Selective extraction solvent recovery using regenerated cellulose membrane under reverse osmosis conditions
US4510047A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 14, 1983 |
| Grant date | Apr 9, 1985 |
| Priority date | — |
| Expiry date | Dec 14, 2003 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC10G21/28
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Selective extraction solvents such as NMP, phenol or furfural employed for the extraction of specialty oils, i.e. lubricating, transformer and insulating oils, to remove undesirable aromatic components therefrom, is itself recovered from the extract stream and/or raffinate streams by preferential ultrafiltration through selective membranes of regenerated cellulose. The extract stream, because of its higher solvent content, is the preferred stream for solvent recovery treatment by the reverse osmosis membrane permeation technique. Solvent recovery employing membrane permeation exhibits the advantage of not being energy intensive as is distillation or stripping. The solvent is recovered at a high enough flux rate and at a high enough level of purity to be introduced back into the solvent extraction process optionally at some point in the process wherein the composition of the recovered solvent approximately matches the composition of the solvent present in the process at the point of introduction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.