Controllable alkylation of benzene with mixed olefins for producing C8-C15 aromatics in jet fuel

Abstract

C8-C15 aromatics are used widely as key components of jet fuel, whereas effectively producing these aromatic components remains a big challenge. We reported the oriented synthesis of C8-C15 aromatic components in jet fuel by alkylation of benzene with mixed ethylene and propylene in vapor-phase over nanosize ZSM-5 (N-ZSM-5) catalyst. The selectivity and yield of aromatics, mainly of carbon number ranging from 8 to 15, could be enhanced by decreasing the particle size of ZSM-5, owing to the faster mass transfer and shorter intraparticle diffusion route for reactants and target products during the reaction process, as well as by increasing the acid strength via decreasing the Si/Al molar ratio, thus improving the alkylation performance conspicuously. In addition, mesopore volume of N-ZSM-5 zeolite showed an increase tendency with decreased particle size, contributing to the carbon chain growth and diffusion of target products. The resultant N-ZSM-5 catalyst showed superior benzene conversion of 40.3%, ethylene and propylene conversion of 99.5% and 99.2%, with aromatic C8-C15 selectivity and yield of 94.8% and 54.9%, respectively, under the optimized reaction conditions.