Claims
- 1. A process for the production of difluoromethane which comprises reacting chlorodifluoromethane with hydrogen at elevated temperature from about 225.degree. to about 400.degree. C. and a pressure ranging from about 2 bar to about 60 bar in the presence of a hydrogenation catalyst comprising palladium carried on an active carbon support wherein palladium is the predominant metal and the % w/w palladium to active carbon is from about 8% w/w to about 20% w/w, the temperature, pressure and catalyst composition being selected such that difluoromethane is produced with a yield of at least 25%, and recycling unreacted starting materials and organic by-products.
- 2. A process as claimed in claim 1 wherein the loading of palladium on the support is in the range from about 8% to about 15% by weight.
- 3. A process as claimed in claim 2 wherein the active carbon employed is such that at a temperature of 250.degree. C., atmospheric pressure and a palladium loading of 10% w/w, the yield of difluoromethane is at least 50%.
- 4. A process as claimed in claim 3 wherein the catalyst comprises one or more metals in addition to palladium carried on an active carbon support.
- 5. A process as claimed in claim 4 wherein the catalyst comprises a Group VIIIa metal in addition to palladium.
- 6. A process as claimed in claim 5 wherein the catalyst comprises palladium and nickel carried on an active carbon support.
- 7. A process as claimed in claim 6 wherein the proportion by weight of palladium and nickel in the catalyst is in the range from about 2:1 to about 500:1.
- 8. A process as claimed in claim 1 wherein the molar proportion of hydrogen to chlorodifluoromethane is in the range from about 1:1 to about 4:1.
Priority Claims (1)
Number |
Date |
Country |
Kind |
9107677 |
Apr 1991 |
GBX |
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Parent Case Info
This is a continuation of application Ser. No. 08/130,411, filed on Oct. 1, 1993, now abandoned which is a continuation of U.S. Pat. No. 07/864,409, filed Apr. 6, 1992, now abandoned.
Foreign Referenced Citations (5)
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Country |
670338 |
Sep 1983 |
CAX |
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EPX |
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EPX |
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DEX |
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Non-Patent Literature Citations (1)
Entry |
Park et al., Thermochemical & Photochemical Studies on Organic Fluorine Compounds, AFOSR Document No. TR-58-99. ASTIA No. AD 162 198, Dept. of Chemistry, University of Colorado. |
Continuations (2)
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Number |
Date |
Country |
Parent |
130411 |
Oct 1993 |
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Parent |
864409 |
Apr 1992 |
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