Process for increasing the enzymatic accessibility of a thermally treated ligno-cellulosic biomass feedstock

Patent metadata

Field	Value
Publication number	US-10233570-B2
Application number	US-201415032649-A
Country	US
Kind code	B2
Filing date	Oct 31, 2014
Priority date	Oct 31, 2013
Publication date	Mar 19, 2019
Grant date	Mar 19, 2019

Abstract

It is disclosed a process for increasing the enzymatic accessibility of a thermally treated ligno-cellulosic biomass feedstock which has been thermally treated at a severity factor. The process comprises a step of fiber shives reduction, for reducing the amount of long shives. The thermally treated ligno-cellulosic biomass after fiber shives reduction is characterized by having an increased glucans accessibility and by forming a slurry having a low viscosity.

First claim

The invention claimed is:

1. A process for increasing the enzymatic accessibility of a thermally treated steam exploded ligno-cellulosic biomass feedstock which has been thermally treated by soaking and steam explosion for a total severity factor of less than 4.0, wherein said thermally treated steam exploded ligno-cellulosic biomass feedstock is free of an added base and comprised of xylans, glucans and lignin and is in physical forms of at least fibres, fines and fiber shives, wherein:
a. the fibres each have a width of 75 μm or less, and a fibre length greater than or equal to 200 μm,
b. the fines each have a width of 75 μm or less, and a fine length less than 200 μm,
c. the fiber shives each have a shive width greater than 75 μm with a first portion of the fiber shives each having a shive length less than 737 μm and a second portion of the fiber shives each having a shive length greater than or equal to 737 μm,

wherein the process is conducted without the addition of a base and comprises a fiber shives conversion step, which converts the fiber shives to fibres or fines such that the percent area of fiber shives having a shive length greater than or equal to 737 μm relative to the total area of fiber shives, fibres and fines of the thermally treated steam exploded ligno-cellulosic biomass after fiber shives conversion is less than the percent area of fiber shives having a shive length greater than or equal to 737 μm relative to the total area of the fiber shives, fibres and fines of the thermally treated steam exploded ligno-cellulosic biomass before fiber shives conversion, wherein the percent area is measured by automated optical analysis, and wherein at least a part of the fiber shives conversion step is done by applying a work in a form of mechanical forces to the thermally treated ligno-cellulosic biomass, and all the work done by all the forms of mechanical forces on the thermally treated steam exploded ligno-cellulosic biomass is less than 500 WH/Kg per kg of the thermally treated steam exploded ligno-cellulosic biomass on a dry basis.

2. The process of claim 1 , wherein the mechanical forces applied to the thermally treated steam exploded ligno-cellulosic biomass is not derived from free-fall or gravity mixing.

3. The process of claim 1 , wherein the mechanical forces are applied using a machine selected from the group consisting of single screw extruders, twin screw extruders, and banburies.

4. The process of claim 1 , wherein the thermally treated steam exploded ligno-cellulosic biomass before fiber shives conversion is characterized by having a viscosity of a slurry of the thermally treated steam exploded ligno-cellulosic biomass before fiber shives reduction in water which is greater than the viscosity of a slurry of the thermally treated steam exploded ligno-cellulosic biomass after fiber shives reduction in water, wherein the viscosities are measured at 25° C., at a shear rate of 10 s −1 and at a dry matter content of 7% by weight of each slurry.

5. The process of claim 1 , wherein the thermally treated steam exploded ligno-cellulosic biomass after fiber shives conversion is characterized by having a viscosity of a slurry of the thermally treated steam exploded ligno-cellulosic biomass after fiber shives reduction in water less than a value selected from the group consisting of 10 Pa s, wherein the viscosity is measured at 25° C., at a shear rate of 10 s −1 and at a dry matter content of 7% by weight of the slurry of the thermally treated steam exploded ligno-cellulosic biomass after fiber shives reduction in the water.

6. The process of claim 1 , wherein the thermally treated steam exploded ligno-cellulosic biomass after fiber shives conversion has a glucans accessibility of the thermally treated steam exploded ligno-cellulosic biomass after fiber shives reduction and the thermally treated steam exploded ligno-cellulosic biomass has a glucans accessibility of the thermally treated steam exploded ligno-cellulosic biomass before fiber shives reduction and the glucans accessibility of the thermally treated steam exploded ligno-cellulosic biomass after fiber shives conversion is greater than the glucans accessibility of the thermally treated steam exploded ligno-cellulosic biomass before fiber shives conversion.

7. A process for increasing the enzymatic accessibility of a thermally treated steam exploded ligno-cellulosic biomass feedstock which has been thermally treated by soaking and steam explosion for a total severity factor of less than 4.0, wherein said thermally treated steam exploded ligno-cellulosic biomass feedstock is free of an added base and comprised of xylans, glucans and lignin and is in physical forms of at least fibres, fines and fiber shives, wherein:
a. the fibres each have a width of 75 μm or less, and a fibre length greater than or equal to 200 μm,
b. the fines each have a width of 75 μm or less, and a fine length less than 200 μm,
c. the fiber shives each have a shive width greater than 75 μm with a first portion of the fiber shives each having a shive length less than 737 μm and a second portion of the fiber shives each having a shive length greater than or equal to 737 μm,

wherein the process comprises separating at least a portion of the fiber shives having a shive length greater than or equal to 737 μm from the thermally treated steam exploded ligno-cellulosic biomass such that the percent area of fiber shives having a shive length greater than or equal to 737 μm relative to the total area of fiber shives, fibres and fines of the thermally treated steam exploded ligno-cellulosic biomass after fiber shives separation is less than the percent area of fiber shives having a shive length greater than or equal to 737 μm relative to the total area of the fiber shives, fibres and fines of the thermally treated steam exploded ligno-cellulosic biomass before fiber shives separation, wherein the percent area is measured by automated optical analysis.

8. The process of claim 7 , wherein the thermally treated steam exploded ligno-cellulosic biomass before fiber shives spearation is characterized by having a viscosity of a slurry of the thermally treated steam exploded ligno-cellulosic biomass before fiber shives separation in water which is greater than the viscosity of a slurry of the thermally treated steam exploded ligno-cellulosic biomass after fiber shives reduction in water, wherein the viscosities are measured at 25° C., at a shear rate of 10 s −1 and at a dry matter content of 7% by weight of each slurry.

9. The process of claim 8 , wherein the thermally treated steam exploded ligno-cellulosic biomass after fiber shives separation is characterized by having a viscosity of a slurry of the thermally treated steam exploded ligno-cellulosic biomass after fiber shives reduction in water less than a value selected from the group consisting of 10 Pa s, wherein the viscosity is measured at 25° C., at a shear rate of 10 s −1 and at a dry matter content of 7% by weight of the slurry of the thermally treated steam exploded ligno-cellulosic biomass after fiber shives reduction in the water.

10. The process of claim 9 , wherein the thermally treated steam exploded ligno-cellulosic biomass after fiber shives separation has a glucans accessibility of the thermally treated steam exploded ligno-cellulosic biomass after fiber shives reduction and the thermally treated steam exploded ligno-cellulosic biomass has a glucans accessibility of the thermally treated steam exploded ligno-cellulosic biomass before fiber shives reduction and the glucans accessibility of the thermally treated steam exploded ligno-cellulosic biomass after fiber shives separation is greater than the glucans accessibility of the t

Assignees

• Biochemtex Spa
• Versalis Spa

Inventors

• Ottonello Piero
• Torre Paolo
• Paravisi Stefano
• Prefumo Chiara
• Pastorino Pietro
• Giordano Dario

Classifications

• C12P19/14

  produced by the action of a carbohydrase {(EC 3.2.x)}, e.g. by alpha-amylase {, e.g. by cellulase, hemicellulase} · CPC title

• C08H8/00 Primary

  Macromolecular compounds derived from lignocellulosic materials {(pretreatment thereof B27N)} · CPC title

• C12P7/10

  substrate containing cellulosic material · CPC title

• C12P19/02

  Monosaccharides (2-ketogulonic acid C12P7/60) · CPC title

• D01G9/14 Primary

  Details of machines or apparatus · CPC title