Pretreatment of lignocellulosic biomass with sulfur dioxide and/or sulfurous acid
First Claim
1. A process for hydrolyzing lignocellulosic biomass comprising:
- a) feeding lignocellulosic biomass and acid into a pretreatment reactor, said acid comprising at least one of sulfur dioxide and sulfurous acid;
b) heating said lignocellulosic biomass in the pretreatment reactor for a time and at a temperature sufficient to provide a slurry comprising pretreated lignocellulosic biomass, said slurry adjacent a headspace comprising sulfur dioxide;
c) removing said slurry from the pretreatment reactor;
d) preventing at least a portion of the sulfur dioxide in the headspace from exiting the pretreatment reactor as the slurry is removed;
e) hydrolyzing cellulose in the removed slurry in the presence of cellulase to produce glucose; and
f) contacting additional lignocellulosic biomass with the sulfur dioxide prevented from exiting the pretreatment reactor in step d) under conditions selected to pretreat the additional lignocellulosic biomass.
1 Assignment
0 Petitions
Accused Products
Abstract
A process for hydrolyzing lignocellulosic biomass includes feeding lignocellulosic biomass into a pretreatment reactor, wherein the pretreatment reactor has a headspace charged with sulfur dioxide previously used in the pretreatment of lignocellulosic biomass. In addition, acid comprising sulfur dioxide and/or sulfurous acid is fed into the pretreatment reactor (e.g., with the lignocellulosic biomass, separate from the lignocellulosic biomass, or a combination thereof) and the lignocellulosic biomass is heated. As the pretreated lignocellulosic biomass is discharged from the pretreatment reactor, at least a portion of the sulfur dioxide used in the pretreatment is retained in the headspace.
-
Citations
21 Claims
-
1. A process for hydrolyzing lignocellulosic biomass comprising:
-
a) feeding lignocellulosic biomass and acid into a pretreatment reactor, said acid comprising at least one of sulfur dioxide and sulfurous acid; b) heating said lignocellulosic biomass in the pretreatment reactor for a time and at a temperature sufficient to provide a slurry comprising pretreated lignocellulosic biomass, said slurry adjacent a headspace comprising sulfur dioxide; c) removing said slurry from the pretreatment reactor; d) preventing at least a portion of the sulfur dioxide in the headspace from exiting the pretreatment reactor as the slurry is removed; e) hydrolyzing cellulose in the removed slurry in the presence of cellulase to produce glucose; and f) contacting additional lignocellulosic biomass with the sulfur dioxide prevented from exiting the pretreatment reactor in step d) under conditions selected to pretreat the additional lignocellulosic biomass. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
-
-
18. A process for pretreating lignocellulosic biomass comprising:
-
a) feeding acid and lignocellulosic biomass into a pretreatment reactor, said acid comprising at least one of sulfur dioxide and sulfurous acid, said acid added to the pretreatment reactor with the lignocellulosic biomass, separate from the lignocellulosic biomass, or a combination thereof; b) adding heat to the pretreatment reactor such that said lignocellulosic biomass and acid are heated for a time and at a temperature sufficient to provide a slurry comprising pretreated lignocellulosic biomass, said slurry disposed within the pretreatment reactor adjacent a headspace, said headspace comprising sulfur dioxide; c) removing the slurry from the pretreatment reactor; d) reserving at least a portion of the sulfur dioxide in the headspace within at least one of the pretreatment reactor and a reservoir connected to the pretreatment reactor as the slurry is removed from the pretreatment reactor; and e) pretreating additional lignocellulosic biomass in the presence of the reserved sulfur dioxide. - View Dependent Claims (19, 20)
-
-
21. A process for hydrolyzing lignocellulosic biomass comprising:
-
a) feeding lignocellulosic biomass and acid into a pretreatment reactor, said acid comprising at least one of sulfur dioxide and sulfurous acid; b) heating said lignocellulosic biomass in the pretreatment reactor for a time and at a temperature sufficient to provide a slurry comprising pretreated lignocellulosic biomass, said slurry adjacent a headspace comprising sulfur dioxide; c) removing at least a portion of said slurry from the pretreatment reactor; d) preventing at least a portion of the sulfur dioxide in the headspace from exiting the pretreatment reactor as the at least a portion of the slurry is removed such that a concentration of sulfur dioxide in at least a region of the headspace of the pretreatment reactor is substantially maintained while the slurry is removed; e) hydrolyzing cellulose in the removed slurry in the presence of cellulase to produce glucose; and f) selecting an amount of make-up sulfur dioxide to be added to the pretreatment reactor in dependence upon an amount of sulfur dioxide prevented from exiting the pretreatment reactor.
-
Specification