Claims
- 1. In a method for dehydrating vicinal diols into diolefins and olefin alcohols, the improvement comprising contacting said vicinal diol under dehydration conditions, effected with said diol in the vapor phase, pure or diluted with an inert gas, at a temperature between 350.degree. and 800.degree.C, and with an hourly space velocity of between about 0.5 and 2.5, with a mechanically strengthened catalyst prepared by the method consisting essentially of forming an intimate mixture of finely divided solid particles of at least one pyrophosphate and at least one acid orthophosphate of at least one metal belonging to the group consisting of lithium, sodium, strontium, and barium into a formed mass in a proportion sufficient to give improved mechanical strength to the resulting catalyst and calcinating said mass at a temperature of between about 400.degree. to 600.degree.C to transform said acid orthophosphate into pyrophosphate.
- 2. A method according to claim 1, comprising recycling the olefin alcohols for dehydration to said diolefin.
- 3. A method according to claim 2, wherein said diol is 2-methyl-2,3-butanediol and said diolefin is isoprene.
- 4. A method according to claim 2, wherein said diol is 2,3-butanediol and said diolefin is butadiene.
- 5. A method according to claim 2 wherein the method for preparing said catalyst said phosphates are mixed in powdered form, wetted to form a paste, extruded, dried, and finally calcinated.
- 6. A method according to claim 3 wherein the method for preparing said catalyst said phosphates are mixed in powdered form, wetted to form a paste, extruded, dried, and finally calcinated.
- 7. A method according to claim 4 wherein the method for preparing said catalyst said phosphates are mixed in powdered form, wetted to form a paste, extruded, dried, and finally calcinated.
- 8. A method according to claim 3 wherein said dehydration temperature is between 400.degree. and 500.degree.C.
- 9. A method according to claim 4 wherein said dehydration temperature is between 400.degree. and 500.degree.C.
Priority Claims (1)
Number |
Date |
Country |
Kind |
70.13791 |
Apr 1970 |
FR |
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Parent Case Info
This is a division of application Ser. No. 396,219, filed Sept. 11, 1973, now issued as Pat. No. 3,893,946, on July 8, 1975, which in turn is a continuation of the prior copending application Ser. No. 132,892, filed Apr. 9, 1971, now issued as Pat. No. 3,781,222, on Dec. 25, 1973.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
3758612 |
Maurin |
Sep 1973 |
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3781222 |
Weisang et al. |
Dec 1973 |
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3846338 |
Kachlova et al. |
Nov 1974 |
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Divisions (1)
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Number |
Date |
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Parent |
396219 |
Sep 1973 |
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Continuations (1)
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Number |
Date |
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Parent |
132892 |
Apr 1971 |
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