Ethylation of benzene with ethanol to ethylbenzene using synthesized HZSM-5 catalysts: effect of synthesis conditions

Abstract

Ethylbenzene (EB) is an important raw material in the petrochemical industry for the production of styrene by the catalytic dehydrogenation. The commercial processes to produce EB is the alkylation of benzene with ethylene. However, the direct use of ethanol as an alkylating agent has also become a suitable substitute for ethylene. Ethanol has gained more attention because it provided a longer catalyst life and higher production efficiency when it was used for the ethylation of benzene accompanied by a HZSM-5 catalyst. In this work studied the ethylation of benzene with ethanol to ethylbenzene (EB) over synthesized HZSM-5 catalysts with SiO₂/Al₂O₃ molar ratios of 157 to 195. The catalysts were characterized by various techniques and tested using a fixed-bed reactor at different reaction temperatures (400 - 500ºC), B/E ratio (2:1, 4:1 and 6:1), and WHSV (15 and 20 h¯¹). The results showed that the HZ5-195(3) catalyst with SiO₂/Al₂O₃, molar ratio of 169 was the most suitable catalyst in terms of benzene conversion and EB selectivity. Moreover, it was observed that the reaction condition; T=500ºC, B/E=4, and WHSV = 20 h¯¹ would be optimal for ethlylation of benzene with ethanol to EB over such a catalyst