Co-pyrolysis of biomass and mineral raw materials

Abstract

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

Description

[0001] Co-pyrolysis of biomass and mineral raw materials

[0002] The present invention relates to a process for the co-pyrolysis of biomass and mineral raw materials for the activation of the mineral raw materials and the use of the pyrolysis product thus produced in the construction sector, in gardening and landscaping, as a carrier and filter material, in battery technology and as a CC>2 sink.

[0003] Technical background

[0004] Industrially produced carbonizates, which can be obtained from a variety of biomass sources such as waste wood, industrial fiber residues, agricultural byproducts, and even algae, offer innovative solutions in modern construction. These carbonizates can serve as ecologically sustainable components in structures by being used as additives, binder components, cement substitutes, or fillers in both cement-based and cement-free building material systems. Their ability to store carbon dioxide absorbed by plants during their growth in the form of char makes them a key element in the strategy to reduce the carbon footprint in the construction industry. The use of carbonizates in building materials not only contributes to CO2 offsetting but also opens up avenues for sustainable construction.They can create carbon sinks that help reduce the Global Warming Potential (GWP) in building materials such as concrete. Furthermore, the carbonates can also adapt the technical properties and characteristics of the building materials. A major obstacle to the use of industrial carbonates is their heterogeneity. The diversity of starting materials and different manufacturing processes results in the end products having different properties, which in turn complicates their integration into building material systems and their production in accordance with norms and standards. Furthermore, industrial carbonates complicate the use of other raw materials. When used in concrete, for example, there is a risk of reduced compressive strength. The production of carbonates of consistent quality and in sufficient quantities is essential for industrial use.Current efforts are focused on optimizing pyrolysis technology, adapting formulations, selecting suitable biomasses, and processing materials (e.g., activation) to achieve this goal. Furthermore, the development of new processes and technologies is being pursued to maximize the performance and efficiency of carbonizates in various applications.

[0005] The activation of mineral raw materials plays a crucial role in the building materials industry, particularly in the production of alternative binders and insulating materials. Developing mineral raw materials such as clay minerals, vermiculite, and perlite for technical applications in the construction industry often requires significant energy input. For example, kaolin, a clay mineral-containing raw material, is thermally activated to enable its use as an alternative binder component in both cement-based and non-cement-based building material systems. This thermal treatment changes the chemical and physical structure of the material, making it more reactive and thus more suitable as a binder component and potentially contributing to the strength development of binder systems. A similar process applies to raw vermiculite and raw perlite, which both expand at temperatures between approximately 700 and 1000 °C.This expansion leads to a significant increase in volume, which improves the insulating properties of these materials and, consequently, a significant improvement in their thermal insulation properties. Vermiculite, which has a high magnesium oxide content, and perlite, which is rich in amorphous silica, thus become efficient thermal insulation materials in the construction industry. However, a major problem with these processes is the high energy consumption. Activation, calcination, and expansion require intensive heat treatment, which is often associated with high fossil fuel consumption and corresponding CO2 emissions. This runs counter to global efforts to reduce greenhouse gas emissions and develop more sustainable production methods.To meet this challenge, the building materials industry is researching alternative technologies, particularly to replace cement as the standard construction material with more sustainable and less energy-intensive materials. These include more energy-efficient calcination processes, the use of renewable energy sources, and the development of materials that can be activated at lower temperatures. Likewise, the recycling and processing of by-products from other industries is being explored to reduce the demand for primary raw materials and the associated environmental impacts. Ongoing research and development in this area aims to minimize the environmental impact of building materials production while maintaining or even improving the quality and performance of the materials.Another goal is to provide durable building materials that can be integrated into a circular economy. This is an important step toward a more sustainable construction industry that operates responsibly, both ecologically and economically.

[0006] New processes are being sought that take into account developments in various sectors, especially the construction industry, and produce new materials based on renewable and ubiquitous raw materials, preferably contributing to reducing the carbon footprint and increasing the sustainability of various industries. The new processes should use as little energy as possible.

[0007] The present invention relates to a process for the co-pyrolysis of biomass and mineral raw materials for the activation of mineral raw materials. During co-pyrolysis, biomass carbonate is produced from the biomass and activated minerals are produced from the mineral raw materials simultaneously. Surprisingly, it was found that the starting materials do not impair either of the two reactions—the carbonization of the biomass and the activation of the mineral raw materials—and that both reactions proceed simultaneously. The mixed materials of biomass carbonate and activated minerals obtained in this way, preferably from a single pyrolysis step, can be used in a variety of ways, for example in construction, gardening and landscaping, as carrier and filter materials, in battery technology, or as sorption materials.By using biomass as the starting material, the pyrolysis product obtained by the process according to the invention can contribute to CO2 compensation. The biomass can contain plant biomass, animal biomass, and / or biogenic residues. Primary minerals, as well as mineral waste products, for example, from mining or industrial processes, can serve as mineral raw materials. Thus, the process according to the invention can also be used to produce cost-effective materials, possibly avoiding supply chain problems.

[0008] Summary of the invention

[0009] The present invention relates to a process for the co-pyrolysis of biomass and mineral raw materials for the activation of the mineral raw materials, comprising the following steps:

[0010] • Providing a mixture containing biomass and mineral raw materials in a weight ratio of biomass and mineral raw materials in the mixture in the range of 75:25 to 55:45, preferably 75:25 to 65:35, more preferably 73:27 to 67:33, particularly preferably 72:28 to 66:32, in particular 70:30, based on the total weight of the mixture of biomass and mineral raw materials;

[0011] • Pyrolysis of the mixture containing biomass and mineral raw materials under low-oxygen conditions at a temperature in the range from 200 to 1500°C, preferably from 250 to 1250°C, most preferably from 300 to 1100°C;

[0012] • Obtaining a pyrolysis product containing biomass carbonate and activated minerals.

[0013] Furthermore, the present invention relates to the use of the pyrolysis product produced by the process as described herein in the construction field, for example as aggregate, binder, cement substitute or filler for building materials in cementitious building material systems, as additive, aggregate, binder, cement substitute or filler for building materials in building material systems with alkaline-activated binders, as dye, as aggregate for improving hydration in flowable building materials and / or as aggregate for asphalt.

[0014] Furthermore, the present invention relates to the use of the pyrolysis product produced by the process as described herein in gardening and landscaping, for example as plant substrate, as aggregate for backing concrete, as joint fill, in palisades, as bedding material, as insulation material, optionally in combination with clay, in tree discs, in dike or dam construction and / or for greening roofs and facades.

[0015] Furthermore, the present invention relates to the use of the pyrolysis product produced by the process as described herein as a carrier and / or filter material, for example as a carrier material for catalysts, as a filter material for exhaust gases or liquid waste streams, as a drying agent, as a balancing and adsorption material for slags and / or as an absorber for impurities and pollutants.

[0016] Furthermore, the present invention relates to the use of the pyrolysis product produced by the process as described herein in energy storage technology, for example in capacitors.

[0017] Finally, the present invention relates to the use of the pyrolysis product produced by the process as described herein as a CC>2 sink.

[0018] In the context of the process according to the invention, the term "co-pyrolysis" refers to a single pyrolysis step under low-oxygen conditions, within a specific temperature range, and over a specific period of time, in which biomass is converted into biomass carbonate and the mineral raw materials are activated simultaneously and under the same conditions. The term "co-pyrolysis" excludes process steps in which biomass is converted into biomass carbonate and the mineral raw materials are activated independently of one another, both temporally and / or spatially.

[0019] Description of the invention

[0020] The present invention relates to a process for the co-pyrolysis of biomass and mineral raw materials for activating the mineral raw materials, comprising the following steps: • Providing a mixture containing biomass and mineral raw materials in a weight ratio of biomass and mineral raw materials in the mixture in the range of 75:25 to 55:45, preferably 75:25 to 65:35, more preferably 73:27 to 67:33, particularly preferably 72:28 to 66:32, in particular 70:30, based on the total weight of the mixture of biomass and mineral raw materials;

[0021] • Pyrolysis of the mixture containing biomass and mineral raw materials under low-oxygen conditions at a temperature in the range from 200 to 1500°C, preferably from 250 to 1250°C, most preferably from 300 to 1100°C;

[0022] • Obtaining a pyrolysis product containing biomass carbonate and activated minerals.

[0023] The weight ratio of biomass and mineral raw materials 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, particularly preferably 72:28 to 66:32, in particular 70:30, based on the total weight of the mixture of biomass and mineral raw materials.

[0024] Surprisingly, it has been found that a mixture in this weight ratio has a higher reactivity than mixtures with higher and lower weight ratios.

[0025] Furthermore, the pyrolysis product prepared from a mixture in this weight ratio surprisingly shows better mechanical properties, in particular with regard to compressive and flexural tensile strengths, compared to pyrolysis products prepared from a mixture with lower weight ratios.

[0026] The biomass and the mineral raw materials are preferably in the form of solids, for example as granules, powder, grains, compacts, pellets, ground material, cuttings, chopped material, logs, shards, spheres, flakes or in similar forms.

[0027] The particle size is typically in the range of 0.01 to 1000 mm, preferably 0.1 to 300 mm. Before or after mixing, the biomass and mineral raw materials can be formed into the desired shape using appropriate shaping processes, for example, by grinding, pelletizing, pressing, cutting, chopping, or similar conventional shaping processes. The selection depends on the respective starting materials and the desired shape and is within the usual expertise of the person skilled in the art.

[0028] However, it is usually preferred, for cost reasons, that the biomass and mineral raw materials remain in their original form.

[0029] The mixture of biomass and mineral raw materials typically contains a water content of less than 50 wt.%, preferably in the range of 0 to 40 wt.%, more preferably in the range of 0 to 30 wt.%, most preferably in the range of 0 to 25 wt.%, based on the total weight of the mixture.

[0030] The water content of the mixture of biomass and mineral raw materials can, if necessary, be reduced by drying the mixture or the individual raw materials before mixing.

[0031] The biomass preferably contains plant biomass, preferably lignin- and / or cellulose-containing biomass such as wood and bamboo, agricultural products, green waste, algae, aquatic plants and mixtures thereof, in particular lignin- and / or cellulose-containing biomass such as wood and bamboo, agricultural products and mixtures thereof.

[0032] The biomass may also contain animal biomass, such as slaughterhouse waste.

[0033] Furthermore, the biomass can also contain biogenic residues, i.e., biogenic materials that have already undergone a utilization cycle, such as waste wood and agricultural residues, sludge such as sewage sludge, compost, fiber residues, and mixtures thereof. Biomass is preferably obtained from agricultural by-products, wood and forestry by-products, biogenic municipal waste, residues from other land, and sewage sludge, as well as industrial residues and residues from energy production.

[0034] Agricultural by-products include, in particular, crop residues such as straw, leaves or shells, animal excrement and surplus biomass.

[0035] Wood and forestry by-products include, in particular, industrial waste wood, which may also contain waste wood, wood residues from wood processing, bark, sawdust, wood dust, branches and crown residues after timber harvesting, and by-products from pulp production.

[0036] Biogenic municipal waste, residues from other areas and sewage sludge include in particular biomass from landscape maintenance and roadside areas, green waste, green waste, sewage sludge from wastewater treatment plants and biomass from water bodies.

[0037] Industrial residues and residues from energy production include, in particular, by-products from biodiesel and bioethanol production, biogenic residues from the paper and pulp industry, residues from the food industry, residues from the feed industry and general production waste such as peels, pomace, fats and whey.

[0038] It is particularly preferred that the biomass contains lignin- and / or cellulose-containing biomass such as wood, bamboo, agricultural products and mixtures thereof.

[0039] The proportion of plant biomass in the biomass is typically at least 50 wt.%, such as 50 to 100 wt.%, preferably 75 to 100 wt.%, particularly preferably 85 to 100 wt.%. In a specific embodiment, the biomass contains 90 to 100 wt.% lignin-containing biomass, for example 95 to 100 wt.% lignin-containing biomass.

[0040] Depending on its origin, the biomass may also contain foreign substances such as plastic, metal, salts, or similar. The proportion of foreign substances in the biomass is typically in the range of 0 to 50 wt%, preferably 0 to 30 wt%.

[0041] The mineral raw materials preferably contain clay minerals such as vermiculite, kaolinite or illite, minerals of the olivine group such as forsterite, minerals of the mica group such as muscovite or biotite, volcanic rocks such as perlite and mixtures thereof.

[0042] Suitable minerals of the mica group include muscovite and biotite.

[0043] Suitable volcanic rocks include perlite.

[0044] Suitable minerals of the olivine group include forsterite.

[0045] Suitable clay minerals include vermiculite, kaolinite, and illite. Kaolinites with a low kaolin content, for example, less than 70 wt.% based on the total weight of kaolinite, are also suitable. These kaolinites with a low kaolin content are produced in large quantities as secondary raw materials and are not suitable for ceramics and paper production.

[0046] The mineral raw materials may contain primary minerals, mineral waste products, for example from mining or industrial processes, or mixtures thereof.

[0047] The mineral raw materials are preferably made from clays and residues from clay production, residues from feldspar production, excavated soil, residues from kaolin and clay production, such as mica-containing residues, for example muscovite, and clay-containing sludge, kaolin-containing sludge from ceramics, pulp and paper production, kaolin-containing sludge from tile and brick production, kaolin-containing sludge from the plastics and paint industry, mineral-containing sewage sludge, mineral-containing sludge from water treatment, red mud, cement fibreboard, vermiculite residues, perlite residues, mineral-containing testers from the food industry, dismantling and demolition of buildings and infrastructure such as bricks, residues from magnesite and dolomite production, residues from mining, raw material extraction and product processing such as overburden and tailings, processing residues from ore processing,Residues from the chemical industry and metallurgy and residues from limestone processing.

[0048] The mineral raw materials preferably contain a calcium carbonate content of less than 10 wt.%, for example from 0 to 7.5 wt.%, preferably 0 to 5.0 wt.%, more preferably 0 to 2.5 wt.%, based on the total weight of the mineral raw materials.

[0049] The mixture may contain foreign substances, such as plastic, metal, salts, or similar, in a proportion of 0 to 40 wt.%, preferably 0 to 25 wt.%. These foreign substances typically originate from the biomass and have entered the biomass, for example, during the utilization and processing cycle.

[0050] The mixture can be premixed and introduced into a pyrolysis furnace as a mixture.

[0051] Alternatively, one component of the mixture, usually the biomass, can first be introduced into the pyrolysis furnace, and then the second component, usually the mineral raw materials, can be added to the first component in the pyrolysis furnace.

[0052] After the mixture containing biomass and mineral raw materials has been produced, it is subjected to pyrolysis.

[0053] Pyrolysis usually takes place in a pyrolysis furnace.

[0054] For this purpose, the mixture is exposed to a temperature in the range of 200 to 1500°C, preferably 250 to 1250°C, and most preferably 300 to 1100°C, under low-oxygen conditions. Under low-oxygen conditions, oxygen contents in the pyrolysis furnace during the pyrolysis step range from 0 to 20 vol.%, preferably 0 to 10 vol.%. The oxygen can originate from the gas phase in the pyrolysis furnace or be formed from the mixture through a chemical reaction during pyrolysis.

[0055] The duration of pyrolysis typically ranges from 1 second (flash pyrolysis) to 3 days, depending on the type of pyrolysis. The duration of pyrolysis is preferably 1 minute to 10 hours, and more preferably 15 minutes to 4 hours.

[0056] The pyrolysis is usually carried out at a pressure in the range of 0 to 5 bar(g), preferably 0 to 1 bar(g), more preferably at 0 bar(g).

[0057] Pyrolysis is usually carried out in a pyrolysis furnace, such as a pyrolysis reactor, rotary kiln, biomass burner, possibly after conversion, or a gas generator.

[0058] The process according to the invention may comprise one or more pyrolysis steps which are carried out successively.

[0059] For this purpose, in one embodiment, the mixture is first subjected to a first pyrolysis step. After this first pyrolysis step, the mixture can be subjected to one or more subsequent pyrolysis steps. The pyrolysis conditions can differ from the previous pyrolysis steps within the ranges specified above. Typically, no more than four pyrolysis steps are carried out consecutively.

[0060] In another embodiment, one component, usually the biomass, is torrefied in a first step. The torrefied component is then mixed with the second component, usually the mineral raw materials. This mixture is then subjected to one or more pyrolysis steps. The conditions of the torrefaction and the subsequent pyrolysis steps can differ from the preceding pyrolysis steps within the ranges mentioned above. Typically, no more than four torrefaction and pyrolysis steps are carried out consecutively.

[0061] In one of these several pyrolysis steps, preferably the final pyrolysis step, the biomass, preferably the pyrolyzed biomass, can be gasified. The gasification conditions may differ from the preceding pyrolysis steps within the aforementioned ranges.

[0062] In a further embodiment, a single pyrolysis step is carried out in the process according to the invention.

[0063] Different reactions take place during pyrolysis.

[0064] Pyrolysis typically takes place under autothermal conditions. Biomass components, preferably volatile components, serve as fuel for the pyrolysis. This reduces the use of external fuels. External fuel is typically required to start the pyrolysis reaction. During pyrolysis, external fuel is usually not required.

[0065] The external fuel for pyrolysis is typically selected from fossil fuels, such as natural gas, petroleum, and coal, preferably natural gas, and renewable fuels, such as hydrogen, bioalcohols, biogas, vegetable oil, and wood materials, and mixtures thereof. To increase the sustainability of the process according to the invention, a transition to higher proportions of renewable fuels is desirable.

[0066] The biomass is carbonized to biomass carbonate. At the elevated temperatures of pyrolysis, the biomass components—for example, lignin, cellulose, and hemicellulose in wood—decompose into smaller molecules such as carbon, liquid pyrolysis oil, and gaseous pyrolysis gas. After the pyrolysis step, the liquid and gaseous components are preferably separated, at least partially, from the solid components. Under pyrolysis conditions, most of the liquid components become gaseous and, together with the gaseous components, are separated from the solid components.

[0067] The gaseous components can be used as fuel in pyrolysis, reducing the need for external fuel sources.

[0068] The biomass carbonate preferably contains a carbon content of at least 1 wt.%, for example in the range from 1 to 95 wt.%, in particular in the range from 10 to 90 wt.%, based on the total weight of the biomass carbonate.

[0069] The mineral raw materials are activated. The form of activation depends on the type of mineral raw materials, the temperature range, and the energy input.

[0070] Certain minerals are activated by transformation.

[0071] For example, certain clay minerals are converted, such as kaolinite into metakaolin. The OH groups of the clay minerals are cleaved at the elevated temperatures of pyrolysis (dehydroxylation). This significantly increases the solubility of silicon and aluminum ions in alkaline environments. This endothermic reaction typically requires activation energies in the range of 100 to 200 kJ / mol.

[0072] Carbonate-containing materials are converted into the corresponding oxides. Other clay minerals, such as vermiculite, and volcanic rocks, such as perlite, expand at the elevated temperatures of pyrolysis. This expansion increases the pore volume of the expanded minerals. In the process, the chemically and physically bound water is transferred into the gas phase. This endothermic reaction typically requires activation energies in the range of 10 to 50 kJ / mol.

[0073] During and / or after the pyrolysis step, the liquid and gaseous pyrolysis products are usually separated from the solid pyrolysis products.

[0074] The liquid and gaseous pyrolysis products can be used, for example, as energy carriers and / or as fuel for pyrolysis. Another product of the process according to the invention is typically a solid pyrolysis product containing biomass carbonate and activated minerals.

[0075] The pyrolysis product can be shaped using conventional molding methods depending on its application.

[0076] The pyrolysis product can also be mixed and formed with other materials. In one embodiment, this can eliminate the need for wetting, as is common today.

[0077] The pyrolysis product can be used in solid form or in the form of a slurry, such as a suspension in water.

[0078] The pyrolysis products obtained by the process according to the invention have a wide range of applications.

[0079] Thus, the pyrolysis products obtained by the process according to the invention can be used in the construction sector.

[0080] For example, the pyrolysis products obtained by the process according to the invention can be used as an additive, aggregate, binder, cement substitute or filler for building materials in cementitious building material systems, as an aggregate, binder, cement substitute or filler for building materials in building material systems with alkaline-activated binders, as a dye, as an aggregate for improving hydration in flowable building materials and / or as an aggregate for asphalt.

[0081] It is shown that the pyrolysis products obtained with the process according to the invention have increased reactivity and improved integration into building material systems compared to pure industrial carbonizates due to a higher ash content and the higher mineral content.

[0082] In addition to a more efficient use of the carbonates, especially when using clay minerals such as kaolinite in the pyrolysis products obtained with the process according to the invention, the need for cement could potentially be reduced and thus the production of building materials could be made more sustainable.

[0083] The pyrolysis products obtained by the process according to the invention can be used, for example, in so-called LC 3 -cements, which can significantly reduce the clinker content in the cement. The reason for this is that the calcined clay minerals exhibit increased solubility of silicon and aluminum ions in alkaline environments, and the released ions react with calcium hydroxide in the hydrating cement, among other substances, to form additional hydrate phases that contribute to strength development.

[0084] When vermiculite and volcanic rocks, such as perlite, are used in the pyrolysis products obtained by the process according to the invention, the expansion of these minerals can produce building materials with low grain density and good thermal and acoustic insulation properties. Examples include structural lightweight concrete.

[0085] Furthermore, the pyrolysis products obtained by the process according to the invention can be used in gardening and landscaping.

[0086] For example, the pyrolysis products obtained by the process according to the invention can be used as plant substrate, as aggregate for backing concrete, as joint fill, in palisades, as bedding material, as insulation material, optionally in combination with clay, in tree discs, in dike or dam construction and / or for greening roofs and facades.

[0087] In addition, the pyrolysis products obtained by the process according to the invention can be used as carrier and / or filter material.

[0088] For example, the pyrolysis products obtained by the process according to the invention can be used as support and / or filter material, for example as a support material for catalysts, as a filter material for exhaust gases or liquid waste streams, as a drying agent, as a balancing and adsorption material for slag, and / or as an absorber for impurities and contaminants. Furthermore, the pyrolysis products obtained by the process according to the invention can be used in energy storage technology, for example in capacitors.

[0089] Finally, the pyrolysis products obtained by the process according to the invention can be used as CC>2 sinks.

[0090] Examples

[0091] Mixtures of softwood as biomass component and kaolin-containing production residues as mineral raw material with a weight fraction of kaolin-containing production residues in the range of 10 wt.% to 30 wt.% were co-pyrolyzed at temperatures of 650°C and 750°C.

[0092] Mineralogical analyses using X-ray diffractometers showed that kaolinite (crystalline) was successfully converted into metakaolin (amorphous) during the experiments and that co-pyrolysis had thus caused a phase transformation of the mineral.

[0093] In addition, the coal products of co-pyrolysis from softwood and kaolin-containing production residues showed a reactivity that is significantly higher than the reactivity of conventional biochar, as shown by a R 3 -Test using a calorimeter showed.

[0094] In this study, coal products produced from clay-to-biomass mixtures in ratios of 23:77, 30:70, and 50:50 were compared. Co-pyrolysis was carried out at 650°C for 15 minutes.

[0095] The chemical composition of the coal products measured by X-ray fluorescence analysis (XRF) as well as the loss of ignition (LOI) is listed in the following table: Table: Chemical composition and loss of ignition at different weight ratios

[0096] A calorimeter determines the heat released by a material by measuring the heat flow generated during physical or chemical processes. The R 3 -Test is a rapid, relevant and reliable (R 3 ) Method for evaluating the pozzolanic reactivity of calcined clays and other cement substitutes. Reference:

[0097] Avet, Francois; 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 85, pp. 1-11. DOI: 10.1016 / j.cemconres.2016.02.015. Figure 1 shows the result of R 3 -Tests for coal products made from mixtures of clay to biomass in the ratios 23 : 77, 30 : 70 and 50 : 50 compared to reference products such as calcined clay, granulated blast furnace slag, fly ash and quartz.

[0098] Surprisingly, it was found that the coal product made from a 30:70 clay to biomass mixture exhibits the highest reactivity. The coal product made from a 30:70 clay to biomass mixture is approximately 20% more reactive than the coal product made from a 50:50 clay to biomass mixture and approximately 40% more reactive than the coal product made from a 23:77 clay to biomass mixture.

[0099] The coal products, made from clay-to-biomass mixtures in a ratio of 30:70 and 50:50, were used in mortar prisms as a cement replacement (10%). The mortar prisms were subjected to compressive strength tests and flexural tensile strength tests according to DIN EN 1015-11 after 7 days and 28 days and compared with mortar prisms containing 10% cement as a standard. The results are shown in Figures 2 and 3.

[0100] The mortar prisms with 10% coal product made from a 30:70 clay to biomass mixture generally exhibit higher compressive and flexural strengths than those with 10% coal product made from a 50:50 clay to biomass mixture. The compressive strengths of the mortar prisms with 10% coal product made from a 30:70 clay to biomass mixture are comparable to the compressive strengths of the standard mortar prisms. The 28-day flexural strength values ​​of the mortar prisms with 10% coal product made from a 30:70 clay to biomass mixture exceed those of the standard mortar prisms.

Claims

Claims 1 . Process for co-pyrolysis of biomass and mineral raw materials for the activation of the mineral raw materials, comprising the following steps: • Providing a mixture containing biomass and mineral raw materials in a weight ratio of biomass and mineral raw materials in the mixture in the range of 75:25 to 55:45, preferably 75:25 to 65:35, more preferably 73:27 to 67:33, particularly preferably 72:28 to 66:32, in particular 70:30, based on the total weight of the mixture of biomass and mineral raw materials; • Pyrolysis of the mixture containing biomass and mineral raw materials under low-oxygen conditions at a temperature in the range from 200 to 1500°C, preferably from 250 to 1250°C, most preferably from 300 to 1100°C; • Obtaining a pyrolysis product containing biomass carbonate and activated minerals.

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

3. The process according to any one of the preceding claims, wherein the biomass comprises plant biomass, preferably lignin- and / or cellulose-containing biomass such as wood and bamboo, agricultural products, green waste, algae, aquatic plants and mixtures thereof, animal biomass, preferably slaughterhouse waste, biogenic residues, preferably waste wood and agricultural residues, sludges such as sewage sludge, compost, fiber residues and mixtures thereof.

4. The process according to any one of the preceding claims, wherein the biomass is obtained from agricultural by-products, wood and forestry by-products, biogenic municipal waste, residues from other areas and sewage sludge as well as industrial residues and residues from energy production.

5. The process according to any one of the preceding claims, wherein the biomass and the mineral raw materials are present as solids.

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

7. The process according to any one of the preceding claims, wherein the pyrolysis takes place under autothermal conditions.

8. The process according to any one of the preceding claims, wherein the minerals are activated by conversion, for example by dehydroxylation.

9. The process according to any one of the preceding claims, wherein kaolinite is activated by conversion to metakaolin.

10. The method according to any one of the preceding claims, wherein the minerals are activated by expansion, such as the expansion of perlite and / or vermiculite. 11 . Use of the pyrolysis product produced by the process according to one of the preceding claims in the construction sector, for example as an additive, aggregate, binder, cement substitute or filler for building materials in cementitious building material systems, as aggregate, binder, cement substitute or filler for building materials in building material systems with alkaline-activated binders, as a dye, as aggregate to improve hydration in flowable building materials and / or as aggregate for asphalt.

12. Use of the pyrolysis product produced by the process according to one of claims 1 to 10 in gardening and landscaping, for example as plant substrate, as aggregate for backing concrete, as joint fill, in palisades, as bedding material, as insulation material, preferably in combination with clay, in tree discs, in dyke or dam construction and / or for greening roofs and facades.

13. Use of the pyrolysis product produced by the process according to one of claims 1 to 10 as a carrier and / or filter material, for example as a carrier material for catalysts, as a filter material for exhaust gases or liquid waste streams, as a drying agent, as a compensating and adsorption material for slags and / or as an absorber for impurities and pollutants.

14. Use of the pyrolysis product produced by the process according to one of claims 1 to 10 in energy storage technology, for example in capacitors.

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

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