EP4271881A1

EP4271881A1 - Method for producing products based on non-woody biomass as raw material

Info

Publication number: EP4271881A1
Application number: EP21840069.5A
Authority: EP
Inventors: Anton Friedl; Maximilian LEHR; Martin MILTNER; Walter WUKOVITS
Original assignee: Technische Universitaet Wien
Current assignee: Technische Universitaet Wien
Priority date: 2020-12-29
Filing date: 2021-12-29
Publication date: 2023-11-08
Also published as: CA3203364A1; WO2022144379A1; US20240175206A1; EP4023813A1

Abstract

The invention relates to a method for producing products based on non-woody biomass as raw material, characterised in that non-woody biomass which contains cellulose, hemicelluloses and lignin and is in the form of particles is subjected to an extraction treatment with an extractant which comprises one or more organic solvents in an organic aqueous mixture of the solvent or solvents with water, wherein the content of fatty acids in the particles is reduced by the extraction treatment of the particles with the solvent by at least 70%, measured as hexanal content in wt.% after accelerated ageing for 72 hours at 90°C, but the content of cellulose, hemicelluloses and lignin is substantially preserved in this extraction treatment.

Description

Process for manufacturing products based on non-woody biomass as raw material

The invention relates to processes for the production of products based on non-woody biomass, in particular processes for the pre-treatment of non-woody biomass.

Non-woody biomass as a raw material for industrial processing into products (e.g. fibreboard or cardboard) contains - in addition to the main components cellulose, hemicelluloses and lignin - many different low and high molecular weight substances such as fatty acids, phenols, alcohols, aldehydes, pinenes, terpenoids and terpenes . These substances are grouped together as so-called extractives (or extractives) because they can be extracted from non-woody biomass using hot water and/or organic solvents (Boutekedj iret et al., in: Alternative Solvents for Natural Products Extraction (2014) , Chemat et al (Eds), 205-219 Martins et al (2017) J Mol Liq 241, 996-1002 Hippenstiel et al (2011) Arch , Food Rev. 12 (1996), 303-350). Many of these extractive substances are "organoleptically relevant substances" since they can lead to odor and taste interactions and impairments in products based on non-woody biomass with the environment relevant to the respective end use (e.g. food in the case of packaging board or room air in the case of fibreboard ) .In addition to extractives, which as volatile hydrocarbons naturally have characteristic odors (e.g. terpenes), aldehydes (especially hexanal) are primarily responsible for this, which are produced by autocatalytic oxidation of the fatty acids naturally occurring in the non-woody biomass, in particular linoleic acid , to be formed (Hatanaka, 1996) .

Furthermore, due to these extraction substances, particles from non-lignifying biomass can coagulate into sticky particles during processing, which is intensified by the fats and waxes that also occur naturally in non-lignifying biomass. These aggregates can also lead to disruptive effects on the surface of the manufactured products (such as cardboard or special papers), which subsequently cause problems in the further processing of the products (e.g. printing). be able. These substances can also have a disruptive effect on the production process by causing deposits on machine parts, rollers and clothing parts, etc. cause.

Currently, fatty acids are not removed from particles for particle-based products such as paperboard or fiberboard. Instead, the auto-oxidation of these fatty acids is inhibited or delayed by the addition of complexing agents such as ethylenediaminetetraacetic acid (EDTA) or diethylenetriaminepentaacetic acid (DTPA) to bind the heavy metal ions, which act as a catalyst, in the products made from particles of non-woody biomass will. However, EDTA and its metal complexes are only poorly and slowly degradable in waste water treatment and are therefore considered ecologically questionable today, which entails ever greater problems, especially for waste water from production plants for products based on non-woody biomass.

Bleaching, delignifying, oxidizing or reducing chemicals can be used in other processes that have been described for improving the organoleptic properties.

DE 10 2009 046 127 A1 describes a method for producing wood fiber materials. WO/0061858 A1 relates to a method for separating lignocellulose-containing biomass into lignin, hemicellulose and cellulose. US Pat. No. 5,698,667 A discloses a pretreatment of a lignocellulosic material by extraction with an organic solvent (eg acetone). DE 10 2014 114 921 A1 relates to a method for producing a "reduced-emission" solid wood product or a "reduced-emission" wood-containing starting material, which is treated with a "buffer solution" with a pH of >6 in order to reduce the emission (essentially of VOCs) to "reduce", however cellulose, hemicellulose and lignin are apparently not substantially preserved and it is not disclosed to what extent the content of fatty acids can be reduced with this method. According to WO 2006/032267 A1, solid wood or wood particles are treated in such a way that the fatty acid esters contained therein are "inhibited, split or oxidized", but not extracted. WO 93/20279 A1 discloses the treatment of cellulose pulp (i.e. no wood particles) with organic solvents , which are separated again after this treatment must . WO 2020/000008 A1 discloses the production of lignin particles. WO 00/34568 A1 relates to a method for producing chemical pulp from wood chips, with hemicellulose and lignin being separated off. EP 2 138 528 A1 relates to a method for producing a cellulosic material with a reduced wood extractive content. DE 10 2016 219 719 B3 discloses a method for producing cellulose, hemicellulose and lignin. EP 2 356 977 A1 relates to the use of Gliditsche wood extracts for the treatment of cellulite.

It is therefore an object of the present invention to reduce the content of releasable odor- and taste-active aldehydes in products based on non-woody biomass, such as cardboard or fibreboard, by auto-oxidation of fatty acids naturally occurring in the non-woody biomass. This should be done without the use or addition of complexing agents.

A further object of the present invention is a significant improvement in the organoleptic properties of the particles based on non-verhol collapsing biomass and aged particles that are produced by this method, so that the products produced with it have little or no odor even without the Have the use or addition of bleaching, delignifying, oxidizing or reducing chemicals. In particular, with the method according to the invention, after aging of the particles from non-wooden biomass (up to 6 months), an undesirable odor and taste changes occurring in the course of this aging in the foodstuffs coming into contact with them are to be prevented.

Finally, a preferred object of the present invention is to remove further ingredients from particles based on non-woody biomass that are undesirable in the planned product, for example terpenes.

Accordingly, the present invention relates to a process for the production of products based on non-woody biomass as a raw material, in which non-woody biomass containing cellulose, hemicelluloses and lignin in the form of particles is subjected to an extraction treatment with an extraction agent, which comprises one or more organic solvents in an organic-aqueous mixture of the solvent or solvents with water, the content of fatty acids in the particles being reduced by the extraction treatment of the particles with the extractant is reduced by at least 70%, measured as hexanal content in wt.% after accelerated aging for 72 h at 90°C, but the content of cellulose, hemicelluloses and lignin is substantially preserved in this extraction treatment.

As has been shown in the course of the present invention, the inventive extraction of the organoleptically questionable substances from the raw materials can significantly improve the organoleptic properties of the particles based on non-woody biomass without the addition of complexing agents, but by removing potential aldehyde sources, especially fatty acids , be achieved. However, it is known that fatty acids as a source of aldehydes and subsequently as a source of organoleptic impairments of these particles can only be quantified satisfactorily with great effort. According to the invention, the hexanal content of the particles after aging was therefore used to assess the success of the extraction. This has proven to be a reliable parameter for the organoleptic properties of the products to be made from the raw material, such as (special) paper, cardboard, fibreboard, etc., which correlates excellently with the (very time-consuming) traditional aging tests (see the investigations and proofs in the example part, below) .

It was found that with the method according to the invention, a large part of the fatty acids and other disruptive substances (pinenes, terpenoids and terpenes, etc.) can be extracted without the substance of non-woody biomass (cellulose, hemicelluloses and lignin) being significantly affected is affected. While any improvement in the removal of fatty acids from the non-woody biomass based raw material has benefits, a significant reduction of at least 70% for suitable large scale commercial use is readily possible with the present process. However, the treatment according to the invention is preferably selected such that the desired reduction is achieved in any case, and a reduction of at least 70%, preferably at least 90%, in particular at least 95%, is achieved. Accordingly, the conditions to be used according to the invention can then be selected, for example on the basis of the nature of the non-woody biomass or of the extractant, so that the hexanal reduction according to the invention in any case results in . In this way, it is also possible to set preferred maximum values in absolute hexanal contents. Although particles with a hexanal content of 2 mg/kg dry matter (DM) can also be used for certain applications, absolute values of less than 1 mg/kgDM are preferred. With the particularly strict guidelines that have been applied in the course of the examples of the present invention, a hexanal content of 0.5 mg/kgTM hexanal (based on dry non-woody biomass) was marked as an empirically determined value below which organoleptic impairments experience has shown that they are no longer perceptible to the senses. Accordingly, a preferred embodiment of the method according to the invention relates to an extraction of the particles based on non-woody biomass to a hexanal content of 0.5 mg/kg DM or below. For particles with a hexanal content of >0.5 mg/kgTM it was found that the risk of organoleptic impairment of the particles also increased with increasing hexanal content.

For the purposes of the present invention, the determination of the hexanal content can, in case of doubt, be carried out using headspace gas chromatography (HS-GC) by approx. 0.2 g of air-dried non-woody biomass particles (90-95 wt% (=% by weight) dry matter content (TSG)) are filled into a headspace vial. In these vials, the non-woody biomass particles must then be sealed and aged at room temperature (approx. 20 °C) for six months in order to oxidize the fatty acids to hexanal. Since this takes a great deal of time and therefore does not permit a timely assessment of the extraction success, the hexanal content is determined according to the present invention via accelerated aging based on DIN ISO 5630-2. This was used to determine the hexanal content in the experiments in the example section (unless explicitly stated otherwise); this method is also decisive in case of doubt for determining the hexanal content for the purposes of the present invention. The non-woody biomass particles are sealed in HS-GC vials, aged for 72 h at 90 °C and then the hexanal content is determined using HS-GC.

The particles are preferably less than 2 mm in size, preferably in the form of fibers, chips or mixtures thereof. This particle characteristic (as "particle size") is defined according to the National Renewable Energy Laboratory (NREL) Laboratory Analytical Procedure (LAP) NREL/TP-510-42620 "Preparation of Samples for Compositional Analysis", to which the NREL LAP NREL/TP-510-42619 "Determination of Extractives in Biomass" also refers. The particle characteristic of the particle size is accordingly formulated on the sieve mesh size (2 mm) of the cutting mill for sample preparation.

The particles based on non-woody biomass used according to the invention are preferably present in the form of fibers, chips or mixtures thereof. This limitation of the particle size to 2 mm, as also specified in the NREL method NREL/TP-510-42620, brings with it the great advantage that, in addition to the relatively easily accessible resin channels, the comparatively difficult to access parenchymal cells where the fatty acids are located , can be easily achieved by extraction (Lehr et al., Removal of wood extractives as pulp (pre-) treatment: a technological review (2021), SN Applied Sciences 3:886).

According to a preferred embodiment, the particles are non-woody biomass, in particular non-woody biomass fibers with average fiber lengths between 0.5 and 2 mm and average fiber diameters between 10 and 50 μm, that have been broken down into fibers by mechanical and/or thermal and/or chemical digestion. Average fiber length and average fiber diameter relate to the average length, determined by optical measurement of the suspended fibers. This optical measurement usually leads to uniform results (regardless of the chosen methodology and analysis device), but the devices PulpEye (http://www.pulpeye.com/products/pulpeye/) and in particular MorFi Fiber have proven to be particularly suitable Analyzer (http://www.tech-pap.com/fiber-and-shive-analyzer-morf i-neo, lab-device, 31.html), proven.

The amount of organic compounds that can be extracted using the method according to the invention will vary depending on the type of non-lignifying biomass and component of the plants from which the particles are obtained. Such organic compounds in bark often vary in the range of 20 to 40%, in olive tree bush cuttings often from 15 and 20 in grapevine bush cuttings often from 5 to 10%; for example, proportions of 16% and 10% were reported for switchgrass, 25% and 16% for fescue, 17% and 5% for maize straw and 21 and 13% for red maple bark (Royer et al., J Food Res 1 (2012) 8-45 Routa et al Nat Res Bioecon Stud 73 (2017) Nat Res Institute (FI) ; Cavalaglio et al., Sustainability 12 (2020), 6678; Thammasouk et al., J. Agric. Food Chem. 45 (1997), 437-443). Accordingly, depending on the type and species of the non-woody biomass, the extractive substance content can range from a single-digit percentage range to several 10%, i.e. usually from 1 to 50%, mostly from 5 to 40% (this information also refers to based on % by weight ) .

According to the invention, all non-woody biomasses containing cellulose, hemicelluloses and lignin and containing organoleptic substances to be removed can be used. According to the invention, however, preference is naturally given to biomass particles from "energy plants" or fast-growing one- and multi-year-old, non-woody C4 or C3 plants, with C4 plants having higher mass growth compared to the C3 plants native to Central Europe are characterized and therefore have a more efficient CCh use and, as a result, higher photosynthetic efficiency. Preferred particles according to the present invention are straw and straw-like substances. In agriculture, "straw" is defined as "dry stalks, stalks and leaves of the threshed cereal species, Defined legumes, oil and fiber plants and also marketed as fuel, among other things. "Straw-like substances" are grass species, whole-plant cereals, miscanthus, Jerusalem artichokes, etc., i.e. the entire above-ground biomass growth of non-woody plants. B. reeds, shrub cuttings, leaves of trees and shrubs, bark, elephant grass, hay, and corn cobs".

DE 10 2009 046 127 A1 describes a method for producing wood fiber materials in which volatile organic compounds (“VOC”), aliphatic and aromatic aldehydes, in particular hexanal and furfural, are reduced, with wood being treated with at least one compound for adjustment a neutral to basic pH (such as NaOH) and at least one complexing agent (such as EDTA or DTPA), emphasizing that no bleaching, delignifying, oxidizing or reducing chemicals are used in such manufacture, and no squeezing of liquid formulation takes place before the plasticization of the wood or the wood chips However, the use of complexing agents such as EDTA and DTPA as mentioned above, a serious waste water and environmental problem. The present invention thus brings decisive advantages over a mere chemical-thermo-mechanical digestion (CTMP), which is known per se, in which wood chips are mixed with sodium sulfite and EDTA, both with regard to environmental aspects and with regard to the effect according to the invention in the ef fi cient depletion of fatty acids from the raw material.

US Pat. No. 5,698,667 A discloses a pretreatment of a lignocellulosic material by extraction with an organic solvent (e.g. acetone) in order to remove wood extractives, such as volatile organic compounds (VOC) and higher-molecular pitch components. without significantly affecting the integrity of the lignocellulosic components of the material. However, no industrially usable depletion of the undesirable ingredients could be achieved (the maximum depletion of pitch and VOCs was 54, 4 and 65% (after two extractions for acetone in water (80/20) and 100% acetone) or maximum 78.2% for pure acetone, although the methodology used there cannot ensure that volatile components pass into the gas phase when the solvent is removed from the extract and that the depletion when determined by the evaporation residue of the extract is to be set even lower.

In contrast, in the method according to the invention, with the help of an extractive pretreatment of particles from non-woody biomass with organic solvents in an organic-aqueous mixture of the solvent or solvents with water, a large part of the fatty acids naturally occurring in the biomass are already removed before further processing (e.g. to cardboard or fiberboard) removed . In addition , this pre - treatment greatly reduces other extractives such as aldehydes , pinenes , phenols and terpenes in the non - woody biomass . According to the invention, the hexanal content has proven itself as an indicator for the auto-oxidation of the fatty acids naturally occurring in the non-woody biomass, especially if it is determined after accelerated aging of the particles (72 h at 90° C.). According to the invention, this hexanal content is reduced by at least 70%, based on the potential of the starting raw material (and--in absolute contents), preferably down to below 0.5 mg/kg DM reduced . As a result, odor and taste interactions of products based on non-woody biomass with the environment relevant to the respective end use (e.g. food in the case of packaging board or room air in the case of fiberboard) can be greatly reduced with the present invention. At the same time, the composition of the particles is not significantly changed by the pretreatment, i.e. cellulose, hemicelluloses and lignin in the non-woody biomass are not significantly reduced (at least by no more than 10%, preferably by no more than 6%, in particular reduced by no more than 4%) extracted and/or degraded, this reduction preferably being determined as an extracted solid mass, based on the starting material, the biomass particles. In addition to reducing the proportion of organoleptically relevant components in the particles, the present invention results in further important product and process advantages, particularly for the production of paper, fibreboard and cardboard:

Insoluble sticky residues based on the organic compounds contained in the non-woody material are removed from the process (or their formation in the production process is prevented) and thus cannot have a disruptive effect on the production process, so that there are no or reduced deposits on machine parts , rollers and clothing parts etc. . comes .

As a result, with the present invention, disruptive effects on the paper/cardboard/fibreboard surface can also be reduced, which subsequently also significantly reduces problems in the further processing of the paper/cardboard/fibreboard (e.g. printing). Due to the significantly lower proportion of these components on the surface and also inside the paper/cardboard/fiber board, there is also increased product quality and an increase in mechanical strength.

Due to the improved product properties mentioned of products that are produced from the particles extracted according to the invention, new areas of application can also be opened up that can currently only be covered with paper/cardboard/fiber board whose fiber components are cellulose and/or treated BCTMP (bleached chemical thermo-mechanical pulp ) (e.g. high-quality packaging boxes ) or for particularly delicate ones Applications that today can only be served with pulp.

In addition, the extractive pre-treatment according to the present invention also greatly reduces the COD loads of the waste water from the process, as a result of which larger production capacities are made possible with the same COD load in the waste water.

The release of odor- and taste-active aldehydes in products based on non-woody biomass, such as cardboard or fibreboards, by auto-oxidation of fatty acids naturally occurring in the non-woody biomass can also be achieved according to the present invention without the addition of complexing agents. The addition of a complexing agent such as EDTA or DTPA in the manufacture of products based on non-woody biomass to reduce the odor and taste of these products becomes superfluous, which eliminates the EDTA/DTPA contamination of the waste water and thus the ( reason) water-related environmental impacts of the production of these products are reduced, as well as the EDTA / DTPA contamination of the products themselves is avoided. Furthermore, in addition to fatty acids, other extractives are also significantly reduced and thus removed from the process, which reduces the extractive loading of the process water in the production of the particles and thus results in lower demands on the wastewater cleaning/treatment. The reduced extractive substance load in the process water also has the advantage that problems in the manufacturing process of the products made from the particles treated according to the invention can be reduced and the quality of the products can be increased. This variant is therefore a particularly environmentally friendly embodiment of the present invention.

In practice, for a specific non-logging type of biomass or for certain non-woody biomass materials for an extraction of at least 70 % of the fatty acids or . to establish a maximum absolute value of hexanal of less than 2 mg/kg dry matter, preferably less than 1 mg/kg dry matter, in particular less than 0.5 mg/kg dry matter (measured in each case as hexanal content in % by weight) of the extracted particles after accelerated aging for 72 h at 90 °C), the necessary specific process conditions (such as size, shape and dry matter content of the particles, choice of extraction agent, water content, temperature, duration of treatment, pH, amount of extraction agent (in relation to on the non-woody biomass used), pressure, number of extraction stages, variants of contacting between the extractant and solid, mode of operation, etc.) can be determined directly and without further inventive step on the basis of the teaching disclosed herein, in particular taking into account the results presented in the example section, especially considering the (usually known) amounts of organic matter (such as fatty acids, pinenes, phenols, terpenes, etc.) in the non-woody biomass, the nature of the non-woody biomass and the requirements for the final product (cardboard, paper, fibreboard, Application in certain areas (food, pharmaceuticals, animal feed, etc.) .

In particular, the present invention can be integrated relatively easily into existing production plants or operated with existing plants.

One or more of the objects set out above can be achieved according to the invention by a method having the features of patent claim 1 . Advantageous configurations with expedient developments of the invention are specified in the respective dependent claims.

The choice of the liquid phase of the extract according to the invention (referred to here as the extraction agent) also depends on the relevant non-woody biomass type (and its natural content of extractives). However, the solvent or solvent mixture in the extraction agent must also be selected in such a way that there is no significant loss of cellulose, hemicelluloses and lignin and the treatment time is not excessively long. According to the invention, mixtures of ethanol, acetone and water with 0-95% by weight ethanol, preferably 50-90% by weight ethanol, and 0-99% by weight acetone, preferably 30-90% by weight -% acetone, exposed as organic-aqueous solvents in the extractant. Examples of other organic solvents that can be used instead of (or for certain purposes together with) ethanol or acetone in the extractant on an industrial scale are methanol, n-propanol and isopropanol.

In the process according to the invention, preferred ratios of extractant to solid/dry substance are 5:1-25:1 (w/w), preferably 8:1-17:1 (w/w). With the ratios and concentrations in the extractant given herein, the following considerations apply: 100% extractant always means the total amount of extractant present after extraction, namely the extractant, including the materials extracted from the particles and that in the non-lignifying biomass -The raw material (in the particles) contained water. However, since the amounts of non-woody biomass feedstock are usually given herein as "non-woody biomass dry matter" and the substances extracted from the non-woody biomass are usually less than 1% of the total mass of the extractant, the ratios before the Extraction essentially (just +/- 1%) also the conditions after the extraction (the possibly existing water content in the non-lignifying biomass starting material, which is usually given in the case of economic utilization, is accordingly always already included in the extraction agent). when using 100% by weight acetone concentration of the extraction agent at 1:10 (solid: extraction agent) thus 1 kg non-woody biomass dry matter and 10 kg acetone. 70% by weight acetone concentration of the extraction agent at 1: 10 ( solid : extraction agent) would then be, for example, 1 kg of non-woody biomass dry matter, 7 kg acetone and 3 kg water. As mentioned, the extracted material would still be added, but experience has shown that it is present at concentrations well below 1% by weight in the extractant and is therefore negligible. Due to the water content in the starting material, according to the invention the organic-aqueous mixture of the solvent(s) preferably contains at least 10% water, preferably at least 7.5% water, in particular at least 5% water, preferably at least in a process with a single extraction step or (e.g in a method with at least two extraction steps) in the first extraction step.

The extraction temperatures can also be determined on the basis of the other non-woody biomass and process parameters, in particular taking into account the energy consumption that higher temperatures require. According to the invention, the treatment preferably takes place at an extraction temperature of 20-150.degree. C., preferably 40-120.degree. C., in particular 50-110.degree.

According to a preferred embodiment, the process according to the invention is operated at normal pressure; in certain cases extraction under pressure can be advantageous (despite the additional energy expenditure of the pressure application). Therefore, according to a preferred embodiment, the treatment according to the invention takes place at an absolute extraction pressure of 1-5 bar, preferably 1-1.49 bar.

The duration of the extraction process according to the invention can also be determined on the basis of the other process parameters, which duration is necessary for the depletion of fatty acids to be achieved. The treatment according to the invention preferably takes place during an extraction time of 10 minutes to 8 hours, preferably 30 minutes to 7 hours, in particular 1 to 5 hours.

In principle, the present method is suitable for all non-woody biomass-based products in which organoleptic properties play a role. The method according to the invention is particularly suitable for products that are in use for a long time, for packaging foodstuffs or are used indoors. The method according to the invention is therefore particularly suitable for the (large-scale) production of cardboard, paper, in particular special paper, fibreboard, chipboard, insulating materials, commodities (for example (or in case of doubt) according to the definition of the Austrian Food Safety and Consumer Protection Act (LMSV, BGBl. I No. 13/2006, idFv 01.10.2020) ), medical devices (e.g. (or in case of doubt) according to the definition of the Austrian Medical Devices Act (MPG, Federal Law Gazette No. 657/1996, idFv 01.10.2020) ), food additives, pharmaceutical additives , such as excipients.

Particularly advantageous process parameters for the extraction treatment according to the present invention are selected from:

treatment with ethanol in a concentration of at least 65% by weight at at least 65°C for a period of at least 3 hours;

treatment with ethanol in a concentration of at least 65% by weight at at least 85°C for a period of at least 30 minutes;

treatment with ethanol in a concentration of at least 70% by weight at at least 105°C for a period of at least 30 minutes;

Treatment with ethanol in a concentration of at least 45% by weight at at least 105°C for a period of at least 5 H;

Treatment with acetone in a concentration of at least 50 wt. -% at at least 40 °C for a period of at least 30 min; or

Treatment with acetone in a concentration of at least 50 wt. -% at at least 20 °C for a period of at least 15 min.

In the context of the present invention, it has been found that both batch and continuous and semi-continuous extractions are possible and can even have an advantageous effect on the extraction result, particularly if the partial residence time per extraction step is a maximum of 1 hour.

It is also essential when determining the process parameters that conditions are selected in which there are no significant losses of the substance of non-woody biomass (i.e. the content of cellulose, hemicelluloses and lignin). It can therefore also be provided that the dry substance content of the particles used is reduced by less than 10%, preferably by less than 5%, in particular by less than 4%, in the treatment according to the invention, this reduction preferably being expressed as the extracted solid mass , based on the starting material , namely the particles based on non - woody biomass , is determined .

As mentioned above, different non-woody plants vary in their levels of VOCs. The specific process parameters according to the invention are also to be adjusted accordingly. However, since this is possible with the disclosure of the invention contained herein for all industrially relevant non-verhol collapsing plant species, the particles used according to the invention can preferably be selected from the industrially relevant non-verhol collapsing plant species, ie z. B. Grain particles, legumes rüchtenparticles, oil plant particles, fiber plant particles, grass particles, in particular miscanthus particles, Jerusalem artichoke particles, reed particles, shrub cuttings particles, leaf particles from trees and shrubs, bark particles, elephant grass particles, hay particles, corn cob particles or mixtures thereof.

According to a preferred embodiment, the particles are mixed with the extraction agent during the treatment.

As mentioned above, a preferred embodiment of the method according to the invention is that the particles be pressed after treatment with the extractant to remove the extractant. After the (extraction) treatment with the extractant, the particles can preferably be cleaned one or more times with an extractant, even more preferably with an organic-aqueous solvent with a concentration similar to or the same as that of the extractant. The extractant used in the extraction and/or washing can be removed from the particles by repeated washing with water and/or steam stripping and/or drying, with steam stripping and/or drying being particularly preferred. Both the extraction agent and the washing water are preferably regenerated for reuse after the process according to the invention. As mentioned, the extractives, especially fatty acids and terpenes, can be separated from the extractant and used as by-products.

With the method according to the invention it is possible to prepare particles in such a way that the content of fatty acids in the particles is reduced in such a way that the product to be produced from the raw materials from non-woody biomass does not have any organoleptically disadvantageous properties. According to the invention, the content of fatty acids in the particles is preferably reduced by at least 75%, preferably by at least 80%, in particular by at least 90%, measured as the hexanal content in wt. -% of the particles in the starting material compared to the extracted particles each after accelerated aging for 72 h at 90 °C.

The particles obtained in this way preferably have a fatty acid content in the particles of less than 2 mg/kg dry matter, preferably less than 1 mg/kg dry matter, in particular less than 0.5 mg/kg dry matter, measured as hexanal content as mass fraction of the extracted particles after accelerated aging for 72 h at 90 °C.

In addition to reducing the hexanal content, it is also possible with the method according to the invention to reduce the mechanical strength of the extracted particles, measured as Tensile Index of test sheets in Nm/g, by at least 10%, preferably by at least 15%, in particular by at least 25%. , to increase, whereby the freeness, measured in ° SR, changes by less than 10%. It has been shown according to the invention that, in addition to the extraction of fatty acids, terpenes and pinenes (along with other VOCs) can also be extracted using the method according to the invention. In a preferred embodiment, the fatty acids, terpenes, pinenes and/or other extractives extracted into the extraction agent are subjected to a further purification process and can then be made available as by-products of the production in an extracted and optionally further purified form. This can be done in particular by mechanical separation technology after the thermal separation of the organic solvent from the organic-aqueous extraction agent in order to separate the precipitated lipophilic extractives (such as fatty acids and resin acids) and an aqueous phase enriched with hydrophilic extractives (such as lignans). win, whereby the hydrophilic extractive substances can be further concentrated by subsequent treatment with thermal separation technology (e.g. membrane separation process and/or adsorption) (Lindemann et al., Selective recovery of polyphenols from MDF process waters by adsorption on a macroporous, crosslinked pyrrolidone-based resin (2019) , Wood Research Volume 74 Issue 2) . The concentration of extractives achieved can be further increased by prior membrane filtration of the extraction agent (Shi et al., Separation of vegetable oil compounds and solvent recovery using commercial organic solvent nanofiltration membranes (2019) , Journal of Membrane Science 588; Weinwurm et al., Lignin Concentration by Nanofiltration and Precipitation in a Lignocellulose Biorefinery (2015), Chemical Engineering Transactions 45, pp. 901-906). The use of the lipophilic extractive fraction obtained by this method is suitable as a feed supplement (WO 2015/071534 A1, US Pat. No. 10,092,610 B2), since the resin acids contained in the lipophilic extractive fraction inhibit the growth of harmful bacteria in the animal's digestive tract and thus prevent digestive disorders , which has already been shown in various studies, especially for poultry (Kettunen et al., Natural resin acid-enriched composition as a modulator of intestinal microbiota and performance enhancer in broiler chicken (2015) , Journal of Applied Animal Nutrition Vol.3; Kettunen et al., Dietary resin acid composition as a performance enhancer for broiler chickens (2017), Journal of Applied Animal Nutrition Vol 5, pp 349-355, Vienola et al., Tall oil fatty acid inclusion in the diet improves performance and increases ileal density of lactobacilli in broiler chickens (2018) British Poultry Science Vol. 59 no. 3 ) .

According to a preferred embodiment, the particles are not given any complexing agents, in particular complexing agents selected from polybasic and polyfunctional carboxylic acids, aminomethylcarboxylic acids, aminomethylphosphonic acids and their compounds, EDTA, DTPA EGTA, EDDS and their salts, polyphenols, tannins, amino acids, peptides, proteins, polycarboxylates , phosphates, polyphosphates, phosphonic acids, polyphosphonates, phosphated, phosphonylated, sulfated and sulfonated polymers, added during the extraction process, especially during the entire manufacturing process for the products made from the particles. In this embodiment, the method according to the invention represents an extremely advantageous and practice-relevant variant, if only for ecological reasons.

According to a further aspect, the present invention relates to a method according to the invention for the production of products based on wood as a raw material, in which - instead of the cellulose, hemicelluloses and lignin-containing, non-woody biomass in the form of particles - wood in The form of wood particles is used as the starting material and the extractives extracted with the extraction agent, i.e. preferably fatty acids, terpenes, pinenes and/or optionally other extractives, are fed to a further purification process, namely by mechanical separation technology after thermal separation of the organic Solvent from the organic-aqueous extractant, with lipophilic extract substances, in particular fatty acids and resin acids, being precipitated and separated, and an aqueous phase enriched with hydrophilic extract substances, in particular lignans, is obtained, with preferably the hydrophilic extract substance fe be further concentrated by subsequent treatment with thermal separation technology, in particular by means of membrane separation processes and / or adsorption. A membrane filtration of the extractant is preferably carried out beforehand during the enrichment of the extract substance. According to a preferred embodiment of this aspect of the present invention, the wood particles are made of coniferous wood particles, preferably spruce wood particles, fir wood particles, pine wood particles, or larch wood particles. particles; Deciduous wood particles, in particular beech wood particles, poplar wood particles, birch wood particles, or eucalyptus wood particles; or mixtures thereof. The lipophilic extractive substance fraction obtained according to the invention is preferably used as a feed supplement.

Further features of the invention result from the claims, the figures and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and/or shown alone in the figures, can be used not only in the combination specified in each case, but also in other combinations, without going beyond the scope of the invention leaving. The invention is therefore also to be considered to include and disclose embodiments that are not explicitly shown and explained in the figures, but that result from the explained embodiments and can be generated by separate combinations of features. Versions and combinations of features are also to be regarded as disclosed which therefore do not have all the features of an originally formulated independent claim. Furthermore, embodiments and combinations of features, in particular through the embodiments presented above, are to be regarded as disclosed which go beyond or deviate from the combinations of features presented in the back references of the claims. In particular, the present invention is explained in more detail using the following examples and the figures, without of course being restricted thereto. Show it:

1 shows the hexanal content at an extraction temperature of 70°C. The x-axis shows the extraction time in h; the y-axis the hexanal content of the extracted wood pulp in mg/kgTM;

2 shows the hexanal content at an extraction temperature of 90°C. The x-axis shows the extraction time in h; the y-axis the hexanal content of the extracted wood pulp in mg/kgTM;

3 shows the hexanal content at an extraction temperature of 110°C. The x-axis shows the extraction time in h; the y-axis the hexanal content of the extracted wood pulp in mg/kgDM;

4 shows the reduction in hexanal content at an extraction temperature of 70.degree. The x-axis shows the extraction time in h; the y-axis the reduction of the hexanal content in % based on dry starting material;

Fig. 5 the hexanal content reduction at 90°C extraction temperature temperature . The x-axis shows the extraction time in h; the y-axis the reduction of the hexanal content in % based on dry starting material;

Fig. 6 the hexanal content reduction at 110 °C extraction temperature. The x-axis shows the extraction time in h; the y-axis the reduction of the hexanal content in % based on dry starting material.

Examples :

The aim of the process developed in this patent is a significant improvement in the organoleptic properties of the particles of non-woody biomass and aged particles of this biomass produced by this process. The unwanted odor that occurs, especially after the particles from non-woody biomass have aged (up to 6 months), and the taste of the food that comes into contact with them, is mainly caused by aldehydes (especially hexanal), which are produced by autocatalytic oxidation of naturally occurring fatty acids (especially linoleic acid) in the non-lignified biomass. As mentioned above, this autocatalytic oxidation is currently prevented industrially - in the processing of wood biomass - by complexing the metal ions present in the wood particles, which act as a catalyst, by adding complexing agents such as ethylenediaminetetraacetic acid (EDTA). . severely slowed down. The method according to the present invention achieves a significant improvement in the organoleptic properties of the particles from non-woody biomass, also without the addition of complexing agents, but by removing potential aldehyde sources, above all fatty acids.

Since fatty acids as a source of aldehydes and subsequently as a source of organoleptic impairments of the particles from non-woody biomass can only be quantified satisfactorily with great effort, and because the application of the technology according to the invention to wood particles has already been carried out corresponding tests (and these represent for a specialist as directly applicable to particles from non-woody biomass) for the assessment of the extraction success of the experiments according to the present invention, the application of the technology according to the invention to wood particles in shown in the following examples, using in particular the hexanal content of the wood particles after aging. At this point it should be noted that 0.5 mg/kgTM Hexanal (relative to dry wood) marks the empirically determined value below which experience has shown that organoleptic impairments are no longer perceptible to the senses. Of course, this also applies to particles from non-woody biomass. The following applies to hexanal contents in wood particles and particles from non-woody biomass > 0.5 mg/kgTM: The higher the hexanal content, the greater the organoleptic impairment of the wood particles or particles from non-woody biomass.

The hexanal content can be determined using headspace gas chromatography (HS-GC) by filling a headspace vial with approx. 0.2 g of air-dried wood particles (90-95 wt% TSG). In these vials, the sealed wood particles must then be aged for six months at room temperature (approx. 20 °C) in order to oxidize the fatty acids to hexanal. Since this takes a lot of time and therefore does not allow a timely assessment of the extraction success, accelerated aging according to DIN ISO 5630-2 was carried out for the present experiments (unless explicitly stated otherwise). The wood particles were sealed in HS-GC vials, aged for 72 h at 90° C. and then the hexanal content was determined using HS-GC. Although this standard for accelerated aging has been withdrawn, the extraction tests carried out in Table 1 show that the method of accelerated aging supplies comparable values and that the hexanal values for accelerated aging are on average even higher and are therefore even safer regarding the extraction success. As mentioned, the tests and test results given in the present example part for the wood particles are essentially the same due to the analogy of the starting materials (wood particles or particles from non-woody biomass) (depending on the comparability of the particles with regard to the organoleptic compounds that are extracted according to the invention; However, this also applies to specific compounds from particles from non-woody biomass, such as terpenes and pinenes, which are analogous to the hexanal analyzed in the following examples (e.g. from linoleic acid).

Table 1

The hexanal content was used for the extraction success of all experiments according to the present invention, since experience has shown that this is the main factor influencing the organoleptic impairment of wood particles but also of particles from non-woody biomass. The extractive substance content using Soxhlet extraction according to the TAPPI standard T204 is too imprecise for this, as Table 2 shows. At this point it should be noted that the TAPPI standard T204 was not used to determine the extractive content of the wood particles in all the tests in this patent, but the NREL method NREL/TP-510-42619, which is very similar to T204, and wood z -Grinding or . 2 mm large wood particles were used as the starting material instead of wood flour.

Table 2 As can be seen in Table 2, the Soxhlet extractions with ethanol differ significantly from those with acetone in terms of the hexanal content, but not significantly in terms of the extractive content. This means that, for example, two differently extracted wood particles can have different organoleptic properties despite not significantly different extractive content. The hexanal content of the wood particles after aging is therefore a much stronger and more accurate indicator of the organoleptic impairment than the extractive content, and was therefore used for the extraction success according to the present invention. In addition, the hexanal content of the starting material and the resulting reduction in the hexanal content were specified for all experiments, since the starting materials are snapshots and the hexanal content can therefore vary greatly from time to time.

Nevertheless, the extracted extractive mass (determined as the evaporation residue of the extract) is an important indicator for the solid mass loss of the extraction, since it - apart from a few very volatile compounds - includes almost the entire extractively removed solid mass. Thus, the evaporation residue of the extract together with the hexanal content of the extracted wood particles is an important measure for assessing the selectivity of the extraction.

Experiment: Comparison of solvents based on Soxhlet extractions

For the pre-selection of solvents, wood grinding samples were extracted with three different solvents. In each case 3 g of air-dried wood pulp were extracted for 24 hours using the Soxhlet method according to the NREL procedure NREL/TP-510-42619. The results are shown in Table 3.

Table 3

Table 3 shows that even with higher hexanal contents in the starting material, ethanol extracts best, followed by acetone. Cyclohexane extracts by far the worst, which means that completely non-polar solvents are unsuitable for the extraction of fatty acids. According to Reichardt and Welton (Reichardt and Welton, Solvents and Solvent Effects in Organic Chemistry ⁴ (2011), Weinheim: Wiley-VCH Verlag GmbH & Co. KGaA, pp 550-552), the empirically determined polarity of cyclohexane is 0 (very non-polar) compared to 0.355 from acetone and 0.654 from ethanol. Nevertheless, extraction with cyclohexane was also able to reduce the hexanal content by 79%.

Experiment 1: Extraction of dry wood pulp

The influence of the parameters solvent concentration, temperature and extraction time was examined on the basis of the extraction of air-dried groundwood (consisting of approx. 95% spruce and 5% pine) with ethanol (EtOH). For this purpose, approx. 2 g of air-dried groundwood were placed in an ethanol-water mixture with a solids:extractant ratio of 1:10 w/w and ethanol concentrations of 50, 70 and 90 wt% at temperatures of 70, 90 and 110 °C for 0.5, 1, 2, 4 and 8 h in small autoclaves. After extraction, the groundwood was pressed, washed with ethanol, pressed again and washed again with deionized water before it was dried, aged and analyzed. In FIGS. 1 to 3, the hexanal contents achieved by the extraction at the different extraction temperatures and solvent concentrations are plotted over the extraction time.

Figures 1 to 3 show that the extraction success with 70 or 90 wt% ethanol is significantly improved compared to enem at 50 wt% - especially at lower temperatures. Ethanol concentrations of 70 or 90 wt% ethanol reduce the hexanal content to a comparable level. With the extraction temperatures, it is apparent that the hexanal content is approximately the same at 90 and 110°C decrease, while at 70°C it is not reduced as much. With 90 wt% ethanol, the hexanal content can even drop below the 0.5 mg/kgTM mark from 90°C, which means that the groundwood extracted under these conditions no longer has any organoleptic impairments, according to experience. Based on the different extraction times, it can be seen that the hexanal content drops the most at the beginning of the extraction, and especially in the first 4 hours. This can also be seen in FIGS. 4 to 6. These figures reflect the extraction successes shown in FIGS. 1 to 3, since the same batch of starting material was used for all experiments in this series of experiments. It is clearly evident that in the worst case (0.5 h with 50 wt% ethanol at 70 wt% the hexanal content could only be reduced by approx. 20%, while with 90 wt% ethanol from 90 °C it was over 95 % has been reduced .

Table 4 shows that despite the high hexanal content reductions achieved in this test series, the extracted solids mass is max. 7 wt% (based on the starting material) - but usually significantly lower. With a determined extractive content of the starting material of approx. 3 wt%, this means that neither hemicelluloses nor lignin are extracted to any significant extent.

Table 4

Experiment 2: Extraction of wet wood pulp with ethanol under different conditions The extraction of moist groundwood represents real conditions much better, especially in cardboard production, than the extraction of dry groundwood, as in test 1. In addition, significantly more sample mass was taken for these tests (factor 225) than for test 1 in order to get a more meaningful to get result. Approx. 450 gTM of mechanically dewatered groundwood (approx. 25 wt% TSG; approx. 95% spruce and 5% pine) were dissolved in an ethanol-water mixture with a solids:solvent ratio of 1:10 w/w and ethanol concentrations of 60 wt% at temperatures of 70 and 90 °C for 2 and 4 hours in an autoclave. After extraction, the groundwood was pressed, washed with ethanol, pressed again and washed again with deionized water before it was dried, aged and analyzed. Table 5 shows the results of these extractions.

Table 5

The tests show that - compared to the extraction of a smaller and, above all, air-dry wood-pulp mass - the tests with mechanically dewatered wood-pulp and more sample mass show higher hexanal contents in the extracted wood-pulp. Nonetheless, over 73% reduction in hexanal content was achieved in each setting.

Experiment 3: Extraction of wet wood pulp with three different organic solvents

Experiment 3 was carried out to test three different technically relevant solvents under real extraction conditions testing. Approx. 450 gTM of mechanically dewatered groundwood (approx. 25 wt% TSG; approx. 95% spruce and 5% pine) were dissolved in a solvent-water mixture with a solids:extractant ratio of 1:10 w/w and a solvent concentration of 70 wt% at a temperature of 70 °C for 4 hours in an autoclave. After extraction, the groundwood was pressed, washed with extraction agent, pressed again and washed again with deionized water before it was dried, aged and analyzed. Table 6 shows the results of these extractions.

As can be seen in Table 6, acetone extracts the unsaturated fatty acids responsible for hexanal formation significantly better than undenatured ethanol. However, the best extraction results were achieved with ethanol that was incompletely denatured with butanone. The one here with 70 wt%, 70°C and 4 h extraction time, the hexanal content of 2.77 mg/kgDM achieved is still well above the 0.5 mg/kgDM limit, but corresponds to a reduction of 80%. With all extractions, the evaporation residue of the extract is only between 2.2 and 2.4 wt% based on the starting material dry mass, which means that with a determined extractive content of 3.6 wt%, the main wood components are cellulose, hemicelluloses and In fact, lignin was not attacked and the extractions were therefore very selective. The abietic acid content of the extractions in this experiment was reduced by 41-55%, based on the starting material. Since abietic acid was chosen here as the key substance for the content of resin acids, a reduction in the content by around 50% is an indication of the clear reduction in resin through the process of this patent.

Experiment 4: Extraction of moist wood pulp with acetone at different solids extractant ratios

The influence of different solids/extractant ratios was investigated in this experiment. Approx. 200 - 450 gTM (depending on the solids: extractant ratio) mechanically dewatered groundwood (approx. 25 wt% TSG; approx. 95% spruce and 5% pine) in an acetone-water mixture consisting of 70 wt% acetone and 30 wt% deionized water with solid:extractant ratios of 1:10, 1:15 and 1:25 w/w at a temperature of 50°C for 1, 2 and 4 hours in an autoclave. After extraction, the groundwood was pressed, washed with extraction agent, pressed again and washed again with deionized water before it was dried, aged and analyzed. The results of these extractions are listed in Table 7.

Table 7

As Table 7 shows, the hexanal content is reduced by over 80% in all extractions (except for the solid:extractant ratio of 1:10 (w/w) at a starting material hexanal content of 14.07 mg/kgDM). reduced. With extraction agent-solids ratios of more than 10:1 (w/w), the reduction in the hexanal content is comparably high and always well over 70% under the same extraction conditions, despite different starting material hexanal contents. The evaporation residue of the extract is less than 3%, which, given the extractive substance content of the starting material of 3.4 - 3.7 wt%, is proof of the quantitative preservation of the lignocellulose components in this process. By reducing the abietic acid content by 31-54%, based on the starting material, this test also showed that the process of this patent can significantly reduce resin.

Experiment 5: Multi-stage extraction of moist wood pulp with acetone

In this experiment, multi-stage extractions were carried out, with fresh, unloaded extraction agent being used for each stage (= one hour each). The wood cut (approx. 400 - 450 gTM; approx. 25 wt% TSG) was pressed out after each extraction stage (to approx. 30 wt% TSG) and mixed with acetone and deionized water (both preheated to an extraction temperature of 50 °C) in such a way that the solid: extractant ratio was 1: 10 and the acetone concentration in the extractant is 70 wt%. The extractions were performed in an autoclave. After extraction, the groundwood was pressed, washed with extraction agent, pressed again and washed again with deionized water before it was dried, aged and analyzed. The results of these extractions are listed in Table 8.

Table 8

As Table 8 shows, the hexanal content is already reduced by more than 80% after the first stage in all extractions, However, it is still well above 0.50 mg/kgDM, especially in the case of a starting material with a higher hexanal content. After stage three, however, the hexanal content in all of the ground wood samples extracted from this test was below 0.50 mg/kgDM, in some cases even below the limit of quantification of 0.20 mg/kgDM. The evaporation residue of the extract is less than 3.5%, which, given the extractive substance content of the starting material of 2.5 - 3.7 wt%, is proof of the quantitative preservation of the lignocellulose components in this process. By reducing the abietic acid content by 55-100%, based on the starting material, this test has also shown that the process of this patent can significantly reduce resin, in particular with an increasing number of extraction stages.

Experiment 6: Multi-stage extraction of moist wood particles of different particle sizes with acetone

The influence of the particle size was examined in this experiment with different extraction parameters. Approx. 650 gTM wood chips (approx. 20 mm; approx. 55 wt% TSG; spruce), approx. 450 gTM shredded wood chips (2 mm mesh size of the cutting mill sieve; approx. 60 wt% TSG; spruce) and approx. 400 gTM mechanically dewatered groundwood (approx. 25 wt% TSG; approx. 95% spruce and 5% fir) in two stages (one hour each) at 50°C and in two stages (30 minutes each) at 21°C extracted in an autoclave. The multi-stage extractions were carried out analogously to experiment 5 by pressing off the wood particles after each extraction stage and mixing them with fresh, unloaded extraction agent. The extraction parameters were 50 °C, extraction times of 1 h per extraction stage and acetone concentrations of 70 wt% in the extractant (extraction parameter 1) and 21 °C, extraction times of 30 min per extraction stage and pure acetone as the added extractant resulting in acetone Concentrations of 70 - 99 wt% depending on the extraction stage and particle size results (extraction parameter 2). The solids: extractant ratios were chosen so that the wood particles were just covered with extractant (1:6 for wood chips and ground wood chips and 1:10 for ground wood). After extraction, the wood particles were pressed (and washed with extractant at extraction parameter 1) and pressed again before being dried, aged and analyzed. The results of this Extractions are listed in Table 9.

Table 9

As Table 9 shows, the hexanal content of wood chips can only be reduced by about 20-30% using the process according to the invention. On the other hand, when the wood chips are ground to a particle size of 2 mm, as also specified by the NREL method NREL/TP-510-42620, the hexanal content can be reduced to approx. 1 mg/kgTM using the process according to the invention, which is hexanal content of 21.36 mg/kgTM a reduction of approx. 95% is equivalent to. With an even smaller particle size, such as groundwood, the reduction in the hexanal content is even higher at approx. 97 1. The two extraction parameters deliver comparable hexanal contents with larger particle sizes, whereas extraction parameter 1 (higher temperature and longer extraction time) deliver significantly better results with smaller particle sizes, especially wood pulp. When reducing the extract evaporation residue based on the extract evaporation residue of the starting material Soxhlet extraction, the extraction parameters deliver better results for all particle sizes. Table 9 also shows that the reduction of the extract evaporation residue based on the extract evaporation residue of the starting material Soxhlet extraction cannot be used as an indicator for the extraction success of the intended method, since, for example, with wood chips even at high Reduction of 73% of the hexanal content by only approx. 20 was lowered, whereas in the case of ground wood, with a reduction in the extract evaporation residue based on the extract evaporation residue of the starting material Soxhlet extraction by 75%, the hexanal content could be reduced by approx. 96%.

Experiment 7: Modification of the mechanical properties by the extractive treatment of groundwood according to the present invention

This experiment serves to investigate the effects of the extractive treatment on the mechanical properties of the extracted wood particles. For this purpose, approx. 300 - 450 gDM (depending on the solids:extractant ratio) mechanically dewatered groundwood (approx. 25 wt% TSG) were dissolved in a solvent-water mixture with solids:extractant ratios of 1:10 and 1: 15 w/w and a solvent concentration of 60 and 70 wt% at temperatures of 50 °C, 70 °C and 90 °C. Ethanol 96 fully undenatured (EtOH pure), ethanol 96 fully incompletely denatured with butanone (EtOH comp.) and acetone were used as solvents. After extraction, the ground wood was pressed, washed with extraction agent, pressed again and washed again with deionized water before sample sheets were formed from it, on the basis of which the mechanical properties were examined. The mass loss results from the evaporation residue of the extract and is related to the starting material dry mass. Table 10 lists the results.

Table 10

As can be seen in Table 10, the degree of grinding and thus the dewatering of the ground wood hardly changes as a result of the extraction, which has the advantage with regard to any further processing (e.g. to cardboard) that existing production plants do not need to be upgraded or relocated. The stiffness index also changes only slightly as a result of the extraction, whereas the tensile index, as a measure of the breaking force, rises sharply and reproducibly. Compared to this high increase of between 20 and 41% on average, the loss of mass due to the evaporation residue of the extract is very low at around 2%. This means that the wood particles gain disproportionately strong strength through the extraction with little mass loss, which is of great importance for the lightweighting trend in the packaging sector in particular. Experiment 8: purification of the extracted extractives

In this test, mechanically dewatered groundwood (approx. 25 wt% TSG; approx. 95% spruce and 5% fir) with a solids/extractant ratio of 1:10 w/w at 50 °C for 1 h in a Autoclave extracted, the extractant composed of 70 wt% acetone and 30 wt% deionized water. After the extraction, the groundwood was pressed out (to approx. 30 wt%) and the extract obtained in this way was worked up as follows: First, the acetone was separated off by distillation by heating the distillation flask to 108° C. and distilling it under atmospheric pressure until equilibrium was established . The remaining residue was centrifuged at 7197 g for 10 min and then the sediment was separated from the supernatant. The supernatant was weighed and its dry matter content determined by gentle drying at room temperature, which essentially corresponds to the content of extracted extractives. The sediment was also weighed and dissolved in a defined mass of pure acetone. From this, the dry matter content was determined analogously to the supernatant. The deposits that had already formed during the distillation were also dissolved in pure acetone. From this, the dry matter content was determined analogously to the sediment. The content of free fatty acids (linolenic acid, linoleic acid, oleic acid and stearic acid, each expressed in linoleic acid equivalents), resin acids (isopimaric acid, palustric acid, dehydroabietic acid and abietic acid, each expressed in abietic acid equivalents) and lignans (isolariciresinol, secoisolariciresinol, conidendric acid, hydroxymatairesinol and matairesinol, each expressed in hydroxymatairesinol equivalents). The results of Trial 1 and Trial 2 (replicates with the same parameters) are listed in Tables 11 and 12.

Table 11

Table 12

As can be seen in Tables 11 and 12, the bulk of the extractive substance accumulates as centrifuged sediment. Despite the reduction in the amount of liquid by approx. 80% (from extract to supernatant), the dry matter content (which here essentially corresponds to the mass of extractive substance) in the supernatant is only at a similarly low level as in the extract (< 1 wt%) due to the selected separation process. . However, the proportion of free fatty acids and resin acids in the supernatant could be reduced to a very low level, while the lignans were enriched. In contrast, the sediment and the deposits contain little or no lignans, but a high content of free fatty acids and resin acids. Although the extractive substances analyzed here (free fatty acids, resin acids and lignans) represent only part of the extractive substances (and dry matter found here), it is clearly evident that with the selected thermal and mechanical separation process (distillation and centrifugation), not only the liquid phase is largely separated from Fatty and resin acids can be freed, but also lipophilic extractives (e.g. fatty acids and resin acids) and hydrophilic extractives (e.g. lignans) as by-products can each be significantly concentrated and purified.

Legend :

STDEV = standard deviation

TM = dry matter

TSG = dry matter content

Preferred embodiments:

In view of the above description of the present invention, the following preferred embodiments of the invention are disclosed herein:

1. A process for the manufacture of products based on non-woody biomass as a raw material, characterized in that cellulose, hemicelluloses and lignin-containing non-woody biomass in the form of particles is subjected to an extraction treatment with an extractant that contains one or comprises several organic solvents in an organic-aqueous mixture of the solvent(s) with water, the content of fatty acids in the particles being reduced by at least 70% by the extraction treatment of the particles with the extraction agent, measured as hexanal content in % by weight after accelerated aging for 72 h at 90°C, but the content of cellulose, hemicelluloses and lignin is essentially preserved in this extraction treatment.

2. The method according to embodiment 1, characterized in that the particles are present with a size of at most 2 mm, the particle size preferably according to the National Renewable Energy Laboratory (NREL) Laboratory Analytical Procedure (LAP) NREL/TP-510-42620 "Preparation of Samples for Compositional Analysis" is defined by the sieve mesh size of 2 mm of the cutting mill for sample preparation.

3. Method according to embodiment 1 or 2, characterized in that the particles are in the form of fibers, chips or mixtures thereof.

4. The method according to one or more of embodiments 1 to 3, characterized in that the particles are broken down into fibrous biomass by mechanical and/or thermal and/or chemical digestion.

5. The method according to one or more of embodiments 1 to 4, characterized in that the particles are biomass fibers with average fiber lengths between 0.5 and 2 mm and average fiber diameters between 10 and 50 μm, with the average fiber length and the mean fiber diameter relates to the mean length, determined by optical measurement of the suspended fibers.

6. The method according to one or more of embodiments 1 to 5, characterized in that the proportion of solvent in the organic-aqueous solvent mixture in the extractant, determined as the concentration of the liquid phase of the extract, consists of 0-95% by weight ethanol, preferably 50-90% by weight ethanol, 0-99% by weight acetone, preferably 30-90% by weight acetone, 0-70% by weight n-propanol, 0-85% by weight iso-propanol and/or 0-99% by weight of methanol.

7. The method according to one or more of embodiments 1 to 6, characterized in that the ratio of extract agent to solid dry substance is 5:1 - 25:1 (w/w), preferably 8:1 - 17:1 (w/w).

8. Process according to one or more of embodiments 1 to 7, characterized in that the extraction treatment is carried out at an extraction temperature of 20-150 °C, preferably 40-120 °C, in particular 50-110 °C.

9. Process according to one or more of embodiments 1 to 8, characterized in that the extraction treatment is carried out at an absolute extraction pressure of 1-5 bar, preferably 1-1.49 bar.

10. The method according to one or more of embodiments 1 to 9, characterized in that the extraction treatment takes place during an extraction time of 10 minutes to 8 hours, preferably 30 minutes to 7 hours, in particular 1 to 5 hours.

11. The method according to one or more of embodiments 1 to 10, characterized in that the method for producing cardboard, paper, in particular fiberboard, chipboard, insulating materials, commodities, medical products, food additives, pharmaceutical additives such as excipients.

12. The method according to one or more of embodiments 1 to 11, characterized in that the extraction treatment is selected from:

treatment with ethanol in a concentration of at least 45% by weight at at least 105°C for a period of at least 5 hours;

treatment with acetone in a concentration of at least 50% by weight at at least 40°C for a period of at least 30 minutes; or

Treatment with acetone in a concentration of at least 50% by weight at at least 20°C for a period of at least 15 minutes.

13. Method according to one or more of the embodiments 1 to 12, characterized in that the treatment with the extraction agent is carried out as a batch, continuous or semi-continuous extraction, preferably with a maximum partial residence time of 1 hour per extraction step.

14. The method according to one or more of embodiments 1 to 13, characterized in that during the extraction treatment the content of cellulose, hemicelluloses and lignin is reduced by less than 10%, preferably by less than 5%, in particular by less than 4%, is reduced, this reduction preferably being determined as the extracted solid mass, based on the starting material, the particles.

15. The method according to one or more of embodiments 1 to 14, characterized in that the particles are selected from grain particles, legume fruit particles, oil plant particles, fibrous plant particles, grass particles, in particular miscanthus particles, Jerusalem artichoke particles, reed particles, shrub cuttings particles, leaf particles from trees and Shrubs, bark particles, elephant grass particles, hay particles, corncob particles, or mixtures thereof.

16. The method according to one or more of embodiments 1 to 15, characterized in that the particles are mixed with the extraction agent during the treatment.

17. The method according to one or more of embodiments 1 to 16, characterized in that the particles are pressed after treatment with the extraction agent in order to remove the extraction agent.

18. The method according to one or more of embodiments 1 to 17, characterized in that, after treatment with the extraction agent, the particles are cleaned one or more times with an extraction agent, preferably with an organic-aqueous solvent with a similar or the same concentration as that of the Extractant to be cleaned.

19. The method according to one or more of embodiments 1 to 18, characterized in that the extraction agent is removed from the particles by one or more washings with water and/or steam stripping and/or drying, preferably by steam stripping and/or drying Will get removed.

20. The method according to one or more of embodiments 1 to 19, characterized in that the content of fatty acids in the particles by extraction of the particles with the extraction agent by at least 75%, preferably by at least 80%, in particular by at least 90%, is reduced, measured as hexanal content in weight. -% of the particles in the starting material compared to the extracted particles after accelerated aging for 72 h at 90 °C.

21 . Method according to one or more of embodiments 1 to 20, characterized in that the content of fatty acids in the particles is reduced by extraction of the particles with the extractant to a content of less than 2 mg/kg dry matter, preferably less than 1 mg/kg dry matter , in particular below 0.5 mg/kg dry matter, measured as the hexanal content as a mass fraction of the extracted particles after accelerated aging for 72 h at 90° C.

22 . Method according to one or more of embodiments 1 to 21, characterized in that terpenes are also extracted in addition to the fatty acids.

23 . Process according to one or more of embodiments 1 to 22, characterized in that the fatty acids, terpenes, pinenes and/or other extractives extracted with the extraction agent are fed to a further purification process, preferably by mechanical separation technology after the thermal separation of the organic solvent from the organic-aqueous extraction agent, with lipophilic extractives, in particular fatty acids and resin acids, being precipitated and separated, and an aqueous phase enriched with hydrophilic extractives, in particular lignans, being obtained, with the hydrophilic extractives preferably being separated by subsequent treatment with Thermal separation technology, in particular by means of membrane separation processes and / or adsorption, are further concentrated.

24 . Method according to embodiment 23, characterized in that the extractant is preceded by membrane filtration during the enrichment of the extractant.

25 . Method according to one or more of embodiments 1 to 24, characterized in that no complexing agents, in particular complexing agents selected from polybasic and polyfunctional carboxylic acids, aminomethylcarboxylic acids, aminomethylphosphonic acids and their compounds, EDTA, DTPA EGTA, EDDS and their salts, polyphenols, tannins, amino acids, peptides, proteins, polycarboxylates, phosphates, polyphosphates, phosphonic acids, polyphosphonates, phosphated, phosphonylated, sulfated and sulfonated polymers, during the extraction process, especially during the entire manufacturing process for the products made from the particles.

26 . Process according to one or more of embodiments 1 to 25, characterized in that the extraction agent and any washing liquids used, in particular water, are regenerated for reuse.

27 . Method according to one or more of embodiments 1 to 26, characterized in that the extraction treatment, in addition to reducing the hexanal content, also reduces the mechanical strength of the extracted particles, measured as Tensile Index of test sheets in Nm/g, by at least 10% , preferably by at least 15%, in particular by at least 25%, with the freeness, measured in °SR, changing by less than 10%.

28 . Process according to one or more of embodiments 1 to 27, characterized in that the organic-aqueous mixture of the solvent or solvents contains at least 10% water, preferably at least 7.5% water, in particular at least 5% water.

29 . Use of the lipophilic extractive substance fraction obtained according to embodiments 23 and 24 as a feed supplement.

30 . Process according to one or more of embodiments 1 to 22 and 25 to 28, for the production of products based on wood as a raw material, the starting material being - instead of the cellulose, hemicelluloses and lignin-containing non-woody biomass in the form of particles - Wood is used in the form of wood particles and the fatty acids, terpenes, pinenes and/or other extractives extracted with the extraction agent are fed to a further purification process, namely by mechanical separation technology after thermal separation of the organic solvent from the organic -aqueous extraction agent, with lipophilic extract substances fe, in particular fatty acids and resin acids, and precipitated are separated, and an aqueous phase enriched with hydrophilic extractive substances, in particular lignans, is obtained, the hydrophilic extractive substances preferably being further concentrated by subsequent treatment with thermal separation technology, in particular by means of membrane separation processes and/or adsorption.

31. Method according to embodiment 30, characterized in that prior membrane filtration of the extraction agent takes place during the enrichment of the extractive substance.

32. The method according to embodiment 30 or 31, characterized in that the wood particles are selected from softwood particles, preferably spruce wood particles, fir wood particles, pine wood particles, or larch wood particles; Deciduous wood particles, in particular beech wood particles, poplar wood particles, birch wood particles, or eucalyptus wood particles; or mixtures thereof.

33. Use of the lipophilic extractive substance fraction obtained according to one or more of embodiments 30 to 33 as a feed supplement.

Further preferred embodiments of the present invention are the following embodiments:

1. A process for the production of products based on non-woody biomass as a raw material, characterized in that cellulose, hemicelluloses and lignin-containing, non-woody biomass in the form of particles is subjected to an extraction treatment with an extractant containing one or more organic solvents or a organic-aqueous mixture of the solvent(s) with water, wherein the content of fatty acids in the particles is reduced by at least 70% by the extraction treatment of the particles with the extraction agent, measured as hexanal content in % by weight after accelerated aging for 72 h at 90°C, but the content of cellulose, hemicelluloses and lignin is essentially retained in this extraction treatment.

2. Method according to embodiment 1, characterized in that the particles are present with a size of less than 5 cm, the particle size preferably being determined by sieving using a square mesh screen, in particular using a square mesh screen with a mesh size of 5 cm or less.

3. Method according to embodiment 1 or 2, characterized in that the particles in the form of fibers, chips, strands, Wood chips or mixtures thereof are present.

4. Method according to one or more of embodiments 1 to 3, characterized in that the particles are broken down into fibrous biomass by mechanical and/or thermal and/or chemical digestion.

6. The method according to one or more of embodiments 1 to 5, characterized in that the solvent content of the organic-aqueous solvent mixture in the extractant, determined as the concentration of the liquid phase of the extract, consists of 0-95% by weight ethanol, preferably 50-90% by weight ethanol, 0-99% by weight acetone, preferably 30-90% by weight acetone, 0-70% by weight n-propanol, 0-85% by weight iso-propanol and/or 0-99% by weight of methanol.

7. The method according to one or more of embodiments 1 to 6, characterized in that the ratio of extractant to solids/dry substance is 5:1 - 25:1 (w/w), preferably 8:1 - 17:1 (w /w) is.

11. The method according to one or more of embodiments 1 to 10, characterized in that the method for producing cardboard, paper, in particular fiberboard, chipboard, Insulating materials, commodities, medical products, food additives, pharmaceutical additives, such as excipients, used in particular for the manufacture of cardboard.

treatment with ethanol in a concentration of at least 70% by weight at at least 105°C for a period of at least 30 minutes; or

Treatment with ethanol in a concentration of at least 45% by weight at at least 105°C for a period of at least 5 hours.

Treatment with acetone in a concentration of at least 50% by weight at at least 40°C for a period of at least 30 minutes.

13. The method according to one or more of embodiments 1 to 12, characterized in that the treatment with the extraction agent is carried out as a batch, continuous or semi-continuous extraction, preferably with a maximum partial residence time of 1 hour per extraction step.

15. The method according to one or more of embodiments 1 to 14, characterized in that the particles are selected from grain particles, legume fruit particles, oil plant particles, fibrous plant particles, grass particles, in particular miscanthus particles, Jerusalem artichoke particles, reed particles, shrub cuttings particles, leaf particles from trees and shrubs, den particles, elephant grass particles, hay particles, corn cob particles, or mixtures thereof.

19. The method according to one or more of embodiments 1 to 18, characterized in that the extraction agent is removed from the particles by washing them once or several times with water or by drying, preferably by drying.

20. The method according to one or more of embodiments 1 to 19, characterized in that the content of fatty acids in the particles is reduced by at least 75%, preferably by at least 80%, in particular by at least 90%, by extraction of the particles with the extraction agent. is reduced, measured as hexanal content in % by weight of the particles in the starting material compared to the extracted particles after accelerated aging for 72 h at 90°C.

21. The method according to one or more of embodiments 1 to 20, characterized in that the content of fatty acids in the particles is reduced by extraction of the particles with the extraction agent to a content of less than 2 mg/kg dry matter, preferably less than 1 mg/kg. kg dry matter, in particular less than 0.5 mg/kg dry matter, measured as hexanal content as mass fraction of the extracted particles after accelerated aging for 72 h at 90°C.

22. The method according to one or more of embodiments 1 to 21, characterized in that terpenes are also extracted in addition to the fatty acids.

23. Method according to one or more of the embodiments 1 to 22, characterized in that the fatty acids, terpenes, pinenes and/or optionally other extractives extracted with the extraction agent are fed to a further purification process.

24 . Method according to one or more of embodiments 1 to 23, characterized in that the particles no complexing agents, in particular complexing agents selected from polybasic and polyfunctional carboxylic acids, aminomethyl carboxylic acids, aminomethyl-phosphonic acids and their compounds, EDTA, DTPA EGTA, EDDS and their Salts, polyphenols, tannins, amino acids, peptides, proteins, polycarboxylates, phosphates, polyphosphates, phosphonic acids, polyphosphonates, phosphated, phosphonylated, sulfated and sulfonated polymers, during the extraction process, especially during the entire manufacturing process for the from products made from the particles.

25 . Process according to one or more of embodiments 1 to 24, characterized in that the extraction agent and any washing liquids used, in particular water, are regenerated for reuse.

26 . Method according to one or more of embodiments 1 to 25, characterized in that the extraction treatment, in addition to reducing the hexanal content, also reduces the mechanical strength of the extracted particles, measured as Tensile Index of test sheets in Nm/g, by at least 10% , preferably by at least 15%, in particular by at least 25%, with the freeness, measured in °SR, changing by less than 10%.

Claims

47 claims :

1. A method for producing products based on non-woody biomass as a raw material, characterized in that cellulose, hemicelluloses and lignin-containing, non-woody biomass in the form of particles is subjected to an extraction treatment with an extractant containing one or more organic solvents in one organic-aqueous mixture of the solvent(s) with water, wherein the content of fatty acids in the particles is reduced by at least 70% by the extraction treatment of the particles with the extraction agent, measured as hexanal content in % by weight after accelerated aging for 72 h at 90°C, but the content of cellulose, hemicelluloses and lignin is essentially retained in this extraction treatment.

2. The method according to claim 1, characterized in that the particles are present in a size of at most 2 mm, the particle size preferably according to the National Renewable Energy Laboratory (NREL) Laboratory Analytical Procedure (LAP) NREL/TP-510- 42620 "Preparation of Samples for Compositional Analysis" is defined by the sieve mesh size of 2 mm of the cutting mill for sample preparation, the particles preferably being in the form of fibers, chips or mixtures thereof.

3. The method according to claim 1 or 2, characterized in that the particles are fiberized by mechanical and / or thermal and / or chemical digestion biomass, in particular biomass fibers with average fiber lengths between 0.5 and 2 mm and average fiber diameters between 10 and 50 pm, where the average fiber length and the average fiber diameter relate to the average length , determined by optical measurement of the suspended fibers.

4. The method according to one or more of claims 1 to 3, characterized in that the solvent content of the organic-aqueous solvent mixture in the extractant, determined as the concentration of the liquid phase of the extract, consists of 0-95% by weight ethanol, preferably 50 - 90% by weight ethanol, 0 - 99% by weight acetone, preferably 30 - 90% by weight acetone, 0 - 70% by weight 48 n-propanol, 0-85% by weight isopropanol and/or 0-99% by weight methanol.

5. The method according to one or more of claims 1 to 4, characterized in that during the extraction treatment the content of cellulose, hemicelluloses and lignin is reduced by less than 10%, preferably by less than 5%, in particular by less than 4% , This reduction preferably being determined as the extracted solid mass, based on the starting material, the particles.

6. The method according to one or more of claims 1 to 5, characterized in that the particles are selected from grain particles, legume fruit particles, oil plant particles, fibrous plant particles, grass particles, in particular miscanthus particles, Jerusalem artichoke particles, reed particles, shrub cutting particles, leaf particles from trees and shrubs, Bark particles, elephant grass particles, hay particles, corn cob particles, or mixtures thereof.

7. The method according to one or more of claims 1 to 6, characterized in that after the treatment with the extraction agent, the particles are cleaned one or more times with an extraction agent, preferably with an organic-aqueous solvent with a similar or the same concentration as that of the Extractant to be cleaned.

8. The method according to one or more of claims 1 to 7, characterized in that the content of fatty acids in the particles is reduced by at least 75%, preferably by at least 80%, in particular by at least 90%, by extraction of the particles with the extraction agent , measured as the hexanal content in % by weight of the particles in the starting material compared to the extracted particles after accelerated aging for 72 h at 90°C.

9. The method according to one or more of claims 1 to 8, characterized in that the content of fatty acids in the particles by extraction of the particles with the extractant to a content of less than 2 mg / kg dry matter, preferably from below 49

1 mg/kg dry matter, in particular less than 0.5 mg/kg dry matter, measured as the hexanal content as the mass fraction of the extracted particles after accelerated aging for 72 h at 90° C.

10 . Process according to one or more of Claims 1 to 9 , characterized in that the extraction not only extracts the fatty acids but also terpenes .

11 . Process according to one or more of Claims 1 to 10, characterized in that the fatty acids, terpenes, pinenes and/or optionally other extractives extracted with the extraction agent are fed to a further purification process, preferably by mechanical separation technology after the thermal separation of the organic solvent from the organic-aqueous extraction agent, with lipophilic extractives, in particular fatty acids and resin acids, being precipitated and separated, and an aqueous phase enriched with hydrophilic extractives, in particular lignans, is obtained, with the hydrophilic extractives preferably being separated by subsequent treatment with Thermal separation technology, in particular by means of membrane separation processes and / or adsorption, are further concentrated.

12 . Method according to Claim 11, characterized in that the extractant is preceded by membrane filtration during the enrichment of the extractive substance.

13 . Method according to one or more of Claims 1 to 12, characterized in that the particles do not contain any complexing agents, in particular complexing agents selected from polybasic and polyfunctional carboxylic acids, aminomethyl carboxylic acids, aminomethyl phosphonic acids and their compounds, EDTA, DTPA EGTA, EDDS and their salts, Polyphenols, tannins, amino acids, peptides, proteins, polycarboxylates, phosphates, polyphosphates, phosphonic acids, polyphosphonates, phosphated, phosphonylated, sulfated and sulfonated polymers, added during the extraction process, especially during the entire manufacturing process for the products made from the particles will . 50

14 . Process according to one or more of Claims 1 to 13, characterized in that the extraction agent and any washing liquids used, in particular water, are regenerated for reuse.

15 . Method according to one or more of Claims 1 to 14, characterized in that the extraction treatment, in addition to reducing the hexanal content, also reduces the mechanical strength of the extracted particles, measured as Tensile Index of sample sheets in Nm/g, by at least 10%, preferably is increased by at least 15%, in particular by at least 25%, with the freeness, measured in °SR, changing by less than 10%.

16 . Use of the lipophilic extract substance fraction obtained according to claims 11 and 12 as a feed supplement.

17 . Process according to one or more of Claims 1 to 10 and 13 to 15, for the production of products based on wood as a raw material, the starting material being - instead of the cellulose, hemicelluloses and lignin-containing, non-woody biomass in the form of particles - Wood is used in the form of wood particles and the fatty acids, terpenes, pinenes and/or other extractives extracted with the extraction agent are fed to a further purification process, namely by mechanical separation technology after the thermal separation of the organic solvent from the organic-aqueous one Extraction agent, in which lipophilic extractives, in particular fatty acids and resin acids, are precipitated and separated, and an aqueous phase enriched with hydrophilic extractives, in particular lignans, is obtained, with the hydrophilic extractives preferably being separated by subsequent treatment with thermal separation technology, esp special by means of membrane separation processes and/or adsorption, are still further concentrated.

18 . 18. Method according to claim 17, characterized in that prior membrane filtration of the extractant takes place during the enrichment of the extractive substance.

19 . Method according to claim 17 or 18, characterized in that that the wood particles are selected from softwood particles, preferably spruce wood particles, fir wood particles, pine wood particles, or larch wood particles; Deciduous wood particles, in particular beech wood particles, poplar wood particles, birch wood particles, or eucalyptus wood particles; or mixtures thereof.

20. Use of the lipophilic extractive substance fraction obtained according to one or more of claims 17 to 19 as a feed supplement.