Operating a reboiler system for fractionating absorber-stills which comprises separately introducing vapors and liquid from the reboiler into the still and mixing absorbed vapors vaporized from the still bottoms with the liquid before its introduction into the still

Claim 1

THE PROCESS OF FRACTIONALLY ABSORBING HYDROCARBONS FROM A MIXTURE OF HIGHER AND LOWER BOILING HYDROCARBONS, THAT INCLUDES INTRODUCING SAID MIXTURE TO A VERTICALLY EXTENDED ABSORPTION AND FRACTIONATING ZONE CONTAINING A VERTICAL SERIES OF TRAYS ABOVE AND BELOW THE MIXTURE INLET, MAINTAINING THE MIXTURE IN SAID ABSORPTION AND FRACTIONATING ZONE AT A TEMPERATURE ABOVE THE VAPORIZING TEMPERATURE OF THE LOWER BOILING HYDROCARBONS UNDER THE EXISTING PRESSURE, INTRODUCING LEAN ABSORPTION OIL TO AN UPPER LOCATION IN SAID ZONE FOR DOWNWARD FLOW COUTERCURRENTLY IN CONTACT WITH RISING VAPORS LIBERATED FROM SAID MIXTURE AND CONCURRENTLY WITH UNVAPORIZED COMPONENTS OF SAID MIXTURE FLOWING DOWNWARDLY BELOW THE INLET, REMOVING UNABSORBED VAPORS FROM THE TOP OF SAID ZONE, PASSING SAID UNVAPORIZED COMPONENTS AND ABSORPTION OIL FROM A LOWER PORTION OF SAID ZONE THROUGH A REBOILING ZONE, SEPARATELY RETURNING VAPORS OF A PORTION OF SAID COMPONENTS AND AN UNVAPORIZED LIQUID STREAM FROM THE REBOILER ZONE TO THE LOWER PORTION OF THE ABSORPTION AND FRACTIONATING ZONE, REMOVING THE RETURNED LIQUID FROM THE BOT-