Catalyst demetallization with a reductive SO2 wash

摘要

A process for the removal of metal poisons such as nickel, iron and/or vanadium from a hydrocarbon conversion catalyst which includes the step of contacting the catalyst with a reductive wash medium comprising an aqueous, preferably saturated, solution of SO2 to remove at least a portion of the metal poisons. The vanadium and nickel metals may be recovered from the resultant used wash solution for possible metallurgical use. The SO2 reductively washed catalyst may also be subjected to a subsequent oxidative wash such as hydrogen peroxide wash prior to its return to the hydrocarbon conversion process.