WO2022003254A1

WO2022003254A1 - A method for producing a dried product comprising non-wood cellulose microfibrils and a dried product obtained therewith

Info

Publication number: WO2022003254A1
Application number: PCT/FI2021/050509
Authority: WO
Inventors: Antti Laukkanen; Marko Lauraeus; Henrikki Mertaniemi; Nikolaos PAHIMANOLIS; Pekka Mononen
Original assignee: Betulium Oy
Priority date: 2020-07-01
Filing date: 2021-07-01
Publication date: 2022-01-06
Also published as: FI20205704A1; FI129547B

Abstract

A method for producing a dried product comprising non-wood cellulose microfibrils and solid carrier, as well as a dried product comprising non-wood cellulose microfibrils and solid carrier are provided. A re-dispersed product is also provided. Further, there is provided use of the dried product and of the re-dispersed product.

Description

A METHOD FOR PRODUCING A DRIED PRODUCT COMPRISING NON-WOOD CELLULOSE MICROFIBRILS AND A DRIED PRODUCT OBTAINED THEREWITH

TECHNICAL FIELD

The present disclosure generally relates to products comprising non-wood cellulose microfibrils and methods for their preparation. The disclosure relates particularly, though not exclusively, to a dried product comprising non-wood cellulose microfibrils and solid carrier, and a method for its preparation.

BACKGROUND

This section illustrates useful background information. Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each claim of this application.

Cellulose is a substance of great industrial importance having numerous applications. Primary source of cellulose in industrial applications is wood-based cellulose pulp. However, in using wood-based raw-material there are several problems such as environmental issues relating to unsustainable use of land and soil and heavy energy consumption required to grow, harvest and process wood- based material. These issues have created a need to find, on one hand, alternative sources of cellulose for producing new cellulosic materials. Further, the industry is constantly searching for more economical methods and raw materials to produce high quality cellulosic products.

In nature, native cellulose is always in a microfibrillar form, being part of wall structures of the plant cell. In primary cell walls, especially in parenchyma cells, cellulose microfibrils are distributed randomly forming a flexible membrane layer together with other polysaccharides, such as pectin and hemicelluloses. In certain plant species, an additional secondary wall structure is formed after the cell is fully- grown, especially in various wood species. In the secondary cell walls, the microfibrils are highly aligned mostly in the same direction and tightly bound to each other through hydrogen-bonding and covalent lignin bridges, forming a very rigid structure.

Cellulose microfibrils located either in primary or secondary cell walls are structurally very similar. Both type of microfibrils consist of highly aligned cellulose macromolecule chains forming mechanically strong cellulose crystals with hydrogen bonded parallel polymer chains. The microfibrils are generally considered to contain only few faults along their axis, although the degree of crystallinity varies between plant species being generally higher for microfibrils obtained from secondary walls. It is commonly understood that, depending on the plant species, 18, 24, or 36 cellulose chains form the smallest aligned structure, which is known as cellulose elementary fibril having diameter of a few nanometers and lengths up to tens of micrometers.

Although the secondary cell walls, for example in wood, are rich of cellulose microfibrils, separation of the structures from the secondary cell walls without damaging the fibrils itself is very difficult. Also, the process is complicated, expensive, and often a chemical pre-treatment is needed. Plant tissues made of primary cell walls, however, form an alternative source for the separation of the microfibrils. Typically, the separation of cellulose microfibrils from primary cell walls is performed in an aqueous environment and the resulting product comprises a significant amount, i.e. mainly, water. Such products with high water content are difficult to handle and to transport. The high water content also limits the end use of the products. It is an aim to solve or alleviate at least some of the problems related to prior cellulosic materials and their production methods. In particular, an aim is to provide a simple, versatile and economical method for producing a dried cellulosic product which can be re-dispersed if desired. SUMMARY

The appended claims define the scope of protection.

According to a first aspect there is provided a method for producing a dried product comprising non-wood cellulose microfibrils and solid carrier, the method comprising:

I) providing a solid carrier and a wet product comprising non-wood cellulose microfibrils; and

II) drying the wet product in the presence of the solid carrier until a dried product having a dry matter content of at least 70 wt-% is obtained, the dried product comprising non-wood cellulose microfibrils and solid carrier. The present method is advantageous in facilitating or enabling drying, particularly at industrial scale, of products comprising non-wood cellulose microfibrils with high water content.

According to a second aspect there is provided a dried product comprising non wood cellulose microfibrils and solid carrier obtainable by the method according to the first aspect. A dried product is advantageous in terms of better stability in storage and lower transportation cost. It has a lower packing density compared to corresponding wet products. Furthermore, in many application areas, a dried product can be more easily applied to processes using existing equipment. Low moisture content is also important for reducing bacterial growth and to prolong shelf- life.

According to a third aspect there is provided a re-dispersed dried product obtainable by re-dispersing a dried product according to the second aspect in water such that the dry matter content of the re-dispersed product is within the range from 0.2 wt-% to 20 wt-%.

According to a fourth aspect there is provided use of the dried product according to the second aspect or the re-dispersed product according to the third aspect as an additive or a component for modifying one or more of: viscosity, mechanical properties, strength, stiffness, toughness, binding properties, suspension stability, gel insensitivity to temperature, material insensitivity to temperature, shear reversible gelation, yield stress, and liquid retention of the composition of matter.

According to a fifth aspect there is provided use of the dried product according to the second aspect or the re-dispersed product according to the third aspect in drilling fluids; aqueous formulations used in oil fields including drilling, completion, fluid loss, work-over, and enhanced oil recovery (EOR) fluids; water-borne paints; coatings; adhesives; cosmetic formulations; water treatment; precipitation aid; soil improvement; wind or water erosion control; dust reduction and dust binding; wet or dry concrete formulation; wet or dry mortars; ready-mix concrete, pre-cast concrete, plasters; aerated concrete; injection grouts; shotcrete; cutting fluids, wet feed formulations, thermoset resins including phenol formaldehyde, melamine formaldehyde, urea formaldehyde resins, melamine-urea-formaldehyde resins; homecare detergents; industrial cleaning agents including liquids with pH higher than 12 or lower than 4. The dried product and the re-dispersed product are advantageous because they are compatible and suitable for controlling stability and/or rheology in the above applications.

According to a sixth aspect there is provided use of the dried product according to the second aspect or the re-dispersed product according to the third aspect in paper & board products; natural or synthetic non-wovens, molded fiber products; natural fiber composites; as such or together with synthetic resin in wood panel products including plywood, particle board, MDF, hardboard, laminated wood panels; pellets including food, feed, fuel, fertilizer pellets; food products; feed products. The dried product and the re-dispersed product are advantageous because they are compatible and suitable for use as a binder and/or barrier agent in the above applications.

According to a seventh aspect there is provided use of the dried product according to the second aspect or the re-dispersed product according to the third aspect in thermoset composites; thermoplastic composites; elastomers including natural or synthetic rubber constructions and tire formulations; insulation materials, including polyurethane and polystyrene foams. The dried product and the re-dispersed product are advantageous because they are compatible and suitable for use as a strengthening agent and/or filler in the above applications.

According to an eighth aspect there is provided use of the dried product according to the second aspect for forming an article of manufacture by pressing the dried product, preferably by hot pressing or by compression molding the dried product. The dried product is advantageous in allowing forming articles of manufacture for example without synthetic resin, such as formaldehyde.

BRIEF DESCRIPTION OF THE FIGURES

Some example embodiments will be described with reference to the accompanying figures, in which:

Fig. 1 schematically shows a process for manufacturing a wet product according to an example embodiment, and steps for separating sample fractions that are used to characterize the wet product. As is shown in Figure 1 , raw material can be partially hydrolyzed either by alkali or by hydrogen peroxide. Fig. 2 shows scanning electron micrographs (A-B) from a dried product produced according to sample 4E of Example 4, and transmission electron micrographs (C-D) from a re dispersed product produced according to sample 4E of Example 4. Scale bars: A: 200 pm, B: 1 pm, C: 5 pm, D: 0.5 pm.

DETAILED DESCRIPTION

Dry matter content in the context of this disclosure refers to the fraction of mass remaining after the removal of volatile components at 105 °C.

Water soluble in the context of this disclosure refers to components present in the liquid fraction of a sample that is fractionated using a common solid-liquid separation technique, such as centrifugation at a relative centrifugal force of 5250 g for 20 minutes, or pressure filtration through a 40-pm membrane.

In an embodiment the term soluble refers to water soluble. In another embodiment the term non-soluble refers to water-insoluble.

Non-wood cellulosic raw material in the present disclosure means cellulosic material obtainable from non-wood raw material. Examples of non-wood cellulosic raw material are plant species that predominantly contain parenchymal cell types and wherein the majority of the cellulose is located in primary cell walls. Examples of non-wood cellulosic raw material include e.g. parenchymal cellulose, cellulose from fruits, vegetables, legumes, cereals, seeds, grains, roots, tubers, sugar beet pulp, potato pulp, cassava pulp, citrus peel, bagasse pith, sweet potato, corn, rice, wheat, soy, and mixtures thereof. Especially well suitable non-wood raw materials are sugar beet pulp, bagasse pith fraction, potato pulp, cassava pulp and mixtures thereof. Preferably, the non-wood cellulose is parenchymal cellulose, i.e. materials predominantly composed of parenchymal cell types wherein the majority of the cellulose is located in primary cell walls.

In addition to comprising cellulose, plant tissues made of primary cell walls are rich in other polysaccharides such as pectin and hemicelluloses, which can be valuable in various applications when used together with cellulose microfibrils. Said other polysaccharides are not forming crystalline structures or fibrils and can be separated as soluble polymers simultaneously when the cellulose microfibrils are separated from primary cell walls. In such a process, the obtained composition is an aqueous mixture of soluble polymers that are surrounding dispersed cellulose microfibrils, microfibril bundles and/or cellulose microfibril aggregates.

A mixture of hydrophilic soluble polysaccharides and cellulose microfibrils enable faster rehydration and re-dispersion of a dried product. However, in wet state the water soluble polysaccharides form particularly sticky materials and corresponding mixtures with cellulose microfibrils are particularly difficult to handle in wet state.

Non-wood cellulose microfibrils refer, in the context of this disclosure, to non-wood cellulose microfibrils or non-wood cellulose microfibril bundles or non-wood cellulose microfibril aggregates that are at least partially separated from cell walls from suitable non-wood cellulosic raw material(s). The aspect ratio of the homogenized microfibrils is typically very high; the length of the microfibrils may be more than one micrometer and the number-average diameter is typically less than 200 nm, such as between 2 and 100 nm. The diameter of microfibril bundles may be greater, but it is usually less than 1 pm. The smallest microfibrils are similar to the so-called elementary fibrils, the diameter of which is typically 2 to 12 nm. There are several widely used synonyms for these separated microfibrils, for example: cellulose nanofibrils (CNF), nanocellulose, microfibrillar cellulose, nanofibrillated cellulose, cellulose nanofibers, nanoscale fibrillated cellulose, m icrof i b ri 11 ated cellulose (MFC), homogenized non-wood cellulose, cellulose microfibrils, or fibrillated non-wood cellulose. Non-wood cellulose microfibrils that have been at least partially separated from the primary cell wall may contain other polysaccharides, such as pectin, hemicellulose, and/or other soluble polysaccharides. The amount of the other polysaccharides depends on the non-wood cellulosic raw material used and on the separation method. The cellulose microfibrils at least partially separated from the primary cell walls may be in a form of expanded fibrillar network, where individual microfibrils or microfibril bundles are still partially bound or entangled to each other, even after they have been subjected to homogenization. Such partially bound or entangled individual microfibrils and/or microfibril bundles may be referred to as non-wood cellulose microfibril aggregates. The size or diameter of these aggregates is typically 10 to 500 micrometers when diluted into water. The size is, however, dependent on the concentration and the degree of homogenization and can be below 200 micrometers when measured by a filtration test. The essentially intact primary cells are not considered to be cellulose microfibrils or microfibril aggregates as understood in this context.

Wet product refers herein to a homogenized product comprising non-wood cellulose microfibrils that has not been dried. Preferably, the wet product comprises or consists substantially of non-wood cellulose microfibrils that has not been dried and water. In an embodiment, the weight of the wet product that is not dry matter is water. As used in the context of this disclosure, the wet product, or wet product comprising non-wood cellulose microfibrils, do not include solid carrier. Accordingly, the total weight of the wet product does not include the solid carrier. However, the wet product and the solid carrier may in some embodiments be provided together as a mixture.

Re-dispersing, in the context of this disclosure, indicates a dry or dried composition or product which has been re-dispersed into water and the rheology profile of the re-dispersed composition or product preferably demonstrates shear-thinning behavior and/or approximately 13-40 % of the original viscosity of a wet product without solid carrier as before the drying. With an aid of additional re-dispersing agents such as hydrophilic polymers, like CMC or liquid activators, recovery of viscosity can be higher. In the context of this disclosure, drying is a process wherein water is removed through evaporation by the use of a suitable method to yield a dried product. Mechanical dewatering or dewatering is used herein for processes in which water is not removed through evaporation but by other means (mechanical means), such as pressing or centrifugation.

Homogenizing in the present disclosure means mechanically treating partially hydrolyzed product to be a continuous gel when in water, even at low concentration such as at 2 wt-% or 4 wt-% used in the viscosity measurements of the Examples. A continuous gel in this context means a mixture of the homogenized product and water, which does not settle out of the continuous phase at rest.

Homogenizing can be carried out by an apparatus suitable for the purpose, e.g. a grinder, a comminutor, a rotor-stator mixer or a grinder such as Ultra-Turrax, Masuko from Masuko Sangyo, rotor-rotor mixers or grinders such as Atrex-type devices, homogenizer such as Ariete-type or Panda-type from GEA Niro-Soavi, fluidizer, micro- or macrofluidizer such as microflu id izer from Microfluidics and/or ultrasonic disintegrator.

The terms partial hydrolysis and partially hydrolyzed product means herein that when the non-wood cellulosic raw material is treated with aqueous alkali solution, or with hydrogen peroxide, partial, but not complete, hydrolysis of the raw material is achieved. Some of the hydrolysis products remain non-soluble (non-soluble cellulosic material), and some are solubilized and can be optionally fractionated from non-soluble components to be analyzed as water-soluble hydrolysis products. In the context of the present disclosure, the term (partial) hydrolysis and (partial) hydrolysis products are considered in a broader context and include depolymerization and/or oxidation/cleaving of molecular bonds.

In an embodiment, where the water insoluble components comprising cellulose microfibrils, typically as cellulose microfibril aggregates, and water soluble components, e.g. hemicellulose, are not separated from each other, i.e. the water soluble components are not fractionated from non-soluble components, a mixture of said water insoluble and water soluble components is obtained. Said mixture can be homogenized after the partial hydrolysis process has proceeded far enough, preferably the homogenization is started when the proportion of the water soluble components to the water insoluble components is at least 20 wt-% of the total dry matter.

The present disclosure provides a method for producing a dried product comprising non-wood cellulose microfibrils and solid carrier, the method comprising:

II) drying the wet product in the presence of the solid carrier until a dried product having a dry matter content of at least 70 wt-%, based on the total weight of the dried product, is obtained, wherein the dried product comprises non-wood cellulose microfibrils and solid carrier. As the solid carrier is comprised in the dried product, it is also included in the dry matter content and total weight of the dried product.

It has surprisingly been found that the presence of a solid carrier facilitates the drying of wet products comprising non-wood cellulose microfibrils. Such wet products are often difficult, if not impossible, to dry on an industrial scale as said wet products are generally very sticky gels or pastes. The presence of the solid carrier during drying significantly reduces the stickiness of the wet product, makes it easier to handle, and shortens the time needed for drying. A further advantage of drying said wet products in the presence of or together with a solid carrier is that the drying can be performed without having to provide the wet product in any specific form, such as wet pellets. Pre-treatment of the wet product may thus be avoided, and the wet product comprising non-wood cellulose microfibrils may be provided to the present method as is. Accordingly, in an embodiment, the method is performed without extruding the wet product prior to the drying or without forming pellets of the wet product prior to the drying.

In an embodiment, the method comprises drying the wet product in the presence of the solid carrier until the dry matter content of the dried product is at least 80 wt-%, preferably at least 88 wt-%, such as 90 wt-%, of the total weight of the dried product. In an embodiment, the dry matter content of the dried product is at most 99 wt-%, preferably at most 98 wt-%, more preferably at most 95 wt-% of the total weight of the dried product. A high dry matter content is preferred as the benefits associated with dried products are then particularly pronounced. However, a small amount of water remaining in the dried product facilitates re-dispersion of the dried product.

The dried product may be ground into a powder-like substance or granules. In an embodiment, the method comprises grinding the dried product to reduce its particle size preferably to 10 pm - 2.5 mm, more preferably to 10 pm - 500 pm. In an embodiment, the maximum dimension of the ground dried product is 2.5 mm, preferably 1 .0 mm, more preferably 500 pm. The grinding of the dried product may be performed with any suitable equipment, for example with a hammer mill or a grain mill. In an embodiment, grinding the dried product comprises passing the ground dried product through a sieve to recover particles of desired size. Reducing the particle size of the dried product further reduces its packing density. Providing the dried product as a powder-like substance facilitates its mixing and use for example with other powder-like components or compositions, for example the use of the dried product in dry mortar.

In an embodiment, the dried product is pelletized or granulated. The dried product may be pelletized or granulated directly after the drying, or after the dried product has been ground. Surprisingly, the dried product comprising solid carrier may be pressed into two or three dimensional objects, for example pellets, as is without additional compounds or components. The pressing may be performed after the drying without any further pre-treatment of the dry product, or after reducing the particle size of the dried product.

In an embodiment, the dry matter content of the wet product is 35 wt-% or less, preferably within the range from 1 wt-% to 35 wt-%, more preferably within the range from 4 wt-% to 30 wt-%, even more preferably within the range from 10 wt-% to 30 wt-%, based on the total weight of the wet product. The dry matter content of the wet product may for example be within the range from 8 wt-% to 30 wt-%, from 4 wt-% to 15 wt-%, from 8 wt-% to 15 wt-%, or from 15 wt-% to 25 wt-%, or from 10 wt-% to 20 wt-%, based on the total weight of the wet product.

In an embodiment, the solid carrier and the wet product are provided in a wt/wt (dry matter/dry matter) ratio selected from the range from 1 :4 to 9:1 , preferably from 1 :2 to 2:1 , more preferably the ratio is 1 :1. The wt/wt ratio of the solid carrier and the wet product is calculated based on the weight of the dry matter in the solid carrier and in the wet product, respectively. Such weight may also be referred to as dry weight. Accordingly, water is excluded from the calculation of the wt/wt ratio between the solid carrier and the wet product. In an embodiment, the ratio is wt/wt (dry matter/dry matter) solid carrier to wet product.

In some embodiments, it may be advantageous to provide excessive amounts of the solid carrier, for example the solid carrier and the wet product may be provided in a wt/wt (dry matter/dry matter) ratio of 20:3. This is advantageous for example when the solid carrier has been selected such that it is a component of a target end product. Example 6 provides an example of this.

In an embodiment, the temperature of the wet product and the solid carrier does not exceed 150 °C, preferably 100 °C, during the drying (step II). In other words, in an embodiment, the temperature of the wet product and the solid carrier is at most 150 °C, preferably at most 100 °C during drying. The drying may be performed with any suitable equipment causing water to evaporate. The drying may for example be performed in an air circulation oven, belt dryer, steam dryer, flash dryer, a direct- heat rotary drier, or any suitable industrial drying device. Preferably, the solid carrier stays in solid state throughout the method. Accordingly, the solid carrier does preferably not melt during the drying. In an embodiment, the solid carrier does not melt or become liquid at temperatures below 200 °C, preferably of 150 °C or less. That is, in an embodiment, the solid carrier has a melting point at 200 °C or above, preferably at 150 °C or above.

In an embodiment, the solid carrier is a hydrophilic carrier, preferably an organic hydrophilic carrier, more preferably an organic hydrophilic carrier comprising cellulose. A hydrophilic solid carrier is advantageous in that it significantly reduces the stickiness of the wet product making it easier to handle and shortens the time needed for drying. Without being bound to any theory, it is believed that the hydrophilic solid carrier draws water from the wet product reducing adhesiveness and facilitating handling of the wet product. In an embodiment, the solid carrier is capable of adsorbing or absorbing water. In an embodiment, the solid carrier is porous. Preferably, the solid carrier is selected from sugar beet pellets, crushed dried sugar beet pellets, dry sugar beet pulp, wood pellets, wood chips, wood dust, saw dust, refined wood chips used for making particle boards or wood panels, mechanical wood pulp, hard wood or soft wood cellulose pulp, paper fluff, recycled paper, any dry feed ingredient including fats, proteins, cellulose containing ingredients, and carbohydrates, or microfibrillar cellulose. Especially suitable carriers are such that are already in use in a target end-use application or used in a target end product.

In a preferred embodiment, the solid carrier comprises or substantially consists of water insoluble polysaccharide(s). For example, the solid carrier may be or comprise cellulose or starch, such as modified starch or cationic starch.

The solid carrier may for example be a compound that is suitable for use as an additive for example in paper andboard products. In an embodiment, the solid carrier is selected from starches, modified starches, especially cationic starch, polyacrylamides, high and low degree of substitution (ds) carboxymethyl cellulose, engineered cellulose additives, , polydiallyldimethylammonium chloride (polyDADMAC), polyethylene imine, and biopolymers obtained by enzymatic polymerization of mono- or disaccharides. Examples of engineered cellulose additives include Ecofill and EcoBond products.

In an embodiment, the solid carrier is an inorganic carrier, preferably a hydrophilic inorganic carrier. Examples of suitable inorganic carriers are CaC03, bentonite, hectorite, or sepiolite.

In an embodiment, the method comprises providing a solid carrier with the proviso that the solid carrier is not (kraft) lignin.

In an embodiment, the method comprises repeating steps I) and II) and recovering at least a portion of the dried product after each step II), and optionally providing a portion of the dried product obtained in step II) as the solid carrier in a subsequent repetition of step I). In other words, the method may comprise circulating a portion of the dried product obtained in step II) back to step I), thus providing the circulated portion of the dried product as the solid carrier. In an embodiment, the solid carrier comprises or consists of the dried product comprising non-wood cellulose microfibrils and solid carrier. In an embodiment, the solid carrier is wet product which has been dried without the presence of any solid carrier thus functioning as a so called seed in the drying step.

In an embodiment, the solid carrier is provided as powder, granules, or particles with dimensions within the range from 0.005 mm to 2.5 mm. In an embodiment, providing a solid carrier comprises reducing the particle size of the solid carrier to obtain granules or particles of the solid carrier with dimensions within the range from 0.1 to 2.5 mm. In an embodiment, the solid carrier has a maximum dimension of 2.5 mm, preferably 1 .0 mm. In an embodiment, the solid carrier is a powder or powder- like substance. The particle size of the solid carrier may be reduced by any suitable method or equipment, for example roller mill, hammer mill, grinder, crusher, cutter, or chipper. Without being bound by any theory, it is believed that providing a solid carrier with certain physical size further facilitates the drying process and further reduces the stickiness of the wet product. Particularly preferred are hydrophilic carriers having certain physical size. Without being bound by any theory, hydrophilic carriers having a certain physical size are believed to quickly absorb excess water thus reducing the stickiness of the wet product particularly well.

The solid carrier need not to be removed from the dried product. The solid carrier may be selected based on the target end-use or target application for which the dried product is intended. Preferably, the solid carrier is selected such that it is a raw material or component of the target end product. Accordingly, in an embodiment the solid carrier is a desired component in an end product, the solid carrier having an inherent chemical, functional and nutritional value in the end product. Selecting a solid carrier that is a desired component in the target end product simplifies the manufacturing process of the end product, reduces the cost of the end product, and reduces the number of undesired components or additives in the end product.

In an embodiment, the wet product is a wet product obtainable through partial hydrolysis of non-wood cellulosic raw material followed by homogenization.

In an embodiment, providing a wet product comprising non-wood cellulose microfibrils comprises: i) treating non-wood cellulosic raw material with an aqueous alkali solution (alkali treatment) to provide a partially hydrolyzed product comprising non-soluble cellulosic material and water soluble hydrolysis products; ii) recovering the partially hydrolyzed product as a whole or recovering the non soluble cellulosic material from the partially hydrolyzed product to provide a recovered product; and iii) homogenizing the recovered product to provide a wet product comprising non-wood cellulose microfibrils.

In another embodiment, providing a wet product comprising non-wood cellulose microfibrils comprises: treating the raw material with hydrogen peroxide (hydrogen peroxide treatment) to provide a partially hydrolyzed product comprising non-soluble cellulosic material and water soluble hydrolysis products; adding aqueous alkali solution to the partially hydrolysed product; recovering the partially hydrolyzed product as a whole to provide a recovered product; and homogenizing the recovered product to provide a wet product comprising non wood cellulose microfibrils.

The hydrogen peroxide treatment has a similar and/or corresponding effect to the raw material as the alkali treatment. In addition, the hydrogen peroxide treated raw material is less sticky before and after the homogenization, which allows using lower amounts of the solid carrier.

In an embodiment wherein the partially hydrolyzed product is provided by hydrogen peroxide treatment, alkali solution is added to the hydrogen peroxide treated raw material (partially hydrolyzed product) to neutralize the partially hydrolyzed product. In a further embodiment wherein the partially hydrolyzed product is provided by hydrogen peroxide treatment, alkali solution is added to the hydrogen peroxide treated raw material (partially hydrolyzed product) to achieve a pH above 6, preferably a pH in the range 7-10, more preferably in the range 9-10 before homogenizing. The alkali treatment or the hydrogen peroxide treatment causes partial hydrolysis and/or depolymerization and/or oxidation/cleaving of molecular bonds of the non wood cellulosic raw material providing a partially hydrolyzed product comprising non-soluble cellulosic material (water insoluble components) and water soluble hydrolysis products (water soluble components). Preferably, the water soluble components and water insoluble components are both directly obtained from the non-wood cellulosic raw material, i.e. they originate from the same material.

Recovering the partially hydrolyzed product as a whole means herein recovering both the non-soluble cellulosic material and water-soluble hydrolysis products preferably together with any aqueous solution or water remaining from the alkali treatment step or from the hydrogen peroxide treatment step. Preferably, no side- stream is removed from the partially hydrolyzed product when the partially hydrolyzed product is recovered as a whole.

In an embodiment where water soluble hydrolysis products have not been fractionated from the wet product, the wet product comprises cellulose less than 50 wt-% based on the total dry matter of the wet product.

A mixture of hydrophilic soluble polysaccharides and cellulose microfibrils comprised in a dried product enable faster rehydration and re-dispersion of the dried product. The water soluble polysaccharides are, however, forming rather sticky materials and corresponding mixtures with cellulose microfibrils are difficult to handle in wet state.

Recovering the non-soluble cellulosic material from the partially hydrolyzed product, or recovering the non-soluble cellulosic material, refer herein to recovering the non soluble cellulosic material but not the water-soluble hydrolysis products. In an embodiment, recovering the non-soluble cellulosic material comprises fractionating water-soluble hydrolysis products from the non-soluble cellulosic material.

In an embodiment, the wet product is a wet product obtainable through partial hydrolysis of non-wood cellulosic raw material followed by homogenization, said wet product comprising water soluble components and water insoluble components, wherein a) from the water soluble components that are larger than 1 kD, at least 50% have a molecular weight of at least 40 kD; and b) the water insoluble components comprise cellulose microfibril aggregates having a number average size below 200 pm; wherein the amount of the dry matter of all water soluble components is at least 20 wt-%, and preferably not more than 75 wt-%, of the total dry matter of the wet product. Such wet products are particularly sticky and difficult to handle wherefore the method of the first aspect is particularly advantageous for obtaining dried products therefrom. Drying such wet products with prior art methods is extremely difficult, if not impossible. In an embodiment, such wet product has a Brookfield viscosity of at least 300 cP determined for aqueous 2 wt-% dry matter content, 50 rpm, vane spindle V-72, preferably measured with model DV3T, RV torque range equipment.

In an embodiment the water soluble components of the partially hydrolyzed product comprise oligo- and polysaccharides with monosaccharide repeating units of D- galactose, L-arabinose, D-galacturonic acid and L-rhamnose. As the skilled person understands, the exact amount of a certain monosaccharide depends on the type of raw material used in the process. However, the polysaccharides are released as hydrolysis products during the partial hydrolysis of the above mentioned alkali treatment (step i) or hydrogen peroxide treatment.

The water soluble components of the partially hydrolyzed product may be analyzed as shown in Fig. 1 . Once the water soluble components have been fractionated from the non-soluble cellulosic material for example by centrifugation at a relative centrifugal force of 5250 g for 20 minutes, or pressure filtration through a 40-pm membrane, water soluble components having a molecular weight smaller than 1 kDa may be separated through ultrafiltration. The water soluble components that have a molecular weight larger than 1 kDa may be further analyzed by size exclusion chromatography (SEC) to obtain a size distribution of the water soluble components having a molecular weight larger than 1 kDa. The monosaccharide repeating units comprised in the water soluble components may be analyzed from the soluble components having a molecular weight larger than 1 kDa by first hydrolyzing the water soluble components to monosaccharides and then analyzing the monosaccharides by reverse phase HPLC optionally complemented by NMR.

In an embodiment, the wet product is a wet product obtainable through partial hydrolysis of non-wood cellulosic raw material using alkali treatment followed by homogenization, the wet product comprising b) water insoluble components comprising cellulose microfibril aggregates having a number average size below 200 pm, wherein water soluble hydrolysis products have been fractionated from the wet product.

In an embodiment the size of the cellulose microfibril aggregates (microfibrils and microfibril bundles) is below 200pm. The size can be determined by using vacuum filtering through various woven filter mesh sizes. At 1 wt-% aqueous mixture preferably at least 95% of the wet product passes a screen having a mesh size of 167x167pm, i.e. also the non-soluble components have a size below 167pm.

In an embodiment the non-soluble components are capable of passing through the screen of a sieve or a filter having a 175x175pm mesh size, the wet product thus not containing large (>200pm) components.

In an embodiment, the non-soluble components comprise cellulose microfibrils and/or microfibril bundles which are smaller than 200 pm. In an embodiment, non soluble components comprise cellulose microfibrils and/or microfibril bundles having a number average diameter between 20-200 nm

In an embodiment, the alkali treatment is conducted using a continuous process. The continuous process may be carried out in an optionally inclined tubular reactor equipped with a single screw conveyor or twin screw conveyor, or in a continuous screw extractor. In another embodiment, the alkali treatment is conducted using a batch process.

In an embodiment, the hydrogen peroxide treatment is conducted using a continuous process. The continuous process may be carried out in an optionally inclined tubular reactor equipped with a single screw conveyor or twin screw conveyor, or in a continuous screw extractor. In another embodiment, the hydrogen peroxide treatment is conducted using a batch process. In an embodiment, the alkali treatment (step i) is carried out at a temperature selected from the range 0-100 °C, preferably 30-100 °C, more preferably 60-100°C, even more preferably 75-90°C.

In an embodiment, the alkali treatment is a continuous extraction process done at 30-50 °C to attain soluble hydrolysis products comprising pectin hydrolysis products that comprise linear or branched polysaccharides consisting of a-(1-4)-linked D- galacturonic acid repeating units.

In an embodiment, the alkali treatment is a continuous extraction process done at 60-90 °C to attain soluble hydrolysis products comprising pectin hydrolysis products that comprises galacturonic acid sugars, and other poly-, oligo-, and monosaccharides that are not pectin based structures.

In an embodiment, the alkali is NaOH or KOH, preferably NaOH. In an embodiment the ratio of alkali to raw material expressed as amount of moles of alkali per 1 kg of dry non-wood cellulosic raw material is at least 0.5 mol/kg, preferably the amount is selected from the range 1.25-4.5 mol/kg, more preferably from the range 1.5-4.5 mol/kg, and even more preferably from the range 1.5-1.75 mol/kg. In another embodiment, the aqueous alkali solution contains at least 0.01 mol/l alkali, preferably 0.01-2 mol/l, most preferably 0.05-0.5 mol/l. Selecting the alkali amount from these ranges provides a beneficial degree of partial hydrolysis.

In an embodiment the hydrogen peroxide treatment is carried out at a temperature selected from the range 60-100°C, preferably 75-90°C.

In an embodiment the ratio of hydrogen peroxide to raw material expressed as an amount of moles of hydrogen peroxide per 1 kg of dry non-wood cellulosic raw material is at least 0.1 mol/kg, preferably the amount is selected from the range 0.5- 4mol/kg, more preferably from the range 1-3mol/kg, and even more preferably from the range 1 .5-2.5 mol/kg.

In an embodiment alkali treatment or hydrogen peroxide treatment is carried out for at least 20min. The exact time for carrying our partial hydrolysis depends on the factors such as moisture content and the type of raw material, concentration of the alkali or the hydrogen peroxide, and temperature. The skilled person is capable of determining an appropriate hydrolysis time e.g. by following the release of hydrolysis product by chemical analysis or the consumption of alkali or hydrogen peroxide by determining a change in the pH. In an embodiment, the partially hydrolyzed product is recovered or the homogenization is started when the proportion of the water soluble components to the water insoluble components is at least 20 wt-% of the total dry matter.

In an embodiment, providing the wet product comprises a chemical modification step selected from oxidation, cationization, acetylation, electrophilic substitution, esterification, and etherification. The chemical modification step may be carried out before, during or after the alkali treatment or the hydrogen peroxide treatment, or the recovering step.

No washing step is necessary between the alkali treatment (step i) and the homogenization (step iii), which is an advantage. For example, the consumption of the alkali solution is reduced and no side streams that are difficult to process further are produced when washing steps are omitted. Nevertheless, a washing step or washing steps may optionally be included if desired as a part of providing the recovered product when the partially hydrolyzed product is obtained using alkali treatment, which provides flexibility and versatility.

In an embodiment, recovering the non-soluble cellulosic material from the partially hydrolyzed product obtained using alkali treatment comprises washing the non soluble cellulosic material with a solvent. The non-soluble cellulosic material may be washed with water or sequences of basic, acid and neutral water.

In an embodiment, the non-soluble cellulosic material of the partially hydrolyzed product obtained using alkali treatment is washed with an alkali before homogenization. In another embodiment, the non-soluble cellulosic material of the partially hydrolyzed product obtained using alkali treatment is washed with an acid followed by alkali wash before homogenization. In yet another embodiment, the non soluble cellulosic material of the partially hydrolyzed product obtained using alkali treatment is washed with water followed by filtration before homogenization.

In an embodiment, the recovering of the non-soluble cellulosic material can be performed simultaneously with the alkali treatment, for example when the alkali treatment is an extraction process, such as counter current extraction or percolation process. Also the optional washing of the non-soluble cellulosic material of the partially hydrolyzed product obtained using alkali treatment may be performed simultaneously with the alkali treatment for example when the alkali treatment is an extraction process. In an embodiment wherein the non-soluble cellulosic material is recovered, the alkali treatment, the recovering of the non-soluble cellulosic material and the optional washing of the non-soluble cellulosic material are conducted using a counter current process or a percolation process, preferably a counter current process. Especially well suitable counter-current processing devices are so called continuous screw extractors.

Percolation process in this context means a process in which the solvent flows through a fixed bed of the solid matrix typically in down-flow mode. Depending on the physical properties of the solvent it may fill the void spaces between the particles or not. There is a constantly high concentration gradient, which results in an almost complete leaching of extractable components.

When the wet product is provided using hydrogen peroxide treatment, the partially hydrolyzed product is recovered as a whole. Accordingly, when the wet product is provided using hydrogen peroxide treatment, providing the wet product is done without fractionating the partially hydrolysed product and/or without washing any portion of the partially hydrolyzed product.

In an embodiment, providing the wet product comprises a concentrating step to increase the dry matter content of the wet product to above 10 wt-%, preferably to 10-35 wt-%, most preferably to 10-25 wt-% based on the total weight of the wet product. The concentrating step may be carried out before, after or during the alkali treatment step (step i) or the recovering step (step ii) or the homogenization step (step iii). The concentrating may be carried out to maintain the concentration at a preselected level or range during selected steps or stages of the process. Preferably, the concentration step is performed by a method based on mechanical dewatering.

In another embodiment, the method is performed without dewatering or the wet product is provided without a concentration step. In an embodiment wherein the partially hydrolyzed product as a whole is recovered, the amount and concentration of the aqueous alkali solution is in the alkali treatment selected such that the aqueous alkali solution is essentially impregnated in the non-wood cellulosic raw material. When essentially all liquid is impregnated in the raw material, bleeding can be avoided. Bleeding is when the raw material cannot withhold all liquid and excess liquid forms a liquid phase which separates from the raw material. In an embodiment wherein the partially hydrolyzed product is recovered as a whole, aqueous alkali solution is used in an amount to obtain a dry matter content within the range from 10 wt-% to 35 wt-%, more preferably from 15 wt-% to 25 wt-% during the alkali treatment. These amounts are preferred to avoid bleeding while providing sufficient amount of alkali solution for the partial hydrolysis.

In an embodiment, the alkali treatment is carried out until essentially all alkali is consumed and the end of partial hydrolysis is reached and there is no need to stop the hydrolysis in any way.

In an embodiment the hydrogen peroxide treatment is carried out by an aqueous hydrogen peroxide solution, such as an aqueous hydrogen peroxide reagent solution. The reagent solution may optionally contain formic acid or another acid.

In an embodiment of the hydrogen peroxide treatment, the initial pH is set to a value within the range 3-5 by an acid. In an embodiment the acid is an organic acid, such as formic acid. In another embodiment the acid is a mineral acid.

In an embodiment, the hydrogen peroxide treatment is carried out at a temperature selected from the range 70-99°C, preferably 80-95°C, more preferably at about 90°C.

In an embodiment, the raw material to which the hydrogen peroxide treatment is used, is or comprises cassava pulp and/or sugar beet pulp.

In an embodiment, the progress of the hydrogen peroxide treatment is monitored by following the decrease of the pH during the hydrolysis. The hydrolysis can thus be stopped when a desired pH level is reached. In an embodiment the hydrogen peroxide treatment may be stopped when the pH has decreased at least about 1 pH unit, about 1.5 pH units, about 2 units, about 2.5 pH units, or about 3 pH units, or more. In an alternative embodiment the partial hydrolysis product is finished when the pH does not change any more. In an embodiment a catalyst, such as FeS0₄, is added to the hydrogen peroxide treatment.

In an embodiment, after the hydrogen peroxide treatment and before homogenization, the pH is set to a value above 6, preferably a value within the range 7-10, more preferably within the range 9-10.

In an embodiment, before the homogenization step, the recovered product is transferred to an intermediate reservoir, or intermediate silo. In embodiments wherein the partially hydrolyzed product is recovered as a whole, using the intermediate silo may for example reduce the residence time of the raw material in the alkali treatment step or the hydrogen peroxide treatment step and partial hydrolysis of the raw material initiated in the alkali treatment step or the hydrogen peroxide treatment step can be allowed to proceed to the desired stage in the intermediate silo before starting the homogenization step.

In an embodiment the homogenization is carried out by using a rotor-rotor homogenizer and/or a high-shear mixer.

Homogenizing may be carried out by using a grinder, comminutor, rotor-rotor- homogenizer, rotor-stator mixer or a grinder such as Ultra-Turrax, Masuko from Masuko Sangyo, rotor-rotor mixer or a grinder such as Atrex-type devices, a homogenizer such as Ariete-type or Panda-type from GEA Niro-Soavi, fluidizer, micro- or macrofluidizer such as microflu id izer from Microfluidics and/or ultrasonic disintegrator.

In an embodiment, the homogenization is performed in the presence of the solid carrier, and the solid carrier and the wet product are provided together as a mixture. The solid carrier may be mixed with the recovered product prior to the homogenization step or the solid carried may be provided into the homogenization process during homogenization.

In an embodiment, the solid carrier is mixed with the wet product, i.e. the mixing is performed after the homogenization step. The solid carrier may also be provided directly to the drying step (step II) without prior mixing with the wet product. In an embodiment, the solid carrier and the wet product comprising non-wood cellulose microfibrils are provided as a (mechanical) mixture. The (mechanical) mixture may have been obtained by mixing the solid carrier with the wet product after homogenisation or by performing the homogenisation in the presence of the solid carrier.

In an embodiment, the solid carrier is impregnated with water prior to, depending on the embodiment, providing the solid carrier, mixing the solid carrier with the recovered product, or introducing the solid carrier to the homogenization process.

Optionally, it is also possible, particularly in embodiments wherein the non-soluble cellulosic material is recovered, to add water before homogenization to carry out the homogenization step in a lower consistency. In an embodiment the homogenization is carried out in an aqueous medium at a dry matter content of not more than 25 wt- %, preferably within the range from 1 wt-% to 15 wt-%, more preferably within the range from 4 wt-% to 15 wt-%, the homogenization optionally followed by a concentrating step.

In an embodiment the recovered product is further treated with an additional amount of alkali during or after homogenization, or any combination of these. Additional alkali hydrolysis may be advantageous to provide a wet product in which the amount of water-soluble hydrolysis products is further increased. Dried products or re dispersed products obtained from the wet product with additional alkali treatment are advantageous when using the dried product or the re-dispersed product with phenolic resins that are alkalic.

In an embodiment the amount of the additional amount of alkali is selected such that the water soluble components comprise at least 50 wt-% of the total dry matter of the wet product after the additional alkali treatment is complete. The process conditions, such as temperature, of the additional alkali treatment can be the same as used in the alkali treatment (step i). The wet product obtained with additional alkali treatment has lower viscosity compared to non-treated product.

In an embodiment where the recovered product is further treated with an additional amount of alkali, the wet product comprises at least 12.5 mol alkali for one kg of dry non-wood cellulosic raw material, and has a maximum Brookfield viscosity of 11000 cP determined for aqueous 8 wt-% cellulosic dry matter content, 50 rpm, spindle RV-6, preferably measured with model DV3T, RV torque range equipment. Cellulosic dry matter content refers to a dry matter content disregarding the contribution of the alkali to the dry matter.

In an embodiment, an additional compound or additional compounds, such as synthetic or natural biocides, mineral or organic acids, water soluble polymers, water insoluble polymers, glycerol, glycol, any type of salt, fragrances, coloring agents, solid carriers, natural fibers, synthetic fibers, feed ingredients, lignin or any combination thereof, are added into the recovered product before or during the homogenization, or into the wet product before drying or during the drying step, or into the dried product.

In an embodiment, the non-wood cellulosic raw material is a raw material comprising parenchymal cellulose.

In an embodiment the non-wood cellulosic raw material is fresh, never dried, or dried.

In an embodiment, the non-wood cellulosic raw material is selected from sugar beet pulp, dry sugar beet pulp, wet sugar beet pulp, sugar beet pellet or any combination thereof.

In an embodiment, the non-wood cellulosic raw material is selected from potato pulp, cassava, bagasse, soya and any combination thereof.

In an embodiment, the non-wood cellulosic raw material is essentially dry, but not pelletized, beet pulp, commonly known as shredded beet pulp.

In an embodiment the non-wood cellulosic raw material is pre-treated by mechanical milling before the alkali treatment. Mechanical milling can be carried out for example by a roller mill. However, any method suitable for reducing the particle size of the non-wood cellulosic raw material for example by milling may be used. Pre-treatment by milling is advantageous when using raw material with a larger size, such as pellets, but it is not mandatory. By the pre-treatment by milling hydration is enhanced, thereby enhancing the treatment with the aqueous alkali solution. Optionally, the wet product may be a bleached wet product. A bleached wet product may be obtained by bleaching the non-wood cellulosic raw material before alkali treatment or hydrogen peroxide treatment, or during alkali treatment or hydrogen peroxide treatment, or by bleaching the recovered product before homogenization or during homogenization, or by bleaching the wet product after homogenization, or any combination thereof.

Suitable bleaching agents include hydrogen peroxide, chlorine, chlorine dioxide, ozone, or any combination of these. In an embodiment the bleaching is performed with hydrogen peroxide utilizing a complexation chelating agent such as diethylenetriaminepentaacetate DTPA or similar, and wherein the chelating agent is preferably added prior to adding hydrogen peroxide.

In another embodiment, the wet product is not a bleached wet product.

The present disclosure provides a dried product comprising non-wood cellulose microfibrils and a solid carrier obtainable by the method according to the first aspect. The dried product demonstrates little self-adhesive properties compared to the wet product or the re-dispersed product and preferably the dried product does not stick to other surfaces it is in contact with. The dried product may be provided in a form of a pellet, a compressed tablet, powder, or a granule.

The present disclosure also provides use of a dried product according to the second aspect for forming an article of manufacture by pressing or compressing the dried product, preferably by hot pressing or by compression molding the dried product.

In other words, there is provided a method for forming an article of manufacture comprising: providing a dried product according to the second aspect, optionally reducing the particle size of the dried product preferably to 10 pm - 500 pm; and/or optionally mixing the dried product with a composition or compound other than the dried product to form a mixture; and pressing, preferably hot pressing or compression molding, the dried product or the mixture to form an article of manufacture. Surprisingly, the dried product comprising non-wood cellulose microfibrils and solid carrier may be pressed directly into a two or three dimensional article of manufacture, physical object or end product. Optionally, the dried product may be mixed with further components, compositions or compounds before the pressing. The dried product may be pressed after the drying step without mechanical pre treatment or after it has been ground into powder-like form. Any method suitable for pressing the dried product into a two or three dimensional object may be used. Preferably, the method is hot pressing or compression molding. For example, ground, powder-like dried product may be used as a reactive component from which two or three dimensional objects can be pressed by applying pressure and optionally heat.

In an embodiment, the pressing is performed at a temperature selected from the range from 100 °C to 175 °C and at a pressure selected from the range from 160 bar to 320 bar, preferably at a temperature selected from the range from 125 °C to 150 °C and at a pressure selected from the range from 160 bar to 320 bar, more preferably at a temperature of 150 °C and a pressure of 160 bar.

In an embodiment, the water content of the dried product is adjusted prior to the pressing, preferably to a water content of 10 wt-% based on the total weight of the dried product. The water content of the dried product may be adjusted for example by spraying the dried product with water.

The present disclosure further provides a re-dispersed dried product obtainable by re-dispersing a dried product according to the second aspect in water such that the dry matter content of the re-dispersed product is within the range from 0.2 wt-% to 20 wt-%, preferably from 2 wt-% to 4 wt-%, based on the total weight of the re dispersed product.

In certain embodiments, the re-dispersed product has a Brookfield viscosity within the range from 210 cP to 420 cP as measured at 50 rpm and 4 wt-% dry matter content with a vane spindle (V72), preferably with a DV3T RV-torque range equipment.. In an embodiment the re-dispersed composition is shear thinning as an aqueous dispersion at 1 - 5 wt-% dry matter content. In an embodiment, the re-dispersing of the dried product may be performed by mixing the dried product with water to obtain a mixture, hydrating the mixture, preferably up to 1 day, most preferably up to 20 minutes, to obtain a hydrated mixture, and mixing the hydrated mixture, preferably using high shear mixing.

Hydrophilic solid carriers in the dried product provides better re-dispersibility of the dried product.

Although not necessary, a liquid activator may in some embodiments be included in the dried product to facilitate re-dispersion of the dried product. Accordingly, in an embodiment, the dried product comprises a liquid activator preferably at least 1 wt- % based on the total weight of the dried product. The liquid activator is either a liquid substance or a liquid solution.

In an embodiment, the liquid activator is added before the homogenization of the recovered product to the recovered product, or during homogenization, or after homogenization to the wet product.

Preferably, the liquid activator comprises 0-30 wt-% water and 70-100 wt-% liquid water miscible substance that facilitates the re-dispersion of the dried product. Non limiting examples of liquid activators include: glycerol, polyol, polyol mixture, polyol mixture with up to 40 % water, polyethylene glycol with a molecular weight below 1000 g/mol, and mixtures thereof. In an embodiment, the activator is a food or feed ingredient or additive. In an embodiment, the activator is glycerol, a liquid hydrated sugar, propylene glycol, or oligomeric or polymeric polyethylene oxide. Preferably, the activator is liquid at room temperature, such as 20 °C.

The dried product and the re-dispersed product of the present disclosure may be used in various fields and applications. For example, the dried product or the re dispersed product may be used as an additive or component for modifying one or more of: viscosity, mechanical properties, strength, stiffness, toughness, binding properties, suspension stability, gel insensitivity to temperature, material insensitivity to temperature, shear reversible gelation, yield stress, and liquid retention of the composition of matter; or in drilling fluids; aqueous formulations used in oil fields including drilling, completion, fluid loss, work-over, and enhanced oil recovery (EOR) fluids; water-borne paints; coatings; adhesives; cosmetic formulations; water treatment; precipitation aid; soil improvement; wind or water erosion control; dust reduction and dust binding; wet or dry concrete formulation; wet or dry mortars; ready-mix concrete, pre-cast concrete, plasters; aerated concrete; injection grouts; shotcrete; cutting fluids, wet feed formulations, thermoset resins including phenol formaldehyde, melamine formaldehyde, urea formaldehyde resins, melamine-urea-formaldehyde resins; homecare detergents; industrial cleaning agents including liquids with pH higher than 12 or lower than 4; or in paper & board products; natural or synthetic non-wovens, molded fiber products; natural fiber composites; as such or together with synthetic resin in wood panel products including plywood, particle board, MDF, hardboard, laminated wood panels; pellets including food, feed, fuel, fertilizer pellets; food products; feed products; or in thermoset composites; thermoplastic composites; elastomers including natural or synthetic rubber constructions and tire formulations; insulation materials, including polyurethane and polystyrene foams.

Particularly, there is provided use of the dried product or the re-dispersed product as a binder.

In an embodiment, the dried product or the re-dispersed product is used as a binder for pellets.

In a further embodiment, the dried product or the re-dispersed product is used as a binder for wood panels, such as particle boards, hard boards, or plywood, with or without synthetical resin(s).

Also, as another particularly interesting application, there is provided use of the dried product or the re-dispersed product as a component or ingredient in animal feed. Feed comprising the dried product or the re-dispersed product may be used for feeding various animals, for example livestock, fur animals, companion animals, cattle, ovine, porcine, poultry, fish, or shrimp.

Further, also as a particularly interesting application, there is provided use of the re dispersed product as a rheology modifier.

The term comprising includes the broader meanings of including, containing, and comprehending, as well as the narrower expressions consisting of and consisting only of. EXAMPLES Example 1

Sugar beet pulp pellets were gently broken using a roller mill and fed together with aqueous NaOH solution to a continuous or batch type reactor heated to 80°C. NaOH dosing was 1.5 mol NaOH/kg broken sugar beet pellets dry matter. The dry matter content (including both the broken sugar beet pellets and the NaOH) in the reactor was 20 wt-%, 25 wt-%, or 30 wt-%, and the residence time in the reactor was 40 minutes. The alkali treated broken sugar beet pellets formed a pulp which was stored for 1.5 or 4 hours in an intermediate tank, after which the partially hydrolyzed product was recovered as a whole.

Table 1.

Example 1.1

Production of fibrillated parenchymal cellulose based on cassava pulp and sugar beet pulp using partial acid hydrolysis. Cassava pulp (powder form, dry matter content 87.8 wt-%, starch content approximately 50 wt-% of dry matter) was treated with hydrogen peroxide solution as follows: Hydrogen peroxide (35 wt-%) 26. Og was dissolved in 489.4 g of water pre-heated to 90 °C. 150.0 g of cassava pulp was mixed with the hydrogen peroxide solution and the mixture was transferred into a polypropylene bottle. The reaction was continued in oven at 90 °C for 60 minutes and thereafter cooled to room temperature using a water bath. The pH of the mixture dropped from around 5.5 to 3.5 during reaction. The total dry matter content of the reacted mixture was determined to be 20.4 wt-% (determined by oven drying at 109 °C for 24 hours), having a solubilized fraction of 15.0 wt-% (or 73.5 wt-% of total dry matter, determined by pressure filtration and oven drying at 109 °C for 24 hours). The sample viscosity and tackiness resulting from high starch content of cassava pulp was reduced, likely due to dextrin ization by hydrogen peroxide, making processing of the material easier.

Sugar beet pulp (crushed pellets, dry matter content 88.9 wt-%) was treated with hydrogen peroxide solution as follows: Hydrogen peroxide (35 wt-%) 26. Og and formic acid (85 wt-%) 2.4 g were dissolved in 325.5 g of water pre-heated to 90 °C. 100.3 g of sugar beet pulp was mixed with the reagent solution and the mixture was transferred into a polypropylene bottle. The reaction was continued in oven at 90 °C for 90 minutes and thereafter cooled to room temperature using a water bath. The pH of the mixture was 3.2 after reaction. The total dry matter content of the reacted mixture was determined to be 20.2 wt-% (determined by oven drying at 109 °C for 24 hours), having a solubilized fraction of 12.6 wt-% (or 62.4 wt-% of total dry matter, determined by pressure filtration and oven drying at 109 °C for 24 hours).

For fibrillation, a sample of the reacted pulp was diluted to 2 wt-%, mixed with a high-speed blender (17000 rpm, 30 seconds) and pH adjusted to 9-10 with 10 wt-% NaOH solution and homogenized (fibrillated) by high-pressure homogenization (Gea Niro Soavi, Panda Plus 1000), two passes at 400 bar. The samples were further mixed with a high-speed blender (17000 rpm, 3 times 10 seconds, with 20 second resting periods in between intervals). Properties of the produced materials (wet products) are shown in Table 1 .1 .

The viscosity of the homogenized samples were measured by Brookfield DV3T viscometer (RV-torque range, Brookfield Engineering Laboratories, Middleboro, USA) equipped with a vane geometry (V-72, diameter 21 .67 mm, length 43.38 mm). The samples were measured at 2 wt-% dry matter content and at 50 rpm and 100 rpm shear rates. The temperature was adjusted to 20 °C prior to measurements.

Turbidity of dilute aqueous dispersions of fibrillated (homogenized) parenchymal cellulose was measured with HACH P2100 turbidimeter. The product was diluted with water to a concentration of 0.2 wt-%, and the sample was agitated for 10 min before the measurement followed by degassing in vacuum to remove entrapped air bubbles from the sample.

The sedimentation volume was determined for 0.2 wt-% cellulose content in transparent 15 ml Falcon test tubes. A total of 13.0 ml sample volume was used and allowed to stand at room temperature for 24 hours to obtain the sedimentation volume i.e. the volume occupied by the sediment material.

Table 1.1 Properties of peroxide digested cassava and sugar beet pulp after fibrillation.

The example shows that hydrogen peroxide can be utilized for producing fibrillated parenchymal cellulose from cassava and sugar beet pulp. The tackiness of hydrogen peroxide treated pulps and corresponding fibrillated products is also significantly reduced, making the processing of the material easier. In addition, the resulting products are light in color and stable against microbial growth due to sterilizing conditions.

The hydrogen peroxide treatment can be enhanced with addition of catalysts, such as FeS04, if not naturally present in the raw material in sufficient amounts to promote Fenton and Fenton-like reactions. The pH of the mixture can be pre adjusted to a suitable range, for example pH=3-5 with suitable organic or mineral acids. Formic acid can be used for pH adjustment, and for forming performic acid in situ. Example 2

Recovered product produced according to Sample 1A of Example 1 was homogenized using a rotor-rotor homogenizer. Crushed sugar beet pulp pellets, crushed wood pellets, paper pulp, fluff pulp, and recycled paper were provided as solid carriers and each of the aforementioned carriers was respectively mixed with the homogenized product at 1 :1 mixing ratio (wt dry matter / wt dry matter). The mixtures were dried in an oven at 60°C to 90 wt-% dry matter content. As a comparative example, homogenized product without a carrier was similarly dried. The dried products were ground using a grain mill. The dried products comprising carrier were re-dispersed to 4.0 wt-% dry matter content and the dried product of the comparative example was re-dispersed to 2.0 wt-% dry matter content, which corresponds to a dry matter content from which the contribution of the solid carrier is disregarded. The re-dispersion was performed by mixing each dried product with water, respectively, and allowing the mixtures to hydrate at room temperature for 30 minutes, after which each mixture was mixed with a shearing mixer, (Bamix mixer, 17000 rpm, three times 10 seconds with a resting period of 20 seconds between the intervals), followed by degassing in vacuum to remove entrapped air bubbles. The re-dispersed products were characterized by their Brookfield viscosities. The viscosities of the re-dispersed products were measured by Brookfield DV3T viscosimeter (RV-torque range, Brookfield Engineering Laboratories, Middleboro, USA) equipped with a vane geometry (V-72, diameter 21.67 mm, length 43.38 mm). The samples were measured at the above mentioned dry matter contents and the temperature was adjusted to 20 °C prior to measurements. The viscosity of the samples was measured at 50 and 100 rpm shear rates.

Table 2.

Example 3

Recovered product produced according to Sample 1A of Example 1 was homogenized using a rotor-rotor homogenizer. CaC03, bentonite, hectorite, and sepiolite were provided as solid carriers and each of the aforementioned carriers was respectively mixed with the homogenized product at 1 :1 or 1 :4 mixing ratio (wt product dry matter on wt carrier dry matter). The mixtures were dried in an oven at 60°C to 90 wt-% dry matter content. As a comparative example, homogenized product without a carrier was similarly dried. The dried products were ground using a grain mill. The dried products comprising carrier were re-dispersed to 4.0 wt-% dry matter content and the dried product of the comparative example was re-dispersed to 2.0 wt-% dry matter content, which corresponds to a dry matter content from which the contribution of the solid carrier is disregarded. The re-dispersion was performed as in Example 2. The re-dispersed products were characterized by their Brookfield viscosities at the aforementioned dry matter contents. The viscosities were measures as described in Example 2 at 50 rpm and 100 rpm. Table 3.

Example 4

Crushed sugar beet pulp pellets were mixed to recovered products produced according to Sample 1A, 1C, and 1D of Example 1, respectively, at 1:1 mixing ratio (wt dry matter / wt dry matter). Each mixture was homogenized using a rotor-rotor homogenizer. The homogenized mixtures were dried in an oven at 60°C to 90 wt-% dry matter content. The dried products were ground using a hammer mill with 2.5 mm or 1.0 mm sieve plate, or a grain mill. The dried products were re-dispersed to 4.0 wt-% dry matter content. The re-dispersion was performed as in Example 2. The re-dispersed products were characterized by their Brookfield viscosities at the aforementioned dry matter content. The viscosities were measures as described in Example 2 at 50 rpm and 100 rpm.

Table 4.

Example 5 Recovered product produced according to Sample 1 B of Example 1 and dry sugar beet pellets were simultaneously fed to a rotor-rotor homogenizer at 1 :1 mixing ratio (wt dry matter / wt dry matter). The homogenized mixture was dried in a continuous direct-heat rotary dryer to 90 wt-% dry matter content. The dried product was ground using a hammer mill with a 5.0 mm sieve plate. After grinding, the bulk density of the dry product was 765 kg/m³. The dried product was re-dispersed to 4.0 wt-% dry matter content. The re-dispersion was performed as in Example 2. The re-dispersed product had a Brookfield viscosity of 410 cP at the aforementioned dry matter content measured as described in Example 2 at 50 rpm.

Example 6 Recovered product produced according to Sample 1A of Example 1 was diluted to 11 wt-% dry matter content during homogenization of said recovered product. The homogenized product was mixed with wood chips at 3:20 mixing ratio (wt product dry matter on wt wood chips dry matter). The mixture was dried in a continuous direct-heat rotary dryer to 98 wt-% dry matter content. The dried product was sprayed with water to adjust the moisture content to 10 wt-%, formed into a mat, and was hot-pressed to produce resin-free, i.e. no-added-formaldehyde, particleboard. The board had a thickness of 14 mm, a density of 950 kg/m³, and the modulus of elasticity in bending, bending strength, and tensile strength perpendicular to the plane of the board complied with the requirements of Type P2 boards according to EN 312. As no formaldehyde-releasing resin was used, the board had a very low level of formaldehyde release in comparison to a conventional particleboard.

Example 7

Dried product produced according to Sample 4B of Example 4 was compressed to disc-shaped objects at a temperature of 100, 125, 150, or 175°C, a surface pressure of 160 or 320 bar, and a pressing time of 2 minutes. The results in Table 5 show that at temperatures lower than 150°C, the higher pressure results in a higher density, whereas at 150°C or above, the higher pressure results in a lower density. This indicates that a certain combination of heat and pressure is required to form a dense object, the highest density in this setting being reached at 160 bar and 150°C. However, some decomposition of the material was observed at the temperature of 175°C, resulting to less dense objects.

Table 5.

Example 8 A sample of dried product produced according to Sample 4E of Example 4 was attached to an aluminum sample holder with two-sided carbon tape and coated with 4 nm Au/Pd coating to prevent charging. The sample was imaged with Zeiss Sigma VP SEM at 2 kV acceleration voltage with secondary electron (SE) detector.

Re-dispersed product produced according to Sample 4E of Example 4 was diluted with distilled water so that the concentration of the non-dissolving fraction was 0.1 wt-%. A sample of the diluted product was placed to an ultrathin carbon film TEM grid. The excess liquid was blotted away with filter paper. The sample was imaged with FEI Tecnai 12 TEM at 120 kV acceleration voltage.

The images are shown in Fig. 2. Panels A and B of Fig. 2 are SEM images of the dried product, and panels C and D of Fig. 2 are TEM images of the re-dispersed product. Panel A shows that the dried product comprises particles with irregular shapes and sizes ranging from 10 pm to 500 pm, the largest fraction within the range from 50-200 pm. Panel B shows that the particles comprise cellulose microfibrils that have a number average diameter between 20-200 nm. Panels C and D show that after re-dispersing, cellulose microfibrils, that typically have a diameter between 20 and 200 nm, form loose bundles or networks of fibrils. It is noted that some of the fibril aggregates that are seen in the images may be formed by capillary forces during TEM sample preparation. Example 9

Dried product produced according to Sample 4A of Example 4 (without re dispersion) was added as a binder to a generic rainbow trout feed recipe at a level of 0.75 wt-% or 1.50 wt-%. As a comparative example, generic rainbow trout feed without any Sample 4A dry product content was provided. The aqua feed pellets were produced using a Brabender Ketse 20/40 twin-screw extruder with a die of 4 mm in diameter. Feed pellet specific density (bulk density) was measured using a 1 -liter measuring cylinder, the pellet hardness was measured using a manual Kahl pellet hardness tester, and the pellet durability index was measured using a Holmen NHP 100 pellet durability tester, a test duration of 60 seconds at 70 mbar. The results of Table 6 show that the dried product improves feed pellet durability and hardness.

Table 6.

Example 10 Native potato starch (Finnamyl, Kokemaki, Finland, dry matter content 85.7 wt-%) was provided as solid carrier and mixed with alkali-treated, fibrillated (homogenized) sugar beet pulp (Dry-matter content 26.1 wt-%) by kneading, to obtain compositions shown in Table 7. A selected mixture of the native potato starch and the alkali- treated, fibrillated sugar beet pulp (Table 7, Entry E) was further heated at 100 °C for 20 minutes to gelatinize starch in situ. Portions of some of the obtained mixtures (Table 7, Entries B, D and E) were crushed and gently dried at 50 °C for 24 hours. Starch containing formulations had reduced stickiness and could easily be crushed and dried.

The viscosities of obtained formulations were measured at 2 wt-% concentration relative to alkali-treated fibrillated sugar beet pulp (SBP) and 240g sample size, according to Table 8. Selected samples (Table 8, Entries 2, 3, 4, 6, 7, 9, 8) were diluted with distilled water (room temperature) and allowed to hydrate for 1 hour, following high-shear mixing (17000 rpm, 3 times 10 seconds, with 20 second resting periods in between intervals). Selected samples (Table 8, Entries 1, 5, 8 and 11) were dispersed in hot water to gelatinize starch, by first hydrating the samples for 1 hour at room temperature and thereafter heating the suspension to 90 °C under stirring. The samples were then mixed with high-shear mixing as above and allowed to cool to room temperature before measurement. As comparative examples, the viscosities of the native potato starch at 5.0 wt-%, fibrillated sugar beet pulp that had not been dried at 2 wt-%, and dried and re-dispersed fibrillated sugar beet pulp at 2 wt-% were measured.

The viscosity of samples were measured by Brookfield DV3T viscometer (RV-torque range, Brookfield Engineering Laboratories, Middleboro, USA) equipped with a vane geometry (V-73 diameter 12.67 mm, length 25.35 mm ). The viscosities of the samples were measured at 2 wt-% relative to fibrillated sugar beet pulp at 50 rpm shear rate. The temperature was adjusted to 20 °C prior to the viscosity measurements.

Table 7. Compositions and treatments of mixtures of alkali treated, fibrillated sugar beet pulp (SBP) and native potato starch.

Table 8. Dispersions of samples in water and resulting Brookfield viscosities. SBP refers to alkali-treated fibrillated (homogenized) sugar beet pulp.

This example shows that the addition of starch is beneficial in reducing material cohesion (stickiness) and thus aid subsequent drying. After the mixture is formed, a heat treatment can be implemented to gelatinize starch in the mixture. Further, dry products containing starch can be re-dispersed in water and rheological properties at least partly preserved. The starch formulations can be gelatinized in hot water at high shear mixing conditions, which is unusual for unmodified native starches, showing a synergistic effect with fibrillated sugar beet pulp.

Example 11

Dried product produced according to Entry E in Table 7 of Example 10 was adjusted to a moisture level of 5 wt-% or 10 wt-% and compressed to disc-shaped objects at a temperature of 90, 120, or 150 °C, and a surface pressure of 160 bar. Higher temperatures in this range generally resulted in higher densities, other parameters being the same. The results in Table 9 indicate that when the moisture level is increased, similar objects may be obtained using lower temperatures or shorter processing times.

Table 9.

Example 12

Dried product produced according to Entry E in Table 7 of Example 10 was mixed with dry saw dust so that the fraction of the dried product in the mixture was 1 wt- %, 5 wt-%, or 10 wt-%. The moisture content of the mixtures was 7 wt-%. The mixtures were compressed to disc-shaped objects at a temperature of 120 or 140°C, a surface pressure of 160 bar, and a pressing time of 2 minutes.

Table 10.

Implementation and embodiments of the present invention are further disclosed in the following numbered clauses:

1. A method for producing a dried product comprising non-wood cellulose microfibrils and solid carrier, the method comprising:

II) drying the wet product in the presence of the solid carrier until a dried product having a dry matter content of at least 70 wt-% is obtained, the dried product comprising non-wood cellulose microfibrils and solid carrier.

2. The method according to clause 1 , comprising drying the wet product in the presence of the solid carrier until the dry matter content of the dried product is at least 80 wt-%, preferably at least 88 wt-%. 3. The method according to clause 1 or 2, wherein the dry matter content of the wet product is 35 wt-% or less, preferably within the range from 1 wt-% to 35 wt-%, more preferably within the range from 4 wt-% to 30 wt-%, even more preferably within the range from 10 wt-% to 30 wt-%.

4. The method according to any one of clauses 1 -3, wherein the solid carrier and the wet product are provided in a wt/wt (dry matter/dry matter) ratio selected from the range from 1 :4 to 9:1 , preferably from 1 :4 to 4:1 , more preferably from 1 :2 to 2:1 , even more preferably the ratio is 1 :1.

5. The method according to any one of clauses 1 -4, comprising grinding the dried product to reduce its particle size preferably to 10 pm - 2.5 mm, more preferably to 10 pm - 500 pm.

6. The method according to any one of clauses 1-5, wherein the solid carrier is a hydrophilic carrier, preferably an organic hydrophilic carrier, more preferably an organic hydrophilic carrier comprising cellulose.

7. The method according to any one of clauses 1-6, comprising repeating steps I) and II) and recovering at least a portion of the dried product after each step II).

8. The method according to clause 7, comprising providing a portion of the dried product obtained in step II) as the solid carrier in a subsequent repetition of step I).

9. The method according to any one of clauses 1 -8, wherein the temperature of the wet product and the solid carrier does not exceed 150 °C, preferably 100 °C, during step II).

10. The method according to any one of clauses 1-9, wherein providing a solid carrier comprises reducing the particle size of the solid carrier to obtain granules or particles of the solid carrier with dimensions within the range from 0.01 mm to 2.5 mm, preferably from 0.1 mm to 2.5 mm.

11 . The method according to any one of clauses 1 -10, wherein the wet product is a wet product obtainable through partial hydrolysis of non-wood cellulosic raw material followed by homogenization.

12. The method according to any one of clauses 1-11 , wherein the wet product is a wet product obtainable through partial hydrolysis of non-wood cellulosic raw material followed by homogenization, said wet product comprising water soluble components and water insoluble components, wherein a) from the water soluble components that are larger than 1 kD, at least 50% have a molecular weight of at least 40 kD; and b) the water insoluble components comprise cellulose microfibril aggregates having a number average size below 200 pm; wherein the amount of the dry matter of all water soluble components is at least 20 wt-% of the total dry matter of the wet product.

13. The method according to clause 12, wherein the wet product has a Brookfield viscosity of at least 300 cP determined for aqueous 2 wt-% dry matter content, 50 rpm, vane spindle V-72.

14. The method according to clause 12 or 13, wherein the water soluble components comprise oligo- and polysaccharides with monosaccharide repeating units of D-galactose, L-arabinose, D-galacturonic acid and L-rhamnose.

15. The method according to any one of clauses 1-11, wherein the wet product is a wet product obtainable through partial hydrolysis of non-wood cellulosic raw material using alkali treatment followed by homogenization, the wet product comprising b) water insoluble components comprising cellulose microfibril aggregates having a number average size below 200 pm, and wherein water soluble hydrolysis products have been fractionated from the wet product.

16. The method according to any one of clauses 12-15, wherein the non-soluble components comprise cellulose microfibrils and/or microfibril bundles which are smaller than 200 pm.

17. A dried product comprising non-wood cellulose microfibrils and a solid carrier obtainable by the method according to any one of clauses 1 -16.

18. A re-dispersed dried product obtainable by re-dispersing a dried product according to clause 17 in water such that the dry matter content of the re-dispersed product is within the range from 0.2 wt-% to 20 wt-%, preferably from 2 to 4 wt-%. 19. The re-dispersed product according to clause 18, having a Brookfield viscosity within the range from 210 cP to 420 cP determined for aqueous 4 wt-% dry matter content, 50 rpm, vane spindle V-72.

20. Use of the dried product according to clause 17 or the re-dispersed product according to clause 18 or 19: as an additive or component for modifying one or more of: viscosity, mechanical properties, strength, stiffness, toughness, binding properties, suspension stability, gel insensitivity to temperature, material insensitivity to temperature, shear reversible gelation, yield stress, and liquid retention of the composition of matter; or in drilling fluids; aqueous formulations used in oil fields including drilling, completion, fluid loss, work-over, and enhanced oil recovery (EOR) fluids; water borne paints; coatings; adhesives; cosmetic formulations; water treatment; precipitation aid; soil improvement; wind or water erosion control; dust reduction and dust binding; wet or dry concrete formulation; wet or dry mortars; ready-mix concrete, pre-cast concrete, plasters; aerated concrete; injection grouts; shotcrete; cutting fluids, wet feed formulations, thermoset resins including phenol formaldehyde, melamine formaldehyde, urea formaldehyde resins, melamine-urea- formaldehyde resins; homecare detergents; industrial cleaning agents including liquids with pH higher than 12 or lower than 4; or in paper & board products; natural or synthetic non-wovens, molded fiber products; natural fiber composites; as such or together with synthetic resin in wood panel products including plywood, particle board, MDF, hardboard, laminated wood panels; pellets including food, feed, fuel, fertilizer pellets; food products; feed products; or in thermoset composites; thermoplastic composites; elastomers including natural or synthetic rubber constructions and tire formulations; insulation materials, including polyurethane and polystyrene foams.

21. Use of the dried product according to clause 17 for forming an article of manufacture by pressing the dried product, preferably by hot pressing or by compression molding the dried product. The foregoing description has provided by way of non-limiting examples of particular implementations and embodiments a full and informative description of the best mode presently contemplated by the inventors for carrying out the invention. It is however clear to a person skilled in the art that the invention is not restricted to details of the embodiments presented in the foregoing, but that it can be implemented in other embodiments using equivalent means or in different combinations of embodiments without deviating from the characteristics of the invention.

Furthermore, some of the features of the afore-disclosed example embodiments may be used to advantage without the corresponding use of other features. As such, the foregoing description shall be considered as merely illustrative of the principles of the present invention, and not in limitation thereof. Hence, the scope of the invention is only restricted by the appended patent claims.

Claims

2. The method according to claim 1 , wherein the solid carrier stays in solid state throughout the method.

3. The method according to claim 1 or 2, comprising drying the wet product in the presence of the solid carrier until the dry matter content of the dried product is at least 80 wt-%, preferably at least 88 wt-%.

4. The method according to any one of claims 1 -3, wherein the dry matter content of the wet product is 35 wt-% or less, preferably within the range from 1 wt-% to 35 wt-%, more preferably within the range from 4 wt-% to 30 wt-%, even more preferably within the range from 10 wt-% to 30 wt-%.

5. The method according to any one of claims 1-4, wherein the solid carrier and the wet product are provided in a wt/wt (dry matter/dry matter) ratio selected from the range from 1 :4 to 9:1 , preferably from 1 :4 to 4:1 , more preferably from 1 :2 to 2:1 , even more preferably the ratio is 1 :1.

6. The method according to any one of claims 1-5, wherein the solid carrier and the wet product are provided as a mixture.

7. The method according to any one of claims 1 -6, comprising grinding the dried product to reduce its particle size preferably to 10 pm - 2.5 mm, more preferably to

10 pm - 500 pm.

8. The method according to any one of claims 1-7, wherein the solid carrier is capable of adsorbing or absorbing water.

9. The method according to any one of claims 1-8, wherein the solid carrier is a hydrophilic carrier, preferably an organic hydrophilic carrier, more preferably an organic hydrophilic carrier comprising cellulose.

10. The method according to any one of claims 1-9, wherein solid carrier comprises or substantially consists of water insoluble polysaccharide(s), preferably cellulose or starch, such as modified starch or cationic starch.

11 . The method according to any one of claims 1-10, comprising repeating steps I) and II) and recovering at least a portion of the dried product after each step II).

12. The method according to claim 11 , comprising providing a portion of the dried product obtained in step II) as the solid carrier in a subsequent repetition of step I).

13. The method according to any one of claims 1 -12, wherein the temperature of the wet product and the solid carrier does not exceed 150 °C, preferably 100 °C, during step II).

14. The method according to any one of claims 1-13, wherein the solid carrier is provided as powder, granules, or particles with dimensions within the range from 0.005 mm to 2.5 mm or wherein providing a solid carrier comprises reducing the particle size of the solid carrier to obtain granules or particles of the solid carrier with dimensions within the range from 0.01 mm to 2.5 mm, preferably from 0.1 mm to 2.5 mm.

15. The method according to any one of claims 1 -14, wherein the wet product is a wet product obtainable through partial hydrolysis of non-wood cellulosic raw material followed by homogenization.

16. The method according to any one of claims 1 -15, wherein the wet product is a wet product obtainable through partial hydrolysis of non-wood cellulosic raw material followed by homogenization, said wet product comprising water soluble components and water insoluble components, wherein a) from the water soluble components that are larger than 1 kD, at least 50% have a molecular weight of at least 40 kD; and b) the water insoluble components comprise cellulose microfibril aggregates having a number average size below 200 pm; wherein the amount of the dry matter of all water soluble components is at least 20 wt-% of the total dry matter of the wet product.

17. The method according to claim 16, wherein the wet product has a Brookfield viscosity of at least 300 cP determined for aqueous 2 wt-% dry matter content, 50 rpm, vane spindle V-72, preferably measured with model DV3T, RV torque range equipment.

18. The method according to claim 16 or 17, wherein the water soluble components comprise oligo- and polysaccharides with monosaccharide repeating units of D-galactose, L-arabinose, D-galacturonic acid and L-rhamnose.

19. The method according to any one of claims 1 -15, wherein the wet product is a wet product obtainable through partial hydrolysis of non-wood cellulosic raw material using alkali treatment followed by homogenization, the wet product comprising b) water insoluble components comprising cellulose microfibril aggregates having a number average size below 200 pm, and wherein water soluble hydrolysis products have been fractionated from the wet product.

20. The method according to any one of claims 16-19, wherein the non-soluble components comprise cellulose microfibrils and/or microfibril bundles which are smaller than 200 pm.

21 . A dried product comprising non-wood cellulose microfibrils and a solid carrier obtainable by the method according to any one of claims 1-20.

22. A re-dispersed dried product obtainable by re-dispersing a dried product according to claim 21 in water such that the dry matter content of the re-dispersed product is within the range from 0.2 wt-% to 20 wt-%, preferably from 2 to 4 wt-%.

23. The re-dispersed product according to claim 22, having a Brookfield viscosity within the range from 210 cP to 420 cP determined for aqueous 4 wt-% dry matter content, 50 rpm, vane spindle V-72, preferably measured with model DV3T, RV torque range equipment.

24. Use of the dried product according to claim 21 or the re-dispersed product according to claim 22 or 23: as an additive or component for modifying one or more of: viscosity, mechanical properties, strength, stiffness, toughness, binding properties, suspension stability, gel insensitivity to temperature, material insensitivity to temperature, shear reversible gelation, yield stress, and liquid retention of the composition of matter; or in drilling fluids; aqueous formulations used in oil fields including drilling, completion, fluid loss, work-over, and enhanced oil recovery (EOR) fluids; water borne paints; coatings; adhesives; cosmetic formulations; water treatment; precipitation aid; soil improvement; wind or water erosion control; dust reduction and dust binding; wet or dry concrete formulation; wet or dry mortars; ready-mix concrete, pre-cast concrete, plasters; aerated concrete; injection grouts; shotcrete; cutting fluids, wet feed formulations, thermoset resins including phenol formaldehyde, melamine formaldehyde, urea formaldehyde resins, melamine-urea- formaldehyde resins; homecare detergents; industrial cleaning agents including liquids with pH higher than 12 or lower than 4; or in paper & board products; natural or synthetic non-wovens, molded fiber products; natural fiber composites; as such or together with synthetic resin in wood panel products including plywood, particle board, MDF, hardboard, laminated wood panels; pellets including food, feed, fuel, fertilizer pellets; food products; feed products; or in thermoset composites; thermoplastic composites; elastomers including natural or synthetic rubber constructions and tire formulations; insulation materials, including polyurethane and polystyrene foams.

25. Use of the dried product according to claim 21 for forming an article of manufacture by pressing the dried product, preferably by hot pressing or by compression molding the dried product.