Method for concentrating nitrogen isotope
US8440058B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 12, 2008 |
| Grant date | May 14, 2013 |
| Priority date | — |
| Expiry date | Mar 7, 2030 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF25J2220/90
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Method for concentrating nitrogen isotope to obtain a final product nitrogen, in which the stable nitrogen isotope, 15N, is concentrated, by low-temperature distillation of raw material nitrogen containing trace amounts of oxygen and argon using a plurality of distillation columns in a cascade arrangement. An argon-oxygen mixture is discharged from the bottom of the final column and 15N-concentrated nitrogen is extracted from a lower intermediate point of the final column. The flow rate of the argon-oxygen mixture discharged from the bottom of the final column is controlled based on the reading of a thermometer installed below the point where the final product 15N-concentrated nitrogen is extracted, thereby providing a stable nitrogen product.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.