Thermodynamic analysis of reactions of catalytic heterocyclization of C 6-hydrocarbons and hydrogen sulphide to alkylthiophenes

Abstract

1. 1. Thermodynamic analysis of the reaction between C 6-paraffins and olefins of normal and isostructure with hydrogen sulphide at 820°K under ambient pressure on a Cr catalyst, shows that the equilibrium constant of the main heterocyclization reaction differs markedly from equilibrium constants of side reactions. 2. 2. The formation of ethyl- and dimethylthiophenes from hydrogen sulphide and hex-1-ene, 2-methylpent-1-ene, 2-methylpent-2-ene, 4-methylpent-1-ene, 4-methylpent-2-ene and 2-methylpentane reaches equilibrium with yields of 82 to 98%, while for 2,3-dimethylbutane-72·4% of equilibrium values. 3. 3. Equilibrium yields of the reaction products of heterocyclization and dehydro-cyclization were calculated during the reaction of n-hexane with H 2S. At 820°K yields of alkylthiophenes are 82·8% and of benzene, 81% while at 750°K they are only 24·4 and 10% of equilibrium values, respectively.