogen sulfide from the exhaust gas. 

Potassium Permanganate. Probably the most widely used process for removing traces of hydrogen sulfide from carbon dioxide is to scmb the gas with an aqueous solution saturated with potassium permanganate [7722-64-7]. Sodium carbonate is added to the solution as buffer. The reaction is as foUows ... 

Citric acid is used to chelate vanadium catalyst in a process for removing hydrogen sulfide from natural and refinery gas and forming elemental sulfur, a valuable product (133). 

Paint and varnish manufacturing Resin manufacturing closed reaction vessel Varnish cooldng-open or closed vessels Solvent thinning Acrolein, other aldehydes and fatty acids (odors), phthalic anhydride (sublimed) Ketones, fatty acids, formic acids, acetic acid, glycerine, acrolein, other aldehydes, phenols and terpenes from tall oils, hydrogen sulfide, alkyl sulfide, butyl mercaptan, and thiofen (odors) Olefins, branched-chain aromatics and ketones (odors), solvents Exhaust systems with scrubbers and fume burners Exhaust system with scrubbers and fume burners close-fitting hoods required for open kettles Exhaust system with fume burners... 

J Consider the coke-oven gas COG sweetening process shown in Fig. 3.22. The basic objective of COG sweetening is the removal of acidic impurities, primarily hydrogen sulfide, from COG (a mixture of H2, CH4, CO, N2, NH3, CO2, and H2S). Hydrogen sulfide m undesirable impurity, because it is corrosive and contributes to SO2 emission when the G... 

Figure 4-4. Vapor-solid equilibrium constants o) for carbon dioxide, b) for hydrogen sulfide. (From Gas Processors Suppliers Association, Bngineerinq Data Book, 10th Edition.)...

Conditions under which the reaction is directed solely toward the formation of the sulfide 46 (yield of up to 89.5%) have been reported (79ZOR1554) Liquid ammonia is used as a solvent, whereas sulfide ions are generated by ammonium sulfide formed directly in the reaction mixture from ammonia and hydrogen sulfide. The sulfide 46 possesses the Z,Z-configuration, providing evidence for a high trans stereoselectivity of the reaction (79ZOR1554). 

Figure 4-439. Approximate failure time of carbon steel is 5% NaCI and various parts per miiiion of hydrogen sulfide. (From Ref. [184].)...

Savinov EN, Gruzdkov YA, Parmon VN (1989) Suspensions of semiconductors with microheterojunctions — A new type of highly efficient photocatalyst for dihydrogen production from solution of hydrogen sulfide and sulfide ions. Int J Hydrogen Energy 14 1-9... 

The above reaction can be driven in the forward direchon by continuously removing hydrogen sulfide from the system. This is accomplished in the sulfide reduction process by incorporating lime, which acts as a scavenger for hydrogen sulfide in accordance with the reaction... 

Pregnant rats exposed to 75 ppm of hydrogen sulfide from gestation days 1-21 had 50% increases in glucose levels (Hayden et al. 1990a). The relevance of this finding to humans is not known. 

Soils may sorb considerable amounts of hydrogen sulfide from the air, retaining most of it in the form of elemental sulfur (Cihacek and Bremner 1993). 

Kanagawa T, Mikami E. 1989. Removal of methanethiol, dimethyl sulfide, dimethyl disulfide, and hydrogen sulfide from contaminated air by Thiobacillus thioparus TK-m. Appl Environ Microbiol 55(3) 555-558. 

Wilson LG, Bressan RA, Filner P. 1978. Light-dependent emission of hydrogen sulfide from plants. Plant Physiol 61 184-189. 

Hydrogen Sulfide. Hydrogen sulfide is a foul-smelling gas that is released into the atmosphere from volcanoes as well as in the course of decay of animal tissues. As an air pollutant, it reacts with almost all metals, with the exception of gold, forming a dark-colored corrosive layer of metal sulfide, commonly known as tarnish, which discolors the exposed surface of most metals. 

ASR Sulfoxide [Alberta Sulfur Research] A process for removing residual sulfur dioxide and hydrogen sulfide from the tail gases from the Claus process by wet scrubbing with a solution containing an organic sulfoxide. Elemental sulfur is produced. It had not been piloted in 1983. 

ATS [Ammonium thiosulfate] A process for removing residual sulfur dioxide from Claus tail gas by absorption in aqueous ammonia to produce ammonium sulfite and bisulfite. Addition of hydrogen sulfide from the Claus unit produces saleable ammonium thiosulfate. Developed by the Pritchard Corporation and first operated by the Colorado Interstate Gas Company at Table Rock, WY. 

Axorb A process for removing carbon dioxide and hydrogen sulfide from gases by scrubbing with an aqueous solution of potassium carbonate containing proprietary additives. 

Bio-SR A process for removing hydrogen sulfide from gas streams. Developed by NKK Industries, Japan. It uses a solution of unchelated iron, regenerated microbiologically. 

Carl Still (2) A process for removing hydrogen sulfide from coke oven gas by scrubbing with aqueous ammonia, itself derived from coke oven gas. Developed in the 1970s by Firma Carl Still, Germany. Operated at the ARMCO steel mill at Middleton, OH. See also Diamox, Still. 

Cataban A process for removing small amounts of hydrogen sulfide from industrial gas streams by oxidation, in aqueous solution, to elemental sulfur. The oxidant is the ferric ion,... 

CATACARB [Catalyzed removal of carbon dioxide] A process for removing carbon dioxide and hydrogen sulfide from gas streams by absorption in hot potassium carbonate solution containing a proprietary catalyst. Developed and licensed by Eickmeyer and Associates, KS, based on work at the U.S. Bureau of Mines in the 1950s. More than a hundred plants were operating in 1997. See also Benfield, Carsol, Hi-pure, Giammarco-Vetrocoke. 

Claus A process for removing hydrogen sulfide from gas streams by the catalyzed reaction with sulfur dioxide, producing elementary sulfur. The process has two stages in the first, one third of the hydrogen sulfide is oxidized with air to produce sulfur dioxide in the second, this sulfur dioxide stream is blended with the remainder of the hydrogen sulfide stream and passed over an iron oxide catalyst at approximately 300°C. The resulting sulfur vapor is condensed to liquid sulfur. 

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