Ethylation of ethylbenzene with ethanol over mordenite-based catalysts: Effects of acidity, desilication and kinetics analysis

This communication reports the kinetics analysis of ethylation of ethylbenzene (EB) with ethanol over large pore size mordenite catalysts. In this regard, two different catalyst samples are selected with SiO₂/Al₂O₃ = 180 and 21, respectively. The higher acidic sample (SiO₂/Al₂O₃ = 21) is desilicated to study the effects of desilication on the EB ethylation. The EB ethylation experiments are conducted in a fluidized CREC Riser Simulator using equimolar amount of EB and ethanol as feed. Under the studied reaction conditions, diethylbenzene (DEB) is the main product while a small amount of benzene and lighter gases are also produced. In addition to DEB, the higher acidic mordenite sample also produces benzene via dealkylation of EB. On the other hand, the large pore size mordenite sample gives triethylbenzene (TEB) as a secondary alkylation product. The desilicated sample shows slightly higher DEB selectivity but the EB conversion with this sample is low. Power law-based kinetics evaluation also confirms the above observations by showing low activation energy for DEB formation while high activation energies for benzene and TEB formations.