Process for the production of intermediate pressure oxygen

摘要

A process is provided for the production of intermediate pressure oxygen. Intermediate pressure is defined as a pressure range between about 15 psia and about 27 psia, and preferably between about 17 psia and about 23 psia. The process uses a double column cryogenic air separation system for the production of oxygen from air which includes a higher pressure column and a lower pressure column, wherein a nitrogen-enriched fraction from the higher pressure column is condensed by indirect heat exchange in a reboiler-condenser that provides at least a fraction of the boilup at the bottom of the lower pressure column. Oxygen is withdrawn from the lower pressure column as a liquid and vaporized. One portion of air is feed air to the higher pressure column and a another portion of air is at least partially condensed by indirect heat exchange with the vaporizing oxygen. The latter portion of air is at least partially condensed at a pressure less than the pressure of the feed air to the higher pressure column. The process is suitable for the production of intermediate pressure oxygen with a purity of at least about 85 mole %.