Two stage coking of residua feeds in unitary reactor

Claim 1

A PROCESS FOR PYROLYTICALLY UPGRADING A HEAVY HYDROCARBON OIL WHICH UPON COKING YIELDS HEAVY GAS OIL OF UNSUITABLE CATALYTIC CRACKING QUALITY WHICH COMPRISES THE STEPS OF PROVIDING A UNITARY REACTION ZONE CONTAINING TWO STAGES, EACH STAGE CONTAINING A DENSE TURBULENT FLUIDIZED BED OF INERT PARTICULATE SOLIDS, CONTACTING THE OIL CHARGING STOCK WITH THE DENSE TURBULENT FLUIDIZED BED IN GHE FIRST STAGE AT A TEMPERATURE IN THE RANGE OF 850* TO 1200*%F. TO PRODUCE VAPOROUS CONVERSION PRODUCTS AND COKE, SEPARATING THE VAPOROUS PRODUCTS TO SEGREGATE A HEAVY GAS OIL FRACTION BOILING WITHIN THE LIMITS OF ABOUT 650*F. TO 1000*F., RECYCLING THE HEAVY RESIDUAL ING ABOVE ABOUT 1000*F., RECYCLING THE HEAVY RESIDUAL FRACTION TO THE FIRST STAGE OF THE REACTOR FOR FURTHER CONVERSION TO LIGHT GAS OIL THEREIN AND RECYCLING ONLY THE HEAVY GAS OIL TO THE SECOND STAGE WHERE IT IS CONTACTED WITH THE DENSE TURBULE@NT FLUIDIZED BED CONTAINED THEREIN AT A HIGHER TEMPERATURE THAN IN THE FIRST STAGE, ONE IN THE RANGE OF ABOUT 1000* TO 1200*F. FOR A VAPOR HOLDING TIME OF ABOUT 1 TO 40 SECONDS SO AS TO CONVERT IT PREDOMINANTLY TO A LIGHTER FRACTION BOILING BELOW ABOUT 430*F.