Carbon dioxide removal type thermal insulation material composition and preparation method thereof

Abstract

The disclosed invention includes a method of making a carbon dioxide-removing insulating material composition and the resulting carbon dioxide-removing insulating material composition, the material composition having sufficiently low thermal conductivity, the material composition is of the carbon dioxide removal type and thus absorbs more CO2 from the atmosphere during its production and use than it emits and can permanently sequestration this CO2. This is achieved by using at least one pyrolysis step of thermally insulating biomass particles bound to a further binder or a binder contained in the material or by directly compositing the thermally insulating biomass particles after pyrolysis to produce a composition that is shaped at macroscopic and microscopic levels.

Description

Technical Field

[0001] The present invention describes a method for manufacturing a carbon dioxide removal type thermal insulation material composition for forming a part of a sustainable building, a carbon dioxide removal type thermal insulation material composition for forming a part of a sustainable building, and the use of pyrolyzed thermal insulation biomass particles for manufacturing a carbon dioxide removal type thermal insulation material composition and products. Background Art

[0002] According to what was reported by Abergel et al. in 2018 (Abergel et al., 2018, 2018 Global Status Report - Towards a zero - emission, efficient and resilient buildings and construction sector. International Energy Agency (IEA) for the Global Alliance for Buildings and Construction.), the construction industry is one of the most important drivers of global climate change, accounting for approximately 39% of global greenhouse gas emissions.

[0003] For older buildings, the life - time carbon emissions are mainly operational emissions (heating, cooling, ventilation), while for modern buildings, embodied carbon emissions (i.e., carbon emissions due to construction product manufacturing, building construction, modernization and replacement measures, and the demolition and disposal of buildings and their materials) are becoming increasingly important, even reaching 50% or more of the life - time carbon emissions ( et al., 2020, Embodied GHG emissions of buildings – The hidden challenge for effective climate change mitigation. Applied Energy 258, 114107. (https: / / doi.org / 10.1016 / j.apenergy.2019.114107)).

[0004] Therefore, in order to address global climate change, it is crucial to develop and use building materials with lower or even negative greenhouse effects. Carbon dioxide removal type materials should be defined herein as materials that absorb more CO2 from the atmosphere during their production and use than they emit and permanently sequester that CO2.

[0005] "Permanent" can be understood here as a time scale related to climate, i.e., approximately 1000 to 10,000 years.

[0006] The most commonly used thermal insulation materials today - synthetic foam materials such as EPS, XPS or PIR / PU and mineral wool (glass wool and asbestos) are characterized by relatively high embodied carbon emissions. According to the 2016 Swiss KBOB inventory, considering the currently available materials with the best thermal performance, the above-mentioned foam materials emit 26.4 to 98.9 kg of CO2 equivalent for insulating one square meter of facade at a U-value of 0.15 W / (m 2 ·K), while mineral wool materials emit 5.9 to 9.2 kg of CO2 equivalent.

[0007] Regarding thermal insulation, even materials based on sustainable raw materials, such as cellulose or wood fiber boards, are net emitters of CO2 and are, according to their performance, in the same order of magnitude as the most sustainable mineral wool. At the same time, these biomass-based thermal insulation materials have lower thermal insulation performance than synthetic foams or mineral wool.

[0008] The thermal conductivity of biomass-based thermal insulation materials is usually ≥ 40 mW / (m·K), and a few materials have a thermal conductivity between 36 and 39 mW / (m·K). Therefore, biomass-based thermal insulation materials cannot be compared with conventional materials such as EPS or mineral wool.

[0009] There is no mention in the prior art of carbon dioxide removal thermal insulation materials or the resulting products, but biochar-containing building materials with some thermal insulation properties can be found in scientific and patent literature. US2022106789A1 claims a load-bearing sandwich structure with a biochar-based insulating layer for use of the structure as a carbon sink.

[0010] US20040076810 discloses a second layer of a carbonaceous insulating material derived from a mixture of carbon fibers and a carbonizable binder as part of a high-temperature insulator with different layers. The carbonized fibers and binder are selected from a list of materials including insoluble starch and soluble sugars. The carbonaceous insulating material is derived from precursors such as cotton or cellulose and has a diameter of 12 microns and an average length of 100 to 1600 microns. The fibers are carbonized in a furnace at about 800 °C, mixed with the binder to form a green preform, and then carbonized at 1000 °C. Carbonization at 800 °C, 1000 °C or even 1800 °C is too high and is associated with high input and high cost. Finally, the achievable thermal conductivity of 0.05 to 0.5 W / mK measured at 800 °C in an argon environment is still too high and needs to be improved for use as a building thermal insulation material.

[0011] The inventors of SE2051123 sought carbon foam materials that are heat-resistant and exhibit relatively large millimeter-sized pores, which also require high carbonization at temperatures above 700 °C. In addition to temperature drawbacks, poor mechanical properties and the lack of specifications for achievable thermal conductivity led to the presumption that such carbon foam materials do not seem to result in the desired carbon dioxide removal type insulation material composition and cannot be used for building insulation.

[0012] So far, no prior art literature has shown an insulation carbon dioxide removal type material composition or the resulting material product that forms part of a sustainable building and can be placed in the soil at the end of its life as a carbon sink for permanent CO2 sequestration. Summary of the Invention

[0013] The object of the present invention is to form a preparation method to obtain an insulation material composition with a sufficiently low thermal conductivity, which is a carbon dioxide removal type, so that more CO2 is absorbed from the atmosphere during its production and use than is emitted, and this CO2 is permanently sequestered.

[0014] The described invention has the following advantages: it is based on recycled (i.e., sustainable) materials, its performance is significantly better than existing biomass-based materials, comparable to current conventional insulation materials, and most importantly, it is a carbon dioxide removal type insulation material that permanently removes CO2 from the atmosphere.

[0015] In order to be able to use the insulation material as a soil enhancer at the end of the material's life, only certain soil - harmless binding additives are suitable.

[0016] In addition, in order to achieve competitive insulation performance, the biomass used as the raw material needs to be shaped at the macro and micro levels.

[0017] At the macro level, the geometry of the biomass needs to be configured such that, for example, pores with an average pore diameter less than about 2 mm to 4 mm are generated during mechanical processes.

[0018] At the micro level, the material needs to become more porous to reduce solid conduction (i.e., heat conduction through the material itself), which is achieved by pyrolysis.

[0019] This problem is solved by using at least partially pyrolyzed biomass, which produces macro inter - particle pores determined by the binding process and geometry of the biomass particles used, and has much smaller pores generated inside the biomass by pyrolysis, which we call additional intra - particle pores.

[0020] Another object of the subject matter of the present invention is to provide a manufacturing method of a carbon dioxide removal type insulation material composition and a product made therefrom. Brief Description of the Drawings

[0021] A further understanding of various aspects of the present invention can be obtained by referring to the following specific embodiments in conjunction with the accompanying drawings. The drawings are briefly described below.

[0022] Figure 1 Shows a schematic cross-section of the resulting carbon dioxide removal type heat insulating material product, mainly showing rod-like pyrolyzed heat insulating material particles having intra-particle gaps, and the pyrolyzed heat insulating material particles are bonded together by an adhesive to form inter-particle pores.

[0023] Figure 2a Shows a graph of the thermal conductivity versus density relationship for a first set of samples of a carbon dioxide removal type heat insulating material composition based on spent coffee grounds before and after the pyrolysis step, while

[0024] Figure 2b Shows according to Figure 2a , a photograph of a sample of a carbon dioxide removal type heat insulating material composition.

[0025] Figure 3a Shows a graph of the thermal conductivity versus density relationship for a second set of samples, this time based on wood fiber particles before and after the pyrolysis step, while

[0026] Figure 3b Shows according to Figure 3a , a photograph of a sheet-like sample of a carbon dioxide removal type heat insulating material composition after pyrolysis.

[0027] Figure 4 Shows the thermal conductivity and mass dependence on the pyrolysis temperature of a wood fiber sample having an inherent binder with a density of about 100 kg / m 3 before pyrolysis. For samples treated at temperatures above 150 °C and below 900 °C, the thermal conductivity is significantly reduced. Detailed Description of the Embodiments

[0028] Disclosed herein is a carbon dioxide removal type heat insulating material composition comprising raw biomass particles, the biomass particles being pyrolyzed and connected with an adhesive to form the resulting carbon dioxide removal type heat insulating material product, for example in the form of a sheet or a cavity filling material. Figure 1 The hollow circles in

[0029] As the raw material, raw biomass particles are used, which exhibit a sheet-like 2D geometry or a rod-like 1D geometry where the particles are preferably constrained in one and two spatial dimensions respectively. The shape of these particles can also be curved. In addition, their average aspect ratio, i.e., the ratio of the maximum spatial extension to the maximum spatial extension in the constrained dimension, should be at least 6. The maximum extension of the sheet and the maximum length of the rod should be between 1 mm and 100 mm, more preferably between 2 mm and 40 mm, and the constrained dimension of the sheet / rod should be on average less than 5 mm, more preferably less than 3 mm. The most preferred maximum thickness of the sheet or rod is below 2 mm. The shaping of the raw biomass particles can be carried out by mechanical processes such as milling, grinding, or cutting.

[0030] Also suitable are raw biomass particles with a hollow shape, which form closed pores or partially open pores with an internal size between 0.01 mm and 4 mm, more preferably between 0.1 mm and 2 mm.

[0031] The raw materials used for the raw biomass particles are, for example, based on wheat straw, wheat bran, wheat grains, wheat husks, sunflower stalks, peanut shells, tree leaves, bamboo, reeds, cattails, seagrass, corn straw, corn cobs, corn kernels, miscanthus stalks, hemp stalk cores, hemp fibers, cotton fibers from recycled clothing, wood fibers, wood wool, wood shavings, cardboard, paper, or coffee silver skin or mixtures thereof. The utilization of waste materials is particularly effective.

[0032] We have tried different binder materials, such as starch, wood glue, cellulose, protein, gluten, lignin, or clay and their mixtures. For some materials, the binder materials contained in the biomass particles themselves, such as lignin or starch, can also be used without adding another binder. The binder material should be harmless so that the entire material can be disposed of in the soil later. In the soil, biochar can act as a soil enhancer and is stable over a long period.

[0033] In the case where starch or modified starch is used as the binder, it can also be based on grains. The approximate mixing ratio is one part of binder to four or more parts of heat-insulating biomass particles. The binding can involve a curing step, such as heating. The binding is usually carried out under some form of compression, such as within a mold or by moving the material between rolling rollers on a conveyor belt. However, the compression can be small and only caused by the weight of the material itself.

[0034] If the biomass used contains such binder materials as lignin or starch, the binder can be an inherent binder or an additionally introduced binder, including starch, wood glue, cellulose, lignin, bioplastics, protein, gluten, geopolymers, adobe, or clay or their mixtures.

[0035] The density of the bonded biomass particles (including the binder) before pyrolysis should be less than 400 kg / m 3 .

[0036] Porosity within and between particles

[0037] Interparticle porosity is the volume of the pores between particles divided by the total bulk volume, while intraparticle porosity is the volume of the pores within a particle divided by the external or encapsulating volume of the particle. Ultimately, the total porosity is the volume of the interparticle and intraparticle pores divided by the total bulk volume of the material.

[0038] By pyrolysis of the raw biomass particles or when using the pyrolyzed raw insulating biomass particles, additional intraparticle porosity is generated. Intraparticle porosity is understood as the fraction of the encapsulating volume of the particle consisting of pores. That is, by pyrolysis, the density of the biomass particles and the binder used (if pyrolysis is carried out after bonding) is reduced by introducing new pores inside the biomass particles, and in the case of pyrolysis after bonding, new pores are also formed in the binder in addition to the pores that usually already exist in the raw biomass particles. An example is the pores present in unpyrolyzed wood, the pore diameter of which is usually less than 0.05 mm. By pyrolyzing the raw biomass particles and then bonding them with a binder, respectively pyrolyzing a carbon dioxide removal type thermal insulation material composition containing a certain amount of raw biomass particles and a certain amount of binder, this additional intraparticle porosity of the carbon dioxide removal type thermal insulation material composition is achieved. The intraparticle porosity is characterized by pores smaller than 0.1 mm and usually less than 0.05 mm.

[0039] In addition, an interparticle porosity with an average pore diameter between 0.01 mm and 4 mm, most preferably less than 2 mm, is introduced. This interparticle porosity refers to the volume fraction of the pores generated between the biomass particles combined with the binder relative to the bulk volume of the carbon dioxide removal type thermal insulation material composition. In the entire composition, the distribution of the pores should be as uniform as possible.

[0040] Pore formation occurs due to the geometry of the particles. When the particles are geometrically constrained by the binder (e.g., by placing them in a template and compressing them to a certain extent, or by rolling them on a conveyor belt), gaps are left between them. Compression caused only by the weight of the material in extreme cases requires that the density of the composite material remains low enough, i.e., less than 300 kg / m 3 if the composite is carried out before pyrolysis, and less than 200 kg / m 3 , more preferably less than 100 kg / m 3 .

[0041] Porosity can be determined using optical or electron microscopy and / or X-ray tomography, optionally using image processing. It can also be derived from measurements of the bulk, encapsulated, and skeletal volumes of the material, where the interparticle porosity is 1 - ρ 块体 / ρ 包封 , and the intraparticle porosity is 1 - ρ 包封 / ρ 骨架 , so the total porosity is the sum of the interparticle and intraparticle porosities.

[0042] The resulting carbon dioxide-removing thermal insulation material composition is characterized by a thermal conductivity ≤ 40 mW / (m·K), preferably ≤ 35 mW / (m·K), and a density ≤ 150 kg / m 3 、more preferably < 100 kg / m 3 . The thermal conductivity is understood here to be determined in a steady state using a guarded hot plate or heat flow meter device in accordance with standard EN12667, where the material is conditioned at room temperature and 50% relative humidity. The resulting carbon dioxide-removing thermal insulation material product has the same properties, with both interparticle pores ≤ 4 mm in size and additional intraparticle pores smaller than 0.1 mm formed in the material. The interparticle pores are formed by the geometry and the bonding process. Thus, they exist both in the material composition and in the product. They are macro pores. The additional intraparticle pores are produced by pyrolysis.

[0043] We have found that structuring the carbon dioxide-removing thermal insulation material composition on two length scales, namely interparticle and intraparticle porosities, is crucial because only the combination of the two allows for very good thermal performance. If only natural large-scale pores are achieved, the result is insufficient, similar to widely described and used biomass-based insulators (such as wood fiber boards, cellulose fibers, straw bales, flax fiber insulation boards, etc.).

[0044] If additional intraparticle pores are introduced only by pyrolysis in a material without suitable interparticle porosity, the thermal conductivity of the material is reduced, but it is still not within the range of conventional insulators in the prior art. For example, when spruce wood is converted to charcoal (a form of biochar), the thermal conductivity in the longitudinal direction is reduced from about 180 mW / (m·K) to about 61 mW / (m·K).

[0045] In the carbon dioxide-removing thermal insulation material composition, most (> 80%) of the interparticle pores (i.e., the pores between the shaped pyrolyzed thermal insulation biomass particles) have an average diameter in the range of 0.01 to 4 mm, more preferably in the range of 0.1 to 2 mm. For a preferred embodiment of the carbon dioxide-removing thermal insulation material composition, the resulting interparticle porosity is at least 50%, and the resulting intraparticle porosity is at least 85%.

[0046] The resulting carbon dioxide-removing thermal insulation material compositions and products mainly comprise pyrolyzed biomass, i.e., >50% by weight, more preferably >70%.

[0047] Possible products are:

[0048] Rigid insulation boards, e.g., 500 x 1000 mm 2 , with a thickness of 10 to 300 mm,

[0049] Flexible insulation boards, e.g., 500 x 1000 mm 2 , with a thickness of 10 to 300 mm,

[0050] Loose fill for cavities, e.g., in wooden elements, where bonding occurs within the cavity,

[0051] Forming irregularly shaped parts,

[0052] Pipe insulation elements, e.g., consisting of half-pipes.

[0053] In a particular embodiment, the extended dimensions of the raw or pyrolyzed thermal insulation biomass particles are arranged at least partially perpendicular to the heat flow in the resulting carbon dioxide-removing thermal insulation material composition, characterized by an anisotropic thermal conductivity.

[0054] Manufacturing method V1: Pyrolysis after bonding

[0055] The first manufacturing method comprises the following steps:

[0056] I. Providing a quantity of biomass particles, such as wood, agricultural by-products, ideally waste-based particles, having a sheet-like 2D geometry or rod-like 1D geometry which means the particles are constrained in one and two spatial dimensions respectively, and the shapes of these particles can also be bent, where the average aspect ratio, i.e., the ratio of the maximum spatial extension to the maximum spatial extension in the constrained dimension, should be at least 6, and where the maximum extension of the sheet and the maximum length of the rod should be between 1 mm and 100 mm, more preferably between 2 mm and 40 mm, and the constrained dimension of the sheet / rod should be on average less than 5 mm, more preferably less than 3 mm, and subsequently

[0057] II. A bonding step, where such raw thermal insulation biomass particles are bonded with an adhesive such as clay or starch into a cohesive material composition with a density lower than 400 kg / m 3 for non-pyrolyzed biomass, where some form of spatial constraint is introduced during the bonding process, e.g., by using a template and compressing or by pressing the material, and where optionally a curing step is performed, e.g., heating the material with the adhesive, and subsequently

[0058] III. Pyrolysis step of the biomass material composition, which is carried out by heating the biomass particle / binder composition to a temperature between 150°C and 700°C, most preferably between 300°C and 600°C, in a reducing oxygen atmosphere. The binder is of course also pyrolyzed in this step.

[0059] Manufacturing method V2: Using the pyrolyzed material

[0060] Optionally, the pyrolyzed material can be used in a method comprising the following steps:

[0061] I. Providing a certain amount of pyrolyzed heat-insulating biomass particles, such as wood, agricultural by-products, ideally waste-based particles, having a sheet-like 2D geometry or rod-like 1D geometry which means that the particles are constrained in one and two spatial dimensions respectively, and the shape of these particles can also be bent, where the average aspect ratio, i.e., the ratio of the maximum spatial extension to the maximum spatial extension in the constrained dimension, should be at least 6, and where the maximum extension of the sheet and the maximum length of the rod should be between 1 mm and 100 mm, more preferably between 2 mm and 40 mm, and the constrained dimension of the sheet / rod should be on average less than 5 mm, more preferably less than 3 mm, and subsequently

[0062] II. Binding step, in which the pyrolyzed heat-insulating biomass particles are combined with the intrinsic binder of the biomass used or an additionally introduced binder such as clay or starch to form a cohesive carbon dioxide removal type heat-insulating material composition with a density lower than 200 kg / m 3 、 most preferably lower than 100 kg / m 3 , where some form of spatial constraint is introduced during the binding process, such as by using a mold and compression or by pressing the material, and where optionally a curing step is carried out, such as heating the material and the binder.

[0063] We carried out pyrolysis using an N2 atmosphere in a furnace, while in another setup pyrolysis was carried out by sealing the original biomass particle / binder composition in a container with a small number of gas outlets and heating it in a furnace.

[0064] The ideal pyrolysis temperature is well below 700°C, starting from 150°C, most preferably between 300°C and 400°C, which results in the best thermal and mechanical properties.

[0065] For the pyrolysis step, the exposure time of the biomass / binder composition to the mentioned high temperature should be in the range of 5 minutes to 10 hours, more preferably between 10 minutes and 5 hours, most preferably between 20 minutes and 3 hours.

[0066] The shrinkage of the material during pyrolysis and the resulting shrinkage of the inter-particle pores must be considered to optimize the thermal conductivity. Pyrolysis reduces the density of the insulating biomass particle / binder composition and creates smaller pores within the insulating biomass particle / binder composition, i.e., smaller intra-particle porosity, such that the solid conduction through the resulting insulating material is reduced compared to the non-pyrolyzed material. The pyrolysis conditions affect the inter-particle porosity, intra-particle porosity, and the chemical composition of the material, such that the thermal conductivity of the carbon dioxide removal type insulating material composition after pyrolysis depends on these pyrolysis conditions, such as the pyrolysis temperature, as Figure 4 shown.

[0067] Hundreds of samples were made with different raw materials and compositions to demonstrate this principle. These also have at least one of the following properties: thermal properties, mechanical properties, fire resistance properties, hygroscopicity.

[0068] Biochar-based materials have better fire performance because a part of the combustion process has occurred through pyrolysis. Depending on the raw materials used, the E-class fire rating specified in EN13501 can be achieved without using flame retardants.

[0069] The carbon dioxide removal type insulating material composition provided herein and the resulting carbon dioxide removal type insulating material product are still carbon dioxide removal type when placed in the soil at the end of their use in buildings. To implement an end-of-life disposal scenario for carbon sequestration in the soil, from a technical perspective, all components of the carbon dioxide removal type insulating material composition must be compatible with their use in the soil, i.e., should not contain any harmful substances such as excessive heavy metals, fluorinated compounds, etc.

[0070] Biochar-based carbon dioxide removal type insulating material compositions are very likely to have a residence time in the soil of more than 1000 years and thus meet the conditions as carbon dioxide removal type materials. Considering the 75% carbon content and the atomic mass ratio of carbon and oxygen, each kilogram of the carbon dioxide removal type insulating material composition contains approximately 2.8 kg of CO2 equivalent. For a biochar insulation board with a density of approximately 100 kg / m 3 3 and a thermal conductivity of 34 mW / (m·K), if the biochar is produced in a CO2-neutral manner, each square meter of insulation can sequester 61.9 kg of CO2 equivalent, with a U-value of 0.15 W / (m 2 2·K).

[0071] Considering carbon sequestration and the carbon emissions avoided by not using EPS, this is almost 100 kg of CO2 equivalent less per square meter than the most commonly used building insulation material EPS in Switzerland. Since the pyrolysis process is an energy-positive process, i.e., it generates waste heat, it can be reasonably inferred that even if the carbon dioxide removal type insulating composition cannot be produced in a carbon-neutral manner, its carbon footprint will be significantly lower than that of other materials such as wood fiber boards.

[0072] Figure 2a Shows the relationship between the thermal conductivity and density of a sample based on coffee silver skin particles bonded with corn starch before and after pyrolysis. The change in density and the improvement in thermal conductivity after pyrolysis are clearly visible in the lower part of the figure, where the curve is fitted to two sets of measured values.

[0073] Figure 2b The photograph in [reference] shows a specific example of the resulting carbon dioxide-removing thermal insulation material product, where pyrolyzed coffee silver skin as the original biomass particles is bonded with starch as the binder.

[0074] In Figure 3a the relationship between the thermal conductivity and density of a sample based on wood fiber particles before and after pyrolysis is shown by the fitted curve. Using starch as the binder material as well, the results after pyrolysis are better.

[0075] Figure 3b The photograph in [reference] shows a specific example of the resulting carbon dioxide-removing thermal insulation material product, where wood fiber as the original thermal insulation biomass particles is bonded with starch as the binder and then pyrolyzed.

[0076] The goal of the present invention is a material with a lower thermal conductivity (≤40 mW / (m·K)). This can only be achieved by using a suitable geometry on a larger scale (millimeter and sub-millimeter levels) to create at least 50% of the necessary inter-particle porosity, and by introducing additional intra-particle porosity in the material itself in the nano- and micro-meter ranges through pyrolysis, as described above, resulting in a total porosity of at least 85%.

[0077] In addition, mixtures of different biomass types can be used, such as wood fiber and wheat straw.

[0078] Example

[0079] 5.0 g of spruce wood fibers with a thickness of less than 0.1 mm and a length of approximately 5 mm (i.e., aspect ratio > 50) were layered into a square mold with internal dimensions of 60 × 60 mm 2 and deionized water was sprayed after each layer. The material was compressed to a thickness of 12 mm and cured and dried in an oven at 150 °C for 3 hours. The bonding occurred due to inherent binder materials such as lignin. After that, the sample was pyrolyzed in a furnace in a container with a gas outlet at 350 °C for 40 minutes. The thermal conductivities before and after pyrolysis were 36.0 mW / (m·K) and 31.9 mW / (m·K), respectively. Since this material only contains untreated wood, its use in soil has direct compliance from a legal perspective, as in some countries, only biochar based on untreated wood is allowed to be used as a soil additive.

[0080] The 6.3 g of coffee silver skin with a thickness less than 0.1 mm and a maximum extension less than 10 mm (i.e., aspect ratio > 100) was layered and placed into a square mold with an internal size of 60×60 mm 2 After each layer, a solution of 13% corn starch in deionized water was sprayed onto each layer of coffee silver skin, resulting in a total addition of 0.9 g (dry weight) of corn starch. The sample was compressed to a thickness of 12 mm and cured and dried at 180 °C for 3 hours. Subsequently, the sample was pyrolyzed in a container with a gas outlet in a furnace at 350 °C for 20 minutes. The thermal conductivities before and after pyrolysis were 38.2 mW / (m·K) and 33.2 mW / (m·K), respectively. The material achieved the E-class fire rating specified in EN13501 without adding any flame retardants.

[0081] 6.0 g of wood wool with a thickness of approximately 0.2 mm, a width of approximately 2.5 mm, and a length up to 60 mm (i.e., aspect ratio of approximately 24) was mixed with a solution of 3.0 g of methyl cellulose in 27.0 g of water and placed into a mold of 60x60 mm 2 and compressed to a thickness of 12 mm. The sample was cured and dried at 120 °C for 4 hours, and then pyrolyzed in a tube furnace with nitrogen purge at 300 °C for 1.5 hours. The thermal conductivities before and after pyrolysis were 43.3 mW / (m·K) and 37.4 mW / (m·K), respectively. For the original wood wool material used, in this example, it was only possible to obtain a thermal conductivity below 40 mW / (m·K) with a combination of the interparticle porosity of the material itself and the additional intraparticle porosity introduced by pyrolysis.

[0082] 6.0 g of wood wool with a thickness of approximately 0.2 mm, a width of approximately 2.5 mm, and a length up to 60 mm (i.e., aspect ratio of approximately 24) was mixed with a solution of 4.5 g of clay in 15.5 g of water and placed into a mold of 60x60 mm 2 and compressed to a thickness of 12 mm. The sample was dried at 120 °C for 4 hours, and then pyrolyzed in a tube furnace with nitrogen purge at 300 °C for 1.5 hours. The thermal conductivities before and after pyrolysis were 43.1 mW / (m·K) and 36.2 mW / (m·K), respectively.

[0083] 6.0 g of wood wool with a thickness of approximately 0.2 mm, a width of approximately 2.5 mm, and a length up to 60 mm (i.e., aspect ratio of approximately 24) was mixed with a dispersion of 3.0 g of gluten in 27.0 g of water and placed into a mold of 60x60 mm 2 and compressed to a thickness of 12 mm. The sample was dried and cured at 120 °C for 4 hours, and then pyrolyzed in a tube furnace with nitrogen purge at 300 °C for 1.5 hours. The thermal conductivities before and after pyrolysis were 44.3 mW / (m·K) and 35.3 mW / (m·K), respectively.

[0084] Approximately 3.1 g of pyrolyzed wheat straw with a thickness of about 0.2 mm, a width of about 4 mm, and a length of about 50 mm (i.e., an aspect ratio of about 13) was layered into a square mold with an internal size of 60×60 mm 2 . The wheat straw had been pyrolyzed in a sealed container with a gas outlet in a furnace at 350 °C for 40 minutes. After each layer, the material was sprayed with a 5% corn starch solution in deionized water, and a total of 25.3 g of the solution was added. The sample was compressed to a thickness of 12 mm and cured and dried at 150 °C for 3 hours. The resulting thermal conductivity was 36.8 mW / (m·K).

[0085] Approximately 5.1 g of pyrolyzed hemp stalk core with a thickness of about 1 - 2 mm, a width of about 3 mm, and a length of about 20 mm (i.e., an aspect ratio of about 7) was mixed with 14.0 g of a 5% dispersion of soy protein in deionized water and placed in a 60x60 mm 2 mold and compressed to a thickness of 12 mm. The hemp stalk core had been pyrolyzed in a sealed container with a gas outlet in a furnace at 350 °C for 40 minutes. The resulting sample was cured and dried at 150 °C for 3 hours. The thermal conductivity of the sample was 38.0 mW / (m·K).

[0086] Approximately 5.1 g of pyrolyzed Miscanthus straw with a thickness of about 0.4 mm, a width of about 2 - 3 mm, and a length of about 15 mm (i.e., an aspect ratio of about 6) was layered into a square mold with an internal size of 60×60 mm 2 . The Miscanthus straw had been pyrolyzed in a sealed container with a gas outlet in a furnace at 350 °C for 40 minutes. After each layer, the material was sprayed with a 2% corn starch solution in deionized water, and a total of 9.9 g of the solution was added. The material was compressed to a thickness of 12 mm and cured and dried at 150 °C for 3 hours. The resulting sample had a thermal conductivity of 36.2 mW / (m·K).

[0087] Old clothes consisting of 100% cotton were shredded using an office shredder to obtain sheet fabric fragments with a thickness of about 0.2 mm, a width of about 1 - 3 mm, and a length of about 7 - 30 mm, i.e., an aspect ratio of about 10. These particles were then pyrolyzed in a sealed container with a gas outlet in a furnace at 350 °C for 40 minutes. Approximately 3.4 g of the particles were layered into a square mold with an internal size of 60x 60 mm 2 . After each layer, the material was sprayed with a 5% corn starch solution in deionized water, and a total of 19.0 g of the solution was added. The material was compressed to a thickness of 12 mm and cured and dried at 150 °C for 3 hours. The resulting sample had a thermal conductivity of 37.3 mW / (m·K).

[0088] The following material constitutes a negative example because it does not meet the geometric shape constraints of the claimed protection. The material is not made of particles, so there is no inter-particle porosity, and thus the thermal conductivity does not reach less than or equal to 40 mW / (m·K). A spruce wood block with dimensions of approximately 70×70×17 mm 3 was pyrolyzed in a sealed container with a gas outlet in a furnace at 350 °C for 120 minutes. The thermal conductivities of the material before and after pyrolysis were 180.5 mW / (m·K) and 61.3 mW / (m·K), respectively, where the heat flow was along the longitudinal direction of the wood.

[0089] The following material constitutes another negative example. The material is made of particles, however, the aspect ratio of the particles is smaller than that required in the claim, so the thermal conductivity does not reach less than or equal to 40 mW / (m·K). Here, a commercially available biochar made from biomass from tree pruning and landscaping green waste was used, which consists of rod-shaped particles with an average length of approximately 10 mm and an average aspect ratio of approximately 2.8. 6.5 g of this biochar was mixed with 3.4 g of starch dissolved in 16.5 water. The mixture was placed in a square mold with internal dimensions of 60x60 mm 2 and compressed to a thickness of 12 mm, and then cured and dried at 150 °C for 3 hours. The thermal conductivity of the resulting sample was 52.3 mW / (m·K).

Claims

1. A method for manufacturing a carbon dioxide removal type thermal insulation material composition, the carbon dioxide removal type thermal insulation material composition being used to form part of a sustainable building, It is characterized in that comprising the following steps: I. Providing a quantity of raw biomass particles having a sheet-like 2D geometry or a rod-like 1D geometry which means that the particles are respectively constrained in one and two spatial dimensions, the shape of the particles being also bendable, wherein the average aspect ratio, i.e., the ratio of the maximum spatial extension to the maximum spatial extension in the constrained dimension is at least 6, wherein the maximum extension of the sheet and the maximum length of the rod are between 2 mm and 60 mm, and wherein the constrained dimension of the sheet / rod is on average between 0.1 mm and 3 mm, II. Gluing the raw biomass particles into a cohesive material composition introducing geometric shape constraints by using the inherent binder of the biomass used or an additionally introduced binder, most preferably by using a subsequent binder curing step before the following steps, III. Pyrolyzing the raw biomass particle / binder composition at a temperature between 150 °C and 700 °C in a reducing oxygen atmosphere to produce a carbon dioxide removal type thermal insulation material composition having interparticle porosity with pore distribution throughout the volume of the material composite and an average cross-section in the range of 0.01 mm to 4 mm.

2. A method for manufacturing a carbon dioxide removal type thermal insulation material composition, the carbon dioxide removal type thermal insulation material composition being used to form part of a sustainable building, characterized in that comprising the following steps: I. Providing a quantity of pyrolyzed thermal insulation biomass particles having a sheet-like 2D geometry or a rod-like 1D geometry which means that the particles are respectively constrained in one and two spatial dimensions, the shape of the particles being also bendable, wherein the average aspect ratio, i.e., the ratio of the maximum spatial extension to the maximum spatial extension in the constrained dimension is at least 6, and wherein the maximum extension of the sheet and the maximum length of the rod are between 2 mm and 60 mm, and the constrained dimension of the sheet / rod is on average between 0.1 mm and 3 mm, II. Gluing the pyrolyzed thermal insulation biomass particles into a cohesive material composition introducing geometric shape constraints by using an additionally introduced binder, most preferably by using a subsequent binder curing step, to produce a carbon dioxide removal type thermal insulation material composition having interparticle porosity with pore distribution throughout the volume of the material composite and an average cross-section in the range of 0.01 mm to 4 mm.

3. The method for manufacturing a carbon dioxide removal type heat insulating material composition according to claim 1 or 2, wherein the obtained material composition has a density of less than 100 kg / m 3 and the heat insulating biomass particles used are based on wheat straw, wheat bran, wheat grains, wheat husks, sunflower stalks, peanut shells, leaves, bamboo, reeds, cattails, seagrass, corn stalks, corn cobs, corn kernels, miscanthus stalks, hemp stalk cores, hemp fibers, cotton fibers from recycled clothing, wood fibers, wood wool, wood shavings, cardboard, paper, or coffee silver skin or a mixture thereof, Resulting in interparticle porosity of a carbon dioxide removal type thermal insulation material composition having interparticle porosity with pore distribution throughout the volume of the material composite and an average cross-section in the range of 0.01 mm to 4 mm.

4. The method for manufacturing a carbon dioxide removal type thermal insulation material composition according to one of the preceding claims, wherein the gluing of the thermal insulation biomass particles into a cohesive material composition by introducing geometric shape constraints by using a binder is achieved by pressing the material on a conveyor belt by using a template or by using a binder.

5. A method for manufacturing a carbon dioxide removal type thermal insulation material composition according to one of the preceding claims, using an inherent binder of the biomass used, such as lignin or starch, or an additionally introduced binder, the additionally introduced binder including starch, wood glue, cellulose, lignin, tannin, bioplastic, protein, gluten, geopolymers, adobe or clay or a mixture thereof.

6. The method for manufacturing a carbon dioxide removal type heat insulating material composition according to claim 1, wherein the density of the cohesive material composition before pyrolysis composed of the raw biomass and the binder used is less than 400 kg / m 3 .

7. The method for manufacturing a carbon dioxide removal type heat insulating material composition according to claim 2, wherein the density of the cohesive material composition composed of heat-insulating biomass particles after pyrolysis and a binder is between 50 kg / m 3 and 100 kg / m 3 .

8. A method for manufacturing a carbon dioxide removal type thermal insulation material composition according to one of the preceding claims, wherein the shaping of the original or pyrolyzed thermal insulation biomass particles is carried out by mechanical processes such as milling, grinding, cutting.

9. A method for manufacturing a carbon dioxide removal type thermal insulation material composition according to one of the preceding claims, wherein the pyrolysis step is carried out using a N2 atmosphere in a furnace, or in another setup by sealing the original biomass particles / binder composition in a container with a small gas outlet and heating the container in a furnace.

10. A method for manufacturing a carbon dioxide removal type thermal insulation material composition according to one of the preceding claims, wherein the exposure time of the biomass particles or the biomass / binder composition at the temperature in the range of 150 °C to 700 °C should be between 5 minutes and 10 hours, more preferably between 10 minutes and 5 hours, and most preferably between 30 minutes and 3 hours.

11. A carbon dioxide removal type thermal insulation material composition for forming a part of a sustainable building, comprising a cohesive mixture of a certain amount of thermally insulated pyrolyzed biomass particles and a binder, capable of being pyrolyzed or not depending on the manufacturing method, characterized in that, the binder is an inherent part of the original non-pyrolyzed biomass, such as lignin or starch, and is subsequently pyrolyzed together with the non-pyrolyzed biomass, or the binder is non-pyrolyzed and additionally introduced before or after pyrolysis, including starch, wood glue, cellulose, lignin, tannin, bioplastic, protein, gluten, geopolymers, adobe or clay or a mixture thereof, wherein the carbon dioxide removal type thermal insulation material composition includes pyrolyzed thermal insulation biomass particles, and the pyrolyzed thermal insulation biomass particles: - have a sheet-like or rod-like geometry meaning that the particles are respectively constrained in one and two spatial dimensions, and the shape of the particles can also be bent, - wherein the average aspect ratio, that is, the ratio of the maximum spatial extension to the maximum spatial extension in the constrained dimension is at least 6, and - wherein the maximum extension of the sheet and the maximum length of the rod are between 2 mm and 60 mm, and the average constrained dimension of the sheet / rod is between 0.1 mm and 3 mm, -Based on wheat straw, wheat bran, wheat grains, wheat husks, sunflower stalks, peanut shells, tree leaves, bamboo, reeds, cattails, seaweeds, corn straws, corn cobs, corn kernels, miscanthus stalks, hemp stalk cores, hemp fibers, cotton fibers from recycled clothing, wood fibers, wood wool, wood shavings, cardboard, paper, or coffee silver skin or a mixture thereof, with a density lower than 100 kg / m 3 , such that there is an inter-particle porosity of the carbon dioxide removal type thermal insulation material composition with a pore distribution over the entire volume of the material composition and an average cross-section in the range of 0.01 mm to 4 mm, so as to exhibit a thermal conductivity of ≤40 mW / (m·K) of the material composition measured along the heat flow direction by conditioning the material state at room temperature and 50% relative humidity according to EN 12667.

12. The carbon dioxide removal type heat insulating material composition according to claim 11, wherein the interparticle porosity is at least 50% and the total porosity of the material composition is at least 85%.

13. The carbon dioxide removal type heat insulating material composition according to any one of claims 11 to 12, wherein the mixing ratio of the binder to the heat insulating biomass particles is at most 1:4 by weight.

14. The carbon dioxide removal type heat insulating material composition according to any one of claims 11 to 13, wherein the obtained carbon dioxide removal type heat insulating material composition and product contain >50% by weight, more preferably >75% by weight of pyrolyzed biomass particles.

15. The carbon dioxide removal type heat insulating material composition according to any one of claims 11 to 14, wherein the extended dimension of the original or pyrolyzed heat insulating biomass particles is arranged at least partially perpendicular to the heat flow in the obtained carbon dioxide removal type heat insulating material composition, showing anisotropic thermal conductivity, wherein the thermal conductivity perpendicular to the heat flow is at least 1.05 times that parallel to the heat flow.

16. The carbon dioxide removal type heat insulating material composition according to any one of claims 11 to 15, the carbon dioxide removal type heat insulating material composition being in the form of a heat insulating plate or template member, wherein the thermal conductivity perpendicular to the plane of the plate or parallel to the heat flow through the template member is the lowest.

17. Use of pyrolyzed heat insulating biomass particles for manufacturing a carbon dioxide removal type heat insulating material composition having an interparticle porosity of at least 50% and a total porosity of at least 85%, the pyrolyzed heat insulating biomass particles having a sheet-like 2D geometry or rod-like 1D geometry meaning that the particles are constrained in one and two spatial dimensions respectively, the shape of the particles being bendable, wherein the average aspect ratio, i.e., the ratio of the maximum spatial extension to the maximum spatial extension in the constrained dimension, is at least 6, and wherein the maximum extension of the sheet and the maximum length of the rod are between 2 mm and 100 mm, and the constrained dimension of the sheet / rod averages between 0.1 mm and 5 mm, showing an interparticle porosity having pores with an average cross-section in the range between 0.01 mm and 4 mm, under geometric shape constraints such as a template or by pressing on a conveyor belt for bonding, using the inherent binder of the biomass used or an additionally introduced binder, such as starch, wood glue, cellulose, lignin, tannin, bioplastic, protein, gluten, geopolymers, adobe or clay or a mixture thereof, showing a resulting thermal conductivity along the heat flow direction of the material composition that is lower than or equal to 40 mW / (m·K).

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