Upgrading naphtha in a single riser fluidized catalytic cracking operation employing a catalyst mixture

摘要

The present invention discloses a catalytic cracking operation featuring a single riser in which a variety of hydrocarbon conversion reactions takes place, a stripping unit in which entrained hydrocarbon material is removed from catalyst and a regeneration zone in which spent cracking catalyst is regenerated, which comprises: (a) converting a relatively high boiling charge material introduced to the riser at a lower level thereof in the presence of a first catalyst component which is an amorphous cracking catalyst and/or a large pore crystalline silicate cracking catalyst to provide lighter products including significant quantities of naphtha; and, (b) converting a naphtha charge material introduced to the riser at a higher level thereof in the presence of a second catalyst componet which is a shape selective medium pore crystalline silicate zeolite catalyst to provide a relatively high octane gasoline product.