Process for enzymatic hydrolysis of lignocellulosic material and fermentation of sugars
The invention relates to a process for the preparation of a sugar product from ligno-cellulosic material, comprising the following steps: a) optionally pre-treatment of the ligno-cellulosic material; b) optionally washing of the optionally pre-treated ligno-cellulosic material; c) enzymatic hydrolysis of the optionally washed and/or optionally pre-treated ligno-cellulosic material using an enzyme composition comprising at least two cellulase and whereby the enzyme composition at least comprises GH61; and d) optionally recovery of a sugar product; wherein during part of the time of the enzymatic hydrolysis, oxygen is added to the ligno-cellulosic material and during part of the time of the enzymatic hydrolysis less oxygen is added to the ligno-cellulosic material compared to the other part of the time of the enzymatic hydrolysis, preferably no oxygen is added to the ligno-cellulosic material.
1. A process for the preparation of a sugar product from ligno-cellulosic material, comprising:
enzymatic hydrolysis of ligno-cellulosic material using an enzyme composition comprising at least two cellulases and whereby the enzyme composition at least comprises GH61; and
wherein:
the enzymatic hydrolysis occurs for a first part of time and a subsequent second part of time;
during the first part of time dissolved oxygen in the ligno-cellulosic material is at a concentration that is at least 50% less than during the second part of time, during the second part of time oxygen is added to the ligno-cellulosic material continuously, and the second part of time is 2% to 80% of the total enzymatic hydrolysis time; and
the ligno-cellulosic material has a dry matter content of 10 wt % or more.
2. A process for the preparation of a sugar product from ligno-cellulosic material, comprising:
enzymatic hydrolysis of ligno-cellulosic material using an enzyme composition comprising at least two cellulases and whereby the enzyme composition at least comprises GH61; wherein:
the enzymatic hydrolysis occurs for a first part of time and a subsequent second part of time;
during the first part of time dissolved oxygen in the ligno-cellulosic material is at a concentration that is at least 50% less than during the second part of time, during the second part of time oxygen is added to the ligno-cellulosic material discontinuously, and the second part of time is 2% to 80% of the total enzymatic hydrolysis time; and
the ligno-cellulosic material has a dry matter content of 10 wt % or more.
3. The process according to claim 1 , wherein the second part of time is 12% to 50% of the total enzymatic hydrolysis time.
4. The process according to claim 1 , wherein the second part of time is 20% to 40% of the total enzymatic hydrolysis time.
5. The process according to claim 1 , wherein, the dissolved oxygen concentration is maintained in the range of 0.02 mol/m 3 to 0.045 mol/m 3 , and wherein dissolved oxygen is measured under normal atmospheric pressure and at about 62° C.
6. The process according to claim 1 , wherein the reactor for the enzymatic hydrolysis has a volume of 1 m 3 or more.
7. The process according to claim 1 , wherein the enzymatic hydrolysis time is 5 to 150 hours.
8. The process according to claim 1 , wherein the enzyme composition used retains activity for 30 hours or more.
9. The process according to claim 1 , wherein the hydrolysis is conducted at a temperature of 45° C. or more.
10. The process according to claim 1 , wherein the enzyme composition is from a fungus, or the enzyme composition comprises a fungal enzyme.
11. The process according to claim 1 , wherein the dry matter content is 14 to 33% wt %.
12. The process according to claim 1 in which the enzymatic hydrolysis takes place in a batch, fed batch and/or continuous culture reactor.
13. The process according to claim 1 in which oxygen is introduced as an oxygen-containing gas, in the form of bubbles.
14. The process of claim 10 , wherein the fungus is of the genus Rasamsonia , or the fungal enzyme is a Rasamsonia enzyme.