Abstract: Processes disclosed are capable of converting biomass into high-crystallinity nanocellulose with surprisingly low mechanical energy input. In some variations, the process includes fractionating biomass with an acid (such as sulfur dioxide), a solvent (such as ethanol), and water, to generate cellulose-rich solids and a liquid containing hemicellulose and lignin; and mechanically treating the cellulose-rich solids to form nanofibrils and/or nanocrystals. The crystallinity of the nanocellulose material may be 80% or higher, translating into good reinforcing properties for composites. The nanocellulose material may include nanofibrillated cellulose, nanocrystalline cellulose, or both. In some embodiments, the nanocellulose material is hydrophobic via deposition of some lignin onto the cellulose surface. Optionally, sugars derived from amorphous cellulose and hemicellulose may be separately fermented, such as to monomers for various polymers.

Abstract: A method of enzymatically hydrolyzing pretreated lignocellulosic biomass at high solids concentration includes introducing pretreated biomass to a hydrolysis reactor, to hydrolyze the cellulose to glucose monomer and glucose oligomers, and circulating a liquid stream, from which glucose is removed to reduce glucose inhibition of cellulose hydrolysis. A surfactant may be added to the hydrolysis reactor. Heat and/or acid treatment of the glucose oligomers may be used to generate additional glucose monomer. Some variations introduce pretreated biomass to a hydrolysis reactor to hydrolyze cellulose to glucose monomer and glucose oligomers, followed by conveying a portion of the solid phase to a mechanical refiner and/or a unit under reduced pressure, to generate a refined and/or exploded solid phase; and recycling the refined and/or exploded solid phase, optionally reheated, back to an input of the hydrolysis reactor.

Abstract: The GreenBox+ technology is suitable to extract hemicellulose sugars prior to pulping of biomass into pulp products. The revenue obtainable from the sugar stream can significantly improve the economics of a pulp and paper mill. An initial extraction and recovery of sugars is followed by production of a pulp product with similar or better properties. Other co-products such as acetates and furfural are also possible. Some variations provide a process for co-producing pulp and hemicellulosic sugars from biomass, comprising: digesting the biomass in the presence of steam and/or hot water to extract hemicellulose into a liquid phase; washing the extracted solids, thereby generating a liquid wash filtrate and washed solids; separating the liquid wash filtrate from the washed solids; refining the washed solids at a refining pH of about 4 or higher, thereby generating pulp; and hydrolyzing the hemicellulose to generate hemicellulosic fermentable sugars.

Abstract: In some variations, the invention provides a process for producing furfural, 5-hydroxymethylfurfural, and/or levulinic acid from cellulosic biomass, comprising: fractionating the feedstock in the presence of a solvent for lignin, sulfur dioxide, and water, to produce a liquor containing hemicellulose, cellulose-rich solids, and lignin; hydrolyzing the hemicellulose contained in the liquor, to produce hemicellulosic monomers; dehydrating the hemicellulose to convert at least a portion of C5 hemicelluloses to furfural and to convert at least a portion of C6 hemicelluloses to 5-hydroxymethylfurfural; converting at least some of the 5-hydroxymethylfurfural to levulinic acid and formic acid; and recovering at least one of the furfural, the 5-hydroxymethylfurfural, or the levulinic acid. Other embodiments provide a process for dehydrating hemicellulose to convert oligomeric C5 hemicelluloses to furfural and to convert oligomeric C6 hemicelluloses to 5-hydroxymethylfurfural.

Abstract: A composition comprising nanocellulose is disclosed, wherein the nanocellulose contains very low or essentially no sulfur content. The nanocellulose may be in the form of cellulose nanocrystals, cellulose nanofibrils, or both. The nanocellulose is characterized by a crystallinity of at least 80%, an onset of thermal decomposition of 300° F. or higher, and a low light transmittance over the range 400-700 nm. Other variations provide a composition comprising lignin-coated hydrophobic nanocellulose, wherein the nanocellulose contains very low or essentially no sulfur content. Some variations provide a composition comprising nanocellulose, wherein the nanocellulose contains about 0.1 wt % equivalent sulfur content, or less, as SO4 groups chemically or physically bound to the nanocellulose. In some embodiments, the nanocellulose contains essentially no hydrogen atoms (apart from hydrogen structurally contained in nanocellulose itself) bound to the nanocellulose.

Abstract: The present invention provides a process for fractionating lignocellulosic biomass, comprising: contacting biomass with SO2, water, and optionally a first solvent, to produce intermediate solids; then contacting the intermediate solids with SO2, water, and a second solvent, to produce cellulose-rich solids and a liquid phase comprising hemicelluloses and lignin. The first concentration of SO2 may be lower or higher than the second concentration of SO2. It is desirable to vary the SO2 and solvent concentrations in different stages to optimize the removal of hemicellulose versus lignin. The resulting cellulose-rich material can contain very low hemicellulose, very low lignin, or both low hemicellulose and low lignin. High-purity cellulose is useful both for producing glucose as well as for cellulose products or derivatives. The hemicelluloses may be hydrolyzed to produce monomeric sugars, and the lignin may be recovered as a co-product.

Abstract: A low-cost process is provided to render lignocellulosic biomass accessible to cellulase enzymes, to produce fermentable sugars. Some variations provide a process to produce ethanol from lignocellulosic biomass (such as sugarcane bagasse or corn stover), comprising introducing a lignocellulosic biomass feedstock to a single-stage digestor; exposing the feedstock to a reaction solution comprising steam or liquid hot water within the digestor, to solubilize the hemicellulose in a liquid phase and to provide a cellulose-rich solid phase; refining the cellulose-rich solid phase, together with the liquid phase, in a mechanical refiner, thereby providing a mixture of refined cellulose-rich solids and the liquid phase; enzymatically hydrolyzing the mixture in a hydrolysis reactor with cellulase enzymes, to generate fermentable sugars; and fermenting the fermentable sugars to produce ethanol. Many alternative process configurations are described.

Abstract: The GreenBox+ technology is suitable to extract hemicellulose sugars prior to pulping of biomass into pulp products. The revenue obtainable from the sugar stream can significantly improve the economics of a pulp and paper mill. An initial extraction and recovery of sugars is followed by production of a pulp product with similar or better properties. Other co-products such as acetates and furfural are also possible. Some variations provide a process for co-producing pulp and hemicellulosic sugars from biomass, comprising: digesting the biomass in the presence of steam and/or hot water to extract hemicellulose into a liquid phase; washing the extracted solids, thereby generating a liquid wash filtrate and washed solids; separating the liquid wash filtrate from the washed solids; refining the washed solids at a refining pH of about 4 or higher, thereby generating pulp; and hydrolyzing the hemicellulose to generate hemicellulosic fermentable sugars.

Abstract: An improved semichemical pulping process is disclosed to reduce washing costs and recovery process costs, while producing equivalent pulp and paper products. In some variations, the invention provides a process for producing a paper product from biomass, comprising: digesting lignocellulosic biomass in the presence of steam and/or hot water to generate an intermediate pulp material and a liquid phase containing extracted hemicelluloses; mechanically refining the intermediate pulp material, to generate a refined pulp material; and introducing the refined pulp material, the liquid phase, and optionally a separate solid material to a paper machine, to produce a paper product. The process optionally employs no washing step. When the liquid phase is washed from the intermediate pulp material or the refined pulp material using an aqueous wash solution, the wash filtrate may be introduced directly or indirectly to the paper machine.

Abstract: A new polystyrene-nanocellulose composite material is disclosed. The composite may contain about 0.01 wt % to about 10 wt %, such as about 0.1 wt % to about 2 wt % of nanocellulose. In some embodiments, the nanocellulose is lignin-coated nanocellulose, such as lignin-coated nanocellulose is obtained from an AVAP® biomass-fractionation process. The nanocellulose may include cellulose nanocrystals and/or cellulose nanofibrils. The polymer composite may be in the form of a polymer melt, or a finished polymer material. The composite is characterized by IZOD impact resistance that is at least 50% (such as 75% or more) higher compared to the polystyrene alone.

Abstract: A process for producing an organic aliphatic product (such as butanol) from lignocellulosic biomass is provided, comprising: (a) fractionating lignocellulosic biomass in the presence of a solvent for lignin, a hydrolysis catalyst, and water, to produce a liquor containing hemicellulose, cellulose-rich solids, and lignin; (b) washing the cellulose-rich solids and separating the cellulose-rich solids from the liquor; (c) enzymatically hydrolyzing the cellulose-rich solids to generate a hydrolysate comprising glucose; (d) detoxifying the hydrolysate by neutralizing the hydrolysate, removing insoluble solids, and removing or oxidizing residual hydrolysis catalyst, thereby generating a purified hydrolysate; (e) fermenting the purified hydrolysate using a suitable microorganism to produce a dilute organic aliphatic product, wherein the microorganism is recycled with a membrane; (f) extracting the dilute organic aliphatic product into a water-immiscible extractant, to generate an intermediate material; and (g) disti

Abstract: A simple process for converting lignocellulosic biomass into fermentation products is disclosed. Biomass may be subjected to a steam or hot-water soak to dissolve hemicelluloses. This step is followed by mechanical refining, such as in a hot-blow refiner, of the cellulose-rich (and lignin-rich) solids. The refined solids are then enzymatically hydrolyzed to generate sugars. Certain embodiments provide a process for producing ethanol, comprising: digesting a cellulosic biomass feedstock with steam or hot water to produce cellulose-rich solids, hemicellulose oligomers, and lignin; conveying the digested stream through a blow-line refiner; separating a vapor from the refined stream; introducing the refined stream to an enzymatic hydrolysis unit to produce sugars; fermenting the sugars to produce ethanol in dilute solution; and concentrating the dilute solution to produce an ethanol product. Enzymes and microorganisms may be introduced at various points in the process.

Abstract: A composition comprising nanocellulose is disclosed, wherein the nanocellulose contains very low or essentially no sulfur content. The nanocellulose may be in the form of cellulose nanocrystals, cellulose nanofibrils, or both. The nanocellulose is characterized by a crystallinity of at least 80%, an onset of thermal decomposition of 300° F. or higher, and a low light transmittance over the range 400-700 nm. Other variations provide a composition comprising lignin-coated hydrophobic nanocellulose, wherein the nanocellulose contains very low or essentially no sulfur content. Some variations provide a composition comprising nanocellulose, wherein the nanocellulose contains about 0.1 wt % equivalent sulfur content, or less, as SO4 groups chemically or physically bound to the nanocellulose. In some embodiments, the nanocellulose contains essentially no hydrogen atoms (apart from hydrogen structurally contained in nanocellulose itself) bound to the nanocellulose.

Abstract: Cellulose precursor materials may be refined (e.g., fibrillated) in an ethanol medium, or other solvent medium, instead of water. Following refining, the solvent may be removed and recycled prior to incorporation into another material, or optionally, following such incorporation. The solvent may assist the incorporation of nanocellulose into another material (e.g., a polymer) for a composite, for example. In some variations, a process comprises fractionating a biomass feedstock in the presence of an acid, a solvent for lignin, and water, to generate cellulose-rich solids and a liquid containing hemicellulose and lignin; mechanically treating the cellulose-rich solids, in the presence of a refining solvent, to form cellulose fibrils and/or cellulose crystals, thereby generating a nanocellulose material; recovering and recycling the refining solvent; and recovering the nanocellulose material or incorporating the nanocellulose material into a composite material.

Abstract: Conventionally, sugarcane processing avoids leaving residual sucrose in the bagasse, since the bagasse will be burned and the value of the sucrose would be lost. However, when coupled with a Green Power+® process to extract hemicelluloses, sucrose may also be extracted and recovered from the bagasse. In some variations, a process includes mechanically treating a feedstock to generate a sucrose-rich stream and lignocellulosic material that intentionally retains a significant amount of the initial sucrose in the feedstock; extracting the lignocellulosic material with steam and/or hot water to produce cellulose-rich solids and an extract liquor containing hemicellulosic oligomers and sucrose; and then hydrolyzing the hemicellulosic oligomers into a hemicellulose sugar stream. Each of the sucrose-rich stream and the hemicellulose sugar stream (containing the starting residual sucrose) may be recovered or further processed (e.g., fermented to ethanol).

Abstract: In some variations, the invention provides a method and additive for improving melt strength and processing stability in polymer blow molding or blown-film extrusion, comprising: providing a polymer or a combination of polymers; forming a melt phase of the polymer(s); and introducing nanocellulose to the melt phase, wherein the introduction of the nanocellulose in step (c) increases the melt strength of the melt phase. The nanocellulose may include hydrophobic or hydrophilic nanocellulose. The nanocellulose may include lignin-coated cellulose nanocrystals and/or lignin-coated cellulose nanofibrils. The nanocellulose may be present in the melt phase at a concentration of about 0.01 wt % to about 10 wt %, for example. The nanocellulose is preferably obtained from an AVAP® lignocellulosic biomass fractionation process.

Abstract: The present invention relates to a process and a culture medium for biofuel and biochemical production by fermentation of lignocellulose biomass. The process describes the use of a solid-liquid mixed blend formed by solid fiber pulp, hydrolysate, and a polypeptide complex. The solid fiber pulp is partially degraded by the polypeptide complex allowing microbe immobilization and, at the same time, releasing substances that affect Clostridium quorum sensing pathways. The present process and culture medium allow the improvement of biofuels and biochemical production, as butanol and acetone in an industrial scale.

Abstract: This invention provides a way to deal with acetic acid derived from biomass, for fermentation of cellulosic sugars. In some variations, a process for producing ethanol from lignocellulosic biomass comprises: extracting hemicelluloses and acetic acid from lignocellulosic biomass; hydrolyzing the hemicelluloses, using an acid catalyst or enzymes, to generate hemicellulose monomers and more acetic acid; fermenting acetic acid to lipids using a suitable lipid-producing microorganism, thereby reducing acetic acid concentration; fermenting hemicellulose monomers to ethanol using a suitable ethanol-producing microorganism; and recovering the ethanol. The co-fermentation of acetic acid and sugars may be carried out in a single fermentor or in separate fermentors. The invention may be applied to fermentation products other than ethanol. In some embodiments, the fermentation product can act as an extraction solvent to extract lipids from the lipid-producing microorganism, such as a lipid-producing yeast.

Abstract: Processes disclosed are capable of converting biomass into high-crystallinity nanocellulose with low mechanical energy input. In some variations, the process includes fractionating biomass with sulfur dioxide or a sulfite compound and water, to generate cellulose-rich solids and a liquid containing hemicellulose and lignin; and mechanically treating the cellulose-rich solids to form nanofibrils and/or nanocrystals. The total mechanical energy may be less than 500 kilowatt-hours per ton. The crystallinity of the nanocellulose material may be 80% or higher, translating into good reinforcing properties for composites. The nanocellulose material may include nanofibrillated cellulose, nanocrystalline cellulose, or both. In some embodiments, the nanocellulose material is hydrophobic via deposition of some lignin onto the cellulose surface. Optionally, sugars derived from amorphous cellulose and hemicellulose may be separately fermented, such as to monomers for various polymers.

Abstract: A method for the production of alcohol and other bioproducts hemicelluloses extracted from biomass prior to thermal conversion of the biomass to energy. The process can be integrated with the host plant process to minimize the energy loss from extracting hemicelluloses. Also disclosed is a Stepwise enzymatic break down of cellulose fibers from a pulping operation which is performed with the redeployment of equipment and vessels contained within typical existing pulp and paper manufacturing mills. The preferred feedstock is highly delignified pulp from acid or alkaline pulping process or from bleaching stage.