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 vapor stream comprising vaporized carboxylic acid and steam and a stripped aqueous stream; (ii) extracting the vaporized carboxylic acid with an organic solvent by contacting the vapor 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: The present invention relates to novel xylose-fermenting yeast strains (for example, yeast of the genus Saccharomyces, e.g., S. cerevisiae) with an enhanced ability to ferment the xylose (and/or another pentose sugar) present in a lignocellulosic hydrolysate to a fermentation product(s) (for example, an alcohol (e.g., ethanol) or a sugar alcohol (e.g., xylitol)).

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: The present invention provides a fermentation process for producing a cellulase enzyme mixture comprising the steps of (a) providing a fungal cell of the genus Myceliophthora or a taxonomically equivalent genus; (b) culturing the fungal cell in a submerged liquid batch culture in which the carbon source comprises about 0% of cellulase-inducing carbon source; (c) culturing the fungal cell from the batch culture from step (b) in a submerged liquid fed-batch and/or continuous culture; and (d) providing the culture of step (c) with a feed solution containing a about 100 wt % non-inducing carbon source (such as glucose, dextrose, sucrose, molasses, fructose, glycerol, xylose, or a combination thereof), wherein the feed solution is provided at a rate that maintains the concentration of non-inducing carbon source in the culture below that which would otherwise repress production of the cellulase enzyme mixture, so as to produce a culture filtrate containing at least 10 g protein/L.

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: The present invention relates to a process for generating steam and recovering salts during a lignocellulosic conversion process. The process comprises de-salting a still bottoms stream; incinerating a stream comprising lignin and the de-salted still bottoms stream in an incinerator; and utilizing the heat generated from said incinerating to produce steam. Further provided is a process that comprises feeding a concentrated still bottoms stream to a crystallizer and forming insoluble solids therein comprising salts. Furthermore, the invention relates to a process for recovering salts from a lignocellulosic conversion process, which process comprises the addition of solvent to a still bottoms stream to precipitate salts therefrom. Also provided is a still bottoms composition, a fertilizer product and a composition for incineration.

Abstract: Provided is a system for hydrolyzing a cellulosic feedstock slurry. The system comprises one or more unmixed reactors for receiving and partially hydrolyzing the cellulosic feedstock slurry so as to produce a mixture of partially hydrolyzed slurry. The unmixed reactors may be plug flow reactors. One or more mixed reactors are downstream of the unmixed reactors for continuing the hydrolysis of the mixture of the partially hydrolyzed slurry. The one or more unmixed and mixed reactors may be connected in series, parallel or a combination thereof.

Abstract: The present invention relates to a method for producing a fermentation product from a sugar hydrolysate. The method comprises fermenting the sugar hydrolysate in a fermentation system with yeast to produce a fermentation broth comprising a fermentation product; introducing acid and an oxidant, such as chlorine dioxide, to the fermentation system so as to expose microbial contaminants in the fermentation system at one or more stages to chlorine dioxide and a pH of less than 3.0; and recovering the fermentation product. In one example of the invention, a yeast slurry obtained from a yeast recycle step is treated with acid and the oxidant.

Abstract: A process for the enzymatic hydrolysis of cellulose to produce a hydrolysis product from a pre-treated cellulosic feedstock is provided. The process comprises introducing an aqueous slurry of the pre-treated cellulosic feedstock at the bottom of a hydrolysis reactor. Axial dispersion in the reactor is limited by avoiding mixing and maintaining an average slurry flow velocity of about 0.1 to about 20 feet per hour, such that the undissolved solids flow upward at a rate slower than that of the liquid. Cellulase enzymes are added to the aqueous slurry before or during the step of introducing. An aqueous stream comprising hydrolysis product and unhydrolyzed solids is removed from the hydrolysis reactor. Also provided are enzyme compositions which comprise cellulase enzymes and flocculents for use in the process. In addition, a kit comprising cellulase enzymes and flocculent is provided.

Abstract: Provided is a process for the enzymatic hydrolysis of cellulose to produce glucose from a pretreated cellulosic feedstock. The process comprises providing an aqueous slurry of the pretreated cellulosic feedstock that has a water content that is less than about 140% of the maximum water holding capacity of the pretreated cellulosic feedstock. The aqueous slurry of the pretreated cellulosic feedstock is fed to one or more unmixed hydrolysis reactors and hydrolyzed with cellulase enzymes therein. In the unmixed hydrolysis reactor(s), the cellulase enzymes hydrolyze a portion of the cellulose to produce soluble sugars, thereby producing a mixture of partially hydrolyzed cellulose containing soluble sugars. The hydrolysis of the cellulose to glucose is continued by feeding the mixture of partially hydrolyzed cellulose to one or more mixed hydrolysis reactors. Also provided are systems for carrying out the foregoing enzymatic hydrolysis.

Abstract: The present invention relates to novel xylose-fermenting yeast strains (for example, yeast of the genus Saccharomyces, e.g., S. cerevisiae) with an enhanced ability to ferment the xylose (and/or another pentose sugar) present in a lignocellulosic hydrolysate to a fermentation product(s) (for example, an alcohol (e.g., ethanol) or a sugar alcohol (e.g., xylitol)).

Abstract: The present invention relates to novel xylose-fermenting yeast strains (for example, yeast of the genus Saccharomyces, e.g., S. cerevisiae) with an enhanced ability to ferment the xylose (and/or another pentose sugar) present in a lignocellulosic hydrolysate to a fermentation product(s) (for example, an alcohol (e.g., ethanol) or a sugar alcohol (e.g., xylitol)).

Abstract: The present invention provides a method for producing glucose from a lignocellulosic feedstock. The method comprises moving a pretreated feedstock slurry that has an undissolved solids content of between about 15 and about 30 wt % through a pipe. Cellulase enzyme is added to the pretreated slurry to produce a slurry comprising cellulase enzyme. A high shear in-line mixing device is used to disperse the cellulase enzyme in the pretreated slurry to produce a pretreated slurry comprising dispersed cellulase enzyme. The pretreated slurry comprising dispersed cellulase enzyme is then subjected to hydrolysis so as to produce glucose from cellulose contained therein.

Abstract: Provided are modified beta-glucosidase enzymes, derived from the Trichoderma reesei Cel3A beta-glucosidase, that exhibit improvements in one or more kinetic parameters (KG, KG2, kcat) comprising amino acid substitutions at one or more of positions 43, 101, 260 and 543. Also provided are genetic constructs comprising nucleotide sequences encoding for modified beta-glucosidase enzymes, methods for the production of modified beta-glucosidase enzymes from host strains and the use of the modified beta-glucosidase enzymes in the hydrolysis of cellulose.

Abstract: The present invention relates to a process for the conversion of a lignocellulosic feedstock involving acid pretreatment. The process comprises the steps of treating the lignocellulosic feedstock with alkali at a pH of between about 8.0 and about 12.0 so as to dissolve acetyl groups present on said lignocellulosic feedstock, while converting less than about 10% of the xylan present in the lignocellulosic feedstock to xylose and less than about 10% of the cellulose to glucose, thereby producing an alkali conditioned feedstock. The alkali conditioned feedstock is then pretreated at a temperature of about 160° C. to about 250° C., at a pH of about 0.5 to about 2.5 for about 0.5 to about 10 minutes so as to hydrolyze about 80 to 100% of the xylan and about 3 to about 15% of the cellulose to produce an acid pretreated feedstock comprising cellulose. The cellulose in the pretreated feedstock can be hydrolyzed to glucose with cellulase and the glucose can be fermented to produce a fermentation product.

Abstract: The present invention provides a process for producing fermentable sugar or a fermentation product from a lignocellulosic feedstock. The process comprises leaching the lignocellulosic feedstock with an aqueous solution to remove at least potassium salts from the lignocellulosic feedstock and without significantly hydrolyzing hemicellulose and cellulose, thereby producing a leached feedstock and leachate. The leachate is removed from the leachate and concentrated. The leached feedstock is hydrolyzed to produce fermentable sugar, which may be fermented to produce a fermentation broth comprising the fermentation product. The concentrated leachate is recirculated to one or more stages in the process involving alkali addition to adjust the pH of a process 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 method for producing a pretreated or hydrolyzed lignocellulosic feedstock. The method comprises feeding a lignocellulosic feedstock to a plug formation device and forming a feedstock plug therein. The plug or segments thereof are fed into an elongate chamber that comprises steam addition means for direct steam addition and a rotating shaft mounted co-axially within the chamber having one or more disintegrating elements mounted on it. Disintegrated feedstock particles are produced in the elongate chamber by the disintegrating elements. The disintegrated feedstock particles are heated by contact with the steam introduced through the steam addition means. The disintegrated feedstock particles are then treated in a reactor to produce the pretreated or hydrolyzed lignocellulosic feedstock. Further provided is a feedstock composition comprising disintegrated feedstock particles.

Abstract: Provided are isolated cellobiohydrolases comprising a modified Glycoside Hydrolase (GH) Family 7 catalytic domain, a GH Family 7 catalytic domain and a modified Family 1 carbohydrate binding module (CBM), or both a modified Family 7 catalytic domain and a modified Family 1 CBM. Such isolated cellobiohydrolases exhibit from 45% to about 99.9% amino acid sequence identity to amino acids 1-436 of SEQ ID NO: 1 or to amino acids 1-438 of SEQ ID NO: 2 and improved activity on process substrates. Also provided are genetic constructs and genetically modified microbes for expressing the isolated cellobiohydrolases, a process for producing the isolated cellobiohydrolases, cellulase enzyme mixtures comprising the isolated cellobiohydrolase and a process for hydrolysing a cellulosic substrate with such cellulase enzyme mixtures.

Abstract: The present invention comprises pretreating a lignocellulosic feedstock with acid at a pH between about 2.0 and about 3.5 to produce a composition comprising an acid pretreated feedstock. The acid pretreated feedstock is then enzymatically hydrolyzed with cellulases and ?-glucosidase. The glucose is fermented by microorganisms to produce a fermentation broth comprising the fermentation product, followed by recovery of the fermentation product. The steps of enzymatically hydrolyzing and fermenting are conducted at a pH below about 4.0.