Process for the production of nitrogen by cryogenic distillation of atmospheric air
US5325674A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Feb 18, 1992 |
| Grant date | Jul 5, 1994 |
| Priority date | — |
| Expiry date | Feb 18, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S62/939
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A process for producing gaseous nitrogen from a mixture to be treated in a distillation column, said mixture comprising nitrogen and oxygen, said process comprising the steps of: PA1 a) compressing the mixture to be treated to a pressure at least equal to the column pressure; PA1 b) cooling the compressed gas mixture and subjecting at least a first portion of said cooled mixture to expansion through a turbine to produce the required refrigeration and thereafter fractionated distillation in the column to obtain at the bottom of the column, an oxygen-enriched fraction and, at the top of the column, a nitrogen-enriched fraction, PA1 c) drawing off at least a portion of the nitrogen-enriched fraction as nitrogen product; PA1 d) compressing the remaining portion of the nitrogen-enriched fraction; PA1 e) recycling at least a portion of the compressed remaining portion of the nitrogen-enriched fraction to the bottom reboiler of the column where it condenses to provide reboil for the column; PA1 f) introducing at least a portion of the condensed nitrogen stream of step e) to the top of the column as additional reflux; and PA1 g) drawing off an oxygen-enriched fraction in liquid form from t…
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