Cryogenic rectification system for producing low purity oxygen using shelf vapor turboexpansion

摘要

A cryogenic rectification system for producing low purity oxygen from an auxiliary column to a double column system and which can also effectively produce nitrogen gas product and/or one or more liquid products wherein the lower pressure column of the double column system is reboiled in part by turboexpanded shelf vapor which is condensed in an intermediate reboiler and preferably subcooled prior to passage into the lower pressure column.