Kinetics of the oxidation of sulphur dioxide over vanadium pentoxide

Abstract

The oxidation of sulphur dioxide over pure vanadium pentoxide has been studied in a back-mix flow reactor under conditions in which both heat and mass transfer resistances to and from the catalyst were minimised, in order to obtain a closer insight into the chemical stages of the reaction. The results were fitted by a non-linear regression technique to the empirical equation Rate =kp^x(SO₂)p^y(O₂)p^z(SO₄). The indices of the partial-pressure terms are temperature-dependent, and possible reasons for this behaviour are discussed. A forced fit to a single mean rate equation over the temperature range 416–490°C yielded an Arrhenius type plot with an activation energy about 49 kcal. mole^–1. While no fundamental significance attaches to this figure, it is higher than that previously noticed, and a possible reason for this is suggested.