CAN MACROSCOPIC PARAMETERS, SUCH AS CONVERSION AND SELECTIVITY, DISTINGUISH BETWEEN DIFFERENT CRACKING MECHANISMS ON ACID CATALYSTS

n-heptane cracking has been carried out for very short time periods on an established reaction mechanism which includes the following group of stream reactions on different zeolites: Initiation reactions (proto lytic cracking), charge isomerization, chain isomerization, hydride tr ansfer, beta-scission-alkylation, desorption-adsorption, and hydrogen transfer-cyclization. It has been observed that a given experimental d istribution of products can be explained by more than just one reactio n scheme. This does not allow one to clearly distinguish the fraction of reactant which disappears via monomolecular initiation reactions wi th respect to bimolecular hydride transfer reactions. (C) 1997 Academi c Press.