Abstract: A method for processing of a lignocellulosic feedstock is provided comprising exposing lignocellulosic feedstock to acid in a reactor to hydrolyze at least hemicellulose present in said lignocellulosic feedstock, wherein during said exposing, a scale deposit comprising lignin forms on the inner surface of said reactor; and treating the scale deposit with an alkali solution at a temperature between about 140° C. and about 250° C. so as to remove scale. Also provided is a method for reducing scale deposit that forms on process equipment during a stage of reacting a lignocellulosic feedstock with acid.

Abstract: A method for recovering inorganic salt during processing of a lignocellulosic feedstock is provided. The method comprises pretreating the lignocellulosic feedstock by adding an acid to the feedstock to produce a pretreated lignocellulosic feedstock. A soluble base is then added to the pretreated lignocellulosic feedstock to adjust the pH and produce a neutralized feedstock. The neutralized feedstock is then enzymatically hydrolyzed to produce an enzyme hydrolyzed feedstock and a sugar stream. Inorganic salt is recovered from either a stream obtained from the lignocellulosic feedstock prior to the step of pretreating, a stream obtained from the pretreated lignocellulosic feedstock, a stream obtained from the neutralized feedstock, a stream obtained from the sugar stream, or a combination of these streams. The inorganic salt may be concentrated, clarified, recovered and purified by crystallization, electrodialysis drying, or agglomeration and granulation, and then used as desired, for example as a fertilizer.

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??P<the lesser of [(Pr?20 psia) and 220 psia], and where ?P is the absolute difference in pressure between Pr and Pdwi in psia.

Abstract: A fermentation process for the production of cellulase mixtures is provided. The process comprises providing a genetically modified host filamentous fungus that overexpresses a Xyr1 transcription factor and/or that is partially or completely deficient in expressing one or more hemicellulase enzyme. The host filamentous fungus is cultured in a medium comprising a carbon source. The carbon source contains from about 60 wt % to about 100 wt % hemicellulose-derived carbohydrate and less than 5% of a cellulase-inducing carbohydrate or contains from about 25 wt % to about 100% wt % hemicellulose-derived sugar alcohol in combination with from about 0 wt % to about 75 wt % glucose, glycerol or a combination thereof.

Abstract: A process for the enzymatic hydrolysis of cellulose to produce a hydrolysis product comprising glucose from a pretreated lignocellulosic feedstock and enzymes for use in the process are provided. The process comprises hydrolyzing an aqueous slurry of a pretreated lignocellulosic feedstock with cellulase enzymes, one or more than one ?-glucosidase enzyme and a binding agent for binding the ?-glucosidase enzyme to fiber solids present in the aqueous slurry. During the hydrolysis, both the cellulase enzyme and ?-glucosidase enzyme bind to the fiber solids. The hydrolysis is performed in a solids-retaining hydrolysis reactor so that unhydrolyzed fiber solids and bound enzyme are retained in the reactor longer than the aqueous phase of the slurry.

Abstract: A method for producing glucose from a lignocellulosic feedstock is provided. The method comprises pretreating the lignocellulosic feedstock with acid to produce a pretreated feedstock composition. A calcium-containing stream is provided that comprises calcium that is obtained from the lignocellulosic feedstock and a calcium carbonate-containing stream is obtained by precipitation of the calcium from the calcium-containing stream. The pH of the pretreated feedstock is adjusted with (a) the calcium carbonate-containing stream; (b) a calcium hydroxide-containing stream that is derived from said calcium carbonate-containing stream by subjecting said calcium carbonate-containing stream to calcination; or (c) a combination of the calcium carbonate-containing stream and the calcium hydroxide-containing stream.

Abstract: A method for obtaining a fermentation product from a sugar hydrolysate obtained from a feedstock containing hemicellulose, by (i) removing suspended fiber solids from said sugar hydrolysate to obtain a clarified sugar solution; (ii) fermenting xylose in the clarified sugar solution in a fermentation reaction with yeast to produce a fermentation broth comprising the fermentation product; (iii) separating the yeast from the fermentation broth to produce a yeast slurry; (vi) treating the yeast slurry thus obtained with an oxidant to kill microbial contaminants, thereby an oxidant-treated yeast slurry; (v) re-introducing at least a portion of the oxidant-treated yeast back to step (ii) to increase the concentration of yeast in said fermentation reaction; and (vi) recovering the fermentation product.

Abstract: The present invention provides a process for obtaining a product stream comprising one or more sulfate salts of potassium, sodium or ammonium from a sugar stream resulting from [processing a lignocellulosic feedstock, said sugar stream which includes calcium sulfate and one or more of these sulfate salts. The process comprises (i) treating the sugar stream to remove calcium, thereby producing a sugar stream containing substantially no calcium, and obtaining a salt stream comprising a calcium salt; (ii) choosing a feed stream that is either (a) a clarified salt stream derived from the salt stream of step (i) after removal of calcium therefrom; or (b) the sugar stream containing substantially no calcium that is produced in step (i); (iii) introducing the feed stream chosen in step (ii) to an ion exchange bed; and (iv) regenerating the ion exchange resin bed of step (iii) with sulfuric acid to produce the product stream.

Abstract: A method for obtaining a concentrated alcohol solution from a lignocellulosic feedstock. The lignocellulosic feedstock is hydrolyzed to prepare a sugar solution. The sugar solution is fermented to produce a fermentation broth comprising alcohol and at least about 1 g ammonium ions/kg fermentation broth. The alcohol in the fermentation broth is then concentrated by distillation to produce an alcohol-enriched vapour. Either before distillation, during distillation or during the azeotrope breaking process, the concentration of ammonia in the alcohol-enriched vapour can be reduced by acid addition to at most about 300 ppm. The alcohol in the alcohol-rich vapour is then further concentrated by an azeotrope breaking process to provide the concentrated alcohol solution.

Abstract: The present invention provides a method for producing glucose from a lignocellulosic feedstock. The method comprises the steps of (i) providing a pretreated lignocellulosic feedstock slurry; (ii) moving the pretreated feedstock slurry through a pipe, which slurry has an undissolved solids content of between about 15 and about 30 wt %; (iii) adding cellulase enzyme to the pretreated slurry to produce a slurry comprising cellulase enzyme; (iv) dispersing the cellulase enzyme added in step (iii) in the pretreated slurry by using a high shear in-line mixing device, thereby producing a pretreated slurry comprising dispersed cellulase enzyme; and thereafter (v) subjecting the pretreated slurry comprising dispersed cellulase enzyme to hydrolysis so as to produce glucose from cellulose contained therein.

Abstract: A method for producing a fermented solution enriched in xylose is provided. The sugar stream that is fermented results from the hydrolysis of a lignocellulosic feedstock and comprises at least a hexose and a pentose. The method comprises fermenting the sugar stream resulting from the hydrolysis of the lignocellulosic feedstock with a microorganism that preferentially ferments the hexose over the pentose. The fermenting is conducted under aerobic conditions and comprises continuously feeding the sugar stream to a fermentation reactor at a dilution rate that converts the hexose to cell mass preferentially over the pentose, thereby reducing the concentration of the glucose in the sugar stream so that the fermented solution thus produced is enriched in the pentose relative to said sugar stream.

Abstract: A modified Family 6 glycosidase enzyme comprising amino acid substitutions at one or more positions selected from the group 182, 367, 399, 400 and 427 is provided (the position determined form alignment of a parental Family 6 glycosidase with SEQ ID NO: 1). Genetic constructs and genetically modified microbes comprising nucleic sequences encoding the modified Family 6 glycosidase are also provided. Family 6 glycosidase of the invention display decreased hydrolysis activity of beta 1-4 linked polysaccharides and increased hydrolysis activity of beta 1-3, 1-4 linked polysaccharides compared with a parental Family 6 glycosidase. Such glycosidases find use in a variety of applications in industry, e.g., in hydrolysis of beta 1-3, 1-4 linked polysaccharides during the processing of cereal grains or the production of alcohol, animal feed or food products.

Abstract: A process for producing ethanol from a pretreated feedstock is provided. The feedstock is selected from grasses, cereal straws, stover, and combinations thereof, and least about 80% of the feedstock has a particle length of between about 2 cm and about 40 cm. This process comprises wetting the feedstock in liquid, pressing the wet feedstock through one roll press or a series of roll presses to remove at least a portion of water and soluble substances from the wetted feedstock and to shear the feedstock to produce feedstock particles of a size suitable for pumping at a solids concentration of about 8% to about 20% when slurried. At least one roll press, or at least one roll press in the series of roll presses comprises rolls with circumferential v-shaped grooves. The pressed feedstock particles are slurried to produce a slurried feedstock having a consistency of between about 8% and about 20%, and the slurried feedstock pumped into a pretreatment reactor.

Abstract: A process for recovering a volatile carboxylic acid from an aqueous stream containing same comprising the steps of: (a) evaporating the aqueous stream to produce a vapour stream comprising the volatile carboxylic acid that has been vapourized and water vapour, which aqueous stream is produced by a conversion process using a lignocellulosic feedstock as a substrate; (b) contacting the vapour stream with an organic solvent so as to extract the volatile carboxylic acid present in the vapour stream, thereby producing a liquid stream comprising the organic solvent and the volatile carboxylic acid, and a water vapour stream, wherein the organic solvent has an atmospheric boiling point of at least about 150° C. and is insoluble in water; and (c) separating the volatile carboxylic acid from the organic solvent.

Abstract: A process for obtaining inorganic salt and acetate salt from cellulosic biomass is disclosed. The cellulosic biomass is pretreated by adding one or more than one acid or base to produce a pretreated cellulosic biomass comprising acetic acid or acetate salt. One or more than one base or acid is then added to the pretreated cellulosic biomass to adjust the pretreated cellulosic biomass to a pH of about 4.0 to about 6.0 to produce a neutralized cellulosic biomass comprising inorganic salt and acetate salt. The neutralized biomass is then hydrolyzed by cellulase enzymes to produce a sugar stream. Streams arising from the processing of the cellulosic biomass to sugar are subjected to ion exclusion chromatography performed at pH 5.0 to about 10.0 to produce a stream comprising an inorganic salt and an acetate salt.

Abstract: A method for recovering inorganic salt during processing of a lignocellulosic feedstock is provided. The method comprises pretreating the lignocellulosic feedstock by adding an acid to the feedstock to produce a pretreated lignocellulosic feedstock. A soluble base is then added to the pretreated lignocellulosic feedstock to adjust the pH and produce a neutralized feedstock. The neutralized feedstock is then enzymatically hydrolyzed to produce an enzyme hydrolyzed feedstock and a sugar stream. Inorganic salt is recovered from either a stream obtained from the lignocellulosic feedstock prior to the step of pretreating, a stream obtained from the pretreated lignocellulosic feedstock, a stream obtained from the neutralized feedstock, a stream obtained from the sugar stream, or a combination of these streams. The inorganic salt may be concentrated, clarified, recovered and purified by crystallization, electrodialysis drying, or agglomeration and granulation, and then used as desired, for example as a fertilizer.

Abstract: A process for recovering a volatile carboxylic acid from an aqueous stream comprising same, the process comprising the steps of: (i) steam stripping the carboxylic acid from the aqueous stream, which aqueous stream is produced by a conversion process using a lignocellulosic feedstock as a substrate, the steam stripping comprising contacting the aqueous stream with steam by flowing the aqueous stream and the steam countercurrent to one another, thereby producing a vapour stream comprising vapourized carboxylic acid and steam and a stripped aqueous stream; (ii) extracting the vapourized carboxylic acid with an organic solvent by contacting the vapour stream with the organic solvent to produce (a) a stream comprising the organic solvent and the carboxylic acid and (b) the steam at least substantially depleted of the carboxylic acid, wherein the organic solvent has an atmospheric boiling point of at least about 150° C.

Abstract: A process for the enzymatic hydrolysis of cellulose to produce a hydrolysis product comprising glucose from a pretreated lignocellulosic feedstock and enzymes for use in the process are provided. The process comprises partially hydrolyzing an aqueous slurry of a pretreated lignocellulosic feedstock with cellulase enzymes, one or more than one ?-glucosidase enzyme and a binding agent for binding the ?-glucosidase enzyme to fiber solids present in the aqueous slurry. The unhydrolyzed fiber solids are then separated from the hydrolyzed slurry. The separated fiber solids thus obtained are then re-suspended in an aqueous solution to produce a re-suspended slurry. The hydrolysis is then continued to produce the hydrolysis product comprising glucose.

Abstract: A method for obtaining a fermentation product from a sugar hydrolysate obtained from a feedstock containing hemicellulose, by (i) removing suspended fiber solids from said sugar hydrolysate to obtain a clarified sugar solution; (ii) fermenting xylose in the clarified sugar solution in a fermentation reaction with yeast to produce a fermentation broth comprising the fermentation product; (iii) separating the yeast from the fermentation broth to produce a yeast slurry; (vi) treating the yeast slurry thus obtained with an oxidant to kill microbial contaminants, thereby an oxidant-treated yeast slurry; (v) re-introducing at least a portion of the oxidant-treated yeast back to step (ii) to increase the concentration of yeast in said fermentation reaction; and (vi) recovering the fermentation product.

Abstract: A system for collecting ligno-cellulosic biomass over a large area to enable the commercial refining of biomass from 2,500 to in excess of 50,000 tons of biomass per day to produce ethanol or other products. The biomass is collected at a series of collection points and then transported through a network of conduit “loops” interconnecting each of the collection points and the central refining plant. The water used to transport the biomass, as a slurry, is recovered and sequentially recycled in the same pipeline system to push the biomass slurry around the system in a “loop.” The outgoing and return legs of each loop optionally are located adjacent each other.