PRODUCTION OF FERMENTABLE C5 AND C6 SUGARS FROM LIGNOCELLULOSIC BIOMASS
First Claim
1. A process for producing fermentable sugars from cellulosic biomass, said process comprising:
- (a) providing a feedstock comprising cellulosic biomass;
(b) extracting said feedstock with an extraction solution including steam and/or hot water under effective extraction conditions to produce an extract liquor containing hemicellulose oligomers, dissolved lignin, and cellulose-rich solids;
(c) separating at least a portion of said cellulose-rich solids from said extract liquor, to produce washed cellulose-rich solids;
(d) removing a portion of glucan contained in said washed cellulose-rich solids by contacting said washed cellulose-rich solids with a liquefaction-focused blend of enzymes, to release glucose oligomers;
(e) co-hydrolyzing said glucose oligomers and said hemicellulose oligomers, with enzymes or an acid catalyst, to produce glucose and hemicellulose monomers; and
(f) recovering said glucose and hemicellulose monomers as fermentable sugars.
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Accused Products
Abstract
In some variations, this invention provides a process for producing fermentable sugars from cellulosic biomass, comprising: extracting biomass with steam or hot water to produce an extract liquor containing hemicellulose oligomers, dissolved lignin, and cellulose-rich solids; separating and washing the cellulose-rich solids; removing a portion of glucan contained in the washed cellulose-rich solids as glucose oligomers using a liquefaction-focused blend of enzymes; co-hydrolyzing glucose oligomers and hemicellulose oligomers, with enzymes or chemical catalyst, to produce glucose and hemicellulose monomers; and recovering the glucose and hemicellulose monomers as fermentable sugars. The liquefaction-focused blend of enzymes contains endoglucanases and exoglucanases. Optionally, the glucose and the hemicellulose monomers may be recovered as separate streams. The residual cellulose (not hydrolyzed) as well as the lignin may be recovered and combusted, or utilized for other purposes, such as for energy-dense pellets.
7 Citations
34 Claims
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1. A process for producing fermentable sugars from cellulosic biomass, said process comprising:
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(a) providing a feedstock comprising cellulosic biomass; (b) extracting said feedstock with an extraction solution including steam and/or hot water under effective extraction conditions to produce an extract liquor containing hemicellulose oligomers, dissolved lignin, and cellulose-rich solids; (c) separating at least a portion of said cellulose-rich solids from said extract liquor, to produce washed cellulose-rich solids; (d) removing a portion of glucan contained in said washed cellulose-rich solids by contacting said washed cellulose-rich solids with a liquefaction-focused blend of enzymes, to release glucose oligomers; (e) co-hydrolyzing said glucose oligomers and said hemicellulose oligomers, with enzymes or an acid catalyst, to produce glucose and hemicellulose monomers; and (f) recovering said glucose and hemicellulose monomers as fermentable sugars. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A process for producing fermentable sugars from cellulosic biomass, said process comprising:
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(a) providing a feedstock comprising cellulosic biomass; (b) extracting said feedstock with an extraction solution including steam and/or hot water under effective extraction conditions to produce an extract liquor containing hemicellulose oligomers, dissolved lignin, and cellulose-rich solids; (c) separating at least a portion of said cellulose-rich solids from said extract liquor, to produce washed cellulose-rich solids; (d) removing a portion of glucan contained in said washed cellulose-rich solids by contacting said washed cellulose-rich solids with a liquefaction-focused blend of enzymes, to release glucose oligomers; (e) hydrolyzing said glucose oligomers with a first hydrolysis catalyst, to produce glucose; (f) hydrolyzing said hemicellulose oligomers with a second hydrolysis catalyst, to produce hemicellulose monomers; and (g) recovering said glucose and hemicellulose monomers, individually or in combination, as fermentable sugars. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
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Specification