Hydrogen sulfide destructive

Pure sulfur compounds containing 9 or 10 carbon atoms were examined in the presence of silica-alumina at 250-300° (391). Liberation of hydrogen sulfide, destructive hydrogenation and hydrogen disproportionation took place forming disulfides, mercaptans, and olefins. 

Hydrogen sulfide, mercaptans, active elemental sulfur, inorganic acids, and ammonia can all attack and corrode copper. The presence of these compounds in fuel can lead to destruction of copper heating lines, cooling coils, and nonferrous metal fittings. Also, hydrogen sulfide and mercaptans can contribute to fuel odor problems. 

The hydrodesulfurization process can fall into either the destructive or nondestructive category. However for heavy feedstocks some hydrocracking is preferred, if not necessary, to remove the sulfur. Thus, hydrodesulfurization in this context falls into the hydrocracking or destructive hydrogenation category. The basic chemical concept of the process remains the same, that is, to convert the organic sulfur in the feedstock to hydrogen sulfide. 

Strong acids and strong bases are corrosive substances that exhibit extremes of pH. They are destructive to materials and flesh. Strong acids can react with cyanide and sulfide compounds to release highly toxic hydrogen cyanide (HCN) or hydrogen sulfide (H2S) gases, respectively. Bases liberate noxious ammonia gas (NH3) from solid ammonium compounds. 

The opposing-reactant geometry has been studied recently by several investigators for a number of catalytic reactions including destruction of NOx [Zaspalis et al., 1991d], conversion of hydrogen sulfide to sulfur [Sloot et al, 1990 and 1992] and oxidation of carbon monoxide [Veldsink et al, 1992]. 

However, if protease activity were involved, such preparations of methloninase from putIda could provide self-destructing enzyme systems for encapsulated, flavor-producing systems (65) that would prevent over-production of methanethiol and hydrogen sulfide. Alternatively, it might be possible to use other sources of methloninase, such as Brevlbacterlum linens (7 35) or Aspergillus oryzae (56, 57), as systems with potentially less protease activity. In any event further studies will be required to determine if alpha-ketobutyrlc acid assays provide suitable data for indexing methloninase activity In flavor systems. 

The selection of materials must also consider oxidation/reduction processes that occur in the absence of an aqueous electrolyte. Examples include sulfidation, destructive oxidation of alloys in air or steam at high temperatures, carburization, nitriding, fuel ash corrosion, and high-temperature hydrogen attack. 

Hydrogen snlflde is a colorless gas, with an offensive odor and a sweetish taste. It is soluble in water, alcohol, oils, sulfur, and many other solvents. It has a specific gravity of 1.1895 with reference to air, and is considered a weak acid. Hydrogen sulfide can be dangerous to personnel on the surface as it is extremely toxic to human and animal life, and is extremely corrosive to most metals as it can cause cracking of drill pipe and tubular goods and destruction of testing tools and wire lines. 

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