Waste treatment system and waste treatment method

Abstract

To provide a waste disposal system and a waste disposal method that can reduce the cost of disposing of waste with a low moisture content.SOLUTION: This waste disposal system is provided with: at least one reforming device for hydrolyzing waste; and a microbial reaction device for converting reformed substances, which have been hydrolyzed by the at least one reforming device and which include at least solids, into small molecules by means of microbes.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a waste treatment system and a waste treatment method.

Background Art

[0002] Patent Document 1 describes a treatment apparatus for organic waste including organic drainage and solid waste such as excess sludge from a sewage treatment plant, food waste such as garbage, and livestock waste. In this treatment apparatus, organic waste is decomposed into soluble low-molecular-weight organic substances and then solid-liquid separated. The separated liquid is subjected to methane fermentation to generate biogas, and the separated solid is composted to generate fertilizer, thereby treating the organic waste.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when treating waste with a lower moisture content than the organic waste shown in Patent Document 1, such as municipal waste, even if the waste is hydrolyzed, most of the treated material is solid, so the amount of biogas generated in the treatment apparatus of Patent Document 1 decreases. Also, although not only fertilizers but also fuels etc. can be produced from the separated solids, since producing biogas is more profitable than producing fertilizers or fuels, there was a risk that the waste treatment cost in the treatment apparatus of Patent Document 1 would increase.

[0005] In view of the above circumstances, at least one embodiment of the present disclosure aims to provide a waste treatment system and a waste treatment method capable of reducing the treatment cost of waste with a low moisture content.

Means for Solving the Problems

[0006] To achieve the above objectives, the waste treatment system relating to this disclosure is The system includes a first and second modifying apparatus, a modifying apparatus for hydrolyzing waste, a solid-liquid separation apparatus for solid-liquid separation of the treated material, which is the waste hydrolyzed in the first modifying apparatus, a microbial reaction apparatus for depolymerizing the modified material, which contains at least solids, from the waste hydrolyzed in the modifying apparatus using microorganisms, and a separation apparatus between the second modifying apparatus and the microbial reaction apparatus for separating unsuitable substances from the modified material that are unsuitable for depolymerization by the microorganisms in the microbial reaction apparatus, wherein the second modifying apparatus hydrolyzes only the solids separated in the solid-liquid separation apparatus. .

[0007] Furthermore, the waste disposal method related to this disclosure is The process includes the steps of hydrolyzing waste, separating the treated material which is the hydrolyzed waste from a solid-liquid product, hydrolyzing only the solid separated in the solid-liquid separation step, and using microorganisms to reduce the molecular weight of a modified product which contains at least a solid from the hydrolyzed solid separated in the solid-liquid separation step, and between the hydrolysis step and the molecular weight reduction step, the process includes the step of separating unsuitable reaction substances from the modified product that are unsuitable for molecular weight reduction by the microorganisms in the molecular weight reduction step. . [Effects of the Invention]

[0008] According to the waste treatment system and waste treatment method of this disclosure, valuable materials can be produced by reducing the molecular weight of hydrolyzed waste using microorganisms without solid-liquid separation, thus enabling low-cost treatment even for waste with low moisture content. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram of the configuration of a waste treatment system according to Embodiment 1 of this disclosure. [Figure 2] This is a schematic diagram showing an example of the configuration of a waste treatment system modification device according to Embodiment 1 of this disclosure. [Figure 3] This is a schematic diagram showing another example of the configuration of a modification device in a waste treatment system according to Embodiment 1 of this disclosure. [Figure 4] This is a schematic diagram showing yet another example of the configuration of a modification device in a waste treatment system according to Embodiment 1 of the present disclosure. [Figure 5] This is a schematic diagram of the configuration of a waste treatment system according to Embodiment 2 of this disclosure. [Figure 6] This is a schematic diagram of a modified example of the waste treatment system according to Embodiment 2 of this disclosure. [Figure 7] This is a schematic diagram of the configuration of a waste treatment system according to Embodiment 3 of this disclosure. [Figure 8] This figure shows an example of spectral data acquired by a near-infrared sensor in a waste treatment system according to Embodiment 3 of this disclosure. [Figure 9]In the waste treatment system according to Embodiment 3 of the present disclosure, it is a diagram showing spectrum data of a plurality of reformed products with different contents of reaction-incompatible substances. [Figure 10] In the waste treatment system according to Embodiment 3 of the present disclosure, it is a diagram showing spectrum data of some reformed products with different reaction-incompatible substance concentrations. [Figure 11] It is a calibration curve of the reaction-incompatible substance concentration in the reformed product used in the waste treatment system according to Embodiment 3 of the present disclosure. [Figure 12] It is a schematic configuration diagram of the waste treatment system according to Embodiment 4 of the present disclosure. [Figure 13] It is a schematic configuration diagram of a part of a modified example of the waste treatment system according to Embodiment 4 of the present disclosure. [Figure 14] It is a schematic configuration diagram of the waste treatment system according to Embodiment 5 of the present disclosure. [Figure 15] It is a schematic configuration diagram of the waste treatment system according to Embodiment 6 of the present disclosure. [Figure 16] It is a schematic configuration diagram of a modified example of the waste treatment system according to Embodiment 6 of the present disclosure.

Mode for Carrying Out the Invention

[0010] Hereinafter, a waste treatment system and a waste treatment method according to an embodiment of the present disclosure will be described based on the drawings. Such an embodiment shows one aspect of the present disclosure, does not limit this disclosure, and can be arbitrarily changed within the scope of the technical idea of the present disclosure.

[0011] (Embodiment 1) <Configuration of the waste treatment system according to Embodiment 1 of the present disclosure> As shown in Figure 1, the waste treatment system 1 according to Embodiment 1 of this disclosure comprises a modifier 2 that hydrolyzes waste such as municipal solid waste in the presence of water or steam, and a microbial reactor 3 that decomposes the modified material hydrolyzed in modifier 2 into low-molecular-weight materials using microorganisms. Municipal solid waste, given as an example of waste, is characterized by its main components being food waste, paper waste, and plastic waste, with a small amount of metal and a relatively low moisture content. The waste treated by the waste treatment system 1 is not limited to municipal solid waste; it can also treat sludge generated from the treatment of wastewater from factories, agricultural waste, and other materials with a higher moisture content than municipal solid waste.

[0012] The reforming apparatus 2 accepts waste directly from a vehicle or plant that collects the waste, and hydrolyzes the waste in a batch manner using steam. Specifically, it is a batch-type reforming apparatus comprising a housing 10 that includes an input port 11 into which the waste is fed and an output port 12 into which the reformed material is discharged. The input port 11 and the output port 12 are each provided with on-off valves 18 and 19, and the housing 10 can be sealed by closing the on-off valves 18 and 19, respectively. The hydrolysis of the waste in the reforming apparatus 2 may be wet hydrolysis, in which steam comes into contact with the waste and heats it, or dry hydrolysis, in which steam does not come into contact with the waste and heats it indirectly. In the case of dry hydrolysis, the moisture in the waste inside the housing 10 evaporates into water vapor, and the waste inside the housing 10 is uniformly heated by this water vapor. In addition, moisture is necessary for hydrolysis, and moisture is supplied when water vapor causes moisture to adhere to the surface of the waste. Although Figure 1 shows one reformer 2, it may also be a configuration in which multiple reformers 2 are connected in series, multiple reformers 2 are connected in parallel, or a combination of a series-connected configuration and a parallel-connected configuration.

[0013] When the reforming device 2 performs wet hydrolysis, as shown in FIG. 2, as an example, the reforming device 2 may be configured such that the housing 10 is provided with at least one steam inlet 13 for steam to flow into the housing 10 and at least one purge nozzle 14 for purging the gas in the housing 10. When the reforming device 2 performs dry hydrolysis, as shown in FIG. 3, as an example, the reforming device 2 may be configured such that the housing 10 is provided with a jacket 15 provided so as to at least partially cover the outer surface of the housing 10. The jacket 15 constitutes a steam flow path through which steam flows. The flow path through which steam passes can also be arranged inside the reactor or on the stirring shaft. In the form of FIG. 3, the jacket 15 constitutes a heating unit that heats the moisture contained in the waste in the housing 10 by the heat of steam so as not to contact the waste and hydrolyzes the waste. Note that the heating unit is not limited to a steam flow path through which steam flows, but may be a flow path through which an arbitrary heating medium such as combustion exhaust gas flows, or may be something that can indirectly heat the waste (particularly, the moisture in the waste) without directly contacting the waste, such as an electric heater. In any form of the reforming device 2, a stirrer 16 for stirring the waste in the housing 10 is provided in the housing 10. The stirrer 16 is driven by a motor 17.

[0014] As shown in FIG. 1, the configuration of the microbial reaction device 3 is not particularly limited, but any configuration may be used as long as it uses the biological action of microorganisms to produce valuable substances using the reformed product obtained by hydrolyzing waste in the reforming device 2 as a raw material. For example, it may be a biogas fermentation tank that produces biogas such as methane as a valuable substance, a saccharification tank that produces sugar as a valuable substance from carbohydrates such as starch and cellulose, a composting device that composts to produce compost, or the like.

[0015] <Operation of the waste treatment system according to Embodiment 1 of the present disclosure> Next, the operation of the waste treatment system 1 according to Embodiment 1 of this disclosure will be described. As shown in Figure 1, the waste received into the housing 10 through the input port 11 is heated by steam while being stirred by the agitator 16 (see Figure 2 or 3). This causes a hydrolysis reaction in the waste. The conditions for this hydrolysis are not particularly limited, but for example, they can be set so that cell sap flows out from cells contained in food waste. Such conditions can be a temperature of room temperature to about 250°C and a pressure of atmospheric pressure to about 40 atmospheres.

[0016] Food waste primarily contains proteins, carbohydrates, and fats. However, hydrolysis of food waste causes pinholes to form in the cell membranes and cell walls, or the cell membranes and cell walls to dissolve, leading to the leakage of cell sap. This breaks down the food waste into smaller particles and reduces high molecular weight components to lower molecular weight. Furthermore, volatile fatty acids (VFAs) such as acetic acid increase.

[0017] In the waste, plant materials such as wood undergo hydrolysis, converting their hydrophobic lignin and hemicellulose components into hydrophilic substances and dissolving them, thus exposing the cellulose. Paper waste also becomes hydrophilic as the chemicals on its surface dissolve. Furthermore, it is finely crushed, softened, and reduced in diameter by being agitated by the agitator 16. Plastic waste is softened by heating and then reduced in diameter by being sheared by agitation in the agitator 16.

[0018] The modified material, which is the waste hydrolyzed in the modification unit 2, contains the various components produced from food waste, paper waste (including wood, etc.), and plastic waste as described above, as well as a small amount of metal that is hardly affected by hydrolysis. Since the water content of the waste with the above composition is relatively low, the composition of the modified material is mostly solid components with only a small amount of liquid. This modified material is discharged from the housing 10 through the discharge port 12 and transferred to the microbial reaction unit 3. If the waste has a high water content, such as sludge, the amount of liquid in the modified material will also increase, resulting in a slurry-like modified material. Even in such cases, the entire modified material is transferred to the microbial reaction unit 3 without solid-liquid separation. In the microbial reaction unit 3, the modified material is broken down into low-molecular-weight substances by the biological action of microorganisms, and valuable materials are produced.

[0019] By hydrolysis, food waste in the waste is broken down into smaller particles, increasing the surface area of ​​the food waste-derived components. This increases the surface area available for biological action by microorganisms, thus promoting the breakdown of molecules into smaller particles. By breaking down the food waste-derived components into smaller particles, the uneven distribution is suppressed and homogenized, which allows for uniform activity of the biological action and stabilizes the breakdown of molecules into smaller particles. Furthermore, the increase in VFA (Volatile Fatty Acid) promotes the breakdown of molecules into smaller particles. In addition, the breakdown of food waste-derived components into smaller molecules suppresses the formation of fatty foam within the microbial reaction unit 3. Such foaming can cause problems such as clogging of the overflow port (not shown) of the microbial reaction unit 3, but this process can suppress the occurrence of such problems.

[0020] In waste materials, hydrolysis exposes cellulose in paper and plant matter, making it easier for microorganisms to access the cellulose and thus promoting demolecularization. Furthermore, hydrolysis makes these components hydrophilic and reduces their diameter, preventing them from floating in the microbial reaction apparatus 3, thus reducing the risk of inhibiting demolecularization. Similarly, hydrolysis reduces the diameter of plastic waste, which also reduces the risk of inhibiting demolecularization.

[0021] In this way, the modified material obtained by hydrolyzing the waste in the modification device 2 can be broken down into low molecular weight in the microbial reaction device 3 without solid-liquid separation to produce valuable materials, so valuable materials can be produced even from waste with a low moisture content. Furthermore, this waste treatment system 1 does not require a device for solid-liquid separation of the modified material and produces only high-value valuable materials such as biogas. Therefore, compared to systems that separate the modified material into solid and liquid, produce biogas from the separated liquid, and manufacture fuels and fertilizers from the separated solid, this system can treat waste at a lower cost.

[0022] As shown in Figure 4, in Embodiment 1, when two reformers 2 (first reformer 2a and second reformer 2b) connected in series are provided, a solid-liquid separator 70 may be provided between the first reformer 2a and the second reformer 2b to separate the reformed material from the first reformer 2a into solid and liquid form, and transfer only the solid separated from the solid to the second reformer 2b. Solid-liquid separation allows nitrogen compounds such as proteins that cause melanoidin production to be separated to the liquid side, thereby suppressing the production of melanoidin during hydrolysis in the second reformer. If melanoidin flows into the methane fermenter, which is a microbial reaction vessel 3, it inhibits methane fermentation. Therefore, by separating the reformed material from the first reformer into solid and liquid form and transferring only the solid separated from the solid to the second reformer, the risk of inhibiting methane fermentation in the methane fermenter can be reduced. Note that since the liquid separated from the solid contains nitrogen compounds, this liquid may be supplied to the methane fermenter by bypassing the second reformer 2b. This allows for the replenishment of nitrogen components in the methane fermentation tank.

[0023] In Embodiment 1, the steam used to heat the waste in the reforming unit 2 may be supplied to the microbial reactor 3 and used as a heat source for maintaining temperature during the microbial reaction in the microbial reactor 3. This reduces operating costs compared to when a separate heat source is provided for the operation of the microbial reactor 3.

[0024] (Embodiment 2) Next, a waste treatment system according to Embodiment 2 will be described. The waste treatment system according to Embodiment 2 is modified from Embodiment 1 by adding a separation device in the microbial reaction apparatus 3 that separates unsuitable substances from the modified material, which do not contribute to the demolecularization by microorganisms, i.e., substances unsuitable for demolecularization. In Embodiment 2, components that are the same as those in Embodiment 1 are given the same reference numerals, and their detailed descriptions are omitted.

[0025] <Configuration of the waste treatment system according to Embodiment 2 of this disclosure> As shown in Figure 5, the waste treatment system 1 according to Embodiment 2 of the present disclosure includes a separation device 4 provided between the modification device 2 and the microbial reaction device 3. The separation device 4 separates the modified material into large particle size components and small particle size components which are smaller than the large particle size components. For example, it is a screen with an arbitrary mesh size, the mesh size of which corresponds to the particle size at the boundary between the large particle size components and the small particle size components. The other configurations are the same as in Embodiment 1.

[0026] <Operation of the waste treatment system according to Embodiment 2 of this disclosure> In the waste treatment system 1 according to Embodiment 2 of this disclosure, the modified material is separated into large-particle components and small-particle components in the separation device 4, and only the small-particle components are supplied to the microbial reaction device 3, where only the small-particle components are depolymerized to produce valuable materials. The main components of the large-particle components are components that still have relatively large particle sizes even after hydrolysis in the modification device 2, and are such as those derived from plastic waste or metals that cannot be depolymerized in the microbial reaction device 3. In other words, the large-particle components and small-particle components are unsuitable and suitable for microbial reactions, respectively.

[0027] In Embodiment 2, large-particle components are separated from the modified material by the separation device 4, and only small-particle components are supplied to the microbial reaction device 3. This reduces the amount of unsuitable material supplied to the microbial reaction device 3. As a result, the risk of inhibition of demolecularization in the microbial reaction device 3 is reduced, and demolecularization can be performed efficiently.

[0028] Regarding a screen as an example of the separation device 4, waste with a total solids concentration (TS) of 53% was hydrolyzed (heated in a sealed container to a predetermined temperature between room temperature and 240°C while stirring, and held for a certain period of time), and the modified material was passed through a screen having a mesh. As a result, while the recovery rate of reaction-compatible materials (organic matter such as paper and kitchen waste) as small particle size components was 40 wt% when the waste was crushed as is and separated by a screen as in the conventional method, a recovery rate of 80 wt% could be obtained by using the method of the present invention, and the proportion of unsuitable materials (plastic waste, etc.) mixed into the reaction-compatible materials could be reduced to 10 wt% or less. Thus, it was found that unsuitable materials can be removed to a certain extent from the hydrolyzed modified material by using a screen, so it can be estimated that by providing the separation device 4 between the modification device 2 and the microbial reaction device 3, the risk of inhibition of low molecular weight reduction in the microbial reaction device 3 can be reduced, and low molecular weight reduction can be carried out efficiently. In this example, a separation example based on differences in particle size was shown, but as a means of separation, specific gravity separation, air separation, wet separation, etc. can also be used. Therefore, the separation device 4 can also be a device using specific gravity separation, air separation, wet separation, etc., or a combination thereof. If the microbial reaction device 3 is a methane fermentation tank, it is necessary to replenish moisture, so wet separation is suitable. If the microbial reaction device 3 is a composting device, it is necessary to maintain low moisture levels, so air separation or screen separation is suitable. To improve the recovery rate of small particle size components, an air jet spray or the like may be used.

[0029] In Embodiment 2, when processing sludge with a relatively high moisture content, the TS of the modified material flowing out of the modification unit 2 will be low, which may prevent the separation of unsuitable materials in the separation unit 4 from being performed properly. In such cases, after hydrolysis is performed in the modification unit 2, the TS of the modified material can be adjusted by performing an operation similar to vacuum drying by opening the purge nozzle 14 (see Figure 2) for a certain period of time. In this case, the purge nozzle 14 constitutes a moisture adjustment device for adjusting the moisture content of the modified material. In this configuration, as shown in Figure 6, a drying device 71 of any configuration capable of adjusting the moisture content of the modified material may be provided in the modified material transfer line 5 connecting the modification unit 2 and the separation unit 4. In this case, a dewatering device may be provided as the moisture adjustment device. Conversely, the moisture adjustment device can also adjust the TS of the modified material by adding water to the modified material to increase its moisture content in order to increase the fluidity of the hydrolyzed modified material. In this case, a water spray may be provided as the moisture adjustment device. Furthermore, if a moisture adjustment device is configured to add water to the small-particle components separated in the separation device 4 and remove excess water, this moisture adjustment device can also function as a washing device to wash off reaction-compatible materials adhering to the reaction-compatible materials. This reduces the content of fermentation inhibitors such as melanoidins in the reaction-compatible materials before supplying them to the microbial reaction device 3, thereby reducing the risk of reaction inhibition in the microbial reaction device 3. Also, if the moisture adjustment device is used as a washing device to wash off the large-particle components, which are the reaction-unsuitable materials, separated in the separation device 4, the small-particle components adhering to the reaction-unsuitable materials can be recovered as reaction-compatible materials, improving the recovery rate of reaction-compatible materials. The moisture adjustment device can also be installed inside the separation device 4. The modified material transfer line 5 may be piping if the modified material is in slurry form, or a conveyor if the modified material is solid. Even if the modified material is solid, the modified material transfer line 5 may be piping if it can be pumped by air or the like.

[0030] (Embodiment 3) Next, a waste treatment system according to Embodiment 3 will be described. The waste treatment system according to Embodiment 3 is modified from Embodiment 2 to estimate the content of unsuitable reaction materials in the modified material. In Embodiment 3, components that are the same as those in Embodiment 2 are given the same reference numerals, and their detailed descriptions are omitted.

[0031] <Configuration of the waste treatment system according to Embodiment 3 of this disclosure> As shown in Figure 7, in Embodiment 3, near-infrared sensors 61 and 62, such as hyperspectral cameras, are provided on both the modified material transfer line 5 and the modified material transfer line 7, which connects the separation device 4 and the microbial reaction device 3. The near-infrared sensors 61 and 62 are each electrically connected to the control device 36. The specific configuration of the modified material transfer line 7 is the same as that of the modified material transfer line 5. The other configurations are the same as in Embodiment 2.

[0032] <Operation of the waste treatment system according to Embodiment 3 of this disclosure> The operation of Embodiment 3 is basically the same as that of Embodiment 2. Embodiment 3 differs from Embodiment 2 in that, while the modified material is being transferred from the modification device 2 to the microbial reaction device 3, near-infrared sensors 61 and 62 acquire spectral data of the modified material, the acquired spectral data is transmitted to the control device 36, and the control device 36 estimates the content of unsuitable reaction substances in the modified material based on the spectral data. The operation that differs from Embodiment 2 will be described below.

[0033] An example of spectral data acquired by near-infrared sensors 61 and 62 is shown in Figure 8. The control device 36 has in advance stored spectral data of modified products with different content of unsuitable reaction substances as a database, as shown in Figure 9 as a, b, and c (not limited to three, there may be four or more). The control device 36 can identify the acquired spectral data (Figure 8) by means of a weighted average method or kernel method, based on combinations of multiple spectral data stored in the database, and estimate the concentration of unsuitable reaction substances based on the weighted values.

[0034] As another example, as shown in Figure 10, spectral data of several modified products with different concentrations of unsuitable reaction substances (10%, 50%, and 100% in Figure 10, but these are merely examples) are acquired, and the change in intensity between two different specific wavelengths (e.g., 1500 nm and 1700 nm) in each spectral data is read. As shown in Figure 11, a relationship (calibration curve) between the concentration of the unsuitable reaction substance and the change in intensity between two different specific wavelengths is created in advance and stored in the control device 36. The control device 36 reads the absorbance at specific wavelengths of the spectral data acquired by the near-infrared sensors 61 and 62, and can estimate the concentration of unsuitable reaction substances in the modified product based on this calibration curve.

[0035] As yet another example, in addition to the near-infrared sensors 61 and 62, a piezoelectric sensor or the like can be installed to measure the weight of the modified material during transport. Since the types of unsuitable substances can also be estimated from the spectral data acquired using the near-infrared sensors 61 and 62, the weight ratio of unsuitable substances to suitable substances in the transported modified material can also be estimated from the types of unsuitable substances and the weight of the modified material.

[0036] Based on the estimated content of unsuitable substances in the modified material, it is possible to detect abnormalities in the modifying device 2 and the separation device 4, as well as abnormalities in the waste being fed into the modifying device 2.

[0037] In Embodiment 3, the content of unsuitable substances in the modified material is estimated using near-infrared sensors 61 and 62, but the system is not limited to this configuration. Near-infrared sensors can also be used to predict the properties of the waste introduced into the modification device 2. For example, the near-infrared sensors can acquire spectral data of the waste, and from the acquired spectral data, the proportions of water, protein, carbohydrates, fats, plastic components, etc., can be determined. Based on the properties of the waste thus obtained, the hydrolysis conditions (temperature, pressure, time, stirring speed, etc.) in the modification device 2 can be set. Separation conditions (mesh size, water content, vibration frequency, etc.) for the separation device 4 can also be set. Alternatively, a digital camera may be used instead of the near-infrared sensors 61 and 62, and the properties of the waste may be predicted based on images taken with the digital camera.

[0038] Furthermore, if the properties of the waste are known in advance, for example, because the waste acceptance route is clear, the hydrolysis conditions in the modification unit 2 and the separation conditions in the separation unit 4 should be set based on those properties. In addition, the properties of the waste can be estimated using AI predictions based on information related to the properties of the waste, such as waste collection dates and event calendars (information related to the type of waste), past waste analysis results, or local purchasing information. That is, the control device 36 may, as a detection device, detect information related to the properties of the waste as an indicator of the hydrolysis status of the waste in the modification unit 2, and then estimate the hydrolysis status based on this indicator.

[0039] (Embodiment 4) Next, a waste treatment system according to Embodiment 4 will be described. The waste treatment system according to Embodiment 4 is modified to adjust the hydrolysis conditions based on the hydrolysis status of the waste in the modification device 2, compared to any of Embodiments 1 to 3. In the following description, Embodiment 4 will be described in a form in which the hydrolysis conditions are adjusted relative to Embodiment 2, but Embodiment 4 may also be configured to adjust the hydrolysis conditions relative to Embodiment 1 or 3. In Embodiment 4, components that are the same as those in Embodiment 2 will be given the same reference numerals, and their detailed descriptions will be omitted.

[0040] <Configuration of the waste treatment system according to Embodiment 4 of this disclosure> In Embodiment 4, the microbial reactor 3 is described as a biogas fermenter 3a that produces biogas such as methane. As shown in Figure 12, the waste treatment system 1 according to Embodiment 4 of the present disclosure includes a gas holder 31 for storing biogas produced in the biogas fermenter 3a, a combustion boiler 32 that generates steam using the biogas stored in the gas holder 31 as fuel, a gas engine 33 that is driven using the biogas stored in the gas holder 31 as fuel, an exhaust gas boiler 34 that generates steam using the heat of the exhaust gas from the gas engine 33, and a dewatering device 35 for dewatering the fermentation residue of the biogas fermenter 3a. Although not an essential component, an injection pipe 37 connecting the dewatering device 35 and the modified material transfer line 5 may be provided.

[0041] The combustion boiler 32 and the exhaust gas boiler 34 are connected to the steam inlet 13 (see Figure 2) or jacket 15 (see Figure 3) of the reformer 2 via a steam supply pipe 38, so that steam generated in the combustion boiler 32 and the exhaust gas boiler 34 is supplied to the reformer 2. The steam supply pipe 38 is equipped with steam supply adjustment valves 39a and 39b for adjusting the amount of steam supplied from the combustion boiler 32 and the exhaust gas boiler 34 to the reformer 2. The waste treatment system 1 includes a combustion boiler control device 32a that controls the temperature and amount of steam generated in the combustion boiler 32, and an exhaust gas boiler control device 34a that controls the temperature and amount of steam generated in the exhaust gas boiler 34. Furthermore, the waste treatment system 1 is equipped with a control device 36, which is electrically connected to the motor 17 that drives the agitator 16 of the reforming device 2, the combustion boiler control device 32a, the exhaust gas boiler control device 34a, and the steam supply amount control valves 39a and 39b. Although not shown in Figure 12, the control device 36 is configured to acquire the hydrolysis status (temperature, pressure, etc.) in the reforming device 2.

[0042] The combustion boiler control device 32a and the exhaust gas boiler control device 34a control the temperature and amount of steam generated in the combustion boiler 32 and the exhaust gas boiler 34, respectively, while the steam supply adjustment valves 39a and 39b adjust the amount of steam supplied to the reformer 2, respectively. As a result, the hydrolysis conditions (temperature and pressure) of the waste in the reformer 2 are adjusted, thus constituting an adjustment device for adjusting the hydrolysis conditions of the waste in the reformer 2. The other configurations are the same as in Embodiment 2.

[0043] <Operation of the waste treatment system according to Embodiment 4 of this disclosure> The process from the hydrolysis of waste in the reformer 2 to the generation of biogas as a valuable material in the microbial reactor 3, i.e., the biogas fermenter 3a, is the same as in Embodiment 2. The biogas generated in the biogas fermenter 3a is stored in the gas holder 31. Depending on the operating status of the combustion boiler 32 and the gas engine 33, biogas is supplied from the gas holder 31 to the combustion boiler 32 and the gas engine 33, respectively. In the combustion boiler 32, steam is generated using biogas as fuel. In the exhaust gas boiler 34, steam is generated by the heat of the exhaust gas from the gas engine. The steam generated in the combustion boiler 32 and the exhaust gas boiler 34 is supplied to the reformer 2 and used for the hydrolysis of waste.

[0044] While there are no particular limitations on the operating methods of the combustion boiler 32 and the exhaust gas boiler 34, an example of an operating method will be described. The exhaust gas boiler 34 must always be operated while the waste is being hydrolyzed in the reformer 2. The combustion boiler 32 is not operated as long as the hydrolysis conditions in the reformer 2 can be adjusted using only the steam generated by the exhaust gas boiler 34. When adjusting the hydrolysis conditions according to the amount of waste fed into the reformer 2 and the composition of the waste components, if the steam generated by the exhaust gas boiler 34 is insufficient, the combustion boiler 32 is operated to supply the reformer 2 with steam generated by both the exhaust gas boiler 34 and the combustion boiler 32. In this way, the range of adjustment for the hydrolysis conditions in the reformer 2 can be broadened compared to the case where only the exhaust gas boiler 34 is used. Furthermore, by installing two or more gas engines 33 and operating a number of gas engines 33 corresponding to the amount of steam generated by the exhaust gas boiler 34, the range of adjustment for the hydrolysis conditions in the reformer 2 can be further broadened.

[0045] To adjust the hydrolysis conditions in the reforming unit 2, it is necessary to detect the hydrolysis status in the reforming unit 2. While there are no particular limitations on the method for detecting the hydrolysis status, one example is described below. The control device 36 detects the torque of the motor 17 as an indicator of the hydrolysis status of the waste in the reforming unit 2. The torque of the motor 17 fluctuates from the time the waste is introduced into the reforming unit 2 until hydrolysis begins, and the torque fluctuates according to the progress of hydrolysis. It is possible to detect the hydrolysis status from the fluctuations in the torque of the motor 17. In addition, it is possible to detect the hydrolysis status from indicators that take into account various measured values ​​such as hydrolysis temperature, pressure, time, and steam supply rate.

[0046] The torque of motor 17 changes over time depending on the composition of the waste. However, if there is no significant difference in the composition of the waste hydrolyzed each time in the reforming device 2, the change in the torque of motor 17 over time can be detected in advance, and the hydrolysis status in the reforming device 2 can be estimated by comparing it with the previously detected change in torque over time. For this reason, the control device 36 that detects the torque of motor 17 constitutes a detection device that detects an indicator of the hydrolysis status of the waste in the reforming device 2. Alternatively, a separate detection device for detecting the torque of motor 17 may be provided in addition to the control device 36, and the control device 36 may be configured to receive a signal related to the torque of motor 17 from this detection device.

[0047] Based on the detection results of the hydrolysis status using the torque of the motor 17, for example, it may be possible that the waste has not been sufficiently pulverized, or that the waste has been pulverized too much, resulting in plastic waste being pulverized to a particle size that would normally be unattainable. In the former case, for example, it may be necessary to increase the hydrolysis temperature, so the amount of steam supplied to the reformer 2 may be increased. In the latter case, for example, from the perspective of the operating cost of the waste treatment system 1, the hydrolysis temperature may be lowered, so the amount of steam supplied to the reformer 2 may be decreased.

[0048] In this way, the control device 36 estimates the hydrolysis status in the reformer 2 based on the torque of the motor 17, and based on the estimated hydrolysis status, controls at least one of the adjustment devices, namely the combustion boiler control device 32a, the exhaust gas boiler control device 34a, and the steam supply amount adjustment valves 39a and 39b, to adjust the temperature (pressure) and supply amount of steam supplied to the reformer 2. As a result, the hydrolysis status in the reformer 2 changes. In this manner, the control device 36 adjusts the hydrolysis conditions in the reformer 2 based on the hydrolysis status in the reformer 2. Furthermore, since the completion / incompleteness of hydrolysis can be determined from this hydrolysis status, it is also possible to adjust the hydrolysis time.

[0049] Thus, in Embodiment 4, a modified material with conditions suitable for microbial reactions can be supplied to the biogas fermentation tank 3a, allowing for efficient biogas production through microbial reactions.

[0050] In Embodiment 2, it was explained that the TS of the modified material may be adjusted by adding water to the modified material to increase its water content in order to increase the fluidity of the hydrolyzed modified material. In Embodiment 4, in order to adjust the TS of the modified material in this way, the water dewatered from the fermentation residue of the biogas fermentation tank 3a in the dewatering device 35 or boiler blowdown water may be supplied to the modified material in the modified material transfer line 5 via the water injection pipe 37. For this reason, the water injection pipe 37 constitutes a water content adjustment device. Since the dewatered water or boiler blowdown water contains ammonia, if the nitrogen content in the waste is low, nitrogen-containing substances can also be supplied to the modified material. From the viewpoint of supplying nitrogen-containing substances, the dewatered water or boiler blowdown water is not limited to being supplied to the modified material in the modified material transfer line 5, but may also be supplied to the biogas fermentation tank 3a or the modified material 2. In this case, the water injection pipe 37 may be connected to the biogas fermentation tank 3a or the modified material 2. Furthermore, in Embodiment 3, the control device 36 estimated the hydrolysis conditions based on the torque of the motor 17, but the hydrolysis conditions may also be estimated based on the current value of the motor 17. In other words, the current value of the motor 17 may be used as an indicator of the hydrolysis status of the waste in the reforming device 2.

[0051] <Modified example of the waste treatment system according to Embodiment 4 of this disclosure> In Embodiment 4, the hydrolysis conditions in the reforming device 2 are adjusted based on the hydrolysis status in the reforming device 2, but the embodiment is not limited to this form. For example, as shown in Figure 13, two separation devices 4a and 4b with different mesh sizes may be provided as the separation device 4, arranged in parallel with respect to the flow of the reformed material. In this case, the mesh size of separation device 4a is smaller than the mesh size of separation device 4b. The reformed material transfer line 5 is provided with a switching device 6 for supplying the reformed material to either separation device 4a or 4b. The motor 17 and the switching device 6 are electrically connected to the control device 36.

[0052] If, after starting hydrolysis, the torque of the motor 17 does not show periodic increases or decreases but instead exhibits irregular fluctuations, and it is considered that the waste is not being properly pulverized, the control device 36 operates the switching device 6 to supply the modified material to the separation device 4b. If the waste is not being properly pulverized, unsuitable materials, especially plastic waste, remain large in size. Therefore, the separation device 4b with a larger mesh size is selected to remove the unsuitable materials, while also allowing even large, suitable materials to be supplied to the biogas fermentation tank 3a. On the other hand, if the periodic increases and decreases are small and it is considered that the waste is being sufficiently pulverized, the control device 36 operates the switching device 6 to supply the modified material to the separation device 4a. This allows even finely pulverized unsuitable materials to be removed.

[0053] Furthermore, although the modified embodiment 4 shown in Figure 13 includes two separation devices 4a and 4b with different mesh sizes, it is not limited to two, and three or more separation devices with different mesh sizes may be provided. This allows for the selection of three or more separation devices with different mesh sizes depending on the hydrolysis status in the modification device 2.

[0054] (Embodiment 5) Next, a waste treatment system according to Embodiment 5 will be described. The waste treatment system according to Embodiment 5 is modified from any of Embodiments 1 to 4 in which the hydrolysis status of the waste in the reforming unit 2 is estimated based on the reaction conditions in the microbial reactor 3, and the hydrolysis conditions for the next batch of waste in the reforming unit 2 are adjusted based on that hydrolysis status. In the following description, the above modification will be applied to Embodiment 4, but Embodiment 5 may also be constructed by applying the above modification to any of Embodiments 1 to 3. In Embodiment 5, components that are the same as those in Embodiment 4 are given the same reference numerals, and their detailed descriptions are omitted.

[0055] <Configuration of the waste treatment system according to Embodiment 5 of this disclosure> As shown in Figure 14, the waste treatment system 1 according to Embodiment 5 of the present disclosure is equipped with at least one of a volatile fatty acid sensor (VFA sensor) 41 for detecting the VFA concentration in the modified material being transported in the modified material transport line 5, or a VFA sensor 42 for detecting the VFA concentration in the biogas fermentation tank 3a. The control device 36 is configured to receive the detection value of at least one of the VFA sensors 41 or 42. The other configurations are the same as in Embodiment 4.

[0056] <Operation of the waste treatment system according to Embodiment 5 of this disclosure> The operation of Embodiment 5 is basically the same as that of Embodiment 4. However, it differs in that it detects the reaction conditions in the biogas fermenter 3a based on the values ​​detected by VFA sensors 41 and 42 as indicators of the hydrolysis status of the waste in the reformer 2, estimates the hydrolysis status in the reformer 2 from those reaction conditions, and adjusts the hydrolysis conditions for the next batch of waste in the reformer 2 based on that hydrolysis status. For this reason, VFA sensors 41 and 42 constitute a detection device that detects indicators of the hydrolysis status of the waste in the reformer 2. The operation for estimating the hydrolysis status of the waste in the reformer 2 will be described below. In the following description, it will be assumed that both VFA sensors 41 and 42 are provided.

[0057] During operation of the waste treatment system 1, the VFA sensor 41 detects the VFA concentration in the modified material discharged from the reforming device 2. The VFA sensor 42 detects the VFA concentration in the contents of the biogas fermenter 3a. The configuration of the VFA sensors 41 and 42 is not particularly limited, and any known sensor can be used to detect the VFA concentration, but as an example, the configuration of a sensor that can be used as the VFA sensor 42 will be described. The biogas fermenter 3a is provided with a contents circulation line that takes out a portion of the contents and returns it to the biogas fermenter 3a, a extraction line that extracts a portion of the contents from the circulation line, and a dilution water supply line that supplies dilution water to the extraction line. A probe for measurement is provided for the contents diluted with dilution water, and the VFA concentration in the contents of the biogas fermenter 3a is detected by irradiating the contents diluted with dilution water with infrared light from the probe and receiving the transmitted light. The VFA sensor 41 that detects the VFA concentration in the modified material discharged from the reforming device 2 can detect the VFA concentration using infrared light.

[0058] Signals regarding the VFA concentration detected by VFA sensors 41 and 42 are transmitted from VFA sensors 41 and 42 to the control device 36. Upper and lower limits for VFA concentration are pre-set in the control device 36, and it determines whether the transmitted VFA concentration is between the upper and lower limits. If the VFA concentration is below the lower limit, the methane fermentation reaction will slow down, so it is necessary to increase the VFA concentration. Specifically, for example, the temperature or amount of steam supplied to the reformer 2 for hydrolysis of the next batch of waste may be increased, the hydrolysis time may be extended, or the amount or number of methane fermentation raw materials supplied per cycle may be increased to increase the total amount of VFA put into the biogas fermenter 3a. Conversely, if the VFA concentration is too high, VFA will accumulate in the biogas fermentation tank 3a, causing rancidity. Therefore, if the detected VFA concentration exceeds the upper limit, measures such as reducing the temperature or amount of steam supplied to the reformer 2 for hydrolysis of the next batch of waste, shortening the hydrolysis time, or adjusting the amount or number of methane fermentation raw materials supplied may be taken.

[0059] In this way, the hydrolysis status of the waste in the reformer 2 is estimated based on the VFA concentration in the reformed material obtained by hydrolysis of the waste and the VFA concentration in the contents of the biogas fermenter 3a. By adjusting the hydrolysis conditions for the next batch of waste in the reformer 2 based on this hydrolysis status, the VFA concentration in the contents of the biogas fermenter 3a for the next batch can be maintained at conditions suitable for methane fermentation, thereby enabling efficient biogas production by microbial reaction.

[0060] In Embodiment 5, VFA sensors 41 and 42 are permanently installed. However, it is also possible to sample the modified material and the contents of the biogas fermentation tank 3a, analyze the VFA concentration contained therein, and calculate the hydrolysis status from the data of the analysis results.

[0061] (Embodiment 6) Next, a waste treatment system according to Embodiment 6 will be described. The waste treatment system according to Embodiment 6 is a modification of Embodiments 1 to 5 in which the operation for detecting the reaction conditions in the microbial reactor 3 is changed. In the following description, a configuration in which the operation for detecting the reaction conditions in the microbial reactor 3 is changed from that of Embodiment 5 will be described, but Embodiment 6 may also be constructed by changing the operation for detecting the reaction conditions in the microbial reactor 3 from any of Embodiments 1 to 4. In Embodiment 6, components that are the same as those in Embodiment 5 are given the same reference numerals, and their detailed descriptions are omitted.

[0062] <Configuration of the waste treatment system according to Embodiment 6 of this disclosure> As shown in Figure 15, the waste treatment system 1 according to Embodiment 6 of this disclosure is equipped with a fermentation inhibitor sensor 51 that detects the concentration of fermentation inhibitors such as melanoidins, flurals, and phenols in the biogas fermenter 3a as an indicator of the hydrolysis status of the waste in the reformer 2. The control device 36 is configured to receive the detected value from the fermentation inhibitor sensor 51. The other configurations are the same as in Embodiment 5, except that VFA sensors 41 and 42 (see Figure 14) are not provided.

[0063] <Operation of the waste treatment system according to Embodiment 6 of this disclosure> The operation of Embodiment 6 is basically the same as that of Embodiment 5. However, the operation for detecting the reaction conditions in the biogas fermenter 3a is different. The operation for detecting the reaction conditions in the biogas fermenter 3a will be described below.

[0064] While the waste treatment system 1 is in operation, the fermentation inhibitor sensor 51 detects the concentration of fermentation inhibitors in the contents of the biogas fermenter 3a. The configuration of the fermentation inhibitor sensor 51 is not particularly limited, and the concentration of fermentation inhibitors can be detected using any known sensor, but as an example, the configuration of a sensor that can be used as the fermentation inhibitor sensor 51 will be described. The biogas fermenter 3a is provided with a contents circulation line that takes out a portion of the contents and returns it to the biogas fermenter 3a, a withdrawal line that withdraws a portion of the contents from the circulation line, and a dilution water supply line that supplies dilution water to the withdrawal line. A probe for measurement is provided for the contents diluted with dilution water, and the concentration of fermentation inhibitors in the contents of the biogas fermenter 3a is detected by irradiating the contents diluted with dilution water with ultraviolet light from the probe and receiving the transmitted light.

[0065] A signal regarding the concentration of fermentation inhibitors detected by the fermentation inhibitor sensor 51 is transmitted from the fermentation inhibitor sensor 51 to the control device 36. The control device 36 has a predetermined upper limit for the concentration of fermentation inhibitors, and it determines whether the transmitted concentration of fermentation inhibitors is below the upper limit. If the concentration of fermentation inhibitors exceeds the upper limit, methane fermentation is inhibited and the reaction slows down, so it is necessary to lower the concentration of fermentation inhibitors. Specifically, the temperature and amount of steam supplied to the reformer 2 for hydrolysis of the waste in the next batch are reduced.

[0066] In Embodiment 6, the hydrolysis status of the waste in the reformer 2 is estimated based on the concentration of fermentation inhibitors detected by the fermentation inhibitor sensor 51. Therefore, the fermentation inhibitor sensor 51 constitutes a detection device that detects the hydrolysis status of the waste in the reformer 2.

[0067] In this way, by estimating the hydrolysis status of the waste in the reformer 2 based on the concentration of fermentation inhibitors in the contents of the biogas fermenter 3a, and by adjusting the hydrolysis conditions of the next batch of waste in the reformer 2 based on this hydrolysis status, the concentration of fermentation inhibitors in the contents of the biogas fermenter 3a for the next batch can be reduced, thereby enabling efficient biogas production by microbial reaction.

[0068] <Modified example of the waste treatment system according to Embodiment 6 of this disclosure> In Embodiment 6, the hydrolysis conditions for the next batch in the reformer 2 are adjusted based on the concentration of fermentation inhibitors in the contents of the biogas fermenter 3a, but the invention is not limited to this form. For example, if the composition of the waste in each batch hydrolyzed in the reformer 2 changes significantly, it may be difficult to adjust the hydrolysis conditions for the next batch to appropriate conditions even if the reaction conditions in the biogas fermenter 3a are adjusted based on the reaction conditions of the previous batch.

[0069] In such cases, as shown in Figure 16, a fermentation inhibitor sensor 51 is provided in the modified material transfer line 5 so as to detect the concentration of fermentation inhibitors in the modified material flowing out of the reforming device 2. Furthermore, a bypass line 8 is provided that branches off from the modified material transfer line 7 connecting the separation device 4 and the biogas fermenter 3a, and rejoins the modified material transfer line 7 downstream of the branching point. At least one bypass tank 52 may be provided in the bypass line 8. A switching device 9 may be provided at the upstream end of the bypass line 8 to supply the modified material flowing out of the separation device 4 to either the bypass tank 52 or the biogas fermenter 3a.

[0070] In this modified example, if the value detected by the fermentation inhibitor sensor 51 exceeds the upper limit, the control device 36 switches the switching device 9 and stores the modified material in the avoidance tank 52 instead of supplying it to the biogas fermenter 3a. When the concentration of fermentation inhibitors in the hydrolyzed modified material from the next batch onward falls below the upper limit, the modified material with a higher concentration of fermentation inhibitors stored in the avoidance tank 52 is gradually mixed with the modified material and supplied to the biogas fermenter 3a. In this way, the concentration of fermentation inhibitors in the contents of the biogas fermenter 3a can be kept below the upper limit, allowing for efficient biogas production through microbial reactions.

[0071] In Embodiment 6, the fermentation inhibitor sensor 51 is permanently installed. However, it is also possible to sample the modified material and the contents of the biogas fermentation tank 3a, analyze the concentration of fermentation inhibitors contained therein, and calculate the hydrolysis status from the data of the analysis results.

[0072] In Embodiment 6, the control device 36 determines the properties of the waste and the hydrolysis conditions, Canada The system may learn the relationship with the water splitting status and adjust the hydrolysis conditions based on the trained model constructed as a result of this learning.

[0073] In embodiments 5 and 6, VFA sensors 41 and 42 and a fermentation inhibitor sensor 51 were described as examples of detection devices, but the invention is not limited to these. Sensors that detect the amount of gas produced in the microbial reactor 3, the VFA concentration in the gas, the pH, electrical conductivity, alkalinity, ammonia concentration, and microbial cell concentration of the contents in the microbial reactor 3 may also be used. Furthermore, sensors that detect pH, electrical conductivity, chromaticity, inhibitor concentration, VFA concentration, ammonia concentration, and particle size distribution during hydrolysis may also be used. By calculating an index using a function based on these detected values, the hydrolysis status of the waste in the reformer 2 can be estimated.

[0074] In embodiments 1 to 6, the reforming device 2 hydrolyzes the waste in a batch manner, but it may also hydrolyze the waste in a flow manner. However, in a reforming device that hydrolyzes in a flow manner, in order to supply the waste to the reforming device, it is conceivable to give the waste fluidity, for example, to supply it as a slurry by reducing the diameter of the waste and supplying it with a large amount of water. In this case, extra energy is required, such as energy to reduce the diameter of the waste and energy to raise the temperature of the water in the slurry during hydrolysis. In contrast, with a reforming device that hydrolyzes in a batch manner, there is no need to reduce the diameter of the waste, and it can be supplied into the reforming device as is, thus eliminating the need for the extra energy required in a reforming device that hydrolyzes in a flow manner.

[0075] The contents described in each of the above embodiments can be understood, for example, as follows:

[0076] [1] A waste treatment system relating to one aspect is: A modification device (2) for hydrolyzing waste, A microbial reactor (3) that decomposes the modified material, which includes at least a solid, from the waste hydrolyzed in the at least one modification device (2) into a low-molecular-weight substance using microorganisms. It is equipped with.

[0077] According to the waste treatment system of this disclosure, since the waste hydrolyzed in the reforming device can be broken down into low molecular weight in the microbial reaction device without solid-liquid separation to produce valuable materials, even waste with a low moisture content (preferably 70% or less) can be treated at low cost.

[0078] [2] A waste treatment system according to another embodiment is the waste treatment system of [1], The at least one reforming device (2) is, The aforementioned waste receiving enclosure (10), The housing (10) has an input port (11) for introducing the waste, An outlet (12) for discharging the modified material from the housing (10), The on / off valves (18, 19) open and close the respective inlet (11) and outlet (12) and Equipped with, The waste material inside the housing (10) is hydrolyzed in a batch manner while the housing (10) is sealed by closing each of the aforementioned on-off valves (18, 19).

[0079] In a flow-type hydrolysis reformer, the waste needs to be made fluid in order to supply it to the reformer. For example, the waste needs to be reduced in diameter and supplied as a slurry in a large amount of water. In this case, extra energy is required, such as energy to reduce the diameter of the waste and energy to heat the water in the slurry during hydrolysis. In contrast, with the configuration described in [2] above, hydrolysis is performed in a batch manner, so there is no need to reduce the diameter of the waste, and it can be supplied into the reformer as is, thus eliminating the need for the extra energy required in a flow-type hydrolysis reformer.

[0080] [3] A waste treatment system according to another embodiment is a waste treatment system of [1] or [2], The at least one reforming device (2) comprises a housing (10) for receiving the waste, The at least one reforming device (2) is configured to supply steam into the housing (10) and to heat and hydrolyze the waste inside the housing (10) with the steam.

[0081] With this configuration, the hydrolysis conditions can be easily adjusted by controlling the steam temperature, pressure, supply rate, etc.

[0082] [4] A waste treatment system according to another embodiment is a waste treatment system of [1] or [2], The at least one reforming device (2) comprises a housing (10) for receiving the waste, The housing (10) includes a heating section (jacket 15) that heats the water contained in the waste within the housing (10) without contacting the waste, thereby hydrolyzing the waste.

[0083] With this configuration, the hydrolysis conditions can be easily adjusted by controlling the steam temperature, pressure, supply rate, etc.

[0084] [5] A waste treatment system relating to another embodiment is a waste treatment system of [1] to [4], In the at least one reforming apparatus (2) described above, hydrolysis is carried out at a temperature ranging from room temperature to 250°C and a pressure ranging from atmospheric pressure to 40 atmospheres.

[0085] This configuration allows for the leakage of cell sap from cells contained in food waste. As a result, the food waste is broken down into smaller particles, and high-molecular-weight components are reduced to lower molecular weight. Furthermore, volatile fatty acids (VFAs) such as acetic acid are increased.

[0086] [6] A waste treatment system according to another embodiment is a waste treatment system of [1] to [5], The first reforming device (2a) and the second reforming device (2b) are defined as at least one reforming device (2), A solid-liquid separator (70) separates the treated waste material, which has been hydrolyzed in the first modification apparatus (2a), from solid to liquid. Equipped with, In the second reforming apparatus (2b), only the solid separated in the solid-liquid separation apparatus (70) is hydrolyzed.

[0087] With this configuration, nitrogen compounds such as proteins that cause melanoidin production can be separated to the liquid side by solid-liquid separation, thereby suppressing melanoidin production during hydrolysis in the second reforming unit. When melanoidin flows into the methane fermentation tank, which is a microbial reaction unit, it inhibits methane fermentation. Therefore, by separating the reformed material from the first reforming unit into solid and liquid phases and transferring only the solid phase to the second reforming unit, the risk of inhibiting methane fermentation in the methane fermentation tank can be reduced.

[0088] [7] A waste treatment system relating to another embodiment is a waste treatment system of [1] to [6], The microbial reaction apparatus (3) is A biogas fermentation tank (3a) for producing biogas, A saccharification tank that produces sugar from carbohydrates, Composting equipment for producing compost and It includes at least one of the following.

[0089] With this configuration, one or more desired valuable materials can be manufactured.

[0090] [8] A waste treatment system according to another embodiment is a waste treatment system of [1] to [7], A separation device (4) is further provided between the at least one modification device (2) and the microbial reaction device (3) for separating unsuitable reaction substances from the modified product that are unsuitable for demolecularization by the microorganisms in the microbial reaction device (3).

[0091] With this configuration, unsuitable materials are separated from the modified material in the separation device, thus reducing the amount of unsuitable materials supplied to the microbial reactor. As a result, the risk of inhibiting the microbial reaction in the microbial reactor is reduced, and the production of valuable materials through the microbial reaction can be carried out efficiently.

[0092] [9] Another waste treatment system is the waste treatment system of [8], The system is equipped with a moisture adjustment device that adjusts the moisture content of the modified material.

[0093] With this configuration, the TS of the reformed material flowing out of the reforming unit can be adjusted, which allows for better separation of unsuitable materials in the separation unit.

[0094]

[10] Another waste treatment system is the waste treatment system of [9], The moisture adjustment device is a drying device (71) that reduces the moisture content of the modified product.

[0095] With this configuration, when processing sludge with a relatively high moisture content, the TS of the modified material flowing out of the modification unit will be low, which may prevent the separation of unsuitable materials in the separation unit from being performed properly. In contrast, with the configuration described in

[10] above, the moisture content of the modified material can be reduced by the drying unit, thereby adjusting the TS of the modified material, and enabling the separation of unsuitable materials in the separation unit to be performed properly.

[0096]

[11] Another waste treatment system is the waste treatment system of [9], The moisture adjustment device is a cleaning device that washes off reaction-compatible substances adhering to the reaction-unsuitable substances.

[0097] With this configuration, the content of fermentation inhibitors in the reaction-compatible material can be reduced before supplying the reaction-compatible material to the microbial reactor, thereby reducing the risk of reaction inhibition in the microbial reactor. Furthermore, by using a moisture adjustment device as a washing device to wash the large-particle components, which are unsuitable for reaction, separated in the separation device, the small-particle components attached to the unsuitable material can be recovered as reaction-compatible material, thereby improving the recovery rate of reaction-compatible material.

[0098]

[12] Another waste treatment system is the waste treatment system of [1] to

[10] , A dewatering device for dewatering the residue from the microbial reaction apparatus (3), The water dewatered by the dewatering device is supplied to at least one of the modified material before it flows into the separation device (4), the modifying device (2), or the microbial reaction device (3) via an injection pipe. It is equipped with.

[0099] With this configuration, since the water obtained by dewatering the residue from the microbial reactor contains ammonia, nitrogen-containing substances can be replenished if the nitrogen content in the waste in the reformer or the contents of the microbial reactor is low.

[0100]

[13] Another waste treatment system is the waste treatment system of [8] to

[12] , The separation device (4) is a screen that separates the modified material into large particle size components and small particle size components with smaller particle sizes than the large particle size components, and the large particle size components are the unsuitable material for the reaction.

[0101] If the microbial reaction apparatus is a composting apparatus, it is necessary to maintain a low moisture content, so screen separation is suitable, as in the configuration described in

[12] above.

[0102]

[14] A further embodiment of the waste treatment system is any of the waste treatment systems described in [1] to

[13] , A detection device (control device 36) for detecting an indicator of the hydrolysis status of the waste in at least one of the reforming devices (2), A control device (combustion boiler control device 32a / exhaust gas boiler control device 34a / steam supply amount control valves 39a, 39b) for adjusting the hydrolysis conditions of the waste in at least one reforming device (2), Control device (36) and Furthermore, The control device (36) estimates the hydrolysis status of the waste based on the indicator detected by the detection device (control device 36), and adjusts the hydrolysis conditions of the waste by operating the adjustment device (32a / 34a / 39a,39b) based on the estimated hydrolysis status.

[0103] With this configuration, modified materials with conditions suitable for microbial reactions can be supplied to the microbial reactor, thus enabling the efficient production of valuable substances through microbial reactions.

[0104]

[15] Another waste treatment system is the waste treatment system of

[14] , The at least one reforming device (2) is, A stirrer (16) for agitating the waste, A motor (17) that drives the agitator (16) and Equipped with, The detection device (36) detects the torque of the motor (17) as the index, The control device (36) estimates the hydrolysis status based on the torque of the motor (17).

[0105] With this configuration, modified materials with conditions suitable for microbial reactions can be supplied to the microbial reactor, thus enabling the efficient production of valuable substances through microbial reactions.

[0106]

[16] Another waste treatment system is the waste treatment system of

[14] , The at least one reforming device (2) is, A stirrer (16) for agitating the waste, A motor (17) that drives the agitator (16) and Equipped with, The detection device (36) detects the current value of the motor (17) as the indicator, The control device (36) estimates the hydrolysis status based on the current value of the motor (17).

[0107] With this configuration, modified materials with conditions suitable for microbial reactions can be supplied to the microbial reactor, thus enabling the efficient production of valuable substances through microbial reactions.

[0108]

[17] Another waste treatment system is the waste treatment system of

[14] , The detection device detects information regarding the properties of the waste as the indicator, The control device estimates the hydrolysis status based on the properties of the waste.

[0109] With this configuration, modified materials with conditions suitable for microbial reactions can be supplied to the microbial reactor, thus enabling the efficient production of valuable substances through microbial reactions.

[0110]

[18] Another waste treatment system is the waste treatment system of

[17] , The control device learns the correspondence between the properties of the waste, the hydrolysis conditions, and the water decomposition status, and adjusts the hydrolysis conditions based on the trained model constructed as a result of the learning.

[0111] With this configuration, the production of valuable substances by microbial reactions can be carried out more efficiently compared to

[18] above.

[0112]

[19] Another waste treatment system is the waste treatment system of

[14] to

[18] , The waste is heated and hydrolyzed by steam supplied to at least one of the reforming devices. The adjustment device adjusts at least one of the steam temperature, pressure, and supply amount.

[0113] This configuration allows for easy adjustment of hydrolysis conditions.

[0114]

[20] A waste disposal method relating to one aspect is: The step of hydrolyzing the waste, The steps of reducing the molecular weight of the modified material, which includes at least a solid, from the hydrolyzed waste, by microorganisms. Includes.

[0115] According to the waste treatment method of this disclosure, valuable materials can be produced by reducing the molecular weight of hydrolyzed waste using microorganisms without solid-liquid separation, thus enabling low-cost treatment even for waste with low moisture content. [Explanation of Symbols]

[0116] 1. Waste disposal system 2. Modification device 2a 1st reformer 2b Second Reforming Unit 3. Microbial reaction apparatus 4 Separation device 10 cabinets 11 Inlet 12 Outlet 15 Jacket (heating section) 16. Agitator 17 Motor 18. Shut-off valve 19. Shut-off valves 36 Control device (detection device) 32a Combustion boiler control device (adjustment device) 34a Exhaust gas boiler control device (regulating device) 35 Dehydration equipment 37 Water injection pipe (moisture adjustment device) 39a Steam supply rate control valve (adjustment device) 39b Steam supply rate control valve (adjustment device) 41 VFA Sensor (Detection Device) 42 VFA Sensor (Detection Device) 51. Fermentation inhibitor sensor (detection device) 70 Solid-liquid separator 71 Drying equipment (moisture adjustment equipment)

Claims

1. A reforming apparatus for hydrolyzing waste, including a first reforming apparatus and a second reforming apparatus, A solid-liquid separation apparatus for separating the treated waste material, which has been hydrolyzed in the first modification apparatus, A microbial reaction apparatus that uses microorganisms to reduce the molecular weight of the modified material, which includes at least a solid, from the waste hydrolyzed in the aforementioned modification apparatus, Between the second modification apparatus and the microbial reaction apparatus, a separation apparatus is provided for separating unsuitable reaction substances from the modified product that are unsuitable for demolecularization by the microorganisms in the microbial reaction apparatus. Equipped with, The second modification apparatus is a waste treatment system that hydrolyzes only the solids separated by the solid-liquid separation apparatus.

2. The waste treatment system according to claim 1, wherein the separation device is a screen that separates the modified material into a large particle size component and a small particle size component with a smaller particle size than the large particle size component, and the large particle size component is the unsuitable material for the reaction.

3. The aforementioned modification apparatus is, The aforementioned housing for receiving waste, The housing has an input port for introducing the waste, An outlet for discharging the modified material from the housing, A shut-off valve that opens and closes the inlet and the outlet, respectively. Equipped with, The waste treatment system according to claim 1 or 2, wherein the housing is sealed by closing each of the aforementioned on-off valves, and the waste inside the housing is hydrolyzed in a batch manner.

4. The modification device comprises a housing for receiving the waste, The waste treatment system according to any one of claims 1 to 3, wherein the reforming device is configured to supply steam into the housing and heat the waste inside the housing with the steam to hydrolyze it.

5. The modification device comprises a housing for receiving the waste, The waste treatment system according to any one of claims 1 to 3, wherein the housing comprises a heating unit that heats the water contained in the waste within the housing so as not to come into contact with the waste, thereby hydrolyzing the waste.

6. The waste treatment system according to any one of claims 1 to 5, wherein hydrolysis is performed in the reforming apparatus at a temperature from room temperature to 250°C and a pressure from atmospheric pressure to 40 atmospheres.

7. The microbial reaction apparatus is A biogas fermentation tank for producing biogas, A saccharification tank that produces sugar from carbohydrates, Composting equipment for producing compost and A waste treatment system according to any one of claims 1 to 6, comprising at least one of the following:

8. A waste treatment system according to any one of claims 1 to 7, comprising a moisture adjustment device for adjusting the moisture content of the modified material.

9. The waste treatment system according to claim 8, wherein the moisture adjustment device is a drying device that reduces the moisture content of the modified material.

10. The waste treatment system according to claim 8, wherein the moisture adjustment device is a cleaning device for washing off reaction-compatible material adhering to the reaction-unsuitable material.

11. A dewatering device for dewatering the residue from the microbial reaction apparatus, An injection pipe supplies the water dewatered by the dewatering device to at least one of the modified material before it flows into the separation device, the modified device, or the microbial reaction device. A waste treatment system according to any one of claims 1 to 9, comprising:

12. A detection device for detecting an indicator of the hydrolysis status of the waste in the reforming apparatus, An adjustment device for adjusting the hydrolysis conditions of the waste in the reforming device, Control device and Furthermore, The waste treatment system according to any one of claims 1 to 11, wherein the control device estimates the hydrolysis status of the waste based on the indicator detected by the detection device, and adjusts the hydrolysis conditions of the waste by operating the adjustment device based on the estimated hydrolysis status.

13. The aforementioned modification apparatus is, A stirrer for agitating the aforementioned waste, The motor that drives the aforementioned agitator and Equipped with, The detection device detects the torque of the motor as the indicator, The waste treatment system according to claim 12, wherein the control device estimates the hydrolysis status based on the torque of the motor.

14. The aforementioned modification apparatus is, A stirrer for agitating the aforementioned waste, The motor that drives the aforementioned agitator and Equipped with, The detection device detects the current value of the motor as the indicator, The waste treatment system according to claim 12, wherein the control device estimates the hydrolysis status based on the current value of the motor.

15. The detection device detects information regarding the properties of the waste as the indicator, The waste treatment system according to claim 12, wherein the control device estimates the hydrolysis status based on the properties of the waste.

16. The waste treatment system according to claim 15, wherein the control device learns the correspondence between the properties of the waste, the hydrolysis conditions, and the hydrolysis status, and adjusts the hydrolysis conditions based on the learned model constructed as a result of the learning.

17. The waste is heated and hydrolyzed by the steam supplied to the reforming device. The waste treatment system according to any one of claims 12 to 16, wherein the adjusting device adjusts at least one of the temperature, pressure, and supply amount of the steam.

18. The step of hydrolyzing the waste, The steps include: separating the treated material, which is the hydrolyzed waste, from solid to liquid; A step of hydrolyzing only the solid separated in the above step of solid-liquid separation, The process involves using microorganisms to reduce the molecular weight of a modified product containing at least a solid, obtained by hydrolyzing only the solid separated in the solid-liquid separation step, and Between the hydrolysis step and the depolymerization step, there is a step of separating unsuitable reaction substances from the modified product that are unsuitable for depolymerization by the microorganisms in the depolymerization step. A waste disposal method that includes [a specific type of waste].

Images