Method and apparatus for increasing concentration of soluble carbohydrate-containing fraction, soluble carbohydrate-containing fraction, solid fraction and uses thereof

Abstract

The invention relates to a method and an apparatus for producing a soluble carbohydrate-containing fraction (10), wherein lignocellulosic material (3) formed by treating a plant-based feedstock (1) is introduced into a separation stage (4). The method comprises at least one solid-liquid separation stage (4) for separating a soluble carbohydrate-containing fraction (10) and / or a wash filtrate (12) from the lignocellulosic material (3), at least part of the soluble carbohydrate-containing fraction (10) and / or the wash filtrate (12) being recycled into the lignocellulosic material (3), in order to increase the concentration of the soluble carbohydrate-containing fraction, solids (11) and at least part of the soluble carbohydrate-containing fraction (10) are supplied from the separation stage. The invention also relates to soluble carbohydrate-containing fractions and solid fractions and to their use.

Description

[0001] The present application is a divisional of an invention patent application filed by the applicant UPM AG with application number 201680009107.X, application date February 5, 2016, and invention name “Method and apparatus for increasing the concentration of a fraction containing soluble carbohydrates, a fraction containing soluble carbohydrates, a solid fraction and use thereof”, which is the Chinese national phase of the international application with application number PCT / FI2016 / 050076, claiming the priority of Finnish invention patent application 20155076, with priority date February 6, 2015. Field of the Invention

[0002] The present invention relates to a method and an apparatus for producing a fraction containing soluble carbohydrates and a solid fraction. The present invention also relates to a fraction containing soluble carbohydrates and an application thereof. The present invention also relates to a solid fraction and an application thereof. Background of the Invention

[0003] Different methods for forming carbohydrates from different raw materials, such as biomass, are known in the art. Many biorefining processes, such as hydrolysis, produce lignin and sugars after processing the biomass.

[0004] Purpose of the Invention

[0005] The object of the present invention is to disclose a method for producing a soluble carbohydrate containing fraction with a high concentration. Another object of the present invention is to produce a soluble carbohydrate containing fraction with increased concentration and improved recoverability. Another object of the present invention is to improve the fractionation of biomass for producing an improved and concentrated liquid fraction containing soluble carbohydrates with high recovery and a solid fraction free of soluble material. Summary of the invention

[0006] The method for increasing the concentration of a soluble carbohydrate containing fraction according to the present invention is characterized as stated in claim 1.

[0007] The device for increasing the concentration of a fraction containing soluble carbohydrates according to the invention is characterized as stated in claim 13.

[0008] The soluble carbohydrate-containing fraction according to the present invention is characterized as described in claim 17.

[0009] The solid fraction according to the present invention is characterized by what is described in claim 19.

[0010] The use of the soluble carbohydrate-containing fraction according to the present invention is characterized as described in claim 23.

[0011] The use of the solid fraction according to the invention is characterized by what is stated in claim 24.

[0012] BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings are included to provide a further understanding of the present invention, constitute a part of the specification, illustrate some embodiments of the present invention, and together with the description help explain the principle of the present invention. In the drawings:

[0014] Figure 1 is a flow chart illustrating a method according to one embodiment of the present invention,

[0015] Figure 2 is a flow chart illustrating a method according to another embodiment of the present invention,

[0016] Figure 3 is a flow chart illustrating a method according to another embodiment of the present invention,

[0017] Figure 4 is a flow chart illustrating a method according to another embodiment of the present invention,

[0018] Figure 5 is a flow chart illustrating a method according to another embodiment of the present invention,

[0019] Figure 6 is a flow chart illustrating a method according to another embodiment of the present invention,

[0020] Figure 7 is a flow chart illustrating a method according to another embodiment of the present invention,

[0021] Figure 8 The results of an example performed according to a method of one embodiment of the present invention are shown.

[0022] Fig. 9 shows the results of an example performed according to a method of one embodiment of the present invention, and

[0023] Fig.10 The results of an example performed according to a method according to one embodiment of the present invention are shown. DETAILED DESCRIPTION OF THE INVENTION

[0024] The present invention relates to a method for increasing the concentration of a liquid fraction containing soluble carbohydrates, for example a soluble carbohydrate-containing fraction, wherein a lignocellulosic material (3) formed by processing a plant-based raw material (1) is introduced into a separation stage (4, 6). In the method of the present invention, the method comprises at least one solid-liquid separation stage (4, 6) for separating a soluble carbohydrate-containing fraction (10) and / or a washing filtrate (12) from the lignocellulosic material (3). The separation stage comprises one or more separation steps. In order to increase the concentration of the soluble carbohydrate-containing fraction, at least a portion of the soluble carbohydrate-containing fraction (10) and / or the washing filtrate (12) is preferably recycled to the lignocellulosic material (3) before the desired separation step of the separation stage (4, 6). Solids (11) and at least a portion of the soluble carbohydrate-containing fraction (10) are supplied from the separation stage. In one embodiment, at least a portion of the washing filtrate (12) is supplied from the separation stage.

[0025] One embodiment of the method of the present invention is shown in Figure 1 Another embodiment of the method of the present invention is shown in Figure 2 Another embodiment of the method of the present invention is shown in Figure 3 Another embodiment of the method of the present invention is shown in Figure 4 Another embodiment of the method of the present invention is shown in Figure 5 Another embodiment of the method of the present invention is shown in Figure 6 Another embodiment of the method of the present invention is shown in Figure 7 .

[0026] The apparatus of the invention comprises at least one solid-liquid separation device (4, 6), into which a lignocellulosic material (3) formed by processing a plant-based raw material (1) is introduced, in which a fraction (10) containing soluble carbohydrates and / or a washing filtrate (12) is separated from the lignocellulosic material (3). Furthermore, the apparatus comprises at least one feeding device, such as a pump, for feeding the lignocellulosic material (3) into the separation device (4, 6). Furthermore, the apparatus comprises at least one recycling device for recycling at least a portion of the fraction (10) containing soluble carbohydrates and / or the washing filtrate (12) to the lignocellulosic material (3), preferably before the desired separation device or separation step, in order to increase the concentration of the fraction containing soluble carbohydrates. Furthermore, the apparatus comprises means, such as discharge means or outlet means, for supplying solids (11) and at least a portion of the fraction (10) containing soluble carbohydrates from the apparatus. In one embodiment, the apparatus comprises means for supplying at least a portion of the washing filtrate (12) from the apparatus.

[0027] The present invention is based on solid-liquid separation. In addition, the present invention is based on the recycling of preferably sugary filtrate, for example, fraction containing soluble carbohydrates and / or washing filtrate, to increase the concentration of fraction containing soluble carbohydrates. In the present invention, the sugar content of fraction containing soluble carbohydrates can be increased by recycling of filtrate in each application. At the same time, the recovery of fraction containing liquid soluble carbohydrates can be increased to form a purer solid fraction containing solids. In addition, the content of carbohydrates and the purity of solids can be improved by means of the present invention. In addition, if washing filtrate is formed in this way, it can be used in the process. In one embodiment, a small amount of washing liquid is used, so that the concentration of soluble compounds can be further increased. In one embodiment, displacement washing is used to further increase the concentration of soluble compounds and improve the purity of solid fractions.

[0028] In this context, a wash filtrate refers to a dilute filtrate from a washing step of washing lignocellulosic material. In this context, a soluble carbohydrate-containing fraction refers to a soluble carbohydrate-containing filtrate separated from lignocellulosic material, preferably with a high concentration. In a preferred embodiment, the wash filtrate and the soluble carbohydrate-containing fraction comprise carbohydrates, preferably C5 sugars (C5H 10 O5 or (C5(H2O) n The soluble carbohydrate-containing fraction may include carbohydrates, such as monosaccharides (C6H 12 O6 or C5H 10 O5), disaccharide (C 12 H 22 O 11 ), oligosaccharides and / or polysaccharides ((C6H 10 O5) n or (C5H8O4) n Preferably, the soluble carbohydrate-containing fraction comprises soluble C5 carbohydrates (C5H 10 O5 or C5(H2O) n ) and other carbohydrates. The wash filtrate and the fraction containing soluble carbohydrates may also contain other components. In a preferred embodiment, the solid comprises carbohydrates, preferably solid C6 carbohydrates (C6H 12 O6 or C6(H2O) n ). The solids may also contain other carbohydrates and other components.

[0029] In this article, plant-based raw materials refer to any plant-based raw materials, such as wood-based raw materials. Plant-based raw materials include lignin, cellulose and hemicellulose. In one embodiment, the plant-based raw materials are selected from the group consisting of wood-based raw materials, wood, lignocellulosic biomass, agricultural residues, bagasse-based materials, sugarcane bagasse, corn-based materials, corn straw, wheat straw, rice straw, woody biomass, perennial woody plants, vascular plants, etc., and mixtures thereof and combinations thereof. In one embodiment, the plant-based raw materials are wood-based raw materials or mixtures comprising wood-based materials. In one embodiment, the plant-based raw materials include plant fragments, such as wood chips.

[0030] In this context, lignocellulosic material refers to any lignocellulosic material formed by treating plant-based raw materials in one or more steps (e.g., pre-treating) using a suitable treatment method. In one embodiment, the lignocellulosic material comprises carbohydrates and lignin. Preferably, the carbohydrate is C n (H2O) n or C n (H2O) n-1 Carbohydrates can include monosaccharides (C6H 12 O6 or C5H 10 O5), disaccharide (C 12 H 22 O 11 ), oligosaccharides and / or polysaccharides ((C6H 10 O5) n or (C5H8O4) n Preferably, the lignocellulosic material comprises carbohydrates, such as soluble C5 carbohydrates (C5H 10 O5 or C5(H2O) n ) and solid C6 carbohydrates (C6H 12 O6 or C6(H2O) n). The lignocellulosic material may contain one or more lignocellulosic material components. Preferably, the lignocellulosic material is in the form of a suspension comprising a liquid (e.g., water). The lignocellulosic material (3) is formed from a plant-based raw material (1) and is treated in one or more treatment steps (2, 5). In one embodiment, the lignocellulosic material is formed or treated by a treatment (preferably a pretreatment) selected from the group consisting of: physical treatment, such as grinding, extrusion, microwave treatment, ultrasonic treatment, and cryotreatment, chemical treatment, such as acid treatment, alkali treatment, ionic liquid treatment, organic solvent treatment, and ozonolysis, physico-chemical treatment, such as steam explosion treatment, ammonia fiber explosion treatment, CO2 explosion treatment, liquid hot water treatment, and wet oxidation, biological treatment, and combinations thereof. Preferably, the plant-based raw material is treated to dissolve hemicellulose. In one embodiment, the lignocellulosic material is formed or treated by the following hydrolysis, such as acid hydrolysis, autohydrolysis, thermal hydrolysis, enzyme hydrolysis, supercritical hydrolysis, and / or subcritical hydrolysis, wherein at least a portion of the lignin is separated from the raw material with the hydrolysis. In one embodiment, lignocellulose is formed or treated by steam explosion, wherein hemicellulose is treated, wherein the polysaccharides of at least a portion of the hemicellulose are degraded into monosaccharides and oligosaccharides. In one embodiment, lignocellulose material is formed or treated in one or more steps by hydrolysis and steam explosion. In one embodiment, lignocellulose material is formed or treated by catalytic pretreatment (e.g., using acid or alkali as catalyst). In the pretreatment process, plant-based raw materials enter the reactor device for pretreatment. Lignocellulose material can be treated by one or more treatments. Treated lignocellulose material can be blown to the discharge tank subsequently. In addition, lignocellulose material can preferably be dehydrated, for example, using a dehydration press to carry out in two stages. Dehydration makes it possible to separate sugar-based streams. In one embodiment, lignocellulose material is composed of fine solid particles. Utilizing fine particle size, high yield and low degradation can be achieved in this method. Preferably, fine solid particles are fibrous particles less than 0.2mm or particles that are difficult to define, or they are particles that are small enough to pass through a Bauer McNett 200 mesh sieve. For example, the particle size of lignocellulosic materials can be measured with optical measuring devices (e.g. Metso FS5) or laser diffraction methods (e.g. Coulter LS230). The particle size values ​​are method dependent, so the values ​​obtained by Metso FS5 and Coulter LS230 are not directly comparable. The particle size of solid particles can be defined based on ISO 16065-N or TAPPI T271. The pretreatment process reduces the particle size and fiber length of the original wood fibers, which can be defined by separating the fibers by boiling the wood in, for example, the sulfuric acid process or impregnation. The sulfuric acid process produces a fiber length that is about 80% of the fiber length after impregnation.

[0031] In one embodiment, after pretreatment, the dry matter content of the lignocellulosic material is 20-80% by weight. The dry matter content is determined by evaporation at 45°C. When the dry matter content is determined at a temperature of 45°C, small molecule organic compounds remain in the material during the drying process of the determination. In one embodiment, the determination of the dry matter content can be performed based on (at least in part or as applied) the laboratory analytical method for standard biomass analysis determined by NREL (National Renewable Energy Laboratory) in Technical Report NREL / TR-510-48087 (Revised in July 2011). In one embodiment, the lignocellulosic material is diluted with a liquid (preferably water) or steam to form a lignocellulosic material fed to the separation stage. In one embodiment, the feed concentration of the lignocellulosic material fed to the solid-liquid separation stage is 2-60% by weight, preferably 5-30% by weight, and more preferably 10-20% by weight. If the feed concentration of the lignocellulosic material is low, the size of the device increases. Preferably, the washing filtrate and / or the fraction containing soluble carbohydrates recycled to the lignocellulosic material are used in the dilution of the lignocellulosic material.

[0032] In one embodiment, the lignocellulosic material is fed to the solid-liquid separation stage using a pump (eg, a single pump or a plunger pump or other suitable pump). The selection of the pump is based on, for example, the feed concentration and / or viscosity of the lignocellulosic material.

[0033] The solid-liquid separation stage may include one or more separation steps. In one embodiment, the solid-liquid separation is performed in one or more separation steps in one separation stage. In one embodiment, the solid-liquid separation stage includes more than one sequential separation steps. In one embodiment, the solid-liquid separation stage includes different processes, which may be performed in separate separation steps. Alternatively, more than one process is performed in one method step.

[0034] In one embodiment, the separation of the fraction containing soluble carbohydrates and the wash filtrate is performed in the same separation step. In one embodiment, the separation of the fraction containing soluble carbohydrates and the wash filtrate is performed in separate separation steps. In one embodiment, the fraction containing soluble carbohydrates is separated in one step. In one embodiment, the fraction containing soluble carbohydrates may be separated in the first step of a two-step method or a multi-step method. In one embodiment, the fraction containing soluble carbohydrates may be separated in the last step of a two-step method or a multi-step method. In one embodiment, the fraction containing soluble carbohydrates may be separated between the first step and the last step. Alternatively, the fraction containing soluble carbohydrates may be separated in more than one step. In one embodiment, a portion of the soluble carbohydrates or a portion of the fraction containing soluble carbohydrates may be separated as part of the pretreatment process for forming and / or treating the lignocellulosic material. In one embodiment, the wash filtrate is separated in one step. In one embodiment, the wash filtrate is separated in more than one step. In one embodiment, the fraction containing soluble carbohydrates and / or the wash filtrate are separated in respective separation steps.

[0035] In one embodiment, the washing filtrate is not separated from the lignocellulosic material (3). Thus, only the soluble carbohydrates containing fraction (10) is separated from the lignocellulosic material (3). In one embodiment, no washing step is performed and no washing filtrate is formed. Thus, only the soluble carbohydrates containing fraction (10) is separated from the lignocellulosic material (3).

[0036] In one embodiment, the method comprises more than one separation stage. In one embodiment, the method comprises more than one sequential separation stage.

[0037] In one embodiment, the apparatus comprises more than one separation device. In one embodiment, the solid-liquid separation stage comprises at least one separation device. In one embodiment, the solid-liquid separation stage comprises more than one separation device. In one embodiment, one or more separation steps may be performed in the same separation device. In one embodiment, the separation device comprises one or more separation steps, such as a separation section.

[0038] In one embodiment, the separator is based on convection washing. In one embodiment, the separator is selected from the group consisting of a filter, a centrifugal device, and a combination thereof. In one embodiment, the separator is selected from the group consisting of a filter press, a vacuum filter, a filter based on negative pressure, a filter based on overpressure, a filter press, other suitable presses, a centrifugal device, and a combination thereof. In one embodiment, the separator is a filter press, a vacuum filter, a filter based on negative pressure, or a filter based on overpressure. Alternatively, the separator can be another washing device that uses a small amount of wash water and washes at a high dry matter content. This allows for good recovery.

[0039] Preferably, the solid-liquid separation stage comprises separating the fraction containing soluble carbohydrates and / or the washing filtrate from the lignocellulosic material. In one embodiment, the fraction containing soluble carbohydrates and / or the washing filtrate from the lignocellulosic material is separated by filtration, centrifugation or a combination thereof. In one embodiment, the filtration is performed by pressurization, negative pressure or overpressure.

[0040] In one embodiment, the solid-liquid separation stage includes filtration, wherein the fraction containing soluble carbohydrates is separated in liquid form to form solid cakes. Preferably, pressure is applied during filtration. In one embodiment, the liquid is separated by pressure difference (e.g., using vacuum or overpressure). In one embodiment, the solid-liquid separation stage includes washing, wherein a small amount of clean water is used to carry out displacement washing of lignocellulosic material to remove most of the sugars, inhibitors and other soluble compounds in the solid lignocellulosic material to provide high recovery of soluble compounds. Preferably, the ratio of washing water to solid is less than 6, preferably less than 3, more preferably less than 1.5. In one embodiment, the solid-liquid separation stage includes filtration and washing. In one embodiment, filtration and washing are carried out in a static chamber (preferably a non-mobile chamber). In one embodiment, filtration and washing are carried out in a device under pressure without mixing between filtration and washing. Preferably, the separation device including filtration and washing is in a vertical or horizontal plane, not in an inclined plane. High concentration and recovery of soluble materials in the liquid phase can be achieved with a small amount of clean water, and solid fractions without soluble compounds can be achieved.

[0041] In one embodiment, the separation stage comprises extraction, liquid separation and washing.

[0042] In one embodiment, the fraction containing soluble carbohydrates and / or the washing filtrate are separated from the lignocellulosic material by filter pressing. In one embodiment, the apparatus comprises at least one filter press as a solid-liquid separation device. In one embodiment, the solid-liquid separation stage comprises one filter press. In one embodiment, the solid-liquid separation stage comprises more than one filter press. In a preferred embodiment, the washing in the filter press is based on liquid displacement. In one embodiment, the filter press comprises a suction step, extrusion, a washing step, extrusion and de-cake. In the suction step, a solid cake is formed and extruded. Preferably, in the suction step, the chamber of the filter press is filled and pre-extruded. In one embodiment, air purge is performed after the suction step or after the first extrusion step to further remove liquid from the cake. Preferably, the fraction containing soluble carbohydrates is separated with the suction step. In the washing step, wash water is pressed through the cake, the cake is extruded, and preferably the cake is dehydrated. In the washing step, the liquid of the cake can be replaced by water. In one embodiment, air purge is performed in the washing step to further remove liquid from the cake. The washing filtrate is separated by squeezing along with the washing step. The dehydrated solid cake is removed from the filter press. Preferably, the dehydrated solid cake forms a solid fraction. An advantage of filter pressing is that all separation steps can be performed with one device.

[0043] In different separation stages, separation can be performed using similar or different separation methods or separation devices.

[0044] In one embodiment, the amount of wash filtrate is optimized by adjusting the ratio of wash water. In one embodiment, the ratio of wash water to solid composition in the wash is 1:1-6:1, preferably 1:1-5:1, more preferably 1:1-4:1, most preferably 1:1-3:1. Preferably, the balance of water is optimized in the process of the present invention.

[0045] In one embodiment, at least a portion of the wash filtrate and / or the fraction containing soluble carbohydrates is recycled to the lignocellulosic material before the separation stage. In one embodiment, at least a portion of the wash filtrate and / or the fraction containing soluble carbohydrates is recycled to the lignocellulosic material before the separation step of the desired separation stage, such as before the first separation step or between two separation steps. In one embodiment, at least a portion of the wash filtrate and / or the fraction containing soluble carbohydrates is recycled back to the lignocellulosic material fed to the same separation stage. In one embodiment, at least a portion of the wash filtrate and / or the fraction containing soluble carbohydrates is recycled to the lignocellulosic material fed to the next separation stage or to the next separation step of the separation stage. In one embodiment, at least a portion of the wash filtrate and / or the fraction containing soluble carbohydrates is recycled by being supplied to a discharge tank, to the inlet side of a solid-liquid separation device, to the inlet side of a feeding device, or to the first step of a solid-liquid separation device, such as to the first step of a filter press device. In one embodiment, at least a portion of the wash filtrate and / or the fraction containing soluble carbohydrates is recycled back to the desired separation step of the separation device, such as a separation section. In one embodiment, at least a portion of the wash filtrate and / or the fraction containing soluble carbohydrates is recycled back to the previous separation step of the separation device, such as a separation section. In one embodiment, at least a portion of the wash filtrate and / or the fraction containing soluble carbohydrates is recycled back to the previous separation step of each separation step in the separation device, such as a separation section. In one embodiment, at least a portion of the wash filtrate and / or the fraction containing soluble carbohydrates is recycled continuously. In one embodiment, at least a portion of the wash filtrate and / or the fraction containing soluble carbohydrates is recycled in each separation step of the separation stage or in each separation stage. The amount of wash water used can be reduced by recycling.

[0046] In one embodiment, the wash filtrate is recycled (preferably all recycled) to the lignocellulosic material. In one embodiment, 80-100% by weight of the wash filtrate is recycled to the lignocellulosic material. In one embodiment, the wash filtrate contains wash water and carbohydrates, such as galactose, glucose, mannose, arabinose, xylose, glucuronic acid and galacturonic acid. In addition, the wash filtrate may contain soluble lignin.

[0047] In one embodiment, at least a portion of the soluble carbohydrate-containing fraction is recycled to the lignocellulosic material. In one embodiment less than 80% by weight, in one embodiment less than 50% by weight, in one embodiment less than 30% by weight, in one embodiment less than 20% by weight of the soluble carbohydrate-containing fraction (based on the total liquid containing soluble carbohydrates and other compounds) is recycled to the lignocellulosic material.

[0048] In one embodiment, in a single-step process, the recycling rate of the soluble carbohydrate-containing fraction without wash filtrate can be 0-95%, more preferably 60-90%. When the wash filtrate is also used as dilution water, the recycling rate of the soluble carbohydrate-containing fraction in a single-step process can be 0-90%, more preferably 35-80%.

[0049] In one embodiment, at least a portion of the soluble carbohydrate containing fraction is recycled to the lignocellulosic material. In one embodiment, the wash filtrate is recycled to the lignocellulosic material. In one embodiment, a mixture of the wash filtrate and the soluble carbohydrate containing fraction is recycled to the lignocellulosic material. In one embodiment, the wash filtrate and the soluble carbohydrate containing fraction are mixed to form a mixture, which mixture is recycled to the lignocellulosic material.

[0050] Preferably, the feed concentration of lignocellulosic material is optimized by the recycle composition.

[0051] In one embodiment, the sugar concentration of the fraction containing soluble carbohydrates is optimized. Preferably, the fraction containing soluble carbohydrates contains soluble C5 carbohydrates. The total carbohydrate content can be measured by HPLC after acid hydrolysis according to standard SCAN-CM 71:09. The monomer carbohydrate content can be directly measured by HPLC from the liquid fraction without acid hydrolysis. The fraction containing soluble carbohydrates may also contain C6 carbohydrates, preferably less than 20% by weight. Preferably, the fraction containing soluble carbohydrates may contain other monosaccharides, disaccharides, oligosaccharides and / or polysaccharides. In one embodiment, the fraction containing soluble carbohydrates contains galactose, glucose, mannose, arabinose, xylose, glucuronic acid and galacturonic acid. In one embodiment, the fraction containing soluble carbohydrates contains soluble C5 carbohydrates, such as C5H 10 O5 or C5(H2O) n, as well as other carbohydrates and some other compounds. In one embodiment, after solid-liquid separation, the concentration of soluble carbohydrates in the fraction containing soluble carbohydrates is higher than 50g / l, preferably higher than 70g / l, and more preferably higher than 100g / l. In one embodiment, after solid-liquid separation, the concentration of soluble carbohydrates in the fraction containing soluble carbohydrates is lower than 250g / l, in one embodiment lower than 200g / l, and in one embodiment lower than 150g / l. In one embodiment, after solid-liquid separation, the concentration of soluble carbohydrates in the fraction containing soluble carbohydrates is 15-280g / l, preferably 30-200g / l, and more preferably 50-165g / l. Preferably, the fraction containing soluble carbohydrates is in the form of a solution. In one embodiment, after solid-liquid separation, the water-soluble substance is 20-425g / l, preferably 45-303g / l, and more preferably 75-250g / l. The water-soluble matter can be determined by the method described below under "gravimetric washing method".

[0052] Preferably, at least a portion of the soluble carbohydrates containing fraction is supplied from the separation stage. The soluble carbohydrates containing fraction may be supplied after any desired step of the separation stage. In one embodiment, the soluble carbohydrates containing fraction is supplied after the first step of the separation stage.

[0053] In one embodiment, a high concentration of soluble carbohydrates-containing fraction (10) may be formed. The soluble carbohydrates-containing fraction is formed from a lignocellulosic material (3) that has been formed by processing a plant-based feedstock (1), wherein the soluble carbohydrates-containing fraction has been formed by separating the soluble carbohydrates-containing fraction (10) and / or a wash filtrate (12) from the solid lignocellulosic material (3) in one or more separation stages (4, 6), and at least a portion of the soluble carbohydrates-containing fraction and / or the wash filtrate is recycled to the lignocellulosic material to increase the concentration of the soluble carbohydrates-containing fraction. The soluble carbohydrates-containing fraction may be used as a component in the manufacture of a final product.

[0054] In one embodiment, a portion of the soluble carbohydrate-containing fraction (14) is separated from the lignocellulosic material (3) following the pretreatment step (2, 5) of forming and / or treating the lignocellulosic material. The soluble carbohydrate-containing fraction (14) may be separated by a similar separation method or apparatus as used in the separation stage (4, 6) or by other suitable separation methods or apparatus.

[0055] In one embodiment, two highly concentrated soluble carbohydrate-containing fractions (10, 14) can be formed with a high recovery of soluble compounds. The two soluble carbohydrate-containing fractions are formed in two or more steps from a lignocellulosic material (3) formed by processing a plant-based feedstock (1). The first soluble carbohydrate-containing fraction (14) is formed by separating a portion of the soluble compounds between the first and last pretreatment steps (2, 5), and the second soluble carbohydrate-containing fraction (10) is formed by separating a majority of the soluble compounds after the last pretreatment step. Preferably, the second soluble carbohydrate-containing fraction (10) is separated in a separation stage (4) such that the soluble carbohydrate-containing fraction and / or the washing filtrate are separated from the solid lignocellulosic material and at least a portion of the soluble carbohydrate-containing fraction and / or the washing filtrate is recycled to the lignocellulosic material to increase the concentration of the soluble carbohydrate-containing fraction. The soluble carbohydrate containing fractions (14) and (10) can be combined or used separately as components in the preparation of the final product. The combined or separate soluble carbohydrate containing fractions can be concentrated for further use.

[0056] In one embodiment, two high concentration soluble carbohydrate-containing fractions (10, 14) can be formed with high soluble compound recovery. The two soluble carbohydrate-containing fractions are formed in two or more steps from a lignocellulosic material (3) formed by processing a plant-based feedstock (1). The first soluble carbohydrate-containing fraction (14) is formed so that the liquid-to-solid ratio (w / w) of the lignocellulosic material is less than 5:1, preferably less than 4:1, more preferably less than 3:1, and most preferably less than 2:1 before separating a portion of the soluble compounds between the first and last pretreatment steps (2, 5). The second soluble carbohydrate-containing fraction (10) is formed by separating most of the soluble compounds after the last pretreatment step. Preferably, the second soluble carbohydrates containing fraction (10) is separated in the separation stage (4) such that the soluble carbohydrates containing fraction and / or the wash filtrate are separated from the solid lignocellulosic material and at least a portion of the soluble carbohydrates containing fraction and / or the wash filtrate is recycled to the lignocellulosic material to increase the concentration of the soluble carbohydrates containing fraction. The amount of fresh wash water is less than 4:1 (liquid:solid (w / w)), preferably less than 3:1, more preferably less than 2:1, most preferably close to 1:1. The efficiency of removing the soluble carbohydrates containing fraction from the solids must be very high and must be higher than 60%, preferably higher than 70%, more preferably higher than 80%, most preferably higher than 90%. The soluble carbohydrates containing fractions (10) and (14) can be combined or used separately as components in the preparation of a final product. The combined or separate soluble carbohydrate containing fractions can be concentrated for further use.

[0057] In one embodiment, a high concentration of soluble carbohydrate-containing fraction (10) can be formed with high recovery of soluble compounds. The soluble carbohydrate-containing fraction is formed in one or more steps from a lignocellulosic material (3) formed by processing a plant-based feedstock (1). The soluble carbohydrate-containing fraction is formed by separating most of the soluble compounds after the last pretreatment step (2, 5), thereby separating the soluble carbohydrate-containing fraction and / or washing filtrate from the solid lignocellulosic material, and at least a portion of the soluble carbohydrate-containing fraction and / or washing filtrate is recycled to the lignocellulosic material to increase the concentration of the soluble carbohydrate-containing fraction. The soluble carbohydrate-containing fraction can be used as a component in the manufacture of a final product. The soluble carbohydrate-containing fraction can be concentrated for further use.

[0058] In one embodiment, a highly concentrated soluble carbohydrate-containing fraction (10) can be formed with a high recovery of soluble compounds. The soluble carbohydrate-containing fraction is formed in one or more steps from a lignocellulosic material (3) formed by processing a plant-based feedstock (1). The soluble carbohydrate-containing fraction is formed by separating most of the soluble compounds after the last pretreatment step (2, 5), whereby the soluble carbohydrate-containing fraction and / or wash filtrate are separated from the solid lignocellulosic material, and at least a portion of the soluble carbohydrate-containing fraction and / or wash filtrate is recycled to the lignocellulosic material to increase the concentration of the soluble carbohydrate-containing fraction. The amount of fresh wash water is less than 4:1 (liquid:solid (w / w)), preferably less than 3:1, more preferably less than 2:1, and most preferably close to 1:1. The efficiency of removing the soluble carbohydrate-containing fraction from the solid must be very high, and must be higher than 70%, preferably higher than 80%, more preferably higher than 90%, and most preferably higher than 95%. The fraction containing soluble carbohydrates can be used as a component in the manufacture of a final product. The fraction containing soluble carbohydrates can be concentrated for further use.

[0059] In one embodiment, the fraction containing soluble carbohydrates is recovered. In one embodiment, the fraction containing soluble carbohydrates is supplied to further processing. In one embodiment, before further processing, the fraction containing soluble carbohydrates is monomerized. In one embodiment, the fraction containing soluble carbohydrates is supplied to the fermentation process. In one embodiment, the fraction containing soluble carbohydrates is used as a raw material in fermentation. In one embodiment, the fraction containing soluble carbohydrates is supplied to the hydrolysis process. In one embodiment, the fraction containing soluble carbohydrates is used as a raw material in hydrolysis, and the hydrolysis is, for example, acid hydrolysis, enzyme hydrolysis, etc. In one embodiment, the fraction containing soluble carbohydrates is supplied to the catalytic treatment process. In one embodiment, the fraction containing soluble carbohydrates is used as a raw material in the catalytic process. The fraction containing soluble carbohydrates can be directly supplied to the fermentation, hydrolysis, catalytic treatment process or other suitable process, or supplied to the fermentation, hydrolysis, catalytic treatment process or other suitable process through a suitable treatment step or additional step (such as an additional concentration step or purification step).

[0060] In one embodiment, at least a portion of the wash filtrate is supplied to another process or process step. In one embodiment, the wash filtrate is used as dilution water for other processes (e.g., in a pretreatment process). In one embodiment, the wash filtrate is used as wash water for other processes.

[0061] Solids (11) are supplied from the solid-liquid separation stage (4, 6). In one embodiment, a solid fraction comprising solids is supplied from the solid-liquid separation stage. In one embodiment, the solid fraction (11) comprising solids is formed from a lignocellulosic material (3) which has been formed by processing a plant-based feedstock (1), such that the solid fraction is formed by separating a soluble carbohydrate-containing fraction (10) and / or a washing filtrate (12) from the solid lignocellulosic material by at least one solid-liquid separation stage (4, 6), at least a portion of the soluble carbohydrate-containing fraction and / or the washing filtrate being recycled to the lignocellulosic material (3), and the solids (11) are recovered from the separation stage. In one embodiment, the solids comprise C6 carbohydrates, for example (C6H 12 O6 or (C6(H2O) n), other solid carbohydrates and lignin, and some other compounds, such as some residual soluble materials. In one embodiment, the solid fraction is in the form of a cake. In one embodiment, after the solid-liquid separation stage, the dry matter content of the cake is 40-80% by weight, preferably 45-70% by weight, and more preferably 50-60% by weight. In one embodiment, after the solid-liquid separation stage, the dry matter content of the cake is 7-70% by weight, preferably 15-45% by weight, and more preferably 25-35% by weight. In one embodiment, after the solid-liquid separation stage, the solid fraction contains less than 15% by weight, preferably less than 6% by weight, and more preferably less than 3% by weight of soluble compounds. In one embodiment, the water-soluble matter is determined by a gravity washing method. The determination by the gravity washing method can be carried out as follows: the dry matter content (DM%) of the raw material (e.g., solid and soluble fraction) is measured at 60°C, the amount of solids remaining after heating the sample to constant weight at 60°C is measured, and the dry matter content is calculated based on the wet weight and the dry weight. In the test, about 10 grams of the whole dry material was washed with the following wet materials, weighed (accurately weighed amount), mixed with hot water (50°C) in a container to a total of 200 g, the mixture was mixed for 20 seconds (Bamix Mono freehand food blender, 'C' blade, speed 1 (7000 rpm)), the mixture was soaked for 5 minutes, and the mixture was mixed for 10 seconds (Bamix Mono freehand food blender, 'C' blade, speed 1 (7000 rpm)). Mono hand food blender, C' blade, speed 1 (7000 rpm), measure the mass of dry filter paper, filter the mixture through a Büchner (diameter 125 mm) and filter paper, when the cake is completely matte (dry), close the inward pressure relief valve, extract the filtrate, wash the blender and container with the filtrate, filter the filtrate through the cake again, wash the cake three times with hot water (100 g), thus maintaining the suction effect at all times, when the cake is completely matte (dry), add washing water (100 g), weigh the foil pan, dry the cake with filter paper in the foil pan, weigh the dried cake with filter paper in the foil pan (60°C), subtract the mass of filter paper and foil pan from the mass of dried cake, filter paper and foil pan, and the solids without soluble matter in the wet material under test, i.e. water-insoluble solids (WIS), can be determined. The water-insoluble solids, WIS%, can be calculated as follows: WIS% = (weight of washed and dried material (e.g., cake)) / (weight of wet slurry (e.g., feedstock) used for washing). The water-soluble matter of dry matter, WS%, can be calculated as follows: WS% = (dry matter (DM%) of initial slurry (e.g., feedstock)) - (water-insoluble solids, WIS%).In one embodiment, the feedstock has a high soluble material content (25-50% of total soluble dry matter), and after the solid-liquid separation stage, the solid fraction contains less than 15% by weight, preferably less than 9% by weight, more preferably less than 5% by weight of soluble compounds, as determined by gravity washing method. In one embodiment, the feedstock has a lower soluble material content (less than 25% of total soluble dry matter), and after the solid-liquid separation stage, the solid fraction contains less than 9% by weight, preferably less than 6% by weight, more preferably less than 3% by weight of soluble compounds, as determined by gravity washing method.

[0062] For example, the particle size of the solid particles can be measured using an optical measuring device (e.g., Metso FS5) or a laser diffraction method (e.g., Coulter LS230). In one embodiment, the particle size of the solid particles can be defined based on ISO 16065-N or TAPPI T271. When the fiber is defined as a material with a length exceeding 0.2 mm, the fiber length of the solid particles can be defined based on ISO 16065-N. When the fiber length is 0.01-7.60 mm, the fiber length of the solid particles can be defined based on TAPPI T271. With respect to Metso FS5, Lc represents the straight length, i.e., the fiber centerline length, which is the fiber length measured from one end of the fiber centerline to the other end. The length-weighted Lc(l) represents the length-weighted fiber length, which is the average fiber length measured by the fiber distribution weighted according to the TAPPI T271 standard. Weight-weighted Lc(w) represents the weight-weighted fiber length, which is also the average fiber length measured from a fiber distribution weighted according to TAPPI T271 standard. Arithmetic Lc(n) represents the arithmetic mean calculated from a population distribution of fibers. In this result, the average length is calculated from the length distribution. F1(l)% represents the length-weighted distribution % (width > 10 μm, length < 0.2 mm). The fiber width is measured as the integrated value from the middle of the fiber to the tapered end.

[0063] In one embodiment, the length-weighted particle length Lc(l) is lower than [(0.4)x(corresponding unrefined kraft pulp fiber length)], preferably lower than [(0.3)x(corresponding unrefined kraft pulp fiber length)], more preferably lower than [(0.2)x(corresponding unrefined kraft pulp fiber length)], and most preferably lower than [(0.1)x(corresponding unrefined kraft pulp fiber length)].

[0064] In one embodiment, the fine particle width (fraction 0-0.2 mm) is lower than [(0.7)x(corresponding unrefined kraft pulp fiber length)], preferably lower than [(0.6)x(corresponding unrefined kraft pulp fiber length)], more preferably lower than [(0.5)x(corresponding unrefined kraft pulp fiber length)], and most preferably lower than [(0.4)x(corresponding unrefined kraft pulp fiber length)].

[0065] In one embodiment, the solid fraction comprises fine solid particles, which are fibrous or poorly defined particles having a longest dimension shorter than 0.2 mm according to the optical Metso FS5 (length-weighted Lc(l) measurement and calculated fraction F1(l)). In one embodiment, the solid fraction of hardwood comprises more than 70 wt.-% (Fl(l)>70%), preferably more than 80 wt.-%, more preferably more than 90 wt.-%, most preferably more than 98 wt.-% of particles having a longest dimension less than 0.2 mm (according to Metso FS5 definition). In one embodiment, the solid fraction of softwood comprises more than 50 wt.-% (Fl(l)>50%), preferably more than 60 wt.-%, more preferably more than 70 wt.-%, most preferably more than 80 wt.-% of particles having a longest dimension less than 0.2 mm (according to Metso FS5 definition).

[0066] In one embodiment, the solid fraction contains fine solid particles that are fibrous or difficult to define particles. The length weighted length Lc(l) of the solid fraction measured based on the TAPPI T271 standard includes all particles detected and meeting the measurement requirements. The fiber length of TAPPI T271 defines the material as having a longest dimension of 0.01-7.60 mm.

[0067] In one embodiment, the solid fraction contains fine solid particles, which are fibrous or difficult to define particles. The length-weighted length Lc(l) of the solid fraction is measured by Metso FS5. The length-weighted Lc(l) value is equal to or less than 40% of the length of the corresponding unrefined kraft pulp fiber, preferably equal to or less than 30%, more preferably equal to or less than 20%, and most preferably equal to or less than 10%. And, the width of the fine particle fraction of the length-weighted particles (Lc(l) fraction 0–0.2 mm) is equal to or less than 70% of the width of the corresponding kraft pulp fiber, preferably equal to or less than 60%, more preferably equal to or less than 50%, and most preferably equal to or less than 40%.

[0068] In one embodiment, the solid fraction of hardwood contains fine solid particles, which are fibrous or poorly defined particles. The length weighted length Lc(l) of the solid fraction is measured by Metso FS5. The length weighted Lc(l) fraction of fibers longer than 0.2 mm is equal to or less than 50%, preferably equal to or less than 35%, more preferably equal to or less than 20%, most preferably equal to or less than 5%.

[0069] In one embodiment, the solid fraction of cork contains fine solid particles, which are fibrous or poorly defined particles. The length weighted length Lc(l) of the solid fraction is measured by Metso FS5. The length weighted Lc(l) fraction over 0.2 mm fiber length is equal to or less than 60%, preferably equal to or less than 45%, more preferably equal to or less than 30%, most preferably equal to or less than 15%.

[0070] In one embodiment, the solid fraction (11) comprising solids is supplied from the solid-liquid separation stage (4, 6). In one embodiment, the solid fraction is supplied after the last solid-liquid separation stage. In one embodiment, at least a portion of the solid fraction is supplied between two separation stages or between two separation steps.

[0071] In one embodiment, the solid fraction is supplied to hydrolysis (which may be selected from the group consisting of acid hydrolysis, enzyme hydrolysis, supercritical hydrolysis and / or subcritical hydrolysis and combinations thereof) or composite material preparation or combustion treatment or other suitable treatment or combinations thereof. The solid fraction may be directly supplied to hydrolysis, composite material preparation, combustion treatment or other suitable treatment, or the solid fraction may be supplied to hydrolysis, composite material preparation, combustion treatment or other suitable treatment through suitable treatment steps or additional steps (e.g., additional concentration steps or purification steps).

[0072] The method according to the invention provides a fraction containing soluble carbohydrates and a solid fraction with high concentration and good quality. The solid fraction has extremely high concentrations of lignin and glucan and their hydrolysates. In addition, the solid fraction has extremely high purity. In the present invention, the balance of water can be optimized. Thus, the content of soluble carbohydrates in the fraction containing soluble carbohydrates can be increased. The present invention shows improved sugar recovery. In addition, the present invention minimizes wastewater and reduces the post-processing costs of the fraction containing soluble carbohydrates. High concentrations are achieved with low energy consumption.

[0073] The present invention provides an industrially applicable, simple and affordable method for preparing a fraction containing soluble carbohydrates having a high concentration. The method according to the present invention is an easy to implement and simple production method. The method according to the present invention is suitable for preparing different saccharide fractions and final products from different raw materials. Example

[0074] The present invention is described in more detail by the following examples with reference to the accompanying drawings.

[0075] Example 1

[0076] In this embodiment, according to Figure 1 The method produces a fraction containing soluble carbohydrates.

[0077] A lignocellulosic material (3) is formed from a plant-based raw material (1) by pretreatment (2). The lignocellulosic material (3) is fed into a solid-liquid separation stage (4) comprising a filter press. In the suction and squeezing steps of the filter press, a soluble carbohydrate-containing fraction (10) comprising C5 sugars is separated from the lignocellulosic material. In the washing step of the filter press, a wash filtrate (12) is separated from the lignocellulosic material (3). Prior to the filter press, the wash filtrate (12) and at least a portion of the soluble carbohydrate-containing fraction (10) are recycled to the lignocellulosic material. A solid cake (11) containing, for example, solids, solid carbohydrates, lignin and some soluble sugar, oligomer and polymer residues is removed from the filter press.

[0078] Example 2

[0079] In this embodiment, according to Figure 2 The method produces a fraction containing soluble carbohydrates.

[0080] A lignocellulosic material (3) is formed from a plant-based raw material (1) by pretreatment (2). The lignocellulosic material (3) is fed into a solid-liquid separation stage (4) comprising a filter press. In the suction and squeezing steps of the filter press, a soluble carbohydrate-containing fraction (10) comprising C5 sugars is separated from the lignocellulosic material. In the washing step of the filter press, a wash filtrate (12) is separated from the lignocellulosic material (3). The wash filtrate (12) is recycled to the lignocellulosic material before the filter press. A soluble carbohydrate-containing fraction (10) comprising C5 sugars is removed from the filter press. A solid cake (11) containing, for example, solids, solid carbohydrates, lignin and some soluble sugars, oligomers and polymer residues is removed from the filter press.

[0081] Example 3

[0082] In this embodiment, according to Figure 3 The method produces a fraction containing soluble carbohydrates.

[0083] A lignocellulosic material (3) is formed from a plant-based raw material (1) by pretreatment (2). The lignocellulosic material (3) is fed into a solid-liquid separation stage (4) comprising a filter press. In the suction and squeezing steps of the filter press, a soluble carbohydrate-containing fraction (10) comprising C5 sugars is separated from the lignocellulosic material. In the washing step of the filter press, a wash filtrate (12) is separated from the lignocellulosic material. The wash filtrate (12) can be recycled to the pretreatment (2) of the lignocellulosic material. Alternatively, the wash filtrate (12) is removed from the filter press and recycled to other processes. Prior to the filter press, at least a portion of the soluble carbohydrate-containing fraction (10) is recycled to the lignocellulosic material. A solid cake (11) containing, for example, solids, solid carbohydrates, lignin and some soluble sugars, oligomers and polymer residues is removed from the filter press.

[0084] Example 4

[0085] In this embodiment, according to Figure 4 The method produces a fraction containing soluble carbohydrates.

[0086] A lignocellulosic material (3) is formed from a plant-based raw material (1) by pretreatment (2). The lignocellulosic material (3) is fed into a solid-liquid separation stage (4) comprising a filtering device. In the filtration, a soluble carbohydrate-containing fraction (10) comprising C5 sugars is separated from the lignocellulosic material. Before the filtering device, at least a portion of the soluble carbohydrate-containing fraction (10) is recycled to the lignocellulosic material. A solid cake (11) containing, for example, solids, solid carbohydrates, lignin and some soluble sugar, oligomer and polymer residues is removed from the filtering device.

[0087] Example 5

[0088] In this embodiment, according to Figure 5 A two-step process is used to produce a fraction containing soluble carbohydrates.

[0089] A lignocellulosic material (3) is formed from a plant-based raw material (1) by pretreatment (2) such as grinding. The lignocellulosic material (3) is fed into a first solid-liquid separation stage (4) comprising a filter press. In the suction and squeezing steps of the filter press, a soluble carbohydrate-containing fraction (10) comprising C5 sugars is separated from the lignocellulosic material. In the washing step of the filter press, a wash filtrate (12) is separated from the lignocellulosic material (3). The wash filtrate (12) and at least a portion of the soluble carbohydrate-containing fraction (10) are recycled to the lignocellulosic material before the first filter press. A portion of the soluble carbohydrate-containing fraction (10) can be removed from the process before the second separation step.

[0090] In a second step, the lignocellulosic material (3) is treated by a treatment stage (5), which is, for example, a physical, chemical or physicochemical treatment, such as a microwave or ultrasonic treatment, or a steam explosion. The lignocellulosic material is fed into a second solid-liquid separation stage (6) comprising a filter press. In the suction and squeezing steps of the filter press, a soluble carbohydrate-containing fraction (10) comprising C5 sugars is separated from the lignocellulosic material. In the washing step of the filter press, the wash filtrate (12) is separated from the lignocellulosic material. Before the first and / or second filter press, the wash filtrate (12) and at least a portion of the soluble carbohydrate-containing fraction (10) are recycled to the lignocellulosic material. At least a portion of the soluble carbohydrate-containing fraction (10) is removed from the process.

[0091] A solid cake (11) containing, for example, solids, solid carbohydrates, lignin and some soluble sugars, oligomers and polymer residues is removed from the filter press.

[0092] Example 6

[0093] In this embodiment, according to Figure 6 A two-step process is used to produce a fraction containing soluble carbohydrates.

[0094] A lignocellulosic material (3) is formed from a plant-based raw material (1) by pretreatment (2) such as grinding. The lignocellulosic material (3) is fed into a first solid-liquid separation stage (4) comprising a filter press. In the suction and squeezing steps of the filter press, a soluble carbohydrate-containing fraction (10) comprising C5 sugars is separated from the lignocellulosic material. In the washing step of the filter press, a wash filtrate (12) is separated from the lignocellulosic material (3). Prior to the second separation device, the wash filtrate (12) and at least a portion of the soluble carbohydrate-containing fraction (10) are recycled to the lignocellulosic material. A portion of the soluble carbohydrate-containing fraction (10) can be removed from the process prior to the second separation step.

[0095] In a second step, the lignocellulosic material (3) is treated by a treatment stage (5), which is, for example, a physical, chemical or physicochemical treatment, such as a microwave or ultrasound treatment, or a steam explosion. The lignocellulosic material is fed into a second solid-liquid separation stage (6) comprising a filter press. In the suction and squeezing steps of the filter press, a soluble carbohydrate-containing fraction (10) comprising C5 sugars is separated from the lignocellulosic material. In the washing step of the filter press, the wash filtrate (12) is separated from the lignocellulosic material. Before the second filter press, the wash filtrate (12) and at least a portion of the soluble carbohydrate-containing fraction (10) are recycled to the lignocellulosic material. At least a portion of the soluble carbohydrate-containing fraction (10) is removed from the process.

[0096] A solid cake (11) containing, for example, solids, solid carbohydrates, lignin and some soluble sugars, oligomers and polymer residues is removed from the filter press.

[0097] Example 7

[0098] In this embodiment, according to Figure 7 The method produces a fraction containing soluble carbohydrates.

[0099] A lignocellulosic material (3) is formed from a plant-based raw material (1) by a first pretreatment (2) (e.g. hydrolysis). After this pretreatment, a portion of the soluble carbohydrates (14) are separated (13) following the first pretreatment step (2). The lignocellulosic material (3) is fed into a second pretreatment step (5) in which the lignocellulosic material is treated, for example, by steam explosion. The lignocellulosic material (3) is then fed into a solid-liquid separation stage (4) comprising a filter press. In the suction and squeezing steps of the filter press, a soluble carbohydrate-containing fraction (10) comprising C5 sugars is separated from the lignocellulosic material. In the washing step of the filter press, a wash filtrate (12) is separated from the lignocellulosic material (3). Prior to the filter press, the wash filtrate (12) and at least a portion of the soluble carbohydrate-containing fraction (10) are recycled to the lignocellulosic material. A solid cake (11) containing, for example, solids, solid carbohydrates, lignin and some soluble sugars, oligomers and polymer residues is removed from the filter press. At least a portion of the soluble carbohydrates-containing fraction (10, 14) is removed from the process.

[0100] Example 8

[0101] In this example, a fraction containing soluble carbohydrates was produced.

[0102] Birch sawdust was pretreated in a one-step autohydrolysis and steam explosion process to dissolve the hemicellulose. The resulting pretreated lignocellulosic material was mixed with hot water and stirred for several hours. Solid-liquid separation was then performed using an Outotec Larox FP 0.3 bidirectional filter press as described in Table 1. The filter area was 0.27 m 2 To simulate the increase in concentration, the filtrate (10) containing soluble carbohydrates from the first extrusion was used as dilution water for the next round. Similarly, after the second filtration, the filtrate containing soluble carbohydrates from the extrusion was used for dilution of the third filtration. Finally, 5 rounds of filtration were performed. The filtration conditions are shown in Table 1.

[0103] Table 1

[0104]

[0105]

[0106] Total carbohydrate content was measured according to the SCAN-CM 71 standard: using acid hydrolysis and HPLC. Figure 8 As shown in , the increase in carbohydrate content closely follows the simulated concentration curve.

[0107] The simulation in this example was performed assuming that the dissolved carbohydrate content in the pretreated lignin material was 15.7%, which was also the value measured for the lignocellulosic material in Example 8. Fig. 9 As shown, the concentration of the soluble carbohydrate-containing filtrate from the process will reach a level of 104 g / l in continued treatment.

[0108] Example 9

[0109] In this example, a fraction containing soluble carbohydrates was produced.

[0110] Birch sawdust was pretreated in a one-step autohydrolysis and steam explosion process to dissolve the hemicellulose. The resulting lignocellulosic material was mixed with hot water and stirred for several hours. Solid-liquid separation was then performed using an Outotec Larox FP 0.3 bidirectional filter press as described in Table 1. The filter area was 0.27 m 2 The amount of washing water is 2:1 (water: non-water-soluble solids).

[0111] In order to simulate the increase in concentration, all the washing filtrate (12) of the process and some of the soluble carbohydrate-containing filtrate (10) of the first extrusion are calculated to be used as dilution water for the next round. Similarly, after the second filtration, the washing filtrate and some of the soluble carbohydrate-containing filtrate of the extrusion are used for dilution of the third filtration. In this case, about 77% of the dilution liquid is the filtrate containing soluble carbohydrates. The recycled soluble carbohydrate-containing fraction is 70% of the total liquid containing soluble compounds. The washing efficiency is assumed to be 90%. Finally, more than 70 rounds are performed. The simulation in this example is carried out assuming that the dissolved carbohydrate content in the pretreated lignin material is 15.7%, which is also the value measured for the lignocellulosic material in Example 8. As Fig.10 As shown, the concentration of the soluble carbohydrate-containing filtrate from the process will reach a level of 102 g / l in continued treatment.

[0112] Example 10

[0113] In this example, liquid and solid fractions were produced.

[0114] Birch sawdust was pretreated in a two-step dilute acid steam explosion treatment to dissolve the hemicellulose and produce a fraction containing soluble carbohydrates. A portion of this fraction containing soluble carbohydrates was removed before the rapid pressure release of the lignocellulosic material in the steam explosion. The resulting lignocellulosic material was mixed with hot water and stirred for a period of time. Then, solid-liquid separation was performed using an Outotec Larox PF 0.1 filter press as described in Table 2. The filter area was 0.1 m 2 The amount of washing water was 1:1 (water: dry matter in the cake) and 3:1. The results are listed in Table 3. The water soluble matter of the dry matter was measured by the gravity washing method.

[0115] Table 2

[0116]

[0117] Table 3

[0118]

[0119] Embodiment 11

[0120] In this example, liquid and solid fractions were produced.

[0121] Birch sawdust was pretreated in a two-step dilute acid steam explosion treatment to dissolve the hemicellulose. The resulting lignocellulosic material was mixed with hot water and stirred for a period of time. Solid-liquid separation was then performed using a vacuum filter as described in Table 4 (laboratory grade vacuum filtration). The filtration area was 0.1 m 2The amount of wash water ranged from 0 to 8.6 (water: dry matter in the cake).

[0122] Table 4

[0123]

[0124] Example 12

[0125] In this example, concentrated liquid and purified solid fractions were produced based on Example 10.

[0126] Birch sawdust was pretreated in a two-step dilute acid steam explosion treatment to dissolve the hemicellulose. The resulting lignocellulosic material was mixed with hot water and stirred for a period of time. Solid-liquid separation was then performed using an Outotec Larox PF 0.1 filter press as described in Table 2. The filter area was 0.1 m 2 . The amount of washing water was 1:1 (water: non-water-soluble solids in the cake) and 3:1. The initial pretreated biomass had a dry matter of 65%, a dry matter of 16% in the first filtration, and a non-water-soluble solid content of 13%. The non-water-soluble solid content remained unchanged in the filter press, while the dry matter content of the slurry increased due to the increase in soluble material in the slurry. The dry matter content of the washed cake was about 50%. Table 5 shows the composition of the solid fraction, which was further washed in the laboratory (as in the gravity washing method) to remove all water-soluble materials. The solid fraction was washed with water to remove residual soluble compounds, and then the various properties were measured.

[0127] In order to simulate the increase in concentration, all the wash filtrate (12) of the process and some of the filtrate containing soluble carbohydrates (10) of the first extrusion were calculated to be used as dilution water for the next round, and similarly after the second filtration, the wash filtrate and some of the filtrate containing soluble carbohydrates of the extrusion were used for dilution of the third filtration. In the case of 1:1 washing, about 83% of the dilution liquid was filtrate containing soluble carbohydrates, and in the case of 3:1, 48% of the dilution liquid was filtrate containing soluble carbohydrates. The washing efficiency was calculated to be 83% (1:1) and 88% (3:1). More than 70 rounds were finally performed. The simulation of this embodiment was carried out with a measured soluble matter content of 18.4% of the pretreated lignocellulosic material. In the case of 1:1 washing, the concentration of the filtrate containing soluble matter from the method reached a level of 135 g / l in the continuous treatment, while in the case of 3:1 washing it reached 99 g / l.

[0128] Table 5

[0129]

[0130]

[0131] Example 13

[0132] In this example, a soluble carbohydrate fraction and a solid fraction are produced.

[0133] Eucalyptus sawdust was pretreated in one-step autohydrolysis and steam explosion treatments to dissolve hemicellulose under two different treatment conditions. The pretreated lignocellulosic material formed was washed with hot water in the laboratory to remove most of the water-soluble compounds. The remaining solids free of water-soluble compounds were measured with two different particle size analyzers. The results of Metso FS5 and Coulter LS230 are shown in Table 6 'Two water-insoluble solids of pretreated eucalyptus-based lignocellulosic materials'.

[0134] Table 6

[0135]

[0136]

[0137] In different embodiments it is suitable to use the method according to the invention to produce a maximum of different types of glycosyl fractions from different raw materials.

[0138] The invention is not limited solely to the embodiments described above; instead, many variations are possible within the scope of the inventive concept defined by the claims.

Claims

1. A method for increasing the concentration of a fraction (10) containing soluble carbohydrates, wherein a lignocellulosic material (3) formed by processing a plant-based raw material (1) is introduced into a separation stage (4), wherein - the process comprises at least one solid-liquid separation stage (4) for separating a fraction (10) containing soluble carbohydrates and / or a washing filtrate (12) from the lignocellulosic material (3), - recycling at least a part of the soluble carbohydrates containing fraction (10) and / or the washing filtrate (12) to the lignocellulosic material (3) for increasing the concentration of the soluble carbohydrates containing fraction, - Solids (11) and at least a portion of the soluble carbohydrate-containing fraction (10) are discharged from the separation stage.

2. The method according to claim 1, characterized in that The soluble carbohydrate containing fraction (10) and / or the wash filtrate (12) are separated from the lignocellulosic material (3) by filtration, centrifugation or a combination thereof.

3. The method according to claim 1 or 2, characterized in that The solid-liquid separation stage (4) comprises filtration, wherein the filtration is carried out by pressurization, negative pressure or excess pressure.

4. The method according to any one of claims 1 to 3, characterized in that The solid-liquid separation stage (4) comprises washing, wherein a displacement washing of the lignocellulosic material is carried out with a small amount of clean water, wherein the ratio of wash water to solids is lower than 6, preferably lower than 3, more preferably lower than 1.

5.

5. The method according to any one of claims 1 to 4, characterized in that The wash filtrate (12) is recycled to the lignocellulosic material (3).

6. The method according to any one of claims 1 to 5, characterized in that At least a portion of the soluble carbohydrates containing fraction (10) is recycled to the lignocellulosic material (3).

7. The method according to any one of claims 1 to 6, characterized in that The mixture of the wash filtrate (12) and the soluble carbohydrates containing fraction (10) is recycled to the lignocellulosic material (3).

8. The method according to any one of claims 1 to 7, characterized in that The feed concentration of the lignocellulosic material (3) is 2-60 wt%, preferably 5-30 wt%, more preferably 10-20 wt%.

9. The method according to any one of claims 1 to 8, characterized in that After solid-liquid separation, the concentration of soluble carbohydrates in the soluble carbohydrate-containing fraction (10) is 15-280 g / l, preferably 30-200 g / l, more preferably 50-165 g / l.

10. The method according to any one of claims 1 to 9, characterized in that The solid-liquid separation stage (4) comprises more than one separation step.

11. The method according to any one of claims 1 to 10, characterized in that The method comprises more than one solid-liquid separation stage (4, 6).

12. The method according to any one of claims 1 to 11, characterized in that The plant-based raw material (1) is a wood-based material or a mixture containing a wood-based material.

13. An apparatus for increasing the concentration of a fraction containing soluble carbohydrates, wherein the apparatus comprises a separation device (4) into which a lignocellulosic material (3) formed by processing a plant-based raw material (1) is introduced, wherein the apparatus comprises at least one solid-liquid separation device (4) for separating a soluble carbohydrate-containing fraction (10) and / or a wash filtrate (12) from the lignocellulosic material (3), - at least one feeding device for feeding the lignocellulosic material (3) into the separation device (4), at least one recycling device for recycling at least a part of the soluble carbohydrates containing fraction (10) and / or the washing filtrate (12) to the lignocellulosic material (3) for increasing the concentration of the soluble carbohydrates containing fraction, - means for feeding the solids (11) and at least a part of the soluble carbohydrates-containing fraction (10) out of the apparatus.

14. The device according to claim 13, characterized in that The apparatus comprises more than one solid-liquid separation device (4, 6).

15. The device according to claim 13 or 14, characterized in that The apparatus comprises at least one filtering device (4) and / or centrifuging device for separating a soluble carbohydrate-containing fraction (10) and / or a wash filtrate (12) from the lignocellulosic material (3).

16. The device according to any one of claims 13 to 15, characterized in that The apparatus comprises at least one of a filter press, a vacuum filter, a negative pressure-based filter or an overpressure-based filter for separating a soluble carbohydrate-containing fraction (10) and / or a wash filtrate (12) from a lignocellulosic material (3).

17. A soluble carbohydrate-containing fraction formed from a lignocellulosic material formed by processing a plant-based feedstock, wherein - forming a soluble carbohydrates containing fraction by separating the soluble carbohydrates containing fraction (10) and / or the washing filtrate (12) from the lignocellulosic material and recycling at least a part of the soluble carbohydrates containing fraction and / or the washing filtrate to the lignocellulosic material to increase the concentration of the soluble carbohydrates containing fraction.

18. The soluble carbohydrate-containing fraction according to claim 17, characterized in that The soluble carbohydrate-containing fraction includes soluble C5 carbohydrates, such as C5H 10 O5 or C5(H2O) n , and other carbohydrates.

19. A solid fraction comprising solids formed from lignocellulosic material, the lignocellulosic material being formed by processing a plant-based feedstock, wherein - forming the solid fraction by separating the soluble carbohydrates containing fraction (10) and / or the washing filtrate (12) from the lignocellulosic material using at least one solid-liquid separation stage, recycling at least a part of the soluble carbohydrates containing fraction and / or the washing filtrate to the lignocellulosic material, - Recovering the solid (11) from the separation stage.

20. The solid fraction according to claim 19, characterized in that The solid fraction contains solid C6 carbohydrates, such as C6H 12 O6 or C6(H2O) n , other solid carbohydrates and lignin.

21. The solid fraction according to claim 19 or 20, characterized in that After the solid-liquid separation stage, the solid fraction comprises less than 15 wt.-%, preferably less than 6 wt.-%, more preferably less than 3 wt.-% of soluble compounds.

22. The solid fraction according to any one of claims 19 to 21, characterized in that The solid fraction comprises fine solid particles having a longest dimension shorter than 0.2 mm.

23. Use of the soluble carbohydrate-containing fraction formed by the method of any one of claims 1 to 12, wherein the soluble carbohydrate-containing fraction is used as a feedstock in fermentation, hydrolysis, catalytic treatment or a combination thereof.

24. Use of a solid fraction comprising a solid formed by the method of any one of claims 1 to 12, wherein the solid fraction is used as a feedstock in hydrolysis, composite material preparation, combustion treatment, or a combination thereof.

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