Carbide product-containing granules, method for producing the same, and use

Abstract

This invention relates to granules used as building materials or aggregates in building materials. Furthermore, this invention relates to a method for producing said granules and the use of said granules. The granules according to this invention contain a binder and a carbonized product, wherein the content of the carbonized product relative to the total weight of the binder and carbonized product in the granules is 30% by weight or more.

Description

Technical Field

[0001] The present invention relates to granules used as a building material or as an aggregate in a building material. The present invention also relates to a method for producing the granules and their use.

Background Art

[0002] The construction industry is an industry with a large amount of CO2 emissions. For example, the cement industry is one of the major sources of greenhouse gas emissions that cause global warming. 4.1 billion tons of cement are produced annually worldwide and contain an average of about 60% CaO. As a result, even under optimal process control, at least 3 billion tons of CO2, that is, about 6 - 8% of the annual CO2 emissions, are emitted due to the release of carbon dioxide bound to lime. For example, about 0.7 kg of CO2 is emitted in the production and use of 1 kg of Portland cement. In order to achieve climate goals and reduce future costs associated with CO2 pricing, it is necessary to reduce the CO2 emissions of the construction industry. As part of this, there is a search for alternative raw materials and replacement possibilities for building materials with particularly high CO2 emissions.

[0003] One of the known options is to use carbonation products in building products. Thereby, CO2 is fixed in the form of carbon, and the building material functions as a carbon sink. However, due to the non-uniform composition and unstable properties of the carbonation products, their application to building materials is limited. Since carbonation products from different sources and production methods have different properties, it is necessary to always adapt the formulation design of building materials. Since the adjustment and modification of residues (chemical treatment, conditioning, activation, etc.) are often complex and uneconomical, the current large-scale industrial utilization is correspondingly limited. However, in order to suppress the climate impact of the construction industry and at the same time suppress the cost increase due to the rising CO2 price, it is necessary to find a solution to incorporate carbonation products into building materials without disadvantages.

[0004] Therefore, there is a lack of efficient and cost-effective homogenization and / or modification methods for adjusting the properties of carbonized products or optimizing their bonding with building material matrices, and there is a need to utilize these intermediate products in various building materials.

[0005] US2020 / 0062646A1 discloses a building material made by mixing cement, sand, and biochar, and then hardening it after adding water. Alternatively, it also describes a method of mixing powdered biochar with rendering material or plaster to process it into coated pellets or homogeneous pellets that can be used as a filler for drywall. A drawback of this method is that the amount of biochar absorbed by the disclosed method is very small (0.1 m³ of wall panel). 2 The limit is approximately 6g per unit. Alternatively, in mortar production, it was possible to achieve a biochar content of slightly less than 1.5 wt.% by dry mass ratio by replacing a portion of the sand with biochar. However, the biochar used here needs to be pulverized after thermal decomposition, which is a high-energy consumption process that consumes additional energy and results in further CO2 emissions. Pulverization further increases the high specific surface area of ​​biochar, allowing it to adsorb more moisture. This strongly affects the workability of the mortar mixture, and as a result, it became necessary to add a high-performance water-reducing agent to the mortar mixture to compensate. Furthermore, the exact moisture requirement of the granules described in US2020 / 0062646A1 is initially unknown, depending on the origin of the carbonization product, and needs to be adjusted to the moisture content in the mortar mixture.

[0006] Therefore, conventional technology has its problems. [Overview of the project]

[0007] The granules described in claim 1, the method described in claim 11, and the use described in claim 14 are described below. Further advantageous developments of the present invention are described in the dependent claims.

[0008] In one embodiment, the present invention may provide granules comprising a binder and a carbonized product. The carbonized product content in the granules is 20% by weight or more, based on the total weight of the binder and carbonized product in the granules. It has been found that by mixing the binder and the carbonized product in granular form, a homogeneous granular composition suitable for further use in construction applications can be easily provided.

[0009] In one embodiment of the present invention, the binder in the granules is selected from clinker cement, Portland cement, calcium aluminate cement, calcium sulfoaluminate cement, calcium sulfate (gypsum), calcium oxide, calcium hydroxide, ash, fly ash, slag, slag sand, alkali metal or alkaline earth metal hydrides, halides, oxides, nitrates, sulfates, carbonates, silicates, phosphates, fluorides, or their organic derivatives such as alcohol salts and acetates, aluminum phosphate compounds, aluminum silicate, clay, calcined alumina, kaolin, pozzolanes, trusses, tuff, organic polymers, or combinations thereof. According to the present invention, all of these binders are suitable for mixing with carbonization products and granulating to produce granules usable for construction applications.

[0010] In further embodiments of the present invention, the carbonization product is selected from the group consisting of biochar, charcoal, pyrolysis sewage sludge, pyrolysis paper and / or pyrolysis corrugated cardboard, pyrolysis fermentation residue, industrial soot, and combinations thereof. According to the present invention, the carbonization product obtained from the above raw materials or manufacturing methods can be used throughout to form granules by mixing with a binder, which can then be used for construction purposes.

[0011] In a further embodiment of the present invention, the content of carbonized products in the granules can be 30% by weight or more, or 40% by weight or more, or 50% by weight or more, or 60% by weight or more, or 65% by weight or more, based on the total weight of the binder and carbonized products in the granules. According to the present invention, it is possible to produce homogeneous granules with a reasonably high carbonized product content depending on the application.

[0012] In further embodiments of the present invention, the particle size of the granules is in the range of approximately 0.1 mm to approximately 32 mm, or approximately 0.2 mm to approximately 2 mm, or approximately 1.5 mm to approximately 5 mm, or approximately 5 mm to approximately 10 mm, or approximately 8 mm to approximately 20 mm, or approximately 20 mm to approximately 32 mm, or approximately 0.1 mm to approximately 1.5 mm, or approximately 20 mm to approximately 25 mm, or approximately 25 mm to approximately 32 mm. For granules consisting of multiple particles according to the present invention, it is guaranteed that the average particle size is in the range of 0.1 mm to approximately 32 mm. The corresponding particle sizes are optimal for construction applications.

[0013] In a further embodiment of the present invention, the granules are homogeneous. In this context, granules can be said to be homogeneous if the binder and the carbonization product are uniformly dispersed within the granules. In this sense, uniform dispersion exists when the carbonization product is dispersed within the binder matrix of the granules and there are no regions containing carbonization product that deviate significantly from the average content.

[0014] In another embodiment of the present invention, the granules may have a layered structure. In this regard, for example, a layered structure is said to exist when the core of the granule is composed solely of a binder or solely of a carbonization product, and each core is covered by a layer of the other component. An arrangement of multiple layers is also considered a layered structure. In particular, depending on the application area of ​​the granules, it may be desirable to have a binder layer on the surface of the granules.

[0015] In one embodiment of the present invention, the granules are substantially composed of a carbonization product and a binder. This corresponds to the case where, with the exception of water, other components are not present in the granules in an amount of 5% by weight or more.

[0016] In one embodiment of the present invention, the granules have a burnt-out content of 15% or more, as measured according to DIN 18128. In other embodiments of the present invention, the particles have a burnt-out content of more than 20%, more than 30%, more than 50%, more than 60%, or more than 70%, as measured according to DIN 18128. In particular, this can be used to demonstrate the presence of oxidizable carbon in the form of carbonized products in the granules of the invention and, accordingly, to provide evidence of CO2 fixation.

[0017] A method for producing granules containing the granules according to the present invention is also part of the present invention, and the production method includes method steps selected from wet granulation, spray drying, fluid bed granulation, melt granulation, or a combination thereof. It has been shown that the granules according to the present invention can be obtained using a variety of production methods.

[0018] In one embodiment of the manufacturing method according to the present invention, the first step is to carbonize biomass, plant material, wood, sewage sludge, paper, cardboard, fermentation residue, or a combination thereof. Following this step, a binder is added and granulation is carried out directly downstream.

[0019] In a further embodiment of the manufacturing method of the present invention, the carbonized product is crushed after or during carbonization, and sieved as necessary, and the carbonized product is d 80 ≤500μm or d 80 The mixture is adjusted to have a particle size distribution of ≤100 μm.

[0020] Furthermore, part of the present invention involves using granules according to the present invention or granules produced by the method of the present invention as aggregates in building materials, bulk insulation materials, aggregates in dry mortar products, acoustic components, aggregates in sound-absorbing materials, additives to crushed concrete, colorants, aggregates for improving fluidity in fluid building materials, aggregates for asphalt, fillers, growing media for plants, aggregates for backfill concrete, joint fillers, fences, paving stones, tree discs or gratings, granules for embankment or dam construction, greening of roofs and exterior walls, catalysts or catalyst carriers, filtration / adsorption, filter media for exhaust gas or wastewater flow, desiccants, absorbents for pollutants or hazardous substances, or combinations thereof. The granules of the present invention have been shown to be widely applicable and suitable for the aforementioned applications. [Brief explanation of the drawing]

[0021] Without limiting the general concept of the invention, the invention will be described in more detail with reference to the drawings.

[0022] [Figure 1] Figure 1 shows a selection example of composite granules having different particle sizes obtained according to an embodiment. [Figure 2] Figure 2 shows micro-CT images of the granules before and 7 days after water storage. [Figure 3] Figure 3 shows a graph of the compressive strength of a mortar formulation after 28 days according to the following example. [Figure 4] Figure 4 shows a graph of the flexural strength of a mortar formulation after 28 days according to the following example. **Mode for Carrying Out the Invention**

[0023] The present invention will be described in detail with reference to its embodiments and drawings.

[0024] The present invention proposes a new solution for expanding the utilization of building materials by homogenizing and adjusting carbonized products. The purpose is to perform granulation processing based on non-uniform raw materials and provide a homogeneous product that can be used as a CO2-negative composite granule.

[0025] This purpose is achieved by combining suitable mineral materials (cement, quicklime, slag sand, fly ash, limestone, kaolin, alumina, etc.) with one or more carbonized products. Thereby, a homogeneous product having an interaction shell adaptable to the corresponding building material matrix can be manufactured. This combination is achieved by granulation. On the other hand, since the granule has a smaller surface area than pure coal particles, the required amount of moisture is small. Compared with pure pyrolite carbon, when used in mortar, the decrease in fluidity during raw state is smaller, and thus the adjustment amount can be significantly reduced.

[0026] The granules of the present invention can basically be used as a substitute for sand in mortar and concrete. In this context, it is possible to replace natural aggregates with spherical and dimensionally stable granules composed of cement stone and coal, the particle size of which can be adjusted within the range of 0 to 32 mm in diameter. Thereby, a member having substantially the same strength as the prior art can be manufactured without replacing natural sand.

[0027] In various embodiments of the present invention, the granules may have a uniform structure or may contain different layer arrangements. Intentional coating during the granulation process allows for the adjustment of various surface properties of the particles (e.g., hydrophobicity, hydrophilicity, roughness, specific surface area, etc.), which interact with the binder matrix in various ways to define the overall properties of the component. These properties can be individually adjusted during the granulation process and adapted and optimized for each application. Depending on the application, the carbonization product content in the granules of the present invention can be adjusted to 70% by weight or more.

[0028] In one embodiment of the present invention, the obtained granules have zero or negative CO2 emissions in terms of the material's CO2 balance, and therefore have a negative emission effect on the material into which the granules of the present invention are introduced.

[0029] The granules of the present invention are independent of the origin of the carbonization product and enable unrestricted use in building material systems. Any known variant, particularly biochar, charcoal, pyrolytic sewage sludge, pyrolytic paper and corrugated cardboard, pyrolytic fermentation residue, industrial soot, and combinations thereof can be used as the carbonization product.

[0030] The granules of the present invention enable the carbon content of carbonized products obtained, for example, by thermal decomposition of biomass, to offset the CO2 emissions of additive components (e.g., mineral binders such as Portland cement). For example, the production and use of 1 kg of Portland cement releases approximately 0.7 kg of CO2. On the other hand, the production of 1 kg of carbonized products with a carbon content of up to 99% fixes approximately 3.67 kg of CO2. Therefore, 191 g of carbonized products can mathematically offset the CO2 emissions of 1 kg of Portland cement.

[0031] The CO2 fixation in the granules of the present invention is also demonstrated by the fact that the burnt-out amount, measured in accordance with DIN18128, is 15% or more.

[0032] Furthermore, unlike powdered carbonization products, the granules of the present invention have been found not to generate carbon dust during transport, storage, and handling, thereby offsetting drawbacks related to occupational health and explosion hazards. This means that the granules of the present invention can be stored in silos and are easy to fill, package, and transport and weigh during use.

[0033] Another advantage of granules is their humidity control due to reversible moisture absorption and release. This ability can be controlled by the selection of materials / raw materials, particularly the carbonization products, as well as process parameters, thus adjusting particle size, density, and porosity.

[0034] The dimensional stability achieved by the granules of this invention is a fundamental prerequisite for further use in various building materials. Due to the water absorption capacity of biochar, volume increase may also occur. Since swelling of individual components in building materials is usually a problem, the swelling behavior of the granules plays a crucial role and must be prevented accordingly. In contrast to free carbon, the granules of this invention sufficiently prevent swelling and can therefore be used in building materials that comply with standards.

[0035] Possible methods for homogenization include wet granulation, spray drying, or fluidized bed granulation or melt granulation.

[0036] In a preferred wet granulation process, a liquid (usually water) is added to the powder mixture intermittently or continuously during a continuous mixing process. If a binder is used, it can be added as a solid or liquid.

[0037] The fluidized bed process is similar to wet granulation.

[0038] In melt granulation, the binder is melted at high temperature during granulation, and the resulting granules reharden at room temperature.

[0039] Through the various methods described above, it has been found that carbonized products, regardless of their origin or manufacturing method, are suitable for use in building material systems without limitations. Furthermore, it has been shown that the amount of carbonized products used in building materials is no longer limited by their material properties, allowing for higher density to be achieved and maximizing the positive effects on climate.

[0040] The granules according to the present invention can be used in a wide range of applications, including construction, horticulture and landscaping, and as functional carrier granules.

[0041] In the field of construction, the granules of the present invention can be used as aggregate for building materials, bulk insulation materials, aggregate for dry mortar products, aggregate for acoustic components and sound-absorbing materials, impact-resistant concrete additives, colorants, aggregates for improving the fluidity of fluid building materials, asphalt aggregates, or fillers.

[0042] In the fields of horticulture and landscaping, it can be used as a plant growing medium, aggregate for backfill concrete, joint filler, fence, paving material, tree discs or gratings, granular material for embankment and dam construction, or for greening roofs and exterior walls.

[0043] The granules of the present invention can be used as a carrier in various applications, including as a catalyst or a carrier material for catalysts, as a filter material for exhaust gas or wastewater flow in filtration / adsorption systems, as a desiccant, or as an adsorbent for impurities and contaminants.

[0044] Parts of the present invention also include any combination of the features and / or limitations described herein, unless they are mutually exclusive. The description of the invention is intended to illustrate specific embodiments. Those skilled in the art will recognize that further modifications and equivalents of the embodiments described herein are possible. Such modifications and equivalents also constitute part of the overall scope of the invention described herein.

[0045] Example 1 Portland cement-bound granules produced from carbonization products (charcoal with a carbon content of 90-92% by weight) were manufactured by the following method: 1 kg of Portland cement (42.5N) was mixed with 2 kg of charcoal in a mixer, and 1.65 kg of water was added to produce wet granules. Depending on the time and rate, granules of different particle sizes were obtained, as shown in Figure 1.

[0046] Regardless of the granule size, the CO2 balance of the material is calculated as follows: 1 kg of cement (OPC) emits approximately 0.7 kg of CO2, while 2 kg of coal (carbonized products containing approximately 91% carbon) fixes approximately 6.68 kg of CO2. In this equation, a total of 5.98 kg of CO2 is fixed in the form of carbon by the binder and coal combined. Therefore, approximately 1.99 kg of CO2 is fixed per 1 kg of granules. In this calculation, added water is not included in the mass balance.

[0047] After storing the obtained granules in water for 7 days, it was confirmed that the granule size remained stable, as shown in Figure 2. The deviation in the difference image (center) is due to granules that moved during storage.

[0048] Example 2 Example 2 relates to the production of a mortar formulation using the granules of the present invention. The effect of replacing a portion of the sand with Biochar or the granules of the present invention was tested using a standard mortar formulation. The standard mortar formulation (control example RB1) consisted of 450g of cement, 1350g of sand, and 225g of water. In comparative examples VB1 and VB2, and in invention examples EB1 and EB2, 5% and 10% by weight of the sand were replaced with the same amount of coal or the granules of the invention, respectively. Table 1 summarizes the mortar composition (excluding water) of the control example, comparative examples, and invention examples.

[0049] [Table 1]

[0050] The prepared mixes were used in mortar prisms, and their compressive strength (DF) or flexural strength (BZF) was tested 28 days after production in accordance with DINEN 196-1. Furthermore, the CO2 balance of the mixes was calculated. The results are shown in Table 2 and Figures 3 and 4. For the CO2 balance calculation, the base values ​​assumed were +0.7 kg of CO2 per kg of cement, 3.34 kg of CO2 per kg of coal, and -1.99 kg of CO2 per kg of granules. Sand was assumed to be CO2 neutral.

[0051] [Table 2]

[0052] Replacing sand with granules and pure coal resulted in decreased compressive and flexural strength of mortar test prisms compared to a reference sample using pure quartz sand. Compared to the addition of granules, the addition of pure coal resulted in a significant decrease in compressive and flexural strength, as well as a significant decrease in workability. Additional water was added to the mixture of granules and pure coal to adjust the flow properties. This resulted in a relatively high water-to-cool ratio in the mix, ultimately leading to a decrease in the strength of the mortar prisms. In mixes using granular coal as a sand substitute, the workability was significantly worse than that of mortar containing granular additives, resulting in a significant increase in water requirements. This explains the significantly lower strength values ​​in the comparison.

[0053] By partially replacing sand with granules, it was possible to dramatically improve the CO2 balance of the mortar mix while keeping the loss of mechanical properties within acceptable limits. On the other hand, the use of coal achieved an even better CO2 balance, but the mechanical properties of the resulting mortar mix fell below acceptable limits. Because the bulk density of granules is lower compared to coal, the density of the resulting mortar mix is ​​also lower.

[0054] Naturally, the present invention is not limited to the embodiments described. Therefore, the above description should be interpreted as descriptive rather than restrictive. The following claims should be understood to mean that the described features are present in at least one embodiment; this does not preclude the presence of other features. The following claims should not be interpreted as meaning that the described features or combinations of described features are present in every embodiment of the present invention. To the extent that the claims and the above description define “first embodiment” and “second embodiment,” this designation is used to distinguish two similar embodiments without establishing priority.

Claims

1. Granules comprising a binder and a carbonized product, wherein the content of the carbonized product in the granules is 30% by weight or more relative to the total weight of the binder and the carbonized product in the granules.

2. Granules according to claim 1, wherein the binder is selected from clinker cement, Portland cement, calcium aluminate cement, calcium sulfoaluminate cement, calcium sulfate (gypsum), calcium oxide, calcium hydroxide, ash, fly ash, slag, slag sand, alkali metal or alkaline earth metal hydrides, halides, oxides, nitrates, sulfates, carbonates, silicates, phosphates, fluorides, or organic derivatives thereof such as alcohol salts or acetates, aluminum phosphate compounds, aluminum silicate, clay, calcined alumina, kaolin, pozzolanes, trusses, tuff, organic polymers, or combinations thereof.

3. Granules according to claim 1 or 2, wherein the carbonization product is selected from the group consisting of biomass, biochar, charcoal, pyrolysis sewage sludge, pyrolysis paper and corrugated cardboard, pyrolysis fermentation residue, industrial soot, and combinations thereof.

4. In the granules according to any one of claims 1 to 3, in each case, based on the total weight of the binder and the carbonization product in the granules, The content of the carbonization product in the granules is 40% by weight or more, or The content of the carbonization product in the granules is 50% by weight or more, or The content of the carbonization product in the granules is 60% by weight or more, or The granules contain 65% by weight or more of the carbonization product.

5. Granules according to any one of claims 1 to 4, wherein the particle size is in the range of 0.1 mm to 32 mm.

6. Granules according to any one of claims 1 to 5, wherein the granules are homogeneous.

7. Granules according to any one of claims 1 to 5, wherein the granules have layers of different structures.

8. Granules according to claim 7, wherein the carbonization product is located in the core of the granules and the binder is located on the surface of the granules.

9. Granules according to any one of claims 1 to 8, wherein granules are substantially composed of a binder and a carbonization product.

10. Granules according to any one of claims 1 to 9, wherein the burnt-out portion is 15% or more when measured according to DIN 18128.

11. A method for producing granules containing granules as described in any one of claims 1 to 10, comprising wet granulation, spray drying, fluid bed granulation, melt granulation, or a combination thereof.

12. A method according to claim 11, comprising carbonizing plant material, sewage sludge, paper, cardboard, fermentation residue, or a combination thereof in a first step, and adding a binder immediately after this step to carry out granulation.

13. In the method according to claim 12, the carbonized product is crushed after or during carbonization, and sieved as necessary, so that the particle size distribution of the carbonized product is d ８０ ≤500 μm or d ８０ A method to ensure that the size is ≤ 100 μm.

14. Use of granules as described in any one of claims 1 to 10, or granules produced by the methods described in claims 11 to 13, as aggregates for building materials, bulk insulation materials, aggregates for dry mortar products, acoustic components, aggregates for sound-absorbing materials, crushed concrete additives, colorants, aggregates for improving the fluidity of fluid building materials, aggregates for asphalt, fillers, growing media for plants, aggregates for backfill concrete, joint fillers, fences, paving stones, discs or gratings for trees, granules for the construction of embankments or dams, greening of roofs and exterior walls, catalysts or catalyst carriers, filtration / adsorption, filter media for exhaust gas or wastewater, desiccants, absorbents for impurities or contaminants, or combinations thereof.

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