Catalytic desulfurization of gasoline via dehydrosulfidation

Abstract

This study presents a potentially attractive route for the desulfurization of gasoline via catalytic dehydrosulfidation, removal of hydrogen sulfide from sulfur-containing molecules. The proposed study involves thermodynamic calculations and experimentation in a fluidized riser simulator at the Chemical Reaction Engineering Centre (CREC) at the University of Western Ontario. A ZSM-5 catalyst was used because of its demonstrated performance for the dehydration of methanol, a parent reaction with an expected similar reaction network. The catalyst was characterized using several techniques, including (a) BET (surface area), (b) ammonia temperature-programmed desorption (concentration of acid sites), and (c) SEM-EDX (sodium content) at various stages of catalyst preparation. The catalytic dehydrodesulfidation reaction was studied using a model compound (ethyl mercaptan, EM) in n-octane (n-Cg) to represent sulfur-contaminated gasoline. The experimental data obtained were successfully fitted using a kinetic model representing the rate of disappearance of the sulfur-containing species.