The alkylation of ethylbenzene in the presence of other aromatic compo
unds has been studied over a pore size regulated MFI zeolite. The arom
atic compounds chosen were of various kinetic diameter, hence they wer
e expected to hinder the movement of reactant molecules both on the ex
ternal surface and within zeolite channels. It was observed that some
of the aromatic compounds got alkylated along with ethylbenzene. The e
ffects of varying the concentration of aromatic compounds in the feed
on ethylbenzene conversion and product distribution have been discusse
d.