Multiple expander process to produce oxygen
US5956974A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 22, 1998 |
| Grant date | Sep 28, 1999 |
| Priority date | — |
| Expiry date | Jan 22, 2018 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF25J2250/52
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The present invention relates to a process for the cryogenic distillation of air in a distillation column system that contains at least one distillation column wherein the boil-up at the bottom of the distillation column producing the oxygen product is provided by condensing a stream whose nitrogen concentration is equal to or greater than that in the feed air stream, which comprises the steps of: (a) generating work energy which is at least ten percent (10%) of the overall refrigeration demand of the distillation column system by at least one of the following two methods: (1) work expanding a first process stream with nitrogen content equal to or greater than that in the feed air and then condensing at least a portion of the expanded stream by latent heat exchange with at least one of the two liquids: (i) a liquid at an intermediate height in the distillation column producing oxygen product and (ii) one of the liquid feeds to this distillation column having an oxygen concentration equal to or preferably greater than the concentration of oxygen in the feed air; and (2) condensing at least a second process stream with nitrogen content equal to or greater than that in the feed air by…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.