Process for enzymatic hydrolysis of lignocellulosic material and fermentation of sugars
The invention relates to a process for the preparation of a fermentation product from ligno-cellulosic material, comprising the following steps: a) optionally pre-treatment b) optionally washing; c) enzymatic hydrolysis; d) fermentation; and e) optionally recovery of a fermentation product; wherein in step c) an enzyme composition is used that has a temperature optimum of 55 degrees C. or more, the hydrolysis time is 40 hours or more and the temperature is 50 degrees C. or more.
1. A process for preparing a biofuel from corn fiber, corn stover or wheat straw comprising:
a) pre-treating the corn fiber, corn stover or wheat straw;
b) enzymatically hydrolyzing the corn fiber, corn stover or wheat straw to produce a hydrolysate;
c) fermenting the hydrolysate into a biofuel; and
d) recovering the biofuel;
wherein enzymes used in step b) comprise of a broth resulting from growth of a filamentous fungal strain in a medium, which have a temperature optimum of 50-70° C.;
wherein a dry matter content of said corn fiber, corn stover or wheat straw in step b) is about 10-33% by weight;
wherein step b) is performed at a pH from about 4-6;
wherein step b) results in a release of at least 70% of available sugar in the corn fiber, corn stover or wheat straw;
wherein step b) occurs from 40-130 hours at a temperature of 50-70° C.; and
wherein in step c), the fermentation is conducted with a yeast strain that is able to ferment at least one C5 sugar selected from the group consisting of arabinose and xylose.
2. The process of claim 1 which uses said corn stover.
3. The process of claim 1 which uses said wheat straw.
4. The process of claim 1 which uses said corn fiber.
5. The process of claim 1 , wherein step b) is performed for about 72 to 120 hours.
6. The process of claim 1 , wherein step c) is performed for 20 to 60 hours.
7. The process of claim 6 , wherein step c) is performed for about 24-48 hours.
8. The process of claim 1 , wherein the total time to perform step b) and step c) is 72 to 150 hours.
9. The process of claim 1 , wherein step b) is performed at a temperature of about 55° C.
10. The process of claim 1 , wherein step b) is performed at a temperature of about 60° C.
11. The process of claim 1 , wherein step b) is performed at a temperature of about 65° C.
12. The process of claim 1 , wherein the dry matter content of said corn fiber, corn stover or wheat straw in step b) is about 14-25%.
13. The process of claim 1 , wherein the filamentous fungal strain is from the genus Penicillium or Talaromyces.
14. The process of claim 13 , wherein the filamentous fungal strain is Talaromyces emersonii.
15. The process of claim 1 , wherein step c) is performed under oxygen-limited conditions.
16. The process of claim 1 , wherein the biofuel is ethanol or butanol.
17. The process of claim 16 , wherein the biofuel is ethanol.
18. The process of claim 1 , wherein step b) results in a release of 90% of available sugar in the corn fiber, corn stover or wheat straw.