Processes for the manufacture and purification of 1,1,2,2,3,3,4,4-octafluorobutane and by-products, and azeotropes with HF
US5948213A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 17, 1998 |
| Grant date | Sep 7, 1999 |
| Priority date | — |
| Expiry date | Jul 17, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/582
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process is disclosed for producing 1,1,2,2,3,3,4,4-octafluorobutane. The process involves (a) reacting a mixture comprising 2,2,3,3-tetrafluorobutane and chlorine to form a mixture of chloro-compounds wherein compounds of the formula C.sub.4 H.sub.x Cl.sub.6-x F.sub.4 (where x is 0 or 1) comprise at least about 50 mole % of the mixture of chloro-compounds; (b) contacting certain chloro-compounds from (a) and hydrogen fluoride with a fluorination catalyst to form a mixture of fluoro-compounds; and (c) contacting certain fluoro-compounds from (b) and hydrogen with a hydrogenolysis catalyst to produce CHF.sub.2 CF.sub.2 CF.sub.2 CHF.sub.2. Sufficient chloro-compounds formed in (a) and sufficient fluoro-compounds formed in (b) are recycled to provide a selectivity to CHF.sub.2 CF.sub.2 CF.sub.2 CHF.sub.2 of at least about 75% based upon the moles of CH.sub.3 CF.sub.2 CF.sub.2 CH.sub.3 reacted in (a). Also disclosed is a process for the purification of at least one compound selected from the group consisting of CCl.sub.2 F(CF.sub.2).sub.2 CCl.sub.3, CCl.sub.2 F(CF.sub.2).sub.2 CCl.sub.2 F, CCl.sub.2 F(CF.sub.2).sub.2 CClF.sub.2, CClF.sub.2 (CF.sub.2).sub.2 CClF.sub.2, CClF.sub.2 (CF.s…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.