Catalytic conversion

Claim 1

IN A CATALYTIC CRACKING OF A SULFUR-BEARING GAS OIL BOILING IN THE RANGE OF 400 TO 1200*F., AT A CRACKING TEMPERATURE IN THE RANGE OF 890 TO 925*F., IN PRESENCE OF NATURAL CATALYST CONTAINING WATER OF HYDRATION, WHEREIN SAID CATALYST IS PERIODICALLY SUBJECTED TO COMBUSTION REGENERATION AT A TEMPERATURE ABOVE SAID CRACKING TEMPERATURE IN THE RANGE OF ABOUT 1050 TO 1090*F. TO REMOVE COMBUSTIBLE MATERIALS FROM ITS SURFACES UNDER WHICH CONDITIONS SAID CATALYST BECOMES DEHYDRATED, THE IMPROVEMENT COMPRISING WITHDRAWING FIRST AND SECOND STREAMS OF CATALYST FROM SAID CRACKING ZONE, PASSING SAID SECOND STREAM OF CATALYST INTO SAID REGENERATION ZONE TO REGENERATE SAID CATALYST, WITHDRAWING SAID SECOND STREAM OF CATALYST FROM SAID REGENERATION ZONE AND ADMIXING THEREWITH SAID FIRST STREAM OF CATALYST IN THE RATIO OF FROM 0.06 TO 5.0 PARTS BY WEIGHT OF CATALYST IN SAID FIRST STREAM WITH ONE PART BY WEIGHT OF CATALYST IN SAID SECOND STREAM WITHDRAWN FROM SAID REGENERATION ZONE TO FORM AN ADMIXTURE OF CATALYST AT A TEMPERATURE NOT LOWER THAN THE TEMPERATURE OF SAID CRACKING, MAINTAINING FROM 0.004 TO 0.16 PART BY WEIGHT OF STEAM IN CONTACT WITH ONE PART BY WEIGHT OF SAID ADMIXTURE OF CATALYST, WHEREBY REHYDRATION OF THE CATALYST TAKES PLACE, AND PASSING THE RESULTING REHYDRATED CATALYST TO SAID CRACKING.