FI122535B - Method of defibrating fibrous raw material and pulp and use thereof - Google Patents

Description

A method for defibrating a fibrous raw material and a pulp and its use

The present invention relates to a process for defibrating a fibrous raw material according to the preamble of claim 1.

According to such a method, the fibrous raw material is contacted with a cooking solvent containing organic solvent to defibrate the raw material.

The invention also relates to a method for recovering lignin 10 according to the preamble of claim 21 and to a method for recovering hemicellulose according to the preamble of claim 27.

Fiberization of a fibrous material, such as wood chips, hereinafter also referred to as "delignification", is carried out mainly in a sulphate (or kraft) or sulphite soup, in which sulfur and sodium chemicals are used as active cooking chemicals in the aqueous cooking liquor. By defibration is meant separation of the fibers by dissolving the lignin which acts as the adhesive. Kraft soup yields prior to bleaching are in the order of 50-53% for hardwood and approximately 46-49% for softwood. After cooking, both the fibrous material and the residual lignin are sulfur-containing and thus inactive.

20

Nowadays, bleaching is increasingly carried out with hydrogen peroxide, which has the drawback of diminishing the mechanical properties of the fiber.

In principle, chemical cooking processes also produce monomeric sugars and lignin derivatives from the lignin-containing raw material. These can be further processed or incinerated. However, the disadvantage of the known methods is that they are generally optimized for only one product. High yields of sugars may result, but lignin and at least most of the hemicellulose are lost or technically difficult to recover. The energy use of the by-product may also be limited by its high water content. 30

The object of the invention is to eliminate the drawbacks of the known methods and to provide a completely new solution for defibrating a fibrous raw material.

2

The invention is based on the idea that the raw material is treated in an organic solvent containing a lower acid of phosphorus. In particular, the invention boils a fibrous raw material in an organic solvent containing hypophosphoric acid or another phosphoric acid derivative of a lower degree of oxidation of phosphorus (lower than orthophosphoric acid).

In the process of the invention for recovering lignin from a lignin-containing fibrous raw material, the lignin dissolved in the cooking solution is precipitated from a solvent by a non-solvent, in particular water.

More specifically, the method according to the invention is essentially characterized by what is stated in the characterizing part of claim 1.

The pulp according to the invention is characterized by what is claimed in claim 17 and the use according to the invention is characterized by claim 18 by claim.

The method for recovering lignin, in turn, is characterized by what is disclosed in the characterizing part of claim 21. The process for recovering hemicellulose is characterized by what is set forth in the characterizing part of claim 27.

The invention provides significant advantages. Thus, the process yields a remarkably high yield and cooking has been found to have a fiber material activating effect. The fibrous material obtained from the cook has interesting properties such as good mechanical properties, reactivity with functionalizing enzymes, and excellent enzymatic hydrolysis to sugars. From the boiled dissolved compounds, lignin is recovered as reactive nanoparticles which have been found to contain ~ 1% chemically bound phosphorus, which may also play a role as a flame retardant. Organo-phosphate groups can bind metal ions and thus act as an ion exchanger.

30

With the new cooking method, fibers made from plant fibers such as wood or reed canary grass and cooked lignin are suitable, for example, for fiber composites and specialty paper solutions, as well as for lignin products (adhesives, coatings, composite matrices). The dclignification according to the invention can also be used as a trituration step 3 for the isolation of hemicellulose. By considering only the lignin yield from the dry weight of the plant material, 60-75% is utilized as useful products.

The invention will now be further explored by means of a detailed description and by way of example.

Figure 1 is a TEM image of nanoparticles of lignin prepared by the invention. Figure 2 shows bar graphs of less than 50 nm and about 100 nm, respectively. Figure 2 shows bar graphs illustrating the enzymatic hydrolysis of the two pulps obtained from Example 10 boiling.

Figure 3 graphically illustrates the effect of Trametes hirsuta laccase on oxygen consumption of lignin masses as a function of measurement time, and Figure 4 shows a corresponding graphical representation of oxygen consumption of LGF-4 lignin in the presence of laccase.

Figure 5 shows bar lengths of the fibers of pulps prepared according to Example 1 and Example 7, respectively, by means of bar graphs; the results can be compared with the literature values shown in Figure 6.

Figure 7 is a graphical representation of the grinding curves, i.e. the tensile index of the masses as a function of grinding.

Figures 8A and 8B, in turn, show the effect of birch pulp produced by the process of the invention on the air permeability of the paper and the smoothness of the sheet surface.

Figure 9 shows two schematic diagrams of pulp treatment, with the upper (1) depicting the sequence where the pulp is treated with laccase and then sheeted to determine its technical properties, and the lower one showing the sequence followed by lacquer spraying, sheet pressing and drying. After that, the technical properties of the sheets are determined.

Figure 10 shows bar graphs for tensile strengths of two samples.

Figures 1A-11C show bar graphs for 15 samples, where "RM" represents a blend of cellulose acetate plastic and organosolv birch fiber (Example 30 5), fiber from CA-RM reed example 10, birch cellulose I, birch cellulose III and birch cellulose III. birch from process steps, sulphate cellulose fiber; after birch cellulose I sulfate cooking, birch cellulose II before bleaching and birch cellulose III bleaching pulp.

4

Fig. 11B shows yield strength comparisons and Fig. 11C shows tensile strength comparisons.

The cooking process of the present invention is based on a hitherto unknown (unidentified) chemical reaction in which the phosphinic acid or its derivative 5 catalyzes the delignification process in an organic solvent while covalently associated with lignin.

Phosphonic acid H3PO2, H2P (0) (0H), its tautomeric form HP (OH) 2, and its salts are potent reducing agents. In this respect, as a cooking chemical, they differ significantly from, e.g.

an active kitsch chemical of the organosolv process, namely the MILOX process. Many other known organic soups use mineral acid (phosphinic acid is a monoprotic acid pKa: 1.2, but weaker than H2SO4 or HCl), but their effect is rather hydrolytic.

15

In addition to phosphinic acid and its tautomeric form, as well as their salts, other derivatives of phosphorus in which the phosphorus has a lower degree of oxidation than ortho-phosphoric acid can be used.

The cooking process seems to be based on the acid-catalyzed delignification of phosphinic acid and on the other hand its ability to chemically bind to lignin. The mechanism of delignification has not been elucidated, but it is possible that the effect of phosphinic acid may be related to the benzyl positions of the phenylpropane moiety of the lignin and the reaction of the acetal or ketal links in the tree structure. There would appear to be organophosphate groups or similar ester groups in the mass.

It has been found that the process of the present invention works well for a variety of plant-based materials. Suitable starting materials are annual and perennial plants. According to one preferred embodiment, the pulp is made of wood. The starting material may be a native wood species such as pine, spruce, birch, aspen or alder, but other wood species such as eucalyptus, maple, cottonwood, mixed tropical hardwood, etc. may be used. In another preferred embodiment, the method of the invention is applied to annual plants such as cereal straw, reed canary grass and bagasse.

5

It should be noted that fibrous raw materials, such as straw and wood, may be mechanically pre-treated (ground, chipped, chipped and mechanical pulp) or classified differently. The goal can be very high quality fiber or only fermentable sugars. The by-product may be hemicellulose and, in all cases, technically useful pure lignin.

Thus, the developed sulfur-free cooking method works well for cane plants, conifers and hardwoods with yields of up to 50-60%, in addition to which 10-15% purified lignin is obtained as particles having a particle size in the order of 50-1010 nm according to TEM. The total yield is thus 60-75% of the starting material.

The cooking can be carried out equally well on wood or dry starting material in natural humidity under almost anhydrous conditions.

Compared to conventional sulphate soup, the yields of spruce soup (50/50 spring wood) in dry conditions, based on the examples below, may be, for example, about 54% or 10% better than the literary value of kraft soup. The residual lignin content for the birch fiber corresponding to a yield of 50% (comparable to the kraft process) was 3.35% and the yield of isolated lignin was 11%. After cooking, the fiber had a glucose content of 89.5% and a xylan content of 7.8%.

The mechanical properties of the birch fiber made by the new process are superior to (reduced) the corresponding pulps as a function of milling.

25 In addition to strength, paper sheets provide valuable properties such as good smoothness and low air permeability. The active residual lignin contained in the fiber can in principle be utilized in the enzymatic enhancement of the sheet. An example of this is an experiment in which a laccase-treated fiber cooked by a novel process gave a 10% higher tensile strength compared to the reference treated fiber (attached). Fibers 30 are well suited, at least for biopolymers (in the case of example cellulose acetate and PLA) as fiber reinforcement in fiber composites.

Birch fibers manufactured according to the method increase the modulus of reinforcement by a factor of 3x. Compared to commercial birch fiber (direct from cooking), the improvement in the module was 10% 6 and 9% higher in yield and tensile strength. The strength values of the reed-fiber composite were comparable to the bleached sulfate process birch fiber reinforcement.

The cooking process can also be used as a biomass pretreatment step in the preparation of fermentable sugars. Combining alkaline extraction with 0.5M NaOH, for example, from reed canary grass in a total yield of ~ 40% yield of material with 100% enzyme hydrolysis (<24 h). The mother liquor is suitable for the separation of hemicellulose. Based on sugar analysis, alkaline treatment increased the glucose content of the fiber by 25% and decreased the xylan content by about 50%. The base treatment also clearly removed residual lignin from fiber 10, so it is also a pulp bleaching process.

Suitable organic parts of the cooking solution are, for example, acetic acid, formic acid ethanol (see also below). The ratio of solvent to starting material can be verified to be more advantageous by recycling the cooking solution. The economic potential can be considered significant because the most objective comparison with the power process (kraft soup) offers at least 10% of the Finnish class advantage in almost any product characteristic.

The cooking process is in principle very gentle and can generally be carried out at about 50 to about 125 ° C. As shown below, the examples have been operated at a temperature of about 75-110 ° C. At lower temperatures, longer processing times are used to enhance the penetration of the cooking chemical into the fiber raw material, such as wood chips. Reaction times could well be increased by a pressurized process. In the case of phosphinic acid, increasing the temperature is not recommended (or should be avoided) because the risk of decomposition of the reagent increases with temperature above 110 ° C.

It is possible to operate under normal atmospheric pressure or at elevated pressure. Overpressure is typically about 1.1 to 10 times normal atmospheric pressure.

The same broth can be recycled several times in the process, whereby a higher concentration of lignin, if it was to be isolated, is also achieved.

On an industrial scale, the amount of phosphinic acid in the cooking solution is, for example, about 0.01 to 10%, preferably about 0.1 to 5%, of hypophosphoric acid by weight of the cooking solution.

7

The amount of phosphinic acid may also be adjusted according to the fiber material to be cooked. Generally, the cooking solution contains about 0.1-50%, particularly about 0.5-20%, of the dry weight of the raw material, hypophosphoric acid.

5 Note that in most of the examples below, the amount of phosphinic acid is considerable (up to 1: 1 relative to the material to be cooked). Part of the large reagent volume has been influenced by the large volume required by the material (e.g. stalk or bark). However, it has been found with the invention that the method works well with the above dosages. Birch provides a good pulp when the dosage of phosphinic acid 10 is e.g. about 10% based on the dry stack of birch.

Suitable solvents are low molecular weight carboxylic acids, aliphatic alcohols (such as formic acid, acetic acid and ethanol as well as propionic acid, n-propanol and isopropanol). Polyols such as 1,2-ethanediol, propanediol and glycerol 15 may also be used.

Regardless of the plant species, the resulting lignin can be made into nanoparticles by a very simple process. By prior art, the production of nanoparticles of lignin is an expensive and complex process that requires high technology on the equipment. In the present invention, nanoparticles of lignin can be prepared by simple precipitation from an aqueous solution.

The specific nature of the particles is high phenol functionality, promoted by the small particle size of the particles, generally about 50-100 nm. Phenol functionality is well visible e.g.

25 in high response to oxidizing enzymes. Organic phosphorus bound to lignin is likely to play a significant role in the lignin dispersion mechanism, which appears to occur spontaneously, without mechanical dispersion or dispersion aids.

According to one embodiment, a small portion of the lignin is intentionally left on the fibers, e.g., the amount of Klason's lignin (about 2-3%), whereby the fiber exhibits very high reactivity to various oxidizing activating chemicals. For example, the activity observed for the laccase enzyme is an order of magnitude higher than that for mechanical pulps.

8

Because the action of laccase is based on an oxidation reaction, in addition to laccase, and at least in some cases, as a substitute chemical, an oxidizing chemical, typically the alkali metal salts of peroxysulfuric acid, may be used.

5

In one embodiment, the activity of the fiber laccase enzyme (Tr. Hirs) 1000 nkat / g at oxygen consumption is DO> 4 mg / L for 30 min or even DO> 5 mg / L in 30 min.

The foregoing features allow further processing of the fibers with functional substrates, whereby the already good technical properties can be modified. This fact becomes particularly important in the manufacture of e.g. fiber-plastic composites, in which case the fiber must in each case be as compatible as possible with the plastic matrix. Even unmodified fibers have been found to be excellent for biopolymer composites and to perform at least with cellulose esters and PLA better than conventional sulfate cellulose pulp.

It has been demonstrated by examples that the physical and strength properties of the fibers are completely at the level of the sulfate masses and in most cases even exceed them.

Particularly advantageous results are obtained when the yield is 48-55%, whereby the fibers bind well together and form a dense network.

In paper technology, therefore, fibers can be used to make airtight, very smooth papers. Since the papermaking background is acidic, the paper 25 is thus well suited, for example, as a base paper for printing electronics or as a conductive paper.

The process can also be understood as a kind of concept where the goal is to utilize wood or reed holistically by fractionating it into polymeric components.

30 The disadvantage of many known methods is that they are good only for one thing at a time. High yields of sugars may result, but lignin and at least most of the hemicellulose are lost or technically difficult to recover. The energy use of the by-product may also be limited by its high water content.

9

The new method has been able to sequentially separate lignin, hemicellulose and cellulose. The effective removal of hemicellulose from the fiber can also be deduced by looking at the sugar compositions of the fibers. The relatively mild base treatment (0.5 M NaOH), for example, reduces the xylose content of the birch fiber. If the base treatment is carried out after the lignin removal 5, the final product is mainly cellulose. The removal of hemicellulose also functions as a bleaching process.

Since enzyme hydrolysis of cellulose has been found to be extremely rapid, the cooking can in principle be directed so that the final product can be made in good yield in microcrystalline cellulose or cellulose fibrils, i.e. partially acidified by cellulose hydrolysis and / or elevated polysaccharide enzyme.

In summary of the above applications, the fibrous material produced by the present cooking 15 can be used as such or further functionalized in fiber composites (either with synthetic or bio-plastics) and in specialty paper and board applications (filters, traceability, if a base-sensitive conductive polymer is present).

20

Lignin can be used directly to replace existing lignin products in existing applications (adhesives, adhesives, wood preservatives, fertilizers, etc.) to provide added value such as fire resistance or microbiological resistance of the wood surface. As nanoparticles or further functionalized, lignin could introduce new properties e.g. fiber composite-25 products both as an additive and possibly also as a matrix material.

When the amount of chemically bound phosphorus is > 1%, the polymeric derivative essentially acts as an ion exchange resin or metal cationic resin in the process of the invention for recovering lignin from a lignin-containing fibrous raw material, thereby separating the lignin from the digestion solution. The pH of the lignin to be precipitated is adjusted to about 4.5 to 6.0, particularly about 5.0 to 5.5.

10

In the process of recovering hemicellulose according to the invention, the fibrous raw material is treated with a cooking medium disclosed to dissolve the lignin, preferably cooking is continued until at least about 20% of the raw material has been dissolved. The fibrous raw material from which a significant amount of the lignin has been removed may be separated from the broth and subsequently treated separately with alkali to dissolve the hemicellulose. In turn, hemicellulose can be separated from the alkali solution by precipitation, e.g. with water, or by membranes or the like. Generally, a significant portion, typically about 25-35 dry weight, of the fibrous feedstock is separated to remove most of the lignin, after which the treated fibrous feedstock is extracted with an alkaline solution of at least about 50% w / w of the cellulose it contains. As alkali, an aqueous solution of an alkali metal or alkaline earth metal hydroxide having a relatively low molarity, e.g. about 0.1 to 5 M, most preferably about 0.1 to 1 M, is used.

The following non-limiting examples illustrate the invention.

Example 1. High yield acetic acid-phosphinic acid soup for dry birch wood

52.8 g of dried birch wood (dry matter 88%), 50.0 g calculated on dry weight, were placed.

20 302.0 g of acetic acid, 82.0 g of water and 60 g of 50% aqueous solution of phosphinic acid (hypophosphoric acid, H3PO2), corresponding to an addition of 30.0 g of 100% phosphinic acid, in a glass reaction vessel so that the pieces of wood were covered with liquid. Subsequently, refluxing was carried out for 24 h at atmospheric pressure and 105 ° C. During the reaction time, the pieces of wood decomposed into a fiber from which the reaction solution (160 g) was filtered off, followed by rinsing the fibers with 216 ml of 70% acetic acid. The fibers were then mixed with water to form a 5% slurry, filtered through a wire, and the filtrate was sucked through a fiber cake once. Finally, the pulp was washed with water in the filter. The water was aspirated under reduced pressure to give a fiber cake dry matter of 29.2%.

Yield: 58.9% fiber calculated on the dry weight of the wood.

Example 2. Birch Soup Reference 11

As a control sample, 53 g (50 g dry) of birch sticks were treated under the reaction conditions of Example 1, but no phosphinic acid was added to the cooking solution.

5

During cooking, the solution turned reddish brown, but the sticks did not decompose into fibers. The sticks were purified by the procedure of Example 1 and the acetic acid solutions, 400 ml, were saved for further analysis.

10 Example 3. High Yield Acetic Acid-Phosphinic Acid Soup for Dry Birch Wood

108 g of dried (solids content 92.4%), equivalent to 100.0 g of dry birch wood, were placed in small pieces in a cooking solution of 462 g containing: 302 g of acetic acid, 30 g of phosphinic acid and 130 g of water. The mixture was boiled for 23 h at 105 ° C under reflux at normal pressure, whereupon the wood decomposed into fibers.

The wood fibers were purified by the method of Example 1. The lignin-containing acetic acid reaction solutions were collected and totaled 536 g. The yield of water-washed pulp was 206 g, dry matter content 30.5%, which corresponds to a yield of 62.8% based on the dry weight of the wood.

20

The fiber obtained the following composition:

Acetone extractants: 2.48%

Klason soluble lignin: 0.54%

Classon gravimetric lignin: 3.52% 25 rhamnose <0.10 arabinose <0.10 galactose <0.10 glucose 86.9% xylose 7.89% 30 mannose 0.50% methylglucuronic acid (MeGlcA) 0.15% galacturonic acid ( GalA) <0.10 total: 95.54%

Example 4. Monitoring of birch sugars in phosphinic acid-acetic acid cooking.

12

Fresh birch wood, 166 g (100 g dry wood), 302 g 5 acetic acid and 60 g 50% phosphinic acid were reacted in a 0.5 L flat-bottomed flask for 35 h at normal pressure and 105 ° C.

After the reaction time, the fiber purification was carried out exactly as described in Example 1.

The yield was 195 g of pulp with a dry matter content of 25.1%. This corresponds to a yield of 48.1% based on the dry weight of the birch fiber

The following composition was determined for birch fiber: 15% Acetone Extractants: 2.80%

Klason soluble lignin: 0.59%

Klason Gravimetric Lignin: 3.40 Sugars Rhamnose <0.10% 20 Arabinose <0.10% Galactose <0.10% Glucose 89.5% Xylose 7.80% Mannose 0.76% 25 Methyl Glucuronic Acid 0.28% Galacturonic Acid < 0.10% glucuronic acid <0.10% total 98.34% 30

The fractions were analyzed for carbohydrate and lignin fractions after ultrafiltration and alkali extraction. The yield of the dissolved polymeric carbohydrate fraction was 5.8% of the dry matter of wood and the yield of the dissolved lignin (as purified nanoparticles) was 8.9% of the dry matter of the wood.

13

Example 5. Preparation of birch fiber suitable for plastic reinforcement by acetic acid phosphine acid cooking from fresh birch wood

Fresh birch wood, 189.4 g (100 g dry wood), 302 g 5 acetic acid and 60 g 50% phosphinic acid are reacted in a 0.5 L flat-bottomed flask for 32 h at normal pressure and 105 ° C. After the reaction time, the fiber purification was carried out exactly as described in Example 1.

The yield was 186 g of pulp with a solids content of 26.6%. This corresponds to 50, 3% 10 yields of fiber based on the dry weight of the wood.

Example 6. Preparation of Spruce Fiber from Classified Pin Chips with Acetic Acid-Phosphinic Acid Soup 43.5 g of dry (91.9% dry matter, 40.0 g dry wood) spruce sticks with a 1: 1 ratio of spring wood were immersed in 578 g of cooking solution containing 482 g of acetic acid, 48 g of phosphinic acid and 48 g of water. The mixture was refluxed under normal pressure for 24 h at 105 ° C. After the reaction time, the fiber purification was carried out exactly as described in Example 1.

Yield: 54% on a dry wood fiber basis.

Example 7. Preparation of spruce fiber from chips by phosphine acetic acid cooking

Fresh spruce chips, 267 g dry matter content 37.2%, which corresponds to 100 g dry spruce 25, were immersed in a cooking solution containing 302 g acetic acid, 30 g 100% calculated phosphinic acid and 30 g water. Wood chips were boiled in solution for 88 h at 105 ° C, whereupon the wood softened and decomposed into fiber as lignin dissolved in acetic acid. After the reaction time, the mother liquor was aspirated under reduced pressure from the pulp to yield 231 g, after which the fiber cake was rinsed with 70% acetic acid gradually to remove lignin and cooking chemicals. The yield of the wash solution was 246 g which was combined with the previous filtrate (mother liquor). The fiber was then washed with water in a 5% slurry, filtered on a wire, and the filtrate was sucked through a fiber cake once. Finally, the pulp was washed with water on a filter and concentrated under reduced pressure.

14

The yield of the moist pulp was 238 g, dry matter content 22.4%, which corresponds to a yield of 53.3% based on the dry matter of wood.

5 Example 8. Removal of lignin from birch bark by acetic acid-phosphinic acid cooking

95.3 g of birch bark, 91.6% dry matter equivalent to 87.3 g of dry bark, were mixed with a cooking solution containing 302 g of acetic acid, 30.0 g of phosphinic acid and 10 117 g of water. The mixture was boiled for 44 h at 105 ° C to dissolve the lignin.

After the reaction time, 400 g of lignin-containing acetic acid solutions were obtained, as described in Example 1, a water-rich polysaccharide-rich, moist mass of 195 g, a dry matter content of 22.4%, corresponding to a 50% yield based on the dry weight of the shell. The following composition was determined for the treated birch bark: 15 rhamnose <0.1% galactose <0.1% glucose 48.6%

Xylose 3.8%

Mannose 0.64% 20 Fructose <0.1%

Total monosaccharides: 53%

Example 9. Preparation of Birch Fiber with Formic Acid-Phosphlinic Acid 25

Birch wood (119 g, 84% dry matter, 100.0 g dry wood) was combined with a cooking solution containing 251 g of formic acid, 25 g of phosphinic acid and 25 g of water. The cooking time was 19h 30 min, during which time the wood completely decomposed into fiber. The ligninous broth was removed from the fiber by vacuum suction and the yield was 268 g.

The pulp was then rinsed with 70% formic acid to remove lignin dissolved. The rinsing solution was collected at 266 g, after which the lignin solutions were combined. The fiber was washed with water as in Example 1. The yield of the moist pulp was 189 g, the dry matter content 23.8% and the birch fiber yield 43.6% based on the dry weight of the wood.

Example 10. Preparation of fiber suitable for plastic reinforcement from reed canary grass with acetic acid-phosphinic acid cooking 5

A reed cardstock amount of 55.3 g (90.3% dry matter), or 50.0g calculated on dry matter, was mixed with 904g of a stock solution of 604g acetic acid, 60g phosphinic acid, and 240g water . The mixture was boiled for 13 h at 105 ° C, whereby the stalk softened and decomposed into fiber. The fiber was purified in Example 1.

10. Yield 134 g wet pulp, dry matter content 20.3%, corresponding to a yield of 54.0%. The wet mass was dried in a convection oven at 60 ° C.

Example 11. Preparation of enzyme hydrolyzable reed pulp by acetic acid-phosphinic acid cooking 55.3 g of a reed cardstock (dry matter content: 90.3%) was mixed with a solution of 604 g of acetic acid, 60 g of phosphinic acid and 240 g of water at baseline. The cooking time at 105 ° C and normal pressure was 5 hours, during which the stalk softened and decomposed into fiber. The broth was sucked out of the pulp by vacuum suction as completely as possible, after which a new batch of 50 g (calculated as dry) was added to the broth and a new 5h brew was carried out. The procedure was repeated and a further 25 g aliquot of the card was mixed with the reconstituted brine solution, followed by a third chain step. After the cooking steps, the pulps were combined and rinsed with 70% acetic acid and then washed with water to pH ~ 5. A total of 120 g of a reed card were treated with the same ketone solution 25. The wet mass yield was 396 g, the dry matter content 18.1%, which corresponds to 57.4% of the total yield. The retention of lignin-concentrated brine from the process was 516 g and 70% of the acetic acid filtrate was 195 g.

166 g, 30.0 g of dry reed mass was further processed by extraction for 4 h with 1000 30 ml of 0.5 N NaOH (pH = 12) at 80 ° C. The treatment was found to bleach the pulp as the residual lignin and hemicellulose dissolved. After the reaction time, the fibers were filtered onto a wire and rinsed with 0.5 N NaOH. Yield 19.9 g of dry fiber, which corresponds to a yield of 66.3% of the fiber extracted by alkali. Thus, the yield of fiber rich in cellulose was 38%, calculated from the raw material.

Example 12. Ethanol-phosphinic acid soup for reed canary grass 16 55.4 g (dry matter content 90.3), 50 µg dry reed cane card was mixed with 5 cooking solutions of 604 g ethanol, 60 g phosphinic acid and 180 g water. The mixture was boiled under reflux (79 ° C) for 30 h. Thereafter, the ethanol was aspirated off under reduced pressure. A dry aliquot of 50.0 g of card was added to the restored ethanol broth and the soup was repeated. After the reaction time, ethanol-containing pulps were rinsed with ethanol, pooled and washed in 3000 mL volume of water and finally rinsed with water on a wire 10. The yield of the pulp was 73.5% based on the dry weight of the raw material.

A mass corresponding to 30.0 g dry weight was subjected to alkali extraction as in Example 10, with a dry cellulose-rich pulp yield of 23.3 g, corresponding to 77.6% yield of ethanol cooked fiber and 57% yield of baseline corsica raw material.

Example 13. Preparation of Lignin Nanoparticles from a Baking Solution by Dilution with Water The acetic acid lignin solution (376 g) obtained from Example 1 was diluted with water to a volume of 3000 ml to form a precipitate of lignin which can be at least once diluted and decanted by dilute acetic acid. Thereafter, a further dilution of water to a volume of 2000 to 3000 ml will no longer sedimentate by gravity but will produce an aqueous dispersion which can be concentrated by high speed centrifugation at 3000 to 5000 rpm / 15 min, lignin washed to pH ~ 5, yield 20.5 g lignin dispersion (dry matter 24.6%) and yield 10.1% based on the dry weight of birch.

A light yellowish precipitate was obtained from the control sample (Example 2) which was sufficient for 30 chemical determinations of phosphorus. Chemical determination of phosphorus was carried out by burning a sample of 1.00 g in a muffle furnace for 6 h / 800 ° C. A long burning time was necessary for the lignin reacted with phosphinic acid to eliminate all carbon. Reference samples burned immediately. After combustion, the inorganic material remaining in the porcelain crucible was dissolved in 5.0 mL of IM HCl and diluted to 100 mL with distilled water. Sample 17 was delivered to Altia Oy's water laboratory and the total phosphorus content was determined by the molybdenum method (total phosphorus in water).

Table 1 shows the yields of the lignin-5 nanoparticles prepared according to the examples described above for different fiber raw materials.

Table 1. Yields of lignin nanoparticles for various plant materials

Raw Material Example Yield%% Phosphorus% P NMR

____ (total) __

Ref. birch 2 «5 (total 0.47 ___H2O precipitates) ___

Aldrich lignin ___ 0.31__ birch_ 1 10.1 TIT 0.96

Koivu__4__11,3 ___

Birch 8 11.7 inner shell _____

Six__7__UJ_ 1.13 I

Flax 6 ___ ___ ^ 4

Ruokohelpi__Π__13,4__

In turn, Table 2 shows the amount of phosphorus bound to lignin for the lignin of Example 1. The assay was performed by 31P (1H) NMR analysis.

Table 2. NMR analysis of birch lignin

Measured 31P {1H} NMR Spectrum The sum of 31P {1H} NMR integrals

Measured 3IP {1 H} NMR Spectrum, DMSO-d 6 5.90 (whole sample)

Lignin, Λ, Ρ (Ή) NMR Spectrum, D2O-I1UOS 1.26% (water soluble fraction)

Phosphorus bound to lignin 5.9-1.26 = 4.64

Percentage of lignin bound phosphorus% 79%

Qualitative

Acetylation of lignin 1 C NMR 170.5 ppm (C = O) -acetylcarbonyl 20.6 ppm (-CH 3) -acetyl methyl

The thermoplasticity of the lignin nanoparticles made from different starting materials was investigated by DSC analysis. The reference sample was a commercial lignin, Protobind 1000. The DSC analysis was run in two 0-125 ° C cycles using a 10 ° C / min rise and fall rate.

5

Table 3. Glass point of organosolv lignin nanoparticles made from different starting materials as determined by DSC. Analytical samples were prepared by drying a purified lignin dispersion sample in a convection oven / 60 ° C.

10

Source of soup Lignin glass point / ° C

isolation 1. cycle 2. cycle

Birch Crumb, Example 1 Example 13 99 95

Reed Moth, Example 12 Example 13 65 61

Reed Moth, Example 10 Example 13 104 102

Reed Moth, Example 11 Example 13 103 102

Linen, Example 14 Example 13 97 110

Protobind 1000, - 107 105 reference lignin

Table 3 shows that the lignins prepared with organic solvent had a glass point at about 100 ° C and that the lignins are thermoplastic. The molecular weights of the lignins are determined by GPC and the results are expected to explain part of the observed differences between the various examples.

Example 14 Fractionation of flax with formic acid-phosphinic acid cooking

57.6 g of flax card (86.7% dry matter, i.e. 50.0 g of flax card) was mixed with a cooking solution of 604 g of formic acid, 60 g of phosphinic acid and 240 g of water. The cooking time at normal pressure was 11 h, when a stalk was broken into fiber. The fiber was purified by the procedure of Examples 1 and 8, yielding a water-washed wet linen fiber mass yield of 141.8% and a dry matter content of 19.2%, corresponding to a 54% yield of linen fiber based on the dry weight of the stalk.

19

A ligninic formic acid solution of 664 g was diluted with water to 3000 ml and prepared by centrifugation washing at pH 5 to produce a 16 g (20.14% dry matter) nanoparticulate dispersion of lignin corresponding to 6.4% yield of purified lignin nanoparticles based on the dry weight of the stalk.

The flax fiber (27 g of dry matter) was mixed with 1000 ml of a 0.5 M NaOH solution and extracted for 24 h at 20 ° C to separate the hemicellulose. After extraction, the pulp was filtered through a wire and the filtrate was sucked through a fiber cake once.

The solution containing the base-soluble polysaccharides was stored and finally the fibers were rinsed in the filter with cold water.

The yield was 116.46 g wet cellulose pulp with a dry matter content of 19.34%. This corresponds to a yield of 45% based on the dry matter of the straw at baseline.

15

Biomass consisted of either a 54% yield of fiber and a 6.4% yield of lignin nanoparticles or a 45% yield of cellulose-rich fiber, 9% alkali-soluble polysaccharides (predominantly hemicellulose) and 6.4% nanoparticles. Overall, the conversion of flax into useful polymeric products was 60.4%.

Example 15. Fractionation of Birch Wood Polymers with Acetic Acid-Phosphinic Acid Cooking

Birch was fractionated with phosphinic acid soup, cellulose, pearl cellulose, and lignin into 25 nanoparticles Starting point (1.000 kg per moist wood, 57% dry matter) 100 g of phosphinic acid and 246 g of water were cooked for 30 h at 100 ° C and normal pressure for 31 h 30 min, during which the wood splinters disintegrated into fiber. The fibers were purified by the method of Example 1 and the lignin nanoparticles were prepared by the method of Example 12. Pearl cellulose was isolated from the fibers by extraction of 2% fiber slurry in IM NaOH solution for 24h at room temperature. The polysaccharide fraction dissolved in the alkali was purified by ultrafiltration through a membrane of 5000 g / mol [cut off] followed by freeze-drying.

Yields calculated on dry weight of the wood at baseline:

Birch fiber 58.3% after cooking

Cellulose 44.5% after alkaline extraction

Pearl Cellulose: 5.8% Mw> 5000 g / mol

Lignin Nanoparticles: 8.9% 10 _ cd o? · O o o o j »o - ^ ^. — I! * ζΛ f- * -O X! ': s' *' · «v. '* ">>» Pj i? * CS \ os?' O V · 'ffi w d · JS Ό t "f" S' i

£ * I

S .o O 'S- »VC <Λ' t-! W; N jr- 3 \! '- <· - »o JS I" t' · '": s 0 Ä' j" '~' °

2 O O O -: O

1 £ p 2 ~ - - 3 $ 1

li _. ja * - 3 '.. f'., 't I

ro] d χ Γ 'x Γ'- 1

♦} S

c / 3 Ϊ i C-? c / i 1 [S O i o! J2 I O ® o »o o

* Not I

£ o

S S.

• g * | ", Jiv, -

C /> Ti P C CV

b S! 3 <o o Odd Ä * -¾ l-Ö

0 S I

-o E · § ...

b S: S d Λ -5 K d O = ® ® ® b o 2 o 2 o -.

-¾ t®. -S d C / 5 'ö | ω s -e §>. «n κ q.

C3 «tU t =:> Λί -> - ® -e

01 Ä 2 iS

Φ 3 g '-f q q q q O * 3 cd r- Ob C-'J <n r- ^ Λ co o kr. r'- f '' m

^ I

3 ^

* S «S _J3 is *, ^^ C.7S

£ * i IN ^^ dd - 73 b ~ d ~ ooodgb O hr a ·· '·· u · "d" eb 2 _ ... - - S'® · - Id- o ä _a & "fi ^ 2 2 'S 2 2

b S § Γο 'ei o o' S

-1 b Tf ä o o o -t O

.-¾ = 3, VS »» C.5 »C O> S f · / jv 'a s ä« 3 3 -,; r; ^ S-f ^ mm · - ~ &> s · * '· ^ Γ2 3 ^>.

5Λ 3 Λ :; s' V; V ^ '' «^ h; .s I S s ;;.: ~ ·; <ίτ, 22

The sugars have been determined by the method described in Bemfeld, based on the reduction of 2-hydroxy-3,5-dinitrobenzoic acid, Bemfeld, P (1955) Amylases, a and b. In Colowick SP and Kaplan NO (eds) Methods of Enzymology, Vol. press, NY, pp. 149-158.

The chemical composition of untreated cellulose after acid addition was analyzed by HPLC (Tenkanen, M., Gellerstedt, G., Vuorinen, T., Teleman, A., Perttula, M., Li, J. and Buchert, J. (1999). Determination of Hexeuronic Acid in Softwood Kraft Pulps by Three Different Methods. Journal of Pulp and Paper Science, 25: 9,306-311).

10

Tenkanen, M. and Siika-Aho, M. (2000) An α-glucuronidase of the Schitzophyllum commune acting on polymeric xylan. Journal ofbiotechnology, 78: 2, 149-161.

The enzymatic hydrolysis of the fiber after organic cooking proved to be very high and also rapid.

Figure 2 illustrates enzyme hydrolysis in the cooking according to Example 10. According to Example 11, the test points for hydrolysis of cooked reed pulp SR-5 pulp 1 and pulp 2 represent the fiber sample before and after base leaching. Base leach 20 clearly removes hydrolysis retardant components such as pearl cellulose from the pulp, which is also well reflected by changes in the sugar composition of the pulp (Table 4). After the alkali treatment, the hydrolysis of the pulp is already 100% after 24 h, which in the assay is equivalent to DNA mg / ml glucose.

The hydrolyzable mass of the pulp treated according to Example 12 is high initially (76%); 2 cooking cycles with recycled solvent did not significantly affect the result. After alkali treatment, the hydrolysis of the pulp was> 90%.

Example 17 30

The reactivity of the fibers prepared according to Example 1 in the oxidation reaction catalyzed by the laccase enzyme was measured as the consumption of dissolved oxygen. Oxygen measurement was made by determining the concentration of oxygen dissolved in the fiber suspension during the laccase treatment. The measurement was made in a sealed sample vessel on a SensorLink PCM800 using 23 oxygen electrodes (Clark). Figure 3 shows that the new organosolv fibers are highly laccase-reactive and can thus be activated for further utilization in the laccase-catalyzed oxidation reaction, for example functionalization.

Example 18. Specific Properties of Lignin Nanoparticles, Laccase Enzyme Activity

Figure 4 shows the oxygen uptake of birch lignin nanoparticles prepared by the method of Example 1 in an oxidation reaction catalyzed by an enzyme laccase.

Oxygen measurement was performed using the oxygen measurement method described in Example 16.

It can be seen from Figure 4 that the lignin nanoparticles prepared by the organosolve-free enzyme described by the invention were highly reactive in the laccase-catalyzed oxidation reaction.

15 Example 19. Fiber length and comparison with commercial mill masses.

Figure 5 shows the lengths of the fibers of pulps prepared according to Example 1 (birch) and Example 7 (six), which are compared with the literature values (Figure 6).

20 The graphs show that fiber length distributions are typical of wood species.

Example 20. Physical and Strength Properties of Fibers.

Figure 7 shows the compensation for the difference in mass densities of the test bag (test bag) of Example 1 compared to commercial mill masses, the reference being birch sulphate cellulose pulp used in the manufacture of test sheets.

The reference curves represent the effect of grinding. All in all, the result is fully comparable to the fibers produced by the sulphate process.

30

Example 21. Mechanical and physical properties of birch fibers

Table 4 gives a comprehensive physical description of the birch pulp prepared by the boil of Example 1 and a comparison with the mill pulps.

24

Table 4. Physical, Strength and Paper Technical Properties of Organosolv Pulp.

Comparison: Commercial Organosolv production of cellulose,

Birch Comparison of factory weight in basis weight compensated.

Tensile Strength X1 (N / m) 7271.0 3389.7 4170.3

Stdev 449.4 112.4

Tensile Strength (N) 109.1 50.8 62.6

Stdev 6.7 1.8

Tensile Index X2 (Nm / g) 101.0 54.6 54.6

Stdev 6.2 1.8

Energy to Break Z1 (J / m2) 93.6 96.5

Stdev 13.3 5.6

Strain at Break% (mJ / g) 2.1 3.9 4.0

Stdev 0.2 0.1

Modulus of Elasticity E

(N / mm2) 9646.8 4525.2 4656.6

Stdev 519.5 199.8

Width (mm) 15 15.0

Breadth (pm) 82 86.0

Grammage (gsm) 72 62.1

Moisture absorption at 50% RH, 23 ° C 9.7 9.0

Air permeance (ml / min) 287

Bendtsen roughness (ml / min) 512

Shape Factor (-) 94.5 87.5

Average fiber length, mm 0.816 0.9

Average fiber width, pm 22.4 21 5

Example 22. Effect of Organosolv fibers on air permeability of paper

The effect of the organosolv fibers according to the invention on the air permeability of the paper is shown in the bar graph of Figure 8.

The test kit is birch cooked according to Example 1. The reference point is commercial birch pulp. There is some correlation between sheet air permeability and smoothness; a sort of optimum according to these 10 quantities would appear to correspond to a fiber yield of 48 to 50% as in Example 4.

Example 23. Effect of Organosolv Fiber Lacquer Reactivity on Sheet Strength.

5

The scheme (Figure 9) illustrates the possibilities of using the enzyme laccase to improve the properties of cartons or papers made from the organosolv fibers of the invention.

The results are shown in the bar graph of Figure 10. The column of sample N1 represents the tensile strength (T. Strcnght = tensile strength) of the present organosolv fiber and the column of sample N2 the tensile strength of the paper sheet treated with laccase enzyme. The laccase treatment of the fibers was performed in a sheet mold at a dosage of 500 nkat / g dry fiber. According to the results obtained, the tensile strength of the paper made from the organosolv fibers made according to the invention could be clearly increased by lacquer treatment.

Example 24. Use of Organosolv Fibers as Plastic Reinforcement 20 Dried birch fiber prepared according to Example 5. The cellulose ester resin was a commercial cellulose triacetate plasticized with 50 php triethyl citrate (TEC).

In Fig. 1 IA, CA-RM represents a blend of cellulose acetate plastic organosolv birch fiber (Example 5), CA-RM reed fiber prepared according to Example 10. Birch cellulose I, birch cellulose II and birch cellulose III represent birch sulphate cellulose fiber from various process steps. After Birch Cellulose I Sulfate Cooking, Birch Cellulose II Before Bleaching and Birch Cellulose III Bleached Pulp.

Figure 1B shows yield strength comparisons. The sample codes are the same as in Fig. 30 1A. Figure 11C shows tensile strength comparisons. The sample codes are the same as in the figure

11A

Cellulose acetate fiber blends generally have better strength properties than 26 reference masses

As a whole, birch fibers produced by the process of the invention gave a comparable result to birch sulphate cellulose when used as a reinforcement of PLA5. In particular, a significant improvement in tensile strength was achieved with 20% of the birch fiber according to the invention as compared to the birch sulphate cellulose pulp from any process step.

Test conditions

Scostcet is compounded with a laboratory-grade Brabendcr eraser blender using Nocke cam mixer arms (volume 80 cm3). The temperatures in the cellulose acetate mixtures were 220 ° C and in the PLA mixtures 190 ° C.

15 Test sticks ('' dog bones '') are made with the Thermo Haake MiniJet injection molding machine.

Injection pressure 600-700 bar, injection time 3-5 s, leaving pressure 320-400 bar, leaving time 15-30 s. Mold temperature with cellulose acetate 40-50 ° C with PLA 25-30 ° C.

Analyzes

The mechanical properties of the test rods were tested on a material testing machine (Instron). PLA + RM birch sticks have not been kept for five days in the standard cabinet in accordance with the standard, but samples have been tested immediately after manufacture. Due to the crystallinity of PLA, the results of these test rods may improve with PLA crystallization. On the other hand, the rods contain hydrophilic fibers which, when absorbed by moisture, may impair the mechanical properties.

Example 25. Preparation of reed cane fiber at low water concentration of water. By taking into account the humidity of the straw, the water content of the mixture is 9.1%. During the reaction time, the stalk softened and decomposed into fiber. Purification of pulp 27 was carried out according to the procedure of Example 1. The fiber yield calculated as dry matter was 54%. Lignin was isolated from acetic acid by the method of Example 13.

Claims (30)

A process for accelerating a fibrous feedstock comprising contacting the feedstock with a cooking solvent containing organic solvent for the production of a fibrous pulp, characterized in that the cooking solution contains hypophosphoric acid or a corresponding reducing phosphoric acid derivative. Process according to Claim 1, characterized in that the cooking solution contains from about 0.01% to about 10% by weight, preferably from about 0.1% to about 5%, of hypophosphoric acid. 10 Process according to Claim 1 or 2, characterized in that the cooking solution contains from about 0.1 to 50%, in particular from about 0.5 to 20%, by weight of the dry weight of the raw material, of hypophosphoric acid. Process according to one of Claims 1 to 3, characterized in that the spent cooking solution is recycled optionally without removing the dissolved components. Process according to one of Claims 1 to 4, characterized in that the cooking solution contains a polar organic solvent. Process according to Claim 4, characterized in that C1-6-alkanoic acid, C1-6-alkanol or polyol or aromatic alcohol having 6-10 carbon atoms or a mixture thereof are used as polar organic solvent. 25 Process according to claim 5, characterized in that the organic solvent is an acid such as formic acid or acetic acid or a mixture thereof, or an alcohol such as methanol, ethanol, n-propanol, iso-propanol, 1,2-ethanediol, propanediol or glycerol, or a mixture of two or more alcohols. 30 Process according to one of the preceding claims, characterized in that the raw material is treated in a cooking solution at a temperature of about 50 to 120 ° C, in particular about 70 to 110 ° C. Method according to one of the preceding claims, characterized in that the raw material is treated in a cooking medium at normal atmospheric pressure. Method according to one of the preceding claims, characterized in that the raw material is obtained from annual or multi-annual plants, in particular the raw material is a stalk of a one-year plant or wood, possibly pre-treated. 11. A process according to claim 10, characterized in that the raw material is ground, chipped or crushed or classified to enrich the desired portion. 10 A process according to any one of the preceding claims, characterized in that the lignin-containing raw material is pulverized, wherein the raw material is pulverized until at least about 40% of its dry matter has been dissolved in the cooking solution. Process according to Claim 12, characterized in that the raw material is defibrated until about 1 to 20% by weight of the original lignin remains in the fibers, in particular the pulping is continued until the lignin content of the pulp is about 1 to 5% by dry weight of the pulp. Method according to Claim 13, characterized in that the lignin content of the pulp is at least close to that of Klason lignin. Process according to one of Claims 1 to 12, characterized in that the raw material is defibrated until about 45 to 52% of its dry matter has been dissolved in the cooking medium. Method according to one of the preceding claims, characterized in that the raw material is defibrated at a total moisture content of less than 20%, preferably less than 10%. 30 A pulp made by a process according to any one of the preceding claims. Use of a pulp according to claim 17 for the production of paper or board. Use of the pulp of claim 17 in composite materials as a fiber component. Use according to claim 19 with a plastic matrix, in particular a biopolymer-based matrix. A process for recovering lignin from a lignin-containing fibrous feedstock comprising dissolving the lignin in a digestion solution from which it is extracted, characterized in that the feedstock is treated with a digestion solution containing an organic solvent containing a hypophosphoric acid or a corresponding reducing agent, the dissolved lignin is precipitated from the solvent with water. A process according to claim 21, characterized in that the pH of the lignin to be precipitated is adjusted to about 4.5 to 6.0, in particular to about 5.0 to 5.5. Process according to claim 21 or 22, characterized in that the lignin is reactive in a laccase-catalyzed oxidation reaction. Process according to claim 21 or 22, characterized in that the lignin is reactive with oxidizing chemicals. Process according to any one of claims 21 to 23, characterized in that reactive nanoparticles containing from about 0.1% to about 5%, in particular about 25%, of chemically bound phosphorus are recovered. Process according to one of Claims 21 to 23, characterized in that lignin containing chemically bound phosphorus in an amount of> 1% is recovered, wherein the polymeric derivative is useful, for example, as an ion exchange resin or as a metal cationic cyanide. 27. A process for recovering hcmiscululose from a lignin-containing fibrous raw material comprising treating the fibrous raw material with an organic cooking solution to dissolve the lignin, characterized in that: - a cooking solution containing hypophosphoric acid or a corresponding reducing agent of at least about the substance has been dissolved, - optionally separating the raw material from the cooking solution, 5. treating it with alkali to dissolve the hemicellulose, followed by - separating the hemicellulose from the alkali. 28. The method of claim 27, wherein a significant portion of the lignin is extracted from the fibrous raw material and the treated fibrous raw material is extracted with an alkaline solution of at least about 50% by weight of the hemicellulose it contains, The process according to claim 27 or 28, wherein the alkali is an aqueous solution of an alkali or alkaline earth metal hydroxide having a molarity of about 15 to about 5 M. Process according to one of Claims 27 to 29, characterized in that the hemicellulose is separated from the alkali solution by precipitation or by membrane.