Patent ID: 7682501

Claim:
A fluid catalytic cracking process for increasing yields of C 3 and C 4 hydrocarbons, comprising: (a) injecting a main feed comprising hydrocarbons with boiling points in the range of 400° F. to 1150° F. into a riser reactor of a fluid catalytic cracking apparatus through a set of main feed injectors, the riser reactor including a downwardly slanted portion and a vertical portion disposed downstream from the downwardly slanted portion, and (b) injecting a light feed comprising hydrocarbons with boiling points of no more than about 440° F. into said fluid catalytic cracking apparatus through a first light feed injector disposed at the lower end of the riser reactor and through a second light feed injector disposed on the downwardly slanted portion of the riser reactor upstream from the first light feed injector, the first and second light feed injectors being positioned at locations at which catalyst flow changes direction and is not uniform.