Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08H—DERIVATIVES OF NATURAL MACROMOLECULAR COMPOUNDS
  • C08H8/00—Macromolecular compounds derived from lignocellulosic materials
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
  • C08B15/00—Preparation of other cellulose derivatives or modified cellulose, e.g. complexes
  • C08B15/02—Oxycellulose; Hydrocellulose; Cellulosehydrate, e.g. microcrystalline cellulose
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L1/00—Compositions of cellulose, modified cellulose or cellulose derivatives
  • C08L1/02—Cellulose; Modified cellulose
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L5/00—Compositions of polysaccharides or of their derivatives not provided for in groups C08L1/00 or C08L3/00
  • C08L5/14—Hemicellulose; Derivatives thereof
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L97/00—Compositions of lignin-containing materials
  • C08L97/005—Lignin
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
  • D21C3/00—Pulping cellulose-containing materials
  • D21C3/20—Pulping cellulose-containing materials with organic solvents or in solvent environment
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
  • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
  • D21C9/10—Bleaching ; Apparatus therefor
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
  • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
  • D21C9/10—Bleaching ; Apparatus therefor
  • D21C9/1084—Bleaching ; Apparatus therefor with reducing compounds
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
  • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
  • D21C9/10—Bleaching ; Apparatus therefor
  • D21C9/12—Bleaching ; Apparatus therefor with halogens or halogen-containing compounds
  • D21C9/14—Bleaching ; Apparatus therefor with halogens or halogen-containing compounds with ClO2 or chlorites
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
  • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
  • D21C9/10—Bleaching ; Apparatus therefor
  • D21C9/16—Bleaching ; Apparatus therefor with per compounds
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/20—Macromolecular organic compounds
  • D21H17/21—Macromolecular organic compounds of natural origin; Derivatives thereof
  • D21H17/24—Polysaccharides
  • D21H17/25—Cellulose
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H27/00—Special paper not otherwise provided for, e.g. made by multi-step processes
  • D21H27/10—Packing paper

Definitions

• the present invention relates to the fields of treating lignocellulosic material.
• the invention relates to a method of fractionating a lignocellulosic material, wherein said method comprises contacting a lignocellulosic material with a specific composition to obtain a liquid fraction comprising said specific composition and dis- solved compounds from the lignocellulosic material, and a solid fraction, and bleach- ing the solid fraction.
• the invention concerns a hemicellulose, cellulose or lignin product, or any combination thereof, obtained by the method of the present inven- tion.
• Lignocellulosic material comprises carbohydrate polymers (cellulose, hemicellu- lose), and an aromatic polymer (lignin).
• Purified cellulose has a well-known use in textile industry or as a raw material for production of cellulose derivatives.
• Purified sulphur free lignin and hemicelluloses can be used as polymers or feedstock in bio- conversion or chemical conversion methods. Purified sulphur free lignin and hemi- celluloses cannot currently be produced in large amounts.
• Lignocellulosic raw material can be converted into many chemicals and materials. Solvents are required for fractionations of lignocellulosic material and treatments of said material with e.g. deep eutectic solvents (DES), Low transition temperature mixture (LTTM) are intensively studied in the literature. DESs/LTTMs are widely used in processes of dissolution and fractionation and may also be used in post- delignification processes of modified lignocellulosic materials. DESs are able to dis- solve e.g. a significant amount of lignin and also carbohydrates (hemicellulose) from the lignocellulosic material.
• DES deep eutectic solvents
• LTTM Low transition temperature mixture
• DESs/LTTMs are widely used in processes of dissolution and fractionation and may also be used in post- delignification processes of modified lignocellulosic materials.
• DESs are able to dis- solve e.g. a significant amount of lignin and
• a fractionation method of the present invention enables purification and recovery of e.g. polymeric compounds of wood as relatively pure fractions.
• the method is based on at least two steps which together create said method for obtaining high purity fractions of wood polymers such as cellulose, hemicellulose and/or lignin.
• deep eutectic solvents (DES) A in figure 1
• bleaching tech- nologies B in figure 1
• extraction C in figure 1
• separation technologies to produce purified fractions from lignocellulosic material (see figure 1 ).
• the present invention thus provides a single method by combining DES treatment with bleaching in an inventive way, thus enabling synergistic effects. And indeed, said single method enables production of large amounts of substantially pure cellulose, (sulphur free) lignin and/or hemicellulose.
• the method of the present invention is very simple, efficient and cost-effective. Due to the effectiveness, less chemicals and fewer bleaching stages are needed in the fractionation method of the present invention compared to the fractionation methods of the prior art. Indeed, the present invention enables easier bleaching of the lignocellulosic material compared to the prior art methods.
• the present invention relates to a method of fractionating a lignocellulosic material, wherein said method comprises contacting a lignocellulosic material with a compo- sition comprising a deep eutectic solvent (DES) to obtain a liquid fraction comprising DES and dissolved compounds from the lignocellulosic material, and a solid fraction, and bleaching the solid fraction.
• a compo- sition comprising a deep eutectic solvent (DES)
• DES deep eutectic solvent
• the present invention relates to a carbohydrate, hemicellulose, cellulose or lignin product or fraction obtained by the method of the present invention.
• the present invention relates to a combination of hemicellulose, cellulose and lignin products or fractions obtained by the method of the present invention.
• the present invention relates to use of the hemicellulose, lignin or cellulose product, or any combination thereof, obtained by the method of the present invention e.g. in industry.
• the present invention relates to use of the cellulose (or cellulose product) obtained by the method of the present invention in textile industry or in production of cellulose derivatives.
• the present invention relates to use of the hemicellulose and/or small molar mass cellulose (or hemicellulose and/or small molar mass cellulose product) obtained by the method of the present invention in industry, e.g. as a sub- strate in the production of specialty chemicals, such as sugars and alcohols, or packing and packaging material.
• Figure 1 shows a fractionation method for lignocellulosic material according to the present invention. Products obtainable by said method are also shown in figure 1 .
• a lignocellulosic material is treated with DES or a composition comprising DES (A).
• Significant amount of lignin and carbohydrates (e.g. hemicellulose) and/or other components are dissolved in said DES or composition (L1 ), i.e. a liquid fraction of the method of the present invention is obtained.
• Dissolved compounds in said liquid fraction are optionally recovered (e.g. separated by membrane filtration and/or precipitation processes) from the liq- uid fraction (D).
• the fractions of lignin (P1 ) and/or hemicellulose (P2) and/or other components are obtained. Residual DES may be purified for reuse (E).
• the solid fraction from DES treatment (S1 ) comprises cellulose and hemicellulose and some lignin.
• the residual lignin of the solid fraction is removed surprisingly efficient by bleaching (B) and after bleaching the solid fraction comprises cellulose and hemi- cellulose (S2).
• Hemicellulose may optionally be extracted from the solid fraction e.g. by alkaline extraction or with hot water (C, L2) and the obtained residual solid ma- terial comprises mainly cellulose (P4).
• the lignin (P1 ), hemicellulose (carbohy- drates) (P2, P3) and cellulose (P4) fractions obtained by the present invention may optionally be further purified.
• lignocellulosic material comprises plant dry matter comprising carbohydrate polymers including cellulose and hemicellulose, and lignin.
• “Lignocellulosic material” includes virgin Ngnocellulosic material such as wood chips or saw dust from, for example, softwood, for example spruce, pine or larch, or from hardwood, such as birch, poplar, aspen, alder, eucalyptus or mixed tropical hard- wood, or mixtures thereof.“Lignocellulosic material” also includes recycled lignocel- lulosic materials as well as waste lignocellulosic material, such as by-products from industry and agriculture such as corn stover, sugarcane, bagasse, cotton, straw etc. and saw mill, pulp mill and paper mill discards.
• Chips includes wood chips, bark chips and nutshells.
• chips refers to slate-like or plate-like particles.
• aqueous liquids means liquids in which there is at least some water pre- sent including for example, industrial effluents such as hot water extraction liquors, extraction liquors from wood pulping mills, waste waters from pharmaceutical plants, waste waters from oil refineries, as well as agricultural run-offs and waterways such as canals and rivers, other bodies of water such as reservoirs, and natural or man- made ponds or lakes.
• industrial effluents such as hot water extraction liquors, extraction liquors from wood pulping mills, waste waters from pharmaceutical plants, waste waters from oil refineries, as well as agricultural run-offs and waterways such as canals and rivers, other bodies of water such as reservoirs, and natural or man- made ponds or lakes.
• “Liquids” may be e.g. aqueous or non-aqueous liquids or anhydrous liquids.
• the“liquid” can be for example be formed by an organic liquid, such as a polar or non-polar organic liquid.
• Such liquids are typically selected from the group of ali- phatic and aromatic alcohols ketones, aldehydes, ethers, esters as well as various hydrocarbon liquids, which may be halogenated.
• the liquid may comprise“a solvent” (i.e. a substance that dissolves a solute resulting in a solution).
• a solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid.
• “Extraction Liquor” or“extraction liquid” is a solution into which organic substances have been extracted from lignocellulosic material.
• Precipitation refers to a creation of a solid from a solution. Precipi- tation utilized in the present invention may be carried out by a decreased tempera- ture either alone or in combination with other methods such as lowering the pH or by adding antisolvents.
• the present invention is based on a single method, wherein DES treatment of lig- nocellulosic material is followed by bleaching, thus enabling simple and cost effec- tive production of large amounts of cellulose (e.g. substantially pure cellulose), (sul- phur free) lignin and/or hemicellulose.
• cellulose e.g. substantially pure cellulose
• sul- phur free lignin and/or hemicellulose
• the methods and techniques provided by this inven- tion enable lignocellulosic material e.g. wood or herbaceous biomass to be fraction- ated very efficiently in a single method, wherein the lignocellulosic material is con- tacted with a composition comprising a solvent in order to obtain i) a liquid fraction comprising said solvent, lignin, hemicellulose and optionally other components, and ii) a solid fraction (comprising e.g. cellulose, hemicellulose and/or lignin).
• a composition comprising a solvent in order to obtain i) a liquid fraction comprising said solvent, lignin, hemicellulose and optionally other components, and ii) a solid fraction (comprising e.g. cellulose, hemicellulose and/or lignin).
• the lignocellulosic material comprises wood, such as softwood, for example spruce, pine or larch, hardwood, such as birch, poplar, aspen, alder, eucalyptus or mixed tropical hardwood, or mixtures thereof.
• the lignocellulosic material comprises or is in the form of wood chips or saw dust.
• the lignocellulosic material has a d 50 particle size of 0.05 mm - 10.0 cm, e.g. 0.05 - 5 mm, 0.1 - 3 mm, 1 - 2 mm, 0.5 cm to 10.0 cm, specifically 2.0 to 7.0 cm, or suitably 4.0 to 6.0 cm.
• the mois- ture content of the lignocellulosic material may be e.g. from 0.5% to 70%, such as 0.5 to 5% (such as about 1 %), 5 to 30%, 30 to 50% or 50 to 60%.
• a lignocellulosic material is contacted with a composition comprising a solvent and thus a liquid fraction is obtained (see (A) and L1 in figure 1 ).
• the liquid fraction comprises dissolved hemi- cellulose, lignin, lipophilic extractives, phenolic extractives, oligosaccharides and/or monosaccharides, other compounds or any combination thereof.
• the liquid fraction comprises at least dissolved hemicellu- loses and/or lignin.
• the lignocellulosic material is treated with a composition comprising DES to remove at least a portion of the hemicellu- loses and/or lignins and/or other components contained therein.
• the liquid fraction obtained by the DES treatment com- prises at least about 30%, 60% or 80% (by mass) or more of the lignin of the ligno- cellulosic material to be treated.
• the liquid fraction obtained by the DES treatment comprises about 70% or less, about 50% or less, about 40% or less, about 30% or less, about 20% or less, about 10% or less, or about 5% or less (by mass) of the hemicellulose of the lignocellulosic material to be treated.
• the liquid fraction obtained by the DES treatment com- prises at least about 30%, 60% or 80% (by mass) or more of the lignin of the ligno- cellulosic material to be treated and about 70% or less, about 50% or less, about 40% or less, about 30% or less, about 20% or less, about 10% or less, or about 5% or less (by mass) of the hemicellulose of the lignocellulosic material to be treated.
• the principal hemicellulose in softwood is galactoglucomannan, which accounts for approx. 20% of the dry material.
• Xylan is the main hemicellulose in hardwood and varies in content within the limits of 15-30% of the dry wood.
• the treatment of the lignocellulosic material with a composition comprising DES is the first stage of the fractionation method.
• At least 30%, e.g. about 35% or about 40% or more, of the dry solids by weight are dissolved in the DES treatment (i.e. when the lignocellulosic material is contacted with a composition comprising DES).
• the liquid fraction obtained after contacting the lignocellulosic material with a composition comprising DES comprises about 40-60% by mass of the dry matter of the lignocellulosic material to be contacted with DES.
• composition of the present invention used for treating the lignocellulosic mate- rial comprises DES and optionally any other agent such as any other solvent, e.g. water or alcohol (such as ethanol, methanol, glycerol, carboxylic acids, guaindine hydrochloride).
• any other solvent e.g. water or alcohol (such as ethanol, methanol, glycerol, carboxylic acids, guaindine hydrochloride).
• the composition comprising DES is a liquid com- position.
• the composition consists of DES only.
• DES refers to a deep eutectic solvent.
• DESs are a type of ionic liquid analogues formed from a eutectic mixture of Lewis or Br ⁇ nsted acids and bases, i.e. a hydrogen bond acceptor (HBA) and a hydrogen bond donor (HBD).
• HBA hydrogen bond acceptor
• HBD hydrogen bond donor
• DESs offer several advantages including their low toxicity, low price, and biodegradability.
• the physicochemical properties of DESs are similar to those of traditional ionic liquids.
• the term DES is used to refer to a mixture of compounds at a ratio that is close to their eutectic point, i.e. where they form a mixture with lowest freezing (or melting) point.
• a DES is made up of two compounds, an HBA and an HBD, but in some cases a complexing agent may be required.
• the term“deep eutectic solvent” or acronym“DES” is used to describe a solvent which comprises two or more separate chemical com- pounds at a ratio that has the lowest melting point.
• Deep eutectic solvents are usually formed by mixing a hydrogen bond acceptor (HBA) such as an ammonium, phosphonium, or sulfonium cation, and a hydrogen bond donor (HBD) such as a carboxylic acid, a urea, or a glycerol.
• HBA hydrogen bond acceptor
• HBD hydrogen bond donor
• Exemplary cati- ons used include, but are not limited to, choline chloride, betaine, N-ethyl-2-hydroxy-N,N-dimethylethanaminium chloride, 2-(chlorocarbonyloxy)-N,N,N-thmethylethana- minium chloride, and N-benzyl-2-hydroxy-N,N.dimethylethanaminium.
• Exemplary hydrogen bond donors include, but are not limited to, urea, acetamide, methylated ureas, glycerol, ethylene glycol, malonic acid, acetic acid, formic acid, lactic acid, adipic acid, oxalic acid, and citric acid.
• Examples of deep eutectic solvents include but are not limited to lactic acid : choline chloride (e.g. in the molar ratio 12:1 - 2:1 , such as 9:1 ), acetic acid : choline chloride (e.g. in the molar ratio 18:1 - 2:1 , such as 9:1 ), sorbitol : choline chloride (e.g.
• glycerol : choline chloride e.g. in the molar ratio 5:1 - 1 :1 , such as 2:1
• boric acid : choline chloride e.g. in the molar ratio 3:1 - 1 :1 , such as 2:1
• formic acid : choline chloride e.g. in the molar ratio 1 :1 - 3:1 , such as 2:1
• carboxylic acids : choline chloride e.g.
• DES is selected from the group consisting of choline chloride/lactic acid, choline chloride/acetic acid, choline chloride/sorbitol glycerol, choline chlo- ride/boric acid, choline chloride/formic acid, and choline chloride/guanidine hydro- chloride, and any combination thereof.
• DES choline chloride/lactic acid has a ratio between choline chloride and lactic acid from 1 :100 to 1 :4 by molar mass, specifically at least 1 :20 by molar mass, suitably about 1 :9 by molar mass.
• a composition comprising DES is contacted with the lignocellulosic material at a ratio between DES and the lignocellulosic ma- terial from 100:1 to 4:1 by mass, specifically at least 20:1 by mass, suitably about 10:1 by mass.
• the lignocellulosic material is allowed to contact with a composition comprising DES for at least 2 hours, at least 5 hours, e.g. 2-25 hours, 5-25 hours, or 10-25 hours, such as 18 hours.
• the lignocellulosic material is allowed to contact with a composition comprising DES at a temperature of at least 60 °C or at least 80 °C, e.g. about 90 to 200 °C or about 90 to 150 °C.
• physical treatment such as increased pressure, microwave irradiation or ultra-sonication, of the lignocellulosic material may be carried out when contacting the lignocellulosic material with a composition comprising DES. These treatments typically decrease the treatment time needed in DES.
• the lignocellulosic material is allowed to contact with a composition comprising DES e.g. less than 2 hours.
• Contacting a lignocellulosic material with a composition comprising DES may be carried out e.g. by adding a DES composition to the lignocellulosic material by one, two, three or several times or contacting the lignocellulosic material with a DES composition one, two, three or several times.
• liquid fraction comprising the composition comprising DES and dissolved compounds is separated from the solid fraction.
• one or more dissolved compounds present in the liquid fraction e.g. at least lignin, hemicelluloses, and/or wood extractives (e.g. fatty and resin acids, sterols and phenolic compounds), are separated from said liquid fraction by a filtration (e.g. molecular or membrane filtration), extraction and/or precipitation (see (D) and P1 and P2 in figure 1 ).
• a filtration e.g. molecular or membrane filtration
• extraction and/or precipitation see (D) and P1 and P2 in figure 1 .
• membrane filtration refers to a technique which is used to separate particles from a liquid for the purpose of pu- rifying it, in other words a solvent and impurities are passed through a semi-perme- able membrane.
• Membrane filtration techniques include nanofiltration, ultrafiltration, microfiltration and reverse osmosis.
• high molar mass hemicelluloses are easier to separate from a liquid fraction by ultrafiltration than hemicelluloses of lower molar mass.
• the precipitation is carried out by adding aqueous liquid such as water to the liquid fraction. Thereby fractions of lignin and/or hemicellulose may be produced.
• the method further comprises purification of lignin from the obtained precipitate or filtrate, e.g. compris- ing cutting and/or dissolving hemicellulose of the obtained precipitate or filtrate with an acid hydrolysis and thereafter optionally filtrating the hydrolyzed precipitate or filtrate to obtain purified lignin.
• purification of lignin from the obtained precipitate or filtrate e.g. compris- ing cutting and/or dissolving hemicellulose of the obtained precipitate or filtrate with an acid hydrolysis and thereafter optionally filtrating the hydrolyzed precipitate or filtrate to obtain purified lignin.
• the purity of lignin precipitated by water from DES solution is about 99% based on the pyrolysis anal- ysis.
• the lignin or hemicellulose fraction obtained e.g. after filtration or precipitation is optionally washed and/or dried.
• the DES contacted with the lignocellulosic ma- terial and wherein at least lignins and/or hemicelluloses have been removed is fur- ther purified for reuse by removing at least part of the carbohydrates, extractives and/or phenols (see (E) in figure 1 ).
• the solid fraction comprises at least cellulose, hemicellulose and/or lignin.
• the solid fraction from DES treatment comprises mostly cellulose and hemicellulose and a minor amount of lignin.
• the solid fraction obtained after contacting a lignocellulosic material with a composition comprising DES has a hemicellulose con- tent which is at least 10%, 20%, 30% or 40% smaller than that of the lignocellulosic material before contacting with the composition comprising DES.
• the hemicellulose content of the solid fraction obtained after contacting the lignocellulosic material with a composition comprising DES is about 90% or less, about 80% or less, or about 70% or less of the hemicellulose content of the lignocellulosic material to be fractionated.
• the cellulose content of the solid fraction obtained after contact- ing the lignocellulosic material with a composition comprising DES is about 60 wt % or more, about 70 wt % or more, about 75 wt % or more, about 80% or more, or about 85 wt % or more.
• the solid fraction obtained after contacting the lignocellulo- sic material with a composition comprising DES has a lignin and/or other component content which is about 70 % or less, about 60 % or less, about 50 % or less, about 40 % or less, or about 30 % or less, about 20 % or less, about 10 % or less, about 5 % or less or about 3 % or less of the lignin content and/or other component content of the lignocellulosic material, respectively, before contacting the lignocellulosic ma- terial with a composition comprising DES.
• the purity of the carbohydrate of the solid frac- tion obtained after contacting the lignocellulosic material with a composition com- prising DES is about 80% or more or about 85% or more. In one embodiment of the invention the purity of the cellulose of the solid fraction obtained after contacting the lignocellulosic material with a composition comprising DES is about 55% or more or about 60% or more, e.g. 63%.
• the residual lignin present in the solid fraction after DES treatment is removed by bleaching (see (B) in figure 1 ).
• bleaching of the lignocellulosic material is carried out after contacting the lignocellulosic material with a composition comprising DES, more specifically after separating the liquid fraction comprising DES and the solid fraction.
• either one or more (e.g. two, three or four) bleaching stages of the solid fraction are carried out.
• One bleaching step is enough for excellent fractionation results of the present disclosure.
• a DES treatment prior to bleaching significantly im- proves the bleaching efficiency, makes bleaching easier and simplifies the bleach- ing process. Without DES treatment many (even 4 or 5 or more) bleaching stages are needed to achieve the very low residual lignin content of the solid fraction ob- tained by the method of the present invention.
• Bleaching is a very common method and any bleaching agents and conditions known to a skilled person may be utilized in the method of the present invention.
• a bleaching agent is an agent that lightens or whitens a substrate through a chemical or biochemical reaction. These reactions may involve the de- struction or modification of chromophoric groups in the substrate as well as the deg- radation of color bodies into smaller, more soluble units that are more easily re- moved in the bleaching process.
• the bleaching is carried out with an agent selected from the group consisting of oxidizing agents (such as chlorine or its derivatives (such as sodium chlorite) or peroxygen or its derivatives (such as hydrogen peroxide, sodium perborate)), reducing agents (such as hydrosulfite (dithionites e.g. sodium dithionite), sodium borohydride, sulfur dioxide, sulfurous acid, bisulfites, sulfites, sodium sulfoxylate formaldehyde); and enzymes; and any combination thereof.
• oxidizing agents such as chlorine or its derivatives (such as sodium chlorite) or peroxygen or its derivatives (such as hydrogen peroxide, sodium perborate)
• reducing agents such as hydrosulfite (dithionites e.g. sodium dithionite), sodium borohydride, sulfur dioxide, sulfurous acid, bisulfites, sulfites, sodium sulfoxylate formaldehyde
• enzymes such as sodium borohydride, sulfur dioxide,
• Chlorine-containing bleaching agents may be divided into four classes: chlorine (e.g. solid chlorine bleaching agents such as chlorinated isocyanurates, e.g. sodium di- chloroisocyanurate dihydrate), hypochlorites (e.g. sodium hypochlorite, calcium hy- pochlorite, bleach liquor, bleaching powder or tropical bleach), N- chloro compounds (e.g. halogenated hydantoins, sodium N-chlorobenzenesulfonamide (chloramine B)), and chlorine dioxide.
• chlorine e.g. solid chlorine bleaching agents such as chlorinated isocyanurates, e.g. sodium di- chloroisocyanurate dihydrate
• hypochlorites e.g. sodium hypochlorite, calcium hy- pochlorite, bleach liquor, bleaching powder or tropical bleach
• N- chloro compounds e.g. halogenated hydantoins, sodium N-chlorobenzenesulf
• Enzymes e.g. in free and/or immobilized form, can be used for example for gener- ation of the oxidizing agent necessary for bleaching as well as for direct bleaching of the textile substrate.
• Suitable enzymes include but are not limited to the glucose oxidases, chloroperoxidases, laccases, and catalases.
• Suitable bleaching conditions include but are not limited to a temperature (e.g. a liquor temperature) from a room temperature (25°C) to 90°C (e.g. 30°C, 40°C, 50°C, 60°C, 70°C, 80°C), and even above 90°C, e.g. for 5 - 90 minutes (e.g. 10, 15, 20, 30, 40, 50, 60, 70, or 80 minutes).
• a temperature e.g. a liquor temperature
• 90°C e.g. 30°C, 40°C, 50°C, 60°C, 70°C, 80°C
• 5 - 90 minutes e.g. 10, 15, 20, 30, 40, 50, 60, 70, or 80 minutes.
• bleaching conditions may be chosen e.g. for chemical agents compared to en- zymes.
• bleaching activators or enhancers, bleach cat- alysts and/or any other suitable agents known to a person skilled in the art may be used in the bleaching of the present invention
• washing tempera- tures include any temperature common to a person skilled in the art, for example below 100°C, below 40°C or even a room temperature (25°C).
• the solid fraction comprises or mainly consists of cellulose and hemicellulose (see S2 in Table 1 and Figure 1 ).
• at least a part or at least a majority of the lignin compounds or frag- ments have been removed from the lignocellulosic material by contacting said ma- terial with a composition comprising DES and bleaching.
• the lignin content of the bleached solid fraction is about 6 wt % or less, about 5 wt % or less, about 4 wt % or less, about 3 wt % or less, or about 2 wt %.
• the hemicellulose content of the bleached solid fraction is about 50% or less, 30% or less, 20% or less or 15% or less of the hemicellulose content of the lignocellulosic material to be fractionated. In one embodiment the cellulose content of the bleached solid fraction is about 65 wt % or more, about 75 % or more, about 80 wt % or more, or about 90 wt %.
• the lignin content of the bleached solid fraction is about 3 wt % or less, about 2 wt % or less, or about 1 wt % or less, and the hemicellulose content is about 20 wt % or less, about 10 wt % or less, or about 5 wt % or less of the mass of the bleached solid fraction, and the cellulose content is about 75 wt % or more, or about 80 wt % or more.
• the purity of the carbohydrate in the DES treated and bleached solid fraction is about 95% or more, or about 98% or more (of the organic material). In one embodiment the purity of the cellulose in the DES treated and bleached solid fraction is about 70% or more, or about 80% or more (of the organic material).
• an extraction of the solid fraction is carried out after bleaching the solid fraction to separate hemicellulose from cellulose (see (C) in figure 1 ).
• Any suitable extraction method known to a person skilled in the art may be utilized in the present method.
• the extraction is car- ried with an aqueous solution, optionally containing an alkaline, acidic or buffering component, to remove a significant portion of the hemicelluloses and/or other com- pounds contained in the bleached solid fraction.
• the extraction is a hot (pressurized) water extraction, said hot water extraction specifically being carried out at a temperature in excess of 100 °C and e.g.
• the treatment time depends on the temperature. Typically the duration is 5 min to 1 day, for example 10 min to 1 day for example 15 min to 720 min. Higher temperatures and longer extraction times lead to higher ex- traction yields, i.e. a greater amount of the hemicelluloses is extracted as the tem- perature and time of extraction increase.
• the extraction can be made using e.g. alkaline compounds, e.g. sodium hydroxide or other chemical, to enhance the dissolution of hemicelluloses.
• the hemicellulose content of a liquid fraction obtained after extraction is about 5 % or more, about 10 % or more, about 20 % or more of the hemicelluloses in the lignocellulosic material to be fractionated (see (C), L2 and P3 in figure 1 and table 1 ).
• the hemicellulose content of a liquid fraction obtained after extraction may depend on the extraction reagent (e.g. water extrac- tion vs. alkali extraction).
• the hemicellulose con- tent of the lignocellulosic material to be extracted is about 16 - 17 % of the hemicel- luloses in the lignocellulosic material to be fractionated (i.e.
• the cellulose content of the extracted solid fraction is about 60 wt % or more, about 80 wt % or more, or about 85 wt % or more, or about 90 wt % or more (see (C) and P4 in figure 1 and table 1 ).
• the cellulose content of a solid fraction obtained after PHWE ex- traction is about 70 wt % or more, about 80 wt % or more, or about 85 wt % or more, or about 90 wt % or more.
• the cellulose content of a solid fraction obtained after alkaline extraction is about 45% or more, about 55% or more, about 60 % or more, about 65% or more, about 80% or more, or about 90% or more of the cellulose content of the lignocellulosic material to be fraction- ated.
• the purity of the cellulose obtained from the optional extraction is about 80 wt% or more, about 90 wt% or more, or even about 95 wt% or 99 wt% or more.
• the purity of the cellulose obtained from the optional extraction is about 80 wt% or more.
• the extraction is made with an alkaline agent (e.g. with so- dium hydroxide such as with 17.5% sodium hydroxide) the purity of the cellulose obtained from the optional alkaline extraction is about 90 wt% or more.
• the solid fraction and extraction liquid are separated.
• the solid fraction comprising cellulose, hemicellulose and lignin (after hot water extraction) or comprising mostly cellulose (after alkaline extraction) is op- tionally washed and/or dried.
• very pure carbohydrate solu- tion is recovered from the extraction liquid.
• a hemicellulose, cellulose or lignin product or fraction, or any combination thereof is obtained by the effective method of the present invention.
• Lignin, hemi- cellulose and cellulose fractions obtained by the present invention are very desirable and useful as raw materials.
• at least a portion of the recovered hemicelluloses, lignin or cellulose is directed to further processing e.g. for use in industry.
• at least a portion of the recovered cellulose is directed to further processing e.g. for use in textile industry or in production of cellulose de- rivatives.
• at least a portion of the recovered hemicelluloses and/or dissolved small molar mass cellulose are directed to further processing for use in industry, e.g.
• Lignin obtained by the present invention may for example be burned as fuel, thus producing energy.
• energy production refers to e.g. production of heat by burning the recovered lignin.
• high quality lignin may be used as a renewable source of aromatic compounds for the chemical indus- try.
• at least a portion of the recovered lignin is directed to further processing for use in industry e.g. for producing energy or as a source of aromatic compounds.
• the hemicellulose (or carbohydrate), cellulose or lignin product obtained by the effective method of the present invention has the following characteristics, respectively.
• the purity of carbohy- drate (P3) is about 85 % or more, 90 % or more, or 95 % or more, and optionally the yield from original wood is about 5% or 10% or more.
• the purity of cellulose (P4) is about 80-99 wt% or more depending on the optional extraction process (PHWE or alkaline extraction), and optionally the yield from orig- inal wood is about 40%, 50%, 60% or more.
• the lignin purity (P1 ) is about 90 wt% or more and yield 40 % or 45 % or more.
• average molar mass of lignin (P1 ) is 5000 g/mol and polydispersity about 2.7.
• Lignin obtained by the present invention is sulphur free in contrast to lignin available today e.g. from kraft pulping process.
• the purity of carbohydrate product (P4) is about 95 wt% or more, about 97 wt% or more, 98 wt% or more, or 99 wt% or more,
• the purity of cellulose product is about 80-99 wt% or more, and/or
• one or more characteristics of the lignin product are selected from the group con- sisting of the lignin product purity about 70 wt% or 80 wt% or 90 wt% or 99 wt% or more, average molar mass of lignin 5000 g/mol, polydispersity about 2.7., and sul- phur free.
• any combination of the hemicellulose, cellulose or lignin product (see e.g. P1 and P3, P1 and P4, P3 and P4, P1 , P3 and P4) obtained by the method of the present invention has specific characteristics.
• the lignin purity (P1 ) is about 70 wt% or 80 wt% or 90 wt% or 99 wt% or more (and optionally yield 40 % or 45 % or more of the lignocellulosic material to be fractionated, and/or optionally said lignin product is sulphur free), and the purity of hemicellulose (P3) is about 80 % or more, 85 % or more, or 90 % or more.
• the lignin purity (P1 ) is about 70 % or 80 % or 90% or 99% or more (and optionally yield 40 %, 41 %, 42 %, 43 %, 44 %, 45 %, 46 % or more of the lignocellulosic material to be fractionated, and/or optionally said lignin product is sulphur free), and the purity of cellulose (P4) is about 80-99% or more.
• the purity of hemicellulose (P3) is about 80 % or more, 85 % or more, or 90 % or more, and the purity of cellulose (P4) is about 80-99 wt% or more.
• the lignin purity (P1 ) is about 70 wt% or 80 wt% or 90 wt% or 99 wt% or more (and optionally yield 40 % or 45 % or more of the lignocellulosic material to be fractionated, and/or optionally said lignin product is sulphur free), the purity of hemicellulose (P3) is about 80 % or more, 85 % or more, or 90 % or more, and the purity of cellulose (P4) is about 80-99 wt% or more.
• the combination of hemicellulose, cellulose and/or lignin products may refer to a combination of e.g. separate products or mixed products.
• the precipitate contained 46% of the lignin of the birch chips. After solid-liquid separation the resid- ual solid material consisted mostly of lignin (purity of lignin was 99%%) (see P1 in figure 1 ). The residual DES may be purified for reuse (E of figure 1 ). Optionally, further purification of lignin in the precipitate was done e.g. by acid hydrolyses, which depolymerize hemicelluloses. By acid hydrolysis hemicelluloses are dissolved in an acid solution.
• the solid fraction after DES treatment still contained about 35% of the original lignin in birch chips (S1 of figure 1 ). This was easily removed by sodium chlorite solution (0.5 mmoi/g). indeed the DES-treatment had a very positive effect on the bleaching efficiency.
• One stage bleaching of DES-treated wood with NaCI0 2 solution (1 g NaCI0 2 / 2.5 g solid matter, 80 mi water, 0.5 ml acetic acid, 75 °C one hour) removed approximately 94% of residual Klason lignin (B of figure 1 ).
• the residual amount of lignin in the DES treated and once bleached lignocellulosic material was only 2% of the original amount of Klason lignin in wood chips.
• the residual solid fraction after extraction contained mainly cellulose, actually about 70% of the original cellulose after PHWE and 60% after alkaline extraction.
• the residual solid fraction or cellulose can be used in the applications where dis- solving pulp are used today e.g. in textile industry or to produce cellulose deriva- tives. Purity of carbohydrates in the P4 fraction is 98% (Table 2).

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