Abstract: A process for obtaining high ethanol yield from the fermentation of an energy crop and for producing a nutritionally enhanced feed co-product is provided. In particular, the process includes converting non-fermentable polysaccharides in an energy crop into fermentable sugar. The fermentable sugars may be fermented into ethanol thereby enhancing the ethanol yield. In addition, separation of ethanol from the fermentation product yields a whole stillage product having enhanced protein content and reduced fiber content. The process requires little or no modification to the configuration of existing commercial ethanol facilities.

Abstract: A process is disclosed for producing a feed co-product by ethanol fermentation of plant matter comprising starch and another polysaccharide selected from the group consisting of hemicellulose and cellulose. The process comprises: (i) carrying out a primary fermentation process, distilling the primary fermentation mixture to form a primary feed co-product derived from the fermentation of the primary fermentation mixture and a primary distillate product comprising ethanol and (ii) carrying out a secondary fermentation process and distilling the secondary fermentation mixture to form the modified feed co-product and a secondary distillate product comprising ethanol.

Abstract: Soak vessels for impregnating biomass with a liquid such as a dilute acid and methods for impregnating biomass are disclosed. In some embodiments, the soak vessel includes an impeller assembly with impellers that create a vortex to submerge the biomass, that agitate and separate contaminants from the biomass and that direct biomass and contaminants to separate vessel outlets.

Abstract: Methods and apparatus for treating, pre-treating, preparing and conveying a cellulosic feedstock, such as for ethanol production, are disclosed. More specifically, the invention relates to methods and apparatus for treating a cellulosic feedstock by mixing and heating the cellulosic feedstock and/or by moistening and heating the cellulosic feedstock. The invention also relates to a holding tank, and a method of utilizing the holding tank whereby bridging may be reduced or eliminated and may result in a product stream from autohydrolysis or hydrolysis having an improved yield. The invention further relates to methods and apparatus for obtaining and conveying a cellulosic feedstock, which may be used for the subsequent production of a fermentable sugar stream from the cellulose and hemicellulose in the cellulosic feedstock wherein the fermentable sugar stream may be used for subsequent ethanol production.

Abstract: Methods for producing ethanol from cellulosic biomass and, in particular, methods for controlling steam explosion pretreatment operations are disclosed. In some particular embodiments, the total solids content of biomass entering a pretreatment digester is calculated to provide operational data and feedback control.

Abstract: A method and apparatus for preparing a cellulosic feedstock are disclosed. Embodiments of the method comprise passing the cellulosic feedstock out of at least one outlet of a vessel (such as a holding tank) and obtaining at least two streams of cellulosic feedstock wherein each stream may be fed different hydrolysis reactors. Embodiments of the apparatus comprise passing the cellulosic feedstock downwardly through the vessel and withdrawing the feedstock from the vessel in two different lateral directions.

Abstract: An apparatus for conveying a cellulosic feedstock is disclosed. The apparatus comprises an enclosed volume having a lower surface comprising a plurality of longitudinally extending portions. Each longitudinally extending portion has an inner surface that is arcuate in transverse section. A plurality of conveyance members are provided within the enclosed volume. Each conveyance member is associated with one of the inner surfaces and configured to sweep the one of the inner surfaces. Additionally, a method for treating a cellulosic feedstock is disclosed. The method comprises providing a cellulosic feedstock being less than 100% saturated moisture. The cellulosic feedstock is introduced into a longitudinally extending enclosed volume, and conveyed longitudinally through the enclosed volume while being mixed.

Abstract: A method and apparatus for conveying a cellulosic feedstock are disclosed. The apparatus, such as a holding tank, has a passage. At the outlet to the passage, a conveyance member is provided to convey the cellulosic feedstock laterally across the outlet. The conveyance member, e.g., at least one screw conveyor, may have a variable pitch along its length. The method comprises passing the cellulosic feedstock through an impregnation chamber to an outlet of the impregnation chamber; passing the cellulosic feedstock from the outlet of the impregnation chamber to an inlet of a holding tank; passing the cellulosic feedstock downwardly through the holding tank; maintaining a generally constant residence time in the holding tank; and subsequently subjecting the cellulosic feedstock to a hydrolysis process.

Abstract: Methods for producing biofuels that involve enhanced separation of oil in co-product process streams are disclosed. In some embodiments, separation is enhanced by addition of an additive such as a surfactant, yeast and/or salt to the co-product process stream.

Abstract: The present invention generally relates to processes for recovery of values from a fermentation mass obtained in producing ethanol. Further, the present invention relates to processes for the recovery of values from an inorganic- and lignin-containing mass. The present invention also relates to processes for the recovery of a fraction having enhanced silica content from a silica-containing mass. Still further, the present invention relates to processes for the recovery of crude ethanol from a fermentation mass. The present invention relates to various lignin-containing products and solutions and mineral-rich products.

Abstract: A method and apparatus for preparing a cellulosic feedstock are disclosed. Embodiments of the method comprise passing the cellulosic feedstock through an optional impregnation chamber to an outlet of the impregnation chamber, passing the cellulosic feedstock from the outlet of the impregnation chamber to a holding tank having an inlet and an outlet, and conveying the cellulosic feedstock downwardly and laterally as it travels through the holding tank. Embodiments of the apparatus comprise at least one sidewall defining a passage. The passage has an upper portion and a lower portion, and the lower portion has a greater cross-sectional area than the upper portion. At least one inlet is provided adjacent the upper portion, and at least one outlet is provided adjacent the lower portion, at an elevation below the inlet.

Abstract: A method and apparatus for preparing a cellulosic feedstock are disclosed. Embodiments of the method comprise passing the cellulosic feedstock through an optional impregnation chamber to an outlet of the impregnation chamber, passing the cellulosic feedstock from the outlet of the impregnation chamber to a holding tank having an inlet and an outlet, and conveying the cellulosic feedstock downwardly and laterally as it travels through the holding tank. Embodiments of the apparatus comprise at least one sidewall defining a passage. The passage has an upper portion and a lower portion, and the lower portion has a greater cross-sectional area than the upper portion. At least one inlet is provided adjacent the upper portion, and at least one outlet is provided adjacent the lower portion, at an elevation below the inlet.

Abstract: A method and apparatus for preparing a cellulosic feedstock are disclosed. Embodiments of the method comprise obtaining a cellulosic feedstock having a moisture content of 30 wt % to 60 wt %; passing the cellulosic feedstock through a heated holding tank; withdrawing the cellulosic feedstock from the holding tank; and, subsequently subjecting the cellulosic feedstock to hydrolysis. Embodiments of the apparatus comprise at least one sidewall defining a volume having an upper portion and a lower portion. At least one inlet is provided adjacent the upper portion, and the inlet is in fluid communication with an impregnation chamber provided upstream from the holding tank. At least one outlet is provided adjacent the lower portion, and the outlet is in fluid communication with hydrolysis reactor positioned downstream from the holding tank. At least one conveyor is positioned adjacent the at least one outlet. A heating jacket provided on at least a portion of the apparatus.

Abstract: A method and apparatus for treating a cellulosic feedstock, such as for subsequent ethanol production, are disclosed. The method comprises determining an initial moisture content of the cellulosic feedstock and adding an amount of moisture to the cellulosic feedstock to obtain a predetermined moisture content of the cellulosic feedstock, wherein the cellulosic feedstock may subsequently be subjected to hydrolysis. The apparatus comprises a moisture sensor that provides an initial moisture content reading of the cellulosic feedstock, and a weight sensor providing the weight of the cellulosic feedstock. A processor is configured to determine an amount of moisture to be added to the cellulosic feedstock based on the weight and the initial moisture content of the cellulosic feedstock to obtain treated cellulosic feedstock having a predetermined moisture content.

Abstract: Methods for producing ethanol from cellulosic biomass and, in particular, methods for controlling steam explosion pretreatment operations are disclosed. In some particular embodiments, the total solids content of biomass entering a pretreatment digester is calculated to provide operational data and feedback control.