Method to purify a crude stream containing hydrochlorofluoroolefin
US11286223B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 10, 2019 |
| Grant date | Mar 29, 2022 |
| Priority date | — |
| Expiry date | Oct 10, 2039 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C17/42
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Disclosed is a method of purifying a stream of crude hydrochlorofluoroolefin refrigerant produced by the reaction of 1,1,3,3 tetrachloropropene (R1230za) or 1,1,1,3,3-pentachloropropane (R240fa) with HF. The process includes a step of removing the cis-(Z) isomer by distillation of the crude refrigerant stream prior to a step of reacting the crude refrigerant stream with a base. The reaction with the base is a necessary step in production of the refrigerant and is done to remove HF and residual HCl from the crude refrigerant stream. Removal of the cis-(Z) isomer before the reaction with the base reduces the amount of toxic flammable trifluoropropyne (TFP) that is produced as a side-reaction during the reaction with the base. In addition, temperature control during the reaction with the base is less critical to minimizing the TFP production if the cis-(Z) isomer is first removed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.