Initial heats of H2S adsorption on activated carbons: Effect of surface features

The sorption of hydrogen sulfide was studied on activated carbons of variou s origins by means of inverse gas chromatography at infinite dilution. The conditions of the experiment were dry and anaerobic. Prior to the experimen ts the surface of some carbon samples was oxidized using either nitric acid or ammonium persulfate. Then the structural parameters of carbons were eva luated from the sorption of nitrogen. From the IGC experiments at various t emperatures, heats of adsorption were calculated. The results showed that t he heat of H2S adsorption under dry anaerobic conditions does not depend on surface chemistry. The dependence of the heat of adsorption on the charact eristic energy of nitrogen adsorption calculated from the Dubinin-Raduskevi ch equation was found. This correlation can be used to predict the heat of H2S adsorption based on the results obtained from nitrogen adsorption. (C) 1999 Academic Press.