Sulfur oxides membrane contamination

Sensitivity to contaminants, both in fuel and oxidant and in fuel cell construction materials, surprisingly has not been studied enough. There is a very corrosive environment inside a fuel cell (hot, humid, and presence of sulfuric acid) which limits the choice of materials. Both catalyst and polymer membrane may be extremely sensitive to contaminants, particularly metal ions. More research in this area is required. 

Natural Gas. The principal sulfur contaminant of natural gas is another gas -hydrogen sulfide. Because it is extremely toxic, civil authorities have long forbidden significant levels of this compound in natural-gas pipelines. Hydrogen sulfide is removed from natural gas by a variety of commercial processes including reaction with aqueous solutions of oxidants, absorption into aqueous solutions of bases, distillation, and selective permeation through membranes. The end product of these processes is elemental sulfur, which can be sold and, in some cases, is worth more than the co-produced natural gas. In 1984, about 24,000 tons (24 million kilograms) of sulfur was produced from natural-gas wells in the United States. 

Properties Wh. ctyst. needles or molten liq. mild odor sol. in alcohol, carbon disulfide si. sol. in ether, hot water very si. sol. in water m.w. 148.12 dens. 1.527 (4 C) vapor pressure 1 mm (96.5 C) m.p. 130.8 C b.p. 295 C sublimes flash pt. (CC) 151 C Toxicology ACGIH TLV7FWA 1 ppm LD50 (oral, mouse) 1500 mg/kg poison by ing. corrosive irritant to eyes, skin, mucous membranes experimental teratogen common air contaminant TSCA listed Precaution Combustible DDT Corrosive material can react with oxidizers mod. explosion hazard as dust exposed to flame violent reaction with nitric acid + sulfuric acid above 80 C Storage Moisture-sensitive... 

Toxicology ACGIH TLV/TWA 1 ppm LD50 (oral, mouse) 1500 mg/kg poison by ing. corrosive irritant to eyes, skin, mucous membranes experimental teratogen common air contaminant TSCA listed Precaution Combustible DOT Corrosive material can react with oxidizers mod. explosion hazard as dust exposed to flame violent reaction with nitric acid + sulfuric acid above 80 C... 

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