External method for reducing transverse oxygen gradients in FCCU regeneration

摘要

A minor portion of the regeneration gas used to regenerate spent fluid catalytic cracking catalyst is employed to combust volatile hydrocarbons in mixture with said spent catalyst prior to said mixture entering the regeneration zone. This serves to reduce and/or minimize transverse oxygen gradients in the dense phase catalyst bed and in the effluent gases therefrom such that excessive or undesirable afterburning in the dilute catalyst phase can be minimized or eliminated.