Patent ID: 6113776
Filing Date: 2000-09-05
Classification: C10G

Abstract:
A fluidized catalytic cracking process for the principally thermal cracking of a secondary feed comprising naphtha having components in a boiling range of from 350-430.degree. F. and the principally catalytic cracking of a primary feed comprising a vacuum gas oil containing hydrocarbons in a boiling range of from 600-1100.degree. F. in an arrangement of separate reaction conduits, the process comprising:a) passing the secondary feed and regenerated catalyst particles to an upstream portion of a thermal contacting conduit and transporting the regenerated catalyst and secondary feedstock through the thermal contacting conduit to convert the feed to a thermal fluid and producing a first quantity of contacted catalyst particles by the deposition of coke on the regenerated catalyst particles;b) discharging contacted catalyst particles and the thermal fluid from a discharge end of the thermal contacting conduit;c) passing the contacted catalyst particles to a blending vessel and blending a carbonized catalyst with the contacted catalyst to produce a blended catalyst stream in substantial thermal equilibrium;d) passing the blended catalyst stream from the blending vessel into a catalytic contacting conduit and contacting the blended catalyst mixture in the catalytic contacting conduit with the primary feed to produce a mixture of catalyst and catalytic fluid;e) separating catalyst from the mixture in a primary catalyst separation zone and recovering a primary effluent stream from the primary catalyst separation zone;f) recovering spent catalyst having a minimum coke content of 0.7 wt % for regeneration in a regeneration zone; and,g) passing the primary effluent and, optionally, a separately recovered portion of the thermal fluid to a fluid separation zone and recovering an olefin product stream comprising ethylene and/or propylene and a primary product stream.