Process for hydrolysis of biomass

• US 4,556,430 A
• Filed: 11/05/1984
• Issued: 12/03/1985
• Est. Priority Date: 09/20/1982
• Status: Expired due to Fees

• Current Assignee: The Trustees of Dartmounth College (Dartmouth College)
• Original Assignee: The Trustees of Dartmounth College (Dartmouth College)
• Inventors: Grethlein, Hans E., Converse, Alvin O.
• Primary Examiner(s): Schor, Kenneth M.
• Application Number:
  US06/668,672
• Time in Patent Office: 393 Days
• Field of Search: 127/36, 127/37, 435/99, 435/105, 435/163, 435/165
• US Class Current: 127/36
• CPC Class Codes: C13K 1/02 obtained by saccharification of cellulosic materials manufacture of fodder A23K10/32

Abstract

A process for hydrolysis of biomass wherein the biomass is mixed with a small amount of an aqueous acid to produce a wet meal. A non-aqueous carrier fluid is used to form a slurry of the biomass, and the temperature and pressure are established at appropriate levels to effect hydrolysis of the biomass to decomposition products that include sugar for a time period that is sufficient for the hydrolysis to occur.

Claims

1. A process for hydrolysis of biomass, that comprises:

mixing particulate biomass with a small amount of an aqueous acid to produce a wet meal;

introducing a non-aqueous liquid carrier to the biomass to produce a slurry, said non-aqueous liquid being immiscible in water; and

continuously feeding the slurry through a reaction zone whose pressure and temperature are controlled for a prescribed time to effect hydrolysis of the carbohydrate component of the biomass to decomposition products that include sugar.

2. A process according to claim 1 wherein the temperature of the slurry is elevated prior to continuously feeding the slurry through a reaction zone.

3. A process according to claim 1 wherein the temperature of the particulate biomass is elevated prior to the introduction of the acid.

4. A process according to claim 1 where in the slurry is pumpable.

5. A process according to claim 1 in which the non-aqueous liquid carrier is a hydrocarbon.

6. A process according to claim 1 in which the non-aqueous liquid carrier is a hydrocarbon derivative.

7. A process according to claim 1 wherein the sugar is dissolved in the aqueous phase, hydrocarbons in the biomass are suspended in the non-aqueous phase, and lignin in the biomass is dissolved preferentially in the non-aqueous phase or is distrbuted between the aqueous phase and the non-aqueous phase.

8. A process according to claim 1 in which the non-aqueous liquid carrier is kerosene.

9. A process according to claim 1 wherein the non-aqueous liquid carrier is perchloroethylene.

10. A process according to claim 1 wherein the pressure is sufficient to maintain the carrier in the liquid phase.

11. A process according to claim 1 wherein the temperature, pressure and prescribed time are interrelated to realize significant hydrolysis to sugars and yet minimize decomposition of the sugars.

12. A process according to claim 11 in which the temperature is in the range from about 160°

C. to 260°

C. and the pressure in the reaction zone is maintained in the range from about 400 psi to 800 psi.

13. A process according to claim 1 wherein the non-aqueous liquid is a hydrocarbon, wherein the slurry is hydrolyzed in a reactor and is pumped through the reaction zone as a continuous flow and wherein sufficient liquid hydrocarbon is introduced to produce a pumpable slurry for continuous flow reaction within the reactor while avoiding surplus water in the decomposition products so that the sugar in the decomposition products is of a high concentration.

14. A process according to claim 1 that includes abruptly terminating all chemical reactions after said prescribed time.

15. A process according to claim 14 in which said terminating is accomplished by abruptly reducing the pressure and thereby effecting flash cooling.

16. A process according to claim 15 wherein the vapor formed upon flashing is separated from the slurry to increase the sugar concentration in the aqueous phase.

17. A process according to claim 14 that further includes separating the solid, the aqueous liquid phase, and the non-aqueous liquid phase from one another.

18. A process according to claim 17 that further includes washing the solid with an aqueous solution to remove the sugars therefrom.

19. A process according to claim 17 that further includes washing the solid with a water to remove the sugars therefrom.

20. A process according to claim 1 wherein the aqueous acid is in the range from about 2 percent to 12 percent.

21. A process according to claim 1 in which the non-aqueous liquid carrier is a liquid fuel, which liquid fuel acts to dissolve lignin and other extractables to increase the amount of the liquid fuel.

22. A process according to claim 1 in which the decomposition products include furfural.

23. A process for hydrolysis of biomass to convert carbohydrate components to sugar, the process comprising:

mixing particulate biomass with a sufficient amount of an aqueous acid to produce a wet meal;

introducing a sufficient amount of a nonaqueous liquid carrier to the biomass to produce a pumpable slurry and to concentrate sugar in the aqueous phase of said slurry;

said non-aqueous liquid being immiscible in water and continuously feeding the slurry through a reaction zone whose pressure and temperature are controlled for a residence time of about 4 to 15 seconds to effect hydrolysis of the carbohydrate component of the biomass to provide decomposition products that include sugar.