摘要:
Some variations provide a new nanolignocellulose composition comprising, on a bone-dry, ash-free, and acetyl-free basis, from 35 wt % to 80 wt % cellulose nanofibrils, cellulose microfibrils, or a combination thereof, from 15 wt % to 45 wt % lignin, and from 5 wt % to 20 wt % hemicelluloses. The hemicelluloses may contain xylan or mannan as the major component. Novel properties arise from the hemicellulose content that is intermediate between high hemicellulose content of raw biomass and low hemicellulose content of conventional nanocellulose. The nanolignocellulose composition is hydrophobic due to the presence of lignin. Processes for making and using the nanolignocellulose compositions are also described.
摘要:
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. The disclosed processes may be employed for other fermentation products.
摘要:
Processes are described for fractionating lignocellulosic biomass into cellulose, hemicellulose, and lignin, comprising fractionating lignocellulosic biomass in the presence of a solvent for lignin (such as ethanol), a hydrolysis catalyst (such as sulfur dioxide), and water, to produce a liquor containing hemicellulose, celluloserich solids, and lignin; hydrolyzing the hemicellulose to produce hemicellulosic monomers; saccharifying the cellulose-rich solids to produce glucose; recovering the hemicellulosic monomers and the glucose, separately or in a combined stream, as fermentable sugars; and fermenting the fermentable sugars to a fermentation product having a higher normal boiling point than water. Process integration of mass and/or energy is disclosed in many specific embodiments. The fermentation product may include an organic acid, an alcohol, a diol, or combinations thereof.
摘要:
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.
摘要:
This invention provides processes and apparatus to convert biomass, including wood and agricultural residues, into low-ash biomass pellets for combustion, alone or in combination with another solid fuel. Some embodiments provide processes for producing hemicellulosic sugars and low-ash biomass from cellulosic biomass, comprising providing an aqueous extraction solution with acetic acid; extracting the feedstock to produce an extract liquor containing soluble ash, hemicellulosic oligomers, acetic acid, dissolved lignin, and cellulose-rich solids; dewatering and drying the cellulose-rich, lignin-rich solids to produce a low-ash biomass; hydrolyzing the hemicellulosic oligomers to produce fermentable hemicellulosic sugars, wherein additional acetic acid is generated; removing a vapor stream comprising vaporized acetic acid from the extract; recycling the vapor or its condensate to provide some starting acetic acid for the extraction solution; and recovering fermentable hemicellulosic sugars. The disclosed processes can produce clean power from biomass. Co-products include fermentation products such as ethanol, fertilizers, and lignin.
摘要:
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. The invention may be applied to any other fermentation product.
摘要:
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. These polymers may be combined with the nanocellulose to form completely renewable composites.
摘要:
In this disclosure, a process for producing biomass pellets and sugars from cellulosic biomass is provided, comprising: extracting the feedstock with steam and/or hot water and optionally with an acid catalyst, to produce cellulose-rich solids and an extract liquor containing hemicellulosic oligomers and lignin; separating the cellulose-rich solids from the extract liquor; filtering the extract liquor to remove at least some of the lignin, thereby generating a filter permeate comprising cleaned extract liquor containing the hemicellulosic oligomers and a filter retentate comprising a lignin-rich stream; hydrolyzing the hemicellulosic oligomers in the cleaned extract liquor with an acid or enzymes, to generate hemicellulosic monomers which are recovered; and pelletizing the cellulose-rich solids to form biomass pellets, wherein the pelletizing utilizes at least some of the lignin-rich stream as a binder or binder component.
摘要:
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 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.