Plural stage purification of propylene oxide
US5262017A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 19, 1993 |
| Grant date | Nov 16, 1993 |
| Priority date | — |
| Expiry date | Apr 19, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D301/32
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Impure propylene oxide is purified by a distillation process wherein it is (a) extractively distilled in a first column using a C.sub.2 to C.sub.6 alkylene glycol extractive distillation agent to form a first overhead fraction comprising propylene oxide, C.sub.5 -C.sub.7 hydrocarbons methanol, water and oxygen-containing impurities, (b) wherein the first overhead fraction is separated in a second column into a second overhead fraction comprising most of the pentanes, pentenes and oxygen-containing impurities and a partially purified propylene oxide bottoms fraction comprising propylene oxide, hexenes, hexanes, and only residual quantities of pentenes and pentanes, (c) wherein the partially purified bottoms fraction is extracting distilled in a third column using a C.sub.7 -C.sub.10 alkane hydrocarbon extractive distillation agent to provide a further purified bottoms fraction containing substantially all of the propylene oxide, hexenes, hexanes charged to the third distillation column, and (d) the further purified bottoms fraction is extractively distilled in a fourth column using a C.sub.7 to C.sub.10 alkane hydrocarbon extractive distillation agent to provide a purified propylene…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.