Manufacturing method of resin composite products

Abstract

To provide a technique for manufacturing a resin composite product, which promotes use of established ash which is a byproduct of coal thermal power generation and contributes to reduction of discharging of carbon dioxides in order to achieve the sustainable development goals (SDGs).SOLUTION: This method for manufacturing a resin composite product comprises the steps of: recovering established ash 26 generated by burying coal ash 25 (25a, 25b) which is a coal combustion residue in thermal power generation 10 at a dedicated disposal site 20 or a metal sulfate 27 generated by desulfurizing a combustion flue gas 24 of a coal; adjusting at least one of the granularity, the blending, and the water content of the recovered established ash 26 or the metal sulfate 27 to generate regenerative powder 28; and heating and mixing a mixture 43 of the regenerative powder 28 and a synthetic resin 29 at a temperature where the synthetic resin 29 melts to take out a molten mixture 36.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a technology for producing resin composite products that contribute to the realization of the Sustainable Development Goals (SDGs) by using by-products of coal-fired power generation. [Background technology]

[0002] Efforts are underway around the world to reduce CO2 emissions, which are believed to be the cause of global warming, and to create a society that reduces the burden on the environment. Under these circumstances, while some countries are trying to reduce their reliance on coal-fired power generation, emerging countries are seeking to make greater use of coal as an energy source from the perspectives of stable supply, economic efficiency, environmental compatibility, and safety.

[0003] Because the amount of CO2 emitted from burning coal is higher than that of other fossil fuels, efforts are being made to reduce emissions by improving power generation efficiency in coal-fired power plants. Furthermore, in order to reduce the environmental burden, coal-fired power plants are equipped with desulfurization equipment that removes sulfur components from exhaust gas after combustion.

[0004] Coal-fired power generation generates large amounts of by-products, including fly ash and clinker ash, as well as gypsum from desulfurization equipment. Japan generates approximately 9 million tons of coal ash annually, with fly ash accounting for approximately 90% of that. Japan also generates approximately 1.7 million tons of gypsum annually from the desulfurization process.

[0005] Fly ash is a spherical particle with a diameter of approximately 0.1 to 300 μm, and is industrially standardized after particle size adjustment (known as "JIS ash") for use as a cement raw material. Clinker ash, which has a porous structure, is widely used in golf courses and road subgrades, intermediate layers for grounds, quay backfills, lightweight embankments such as terre armée, taking advantage of its excellent properties of light weight, drainage, breathability, water retention, and fertilizer retention. Gypsum is also mostly used as a blending aid for cement raw materials or in gypsum boards (e.g., Non-Patent Documents 1 and 2). [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] Carbon Frontier Organization website (https: / / www.jcoal.or.jp / ashdb / whatash / ashoutline.html) [Non-patent document 2] Japan Cement Association website (https: / / www.jcassoc.or.jp / cement / 1jpn / jc.html#03) Summary of the Invention [Problem to be solved by the invention]

[0007] However, the reality is that many of the by-products of coal-fired power generation mentioned above are not used and are instead buried in dedicated disposal sites. Specifically, clinker ash that exceeds demand and fly ash that does not meet industrial standards (known as "JIS non-compliant ash") are subject to burial disposal. Looking at recent trends in the use of coal ash, it is predicted that dedicated disposal sites will become increasingly overwhelmed, and there is a need to secure capacity and improve environmental aspects.

[0008] Here, we distinguish between coal ash immediately after being discharged from coal-fired power plants and coal ash that has been buried in dedicated disposal sites as "new ash." If the use of pre-made ash could be promoted, it would not only extend the life of the current dedicated disposal sites, but would also have many advantages, such as allowing for flexible shipments of existing large stocks according to demand.

[0009] However, this explanation for prioritizing the use of existing ash over newly produced ash is not sufficiently rational or necessary. Furthermore, a system to provide incentives to encourage the use of coal ash has not yet been established.

[0010] The present invention was made in consideration of these circumstances, and provides a manufacturing technology for resin composite products that promotes the use of pre-made ash, a by-product of coal-fired power generation, and contributes to reducing carbon dioxide emissions in order to achieve the Sustainable Development Goals (SDGs). [Means for solving the problem]

[0011] The method for producing a resin composite product according to the present invention is to use coal ash, which is a residue of coal combustion in thermal power generation. Turn and recovering the recovered preformed material. Ash The method includes a step of adjusting at least one of particle size, blending, and water content to produce recycled powder, and a step of heating and kneading a mixture of the recycled powder and synthetic resin at a temperature at which the synthetic resin melts, and removing the molten mixture. and further blending the regenerated powder with a dispersion of at least one of layered silicate, polysaccharide nanofiber, and hydrophilic cellulose derivative dispersed in water or polyhydric alcohol to form the mixture. . [Effects of the Invention]

[0012] The present invention provides a manufacturing technology for resin composite products that promotes the use of pre-made ash, a by-product of coal-fired power generation, and contributes to reducing carbon dioxide emissions in order to achieve the Sustainable Development Goals (SDGs). [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic diagram illustrating a method for manufacturing a resin composite product according to a first embodiment of the present invention. [Figure 2] FIG. 10 is a side view showing a manufacturing apparatus for a resin composite product that is applied to the second and third embodiments of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] (First embodiment) Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a schematic diagram illustrating a method for manufacturing a resin composite product according to a first embodiment of the present invention (hereinafter simply referred to as "the manufacturing method"). As described above, the manufacturing method includes the steps of burying coal ash 25 (25a, 25b), which is the residue of coal combustion in a thermal power plant 10, in a dedicated disposal site 20, and recovering the resulting pre-formed ash 26 or metal sulfates 27 produced by desulfurizing coal combustion flue gas 24; adjusting at least one of the particle size, blending, and moisture content of the recovered pre-formed ash 26 or metal sulfates 27 to produce recycled powder 28; and heating and kneading a mixture 43 of the recycled powder 28 and a synthetic resin 29 at a temperature at which the synthetic resin 29 melts, and extracting a molten mixture 36.

[0015] As shown in Fig. 1, in a coal-fired power plant 10, pulverized coal (not shown) is combusted in a boiler 11, and the resulting energy is converted into electricity by a turbine 12 and a generator 13. This combustion of coal generates a large amount of coal ash 25 (25a, 25b), equivalent to about 10% of the coal. This coal ash 25 is then classified into fly ash 25a and clinker ash 25b.

[0016] The main components of this coal ashes 25 (25a, 25b) are silica (SiO2) and alumina (Al2O3), accounting for 70 to 80%, and other components include iron oxide (Fe2O3), calcium oxide (CaO), magnesium oxide (MgO), sodium oxide (Na2O), potassium oxide (K2O), etc.

[0017] Fly ash 25a is formed when particles of molten coal ash 25 float in the high-temperature combustion gas, are cooled at the low-temperature boiler outlet, and become glassy spherical particles, which are then collected by electrostatic precipitator 14. This fly ash 25a is a mixture of spherical and irregular shapes with an average particle size of 10 to 30 μm.

[0018] Furthermore, the combustion flue gas 24 is subjected to absorption of sulfur oxides (SOx) in a flue gas desulfurizer 22, and then released into the atmosphere from a chimney 15. Metal sulfates 27 generated from the sulfur oxides (SOx) in the flue gas desulfurizer 22 are collected in a tank 23. Note that sulfur oxides (SOx) are generated as the sulfur content in coal is burned, and the type of flue gas desulfurizer 22 that absorbs the sulfur oxides (SOx) and generates the metal sulfates 27 is not particularly limited.

[0019] The lime-gypsum method is a method in which limestone (CaCO3) is made into a slurry and reacted with SOx inside the flue gas desulfurizer 22 to recover gypsum (CaSO4) as metal sulfate 27. The magnesium hydroxide method is a method in which magnesium hydroxide (Mg(OH)2) is reacted with SOx inside the flue gas desulfurizer 22 to recover magnesium sulfate (MgSO4) as metal sulfate 27.

[0020] Since metal sulfate 27 is a hydrate, resin composite products containing it can be treated as non-combustible and flame-retardant products under the Fire Service Act by setting the oxygen index to 26 or higher. However, metal sulfate 27 tends to agglomerate, and thus has rarely been filled into resin composite products until now. However, by heating and kneading the molten mixture 36 together with a liquid medium (water), the dispersibility of metal sulfate 27 can be improved. Furthermore, the liquid medium (water) retains water by hydrogen bonding with metal sulfate 27, further improving the flame retardancy of the resin composite product. Furthermore, the hydrogen-bonded water also functions as a plasticizer, improving the toughness of the resin composite product.

[0021] Fly ash 25a collected by electrostatic precipitator 14 is stored in silo 16a as "raw powder" and then separated by classifier 21 according to particle size. The fine and coarse particles obtained by classifier 21 are called fine fly ash 25a1 and coarse fly ash 25a2, and are stored in separate silos 16a1 and 16a2, respectively.

[0022] On the other hand, the clinker ash 25b is formed when particles of the coal ash 25 inside the boiler 11 adhere to each other to form porous lumps that remain inside the boiler 11. This clinker ash 25b falls and accumulates in a water tank (clinker hopper 17) provided at the bottom of the boiler 11. It is then crushed into sand by a crusher (not shown), dehydrated in a dewatering tank 18, and stored in the silo 16b in the sandy state.

[0023] In this way, the fly ashes 25a, 25a1, 25a2, clinker ash 25b, and metal sulfates 27 recovered from the combustion gas 24 and stored in the silos 16a, 16a1, 16a2, 16b, and tank 23 are shipped at appropriate times depending on their intended use.

[0024] However, the balance between supply and demand for the fly ash 25a and clinker ash 25b produced in this way is actually biased towards the supply side. For this reason, the excess fly ash 25a and clinker ash 25b produced and the fly ash 25a3 (JIS non-compliant ash) remaining in the classifier 21 are buried in a dedicated disposal site 20.

[0025] Coal ash 25 buried in dedicated disposal site 20 in this way is called ready-made ash 26. In contrast, coal ash 25 stored in silos 16a, 16a1, 16a2, and 16b, which retains the properties it had immediately after discharge, is called "new ash" to distinguish it. This ready-made ash 26 is characterized by less pozzolanic reactivity and stability when used compared to new ash, as a result of the pozzolanic action caused by natural moisture and pressure during the disposal process.

[0026] The resin composite product manufacturing apparatus 50A (50) (simply referred to as "manufacturing apparatus 50A") applied to the first embodiment is composed of a raw material supply unit 40A (40) and an extruder 30A (30). The raw material supply unit 40A includes an adjustment unit 41 that adjusts the particle size, composition, and moisture content of the preformed ash 26 collected from the dedicated disposal site 20, and a resin container 45 that stores pelletized synthetic resin 29. A mixing tank (not shown) may be provided separately to mix the recycled powder 28 and the synthetic resin 29 to form a mixture 43.

[0027] Suitable synthetic resins 29 are polyolefin thermoplastic resins such as low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP), ethylene-vinyl acetate copolymer (EVA), and ethylene-ethyl acrylate copolymer (EEA), which are molded into pellets.

[0028] Furthermore, without being limited to these, other resins that have the property of being thermoplastic when heated and can generally be extruded can be used without particular restrictions, such as polycarbonate resin (PC), polyethylene terephthalate resin (PET), acrylic butylene styrene (ABS), polyvinyl chloride (PVC), polystyrene (PS), polyamide (PA), etc. Furthermore, synthetic resin 29 may be a mixture of two or more of these thermoplastic resins, and recycled products of these thermoplastic resins can also be used.

[0029] Here, the adjustment unit 41 uses equipment with various functions depending on the adjustment function to be performed. The properties of the ready-made ash 26 differ depending on the origin (fly ash 25a, 25a1, 25a2, 25a3, clinker ash 25b) of the coal ash 25 buried in the dedicated disposal site 20. Therefore, the blending adjustment in the adjustment unit 41 involves mixing multiple types of coal ash 25 of different origins while adjusting the blending ratio according to the intended use.

[0030] The blending adjustment by the adjustment unit 41 may use not only existing ash 26 buried at the dedicated disposal site 20, but also new ash stored in silos 16a, 16a1, 16a2, 16b, etc. without being buried. Furthermore, the blending adjustment may also use incineration ash from combustion equipment. Furthermore, the blending adjustment may also use metal sulfates 27 (gypsum (CaSO4), magnesium sulfate (MgSO4)) stored in the tank 23.

[0031] Furthermore, the particle size distribution of the pre-made ash 26 becomes coarse due to the granulation caused by the pozzolanic action that progresses during its residence at the dedicated disposal site 20. Therefore, particle size adjustment in the adjustment unit 41 is a function that refines the particles of the pre-made ash 26 and homogenizes the particle size distribution by causing them to collide with each other and grind them using high-speed rotary crushers such as hammer mills and pin mills, or container-driven mills that use grinding media (rods, balls, beads, etc.) such as rotary mills, vibration mills, and planetary mills. This particle size adjustment can be more efficiently achieved by blending coal ash 25 with a smaller particle size in advance.

[0032] Furthermore, the presence of a liquid medium such as water is known to be effective in uniformly dispersing the pre-formed ash 26 in the synthetic resin 29 at a high blending ratio during the process of heating and kneading the molten mixture 36. This is because when pre-formed ash 26 powder, synthetic resin 29, and the liquid medium are heated and kneaded in a sealed environment, the water acts to form a finely dispersed phase of the pre-formed ash 26 in the fluid matrix phase of the synthetic resin 29. In other words, the liquid medium prevents the powder from agglomerating in the synthetic resin fluid during heating and kneading, homogenizing the composite at a microscopic level. The action of the liquid medium in a sealed system at high temperature and pressure prevents re-agglomeration of the pre-formed ash 26 powder, resulting in a finely and uniformly dispersed phase in the molten matrix.

[0033] A certain amount of moisture may be added to the newly produced ash 26 during the burial period at the dedicated disposal site 20 or during the above-mentioned particle size adjustment. Furthermore, because the clinker ash 25b is crushed into sand by a crusher (not shown) in the presence of a large amount of water, it is stored in the silo 16b in a moist state even after being dehydrated in the dehydration tank 18. On the other hand, the raw powder fly ash 25a is stored in the silo 16a in an absolutely dry state with almost no moisture content, as can be seen from the production process shown in Figure 1.

[0034] Therefore, the adjusting unit 41 adjusts the moisture content of the recycled powder 28 to an appropriate level. This adjustment of the moisture content of the recycled powder 28 includes not only the addition of a new liquid medium (water, alcohol, etc.) but also the dehydration of moisture already contained in the recycled powder 28.

[0035] In the above description, the blending of recycled powder 28 has been explained on the assumption that pre-formed ash 26 is used as the main component. However, recycled powder 28 may also be blended and adjusted using metal sulfate 27 generated in flue gas desulfurizer 22 and stored in tank 23 as the main component, without using pre-formed ash 26.

[0036] The extruder 30 is composed of an input section 31 into which a mixture 43 of recycled powder 28 and synthetic resin 29 is input, a cylinder 33 which forms an airtight container and has an input section 31 located upstream and a die section 35 located downstream from which a molten kneaded body 36 is extruded, a drive section 32 which rotates a screw (not shown) around its axis inside the cylinder 33 to extrude the heated mixture 43 from upstream to downstream to form the molten kneaded body 36, and a vent section 34 which opens the cylinder 33, which is an airtight container, to the atmosphere and discharges moisture contained in the molten kneaded body 36 to the outside.

[0037] Any suitable extruder 30 can be used as long as it is capable of feeding the mixture 43 into a sealed container, kneading it by heating it at a temperature at which the synthetic resin 29 melts, and forming a molten kneaded mixture 36. For this reason, the kneading means is not limited to a continuous type such as the illustrated extruder 30, and may be a batch type such as a Banbury type, kneader, or roller type, although not shown.

[0038] In the vent section 34, the liquid medium 37 contained in the molten kneaded material 36 is discharged to the outside of the sealed container at a pressure equivalent to atmospheric pressure. The molten kneaded material 36 thus dehydrated is taken out from the most downstream side of the cylinder 33. Then, the molten kneaded material 36 taken out of the extruder 30 is branched into bundles in the die section 35, cooled and solidified, and then chopped into pellet-shaped resin composite materials.

[0039] The pellets thus formed are melted again by a known method and molded in a resin molding machine to form a resin composite product. Alternatively, the molten kneaded material 36 taken out of the extruder 30 can be directly fed into a resin molding machine to form a resin composite product.

[0040] (Second embodiment) Next, a second embodiment of the present invention will be described with reference to Fig. 2. Fig. 2 is a side view showing a manufacturing apparatus 50B (50) for a resin composite product (hereinafter referred to as "manufacturing apparatus 50B") equipped with a raw material supply unit 40B (40) applied to the second embodiment of the present invention.

[0041] The raw material supply unit 40B (40) of the second embodiment differs from the raw material supply unit 40A of the first embodiment in that it is configured to blend a dispersion 48, in which at least one of metal sulfate 27, layered silicate, polysaccharide nanofiber, and hydrophilic cellulose derivative is dispersed in water or polyhydric alcohol, with the regenerated powder 28. In Fig. 2, parts having the same configuration or function as those in Fig. 1 are indicated by the same reference numerals, and redundant explanations will be omitted.

[0042] The raw material supply unit 40B of the second embodiment includes an adjustment unit 41 and a resin container 45 common to the raw material supply unit 40A (FIG. 1), as well as a supply unit 46 that supplies a dispersion 48 and a mixing tank 42 that mixes the recycled powder 28 and the dispersion 48. The process by which the recycled powder 28, the dispersion 48, and the synthetic resin 29 are finally mixed into the mixture 43 is not particularly limited. In the embodiment, an example has been shown in which the recycled powder 28 and the dispersion 48 are mixed first and then the synthetic resin 29 is mixed. However, the recycled powder 28 and the synthetic resin 29 may be mixed first and then the dispersion 48 is mixed, or the dispersion 48 and the synthetic resin 29 may be mixed first and then the recycled powder 28 is mixed, or the dispersion 48, the synthetic resin 29, and the recycled powder 28 may be mixed together.

[0043] As the layered silicate, bentonite, which is mainly composed of montmorillonite, is preferably used. When the layered silicate swells and gels in a liquid medium, it exfoliates into single layers, forming nano-sized sheets. When this gel-like layered silicate is mixed with pelleted synthetic resin 29, the viscosity of the gel-like layered silicate causes the layered silicate to spread on the surface of the pelleted synthetic resin 29.

[0044] When the mixture 43 is kneaded at the melting temperature of the synthetic resin 29, the excess water (liquid medium) acts to uniformly disperse the recycled powder 28 into the molten synthetic resin 29. When the excess water contained in the molten kneaded mixture 36 is vaporized and discharged, the recycled powder 28 is finely and uniformly dispersed in the continuous phase of the synthetic resin 29. At this time, the nanosheets of the layered silicate bridge the molecular chains of the synthetic resin 29 and the recycled powder 28, thereby improving the interfacial adhesion between the synthetic resin 29 and the recycled powder 28. Note that the metal sulfate 27 also improves the interfacial adhesion between the synthetic resin 29 and the recycled powder 28, similar to the layered silicate.

[0045] Suitable polysaccharide nanofibers are cellulose nanofibers, chitin nanofibers, or nanofibers with similar molecular chain structures. These polysaccharide nanofibers are highly hydrophilic and are often defibrated using water as a dispersion medium, and may be prepared as a dispersion 48 dissolved in a liquid medium (water) from the beginning. The polysaccharide nanofibers are unevenly distributed at the interface between the synthetic resin 29 and the recycled powder 28, improving adhesion.

[0046] Hydrophilic cellulose derivatives can be obtained by introducing functional groups or substituting atoms into the hydroxyl groups of cellulose molecules, and a suitable example is cellulose ether, which is widely used as a thickener in food and pharmaceutical applications. Cellulose ether has a much better affinity for water than cellulose fiber, so it dissolves in water to form a dispersion.

[0047] Examples of such cellulose ethers include methyl cellulose, ethyl cellulose, ethyl methyl cellulose, carboxyl methyl cellulose, carboxyethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, benzyl cellulose, trityl cellulose, cyanoethyl cellulose, aminoethyl cellulose, etc. The hydrophilic cellulose derivative is not limited to such cellulose ethers, and any suitable cellulose derivative can be used as long as it can be dissolved in a solvent to form the dispersion 48.

[0048] The polyhydric alcohol is preferably a glycol such as ethylene glycol or 1,4-butanediol. Two or more of these polyhydric alcohols can be used. This polyhydric alcohol acts to uniformly disperse the recycled powder 28 in the molten mixture 36 that is being heated and kneaded. In this way, a resin composite product manufactured using the dispersion 48 exhibits excellent mechanical strength.

[0049] (Third embodiment) Next, a third embodiment of the present invention will be described with reference to Fig. 2. Fig. 2 is a side view showing a manufacturing apparatus 50B (50) equipped with an extruder 30B (30) applied to the third embodiment of the present invention.

[0050] The third embodiment differs from the extruder 30A of the first embodiment in that the extruder 30B is configured to perform dehydration at a set pressure higher than atmospheric pressure in a dehydration section 52 provided above an outlet 55 for the molten kneaded body 36. In Fig. 2, parts having the same configuration or function as those in Fig. 1 are denoted by the same reference numerals, and redundant explanations will be omitted.

[0051] 2, dehydration sections 52 (521, 522, 523) are installed in three stages. The moisture contained in the molten kneaded material 36 is sequentially discharged from the dehydration sections 52 (521, 522, 523) in which the throttle amounts of the open valves 51 (511, 512, 513) are adjusted. The most downstream dehydration section 523 is provided with a decompression pump 39 and a trap 38.

[0052] In FIG. 2, the opening of the open valves 51 (511, 512, 513) provided in each dehydration section 52 (521, 522, 523) is adjusted so that the internal pressure of the dehydration section 52 (521, 522, 523) is set in a gradient of P1>P2=P0>P3 from the upstream. In this case, the open valve 51 for setting the internal pressures P2 and P3 is set to be fully open. Dehydration at a higher pressure than atmospheric pressure P0, such as internal pressure P1, is effective in preventing excessive evaporation of water and suppressing aggregation of filler when the molten kneaded body contains a large amount of water.

[0053] It is desirable that the dehydration in the dehydration section 52 be carried out so that the moisture content at the thermal flow temperature is 1% or less. In this way, molded products made using a resin composite product whose moisture content is controlled to a certain level or less do not suffer from molding defects due to water foaming or the like.

[0054] In this embodiment, in addition to pellets, various resin composite products listed below can be produced from the molten kneaded body 36 taken out of the extruder 30.

[0055] Product for underground installation, density 1.5g / cm 3 The above products, flat yarn, products used for storage or transportation, bags or boxes used for packaging or delivery, products whose resin is polyolefin and has flame retardancy with an oxygen index of 26 or more, products whose resin is polyvinyl chloride and is used for building materials or civil engineering purposes, products whose resin is polystyrene or polyolefin and is microwave-safe, and products whose resin is polyethylene and is used for frozen foods.

[0056] The density mentioned above is 1.5 g / cm 3 The above products have excellent injection moldability because the fluidity of the molten mixture 36 is not easily reduced even when the fly ash 25a is heavily filled. This allows the high density of the product to be utilized to manufacture resin composite products such as weights for use at construction sites.

[0057] For the flat yarn products mentioned above, it has been considered impossible to use a resin composite material containing a filler until now. However, by blending recycled powder such as pre-made ash, a flat yarn using a resin composite material with sufficient performance for practical use can be provided.

[0058] Furthermore, resin composite products with a synthetic resin content of less than 50% are considered non-plastic products, which can provide incentives for their active use. Resin composite products containing clinker ash as a filler have excellent rigidity and buckling strength, making them suitable for resin composite products such as the corrugated pipes needed for undergrounding electric cables. Even when using LLDPE, LDPE, or recycled resins of these materials as the matrix, they exhibit sufficient rigidity.

[0059] Furthermore, resin composite products containing gypsum, especially those using polyvinyl chloride as the synthetic resin 29, can be highly flame-retardant. This makes them suitable for building materials and civil engineering applications. Gypsum, a metal sulfate 27 produced by desulfurizing combustion flue gas 24 in thermal power plants 10, is highly safe and has a high whiteness, making it suitable for food applications. Furthermore, gypsum contains a large amount of bound water, making it heat-resistant and suitable for microwave ovens. In particular, when polyethylene is used as the synthetic resin 29, it is suitable for use in resin composite products for frozen foods. Furthermore, the presence of a polyhydric alcohol as a liquid medium during the heating and kneading process of the molten kneaded mass 36 allows for more effective removal of the adhering water, which functions as a plasticizer, resulting in a resin composite product suitable for frozen foods.

[0060] Furthermore, when these resin composite products are incinerated, the amount of carbon dioxide generated by the synthetic resin 29 equivalent to the amount of recycled powder 28 (pre-formed ash 26, metal sulfate 27) filled in them can be considered to have reduced emissions. For this reason, the amount of carbon dioxide emission reduction can be set according to the amount of recycled powder 28 filled in, and it can be attached to the resin composite product as a point where separation and storage are possible.

[0061] As a result, the more a product with a higher blending ratio of recycled powder 28 is used, the more points are accumulated for the carbon dioxide emission reduction performance. This provides an incentive for users of resin composite products to use resin composite products with a high blending ratio, and an incentive for manufacturers to actively develop resin composite products with a high blending ratio.

[0062] In this way, by effectively utilizing the existing ash 26 and / or the metal sulfate 27 (gypsum) produced by flue gas desulfurization, which are buried in large quantities in the dedicated disposal site 20, as a filler for resin composite products, it is possible to reduce greenhouse gases released into the environment and make a significant contribution to preventing global warming.

[0063] The manufacturing method of a resin composite product according to the embodiment described above allows the buried pre-made ash 26 to be reused, which leads to the extension of the life of the dedicated coal ash disposal site 20 currently in operation. Furthermore, because the pre-made ash 26 is already stocked in large quantities at the dedicated disposal site 20, shipments can be flexibly accommodated according to demand. Furthermore, by dispersing and compounding the pre-made ash 26 and metal sulfates 27, which are by-products of thermal power generation 10, in synthetic resin 29 as fillers, the amount of synthetic resin 29 produced from fossil resources can be reduced, and a resin composite product that contributes to the realization of the SDGs can be developed. [Explanation of symbols]

[0064] 10...Coal-fired power generation, 11...Boiler, 12...Turbine, 13...Generator, 14...Electrostatic precipitator, 15...Chimney, 16a, 16a1, 16a2, 16b...Silo, 17...Clinker hopper, 18...Dehydration tank, 20...Dedicated disposal site, 21...Classifier, 22...Flue gas desulfurizer, 23...Tank, 24...Combustion flue gas, 25...Coal ash, 25a...Fly ash, 25b...Clinker ash, 26...Pre-formed ash, 27...Metal sulfate, 28...Recycled powder, 29...Synthetic synthetic resin, 30 (30A, 30B)...extruder, 31...feeding section, 32...drive section, 33...cylinder, 34...vent section, 35...die section, 36...molten kneaded body, 37...liquid medium, 38...trap, 39...vacuum pump, 40 (40A, 40B)...raw material supply section, 41...adjustment section, 42...mixing tank, 43...mixture, 45...resin container, 46...supply section, 48...dispersion body, 50 (50A, 50B)...manufacturing apparatus, 51...open valve, 52...dehydration section, 55...outlet.

Claims

1. A process of collecting coal ash, which is a residue of coal combustion in thermal power generation, by burying it at a dedicated disposal site and generating ash; A step of adjusting at least one of the particle size, composition, and moisture content of the recovered ash to make it into a recycled powder; A method for producing a resin composite product, comprising: a step of heating and kneading the mixture of the recycled powder and the synthetic resin at a temperature at which the synthetic resin melts, and removing the molten kneaded mixture; A method for manufacturing a resin composite product in which the recycled powder is further blended with a dispersion in which at least one of layered silicate, polysaccharide nanofiber, and hydrophilic cellulose derivative is dispersed in water or a polyhydric alcohol to form the mixture.

2. In the method for manufacturing a resin composite product according to claim 1, A method for producing a resin composite product, comprising the step of dehydrating the molten kneaded body at a set pressure higher than atmospheric pressure in a dehydration section provided above the outlet of the molten kneaded body.

3. In the method for manufacturing a resin composite product according to claim 1, In the step of preparing the regenerated powder, The method for producing a resin composite product further comprises blending the coal ash or incineration ash from a combustion facility that has been stored without being buried.

4. In the method for manufacturing a resin composite product according to claim 1, The coal ash is at least one of clinker ash and fly ash.

5. In the method for manufacturing a resin composite product according to claim 1, The method for producing a resin composite product comprises converting the removed molten kneaded product into pellets, a molded product, or a molded product via the pellets.

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