Fractional distillation

Claim 1

AN INTERNAL-REFRIGERANT LOW-TEMPERATURE FRACTIONAL DISTILLATION METHOD FOR SEPARATING AMULTI-COMPONENT MIXTURE OF VAPORIZABLE MATERIAL INTO A LOW-BOILING FRACTION AND A HIGH-BOILING FRACTION, WHICH COMPRISES: PASSING SAID MIXTURE INTO A FRACTIONATION ZONE; WITHDRAWING FROM THE KETTLE PROTION OF SAID FRACTIONATION ZONE, A LIQUID STREAM AS THE HIGH-BOILING FRACTION OF SAID MIXTURE; PASSING AT LEAST A FIRST PORTION OF SAID STREAM INTO INDIRECT HEAT-EXCHANGE RELATIONSHIP WITH OVERHEAD VAPORS OF SAID FRACTIONATION ZONE TO CONDENSE AT LEAST A PORTION OF SAID OVERHEAD VAPORS AND TO VAPORIZE AT LEAST A PORTION OF THE FIRST PORTION; UTILIZING A PORTION OF THE RESULTING CONDENSED OVERHEAD PRODUCT AS REFLUXING LIQUID IN SAID FRACTIONATION ZONE; WITHDRAWING THE BALANCE OF SAID CONDENSED OVERHEAD PRODUCT AS THE LOW-BOILING FRACTION OF SAID MIXTURE; COMPRESSING THE VAPORIZED PORTION OF SAID LIQUID STREAM; PASSING A MAJOR PORTION OF SAID COMPRESSED STREAM BACK INTO SAID KETTLE PORTION OF SAID FRACTIONATION ZONE TO TRANSFER HEAT FROM SAID COMPRESSED STREAM TO SAID KETTLE PRODUCT; COMPRESSING FURTHER THE MINOR PORTION OF SAID STREAM; COOLING SAID MINOR PORTION ; PASSING SAID COOLED MINOR PORTION BACK INTO SAID KETTLE PORTION OF SAID FRACTIONATION ZONE; REGULATING THE PASSAGE OF SAID FRIST PORTION OF SAID LIQUID STREAM TO SAID HEAT EXCHANGE RELATIONSHIP IN RESPONSE TO THE PRESSURE OF SAID CONDENSED OVERHEAD PRODUCT; AND REGULATING THE FLOW RATE OF SAID MAJOR PORTION OF SAID COMPRESSED STREAM IN RESPONSE TO THE CONCENTRATION OF THE HIGH-BOILING FRACTION IN SAID FRACTIONATION ZONE AT A SELECTED POINT OF ANALYSIS.