ZEOLITE-BETA CATALYZED C-7 AND C-9 AROMATICS TRANSFORMATION

Transformation of commercial C-7 and C-9 aromatic streams to xylenes o ver zeolite beta have been studied. These results have been compared w ith those obtained on other zeolites like ZSM-5 and mordenite. The eff ect of variations in reaction parameters like temperature, weight hour ly space velocity (WHSV) and feed composition on xylene formation was considered. The trimethylbenzenes became disproportionated, while ethy ltoluenes underwent de-ethylation followed by disproportionation of pr oduct toluene. The highest yield of xylenes was obtained with a feed c onsisting of nearly equal proportions of toluene and 1,3,5-trimethylbe nzene. Lower WHSV and higher temperature enhanced the formation of xyl enes.