Method of circulating catalyst between a catalyst regenerator and an external catalyst cooler

Abstract

This invention relates to efficiently regenerating catalyst particles by minimizing the formation of localized 'hot spots' and 'cold spots' in a regeneration zone. Specifically this invention relates to a method for controlling regenerator temperature in an oxygenates-to-olefins system, comprising the steps of: contacting an oxygenate feed in a reactor with a catalytically effective amount of molecular sieve-containing catalyst under conditions effective for converting said oxygenate to a product containing light olefins and forming a coked catalyst; contacting a portion of the coked catalyst in a regenerator, having a catalyst bed height (H), an inlet height (H), and an outlet height (H), with an oxygen-containing regeneration medium under conditions effective to at least partially regenerate the coked catalyst; and conducting a portion of the catalyst from the regenerator to a catalyst cooler to form a cooled catalyst portion, wherein His greater than H.