Patent ID: 7270739

Claim:
A process for producing increased amounts of propylene from naphtha-boiling-range feedstreams comprising: (a) fractionating a naphtha-boiling-range feedstream to produce at least a C 6 -rich fraction and a C 6 -lean fraction, wherein the C 6 -rich fraction contains at least 50 wt % C 6 compounds; (b) injecting at least a portion of said C 6 -lean fraction into a reaction stage, said reaction stage containing a cracking catalyst comprising at least one molecular sieve having an average pore diameter of less than about 0.7 nm wherein said C 6 -lean fraction contacts said cracking catalyst under effective cracking conditions thereby resulting in at least a product stream; (c) injecting at least a portion of said C 6 -rich fraction into the reaction stage at a place downstream from the C 6 -lean fraction; (d) fractionating at least a portion of said product stream of step (b) to produce at least a fraction rich in propylene; and (e) collecting at least a portion of the fraction rich in propylene.