Method for reducing the temperature in a regeneration zone of a fluid

Abstract

A method for operating a fluid catalytic cracking unit comprising a regeneration zone and a reaction zone with a relatively reduced temperature in the regeneration zone while processing a hydrocarbon feedstock having a 50 volume percent distillation temperature greater than about 500.degree. F. which method comprises contacting the feedstock in a reaction zone with a mixture of regenerated fluidizable cracking catalyst and fluidizable low coke make solid particles comprising a refractory inorganic oxide in a ratio of low coke make solid particles to cracking catalyst from about 1:100 to about 10:1, the low coke made solid particles having a surface area of less than about 5 m.sup.2 /g and a coke making capability of less than about 0.2 weight percent coke on the spent low coke make solid particles in the ASTM standard method for testing cracking catalyst by microactivity test (MAT); separating the resulting vaporized hydrocarbon products from the mixture of deactivated fluidizable cracking catalyst and fluidizable low coke made solid particles; recovering the resulting vaporized hydrocarbon products; passing the mixture of cracking catalyst and low coke made solid particles to the regeneration zone for regeneration by removal of coke; and passing the resulting regenerated mixture of cracking catalyst and low coke make solid particles from the regeneration zone to the reaction zone to contact the feedstock as described above whereby the regeneration zone temperature is maintained at a reduced temperature as compared to an equivalent operation without the use of the fluidizable low coke make solid particles while simultaneously not affecting the operation of the reaction zone.