Thiophane, oxidation

N2. Sulfur containing odorants (mercaptans, disulfides, or commercial odorants) are added for leak detection. Because neither fuel cells nor commercial reformer catalysts are sulfur tolerant, the sulfur must be removed. This is usually accomplished with a zinc oxide sulfur polisher and the possible use of a hydrodesulfurizer, if required. The zinc oxide polisher is able to remove the mercaptans and disulfides. However, some commercial odorants, such as Pennwalf s Pennodorant 1013 or 1063, contain THT (tetrahydrothiophene), more commonly known as thiophane, and require the addition of a hydrodesulfurizer before the zinc oxide catalyst bed. 

The hydrodesulfurizer will, in the presence of hydrogen, convert the thiophane into H2S that is easily removed by the zinc oxide polisher. The required hydrogen is supplied by recycling a small amount of the reformed natural gas product. Although a zinc oxide reactor can operate over a wide range of temperatures, a minimum bed volume is achieved at temperatures of 350 to 400°C (660 to 750°F). 

SuMur compounds compounds containing reduced or oxidized sulfur, seldom both (Table). Biochemically important S.a are the sulfur amino adds (see L-C eine, L-Methionine), biotin (thiophane ting) and thiamin (thiazole ting) (see Vitamins), sul-fatides (complex lipids of the nervous system see dy-colipids), and thiol peptides (see Glutathione, Vasopressin, Oxytodn, Insulin). S.c. also include Penicillin (see), and the sulfonamid which are important synthetic therapeutic agents. Hie mustard oil glycosides contain both oxidiz and reduced sulfur. Sulfate esters (see) are excreted by animals. 

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