Claims
- 1. A process of producing a mixture comprising tetrahydrofuran and 1,4-butanediol wherein the mole ratio of tetrahydrofuran to 1,4-butanediol is from about 0.02 to about 0.50, said process comprising reacting dimethylsuccinate with hydrogen in the presence of a copper chromite catalyst at a temperature from about 170.degree. C. to about 220.degree. C.
- 2. The process of claim 1 wherein the reaction is conducted at in the presence of a solvent comprising methanol.
- 3. The process of claim 1 wherein said mixture comprises tetrahydrofuran, 1,4-butanediol, water and methanol.
- 4. The process of claim 3 wherein tetrahydrofuran and 1,4-butanediol are removed from said mixture by
- (1) feeding said mixture into a first distillation zone wherein the butanediol is separated from said mixture and the remaining components are taken overhead as stream A;
- (2) feeding stream A into a second distillation zone in which tetrahydrofuran, water and methanol are taken overhead as stream B;
- (3) feeding stream B into a first tower wherein stream C containing tetrahydrofuran and methanol is taken overhead;
- (4) feeding stream C into a second tower wherein methanol is taken overhead and pure tetrahydrofuran is in the bottoms;
- (5) recycling the overhead from the second tower to stream B prior to entry into the first tower, wherein the second tower is operated at a pressure greater than the first tower.
- 5. A process of producing a mixture comprising tetrahydrofuran and 1,4-butanediol wherein the mole ratio of tetrahydrofuran to 1,4-butanediol is greater than 0.50 up to about 10, said process comprising reacting dimethylsuccinate with hydrogen in the presence of a copper chromite catalyst at a temperature from about 220.degree. to about 350.degree. C.
- 6. The process of claim 5 wherein the reaction is conducted at a temperature from about 230.degree. to about 270.degree. C.
- 7. The process of claim 5 wherein said mixture comprises tetrahydrofuran, 1,4-butanediol, water and methanol.
- 8. The process of claim 7 wherein tetrahydrofuran and 1,4-butanediol are removed from said mixture by
- (1) feeding said mixture into a first distillation zone wherein the butanediol is separated from said mixture and the remaining components are taken overhead as stream A;
- (2) feeding stream A into a second distillation zone in which tetrahydrofuran, water and methanol are taken overhead as stream B;
- (3) feeding stream B into a first tower wherein stream C containing tetrahydrofuran and methanol is taken overhead;
- (4) feeding stream C into a second tower wherein methanol is taken overhead and pure tetrahydrofuran is in the bottoms;
- (5) recycling the overhead from the second tower to stream B prior to entry into the first tower
- wherein the second tower is operated at a pressure greater than the first tower.
- 9. The process of claim 8 wherein said first tower is operated at a pressure of about 0.5 to about 2 atmospheres.
- 10. The process of claim 8 wherein said second tower is operated at a pressure of about 2 to about 20 atmospheres.
- 11. The process of claim 10 wherein said second tower is operated at a pressure of about 6 to about 12 atmospheres.
- 12. The process of claim 8 wherein said first tower is operated at 1 atmosphere and said second tower is operated at 7 atmospheres.
- 13. The process of claim 8 wherein the methanol present in the bottoms in the distillation of step (3) is separated from water in a subsequent distillation step.
Parent Case Info
This is a continuation-in-part of Ser. No. 710,016, filed on Mar. 11, 1985, now U.S. Pat. No. 4,613,707.
US Referenced Citations (12)
Foreign Referenced Citations (2)
Number |
Date |
Country |
1037487 |
Aug 1978 |
CAX |
1512751 |
Jan 1976 |
GBX |
Non-Patent Literature Citations (2)
Entry |
Abu-Eishah, S. I., "Distillation Process for Separation of Homogeneous Binary Azeotropic Mixtures"-Dissertation, (1982). |
Couteau et al., "Hydrogenation of dialkyl maleates or fumarates over Ba-stabilized Cu Chromite", Chemical Abstracts, p. 474, vol. 85, 1976. |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
710016 |
Mar 1985 |
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