Cracking catalysts containing phosphate treated zeolites, and method of

Abstract

A process for preparing a zeolite containing catalyst which has improved attrition resistance, and causes improved octane with no appreciable change in dry gas and coke make when used during catalytic cracking processes is disclosed. The catalyst is prepared by modifying the zeolite with a phosphate containing solution. The zeolite preferably includes an REY large pore zeolite. Treatment of the zeolite is best accomplished in an aqueous solution, at a pH range from about 2 to about 6, containing a water soluble phosphate compound. The phosphate treatment of the zeolite is carried out by deagglomerating the zeolite in an aqueous mixture in the presence of an aqueous phosphate containing solution, such as an aqueous solution of ammonium monohydrogen phosphate. The aqueous mixture containing phosphate modified zeolite is then combined with matrix precursors to form a slurry. The slurry is preferably spray dried to form the catalyst having a diameter less than 200 microns. The novel catalyst is used in the catalytic cracking of hydrocarbons in an FCC, moving bed or other catalytic cracking apparatus. The catalyst can be used for treating resids in which the hydrocarbon feedstock has a higher average molecular weight, a lower API gravity and/or a higher metals content than gas oil.