CO-CATALYZED CONVERSION OF H2S TO H-2+S .1. REACTION BETWEEN CO AND H2S

The first step in the two-step CO-catalyzed conversion of H2S to H-2 a nd sulfur, reactions 1 and 2, has been studied in order to establish t he optimal experimental conditions for the reaction. Without a catalys t, H2S conversions of the order of only 1-2% could be achieved. NiS on alumina proved to be an efficient catalyst, and at 267 degrees C, H2S conversions reached 52% or 100% of the thermodynamic limit. Small amo unts of CO2 and CS2 have also been detected among the products. In com parative experiments using CoS on alumina as the catalyst, up to 67% c onversion, representing 100% of the thermodynamic equilibrium H-2 yiel d, could be achieved at a substantially lower temperature, 177 degrees C. Furthermore, formation of CO2 and CS2 was found to be negligible ( <1%) at this low temperature, eliminating the need for the suppression of the COS disproportionation reaction.