Catalyst

Claim 1

A PROCESS FOR CONVERTING A HEAVY HYDROCARBON FEED STOCK INTO LIGHTER PRODUCTS WHICH COMPRISES MIXING FINELY DIVIDED COKE HEATED TO ABOUT 1200 TO 1300*F. WITH THE FEED STOCK PREHEATED TO ABOUT 600 TO 800*F. TO FORM A DILUTE SUSPENSION HAVING A RELATIVELY HIGH TEMPERATURE BETWEEN ABOUT 1075* AND 1150*F., PASSING THE HOT SUSPENSION THROUGH A NARROWLY CONFINED, ELONGATED VAPORIZING ZONE SO AS PARTIALLY TO VAPORIZE THE FEED DURING A RESIDENCE TIME NOT IN EXCESS OF 1 SECOND AT THE AFORESAID RELATIVELY HIGH TEMPERATURE, THEREAFTER PASSING THE HOT SUSPENSION OF FEED VAPORS, UNVAPORIZED FEED AND COKE DIRECTLY INTO A DENSE BED OF FINELY SUBDIVIDED COKE AT A POINT NEAR THE UPPER LEVEL THEREOF AND WITHIN ABOUT 3 FEET BELOW THE UPPER LEVEL OF SAID BED MAINTAINED IN THE LOWER PART OF A COKING ZONE, PASSING AN INERT GAS UPWARDLY THROUGH SAID BED AT A VELOCITY CONTROLLED TO MAINTAIN SAID BED IN DENSE FLUIDIZED CONDITION, ALSO INTRODUCING A RELATIVELY COOL HYDROCARBON STREAM INTO SAID BED SO AS TO MAINTAIN THE COKING ZONE AT A RELATIVELY LOW TEMPERATURE BETWEEN ABOUT 925* AND 975*F. WHEREBY THE DILUTE SUSPENSION FROM THE VAPORIZING ZONE IS RAPIDLY QUENCHED WITHOUT SUBSTANTIAL CONDENSATION TO MINIMIZE THERMAL CRACKING THEREOF, WITHDRAWING DISENGAGED VAPORS