System for using emitted substance

Abstract

The present invention provides a system that can effectively use thermal energy or carbon dioxide emitted under conditions that are most favorable for a side that uses the emitted substance in a process for producing a plant-based raw material while reducing carbon dioxide emissions. The present invention is characterized by comprising: a combustion device (40) that is used when producing silica or carbon from a plant-based raw material (9); and a thermal energy recovery device (10) that absorbs heat inside the combustion device and recovers thermal energy, wherein the thermal energy recovery device recovers the thermal energy generated when the plant-based raw material itself is combusted.

Description

Waste utilization system

[0001] The present invention relates to a system that utilizes the heat or carbon dioxide generated when plant-based raw materials are burned and converted into materials for other facilities.

[0002] From the perspective of carbon neutrality, carbon and silica produced by burning plant-based raw materials have traditionally been used in battery materials, conductive materials, heating elements, tires, building materials, etc. In particular, carbon materials with large specific surface areas have been used as materials for batteries and capacitors. Carbon materials with excellent electrical conductivity have also been widely used as heating materials and shielding materials.

[0003] As such, various inventions have been proposed as methods for producing carbon materials from plant-based raw materials. For example, Patent Document 1 describes a method for producing a carbon material, in which a carbonaceous raw material is activated with an alkali metal compound to obtain activated carbon or activated carbon fiber with a high specific surface area, by surrounding the reaction system (a composition containing the carbonaceous raw material and the alkali metal compound) with a carbon-based powder layer and, if necessary, further including an inorganic compound layer in the carbon-based powder layer for activation. Also, a method for producing a carbon material, in which the temperature rise rate during activation is set to 20°C / hr or less, thereby increasing the yield of the carbon material per container. An electric double layer capacitor uses activated carbon or activated carbon fiber obtained by this production method as an electrode material.

[0004] Furthermore, a boiler system that uses biomass as fuel has been proposed. For example, Patent Document 2 discloses a biomass boiler system that includes a biomass boiler 10 installed in a boiler room 2, a fuel storage unit 20 that stores biomass fuel 3, a fuel supply unit 30 that supplies the biomass fuel 3 from the fuel storage unit 20 to the biomass boiler 10, and a drying unit 40 that recovers waste heat from the biomass boiler 10 and dries the biomass fuel 3. The drying unit 40 includes a drying hot air generator 41 that uses the recovered waste heat to heat exhaust air EA from the boiler room 2 to generate drying hot air HA, and a drying hot air inlet duct 42 that introduces the drying hot air HA from the drying hot air generator 41 into the fuel storage unit 20 to dry the biomass fuel 3.

[0005] JP 2002-362915 A JP 2024-3488 A

[0006] As in the patent document, when plant-based raw materials are used as fuel, the ash of the plant-based raw materials must be disposed of as waste, which results in the problem of a large amount of waste being generated.

[0007] The present invention has been made to solve the above-mentioned problems, and aims to provide a system that can effectively utilize the thermal energy or carbon dioxide that is emitted in a state that is favorable for the user of the waste during the process of producing plant-based raw materials while reducing carbon dioxide emissions and waste.

[0008] The system comprises a combustion device used when producing silica or carbon from plant-derived raw materials, and a thermal energy recovery device that absorbs heat inside the combustion device and recovers thermal energy, wherein the thermal energy recovery device recovers thermal energy generated when the plant-derived raw materials themselves combust.

[0009] The above features make it possible to effectively utilize waste materials while producing materials such as silica and carbon without using extra energy.

[0010] FIG. 1 is a schematic diagram of an effluent utilization system according to an embodiment; FIG. 2 is an example of a combustion device according to an embodiment; FIG. 3 is a schematic diagram of an effluent utilization system according to an embodiment; FIG. 4 is an example of a combustion device according to an embodiment; FIG. 5 is a schematic diagram of an effluent utilization system according to an embodiment; FIG. 6 is an example of a combustion device according to an embodiment; FIG. 7 is a process flow of silica according to an embodiment; FIG. 8 is a process flow of carbon according to an embodiment.

[0011] The waste utilization system according to the present invention will be described in detail with reference to the drawings. Note that the embodiments and drawings described below are intended to exemplify some of the embodiments of the present invention, and are not intended to limit the scope of the present invention, and may be modified as appropriate within the scope of the present invention.

[0012] <Biomass Material> The plant raw material 9 for producing silica or carbon will be described. In the present invention, food residues or discarded plant raw materials 9 are used to produce silica or carbon as a final product. Plants, wood, etc. are used as the plant raw material 9, but in particular, if discarded plant raw materials 9 such as residues obtained when plants are harvested are used as a raw material for producing graphene, the raw material can be obtained inexpensively.

[0013] Table 1 is a table of ingredients for plant-based raw material 9. In Table 1, the proportions of the ingredients constituting the raw material shown on the left are shown as percentages on the right. For example, rice straw contains 37.4% carbon (C), 0.53% nitrogen (N), 0.06% phosphorus (P), 0.14% phosphoric acid (PO), 1.75% potassium (K), 2.11% potash (KO), 0.05% calcium (Ca), 0.19% magnesium (Mg), and 0.11% sodium (Na).

[0014] Here, the porous plant-derived silicon-containing raw material 9 does not undergo substantial change even when carbonized at low temperatures (300°C or higher and 1000°C or lower), and the arrangement of pores can be maintained by removing the silicon.

[0015] Many plant-derived raw materials 9 have a structure in which cells are regularly arranged along the axis and the cell walls are thickened by the deposition of silicic acid. Furthermore, there are narrow compressed cell rows between the silicified cell rows, and by removing silicon and other substances after carbonization, it is possible to obtain a carbon material with a high specific surface area.

[0016] Plant-derived raw materials 9 containing 10% or more of silicic acid include rice husks, bamboo, and horsetail, and those containing a high amount of silicic acid, between 13% and 35%, are suitable. When silica is required, these plant-derived raw materials 9 are the best.

[0017] Examples of plant-based raw materials 9 containing a large amount of organic matter are shown in Table 1. Among these, plant-based raw materials 9 containing 10% or less silica include, in addition to rice straw, wheat straw, barley straw, wheat husk, barley husk, cocoa husk, rice bran, buckwheat straw, soybean vines, sweet potato vines, turnip leaves, carrot leaves, corn stalks, sugarcane tops, sake lees, coconut shells, coconut meal, peanut shells, mandarin orange peel, coffee husks, coffee grounds, shochu lees, beer lees, red cedar sawdust, larch bark, and fallen ginkgo leaves. Plants themselves may also be used instead of residues.

[0018] Bamboo is also a valuable nutrient source, as its cellulose, hemicellulose, and lignin are its cellulose components, and its minerals include iron, magnesium, calcium, manganese, copper, and nickel. Furthermore, when bamboo leaves are burned, silanol groups (Si-OH) are extracted, which become SiO4 during the burning process. Bamboo and its leaves contain particularly high amounts of silicic acid, and the amount of silicic acid varies depending on the time of harvest.

[0019]

[0020] Tables 2 and 3 are tables showing the component composition of rice husks as an example of the plant material 9 that is most suitable for the method of producing silica or carbon in the present invention, among the plant materials 9 in Table 1 described above.

[0021] Table 2 shows the percentages of the components that make up the raw material. For example, moisture is 8% to 10%, ash is 10% to 18%, lipids are 0.1% to 0.5%, lignin is 18% to 25%, hemicellulose is 16% to 20%, cellulose is 30% to 35%, and others are 5% to 10%. Thus, the main components that become silica or carbon are lignin, hemicellulose, and cellulose.

[0022] Table 3 shows the chemical composition of the inorganic substances of the plant-derived raw material 9 shown in Table 2. The plant-derived raw material 9 shown in Table 2 contains 80 wt% organic substances such as cellulose and 20 wt% inorganic substances. The chemical composition of the inorganic substances in Table 3 is 92.14 wt% SiO2, 0.04 wt% Al2O3, 0.48 wt% CaO, 0.03 wt% Fe2O3, 3.2 wt% K2O, 0.16 wt% MgO, 0.18 wt% MnO, and 0.09 wt% Na2O. The plant-derived raw material 9 shown in Table 2 contains silicon dioxide (SiO ２ ) is included.

[0023] (Example 1) Next, an overview of the system of the present invention will be described with reference to Figures 1 and 2 for Example 1. Figure 1 is a schematic diagram of an exhaust utilization system 1. A heat exchange device 10, exemplified by a boiler, recovers heat generated in a combustion device 40 and sends the heat energy to a thermal energy utilization facility 20.

[0024] The thermal energy utilization facility 20 is not limited to a facility, and may be a manufacturing facility or machine provided outside the waste utilization system 1, and may be used to dry the plant-derived raw material 9 to be input.

[0025] In the present invention, steam is used as an example of the medium for recovering thermal energy, but other materials such as hot water in a gas-liquid two-phase flow may also be used, as well as gases such as carbon dioxide, low-boiling substances with a boiling point lower than that of water (such as a mixture of water and ammonia), or oil.

[0026] The thermal energy recovered by these media is used in power generation facilities that generate electricity using steam power generation, binary power generation, etc. Also, greenhouses that use petroleum to grow flowers, vegetables, or fruits can use the thermal energy recovered by this system instead of the energy needed to burn petroleum, etc.

[0027] In addition to the above, the thermal energy recovered by these media can be used for heating equipment, providing hot water, drying equipment for grains, etc. It can also be used for initial warm-up of equipment for manufacturing rubber and resin. These can be used to power steam boilers required in factories.

[0028] The heat exchanger 10 sends water from the water supply device 11 to the gas-liquid separator 13. The heat exchanger 10 sends the water sent to the gas-liquid separator 13 to the water tank 12 as make-up water and heat exchange means.

[0029] The water 15 sent to the water tank 12 absorbs heat from within the combustion device 40 through a steam pipe 49 serving as a pipe-like heat exchange means within the combustion device 40 and the water tank 12, converting the water into steam 16, which is then sent to the gas-liquid separator 13. The heat exchanger 10 sends steam 17 from the gas-liquid separator 13 to the thermal energy utilization facility 20.

[0030] Next, a description will be given of the recovery of carbon dioxide 33. Exhaust gas 35 generated when the plant-based raw material 9 is combusted by the combustion device 40 contains tar produced when the organic matter is burned and is mixed with carbon dioxide 33 gas, and is discharged from an exhaust pipe (not shown).

[0031] Therefore, when exhausting, clean carbon dioxide 33 is sent to the carbon dioxide utilization facility 30 through a filter device 31. The filter device 31 uses water, activated carbon, rice husks, rice husk ash, etc. as a filter. In particular, rice husk ash and rice husks have a BET specific surface area of ​​300 m ２ / g~1200m ２ / g, the amount of physical adsorption is large.

[0032] Furthermore, rice husk charcoal carbonized at temperatures between 400°C and 800°C is also excellent at chemically absorbing ammonia and the like, making it ideal for filters.

[0033] The combustion device 40 described in the embodiment is a schematic diagram of a continuous combustion furnace as an example, as shown in Figure 2. The organic matter decomposition zone 42, which is the first zone after the material is introduced through the inlet 45, preferably has a temperature of 300°C to 600°C for decomposing and combusting organic matter such as cellulose and lignin. Therefore, organic matter such as cellulose is actively combusted, and a large amount of carbon dioxide 33 is also emitted.

[0034] The temperature near the outlet 47 depends on the material being extracted, but an optimum temperature is between 600°C and 1300°C when extracting silica or carbon. In particular, when the plant-based material 9 is baked at a temperature of 600°C or higher, it can spontaneously combust, eliminating the need for additional fuel. It is desirable to install a heat exchanger in the spontaneous combustion region 43 in this spontaneous combustion state.

[0035] Next, a combustion device 40 incorporating the heat exchange device 10 of Fig. 1 will be described with reference to Fig. 2. The same components as those described above are designated by the same reference numerals and will not be described again.

[0036] In the combustion device 40 shown in FIG. 2 , trays carrying plant-based materials 9 on a conveyor belt 53 are placed on the conveyor belt 53 between rollers R by a drive motor 52 from an entrance 45 or the plant-based materials 9 are conveyed to an exit 47 .

[0037] The combustion device 40 is provided with heater devices 55 for burning the plant-based material 9 above and below the conveyor belt 53. The heater devices 55 may be electric heaters, induction heaters, plasma heaters, gas heaters, or the like.

[0038] The combustion device 40 incorporates the heat exchange device 10 as an integral part, and in particular, the spontaneous combustion area 43 where the plant-derived raw material 9 burns spontaneously is provided with a water tank 12 that serves as stored water and heat exchange means, and a steam pipe 49 that also serves as heat exchange means.

[0039] The water tank 12 and steam pipe 49, which are heat exchange means, are provided around the conveyor belt 53. In particular, the steam pipe 49 passes along the side of the conveyor belt 53, and the water tank 12 is disposed immediately below the conveyor belt 53.

[0040] The combustion device 40 has a plurality of compartments each having different temperature zones. The first compartment, an organic matter decomposition zone 42, preferably has a temperature of 300°C to 600°C for decomposing and combusting organic matter such as cellulose and lignin.

[0041] Next, the temperature in the preparation region 44 for spontaneous combustion is preferably 600°C to 1300°C, and the temperature is raised to a level at which the plant material 9 will spontaneously combust without the need for heat. Here, spontaneous combustion refers to the natural continuation of combustion of the organic matter in the plant material 9 itself.

[0042] The heat exchanger 10 is integrated into the spontaneous combustion area 43 where the fuel burns spontaneously, and a water tank 12 serving as stored water and heat exchange means and a steam pipe 49 serving as heat exchange means are provided.

[0043] The organic matter decomposition zone 42 is provided near the inlet and has a plurality of temperature zones ranging from 200° C. to 600° C. The exhaust gas 35 discharged from this zone is a gas containing carbon dioxide 33.

[0044] Furthermore, this gas contains organic tar, which becomes liquid tar when cooled. Since this tar easily clogs the filter device 31, it is recommended to use a filter with excellent chemical or physical adsorption properties, such as rice husk ash or activated carbon.

[0045] The carbon dioxide 33 that has passed through the filter device 31 is discharged in a clean state from an exhaust port and sent to the carbon dioxide utilization facility 30. Exhaust gas 35 may be collected not only from the organic decomposition zone 42 but also from the preparation zone 44 and the spontaneous combustion zone 43.

[0046] (Embodiment 2) Next, an outline of the system of the present invention will be described with reference to Figures 3 and 4 for embodiment 2. The same components as those in embodiment 1 are designated by the same reference numerals and will not be described again. Figure 3 is a schematic diagram of an exhaust utilization system 1. In Figure 4, a heat exchanger 10 recovers heat generated in a combustion device 40 and sends thermal energy to.

[0047] In the present invention, water is used as an example of the medium for recovering thermal energy, but other possible media include hot water such as a gas-liquid two-phase flow, gases such as carbon dioxide, low-boiling substances with a boiling point lower than that of water (such as a mixture of water and ammonia), and oil.

[0048] The thermal energy recovered by these media is used in power generation facilities that generate electricity using steam power generation, binary power generation, etc. Also, greenhouses that use petroleum to grow flowers, vegetables, or fruits can use the thermal energy recovered by this system instead of the energy needed to burn petroleum, etc.

[0049] In addition, the thermal energy recovered by these media can be used for heating facilities, hot water use, drying facilities for grains, etc. It can also be used for initial warm-up of equipment for manufacturing rubber or resin.

[0050] The heat exchange device 10 sends water 14 from a water supply device 11 to a hot water tank 18, which serves as heat exchange means, by a drive pump M. Hot water 16 heated in the hot water tank 18 is sent to a second heat exchanger 21. The second heat exchanger 21 exchanges heat with a second medium 23, and the resulting thermal energy is utilized in a thermal energy utilization facility 20. The second heat exchanger 21 returns a drain 19 from the second heat exchanger 21 to the water supply device 11.

[0051] Next, a combustion device 40 incorporating the heat exchange device 10 of Fig. 3 will be described with reference to Fig. 4. The same components as those described above are designated by the same reference numerals and will not be described again. Only the differences from the first embodiment will be described below.

[0052] The combustion device 40 has the heat exchange device 10 built in as an integral part, and in particular, a hot water tank 18 serving as stored water and heat exchange means is provided in the spontaneous combustion area 43 where the plant material 9 burns spontaneously.

[0053] A hot water tank 18, which is a heat exchange means, is provided around the conveyor belt 53. In particular, the hot water tank 18 is disposed immediately below the conveyor belt 53.

[0054] (Embodiment 3) Next, an overview of the system of the present invention will be described for embodiment 3 with reference to Fig. 5. The same components as those in the above-described embodiments 1 and 2 are designated by the same reference numerals and will not be described again. Only the differences from embodiments 1 and 2 will be described below.

[0055] 5 differs from the first and second embodiments in that the gas-liquid separator 13 is provided externally. In this embodiment, in order to transport thermal energy to a distant location for use at the facility, the hot water in the hot water tank 18 is pressurized by a water supply motor to increase the pressure above the saturated vapor pressure, and the hot water is converted into a single-phase flow of water (or liquid for other media) and transported to the thermal energy utilization facility 20.

[0056] The hot water tank 18, which is a heat exchange means, is transported to the thermal energy utilization facility 20, where steam 17 is generated in the gas-liquid separator 13. This makes it possible to transport the water long distances while minimizing heat loss. The drain 19 from the gas-liquid separator 13 is then returned to the water supply device 11.

[0057] The waste utilization system 1 of the present invention is a system capable of transporting thermal energy over long distances.

[0058] The heat exchanger 10 is equipped with a drive pump M, and is preferably located in a location where maintenance is as easy as possible. For example, it may be located away from the conveyor belt 53 and away from the heat source, but it is preferable to locate it as close as possible to the heater device 55 of the combustion device.

[0059] (Embodiment 4) Next, an overview of the system of the present invention will be described for embodiment 4 with reference to Fig. 6. The same components as those in the above-described embodiments 1 to 3 are designated by the same reference numerals and will not be described again. Only the differences from embodiments 1 to 3 will be described below.

[0060] The exhaust utilization system 1 shown in Fig. 5 differs from the first and second embodiments in that the hot water heat-exchanged in the combustion device 40 is utilized in a complementary manner and a boiler device is provided externally. The combustion device 40 is also structurally different.

[0061] Figure 6 shows the combustion device 40. The combustion device 40 is equipped with a hot water tank 18 for heat exchange or a heat absorption tube. Normally, an alumina porcelain hot plate is provided on the entire wall surface to cover the heater device 55. However, near the hot water tank 18 (the upper heat exchange means), an alumina porcelain hot plate is not provided near the exhaust port. Instead, an exhaust duct is provided, and heat drawn by the exhaust gas due to negative pressure is absorbed by the hot water tank 18 to heat the medium. Furthermore, when the thermal energy from spontaneous combustion is insufficient, the heater device 55 is extended to the spontaneous combustion region 43 as a supplementary measure to completely combust the organic matter.

[0062] With the above-described structure, the thermal energy obtained by heat exchange within the combustion device 40 can be effectively utilized as hot water for external boiler equipment or air conditioning equipment.

[0063] <Method for Producing Silica> Next, a method for producing silica (also called silicon dioxide) using the systems of Examples 1 to 3 described above and rice husks from the plant-based raw material 9 of this embodiment will be described with reference to FIG. 7 .

[0064] The plant-based raw material 9 is pulverized (S41). Since the fine particle size is obtained in the fine pulverization step (S45), the pulverization is sufficient to allow water to penetrate the inside of the plant-based raw material 9. Furthermore, since the plant-based raw material 9 undergoes the dehydration step (S43), the pulverization is sufficient as long as the pulverized particles are small enough not to slip through the meshes of the dehydration container. The optimal size after pulverization is approximately 5 to 10 mm. Examples of pulverization methods include a mill, a mixer, and a grinder.

[0065] Next, the crushed plant-based raw material 9 (S41) is washed with water (S42). For example, the rice husks are soaked in pure water. After soaking the rice husks for about a day, stones, mud, etc. are washed away. The liquid temperature is preferably between room temperature and 80°C. The water washing (S42) may be performed by pouring water and then stirring. Alternatively, washing may be performed by pouring water little by little while stirring.

[0066] Next, the washed plant-derived raw material 9 is placed in a dehydration vessel and dehydrated using a rotary dehydrator such as a washing machine (S43). The rotation speed during dehydration is preferably 300 to 3000 rpm, and most preferably 500 to 1500 rpm.

[0067] Dehydration removes impurities along with the water. It is then possible to move on to the next firing process without going through the drying process. It has been confirmed that this dehydration process by rotation also promotes the decomposition of the rice husk structure, making it possible to move on to the next process without going through the drying process. This has made it possible to reduce manufacturing time by eliminating processes.

[0068] Next, in the firing step (S44), the plant-derived raw material 9 is placed in the combustion device 40, the inside of the furnace is brought to atmospheric pressure so that oxygen can be supplied, and the plant-derived raw material 9 is burned at a temperature of 300°C to 600°C in the organic matter decomposition zone 42.

[0069] After that, the furnace is made ready to supply oxygen, the temperature inside the furnace is raised to 600°C, and after maintaining the temperature at 600°C for a fixed period of about 1 to 3 hours, the temperature inside the furnace is raised to between 700°C and 1000°C, after which the rice husks themselves are naturally fired, resulting in a total firing time of several hours to one day.

[0070] After that, the fire naturally goes out, and the burned silica 5 is removed from the combustion device. After the combustion holding time has passed, there is no need to use energy, which reduces costs. By maintaining the temperatures of 300°C and 600°C, which require the most energy when burning rice husks, for a certain period of time, the silica can be completely burned, improving the purity of the silica.

[0071] Next, the silica 5 is pulverized in the same manner as in S5 described above (S45). The pulverized silica 5 has a particle size distribution ranging from 5 to 20 μm. The silica can be pulverized using a jet mill, a ball mill, a bead mill, or the like.

[0072] Next, melting and spheroidizing is carried out in the same manner as in S6 described above (S46). In the plasma or gas thermal spraying method, crushed silica powder is supplied into a high-temperature flame of 2000°C or higher to melt the silica, and the molten silica, which has been spheroidized by surface tension, is rapidly cooled to obtain spherical silica particles. Because the molten silica is rapidly cooled, the obtained spherical silica particles become amorphous.

[0073] Alternatively, the silica 5 may be spheroidized by a molten flame method, and the temperature of the flame treatment is 1750° C. to 2500° C. Alternatively, spray drying may be used as a spheroidization method.

[0074] In addition, in the plasma melting process, a large volume of thermal plasma is generated and melted at a high temperature exceeding 10,000° C. by a high-frequency induction plasma method, thereby producing a spherical powder of silica 5 with high sphericity. Then, in the final stage, amorphous spherical silica particles 11 are produced (S47).

[0075] <Method for Producing Carbon> Next, a method for producing carbon 7 using the systems of Examples 1 to 3 and wheat husks, which are part of the plant-based raw material 9 of this embodiment, will be described with reference to Fig. 8. This method is particularly suitable for producing carbon 7 used as a conductive material.

[0076] The plant-based raw material 9 is pulverized. Since microparticulation is performed last, this step requires only pulverization to the extent that the particles penetrate the interior of the plant when immersed in water. Furthermore, since the dehydration step will be performed, the particles should be small enough to not slip through the slits or holes. The optimal size after pulverization is approximately 5 mm to 10 mm. Examples of pulverization methods include mills, mixers, grinders, etc. Furthermore, a specific pulverization step is not necessary; it is sufficient that water or the like penetrates the raw material during washing.

[0077] Next, the crushed plant-based raw material 9 is washed with water (S22). For example, the rice husks are soaked in pure water. After soaking the rice husks for about one hour to one day, stones, mud, etc. are washed away. The liquid temperature is preferably between room temperature and 80°C. The water washing (S22) may be carried out by pouring water and then stirring with a stirrer. Alternatively, washing may be carried out by pouring water little by little while stirring. For stirring, a vortex device or a device that stirs by rotating blades may be used, or a stirrer device may be used.

[0078] Next, the washed plant-derived raw material 9 is placed in the dehydration vessel described above and dehydrated using a rotary dehydrator such as a washing machine (S23). The rotation speed during dehydration is preferably 300 to 3000 rpm, and most preferably 500 to 1500 rpm.

[0079] The optimal gravitational acceleration during centrifugation by the spin-drying device is approximately 2 G to 5 G. The spin-drying device may be the same device for all steps from washing to rinsing and spin-drying (S22 to S23), or may have a structure in which the spin-drying container is housed or attached.

[0080] Dehydration removes impurities along with the moisture. The plant-based raw material 9 can then be moved to the next baking step while still wet, without going through a drying step. It has been confirmed that this dehydration step by rotation also promotes decomposition of the plant-based raw material 9's tissue, allowing it to proceed to the next step without a drying step.

[0081] Therefore, it became possible to reduce the manufacturing time by eliminating the drying process. Furthermore, when the water is removed by centrifugation during dehydration, the destruction of the cell walls of the plant raw material 9 is promoted, and the destruction reaches further inside.

[0082] Therefore, even in the examples, if rotary dehydration is performed, the drying step is not necessarily required, but drying further reduces the impact of rust, etc. on the combustion equipment. Also, compared to the step of activating the material together with a solid alkaline material, the impact on the combustion equipment is even less.

[0083] Next, in the firing step (S24), the plant-based raw material 9 is placed in a furnace, which is filled with argon gas or nitrogen gas to create an oxygen-free environment, and the temperature inside the furnace is raised to 1100°C and maintained at 1100°C for a fixed period of time of about 1 to 10 hours. Thereafter, the plant-based raw material 9 is naturally fired for a total firing time of 1 day. This produces carbon 7.

[0084] Furthermore, in the baking step (S24), the plant-derived raw material 9 after the dehydration step (S23) is not completely dried, but rather remains slightly moist when it is transferred to the baking step (S24). Therefore, so-called steam activation occurs in the initial stage, which leads to the destruction and decomposition of cell walls.

[0085] Furthermore, steam activation generates micropores, making it easier to form a porous material similar to activated carbon. In the calcination step (S24), it is advisable to use a rotary kiln-type carbonization device, an induction heating furnace, an electric furnace, a continuous carbonization furnace, or the like.

[0086] Furthermore, during the water washing (S22), the plant-derived raw material 9 is placed in a container such as a pressure cooker, and pressure is applied to the plant-derived raw material 9 together with water at 2 to 2.45 atmospheres, and a temperature of 120 to 128°C is applied, which quickly destroys the cell walls of the plant-derived raw material 9, leading to the removal of impurities and an improvement in purity.

[0087] The silica or carbon obtained by such a production method was carbonized as each simple substance, and the specific surface area was measured using the BET adsorption isotherm based on the amount of nitrogen adsorbed at liquid nitrogen temperature.

[0088] The first plant raw material 11, such as bamboo or rice husk, has a specific surface area of ​​300 m ２ / g~1200m ２ In particular, by adding a material with a large specific surface area, it is possible to add a function of easily adsorbing water. ２ / g or more is preferred.

[0089] Wheat and barley husks, cocoa husks, sake lees, shochu lees, beer lees, etc. are 15m ２ / g to 80m ２ / g. Wheat and barley husks, shochu lees, and beer lees were 15m ２ / g to 35m ２ The sake lees were 40 ml ２ / g to 70m ２ / g. The cocoa shells were 45m ２ / g to 75m ２ / g.

[0090] Such a small specific surface area is ideal for maintaining the strength of the rubber as a reinforcing material. If it is too large, it will absorb too much chemicals, etc., so it is recommended to use a surface area of ​​100m. ２ / g or less is preferred.

[0091] The conductive properties of each carbonized silica or carbon were measured by measuring the resistance value of the powder. －２ Ω cm, sake lees is 2.5 x 10 －２ Ω cm, and cocoa shells are 2.5 x 10 －２ Ω cm, and rice husk charcoal is 2.3 × 10 －２ The powder resistance values ​​of wheat and barley husks, cocoa husks, sake lees, shochu lees, and beer lees are approximately 1 to 5 × 10 －２ It is Ω·cm.

[0092] In addition, the purity of wheat and barley husks, shochu lees, and beer lees was 70% wt to 85% wt of C (carbon), 3 wt% to 15 wt% of Si (silicon), and the remaining metal impurities were 0.7 wt% to 1.7 wt% of Na, 0.7 wt% to 1.7 wt% of Mg, 1.5 wt% to 4 wt% of P and K, and 0.35 wt% to 1.0 wt% of Ca.

[0093] Furthermore, to further improve the purity of wheat and barley husks, shochu lees, and beer lees, acid treatment with hydrofluoric acid or the like resulted in C (carbon) of 86% to 95% wt., Si (silicon) of 3 to 9 wt., and the remaining metal impurities were K of 0.35 to 7 wt.

[0094] (Technical Features) Examples of technical features of this embodiment are shown below in parentheses, but these are not particularly limiting and are merely examples, and the effects expected from these features will also be described.

[0095] <Feature 1> The system includes a combustion device (e.g., mainly a combustion device 40) used when producing silica or carbon from plant-based raw materials (e.g., mainly a plant-based raw material 9), and a thermal energy recovery device (e.g., mainly a heat exchanger 10) that absorbs heat inside the combustion device and recovers thermal energy, and the thermal energy recovery device recovers thermal energy generated when the plant-based raw materials combust.

[0096] The above features make it possible to effectively utilize waste materials while producing materials such as silica and carbon without using extra energy.

[0097] <Feature 2> A steam conversion device (e.g., mainly a heat exchange means (steam pipe 49)) that converts a medium into steam is provided around a conveying device (e.g., mainly a conveying belt 53) that conveys the plant-based raw material that burns itself, and the medium is sent from the steam conversion device to a gas-liquid separation device (e.g., mainly a gas-liquid separation device 13) that separates the medium into gas and liquid.

[0098] These features make it possible to effectively utilize waste materials while producing materials such as silica and carbon without using extra energy. Also, it is possible to efficiently absorb heat energy from a location close to the transport device.

[0099] <Feature 3> The waste utilization system according to claim 1, characterized in that a heat exchanger (e.g., mainly a heat exchange means (hot water tank 18)) that transfers heat to a medium is provided around the transport device that transports the self-combusting plant-based raw material, and the liquid medium that accumulates the thermal energy obtained by the heat exchange is transported to an external facility (e.g., mainly a thermal energy utilization facility 20) by a drive pump (e.g., mainly a drive pump M).

[0100] These features make it possible to effectively utilize the waste while producing materials such as silica and carbon without using extra energy. In addition, the liquid medium makes it easy to handle.

[0101] The medium is transported by the drive pump in a single-phase flow state with a pressure equal to or greater than the saturated vapor pressure.

[0102] These features allow for the effective use of waste materials while producing materials such as silica and carbon without using extra energy. In addition, because it is a single-phase flow, there is little heat loss and it can be easily transported to equipment or facilities.

[0103] The incinerator includes a combustion device (e.g., mainly a combustion device 40) used when producing silica or carbon from plant-based raw materials (e.g., mainly a plant-based raw material 9), and a carbon dioxide capture device (e.g., mainly an exhaust pipe and filter device 31) that captures carbon dioxide inside the incinerator, and the carbon dioxide capture device is characterized by capturing carbon dioxide (e.g., mainly carbon dioxide 33) emitted from a temperature range where organic matter is most combustible when the plant-based raw materials are combusted.

[0104] The above features make it possible to effectively utilize waste materials while producing materials such as silica and carbon without using extra energy.

[0105] The temperature range in which the organic matter burns most is between 300°C and 600°C.

[0106] These features make it possible to effectively utilize waste materials while producing materials such as silica and carbon without using extra energy. Also, since carbon dioxide is emitted in the largest amount, it is possible to absorb a large amount of carbon dioxide.

[0107] The recovered carbon dioxide is used in a facility for growing plants.

[0108] The above features make it possible to effectively utilize waste materials while producing materials such as silica and carbon without using extra energy. Furthermore, by utilizing carbon dioxide in the plant-growing facility, it is possible to utilize a large amount of carbon dioxide. It is also an effective system for reducing carbon dioxide.

[0109] The carbon dioxide capture device is characterized by including a filter device (for example, mainly the filter device 31) that uses rice husk charcoal or rice husks.

[0110] The above features make it possible to effectively utilize waste materials while producing materials such as silica and carbon without using extra energy.In addition, since plant-based raw materials and the products produced by this system can be used as they are, this is an ideal system for utilizing plant-based waste.

[0111] The carbon dioxide recovery device is characterized by including a filter device (for example, mainly a filter device 31) that recovers carbon dioxide through water.

[0112] These features make it possible to effectively utilize the waste while producing materials such as silica and carbon without using extra energy. In addition, by using water, it is possible to recover carbon dioxide beyond the saturation point that could not be dissolved in water, and the carbon dioxide dissolved in the water can also be effectively utilized later.

[0113] The waste utilization system of the present invention can be used in various energy facilities such as manufacturing equipment and air conditioning in manufacturing facilities, as well as factories and the like that require carbon dioxide.

[0114] 1...Emission utilization system, 5...Silica, 7...Carbon, 9...Plant-based raw material, 10...Heat exchange device, 13...Gas-liquid separator, 18...Hot water tank, 20...Thermal energy heat utilization facility, 30...Carbon dioxide utilization facility, 31...Filter device, 33...Carbon dioxide, 40...Combustion device, 42...Organic matter decomposition area, 43...Spontaneous combustion area, 49...Steam pipe, 53...Conveyor belt, M...Drive pump.

Claims

1. A waste utilization system comprising: a combustion device used in producing silica or carbon from plant-based raw materials; and a thermal energy recovery device that absorbs heat inside the combustion device and recovers thermal energy, wherein the thermal energy recovery device recovers thermal energy generated when the plant-based raw materials are combusted themselves.

2. The waste utilization system described in claim 1, characterized in that a steam conversion device that converts the medium into steam is provided around the transport device that transports the plant-based raw material that burns itself, and the medium is sent from the steam conversion device to a gas-liquid separation device that separates the medium into gas and liquid.

3. The waste utilization system described in claim 1, characterized in that a heat exchanger that transfers heat to a medium is provided around the transport device that transports the plant-based raw material that burns itself, and the liquid medium that accumulates the thermal energy obtained by the heat exchange is transported to external equipment by a drive pump.

4. The waste utilization system according to claim 3, wherein the medium is transported by the drive pump in a single-phase flow state with a pressure equal to or greater than the saturated vapor pressure.

5. A system for utilizing exhaust materials, comprising: a combustion device used in producing silica or carbon from plant-based raw materials; and a carbon dioxide recovery device that recovers carbon dioxide inside the incinerator, wherein the carbon dioxide recovery device recovers carbon dioxide emitted from the temperature range in which organic matter is most combustible when the plant-based raw materials are burned.

6. The waste utilization system according to claim 5, characterized in that the temperature range in which the organic matter burns most is between 300°C and 600°C.

7. The waste utilization system according to claim 5, characterized in that the recovered carbon dioxide is utilized in a plant-growing facility.

8. The exhaust utilization system according to claim 5, characterized in that the carbon dioxide capture device is equipped with a filter device using rice husk charcoal or rice husks.

9. The exhaust utilization system according to claim 5, characterized in that the carbon dioxide recovery device is provided with a filter device that recovers carbon dioxide through water.

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