Patent ID: 7374662

Claim:
A process for conversion of a hydrocarbon feedstock comprising at least one relatively heavy main feedstock comprising hydrocarbons with a boiling point above approximately 350° C., and at least one relatively light secondary feedstock comprising hydrocarbons with a boiling point below approximately 320° C., wherein, said relatively heavy main feedstock, representing at least 50 wt. % of said hydrocarbon feedstock, is cracked in at least one fluidized-bed catalytic cracking reactor in the presence of a cracking catalyst, said relatively light secondary feedstock is cracked in a fluidized bed with the same cracking catalyst, separately or mixed with said main feedstock, said secondary feedstock comprising olefins with at least 8 carbon atoms which were produced in at least one stage of oligomerization of a feedstock comprising light olefins with 4 and/or 5 carbon atoms, followed by a fractionation stage to separate a part at least of the oligomerization effluent, which part is evacuated directly without feeding the catalytic cracking reactor, said evacuated part comprising at least a part of the oligomers produced, said part comprising di-isobutene and/or tri-isobutene, effluents from cracking of the main feedstock and of the secondary feedstock are fractionated in a common fractionation zone, and the catalyst used for cracking the main feedstock and that used for cracking the secondary feedstock are regenerated in a common regeneration zone, to produce at least gasoline and propylene, separating the gasoline, and wherein at least a part of said evacuated fraction comprising di-isobutene is added to at least a part of the gasoline produced directly by cracking, to produce a gasoline base.