Method of processing lignocellulosic feedstock for enhanced xylose and ethanol production
First Claim
1. A method of producing xylose comprising, in this order:
- a) leaching a lignocellulosic feedstock comprising greater than about 20% (w/w) cellulose, said leaching comprising contacting said feedstock with at least one aqueous solution of about pH 6 to about pH 9 for between about 2 minutes and about 5 hours, at a temperature of about 25°
C. to about 80°
C. to produce a leached feedstock and a leachate;
b) removing leachate from said leached feedstock; and
c) treating said leached feedstock with an aqueous solution at a temperature of at least about 100°
C. and at a pH of about 0.5 to about 2.5 to produce a composition comprising xylose and a treated feedstock.
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Abstract
The present invention provides a method of producing xylose from lignocellulosic feedstock. The method comprises disrupting lignocellulosic feedstock; leaching the lignocellulosic feedstock by contacting the feedstock with at least one aqueous solution for a period greater than about 2 minutes to produce a leached feedstock and a leachate; removing the leachate from the leached feedstock; acidifying the leached feedstock to a pH between about 0.5 and about 3 to produce an acidified feedstock, and; reacting the acidified feedstock under conditions which disrupt fiber structure and hydrolyze a portion of hemicellulose and cellulose of the acidified feedstock, to produce a composition comprising xylose and a pretreated feedstock. The xylose may be purified from the pretreated feedstock or it may be converted to ethanol with the pretreated feedstock.
75 Citations
53 Claims
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1. A method of producing xylose comprising, in this order:
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a) leaching a lignocellulosic feedstock comprising greater than about 20% (w/w) cellulose, said leaching comprising contacting said feedstock with at least one aqueous solution of about pH 6 to about pH 9 for between about 2 minutes and about 5 hours, at a temperature of about 25°
C. to about 80°
C. to produce a leached feedstock and a leachate;b) removing leachate from said leached feedstock; and c) treating said leached feedstock with an aqueous solution at a temperature of at least about 100°
C. and at a pH of about 0.5 to about 2.5 to produce a composition comprising xylose and a treated feedstock. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 52)
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51. A method of producing xylose and glucose comprising, in this order:
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a) leaching a mechanically-disrupted or preconditioned lignocellulosic feedstock comprising greater than about 20% (w/w) cellulose, said leaching being conducted prior to any chemical treatment of said lignocellulosic feedstock, comprising contacting said feedstock with at least one aqueous solution of pH 6 to 9 for a period greater than 2 minutes at a temperature of 25°
C. to about 80°
C. to produce a leached feedstock and a leachate;b) removing the leachate from said leached feedstock; and c) treating said leached feedstock with an aqueous solution at a temperature of at least about 100°
C. with ammonia under conditions which disrupt fiber structure of the leached feedstock and hydrolyze a portion of hemicellulose in said leached feedstock to produce a composition comprising a treated feedstock; andd) treating said composition with an enzyme comprising cellulase under conditions which hydrolyze cellulose in said leached feedstock to glucose, thereby producing a sugar solution comprising xylose and glucose. - View Dependent Claims (53)
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Specification