Kinetic study of alkylation of benzene with ethanol over bimetallic modified HZSM-5 zeolite catalyst and effects of percentage metal loading

Abstract

Alkylation of benzene with ethanol was analyzed using shape selective boron–magnesium bimetallic HZSM-5 (Si/Al = 90) zeolite catalyst. The alkylation of benzene with ethanol (2:1 by volume) produces ethylbenzene as primary product and others like 1, 2-Diethylbenzene, 1, 4-Diethylbenzene, and xylene mixtures as secondary products. The physiochemical properties of catalyst were characterized by XRD, BET, TGA, FTIR, NH3-TPD, and FE-SEM. The feed and products were analyzed by gas chromatography and mass spectroscopy. B–Mg bimetallic catalysts supported on HZSM-5 zeolite catalyst with SAR = 90 were synthesized by the incipient wetness impregnation method and examined for alkylation of benzene with ethanol. Total metal loading of 5, 10, and 15% was used for catalyst synthesis. The highest selectivity of ethylbenzene (76.22%) was obtained by (Mg + B)-15%-HZSM-5 and the lowest ethylbenzene selectivity (49.15%) was obtained by (Mg + B)-5%-HZSM-5 using 2:1 benzene-to-ethanol ratio by volume. A reaction scheme with three parallel routes leading to the formation of ethylbenzene, diethylbenzene, and triethylbenzene was considered for the kinetic study. The kinetic parameters were determined using Langmuir–Hinshelwood–Hougen–Watson (LHHW)-type kinetic model. LHHW model could satisfactorily correlate the rate data and this model gives good fit between the experimental and calculated data.