Conversion of carbon monoxide

Claim 1

In a process for continuous catalytic cracking of hydrocarbons by contacting said hydrocarbons in a reactor with a circulating inventory of active particle form cracking catalyst under cracking conditions to produce lighter hydrocarbons and concurrently deposit on said catalyst an inactivating carbonaceous deposit, transferring catalyst so inactivated to contact in a regenerator with an oxidizing gas for combustion of said deposit to regenerate said active catalyst and product oxides of carbon as combustion products for discharge from the system, returning so regenerated active catalyst to said reactor for contact with hydrocarbons and maintaining a desired quantity of catalyst at a desired level of cracking activity as catalyst is lost from said inventory by attrition or declines in activity with time in service by adding fresh catalyst to said circulating inventory; the improved method of adding said fresh catalyst to maintain quantity and activity of said inventory and concurrently provide activity for oxidizing carbon monoxide to carbon dioxide in said regenerator which comprises supplying said fresh catalyst as an intimate and substantially uniform blend of a minor portion of particles containing from 20 to 80 ppm of platinum, iridium, osmium, palladium, rhodium, ruthenium or rhenium and a major portion of active cracking catalyst, the proportions of said minor and major portions being such that said blend contains no more than 10 ppm of said metal, the particles of said minor portion being constituted by porous solid impregnated with said metal which particles have been calcined in air without added steam.