Recovery of acetylene from gases containing it in small proportion

Claim 1

A METHOD FOR THE RECOVERY OF ACETYLENE FROM A FIRST GAS STREAM CONTAINING THE SAME IN MINOR QUANTITIES AND ALSO CONTAINING HEAVIER ACETYLENES, CARBON DIOXIDE, AND NITROGEN WHICH COMPRISES CONTACTING SAID STREAM WITH A SOLVENT AND ABSORBING ONLY A MINOR PORTION OF SAID FIRST GAS STREAM TO OBTAIN AN ENRICHED SOLVENT CONTAINING SUBSTANTIALLY ALL OF SAID ACETYLENE AND SAID HEAVIER ACETYLENES ORIGINALLY CONTAINED IN SAID FIRST GAS STREAM AND ALSO CONTAINING CARBON DIOXIDE AND NITROGEN, AND TO OBTAIN A RESIDUE GAS, PASSING SAID ENRICHED SOLVENT AS THE SOLE FEED CONTAINING ACETYLENE TO A DESORPTION ZONE AND DESORBING THEREIN AT LEAST A PORTION OF THE NITROGEN FROM SAID ENRICHED SOLVENT TO FORM A SECOND STREAM CONTAINING SAID DESORBED NITROGEN, THEN REMOVING SUBSTANTIALLY ALL OF THE REMAINING ABSORBED COMPONENTS FROM SAID SOLVENT TO FORM A THIRD GAS STREAM AND THEN TREATING SAID THIRD GAS STREAM BY CONTACTING THE SAME WITH A SOLVENT AND THEREBY ABSORBING IN SAID SOLVENT SUBSTANTIALLY ALL OF THE HYDROCARBON COMPONENTS OTHER THAN ACETYLENE, AND THEREBY FORMING TWO STREAMS, NAMELY, A FOURTH GAS STREAM CONTAINING SUBSTANTIALLY ALL OF THE ACETYLENE IN SAID THIRD GAS STREAM AND AN ENRICHED SOLVENT CONTAINING SUBSTANTIALLY ALL OF THE HEAVIER ACETYLENES IN SAID THIRD GAS STREAM, SAID FOURTH STREAM BEING A PRODUCT OF THE PROCESS.