TRANSALKYLATION AND DISPROPORTIONATION OF TOLUENE AND C-9 AROMATICS OVER ZEOLITE-BETA

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.