KINETICS OF COMBUSTION OF CARBON IN CARBONACEOUS DEPOSITS ON ZEOLITE CATALYSTS FOR FLUID CATALYTIC CRACKING UNITS (FCCU) - COMPARISON BETWEEN PT AND NON PT-CONTAINING CATALYSTS

The combustion kinetics of carbon in carbonaceous deposits, or 'coke', on fluid catalytic cracking (FCC) zeolite catalysts was studied under differential reactor conditions, in an air stream, at atmospheric pre ssure, and in a temperature range of 550-710 degrees C. Catalysts with and without Pt were first coked and then subsequently regenerated. Al though platinum catalyzes the conversion of CO to CO2, experimental fi ndings revealed the lack of any catalytic effect of Pt on carbon burni ng rates. Experiments were also conducted with an equilibrium catalyst from a commercial FCC unit. This catalyst exhibited higher burning ra tes than catalysts containing coke deposited in a laboratory reactor. It is believed, however, that the higher burning rate is due to the hi gh metal content of heavy metals like V and Ni. (C) 1998 Elsevier Scie nce Ltd. All rights reserved.