Gas separation process and apparatus

Claim 1

A PROCESS OF SEPARATING AN IMPURE GASEOUS MIXTURE COMPRISING HYDROGEN, NITROGEN AND CARBON MONOXIDE INTO A PRODUCT FRACTION OF HYDROGEN AND NITROGEN, AND A RESIDUAL FRACTION RICH IN CARBON MONOXIDE, WHICH PROCESS COMPRISES THE STEPS OF: (1) COOLING AND CLEANING SAID GASEOUS MIXTURE IN A FIRST REGENERATOR; (2) RECTIFYING THE RESULTANT COOLED AND CLEANED GASEOUS MIXTURE WHILE EMPLOYING LIQUID NITROGEN AS REFLUX, THEREBY OBTAINING SAID PRODUCT FRACTION OF HYDROGEN AND NITROGEN AND SAID RESIDUAL FRACTION RICH IN CARBON MONOXIDE; (3) SEPARATING SAID PRODUCT FRACTION INTO A PLURALITY OF STREAMS AND PASSING A MINOR PORTION OF SAID PRODUCT FRACTION THROUGH PASSAGES OF A SECOND REGENERATOR WHICH PASSAGES HAD BEEN IMMEDIATELY PREVIOUSLY EMPLOYED FOR COOLING AND CLEANING SAID GASEOUS MIXTURE, TO REMOVE IMPURITIES IN SAID PASSAGES, WHEREBY SAID PORTION OF SAID PRODUCT FRACTION IS SACRIFIED FOR PURGING SAID PASSAGES OF IMPURITIES, THEREBY ELIMINATING ANY NEED FOR AN AIR SEPARATION SYSTEM AND ANY NEED FOR THOROUGHLY WASHING THE IMPURE GASEOUS MIXTURE TO REMOVE SUBSTANTIALLY ALL TRACES OF CARBON DIOXIDE PRIOR TO CLEANING SAID GASEOUS MIXTURE IN SAID FIRST REGENERATOR; AND (4) PASSING A MAJOR PORTION OF SAID PRODUCT FRACTION THROUGH PASSAGES OF A THIRD REGENERATOR, WHICH PASSAGES HAD BEEN IMMEDIATELY PREVIOUSLY CLEANSED OF IMPURITES.