ELEVATED PRESSURE AIR SEPARATION PROCESS WITH USE OF WASTE EXPANSION FOR COMPRESSION OF A PROCESS STREAM

摘要

The present invention relates to an elevated pressure air separation cryogenic process wherein feed air is compressed, treated to remove water and carbon dioxi de, cooled to cryogenic temperature in a main heat exchanger having a cold end and a warm end and fed to a distillation column system having at least two (2) distill ation columns for separation into at least a nitrogen-enriched product, an oxygen-enri ched product and a gaseous waste stream characterized in that at least a portion of s aid waste stream is (isentropically) expanded to produce work and work produced by t he expansion is used to provide at least a portion of the work required to compress a process stream other than the gaseous waste stream at a temperature warmer than the temperature of the cold end of said main heat exchanger. The alternative process streams to be compressed can be: at least a portion of the feed air, at least a portion of the oxygen-enriched product or at least a portion of the nitrogen-enriched produ ct.