A process for preparation of fibrillated cellulose

Abstract

The present disclosure relates to a cost-effective process for preparing a fibrillated cellulose material (microfibrillated and / or nanofibrillated) from agricultural or non-woody plant products and / or byproducts including crop-derived bran or fibres. The process comprises obtaining a feedstock, subjecting it to starch and oil removal, pretreating to remove lignin and hemicellulose, separating the solids using a solids-liquids separation, cleaning / bleaching, reslurrying, defibrillising, pressing to remove water and packaging as a microfibrillated and / or nanofibrillated cellulosic paste comprising 2 wt% to 10 wt% of microfibrillated and / or nanofibrillated cellulose dry solids. The feedstock is low in lignin content with lignin being less than 15% of the microfibrillated and / or nanofibrillated cellulose product on a dry basis.

Description

DescriptionTitle of Invention: A PROCESS FOR PREPARATION OF FIBRILLATED CELLULOSE CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of Indian Provisional Patent Application No.202541021569 filed March 11, 2025, which is incorporated herein by reference for all purposes in its entirety.FIELD

[0002] The present disclosure relates to a method for producing cellulose, especially fibrillated cellulose. The present disclosure also relates to a fibrillated cellulose product.BACKGROUND

[0003] In the past, the focus had been on the utilization of petroleum-derived materials and products for various applications. However, increasing environmental regulations encourage using bio-based materials to replace petroleum-based products. Because of their extended half-lives and inability to biodegrade in the environment, synthetic polymers are a nuisance to the ecosystem. In addition, landfills are quickly filling up, which will eventually limit the amount of land that can be used for other beneficial activities. For instance, biomaterials based on novel natural fibres are finding more use in the industry than ever.

[0004] It is well known that materials of micro / nanoscale dimensions can offer some unique capabilities that are not possible with larger-sized particles. The surface area of a particle increases with decreasing size, increasing the likelihood of favourable interactions with other materials. Fibrillated cellulose is a micromaterial / nanomaterial derived from cellulose fibres, which are mechanically processed to create fine fibrils. Fibrillated cellulose opens up new opportunities for creating robust and lightweight materials useful for a host of end-use applications. In contrast to other fibres obtained from the same sources, fibrillated cellulose has been discovered to have superior physical, barrier, thermal, and mechanical characteristics.

[0005] Woody and non-woody lignocellulosic biomass have been used in the preparation of cellulose. Non-woody plants have thin, weak stems and are subject to yearly death in the ground. They go by the name herbaceous plants as well. Specific examples of lignocellulosic non-woody biomass include grasses, agricultural residue, maize cobs, rice husks, cereal plant stems, and nutshells from plant fruits.

[0006] Large-scale plant production from agricultural waste and crop wastes is gaining interest. Therefore, in the near future, this category of biomass source may representa significant alternative for the extraction of cellulose. This is due to the non-woody plants' quicker growth cycles, minimal watering needs, yearly renewability, low lignin content, and high cellulose yields. These non-woody biomass resources are countless. No human activity is endangered by their use; on the contrary, they create a better, more sustainable environment. If not used, agricultural or garden wastes are often disposed of by burning or dumping them, which causes pollution.

[0007] Nanofibrillated cellulose (NFC) is a versatile material with wide-ranging applications in food, emulsifiers, packaging, composites, electronics, and biomedical engineering. Traditional production methods often rely on wood-based sources and energy-intensive techniques, making them less sustainable and less cost-efficient. Agricultural residues, particularly those from fruit and vegetable processing or crop-based sources, present an attractive alternative due to their abundance, affordability, lower lignin content, and high cellulose levels. However, transforming these residues into NFC requires overcoming key challenges such as breaking down the fibre matrix, separating components, and effectively managing hemicellulose, lignin, protein, and oil content, all while reducing energy consumption and minimizing chemical usage.

[0008] At present, there are various known enzymatic or chemical treatments in combination with mechanical techniques to produce fibrillated cellulose from non-woody lignocellulosic biomass. Despite continued research and development, there is still a need in the industry to improve the procedures for producing fibrillated cellulose from non-woody lignocellulosic biomass. High energy usage is one issue, hence an energy-efficient approach is required. Additionally, a procedure that enhances the characteristics of fibrillated cellulosic product is required.OBJECTS

[0009] Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows.

[0010] It is an object of the present disclosure to ameliorate one or more problems of the prior art or to at least provide a useful alternative.

[0011] An object of the present disclosure is to provide a process for the preparation of fibrillated cellulose (microfibrillated and / or nanofibrillated).

[0012] Another object of the present disclosure is to provide a cost-effective way of producing fibrillated cellulose material.

[0013] It is yet another objective of the present disclosure is to provide a method for producing fibrillated cellulose from agricultural fibre residues, preferentially derived from food sources, through a combination of mechanical, chemical, and oxidative treatments, with the inclusion of an extrusion step for rapid fibre pre-treatment, matrix disruption and partial fibrillation.

[0014] Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.DEFINITIONS

[0015] As used in the present specification, the following words and phrases are generally intended to have the meanings as set forth below, except to the extent that the context in which they are used indicates otherwise.

[0016] ‘Fibrillated cellulose’ means cellulose that has been mechanically or chemically processed to create a network of fine, thread-like micro- or nano-fibres (fibrils).

[0017] ‘Non-woody plant sources’ are plants that have thin, weak stems and are subject to yearly death in the ground.

[0018] ‘Non-woody feedstock’ means feedstock for the production of fibrillated cellulose that is derived from agricultural or non-woody plant products and / or byproducts.SUMMARY OF THE INVENTION

[0019] The present invention discloses a method for producing fibrillated cellulose from agricultural or non-woody plant products and / or byproducts including crop-derived bran or fibres. For the purposes of this invention, agricultural and / or non-woody plant products and / or byproducts are collectively referred to as 'non-woody feedstock’. At one step, a feedstock comprising a non-woody feedstock is obtained. In one embodiment, the feedstock comprises lignin in an amount of less than 15% of a total composition of the feedstock on a dry basis.

[0020] In one embodiment, the non-woody feedstock is selected from the group consisting of an energy crop, residual material from a processing of plant biomass, and agricultural waste.

[0021] In an embodiment, the energy crop is selected from the group consisting of switchgrass, miscanthus, com, sugarcane, sweet sorghum, soybean, rapeseed, jatropha, and oil palm.

[0022] In another embodiment, the residual material from the processing of plant biomass comprises food and beverage processing wastes, vegetable and fruit processing residues from animal feed producers, brewers, ethanol plants, mills, and the like.

[0023] In one embodiment, the agricultural waste comprises husks, bran, fibre, leaves, fruit pits, straw, stover, or combinations thereof. In an exemplary embodiment, agricultural waste is at least one material selected from the group consisting of com husks, oat bran, coffee husks, wheat bran, sugar cane tops, sugar cane leaves, rice husks, and barley husks or bran. In one embodiment, the stover is at least one selected from the group consisting of corn stover, soybean stover, and sorghum stover.

[0024] The non-woody feedstock is treated to remove residual non-fibrous components including starch, protein, sugars and oil to obtain a fibre-enriched material. In a subsequent step, the fibre-enriched material is pretreated to solubilize lignin and hemicellulose, thereby obtaining a pretreated material.

[0025] In one embodiment, the pretreatment is selected from a physical treatment,a chemical treatment, a mechanical treatment using twin screw extrusion, or combinations thereof. In one embodiment, the physical treatment is selected from ultrasonic treatment, microwave-assisted treatment, or high-pressure H2O / CO2treatment, and the chemical treatment is selected from alkaline extraction, alkaline treatment, oxidative treatment, acidic treatment, acid extraction, organosolv treatment, ionic liquid treatment, deep eutectic solvent treatment, alkali-peroxide treatment, alkaline-assisted hydrothermal treatment, and acid-assisted hydrothermal treatment.

[0026] The pretreated material is separated into solids comprising cellulosic material and an aqueous phase comprising solubilized material through a solid-liquid separation system or a solid-liquid separation method. In one embodiment, the solid-liquid separation method is performed using at least one of the methods selected from the group consisting of mechanical, chemical, thermal, filtration, centrifugation, filter press and solvent extraction system.

[0027] In one embodiment, the resultant cellulosic material comprises a cellulose content of over 50% on a dry basis. In another embodiment, the cellulosic material comprises a cellulose content of over 60% on a dry basis. In yet another embodiment, the cellulosic material comprises a cellulose content of over 70% on a dry basis. In yet another embodiment, the cellulosic material comprises a cellulose content of over 80% on a dry basis.

[0028] The cellulosic material is later subjected to at least one of a cleaning and bleaching step to obtain a cellulose cake. In one embodiment, the cellulosic material may be directed to a cleaning step to remove impurities, followed by a bleaching step to obtain a cellulose cake. In one embodiment, the bleaching method is at least one selected from the group consisting of ozone bleaching, alkaline-peroxide bleaching, and sodium hypochlorite bleaching, with intermittent washing. In one embodiment, the cellulose cake contains 70% cellulose on a dry basis. In another embodiment, the cellulose cake contains 80% cellulose. In yet another embodiment, the cellulose cake contains 90% cellulose.

[0029] The cellulose cake is reslurried and defibrillated using a defibrillation method to obtain a fibrillated cellulose slurry including at least one of microfibrillated and nanofibrillated cellulose slurry. In one embodiment, the cellulose cake is reslurried and defibrillated using at least one technique selected from the group consisting of ahigh-pressure homogenizer, double disk grinder, ball mill, aqueous counter collision, extrusion, ultrasonication, and cryo-crushing method.

[0030] The fibrillated cellulose slurry is directed to a centrifuge to separate the fibrillated cellulose slurry from water. The fibrillated cellulose slurry is then pressed to remove excess water and form a fibrillated cellulose product. Further, the fibrillated cellulose product could be packaged as a fibrillated cellulose paste to contain 2 wt% to 10 wt% of dry solids of fibrillated cellulose. In one embodiment, the fibrillated cellulose could be packaged as a microfibrillated and / or nanofibrillated cellulosic paste comprising 2 wt% to 10 wt% of microfibrillated and / or nanofibrillated cellulose dry solids.

[0031] The fibrillated cellulose product is a bio-based material suitable for use as a food additive, texturizing agent, stabilizer, thickener, Pickering emulsion, extruded or 3D-printed food ingredient, food packaging material, protective barrier, coating, encapsulating agent for nutrients, oil replacement, and calorie-reduced food ingredient. At yet another step, the method involves, applying cleaning, purification, and brightening to remove residual impurities, enhances brightness, and improves the quality of the cellulose.

[0032] In one embodiment, the method enables rapid disruption of the fibre matrix of the feedstock through a combination of mechanical and chemical means, which involves application of grinding, mixing, and high shear forces. The process utilizes extrusion, among other techniques, and is completed in under two minutes in a continuous manner, applying high shear and grinding forces to achieve partial defibrillation of the cellulose. The use of the feedstocks, in combination with the described processes, facilitates rapid and total disruption of the fibre matrix, leading to partial defibrillation of the cellulose structure. This is achieved through the selection of a low-lignin feedstock in conjunction with high mechanical shear forces acting on the fibre, combined with the chemical reactions occurring within the fibre matrix.

[0033] The process includes chemical treatment, which includes chemical agents such as alkalis, ranging from 8% to 16%, and hydrogen peroxide, ranging from 8% to 16%, are applied either individually or in combination. The chemical treatment involves acids, ionic liquids, deep eutectic solvents, enzymes, or combinations thereof. The application occurs before, during, or after the mechanical processing step. The use of a twin-screw, conical or planetary extruder optimizes the process by providing high shear forces, efficient mixing, precise temperature control, and accurate chemical and moisture introduction at various stages during extrusion. The extruder may include mass flow-based feed and chemical dosing systems, suitable materials of construction for specific chemical processes, venting ports where necessary, kneading blocks, transport sections, backflow sections, and a suitable die for optimized processing.

[0034] The method includes the separation of the soluble hemicellulose and lignin fractions from the insoluble cellulose fraction using centrifugation, a filter press, a screw press, or any other machine that enables cellulose containment while removing impurities through sparging, followed by subsequent dewatering. An optional further cleaning step is applied to the cellulose using chemical treatments. This step includes the use of hemicellulose- active enzymes for hydrolysis, removal, and optional recovery of partially hydrolyzed hemicellulose, oxidative methods such as ozone sparging, or a combination of these chemical steps in a sequence with or without intermittent washing and dewatering. This process increases cellulose purity to greater than 60%, ideally exceeding 70%, and more preferably exceeding 80%. An additional step may be performed either independently or in combination with the described method to enhance the brightness of the cellulose, thereby increasing its market value.

[0035] The cellulose obtained undergoes further defibrillation through high-pressure homogenization. This method is particularly effective for the selected feedstocks due to their aspect ratios, allowing for efficient defibrillation. The cellulose may also be further processed using alternative defibrillation methods, either as a substitute for or in combination with high-pressure homogenization. These methods may include disk grinding, ball milling, hydrodynamic cavitation, high-intensity sonication, grinding, microfluidization, cryogenic milling, or bead milling. The defibrillation step is carried out with reduced energy input due to the low lignin nature of the feedstock, the high shear forces applied during the mechanical and chemical disruption process, and the low aspect ratio of the cellulose resulting from the specific feedstock selection.

[0036] The cellulose fibres obtained exhibit reduced aspect ratios compared to woodbased cellulose, high specific surface areas, high absorption capacities, and a high degree of fibrillation. A pre-treatment step may be applied to the cellulose before defibrillation, wherein chemical modifications are introduced to modify the surface chemistry and reduce hydrogen bonding. This modification enhances the ease and degree of defibrillation and may include, but is not limited to, the introduction of carboxyl groups. A method is also provided for treating the cellulose to modify its surface chemical properties, enhancing specific properties for targeted applications.

[0037] Hemicellulose may be recovered using techniques such as ultrafiltration, diafiltration, nanofiltration, chromatography, ion exchange, or combinations thereof. The hemicellulose fraction may be recovered in its native, partially hydrolyzed, or fully hydrolyzed form, providing a valuable side stream for further applications. The defibrillated or partially defibrillated cellulose undergoes drying or partial drying using high-speed centrifugation, a filter press, a screw press, filtration, flocculation / coagulation, vacuum-assisted compression, spray drying, freeze-drying, supercritical CO2drying, hot air drying, drum drying, vacuum drying, or combinations of thesemethods. The resulting cellulose product may be in the form of a solution (1-4% dry matter basis), a paste (4-30% dry matter basis), a dry paste (>30% dry matter basis), or a powder.

[0038] The cellulose fibres exhibit properties suitable for applications requiring high specific surface area, absorbent capacity, and fibrillation. These applications include, but are not limited to, bioplastics, advanced paper products, biomedical materials, and high-performance textiles. The method is scalable for industrial production, utilizing widely available feedstocks from diverse food and beverage processing industries. The system can integrate modular processing units to ensure flexibility and adaptability to different production scales.

[0039] The process leverages the use of low-lignin feedstocks, reducing waste and promoting the sustainable utilization of agricultural and food processing by-products. The combination of twin-screw extrusion and chemical or enzymatic treatments achieves significant fibre matrix disruption in under two minutes, thereby improving process throughput and reducing overall operational costs. The system accommodates variations in feedstock composition, including lignin, hemicellulose, and cellulose content, by adjusting extrusion parameters and treatment conditions accordingly. The characteristics of the final cellulose product can be tailored by controlling processing conditions during the extrusion, reaction, defibrillation, and surface modification stages to meet specific application requirements.BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The detailed description is set forth with reference to the accompanying drawings.The use of the same reference numerals may indicate similar or identical items.Various embodiments may utilize elements and / or components other than those illustrated in the drawings, and some elements and / or components may not be present in various embodiments. Throughout this disclosure, depending on the context, singular and plural terminology may be used interchangeably. These drawings are for explanatory purposes and should not be construed as limiting the scope of the invention.

[0041] FIG. 1 exemplarily illustrates a method for producing fibrillated cellulose, according to an embodiment of the present invention.DETAILED DESCRIPTION

[0042] In the following description, various aspects of the present disclosure will be described. For purposes of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the present disclosure. However, it will also be apparent to those skilled in the art that the device, apparatus, or method of the present disclosure may be practiced without the specific details herein, whereby itis to be distinctly understood that the following descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.

[0043] The present invention discloses a method for producing fibrillated cellulose from agricultural or non- woody plant products and / or byproducts including crop-derived bran or fibres. For the purposes of this invention, agricultural or non-woody plant products and / or byproducts are collectively referred to as 'non-woody feedstock’.

[0044] FIG. 1 exemplarily illustrates a flowchart 100 of a method for producing fibrillated cellulose, according to an embodiment of the present invention. At step 102, a feedstock comprising a non-woody feedstock is obtained. In one embodiment, the feedstock comprises lignin in an amount of less than 15% of a total composition of the feedstock on a dry basis. In another embodiment, the lignin content of the feedstock is limited to no more than 20% on a dry basis.

[0045] In one embodiment, the non-woody feedstock is selected from the group consisting of an energy crop, residual material from a processing of plant biomass, and agricultural waste.

[0046] In an embodiment, the energy crop is selected from the group consisting of switchgrass, miscanthus, com, sugarcane, sweet sorghum, soybean, rapeseed, jatropha, and oil palm.

[0047] In another embodiment, the residual material from the processing of plant biomass comprises food and beverage processing wastes, vegetable and fruit processing residues from animal feed producers, brewers, ethanol plants, mills, and the like.

[0048] In one embodiment, the agricultural waste comprises husks, bran, fibre, leaves, fruit pits, straw, stover, or combinations thereof. In an exemplary embodiment, the agricultural waste is at least one material selected from the group consisting of corn husks, oat bran, coffee husks, wheat bran, sugar cane tops, sugar cane leaves, rice husks, and barley husks or bran. In one embodiment, the stover is at least one selected from the group consisting of corn stover, soybean stover, and sorghum stover.

[0049] At step 106, residual non-fibrous components such as starch, sugars, protein and oil are removed from the non-woody feedstock to obtain a fibre-enriched material.

[0050] If the oil content of the feedstock exceeds 5% on a dry basis, a defatting or oil removal step is implemented using mechanical separation techniques or solvent-based extraction processes to enhance the efficiency of subsequent processing steps. In order to remove residual starch, one or more of the following methods may be employed: physical abrasion or milling to dislodge and separate starch granules; washing with water or dilute solutions, optionally supplemented with enzymatic treatment utilizing alpha-amylase, beta-glucanase, or other starch-hydrolyzing enzymes to facilitate starch breakdown; airflow-based separation to distinguish and extract less dense fibres from denser starch particles; application of centrifugal forces in conjunction with sizeexclusion meshes to enable efficient segregation of starch from fibre; or a sequential combination of the aforementioned techniques to achieve comprehensive starch removal, thereby ensuring an optimized fibre-enriched material for further processing.

[0051] In one embodiment, the removal of residual non-fibrous components, including sugars, starch, protein, and oil / fat, is carried out using one or a combination of the following methods. In one embodiment, dry separation techniques are employed, including aspiration, centrifugation, and selective particle size sieving, to isolate fibrous material from non-fibrous components. In another embodiment, wet separation techniques are utilized, wherein enzymatic treatments facilitate the solubilization and removal of starch and protein, while enzymes or surfactants assist in the release and subsequent removal of fat or oil, followed by washing and centrifugation.

[0052] In yet another embodiment, washing with water is combined with dewatering techniques, wherein separation is performed using a centrifuge or a machine that applies centrifugal forces in conjunction with sieves or mesh, optionally combined with sparging, a filter press, a screw press, or any other sparging and / or dewatering technology. In a further embodiment, optional solvent extraction or physical pressing is applied, either individually or in combination, to remove oil when the oil content exceeds 5% on a dry matter (DM) basis.

[0053] At step 108, the fibre-enriched material is pretreated to solubilize lignin and hemicellulose, thereby obtaining a pretreated material.

[0054] In one embodiment, the pretreatment is selected from a physical treatment, a chemical treatment, or combinations thereof. In one embodiment, the physical treatment is selected from ultrasonic treatment, micro wave-assisted treatment, or high- pressure H2O / CO2treatment, and the chemical treatment is selected from alkaline extraction, acid extraction, organosolv treatment, ionic liquid treatment, deep eutectic solvent treatment, alkali-peroxide treatment, alkaline-assisted hydrothermal treatment, and acid-assisted hydrothermal treatment.

[0055] In another embodiment, the cleaned fibre material is introduced into a twin-screw extruder, where mechanical shear forces, thermal energy, and chemical agents are applied to effectively disrupt the fibre matrix. The twin-screw extrusion process is advantageous due to its ability to generate high shear forces while allowing precise control over key processing parameters, including temperature, residence time, and mixing intensity. The extruder is configured to accommodate various moisture levels of the fibre feed, which may be in a dry, moist, or wet state, with a moisture content ranging from 5% to 30%, preferably between 10% and 20%, and more preferably between 12% and 15%. Extruder barrels are segmented into multiple zones to enable precise temperature control, with specific configurations that may include a feed zone, compression zone, and discharge zone. The zones are optimized to facilitate efficientchemical reactions, fibre pre-treatment, matrix disruption, and cellulose fibrillation. The barrels further incorporate multiple ports for controlled water addition, particularly when processing dry feedstock, as well as for the introduction of chemical agents at various stages to enhance reaction kinetics and improve fibre matrix disruption. The final barrel may be open or equipped with a specific die, and venting ports may be included where necessary. The extruder screws are co-rotating and intermeshing, designed with multiple sections that include conveying elements for material transport, kneading blocks to apply localized high shear forces, and reverse flow elements that enhance mixing intensity and extend residence time within the extruder. The optimization of shear forces is further achieved through specific screw design configurations, incorporating high-pitch conveying segments to facilitate material flow and low-pitch segments to generate shear. Additionally, adjustable clearance between the screw and barrel are employed to further refine shear force application, thereby enhancing the efficiency of fibre matrix disruption and pre-fibrillation.

[0056] In another embodiment, the present invention utilizes chemical treatment to facilitate fibre matrix disruption, enhance cellulose accessibility, and enable efficient separation of lignocellulosic components. The chemical treatment includes an alkaline treatment using alkalis such as sodium hydroxide (NaOH), potassium hydroxide (KOH), or calcium hydroxide (CaOH) at concentrations ranging from 8% to 16% (on a dry weight basis of the feedstock) to weaken lignin and hemicellulose bonds. In another embodiment, the chemical treatment comprises an oxidative treatment incorporating hydrogen peroxide (H2O2) at ratios of 8% to 16% (on a dry weight basis), thereby improving cellulose accessibility. In yet another embodiment, an alkaline-peroxide treatment is employed, wherein the pH is maintained above 12 before the peroxide is introduced at a concentration of 8% to 16% (on a dry matter basis) and at a temperature of 80°C to 95°C to achieve solubilization of lignin and hemicellulose, thereby facilitating improved separation downstream.

[0057] In yet another embodiment, the chemical treatment involves acidic hydrolysis using acids such as sulfuric acid, hydrochloric acid, or phosphoric acid to hydrolyze hemicellulose and disrupt lignin structures. In yet another embodiment, the process employs ionic liquids such as l-ethyl-3-methylimidazolium acetate ([EMIM]0Ac) or l-butyl-3-methylimidazolium chloride ([BMIM]C1) to selectively dissolve lignin and hemicellulose. In another embodiment, deep eutectic solvents (DES), including choline chloride combined with urea or choline chloride combined with lactic acid, are utilized for effective lignocellulosic fractionation.

[0058] In one embodiment, the present invention integrates mechanical and chemical pretreatment to ensure rapid and efficient fibre matrix disruption. The combination of mechanical shear forces with chemical treatments results in partial defibrillation of thecellulose, reducing the energy input required for subsequent mechanical fibrillation. In another embodiment, the process is completed in under two minutes, leveraging the rapid and continuous nature of the treatment to enhance process efficiency and scalability. In yet another embodiment, the invention is implemented in a continuous or semi-continuous manner to optimize throughput and industrial applicability.

[0059] At step 110, the pretreated material is separated into solids comprising cellulosic material and an aqueous phase comprising solubilized material through a solidliquid separation system or a solid-liquid separation method. In one embodiment, the solid-liquid separation method is performed using at least one of the methods selected from the group consisting of mechanical, chemical, thermal, filtration, centrifugation, filter press and solvent extraction system. In one embodiment, the resultant cellulosic material comprises a cellulose content of over 50% on a dry basis. In another embodiment, the cellulosic material comprises a cellulose content of over 60% on a dry basis. In yet another embodiment, the cellulosic material comprises a cellulose content of over 70% on a dry basis. In yet another embodiment, the cellulosic material comprises a cellulose content of over 80% on a dry basis.

[0060] At step 112, the cellulosic material is subjected to at least one of a cleaning and bleaching step to obtain a cellulose cake. In one embodiment, the cellulosic material may be directed to a cleaning step to remove impurities, followed by a bleaching step to obtain a cellulose cake. In one embodiment, the bleaching method is at least one selected from the group consisting of ozone bleaching, alkaline-peroxide bleaching, and sodium hypochlorite bleaching, with intermittent washing.

[0061] In one embodiment, the cellulose cake contains 70% cellulose on a dry basis.In another embodiment, the cellulose cake contains 80% cellulose. In yet another embodiment, the cellulose cake contains 90% cellulose.

[0062] In one embodiment, the cellulose fraction or material is subjected to an optional cleaning, purification, and brightening process to enhance its quality and suitability for various applications. This process may involve washing with water or dilute alkaline solutions to remove residual impurities. In another embodiment, the purification step includes oxidative treatment using a combination of peroxide and sodium hydroxide to improve brightness and further purify the cellulose. In yet another embodiment, the purification step is carried out using ozonation, or a combination of alkaline-peroxide treatment and ozonation, which may be implemented in multiple steps with various sequencing to optimize impurity removal and fibre brightening.

[0063] In a further embodiment, the purification and brightening step is tailored based on the intended end use of the cellulose and market requirements, making it an optional but beneficial stage in the process. In another embodiment, this step includes, either in conjunction with or as an alternative to the aforementioned treatments,an enzymatic process for hydrolyzing hemicellulose bound to the cellulose. This enzymatic hydrolysis facilitates cellulose purification and enables hemicellulose recovery as a valuable byproduct. In yet another embodiment, the sequence and choice of purification treatments are optimized based on the specific feedstock composition and processing conditions to achieve the desired cellulose properties.

[0064] At step 114, the cellulose cake is reslurried and defibrillated using a defibrillation method to obtain a fibrillated cellulose slurry including at least one of microfibrillated and nanofibrillated cellulose slurry. In one embodiment, the cellulose cake is reslurried and defibrillated using any of, or a combination of, and not limited to, the following: a high-pressure homogenizer, double disk grinder, ball mill, aqueous counter collision, extrusion, ultrasonication, and cryo-crushing method.

[0065] In one embodiment, the partially defibrillated cellulose is subjected to further processing to obtain nanofibrillated cellulose (NFC) through a defibrillation method. In one embodiment, the defibrillation is carried out using high-pressure homogenization, wherein the cellulose slurry is passed through a high-pressure homogenizer, subjecting it to high shear forces that facilitate complete fibrillation. This process is performed with multiple passes, wherein the number of passes ranges from no less than two and no more than ten, and the applied pressure ranges from 400 to 1400 bar, preferably between 800 and 1300 bar, and more preferably between 1000 and 1200 bar.

[0066] In another embodiment, alternative fibrillation techniques are utilized to achieve NFC, including but not limited to ultrasonication, microfluidization, disk grinding, ball milling, grinding, or any combination thereof. In yet another embodiment, these fibrillation techniques are applied in subsequent steps, either individually or in combination with high-pressure homogenization, to optimize fibrillation efficiency and obtain NFC with desired structural and functional properties. In a further embodiment, the choice of fibrillation technique is determined based on the specific feedstock properties, process conditions, and intended application of the NFC product.

[0067] At step 116, the fibrillated cellulose slurry is directed to a centrifuge to separate the fibrillated cellulose slurry from water.

[0068] At step 118, the fibrillated cellulose slurry is pressed to remove excess water and form a fibrillated cellulose product. Further, the fibrillated cellulose product could be packaged as a fibrillated cellulose paste to contain 2 wt% to 10 wt% of dry solids of fibrillated cellulose. In one embodiment, the fibrillated cellulose could be packaged as a microfibrillated and / or nanofibrillated cellulosic paste comprising 2 wt% to 10 wt% of microfibrillated and / or nanofibrillated cellulose dry solids.

[0069] In one embodiment, the fibrillated cellulose is subjected to a dewatering and / or drying process to achieve the desired moisture content and facilitate further processing. In one embodiment, dewatering is performed using centrifugation, wherein high-speedcentrifuges are employed to remove free water from cellulose suspensions by applying centrifugal forces, particularly suitable for coarse cellulose fibres and less dense cellulose nanofibril (CNF) suspensions. In another embodiment, pressure filtration is utilized, wherein hydraulic or pneumatic pressure is applied to expel water through fine filtration media, making it advantageous for handling high-solid-content slurries in scalable operations.

[0070] In yet another embodiment, mechanical dewatering is performed using screw pressing, where the cellulose or CNF suspension is compressed between a rotating screw and a stationary surface to achieve high solids content with minimal energy input. In a further embodiment, roll pressing is employed, utilizing sequential pressing with rollers to remove interstitial water, which is particularly suitable for cellulose sheets and semi-continuous processes.

[0071] In another embodiment, drying is performed using convective drying, wherein heated air or gases flow over the material to remove moisture, utilizing fluidized bed dryers or direct air dryers to ensure uniform drying rates. In one embodiment, conductive drying is applied, wherein heat is transferred directly from heated surfaces to the material using drum dryers or vacuum contact dryers, ensuring precise control over drying conditions and preventing overheating. In another embodiment, infrared (IR) drying is used, wherein high-energy infrared radiation penetrates the material, facilitating the evaporation of water molecules, making it particularly efficient for thin films or layers of CNF.

[0072] In yet another embodiment, micro wave drying is employed, wherein electromagnetic waves generate heat within the material to ensure rapid and uniform moisture removal, particularly advantageous for CNF due to its high surface area. In another embodiment, freeze-drying is applied, wherein the CNF slurry is frozen, and water is sublimated under vacuum conditions to preserve the nanoscale structure and minimize shrinkage. In one embodiment, supercritical drying is used, wherein supercritical CO2is employed to extract water without causing surface tension-induced damage, making it particularly suitable for high-purity CNF applications. In another embodiment, aerogel production is performed, wherein CNF suspensions are gelled, solvent-exchanged, and dried to form highly porous aerogels, maintaining the integrity of the nanostructure while enhancing the material’s lightweight properties.

[0073] In a further embodiment, a hybrid approach is utilized by combining multiple dewatering and drying techniques to optimize process efficiency for specific applications. In one embodiment, mechanical dewatering is combined with convective drying, wherein bulk water is removed mechanically before undergoing convective drying to reach the desired moisture level. In another embodiment, microwave-assisted freeze drying is performed, wherein microwave energy accelerates sublimation infreeze-dried CNF, reducing processing time while maintaining the structural integrity of the nanofibres. In yet another embodiment, integrated roll pressing and IR drying is applied, wherein roll pressing pre-concentrates CNF suspensions, followed by IR drying to achieve high throughput in industrial applications.

[0074] In one embodiment, the present invention includes an optional step for the recovery and purification of hemicellulose as a valuable by-product of the pre-treatment process. The composition and structure of the recovered hemicellulose depend on the specific pre-treatment method applied. In one embodiment, acid pre-treatment is utilized, wherein hemicellulose is predominantly hydrolyzed into monosaccharide sugars and some oligosaccharides, with the degree of hydrolysis being dependent on factors such as acid concentration, reaction time, and temperature. The resulting monosaccharides are suitable for applications in fermentation processes for the production of biofuels, biochemicals, or as chemical building blocks for various industrial applications.

[0075] In another embodiment, hemicellulose recovery is performed following an alkaline combined with peroxide pre-treatment, wherein the hemicellulose remains largely intact and unhydrolyzed. This native form of hemicellulose retains its structural integrity, making it suitable for higher-value functional applications in industries such as food and pharmaceuticals. In yet another embodiment, deep eutectic solvents (DES) are employed as a pre-treatment method, wherein DES formulations such as choline chloride combined with urea or lactic acid selectively dissolve lignin while partially solubilizing hemicellulose. Most DES-based treatments retain hemicellulose in its unhydrolyzed state, preserving its native structure. In some cases, depending on the acidity or hydrogen bonding properties of the DES, slight hydrolysis may occur, yielding oligosaccharides that are applicable in dietary fibres, bioplastics, or fermentation processes.

[0076] In a further embodiment, hemicellulose is recovered following ionic liquid (IL) pre-treatment, wherein ionic liquids such as l-ethyl-3-methylimidazolium acetate ([EMIM]0Ac) or l-butyl-3-methylimidazolium chloride ([BMIM]C1) disrupt the lignocellulosic matrix by breaking hydrogen bonds and solubilizing lignin and hemicellulose. In another embodiment, hemicellulose extracted using ILs remains largely intact; however, prolonged exposure or elevated temperatures may lead to partial depolymerization into oligosaccharides. The recovered hemicellulose fractions can be tailored for high-value applications, including prebiotics, food additives, and pharmaceutical formulations.

[0077] In one embodiment, the recovered hemicellulose undergoes purification using various techniques to enhance its commercial utility. In another embodiment, ion exchange resins are employed to selectively purify hemicellulose fractions based on ionic properties, providing an effective means for separating charged components.In yet another embodiment, precipitation using ethanol or other solvents is utilized to recover purified hemicellulose. In a further embodiment, membrane filtration techniques such as ultrafiltration (UF) or nanofiltration (NF) are applied to achieve selective separation and concentration of specific hemicellulose fractions.

[0078] In one embodiment, enzymatic hydrolysis is combined with ultrafiltration or nanofiltration in a continuous enzymatic membrane reactor to selectively recover hydrolyzed or partially hydrolyzed hemicellulose-derived products. In another embodiment, adsorption chromatography is used for precise separation and purification of hemicellulose subcomponents based on molecular size and affinity. In yet another embodiment, dialysis is performed to separate smaller molecular weight impurities from hemicellulose solutions, ensuring a purified and high-value hemicellulose product suitable for various industrial applications.

[0079] The cellulose nanofibres (CNFs) produced by the disclosed method exhibit distinct physical, morphological, mechanical, thermal, surface chemistry, optical, rheological, and barrier properties, making them suitable for a wide range of applications. In one embodiment, the CNFs possess a diameter of approximately 5-50 nm and a length ranging from 500 nm to several micrometres, with an aspect ratio greater than 50. The specific surface area, as determined by BET analysis, ranges between 100-200 m2 / g, and the crystallinity index is at least 80%, as measured using X-ray diffraction (XRD), ensuring superior mechanical properties and thermal stability. The morphology of the CNFs is highly uniform, as verified by scanning electron microscopy (SEM) and transmission electron microscopy (TEM).

[0080] In another embodiment, the CNFs exhibit enhanced mechanical properties, including a tensile strength greater than 1 GPa and an elastic modulus ranging from 100 to 140 GPa, making them suitable as reinforcement materials in composite applications.The CNFs also demonstrate significant thermal stability, with a decomposition temperature above 250°C, as determined by thermogravimetric analysis (TGA), and a glass transition temperature of approximately 200°C. In one embodiment, the surface chemistry of the CNFs is characterized by the presence of hydroxyl functional groups, with a carboxyl content ranging from 0.1- 1.0 mmol / g, contributing to their high surface charge density and colloidal stability in aqueous systems. The CNFs are also amenable to functionalization with silanes, polymers, or other chemical groups for tailored applications.

[0081] In yet another embodiment, the CNFs exhibit exceptional optical properties, with thin films demonstrating high optical transparency of 90% or greater in the visible spectrum, as measured by UV-Vis spectrophotometry. The refractive index of the CNFs is approximately 1.5. Rheologically, CNF suspensions display shear-thinning behaviour, making them ideal for coatings and 3D printing applications. The CNFsalso have the ability to form stable gels at concentrations as low as 0.5% (w / v). The barrier properties of CNF films include oxygen permeability values of less than 0.02 cc-mm / m2 / day at 23°C and 50% relative humidity, making them suitable for food packaging applications. Additionally, their moisture resistance can be enhanced through hydrophobic modifications.

[0082] In one embodiment, the CNFs are completely biodegradable under natural conditions and exhibit no evidence of cytotoxicity in in vitro studies, making them suitable for biomedical applications. Due to these unique properties, the CNFs can be applied across a broad range of industries. In one embodiment, CNFs are used as high-strength, lightweight reinforcement materials in polymer composites, cementitious materials, and construction applications. In another embodiment, CNFs are utilized in packaging materials, including high-oxygen-barrier films and biodegradable packaging solutions. In yet another embodiment, CNFs serve as functional components in biomedical applications such as drug delivery carriers, tissue engineering scaffolds, and wound dressings with antimicrobial properties.

[0083] In a further embodiment, CNFs are integrated into flexible electronics, conductive composites, and energy storage devices, including supercapacitors, batteries, and fuel cells, enhancing their performance and durability. In yet another embodiment, CNFs function as rheological modifiers and stabilizers in coatings, paints, and cosmetics, where their gel-forming properties provide stability and viscosity enhancement. In one embodiment, CNFs are employed in water purification technologies as adsorbents for heavy metals and organic pollutants, as well as filtration membranes with high surface area and porosity. Additionally, CNFs are incorporated into 3D printing and additive manufacturing as bio-inks for biomedical applications and as reinforcing agents in printed structures.

[0084] In another embodiment, CNFs are used in textile and nonwoven materials to enhance strength, thermal regulation, and antibacterial properties, making them suitable for high-performance textiles and durable nonwoven mats. In yet another embodiment, CNFs are applied in agricultural and horticultural industries, serving as components in hydrogels for soil water retention and as carriers for controlled-release fertilizers and pesticides. By leveraging these distinct properties, CNFs enable the development of innovative and sustainable solutions across diverse industrial applications.

[0085] The various elements, steps and processing techniques that may be involved in the process of the present disclosure are described herein for a thorough understanding of a person skilled in the art.Feedstock

[0086] In one embodiment, the feedstock comprises a non- woody feedstock. In one embodiment, the non- woody feedstock is selected from the group consisting of: (i)an energy crop, (ii) residual material from the processing of plant biomass, and (iii) agricultural waste.Further, straw refers to the stem, stalk, and / or leaf portion of crops that remains after the starch and / or sugar-containing components have been removed for consumption.

[0087] In an embodiment, the energy crop is selected from the group consisting of switchgrass, miscanthus, com, sugarcane, sweet sorghum, soybean, rapeseed, jatropha, and oil palm.

[0088] In another embodiment, the residual material from the processing of plant biomass comprises food and beverage processing wastes, vegetable and fruit processing residues from animal feed producers, brewers, ethanol plants, mills, and the like.

[0089] In one embodiment, the agricultural waste comprises husks, bran, fibre, leaves, fruit pits, straw, stover, or combinations thereof. In an exemplary embodiment, the agricultural waste is at least one material selected from the group consisting of corn husks, oat bran, coffee husks, wheat bran, sugar cane tops, sugar cane leaves, rice husks, and barley husks or bran. Further, the stover refers to the stalk and foliage portion of crops after the removal of starch and / or sugar-containing components. In one embodiment, the stover is at least one selected from the group consisting of corn stover, soybean stover, and sorghum stover.Dehulling

[0090] In one embodiment, dehulling refers to the process of separating the outer shell or hull from the grain kernel. The outer shell or hull is then used as the non- woody feedstock in the method of the present invention. In one embodiment, the grain is subjected to dehulling or fibre removal, typically achieved through a combination of grinding, milling, sieving, and aspiration.

[0091] In one embodiment, the hulls are removed from the grain kernel through a process that involves physical separation of the kernels from their hulls, utilizing the difference in specific gravity between the kernels and hulls, where the hulls are lighter than the grains, to facilitate separation. The remaining grains are then sorted based on size, as not every grain will have its hull removed, with larger hulls being separated from the kernels due to size distinctions.

[0092] In one embodiment, the dehulling process is employed to remove the hulls from various types of grains including, but not limited to, rice, barley, oats, wheat, or similar grains.Starch Removal by Dry or Wet Process

[0093] Starch is a polymeric carbohydrate found in agricultural products such as wheat, maize, barley, corn, oats, rice, and potatoes. Removing starch, or ensuring a low ornegligible starch content in the fibre stream, is crucial to prevent Maillard reactions, avoid off-colours and browning, and achieve a higher purity end product.

[0094] Starch removal could be carried out through methods including a dry process and a wet process. The dry process involves breaking the endosperm into cells or cell fragments without intentionally separating starch from the protein, with the exception of protein displacement milling by air classification, which is a specific variation of dry milling.

[0095] In contrast, the wet process is a maceration process that induces physical and chemical changes in the starch, protein, and cell- wall material components, leading to a complete dissociation of the endosperm cell contents. This results in the release of starch granules from the protein network in which they are enclosed.

[0096] In one embodiment, the dry process is conducted using a bran finisher. In another embodiment, the wet process involves slurrying the grain and subjecting the grain to an enzyme that breaks down starch and protein, followed by a solid- liquid separation and washing step to remove the starch and sugars. A fibre-enriched material is obtained post starch removal.

[0097] Pretreatment of Fibre-Enriched Material to Solubilize Lignin and Hemicellulose

[0098] Natural fibres often contain contaminants and undesired chemicals when harvested from plants, soil, or animals. Therefore, chemical pretreatment is essential for green fibres and fibre-enriched materials to eliminate the undesirable components. This process enhances the fibre strength, making the fibre the primary reinforcement for carrying loads in composite materials, which in turn improves the mechanical properties of the composite. Pretreatment techniques for fibre-enriched material typically involve chemical processes, drying, heating in a furnace, and other steps that enhance the fibre’s surface roughness, thereby strengthening the bond between the fibre and the surrounding matrix.

[0099] The fibre-enriched material is subjected to pretreatment to solubilize both lignin and hemicellulose. This can be accomplished through various methods, including physical, chemical, or a combination of both. In one embodiment, pretreatment is carried out using at least one treatment selected from the group consisting of alkaline extraction, acid extraction, high-pressure H2O / CO2, organosolv, ionic liquid treatment, deep eutectic solvent, alkali-peroxide treatment, alkaline-assisted hydrothermal treatment, acid-assisted hydrothermal treatment, ultrasonic treatment, and microwave-assisted treatment.

[0100] In one embodiment, the effectiveness of utilizing a twin-screw extruder for the chemical pre-treatment of cellulose is evaluated in comparison to a conventional reactor vessel. The methodology involves a comparative analysis of two production methods: (1) standard chemical pre-treatment conducted in a reactor vessel and (2)chemical pre-treatment performed using a twin-screw extruder while applying the same chemical formulation. Following pre-treatment, the cellulose is subjected to a separation process using a centrifuge, washed once with water, and analyzed using BET analysis to determine the specific surface area, which serves as a proxy for the degree of fibrillation.

[0101] The results indicate that cellulose pre-treated in the twin-screw extruder exhibits a 2.5-fold increase in specific surface area compared to cellulose pre-treated in the reactor vessel. This demonstrates that the twin-screw extruder significantly enhances the degree of cellulose fibrillation during chemical pre-treatment. In another embodiment, the use of the twin-screw extruder reduces the energy required for subsequent processing steps, thereby improving overall process efficiency.Solids-Liquid Separation

[0102] The pretreated material may undergo solids-liquid separation to isolate the solids, which comprise cellulosic material, from the aqueous phase, which contains the solubilized material. There are several advantages associated with the solids-liquid separation. In an embodiment, substantially all of the solubilized material are separated from the solids by the solids-liquid separation.

[0103] In one embodiment, the solids-liquid separation is achieved using at least one method selected from the group consisting mechanical, chemical, thermal, or filtration techniques. Exemplary mechanical techniques include centrifugation, filtering, pressing including pressing using a screw or nip press, draining, and sedimentation. An example of a chemical technique is the addition of flocculating agents. Thermal techniques include, but are not limited to, evaporation, drying, flashing, and distillation. Filtration techniques include, but are not limited to, microfiltration, plate and frame filtration, cross-flow filtration, pressure filtration, and vacuum filtration. Additionally, a washing phase may be incorporated into the solids-liquid separation process.Fibrillated Cellulose Slurry

[0104] To obtain fibrillated cellulose slurry, a homogenizer may be employed. The fibrous material is subjected to high pressure while being homogenised in a homogeniser. The pressure of the dispersion is through-flow, causing all of the dispersion of fibrous material to transform into micro / nanoscale fibrillated cellulose. Fibrillation is the process of breakdown of materials. At a given pressure, fibrous material dispersion flows via a narrow through-flow gap, and the dispersion is linear. The removal of fibrillation from fibrous material is caused by the shearing force and impact to dispersion produced by the increase in speed.

[0105] In other embodiments, the cellulose cake is reslurried and defibrillated using one or more methods, including, but not limited to, high-pressure homogenization, double disk grinding, ball milling, aqueous counter collision, extrusion, ultrasonication, and cryo-crushing.

[0106] The microfibrillated and / or nanofibrillated cellulosic product produced by the methods described herein has various applications, including, but not limited to, food additives such as texturizing agents, stabilizers, thickeners, pickering emulsions, extruded and 3D-printed food, food packaging in multi-layer packaging, protective barriers for fruit to increase shelf life and reduce oxidation, coatings for food protection, encapsulating agents for nutrients, vitamins, and nutraceuticals, oil replacements, and calorie -reduced food. The microfibrillated and / or nanofibrillated cellulose product is characterized by a high aspect ratio and enhanced mechanical properties suitable for food applications. The present disclosure envisages a process that utilizes agricultural waste as a source material for producing microfibrillated and / or nanofibrillated cellulose.

[0107] Advantageously, the method of the present invention enables the upcycling and utilization of waste or low-value materials to create higher-value products. The process has a relatively low energy input compared to current methods, due to the combination of the cellulose's inherent properties from the specified sources and the efficient technologies used for defibrillation. The microfibrillated and / or nanofibrillated cellulosic product produced by the disclosed process is a highly versatile, bio-based material suitable for food applications, as it is derived from food-origin sources.

[0108] The fibrillated cellulose product obtained by the method of the present invention is a bio-based material suitable for use as a food additive, texturizing agent, stabilizer, thickener, Pickering emulsion, extruded or 3D-printed food ingredient, food packaging material, protective barrier, coating, encapsulating agent for nutrients, oil replacement, and calorie-reduced food ingredient. Optionally, the method involves, applying cleaning, purification, and brightening to remove residual impurities, enhances brightness, and improves the quality of the cellulose.

[0109] The foregoing description of the specific embodiments so fully reveals the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and / or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that theembodiments herein can be practised with modification within the spirit and scope of the embodiments as described herein.

[0110] Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

[0111] The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.

[0112] Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.

[0113] The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher / lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.

[0114] While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.

Claims

Claims

1. A method for producing fibrillated cellulose, the method comprising:i. obtaining a feedstock comprising a non-woody feedstock; ii. removing residual non-fibrous components from the non- woody feedstock to obtain a fibre-enriched material; iii. pre-treating the fibre-enriched material to solubilize lignin and hemicellulose, thereby obtaining a pretreated material; iv. separating the pretreated material into solids comprising cellulosic material and an aqueous phase comprising solubilized material through a solid-liquid separation method;v. subjecting the cellulosic material to at least one of cleaning and bleaching method to obtain a cellulose cake;vi. reslurrying and defibrillating the cellulose cake using a defibrillation method to obtain a fibrillated cellulose slurry including at least one of microfibrillated and nanofibrillated cellulose slurry;vii. directing the fibrillated cellulose slurry to a centrifuge to separate the fibrillated cellulose slurry from water, and viii. pressing the fibrillated cellulose slurry from step (vii) to remove excess water and forming a fibrillated cellulose product.

2. The method of claim 1, wherein the method comprisesi. cleaning, purification, and brightening of the fibrillated cellulose product;ii. packaging the fibrillated cellulose product as a microfibrillated cellulosic paste comprising 2 wt% to 10 wt % of microfibrillated cellulose dry solids; andiii. packaging the fibrillated cellulose product as a nanofibrillated cellulosic paste comprising 2 wt% to 10 wt % of nanofibrillated cellulose dry solids.

3. The method of claim 1, wherein the feedstock comprises lignin in an amount of less than 15% of a total composition of the feedstock on a dry basis.

4. The method of claim 1, wherein the non- woody feedstock is selected from the group consisting of an energy crop, residual material from a processing of plant biomass, and agricultural waste,wherein the energy crop selected from the group consisting of switchgrass, miscanthus, com, sugarcane, sweet sorghum, soybean, rapeseed, jatropha, and oil palm,wherein the residual material from the processing of plant biomass comprises food and beverage processing wastes, vegetable and fruit processing residues from animal feed producers, brewers, ethanol plants, and mills, andwherein the agricultural waste comprises husks, bran, fibre, leaves, fruit pits, straw, stover, or combinations thereof.

5. The method of claim 4, wherein the agricultural waste is at least one material selected from the group consisting of corn husks, oat bran, coffee husks, wheat bran, sugar cane tops, sugar cane leaves, rice husks, and barley husks or bran, and wherein the stover is at least one selected from the group consisting of corn stover, soybean stover, and sorghum stover.

6. The method of claim 1, wherein the pretreatment is selected from a physical treatment, a chemical treatment, a mechanical treatment using twin screw extrusion, or a combination thereof, wherein the physical treatment is selected from ultrasonic treatment, microwave-assisted treatment, or high-pressure H2O / CO2treatment, andwherein the chemical treatment is selected from alkaline extraction, alkaline treatment, oxidative treatment, acidic treatment, acid extraction, organosolv treatment, ionic liquid treatment, deep eutectic solvent treatment, alkali-peroxide treatment, alkaline-assisted hydrothermal treatment, and acid- assisted hydrothermal treatment.

7. The method of claim 1, wherein the cellulosic material has a cellulose content of over 50% on a dry basis, and wherein the cellulose cake has a cellulose content of over 70% on a dry basis.

8. The method of claim 1, wherein the defibrillation method is selected from a group consisting of high-pressure homogenization, double disk grinding, ball milling, aqueous counter collision, extrusion, ultrasonication, and cryo-crushing method.

9. The method of claim 1, wherein the solid-liquid separation method is performed using at least one of the methods selected from the group consisting of mechanical, chemical, thermal, filtration, centrifugation, filter press and solvent extraction system.

10. The method of claim 1, wherein the bleaching method is at least one selected from the group consisting of ozone bleaching, alkaline-peroxide bleaching, and sodium hypochlorite bleaching, with intermittent washing.

11. The method of claim 1, further comprises a step of: optionally, recovering and purifying hemicellulose as a by-product.

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