Kinetics of the desulfurization of thiophene: Reactions of thiophene and butene

Abstract

The kinetics of the desulfurization of thiophene on a representative CoOMoO 3 Al 2 O 3 were studied in the temperature range of 250–313 °C for partial pressures of thiophene from 20 to 160 Torr and for partial pressures of hydrogen from 550–750 Torr. Rates of butene hydrogenation were determined in the same experiments for butene partial pressures from 3 to 31 Torr. In addition, separate experiments were carried out on the direct hydrogenation of 1-butene in the absence of thiophene on the same catalyst. Results are also presented for kinetics of the isomerization of 1-butene. The rate correlations developed for these data are generally consistent with the view that the primary hydrogenolysis of thiophene and the hydrogenation of butene occur on different sites, although there is some parallelism of the response of these reactions to pyridine poisoning. A combined model is presented to represent the contributions of strongly and reversibly chemisorbed hydrogen in the reaction of thiophene.