Hydrogen containing gases, sulfur

Fuel processing may be defined as the conversion of a raw fuel to a hydrogen-containing gas being compatible with the requirements of a PEMFC. Since it is well known that PEMFC stacks are sensitive to fuel contaminants such as CO, sulfur-containing compounds, ammonia, unsaturated hydrocarbons, etc., a fuel processor is typically built with several reaction stages. 

Nitrogen oxide sampling is simpler. This gas is drawn into an evacuated sample flask containing dilute sulfuric acid and hydrogen peroxide. The flask is shaken and allowed to stand for 16 h before the flask pressure is measured. Then the solution is made alkaline, and the nitrogen oxides are deterrnined by the phenoldisulfonic colorimetric test. 

Methods of Purification. Although carbon dioxide produced and recovered by the methods outlined above has a high purity, it may contain traces of hydrogen sulfide and sulfur dioxide, which cause a slight odor or taste. The fermentation gas recovery processes include a purification stage, but carbon dioxide recovered by other methods must be further purified before it is acceptable for beverage, dry ice, or other uses. The most commonly used purification methods are treatments with potassium permanganate, potassium dichromate, or active carbon. 

This process is used to treat gas streams containing high concentrations of H2S. The chemistry of the units involves partial oxidation of hydrogen sulfide to sulfur dioxide and the catalytically promoted reaction of hh.S and SO2 to produce elemental sulfur. The reactions are staged and arc. is lollows ... 

In the blast furnace, the reaction of the nitrogen in the blast with coke leads to the formation of poisonous chemicals such as hydrogen cyanide and cyanogens, and each cubic meter of the blast furnace gas contains from 200 to 2000 mg of these compounds. The blast furnace gas is scrubbed with water in the dust collection system the cyanide compounds dissolve in the water, which is then discharged after the compounds have been destroyed. Another poisonous emission in blast furnace operations is hydrogen sulfide. The sulfur present in the coke is converted into calcium sulfide in the slag, the water-quenching of... 

Trester, P.W. and Staley, H.G., Assessment and investigation of containment materials for the sulfur-iodine thermochemical water-splitting process for hydrogen production, Gas Research Institute report GRI-80/0081,1981. 

Townsend A process for removing hydrogen sulfide from natural gas by absorption in triethylene glycol containing sulfur dioxide. Part of the sulfur produced is burnt to sulfur dioxide in order to provide this solution. The hydrogen sulfide and sulfur dioxide react in the presence of water to generate elemental sulfur. Invented in 1959 by F. M. Townsend. 

If sulfuric acid is produced, the S02 containing gas does not require fuel gas or reducing gas, except for providing process heat. If elemental sulfur is to be produced, it is generally done by the Claus reaction previously discussed. In that case, two-thirds of the S02 is catalytically hydrogenated to S02 ... 

Lozano and Barba [82] electrolyzed 2-chloro-2-phenylacetyl chloride at mercury in methylene chloride and obtained derivatives of pyran-2-one and pyran-4-one, where R is H and C6H5CH2CO, respectively, at high and low current density (Scheme 6). In later work [83], the same workers reduced 2-bromo-2,2-diphenylacetyl bromide in methylene dichloride saturated with hydrogen sulfide gas three sulfur-containing... 

Copper and copper-containing alloys are susceptible to attack by elemental sulfur and hydrogen sulfide as well as organically bound sulfur. Active or elemental sulfur and hydrogen sulfide gas can attack copper to form copper sulfide, a dark-brown to black compound. This can be seen through ASTM D-130 copper corrosion testing. 

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