Process for the preparation of krypton-rich gases

Claim 1

A PROCESS FOR THE PREPARATION OF A KRYPTONRICH GAS FRACTION, WHICH COMPRISES PREPARING A GAS MIXTURE COMPRISING NITROGEN AND HYDROGEN BY REACTION OF OXYGEN-ENRICHED AIR AND STEAM WITH CARBONACEOUS MATERIAL IN A PRODUCER-GAS GENERATOR, SYNTHESIZING AMMONIA AT A PRESSURE ABOUT 300 ATMOSPHERES FROM SAID GAS MIXTURE, PURGING THE NON-REACTING GASES FROM THE AMMONIA SYNTHESIS, BY THE WITHDRAWING A FRACTION OF THE UNREACTED GASES, SUBSEQUENT TO CONDENSING OF THE RESULTING AMMONIA, FROM THE MAIN PORTION GAS MIXTURE, EXPANDING THE PURGED GAS MIXTURE TO REDUCE THE PRESSURE THEREOF TO ABOUT 30 ATMOSPHERES AND COOL THE GAS TO SLIGHTLY ABOVE THE DEW POINT OF METHANE AT SAID EXPANDED PRESSURE, WASHING SAID EXPANDED GAS MIXTURE IN COUNTERCURRENT WITH A LIQUIFIED METHANE FRACTION, COLLECTING THE RESULTING WASH LIQUID CONTAINING KRYPTON, RECTIFYING SAID WASH LIQUID TO SEPARATE ARGON THEREFROM, REDUCING THE PRESSURE UPON THE ARGON DELETED FRACTION, RECTIFYING THE SAME TO SEPARATE METHANE THEREFROM, AND COLLECTING THE RESULTING KRYPTON-RICH RESIDUE.