Claims
- 1. A process for the production of bis(fluoromethyl)ether which comprises reacting formaldehyde with hydrogen fluoride in a single reaction/distillation column operated under conditions of temperature and pressure so as to simultaneously (i) produce said bis(fluoromethyl)ether and by-product water and (ii) separate a by-product liquid phase in which the mole ratio of bis(fluoromethyl)ether to water is less than 1 from a desired product vapour phase in which the mole ratio of bis(fluoromethyl)ether to water is greater than 1.
- 2. A process as claimed in claim i in which the molar ratio of formaldehyde to hydrogen fluoride is in the range from about 1:2 to about 1:10.
- 3. A process as claimed in claim 1 in which the formaldehyde and hydrogen fluoride are caused to flow in counter-current in the column.
- 4. A process as claimed in claim 3 in which the formaldehyde and at least a part of the hydrogen fluoride are fed to the column through different inlets.
- 5. A process as claimed in claim 4 in which formaldehyde is fed to the distillation column at a position above that at which at least a part of the hydrogen fluoride is fed to the column.
- 6. A process as claimed in claim 1 in which the formaldehyde is fed to the column as a solution of formaldehyde in hydrogen fluoride.
- 7. A process for the production of difluoromethane which comprises the steps of (a) contacting formaldehyde with hydrogen fluoride in a reaction distillation column as defined in claim 1 and (b) feeding the bis(fluoromethyl)ether to a reaction zone whereby to convert the bis(fluoromethyl)ether to difluoromethane.
- 8. A process as claimed in claim 7 in which step (b) comprises heating the bis(fluoromethyl)ether to elevated temperature in the vapour phase, optionally in the presence of catalyst.
- 9. A process as claimed in claim 8 in which the catalyst comprises a metal selected from the group consisting of nickel, chromium, aluminum and iron or an alloy of at least one of these metals, or an oxide, fluoride or oxyfluoride thereof.
- 10. A process for the production of bis(fluoromethyl)ether which comprises reacting formaldehyde with hydrogen fluoride in a distillation column operated at a temperature in the reaction section of the column which at the particular pressure employed corresponds to a temperature of from about 50.degree. C. to about 80.degree. C. at atmospheric pressure, to produce bis(fluoromethyl)ether and water and withdrawing a vapor in which the mole ratio of bis(fluoromethyl)ether to water is greater than 1.
- 11. A process for the production of bis(fluoromethyl)ether which comprises reacting formaldehyde with hydrogen fluoride in a distillation column to produce bis(fluoromethyl)ether and water and withdrawing a vapor in which the mole ratio of bis(fluoromethyl)ether to water is greater than 1 and wherein the molar ratio of formaldehyde to hydrogen fluoride fed to the distillation column is in the range from about 1:0.5 to about 50:1.
- 12. A process for the production of bis(fluoromethyl)ether which comprises reacting formaldehyde with hydrogen fluoride in a distillation column operated with a reflux ratio in the range from about 0.1 to about 10, to produce bis(fluoromethyl)ether and water and withdrawing a vapor in which the mole ratio of bis(fluoromethyl)ether to water is greater than 1.
Priority Claims (1)
Number |
Date |
Country |
Kind |
9124087 |
Nov 1991 |
GBX |
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Parent Case Info
This is a continuation of U.S. application Ser. No. 08/145,668, filed Nov. 4, 1993, now U.S. Pat. No. 5,344,998, which is a continuation of U.S. application Ser. No. 07/974,710, filed Nov. 12, 1992, now abandoned.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
3377394 |
Boudakian et al. |
Apr 1968 |
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4143078 |
Gibbs et al. |
Mar 1979 |
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5073236 |
Gelbein et al. |
Dec 1991 |
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Foreign Referenced Citations (2)
Number |
Date |
Country |
1025856 |
Mar 1958 |
DEX |
2126216 |
Mar 1984 |
GBX |
Non-Patent Literature Citations (2)
Entry |
Weinmayr, Hydrogen Fluoride as a Condensing Agent. VI. REactions of Fluoroolefins with Formaldehyde in . . . , The Journal of Organic Chemistry, vol. 28, No. 2, Feb., 1963, pp. 492-494. |
West German Published Patent Application 1 025 856, Production of bis-methyl chloride ether, 1985. |
Continuations (2)
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Number |
Date |
Country |
Parent |
145668 |
Nov 1993 |
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Parent |
974710 |
Nov 1992 |
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