METHODS AND SYSTEMS FOR ENZYMATIC HYDROLYSIS OF PRETREATED BIOMASS AT HIGH SOLIDS CONCENTRATIONS

• US 20170204440A1
• Filed: 09/27/2016
• Published: 07/20/2017
• Est. Priority Date: 09/29/2015
• Status: Abandoned Application

• Current Assignee: API Intellectual Property Holdings, LLC
• Original Assignee: API Intellectual Property Holdings, LLC
• Inventors: RETSINA, Theodora, ZEBROSKI, Ryan
• Application Number:
  US15/276,834
• Publication Number:
  US 20170204440A1
• Time in Patent Office: Days
• CPC Class Codes: C12P 19/02 Monosaccharides 2-ketogulonic acid C12P7/60
• CPC Class Codes: C12P 19/14 produced by the action of a carbohydrase (EC 3.2.x), e.g. by alpha-amylase , e.g. by cellulase, hemicellulase
• CPC Class Codes: C12P 2203/00 Fermentation products obtained from optionally pretreated or hydrolyzed cellulosic or lignocellulosic material as the carbon source

Abstract

A method of enzymatically hydrolyzing pretreated lignocellulosic biomass at high solids concentration includes introducing pretreated biomass to a hydrolysis reactor, to hydrolyze the cellulose to glucose monomer and glucose oligomers, and circulating a liquid stream, from which glucose is removed to reduce glucose inhibition of cellulose hydrolysis. A surfactant may be added to the hydrolysis reactor. Heat and/or acid treatment of the glucose oligomers may be used to generate additional glucose monomer. Some variations introduce pretreated biomass to a hydrolysis reactor to hydrolyze cellulose to glucose monomer and glucose oligomers, followed by conveying a portion of the solid phase to a mechanical refiner and/or a unit under reduced pressure, to generate a refined and/or exploded solid phase; and recycling the refined and/or exploded solid phase, optionally reheated, back to an input of the hydrolysis reactor.

Claims

1. A method of enzymatically hydrolyzing pretreated lignocellulosic biomass at high solids concentration, said method comprising:

(a) providing pretreated lignocellulosic biomass containing cellulose;

(b) introducing said pretreated lignocellulosic biomass to a hydrolysis reactor under effective hydrolysis conditions and in the presence of enzymes including cellulases, to hydrolyze said cellulose to glucose monomer and glucose oligomers; and

(c) circulating a liquid stream in a circulation line configured from an output of said reactor back to an input of said hydrolysis reactor, wherein at least a portion of said glucose monomer is removed from said circulation line to reduce glucose inhibition of cellulose hydrolysis,

wherein said method further comprises a glucose oligomer hydrolysis step to generate additional glucose monomer from said glucose oligomers.

2. The method of claim 1, wherein said glucose oligomer hydrolysis step is integrated with step (b).

3. The method of claim 1, wherein said glucose oligomer hydrolysis step is integrated with step (c).

4. The method of claim 1, wherein at least a portion of said glucose oligomers is also removed from said circulation line to reduce glucose oligomer inhibition of cellulose hydrolysis.

5. The method of claim 1, wherein additional cellulase enzymes are introduced to said circulation line, to convert said glucose oligomers to said additional glucose monomer.

6. The method of claim 1, wherein said method further comprises introducing a surfactant to said hydrolysis reactor during step (b) or step (c).

7. The method of claim 6, wherein said surfactant includes lignin.

8. A method of enzymatically hydrolyzing pretreated lignocellulosic biomass at high solids concentration, said method comprising:

(a) providing pretreated lignocellulosic biomass containing cellulose;

(b) introducing said pretreated lignocellulosic biomass to a hydrolysis reactor under effective hydrolysis conditions and in the presence of enzymes including cellulases, to hydrolyze a portion of said cellulose to glucose monomer and glucose oligomers present in a liquid phase, wherein non-hydrolyzed cellulose remains in a solid phase; and

(c) conveying a portion of said solid phase to a mechanical refiner, to generate a refined solid phase; and

(d) recycling said refined solid phase back to an input of said hydrolysis reactor.

10. The method of either one of claim 8 or 9, wherein said method further comprises an oligomer hydrolysis step of said glucose oligomers to generate additional glucose monomer.

11. The method of either one of claim 8 or 9, wherein said method further comprises introducing a surfactant to said hydrolysis reactor.

12. The method of either one of claim 8 or 9, wherein said pretreated lignocellulosic biomass is a pulp material, derived from wood or lignocellulosic biomass, selected from the group consisting of kraft pulp, sulfite pulp, soda pulp, mechanical pulp, thermomechanical pulp, chemimechanical pulp, and combinations thereof.

13. The method of either one of claim 8 or 9, wherein said pretreated lignocellulosic biomass is obtained from steam or hot-water extraction of lignocellulosic biomass.

14. The method of either one of claim 8 or 9, wherein said pretreated lignocellulosic biomass is present in said hydrolysis reactor at a solids concentration of about 20 wt % or more.

15. The method of either one of claim 8 or 9, wherein a first amount of enzymes is introduced at a first solids concentration, wherein a second amount of enzymes is introduced at a second solids concentration, and wherein said second solids concentration is higher than said first solids concentration.

9. A method of enzymatically hydrolyzing pretreated lignocellulosic biomass at high solids concentration, said method comprising:

(a) providing pretreated lignocellulosic biomass containing cellulose;

(b) introducing said pretreated lignocellulosic biomass to a hydrolysis reactor under effective hydrolysis conditions and in the presence of enzymes including cellulases, to hydrolyze a portion of said cellulose to glucose monomer and glucose oligomers present in a liquid phase, wherein non-hydrolyzed cellulose remains in a solid phase;

(c) feeding a portion of said solid phase to a unit under reduced pressure, to generate an exploded solid phase; and

(d) recycling said exploded solid phase, optionally reheated, back to an input of said hydrolysis reactor.