Distillation strategies for the production of carbon monoxide-free nitrogen
US5351492A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 23, 1992 |
| Grant date | Oct 4, 1994 |
| Priority date | — |
| Expiry date | Sep 23, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S62/92
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The present invention relates an improvement to a cryogenic process for the separation of air which produces at least a nitrogen product and is carried out in a distillation column system having at least one distillation column from which the nitrogen product is produced. The distillation column of the distillation column system must comprise a rectifying section. In the process of the present invention, air is compressed, freed of impurities which will freeze out at cryogenic temperatures, cooled to near its dew point and fractionated in the distillation column system to produce the nitrogen product. The improvement is the operation of the distillation column such that the ratio of downward liquid to upward vapor flow rate (L/V) is no less than 0.65, preferably greater than 0.75, but less than 1.0 in the rectifying section of a distillation column from which the nitrogen product is produced. The flowrates are in moles per unit time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.