System for using emitted substance
The system addresses waste and emissions from plant-based fuel by integrating a combustion device with thermal and carbon dioxide recovery, enabling efficient production of silica and carbon while reducing emissions and waste.
Patent Information
- Application Number
- JP2024058599
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-04-01
- Publication Date
- 2025-10-14
AI Technical Summary
The disposal of ash generated from plant-based raw materials used as fuel leads to significant waste and carbon dioxide emissions, necessitating a system that can effectively utilize thermal energy and carbon dioxide produced during their combustion.
A system comprising a combustion device that produces silica or carbon from plant-based materials, integrated with a thermal energy recovery device to absorb and recover heat, and a carbon dioxide recovery device to capture and utilize emissions, utilizing a heat exchanger and filter device to efficiently convert and utilize thermal energy and carbon dioxide.
The system effectively utilizes waste materials to produce silica and carbon while reducing carbon dioxide emissions by recovering thermal energy and capturing carbon dioxide without additional energy input, making it an efficient and sustainable process.
Smart Images

Figure 2025155128000001_ABST
Abstract
Description
[Technical Field]
[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. [Background technology]
[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 described above, various inventions have been proposed as methods for producing carbon materials from plant-derived 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. It also describes 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 the 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 has 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 introduction 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. [Prior art documents] [Patent documents]
[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-362915 [Patent Document 2] Japanese Patent Application Laid-Open No. 2024-3488 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]
[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. [Means for solving the problem]
[0008] A combustion device used in producing silica or carbon from plant-based raw materials; a thermal energy recovery device that absorbs heat inside the combustion device and recovers thermal energy, The thermal energy recovery device is characterized by recovering thermal energy generated when the plant-derived raw material itself is combusted. [Effects of the Invention]
[0009] The above features make it possible to effectively utilize waste materials while producing materials such as silica and carbon without using extra energy. [Brief explanation of the drawings]
[0010] [Figure 1] 1 is a schematic diagram of an exhaust utilization system according to an embodiment. [Figure 2] 1 is an example of a combustion device according to an embodiment. [Figure 3] 1 is a schematic diagram of an exhaust utilization system according to an embodiment. [Figure 4] 1 is an example of a combustion device according to an embodiment. [Figure 5] 1 is a schematic diagram of an exhaust utilization system according to an embodiment. [Figure 6] 1 is an example of a combustion device according to an embodiment. [Figure 7] 1 is a process flow of silica in an embodiment. [Figure 8] 1 is a process flow of carbon according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION
[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 materials> The plant-based raw material 9 for producing silica or carbon will be described. The present invention produces silica or carbon as a final product using food residues or discarded plant-based raw material 9. Plants, wood, etc. are used as the plant-based raw material 9, but if discarded plant-based raw material 9 such as residues from harvesting plants is used as the raw material for producing graphene, it is possible to obtain the raw material at low cost. [Table 1]
[0013] Table 1 is a list of the ingredients of plant-based raw materials 9. Table 1 shows the proportions of the ingredients that make up the raw materials shown on the left, with the percentages shown 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 plant-derived silicon-containing porous plant raw material 9 undergoes no 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-based raw materials 9 containing 10% or more of silica include rice husks, bamboo, and horsetail, and those with a high silica content of 13% or more and 35% or less are suitable. When silica is required, these plant-based raw materials 9 are the best.
[0017] Examples of plant-based raw materials9 that contain a high amount of organic matter are shown in Table 1. Among these, plant-based raw materials9 with a silica content of 10% or less 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 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's cellulose is made up of cellulose, hemicellulose, and lignin, and its minerals include iron, magnesium, calcium, manganese, copper, and nickel. Furthermore, when bamboo leaves are burned, silanol groups (Si-OH) are extracted and become SiO4 during the burning process. In particular, silicic acid is found in large amounts in bamboo and bamboo leaves, and the amount of silicic acid varies depending on the time of harvest.
[0019] [Table 2] [Table 3]
[0020] Tables 2 and 3 are tables showing the component composition of rice husks as an example of the plant raw material 9 most suitable for the method of producing silica or carbon in the present invention, among the plant raw 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 matter in plant-based raw material 9 shown in Table 2. Plant-based raw material 9 shown in Table 2 is 80 wt% organic matter such as cellulose, and 20 wt% inorganic matter. The chemical composition of the inorganic matter 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. Plant-based raw material 9 shown in Table 2 contains a large amount of silicon dioxide (SiO2) in its inorganic matter.
[0023] Example 1 Next, an outline of the system of the present invention will be described with reference to FIG. 1 and FIG. 2 for a first embodiment. 1 is a schematic diagram of an exhaust utilization system 1. A heat exchanger 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 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 the steam pipe 49, which serves 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 the steam 17 within the gas-liquid separator 13 to the thermal energy utilization facility 20.
[0030] Next, we will explain how to recover carbon dioxide 33. Exhaust gas 35 generated when the plant-based raw material 9 is combusted by the combustion device 40 contains tar from the burning of organic matter 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 a 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 300m 2 / g~1200m 2 / g, so the amount of physical adsorption is large.
[0032] Furthermore, rice husk charcoal carbonized at temperatures between 400 and 800°C is also excellent at chemically absorbing ammonia and other substances, 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 material is introduced through an 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, resulting in the emission of large amounts of carbon dioxide 33.
[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 given the same reference numerals and will not be described again.
[0036] In the combustion device 40 shown in FIG. 2, a tray carrying plant-based material 9 on a conveyor belt 53 is placed on the conveyor belt 53 between rollers R by a drive motor 52 from an entrance 45, or the plant-based material 9 is 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-based 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 burning organic matter such as cellulose and lignin.
[0041] Next, in the preparation region 44 for spontaneous combustion, the temperature 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 additional 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 located near the inlet and has multiple 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. This tar tends to clog the filter device 31, so 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 outlet and sent to the carbon dioxide utilization facility 30. Exhaust 35 may be collected from the preparation zone 44 and the pyrolysis zone 43 as well as the organic destruction zone 42 .
[0046] Example 2 Next, an outline of the system of the present invention will be described for a second embodiment with reference to Figures 3 and 4. The same components as those in the first embodiment will be assigned the same reference numerals and will not be described again. Fig. 3 is a schematic diagram of the exhaust utilization system 1. In Fig. 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 exchanger 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 drain 19 from 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 given 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, the spontaneous combustion area 43 where the plant material 9 burns spontaneously is provided with a hot water tank 18 serving as stored water and heat exchange means.
[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] Example 3 Next, an overview of the system of the present invention will be described for a third embodiment with reference to Fig. 5. The same components as those in the first and second embodiments are designated by the same reference numerals and will not be described again. Only the differences from the first and second embodiments will be described below.
[0055] The effluent utilization system 1 shown in Figure 5 differs from the first and second embodiments in that a gas-liquid separator 13 is provided externally. In this embodiment, in order to transport thermal energy to a distant location and utilize it at a facility, the hot water in the hot water tank 18 is pressurized by a water supply motor, and the pressure is increased to a value equal to or greater than the saturated vapor pressure, forming a single-phase flow of water (or liquid for other media) which is then 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 that can transport thermal energy over long distances.
[0058] The heat exchanger 10 is provided with a drive pump M, which is preferably located in a place where maintenance is as easy as possible. For example, it should be located in a place away from the conveyor belt 53 and away from the heat source.
[0059] Example 4 Next, an overview of the system of the present invention will be described for a fourth embodiment with reference to Fig. 6. The same components as those in the first to third embodiments are designated by the same reference numerals and will not be described again. Only the differences from the first to third embodiments 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] Fig. 6 shows the combustion device 40. The combustion device 40 is equipped with a hot water tank 18 for heat exchange or a pipe for absorbing heat. In this case, an alumina porcelain hot plate is usually provided on the entire wall surface to cover the heater device 55, but in the vicinity of the hot water tank 18, which is the upper heat exchange means, an alumina porcelain hot plate is not provided only near the exhaust port, and an exhaust duct is provided so that the heat drawn by the exhaust due to negative pressure is absorbed into the hot water tank 18 and heats the medium. Also, when the thermal energy from spontaneous combustion is insufficient, the heater device 55 is extended to the spontaneous combustion region 43 as a supplement to completely burn 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] <Silica manufacturing method> Next, a method for producing silica (also called silicon dioxide) using the systems of Examples 1 to 3 described above and rice husks, which are one of the plant raw materials 9 of this embodiment, will be described with reference to FIG.
[0064] The plant-derived raw material 9 is pulverized (S41). The fine particles are formed in the fine pulverization step (S45), which requires only pulverization to the extent that water can penetrate the particles. Since the plant-derived raw material 9 will be subjected to the dehydration step (S43), the particles should be small enough to not 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, mixer, grinder, etc.
[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 container and dehydrated in a rotary dehydration device 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 in the organic matter decomposition region 42 at a temperature of 300 to 600°C.
[0069] After that, oxygen is supplied, the temperature inside the furnace is raised to 600°C, and after maintaining the temperature at 600°C for a certain 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, and the total firing time is reduced to several hours to a day.
[0070] After the fire has died down naturally, the burned silica 5 is removed from the combustion device. Once 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 (S45) in the same manner as in S5 described above. The pulverized silica 5 has a particle size distribution ranging from 5 to 20 μm. Methods for pulverizing this silica include jet mills, ball mills, and bead mills.
[0072] Next, melting and spheroidizing are carried out in the same manner as in S6 described above (S46). In plasma or gas thermal spraying, crushed silica powder is fed 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 then rapidly cooled to obtain spherical silica particles. Because the molten silica is rapidly cooled, the resulting 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 plasma melting, 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 spherical powder of silica 5 with high sphericity. Then, in the final stage, amorphous spherical silica particles 11 are produced (S47).
[0075] <Carbon manufacturing method> Next, a method for producing carbon 7 using the systems of Examples 1 to 3 and wheat husks, which are one of the plant-based raw materials 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 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 to 10 mm. Examples of pulverization methods include mills, mixers, grinders, etc. 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 performed by pouring water and then stirring with a stirrer. Alternatively, washing may be performed by adding water little by little while stirring. The stirring may be performed using a vortex device or a device that stirs by rotating blades, or a stirrer device or the like.
[0078] Next, the washed plant-derived raw material 9 is placed in the above-mentioned dehydration container and dehydrated in a rotary dehydration device 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] Furthermore, the gravitational acceleration during centrifugation by the spin-drying device is preferably about 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. This allows the plant-based raw material 9 to proceed to the next firing step while still wet, without going through a drying step. It has been confirmed that this rotational dehydration step 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 shorten the manufacturing time by eliminating the drying process. In addition, when the water is removed by centrifugation during dehydration, the destruction of the cell walls of the plant-derived raw material 9 is promoted, and the destruction progresses further to the 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. The temperature inside the furnace is raised to 1100°C and maintained at 1100°C for a fixed period of time, approximately 1 to 10 hours. The plant-based raw material 9 is then naturally fired for a total firing time of one 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, whereby the cell walls of the plant-derived raw material 9 are quickly destroyed, 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-based raw material 11, bamboo, rice husk, etc., has a specific surface area of 300 m 2 / g~1200m 2 / g. 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 / g. The sake lees were 40m 2 / g to 70m 2 / g. The cocoa shells were 45m 2 / g to 75m 2 / g.
[0090] This small specific surface area makes it ideal for maintaining strength as a reinforcing material for rubber. If it were too large, it would absorb too much chemicals, so it is recommended to limit the specific surface area to 100m. 2 / g or less is preferable.
[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 2.5×10 -2 Ω·cm, and cocoa shells are 2.5×10 -2 Ω·cm, and rice husk charcoal is 2.3×10 -2 The powder resistivity of wheat and barley husks, cocoa husks, sake lees, shochu lees, and beer lees is approximately 1 to 5 × 10 -2 Ω·cm.
[0092] In addition, the purity of wheat and barley husks, shochu lees, and beer lees was 70% to 85% wt of C (carbon), 3% to 15% wt of Si (silicon), and the remaining metal impurities were 0.7% to 1.7% Na, 0.7% to 1.7% Mg, 1.5% to 4% P and K, and 0.35% to 1.0% 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) contents of 86% to 95% by weight, Si (silicon) contents of 3 to 9% by weight, and the remaining metal impurities were K, which was 0.35 to 7% by weight.
[0094] (Technical features) Below, examples of the technical features of this embodiment are shown in parentheses, but they are not particularly limiting and are merely examples, and the effects that can be expected from these features will also be described.
[0095] <Feature 1> A combustion device (e.g., mainly a combustion device 40) used in producing silica or carbon from a plant-based raw material (e.g., mainly a plant-based raw material 9); a thermal energy recovery device (e.g., mainly a heat exchange device 10) that absorbs heat inside the combustion device and recovers thermal energy; The thermal energy recovery device is characterized by recovering thermal energy generated when the plant-derived raw material itself is combusted.
[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 converter (e.g., mainly a heat exchange means (steam pipe 49)) that converts the medium into steam is provided around a conveyor (e.g., mainly a conveyor belt 53) that conveys the plant-based raw material that burns itself, and the medium is sent from the steam converter to a gas-liquid separator (e.g., mainly a gas-liquid separator 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 described in claim 1 is characterized in that a heat exchange device (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 plant-based raw material that burns itself, and the liquid medium that accumulates the thermal energy obtained by 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 waste materials while producing materials such as silica and carbon without using extra energy. In addition, since it is a liquid medium, it is 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] A combustion device (e.g., mainly a combustion device 40) used in producing silica or carbon from a plant-based raw material (e.g., mainly a plant-based raw material 9); A carbon dioxide recovery device (e.g., mainly an exhaust pipe and filter device 31) for recovering carbon dioxide inside the incinerator is provided. The carbon dioxide recovery device is characterized by recovering carbon dioxide (for example, mainly carbon dioxide 33) emitted from the temperature range in which organic matter is most combustible when burning plant-derived raw materials.
[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 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 capture device is characterized by including a filter device (for example, mainly a filter device 31) that captures carbon dioxide through water.
[0112] These features make it possible to effectively utilize waste materials 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 saturation that could not be dissolved in water, and the carbon dioxide dissolved in the water can also be effectively utilized later. [Industrial Applicability]
[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. [Explanation of symbols]
[0114] 1. Wastewater utilization system, 5. Silica, 7. Carbon, 9. Plant-based raw materials 10... Heat exchanger, 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 decomposition area, 43...Self-combustion area, 49···Steam pipe, 53···Conveyor belt, M···Drive pump.
Claims
1. A combustion device used in producing silica or carbon from plant-based raw materials; a thermal energy recovery device that absorbs heat inside the combustion device and recovers thermal energy, The thermal energy recovery device is a waste utilization system that recovers thermal energy generated when the plant-based raw material itself is combusted.
2. The system for utilizing waste material according to claim 1, characterized in that a steam conversion device that converts the medium into steam is provided around a 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 heat exchange is transported to external equipment by a drive pump.
4. 4. The system for utilizing effluent 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 combustion device used in producing silica or carbon from plant-based raw materials; a carbon dioxide recovery device that recovers carbon dioxide inside the incinerator; The carbon dioxide recovery device is a system for utilizing exhaust materials, characterized in that it recovers carbon dioxide emitted when burning plant-based raw materials in the temperature range in which organic matter is most combustible.
6. 6. The waste utilization system according to claim 5, wherein the temperature range in which the organic matter burns most is between 300°C and 600°C.
7. 6. The system for utilizing waste matter according to claim 5, wherein the recovered carbon dioxide is utilized in a facility for growing plants.
8. 6. The exhaust utilization system according to claim 5, wherein the carbon dioxide capture device is provided with a filter device using rice husk charcoal or rice husks.
9. 6. The system for utilizing exhaust materials according to claim 5, wherein the carbon dioxide recovery device includes a filter device that recovers carbon dioxide through water.
Citation Information
Patent Citations
Carbon material and manufacturing method thereof and application thereof
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