Separation of olefins from paraffins using ionic liquid solutions
US6339182B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 12, 2000 |
| Grant date | Jan 15, 2002 |
| Priority date | — |
| Expiry date | Dec 12, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P30/40
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Methods for separating olefins from non-olefins, such as parafins, including cycloparaffins, oxygenates and aromatics, are provided. The methods use metal salts to complex olefins, allowing the non-olefins to be separated by a variety of methods, including decantation and distillation. The metal salts are dissolved in ionic liquids, which tend to have virtually no vapor pressure, and which poorly solubilize the non-olefins. Accordingly, the non-olefins phase separate well, and can be distilled without carrying over any of the ionic liquid into the distillate. Preferred salts are Group IB salts, more preferably silver salts. A preferred silver salt is silver tetrafluoroborate. Preferred ionic liquids are those which form stable solutions or dispersions of the metal salts, and which do not dissolve the non-olefins. Further, if the olefins are subject to isomerization, the ionic liquid is preferably relatively non-acidic. The methods involve forming a solution of a suitable olefin-complexing salt in an appropriate ionic liquid. An olefin-containing mixture is contacted with the ionic liquid/salt solution, and the olefins are adsorbed. After the paraffins are removed, the olefins can b…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.