Process for recovering olefins in polyolefin plants
US9073808B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 15, 2014 |
| Grant date | Jul 7, 2015 |
| Priority date | — |
| Expiry date | Sep 15, 2034 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C7/09
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for recovering unreacted olefin in a polyolefin manufacturing process comprising the treatment of a purge bin vent gas. The process involves cooling and condensing the vent gas (purge stream), which contains at least an olefin, a paraffin, and nitrogen, to produce a liquid condensate and an uncondensed (residual) gas stream. Both streams are then passed through membrane separation steps. The membrane separation of the uncondensed gas stream results in a residue stream containing mostly nitrogen and/or paraffin and a permeate stream enriched in either C2+ hydrocarbons or olefin, depending on the type of separation. The permeate from this step is recirculated within the process prior to the condensation step. The membrane separation of the condensate results in a residue stream containing paraffin and a permeate stream enriched in olefin, which may be recycled to the polymerization reactor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.