How desiccant is manufactured

Abstract

To recycle incineration bottom ash with reduced use of energy.SOLUTION: A method for producing a desiccant includes a sizing step S11 for sizing incineration bottom ash, a carbonation step S12 for carbonating the incineration bottom ash with a predetermined range of particle sizes after the sizing step S11, and a production step S13 for producing a desiccant comprising the carbonated incineration bottom ash after the carbonation step S12.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a method for producing a desiccant. [Background technology]

[0002] It is known that molten slag, which is made by melting and solidifying incineration ash generated at incineration facilities, can be used as a construction material (for example, Patent Document 1). Melting reduces the volume of incineration ash and can render heavy metals harmless. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-194240 Summary of the Invention [Problem to be solved by the invention]

[0004] However, melting requires a huge amount of energy to melt the incineration ash at a high temperature of over 1000℃ and then solidify it by cooling, which makes it difficult to apply to general use. In addition, the recycling rate of incineration ash relative to the amount of waste generated remains low, and new developments are needed.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and has an object to provide a method for producing a desiccant that can recycle incineration bottom ash in an energy-saving manner. [Means for solving the problem]

[0006] In order to achieve the above object, a method for producing a desiccant according to one embodiment of the present disclosure includes a classification process for classifying incineration bottom ash, a carbonation process for carbonating the incineration bottom ash having a particle size within a predetermined range after the classification process, and a production process for producing a desiccant containing the incineration bottom ash that has been carbonated after the carbonation process.

[0007] In a preferred embodiment of the method for producing a desiccant, the bottom ash is agitated during the carbonation process.

[0008] In a preferred embodiment of the method for producing a desiccant, the predetermined range is 150 μm or more and 2.5 mm or less. Effect of the Invention

[0009] According to the present disclosure, incineration bottom ash can be recycled as a desiccant while saving energy. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a flowchart showing a method for producing a desiccant according to an embodiment. [Diagram 2] FIG. 2 is a schematic diagram illustrating an example of a system for producing a desiccant according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present disclosure will be described in detail below with reference to the drawings. Note that the present disclosure is not limited to the description of the following embodiments. In addition, the components in the following embodiments include those that are replaceable and easy for a person skilled in the art, or those that are substantially the same. Furthermore, the components in the embodiments described below can be omitted, replaced, or modified in various ways without departing from the gist of the present disclosure. In the following embodiments, components necessary for illustrating the embodiments of the present disclosure will be described, and other components will be omitted.

[0012] (Embodiment) Fig. 1 is a flowchart showing a method for manufacturing a desiccant 100 according to an embodiment. Fig. 2 is a schematic diagram showing an example of a manufacturing system 1 for a desiccant 100 according to an embodiment. The manufacturing method for a desiccant 100 according to an embodiment is a method for manufacturing a desiccant 100 containing incineration bottom ash 110 as an ingredient. The desiccant 100 has hygroscopicity and water absorbency. Note that, although the desiccant 100 is described below as being in the form of granules, it may be in the form of tablets in the present disclosure.

[0013] 1, the method for producing the desiccant 100 of the embodiment includes a classification step S11, a carbonation step S12, and a production step S13. Also, as shown in FIG. 2, the production system 1 for the desiccant 100 of the embodiment includes a classifier 10, a carbonation treatment device 20, and a production facility 30.

[0014] The classification step S11 is a step of classifying the incineration bottom ash 110. The incineration bottom ash 110 refers to the incineration residue recovered from the bottom of an incineration furnace, etc., and is distinguished from the incineration fly ash that is blown up together with the combustion gas and collected by a dust collector. The components of the incineration bottom ash 110 mainly include calcium oxide (CaO), silicon dioxide (SiO2), aluminum oxide (Al2O3), etc.

[0015] In the embodiment, the classification step S11 is performed in a classifier 10 of the manufacturing system 1. As shown in Fig. 2, the classifier 10 classifies the incineration bottom ash 110 discharged from the incineration facility according to particle size, shape, and the like. The incineration bottom ash 110 is classified by the classifier 10 into incineration bottom ash 111 having a particle size within a predetermined range and incineration bottom ash 112 having a particle size outside the predetermined range, and only the incineration bottom ash 111 having a particle size within the predetermined range is transported to the carbonation treatment device 20. In the embodiment, the predetermined range is 150 µm or more and 2.5 mm or less.

[0016] The classifier 10 may be a classification and sorting equipment having a function of separating incineration bottom ash, scrap iron, iron-based impurities, etc. from the incineration residue. The classification and sorting equipment roughly separates the incineration residue using, for example, a skeleton bucket. Residues smaller than a predetermined size are, for example, disposed of as a final disposal. The classification and sorting equipment collects large scrap iron from granules and powders of a predetermined size or larger using, for example, a weak magnetic separator. Next, the classification and sorting equipment removes fine iron-based impurities such as nails and wires using, for example, a strong magnetic separator. The collected scrap iron is disposed of, for example, by a specialized company. Next, the classification and sorting equipment classifies powders such as the incineration bottom ash 110 according to particle size and shape, etc. Residues larger than a predetermined size are, for example, disposed of as a final disposal.

[0017] The carbonation step S12 is a step of carbonating the incineration bottom ash 111 having a particle size within a predetermined range. The carbonation step S12 is a step of bringing the incineration bottom ash 111 into contact with carbon dioxide gas (carbon dioxide (CO2)). The carbon dioxide gas used in the carbonation step S12 is, for example, carbon dioxide gas discharged from a thermal power plant that uses coal, petroleum, natural gas, or the like as fuel.

[0018] In the embodiment, the carbonation step S12 is performed in the carbonation treatment device 20 of the manufacturing system 1. As shown in Fig. 2, incineration bottom ash 111 having a particle size within a predetermined range conveyed from the classifier 10 is carried into the carbonation treatment device 20. Carbon dioxide gas is introduced into the carbonation treatment device 20.

[0019] In the carbonation step S12, the incineration bottom ash 111 is placed in a container (carbonation treatment tank) of the carbonation treatment device 20. The container is, for example, a portable container having a substantially rectangular parallelepiped shape. The portable container can be placed on the bed of a vehicle, for example. The container has a partition wall that divides the internal space vertically. The partition wall is a plate-shaped member parallel to the bottom surface of the container and has multiple ventilation holes. The incineration bottom ash 110 is placed on the partition wall.

[0020] With the incineration bottom ash 111 placed on the partition, carbon dioxide gas is introduced into the space below the partition. The carbon dioxide gas comes into contact with the incineration bottom ash 111 through the ventilation hole in the partition. The incineration bottom ash 111 is carbonated by absorbing the carbon dioxide gas. Specifically, calcium components such as calcium oxide contained in the incineration bottom ash 111 are carbonated, and calcium carbonate (CaCO3) is generated. Carbon dioxide is absorbed into the incineration bottom ash 111 by the carbonation process S12.

[0021] That is, carbon dioxide is fixed in the incineration bottom ash 111 as carbonate. Furthermore, heavy metals such as lead (Pb) contained in the incineration bottom ash 111 become less soluble by the carbonation step S12. In addition, during the carbonation process in the carbonation step S12, that is, while carbon dioxide gas is being introduced into the container containing the incineration bottom ash 111, it is preferable to stir the incineration bottom ash 111 so that the carbonation gas is uniformly in contact with the incineration bottom ash 111. The incineration bottom ash 120 that has been subjected to the carbonation process is transported to the manufacturing facility 30.

[0022] The manufacturing process S13 is a process for manufacturing the desiccant 100 containing the carbonation-treated incineration bottom ash 120 as an ingredient. In the embodiment, the manufacturing process S13 is performed in the manufacturing equipment 30 of the manufacturing system 1. As shown in FIG. 2, the incineration bottom ash 120 discharged from the carbonation treatment device 20 is delivered to the manufacturing equipment 30.

[0023] The manufacturing equipment 30 includes a filling machine or the like that fills the packaging material with the incineration bottom ash 120. In the manufacturing process S13, for example, when manufacturing a desiccant 100 containing less than 100% of the incineration bottom ash 120, the manufacturing equipment 30 includes a kneading machine or the like that kneads the incineration bottom ash 120 with other component substances. In the manufacturing process S13 of the embodiment, a granular desiccant 100 is manufactured, but in the manufacturing process S13, for example, when a tablet desiccant is manufactured, the manufacturing equipment 30 includes a tablet press, a film coating machine, a dryer, a packaging machine, or the like.

[0024] As described above, the manufacturing method of the desiccant 100 of the embodiment includes a classification process S11 for classifying the incineration bottom ash 110, a carbonation process S12 for carbonating the incineration bottom ash 111 having a particle size within a predetermined range after the classification process S11, and a manufacturing process S13 for manufacturing the desiccant 100 containing the incineration bottom ash 120 that has been subjected to the carbonation process after the carbonation process S12 as a component.

[0025] The incineration bottom ash 110 has a porous pore structure, and this pore structure provides excellent moisture absorption and water absorption effects. By limiting the particle size of the incineration bottom ash 110 used in the desiccant 100 in the classification step S11 to a predetermined range, the pore structure of the incineration bottom ash 110 can be made uniform, so that the moisture absorption and water absorption effects of the desiccant 100 can be made uniform. In addition, the carbonation step S12 can make heavy metals such as lead contained in the incineration bottom ash 110 less soluble, so that the elution of lead and the like from the desiccant 100 containing the carbonated incineration bottom ash 120 as a component can be suppressed. Furthermore, the manufacturing method of the desiccant 100 of the embodiment can recycle the incineration bottom ash 110 simply and with less energy than melting, which requires high temperature or cooling from high temperature.

[0026] In the manufacturing method of the desiccant 100 according to the embodiment, the incineration bottom ash 111 is stirred during the carbonation process S12. This makes it possible to make the degree of carbonation of the incineration bottom ash 120 carbonated by the carbonation treatment device 20 or the like uniform.

[0027] In the manufacturing method of the desiccant 100 according to the embodiment, the predetermined range is 150 μm or more and 2.5 mm or less. This makes it possible to make the moisture absorption effect and water absorption effect of the desiccant 100 uniform and improve the moisture absorption effect and water absorption effect.

[0028] Each configuration described in each embodiment may be combined with other configurations in each embodiment without departing from the spirit of the invention. Furthermore, each of these configurations may be combined with configurations in other embodiments different from each embodiment without departing from the spirit of the invention. Furthermore, various modifications may be made without departing from the spirit of the invention.

[0029] For example, the carbon dioxide gas used in the carbonation step S12 does not necessarily have to be carbon dioxide gas discharged from a thermal power plant that uses coal, petroleum, natural gas, or the like as fuel. The carbon dioxide gas may be carbon dioxide gas discharged from, for example, a factory such as a cement manufacturing plant, a chemical plant, an incineration facility, or the like. The carbon dioxide gas may be gas generated for use in the carbonation step S12. [Explanation of symbols]

[0030] 1. Manufacturing System 10 Classifier 20 Carbonation treatment device 30 Manufacturing equipment 100 Desiccant 110, 111, 112, 120 Bottom ash S11 Classification process S12 Carbonation process S13 Manufacturing process

Claims

1. A classification process for classifying the incineration bottom ash; A carbonation process in which the incineration bottom ash having a particle size of 150 μm or more and 2.5 mm or less is carbonated without adding water after the classification process; a manufacturing process for manufacturing a desiccant containing the incineration bottom ash that has been subjected to a carbonation treatment after the carbonation process; A method for producing a desiccant, comprising:

2. In the carbonation step, the incineration bottom ash is stirred during the carbonation treatment. A method for producing the desiccant according to claim 1.

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