SOLVO-THERMAL HYDROLYSIS OF CELLULOSE

• US 20100048884A1
• Filed: 07/16/2009
• Published: 02/25/2010
• Est. Priority Date: 07/16/2008
• Status: Active Grant

• Current Assignee: Renmatix, Inc.
• Original Assignee: Renmatix, Inc.
• Inventors: KILAMBI, Srinivas
• Granted Patent: US 8,546,560 B2
• Time in Patent Office: Days
• US Class Current: 536/56
• CPC Class Codes: C07H 1/08 from natural products
• CPC Class Codes: C13K 1/00 Glucose separation from invert sugar C13K3/00; Glucose-containing syrups
• CPC Class Codes: C13K 1/02 obtained by saccharification of cellulosic materials manufacture of fodder A23K10/32
• CPC Class Codes: C13K 11/00 Fructose separation from invert sugar C13K3/00

Abstract

The invention relates to a process for hydrolyzing cellulose, comprising: (a) contacting cellulose with a fluid mixture comprising supercritical CO₂ and sub-critical or near-critical water to form a reactant mixture at a first temperature and first pressure for a first time period, wherein a reaction occurs and forms one or more hydrolysis products; (b) quenching the reaction; and (c) recovering at least one hydrolysis product.

Claims

1. A process for hydrolyzing cellulose, comprising:

(a) contacting cellulose with a fluid mixture comprising supercritical CO₂ and sub-critical or near-critical water to form a reactant mixture at a first temperature and first pressure for a first time period, wherein a reaction occurs and forms one or more hydrolysis products;

(b) quenching the reaction; and

(c) recovering at least one hydrolysis product.

2. The process of claim 1, wherein the first temperature is about 270°

C. to about 320°

C.

3. The process of claim 1, wherein the first pressure is about 180 bar to about 350 bar.

4. The process of claim 1, wherein the fluid mixture comprises about 5 wt % to about 20 wt % CO₂.

5. The process of claim 1, wherein the reaction is performed at a pH of about 3 to about 5.

6. The process of claim 1, wherein the first time period is about 1 s to about 30 s.

7. The process of claim 1, wherein the reaction is quenched by cooling the reactant mixture to a temperature of about 30°

C. to about 80°

C.

8. The process of claim 1, wherein prior to step (a), the cellulose is solubilized by (1) contacting the cellulose with near-critical or supercritical water at a second temperature and a second pressure for a second time period;

and (2) quenching the solubilization reaction.

9. The process of claim 8, wherein the second temperature is about 373°

C. to about 420°

C.

10. The process of claim 8, wherein the second pressure is about 200 bar to about 350 bar.

11. The process of claim 8, wherein the second time period is about 0.1 s to about 5 s.

12. The process of claim 8, wherein the solubilization reaction is quenched by lowering the temperature to about 280°

C.

13. The process of claim 8, wherein the solubilization reaction is quenched with CO₂ and optionally water.

14. The process of claim 1, wherein the at least one hydrolysis product is selected from the group consisting of glucose, fructose, mannose, cellobiose and oligomers thereof.

15. The process of claim 1, wherein the process is a continuous process, a semi-continuous process or a batch process.

24. A composition comprising at least one product of cellulose hydrolysis following a process according to claim 1, wherein the at least one product is selected from the group consisting of glucose, fructose, mannose, cellobiose and oligomers thereof.

16. A process for hydrolyzing cellulose, comprising:

(a) supplying a slurry comprising cellulose, water and CO₂ at a first temperature;

(b) heating the slurry at a second temperature and a pressure for a first time period, wherein the CO₂ is supercritical CO₂ and the water is near-critical or supercritical water, and wherein a hydrolysis reaction occurs;

(c) quenching the reaction; and

(d) recovering at least one hydrolysis product.

17. The process of claim 16, wherein the first temperature is about 220 to about 280°

C.

18. The process of claim 16, wherein the second temperature is about 371 to about 377°

C.

19. The process of claim 16, wherein the pressure is about 225 bar.

20. The process of claim 16, wherein the first time period is about 0.12 to about 0.3 seconds.

21. A system for hydrolyzing cellulose to form glucose, and optionally fructose, comprising:

a reactor configured for contacting cellulose with a reactive fluid at a temperature and pressure above the critical point of carbon dioxide but at least one of the temperature and pressure of the fluid is beneath the critical temperature and pressure for water;

a heating device configured for heating the reactive fluid to the desired temperature;

a back-pressure regulator located downstream of the reactor for maintaining the desired pressure; and

a heat exchanger configured for cooling the reaction and located downstream of the reactor.

22. The system of claim 21, further comprising a filtration device configured for separating at least a portion of the fractionated product in solid state from the fractioned and cooled reaction mixture.

23. A composition comprising cellulose and/or glucose in a mixture of carbon dioxide and water at a temperature and pressure above the critical point for carbon dioxide and below the critical point for water.