PROCESS AND PLANT FOR RECOVERING ARGON IN A SEPARATION UNIT FOR A PURGE GAS USED IN THE SYNTHESIS OF AMMONIA

摘要

A plant for producing an argon-rich stream from a mixture formed by a purge fluid in an ammonia production plant comprises: at least one phase separator (7, 17); a methane scrubbing column (21); a methane separation column (31); a nitrogen/argon separation column (41); a line for sending the mixture into at least one phase separator, to produce at least a hydrogen-enriched gas and a hydrogen-depleted liquid; a line for sending at least a portion of the hydrogen-depleted liquid into the bottom of the methane scrubbing column, to form an overhead gas and a bottoms liquid; a line for sending at least a portion of the bottoms liquid from the methane scrubbing column to the methane separation column, to produce a methane-enriched bottoms liquid and a methane-depleted overhead gas; a line for sending at least a portion of the methane-depleted overhead gas to the nitrogen/argon separation column, to form a nitrogen-enriched fluid as overhead of said column; a line for withdrawing an argon-rich liquid as bottoms of said column, serving as product; and a line for sending at least a portion of the methane-enriched bottoms liquid to the top of the methane scrubbing column.