Method for purification of a solvent for separation of styrene by extractive distillation and for separation of styrene
US11465953B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Jan 9, 2019 |
| Grant date | Oct 11, 2022 |
| Priority date | — |
| Expiry date | Jul 2, 2039 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C7/10
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method for purification of a styrene-containing feedstock includes steps of introducing the styrene-containing feedstock into the middle of an extractive distillation column, and a solvent for the extractive distillation into the upper part of the column; discharging a raffinate oil from the top of the column, and a rich solvent rich in styrene from the bottom of the column. The rich solvent is then introduced into the middle of the solvent recovery column for vacuum distillation to obtain a crude styrene from the top of the solvent recovery column, and a lean solvent is discharged from the bottom of the solvent recovery column and recycled to the upper part of the extractive distillation column. A portion of the rich solvent is sent to a solvent purification zone for a liquid-liquid extraction using water to obtain a mixture of a styrene polymer and styrene.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.