Fluid catalytic cracking process

A fluid catalytic cracking unit (FCCU) for production of petrochemical feedstock fractions comprises a first reactor to receive a stream of desalinated crude oil and produce a first cracked product stream; a second reactor to receive a stream of light cracked naphtha (LCN) and produce a second cracked product stream; a third reactor to receive a bottom stream and produce a third cracked product stream; and a fractionating column and gas concentration section to separate components of the first cracked product stream, the second cracked product stream, and the third cracked product stream to produce, upon further fractionation, Ethylene, Propylene, Butylene, Benzene, Toluene and Xylene as the petrochemical feedstock fractions.