AM-00-23 CORRELATION OF FEEDSTOCK CHEMICAL PROPERTIES WITH CONVERSION AND COKE YIELD IN HEAVY ATMOSPHERIC RESIDUE CRACKING

Description:

Catalytic cracking feed conversion factors are useful tools for crude oil value estimates and FCC unit optimization. Methods that calculate such factors for feedstocks boiling in 320°C to 550°C range are available in the literature [1,2] . With the start-up of PETROBRAS residue crackers, processing feedstocks with a substantial portion heavier than the VGO endpoint, new analytical procedures for residue characterization, capable of generating conversion and coke selectivity factors for extremely heavy feedstocks, were necessary. A set of fifteen atmospheric residues (ATRs), covering the whole range of crude oils processed in PETROBRAS refineries was characterized by advanced and traditional methods, and then ran in a circulating pilot riser with equilibrium catalyst. Kinetic constants of a three lump catalytic cracking model were calculated with the pilot riser results and correlated with the feed characterization parameters, allowing for conversion and selectivity prediction based on feed properties.