FCC gasoline desulfurization using a ZSM-5 catalyst: Interactive effects of sulfur containing species and gasoline components

This study evaluates the influence of gasoline hydrocarbon components on thiophene conversion over H-ZSM5 zeolite. Experiments are carried out in a CREC fluidized riser simulator under mild conditions using thiophene/hydrocarbon mixtures as representatives of gasoline. Results show a high and selective thiophene conversion, forming H2S, aromatics, alkyl-thiophenes, benzothiophene, and coke. It is also found that gasoline octane number is enhanced and olefin content reduced. This is accomplished with minimum gasoline losses. On the basis of the data reported it is hypothesized that thiophene conversion takes place via ring opening and alkylation, with gasoline hydrocarbon components having key roles as hydrogen donors in thiophene ring opening reactions as well as co-reactants in thiophene alkylation. These observations are in good agreement with previous thermodynamic and kinetic analysis developed using sulfur containing compounds by the CREC-UWO research group [4,10].