Method of producing lower alcohols from glycerol

• US 7,816,567 B2
• Filed: 12/22/2009
• Issued: 10/19/2010
• Est. Priority Date: 04/22/2002
• Status: Expired due to Term

• Current Assignee: Renewable Alternatives LLC, Curators of the University of Missouri (University of Missouri)
• Original Assignee: Renewable Alternatives LLC, Curators of the University of Missouri (University of Missouri)
• Inventors: Dasari, Mohanprasad, Sutterlin, William Rusty, Suppes, Galen J.
• Primary Examiner(s): Price; Elvis O
• Application Number:
  US12/645,213
• Publication Number:
  US 20100099924A1
• Time in Patent Office: 301 Days
• Field of Search: 568/861
• US Class Current: 568/861
• 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 31/205 1,3-Propanediol; 1,2-Propanediol
• 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

Abstract

A reactive-separation process converts glycerin into lower alcohols, having boiling points less than 200° C., at high yields. Conversion of natural glycerin to propylene glycol through an acetol intermediate is achieved at temperatures from 150° to 250° C. at a pressure ranging from 1 and 25 bar. The preferred applications of the propylene glycol are as an antifreeze, deicing compound, or anti-icing compound. The preferred catalyst for this process in a copper-chromium powder.

Claims

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

combining a glycerol-containing feedstock with a catalyst that is capable of hydrogenating glycerol, to form a reaction mixture;

heating the reaction mixture to a temperature ranging from 150°

to 250°

C. and at a pressure ranging from 0.2 to 25 bar;

simultaneously with the step of heating, removing vapor effluent from the reaction mixture by the action of hydrogen gas to form removed products, and

catalytically reacting the removed products to yield propylene glycol.

2. The process of claim 1, wherein the glycerol-containing feedstock used in the step of combining contains from 5% to 15% water by weight.

3. The process of claim 1, wherein the catalyst used in the step of combining is a heterogeneous catalyst selected from the group consisting of palladium, nickel, rhodium, copper, zinc, chromium and combinations thereof.

4. The process of claim 1, where in the catalyst used in the step of combining is a copper chromite catalyst.

5. The process of claim 1, wherein the catalyst used in the step of catalytically reacting is a heterogeneous catalyst selected from the group consisting of palladium, nickel, rhodium, copper, zinc, chromium and combinations thereof.

6. The process of claim 1, where in the catalyst used in the step of catalytically reacting is a copper chromite catalyst.

7. The process of claim 5, wherein the temperature used in the heating step ranges from 180°

C. to 220°

C.

8. The process of claim 6, wherein the pressure used in the heating step ranges from 0.8 to 5 bar.

9. The process of claim 1, wherein the temperature used in the heating step ranges from 180°

C. to 220°

C.

10. The process of claim 9, wherein the pressure used in the heating step ranges from 0.8 to 5 bar.

11. The process of claim 9 wherein the step of catalytically reacting is performed at a higher pressure than the step of heating.