Kinetics of the catalytic removal of the sulphur components from the light cycle oil of a catalytic cracking unit

First order kinetics for the hydrodesulphurization of 40 sulphur components of the benzothiophene and dibenzothiophene families were determined using experimental data obtained with a light cycle oil. Substituents next to the sulphur atom reduce the reactivity with respect to the nonsubstituted component. Hougen Watson rate equations for substituted dibenzothiophenes were related to those for the head of the family, dibenzothiophene, through global multiplication factors f(sigma sDBT) and f(tau). These factors are the products of the electronic and steric effects of the substituents on the adsorption equilibrium constants and of the electronic effects on the rate coefficients. They were evaluated for a number of substituted dibenzothiophenes.