Hydrogen sulphide emission control by combined adsorption and catalytic combustion

The removal of low concentrations of hydrogen sulfide by adsorption and catalytic combustion has been studied. Concentration of hydrogen sulfide by adsorption from waste-gas streams is best effected by molecular sieve 13X, if the stream is dry, and by activated carbon, if the gas stream is moist. Low-temperature catalytic oxidation of hydrogen sulphide in moist gas streams can be effected over activated carbon. The reaction appears to involve ionized hydrogen sulfide, dissolved in water condensed in the pores of the carbon. At high temperatures, both supported platinum and palladium catalysts are found to be oxidation catalysts. Palladium is the best catalyst for methane oxidation but is partially deactivated in the presence of sulfur-containing gases. In contrast, platinum was more active for the same reaction in the presence of sulfur-containing gases. Both metals were found to promote the oxidation of hydrogen sulfide above ca. 150 degrees C. The power rate laws describing the kinetics of reaction were determined. (C) 1998 Elsevier Science B.V. All rights reserved.