Claims
- 1. A process for purifying a mixture of 1,1,1-trifluoro-2-fluoroethane and a 1,1-difluoro-2-chloroethylene impurity, said process comprising reacting, at temperatures ranging from 200.degree. to 450.degree. C., said mixture with hydrofluoric acid in the presence of a chrome oxide catalyst in the carried form, wherein:
- said chrome oxide catalyst being of a substantially crystalline structure such that at least 60% by weight of said chrome oxide catalyst is of a non-amorphous crystalline structure, and
- said chrome oxide catalyst having been prepared by a method comprising:
- (a) impregnating a catalyst carrier with CrCl.sub.3 .cndot.H.sub.2 O, and
- (b) charging said impregnated catalyst carrier into a reactor and fluidizing it with an air flow at temperatures higher than 350.degree. C. and up to 500.degree. C. to convert the CrCl.sub.3 .cndot.H.sub.2 O at least prevailingly to Cr.sub.2 O.sub.3 and thus producing a chrome oxide catalyst being of a substantially crystalline structure such that at least 60% by weight of said chrome oxide catalyst is of a non-amorphous crystalline structure.
- 2. A process according to claim 1, said catalyst carrier which is impregnated consisting of at least partially fluorinated alumina.
- 3. A process according to claim 2, wherein at least 90% by weight of the alumina is fluorinated.
- 4. A process according to claim 1, wherein said catalyst carrier is impregnated with CrCl.sub.3 .cndot.H.sub.2 O from an aqueous solution of CrCl.sub.3 .cndot.H.sub.2 O by operating in alternating successive stages of impregnation and drying.
- 5. A process according to claim 1, wherein the fluidized air flow for conversion of the CrCl.sub.3 .cndot.H.sub.2 O to Cr.sub.2 O.sub.3 to produce a chrome oxide catalyst is at a temperature of from 400.degree. C. to 500.degree. C.
Priority Claims (1)
Number |
Date |
Country |
Kind |
MI91A3465 |
Dec 1991 |
ITX |
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Parent Case Info
This is a divisional of U.S. application Ser. No. 08/243,066 filed May 16, 1994, now U.S. Pat. No. 5,475,168, which is a continuation of U.S. application Ser. No. 07/995,127, filed Dec. 22, 1992 now abandoned.
US Referenced Citations (7)
Divisions (1)
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Date |
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Parent |
243066 |
May 1994 |
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Continuations (1)
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995127 |
Dec 1992 |
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