Patent ID: 6230519
Filing Date: 2001-05-15
Classification: F25J,Y10S

Abstract:
A process for the production of gaseous nitrogen and gaseous oxygen by the cryogenic rectification of feed air comprising:(A) compressing a multicomponent refrigerant fluid, cooling the compressed multicomponent refrigerant fluid, expanding the cooled, compressed multicomponent refrigerant fluid to generate refrigeration, and warming the expanded multicomponent refrigerant fluid by indirect heat exchange with said cooling compressed multicomponent refrigerant fluid and also with feed air to produce cooled feed air;(B) passing the cooled feed air into a higher pressure cryogenic rectification column and separating the feed air by cryogenic rectification within the higher pressure cryogenic rectification column into nitrogen-enriched fluid and oxygen-enriched fluid;(C) passing nitrogen-enriched fluid and oxygen-enriched fluid into a lower pressure cryogenic rectification column, and separating the fluids passed into the lower pressure column by cryogenic rectification to produce nitrogen-rich fluid and oxygen-rich fluid;(D) withdrawing nitrogen-rich fluid from the upper portion of the lower pressure column and recovering the withdrawn nitrogen-rich fluid as product gaseous nitrogen; and(E) withdrawing oxygen-rich fluid from the lower portion of the lower pressure column and recovering the withdrawn oxygen-rich fluid as product gaseous oxygen.