Method of producing lower alcohols from glycerol

• US 8,252,961 B2
• Filed: 12/19/2008
• Issued: 08/28/2012
• Est. Priority Date: 04/22/2002
• Status: Active Grant

• Current Assignee: Curators of the University of Missouri (University of Missouri)
• Original Assignee: Curators of the University of Missouri (University of Missouri)
• Inventors: Suppes, Galen J.
• Primary Examiner(s): WITHERSPOON, SIKARL A
• Application Number:
  US12/340,371
• Publication Number:
  US 20090105509A1
• Time in Patent Office: 1,348 Days
• Field of Search: 568/861, 568/862
• US Class Current: 568/861
• CPC Class Codes: C07C 27/04 by reduction of oxygen-containing compounds C07C29/14 takes precedence
• CPC Class Codes: C07C 29/145 with hydrogen or hydrogen-containing gases
• CPC Class Codes: C07C 29/60 by elimination of -OH groups, e.g. by dehydration C07C29/34 takes precedence
• CPC Class Codes: C07C 31/202 Ethylene glycol
• CPC Class Codes: C07C 31/205 1,3-Propanediol; 1,2-Propanediol
• CPC Class Codes: C07C 31/225 Glycerol
• CPC Class Codes: C07C 45/52 by dehydration and rearrangement involving two hydroxy groups in the same molecule
• CPC Class Codes: C07C 49/17 containing hydroxy groups sugars C07H
• CPC Class Codes: C09K 3/185 Thawing materials
• CPC Class Codes: C09K 5/10 Liquid materials
• CPC Class Codes: C09K 5/20 Antifreeze additives therefor, e.g. for radiator liquids for application to surfaces C09K3/18; inhibiting corrosion by liquids C23F11/00
• CPC Class Codes: Y02P 20/52 using catalysts, e.g. selective catalysts

Abstract

This invention relates generally to a process for value-added processing of fats and oils to yield glycerol and glycerol derivatives. More particularly, the process converts glycerol to acetol and then acetol to propylene glycol to produce a propylene glycol with ultra-low amounts of ethylene glycol. The propylene glycol thus produced may be used as an antifreeze, deicing compound, or anti-icing compound.

Claims

1. A process for converting glycerol to acetol with high selectivity, comprising the steps of:

(a) contacting a glycerol-containing material with a catalyst that is capable of dehydrating glycerol, in order to form a reaction mixture;

(b) reacting the reaction mixture under a first condition for reaction to dehydrate the glycerol with resultant formation of acetol as a main component of a first reaction product, said first condition including a temperature within a range from 150°

C. to 250°

C. and a pressure within a range from 0.02 bar to 25 bar;

(c) separating the acetol formed in step (b) from other components in the first reaction product;

(d) reacting the separated acetol from step (c) to form a second reaction product.

2. The process of claim 1, wherein the second reaction product comprises propylene glycol.

3. The process of claim 1, wherein more than 50% (w/w) of the second reaction product is propylene glycol.

4. The process of claim 3, wherein more than 80% (w/w) of the second reaction product is propylene glycol.

5. The process of claim 1, wherein said first condition is in favor of formation of acetol.

6. The process of claim 5, wherein the first condition includes a temperature within a range from 190°

C. to 250°

C.

7. The process of claim 6, wherein the first condition includes a temperature within a range from 200°

C. to 230°

C.

8. The process of claim 5, wherein the first condition includes a pressure within a range from 0.05 bar to 1.2 bar.

9. The process of claim 8, wherein the first condition includes a pressure within a range from 0.1 bar to 0.3 bar.

10. The process of claim 5, wherein the molar ratio of hydrogen to glycerol is about 0.1.

11. The process of claim 1, wherein step (d) is performed under a second condition that is in favor of formation of propylene glycol.

12. The process of claim 11, wherein the second condition includes a temperature within a range from 140°

C. to 220°

C.

13. The process of claim 12, wherein the second condition includes a temperature within a range from 160°

C. to 200°

C.

14. The process of claim 11, wherein the second condition includes a pressure within a range from 1.2 bar to 500 bar.

15. The process of claim 14, wherein the second condition includes a pressure within a range from 2 bar to 30 bar.

16. The process of claim 11, wherein the molar ratio of hydrogen to glycerol is between 1 to 1000.

17. The process of claim 16, wherein the molar ratio of hydrogen to glycerol is between 1.2 to 15.

18. The process of claim 1, wherein acetol is substantially separated from at least one component selected from the group consisting of ethylene glycol and propylene glycol in step (c).

19. The process of claim 1, wherein the acetol subjected to the reaction of step (d) is substantially free from ethylene glycol.

20. The process of claim 1, wherein at least 70% by weight of ethylene glycol present in the first reaction product is removed from the acetol.

21. The process of claim 1, wherein at least 90% by weight of ethylene glycol present in the first reaction product is removed from the acetol.

22. The process of claim 1, wherein acetol is substantially separated from hydrogen and water in step (c).

23. The process of claim 22, wherein the separated hydrogen and water are recycled.

24. The process of claim 1 further comprising a step (e) wherein the second reaction product is separated from other components present in the second reaction product.

25. The process of claim 24, wherein acetol is substantially separated from propylene glycol in step (e).

26. The process of claim 1, where the maximum pressure of the first reaction condition is less than 4 bar, and the step (d) of reacting is also conducted at a pressure of less than 4 bar.