Conversion of carbohydrates to levulinic acid esters

Patent metadata

Field	Value
Publication number	US-9676697-B2
Application number	US-201615051288-A
Country	US
Kind code	B2
Filing date	Feb 23, 2016
Priority date	Aug 2, 2012
Publication date	Jun 13, 2017
Grant date	Jun 13, 2017

Abstract

The present invention relates to the field of converting carbohydrates into levulinic acid, a platform chemical for many chemical end products. More specifically the invention relates to a method for converting carbohydrates such as mono-, di- or polysaccharides, obtained from for example biomass production into a suitable levulinic acid ester in the presence of a zeolite or zeotype catalyst and a suitable alcohol, and the ester may be further converted into levulinic acid if desired.

First claim

The invention claimed is:

1. A method of converting a saccharide into a levulinic acid ester, comprising heating the saccharide to a temperature between 120° C. and 200° C. in the presence of a zeolite or zeotype catalyst with a pore size diameter of at least 6 Å, wherein the effective number of total acid sites (measured by the TPD-NH3 method) in the catalyst is above 250 μmol/g, and the ratio between the number of medium acid sites (type 1) and strong acid sites (type 2) (measured by the TPD-NH3 method) is between 1:0.3 and 1:1; and a C 1 -C 4 alcohol solvent in a pressurized batch reactor;
wherein the saccharide is selected from the group consisting of fructose, a fructose-containing disaccharide, a fructose-containing oligosaccharide, and a fructose-containing polysaccharide or a mixture thereof; and
wherein the pressure in the reactor is at least 2 bar.

2. The method according to claim 1 , wherein the catalyst has a pore size diameter between 6 and 8 Å.

3. The method according to claim 1 , wherein the ratio between the number of medium acid sites (type 1) and strong acid sites (type 2) (measured by the TPD-NH3 method) is between 1:0.3 and 1:0.95.

4. The method according to claim 1 , wherein the ratio between the number of medium acid sites (type 1) and strong acid sites (type 2) (measured by the TPD-NH3 method) is between 1:0.5 and 1:0.95.

5. The method according to claim 1 , wherein the saccharide is a monosaccharide, a disaccharide, or a polysaccharide, or a combination thereof.

6. The method according claim 1 , wherein the catalyst is selected from the group consisting of HY zeolites and Hbeta zeolites.

7. The method according to claim 1 , wherein the catalyst is selected from the group consisting of HY 6, HY 30, Hbeta 12.5 and Hbeta 19.

8. The method according to claim 1 , wherein the catalyst is selected from the group consisting of HY 6, Hbeta 12.5 and Hbeta 19.

9. The method according to claim 1 , wherein the catalyst is a mesozeolite.

10. A method according to claim 1 , wherein the C 1 -C 4 alcohol solvent is selected from the group consisting of methanol, ethanol, n-propanol, isopropanol, 1-butanol, 2-butanol and tert-butanol.

11. The method according to claim 1 , wherein the saccharide is heated in the solvent in the presence of the catalyst in a pressurized reactor to a suitable temperature at or above 140° C.

12. The method according to claim 11 , wherein the saccharide and solvent is heated in the pressurized reactor to or above 160° C.

13. The method according to claim 1 , wherein the pressure in the reactor is about 20 bar.

14. The method according to claim 1 , wherein the levulinic acid ester is methyl levulinate (MLevu) or ethyl levulinate (ELevu).

15. The method according to claim 1 , wherein the levulinic acid ester is methyl levulinate (MLevu).

16. The method according to claim 15 , wherein the yield of methyl levulinate (MLevu) is at least 40%.

17. A method for the manufacture of levulinic acid, wherein the levulinic acid ester obtained according to claim 1 is hydrolyzed to obtain levulinic acid, wherein the hydrolysis is acidic, basic or enzymatic.

18. The method according to claim 1 , wherein the saccharide is obtained from a biomass or biowaste.

19. The method according to claim 1 , wherein the pressure in the reactor is at least 4 bar.

20. The method according to claim 1 , wherein the pressure in the reactor is at least 10 bar.

21. The method according to claim 1 , wherein the saccharide is selected from the group consisting of fructose, sucrose and inulin, or a mixture thereof.

Assignees

• Univ Danmarks Tekniske

Inventors

• Saravanamurugan Shunmugavel
• Riisager Anders

Classifications

• C07C51/09

  from carboxylic acid esters or lactones · CPC title

• C12P7/42

  Hydroxy-carboxylic acids · CPC title

• C07C67/00 Primary

  Preparation of carboxylic acid esters · CPC title

• C07C59/185

  Saturated compounds having only one carboxyl group and containing keto groups · CPC title

• C07C69/716

  Esters of keto-carboxylic acids {or aldehydo-carboxylic acids} · CPC title