Process for separating air by cryogenic distillation and installation for implementing this process

摘要

A process and an apparatus for separating air by cryogenic distillation. The apparatus has a medium pressure column thermally coupled to a low pressure column. Compressed and purified air is cooled to cryogenic temperature in an exchanger, and sent at least partly to the medium pressure column. Streams enriched in oxygen and nitrogen are sent from the medium pressure column to the low pressure column and, streams enriched in nitrogen and oxygen are removed from the low pressure.