Transalkylation and disproportionation (TADP) of toluene and C-9 aroma
tics from a commercial stream have been studied over a zeolite possess
ing a three-dimensional, 12-membered ring pore system. The study encom
passed the effect of C-9 aromatics content in feed on TADP. Formation
of xylenes was maximum with a feed containing 50: 50 toluene and C-9 a
romatics. In order to understand the role of different C-9 aromatics i
n TADP, experiments using individual C-9 aromatics with and without to
luene mixture as feed were carried out. An interesting observation of
these experiments was that ethyltoluenes produced xylenes through disp
roportionation of toluene generated from their deethylation. The total
yield of xylenes was much less than that obtained from trimethyl benz
enes. A reaction scheme accounting all the reactions taking place duri
ng TADP is proposed.