METHOD FOR LOW WATER HYDROLYSIS OR PRETREATMENT OF POLYSACCHARIDES IN A LIGNOCELLULOSIC FEEDSTOCK
First Claim
1. A method for hydrolyzing polysaccharides in a lignocellulosic feedstock to produce monosaccharides, comprising:
- a) providing interconnected dewatering, plug formation and reaction zones, each of the dewatering, plug formation and reaction zones being provided with an inlet zone and an outlet zone, the outlet zone of the dewatering zone being operationally associated with the inlet zone of the plug formation zone and the outlet zone of the plug formation zone being operationally associated with the inlet zone to the reaction zone, wherein the pressure (Pr) in the reaction zone is from about 90 to about 680 psia;
b) feeding an aqueous slurry of the lignocellulosic feedstock to the dewatering zone to produce a partially dewatered lignocellulosic feedstock and an aqueous liquid, wherein the pressure (Pdwi) of the aqueous slurry of the lignocellulosic feedstock at the inlet zone of the dewatering zone is related to Pr as follows;
0≦
Δ
P<
the lesser of [(Pr−
20 psia) and 220 psia], andwhere Δ
P is the absolute difference in pressure between Pr and Pdwi in psiac) withdrawing, from the dewatering zone, a portion of the aqueous liquid to produce a withdrawn aqueous liquid, the withdrawn aqueous liquid being substantially free of solid lignocellulosic feedstock, and at a pressure which is lower than the pressure of the aqueous slurry of the lignocellulosic feedstock at the inlet zone of the dewatering zone;
d) moving the partially dewatered lignocellulosic feedstock from the outlet zone of the dewatering zone to the inlet zone of the plug formation zone;
e) forming a plug of lignocellulosic feedstock within the plug formation zone to provide a pressure seal between the outlet zone of the dewatering zone and the inlet zone of the reaction zone;
f) feeding the plug of lignocellulosic feedstock from the outlet zone of the plug formation zone to the inlet zone of the reaction zone, wherein the pressure at the outlet zone of the plug formation zone is substantially the same as the pressure at the inlet zone to the reaction zone;
g) maintaining suitable temperature and pH conditions in the reaction zone to hydrolyze polysaccharides in the lignocellulosic feedstock to produce the monosaccharides; and
h) recovering the monosaccharides produced in step g).
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Abstract
A method is provided for hydrolyzing polysaccharides in a lignocellulosic feedstock to produce monosaccharides or pretreating a lignocellulosic feedstock, in which an aqueous slurry of the lignocellulosic feedstock is fed into a pressurized dewatering zone wherein the feedstock is partially dewatered and then is compressed into a plug. The plug is introduced into a reaction zone that operates at a pressure (Pr) equal to greater than about 90 psia and under suitable temperature and pH conditions to hydrolyze the polysaccharides or pretreat the feedstock. The plug provides a pressure seal between the outlet of the dewatering zone and the reaction zone. The pressure (Pdwi) of the aqueous slurry of the lignocellulosic feedstock at the inlet of the dewatering device is related to Pr as follows:
- 0≦ΔP<the lesser of [(Pr−20 psia) and 220 psia], and
- where ΔP is the absolute difference in pressure between Pr and Pdwi in psia.
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Citations
44 Claims
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1. A method for hydrolyzing polysaccharides in a lignocellulosic feedstock to produce monosaccharides, comprising:
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a) providing interconnected dewatering, plug formation and reaction zones, each of the dewatering, plug formation and reaction zones being provided with an inlet zone and an outlet zone, the outlet zone of the dewatering zone being operationally associated with the inlet zone of the plug formation zone and the outlet zone of the plug formation zone being operationally associated with the inlet zone to the reaction zone, wherein the pressure (Pr) in the reaction zone is from about 90 to about 680 psia; b) feeding an aqueous slurry of the lignocellulosic feedstock to the dewatering zone to produce a partially dewatered lignocellulosic feedstock and an aqueous liquid, wherein the pressure (Pdwi) of the aqueous slurry of the lignocellulosic feedstock at the inlet zone of the dewatering zone is related to Pr as follows; 0≦
Δ
P<
the lesser of [(Pr−
20 psia) and 220 psia], andwhere Δ
P is the absolute difference in pressure between Pr and Pdwi in psiac) withdrawing, from the dewatering zone, a portion of the aqueous liquid to produce a withdrawn aqueous liquid, the withdrawn aqueous liquid being substantially free of solid lignocellulosic feedstock, and at a pressure which is lower than the pressure of the aqueous slurry of the lignocellulosic feedstock at the inlet zone of the dewatering zone; d) moving the partially dewatered lignocellulosic feedstock from the outlet zone of the dewatering zone to the inlet zone of the plug formation zone; e) forming a plug of lignocellulosic feedstock within the plug formation zone to provide a pressure seal between the outlet zone of the dewatering zone and the inlet zone of the reaction zone; f) feeding the plug of lignocellulosic feedstock from the outlet zone of the plug formation zone to the inlet zone of the reaction zone, wherein the pressure at the outlet zone of the plug formation zone is substantially the same as the pressure at the inlet zone to the reaction zone; g) maintaining suitable temperature and pH conditions in the reaction zone to hydrolyze polysaccharides in the lignocellulosic feedstock to produce the monosaccharides; and h) recovering the monosaccharides produced in step g). - View Dependent Claims (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)
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2. A method for hydrolyzing polysaccharides in a lignocellulosic feedstock to produce monosaccharides, comprising:
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a) providing interconnected dewatering, plug formation and reaction zones, each of the dewatering, plug formation and reaction zones being provided with an inlet zone and an outlet zone, the outlet zone of the dewatering zone being operationally associated with the inlet zone of the plug formation zone and the outlet zone of the plug formation zone being operationally associated with the inlet zone to the reaction zone, wherein the pressure (Pr) in the reaction zone is from about 300 to about 680 psia; b) feeding an aqueous slurry of the lignocellulosic feedstock to the dewatering zone to produce a partially dewatered lignocellulosic feedstock and an aqueous liquid, wherein the pressure (Pdwi) of the aqueous slurry of the lignocellulosic feedstock at the inlet zone of the dewatering zone is related to Pr as follows; 0≦
Δ
P<
220 psia, andwhere Δ
P is the absolute difference in pressure between Pr and Pdwi in psiac) withdrawing, from the dewatering zone, a portion of the aqueous liquid to produce a withdrawn aqueous liquid, the withdrawn aqueous liquid being substantially free of solid lignocellulosic feedstock, and at a pressure which is lower than the pressure of the aqueous slurry of the lignocellulosic feedstock at the inlet zone of the dewatering zone; d) moving the partially dewatered lignocellulosic feedstock from the outlet zone of the dewatering zone to the inlet zone of the plug formation zone; e) forming a plug of lignocellulosic feedstock within the plug formation zone to provide a pressure seal between the outlet zone of the dewatering zone and the inlet zone of the reaction zone; f) feeding the plug of lignocellulosic feedstock from the outlet zone of the plug formation zone to the inlet zone of the reaction zone, wherein the pressure at the outlet zone of the plug formation zone is substantially the same as the pressure at the inlet zone to the reaction zone; g) maintaining suitable temperature and pH conditions in the reaction zone to hydrolyze polysaccharides in the lignocellulosic feedstock to produce the monosaccharides; and h) recovering the monosaccharides produced in step g).
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3. A method for producing a pretreated lignocellulosic feedstock comprising:
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a) providing interconnected dewatering, plug formation and reaction zones, each of the dewatering, plug formation and reaction zones being provided with an inlet zone and an outlet zone, the outlet zone of the dewatering zone being operationally associated with the inlet zone of the plug formation zone and the outlet zone of the plug formation zone being operationally associated with the inlet zone to the reaction zone, wherein the pressure (Pr) in the reaction zone is from about 90 to about 680 psia; b) feeding an aqueous slurry of the lignocellulosic feedstock to the dewatering zone to produce a partially dewatered lignocellulosic feedstock and an aqueous liquid, wherein the pressure (Pdwi) of the aqueous slurry of the lignocellulosic feedstock at the inlet zone of the dewatering zone is related to Pr as follows; 0≦
Δ
P<
the lesser of [(Pr−
20 psia) and 220 psia], andwhere Δ
P is the absolute difference in pressure between Pr and Pdwi in psiac) withdrawing, from the dewatering zone, a portion of the aqueous liquid to produce a withdrawn aqueous liquid, the withdrawn aqueous liquid being substantially free of solid lignocellulosic feedstock, and at a pressure that is lower than the pressure of the aqueous slurry of the lignocellulosic feedstock at the inlet zone of the dewatering zone; d) moving the partially dewatered lignocellulosic feedstock from the outlet zone of the dewatering zone to the inlet zone of the plug formation zone; e) forming a plug of lignocellulosic feedstock within the plug formation zone to provide a pressure seal between the outlet zone of the dewatering zone and the inlet zone of the reaction zone; f) feeding the plug of lignocellulosic feedstock from the outlet zone of the plug formation zone to the inlet zone of the reaction zone, wherein the pressure at the outlet zone of the plug formation zone is substantially the same as the pressure at the inlet zone to the reaction zone; and g) pretreating the lignocellulosic feedstock in the reaction zone to produce the pretreated feedstock.
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40. A system for the pretreatment or hydrolysis of a lignocellulosic feedstock including interconnected dewatering, plug formation and reactor devices wherein the pressure (Pr) in the reaction device is from about 90 to about 680 psia, comprising:
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a pump or pumps for pumping an aqueous slurry of the lignocellulosic feedstock into the dewatering device at a pressure between about 70 psia and about 900 psia and wherein the pressure (Pdwi) of the aqueous slurry of the lignocellulosic feedstock at the inlet of the dewatering device is related to Pr as follows; 0≦
Δ
P<
the lesser of [(Pr−
20 psia) and 220 psia], andwhere Δ
P is the absolute difference in pressure between Pr and Pdwi in psia;means within the dewatering device for removing aqueous liquid from the aqueous slurry of the lignocellulosic feedstock to form a partially dewatered lignocellulosic feedstock; means for withdrawing aqueous liquid from within the dewatering device; means for urging the partially dewatered lignocellulosic feedstock from the dewatering device into the plug formation device to form a plug of the lignocellulosic feedstock; and means for discharging the plug of lignocellulosic feedstock from the plug formation device and feeding the lignocellulosic feedstock into the reaction device which is at a pressure that is substantially the same as the pressure of the plug of lignocellulosic feedstock that is discharged from the plug formation device. - View Dependent Claims (41, 42, 43)
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44. A method for producing a pretreated lignocellulosic feedstock comprising:
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a) providing interconnected dewatering, plug formation and reaction zones, each of the dewatering, plug formation and reaction zones being provided with an inlet zone and an outlet zone, the outlet zone of the dewatering zone being operationally associated with the inlet zone of the plug formation zone and the outlet zone of the plug formation zone being operationally associated with the inlet zone to the reaction zone, wherein the pressure (Pr) in the reaction zone is from about 90 to about 680 psia; b) feeding an aqueous slurry of the lignocellulosic feedstock to the dewatering zone to produce a partially dewatered lignocellulosic feedstock and an aqueous liquid, wherein the pressure (Pdwi) of the aqueous slurry of the lignocellulosic feedstock at the inlet zone of the dewatering zone is related to Pr as follows; 0≦
Δ
P<
the lesser of [(Pr−
20 psia) and 220 psia], andwhere Δ
P is the absolute difference in pressure between Pr and Pdwi in psiac) withdrawing, from the dewatering zone, a portion of the aqueous liquid to produce a withdrawn aqueous liquid, the withdrawn aqueous liquid being substantially free of solid lignocellulosic feedstock, and at a pressure which is lower than the pressure of the aqueous slurry of the lignocellulosic feedstock at the inlet zone of the dewatering zone; d) moving the partially dewatered lignocellulosic feedstock from the outlet zone of the dewatering zone to the inlet zone of the plug formation zone; e) forming a plug of lignocellulosic feedstock within the plug formation zone to provide a pressure seal between the outlet zone of the dewatering zone and the inlet zone of the reaction zone; f) feeding the plug of lignocellulosic feedstock from the outlet zone of the plug formation zone to the inlet zone of the reaction zone, wherein the pressure at the outlet zone of the plug formation zone is substantially the same as the pressure at the inlet zone to the reaction zone; g) adding acid to the partially dewatered lignocellulosic feedstock prior to the entry of the plug of the lignocellulosic feedstock into the reaction zone or to the reaction zone; and h) maintaining a temperature of between about 180°
C. and about 260°
C., a pH of between about 0.5 and about 3 for between about 10 seconds and about 600 seconds to pretreat the lignocellulosic feedstock thereby hydrolyzing hemicellulose contained in the feedstock to xylose.
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Specification