Catalytic hydrocracking with the use of a silica-zirconia composite

Claim 1

A PROCESS FOR HYDROCRACKING A HYDROCARBON CHARGE WHICH COMPRISES CONTACTING THE SAME IN THE PRESENCE OF HYDROGEN AT A TEMPERATURE BETWEEN ABOUT 600*F. AND ABOUT 1050*F., AT A LIQUID HOURLY SPACE VELOCITY BETWEEN ABOUT 0.1 AND ABOUT 10, A HYDROGEN PARTICAL PRESSURE BETWEEN ABOUT 100 AND ABOUT 5000 POUNDS PER SQUARE INCH GAUGE EMPLOYING A MOLAR RATIO OF HYDROGEN TO HYDROCARBON CHARGE BETWEEN ABOUT 2 AND ABOUT 80 WITH A CATALYST COMPOSED OF A DEHYDROGENATION COMPONENT DEPOSITED ON A BASE CONSISTING ESSENTIALLY OF SILICA AND ZIRCONIA HAVING A ZIRCONIA CONTENT OF BETWEEN ABOUT 2 AND ABOUT 20 PERCENT BY WEIGHT, PREPARED BY REACTING A WATER-SOLUBLE ZIRCONIUM COMPOUND AND AN ALKALI METAL SILICATE TO EFFECT FORMATION OF A GELABLE SOL CONSISTING ESSENTIALLY OF SILICA AND ZIRCONIA CHARACTERIZED BY A PH IN EXCESS OF 6 AND A ZIRCONIA CONTENT, ON A DRY BASIS, OF BETWEEN ABOUT 2 AND ABOUT 20, PERMITTING SAID SOL TO SET FORMING A SILICA-ZIRCONIA GEL, REDUCING THE PH OF SAID GEL TO BELOW 5 AND MAINTAINING THE GEL UNDER SUCH CONDITIONS OF REDUCED PH WHILE IN CONTACT WITH AN AQUEOUS MEDIUM AT A TEMPERATURE IN THE APPROXIMATE RANGE OF 150 TO 220*F. FOR A PERIOD OF AT LEAST ABOUT 1 HOUR UNDER CONDITIONS OF SUBSTANTIALLY ATMOSPHERIC PRESSURE, THEREAFTER WASHING THE GEL FREE OF SOLUBLE MATTER, DRYING AND CALCINING.