Perfluorocompound separation and purification method and system
US5779863A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jan 16, 1997 |
| Grant date | Jul 14, 1998 |
| Priority date | — |
| Expiry date | Jan 16, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C17/383
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Provided is a novel method and system for separating and purifying perfluorocompounds (PFCs). The method comprises the steps of: (a) introducing a perfluorocompound-containing gas stream into a first distillation column; (b) removing a light product from the first column, and removing a heavy product from the first column; (c) introducing the first column light product into a second distillation column; (d) removing a light product from the second column, and removing a heavy product from the second column; (e) introducing the second column light product into a third distillation column; and (f) removing a light product from the third column, and removing a heavy product from the third column. The method and system can be advantageously used in the treatment of exhaust gases from semiconductor processing tools, and results in highly purified PFCs which can be recycled, thereby avoiding the release of PFCs into the atmosphere.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.