Separation of carbon dioxide from gaseous mixtures

Claim 1

A PROCESS FOR THE SEPARATION OF CARBON DIOXIDE FROM A GAS STREAM COMPRISING CARBON DIOXIDE IN ADMIXTURE WITH HYDROGEN WHICH COMPRISES COOLING SAID MIXTURE AT A PRESSURE OF AT LEAST 200 P.S.I.G. TO A TEMPERATURE SUFFICIENTLY BELOW THE DEW POINT OF CARBON DIOXIDE IN SAID MIXTURE THAT CONDENSATION OF A MAJOR PORTION OF SAID CARBON DIOXIDE FROM SAID MIXTURE IS EFFECTED, WITHDRAWING RESULTING LIQUEFIED CARBON DIOXIDE FROM CONTACT WITH RESIDUAL GAS COMPRISING HYDROGEN AND A MINOR PORTION OF SAID CARBON DIOXIDE, CONTACTING SAID RESIDUAL GAS IN AN ABSORPTION ZONE WITH AN ORGANIC LIQUID ABSORBENT EFFECTIVE FOR SELECTIVE ABSORPTION OF CARBON DIOXIDE AT SAID PRESSURE AND AT SAID REDUCED TEMPERATURE EFFECTING SUBSTANTIALLY COMPLETE ABSORPTION OF SAID CARBON DIOXIDE, WITHDRAWING FROM SAID ABSORPTION ZONE SAID ABSORBENT CONTAINING ABSORBED CARBON DIOXIDE, REDUCING THE PRESSURE ON SAID WITHDRAWN CARBON DIOXIDE TO A PRESSURE AT WHICH THE BOILING POINT OF LIQUID CARBON DIOXIDE IS BELOW THE CONDENSATION TEMPERATURE OF CARBON DIOXIDE IN SAID FEED GAS MIXTURE BUT ABOVE ATMOSPHERIC PRESSURE, EFFECTING HEAT EXCHANGE BETWEEN SAID LIQUID CARBON DIOXIDE AT SAID REDUCED PRESSURE AND THE INCOMING FEED GAS MIXTURE EFFECTING CONDENSATION OF CARBON DIOXIDE FROM SAID FEED GAS, EFFECTING EXPANSION OF GASEOUS CARBON DIOXIDE RESULTING FROM VAPORIZATION OF LIQUID CARBON AIOXIDE AT SAID REDUCED PRESSURE TO A SUBSTANTIALLY LOWER PRESSURE WHEREBY THE TEMPERATURE OF THE GASEOUS CARBON DIOXIDE IS SUBSTANTIALLY LOWERED, AND PASSING RESULTING LOW TEMPERATURE GASEOUS CARBON DIOXIDE IN INDIRECT HEAT EXCHANGE WITH SAID FEED GAS FOLLOWING COOLING OF SAID FEED GAS BY VAPORIZATION OF SAID LIQUID CARBON DIOXIDE WHEREBY THE TEMPERATURE OF SAID FEED GAS IS FURTHER REDUCED.