Separation of hydrocarbons

Claim 1

A VAPOR-LIQUID EXTRACTION PROCESS FOR SEPARATING LESS SATURATED HYDROCARBONS FROM MORE SATURATED HYDROCARBONS OF SUBSTANTIALLY THE SAME CARBON CONTENT AND HAVING FROM 2 TO ABOUT 2 CARBON ATOMS, WHICH COMPRISES CONTACTING A MIXTURE OF THE SAID HYDROCARBONS IN THE VAPOR PHASE WITH A LIQUID AMMONIA SOLVENT IN A COUNTERCURRENT VAPORLIQUID EXTRACTION ZONE WHEREIN AT LEAST 150 WT. PERCENT LIQUID AMMONIA IS MAINTAINED IN THE LIQUID PHASE, SAID EXTRACTION ZONE HAVING AN UPPER STRIPPING SECTION AND A LOWER ENRICHING SECTION, FEEDING THE HYDROCARBON MIXTURE TO BE SEPARATED BETWEEN SAID STRIPPING AND ENRICHING SECTIONS, WITHDRAWING FROM SAID UPPER SECTION A HYDROCARBON VAPOR STREAM CONTAINING THE MORE SATURATED HYDROCARBON AND AMMONIA, AND WITHDRAWING FROM SAID LOWER SECTION A HYDROCARBON LIQUID STREAM CONTAINING THE LESS SATURATED HYDROCARBON AND AMMONIA, COOLING THE HYDROCARBON VAPOR STREAM TO SEPARATE TWO LIQUID LAYERS ONE OF WHICH IS RICH IN AMMONIA AND THE OTHER RICH IN HYDROCARBON, RETURING A SUBSTANTIAL PART OF THE AMMONIA RICH LAYER TO THE VAPOR-LIQUID EXTRACTION ZONE, RECOVERING AMMONIA SOLVENT FROM THE LIQUID HYDROCARBON STREAM, AND RETURNING THE SAID RECOVERED AMMONIA SOLVENT TO THE SAID STRIPPING SECTION.