Nitrogen rejection method and apparatus
US7373790B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 14, 2006 |
| Grant date | May 20, 2008 |
| Priority date | — |
| Expiry date | Jun 14, 2026 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S62/927
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Nitrogen is rejected from a pressurized feed gas stream comprising methane and nitrogen by cooling the feed gas stream in a main heat exchanger and rectifying the cooled feed gas stream in a double rectification column comprising a higher pressure rectification column, a lower pressure rectification column, and a condenser-reboiler placing the higher pressure column in heat exchange relationship with the lower pressure column. A pump withdraws a methane product stream from the column. The methane product stream is pressurized by the pump and is vaporized in the main heat exchanger. The pressurized feed gas stream is expanded with the performance of external work in an expansion turbine 6 upstream of the main heat exchanger.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.