Claims
- 1. A method for producing elevated pressure oxygen comprising:
- (A) condensing feed air, passing condensed feed air into a higher pressure column, and separating feed air within the higher pressure column into nitrogen-enriched fluid and oxygen-enriched liquid;
- (B) passing nitrogen-enriched fluid into a lower pressure column, passing a first portion of the oxygen-enriched liquid from the higher pressure column into the lower pressure column and producing oxygen-rich liquid within the lower pressure column;
- (C) passing argon-containing fluid from the lower pressure column into an argon column and producing argon-richer vapor within the argon column;
- (D) condensing the argon-richer vapor by indirect heat exchange with a second portion of the oxygen-enriched liquid from the higher pressure column which is substantially completely vaporized to produce oxygen-enriched vapor, and passing oxygen-enriched vapor into the lower pressure column below where the oxygen-enriched liquid is passed into the lower pressure column;
- (E) withdrawing oxygen-rich liquid from the lower pressure column, increasing the pressure of the withdrawn oxygen-rich liquid, and vaporizing the pressurized oxygen-rich liquid to condense said feed air and to produce elevated pressure oxygen; and
- (F) recovering elevated pressure oxygen product.
- 2. The method of claim 1 further comprising turboexpanding a second feed air portion and passing the turboexpanded feed air portion into at least one of the higher pressure and lower pressure columns.
- 3. The method of claim 1 further comprising recovering fluid from the argon column having an argon concentration within the range of from 90 to 100 mole percent.
- 4. The method of claim 1 wherein the oxygen-enriched vapor is passed into the lower pressure column at least 1 equilibrium stage below where the oxygen-enriched liquid is passed into the lower pressure column.
Parent Case Info
This is a continuation-in-part of application Ser. No. 08/619,383 filed Mar. 21, 1996, now abandoned.
US Referenced Citations (15)
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
619383 |
Mar 1996 |
|