FCC gasoline desulfurization by pervaporation: Effects of gasoline components

Detailed investigations of the influence of fluid catalytic cracking (FCC) gasoline components on membrane performance have been rarely conducted. This is related to the fact that gasoline is a complex mixture composed of hundreds of components. It is also necessary to investigate the composition change of gasoline components during membrane treatment, since the research is helpful in analyzing the octane number loss. Typical hydrocarbon and sulfur components were studied for their effect on pervaporation (PV) performance and swelling degree through polyethylene glycol (PEG) membranes. The results demonstrated that the increasing aromatics, alkenes and sulfur content in feed led to the increased flux and decreased sulfur enrichment factor due to the exacerbated membrane swelling. However, alkanes and cycloalkanes had little influence on membrane swelling and PV performance. Membrane performance comparison for model compounds and gasoline feed was also conducted to examine above conclusion. Hydrocarbon group, sulfur species distribution and octane number of feed and permeate sample were obtained by gas chromatography (GC) analysis, and the results suggested that aromatics content increased and other hydrocarbon groups content changed little through PV process. Additionally, the overall analysis indicated that higher sulfur enrichment factor and lower flux were usually achieved with lower sulfur level feed.