Heavy hydrocarbon recovery from pressure swing adsorption unit tail gas
US6610124B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 12, 2002 |
| Grant date | Aug 26, 2003 |
| Priority date | — |
| Expiry date | Mar 12, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/151
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A pressure swing adsorption process for the separation of impurities such as nitrogen and carbon dioxide and recovery of hydrocarbons from a natural gas stream utilizes two separate adsorption systems, the first containing an adsorbent selective for nitrogen, carbon dioxide or both and the second containing a hydrocarbon-selective adsorbent. In the process, the natural gas stream is passed through a first adsorbent to form a product stream enriched with methane and to adsorb nitrogen and/or carbon dioxide and which further co-adsorbs at least a portion of the hydrocarbons contained in the feed stream. The hydrocarbons are recovered by passing a low pressure waste stream from the first pressure swing adsorption stage which contains co-adsorbed nitrogen and/or carbon dioxide and hydrocarbons and directing the waste stream to the second pressure swing adsorption stage to adsorb the hydrocarbons and produce a product stream enriched in nitrogen and/or carbon dioxide. The hydrocarbons are recovered from the hydrocarbon-selective adsorbent by an intermediate pressure methane-containing stream from the first pressure swing adsorption stage which purges the adsorbent in the second stage an…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.