HYDROGEN-SULFIDE EMISSION CONTROL BY COMBINED ADSORPTION AND CATALYTIC COMBUSTION

The removal of low concentrations of hydrogen sulfide by adsorption an d catalytic combustion has been studied. Concentration of hydrogen sul fide by adsorption from waste-gas streams is best effected by molecula r sieve 13X, if the stream is dry, and by activated carbon, if the gas stream is moist. Low-temperature catalytic oxidation of hydrogen sulp hide in moist gas streams can be effected over activated carbon. The r eaction appears to involve ionized hydrogen sulfide, dissolved in wate r condensed in the pores of the carbon. At high temperatures, both sup ported platinum and palladium catalysts are found to be oxidation cata lysts. Palladium is the best catalyst for methane oxidation but is par tially deactivated in the presence of sulfur-containing gases. In cont rast, platinum was more active for the same reaction in the presence o f sulfur-containing gases. Both metals were found to promote the oxida tion 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.