Nanolignocellulose compositions and processes to produce these compositions

Abstract

To provide a technique to improve a strength of a weak cellulose fiber and improve certain properties of paper, corrugating medium pulp and pulp products.SOLUTION: 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.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] Priority Data This international patent application claims the priority of U.S. Provisional Patent Application No. 62 / 523,293, filed on June 22, 2017, and U.S. Patent Application No. 16 / 014,589, filed on June 21, 2018, each of which is incorporated herein by reference.

[0002] The present invention generally relates to nanocellulose and related materials produced by fractionating lignocellulosic biomass and further processing the cellulose fraction.

Background Art

[0003] Biomass purification (or biorefining) has become more prevalent in the industry. Cellulose fibers and sugars, hemicellulose sugars, lignin, syngas, and derivatives of these intermediates are being utilized in chemical and fuel production. In fact, we are currently observing the commercialization of integrated biorefineries that can process incoming biomass in much the same way that petroleum refineries currently process crude oil. Underutilized lignocellulosic biomass feedstocks are potentially much cheaper than petroleum, carbon-based, and far better from an environmental life cycle perspective.

[0004] Lignocellulosic biomass is the most abundant renewable material on Earth and has long been recognized as a potential feedstock for manufacturing chemicals, fuels, and materials. Lignocellulosic biomass typically mainly comprises cellulose, hemicellulose, and lignin. Cellulose and hemicellulose are natural polymers of sugars, and lignin is an aromatic / aliphatic hydrocarbon polymer that reinforces the entire biomass network. Some forms of biomass (e.g., recycled materials) do not contain hemicellulose.

[0005] Despite being the most abundant natural polymer on Earth, cellulose has only recently attracted attention as a nanostructured material in the form of nanocrystalline cellulose (NCC), nanofibrillated cellulose (NFC), and bacterial cellulose (BC). Nanocellulose has been developed for use in a wide range of applications such as polymer reinforcement, antimicrobial films, biodegradable food packaging, printing paper, pigments and inks, paper and paperboard packaging, barrier films, adhesives, biocomposites, wound healing, pharmaceuticals and drug delivery, textiles, water-soluble polymers, construction materials, recyclable interior and structural components in the transportation industry, rheology modifiers, low-calorie food additives, cosmetic thickeners, pharmaceutical tablet binders, bioactive paper, pickering stabilizers for emulsions and particle-stabilized foams, coating formulations, films for optical switching, and detergents.

[0006] Biomass-derived pulp can be converted to nanocellulose by mechanical processing. The process can be simple, but disadvantages include high energy consumption, damage to fibers and particles due to intense mechanical treatment, and a wide distribution of fibril diameter and length.

[0007] In the art, there is a need for improved processes for generating nanocellulose from biomass at reduced energy costs. Also, in the art of generating nanocellulose, there is a need for improved starting materials (i.e., biomass-derived pulp). For some applications, it is desirable to produce nanocellulose with high hydrophobicity.

[0008] There is also a need in the art to enhance the strength of weak cellulose fibers and improve specific properties of paper, core stock pulp, and pulp products. SUMMARY OF THE INVENTION

[0009] Some variations provide a nanolignocellulose composition that, on an absolutely dry, ash-free, and acetyl-free basis, contains from about 35 wt% to about 80 wt% cellulose nanofibrils, cellulose microfibrils, or a combination thereof, from about 15 wt% to about 45 wt% lignin, and from about 5 wt% to about 20 wt% hemicellulose. The hemicellulose may contain xylan or mannan as a main component.

[0010] In certain embodiments, the composition contains from about 40 wt% to about 70 wt% cellulose nanofibrils, cellulose microfibrils, or a combination thereof, on an absolutely dry, ash-free, and acetyl-free basis.

[0011] In certain embodiments, the composition contains from about 45 wt% to about 60 wt% cellulose nanofibrils, cellulose microfibrils, or a combination thereof, on an absolutely dry, ash-free, and acetyl-free basis.

[0012] In certain embodiments, the composition contains from about 20 wt% to about 40 wt% lignin, on an absolutely dry, ash-free, and acetyl-free basis.

[0013] In certain embodiments, the composition contains from about 25 wt% to about 35 wt% lignin, on an absolutely dry, ash-free, and acetyl-free basis.

[0014] In certain embodiments, the composition contains from about 7 wt% to about 15 wt% hemicellulose, on an absolutely dry, ash-free, and acetyl-free basis.

[0015] In certain embodiments, the composition contains from about 8 wt% to about 14 wt% hemicellulose, on an absolutely dry, ash-free, and acetyl-free basis.

[0016] In some embodiments, the nanolignocellulose composition is characterized by at least 99% filtration completion (e.g., 100% completion) in less than 100 minutes.

[0017] The present invention also provides a pulp product or paper product containing the disclosed nanolignocellulose composition.

[0018] Some variations provide a process for producing a nanolignocellulose composition, the process comprising: (a) providing a lignocellulosic biomass feedstock; (b) digesting the feedstock in a digestion chamber with a reaction solution containing steam and / or hot water under effective reaction conditions to produce a digestion stream containing cellulose-rich solids, hemicellulose, and lignin; (c) optionally washing the cellulose-rich solids to remove at least a portion of the hemicellulose oligomers and / or at least a portion of the lignin from the cellulose-rich solids; (d) mechanically treating the cellulose-rich solids to form a nanolignocellulose composition containing cellulose nanofibrils and / or cellulose nanocrystals, hemicellulose, and lignin; (e) recovering the nanolignocellulose composition.

[0019] In some processes, the nanolignocellulose composition comprises, on an absolutely dry, ash-free, and non-acetyl basis, about 35 wt% to about 80 wt% cellulose nanofibrils, cellulose microfibrils, or a combination thereof, about 15 wt% to about 45 wt% lignin, and about 5 wt% to about 20 wt% hemicellulose. In some processes, the nanolignocellulose composition is characterized by at least 99% filtration completion in less than 100 minutes.

[0020] The process may further include a pulp product or paper product containing the nanolignocellulose composition. For example, the nanolignocellulose composition may be fed to a paper machine for manufacturing a paper product.

[0021] BRIEF DESCRIPTION OF THE DRAWINGS

[0022] ​

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[0023] This description enables one skilled in the art to make and use the invention, which describes some embodiments, adaptations, variations, alternatives, and uses of the invention. These and other embodiments, features, and advantages of the invention will become more apparent to one skilled in the art when considered in conjunction with the following detailed description of the invention along with any accompanying drawings.

[0024] As used in this specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. All percentages of compositions and ranges based thereon are by weight percentage unless otherwise indicated. All numbers or conditions of a range are meant to include any specific value within the range rounded to any suitable decimal point.

[0025] Unless otherwise indicated, all numbers expressing parameters, reaction conditions, concentrations of components, etc. used in the specification and claims are to be understood as being modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and appended claims are approximations that may vary depending at least upon the particular analytical technique employed.

[0026] The term "comprising", which is synonymous with "including", "containing", or "characterized by", is inclusive or open-ended and does not exclude additional, unrecited elements or method steps. "Comprising" is a term of claim recitation that means that the named claim elements are essential, but other claim elements may be added and still form a construct within the scope of the claim.

[0027] As used herein, the phrase "consisting of" excludes any element, step, or ingredient not specified in the claims. When the phrase "consisting of" (or a variation thereof) appears in the body of a claim rather than immediately following the preamble, it limits only the elements recited in that claim, and other elements are excluded from the claim as a whole. As used herein, the phrase "consisting essentially of" limits the claims to the specified element or method step, and those that do not substantially affect the basis and novel features (if any) of the claimed subject matter.

[0028] With respect to the terms "comprising", "consisting of", and "consisting essentially of", when one of these three terms is used herein, the present disclosure and the claimed subject matter may include the use of either of the other two terms. Thus, in some embodiments not otherwise explicitly recited, any instance of "comprising" may be replaced by "consisting of" or alternatively, "consisting essentially of".

[0029] Some variations are based on the discovery of a surprisingly simple process for converting lignocellulosic biomass into nanocellulose or nanolignocellulose. The biomass can be subjected to steam or hot water soaking to decompose hemicellulose. Following this step, mechanical purification of the cellulose-rich (and lignin-rich) solid is performed.

[0030] Some variations provide a nanolignocellulose composition comprising, on an absolutely dry, ash-free, and acetyl-free basis, from about 35 wt% to about 80 wt% cellulose nanofibrils, cellulose microfibrils, or a combination thereof, from about 15 wt% to about 45 wt% lignin, and from about 5 wt% to about 20 wt% hemicellulose.

[0031] In various embodiments, the nanolignocellulose composition may include, on an absolutely dry, ash-free, and acetyl-free basis, about (or at least about, or at most about) 30, 35, 40, 45, 50, 55, 60, 65, 75, 75, 80, 85, or 90 weight percent of cellulose nanofibrils, cellulose microfibrils, or combinations thereof.

[0032] In various embodiments, the nanolignocellulose composition may include, on an absolutely dry, ash-free, and acetyl-free basis, about (or at least about, or at most about) 10, 15, 20, 25, 30, 35, 40, 45, or 50 weight percent of lignin.

[0033] In various embodiments, the nanolignocellulose composition may include, on an absolutely dry, ash-free, and acetyl-free basis, about (or at least about, or at most about) 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 weight percent of hemicellulose. The hemicellulose may contain xylan or mannan as a main component.

[0034] "On an absolutely dry, ash-free, and acetyl-free basis" means that the listed concentrations are (i) free of any water, including no H-OH groups chemically contained in, for example, sugar polymers, (ii) free of any ash, including both hydrophobic ash (e.g., sand or dust) and bound ash (e.g., metal oxides not easily extractable from solids), and (iii) neither acetyl groups bound to the hemicellulose component nor free acetic acid derived from acetyl groups.

[0035] In certain embodiments, the composition includes, on an absolutely dry, ash-free, and acetyl-free basis, about 40 weight percent to about 70 weight percent of cellulose nanofibrils, cellulose microfibrils, or combinations thereof.

[0036] In certain embodiments, the composition includes, on an absolutely dry, ash-free, and acetyl-free basis, about 45 weight percent to about 60 weight percent of cellulose nanofibrils, cellulose microfibrils, or combinations thereof.

[0037] In certain embodiments, the composition comprises from about 20 wt% to about 40 wt% lignin on an ash-free, acetyl-free, and dry-weight basis.

[0038] In certain embodiments, the composition comprises from about 25 wt% to about 35 wt% lignin on an ash-free, acetyl-free, and dry-weight basis.

[0039] In certain embodiments, the composition comprises from about 7 wt% to about 15 wt% hemicellulose on an ash-free, acetyl-free, and dry-weight basis.

[0040] In certain embodiments, the composition comprises from about 8 wt% to about 14 wt% hemicellulose on an ash-free, acetyl-free, and dry-weight basis.

[0041] The nanolignocellulose composition may contain water, for example, as moisture or in a solid slurry. The nanolignocellulose composition may contain at least about (or at least about, or at most about) 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90 wt% or more water on an ash-free and acetyl-free basis (although on a wet-weight basis).

[0042] The nanolignocellulose composition may contain ash. The nanolignocellulose composition may contain at least about (or at least about, or at most about) 0.1, 0.5, 1, 2, 3, 4, 5 wt% or more ash on an ash-free and acetyl-free basis.

[0043] The nanolignocellulose composition may contain acetyl groups. The nanolignocellulose composition may contain at least about (or at least about, or at most about) 0.1, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 wt% or more acetyl content on an ash-free and dry-weight basis.

[0044] In some embodiments, the nanolignocellulose composition is characterized by at least 99% filtration completion (e.g., 100% completion) in less than 100 minutes.

[0045] The present invention also provides a pulp product or paper product containing the disclosed nanolignocellulose composition.

[0046] In some variations, a paper mill co-produces nanolignocellulose and returns this material back into its own supply as a means to create stronger sheets, or smoother sheets, or enable a less expensive supply of the final paper product. In some embodiments, the nanolignocellulose is produced using an existing low-consistency refiner as a sideline operation at or near the mill. At least some of the resulting nanolignocellulose is returned to the blend.

[0047] This concept can lead to the ability to use lower-cost woody materials as the main raw material for producing pulp. Many paper mills use a blend of hardwoods and softwoods to achieve the desired combination of strength and sheet formation / smoothness. In addition to replacing higher-cost raw materials, nanolignocellulose can act as a retention aid for the paper machine. Thus, the paper machine can utilize the function of the retention aid and the sheet strength from the same material (nanolignocellulose).

[0048] The principles of the present invention can be applied to any type of pulp or mill, including chemical (e.g., AVAP®, Kraft, or sulfite), mechanical, thermomechanical, chemithermomechanical, hydrothermal-mechanical (e.g., GreenBox+® or GP3+™), or other types of pulping. Chemical pulping generally breaks down lignin and hemicellulose into small water-soluble molecules, which can be washed away from the cellulose fibers without depolymerizing the cellulose fibers. AVAP® pulping removes lignin and hemicellulose without significant glycolysis, allowing for the recovery of all major components (cellulose, hemicellulose, and lignin). Various mechanical pulping methods, such as groundwood and refiner mechanical pulping, physically tear cellulose fibers apart. Considerable lignin remains attached to the fibers. Since the fibers can be cut, the strength is impaired. Related hybrid pulping methods use a combination of chemical and heat treatment to initiate a shortened chemical pulping process, followed by mechanical treatment to separate the fibers. These hybrid methods include thermomechanical pulping and chemithermomechanical pulping. The chemical and heat treatment reduce the amount of energy subsequently required by the mechanical treatment and also reduce the amount of strength loss experienced by the fibers.

[0049] In some preferred embodiments, the present invention is applied to a thermomechanical pulp mill or a hydrothermal-mechanical pulp mill.

[0050] In some embodiments, some of the thermomechanical or hydrothermal-mechanical pulp generated from a normal pulping operation is sent to a sideline nanocellulose production operation involving mechanical refining of the thermomechanical or hydrothermal-mechanical pulp to produce nanocellulose particles (e.g., cellulose nanofibrils). The co-owned U.S. patent application Ser. No. 15 / 278,800, filed Sep. 28, 2016, and titled "PROCESSES FOR PRODUCING NANOCELLULOSE, AND NANOCELLULOSE COMPOSITIONS PRODUCED THEREFROM", is incorporated herein by reference for its teachings regarding converting thermomechanical or hydrothermal-mechanical pulp to nanocellulose in some embodiments.

[0051] In some variations, nanocellulose can be added to a furnish pulp having insufficient strength properties such that the resulting composite meets or exceeds the strength properties required for the intended use of the composite. The principles of these embodiments are not limited to any particular source of furnish or nanocellulose, but a preferred embodiment combines a furnish produced by steam or hot water extraction (known as the GreenBox+(R) technology) with nanocellulose produced by purifying a pulp obtained by acid solvent fractionation of biomass (known as the AVAP(R) technology).

[0052] In some preferred embodiments, steam extraction or hot water extraction of the starting biomass is used to produce pulp, which is then refined and optionally washed to produce a furnish pulp. For exemplary process conditions for producing furnish pulp in various embodiments, reference is made to the co-owned U.S. patent application Ser. No. 14 / 044,784, filed Oct. 2, 2013, and published as US20140096922A1 on Apr. 10, 2014, which is incorporated herein by reference.

[0053] In some embodiments, hot water extraction of the starting biomass is used to produce pulp, which is then purified to produce nanolignocellulose. As used herein, "nanolignocellulose" is a material containing particles of cellulose that are closely (i.e., chemically and / or physically) associated with a substantial amount of lignin and hemicellulose. The cellulose (within the nanolignocellulose particles) can include nanofibrils and / or microfibrils. The percentage of lignin (within the nanolignocellulose particles) is typically at least about 20 wt%, and the percentage of hemicellulose (within the nanolignocellulose particles) is typically at least about 5 wt%. Certain embodiments use the hot water digestion and / or purification described in co-owned U.S. Patent Application No. 15 / 047,608, published as US20160244788 on August 25, 2016, which is incorporated herein by reference. That is, a material containing particles of cellulose that are closely (i.e., chemically and / or physically) associated with a substantial amount of lignin and hemicellulose. The cellulose (within the nanolignocellulose particles) can include nanofibrils and / or microfibrils. The percentage of lignin (within the nanolignocellulose particles) is typically at least about 20 wt%, and the percentage of hemicellulose (within the nanolignocellulose particles) is typically at least about 5 wt%. Certain embodiments use the hot water digestion and / or purification described in co-owned U.S. Patent Application No. 15 / 047,608, published as US20160244788 on August 25, 2016, which is incorporated herein by reference.

[0054] Effective hot water extraction conditions can include contacting the lignocellulosic biomass with steam and / or hot water in a saturated, superheated, or supersaturated form at various pressures. In some embodiments, the HWE step is performed using liquid hot water at a temperature of about 140 - 220 °C, such as about 150 °C, 160 °C, 170 °C, 175 °C, 180 °C, 185 °C, 190 °C, 200 °C, or 210 °C. In some embodiments, the HWE step is performed using liquid hot water with a residence time of about 1 minute to about 60 minutes, such as about 2, 2.5, 3, 3.5, 4, 5, 7.5, 10, 12.5, 15, 20, 25, 30, 35, 40, 45, 50, or 55 minutes.

[0055] In certain embodiments, nanocellulose coated with lignin (preferably cellulose nanofibrils coated with lignin) is added to the base paper pulp. Without being limited by theory, the lignin in the nanofibrils can enhance the moisture resistance of the base paper. The production of nanocellulose coated with lignin is described in detail below. In some embodiments, the lignin fills the voids between the fibers during pressing.

[0056] Using well-known techniques, the core paper product can be produced from core paper pulp that has been modified (with nanocellulose). See, for example, Twede and Selke, “Cartons, crates and corrugated board: handbook of paper and wood packaging technology,” DEStech Publications, pages 41-56, 2005, and Foster, “Boxes, Corrugated” in The Wiley Encyclopedia of Packaging Technology, 1997, eds. Brody A and Marsh K, 2nd ed.

[0057] As used herein, “nanocellulose” is broadly defined to include a wide range of cellulose materials including, but not limited to, microfibrillated cellulose (or cellulose microfibril), nanofibrillated cellulose (or cellulose nanofibril), microcrystalline cellulose, nanocrystalline cellulose, and particulate or fibrillated dissolved pulp. Typically, the nanocellulose provided herein will include particles having at least one length dimension (e.g., diameter) on the nanometer scale.

[0058] “Nanofibrillated cellulose” or equivalently “cellulose nanofibril” means cellulose fibers or regions containing nanometer-sized particles or fibers, or micron-sized and nanometer-sized particles or fibers. “Nanocrystalline cellulose” or equivalently “cellulose nanocrystal” means cellulose particles, regions, or crystals containing nanometer-sized domains, or micron-sized and nanometer-sized domains. “Micron size” includes 1 μm to 100 μm, and “nanometer size” includes 0.01 nm to 1000 nm (1 μm). Larger domains (including long fibers) may also be present in these materials.

[0059] Specific exemplary embodiments of the present invention are described herein. These embodiments are not intended to limit the scope of the claimed invention. The order of steps can vary, some steps may be omitted, and / or steps may be added. References herein to a first step, a second step, etc. are for the purpose of exemplifying some embodiments only.

[0060] Some variations provide a pulp product comprising cellulose and nanolignocellulose, the nanocellulose comprising cellulose nanofibrils and / or cellulose nanocrystals, and the nanolignocellulose being derived from cellulose in a step separate from the pulping process that produces the cellulose.

[0061] In some embodiments, the pulping process is thermomechanical pulping or hydrothermal-mechanical pulping. The pulp product can be paper or a structure different from paper (e.g., a box, panel, engineered wood, etc.).

[0062] In a preferred embodiment, the pulp product is stronger than an otherwise identical pulp product that does not contain nanolignocellulose. In some embodiments, the pulp product is smoother than an otherwise identical pulp product that does not contain nanolignocellulose.

[0063] The pulping process is, in certain embodiments, thermomechanical pulping, and the nanolignocellulose consists essentially of nanofibrils containing cellulose, lignin, and hemicellulose. The nanofibrils can be produced by mechanically refining a cellulose precursor (having a significant amount of lignin and hemicellulose) from thermomechanical pulping.

[0064] Other variations provide a furnish pulp composition comprising cellulose pulp and nanolignocellulose, where the nanolignocellulose comprises hydrophobic nanofibrils. In some embodiments, the nanolignocellulose is present at a concentration of at least 0.1 wt%, 0.5 wt%, 1 wt%, 2 wt%, 5 wt%, or 10 wt% of the composition on a dry weight basis. In certain embodiments, the nanolignocellulose is a significant portion of the pulp furnish, i.e., 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt% or more.

[0065] In some embodiments of the furnish pulp composition, the cellulose pulp is mechanical pulp or thermomechanical pulp (e.g., GreenBox+® pulp). In some embodiments, the cellulose pulp is chemical pulp (e.g., AVAP® , kraft, sulfite, or soda pulp).

[0066] In some embodiments, the process further includes producing a furnish product from the furnish pulp composition. The first amount of lignocellulosic biomass and the second amount of lignocellulosic biomass can be from the same source of biomass or different sources of biomass.

[0067] In some embodiments, the nanolignocellulose is lignin-containing hydrophobic cellulose. In some or other embodiments, the nanolignocellulose is primarily in the form of nanofibrils, microfibrils, or combinations thereof.

[0068] In some embodiments, a system for performing the disclosed process is provided. The system can include a first subsystem that produces a first pulp at a first location and a second subsystem that produces nanolignocellulose at a second location different from the first location. The production of the final product can be performed at one of the first or second subsystems, or at another location.

[0069] In some embodiments, the nanolignocellulose is derived from a biomass source selected from the group consisting of hardwoods, softwoods, agricultural waste, and combinations thereof.

[0070] In some embodiments, the nanolignocellulose is obtained by fractionating biomass in the presence of an acid, a solvent for lignin, and water to produce a cellulose-rich solid and a liquid phase, and then mechanically purifying the cellulose-rich solid to produce the nanolignocellulose. In certain embodiments, the acid is sulfur dioxide and the solvent is ethanol. In certain embodiments, the AVAP® process is used to produce nanolignocellulose for reinforcing cellulose fibers.

[0071] "Reinforcing" can be achieved in various embodiments by simple mixing, grinding, pulverizing, stirring, deposition / drying, or other processes.

[0072] In some embodiments, the method further includes producing a single-fiber product from the cellulose fibers. In these or other embodiments, the method further includes producing a composite from the cellulose fibers. Reinforcement with nanolignocellulose of weak fibers can increase the strength in composite and single-fiber products, as well as other products.

[0073] In some embodiments, the product is first made from cellulose fibers and then the (non-pulp) product is reinforced with nanolignocellulose. In these embodiments, the reinforcement can be performed, if desired, on the bulk product or on selected surfaces or regions, for example.

[0074] The biomass feedstock can be selected from hardwood, softwood, forest residues, eucalyptus, industrial waste, pulp and paper waste, consumer waste, or combinations thereof. Some embodiments utilize agricultural waste, including lignocellulosic biomass associated with edible crops, annual grasses, energy crops, or other annually renewable feedstocks. Exemplary agricultural waste includes, but is not limited to, corn stover, corn fiber, wheat straw, sugarcane bagasse, sugarcane straw, rice straw, oat straw, barley straw, miscanthus, energy cane straw / residue, or combinations thereof. The processes disclosed herein benefit from feedstock flexibility, which is effective for a wide range of cellulose-containing feedstocks.

[0075] As used herein, "lignocellulosic biomass" means any material containing cellulose, lignin, and hemicellulose. Mixtures of one or more types of biomass can be used. In some embodiments, the biomass feedstock includes both a lignocellulosic component (e.g., those described above) and, in addition, a sucrose-containing component (e.g., sugarcane or energy cane) and / or a starch component (e.g., corn, wheat, rice, etc.). Various moisture levels can be associated with the starting biomass. The biomass feedstock may or may not be relatively dry. Generally, the biomass is in the form of particulates or chips, although the particle size is not critical in the present invention.

[0076] In some embodiments, the cellulose-rich solid is processed with a total mechanical energy of less than about 5000 kilowatt-hours per ton of the cellulose-rich solid, e.g., less than about 4000, 3000, 2000, or 1000 kilowatt-hours per ton of the cellulose-rich solid. The energy consumption can be measured in any other suitable unit. An ammeter that measures the current drawn by the motor driving the mechanical processing device is one way to obtain an estimate of the total mechanical energy.

[0077] Mechanical treatment can use one or more known techniques such as, but not limited to, grinding, milling, rolling, sonication, or any other means that forms and / or releases nanofibrils and / or nanocrystals in cellulose. In essence, any type of mill or device that physically separates fibers into fibrils can be utilized. Such mills are well-known in the industry and include, without limitation, Valley beaters, single disk refiners, double disk refiners, conical refiners (including both wide and narrow angle), cylindrical refiners, homogenizers, microfluidizers, and other similar grinding or milling devices. See, for example, Smook, Handbook for Pulp & Paper Technologists, Tappi Press, 1992, and Hubbe et al., “Cellulose Nanocomposites: A Review,” BioResources 3(3), 929-980 (2008).

[0078] The degree of mechanical treatment can be monitored during the process by any of several means. Certain optical instruments can provide continuous data regarding fiber length distribution and fines percentage, either of which can be used to define the endpoint of the mechanical treatment step. Time, temperature, and pressure can vary during mechanical treatment. For example, in some embodiments, sonication can be utilized at ambient temperature and pressure for a time period of about 5 minutes to 2 hours.

[0079] In some embodiments, a portion of the cellulose-rich solid is converted to nanofibrils while the remainder of the cellulose-rich solid is not fibrillated. In various embodiments, about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 99%, or substantially all of the cellulose-rich solid is fibrillated into nanofibrils. In some embodiments, a portion of the nanofibrils is converted to nanocrystals while the remainder of the nanofibrils is not converted to nanocrystals. During drying, some of the nanocrystals can also combine together to form nanofibrils.

[0080] After mechanical treatment, the nanocellulose material can be classified by particle size. A portion of the material can be subjected to another process such as enzymatic hydrolysis to produce glucose. Such materials can have, for example, good crystallinity but may not have the desired particle size or degree of polymerization.

[0081] The process can further include treatment of the cellulose-rich solid with one or more enzymes or one or more acids. When acids are used, they can be selected from the group consisting of sulfur dioxide, sulfurous acid, lignosulfonic acid, acetic acid, formic acid, and combinations thereof. Acids associated with hemicellulose such as acetic acid or uronic acid can be used alone or in combination with other acids. The process can also include heat treatment of the cellulose-rich solid. In some embodiments, the process does not use enzymes or acids.

[0082] When acids are used, the acids can be strong acids such as, for example, sulfuric acid, nitric acid, or phosphoric acid. Weak acids can be used under more severe temperatures and / or times. Enzymes that hydrolyze cellulose (i.e., cellulase) and optionally hemicellulose (i.e., with hemicellulase activity) can be used instead of acids or potentially at any point in a sequential configuration either before or after acidic hydrolysis.

[0083] In some embodiments, the process includes enzymatically treating the cellulose-rich solid to hydrolyze the amorphous cellulose. In other embodiments, or sequentially before or after the enzymatic treatment, the process may include acid treating the cellulose-rich solid to hydrolyze the amorphous cellulose.

[0084] In some embodiments, the process further includes enzymatically treating the crystalline cellulose. In other embodiments, or sequentially before or after the enzymatic treatment, the process further includes acid treating the crystalline cellulose.

[0085] If desired, enzymatic treatment can be used before mechanical treatment, or in some cases simultaneously therewith. However, in a preferred embodiment, enzymatic treatment is not necessary to hydrolyze the amorphous cellulose or weaken the fiber wall structure prior to the isolation of the nanofibers.

[0086] After mechanical treatment, nanolignocellulose can be recovered. Separation of cellulose nanofibrils and / or nanocrystals can be achieved using a device capable of disrupting the ultrastructure of the cell wall while maintaining the integrity of the nanofibrils. For example, a homogenizer can be used. In some embodiments, cellulose aggregate fibrils having component fibrils in the range of 1 to 100 nm in width are recovered and the fibrils are not completely separated from each other.

[0087] In some embodiments, the nanolignocellulose material is characterized by an average length-to-width aspect ratio of from about 10 to about 1000, such as about 15, 20, 25, 35, 50, 75, 100, 150, 200, 250, 300, 400, or 500. Nanofibrils are generally associated with higher aspect ratios than nanocrystals. For example, the nanocrystals can have a length range of about 100 nm to 500 nm and a diameter of about 1 to 10 nm. The nanofibrils can have a length of about 2000 nm and a diameter range of 5 to 50 nm, which converts to an aspect ratio of 40 to 400. In some embodiments, the aspect ratio is less than 50, less than 45, less than 40, less than 35, less than 30, less than 25, less than 20, less than 15, or less than 10.

[0088] Optionally, the process further includes hydrolyzing the amorphous cellulose to glucose, recovering the glucose, and fermenting the glucose to a fermentation product. Optionally, the process further includes recovering, fermenting, or further processing hemicellulose sugars derived from some of the hemicellulose. Optionally, the process further includes recovering, combusting, or further processing the lignin.

[0089] The glucose produced from the hydrolysis of amorphous cellulose can be incorporated into the overall process to produce ethanol or another fermentation co-product. Thus, in some embodiments, the process further includes hydrolyzing the amorphous cellulose to glucose and recovering the glucose. The glucose can be purified and sold. Or the glucose can be fermented to a fermentation product such as, but not limited to, ethanol. The glucose or fermentation product can be recycled to an initial step such as hemicellulose sugar processing, if desired.

[0090] When hemicellulose saccharides are recovered and fermented, they can be fermented to produce monomers or their precursors. The monomers can be polymerized to produce a polymer, which can then be combined with the nanocellulose material to form a polymer-nanocellulose composite.

[0091] In some embodiments, the process further includes chemically converting the nanolignocellulose material into one or more nanolignocellulose derivatives. For example, the nanolignocellulose derivative can be selected from the group consisting of nanolignocellulose esters, nanolignocellulose ethers, nanolignocellulose ether esters, alkylated nanolignocellulose compounds, cross-linked nanolignocellulose compounds, acid-functionalized nanolignocellulose compounds, base-functionalized nanolignocellulose compounds, and combinations thereof.

[0092] Various types of nanolignocellulose functionalization or derivatization can be used, such as functionalization with polymers, chemical surface modification, functionalization with nanoparticles (i.e., other nanoparticles than nanolignocellulose), modification with inorganic substances or surfactants, or biochemical modification.

[0093] High loadings of lignin have been achieved in thermoplastics. Even higher loading levels are obtained with well-known modifications of lignin. The preparation of useful polymer materials containing substantial amounts of lignin has been the subject of investigation for over 30 years. Typically, lignin can be blended into polyolefins or polyesters by extrusion at up to 25 - 40 wt% while meeting mechanical characteristics. Different approaches have been used to increase the compatibility between lignin and other hydrophobic polymers. For example, chemical modification of lignin can be achieved by esterification with long-chain fatty acids.

[0094] A significant factor limiting the use of lightweight nanocellulose for strength improvement in composites is the inherent hydrophilicity of cellulose. Surface modification of the nanocellulose surface to impart hydrophobicity and enable uniform dispersion in a hydrophobic polymer matrix is an area of active research. The nanolignocellulose provided herein has been found to be hydrophobic.

[0095] Optionally, the process for producing a hydrophobic nanolignocellulose material may further include chemically modifying lignin to increase the hydrophobicity of the nanolignocellulose material. Any known chemical modification may be performed on lignin to further increase the hydrophobicity of the nanolignocellulose material provided by embodiments of the present invention.

[0096] Some variations of the present invention are based on a relatively simple process for producing a high-viscosity compound made from cellulose biomass. The high-viscosity compound will act as a rheology modifier when mixed in small proportions with different fluids such as drilling fluids, paints, etc.

[0097] In hydraulic fracturing fluid formulations, particularly water-based and oil-based formulations, these compositions can function as gelling agents. Easy mixing and handling allows for customization with respect to the characteristics of each reservoir. Some of the properties of these rheology modifiers exhibit strong advantages when compared to currently available products on the market. Some of these properties are higher thermal stability, strong shear thinning, thixotropy, and water solubility. Another important property of these new compounds is that they are biodegradable and their production does not involve any chemicals other than biomass and water.

[0098] Some variations provide a process for producing a nanocellulose material, the process comprising (a) providing a lignocellulose biomass feedstock, and (b) Digest the feedstock in a digestion chamber with a reaction solution containing steam and / or hot water under effective reaction conditions to produce a digestion stream containing cellulose-rich solids, hemicellulose, and lignin. (c) Optionally wash the cellulose-rich solids to remove at least a portion of the hemicellulose oligomers and / or at least a portion of the lignin from the cellulose-rich solids. (d) Mechanically process the cellulose-rich solids to form a nanocellulose material containing cellulose nanofibrils and / or cellulose nanocrystals. (e) Recover the nanolignocellulose material.

[0099] The process may further include treatment of the cellulose-rich solids with one or more enzymes (e.g., cellulase) or one or more acids, such as sulfur dioxide, sulfurous acid, lignosulfonic acid, acetic acid, formic acid, or combinations thereof. The process may further include heat treatment of the cellulose-rich solids. In some embodiments, steps (b)-(d) do not use any enzymes or externally added acids.

[0100] The nanocellulose material may include cellulose nanofibrils or a mixture of cellulose nanofibrils and cellulose nanocrystals. FIGS. 1A-1C show SEM images of exemplary nanocellulose experimentally produced by purifying and homogenizing materials generated from hot water extraction of biomass. The nanocellulose material may also include lignin, including lignin particles with a diameter of less than 1 micron. The process may include bleaching the cellulose-rich solids and / or bleaching the nanocellulose material after it is produced.

[0101] In some embodiments, the process further includes recovering, fermenting, or further processing the hemicellulose saccharides derived from the hemicellulose oligomers. For example, the hemicellulose saccharides can be fermented into fermentation products such as (but not limited to) ethanol.

[0102] In some embodiments, the process further comprises hydrolyzing a cellulose-rich solid portion to glucose, recovering the glucose, and optionally fermenting the glucose to a fermentation product such as n-butanol or 1,4-butanediol.

[0103] The process may further comprise recovering, burning, or further processing the lignin washed from the cellulose-rich solid. Some or all of the initial lignin (in the starting material) may become part of the nanocellulose material, which is at least partially hydrophobic due to the presence of lignin.

[0104] In some embodiments, the process further comprises chemically converting the nanocellulose material to one or more nanocellulose derivatives. For example, the nanocellulose derivative may be selected from the group consisting of nanocellulose esters, nanocellulose ethers, nanocellulose ether esters, alkylated nanocellulose compounds, cross-linked nanocellulose compounds, acid-functionalized nanocellulose compounds, base-functionalized nanocellulose compounds, and combinations thereof.

[0105] In certain embodiments, step (d) comprises disk refining followed by homogenization of the cellulose-rich solid. Step (d), or a portion thereof, may be performed at a solids consistency of at least 10 wt%, such as at least 20 wt%.

[0106] The process, in some embodiments, comprises fracturing the cellulose fibers contained in the cellulose-rich solid. Fracturing of the fibers can be achieved, for example, using steam explosion and / or rapid decompression. In certain embodiments, step (d) optionally utilizes a roller mill refiner with decompression.

[0107] Some variations of the present invention provide a process for producing a biomass-derived rheology modifier from cellulose biomass, the process comprising (a) Providing a raw material containing cellulose biomass; (b) digesting the raw material in a digestion chamber with a reaction solution containing steam and / or hot water under effective reaction conditions to produce a digestion stream containing cellulose-rich solids, hemicellulose, and lignin; (c) purifying the cellulose-rich solids in a first high-intensity purification unit, thereby producing purified cellulose solids; (d) washing the purified cellulose solids after step (c) and / or washing the digestion stream before step (c) prior to purification, thereby producing washed purified cellulose solids; (e) gelling the washed purified cellulose solids in a second high-intensity purification unit, thereby producing gelled cellulose solids; (f) homogenizing the gelled cellulose solids in a high-shear homogenizer, thereby producing a biomass-derived rheology modifier containing cellulose nanofibrils, cellulose nanocrystals, or a mixture of cellulose nanofibrils and cellulose nanocrystals.

[0108] Optionally, the process further includes wet or dry cleaning the raw material before step (b). Optionally, whether or not the raw material is cleaned, the process further includes reducing the size of the raw material before step (b).

[0109] Step (b) can be carried out at a digestion temperature of about 140 °C to about 210 °C. Step (b) can be carried out over a digestion time of about 5 minutes to about 45 minutes. Step (b) can be carried out at a liquid / solid weight ratio of about 2 to about 6.

[0110] The process can include hot or cold blow vacuum of the digestion stream after step (b).

[0111] The first high-intensity refining unit can utilize, for example, a disk or a conical plate. In various embodiments, the first high-intensity refining unit transfers energy to the cellulose-rich solid in an amount of about 20 kW / ton to about 200 kW / ton (on an absolutely dry basis).

[0112] The washing in step (d) can be carried out at a temperature of about 18 °C to about 95 °C. In some embodiments, the washing in step (d) utilizes a pressure screw press.

[0113] The second high-intensity refining unit can utilize, for example, a disk or a conical plate. The first and second high-intensity refining units preferably have different patterns with different groove and dam dimensions. In various embodiments, the second high-intensity refining unit transfers energy to the washed refined cellulose solid in an amount of about 20 kW / ton to about 200 kW / ton (on an absolutely dry basis).

[0114] In some embodiments, the high-shear homogenizer transfers a shear force equal to the shear generated under a pressure of about 10,000 psig to about 25,000 psig.

[0115] In some embodiments, the washed refined cellulose solid is stored for a period of time before step (e). Step (e) can be carried out at a location different from steps (a) to (d). Also, step (f) can be carried out at a location different from steps (a) to (e).

[0116] Another variation of the present invention provides a process for generating a biomass-derived rheology modifier from cellulose biomass, the process comprising (a) providing a pretreated feedstock containing a cellulose-rich solid; (b) refining the cellulose-rich solid in a first high-intensity refining unit, thereby producing a refined cellulose solid; (c) Optionally, the purified cellulose solid is washed after step (b), and / or optionally, the digestion stream is washed before step (b) prior to purification, thereby producing a washed purified cellulose solid. - producing a washed purified cellulose solid; (d) gelling the washed purified cellulose solid in a second high-intensity purification unit, thereby producing a gelled cellulose solid; (e) homogenizing the gelled cellulose solid in a high-shear homogenizer, thereby producing a biomass-derived rheology modifier containing cellulose nanofibrils.

[0117] In some embodiments, the pretreated feedstock is kraft pulp derived from wood or lignocellulosic biomass. In some embodiments, the pretreated feedstock is sulfite pulp derived from wood or lignocellulosic biomass. In some embodiments, the pretreated feedstock is soda pulp derived from wood or lignocellulosic biomass. In some embodiments, the pretreated feedstock is mechanical pulp derived from wood or lignocellulosic biomass. In some embodiments, the pretreated feedstock is thermomechanical pulp derived from wood or lignocellulosic biomass. In some embodiments, the pretreated feedstock is chemimechanical pulp derived from wood or lignocellulosic biomass.

[0118] A variant of the present invention provides an aqueous hydraulic fracturing fluid formulation or additive comprising (i) a nanocellulose material produced according to the described process or (ii) a biomass-derived rheology modifier produced according to the described process.

[0119] A variant of the present invention provides an oil-based hydraulic fracturing fluid formulation or additive comprising (i) a nanocellulose material produced according to the described process or (ii) a biomass-derived rheology modifier produced according to the described process.

[0120] Variations of the present invention provide water-based drilling fluid formulations or additives comprising (i) nanocellulose materials produced according to the described process or (ii) biomass-derived rheology modifiers produced according to the described process.

[0121] Variations of the present invention provide oil-based drilling fluid formulations or additives comprising (i) nanocellulose materials produced according to the described process or (ii) biomass-derived rheology modifiers produced according to the described process.

[0122] Some variations provide polymer-nanocellulose composites comprising (i) nanocellulose materials produced according to the described process or (ii) biomass-derived rheology modifiers produced according to the described process. Exemplary polymers include, but are not limited to, polyactide, poly(vinyl alcohol), polyethylene, polypropylene, and the like.

[0123] In some embodiments, the process forms high-viscosity compounds having a size of 1 micron to 100 microns, such as 15 microns to 50 microns. These new compounds, produced without any chemicals (other than biomass and water), can be used as rheology modifiers and are completely biodegradable since they are cellulose-based.

[0124] The process exhibits several advantages. The design allows the process to be fully integrated in one line from the start with biomass to the production of high-viscosity compounds. Alternatively, the process may be divided into several modules that can be located in different geographical locations.

[0125] The biomass feedstock can be hardwood, softwood, forest waste, agricultural waste (e.g., sugarcane bagasse) ) can be selected from industrial waste, consumer waste, or a combination thereof. In any of these processes, the raw material may include sucrose. In some embodiments where sucrose is present in the raw material, most of the sucrose is recovered as part of the fermentable sugars.

[0126] Some embodiments of the present invention enable the treatment of "agricultural waste", which, for the purposes of the present invention, is intended to include lignocellulosic biomass associated with edible crops, annual plants, energy crops, or other annually renewable raw materials. Exemplary agricultural wastes include, but are not limited to, corn stover, corn fiber, wheat straw, sugarcane bagasse, rice straw, oat straw, barley straw, miscanthus, energy cane, or combinations thereof. In certain embodiments, the agricultural waste is sugarcane bagasse, energy cane bagasse, sugarcane stalks, or energy cane stalks.

[0127] In some embodiments, the process further includes wet or dry cleaning the raw material prior to step (b). In some embodiments, the process further includes reducing the size of the raw material prior to step (b). The process may include size reduction, hot water immersion, draining, steaming, or other operations upstream of the digestion chamber.

[0128] Step (b) can be carried out at a digestion temperature of about 140°C to about 210°C, such as about 175°C to about 195°C. Step (b) can be carried out over a digestion time of about 5 minutes to about 45 minutes, such as about 15 minutes to about 30 minutes. Step (b) can be carried out at a liquid / solid weight ratio of about 2 to about 6, such as about 3, 3.5, 4, 4.5, or 5.

[0129] In some embodiments, the reaction solution includes vapor in a saturated, superheated, or supersaturated form. In some embodiments, the reaction solution includes hot water.

[0130] The pressure in the pressurized vessel can be adjusted to maintain the aqueous liquor as a liquid, vapor, or a combination thereof. Exemplary pressures are from about 1 atm to about 30 atm, such as about 3 atm, 5 atm, 10 atm, or 15 atm.

[0131] The solid-phase residence time in the digestion chamber (pressurized extraction vessel) can vary from about 2 minutes to about 4 hours, such as from about 5 minutes to about 1 hour. In certain embodiments, the digestion chamber residence time is controlled to be from about 5 to 15 minutes, such as 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 minutes. The liquid-phase residence time in the digestion chamber can vary from about 2 minutes to about 4 hours, such as from about 5 minutes to about 1 hour. The gas-phase residence time in the digestion chamber can vary from about 1 minute to about 2 hours, such as from about 3 minutes to about 30 minutes, etc. The residence times of the solid phase, liquid phase, and gas phase can all be approximately the same, or they can be independently controlled according to the technical principles of the reactor (e.g., recirculation and internal recirculation strategies).

[0132] In some embodiments, the process further includes a hot blow depressurization of the digestion stream after step (b). Alternatively, a cold blow depressurization of the digestion stream can be used after step (b).

[0133] To effect depressurization, a blow tank can be placed between the digestion chamber and the purification unit. In some embodiments, the vapor is separated from the blow tank and heat is recovered from at least a portion of the above. Optionally, at least a portion of the vapor is compressed and returned to the digestion chamber, and / or at least a portion of the vapor is purged from the process. It should be noted that "blow tank" is intended to be broadly construed to include not only a tank, but any other device or equipment that can enable depressurization in the process stream. Thus, the blow tank (or blow means) can be a tank, vessel, pipe section, valve, separation device, or other unit. and can be.

[0134] Each mechanical refiner can be selected from the group consisting of a hot blow refiner, a hot stock refiner, a disk refiner, a conical refiner, a cylindrical refiner, an in-line diffibrator, a homogenizer, and combinations thereof. Mechanical treatment (refining) may be carried out using one or more known techniques such as grinding, milling, beating, sonication, or any other means for reducing the cellulose particle size, but is in no way limited thereto. Such refiners are well known in the art and include, but are not limited to, Valley beaters, single disk refiners, double disk refiners, conical refiners (including both wide and narrow angle), cylindrical refiners, homogenizers, microfluidizers, and other similar grinding or milling devices. See, for example, Smook, Handbook for Pulp & Paper Technologists, Tappi Press, 1992.

[0135] Refining can be carried out at a wide range of solids concentrations (consistencies), including from about 2% to about 50% consistency, such as about 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 15%, 20%, 30%, 35%, or 40% consistency.

[0136] Each mechanical refiner can be configured to deliver from about 20 to about 200 kW / ton (i.e., the refining power (kW) per ton of fiber based on the solid phase converted to the refined stream). In certain embodiments, the mechanical refiner is configured to deliver a refining power of from about 75 to about 150 kW per ton of fiber. For example, a mechanical refiner having plates can be adjusted by changing the plate type, gap, speed, etc. to achieve these power inputs.

[0137] The degree of mechanical treatment can be monitored during the process by any of several means. Certain optical devices can provide continuous data regarding fiber length distribution and fibrillation %, either of which can be used to define the endpoint of the mechanical treatment step. Time, temperature, and pressure can vary during mechanical treatment. For example, in some embodiments, sonic treatment can be utilized at ambient temperature and pressure for a time period of about 5 minutes to about 2 hours.

[0138] In some embodiments, a portion of the cellulose-rich solid is converted to fibrillation and / or gelation, while the remainder of the cellulose-rich solid is not fibrillated and / or gelled. In various embodiments, about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 99%, or substantially all of the cellulose-rich solid is fibrillated and / or gelled.

[0139] The first high-intensity refining unit can utilize, for example, a disk or a conical plate. In some embodiments, the first high-intensity refining unit transfers energy to the cellulose-rich solid in an amount of about 20 kW / ton to about 200 kW / ton (dry basis), for example, about 75 kW / ton to about 150 kW / ton (dry basis).

[0140] In some embodiments, the washing in step (d) is performed at a temperature of about 18 °C to about 95 °C, for example, about 70 °C to about 80 °C. The washing in step (d) can use a pressure screw press.

[0141] In some embodiments, the second high-intensity refining unit utilizes a disk or a conical plate. The first and second high-intensity refining units preferably have different patterns with different groove and dam dimensions. In some embodiments, the second high-intensity refining unit transfers energy to the refined cellulose solid washed in an amount of about 20 kW / ton to about 200 kW / ton (dry basis), for example, about 75 kW / ton to about 150 kW / ton (dry basis).

[0142] In some embodiments, a high shear homogenizer (or other unit operation capable of imparting shear) imparts a shear force equal to the shear generated under a pressure of about 1,000 psig to about 50,000 psig, such as about 10,000 psig to about 25,000 psig.

[0143] The washed and purified cellulose solid can be stored for some time prior to step (e), which can be done at a location different from steps (a)-(d). In some embodiments, step (f) is not done at a location different from steps (a)-(e).

[0144] In some embodiments, the biomass-derived rheology modifier can be characterized by a particle size (e.g., fiber or fibril length or effective length) of about 1 micron to about 100 microns, such as about 1 micron to about 50 microns. In certain embodiments, the majority of the particles (e.g., about 50%, 60%, 70%, 80%, 90%, or 95%) are in the size range of 10-15 microns. The biomass-derived rheology modifier can include particles less than 5 microns, such as particles 4, 3, 2, 1 micron or less (i.e., nanoparticles). The width of the particles can be less than 1 micron. Particles greater than 100 microns, such as 150, 200, 250, 300, 400, 500 microns or more can be present.

[0145] In some embodiments, the biomass-derived rheology modifier may have a particle size (e.g., length or effective length) of about 10 microns or less, such as about 9, 8, 7, 6, 5, 4, 3, 2, 1 micron or less. In certain embodiments, the nanocellulose particle length is about 900, 800, 700, 600, 500, 400, 300, 200, 100 nm or less. In these or other embodiments (including lengths greater than 1 micron), the nanocellulose particle diameter may be from about 3 nm to about 1000 nm, such as from about 5 nm to about 500 nm, or from about 10 nm to about 200 nm, or about 5, 10, 15, 20, 25, 30, 40, 50, 60, 70, 80, 90, 100, 150, 200, 250, 300, 350, 400, or 450 nm. In some of these embodiments, the nanoparticles (or portions thereof) may be characterized as nanocrystals.

[0146] The rheology modifier compound is a mainly cellulose-based polymer having some microcrystalline shape such as nanocellulose containing some of the initial biomass lignin in its structure. In some embodiments, the compound properties are mainly hydrophilic, enabling strong stability of water-based drilling fluids and water-based fracturing fluids. In some embodiments having a lignin content and suitable high-strength purification, the compound is hydrophobic, moderately hydrophobic, or a combination of hydrophilic and hydrophobic.

[0147] The present disclosure provides a water-based hydraulic fracturing fluid formulation or additive comprising a biomass-derived rheology modifier produced according to the processes described herein.

[0148] The present disclosure provides an oil-based hydraulic fracturing fluid formulation or additive comprising a biomass-derived rheology modifier produced according to the processes described herein.

[0149] The present disclosure provides a water-based drilling fluid formulation or additive comprising a biomass-derived rheology modifier produced according to the processes described herein.

[0150] The present disclosure provides an oil-based drilling fluid formulation or additive comprising a biomass-derived rheology modifier produced according to the processes described herein.

[0151] The process may further comprise removal of one or more fermentation inhibitors (e.g., acetic acid or furfural) by stripping. This stripping may be performed by treating the hydrolyzed cellulose stream prior to fermentation. Alternatively, or in addition, stripping may be performed in a stream following digestion, such as a blow line.

[0152] In some embodiments, the process further comprises fermenting the fermentable saccharides contained in the liquid phase derived from the initial digestion to a dilute fermentation product. The process may further comprise concentration and purification of the fermentation product. The fermentation product may be selected from, for example, ethanol, n-butanol, 1,4-butanediol, succinic acid, lactic acid, or combinations thereof. Also, the solid stream containing lignin may be removed either before fermentation or downstream of fermentation.

[0153] The step may comprise conditioning the hydrolyzate to remove some or most of the volatile acids and other fermentation inhibitors. Vaporization may comprise flaring or stripping and removing sulfur dioxide, if present, prior to removing the volatile acids. The vaporization step is preferably carried out at an acetic acid dissociation pH of less than 4.8, most preferably at a pH selected from about 1 to about 2.5. In some embodiments, additional vaporization steps may be used. These additional vaporization steps may be carried out under different conditions (e.g., temperature, pressure, and pH) with respect to the first vaporization step.

[0154] In some embodiments, some or all of the vaporized organic acid is recycled as vapor or condensate to the first step (cooking step) and can help remove hemicellulose or minerals from the biomass. This recycling of the organic acid, such as acetic acid, is optimized with process conditions that can vary depending on the amount recycled and can improve the cooking effect.

[0155] The step can include recovering fermentable sugars that can be stored, transported, or processed. The step can include fermenting the fermentable sugars into co-products (the primary product being a rheology modifier).

[0156] The step can include preparing a solid residue (containing lignin) for combustion. This step can include purifying, milling, fluidizing, compacting, and / or pelletizing the dried extruded biomass. The solid residue can be supplied to the boiler in the form of fine powder, loose fibers, pellets, briquettes, extrudates or any other suitable form. Known equipment can be used to extrude the solid residue through a pressure chamber to form pellets or briquettes of non-uniform size.

[0157] Following fermentation, the residual solids (such as distillation residues) can be recovered in solid or slurry form, or combusted, or recycled and combined into biomass pellets. The use of fermentation residual solids may require further removal of minerals. Generally, after concentration of the distillation residue, any remaining solids can be used for combustion.

[0158] Alternatively, or in addition, the process can include recovering the residual solids as a fermentation co-product in solid, liquid, or slurry form. Since fermentation co-products are typically rich in potassium, nitrogen, and / or phosphite, they can be used as a fermentation agent or fermentation agent composition.

[0159] The process can be continuous, semi-continuous, or batch. When continuous or semi-continuous, the stripping column can be operated countercurrently, cocurrently, or a combination thereof.

[0160] The process may further comprise bleaching the cellulose-rich solid before and / or as part of the purification. Alternatively, or in addition, the process may further comprise bleaching the purified material, the gelling material, or the homogenized material. Any known bleaching technique or sequence, including enzymatic bleaching, may be used.

[0161] The rheology modifiers provided herein can be incorporated into drilling fluids, drilling fluid additives, fracturing fluids, and fracturing fluid additives. The rheology modifiers can be present at a wide range of concentrations, such as from about 0.001 wt% to about 10 wt% or more, such as about 0.01 wt%, 0.05 wt%, 0.1 wt%, 0.5 wt%, 1 wt%, or 2 wt%.

[0162] In some variations, the present invention relates to a group of cellulose compounds that can be used in different applications. One of the applications is to use them as product improvers for drilling fluids. The rheology modifiers can perform one or more functions in drilling fluids. For example, the rheology modifiers can serve as gelling agents that increase viscosity, or generally as thickeners. The rheology modifiers can serve as friction reducers. Also, the rheology modifiers can be drilling polymers that replace or are added to other polymers.

[0163] Drilling fluids are fluids used in drilling in the natural gas and oil industries and other industries using large drilling equipment. Drilling fluids are used to lubricate, provide hydrostatic pressure, keep the drill cool, and keep the holes drilled by the drill cuttings as clean as possible. The rheology modifiers provided herein are suitable as additives to these drilling fluids.

[0164] In some embodiments, an enzyme can be used as a "breaker" with the composition to decompose the rheology modifier after a certain period or under specific conditions (such as temperature or pH).

[0165] In some embodiments, lignosulfonate is incorporated for improved lubricity in drilling applications. Also, the ability of lignosulfonate to reduce the viscosity of mineral slurries can be beneficial in oil drilling muds.

[0166] In some embodiments, natural lignin or non-sulfonated lignin, or non-sulfonated lignin derivatives are incorporated into the composition.

[0167] Some embodiments provide a drilling fluid additive that includes a rheology modifier.

[0168] Some embodiments provide a drilling fluid additive that includes a rheology modifier, and the additive further includes lignosulfonate.

[0169] Some embodiments provide a drilling fluid additive that includes a rheology modifier, and the additive further includes non-sulfonated lignin.

[0170] Some embodiments provide a drilling fluid additive that includes a rheology modifier, and the additive further includes a crosslinking agent.

[0171] Some embodiments provide a drilling fluid additive that includes a crosslinked rheology modifier and lignosulfonate.

[0172] Some embodiments provide a drilling fluid that includes the disclosed drilling fluid additive. The drilling fluid can be a water-based drilling fluid, an oil-based drilling fluid, or a hybrid water-based / oil-based drilling fluid.

[0173] In various embodiments, the drilling fluid further includes one or more of a biomass-derived weighting material, a biomass-derived filtration control agent, a biomass-derived rheology control agent, a biomass-derived pH control agent, a biomass-derived lost circulation material, a biomass-derived surface active modifier, a biomass-derived lubricant, and a biomass-derived flocculant, and / or a biomass-derived stabilizer.

[0174]

[0174]

[0175]

[0174]

[0176]

[0174]

[0177]

[0174]

[0178] The rheology modifier can be crosslinked for robust gelation in the fracturing fluid. In some embodiments, crosslinking of the rheology modifier can result in a stronger gel that is more hydratable.

[0179] Ash derived from biomass (from the biomass structure) or sand (from washing) can be used as proppant to replace the mined silica.

[0180] In other variations, the present invention provides a fracturing fluid additive.

[0181] Some embodiments provide a fracturing fluid additive that includes a rheology modifier.

[0182] Some embodiments provide a fracturing fluid additive that includes a rheology modifier, and the additive further includes lignosulfonate.

[0183] Some embodiments provide a fracturing fluid additive that includes a rheology modifier, and the additive further includes non-sulfonated lignin.

[0184] Some embodiments provide a fracturing fluid additive that includes a rheology modifier, and the additive further includes a crosslinking agent.

[0185] Some embodiments provide a fracturing fluid additive that includes a crosslinked rheology modifier and lignosulfonate.

[0186] Some embodiments provide a fracturing fluid that includes the disclosed fracturing fluid additive. The fracturing fluid can be a water-based fracturing fluid, an oil-based fracturing fluid, or a hybrid water-based / oil-based fracturing fluid.

[0187] In addition to the disclosed fracturing fluid additives, the fracturing fluid may further include one or more of biomass-derived acids (such as acetic acid, formic acid, levulinic acid, and / or lignosulfonic acid), biomass-derived corrosion inhibitors (such as lignin or lignin derivatives), biomass-derived fracture reducers (such as lignosulfonic acid or lignosulfonic acid derivatives), biomass-derived clay control agents, biomass-derived crosslinking agents, biomass-derived scale inhibitors, biomass-derived breakers, biomass-derived iron control agents, biomass-derived biocides (such as biomass hydrolyzates), and / or recycled or recovered water sources from biorefineries. Typically, the fracturing fluid carrier is intended to carry, contain, or be combined with proppant that can be biomass-derived proppant (such as ash contained within the structure of the biomass and / or sand, ash, mud collected with the biomass).

[0188] Some variations of the present invention provide a method of using a fracturing fluid additive, the method including combining the disclosed fracturing fluid additive with a base fluid to produce a fracturing fluid. Some methods include introducing the fracturing fluid additive directly or indirectly into a geological formation.

[0189] Some variations are that the process for producing the fracturing fluid additive includes purifying biomass under effective pretreatment conditions and purification conditions to produce the disclosed fracturing fluid additive. In some embodiments, the pretreatment conditions include the production of lignosulfonic acid, which is optionally not completely removed and is present in the fracturing fluid additive. In some embodiments, the fracturing fluid additive includes a liquid slurry derived from the process. For example, the slurry may contain a rheology modifier derived from biomass as well as water and pretreatment chemicals (such as solvents, acids, bases, etc.).

[0190] The rheology modifiers of some embodiments are characterized by an average cellulose degree of polymerization of from about 100 to about 2000, such as from about 400 to about 1200 or from about 500 to about 800. In certain embodiments, the rheology modifier does not contain enzymes.

[0191] The present disclosure is not limited to rheology modifiers by any means. As disclosed, the materials produced by multiple purification steps (after biomass pretreatment) can be used in a wide range of applications. For example, rheology modifiers can be incorporated into products selected from the group consisting of structures, foams, aerogels, polymer composites, carbon composites, films, coatings, coating precursors, current or voltage carriers, filters, membranes, catalysts, catalyst supports, coating additives, paint additives, adhesive additives, cement additives, paper coatings, thickeners, rheology modifiers, additives for drilling fluids, and combinations or derivatives thereof.

[0192] Some embodiments provide products having sensor, catalyst, antibacterial material uses, current conduction and energy storage capabilities. Cellulose crystals have the ability to assist in the synthesis of metal and semiconductor chains.

[0193] Some embodiments provide composites containing purified cellulose and carbon-containing materials, such as, but not limited to, lignin, graphite, graphene, or carbon aerogel.

[0194] Cellulose crystals may be combined with the stabilizing properties of surfactants and can be utilized in the fabrication of the structures of various semiconductor materials.

[0195] The reactive surface of -OH side chain groups in refined cellulose facilitates grafting chemical species to achieve different surface properties. Through surface functionalization, it becomes possible to adjust the particle surface chemistry to facilitate self-assembly, control the dispersion within a wide range of matrix polymers, and control the binding strength both between particles and between particles and the matrix. The composite can be transparent, can have a tensile strength higher than that of cast iron, and can have a very low coefficient of thermal expansion. Potential applications include, but are not limited to, barrier films, antibacterial films, transparent films, flexible displays, reinforcing fillers for polymers, biomedical implants, pharmaceuticals, drug delivery, fibers and textiles, templates for electronic components, separation membranes, batteries, supercapacitors, electroactive polymers, and many others.

[0196] Other suitable applications of the present invention include reinforced polymers, adhesives, high-strength spun fibers and textiles, advanced composites, films for barrier and other properties, coating additives, paints, lacquers, adhesives, switchable optical devices, pharmaceuticals and drug delivery systems, bone replacement and tooth restoration, improved paper, packaging and building products, food and cosmetic additives, catalysts, and hydrogels.

[0197] Aerospace and transportation composites can benefit from these rheology modifiers. Automobile applications include cellulose composites with polypropylene, polyamide (e.g., nylon), or polyester (e.g., PBT).

[0198] The rheology modifiers provided herein may be suitable as strength-enhancing additives for renewable and biodegradable composites. The cellulose fibril structure can function as a binder between two organic phases for improved fracture toughness and prevention of crack formation for applications in packaging, building materials, electrical appliances, and renewable fibers.

[0199] The rheology modifiers provided herein can be transparent, dimensionally stable strength enhancing additives and substrates for applications in flexible displays, flexible circuits, printable electronics, and flexible solar panels. Cellulose incorporated into a substrate sheet is formed, for example, by vacuum filtration, dried under pressure, and fired. In the sheet structure, cellulose functions as an adhesive between filler aggregates. The formed fired sheet is smooth and flexible.

[0200] The rheology modifiers provided herein can be suitable for composites and cement additives that enable crack reduction as well as increased toughness and strength. Foamed cellular cellulose-concrete hybrid materials enable lightweight structures with reduced cracking and enhanced strength.

[0201] Strength enhancement with cellulose enhances both the bonding area and the bond strength for applications in high-strength, high-bulk, high filler content papers and board papers with enhanced moisture and oxygen barrier properties. In particular, the paper pulp industry can benefit from the rheology modifiers provided herein. Benefit.

[0202] Porous cellulose can be used in cellular bioplastics, insulators and plastics, and bioactive membranes and filters. Highly porous cellulose materials are generally of high interest in the manufacture of filtration media and in biomedical applications, such as dialysis membranes.

[0203] The rheology modifiers provided herein can be suitable as additives for improving the durability of paints, protective coatings, and varnishes against wear caused by ultraviolet radiation.

[0204] The rheology modifiers provided herein are suitable as thickeners in foods and cosmetics. The rheology modifiers can be used as thixotropic, biodegradable, dimensionally stable (stable against temperature and salt addition) thickeners. The rheology modifier materials provided herein can be suitable as Pickering stabilizers for emulsions and particle-stabilized foams.

[0205] The large surface area of these rheology modifiers, in combination with their biodegradability, makes the rheology modifiers attractive materials for highly porous, mechanically stable aerogels.

[0206] In some embodiments, the process includes forming a structure that includes a nanolignocellulose material or a derivative thereof.

[0207] In some embodiments, the process includes forming a foam or aerogel that includes a nanolignocellulose material or a derivative thereof.

[0208] In some embodiments, the process includes combining a nanolignocellulose material or a derivative thereof with one or more other materials to form a composite. For example, the other material can include a polymer selected from polyolefins, polyesters, polyurethanes, polyamides, or combinations thereof. Alternatively, or in addition, the other material can include various forms of carbon.

[0209] In some embodiments, the process includes forming a film that includes a nanolignocellulose material or a derivative thereof. The film is optically transparent and flexible in certain embodiments.

[0210] In some embodiments, the process includes forming a coating or coating precursor that includes a nanolignocellulose material or a derivative thereof. In some embodiments, the nanolignocellulose-containing product is a paper coating.

[0211] In some embodiments, the nanolignocellulose-containing product is configured as a catalyst, a catalyst support, or a co-catalyst. In some embodiments, the nanolignocellulose-containing product is electrochemically configured to hold or store an electric current or voltage.

[0212] In some embodiments, the nanolignocellulose-containing product is incorporated into a filter, a membrane, or other separation device.

[0213] In some embodiments, the nanolignocellulose-containing product is incorporated as an additive into a coating, a paint, or an additive. In some embodiments, the nanolignocellulose-containing product is incorporated as a cement additive.

[0214] In some embodiments, the nanolignocellulose-containing product is incorporated as a thickener or a rheology modifier. For example, the nanolignocellulose-containing product can be an additive in drilling fluids, such as, but not limited to, oil recovery fluids and / or gas recovery fluids, or fracturing fluids.

[0215] The nanolignocellulose-containing product can include any of the disclosed nanolignocellulose compositions. Many nanolignocellulose-containing products are possible. For example, the nanolignocellulose-containing product can be selected from the group consisting of a structure, a foam, an aerogel, a polymer composite, a carbon composite, a film, a coating, a coating precursor, an electric current or voltage carrier, a filter, a membrane, a catalyst, a catalyst support, a coating additive, a paint additive, an adhesive additive, a cement additive, a paper coating, a thickener, a rheology modifier, an additive for drilling fluids, and combinations or derivatives thereof.

[0216] Certain nanolignocellulose-containing products provide, for example, high transparency, good mechanical strength, and / or enhanced gas (e.g., O2 or CO2) barrier properties. Certain nanolignocellulose-containing products containing the hydrophobic nanocellulose materials provided herein can be useful, for example, as anti-wetting and anti-freezing coatings.

[0217] Some embodiments provide nanolignocellulose-containing products having uses as sensors, catalysts, antibacterial materials, current conduction, and energy storage capabilities.

[0218] Some embodiments provide composites containing nanolignocellulose and carbon-containing materials such as, but not limited to, lignin, carbon black, graphite, graphene, or carbon aerogel.

[0219] The reactive surface of the -OH side chain groups in nanolignocellulose facilitates grafting chemical species to achieve different surface properties. Surface functionalization enables tuning of the particle surface chemistry to facilitate self-assembly, controlled dispersion within a wide range of matrix polymers, and control of the binding strength both between particles and between particles and the matrix. The composites can be transparent, can have a tensile strength higher than that of cast iron, and can have a very low coefficient of thermal expansion. Potential uses include, but are not limited to, barrier films, antibacterial films, transparent films, flexible displays, reinforcing fillers for polymers, biomedical implants, pharmaceuticals, drug delivery, fibers and textiles, templates for electronic components, separation membranes, batteries, supercapacitors, electroactive polymers, and many others.

[0220] Other nanolignocellulose applications suitable for the present invention include reinforced polymers, high-strength spun fibers and fabrics, advanced composites, films for barriers and other properties, coating additives, paints, lacquers, and adhesives, switchable optical devices, pharmaceuticals and drug delivery systems, bone replacement and dental restorations, improved paper, packaging and building products, food and cosmetic additives, catalysts, and hydrogels.

[0221] For aerospace and automotive applications, nanolignocellulose composites with polypropylene, polyamide (e.g., nylon), or polyester (e.g., PBT) can be mentioned.

[0222] The nanolignocellulose materials provided herein are suitable as strength-enhancing additives for renewable biodegradable composites. The cellulose nanofibril structure can function as a binder between two organic phases for improved fracture toughness and prevention of crack formation for applications in packaging, building materials, electrical appliances, and renewable fibers.

[0223] The nanolignocellulose materials provided herein are suitable as transparent and dimensionally stable strength-enhancing additives and substrates for applications in flexible displays, flexible circuits, printable electronics, and flexible solar panels. The nanolignocellulose incorporated into the substrate sheet is formed, for example, by vacuum filtration, dried under pressure, and fired. In the sheet structure, the nanocellulose functions as an adhesive between filler aggregates. The formed fired sheet is smooth and flexible.

[0224] The nanolignocellulose materials provided herein are suitable for composites and cement additives that enable crack reduction and increased toughness and strength. The foamed cellular nanolignocellulose-concrete hybrid material enables a lightweight structure with crack reduction and enhanced strength.

[0225] The strength enhancement with nanolignocellulose enhances both the bonding area and bonding strength for applications in high-strength, high-bulk, high filler content papers and boards with enhanced moisture and oxygen barrier properties. In particular, the pulp and paper industry can benefit from the nanolignocellulose materials provided herein.

[0226] Nanofibrillated cellulose nanopaper has a higher density and higher tensile mechanical properties than conventional paper. It can be optically transparent and flexible, and can have low thermal expansion properties and excellent oxygen barrier properties. The functionality of the nanopaper can be further expanded by incorporating other entities such as carbon nanotubes, nanoclays, or conductive polymer coatings.

[0227] Rojo et al., “Comprehensive elucidation of the effect of residual lignin on the physical, barrier, mechanical, and surface properties of nanocellulose films,” Green Chem., 2015, 17, 1853 - 1866 is incorporated herein by reference.

[0228] Porous nanolignocellulose can be used in foam bioplastics, insulators and plastics, as well as bioactive membranes and filters. Highly porous materials generally attract high interest in the manufacture of filtration media, as well as in biomedical applications, such as dialysis membranes.

[0229] The nanolignocellulose materials provided herein are suitable as coating materials having an oxygen barrier and an affinity for lignocellulose for applications in food packaging and printing papers.

[0230] The nanolignocellulose materials provided herein are suitable as additives for improving the durability of paints, protective coatings, and varnishes against wear caused by ultraviolet radiation.

[0231] The nanolignocellulose materials provided herein are suitable as thickeners in foods and cosmetics. Nanolignocellulose can be used as a thixotropic, biodegradable, dimensionally stable (stable to temperature and salt addition) thickener. The nanolignocellulose materials provided herein are suitable as Pickering stabilizers for emulsions and particle-stabilized foams.

[0232] The large surface area of these nanolignocellulose materials, in combination with their biodegradability makes them attractive materials for rheology modifiers in highly porous mechanically stable aerogels.

[0233] The present invention provides a system configured to carry out the disclosed processes, and compositions produced therefrom. Any stream produced by the disclosed processes can be partially or fully recovered, purified or further processed, and / or marketed or sold.

[0234] This detailed description refers to multiple embodiments of the invention and non-limiting examples of how the invention can be understood and implemented. Other embodiments that do not provide all of the features and advantages described herein can be utilized without departing from the spirit and scope of the invention. The invention incorporates routine experimentation as well as optimization of the methods and systems described herein. Such changes and modifications are considered to be within the scope of the invention as defined by the claims.

[0235] All publications, patents, and patent applications cited herein are hereby incorporated by reference in their entirety as if each individual publication, patent, or patent application were specifically and individually set forth herein.

[0236] If the above methods and steps indicate specific events that occur in a specific order, one of ordinary skill in the art will recognize that the order of the specific steps can be changed and that such changes will comply with the variations of the present invention. In addition, the specific steps can be performed not only sequentially but also, where possible, simultaneously in a parallel process.

[0237] Accordingly, to the extent that there are variations of the present invention that are within the scope of the spirit of the present disclosure or equivalent to the present invention as found in the appended claims, it is intended that the claims cover those variations as well. The present invention is to be limited only by the claims.

Example

[0238] Example 1: Nanocrystalline cellulose produced from softwood Softwood (pine) chips are processed in a pilot steam gun digester at a temperature of 185°C for 20 minutes to obtain a pulp yield of about 80%. The pulp is passed through a pilot plant disk refiner to defibrate the cooked chips to a freeness of about 100. The freeness of the pulp provides a measure of the rate at which a dilute suspension of the pulp can be drained (see TAPPI T221 “Drainage Time of Pulp”). Thereafter, the pulp is passed through a laboratory-scale homogenizer three times targeting 80 - 85% fines to obtain unwashed nanocrystalline cellulose. The percentage of fines (refined material) can be increased by increasing the number of passes through the homogenizer. The unwashed nanocrystalline cellulose is washed three times with about 2, 1, and 1 kg of water per kg of pulp at 60°C for 30 minutes to obtain washed nanocrystalline cellulose.

[0239] Figure 2 shows a 40-fold magnified optical micrograph of the washed nanocrystalline cellulose produced in this example.

[0240] The nanolignocellulose in this example is a combination of precipitated lignin particles (particle size of about 50 to 300 nanometers), lignocellulose nanofibrils (length of about 500 nanometers, width of about 10 to 500 nanometers, length of several tens of microns), and lignocellulose fines (length less than 76 microns and width less than 5 microns).

[0241] The washed solid is analyzed for its composition. The total carbohydrate is about 66.8 wt% of the solid. Glucan is 54 wt%, xylan is 9.2 wt%, galactan is 1.3 wt%, arabinan is 0.6 wt%, and mannan is 1.7 wt%. The acetyl group concentration is 1.9 wt% in the solid. The total lignin is 35.8 wt%, of which 33.3 wt% (based on the solid) is Klason lignin and 2.5 wt% (based on the solid) is acid-soluble lignin.

[0242] The liquid phase analysis shows 0.98 wt% glucose, 7.44 wt% xylose, 0.42 wt% galactose, 0.35 wt% arabinose, and 0.79 wt% mannose, and all sugars are percentages based on the initial total solids (%), based on wood. Formic acid is 0.07 wt%, acetic acid is 0.28 wt%, HMF is 0.02 wt%, furfural is 0.02 wt%, and dissolved lignin is 1.82 wt%, and again, all are percentages based on the initial total solids.

[0243] Example 2: Nanolignocellulose Produced from Hardwood Process hardwood chips in a pilot steam gun digester at a temperature of 185 °C for 15 minutes to obtain a pulp yield of approximately 80%. Pass the pulp through a pilot plant disk refiner to fibrillate the cooked chips to a freeness of approximately 100. Then pass the pulp through a laboratory-scale homogenizer three times targeting 80 - 85% fines to obtain unwashed nanolignocellulose. The percentage of fines (refined material) can be increased by increasing the number of passes through the homogenizer. Wash the unwashed nanolignocellulose three times with approximately 2, 1, and 1 kg of water per kg of pulp at 60 °C for 30 minutes each to obtain washed nanolignocellulose.

[0244] Figure 3 shows a 40x optical micrograph of the washed nanolignocellulose produced in this example.

[0245] The pulp produced in this example was also passed through a homogenizer seven times to obtain 92% fines. This was compared to a bleached softwood Kraft pulp (Masuko refining, 14 passes, 93% fines (by region)). Figure 4 is a graph of the filtration rate of this nanolignocellulose compared to a prior art Kraft pulp. Filtration was by Buchner filtration at 0.8 wt% total solids, with a starting volume of 450 mL (the total available filtrate is estimated to be 430 mL based on 17% total solids in the nanocellulose pad). The filter paper was Whatman 4 (pore size 20 - 25 μm).

[0246] Figure 4 shows a much higher filtration rate for this nanolignocellulose compared to bleached Kraft fibrils. Specifically, the nanolignocellulose reaches essentially 100% filtration completion in less than 100 minutes. Due to the high lignin content, the water retention value and drainage of the nanolignocellulose fibrils are much higher than those of pure cellulose fibrils. This is considered a major performance attribute for using nanolignocellulose in a paper machine.

Claims

1. A nanolignocellulosic composition comprising, on a bone dry, ash free, and acetyl free basis, about 35% to about 80% by weight cellulose nanofibrils, cellulose microfibrils, or a combination thereof, about 15% to about 45% by weight lignin, and about 5% to about 20% by weight hemicellulose.

2. 2. The nanolignocellulosic composition of claim 1, wherein the composition comprises about 40% to about 70% by weight cellulose nanofibrils, cellulose microfibrils, or a combination thereof on a bone dry, ash free, and acetyl free basis.

3. 2. The nanolignocellulosic composition of claim 1, wherein the composition comprises about 45% to about 60% by weight cellulose nanofibrils, cellulose microfibrils, or a combination thereof on a bone dry, ash free, and acetyl free basis.

4. 2. The nanolignocellulosic composition of claim 1, wherein the composition comprises about 20% to about 40% by weight lignin on a bone dry, ash-free, and acetyl-free basis.

5. 2. The nanolignocellulosic composition of claim 1, wherein the composition comprises about 25% to about 35% by weight lignin on a bone dry, ash-free, and acetyl-free basis.

6. 10. The nanolignocellulosic composition of claim 1, wherein the composition comprises about 7% to about 15% by weight hemicellulose on a bone dry, ash free, and acetyl free basis.

7. 2. The nanolignocellulosic composition of claim 1, wherein the composition comprises about 8% to about 14% by weight hemicellulose on a bone dry, ash free, and acetyl free basis.

8. The nanolignocellulose composition of claim 1 , wherein the hemicellulose contains xylan as a major component.

9. The nanolignocellulose composition of claim 1 , wherein the hemicellulose contains mannan as a major component.

10. 2. The nanolignocellulosic composition of claim 1, wherein the nanolignocellulosic composition is characterized by at least 99% filtration completion in less than 100 minutes.

11. A pulp or paper product comprising the nanolignocellulosic composition of claim 1.

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