CATALYTIC CYCLES FOR HYDROCARBON CRACKING ON ZEOLITES

Catalytic cracking of hydrocarbons takes place via elementary reaction s such as initiation processes to form carbenium ions, olefin adsorpti on/desorption steps, isomerization, beta-scission, oligomerization, an d hydride ion transfer steps. These elementary steps involving reactiv e carbenium ion surface intermediates are the essential components of catalytic cracking that lead to various catalytic cycles and their cor responding stoichiometric reactions. This review outlines methods used to quantify reaction kinetics for catalytic cracking and describes ho w the rates of specific catalytic cycles are controlled by catalyst tr eatment (e.g., steaming) and process conditions (e.g., conversion and temperature).