Fractionation in coker scrubber of heavy gas oils containing a high concentration of metal contaminants

Claim 1

IN A PROCESS FOR COKING A RESIDUAL HYDROCARBON OIL BY CONTACTING THE RESIDUAL OIL COKING CHARGE STOCK AT A COKING TEMPERATURE WITH A BODY OF INERT PARTICULATE SOLIDS MAINTAINED IN THE FORM OF A DENSE TURBULENT FLUIDIZED BED IN A COKING ZONE TO PRODUCE VAPORS REMOVING VAPORS OVERHEAD FROM SAID COKING ZONE AND PASSING THEM TO A SCRUBBING-FRACTIONATION ZONE, SCRUBBING AND COOLING SAID VAPORS THEREIN TO A TEMPERATURE SUFFICIENT TO CONDENSE A HEAVY HYDROCARBON FRACTION AND FRACTIONATING THE REMAINING VAPORS TO SEPARATE A LIGHTER GAS OIL DISTILLATE FRACTION SUBSTANTIALLY FREE OF METAL CONTAMINANTS, CIRCULATING THE INERT SOLIDS THROUGH A HEATING ZONE WHEREIN A PORTION OF THE INERT SOLIDS ARE HEATED AND BACK TO SAID COKING ZONE TO SUPPLY HEAT THERETO, THE IMPROVED METHOD OF REMOVING METAL CONTAMINANTS FROM A HEAVY GAS OIL DISTILLATE FRACTION BOILING ABOVE ABOUT 85/* F. AND CONTAINING A HIGH CONCENTRATION OF METAL CONTAMINANTS WHICH COMPRISES THE STEPS OF FEEDING SAID HEAVY GAS OIL FRACTION TO SAID SCRUBBING-FRACTIONATING ZONE TO VAPORIZE PART OF SAID HEAVY GAS OIL, SCRUBBING AND COOLING SAID VAPORS THEREIN AT A TEMPERATURE IN THE RANGE OF 950*F. TO 1050*F. TO CONDENSE A HEAVY CONDENSATE FRACTION BOILING PREDOMINATLY ABOVE 1015*F. AND CONTAINING SUBSTANTIALLY ALL THE METAL CONTAMINANTS, FRACTIONATING THE REMAINING VAPORS TO SEPARATE A LIGHTER GAS OIL FRACTION SUBSTANTIALLY FREE OF METAL CONTAMINANTS RECYCLING AT LEAST A PORTION OF SAID HEAVY CONDENSATE FRACTION TO SAID COKING ZONE AND RECOVERING A LIGHTER GAS OIL PRODUCT FRACTION INCLUDING THAT DERIVED FROM SAID COKING STEP AND THAT DERIVED FROM SAID CONTAMINANTED HEAVY GAS OIL FRACTION, SUBSTANTIALLY FREE OF METAL CONTAMINANTS.