Process for the separation of hydrogen fluoride, 1,1-dichloro-1-fluoroethane and 1-chloro-1,1-difluoroethane from liquid mixtures thereof
US4975156A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 4, 1989 |
| Grant date | Dec 4, 1990 |
| Priority date | — |
| Expiry date | May 4, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S203/90
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
1,1-Dichloro-1-fluoroethane, 1-chloro-1,1-difluoroethane and hydrogen fluoride are separated from their liquid mixtures, such as liquid mixtures resulting from the hydrofluorination, of 1,1,1-trichloroethane or vinylidene chloride. 1,1-Dichloro-1-fluoroethane and 1-chloro-1,1-difluoroethane are first separated by distillation into their respective mixtures with hydrogen fluoride, which are thereafter subjected to parallel phase separations resulting in two hydrogen fluoride-enriched liquid phases, a 1-chloro-1,1-difluoroethane-enriched liquid phase and a 1,1-dichloro-1-fluoroethane-enriched liquid phase. 1-Chloro-1,1-difluoroethane and 1,1-dichloro-1-fluoroethane are purified from the respective halohydrocarbon-enriched liquid phases by distillation. The hydrogen fluoride-enriched stream generated from the phase separation of the hydrogen fluoride/1,1-dichloro-1-fluoroethane mixture is recycled to the hydrofluorination reaction mixture.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.