WO2025201615A1 - Method for the comprehensive processing of meadow grasses and meadow grass processing plant - Google Patents

Abstract

The invention relates to the field of agriculture and to the pulp and paper industry, and more particularly to methods for processing cellulose-containing meadow plants. The technical result, which consists in permitting the efficient, comprehensive and waste-free processing of meadow plants, is achieved in that the claimed method includes first comminuting perennial grass hay, separating the comminuted hay into stem, leaf and seed fractions, granulating the leaf fraction to produce animal feed, re-comminuting the seed and stem fractions, using the seed fraction as an additive to the leaf fraction or for producing a nutrient medium for cultivating proteins, and using the chaff of the stem fraction to produce a cellulose-containing powder, a cellulose-containing pulp, cellulose-containing fibre, hydrolysates and lignin, wherein cellulose-containing powder is produced by grinding chaff to a powder; cellulose-containing pulp is produced by subjecting chaff to hydrolysis in a hydrotropic solution, whereupon hydrolysate is separated from cellulose-containing fibres for the production of hydrolysate-based fertilizers and the fibres are refined to a cellulose-containing pulp; and cellulose-containing fibre is obtained by subjecting chaff to pre-hydrolysis in water, whereupon hydrolysate is separated from the cellulose-containing pulp for use as a nutrient medium for cultivating yeast, protein and microprotein by bioconversion and the remaining cellulose-containing pulp is subjected to hydrolysis in a hydrotropic solution to remove lignin, after which the cellulose-containing pulp is subjected to refining to obtain cellulose-containing fibre and the lignin-containing filtrate is subjected to separation such that the cooking liquor from the lignin-containing residue can be reused, and the lignin-containing residue is washed with water and then dried.

Description

METHOD FOR COMPLEX PROCESSING OF MEADOW GRASSES AND A TECHNOLOGICAL COMPLEX FOR PROCESSING MEADOW GRASSES

DESCRIPTION

The invention relates to the field of agriculture and to the pulp and paper industry, namely to methods for processing cellulose-containing meadow plants [C13K 1/02, D21H 11/12, D21C 1/00, D21C 1/02, D21C 3/00, D21C 3/04].

The problem of raw material supply is pressing in the modern world, as it directly impacts a country's industrial potential and future growth. One type of raw material widely used in the production of various products is cellulose. Until recently, the main source of cellulose was the wood of deciduous and coniferous trees, but the search for cellulose sources and research in this area have made it possible to obtain cellulose from grassy biomass. Grassy cellulose production technologies, to varying degrees, replicate wood cellulose production technologies and share the same disadvantages: enormous water turnover; high yields of difficult-to-utilize byproducts; high energy consumption; and low efficiency.

The prior art discloses a METHOD FOR PRODUCING A SUSPENSION BASED ON GRASS FIBROUS MATERIALS FOR MANUFACTURING PAPER OR CARDBOARD [EA 029141 B1, published: 02/28/2018], comprising the following stages: a) collecting meadow grass; b) cleaning the meadow grass mechanically or by blowing air and/or washing with water; c) cutting the meadow grass into fractions from 100 to 0.1 mm; d) crushing the meadow grass by fibrillation; d) producing granules from the meadow grass; e) suspending the meadow grass in water; g) adding fractions of cellulose fibers and/or paper waste and/or auxiliary substances to the suspension.

The disadvantage of the analogue is the high content of lignin and protein in paper/cardboard due to the use of raw materials in this method that are not purified from ballast substances, as well as the use of not only stems, but also leaves of meadow plants, which reduce physical and mechanical properties of the product and which do not allow the use of the resulting raw materials in the production of paper/cardboard without the addition of primary or secondary wood pulp fibers in a volume of at least 60%.

In terms of consumer properties, the resulting product is inferior to technologies for processing the original cellulose-containing raw material using hydrolysis (hydrolysis cooking) due to the fact that the product has a large weight, low density and rigidity, and low consumer qualities.

In modern production, chemical-thermomechanical pulp produced from cellulose-containing raw materials is used.

Also known is a CONTINUOUS METHOD FOR PRODUCING CELLULOSE FROM HERBALI PLANT RAW MATERIALS [RU 2636556 C1, published: 23.11.2017], which includes the following stages:

(I) preparing herbaceous plant material by grinding it into pieces of 1.5-30 cm in length and 0.5-15 mm in diameter and removing dust particles from said material using a fan,

(II) continuous cooking of the dust-free herbaceous plant material prepared in step (I) in a cooking unit which is a vertical column with smooth internal walls, into the upper part of which a conveyor continuously feeds the herbaceous plant material, characterized in that, in parallel with the feeding of the dust-free material, cooking chemicals (a group consisting of NaOH and NaCl or NazSCh), fresh water, regenerated water and steam are continuously fed into the upper part of said cooking unit, the cooking temperature is 70-100°C, and in the course of the described continuous cooking method a suspension is formed with the following composition (on average):

(a) weight percentage of NaOH 0.9-1.5;

(b) weight percentage of NaCl or NazSO4 0.15-0.4; and

(c) weight percentage of herbaceous plant material 15-18; where the concentration of ingredients is calculated from the weight of the liquid phase;

- the decomposition of non-cellulosic material from herbaceous plant raw materials occurs during the transition of the mass from the upper to the lower part of the said digester solely under the influence of gravity, which lasts from 40 minutes to 2 hours, and

- the cooked paper pulp is concentrated in the lower part of the cooking unit (10) and is continuously removed from the lower part of the said unit at a rate equal to the feed rate brewing unit (10) using a conveyor, which allows for compensation of hydraulic pressure.

The continuous method for producing cellulose pulp also includes the following steps:

(III) dispersion, during which the cooked pulp suspension obtained in step (II) is treated with a dispersant;

(IV) dilution, during which the paper pulp, which has been dispersed in stage (III), is diluted with water in a special chamber to obtain from an initial paper pulp concentration of 15-18 weight percent a concentration of 3-6 weight percent;

(V) sorting and fractionating, during which the diluted suspension obtained in step (IV) passes through a sorting and fractionating device equipped with a sieve with cells of 0.1-0.5 mm and is separated into two fractions;

- the first fraction is the one that did not pass through a sieve with cells of 0.1-0.5 mm in an amount of no more than 50 weight percent; and

- the second fraction is the one that has passed through a sieve with 0.1-0.5 mm cells in an amount of at least 50 weight percent, which is considered high-quality material for further processing, which is fed into an additional chamber.

The first fraction obtained at stage (V) is then ground in grinders 1-3, and then:

(a) returns to the additional chamber at stage (IV) to repeat stages (IV) and (V); or

(b) is transmitted directly to the additional chamber.

The material collected in the additional chamber then goes through a process that includes the following steps: concentration in a dewaterer to remove black liquor (recovered liquid phase), dilution in an additional chamber with fresh water and preparation of pulp in communicating chambers; and optionally, bleaching of the paper pulp in a bleaching chamber, which is controlled by a valve, resulting in a pulp suitable for making paper or producing pulp sheets; wherein the used water recovered in the dewaterer is returned through piping to the digester at stage (II) and to the dilution chamber at stage (IV). A disadvantage of the analogue is the use of acids and alkalis during processing, the use of which reduces the possibility of using the resulting cellulose and by-products as environmentally friendly raw materials for the production of feed and paper suitable for food products.

The closest in technical essence is the METHOD OF PROCESSING CELLULOSE-CONTAINING RAW MATERIALS [RU 2456394, published: 08.12.2010], which includes prehydrolysis, cooking lignocellulose in a 30% hydrotropic solution for 1-3 hours, filtering the resulting cellulose, washing it with a 30% hydrotropic solution, subsequent washing with water, bleaching the cellulose mass with hydrogen peroxide in a sodium hydroxide solution to obtain bleached cellulose, treating it with an acid solution followed by treatment with a solvent, filtration and drying, while the spent cooking solution - filtrate - is treated with water at a temperature of 50 ° C, lignin is filtered, washed and dried, and miscanthus or fruit shells of cereal crops, or straw are used as cellulose-containing raw materials cereal crops.

The main technical challenge of the analogs and prototype is the use of single-process technologies for processing cellulose-containing raw materials, the end product of which is a single product—that is, cellulose-containing powder, fibrous materials, or chemithermomechanical pulp, obtained, among other things, from the vegetative stem and leaf parts of plants. This is inefficient due to the low quality of the resulting cellulose-containing raw material due to the high protein content, which is an antagonist to cellulose, and uneconomical due to the large amount of waste generated during processing. Thus, it is more practical to use the protein-rich leaf fraction, after separation from the stem fraction, in feed production.

Furthermore, the methods claimed in the analogs and prototype do not address the problem of obtaining and using pure extractive substances contained in the hydrolysate. The use of acids and alkalis in processing does not allow for the production of an environmentally friendly final product without additional neutralization steps, nor does it allow for the use of derivatives such as the hydrolysate as a nutrient medium for cultivating microorganisms such as feed yeast, mycoproteins, microbial feed protein, etc. The plant material used for processing pulp on an industrial scale requires significant land for cultivation. This requires the use of land allocated for agricultural purposes, primarily for the production of livestock feed. In this case, a differentiated approach to land allocation from this agricultural sector is required, and using hay solely for pulp production, without utilizing the leaf fraction, is wasteful.

The objective of the invention is to eliminate the shortcomings of analogues and prototypes.

The technical result of the invention consists in providing the possibility of efficient complex waste-free processing of meadow grasses, including the stages of obtaining cellulose from the stem fraction, bio-feed from the leaf fraction, protein from the hydrolysate of the stem fraction and native reactive lignin.

The said technical result is achieved due to the fact that the method for the complex processing of meadow grasses, characterized by the fact that it includes preliminary chopping of hay of perennial cereal grasses, separation of the chopped hay with the possibility of separating the stem, leaf and seed fractions from each other, granulating the leaf fraction to obtain animal feed and re-chopping the seed and stem fractions, after which the chopped seed fraction is used as an additive to the granulated leaf fraction or to obtain a nutrient medium for cultivating proteins, and the chopped stem fraction is used as raw material for obtaining a cellulose-containing powder, a cellulose-containing mass, a cellulose-containing fibrous material, hydrolysates and lignin, wherein to obtain a cellulose-containing powder, the chopped stem fraction is ground into powder, to obtain a cellulose-containing mass, the chopped stem fraction is subjected to hydrolysis in a hydrotropic solution with the possibility of removing lignin from the cellulose-containing mass, After hydrolysis is complete, the hydrolyzate is separated from the cellulose-containing fibers to obtain fertilizers based on it, and the fibers are refined into a cellulose-containing mass; to obtain cellulose-containing fiber, the chopped stem fraction is subjected to pre-hydrolysis in water; after pre-hydrolysis, the hydrolyzate is separated from the cellulose-containing mass. for use as a nutrient medium for cultivating yeast, protein and mycoprotein by bioconversion, and the separated cellulose-containing mass is subjected to hydrolysis in a hydrotropic solution with the possibility of removing lignin from the cellulose-containing mass, after completion of the hydrolysis, the cellulose-containing mass is subjected to refining to obtain cellulose-containing fiber, and the lignin-containing filtrate obtained as a result of hydrotropic cooking is subjected to separation with the possibility of separating the cooking solution from the lignin-containing sediment for reuse, the lignin-containing sediment is washed with water and dried.

In particular, preliminary crushing of hay from perennial cereal grasses is carried out to a fraction size of 10 to 30 mm.

In particular, separation is carried out using dry methods.

In particular, the stem fraction is re-crushed into chopped material ranging in size from 1 to 10 mm.

In particular, the seed fraction, after repeated grinding, is partially or completely used as an additive to the leaf fraction during its granulation.

In particular, the chopped stem fraction is ground into a powder with a particle size of no more than 1 mm to obtain cellulose-containing powder.

In particular, a 30% sodium benzoate solution is used as a hydrotropic solution for hydrolysis to obtain a cellulose-containing mass.

In particular, a 40% sodium benzoate solution is used as a hydrotropic solution for hydrolysis to obtain cellulose-containing fiber.

In particular, hydrolysis in a hydrotropic solution is carried out for 1-3 hours.

In particular, hydrolysis in a hydrotropic solution is carried out at a temperature of 40-50 °C.

In particular, before refining, the fibers are moistened in water to obtain cellulose-containing mass.

In particular, prehydrolysis of chopped peas in water is carried out at a temperature of 140°C.

In particular, prehydrolysis of chopped peas in water is carried out for 0.5-1 hour.

The said technical result is achieved due to the fact that the technological complex for the comprehensive processing of meadow grasses, including a preliminary preparation line and three technological sections for obtaining cellulose-containing powder, cellulose-containing mass and cellulose-containing fiber, a line pre-treatment includes means for loading hay of perennial cereal grasses, a chopper for chopping hay, a separator for separating the stem, leaf and seed fractions from each other after chopping, a granulator of the leaf fraction, choppers for the stem and seed fractions, means for storing granules of the leaf and seed fractions, the outlet of the separator with the separated stem fraction is connected to the chopper of the stem fraction, the outlet of the separator with the separated leaf fraction is connected to the granulator, and the outlet of the separator with the separated seed fraction is connected to the chopper of the seed fraction, the granulator of the leaf fraction and the chopper of the seed fraction are connected to means for storing granules of the leaf fraction and powder of the seed fraction, respectively, the outlet of the pre-treatment line is connected to the process sections by a transfer device configured to feed chopped stem fraction to the process sections, the process section for obtaining cellulose-containing powder contains a chopper connected in series The process section for obtaining the cellulose-containing mass comprises a hydrolysis reactor, a pressing unit for separating the hydrolysate, a refiner, a cellulose-containing mass means, and a hydrolysate storage means connected to the pressing unit, which are connected in series. The process section for obtaining the cellulose-containing fiber comprises a pre-hydrolysis reactor and a pressing unit connected to it, the pressing unit is connected to the hydrolysis reactor and a means for storing the hydrolysate obtained during the pre-hydrolysis. A refiner and a means for storing lignin are connected to the hydrolysis reactor. The refiner is connected to a means for storing the cellulose-containing fiber. A reactor-fermenter for bioconversion of the hydrolysate and means for storing the producers obtained in the reactor-fermenter are connected in series to the means for storing the hydrolysate.

In particular, the loading means are designed in the form of a loading hopper or a feeding conveyor.

In particular, the means for storing granules, seed fraction powder, cellulose-containing powder, mass, and fiber are made in the form of bunkers. In particular, the storage facilities for hydrolysate, lignin, and feed protein are made in the form of containers.

In particular, the separator is of a dry type.

In particular, loading means, crushers, separators, granulators, and storage means are connected into a process line by conveyors.

In particular, crushers for chopping hay and stem fraction are made in the form of crushers, roller or knife.

In particular, the seed fraction crusher is made in the form of a mill.

In particular, the crusher for converting chaff into cellulose-containing powder is made in the form of a conical refiner or a disc crusher.

In particular, the hydrolysis reactor, the pressing unit, the refiner and the means for storing the cellulose-containing mass, as well as the hydrolysis reactor with the transfer unit of the section for obtaining the cellulose-containing mass are connected to each other by conveyors.

In particular, the pressing unit of the section for obtaining cellulose-containing mass is made in the form of a centrifuge, press, and extruder.

In particular, the pressing unit is connected to the hydrolysate storage facility by a pipeline.

In particular, the pre-hydrolysis reactor, the pressing unit, the hydrolysis reactor, the refiner, the cellulose-containing fiber storage facility, and the pre-hydrolysis reactor with the cellulose-containing fiber production section loader are interconnected by conveyors.

In particular, the pressing unit of the section for obtaining cellulose-containing fiber is made in the form of sieves, a press, a centrifuge or an extruder.

In particular, the pressing unit and the hydrolysis reactor are connected to the storage facilities for hydrolysate and lignin by pipelines.

In particular, the means for storing cellulose-containing mass and cellulose-containing fiber are made in the form of drying bins equipped with stirrers.

Brief description of the drawings.

Fig. 1 shows a block diagram of the complex processing of meadow grasses.

Fig. 2 shows the structural diagram of a complex for the comprehensive processing of meadow grasses. The following are indicated on the figures: 1 - loading hopper, 2 - crushers, 3 - separator, 4 - granulator, 5 - hopper for storing granules, 6 - reloader, 7 - hopper for storing cellulose-containing powder, 8 - hydrolysis reactors, 9 - squeezing units, 10 - refiners, 11 - hopper for storing cellulose-containing mass, 12 - containers for hydrolysate, 13 - reactor for pre-hydrolysis, 14 - hopper for cellulose-containing fiber, 15 - container for lignin, 16 - reactor-fermenter, 17 - container for feed protein, 18 - hopper for storing seed fraction.

Implementation of the invention.

The essence of the claimed invention is the creation of a waste-free technology for the complex processing of meadow, primarily perennial cereal plants, with the aim of obtaining cellulose-containing powder, cellulose-containing mass for the production of paper, high-protein animal feed, hydrolysate as a base for mineral fertilizers, hydrolysate as a nutrient medium for the cultivation of yeast, microbial protein and mycoproteins, lignin.

The following grasses are used as feedstock: timothy grass, meadow fescue, cocksfoot, awnless brome, tall ryegrass, multi-cut ryegrass, festulolium, wheatgrass, wheatgrass, Siberian couch grass, meadow foxtail, and others, or a combination of these in varying proportions. Other meadow plants are permitted in perennial grass hay, but not more than 50%.

Table 1 shows the percentage of essential nutrients in various plants. Table 2 shows the percentage of protein in plant stems and leaves.

Table 1.

Table 2. The tables show that plant stems contain up to 50% less protein than leaves, which increases the proportion of plant pulp in the pulp slurry used for paper/cardboard production, as only plant stems are used for this purpose. Toward the end of the growing season, the nutritional value of plants decreases due to increased fiber content, decreased protein content, and reduced digestibility of the feed.

Perennial grasses are characterized by an increase in fiber content and the proportion of ears (panicles) depending on the growing season. Table 3 shows an example of the ratio of stems, leaves, and ears (panicles) in the awnless brome crop by growing season.

Table 3.

Table 4 shows the average crude fiber content of some perennial meadow grasses at different stages of vegetation (in percent).

Table 4.

In terms of obtaining pulp from the stem fraction, it is preferable to harvest the feedstock (hay) during the fruiting phase, when the stem content is at its maximum weight, accounting for 56.5% of the total feedstock mass. The content of ears (seed fraction) also reaches its maximum value during this period, at 27.8% of the total mass. Disposing of the seed fraction as waste is impractical for the comprehensive processing of meadow grasses, which requires utilizing the full range of feedstock components and derivatives obtained during processing. The present invention proposes using such a significant amount of ears containing nutrient-rich seeds as an additive for granulated feed made from the leaf fraction and a nutrient medium for cultivating proteins.

The method for the complex processing of meadow grasses is characterized by stages (see Fig. 1), where in the first preliminary stage, chopped stem fraction is obtained from the hay of perennial cereal plants for obtaining cellulose-containing raw materials in the form of powder, mass or fibrous material, a granulated leaf fraction for obtaining animal feed and a seed fraction for use as an additive in animal feed or in a nutrient medium for cultivating proteins, and the second stage can be carried out in one, two or three directions, as a result of which cellulose-containing powder and/or cellulose-containing mass and hydrolysate are obtained as a basis for mineral fertilizers, and/or fibrous cellulose-containing mass, hydrolysate as a nutrient medium for cultivating proteins, protein and hydrolytic lignin.

To obtain chopped stem fraction, leaf fraction granules, and seed fraction, perennial grass hay is first crushed mechanically, for example, in crushers, shredders, etc., to a fraction of 10 to 30 mm. The limits for fractional crushing of hay from 10 to 30 mm are determined by the fact that when hay is crushed to a size smaller than 10 mm, which primarily determines the crushing size of the stem fraction, the leaf fraction, which has a more fragile structure, is crushed more finely and can turn into fine dust, which is not used in further processing. In this case, the yield of finished products decreases, which negatively impacts overall production efficiency. Chopping hay to a size greater than 30 mm is also impractical, since with coarser chopping, the leaf and seed fractions are not completely separated from the stem fraction, which ultimately increases the protein content in the stem fraction, which negatively affects the quality of the cellulose subsequently obtained from the stem fraction.

Next, in the first stage, the chopped hay is separated into stem, leaf, and seed fractions. Separation is primarily accomplished using dry methods, such as air separation, sieves, vibrating tables, and the like.

After separation of the hay, the leaf fraction is sent for granulation, the seed fraction is sent for grinding into powder (flour), and the stem fraction is sent for re-grinding into chopped pieces of 1 to 10 mm in size. Powder (flour) of seed fractions can be partially or completely used as an additive to the leaf fraction during its granulation.

Granulation of the leaf fraction is necessary to change the structural and mechanical properties of hay, reduce oxidative processes in granules in order to increase its digestibility and nutritional value, and also to reduce the cost of transportation.

The need to crush the stem fraction into chopped material with a size of 1 to 10 mm is dictated by the fact that some of the cellulose-containing raw material obtained in the first stage undergoes hydrolysis, and crushing the raw material to a chopped material smaller than 10 mm improves the diffusion of liquid solutions into the chopped material and increases the efficiency of hydrolysis. Increasing the diffusion of liquid solutions into the chopped material also allows for a reduction in the water-to-solid ratio during subsequent hydrolysis of the chopped material, which in turn leads to a reduction in the amount of solution extracted and, consequently, an increase in its concentration. Reducing the stem fraction to a size smaller than 1 mm is impractical, as chopped material of this size is prone to caking and clumping, which reduces flowability, leads to deterioration in consumer properties, and leads to a loss of quality of the chopped stem fraction.

As a result of the first stage, the following products are obtained: chopped stem fraction, granulated leaf fraction for further use as animal feed, and powder (flour) of the seed fraction for further use as an additive to the granulated leaf fraction or for obtaining a nutrient medium for cultivating proteins.

The resulting chopped stem fraction is used as raw material for producing cellulose-containing powder, cellulose-containing pulp, cellulose-containing fibrous material, and derivatives such as hydrolysate and lignin. These derivatives are produced by dividing the chopped stem fraction obtained in the first stage among three process sections in a ratio dependent on the desired final product ratio. For example, the chopped stem fraction obtained in the first stage is divided among three process sections in a ratio of 6:3:1 to produce raw material for packaging cardboard, or 3:3:4 to produce raw material for printing, design, or technical cardboard with enhanced strength characteristics.

To obtain cellulose-containing powder, the first part of the chopped stem fraction after the first stage of complex processing is fed to the first technological A section where the aforementioned chopped stalk is ground into a powder with a particle size of no more than 1 mm. A conical refiner and/or a disc grinder (mill) are used for grinding. The resulting powder is then used in paper and cardboard production to produce a cellulose-containing suspension using methods known in the art. To obtain a cellulose-containing pulp, the second portion of the chopped stalk fraction, after the first stage of complex processing, is fed to the second section of the process line, where the following steps are performed: hydrolysis of the chopped stalk fraction, separation of the hydrolysate by squeezing, wetting of the cellulose-containing fiber in water, and refining of the fiber to produce a cellulose-containing pulp.

Hydrolysis of chopped stem fraction is carried out in a 30% sodium benzoate solution for 1-3 hours at 40-50°C. Hydrolysis, or hydrotropic cooking, is a neutral method of producing cellulose, and its main purpose is to cleave the glycosidic bonds that link monosaccharide residues in the polysaccharide molecule and isolate lignin. Hydrotropic cooking allows for high-yield cellulose production due to the use of a virtually neutral cooking solution. The hydrotropic substance, sodium benzoate, significantly increases the solubility of lignin in the cooking solution. Sodium benzoate is the sodium salt of benzoic acid. It is a food additive belonging to the group of preservatives with the number E211. It is a white powder with no odor or a slight odor of benzaldehyde.

Hydrolysis with a 30% hydrotropic solution allows for the maximum removal of lignin from industrial cellulose; using a lower concentration solution results in the precipitation of lignin from the filtrate residue on the surface of the target cellulose. Sodium benzoate was chosen for its following properties: it is stable in water at temperatures above 300°C, is non-corrosive, and dissociates weakly during acidification, thus not lowering the solution pH and not affecting cellulose autohydrolysis. In addition to sodium benzoate, other hydrotropic salts that can be used include alkaline salts of naphthoic acid, benzenesulfonic acid, naphthalenesulfonic acid, as well as their homologues and derivatives, salts of thiophenecarboxylic acids, derivatives of the hydroaromatic series, such as alkaline salts of naphthenic acids, abietic and sylvatic acids, and salts of various fatty aromatic and aliphatic acids.

A decrease in the concentration of sodium benzoate solution during hydrolysis has a negative effect on the quality of the target cellulose, leading to an increase in the mass fraction Acid-insoluble lignin. Increasing the concentration of sodium benzoate solution does not significantly improve the quality of the target pulp and also leads to additional consumption of hydrotropic salts. Therefore, it is advisable to use a 30% sodium benzoate solution.

Increasing the duration of hydrotropic cooking does not improve the quality of the target pulp, but leads to a decrease in yield. Reducing the cooking time to less than 1 hour leads to a sharp deterioration in pulp quality. This is due to insufficient time for the lignocarbohydrate complex to be broken down and the free cellulose to be released by dissolving the lignin in the hydrotropic solution. An increased pulp yield and a low alpha-cellulose content confirm the presence of undercooked raw materials.

Increasing the temperature from 40°C to 50°C increases the yield by approximately 5%. This is because at elevated temperatures, compared to room temperature, solvation processes occur more rapidly, resulting in more complete formation of the curd-like lignin precipitate from the reaction mixture during precipitation. Further increases in temperature do not result in an increase in lignin yield.

After the hydrolysis stage, the resulting cellulose-containing fiber is pressed to separate the hydrolysate from the fiber. Pressing is performed by any known method, such as a centrifuge, press, extruder, etc.

The hydrolysate is sent to a separate container for subsequent production of fertilizers, while the cellulose-containing mass, a brown fibrous material containing uncooked raw material (no more than 5% by weight), undergoes refining. The use of sodium benzoate as a hydrotropic agent, which, as noted above, acts as a preservative, prevents the growth and spread of microbes, fungi, and bacteria in the hydrolysate. This allows for its long-term storage before further use.

Refining is carried out using any known method to grind cellulose-containing fibers into a cellulose-containing mass. Before grinding, the fibers are soaked in water to create a more flexible mass and facilitate the grinding process. The output from the second section is a cellulose-containing mass of a characteristic brown color, which can be further processed depending on needs. They can be bleached, or they can be used as final raw materials for producing paper and cardboard products with environmentally friendly properties.

To obtain cellulose-containing fiber, one portion of the chopped stem fraction, after the first stage of complex processing, is fed to the third section of the process line, where the following steps are performed: aqueous hydrolysis of the chopped stem fraction, separation of the hydrolysate by pressing, hydrolysis of the pulp in a hydrotropic solution, and refining of the pulp to obtain cellulose-containing fibrous material. Prehydrolysis of the chopped stem fraction (aqueous hydrolysis) in the third stage is carried out in water in separate reactors, such as autoclaves, at a temperature of 140°C for 0.5-1 hour. This prehydrolysis stage allows for the partial removal of extractive substances and hemicellulose, ultimately ensuring higher-quality cellulose and a purer lignin solution obtained in subsequent stages, as well as the production of a hydrolysate with a high sugar content, which allows for the use of this hydrolysate, for example, by bioconversion, for the cultivation of fodder yeast, mycoprotein, or microbial feed protein by any known method. Furthermore, prehydrolysis reduces the cooking time and energy consumption. Hydrotropic cooking without prehydrolysis produces pulp with a reduced alpha-cellulose content, an increased lignin content, and increased ash content. The prehydrolysis step is necessary for subsequent lignin recovery because, without this step, the cooking liquor becomes acidified, reducing the solubility of native lignin in the liquor. This, in turn, prevents the same cooking liquor from being used ten or more times. Furthermore, diluting the acidified cooking liquor can contaminate the target lignin with benzoic acid, necessitating an additional purification step for the target lignin.

At the end of the prehydrolysis stage, the hydrolysate is separated by any known method, such as draining or squeezing on sieves, pressing, centrifugation, or extrusion. The hydrolysate is sent for further bioconversion. The separated cellulose-containing mass is sent to the hydrolysis stage (hydrotropic cooking) in a hydrotropic solution to maximize the removal of lignin from the pulp. Cellulose-containing mass. The resulting lignin can be used to produce biofuels, sorbents, etc.

One of the advantages of the claimed method is the production of a pure hydrolysate from the prehydrolysis stage during the comprehensive processing of meadow grasses. This hydrolysate is subsequently used as a nutrient medium (substrate) for cultivating yeast, protein, and mycoprotein, which contain a large number of beneficial bacteria, unicellular yeast, actinomycetes (a group of microorganisms combining the characteristics of bacteria and fungi), filamentous fungi, and/or microbial associations. Plants are known to contain nitrogen-free extractive substances, including sugars, starch, glycogen, inulin, soluble parts of cellulose, hemicellulose, lignin, pectin, etc. The large amount of carbohydrates in plant biomass provides a source of potential energy in the form of sugars, which can be used in a variety of industrial and agricultural processes. Despite the separation of the leaf fraction of meadow grasses from their stem fraction in the first stage of the claimed method, the leaf fraction still contains some plant matter in the form of strong polymers such as cellulose, hemicellulose, and lignin, which are partially or completely indigestible as nutrients by livestock (except cattle) and poultry. To enhance the nutritional value and improve the digestibility of plant material components, the present invention proposes using the derivatives isolated during the comprehensive processing of meadow grasses, namely, the hydrolysate, including the addition of the seed fraction powder (flour) obtained in the first stage, to obtain protein-rich biomass from the hydrolysate using bioconversion. The bioconversion products of plant materials are used in animal feed (fodder yeast, various microbial synthesis preparations), as well as as medicines, chemicals, etc. Microorganisms such as bacteria, yeast, and microscopic fungi are used for the bioconversion of carbohydrates in plant materials. Additional microbiological proteinization of the leaf fraction (granules) obtained in the first preparatory stage of complex processing allows for a significant increase in protein content due to plant carbohydrates, which are absorbed by microorganisms and converted into microbial biomass proteins at the rate of obtaining 25 g of protein from 100 g of sugar (conversion coefficient - 0.25). Bioconversion of the hydrolysate obtained at the prehydrolysis stage is carried out by fermentation using known methods, such as deep, surface, aerobic, anaerobic, periodic, continuous, using a monoculture or mixed association of microorganisms, etc.

For example, to obtain a fermentation product from a liquid hydrolysate, a submerged cultivation method can be used, carried out in a liquid nutrient medium. Submerged cultivation is carried out in fermenters equipped with mixing devices, aeration systems, and temperature and pH regulation. The nutrient media are sterilized in fermenters or continuous sterilization units. The advantages of the submerged cultivation method include a high level of mechanization and automation of the process, the ability to conduct the process under sterile conditions, with adjustable pH and medium composition, and in a continuous mode, which significantly improves economic performance and ensures the genetic stability of the producer microorganisms.

Bioconversion of the hydrolysate obtained by the method described in the present invention makes it possible to replenish feed protein, and the producers of feed protein can be bacteria, yeast, microscopic algae, micro- and macromycetes.

Advantages of biomass production using microbial synthesis:

1) high rate of biomass accumulation, which is 500-5000 times higher than that of plants or animals;

2) microbial cells accumulate a large amount of protein (yeast - 9 to 60%, bacteria - up to 75% by weight);

3) there is no multi-stage process in the production of microbial protein;

4) the biosynthesis process takes place under mild conditions at a temperature of 30-45°C, pH 3-6 and pressure of ~ 0.1 MPa;

5) the process is less labor-intensive compared to obtaining agricultural products and organic protein synthesis.

The next stage of complex processing involves hydrolysis (hydrotropic cooking) of the chopped stem fraction. A 40% sodium benzoate solution is used for hydrolysis. The use of a 40% sodium benzoate solution, as opposed to the use of a 30% sodium benzoate solution in the second stage of complex processing, is due to the fact that dry chopped stem fraction was used for hydrolysis in the second stage, while hydrotropic cooking (hydrolysis in The wet pulp obtained after prehydrolysis is subjected to hydrotropic solution (hydrotropic solution). As mentioned above, a decrease in the concentration of sodium benzoate solution negatively impacts the quality of the target pulp. Therefore, to achieve the sodium benzoate solution concentration in the pulp after aqueous hydrolysis, it is increased to 40%, which in the wet pulp decreases to 30%.

Hydrolysis is carried out for 1-3 hours at a temperature of 40-50°C. Increasing the hydrolysis time does not improve the quality of the target pulp but leads to a decrease in yield, while reducing the cooking time to less than 1 hour leads to a sharp deterioration in pulp quality. Increasing the temperature from 40°C to 50°C increases the yield by approximately 5%. This is because at elevated temperatures, compared to room temperature, solvation processes occur more rapidly, therefore the formation of a curd-like precipitate of lignin from the reaction mixture during precipitation is more complete. Further increases in temperature do not result in an increase in lignin yield.

After the hydrolysis stage, the resulting cellulose-containing mass is refined, and the filtrate obtained from hydrotropic cooking, containing lignin, is poured into a separate container for subsequent separation, such as decanting to separate the cooking liquor from the lignin-containing precipitate. The cooking liquor is recovered for reuse in hydrolysis by filtering it and adjusting the sodium benzoate concentration to the required 40%. The lignin-containing precipitate is washed with water to remove the cooking liquor. The liquid lignin is dried using methods known in the art. The resulting powdered lignin is packaged in industrial containers.

Refining is carried out by any known method to obtain cellulose-containing fiber. Unlike the second section, the pulp is not wetted before grinding in this third section, as it has sufficient moisture for refining. The output from the third section is a cellulose-containing fiber of a characteristic brown color, which can then be bleached, depending on needs, or used as a final raw material for the production of environmentally friendly paper and cardboard products. To implement the proposed method, a technological complex for the comprehensive processing of meadow grasses is used. The complex consists of a pre-treatment line and three processing sections for producing cellulose-containing powder, cellulose-containing mass, cellulose-containing fiber, and related products.

The pre-treatment line includes a loading bin 1 (see Fig. 2) or a feed conveyor for loading perennial cereal hay, a chopper 2 for chopping hay, a separator 3, choppers 2 for separately chopping the stem and seed fractions, a granulator 4, storage means in the form of a bin for storing granules 5 of the leaf fraction and a bin for storing the seed fraction 18. Separator 3 is of the dry type, to the input of which chopped hay is fed. The outlet of separator 3 with the separated stem fraction is connected to chopper 2 of the stem fraction, the outlet of separator 3 with the separated leaf fraction is connected to granulator 4, the outlet of separator 4 with the separated seed fraction is connected to chopper 2 of the seed fraction into powder (flour). Granulator 4 is connected to the bin for storing granules 5 of the leaf fraction. The seed fraction chopper 2 is connected to the seed fraction storage bin 18. The loading bin 1 for loading meadow grass hay, the choppers 2, the separator 3, the granulator 4, the bin for storing granules 5 for the leaf fraction, and the seed fraction storage bin 18 are connected in a process line by conveyors, preferably of the closed type, such as auger conveyors. The choppers 2 for chopping hay and the stem fraction may be designed as crushers, such as roller or knife crushers, and the seed fraction crusher 2 for crushing into powder (flour) may be designed as a mill.

The output of the pre-treatment line is connected to the process sections by a transfer machine 6, which ensures the transfer of chopped stem fraction to the process sections.

The first process section for producing cellulose-containing powder comprises a grinder 2 and a storage means in the form of a cellulose-containing powder storage bin 7, connected to a transfer device 6 at the entrance to the process section and to each other by conveyors, preferably closed-type, such as screw conveyors. The grinder 2 is designed as a conical refiner and/or a disc grinder. The second process section for the cellulose-containing mass comprises a hydrolysis reactor 8, a pressing unit 9, a refiner 10, a hydrolysate tank 12 and a storage means in the form of a bin for storing the cellulose-containing mass 11. The hydrolysis reactor 8, the pressing unit 9, the refiner 10 and the bin for storing the cellulose-containing mass 11, as well as the hydrolysis reactor 8 with the transfer unit 6 at the entrance of the section are interconnected by conveyors, preferably of a closed type, for example, screw conveyors. The pressing unit 9 is designed, for example, in the form of a centrifuge, press, extruder, etc. and is connected to the hydrolysate tank 12 by a pipeline. Wetting of the fiber before feeding it to the refiner 10 via a conveyor or directly in the refiner 10 is carried out by spraying water from nozzles.

The third process section for obtaining cellulose-containing fiber comprises a prehydrolysis reactor 13, a pressing unit 9, a hydrolysis reactor 8, a refiner 10, storage means in the form of a bin for storing cellulose-containing fiber 14, tanks for hydrolysate 12 and lignin filtrate 15. The prehydrolysis reactor 13, the pressing unit 9, the hydrolysis reactor 8, the refiner 10, the bin for storing cellulose-containing fiber 14, as well as the prehydrolysis reactor 13 with the transfer unit 6 at the entrance of the section are connected to each other by conveyors, preferably of a closed type, for example, screw conveyors. The pressing unit 9 is designed as sieves, a press, a centrifuge, or an extruder. The pressing unit 9 and the hydrolysis reactor 8 are connected to the tanks for hydrolysate 12 and lignin 15 by pipelines.

Hydrolysate tank 12 is connected via a pipeline to at least one bioconversion reactor-fermenter 16. The number of fermentation reactors 16 depends on the producers used for growing the microbial protein and the type of microbial protein being grown. For example, three fermentation reactors 16 may be used to grow feed yeast, mycoproteins, and microbial feed protein. Fermentation reactor 16 is equipped with a stirrer, water for cooling, steam for heating the internal volume and the thickness of the culture medium in fermentation reactor 16, air for aeration, and pure culture. Feed protein tank 17 is connected to the outlet of fermentation reactor 16.

The bins for the cellulose-containing mass 11 and the fibre 14 of the second and third process sections can be made in the form of drying bins equipped with stirrers. The technological complex for processing meadow grasses is used as follows.

The feedstock, consisting of dried perennial meadow grasses (hay), is fed into loading bin 1. From bin 1, the hay is fed via a conveyor to first chopper 2, where it is mechanically chopped into fractions ranging in size from 10 to 30 mm. From first chopper 2, the chopped mixture of stem, leaf, and seed fractions is fed via a conveyor to separator 3. Separator 3 separates the leaf, stem, and seed fractions. Next, the separated leaf fraction is fed via a conveyor to granulator 4, which produces pellets of the leaf fraction, suitable as nutritious animal feed. These pellets are then conveyed to granule storage bin 5 for subsequent shipment to the consumer. The seed fraction separated in separator 3 is fed via conveyor to crusher 2, where it is mechanically ground into powder (flour). The crushed seed fraction from crusher 2 is fed into seed fraction storage bin 18 or can be fed directly to granulator 4. The stem fraction separated in separator 3 is fed via conveyor to a second crusher 2, where the stem fraction is mechanically ground to a chopped particle size of 1-10 mm.

Next, the chopped stem fraction from the second crusher 2 is fed via a conveyor to the transfer unit 6, where the chopped material is divided into one, two or three streams depending on the need for the final product and is fed by conveyors to the process sections for further processing.

One of the chopped material flows for obtaining cellulose-containing powder is fed by the transfer machine 6 via a conveyor to the shredder 2 of the first process section, in which the chopped material is crushed into a powder with a fraction size of up to 1 mm and, after crushing, is fed into the cellulose-containing powder storage bin 7. Subsequently, the said powder is unloaded for suspension and the production of paper and cardboard products. The second of the chopped material flows from the transfer machine 6 is fed via a conveyor to the second process section for its hydrolysis in the hydrolysis reactor 8 in a 30% sodium benzoate solution for 1-3 hours at a temperature of 40-50 °C. Upon completion of the hydrolysis process, the resulting mass is fed by a conveyor to the squeezing unit 9, where the mass is squeezed to separate the liquid portion in the form of a hydrolyzate, which is fed through a pipeline into a separate tank for hydrolyzate 12 and a plastic fibrous mass, which is fed conveyor into refiner 10. In refiner 10, the mass is ground and fed by conveyor into cellulose-containing mass storage bin 11. Subsequently, hydrolysate from hydrolysate tank 12 is unloaded for obtaining mineral fertilizers based on it, and cellulose-containing mass from said bin 11 is unloaded for the production of paper and cardboard products, including by adding it to a suspension prepared from cellulose-containing powder obtained in the first technological section of the complex.

The third of the chopped ash streams from the transfer unit 6 is fed via a conveyor to the pre-hydrolysis reactor 13 of the third process section of the complex, where the pre-hydrolysis of the chopped ash is carried out in water at a temperature of 140°C for 0.5-1 hour. Upon completion of the pre-hydrolysis process, the resulting mass is fed by a conveyor to the pressing unit 9, where the mass is pressed to separate the liquid portion in the form of a hydrolyzate, which is fed via a pipeline to a separate tank for hydrolyzate 12 and a plastic fibrous mass, which is fed by a conveyor to the hydrolysis reactor 8 for hydrotropic cooking with the supply of a 40% sodium benzoate solution for 1-3 hours at a temperature of 40-50°C. Upon completion of the hydrolysis process, the resulting mass is fed by a conveyor to the refiner 10, where the mass is ground and then fed by a conveyor to the cellulose-containing fiber storage bin 14.

The liquid lignin-containing phase of the substance from hydrolysis reactor 8 can be separated, for example, by decanting to separate the cooking liquor from the lignin-containing precipitate. The cooking liquor is recovered for reuse in hydrolysis by filtration and addition of sodium benzoate to the required concentration of 40%. The lignin-containing precipitate is washed with water to remove the cooking liquor and sent to lignin tank 15, from which the lignin is then fed for drying, for example, by spraying, freeze-drying, etc., to obtain lignin powder. The resulting powdered lignin is packaged in industrial containers.

Subsequently, the cellulose-containing fiber from the bin 14 is loaded for the production of paper and cardboard products, including by adding it to a suspension prepared from the cellulose-containing powder obtained in the first technological section of the complex, including using the cellulose-containing mass obtained in the second technological section or using the said cellulose-containing mass without using Cellulose-containing powder. Lignin from lignin tank 15 is shipped for further processing, such as the production of biofuels, sorbents, etc., or sent for drying and packaging.

The hydrolysate stored in hydrolysate tank 12 is subsequently used as a nutrient medium for the cultivation of fodder yeast, mycoprotein, or microbial feed protein via bioconversion. For this purpose, the hydrolysate from hydrolysate tank 12 is fed to at least one fermenter-reactor 16. The number of fermenter-reactors 16 in the bioconversion stage depends on the producers used for microbial protein cultivation and the type of microbial protein being cultivated. For example, three fermenter-reactors 16 may be used in the bioconversion stage to cultivate fodder yeast, mycoprotein, and microbial feed protein. The protein obtained from the aforementioned hydrolysate can also be used to enrich the leaf fraction granules obtained during the preparatory stage. Fermentation reactor 16 is equipped with a stirrer, water for cooling, steam for heating the internal volume and the thickness of the culture medium in the fermentation reactor 16, and air for aeration and the pure culture. A feed protein tank 17 is connected to the outlet of fermentation reactor 16.

In one embodiment, bioconversion is carried out as follows. Initially, the pure culture is introduced into a small seeding apparatus (not shown in the figures) with a nutrient medium, the pH of which is adjusted to 5.5-5.8 with ammonia water or lime milk. Cultivation is carried out until the medium accumulates 3.5-4.0 g of cells/L on an absolutely dry basis. This typically requires 15-18 hours. The suspension from the seeding apparatus is then transferred to a large seeding apparatus (not shown in the figures), pre-filled with nutrient medium and sterile water in a ratio of 1:6 to 1:8. Aeration is turned on, and cultivation is carried out with constant top-up of nutrient medium and ammonia water to maintain the desired pH. The next step involves growing the seed culture in reactor-fermenter 16, filled 10% by volume with sterile or boiled water. Approximately 0.5 ^m³ of nutrient medium is added, and the entire contents are pumped out from the large seeding apparatus. The seed material is grown without collecting the suspension for 8-9 hours with intensive aeration and constant topping up of the nutrient medium until the biomass accumulates in reactor-fermenter 16 at a rate of 4-5 g ASW/L. After this, the seed culture is collected for the main production at a rate of 1.3-1.7 ^m³ /h. While simultaneously adding nutrient medium, the seed powder obtained in the first stage can be added to the reactor-fermenter 16 from the seed fraction storage bin 18. The fermentation process lasts from 5 to 10 days, after which the seed preparation cycle resumes. The reactor-fermenter 16 is the main apparatus in the bioconversion stage, ensuring the growth and development of microorganism populations in the liquid phase; transporting nutrients to the microorganism cells; removing metabolic products from the microbial cells; and removing heat from the environment. The following stages of the feed biomass production process flow chart follow:

- thickening of the suspension of microorganisms, during which the concentration of biomass increases to 12-16% of the ASW;

- heat treatment of the suspension, in which, when microorganisms are heated to a temperature of 75-85 °C for 10-40 minutes, the producer strain and almost all accompanying microflora die;

- concentration of the suspension by evaporation to 23-25% ASV;

- drying to form a finished product with a moisture content of ~ 10% (by weight).

After this, the prepared feed biomass is subjected to granulation and drying before packaging and packing the finished product or fed to the granulator 4 at the stage of granulating the leaf fraction of the first preparatory stage, where the biomass obtained by bioconversion is mixed with the leaf fraction before forming granules.

The proposed method enables the comprehensive processing of cellulose-containing grasses and a rapid response to current needs for obtaining various raw materials (products) in the required volume and quality by rerouting raw material flows between process sections. Furthermore, the proposed comprehensive processing of cellulose-containing grasses ensures waste-free production by eliminating the use of acids and alkalis, which limit the application of raw materials and simplify the production of environmentally friendly raw materials.

The resulting products (raw materials) can be used in a variety of ways. For example, the granules of the leaf fraction obtained during the first preliminary stage are used for animal feed as a high-protein product, as the leaf fraction is known to have the highest protein content. Enriching these leaf fraction granules with seed fraction powder or protein obtained by bioconversion of the hydrolysate obtained after the prehydrolysis stage, including with the addition of seed fraction powder, increases the protein concentration in this animal feed. The hydrolysate obtained after the hydrolysis stage in the second section can be used as a base for producing mineral fertilizers. The cellulose-containing powder obtained at the output of the first section, the cellulose-containing mass obtained at the output of the second section, and the cellulose-containing fiber obtained at the output of the third section can be used either individually, to produce paper and cardboard products of varying quality and purpose, or in various combinations when mixed during the paper and cardboard production stage, which expands the product line. This combined model allows for flexible production setup, eliminating downtime of production lines when demand for any product decreases, by redirecting raw materials to one or two of the three process sections.

The claimed invention makes it possible to implement the principle of biorefining—the most complete and efficient processing of plant materials (meadow grasses)—and allows for the production of plant cellulose from the fiber-rich stem fraction, nutritious feed from the protein-rich leaf fraction, various types of protein from the hydrolyzed stem fraction, granulated feed enriched with protein, and native reactive lignin.

Claims

FORMULA 1. A method for the comprehensive processing of meadow grasses, characterized in that it includes preliminary chopping of hay of perennial cereal grasses, separation of the chopped hay with the possibility of separating the stem, leaf and seed fractions from each other, granulating the leaf fraction to obtain animal feed and re-chopping the seed and stem fractions, after which the chopped seed fraction is used as an additive to the granulated leaf fraction or to obtain a nutrient medium for cultivating proteins, and the chopped stem fraction is used as raw material for obtaining a cellulose-containing powder, a cellulose-containing mass, a cellulose-containing fibrous material, hydrolysates and lignin, wherein to obtain a cellulose-containing powder, the chopped stem fraction is ground into powder, to obtain a cellulose-containing mass, the chopped stem fraction is subjected to hydrolysis in a hydrotropic solution with the possibility of removing lignin from the cellulose-containing mass, after the hydrolysis is completed, it is separated from cellulose-containing fibers are hydrolyzed to obtain fertilizers based on them, and the fibers are refined into a cellulose-containing mass, in order to obtain cellulose-containing fiber, the chopped stem fraction is subjected to pre-hydrolysis in water, after the pre-hydrolysis is completed, the hydrolyzate is separated from the cellulose-containing mass for use as a nutrient medium for cultivating yeast, protein and mycoprotein by bioconversion, and the separated cellulose-containing mass is subjected to hydrolysis in a hydrotropic solution with the possibility of removing lignin from the cellulose-containing mass, after the hydrolysis is completed, the cellulose-containing mass is refined to obtain cellulose-containing fiber, and the lignin-containing filtrate obtained as a result of hydrotropic cooking is subjected to separation with the possibility of separating the cooking solution from the lignin-containing sediment for reuse, the lignin-containing sediment is washed with water and dried. 2. The method according to paragraph 1, characterized in that the preliminary crushing of hay from perennial cereal grasses is carried out to a fraction of 10 to 30 mm in size. 3. The method according to paragraph 1, characterized in that separation is carried out using dry methods. 4. The method according to paragraph 1, characterized in that the repeated crushing of the stem fraction is carried out into chopped material with a size of 1 to 10 mm. 5. The method according to claim 1, characterized in that the seed fraction, after repeated grinding, is partially or completely used as an additive to the leaf fraction during its granulation. 6. The method according to paragraph 1, characterized in that the chopped stem fraction for obtaining the cellulose-containing powder is ground into a powder with a particle size of no more than 1 mm. 7. The method according to claim 1, characterized in that a 30% solution of sodium benzoate is used as a hydrotropic solution for hydrolysis to obtain a cellulose-containing mass. 8. The method according to claim 1, characterized in that a 40% solution of sodium benzoate is used as a hydrotropic solution for hydrolysis to obtain cellulose-containing fiber. 9. The method according to claim 1, characterized in that hydrolysis in a hydrotropic solution is carried out for 1-3 hours. 10. The method according to claim 1, characterized in that hydrolysis in a hydrotropic solution is carried out at a temperature of 40-50 °C. 11. The method according to claim 1, characterized in that before refining, the fibers are wetted in water when obtaining the cellulose-containing mass. 12. The method according to paragraph 1, characterized in that the prehydrolysis of the chopped grain in water is carried out at a temperature of 140°C. 13. The method according to paragraph 1, characterized in that the prehydrolysis of the chopped grain in water is carried out for 0.5-1 hour. 14. A technological complex for the comprehensive processing of meadow grasses, including a pre-treatment line and three technological sections for obtaining cellulose-containing powder, cellulose-containing mass and cellulose-containing fiber, the pre-treatment line includes means for loading hay of perennial cereal grasses, a chopper for chopping hay, a separator for separating the stem, leaf and seed fractions from each other after chopping, a granulator of the leaf fraction, choppers for the stem and seed fractions, means for storing granules of the leaf and seed fractions, an outlet of the separator with separated stem fraction is connected to a stem fraction crusher, the outlet of the separator with the separated leaf fraction is connected to a granulator, and the outlet of the separator with the separated seed fraction is connected to a seed fraction crusher, the leaf fraction granulator and the seed fraction crusher are connected to means for storing granules of the leaf fraction and seed fraction powder, respectively, the outlet of the pre-treatment line is connected to the process sections by a transfer device configured to feed chopped stem fraction to the process sections, the process section for obtaining cellulose-containing powder contains a series-connected crusher for chopping into powder and a means for storing cellulose-containing powder, the process section for obtaining cellulose-containing mass contains a series-connected reactor for hydrolysis, a squeezing unit for separating the hydrolysate, a refiner, a means for cellulose-containing mass and a means for storing the hydrolysate connected to the squeezing unit, the process section for obtaining cellulose-containing fiber contains a reactor for prehydrolysis and a pressing unit connected to it, the pressing unit is connected to a hydrolysis reactor and a means for storing the hydrolysate obtained during prehydrolysis, a refiner and a means for storing lignin are connected to the hydrolysis reactor, the refiner is connected to a means for storing cellulose-containing fiber, a reactor-fermenter for bioconversion of the hydrolysate and means for storing the producers obtained in the reactor-fermenter are connected in series to the means for storing the hydrolysate. 15. The complex according to paragraph 14, characterized in that the loading means are made in the form of a loading hopper or a feed conveyor. 16. The complex according to paragraph 14, characterized in that the means for storing granules, seed fraction powder, cellulose-containing powder, mass, and fiber are made in the form of bunkers. 17. The complex according to paragraph 14, characterized in that the means for storing hydrolyzate, lignin, and feed protein are made in the form of containers. 18. The complex according to paragraph 14, characterized in that the separator is of the dry type. 19. The complex according to paragraph 14, characterized in that the loading means, crushers, separator, granulator, and storage means are connected into a process line by conveyors. 20. The complex according to paragraph 14, characterized in that the crushers for crushing hay and stem fraction are made in the form of crushers, roller or knife. 21. The complex according to item 14, characterized in that the seed fraction crusher is made in the form of a mill. 22. The complex according to paragraph 14, characterized in that the crusher for converting the chopped material into cellulose-containing powder is made in the form of a conical refiner or a disk crusher. 23. The complex according to paragraph 14, characterized in that the hydrolysis reactor, the pressing unit, the refiner and the means for storing the cellulose-containing mass, as well as the hydrolysis reactor with the transfer unit of the section for obtaining the cellulose-containing mass are connected to each other by conveyors. 24. The complex according to paragraph 14, characterized in that the pressing unit of the section for obtaining the cellulose-containing mass is made in the form of a centrifuge, press, or extruder. 25. The complex according to item 14, characterized in that the pressing unit of the section for obtaining the cellulose-containing mass is connected to the hydrolyzate storage means by a pipeline. 26. The complex according to paragraph 14, characterized in that the pre-hydrolysis reactor, the pressing unit, the hydrolysis reactor, the refiner, the means for storing cellulose-containing fiber, as well as the pre-hydrolysis reactor with the transfer unit of the section for obtaining cellulose-containing fiber are connected to each other by conveyors. 27. The complex according to paragraph 14, characterized in that the pressing unit of the section for obtaining cellulose-containing fiber is made in the form of sieves, a press, a centrifuge or an extruder. 28. The complex according to item 14, characterized in that the pressing unit for obtaining cellulose-containing fiber and the hydrolysis reactor are connected to the means for storing the hydrolyzate and lignin by pipelines. 29. The complex according to paragraph 14, characterized in that the means for storing the cellulose-containing mass and cellulose-containing fiber are made in the form of drying bins equipped with agitators.