Alkylation of benzene with ethanol to ethylbenzene using commercial HZSM-5 catalysts

Abstract

Ethylbenzene (EB), usually produced via alkylation of benzene with ethylene, is one of the most important alkylbenzenes because it is a key intermediate in the manufacture of styrene which is one of the most important industrial monomers. Some investigations have been in search of other alkylating agents as a substitute for ethylene. The direct use of ethanol as an alkylating agent has gained more attention as ethanol has become surplus to petroleum industry due to the underestimated production with high efficacy. In this work, the reaction was carried out in a fixed-bed continuous down-flow reactor at atmospheric pressure by using commercially available HZSM-5 zeolite catalysts with Si02/Al203 ratios of 23 to 195 under various conditions: temperature (300 c to 500 ๐C), benzene/ethanol (B/E) ratio (1 to 4), and WHSV (5 h'1 to 20 h'1). The results indicate that a temperature of 300 .c, a WHSV of 20 h'1, and a B/E feed ratio of 4 would be the optimal parameters for alkylation of benzene with ethanol to EB by using the commercial HZSM-5 catalyst with SiO2/AI2O3 ratio of 23. In addition, the commercial HZSM-5 catalyst with SiO2/AI2O3 ratio of 23 was found to be active up to 30 h before its catalytic activity was declined due to the coke formation.