to remove fuel gases that contain by products of coke combustion via outlet 6 the regenerated catalyst is recycled to mixing zones 70 a and 70 b through downer lines 1 a and 1 b respectively the catalyst used in the process described herein can be conventionally known or future developed catalysts used in fcc processes e g zeolites silica alumina carbon monoxide burning promoter additives bottoms cracking additives light olefin producing additives and any other catalyst additives routinely used in the fcc process in certain embodiments a suitable cracking zeolites in the fcc process include zeolites y rey usy and re usy for enhanced naphtha cracking potential a preferred shaped selective catalyst additive can be employed e g as used in fcc processes to produce light olefins and increase fcc gasoline octane is zsm 5 zeolite crystal or other pentasil type catalyst structure this zsm 5 additive can be mixed with the cracking catalyst zeolites and matrix structures in conventional fcc catalyst and is particularly suitable to maximize and optimize the cracking of the crude oil fractions in the downflow reaction zones accordingly the process herein uses a crude oil as a raw material with no preprocessing or minimal preprocessing to reduce the conradson carbon residue content and the total metals content for direct conversion into light olefins within the fcc process having two down flow reactors operating in high severity modes a particular advantage concerns the amount.