CN110832139A - Nanohllocelluiose compositions and methods for producing these compositions - Google Patents

Abstract

Some variations provide a novel nano-lignocellulosic composition comprising, on a dry-out, ash-free and acetyl-free basis: 35 to 80 wt% of cellulose nano-fibrils, cellulose microfibrils, or a combination thereof; 15 to 45 wt% lignin; and 5 to 20 wt% hemicellulose. Hemicellulose may contain xylan or mannan as a main component. Novel properties result from the hemicellulose content being between the high hemicellulose content of the raw biomass and the low hemicellulose content of conventional nanocellulose. Due to the presence of lignin, the nano-lignocellulosic composition is hydrophobic. Methods for making and using the nano-lignocellulosic compositions are also described.

Description

Nano-lignocellulose compositions and methods for producing these compositions

priority information

This international patent application claims priority to US Provisional Patent Application No. 62/523,293, filed June 22, 2017, and US Patent Application No. 16/014,589, filed June 21, 2018, each of which Incorporated herein by reference.

technical field

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

Background technique

Biomass refining (or biorefining) is becoming more and more common in industry. Cellulosic fibers and sugars, hemicellulose sugars, lignin, syngas, and derivatives of these intermediates are used to produce chemicals and fuels. In fact, we are now observing the commercialization of integrated biorefineries capable of processing incoming biomass in much the same way that refineries are now processing crude oil. The potential of underutilized lignocellulosic biomass feedstocks is that carbon based is much cheaper than petroleum and much better from an environmental life cycle point of view.

Lignocellulosic biomass is the most abundant renewable material on the planet and has long been recognized as a potential feedstock for the production of chemicals, fuels and materials. Lignocellulosic biomass normally consists primarily of cellulose, hemicellulose and lignin. Cellulose and hemicellulose are natural polymers of sugars, and lignin is an aromatic/aliphatic hydrocarbon polymer that strengthens the entire biomass network. Some forms of biomass (eg, recycled materials) do not contain hemicellulose.

Despite being the most available natural polymer on Earth, cellulose has only recently emerged as a nanostructured material in the form of nanocrystalline cellulose (NCC), nanofibrillar cellulose (NFC) and bacterial cellulose (BC). Nanocellulose is being developed for a wide variety of applications such as polymer reinforcement, antimicrobial films, biodegradable food packaging, printing paper, pigments and inks, paper and cardboard packaging, barrier films, adhesives, biolaminates Materials, wound healing, drug and drug delivery, textiles, water-soluble polymers, construction materials, recyclable interior and structural components for the transportation industry, rheology modifiers, low-calorie food additives, cosmetic thickeners, pharmaceutical tablets Binders, bioactive papers, pickering stabilizers for emulsions and particle-stabilized foams, coating formulations, films for optical switching, and detergents.

Biomass-derived pulp can be converted into nanocellulose by mechanical processing. While this method may be simple, disadvantages include high energy consumption, fiber and particle damage due to intensive mechanical treatment, and a broad distribution of fibril diameters and lengths.

There is a need in the art for improved methods of producing nanocellulose from biomass with reduced energy costs. Also, there is a need in the art for improved starting materials (ie biomass-derived slurries) to produce nanocellulose. For some applications, it is desirable to produce nanocellulose with high hydrophobicity.

There is also a need in the art to increase the strength of weak cellulosic fibers, and to improve certain properties of paper, corrugating core pulp and stock products.

SUMMARY OF THE INVENTION

Some variations provide a nano-lignocellulose composition, on a dry, ash-free, and acetyl-free basis, comprising: about 35 wt % to about 80 wt % cellulose nanofibrils, cellulose microfibrils fiber or a combination thereof; about 15 wt% to about 45 wt% lignin; and about 5 wt% to about 20 wt% hemicellulose. Hemicellulose may contain xylan or mannan as a major component.

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

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

In certain embodiments, the composition comprises about 20 wt % to about 40 wt % lignin on a dry, ash-free, and acetyl-free basis.

In certain embodiments, the composition comprises about 25 wt % to about 35 wt % lignin on a dry, ash-free, and acetyl-free basis.

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

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

In some embodiments, the nano-lignocellulose composition is characterized by at least 99% filtration (eg, 100% complete) in less than 100 minutes.

The present invention also provides pulp products or paper products containing the disclosed nano-lignocellulose compositions.

Some variations provide a method for producing a nano-lignocellulose composition, the method comprising:

(a) providing lignocellulosic biomass feedstock;

(b) digesting the feedstock with a reaction solution comprising steam and/or hot water in a digester under effective reaction conditions to produce a digest comprising cellulose-rich solids, hemicellulose oligomers and lignin logistics;

(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 solid to form a nanolignocellulose composition comprising cellulose nanofibrils and/or cellulose nanocrystals, hemicellulose and lignin; and

(e) Recovery of the nano-lignocellulose composition.

In some methods, the nano-lignocellulose composition, on a dry, ash-free and acetyl-free basis, comprises: about 35 wt % to about 80 wt % of cellulose nanofibrils, cellulose microfibrils fibers or a combination thereof; about 15 wt % to about 4 wt % lignin; and about 5 wt % to about 20 wt % hemicellulose.

In some methods, the nano-lignocellulose composition is characterized by at least 99% filtration being completed in less than 100 minutes.

The method may also include producing a pulp product or a paper product containing the nano-lignocellulose composition. For example, the nano-lignocellulose composition can be fed to a paper machine to produce paper products.

Description of drawings

1A is an SEM image of an exemplary nanocellulose experimentally produced by refining and homogenizing material produced from hot water extraction of biomass.

Figure IB is an SEM image of an exemplary nanocellulose experimentally produced by refining and homogenizing material produced from hot water extraction of biomass.

Figure 1C is an SEM image of an exemplary nanocellulose experimentally produced by refining and homogenizing material produced from hot water extraction of biomass.

FIG. 2 is a 40× magnification optical micrograph of the washed nano-lignocellulose produced in Example 1. FIG.

3 is a 40× magnification optical micrograph of the washed nano-lignocellulose produced in Example 2. FIG.

Figure 4 is a graph of the filtration rate of nano-lignocellulose of Example 2 compared to prior art kraft pulp.

Detailed ways

This description will enable those skilled in the art to make and use the invention, and it describes various embodiments, adaptations, variations, alternatives, and uses of the invention. These and other embodiments, features and advantages of the present invention will become more apparent to those skilled in the art when referenced to the following detailed description of the invention in conjunction with any accompanying drawings.

As used in this specification and the appended claims, a reference without a quantitative indication includes the plural reference unless the context clearly dictates otherwise. Unless otherwise defined, 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 compositional numbers and ranges on a percentage basis are by weight unless otherwise indicated. All numbers or conditional ranges are meant to include any particular value contained within that range, rounded to any suitable decimal point.

Unless stated otherwise, all numbers used in the specification and claims representing parameters, reaction conditions, component concentrations, etc., should be understood to be modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon at least the particular analytical technique employed.

The term "comprising" is synonymous with "comprising," "containing," or "characterized by," is inclusive or open-ended, and does not exclude additional, unrecited elements or method steps. "Comprising" is a technical term used in claim language to mean that a specified claim element is essential, but that other claim elements may be added and still form constructs within the scope of the claim.

As used herein, the phrase "consisting of" excludes any element, step, or ingredient not expressly recited in the claim. When the phrase "consisting of" (or variations thereof) appears in a clause of the body of a claim rather than immediately following the preamble, it is limited only to the elements recited in that clause; the claim as a whole The point of view does not exclude other elements. As used herein, the phrase "consisting essentially of" limits the scope of a claim to the specifically stated elements or method steps, plus those elements or method steps that do not materially affect the basic and novel characteristics of the claimed subject matter .

With respect to the terms "comprising," "consisting of," and "consisting essentially of," where one of these three terms is used herein, the presently disclosed and claimed subject matter may include the use of the other two any of the terms. Thus, in some embodiments not expressly recited otherwise, "comprising" in any event may be replaced by "consisting of," or by "consisting essentially of."

Some variations are premised on the discovery of a surprisingly simple method for converting lignocellulosic biomass to nanocellulose or nanolignocellulose. The biomass can be soaked in steam or hot water to dissolve the hemicellulose. This step is followed by mechanical refining of the cellulose-rich (and lignin-rich) solids.

Some variations provide a nano-lignocellulose composition, on a dry, ash-free, and acetyl-free basis, comprising: about 35 wt % to about 80 wt % cellulose nanofibrils, cellulose microfibrils fiber or a combination thereof; about 15 wt% to about 45 wt% lignin; and about 5 wt% to about 20 wt% hemicellulose.

In various embodiments, the nano-lignocellulose composition may comprise about (or at least about, or at most about) 30 wt %, 35 wt %, 40 wt %, 45 wt %, 50 wt %, 55 wt %, 60 wt %, 65 wt %, 75 wt %, 75 wt %, 80 wt %, 85 wt %, or 90 wt % of cellulose nanofibrils, cellulose microfibrils, or a combination thereof.

In various embodiments, the nano-lignocellulose composition may comprise about (or at least about, or at most about) 10 wt %, 15 wt %, 20 wt %, 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, or 50wt% lignin.

In various embodiments, the nano-lignocellulose composition may comprise about (or at least about, or at most about) 2 wt %, 3 wt %, 4 wt %, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 13wt%, 14wt%, 15wt%, 16wt%, 17wt%, 18wt%, 19wt%, or 20wt% cellulose. Hemicellulose may contain xylan or mannan as a major component.

"A dry, ash-free and acetyl-free basis" means that the stated concentration (i) is absolutely free of any water, such as H-OH groups chemically contained in the sugar polymer; ( ii) free of any ash, including loose ash (eg, sand or dirt) and bound ash (eg, metal oxides that are not easily extracted from solids); and (iii) free from hemicellulose components A bound acetyl group, or free acetic acid derived from an acetyl group.

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

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

In certain embodiments, the composition comprises about 20 wt % to about 40 wt % lignin on a dry, ash-free, and acetyl-free basis.

In certain embodiments, the composition comprises about 25 wt % to about 35 wt % lignin on a dry, ash-free, and acetyl-free basis.

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

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

The nano-lignocellulose composition may contain water as moisture or in a slurry of solids. Nano-lignocellulose compositions, on an ash-free and acetyl-free basis (but on a wet basis), may contain at least about (or at least about, or at most about) 5 wt %, 10 wt %, 15 wt %, 20 wt % %, 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 60wt%, 70wt%, 80wt%, 90wt% or higher water.

The nano-lignocellulose composition may contain ash. The nano-lignocellulose composition, on a dry and acetyl-free basis, may contain at least about (or at least about, or at most about) 0.1 wt %, 0.5 wt %, 1 wt %, 2 wt %, 3 wt %, 4 wt % %, 5wt% or higher ash.

The nano-lignocellulose composition may contain acetyl groups. The nano-lignocellulose composition, on a dry and ash-free basis, may contain at least about (or at least about, or at most about) 0.1 wt %, 0.5 wt %, 1.0 wt %, 1.5 wt %, 2.0 wt % , 2.5 wt%, 3.0 wt% or more of acetyl groups.

In some embodiments, the nano-lignocellulose composition is characterized by at least 99% filtration (eg, 100% complete) in less than 100 minutes.

The present invention also provides pulp products or paper products containing the disclosed nano-lignocellulose compositions.

In some variations, paper mills co-produce nano-lignocellulose and add this material back to their own feed for use in making stronger paper, or smoother paper, or to provide a final paper product Cheaper way of feeding. In some embodiments, the nano-lignocellulose is produced as a sideline operation at the paper mill or a nearby paper mill using existing low compatibility refiners. At least some of the resulting nano-lignocellulose is added back to the admixture.

This concept could lead to the ability to produce pulp using low cost wood as the primary feedstock. Many paper mills use mixtures of hardwoods and softwoods to achieve the desired combination of strength and paper formation/smoothness. In addition to replacing higher-cost raw materials, nano-lignocellulose can also act as a retention aid for paper machines. Thus, paper machines can take advantage of the function of retention aids and the strength of the paper from the same material (nano-lignocellulose).

牛皮、或亚硫酸盐)、机械、热机械、化学热机械、水热机械的(例如

或GP3+^TM)或其他类型的制浆。化学制浆通常将木质素和半纤维素降解为小的水溶性分子，这些分子可以在不会使纤维素纤维解聚的情况下从纤维素纤维上洗掉。

制浆在不显著降解糖的情况下去除木质素和半纤维素，使得可以回收所有主要组分(纤维素、半纤维素和木质素)。各种机械制浆方法，例如磨木和精制机机械制浆，物理上将纤维素纤维彼此撕裂。许多木质素仍然附着在纤维上。因为可能会切断纤维，所以强度受损。相关的混合制浆方法使用化学处理和热处理的组合来开始简化的化学制浆过程，然后进行机械处理以分离纤维。这些混合方法包括热机械制浆和化学热机械制浆。化学处理和热处理减少了机械处理随后所需的能量的量，也减少了纤维所遭受的强度损失的量。The principles of the present invention can be applied to any type of pulp or pulp mill, including chemical (eg,

cowhide, or sulfites), mechanical, thermomechanical, chemical thermomechanical, hydrothermal mechanical (e.g.

or GP3+ ^™ ) or other types of pulping. Chemical pulping typically degrades lignin and hemicellulose into small water-soluble molecules that can be washed from cellulosic fibers without depolymerizing them.

Pulping removes lignin and hemicellulose without significantly degrading the sugars so that all major components (cellulose, hemicellulose and lignin) can be recovered. Various mechanical pulping methods, such as groundwood and refiner mechanical pulping, physically tear cellulose fibers from each other. Much of the lignin is still attached to the fibers. Strength is compromised because fibers may be cut. A related hybrid pulping method uses a combination of chemical treatment and thermal treatment to start a simplified chemical pulping process, followed by mechanical treatment to separate fibers. These mixing methods include thermomechanical pulping and chemithermomechanical pulping. Chemical and thermal treatments reduce the amount of energy required for subsequent mechanical treatment and also reduce the amount of strength loss suffered by the fibers.

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

In some embodiments, some of the thermomechanical or hydrothermal mechanical pulp produced by normal pulping operations is sent to a sideline nanocellulose production operation (including mechanical refining of the thermomechanical or hydrothermal mechanical pulp) to produce Nanocellulose particles (eg cellulose nanofibrils). Commonly owned U.S. Patent Application No. 15/278,800, filed September 28, 2016, entitled "PROCESSES FOR PRODUCING NANOCELLULOSE, AND NANOCELLULOSE, PROCESSES FOR PRODUCING NANOCELLULOSE COMPOSITIONSPRODUCED THEREFROM)" is hereby incorporated by reference for its teachings in some embodiments of converting thermomechanical or hydrothermal mechanical slurries to nanocellulose.

技术)产生的瓦楞芯纸与通过对由生物质的酸性溶剂分馏(称为技术)获得的浆料进行精制而产生的纳米纤维素进行组合。In some variations, nanocellulose can be added to corrugating pulp with insufficient strength properties such that the resulting composite meets or exceeds the strength properties required for the intended application. While the principles of these embodiments are not limited to any particular source of corrugated paper or nanocellulose, preferred embodiments will be by steam or hot water extraction (referred to as

technology) produced corrugated paper with an acidic solvent fractionation (called technology) to combine the nanocellulose produced by refining the pulp obtained.

In some preferred embodiments, steam extraction or hot water extraction of the starting biomass is employed to produce a pulp, which is then refined and optionally washed to produce a corrugated pulp. Reference is made to commonly owned US Patent Application No. 14/044,784, filed October 2, 2013 (published as US 20140096922 A1 on April 10, 2014), which is directed herein to use in various embodiments for the production of corrugating core pulp The exemplary process conditions for are incorporated herein by reference.

In some embodiments, the starting biomass is extracted with hot water to produce a slurry, which is then refined to produce nanolignocellulose. As used herein, "nanolignocellulose" is a material containing cellulose particles that are tightly bound (ie, chemically and/or physically bound) to large amounts of lignin and hemicellulose. Cellulose (within nano-lignocellulose particles) may 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 employ hot water digestion and/or refining as described in commonly owned US Patent Application No. 15/047,608 (published as US20160244788 on August 25, 2016), which is incorporated herein by reference Incorporated herein by reference.

Effective hot water extraction conditions may include contacting the lignocellulosic biomass with steam (in saturated, superheated or supersaturated form at various pressures) and/or hot water. In some embodiments, the HWE step is performed using liquid hot water at a temperature of about 140-220°C, eg, 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, eg, about 2 minutes, 2.5 minutes, 3 minutes, 3.5 minutes, 4 minutes, 5 minutes, 7.5 minutes, 10 minutes , 12.5 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, or 55 minutes.

In certain embodiments, lignin-coated nanocellulose, preferably lignin-coated cellulose nanofibrils, is added to the corrugated pulp. Without being bound by theory, lignin in nanofibrils can enhance the moisture resistance of corrugated core paper. The production of lignin-coated nanocellulose is described in detail below. In some embodiments, the lignin fills the voids between the fibers during pressing.

Corrugated paper products can be produced from modified (with nanocellulose) corrugated paper pulp using well known techniques. See, eg, 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, edited by Brody A and Marsh K, 2nd edition).

As used herein, "nanocellulose" is broadly defined to include a range of cellulosic materials including, but not limited to, microfibrillated cellulose (or cellulose microfibrils), nanofibrillated cellulose (or cellulose nanofibrils), microcrystalline cellulose, nanocrystalline cellulose, and micronized or fibrillated dissolving slurries. Typically, the nanocellulose provided herein will comprise particles having a length dimension (eg, diameter) of at least one nanoscale.

"Nanofibrillated cellulose" or equivalently "cellulose nanofibrils" refers to cellulose fibers or domains that contain nanoscale particles or fibers, or both microscale and nanoscale particles or fibers. "Nanocrystalline cellulose" or equivalently "cellulose nanocrystals" refers to cellulose particles, domains or crystals that contain nanoscale domains, or both microscale domains and nanoscale domains. "Microscale" includes 1 μm to 100 μm, and “nanoscale” includes 0.01 nm to 1000 nm (1 μm). Larger domains (including long fibers) can also be present in these materials.

Certain exemplary embodiments of the present invention will now be described. These embodiments are not intended to limit the scope of the invention as claimed. The order of steps may vary, some steps may be omitted, and/or other steps may be added. The first steps, second steps, etc. mentioned herein are only for the purpose of illustrating some embodiments.

Some variations provide a pulp product comprising cellulose and nano-lignocellulose, wherein the nano-cellulose comprises cellulose nanofibrils and/or cellulose nanocrystals, and wherein the nano-lignocellulose is pulped with The process is derived from cellulose in a separate step for producing cellulose.

In some embodiments, the pulping process is thermomechanical pulping or hydrothermal mechanical pulping. The pulp product may be paper or a structural object other than paper (eg, boxes, boards, engineered wood, etc.).

In a preferred embodiment, the pulp product is stronger than an otherwise identical pulp product without the nanolignocellulose. In some embodiments, the pulp product is smoother than an otherwise identical pulp product without nanolignocellulose.

The pulping process is thermomechanical pulping in certain embodiments, and the nanolignocellulose consists essentially of nanofibrils containing cellulose, lignin, and hemicellulose. Nanofibrils can be produced by mechanical refining of cellulose precursors (with significant amounts of lignin and hemicellulose) from thermomechanical pulping.

Other variations provide corrugated core pulp compositions comprising cellulose pulp and nano-lignocellulose, wherein the nano-lignocellulose includes hydrophobic nanofibrils. In some embodiments, the nano-lignocellulose is present at a concentration of at least about 0.1 wt %, 0.5 wt %, 1 wt %, 2 wt %, 5 wt %, or 10 wt % of the composition on a dry basis. In certain embodiments, the nano-lignocellulose is a significant portion of the pulp feed, ie, about 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt% or more.

浆料、牛皮纸浆、亚硫酸盐浆料或苏打浆料)。In some embodiments of the corrugating pulp composition, the cellulosic pulp is a mechanical pulp or a thermomechanical pulp (eg, slurry). In some embodiments, the cellulose pulp is a chemical pulp (eg,

pulp, kraft pulp, sulfite pulp or soda pulp).

In some embodiments, the method further includes producing a corrugated core product from the corrugated core pulp composition. The first amount of lignocellulosic biomass and the second amount of lignocellulosic biomass can be from the same biomass source or different biomass sources.

In some embodiments, the nano-lignocellulose is a lignin-containing hydrophobic cellulose. In these or other embodiments, the nanolignocellulose is primarily in the form of nanofibrils, microfibrils, or mixtures thereof.

In some embodiments, a system for performing the disclosed method is provided. The system can include a first subsystem for producing a first slurry at a first location and a second subsystem for producing nanolignocellulose at a second location different from the first location. Production of the final product may take place at one of the first subsystem or the second subsystem or at other locations.

In some embodiments, the nano-lignocellulose is derived from a biomass source selected from the group consisting of hardwood, softwood, agricultural waste, and combinations thereof.

方法制造用于增强纤维素纤维的纳米木质纤维素。In some embodiments, nano-lignocellulose is obtained by fractionating biomass in the presence of an acid, a solvent for lignin, and water to generate a cellulose-enriched solid and liquid phase; then cellulose-enriched solid mechanical refining to generate nano-lignocellulose. In certain embodiments, the acid is sulfur dioxide and the solvent is ethanol. In some embodiments, using

The method manufactures nano-lignocellulose for reinforcing cellulose fibers.

"Enhancing" may be achieved in various embodiments by simple mixing, grinding, grinding, stirring, deposition/drying, or other processing.

In some embodiments, the method further comprises producing a monofilament product from cellulosic fibers. In these or other embodiments, the method further includes producing the composite material from the cellulosic fibers. Reinforcing weak fibers with nano-lignocellulose can increase the strength of composites and single-fiber products, as well as other products.

In some embodiments, the product is first made from cellulosic fibers, and then the product (not pulp) is reinforced with nano-lignocellulose. In these embodiments, if desired, for example, the overall product or selected surfaces or areas may be enhanced.

The biomass feedstock may 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 food crops, annual grasses, energy crops, or other annual renewable feedstocks. Exemplary agricultural wastes include, but are not limited to, corn stover, corn fiber, wheat stover, bagasse, sugarcane stover, rice straw, oat stover, barley stover, miscanthus, energy cane stover/bagasse, or combinations thereof. The method disclosed herein benefits from feedstock flexibility; it is effective on a wide variety of cellulose-containing feedstocks.

As used herein, "lignocellulosic biomass" refers to any material containing cellulose, lignin, and hemicellulose. Mixtures of one or more types of biomass can be used. In some embodiments, the biomass feedstock comprises lignocellulosic components (eg, corn, wheat, rice, etc.) in addition to sucrose-containing components (eg, sugar cane or energy cane) and/or starch components (eg, corn, wheat, rice, etc.). such as the aforementioned lignocellulose). Various moisture levels can be associated with the starting biomass. The biomass feedstock need not, but can be relatively dry. Generally, biomass is in the form of particles or chips, but particle size is not critical in the present invention.

In some embodiments, the total mechanical energy of the process is less than about 5000 kWh/ton cellulose-rich solids, such as less than about 4000 kWh/ton cellulose-rich solids, 3000 kWh/ton cellulose-rich solids, 2000 kWh/ton of cellulose-rich solids or 1000 kWh/ton of cellulose-rich solids of cellulose-rich solids. Energy consumption can be measured in any other suitable unit. An ammeter that measures the current drawn by the electric motor driving the mechanical processing device is one way to obtain an estimate of the total mechanical energy.

Mechanical treatment may use one or more known techniques such as, but in no way limited to, grinding, milling, beating, sonication, or any other means to form or release nanofibrils and/or nanocrystals in cellulose. Essentially, any type of mill or equipment that physically separates fibers into fibrils can be utilized. Such mills are well known in the industry and include, but are not limited to, Valley beaters, single-disc refiners, double-disc refiners, cone refiners - including high and low angle, cylindrical refiners, homogenizers machine, microfluidizer and other similar grinding or grinding equipment. See, eg, Smook, Handbook for Pulp & Paper Technologists, Tappi Press, 1992; and Hubbe et al., "Cellulose Nanocomposites: A Review," BioResources 3(3), 929-980 (2008).

The degree of mechanical treatment can be monitored during the process by any of a number of means. Certain optical instruments can provide continuous data on fiber length distribution and % fineness, either of which can be used to define the end point of the mechanical treatment step. Time, temperature and pressure during mechanical treatment can vary. For example, in some embodiments, sonication at ambient temperature and pressure for a time period of about 5 minutes to 2 hours may be utilized.

In some embodiments, a portion of the cellulose-rich solids is converted to nanofibrils, while the remainder of the cellulose-rich solids 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 Solids are fibrillated into nanofibrils. In some embodiments, a portion of the nanofibrils are converted to nanocrystals, while the remainder of the nanofibrils are not converted to nanocrystals. During drying, some nanocrystals may recover together and form nanofibrils.

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

The method may also include treating the cellulose-rich solid with one or more enzymes or one or more acids. When acids are used, they may 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 or uronic acids, can be used alone or in combination with other acids. Additionally, the method may include treating the cellulose-rich solids with heat. In some embodiments, the method does not use any enzymes or acids.

When an acid is used, the acid can be a strong acid, such as sulfuric acid, nitric acid or phosphoric acid. At more stringent temperatures and/or times, weaker acids can be used. Enzymes that hydrolyze cellulose (ie cellulase) and possibly hemicellulose (ie have hemicellulase activity) can be used in place of acid or possibly in a sequential configuration before or after acid hydrolysis.

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

In some embodiments, the method further comprises enzymatically treating the crystalline cellulose. In other embodiments, or sequentially before or after the enzymatic treatment, the method further comprises acid treating the crystalline cellulose.

If desired, enzymatic treatment may be employed prior to or possibly concurrently with mechanical treatment. However, in a preferred embodiment, it is not necessary to perform an enzymatic treatment to hydrolyze the amorphous cellulose or weaken the structure of the fiber wall prior to isolation of the nanofibers.

After mechanical treatment, nano-lignocellulose can be recovered. Isolation of cellulose nanofibrils and/or nanocrystals can be accomplished using a device capable of disintegrating 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 are recovered with component fibrils in the range of 1-100 nm in width, wherein the fibrils have not yet been completely separated from each other.

In some embodiments, the nano-lignocellulosic material is characterized by particles having an average length-width aspect ratio of from about 10 to about 1000, eg, about 15, 20, 25, 35, 50, 75, 100, 150, 200, 250 , 300, 400 or 500. Nanofibrils typically involve higher aspect ratios than nanocrystals. For example, nanocrystals can have a length ranging from about 100 nm to 500 nm and a diameter of about 1 nm to 10 nm. The nanofibrils were approximately 2000 nm in length, with diameters ranging from 5 nm to 50 nm, translating 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.

Optionally, the method further includes hydrolyzing the amorphous cellulose to glucose, recovering the glucose, and fermenting the glucose into a fermentation product. Optionally, the method further comprises recovering, fermenting or further processing hemicellulose sugars derived from some of the hemicellulose. Optionally, the method further comprises recovering, burning or further processing the lignin.

Glucose produced from hydrolysis of amorphous cellulose can be integrated into the overall process to produce ethanol or other fermentation co-products. Accordingly, in some embodiments, the method further comprises hydrolyzing the amorphous cellulose to glucose, and recovering the glucose. Glucose can be purified and sold. Alternatively, glucose can be fermented to a fermentation product such as, but not limited to, ethanol. If desired, the glucose or fermentation product can be recycled to the front end, eg for hemicellulose sugar processing.

When hemicellulose sugars are recovered and fermented, they can be fermented to produce monomers or their precursors. Monomers can be polymerized to produce polymers, which can then be combined with nanocellulose materials to form polymer-nanocellulose composites.

In some embodiments, the method further comprises chemically converting the nano-lignocellulosic material to one or more nano-lignocellulosic derivatives. For example, the nano-lignocellulose derivative can be selected from nano-lignocellulose esters, nano-lignocellulose ethers, nano-lignocellulose ether esters, alkylated nano-lignocellulose compounds, cross-linked nano-lignocellulose compounds, acid functional The group consisting of nano-lignocellulose compounds, alkali-functionalized nano-lignocellulose compounds, and combinations thereof.

Various types of nano-lignocellulose functionalization or derivatization can be employed, such as functionalization with polymers, chemical surface modification, functionalization with nanoparticles (i.e. nanoparticles other than nano-lignocellulose), Modification with inorganic substances or surfactants, or biochemical modification.

High loadings of lignin have been achieved in thermoplastics. Higher loading levels were obtained with known lignin modifications. The preparation of useful polymeric materials containing substantial amounts of lignin has been the subject of research for more than three decades. Typically, lignin can be blended into polyolefins or polyesters by extrusion at up to 25-40 wt% while satisfying mechanical properties. To increase the compatibility between lignin and other hydrophobic polymers, different methods have been used. For example, chemical modification of lignin can be accomplished by esterification with long chain fatty acids.

An important factor limiting the application of strength-enhancing lightweight nanocellulose in composites is the inherent hydrophilicity of cellulose. Surface modification of nanocellulose surfaces to impart hydrophobicity to enable uniform dispersion in hydrophobic polymer matrices is an active area of research. It has been found that nano-lignocelluloses as provided herein are hydrophobic.

Optionally, the method for producing a hydrophobic nano-lignocellulosic material may further comprise chemically modifying lignin to increase the hydrophobicity of the nano-lignocellulosic material. Any known chemical modification of lignin can be performed to further increase the hydrophobic properties of the nano-lignocellulosic materials provided by embodiments of the present invention.

Some variations of the present invention presuppose relatively simple methods to generate high viscosity compounds made from cellulosic biomass. The high viscosity compounds will act as rheology modifiers when mixed in small proportions with different fluids such as drilling fluids, coatings and the like.

In hydraulic fracturing fluid formulations, especially water-based formulations but also oil-based formulations, these compositions can function as gelling agents. Ease of mixing and handling allows customization for individual reservoir properties. The multiple properties of these rheology modifiers provide powerful advantages when compared to products currently available on the market. Some of these properties are higher thermal stability, strong shear thinning, thixotropic quality and water solubility. Another important property of these new compounds is that they are biodegradable and their production does not involve any other chemicals besides biomass and water.

Some variations provide a method for producing a nanocellulose material, the method comprising:

(a) providing lignocellulosic biomass feedstock;

(b) digesting the feedstock with a reaction solution comprising steam and/or hot water in a digester under effective reaction conditions to produce a digest comprising cellulose-rich solids, hemicellulose oligomers and lignin logistics;

(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 solid to form a nanocellulose material containing cellulose nanofibrils and/or cellulose nanocrystals; and

(e) Recovery of nanocellulose material.

The method may also include treating the cellulose-rich solid with one or more enzymes (eg, cellulase) or with one or more acids such as sulfur dioxide, sulfurous acid, lignosulfonic acid, acetic acid, formic acid, or a combination thereof . The method may also include treating the cellulose-rich solids with heat. In some embodiments, steps (b)-(d) do not use any enzymes or added acids.

The nanocellulose material may comprise cellulose nanofibrils or a mixture of cellulose nanofibrils and cellulose nanocrystals. 1A-1C show SEM images of exemplary nanocelluloses experimentally produced by refining and homogenizing materials produced from hot water extraction of biomass. The nanocellulose material may also contain lignin, which contains lignin particles less than 1 micron in diameter. The method may include post-production bleaching of the cellulose-rich solid and/or bleaching of the nanocellulose material.

In some embodiments, the method further comprises recovering, fermenting or further processing the hemicellulose sugars derived from the hemicellulose oligomers. For example, hemicellulose sugars can be fermented into fermentation products such as, but not limited to, ethanol.

In some embodiments, the method further comprises hydrolyzing a portion of the cellulose-rich solids to glucose; recovering the glucose; and optionally fermenting the glucose to a fermentation product, such as n-butanol or 1,4-butanediol.

The method may also include recovering, combusting, or further processing the lignin washed from the cellulose-rich solids. Some or all of the initial lignin (in the starting material) may become part of the nanocellulose material, which will be at least partially hydrophobic due to the presence of the lignin.

In some embodiments, the method further comprises chemically converting the nanocellulose material to one or more nanocellulose derivatives. For example, the nanocellulose derivative can 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, bases The group consisting of functionalized nanocellulose compounds and combinations thereof.

In certain embodiments, step (d) comprises pan refining followed by homogenization of the cellulose-rich solids. Step (d) or a portion thereof may be carried out at a solid consistency of at least 10 wt %, eg at least 20 wt %.

In some embodiments, the method includes exploding cellulose fibers contained in the cellulose-rich solid. For example, steam explosion and/or rapid decompression can be used to achieve fiber explosion. In certain embodiments, step (d) utilizes a blow-line refiner, optionally under reduced pressure.

Some variations of the present invention provide a method for producing a biomass-derived rheology modifier from cellulosic biomass, the method comprising:

(a) providing a feedstock comprising cellulosic biomass;

(b) digesting the feedstock with a reaction solution comprising steam and/or hot water in a digester under effective reaction conditions to produce a digest comprising cellulose-rich solids, hemicellulose oligomers and lignin logistics;

(c) refining the cellulose-rich solids in a first high-intensity refining unit to produce refined cellulose solids;

(d) washing the refined cellulosic solids after step (c), and/or washing the digest stream prior to step (c) and then refining, thereby producing washed refined cellulosic solids;

(e) gelling the washed refined cellulosic solids in a second high intensity refining unit to produce gelled cellulosic solids; and

(f) Homogenizing the gelled cellulose solids in a high shear homogenizer to produce a biogenic raw material containing cellulose nanofibrils, cellulose nanocrystals or a mixture of cellulose nanofibrils and cellulose nanocrystals Rheology modifiers for substances.

Optionally, the method further comprises wet or dry cleaning the feedstock prior to step (b). Optionally, whether or not the feedstock is cleaned, the method further comprises reducing the size of the feedstock prior to step (b).

Step (b) can be carried out at a digestion temperature of from about 140°C to about 210°C. Step (b) can be performed for 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.

The method may include, after step (b), performing a hot or cold sparge decompression of the digested stream.

The first high-strength refining unit may utilize, for example, disks or conical plates. In various embodiments, the first high-intensity refining unit delivers energy to the cellulose-rich solids in an amount from about 20 kW/ton to about 200 kW/ton on a dry basis.

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

The second high strength refining unit may utilize, for example, disks or conical plates. The first high-intensity refining unit and the second high-intensity refining unit preferably have different patterns with different groove and dam sizes. In various embodiments, the second high intensity refining unit delivers energy to the washed refined cellulosic solids in an amount of from about 20 kW/ton to about 200 kW/ton on a dry basis.

In some embodiments, the shear force delivered by the high shear homogenizer is equal to the shear force produced at a pressure of about 10,000 psig to about 25,000 psig.

In some embodiments, the washed refined cellulose solids are stored for a period of time prior to step (e). Step (e) may be performed at a different location than steps (a)-(d). Also, step (f) may be performed at a different location than steps (a)-(e).

Other variations of the present invention provide a method for producing biomass-derived rheology modifiers from cellulosic biomass, the method comprising:

(a) providing a pretreated feedstock comprising cellulose-rich solids;

(b) refining the cellulose-rich solids in a first high-intensity refining unit to produce refined cellulose solids;

(c) optionally washing the refined cellulosic solids after step (b), and/or optionally washing the digest stream prior to step (b) and then refining, thereby producing washed refined cellulosic solids;

(d) gelling the washed refined cellulose solids in a second high intensity refining unit to produce gelled cellulose solids; and

(e) Homogenizing the gelled cellulose solids in a high shear homogenizer to produce a biomass-derived rheology modifier containing cellulose nanofibrils.

In some embodiments, the pretreated feedstock is kraft pulp derived from wood or lignocellulosic biomass. In some embodiments, the pretreated feedstock is a sulfite slurry 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 a thermomechanical pulp derived from wood or lignocellulosic biomass. In some embodiments, the pretreated feedstock is a chemical mechanical pulp derived from wood or lignocellulosic biomass.

A variation of the present invention provides a water-based hydraulic fracturing fluid formulation or additive comprising (i) a nanocellulose material produced according to the method or (ii) a biomass-derived rheology produced according to the method modifier.

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

A variation of the present invention provides a water-based drilling fluid formulation or additive comprising (i) a nanocellulose material produced according to the method or (ii) a biomass-derived rheology-modified produced according to the method agent.

A variation of the present invention provides an oil-based drilling fluid formulation or additive comprising (i) a nanocellulose material produced according to the method or (ii) a biomass-derived rheology modified according to the method agent.

Some variations provide a polymer-nanocellulose composite comprising (i) a nanocellulose material produced according to the method or (ii) a biomass-derived rheology modifier produced according to the method . Exemplary polymers include, but are not limited to, polylactide, poly(vinyl alcohol), polyethylene, polypropylene, and the like.

In some embodiments, the method produces a high viscosity compound having a size between 1 micron and 100 microns, eg, between 15 microns and 50 microns. These new compounds without any chemicals (except biomass and water) can be used as rheology modifiers and are fully biodegradable as they are based on cellulose.

The method provides several advantages. The design allows the process to be fully integrated in one line from start-up with biomass to production of high viscosity compounds. Alternatively, the method may be divided into multiple modules, which may be located in different geographic locations.

Biomass feedstocks may be selected from hardwoods, softwoods, forest residues, agricultural wastes (eg, bagasse), industrial wastes, consumer wastes, or combinations thereof. In any of these methods, the feedstock may comprise sucrose. In some embodiments where sucrose is present in the feedstock, most of the sucrose is recovered as part of the fermentable sugars.

Some embodiments of the present invention enable the processing of "agricultural waste," which for present purposes is meant to include lignocellulose associated with food crops, annual grasses, energy crops, or other annual renewable feedstocks biomass. Exemplary agricultural wastes include, but are not limited to, corn stover, corn fiber, wheat stover, bagasse, straw, oat stover, barley stover, miscanthus, energy cane, or combinations thereof. In certain embodiments, the agricultural waste is bagasse, energy bagasse, sugarcane straw, or energy cane straw.

In some embodiments, the method further comprises wet or dry cleaning the feedstock prior to step (b). In some embodiments, the method further comprises reducing the size of the feedstock prior to step (b). Methods may include size reduction, hot water soaking, dehydration, steaming, or other operations upstream of the digester.

Step (b) can be carried out at a digestion temperature of about 140°C to about 210°C, eg, about 175°C to about 195°C. Step (b) may be performed for a digestion time of about 5 minutes to about 45 minutes, eg, 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, eg, about 3, 3.5, 4, 4.5, or 5.

In some embodiments, the reaction solution contains steam in saturated, superheated or supersaturated form. In some embodiments, the reaction solution contains hot water.

The pressure in the pressurized vessel can be adjusted to maintain the aqueous feed as a liquid, a vapor, or a combination thereof. Exemplary pressures are from about 1 atm (atmospheric pressure) to about 30 atm, eg, about 3 atm, 5 atm, 10 atm, or 15 atm.

The solid phase residence time of the digester (pressurized extraction vessel) can vary from about 2 minutes to about 4 hours, eg, about 5 minutes to about 1 hour. In certain embodiments, the residence time of the digester is controlled at about 5 to 15 minutes, such as 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes minutes or 15 minutes. The liquid phase residence time of the digester can vary from about 2 minutes to about 4 hours, eg, about 5 minutes to about 1 hour. The gas phase residence time of the digester can vary from about 1 minute to about 2 hours, eg, about 3 minutes to about 30 minutes. The solid phase residence time, liquid phase residence time, and gas phase residence time may all be approximately the same, or they may be independently controlled according to reactor engineering principles (eg, recirculation and internal recirculation strategies).

In some embodiments, the method further comprises, after step (b), performing thermal spray decompression of the digested stream. Alternatively, cold spray decompression of the digested stream after step (b) may be employed.

To reduce the pressure, a spray tank can be placed between the digester and the refining unit. In some embodiments, the vapors are separated from the spray can and heat is recovered from at least some of the vapors. Optionally, at least some of the vapor is compressed and returned to the digester, and/or at least some of the vapor is purged from the process. Note that "spray tank" should be broadly understood to include not only tanks, but any other device or equipment capable of allowing pressure reduction in the process stream. Thus, the spray tank (or spray mechanism) may be a tank, container, pipe section, valve, separation device or other unit.

Each mechanical refiner may be selected from the group consisting of thermal jet refiners, hot stock refiners, disc refiners, cone refiners, cylindrical refiners, in-line fiber separators, homogenizers, and combinations thereof. Mechanical treatment (refining) may employ one or more known techniques such as, but in no way limited to, grinding, milling, beating, sonication, or any other method of reducing the particle size of cellulose. Such refiners are well known in the industry and include, but are not limited to, Valley beaters, single-disc refiners, double-disc refiners, cone refiners - including both high and low angle, cylindrical refiners, Homogenizers, microfluidizers, and other similar grinding or grinding devices. See, eg, Smook, Handbook for Pulp & Paper Technologists, Tappi Press, 1992.

Refining can be carried out at a wide range of solids concentrations (consistencies), including 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.

Each mechanical refiner can be configured to deliver from about 20 kW/ton to about 200 kW/ton (ie, kilowatts of refining power/ton of fiber, based on solids converted to a refining stream). In certain embodiments, the mechanical refiner is configured to deliver about 75 kilowatts of refining power/ton of fiber to about 150 kilowatts of refined power/ton of fiber. For example, a mechanical refiner with a plate can be adjusted to achieve these power inputs by changing plate type, gap, speed, etc.

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

In some embodiments, a portion of the cellulose-rich solids is converted to be fibrillated and/or gelled, while the remainder of the cellulose-rich solids 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-enriched The solids are fibrillated and/or gelled.

The first high-strength refining unit may utilize, for example, disks or conical plates. In some embodiments, the first high-intensity refining unit delivers energy from about 20 kW/ton to about 200 kW/ton on a dry basis, such as from about 75 kW/ton to about 150 kW/ton on a dry basis ) to the cellulose-rich solids.

In some embodiments, the washing in step (d) may be performed at a temperature of about 18°C to about 95°C, eg, about 70°C to about 80°C. The washing in step (d) can utilize a pressurized screw press.

In some embodiments, the second high-intensity refining unit utilizes disks or conical plates. The first high-intensity refining unit and the second high-intensity refining unit preferably have different patterns with different groove and baffle sizes. In some embodiments, the second high-intensity refining unit delivers energy from about 20 kW/ton to about 200 kW/ton on a dry basis, such as from about 75 kW/ton to about 150 kW/ton on a dry basis ) to the washed refined cellulose solids.

In some embodiments, the high shear homogenizer (or other unit operation capable of applying shear) delivers a shear force equal to that generated at a pressure of about 1,000 psig to about 50,000 psig, eg, about 10,000 psig to about 25,000 psig shear force.

The washed refined cellulose solids may be stored for a period of time prior to step (e), which may be performed at a different location than steps (a)-(d). In some embodiments, step (f) is not performed at a location other than steps (a)-(e).

In some embodiments, the biomass-derived rheology modifier can be characterized by a particle size (eg, fiber or fibril length or effective length) of about 1 to about 100 microns, eg, about 1 to about 50 microns. In certain embodiments, a majority (eg, about 50%, 60%, 70%, 80%, 90%, or 95%) of the particles are in the size range of 10-15 microns. Biomass-derived rheology modifiers may comprise particles (ie, nanoparticles) smaller than 5 microns, eg, 4 microns, 3 microns, 2 microns, 1 micron, or smaller. The width of the particles may be less than 1 micron. There may be particles larger than 100 microns, eg, 150 microns, 200 microns, 250 microns, 300 microns, 400 microns, 500 microns or larger.

In some embodiments, the biomass-derived rheology modifier can be characterized by a particle size (eg, length or effective length) of less than about 10 microns, eg, about 9 microns, 8 microns, 7 microns, 6 microns, 5 microns, 4 microns, 3 microns, 2 microns, 1 micron or less. In certain embodiments, the nanocellulose particles are about 900 nm, 800 nm, 700 nm, 600 nm, 500 nm, 400 nm, 300 nm, 200 nm, 100 nm or less in length. In these or other embodiments (including more than 1 micron in length), the nanocellulose particle size can be about 3 nm to about 1000 nm, for example, about 5 nm to about 500 nm, or about 10 nm to about 200 nm, or about 5 nm, 10 nm, 15 nm , 20 nm, 25 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, or 450 nm. In some of these embodiments, the nanoparticles (or a portion thereof) can be characterized as nanocrystals.

The rheology modifier compound is primarily a cellulose based polymer with some microcrystalline-like nanocellulose in the structure comprising some of the original biomass lignin. In some embodiments, the compound is predominantly hydrophilic in nature, making water-based drilling fluids and water-based fracturing fluids highly stable. In some embodiments with lignin content and suitable high intensity refining, the compound is hydrophobic, moderately hydrophobic, or a combination of hydrophilic and hydrophobic.

The present disclosure provides water-based hydraulic fracturing fluid formulations or additives comprising biomass-derived rheology modifiers produced according to the methods described herein.

The present disclosure provides oil-based hydraulic fracturing fluid formulations or additives comprising biomass-derived rheology modifiers produced according to the methods described herein.

The present disclosure provides water-based drilling fluid formulations or additives comprising biomass-derived rheology modifiers produced according to the methods described herein.

The present disclosure provides oil-based drilling fluid formulations or additives comprising biomass-derived rheology modifiers produced according to the methods described herein.

The method may also include removing one or more fermentation inhibitors (eg, acetic acid or furfural) by stripping. This stripping can be carried out by treating the hydrolyzed cellulose stream prior to fermentation. Alternatively, or in addition, the stream may be stripped after digestion, for example in a blow-off line.

In some embodiments, the method further comprises the step of fermenting the fermentable sugars contained in the liquid phase obtained from the initial digestion to a dilute fermentation product. The method may also include concentrating and purifying 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 lignin-containing solids stream can be removed prior to fermentation or downstream of fermentation.

Steps may include conditioning the hydrolysate to remove some or most of the volatile acids and other fermentation inhibitors. Evaporation may include flashing or stripping to remove sulfur dioxide, if any, prior to removing volatile acids. The evaporation step is preferably carried out at an acetic acid dissociation pH below 4.8, most preferably the pH is selected from about 1 to about 2.5. In some embodiments, additional evaporation steps may be employed. These additional evaporation steps may be performed under different conditions (eg, temperature, pressure, and pH) relative to the first evaporation step.

In some embodiments, some or all of the evaporated organic acids may be recycled to the first step (digestion step) as vapor or condensate to assist in the removal of hemicellulose or minerals from the biomass. This recycle of organic acid, eg acetic acid, can be optimized, along with process conditions that can vary depending on the amount of recycle, to improve cooking effectiveness.

The steps may include recovering the fermentable sugars, which may be stored, transported or processed. The steps may include fermenting the fermentable sugars into co-products (the main product being a rheology modifier).

The steps may include preparing a solid residue (containing lignin) for combustion. This step may include refining, grinding, fluidizing, compacting and/or granulating the dried extracted biomass. The solid residue may be fed to the boiler in the form of fine powder, loose fibers, granules, agglomerates, extrudates, or any other suitable form. Using known equipment, the solid residue can be extruded through a pressurized chamber to form particles or agglomerates of uniform size.

After fermentation, residual solids (eg, distillation residues) can be recovered, either combusted as solids or slurry, or recycled to combine into biomass pellets. Use of fermentation residual solids may require further demineralization. In general, after concentrating the distillation bottoms, any remaining solids are available for combustion.

Alternatively, or in addition, the method may include recovering residual solids as a fermentation co-product in solid, liquid, or slurry form. The fermentation co-product can be used as a fertilizer or fertilizer ingredient as it will generally be rich in potassium, nitrogen and/or phosphorus.

The process can be continuous, semi-continuous or batch. When continuous or semi-continuous, the stripper can be operated in countercurrent, cocurrent, or a combination thereof.

The method may also include bleaching the cellulose-rich solids prior to and/or as part of the refining step. Alternatively, or in addition, the method may further comprise bleaching the refined material, the gelled material or the homogenized material. Any known bleaching technique or sequence can be employed, including enzymatic bleaching.

Rheology modifiers as provided herein can be incorporated into drilling fluids, drilling fluid additives, fracturing fluids, and fracturing fluid additives. The rheology modifier can be present in various concentrations, eg, from about 0.001 wt% to about 10 wt% or more, eg, about 0.01 wt%, 0.05 wt%, 0.1 wt%, 0.5 wt%, 1 wt%, or 2 wt%.

In some variations, the present invention relates to a group of cellulosic compounds that can be used in different applications. One of the applications is to use them as product enhancers for drilling fluids. Rheology modifiers can perform one or more functions in the drilling fluid. For example, rheology modifiers can often act as viscosity-increasing gelling agents, or tackifiers. Rheology modifiers can act as friction reducers. Also, the rheology modifier may be a drilling polymer, substituted for or added to other polymers.

Drilling fluids are fluids used in drilling wells in the gas and oil industries and other industries that use large drilling equipment. Drilling fluids are used to lubricate, provide hydrostatic pressure, keep the drill bit cool, and keep the borehole as free of cuttings as possible. The rheology modifiers provided herein are suitable as additives to these drilling fluids.

In some embodiments, enzymes may be used with the composition as "breakers" to break down the rheology modifier after a period of time or under certain conditions (eg, temperature or pH).

In some embodiments, lignosulfonates are incorporated to enhance lubricity in drilling applications. Additionally, the ability of lignosulfonates to reduce the viscosity of mineral slurries can be beneficial in petroleum drilling muds.

In some embodiments, native lignin or non-sulfonated lignin or non-sulfonated lignin derivatives are incorporated into the composition.

Some embodiments provide drilling fluid additives comprising rheology modifiers.

Some embodiments provide a drilling fluid additive comprising a rheology modifier, wherein the additive further comprises a lignosulfonate.

Some embodiments provide a drilling fluid additive comprising a rheology modifier, wherein the additive further comprises non-sulfonated lignin.

Some embodiments provide a drilling fluid additive comprising a rheology modifier, wherein the additive further comprises a crosslinking agent.

Some embodiments provide drilling fluid additives comprising cross-linked rheology modifiers and lignosulfonates.

Some embodiments provide drilling fluids comprising the disclosed drilling fluid additives. The drilling fluid may be a water-based drilling fluid, an oil-based drilling fluid, or a mixed water-based/oil-based drilling fluid.

In various embodiments, the drilling fluid further comprises one or more of the following: biomass-derived weighting materials, biomass-derived filtration control agents, biomass-derived rheology control agents, biomass-derived weighting materials Biomass pH Controlling Agents, Biomass-Derived Loss-Like Materials, Biomass-Derived Surface Active Modifiers, Biomass-Derived Lubricants, and Biomass-Derived Flocculants, and/or Biomass-Derived stabilizer.

In some variations, the present invention provides a method of use of a drilling fluid additive, the method comprising incorporating the disclosed drilling fluid additive into a base fluid to produce a drilling fluid. In some variations, the present invention provides a method comprising directly or indirectly introducing the disclosed drilling fluid additive into a geological formation.

In some variations, the drilling method includes introducing, directly or indirectly, a drilling fluid additive into the geological formation, wherein the drilling fluid additive includes an enzyme that degels under effective conditions. In a related variation, the drilling method includes the direct or indirect introduction of a drilling fluid additive into the geological formation, followed by the introduction of an enzyme for degelling under effective conditions.

Some variations provide a method for producing a drilling fluid additive comprising refining biomass under effective pretreatment conditions and refining conditions to produce a drilling fluid additive as disclosed. In some embodiments, effective pretreatment conditions include the formation of lignosulfonic acid. Optionally, at least a portion of the lignosulfonic acid is not removed and is still present in the drilling fluid additive. In certain embodiments, the drilling fluid additive comprises the liquid slurry obtained from the method. For example, the slurry may contain biomass-derived rheology modifiers as well as water and pretreatment chemicals (eg, acids, solvents, etc.).

Another application for these compositions is their use as product enhancers for hydraulic fracturing fluids. This improvement in purpose is due in particular to their effect on reduced friction, improved proppant pumping at higher rates at reduced pressure, and predictable viscosity at high temperatures. In addition, these products are fully biodegradable; they are produced from biomass and are less prone to biofouling than other products such as galactomannan derivatives.

Rheology modifiers can be cross-linked to gel firmly in the fracturing fluid. In some embodiments, crosslinking of the rheology modifier results in stronger gels with more hydration.

Biomass-derived ash (from biomass structures) or sand (from scrubbing) can be used as proppants in place of mined silica.

In other variations, the present invention provides fracturing fluid additives.

Some embodiments provide fracturing fluid additives comprising rheology modifiers.

Some embodiments provide a fracturing fluid additive comprising a rheology modifier, wherein the additive further comprises a lignosulfonate.

Some embodiments provide a fracturing fluid additive comprising a rheology modifier, wherein the additive further comprises non-sulfonated lignin.

Some embodiments provide a fracturing fluid additive comprising a rheology modifier, wherein the additive further comprises a crosslinking agent.

Some embodiments provide fracturing fluid additives comprising a cross-linked rheology modifier and a lignosulfonate.

Some embodiments provide fracturing fluids comprising the disclosed fracturing fluid additives. The fracturing fluid can be a water-based fracturing fluid, an oil-based fracturing fluid, or a hybrid water-based/oil-based fracturing fluid.

In addition to the disclosed fracturing fluid additives, the fracturing fluid may include one or more of the following: biomass-derived acids (eg, acetic acid, formic acid, levulinic acid, and/or lignosulfonic acid) , biomass-derived corrosion inhibitors (such as lignin or lignin derivatives), biomass-derived friction reducers (such as lignosulfonates or lignosulfonate derivatives), biomass-derived Clay control agents, biomass-derived cross-linking agents, biomass-derived scale inhibitors, biomass-derived disruptors, biomass-derived iron control agents, biomass-derived biocides (e.g., biomass hydrolysate), and/or recycled or recovered water sources from biorefining. Typically, fracturing fluids carry, contain, or are intended to be combined with proppants, which may be biomass derived proppants (eg, ash contained in the biomass structure and/or sand, ash collected with the biomass) or dirt).

Some variations of the present invention provide a method of use of a fracturing fluid additive, the method comprising incorporating the disclosed fracturing fluid additive into a base fluid to produce a fracturing fluid. Some methods include the direct or indirect introduction of fracturing fluid additives into geological formations.

In some variations, methods for producing fracturing fluid additives include refining biomass under effective pretreatment conditions and refining conditions to produce the disclosed fracturing fluid additives. In some embodiments, the pretreatment conditions include the generation of lignosulfonic acid, which is optionally not completely removed and is present in the fracturing fluid additive. In some embodiments, the fracturing fluid additive comprises the liquid slurry obtained by the method. For example, the slurry may contain biomass-derived rheology modifiers as well as water and pretreatment chemicals (eg, acids, solvents, etc.).

The rheology modifiers of some embodiments are characterized by an average cellulose degree of polymerization of about 100 to about 2000, such as about 400 to about 1200 or about 500 to about 800. In certain embodiments, the rheology modifier is free of enzymes.

The present disclosure is in no way limited to rheology modifiers. The material produced by the multiple refining steps as disclosed (after biomass pretreatment) can be used in a variety of applications. For example, the rheology modifier can be incorporated into a product selected from the group consisting of: structured objects, foams, aerogels, polymer composites, carbon composites, films, coatings, coating precursors , current or voltage carriers, filters, membranes, catalysts, catalyst substrates, coating additives, coating additives, adhesive additives, cement additives, paper coatings, thickeners, rheology modifiers, drilling fluid additives, and combinations or derivatives thereof.

Some embodiments provide products for applications in sensors, catalysts, antimicrobial materials, current carrying capabilities, and energy storage capabilities. Cellulose crystals have the ability to assist in the synthesis of metal and semiconductor chains.

Some embodiments provide composites comprising refined cellulose and carbonaceous materials such as, but not limited to, lignin, graphite, graphene, or carbon aerogels.

Cellulose crystals can be combined with the stabilizing properties of surfactants and used to fabricate the architecture of various semiconductor materials.

The reactive surface of pendant –OH groups in refined cellulose facilitates the grafting of chemicals to achieve different surface properties. Surface functionalization allows tailoring of particle surface chemistry to facilitate self-assembly, controlled dispersion in a wide variety of matrix polymers, and control over particle-particle and particle-matrix bond strengths. Composites can be transparent, have greater tensile strength than cast iron, and have a very low coefficient of thermal expansion. Potential applications include, but are not limited to: barrier films, antimicrobial 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 other applications.

Other applications suitable for the present invention include: reinforcing polymers; adhesives; high strength spun fibers and textiles; advanced composites; films for barrier and other properties; switchable optical devices; drug and drug delivery systems; bone replacement and dental restorations; improved paper; packaging and construction products; additives for food and cosmetics; catalysts; and hydrogels.

Aerospace and transportation composites can benefit from these rheology modifiers. Automotive applications include cellulosic composites with polypropylene, polyamide (eg nylon) or polyester (eg PBT).

The rheology modifiers provided herein may be suitable as strength enhancing additives for renewable and biodegradable composite materials. The fibrillar structure of cellulose can act as a binder between the two organic phases, improving fracture toughness and preventing crack formation in packaging, building materials, appliances, and renewable fiber applications.

The rheology modifiers provided herein can be used as transparent and dimensionally stable strength-enhancing additives and substrates in flexible displays, flexible circuits, printable electronics, and flexible solar panel applications. For example, cellulose is incorporated into substrate sheets formed by vacuum filtration, drying under pressure, and calendering. In the sheet-like structure, cellulose acts as a glue between filler aggregates. The resulting calendered sheet is smooth and flexible.

The rheology modifiers provided herein may be suitable for use in composites and cement additives, allowing for crack reduction and increased toughness and strength. The cellular cellulose-concrete hybrid material of the foam allows for lightweight construction and increases crack reduction and strength.

Strength enhancement with cellulose increases both bond area and bond strength in high strength, high bulk, high filler content paper and paperboard applications with improved moisture and oxygen barrier properties. The pulp and paper industries in particular can benefit from the rheology modifiers provided herein.

Porous cellulose can be used in porous bioplastics, insulators and plastics, as well as in bioactive membranes and filters. Highly porous cellulosic materials are of high interest generally in the manufacture of filter media and for biomedical applications such as in dialysis membranes.

The rheology modifiers provided herein may be suitable as additives to improve the durability of coatings, protective coatings and varnishes to abrasion from ultraviolet radiation.

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

The large surface area of these rheology modifiers combined with their biodegradability makes them attractive materials for highly porous, mechanically stable aerogels.

In some embodiments, the method includes forming a structural object comprising a nano-lignocellulosic material or a derivative thereof.

In some embodiments, the method includes forming a foam or aerogel comprising a nano-lignocellulosic material or a derivative thereof.

In some embodiments, the method includes combining the nano-lignocellulosic material or derivative thereof with one or more other materials to form a composite material. For example, other materials may include polymers selected from polyolefins, polyesters, polyurethanes, polyamides, or combinations thereof. Alternatively, or in addition, other materials may include various forms of carbon.

In some embodiments, the method includes forming a film comprising a nano-lignocellulosic material or a derivative thereof. In certain embodiments, the film is optically clear and flexible.

In some embodiments, the method includes forming a coating or coating precursor comprising a nano-lignocellulosic material or a derivative thereof. In some embodiments, the nano-lignocellulose-containing product is a paper coating.

In some embodiments, the nano-lignocellulose-containing product is configured as a catalyst, catalyst substrate, or co-catalyst. In some embodiments, the nano-lignocellulose-containing product is electrochemically configured to carry or store electrical current or voltage.

In some embodiments, the nano-lignocellulose-containing product is incorporated into a filter, membrane, or other separation device.

In some embodiments, the nano-lignocellulose-containing product is incorporated as an additive into a coating, coating, or adhesive. In some embodiments, the nano-lignocellulose-containing product is incorporated as a cement additive.

In some embodiments, the nano-lignocellulose-containing product is incorporated as a thickener or rheology modifier. For example, the nano-lignocellulose-containing product may be an additive in drilling fluids such as, but not limited to, oil and/or gas production fluids, or fracturing fluids.

The nanolignocellulose-containing product can include any of the disclosed nanolignocellulose compositions. Many nano-lignocellulose-containing products are possible. For example, a nano-lignocellulose-containing product may be selected from the group consisting of: structured objects, foams, aerogels, polymer composites, carbon composites, films, coatings, coating precursors, current or voltage carriers , filters, membranes, catalysts, catalyst substrates, coating additives, paint additives, adhesive additives, cement additives, paper coatings, thickeners, rheology modifiers, drilling fluid additives, and combinations or derivatives thereof thing.

For example, certain nano-lignocellulose-containing products provide high clarity, good mechanical strength, and/or enhanced gas (eg, _O2 or _CO2 ) barrier properties. For example, certain nanolignocellulose-containing products containing the hydrophobic nanocellulose materials provided herein can be used as moisture- and ice-resistant coatings.

Some embodiments provide nano-lignocellulose-containing products suitable for use in sensors, catalysts, antimicrobial materials, current carrying and energy storage capabilities.

Some embodiments provide composites comprising nano-lignocellulose and carbonaceous materials such as, but not limited to, lignin, carbon black, graphite, graphene, or carbon aerogels.

The reactive surface of pendant –OH groups in nanolignocellulose facilitates the grafting of chemicals to achieve different surface properties. Surface functionalization allows tailoring of particle surface chemistry to facilitate self-assembly, controlled dispersion within a wide variety of matrix polymers, and control over particle-particle and particle-matrix bond strengths. Composites can be transparent, have greater tensile strength than cast iron, and have a very low coefficient of thermal expansion. Potential applications include, but are not limited to: barrier films, antimicrobial 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 other applications.

Other nano-lignocellulose applications suitable for the present invention include: reinforced polymers; high strength spun fibers and textiles; advanced composites; films for barrier and other properties; switchable optical devices; drug and drug delivery systems; bone replacement and dental restorations; improved paper; packaging and construction products; food and cosmetic additives; catalysts; and hydrogels.

Aerospace and automotive applications include nano-lignocellulosic composites with polypropylene, polyamide (eg nylon) or polyester (eg PBT).

The nano-lignocellulosic materials provided herein are suitable as strength-enhancing additives for renewable and biodegradable composite materials. The nanofibrillar structure of cellulose can act as a binder between two organic phases, thereby improving fracture toughness and preventing crack formation in packaging, building materials, appliances, and renewable fiber applications.

The nano-lignocellulose materials provided herein are suitable as transparent and dimensionally stable strength-enhancing additives and substrates in applications in flexible displays, flexible circuits, printable electronics, and flexible solar panels. For example, nano-lignocellulose is incorporated into substrate sheets formed by vacuum filtration, drying under pressure, and calendering. In the sheet-like structure, nanocellulose acts as a glue between filler aggregates. The resulting calendered sheet is smooth and flexible.

The nano-lignocellulosic materials provided herein are suitable for composites and cement additives, allowing to reduce cracks and increase toughness and strength. The porous nano-lignocellulose-concrete hybrid material of the foam allows for a lightweight structure and increases crack reduction and strength.

Enhanced strength with nano-lignocellulose increases both bond area and bond strength in high strength, high bulk, high filler content paper and paperboard applications with improved moisture and oxygen barrier properties. The pulp and paper industries in particular can benefit from the nano-lignocellulosic materials provided herein.

Nanofibrillated cellulose nanopaper has higher density and higher tensile mechanical properties than conventional paper. It can also be optically clear and flexible, with low thermal expansion and excellent oxygen barrier properties. The functionality of nanopaper can be further broadened by adding other entities such as carbon nanotubes, nanoclays or conductive polymer coatings.

Rojo et al., Comprehensive elucidation of the effect of residual ligninon the physical, barrier, mechanical and surface properties of nanocellulose films", Green Chem., 2015, 17, 1853-1866, incorporated herein by reference.

Porous nano-lignocellulose can be used in porous bioplastics, insulators and plastics, as well as in bioactive membranes and filters. Highly porous materials are of high interest generally in the manufacture of filter media and for biomedical applications, such as in dialysis membranes.

The nano-lignocellulosic materials provided herein are suitable as coating materials with oxygen barrier properties and wood fiber affinity in food packaging and printing paper applications.

The nano-lignocellulosic materials provided herein are suitable as additives to improve the durability of coatings, protective coatings and varnishes against abrasion by UV radiation.

The nano-lignocellulosic materials provided herein are suitable as thickeners in food and cosmetics. Nano-lignocellulose can be used as a thixotropic, biodegradable, dimensionally stable thickener (stable to temperature and salt addition). The nano-lignocellulosic materials provided herein are suitable as Pickering stabilizers for emulsions and particle stabilized foams.

The large surface area of these nano-lignocellulosic materials combined with their biodegradability makes them attractive materials for highly porous, mechanically stable aerogels.

The present invention also provides systems configured to perform the disclosed methods and compositions resulting therefrom. Any stream produced by the disclosed methods may be partially or fully recovered, purified or further processed, and/or marketed or sold.

In this detailed description, reference has been made to various embodiments of the invention as well as non-limiting examples of how the invention may be understood and practiced. Other embodiments may be utilized that do not provide all of the features and advantages set forth herein without departing from the spirit and scope of the present invention. The present invention includes routine experimentation and optimization of the methods and systems described herein. Such modifications and variations are considered to be within the scope of the present invention as defined by the claims.

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

Where the above-described methods and steps indicate certain events occurring in a certain order, those of ordinary skill in the art will recognize that the order of certain steps may be modified and that such modifications are consistent with variations of the present invention. Additionally, certain steps may be performed concurrently in parallel processes, where possible, as well as sequentially.

Therefore, to the extent that there are variations of the invention that are within the spirit of this disclosure or equivalent to the invention found in the dependent claims, it is intended that this patent will also cover such variations. The invention is limited only by what is claimed.

Example

Example 1: Nano-lignocellulose produced from cork

Softwood (pine) chips were processed in a pilot steam gun digester at a temperature of 185°C for 20 minutes, resulting in a pulp yield of about 80%. The pulp was passed through a pilot plant pan refiner to defibrate the cooked wood chips to a freeness of about 100. The freeness of the pulp gives a measure of the draining rate of the thin pulp suspension (see TAPPI T221 "Drainage Time of Pulp"). The slurry was then passed through a laboratory-scale homogenizer three times to reach the target of 80-85% fines, resulting in unwashed nanolignocellulose. The percentage of fines (refined material) can be increased by more passes through the homogenizer. Unwashed nano-lignocellulose was washed 3 times with water at 60°C at approximately 2 kg water/kg pulp, 1 kg water/kg pulp, and 1 kg water/kg pulp for 30 min each, resulting in washed Nano lignocellulose.

Figure 2 shows a 4Ox magnification optical micrograph of the washed nano-lignocellulose produced in this example.

The nano-lignocelluloses in this example are precipitated lignin particles (about 50 to 300 nanometers in diameter), lignocellulose nanofibrils (about 500 nanometers in length, about 10 to 500 nanometers in width, and tens of microns) and lignocellulosic fines (length < 76 microns and width < 5 microns).

The composition of the washed solids was analyzed. Total carbohydrates were about 66.8 wt% solids. Dextran was 54 wt%, xylan was 9.2 wt%, galactan was 1.3 wt%, arabinan was 0.6 wt%, and mannan was 1.7 wt%. The acetyl group concentration in the solid was 1.9 wt%. The total lignin was 35.8 wt%, of which 33.3 wt% (on solids) was Klason lignin and 2.5 wt% (on solids) was acid soluble lignin.

Liquid phase analysis showed 0.98 wt% glucose, 7.44 wt% xylose, 0.42 wt% galactose, 0.35 wt% arabinose, and 0.79 wt% mannose, all sugars as % to original total solids (% to wood) . Formic acid was 0.07 wt%, acetic acid was 0.28 wt%, HMF was 0.02 wt%, furfural was 0.02 wt%, and dissolved lignin was 1.82 wt%, all again as a percentage of the original total solids.

Example 2: Nano-lignocellulose produced from hardwood

The hardwood chips were processed in a pilot steam gun digester at a temperature of 185°C for 15 minutes, resulting in a pulp yield of about 80%. The pulp was passed through a pilot plant pan refiner to defibrate the cooked wood chips to a freeness of about 100. The slurry was then passed through a laboratory-scale homogenizer three times to reach the target of 80-85% fines, resulting in unwashed nanolignocellulose. The percentage of fines (refined material) can be increased by more passes through the homogenizer. Unwashed nano-lignocellulose was washed 3 times with water at 60°C at approximately 2 kg water/kg pulp, 1 kg water/kg pulp, and 1 kg water/kg pulp for 30 minutes each, resulting in washed Nano lignocellulose.

Figure 3 shows a 4Ox magnification optical micrograph of the washed nanolignocellulose produced in this example.

The slurry produced in this example was also passed through the homogenizer 7 times, yielding 92% fines. This is compared to bleached softwood kraft pulp, which was Masuko refined, 14 passes, and 93% fines by area. Figure 4 is a graph of the filtration rate of the nano-lignocellulose compared to prior art kraft pulp. Filtration was Buchner filtration at 0.8 wt% total solids with a starting volume of 450 mL (based on 17% total solids in the nanocellulose pad, the total available filtrate was assumed to be 430 mL). The filter paper was Whatman 4 (pore size 20-25 μm).

Figure 4 shows the higher filtration rate of the nano-lignocellulose relative to bleached kraft fibrils. In particular, the nano-lignocellulose is substantially 100% filtered in less than 100 minutes. Due to the high lignin content, the water retention value and draining rate of nano-lignocellulose fibrils are much higher than those of pure cellulose fibrils. This is believed to be a key performance attribute for the use of nano-lignocellulose on paper machines.

Claims (11)

1. A nano-lignocellulosic composition comprising, on a dry, ash-free and acetyl-free basis: about 35 wt% to about 80 wt% of cellulose nano-fibrils, cellulose microfibrils, or a combination thereof; about 15 wt% to about 45 wt% lignin; and about 5 wt% to about 20 wt% hemicellulose.

2. The nano-lignocellulosic composition according to claim 1, wherein the composition comprises about 40 to about 70 wt% of cellulose nano-fibrils, cellulose micro-fibrils, or a combination thereof, on a dry-out, ash-free, and acetyl-free basis.

3. The nano-lignocellulosic composition according to claim 1, wherein the composition comprises about 45 to about 60 wt% of cellulose nano-fibrils, cellulose micro-fibrils, or a combination thereof, on a dry-out, ash-free, and acetyl-free basis.

4. The nano-lignocellulosic composition of claim 1 wherein the composition comprises about 20 to about 40 wt% lignin on a dry-out, ash-free and acetyl-free basis.

5. The nano-lignocellulosic composition of claim 1 wherein the composition comprises about 25 to about 35 wt% lignin on a dry-out, ash-free and acetyl-free basis.

6. The nano-lignocellulosic composition according to claim 1, wherein the composition comprises about 7 to about 15 wt% hemicellulose, on a dry-out, ash-free and acetyl-free basis.

7. The nano-lignocellulosic composition according to claim 1, wherein the composition comprises about 8 to about 14 wt% hemicellulose, on a dry-out, ash-free and acetyl-free basis.

8. The nano-lignocellulosic composition according to claim 1, wherein the hemicellulose contains xylan as a main component.

9. The nano-lignocellulosic composition according to claim 1, wherein the hemicellulose contains mannan as a main component.

10. The nano-lignocellulosic composition according to claim 1, wherein the nano-lignocellulosic composition is characterized by: at least 99% filtration was completed in less than 100 minutes.

11. A pulp product or paper product containing the nano-lignocellulosic composition according to claim 1.

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