Recovery of ethylene

Claim 1

A PROCESS FOR THE SEPARATION AND RECOVERY OF ETHYLENE FROM A GASEOUS MIXTURE OF ETHYLENE AND ETHANE AND CONTAINING SUCH OTHER CONSTITUENTS AS METHANE AND HYDROGEN COMPRISING ADMIXING SAID GASEOUS MIXTURE WITH A LIQUID SATURATED PARAFFINIC HYDROCARBON SELECTED FROM THE GROUP OF SATURATED PARAFFINIC HYDROCARBONS CONTAINING 6 TO 9 CARBON ATOMS PER MOLECULE AS AN ABSORBENT, SUBJECTING SAID ADMIXTURE TO LIQUID-GAS ABSORPTION CONDITIONS, SEPARATING THE ADMIXTURE INTO A LIQUID PHASE RICH IN ETHANE AND CONTAINING SOME ETHYLENE AND SAID OTHER CONSTITUENTS AND A GAS PHASE ENRICHED IN ETHYLENE; EXTRACTING SAID LIQUID PHASE RICH IN ETHANE AND CONTAINING SOME ETHYLENE AND SAID OTHER CONSTITUENTS WITH A LIQUID EXTRACTION SOLVENT SELECTED FROM THE GROUP CONSISTING OF MONOSUBSTITUTED METHANES CONTAINING THE SUBSTITUTION GROUPS -NO2 AND -CN UNDER LIQUID-LIQUID EXTRACTION CONDITIONS, FROM THE EXTRACTION OPERATION SEPARATING SAID LIQUID SATURATED PARAFFINIC HYDROCARBON RICH IN ETHANE AND CONTAINING A PORTION OF SAID OTHER CONSTITUENTS AS A FIRST LIQUID PHASE AND SAID LIQUID EXTRACTION SOLVENT RICH IN ETHYLENE AND CONTAINING SOME ETHANE AND ANOTHER PORTION OF SAID OTHER CONSTITUENTS AS A SECOND LIQUID PHASE, SUBJECTING SAID SECOND LIQUID PHASE TO STRIPPING CONDITIONS AND RECOVERING THEREFROM SAID EXTRACTION SOLVENT AND RETURNING THE RECOVERED EXTRACTION SOLVENT TO THE EXTRACTION OPERATION, ALSO RECOVERING STRIPPED GASES RICH IN ETHYLENE AND RECYCLING SAME INTO THE GASEOUS FEED TO THE PROCESS, SUBJECTING SAID FIRST LIQUID PHASE TO STRIPPING CONDITIONS, RECOVERING SAID LIQUID SATURATED PARAFFINIC HYDROCARBON FROM THIS LATTER STRIPPING OPERATION AND RECYCLING SAME TO THE FIRST ADMIXING STEP AS SAID LIQUID PARAFFINIC HYDROCARBON, ALSO RECOVERING STRIPPED GASES RICH IN ETHANE AND CONTAINING SOME METHANE AND HYDROGEN FROM THIS LATTER STRIPPING OPERATION AS A MINOR PRODUCT OF THE PROCESS, RECOVERING THE ETHYLENE BY CONTACTING SAID GAS PHASE ENRICHED IN ETHYLENE WITH A SOLUTION COMPRISING ORTHOANISIDINE AND 5 TO 18 PER CENT CUPROUS SALT AT A TEMPERATURE BETWEEN THE LIMITS OF -22* F. TO 86* F. UNDER A PRESSURE BETWEEN THE LIMITS OF ATMOSPHERIC TO 500 POUNDS PER SQUARE INCH GAUGE, FROM THIS CONTACTING OPERATION SEPARATING A GAS PHASE RICH IN ETHANE AND CONTAINING METHANE AND HYDROGEN AS A PORTION OF THE SECONDARY PRODUCT OF THE PROCESS AND A LIQUID PHASE COMPRISING A CUPROUS SALT-ORTHOANISIDINE SOLUTION OF ETHYLENE, SUBJECTING THIS LATTER SOLUTION TO DESORPTION CONDITIONS, RECOVERING CUPROUS SALT-ORTHOANISIDINE SOLUTION, RETURNING SAME TO ITS CONTACTING OPERATION AND RECOVERING ETHYLENE AS THE MAIN PRODUCT OF THE PROCESS.