Catalytic cracking of petroleum hydrocarbons with a clay treated catalyst

Claim 1

A CATALYTIC CRACKING PROCESS WHICH COMPRISES CRACKING A SULPHUR-CONTAINING PETROLEUM FEEDSTOCK IN THE PRESENCE OF A CATALYST CONSISTING ESSENTIALLY OF A MONTMORILLONITE CLAY WHICH HAS BEEN HEATED TO A TEMPERATURE BETWEEN ABOUT 500* C. AND 700* C. TO REMOVE SUBSTANTIALLY COMPLETELYL THE COMBINED HYDROXYL GROUPS WITHOUT CAUSING ANY PHYSICAL DISRUPTION OF THE CLAY, AND FROM WHICH CLAY, AS IT IS EMPLOYED IN THE CRACKING STEP, THE COMBINED HYDROXYL GROUPS ARE SUBSTANTIALLY COMPLETELY ABSENT, SAID TEMPERATURE BEING IN INVERSE RELATIONSHIP TO THE IRON OXIDE CONTENT PRESENT IN CLAY SUCH THAT WHEN THE IRON OXIDE CONTENT IS LESS THAN 1.5% THE TEMPERATURE WILL BE ABOUT 700* C., AND WHEN THE IRON OXIDE CONTENT IS MORE THAN 7%, THE TEMPERATURE WILL BE ABOUT 500* C., SEPARATING FROM THE CRACKED PRODUCTS A LIQUID FRACTION AND A HYDROGEN-CONTAINING GASEOUS FRACTION, PASSING SAID LIQUID FRACTION AND SAID HYDROGEN-CONTAINING GASEOUS FRACTION OVER A SULPHUR-RESISTANT HYDROGENATION CATALYST UNDER CONDITIONS SUCH THAT THE SATURATION OF OLEFINES AND THE HYDROGENATION OF SULPHUR COMPOUNDS CONTAINED IN SAID LIQUID FRACTION ARE EFFECED, SAID HYDROGEN-CONTAINING G ASEOUS FRACTION CONSTITUTING THE WHOLE OF THE HYDROGEN SUPPLIED TO THE SATURATON-HYDROGENATION OPERTION, AND SEPARATING THE HYDROGENATE PRODUCTS INTO A GASEOUS FRACTION AND A DESULPHURIZED LIQUID FRACTION.