US3947558A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of recovering HF from mixtures containing C1 -C3 halocarbon compounds
Assignee: Dow Chemical Nederland BV
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Filing: 1973-08-16
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Granted: 1976-03-30
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Expires: 1993-08-16
Abstract
Abstract Hydrogen fluoride can be separated from an organic mixture of fluorinated C 1 -C 3 compounds and recovered for reuse by selectively absorbing the HF in a glycol in which the HF is soluble, but the fluorinated organic compound is substantially insoluble. If desired, HF can be obtained in anhydrous form.
Inventors
- 👤 A. Theodorus van Eijl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:39
CPC Classifications
C; C07; C07C; C07C17/00; C07C17/38; C01; C01B; C01B7/00; C01B7/19; C01B7/191
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
125 words
A method of recovering the HF which is dissolved in the organic layer obtained after fluorinating a C 1 -C 3 chlorinated hydrocarbon and after separating HCl and cooling to form an HF rich layer and said organic layer, comprising commingling (a) the substantially HCl free organic C 1 -C 3 halocarbon layer containing chloro-, chlorofluoro-, and fluorocarbons with (b) a glycol lean in HF and which is liquid at the temperature employed and which has from 2 to 8 C atoms, forming a glycol layer having hydrogen fluoride selectively dissolved therein and a C 1 -C 3 halocarbon layer containing chloro-, chlorofluoro- and fluorocarbons, separating the C 1 -C 3 halocarbon layer from the glycol layer and recovering hydrogen fluoride from the glycol layer.
Claim 2
Independent Claim
125 words
A method of recovering the HF which is dissolved in the organic layer obtained after fluorinating a C 1 -C 3 chlorinated hydrocarbon and after separating HCl and cooling to form an HF rich layer and said organic layer, comprising commingling (a) the substantially HCl free organic C 1 -C 3 halocarbon layer containing chloro-, chlorofluoro-, and fluorocarbons with (b) a glycol lean in HF and which is liquid at the temperature employed and which has from 2 to 8 C atoms, forming a glycol layer having hydrogen fluoride selectively dissolved therein and a C 1 -C 3 halocarbon layer containing chloro-, chlorofluoro- and fluorocarbons, separating the C 1 -C 3 halocarbon layer from the glycol layer and recovering hydrogen fluoride from the glycol layer.
Claim 3
Dependent Claim
12 words
The method of claim 1 in which the glycol is ethylene glycol.
Claim 4
Dependent Claim
12 words
The method of claim 1 in which the glycol is propylene glycol.
Claim 5
Dependent Claim
26 words
The method of claim 1 in which step of commingling of the C 1 -C 3 chloro-, chlorofluoro and fluorocarbon layer with a glycol is repeated.
Claim 6
Dependent Claim
19 words
The method of claim 1 in which the halocarbon is a mixture of carbon tetrachloride, trichlorofluoro methane and dichlorodifluoromethane.
Claim 7
Dependent Claim
19 words
The method of claim 1 in which the halo carbon is a mixture of tetra chloroethylene, trichlorotrifluoroethane and dichlorotetrafluoroethane.
Claim 8
Dependent Claim
21 words
The method of claim 1 wherein the lean glycol is recycled and commingled with the said C 1 -C 3 halocarbon.
Claim 9
Dependent Claim
12 words
The method of claim 7 in which the glycol is ethylene glycol.
Claim 10
Dependent Claim
12 words
The method of claim 7 in which the glycol is propylene glycol.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-03-30 | 1979-09-29 | 1980-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-30 | 1983-09-29 | 1984-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-30 | 1987-09-29 | 1988-03-30 | $7700.00 | Window Closed / Lapsed |