CATALYTIC CRACKING OF A GIPPSLAND REDUCED CRUDE ON ZEOLITE CATALYSTS

Cracking reactions of a Gippsland reduced crude have been investigated at 520-degrees-C over HY and HZSM-5. Gasolines with similar character istics can be obtained on both zeolites, although the mechanistic rout es to these products are quite distinct. Changes in aromatic product s electivities are consistent with the zeolite pore geometries. Minor qu antities of aromatics are formed via hydrogen transfer processes invol ving product olefins and naphthenes over the faujasite and the cyclisa tion (and to a lesser extent oligomerisation) cf olefinic species on t he pentasil. Dehydrogenation of naphthenic species in the feedstock is also important for aromatic formation. While paraffins are formed via hydrogen transfer processes together with cracking and isomerisation of feed paraffins on HY, only the latter route can explain formation o f saturated species on HZSM-5. The removal of linear paraffins from th e GRC was traced as a function of conversion on HY. It was found that the relative reactivity of the linear paraffins increased monotonicall y with paraffin chain length. (C) 1994 Academic Press. Inc.