Gasoline sulfur reduction in fluid catalytic cracking

In a fluid catalytic cracking process in which a heavy hydrocarbon feed comprising organosulfur compounds is catalytically cracked to lighter products by contact in a cyclic catalyst recirculation cracking process with a circulating fluidizable catalytic cracking catalyst inventory consisting of particles having a size ranging from about 20 to about 100 microns, comprising:

• (i) catalytically cracking the feed in a catalytic cracking zone operating at catalytic cracking conditions by contacting feed with a source of regenerated cracking catalyst to produce a cracking zone effluent comprising cracked products and spent catalyst containing coke and strippable hydrocarbons;
• (ii) discharging and separating the effluent mixture into a cracked product rich vapor phase and a solids rich phase comprising spent catalyst;
• (iii) removing the vapor phase as a product and fractionating the vapor to form liquid cracking products including gasoline,
• (iv) stripping the solids rich spent catalyst phase to remove occluded hydrocarbons from the catalyst,
• (v) transporting stripped catalyst from the stripper to a catalyst regenerator;
• (vi) regenerating stripped catalyst by contact with oxygen containing gas to produce regenerated catalyst;
• and
• (vii) recycling the regenerated catalyst to the cracking zone to contact further quantities of heavy hydrocarbon feed,
• the improvement which comprises
• reducing the sulfur content of a the gasoline portion of the liquid cracking products, by catalytically cracking the feed fraction at elevated temperature in the presence of a product sulfur reduction catalyst which comprises a porous molecular sieve having (i) a first metal component which is within the interior pore structure of the molecular sieve and which comprises a metal in an oxidation state greater than zero and (ii) a second metal component which is within the interior pore structure of the molecular sieve and which comprises cerium.