SELECTIVE FORMATION OF CYMENES OVER LARGE-PORE ZEOLITES

The catalytic properties of zeolite beta in the isopropylation of tolu ene, and transalkylation of toluene with cumene in the production of c ymenes are reported. The influence of various reaction parameters such as temperature, space velocity, mole ratio of the reactants and time- on-stream are discussed. The activity and selectivity of zeolite beta is compared with those of mordenite and ZSM-12. Zeolite beta did not e xhibit any product shape selectivity for any of the cymene isomers. Ho wever, the stable activity and higher selectivity to cymenes in zeolit e beta is attributed to its highly siliceous nature and interconnectin g channel system.