Cofiring of biomass with mineral feedstocks

Abstract

The invention relates to a method for the co-pyrolysis of biomass and mineral feedstock to activate the mineral feedstock, and the use of the resulting pyrolysis products in the construction industry, in horticulture and landscaping, as carrier materials and filter materials, in energy storage technology and as a CO2 sink.

Description

[0001] This invention relates to a method for co-pyrolysis of biomass and mineral raw materials for activating mineral raw materials, and the use of the pyrolysis products obtained therefrom in the construction field, horticulture and landscaping, as carrier materials and filter materials, in battery technology, and as CO2 sinks. Technical Background

[0002] Industrially produced carbonisates, obtainable from a variety of biomass sources such as waste wood, industrial waste fibers, agricultural byproducts, and even algae, offer innovative solutions for modern construction. These carbonisates serve as environmentally sustainable components in buildings by being used as additives, binder components, cement substitutes, or fillers in cement-based and cement-free building material systems. The ability of carbonisates to store carbon dioxide absorbed by plants during growth makes them a key element in the construction industry's strategy to reduce its CO2 footprint. The use of carbonisates in building materials not only contributes to CO2 offsetting but also opens pathways to sustainable construction. Carbonisates can form carbon sinks, helping to reduce the global warming potential (GWP) of building materials such as concrete. Furthermore, carbonisates can be used to adjust the technical properties or characteristics of building materials. A major obstacle to the use of industrial carbonisates is their inhomogeneity. Due to the diversity of starting materials and variations in production processes, the final products have different properties, which complicates the integration of these products into building material systems and their production in a standardized and conventional manner. Furthermore, industrial carbonides can complicate the use of other raw materials. For example, when used in concrete, there is a risk of reduced compressive strength. Producing consistently high-quality and sufficient quantities of carbonides is crucial for industrial applications. Currently, efforts are focused on optimizing pyrolysis technologies, adjusting formulations, selecting suitable biomass, and treating materials (e.g., activation). In addition, significant efforts are being made to develop new processes and technologies aimed at maximizing the performance and efficiency of carbonides in various applications.

[0003] The activation of mineral raw materials is crucial in the building materials industry, especially in the production of alternative cementitious materials and insulating materials. Enabling mineral raw materials such as clay minerals, vermiculite, and perlite for technical applications in the construction industry typically requires significant energy consumption. For example, kaolin, a raw material containing clay minerals, undergoes thermal activation to enable its use as an alternative cementitious component in both cement-based and non-cement-based building material systems. This heat treatment alters the chemical and physical structure of the material, making it more reactive and thus more suitable as a cementitious component, promoting the strength development of the cementitious system. The same applies to raw vermiculite and perlite ore, both of which expand at temperatures between approximately 700°C and 1000°C. This expansion significantly increases their volume, thereby improving their insulating properties and accompanying improvements in thermal insulation. Vermiculite with a high magnesium oxide content and perlite rich in amorphous silica thus become highly efficient insulating materials in the construction industry. However, a major problem with these processes is their high energy consumption. Activation, calcination, and expansion require intense heat treatment, which typically involves the consumption of large amounts of fossil fuels and corresponding CO2 emissions. This is inconsistent with global efforts to reduce greenhouse gas emissions and develop more sustainable production methods. To address this challenge, the building materials industry is researching alternative technologies, particularly to replace cement as a conventional building material with more sustainable and energy-efficient materials. These technologies include more energy-efficient calcination processes, the use of renewable energy, and the development of materials that can be activated at lower temperatures. Research is also underway on the recycling and treatment of byproducts from other industries to reduce the demand for primary feedstocks and their associated environmental impact. The goal of ongoing research and development in this area is to minimize the environmental impact of building materials production while maintaining or even improving material quality and performance. Another objective is to provide durable building materials that can be incorporated into the circular economy. This is an important step towards a more sustainable construction industry that acts responsibly in both environmental and economic terms.

[0004] The aim is to find new processes that take into account developments across various sectors, particularly the construction industry, and produce new materials based on renewable and ubiquitous raw materials. These materials should ideally contribute to reducing the CO2 footprint and improving sustainability across sectors. The energy consumption of these new processes should be as low as possible.

[0005] This invention relates to a method for the co-pyrolysis of biomass and mineral feedstocks for activating mineral feedstocks. During co-pyrolysis, biomass char is formed from biomass, while activated minerals are formed from the mineral feedstocks. Surprisingly, the starting materials do not adversely affect either of these reactions, i.e., they do not adversely affect the carbonization of the biomass and the activation of the mineral feedstocks, and the two reactions occur simultaneously. Preferably, the mixture of biomass char and activated minerals obtained in this manner through a single pyrolysis step can be used for a variety of applications, such as in the construction industry, horticulture and landscaping, as a carrier and filter material, in battery technology, or as an adsorbent. Because biomass is used as the starting material, the pyrolysis products obtained by the method of this invention can contribute to CO2 compensation. The biomass can contain plant biomass, animal biomass, and / or bio-derived waste. The mineral feedstocks used can be primary minerals or mineral waste products, such as mineral waste products from mining or industrial processes. Therefore, the method of this invention can also be used to produce cost-effective materials while potentially avoiding supply chain problems. Summary of the Invention

[0006] This invention relates to a method for the co-pyrolysis of biomass and mineral raw materials for activating mineral raw materials, comprising the following steps:

[0007] • Provides a mixture containing biomass and mineral feedstock, wherein the weight ratio of biomass to mineral feedstock in the mixture is in the range of 75:25 to 55:45, preferably 75:25 to 65:35, more preferably 73:27 to 67:33, further preferably 72:28 to 66:32, and most preferably 70:30, based on the total weight of the mixture.

[0008] • Under low oxygen conditions, a mixture containing biomass and mineral raw materials is pyrolyzed at a temperature ranging from 200°C to 1500°C, preferably from 250°C to 1250°C, and most preferably from 300°C to 1100°C.

[0009] • Obtain pyrolysis products containing biomass carbonization and activated minerals.

[0010] The present invention also relates to the use of pyrolysis products obtained by the methods described herein in the construction field, such as as aggregates, cementitious materials, cement substitutes or fillers in cementitious building material systems, as additives, aggregates, cementitious materials, cement substitutes or fillers in building material systems having alkali-activated binders, as dyes, as aggregates for improving hydration in flowable building materials, and / or as aggregates for asphalt.

[0011] The present invention also relates to the use of pyrolysis products obtained by the methods described herein in horticulture and landscaping, such as as plant substrates, as aggregates for base mix concrete, as joint fillers, in fences, as bedding materials, as insulation materials (possibly used in combination with loam), in tree grates, in the construction of embankments or dams, and / or in roof and facade greening.

[0012] The present invention also relates to the use of pyrolysis products obtained by the methods described herein as carrier materials and / or filter materials, such as carrier materials for catalysts, filter materials for waste gas or liquid waste streams, desiccants, compensating and adsorbing materials for slag, and / or absorbents for impurities and pollutants.

[0013] The present invention also relates to the use of pyrolysis products obtained by the methods described herein in energy storage technologies, such as in capacitors.

[0014] Finally, the present invention relates to the use of pyrolysis products obtained by the methods described herein as CO2 sinks.

[0015] In the context of the method according to the invention, the term "co-pyrolysis" refers to a single pyrolysis step carried out under low-oxygen conditions, within a certain temperature range, and for a certain time, in which the conversion of biomass to biomass char and the activation of mineral feedstock occur simultaneously and under the same conditions. The term "co-pyrolysis" does not include process steps in which the conversion of biomass to biomass char and the activation of mineral feedstock occur at different times and / or different locations.

[0016] Description of the invention

[0017] This invention relates to a method for the co-pyrolysis of biomass and mineral raw materials for activating mineral raw materials, comprising the following steps:

[0018] • Provides a mixture containing biomass and mineral feedstock, wherein the weight ratio of biomass to mineral feedstock in the mixture is in the range of 75:25 to 55:45, preferably 75:25 to 65:35, more preferably 73:27 to 67:33, further preferably 72:28 to 66:32, and most preferably 70:30, based on the total weight of the mixture.

[0019] • Under low oxygen conditions, a mixture containing biomass and mineral raw materials is pyrolyzed at a temperature ranging from 200°C to 1500°C, preferably from 250°C to 1250°C, and most preferably from 300°C to 1100°C.

[0020] • Obtain pyrolysis products containing biomass carbonization and activated minerals.

[0021] The weight ratio of biomass to mineral raw materials in the mixture, based on the total weight of the mixture, is in the range of 75:25 to 55:45, preferably 75:25 to 65:35, more preferably 73:27 to 67:33, further preferably 72:28 to 66:32, and most preferably 70:30.

[0022] Surprisingly, it was found that the mixture with this weight ratio was more reactive than the mixture with a higher or lower weight ratio.

[0023] Furthermore, compared to pyrolysis products prepared from mixtures with a lower weight ratio, pyrolysis products prepared from mixtures with this weight ratio surprisingly exhibit better mechanical properties, especially in terms of compressive strength and flexural strength.

[0024] Biomass and mineral raw materials are preferably in solid form, such as granules, powders, pellets, briquettes, pellets, ground materials, cut materials, shredded materials, wood blocks, fragments, spheres, flakes or similar forms.

[0025] The particle size is typically in the range of 0.01 to 1000 mm, preferably 0.1 to 300 mm.

[0026] Before or after mixing, biomass and mineral feedstocks can be shaped into the desired form using appropriate shaping methods, such as grinding, granulation, pressing, cutting, shredding, or similar conventional shaping methods. The specific choice depends on the particular starting material and the desired form, and falls within the general expertise of those skilled in the art.

[0027] However, for cost reasons, it is generally preferred to keep biomass and mineral feedstocks in their original form.

[0028] The water content of the mixture of biomass and mineral raw materials, based on the total weight of the mixture, is generally less than 50% by weight, preferably in the range of 0% to 40% by weight, more preferably in the range of 0% to 30% by weight, and most preferably in the range of 0% to 25% by weight.

[0029] If necessary, the moisture content of the mixture of biomass and mineral raw materials can be reduced by drying the mixture or by drying the starting materials before mixing.

[0030] The biomass preferably contains plant biomass, and more preferably biomass containing lignin and / or cellulose, such as wood and bamboo, agricultural products, green plant trimmings, algae, aquatic plants and mixtures thereof, especially biomass containing lignin and / or cellulose, such as wood and bamboo, agricultural products and mixtures thereof.

[0031] Biomass can also contain animal biomass, such as slaughterhouse waste.

[0032] In addition, biomass may also contain bio-derived waste, which is bio-derived material that has already undergone a life cycle, such as waste wood and agricultural waste, sludge (e.g., sewage sludge), compost, waste fiber and mixtures thereof.

[0033] Biomass is preferably derived from agricultural by-products, timber industry and forestry by-products, bio-based urban waste, waste from other land sources and clear sludge, as well as industrial waste and energy production waste.

[0034] Agricultural byproducts, especially harvest waste such as straw, leaves or husks, animal excrement, and surplus biomass.

[0035] Timber industry and forestry by-products, especially industrial timber waste, may also contain waste timber, waste wood from timber processing, bark, sawdust, wood flour, branches and residual tree crowns after timber harvesting, and by-products of pulp production.

[0036] Biomass from urban waste sources, waste from other land sources and clarified sludge, especially biomass from land management and biomass from roadside land, greening trimmings, greening waste, sewage sludge from wastewater treatment plants, and biomass from water bodies.

[0037] Industrial waste and energy production waste, especially byproducts of biodiesel and bioethanol production, bio-derived waste from the paper and pulp industry, waste from the food industry, waste from the feed industry, and general production waste such as shells, pomace, fat, and whey.

[0038] Particularly preferred are biomass containing lignin and / or cellulose, such as wood, bamboo, agricultural products and mixtures thereof.

[0039] The proportion of plant biomass in the biomass is usually at least 50% by weight, for example, 50% to 100% by weight, preferably 75% to 100% by weight, and more preferably 85% to 100% by weight.

[0040] In one specific embodiment, the biomass contains 90% to 100% by weight of lignin-containing biomass, for example, 95% to 100% by weight of lignin-containing biomass.

[0041] Depending on its source, biomass may also contain foreign substances such as plastics, metals, salts, or the like. The proportion of foreign substances in biomass is typically in the range of 0% to 50% by weight, preferably 0% to 30% by weight.

[0042] The mineral raw materials preferably contain clay minerals, such as vermiculite, kaolinite, or illite; peridot group minerals, such as forsterite; mica group minerals, such as muscovite or biotite; volcanic rocks, such as perlite; and mixtures thereof.

[0043] Suitable mica group minerals include muscovite or biotite.

[0044] Suitable volcanic rocks include perlite.

[0045] Suitable peridot group minerals include, for example, magnesium peridot.

[0046] Suitable clay minerals include vermiculite, kaolinite, and illite. Kaolinite with low kaolin content is also suitable; for example, kaolinite with a kaolin content of less than 70% by weight of the total kaolinite. For example, this type of low-kaolinite kaolinite can be obtained in large quantities as a secondary raw material and is not suitable for use in ceramics and paper production.

[0047] Mineral raw materials may contain primary minerals, mineral waste products (such as mineral waste products from mining or industrial processes), or mixtures thereof.

[0048] The mineral raw materials preferably consist of the following materials: clay and clay production waste; feldspar production waste; excavated soil; kaolin and clay production waste, such as mica-containing residues (e.g., muscovite) and clay-containing slurries; kaolin-containing slurries from ceramics and pulp production and paper production; kaolin-containing slurries from tile and brick production; kaolin-containing slurries from the plastics and coatings industries; mineral-containing sewage sludge; mineral-containing sludge from water treatment; red mud; cement fiberboard; vermiculite waste; perlite waste; mineral-containing testers from the food industry; materials from the demolition and dismantling of buildings and infrastructure, such as bricks; magnesite and dolomite production waste; waste from mining, raw material extraction and product processing, such as capping materials and waste rock pile materials; processing residues from ore processing; chemical and metallurgical waste; and limestone processing waste.

[0049] Preferably, the calcium carbonate content of the mineral raw materials is less than 10% by weight, for example, from 0% to 7.5% by weight, more preferably from 0% to 5.0% by weight, and more preferably from 0% to 2.5% by weight, based on the total weight of the mineral raw materials.

[0050] The mixture may contain foreign substances, such as plastics, metals, salts or the like, in proportions of 0% to 40% by weight, preferably 0% to 25% by weight. These foreign substances are typically derived from biomass, for example, entering the biomass during its use and processing cycles.

[0051] The mixture can be premixed and added to the pyrolysis furnace in the form of a mixture.

[0052] Another possible approach is to first preload one component of the mixture (usually biomass) into the pyrolysis furnace, and then add a second component (usually mineral feedstock) to the first component in the pyrolysis furnace.

[0053] After preparing a mixture containing biomass and mineral raw materials, the mixture is pyrolyzed.

[0054] Pyrolysis is usually carried out in a pyrolysis furnace.

[0055] Therefore, under low-oxygen conditions, the mixture is placed at a temperature ranging from 200°C to 1500°C, preferably from 250°C to 1250°C, and most preferably from 300°C to 1100°C.

[0056] "Low oxygen conditions" refers to an oxygen content of 0% to 20% by volume, preferably 0% to 10% by volume, in the pyrolysis furnace during the pyrolysis step. The oxygen can originate from the gas phase in the pyrolysis furnace or can be formed by the mixture through a chemical reaction during pyrolysis.

[0057] Depending on the type of pyrolysis, the duration of pyrolysis typically ranges from 1 second (flash pyrolysis) to 3 days. Preferably, the duration of pyrolysis is from 1 minute to 10 hours, and more preferably from 15 minutes to 4 hours.

[0058] Pyrolysis is typically carried out at pressures in the range of 0 to 5 bar (g), preferably in the range of 0 to 1 bar (g), and more preferably at 0 bar (g).

[0059] Pyrolysis is typically carried out in a pyrolysis furnace, such as a pyrolysis reactor, a rotary furnace, or, if necessary, a modified biomass burner or gas generator.

[0060] The method of the present invention may include one or more pyrolysis steps performed sequentially.

[0061] Therefore, in one embodiment, the mixture is first subjected to a first pyrolysis step. Following the first pyrolysis step, one or more additional pyrolysis steps may be performed sequentially on the mixture. The pyrolysis conditions here may differ from the pyrolysis conditions of the previous pyrolysis steps within the range described above. Typically, no more than four pyrolysis steps are performed sequentially.

[0062] In another embodiment, a component (typically biomass) is roasted in a first step. The roasted component is then mixed with a second component (typically a mineral feedstock). This mixture is subsequently subjected to one or more pyrolysis steps. The roasting conditions and conditions for subsequent pyrolysis steps can differ from those of the earlier pyrolysis steps within the range described above. Typically, no more than four roasting and pyrolysis steps are performed sequentially.

[0063] In one of these multiple pyrolysis steps, preferably in the last pyrolysis step, the biomass (preferably pyrolyzed biomass) can be gasified. The gasification conditions can differ from those of the previous pyrolysis steps within the range described above.

[0064] In another embodiment, a single pyrolysis step is performed in the method of the present invention.

[0065] Different reactions occur during pyrolysis.

[0066] Pyrolysis is typically carried out under autothermal conditions. Here, components of the biomass (preferably the highly volatile components) are used as fuel for pyrolysis. This reduces the need for external fuel. Initiating a pyrolysis reaction usually requires external fuel. During pyrolysis, external fuel is generally not required.

[0067] The external fuel used for pyrolysis is typically selected from fossil fuels (e.g., natural gas, oil, and coal, preferably natural gas), renewable fuels (e.g., hydrogen, bioethanol, biogas, vegetable oil, and wood materials), and mixtures thereof. To improve the sustainability of the method of the present invention, it is desirable to shift towards the use of a higher proportion of renewable fuels.

[0068] Biomass is carbonized into biomass char. Here, at the high temperatures of pyrolysis, biomass components (e.g., lignin, cellulose, and hemicellulose in the case of wood) break down into smaller molecules, such as carbon, liquid pyrolysis oil, and gaseous pyrolysis gas.

[0069] Preferably, after the pyrolysis step, the liquid and gaseous components are at least partially separated from the solid components. Most of the liquid components turn into gas under pyrolysis conditions and are separated from the solid components along with the gaseous components.

[0070] The gaseous components can be used as fuel in pyrolysis. This reduces the need for external fuel sources.

[0071] Preferably, the carbon content of the biomass char is at least 1% by weight, for example, in the range of 1% to 95% by weight, especially in the range of 10% to 90% by weight, based on the total weight of the biomass char.

[0072] The mineral raw materials are activated. The form of activation depends on the properties of the mineral raw materials, the temperature range, and the energy input.

[0073] Some minerals are activated through transformation.

[0074] For example, some clay minerals undergo transformation, such as kaolinite transforming into metakaolinite. Here, the OH groups present in the clay minerals are removed at the high temperatures of pyrolysis (dehydroxylation). This significantly increases the solubility of silicon and aluminum ions in alkaline media. This endothermic reaction typically requires an activation energy in the range of 100 to 200 kJ / mol.

[0075] Materials containing carbonates are transformed into their corresponding oxides.

[0076] Other clay minerals (such as vermiculite) and volcanic rocks (such as perlite) expand at the high temperatures of pyrolysis. This expansion increases the pore volume of the expanded minerals. Simultaneously, chemically bound and physically bound water are converted into the gas phase. This endothermic reaction typically requires an activation energy in the range of 10 to 50 kJ / mol.

[0077] During and / or after the pyrolysis step, liquid and gaseous pyrolysis products are typically separated from solid pyrolysis products.

[0078] Liquid and gaseous pyrolysis products can be used, for example, as energy carriers and / or fuels for pyrolysis.

[0079] Another product of the method of the present invention is typically a solid pyrolysis product containing biomass carbonization and activated minerals.

[0080] Pyrolysis products can be shaped using conventional molding methods, depending on their application areas.

[0081] Here, the pyrolysis products can also be mixed with other materials and molded. Therefore, in one embodiment, the currently commonly used water saturation treatment can be omitted.

[0082] The pyrolysis products can be used in solid or slurry form, such as as a suspension in water.

[0083] The pyrolysis products obtained by the method of this invention can be used for a variety of purposes.

[0084] For example, the pyrolysis products obtained by the method of the present invention can be used in the construction industry.

[0085] For example, the pyrolysis products obtained by the method of the present invention can be used as building material additives, aggregates, cementitious materials, cement substitutes or fillers in cementitious building material systems, as building material aggregates, cementitious materials, cement substitutes or fillers in building material systems with alkali-activated cementitious materials, as dyes, as aggregates for improving hydration in flowable building materials, and / or as aggregates for asphalt.

[0086] It has been found that, compared with pure industrial carbon compounds, the pyrolysis products obtained by the method of the present invention have higher reactivity due to their higher ash content and higher mineral content, and can be better integrated into building material systems.

[0087] In addition to making more efficient use of carbides, especially when clay minerals such as kaolinite are used in the pyrolysis products obtained by the method of the present invention, there is also the potential to reduce the amount of cement required, thereby making the production of building materials more sustainable.

[0088] The pyrolysis products obtained by the method of the present invention can, for example, be used in so-called LC. 3 In cement, this significantly reduces the clinker content. This is because silicon and aluminum ions in calcined clay minerals exhibit higher solubility in alkaline media. The released ions react with calcium hydroxide and other substances in the hydrating cement, forming additional hydrated phases that contribute to strength development.

[0089] When vermiculite and volcanic rocks (e.g., perlite) are used in the pyrolysis products obtained by the method of this invention, the expansion of these minerals enables the production of building materials with low particle density and good thermal and acoustic insulation properties. An example is structural lightweight concrete.

[0090] Furthermore, the pyrolysis products obtained by the method of the present invention can be used in horticulture and landscaping.

[0091] For example, the pyrolysis products obtained by the method of the present invention can be used as plant substrates, as aggregates for base concrete mixtures, as joint fillers, in fences, as bedding materials, as insulation materials (possibly used in combination with soil), in tree pit grids, in the construction of dikes or dams, and / or for roof and facade greening.

[0092] Furthermore, the pyrolysis products obtained by the method of the present invention can be used as carrier materials and / or filter materials.

[0093] For example, the pyrolysis products obtained by the method of the present invention can be used as carrier materials and / or filter materials, such as carrier materials for catalysts, filter materials for waste gas or liquid waste streams, desiccants, compensating and adsorbing materials for slag, and / or absorbents for impurities and contaminants.

[0094] Furthermore, the pyrolysis products obtained by the method of the present invention can be used in energy storage technologies, such as in capacitors.

[0095] Finally, the pyrolysis products obtained by the method of the present invention can be used as a CO2 sink. Example

[0096] The mixture of softwood (or cork) as a biomass component and kaolin-containing production waste as a mineral raw material is co-pyrolyzed at temperatures of 650°C and 750°C, wherein the weight proportion of kaolin-containing production waste is in the range of 10% to 30% by weight.

[0097] Mineralogical analysis using X-ray diffraction showed that kaolinite (crystalline state) successfully transformed into metakaolinite (amorphous state) during the experiment, indicating that the mineral underwent a phase transition due to co-pyrolysis.

[0098] In addition, R was performed using a calorimeter. 3 Tests show that the charcoal products obtained by co-pyrolysis of coniferous wood and kaolin-containing production waste have a much higher reactivity than conventional plant charcoal.

[0099] Here, charcoal products prepared from clay-biomass mixtures in ratios of 23:77, 30:70, and 50:50 are compared with each other. Co-pyrolysis was carried out at 650°C for 15 min.

[0100] The chemical composition and loss on ignition (LOI) of the charcoal products, as determined by X-ray fluorescence analysis (XRF), are listed in the table below:

[0101] Table: Chemical composition and loss on ignition at different weight ratios

[0102]

[0103] A calorimeter determines the heat of reaction released by a material by measuring the heat flow generated during a physical or chemical process. 3 The test is a rapid, relevant, and reliable method for evaluating the pozzolanic reactivity of calcined clay and other cement substitutes (= R). 3 )method.

[0104] References:

[0105] Avet, François; Snellings, Ruben; Alujas Diaz, Adrian; Ben Haha, Mohsen; Scrivener, Karen (2016): Development of a new rapid, relevant and reliable (R3) test method to evaluate the pozzolanic reactivity of calcined kaolinitic clays. In: Cement and Concrete Research, Vol. 85, pp. 1–11. DOI: 10.1016 / j.cemconres.2016.02.015.

[0106] Figure 1 The figure shows the R values ​​of charcoal products made from clay-biomass mixtures at ratios of 23:77, 30:70, and 50:50, compared to reference products such as calcined clay, slag sand, fly ash, and quartz. 3 Test results.

[0107] Surprisingly, the charcoal product made from a clay-biomass mixture at a ratio of 30:70 exhibited the highest reactivity. The reactivity of the charcoal product made from a clay-biomass mixture at a ratio of 30:70 was approximately 20% higher than that made from a mixture at a ratio of 50:50, and approximately 40% higher than that made from a mixture at a ratio of 23:77.

[0108] Charcoal products prepared from clay-biomass mixtures at ratios of 30:70 and 50:50 were used as a cement substitute (10%) in mortar prism specimens. Compressive and flexural strengths of the mortar prism specimens were tested according to DIN EN 1015-11 after 7 and 28 days, and compared with mortar prism specimens containing 10% cement as a standard. Results are shown in... Figure 2 and Figure 3 .

[0109] Mortar prism specimens containing 10% of a clay-biomass mixture in a 30:70 ratio generally exhibit higher compressive and flexural strengths than those containing 10% of a mixture in a 50:50 ratio. The compressive strength of mortar prism specimens containing 10% of a clay-biomass mixture in a 30:70 ratio is comparable to that of standard mortar prism specimens. The 28-day flexural strength of mortar prism specimens containing 10% of a clay-biomass mixture in a 30:70 ratio exceeds that of standard mortar prism specimens.

Claims

1. A method for co-pyrolysis of biomass and mineral raw materials for activating mineral raw materials, comprising the following steps: • Provides a mixture containing biomass and mineral feedstock, wherein the weight ratio of the biomass to the mineral feedstock in the mixture, based on the total weight of the mixture, is in the range of 75:25 to 55:45, preferably 75:25 to 65:35, more preferably 73:27 to 67:33, further preferably 72:28 to 66:32, and most preferably 70:30; • Under low-oxygen conditions, the mixture containing the biomass and the mineral raw material is pyrolyzed at a temperature ranging from 200°C to 1500°C, preferably from 250°C to 1250°C, and most preferably from 300°C to 1100°C. • Obtain pyrolysis products containing biomass carbonization and activated minerals.

2. The method according to claim 1, wherein, The mineral raw materials contain clay minerals, such as vermiculite, kaolinite, or illite; mica group minerals, such as muscovite or biotite; volcanic rocks, such as perlite; peridot group minerals, such as forsterite; and mixtures thereof.

3. The method according to any one of the preceding claims, wherein, The biomass includes plant biomass, preferably biomass containing lignin and / or cellulose, such as wood and bamboo, agricultural products, green plant trimmings, algae, aquatic plants and mixtures thereof; animal biomass, preferably slaughterhouse waste; and bio-derived waste, preferably waste wood and agricultural waste, sludge (e.g., sewage sludge), compost, waste fiber and mixtures thereof.

4. The method according to any one of the preceding claims, wherein, The biomass is derived from agricultural by-products, timber industry and forestry by-products, bio-sourced urban waste, waste and clarified sludge from other land sources, as well as industrial waste and energy production waste.

5. The method according to any one of the preceding claims, wherein, The biomass and the mineral raw materials are in solid form.

6. The method according to any one of the preceding claims, wherein, Based on the total weight of the mixture, the water content of the mixture of biomass and mineral raw materials is less than 50% by weight, preferably in the range of 0% to 40% by weight, more preferably in the range of 0% to 30% by weight, and most preferably in the range of 0% to 25% by weight.

7. The method according to any one of the preceding claims, wherein, The pyrolysis is carried out under self-heating conditions.

8. The method according to any one of the preceding claims, wherein, The mineral is activated through transformation, for example, through dehydroxylation.

9. The method according to any one of the preceding claims, wherein, Kaolinite is activated by transforming into metakaolinite.

10. The method according to any one of the preceding claims, wherein, The minerals are activated by expansion, for example by the expansion of perlite and / or vermiculite.

11. Use of the pyrolysis product obtained by any one of the preceding claims in the construction field, for example as an additive, aggregate, cementitious material, cement substitute or filler in cementitious building material systems, as an aggregate, cementitious material, cement substitute or filler in building material systems having alkali-activated cementitious materials, as a dye, as an aggregate for improving hydration in flowable building materials, and / or as an aggregate for asphalt.

12. Use of the pyrolysis product obtained by any one of claims 1 to 10 in horticulture and landscaping, for example as a plant substrate, as aggregate for base concrete mixes, as a sealant, in fences, as a subbase material, as an insulation material (preferably used in combination with loam), in tree pit grids, in the construction of dikes or dams, and / or in roof and facade greening.

13. Use of the pyrolysis product obtained by any one of claims 1 to 10 as a carrier material and / or filter material, for example as a carrier material for catalysts, as a filter material for waste gas or liquid waste streams, as a desiccant, as a compensating and adsorbing material for slag, and / or as an absorbent for impurities and contaminants.

14. Use of the pyrolysis product obtained by the method of any one of claims 1 to 10 in energy storage technology, for example, in capacitors.

15. Use of the pyrolysis product obtained by any one of claims 1 to 10 as a CO2 sink.

Images