Method for reducing chloride emissions from a moving bed catalyst regeneration process

Abstract

A method is disclosed for decreasing the emissions of chlorine-containing species from a moving bed process for regenerating spent catalyst particles with a recycle gas stream. A recycle gas stream contacts spent catalyst particles at regeneration conditions, thereby producing a flue gas stream. The flue gas stream which contains chlorine-containing species contacts spent catalyst particles at sorption conditions. The sorption conditions are characterized by the substantial absence of carbon combustion. The spent catalyst particles sorb the chlorine-containing species from the flue gas stream, thereby producing the recycle gas stream. A portion of the recycle gas stream is vented from the process. This method captures and returns to the process the chlorine-containing species that would be lost from the process and that would need to be replaced by the injection of make-up chlorine-containing species. This method results in a significant savings in capital and operating costs of the process. This method is adaptable to many processes for the catalytic conversion of hydrocarbons in which deactivated catalyst particles are regenerated in a moving bed.