CATALYTIC CRACKING OF A BINARY MIXTURE ON ZEOLITE CATALYSTS

The catalytic cracking of 1-methylnaphthalene individually and in binary combination with n-hexadecane on zeolite catalysts is reported. It is shown that for cracking of the polyaromatic feed over HY zeolite, the major processes are isomerisation and disproportionation. In the binary mixture, product selectivity is unchanged when compared to cracking of the individual components. The relative reactivity of the linear alkane in the presence of the alkyldiaromatic is significantly reduced, and may be attributed to blockage of either zeolite pores or acid sites on the zeolite surface. For cracking of the binary mixture over a combination of HY and HZSM-5 zeolites, shifts in product selectivity when compared to those for cracking over the faujasite catalyst alone, suggest that the pentasil additive acts to suppress bimolecular hydrogen transfer processes on HY zeolite.