Catalytic cracking and improved catalyst therefor

Claim 1

IN THE PROCESS FOR THE CATALYSTIC CRACKING OF A HYDROCARBON OIL TO PRODUCE CATALYTICALLY CRACKED GASOLINE AND C3 AND C4 OLEFINS THE IMPROVEMENT WHICH COMPRISES CONTACTING THE HYDROCARBON OIL TO BE CRACKED IN THE VAPOR PHASE AT A TEMPERATURE BETWEEN 850* F. AND 1050* F. AND A PRESSURE FROM 1 TO 4 ATMOSPHERE ABSOLUTE WITH A SOLID CATALYST PREPARED BY REACTING AT A PH MAINTAINED AT A VALUE OF AT LEAST 10.0 WITH A SODIUM SILICATE SOLUTION CONTAINING BETWEEN ABOUT 6% AND 15% OF SIO2, A DILUTE SOLUTION OF A WATER SOLUBLE SALT OF A METAL SELECTED FROM THE GROUP CONSISTING OF MAGNESIUM, CALCIUM, AND MIXTURE THEREOF, SAID DILUTE SOLUTION BEING FROM ABOUT 0.05 TO 0.5 MOLAR AND BEING IN AN AMOUNT TO SUPPLY FROM ABOUT 1/50 TO 1/5 MOLE OF THE METAL SALT PER MOLE OF SIO2'' BRINGING THE PH OF THE REACTION MIXTURE TO A VALUE IN THE RANGE OF 10.0 TO 10.5, THEN ADDING TO SAID REACTION MIXTURE A SOLUTION OF A WATER SOLUBLE SALT OF ALUMINUM IN AN AMOUNT TO INCORPORATE BETWEEN 12 AND 30% AL203 BASED ON THE CALCINED CATALYST AND ADDING AMMONIUM HYDROXIDE DURING THE ADDITION OF SAID ALUMINUM SALT SOLUTION AT A RATE ADJUSTED TO PREVENT THE PH OF THE REACTION MIXTURE FROM DROPPING BELOW 9.0, THEN FILTERING, WASHING AND CALCINING THE RESULTING HYDROGEL.