Method for producing a molded part from a molding compound

Abstract

A method for producing a molded part comprising a method for producing a molding compound, wherein the method for producing the molding compound comprises: a) Providing lignocellulosic plants and / or lignocellulosic plant fibers; b) Crushing of the lignocellulose-containing plants and / or lignocellulose-containing plant fibers; c) Performing partial delignification and hemicellulose hydrolysis, wherein the partial delignification and hemicellulose hydrolysis in step c) comprises the following steps: - Boiling the crushed lignocellulose-containing plants and / or the crushed lignocellulose-containing plant fibers in a substance selected from a group comprising sodium hydroxide, hydrogen peroxide, calcium hydroxide, either individually or any combination thereof; - Treatment of the crushed and cooked lignocellulose-containing plants and / or the crushed and cooked lignocellulose-containing plant fibers with an agent selected from a group comprising carboxylic acid, mineral acid, either individually or a combination thereof; and further The process for manufacturing a molded part includes: d) Shaping the molding compound obtained in c) into a molded part.

Description

Field of invention

[0001] The present invention relates to a method for producing a molded part from a molding compound.

[0002] The molded parts according to the invention are suitable, for example, as workpieces, shaping components in a piece of furniture or furnishing, composite materials, cladding parts for buildings or building components, fillers, coatings, insulating materials or building materials, in particular acoustic insulation material, building material panels and thermal insulation material. State of the art

[0003] Molded parts are used in a wide variety of industrial sectors, for example in the automotive industry, buses, rail vehicles, and aircraft for trim panels and other interior components. In buildings, molding compounds are used as building materials, insulation, and furniture.

[0004] Depending on the application, materials must be as lightweight as possible while maintaining their shape. Many currently used composite materials, particularly those in the mobile industry, have a complex structure and are extremely expensive and costly to manufacture. To reduce weight and preserve acoustic properties, up to ten individual layers of various materials are sometimes used to produce the desired molded parts or the products derived from them.

[0005] Besides the complex manufacturing process, questions regarding recycling and the health risks of the individual materials also play a role. Many of the materials used can only be recycled using elaborate processes or disposed of after use, posing significant environmental problems. Furthermore, there are hidden product properties that are problematic both during and after use, such as fire retardants, flame retardants, solvents, and plasticizers.

[0006] Another significant factor is the long-term and sustainable availability of raw materials for manufacturing the molded parts. Fossil raw materials will only be available in limited quantities in the medium to long term and are increasingly criticized due to their contribution to global warming and limited recyclability. It is foreseeable that products made from increasingly scarce fossil resources will become more expensive as the prices of these dwindling resources rise. Furthermore, resource scarcity also contributes to the reduced functionality of supply chains. For these reasons, efforts are warranted to replace molded parts made from petroleum-based and increasingly scarce raw materials with ecologically sound, renewable raw materials that are permanently available in nature.

[0007] The processes known to date, such as those described in DE 31 05 596 C2, DE 23 19 759 A, DE 10 2004 012 458 B4, EP 2 193 899A1, EP 2 974 841 A1, or US 5,076,986, represent initial approaches but are unsatisfactory for a variety of reasons. Firstly, additives that are ecologically problematic are still used, and secondly, a number of desired product properties are not achieved. Although some materials of natural origin are used, these still require energy- and labor-intensive processing. Furthermore, they do not close the sustainable, ecological material and product cycle in the sense of a circular economy. Background of the invention

[0008] Typically, materials made of melamine resin foam or EPS are used in soundproofing and thermal insulation; these are plastics that must be disposed of in landfills at the end of their life cycle. Ecological alternatives to plastics already exist, for example, those made from wood fibers.

[0009] Compared to the cultivation of crops like timber, which requires additional land and water, hop by-products do not require any extra resources, as they utilize waste products that would otherwise go to waste. The Hallertau region is world-renowned for its extensive hop fields. With an annual yield of over 41,000 tons of hop cones on approximately 17,000 hectares, the Hallertau holds a leading position: it represents the largest contiguous hop-growing area in the world, accounting for about a third of global hop production. It is also worth noting that hop processing generates around 250,000 tons of biomass, which is currently only used to a limited extent. This hop waste, consisting of stems, leaves, the support wires, and unwanted cones, makes up about 85% of the total plant mass. Current practice involves spreading this waste on separate fields for fermentation.This process can be problematic because the sap from the plant matter can seep into the groundwater, and the Hallertau region is already struggling with elevated nitrate levels in its groundwater. Furthermore, chemical reactions during fermentation repeatedly lead to fires and simultaneously result in high greenhouse gas emissions. Approximately 20% of the waste generated in the Hallertau is sold to the Wolnzach biogas plant for thermal treatment, which is already operating at full capacity. The farms are then obligated to take back the resulting digestate and spread it on their fields, a step that many hop growers find burdensome.

[0010] Currently, 25-30% of the world's industrial hemp is cultivated in the EU. With the partial legalization of cannabis by the German government on April 1, 2024, an increase in cannabis plantations in Germany is expected.

[0011] A large portion, approximately 20-30%, of the hemp plant, particularly the stalks and leaves, often finds only limited use. They are frequently considered by-products and in some cases even discarded or used as animal feed, mulch, or for energy production. The focus is usually on the valuable hemp seeds or hemp fibers, while the remaining parts are currently used less extensively, although there is growing interest in the sustainable, holistic utilization of the entire plant. Object of the invention

[0012] Against this background, the object of the present invention is to provide a method dedicated to the use of lignocellulose-containing plants, in particular the use of plants of the hemp family (Cannabaceae), preferably hops and / or other plants of the hemp family (Cannabaceae) such as hemp, and in particular previously unused hop waste and / or waste of other plants of the hemp family (Cannabaceae), in order to produce high-quality and sustainable materials.

[0013] The main object of the present invention is to produce high-quality and recyclable molded parts from hops, preferably hop vines, and / or by-products of the hop harvest or waste thereof; and / or from other plants of the hemp family (Cannabaceae), preferably hemp, and / or by-products of the harvest of the hemp family (Cannabaceae).

[0014] This task is solved using the independent claim. The dependent claims further develop the core idea of ​​the invention.

[0015] The development and production of molded parts according to the invention, using molding compounds according to the invention, is based on a comprehensive approach that combines ecological sustainability, circularity, and technical performance. Description of the invention

[0016] In a first aspect, the invention provides a method for manufacturing a molded part, comprising I) a method for producing a molding compound, the process for producing the molding compound comprises the following process steps: Step a) Providing lignocellulosic plants and / or lignocellulosic plant fibers; Step b) Shredding the lignocellulose-containing plants and / or lignocellulose-containing plant fibers; Step c) Performing partial delignification and hemicellulose hydrolysis, wherein the partial delignification and hemicellulose hydrolysis in step c) comprises the following steps: - Boiling the crushed lignocellulose-containing plants and / or the crushed lignocellulose-containing plant fibers in a substance selected from a group comprising sodium hydroxide, hydrogen peroxide, calcium hydroxide, either individually or any combination thereof; - Treatment of the crushed and cooked lignocellulose-containing plants and / or the crushed and cooked lignocellulose-containing plant fibers with an agent selected from a group comprising carboxylic acid, mineral acid, either individually or a combination thereof; and further The process for manufacturing a molded part includes the following process step II): d) Shaping the molding compound obtained in c) into a molded part.

[0017] Thus, the process for producing a molding compound, which is part of the inventive process for producing a molded part, includes as step c) the performance of a partial delignification and hemicellulose hydrolysis.

[0018] In an optional step, after the shredding of the lignocellulosic plants and / or lignocellulosic plant fibers and before carrying out partial delignification and hemicellulose hydrolysis, lignocellulosic plant fibers are recovered from the shredded plants by separating them from the remaining plant components. If this optional step is performed, the subsequent steps yield either lignocellulosic plant fibers alone or lignocellulosic plant fibers in combination with lignocellulosic plants.

[0019] In a preferred embodiment of the invention, the hop fibers are obtained in this optional step by separating them from the shives. This is achieved by separating the different components (fiber and shives) of the shredded hop vine material from step b) using a sieve and / or a vibrator, preferably a drum sieve.

[0020] If this optional step is not carried out in the process according to the invention, there is no deliberate recovery of lignocellulosic plant fibers, but the lignocellulosic plants are exposed to the further process steps - without, for example, a separation of the hop vines from the hop fibers and shives.

[0021] In the process according to the invention, lignocellulose-containing plants and / or lignocellulose-containing plant fibers are provided, wherein in step a) of the process according to the invention these are preferably provided as dried lignocellulose-containing plants and / or dried lignocellulose-containing plant fibers.

[0022] The term "molding compound," as used here, preferably encompasses a compound which, when pressed into a mold, yields a molded part, e.g., a plate or panel. Furthermore, the molding compound according to the invention can be used as a molded part in any desired shape and in various layer thicknesses.

[0023] The crushing of the hop fibers in step b) is preferably carried out using cutting mills, shredders, green waste shredder mills and / or rollers, preferably by means of a hammer mill.

[0024] For the sake of completeness, it should be noted that before step a) - the provision of the hop fibers - a first pre-crushing step usually already takes place during the classic hop harvest by the processing agricultural businesses.

[0025] Here, the approximately 7-meter-long hop vines are pulled down and, as part of the hop harvest, chopped into smaller pieces by a picking machine at the farmer's site. The length of the vines can vary considerably, but due to their biological properties, the fibers are usually no longer than 1 meter, even if the vines themselves are longer.

[0026] In a further embodiment of the invention, the lignocellulosic plants are plants of the Cannabaceae family. Preferably, the plants of the Cannabaceae family are hops, preferably hop vines, and / or other plants of the Cannabaceae family, preferably hemp.

[0027] Particularly preferred are lignocellulose-containing plant fibers, with hop fibers being the preferred choice.

[0028] Hop fibers are a byproduct of hop production. Therefore, hop fibers offer a significant price advantage compared to other natural fibers.

[0029] The traditional building materials sector generates significant CO2 emissions through the production and use of materials such as concrete, steel, and plastics. Furthermore, many of these building materials are not recyclable at the end of their lifespan. The idea behind this invention is to use hop waste or byproducts of the hop harvest as raw materials for recyclable building materials instead of conventional materials, thereby significantly reducing the emission of climate-damaging greenhouse gases.

[0030] While planting and harvesting hops does require a considerable amount of energy and water, the hops are not grown for the production of molding compounds and molded parts, but rather for the further processing of hop cones in the beer industry. Consequently, by using previously unused or neglected byproducts of the hop harvest as raw materials, the present description processes biomass that is generated anyway and does not consume any additional resources in the form of energy, water, or land.

[0031] Securing the by-products of the hop harvest is crucial, as it represents the beginning of the value chain. The logistical challenges of harvesting lie in the need to consider various criteria, such as the large quantity of hop biomass, preventing premature fermentation, drying the hop vines, shredding the remaining vines, separating the metal, and handling the vine shreds.

[0032] After harvesting, the hop vine clippings begin to ferment quickly due to their high moisture content. This poses the risk of releasing methane and CO2 emissions into the atmosphere, contributing to global warming.

[0033] In addition to CO2 emissions, the fermentation processes also negatively impact the quality of the hop fibers, as they are partially decomposed. Besides fermentation, mold growth also poses a problem for further processing.

[0034] As is common practice, part of the harvest is transported by hop growers to biogas plant operators. There, some of it is processed in biogas plants. However, these plants cannot process all the unused biomass. The surplus is either spread on agricultural fields specifically designated for this purpose or distributed on the original hop fields. For cost reasons, the metal support wire is not separated from the hop vine. Spreading the metal wire and vine clippings simultaneously unnecessarily burdens the soil. In biogas plants, on the other hand, the metal wire is mechanically removed before fermentation.

[0035] To prevent fermentation and ensure safe storage of the vine cuttings, for example, the vine cuttings can be dried in drying containers using waste heat from the local biogas plant immediately after harvesting and then taken to a safe storage location.

[0036] The partial delignification of, for example, hop fibers serves to create a matrix that is bound by the lignin contained in the fibers. This process, described in c), is based on the targeted chemical treatment of the hop fibers to partially dissolve the lignin and improve its binding properties without completely dissolving it.

[0037] Preferably, in step c), the comminuted lignocellulosic plants and / or the comminuted lignocellulosic plant fibers are boiled with a combination of sodium hydroxide and hydrogen peroxide or, alternatively, with a combination of sodium hydroxide and calcium hydroxide, preferably with the addition of water in both cases. Subsequently, the pH is preferably lowered to 4 to 5 by adding carboxylic acids and / or mineral acids, preferably acetic acid and / or nitric acid and / or hydrochloric acid.

[0038] In a particularly preferred embodiment, the treatment in step c) is carried out according to the following procedure: 1. The hop raw material (10 parts by weight) is treated with a combination of sodium hydroxide (0.5-2 parts, preferably 1-1.5 parts) and hydrogen peroxide (1-5 parts, preferably 2 parts), or alternatively with a combination of sodium hydroxide and calcium hydroxide (0.1-1 parts, preferably 0.2-0.4 parts), and in both cases with water (50-200 parts, preferably 100 parts) at a temperature of 70-120 °C, preferably 80 °C, for a period of up to 3 hours, preferably 1-1.5 hours. This alkaline step promotes partial delignification and prepares the fiber structure for subsequent bonding. 2. The pH is then lowered to 4-5 by adding carboxylic acids and / or mineral acids, preferably acetic acid (1-5 parts, preferably 2-3 parts) and / or nitric or hydrochloric acid. This treatment is carried out at 70-120 °C, preferably 80 °C, for up to 90 minutes, preferably 30-45 minutes, to stabilize the lignin fragments and further condition the fiber structure. 3. The material can then be filtered through a sieve and / or filter bag and washed in water by immersing and turning it over. This ensures the removal of unwanted reaction byproducts.

[0039] Partial delignification chemically modifies the lignin contained in the fibers so that it continues to function as a natural binder, while the fibers retain their structural integrity. This enables the formation of a coherent matrix that can be processed into stable molded parts without external binders.

[0040] Process c) therefore utilizes the oxidative action of hydrogen peroxide under alkaline conditions to cleave ether and carbon-carbon bonds in the lignin. The subsequent pH reduction stabilizes the remaining lignin and optimizes it for fiber matrix formation. The use of preferably sodium hydroxide and optionally calcium hydroxide further contributes to fiber swelling, which in turn strengthens the mechanical bonding within the matrix.

[0041] To increase the efficiency of the separation process, the entire procedure or individual steps thereof can be repeated if necessary.

[0042] Hop fibers and water do not require the addition of binders, as a binder-free material is already formed after the molding compound has dried.

[0043] A remarkable aspect is that, when process step c) is applied, no adhesive or binder needs to be added to the molding compound at any point. The adhesive in the molding compound is a compound derived from the hop vine's own lignin content.

[0044] The aforementioned process steps according to the invention may also include further intermediate steps, preliminary and / or subsequent steps.

[0045] The combination of the above-mentioned various parameters such as fiber length, chemical partial delignification, and hemicellulose hydrolysis enables the production of a wide range of products with a broad spectrum of properties such as hardness, elongation, heat and sound insulation, which are based on the molding compound according to the invention.

[0046] A molded part is produced by means of a shaping process using the molding compound. In step d), the shaping of the molding compound is preferably carried out by injection molding or die casting processes, and in a preferred embodiment by a pressing process, so that a molded part is obtained after the pressing process.

[0047] The molding compound is preferably pressed and dried. The result is a sheet or panel that is very light, very porous, but also very stable due to the lignin bonding. After completing the process described in step c), this panel is characterized by its lack of binders.

[0048] When combining hop fibers and lime, the hops are preferably pressed and dried with lime. The resulting board is robust and versatile.

[0049] In a further embodiment of the invention, interfering components are removed at least as far as possible before step a), in step a), or after step b). These interfering components could, for example, be metal wires used in hop cultivation.

[0050] The removal of the interfering components is preferably carried out by means of magnetic separation and / or sedimentation.

[0051] In a further embodiment of the invention, the lignocellulose-containing plants are comminuted in step b) to a fiber length between 0.5 mm and 100 cm, preferably to a fiber length between 0.5 mm and 25 cm, particularly preferably between 0.5 cm and 15 cm.

[0052] In a further embodiment of the invention, the shaping of the molding compound into the molded part is carried out by placing the molding compound into a mold frame and pressing the molding compound contained in the mold frame.

[0053] The pressing process is carried out with a pressure preferably between 1 and 20 tons.

[0054] In a further embodiment of the invention, the partial delignification and hemicellulose hydrolysis in step c) further comprises a filtration and / or washing step.

[0055] This filtration and / or washing step is preferably carried out using a sieve or a filter bag.

[0056] In a further embodiment of the invention, the mineral acid used in step c) is acetic acid.

[0057] In another embodiment of the invention, the molded part is a cladding part, a furnishing for a building or building component, a filler, a coating, an insulating material or a building material.

[0058] Preferably, the building material is an acoustic insulation material, a building material panel or a thermal insulation material.

[0059] The good sound absorption values ​​of the molded parts according to the invention are particularly noteworthy.

[0060] In tests of the hop-based panels according to the invention, an absorption value of 0.55 Aw was achieved. This places the panel according to the invention in line with the average performance of commercially available and non-sustainable synthetic absorbers, such as Basotect from BASF.

[0061] The Aw value represents the weighted sound absorption coefficient, which is determined according to ISO 11654. Aw = 0 means that no absorption takes place – all incident sound is reflected. At Aw = 1, all incident sound is absorbed; no reflection occurs.

[0062] Initial flammability tests have already been conducted with hop vine shreds at the PÜZ fire protection testing facility of the Technical University of Munich. These preliminary tests resulted in a building material classification of B2 according to DIN 4102-1, indicating normal flammability. This means that hops, as a natural plant without any additives, already achieve the required building material classification for comparable products on the market in the areas of acoustics and thermal insulation. Regarding thermal conductivity, initial preliminary tests at the IFT Rosenheim institute showed that the hop vine shreds achieved a value of 0.053–0.058 W / (mK), making them comparable to wood fiber and straw insulation and providing better insulation than reed or wood wool insulation.

[0063] The sound absorption value of the inventive hop panel is therefore already on par with that of commercially available synthetic absorbers.

[0064] The components according to the invention also meet the required standards with regard to flammability, thermal conductivity and fire protection class. Examples Example 1: Hops + process according to the invention

[0065] In a first step (a), the harvested and kiln-dried hop material was prepared. In a second step (b), the prepared hop material was shredded with a green waste chipper, then the dust and impurities were removed with a rotary screen and a magnetic separator, and the hops were filled into big bags.

[0066] 500 g of the extracted material was then boiled with 50 g NaOH, 10 g Ca(OH)2, and 5 liters of water at 80 °C for 1.5 hours. The pH was reduced to 4 by adding 150 ml of acetic acid and boiling below 80 °C for 45 minutes. The material was then placed in a filter net and subsequently washed in 3 cycles of 5 liters of water each, for 5 minutes each time.

[0067] The matrix was then poured into a negative mold, pressed into a plate under 5 tons of pressure, and dried in the air until dry. Example 2: Hops + process according to the invention

[0068] In a first step (a), the harvested and kiln-dried hop material was prepared. In a second step (b), the prepared and dried hop material was shredded with a green waste chipper, then the dust and impurities were removed with a rotary screen and a magnetic separator, and the product was filled into big bags.

[0069] 500 g of the extracted material was boiled with 75 g NaOH, 200 g H₂O₂, and 5 liters of water at 80 °C for 1 hour. The pH was reduced to 5 by adding 100 ml of acetic acid and boiling below 80 °C for 45 minutes. The material was then placed in a filter mesh and subsequently washed in three cycles of 5 liters of water for 5 minutes each. The matrix was then placed in a negative mold, pressed into a plate under 5 tons of pressure, and air-dried until dry. Table 1: Comparison of the panels according to the invention compared to commercially available panels Comparison criteria category Inventive Acoustic panels made from agricultural hop waste products Whisperwool - Akusti kpaneeleausSchafwolleWollfilzundBindemittel hemp - Acoustic panels made of hemp and binder DeVorm - Acoustic panels made from partially recycled PET and binder WoodUp - Acoustic panels made of felt and recycled PET, glued StramenTec - Drywall elements made of straw Basotect (BASF) - Acoustic element made of foam made of melamine resin with fabric covering Sound absorber class / αW value according to DIN EN ISO 11654 effectiveness C / 0.55 (at 40mm thickness) D / 0.35 (at 12mm thickness) D / 0.55 (at 20mm thickness) D / 0.25 (at 10mm thickness) D / 0.3 (at 22mm thickness) No sound absorber (soundproof wall 42dB+) C / 0.6 (at 40mm thickness) Fire protection class for building materials effectiveness B2 normally flammable Flammable B1 flame-retardant unknown unknown Fire wall F90 B1 flame-retardant Fully biodegradable sustainability Yes, according to the procedure. Optional step Conditional No No No Yes No Bio-based binders sustainability Yes, plant-derived lignin No No No No Yes Yes Single-variety separation possible sustainability Yes No No Yes No Yes Conditional Recycling:Cradleto CradlewithoutDowncyclin9 sustainability Yes Yes No No No Yes No No additional resource consumption sustainability Yes Yes No No No No No CO2-negative v sustainability Conditional No Conditional No No Conditional No

[0070] The panels according to the invention guarantee industry-standard performance with regard to all structural material properties, such as sound absorption or fire protection class.

[0071] The use of bio-based and water-soluble binders ensures the reuse of raw materials after the product's lifespan.

[0072] Building materials can thus be reintroduced into a new life cycle after their service life without any loss of quality or resources by being incorporated as a raw material directly into the optional step or step c) of the process after prior crushing.

[0073] The molding compounds and molded parts according to the invention consist of a renewable raw material. They extract carbon dioxide from the atmosphere and store it permanently, while additionally avoiding CO2 emissions by not fermenting the hop waste in open fields. Example 3: Hops + binder (steps a) + c)) Table 2: Material samples and their recipes Material sample hop binder Water A ratio 200 g hops 22 100 g latex milk1 - B relationship 400 g hops 31 1,200 g lime3 1.800 g4,5 C ratio 400 g hops 11 1,200 g lime3 1.200 g3 ratio 250 g hops 21 750 g lime3 750 g3 relationship 300 g hops 11 900 g clay3 600 g2 F-ratio 300 g hops 21 1,200 g clay4 600 g2

[0074] The crushed hop vines were mixed with binders and water according to step b). Step c) according to claim 1 was therefore not carried out. The mixing ratios can be found in the table.

[0075] The material was mixed by hand, then mechanically pressed with 5 tons of pressure, and subsequently dried for several days at room temperature. List of characters Fig. Figure 1 shows a photograph of panels produced according to the process according to the invention. Fig. Figure 2 shows a schematic representation of the mixture of hops with a binding agent. Fig. Figure 3 shows a photograph of material samples according to the invention containing clay, lime and natural latex, the ratio of hops, binder and water of panels A to F being shown in Table 2.

Claims

[1] A process for producing a molded part comprising a process for producing a molding compound, wherein the process for producing the molding compound comprises: a) Providing lignocellulosic plants and / or lignocellulosic plant fibers; b) Crushing of the lignocellulose-containing plants and / or lignocellulose-containing plant fibers; c) Performing partial delignification and hemicellulose hydrolysis, wherein the partial delignification and hemicellulose hydrolysis in step c) comprises the following steps: - Boiling the crushed lignocellulose-containing plants and / or the crushed lignocellulose-containing plant fibers in a substance selected from a group comprising sodium hydroxide, hydrogen peroxide, calcium hydroxide, either individually or any combination thereof; - Treatment of the crushed and cooked lignocellulose-containing plants and / or the crushed and cooked lignocellulose-containing plant fibers with an agent selected from a group comprising carboxylic acid, mineral acid, either individually or a combination thereof; and further The process for manufacturing a molded part includes: d) Shaping the molding compound obtained in c) into a molded part. [2] Method for producing a molded part according to claim 1, wherein, after comminuting the lignocellulose-containing plants and / or lignocellulose-containing plant fibers and prior to carrying out partial delignification and hemicellulose hydrolysis, the recovery of lignocellulose-containing plant fibers from the comminutated lignocellulose-containing plants is carried out by separating the lignocellulose-containing plant fibers from the remaining components of the lignocellulose-containing plants. [3] Method for producing a molded part according to claim 1 or claim 2, wherein the molded part is a cladding part, a furnishing for a building or building component, a filler, a coating, an insulating material or a building material, wherein the building material is preferably an acoustic insulating material, a building material panel or a thermal insulating material. [4] Method for producing a molded part according to any one of claims 1 to 3, wherein the lignocellulose-containing plants are plants of the Cannabaceae family, preferably hops and / or hemp. [5] Method according to any one of claims 1 to 4, wherein in step a) or after step b) interference components are removed at least to a large extent, wherein the removal of the interference components is preferably carried out by means of magnetic deposition and / or sedimentation. [6] Method according to any one of claims 1 to 5, wherein the comminution of the lignocellulose-containing plants in step b) is carried out to a fiber length between 0.5 mm and 25 cm. [7] Method according to any one of claims 1 to 6, wherein the shaping is carried out by placing the molding compound into a mold frame and pressing the molding compound contained in the mold frame with a pressure between preferably 1 and 20 tons. [8] Method according to any one of claims 1 to 7, wherein the partial delignification and hemicellulose hydrolysis in step c) further comprises a filtration and / or washing step, wherein this filtration and / or washing step is preferably carried out using a sieve or a filter bag. [9] Method according to any one of claims 1 to 8, wherein the mineral acid in step c) is an acetic acid.

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