Regeneration of platinized alumina reforming catalysts by the use of chlorine

Abstract

1. Treatment of spent platinized alumina catalyst with a mixture of air and chlorine (chlorine concentration, 0.4 to 5.0% by volume) at a temperature of 350° to 500° C allows one to significantly raise its activity and improve its selectivity. 2. Treatment of spent catalyst with chlorine causes a notable change in the chemical composition of the catalyst; the chlorine content is increased and the content of certain metallic impurities is decreased, especially iron. 3. Change in the conditions of treatment of the catalyst with chlorine (temperature, chlorine concentration, space velocity of the feed of chlorine-containing gas, duration of chlorination) within indicated ranges does not exert an effect on the chemical composition established after chlorination or the catalytic properties of the catalyst. 4. To lower the cracking ability of the catalyst after chlorination it is necessary to treat it with air at 500°C until a chlorine content of 0.8–0.9% by weight in it is established.