Process for preparing 1,3-alkanediols from 3-hydroxyesters

• US 20020161268A1
• Filed: 11/29/2001
• Published: 10/31/2002
• Est. Priority Date: 11/29/2000
• Status: Active Grant

• Current Assignee: Korea Research Institute of Chemical Technology, Samsung Electronics Co. Ltd.
• Original Assignee: Korea Research Institute of Chemical Technology, Samsung Electronics Co. Ltd.
• Inventors: Jang, Eun Joo, Lee, Ho Sun, Lee, Jung Ho, Shin, Hyun Kwan, Kim, Hyung Rok, Han, Yo Han, Lee, Byeong No
• Granted Patent: US 6,617,477 B2
• Time in Patent Office: Days
• US Class Current: 568/864
• CPC Class Codes: B01J 23/72 Copper
• CPC Class Codes: C07C 29/149 with hydrogen or hydrogen-containing gases
• CPC Class Codes: C07C 31/205 1,3-Propanediol; 1,2-Propanediol

Abstract

A process for preparing an 1,3-alkanediol from a 3-hydroxyester includes hydrogenating a 3-hydroxyester in an alcohol-containing solvent in the presence of a hydrogenation catalyst prepared by adding an alkaline precipitator to an aqueous solution containing a copper salt to form particles, and then aging the particles following addition of colloidal silica thereto. Novel hydrogenation catalysts so prepared are also disclosed.

Claims

1. A process for preparing a 1,3-alkanediol from a 3-hydroxyester, which comprises the step of hydrogenating a 3-hydroxyester in the presence of a catalyst prepared by adding an alkaline precipitator to an aqueous solution containing a copper salt to form particles and then aging the particles following the addition of colloidal silica thereto.

2. The process according to claim 1, wherein the alkaline precipitator is an alkali metal carbonate or sodium hydroxide.

3. The process according to claim 1, wherein the catalyst comprises CuO and SiO₂ in the ratio of about 9:

1 to about 5;

5 by weight.

4. The process according to claim 1, wherein the catalyst further comprises at least one additional promoter selected from the group consisting of Re, Pd, Ru, Pt, Rh, Ag, Se, Te, Mo and Mn in an amount from about 0.001 to about 10 mol % based on Cu.

5. The process according to claim 1, wherein the catalyst is modified with one alkylsilane compound selected from the group consisting of trialkoxymonoalkylsilane, dialkoxydialkylsilane and monoalkoxytrialkylsilane, wherein each alkyl group includes 1 to 30 carbon atoms, and wherein each alkoxy group is independently a linear or branched alkoxy group.

6. The process according to claim 5, wherein each alkoxy group is independently a methoxy or ethoxy group.

7. The process according to claim 1, wherein the 3-hydroxyester is represented by the following formulas (I) or (II):

8. The process according to claim 7, wherein in formulas (I) and (II), R is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutenyl, t-butyl, cyclohexyl, or cyclohexanemethyl.

9. The process according to claim 7,wherein the 3-hydroxyester is methyl 3-hydroxypropionate.

10. The process according to claim 1, wherein the hydrogenation reaction is carried out by a liquid-gas phase process in a mixed solvent comprising an alcohol and a high-boiling point solvent which boils at a higher temperature than the 1,3-alkanediol does.

11. The process according to claim 10, wherein the high-boiling point solvent is selected from the group consisting of tetra(ethylene glycol)dimethyl ether, penta(ethylene glycol)dimethyl ether and sulfolane, and wherein the weight ratio of the alcohol to the high-boiling point solvent ranges from about 5:

95 to about 90;

10 (w/w).

12. The process according to claim 10, wherein the 3-hydroxyester is dissolved in the mixed solvent to a concentration of about 2 to about 95% by weight.

13. The process according to claim 10, wherein the hydrogenation reaction is carried out at a temperature of about 100 to about 250°

C. under a pressure of about 50 to about 3,000 psig in a fixed bed reactor.

14. The process according to claim 13, wherein the hydrogenation reaction is carried out while maintaining the molar ratio of the introduced H₂ gas to the 3-hydroxyester in the range from about 10:

1 to about 300;

1 (m/m).

15. The process according to claim 1, wherein the hydrogenation reaction is carried out by a gas phase process in a low-boiling point alcohol solvent which boils at a lower temperature than the 1,3-alkanediol does.

16. The process according to claim 15, wherein the low-boiling point alcohol solvent is methanol.

17. The process according to claim 15, wherein the weight ratio of the 3-hydroxyester to the alcohol solvent ranges from about 10:

90 to about 90;

10 (w/w).

18. The process according to claim 15, wherein the hydrogenation reaction is carried out at a temperature of about 130 to about 200°

C. under a pressure of about 100 to about 3,000 psig in a fixed bed reactor.

19. The process according to claim 18, wherein the hydrogenation reaction is carried out while maintaining the molar ratio of the introduced H₂ gas to the 3-hydroxyester in the range from about 300:

1 to about 3,000;

1 (m/m).

20. A hydrogenation catalyst for preparing a 1,3-alkanediol from a 3-hydroxyester, the catalyst being prepared by a process comprising the steps of (i) adding an alkaline precipitator to an aqueous solution containing a copper salt to form particles, and subsequently (ii) aging the particled following the addition of colloidal silica thereto.

21. A hydrogenation catalyst prepared by adding an alkaline precipitator to an aqueous solution containing a copper salt to form particles and then aging the particles following the addition of colloidal silica thereto,

wherein the catalyst further comprises at least one promotor selected from the group consisting of Re, Pd, Ru, Pt, Rh, Ag, Se, Te, Mo and Mn.