High octane gasoline prodn. by fluid catalytic cracking - using low sodium zeolite with low alkali content hydrocarbon charge

摘要

In the fluid catalytic cracking of a hydrocarbon charge, the improvement comprises using fresh zeolite catalyst particles contg. less than 1.5 wt.% alkali metal oxide, maintaining the alkali content of the charge below 0.5 ppm and controlling the amt. of alkali metal oxide that comes into contact with catalyst inventory throughout cracking, steam stripping and regeneration so that the alkali metal oxide content of the equilibrium catalyst is maintained below 2%, based on the weight zeolite in the fresh catalyst. By controlling the Na content of the ultra stable zeolite used, the octane rating of the resulting gasoline fraction is maintained at a high level over repeated cycles of charge contact and regeneration.