Separation and recovery of ethylene

Claim 1

A PROCESS FOR THE PRODUCTION OF ETHYLENE WHICH COMPRISES: CRACKING A STREAM OF NORMALLY GASEOUD HYDROCARBONS IN A CRACKING ZONE UNDER CRACKING CONDITIONS TO PRODUCE A CRACKING ZONE GASEOUS EFFLUENT CONTAINING HYDROGEN AND C1 TO C5 PLUS HYDROCARBONS; COMPRESSING SAID EFFLUENT; PASSING SAID COMPRESSED EFFLUENT TO A FIRST ABSORPTION ZONE AND THEREIN REMOVING SUBSTANTIALLY ALL OF SAID C5 PLUS HYDROCARBONS AND A PORTION OF SAID C3 AND C4 HYDROCARBONS; CONTACTING THE RESULTING MIXTURE OF HYDROGEN AND C1 TO C4 HYDROCARBONS WITH A PREDOMINANTLY ETHANE ABSORBENT UNDER A ABSORPTION CONDITIONS IN A SECOND ABSORPTION ZONE TO ABSORB THEREBY C2 TO C4 PLUS HYDROCARBONS AND A MINOR PORTION OF SAID C1 HYDROCARBONS; PASSING THE RESULTING RICH ABSORBENT TO A STRIPPING ZONE; STRIPPING C1 HYDROCARBON FROM SAID RICH ABSORBENT IN SAID STRIPPING ZONE; PASSING REMAINING RICH ABSORBENT TO A FRACTIONATION ZONE; FRACTIONATING SAID REMAINING RICH ABSORBENT TO OBTAIN ETHYLENE AS AN OVERHEAD PRODUCT AND A BOTTOMS PRODUCT COMPRISING SAID PREDOMINANTLY ETHANE ABSORBENT; RETURNING A PORTION OF SAID BOTTOMS PRODUCT TO SAID SECOND ABSORPTION ZONE AS THE SAID ETHANE ABSORBENT EMPLOYED THEREIN; AND RETURINING ANOTHER PORTION OF SAID BOTTOMS PRODUCT TO SAID CRACKING ZONE AS A PORTION OF THE CHARGE THERETO.