Method for removing unsaturated halogenated impurities from 2,3,3,3-tetrafluoropropene (HFO-1234yf)
US10233137B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 13, 2017 |
| Grant date | Mar 19, 2019 |
| Priority date | — |
| Expiry date | Oct 13, 2037 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C17/395
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A method for removing unsaturated halogen impurities from 2,3,3,3-tetrafluoropropene (HFO-1234yf) of the type that may otherwise be difficult to separate from HFO-1234yf due to the impurities having boiling points which are close to that of HFO-1234yf and/or the potential of one or more of the impurities to form azeotropic mixtures with HFO-1234yf. A HFO-1234yf stream including unsaturated halogenated impurities is first passed through a caustic scrubber and is then passed through an acid scrubber. In the caustic scrubber and acidic scrubber, undesirable impurities are removed, in particular, 3,3,3-trifluoropropene (1243zf), 1-chloro-1-fluoroethylene (1131a), vinyl chloride (1140), and/or 1-chloro-2-fluoroethylene (1131).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.