waste treatment system

Abstract

A waste treatment system equipped with a hydrothermal treatment device has a simple configuration and is capable of reducing the amount of odor emitted into the atmosphere. [Solution] The system comprises a release steam line configured to discharge steam from the hydrothermal treatment device, a methane fermentation tank configured to produce methane gas using the liquid portion of the hydrothermal treatment product, a biomass-derived material treatment device, an odor line through which odors are discharged from the biomass-derived material treatment device, and deodorization equipment configured to deodorize the odors discharged from the biomass-derived material treatment device, wherein the release steam line is connected to the biomass-derived material treatment device and is configured to supply steam discharged from the hydrothermal treatment device to the biomass-derived material treatment device, and the biomass-derived material treatment device is configured to perform heat exchange between the steam supplied from the release steam line and a substance derived from the biomass.

Description

[Technical Field]

[0001] The present disclosure relates to waste treatment systems. [Background technology]

[0002] Patent Document 1 discloses a waste treatment system in which biomass contained in waste is hydrothermally treated with high-temperature, high-pressure steam, a liquid such as a solution or slurry is separated from the hydrothermally treated product, and the liquid is used to generate gas, for example, methane fermentation, using microorganisms. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-95036 Summary of the Invention [Problem to be solved by the invention]

[0004] In the waste treatment system described in Patent Document 1, steam is discharged from the hydrothermal treatment device after the hydrothermal treatment reaction of biomass. This steam contains an odor, and it is undesirable to release the odor directly into the atmosphere. Furthermore, when a deodorization facility is installed to reduce the amount of odor released into the atmosphere, if a large amount of steam is discharged from the hydrothermal treatment device, the deodorization facility tends to become large, which can complicate the configuration of the waste treatment system.

[0005] In view of the above circumstances, at least one embodiment of the present disclosure aims to provide a waste treatment system equipped with a hydrothermal treatment device that has a simple configuration and can reduce the amount of odor emitted into the atmosphere. [Means for solving the problem]

[0006] In order to achieve the above object, a waste treatment system according to at least one embodiment of the present disclosure comprises: a hydrothermal treatment device configured to hydrothermally treat biomass contained in waste using steam and discharge a hydrothermally treated product of the biomass; a release steam line connected to the hydrothermal treatment device and configured to discharge steam from the hydrothermal treatment device; a methane fermenter configured to produce methane gas using the liquid portion of the hydrothermal treatment product discharged from the hydrothermal treatment device; a biomass-derived material processing device configured to process the biomass-derived material; an odor line connected to the biomass-derived material treatment device, through which odors are discharged from the biomass-derived material treatment device; a deodorization facility connected to the odor line and configured to deodorize the odor discharged from the biomass-derived material treatment device; Equipped with the release steam line is connected to the biomass-derived material treatment device and is configured to supply the steam discharged from the hydrothermal treatment device to the biomass-derived material treatment device; The biomass-derived material treatment device is configured to perform heat exchange between the steam supplied from the release steam line and the material derived from the biomass. [Effects of the Invention]

[0007] According to at least one embodiment of the present disclosure, a waste treatment system including a hydrothermal treatment device is provided that can reduce the amount of odor emitted into the atmosphere with a simple configuration. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram showing a schematic configuration of a waste treatment system 2 according to an embodiment of the present disclosure. [Figure 2] 2 is a schematic cross-sectional view for explaining an example of the general configuration of a mixing adjustment tank 8. FIG. [Figure 3]FIG. 2 is a diagram illustrating an example of a method for cleaning the drum screen 9 using steam supplied from a release steam line 24. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, several embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the invention. For example, expressions expressing relative or absolute arrangement such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial" not only express such an arrangement exactly, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained. For example, expressions such as "identical," "equal," and "homogeneous" that indicate that something is in an equal state not only indicate a state of strict equality, but also indicate a state in which there is a tolerance or a difference to the extent that the same function is obtained. For example, expressions representing shapes such as a square shape or a cylindrical shape not only represent shapes such as a square shape or a cylindrical shape in the strict geometric sense, but also represent shapes including uneven portions, chamfered portions, etc., to the extent that the same effect can be obtained. On the other hand, the expressions "comprise," "include," "have," "includes," or "have" of one element are not exclusive expressions that exclude the presence of other elements.

[0010] FIG. 1 is a diagram showing a schematic configuration of a waste treatment system 2 according to an embodiment of the present disclosure. In the exemplary embodiment shown in FIG. 1, the waste treatment system 2 includes a hydrothermal treatment device 4, a coarse separation device 6, a mixing and adjustment tank 8, a drum screen 9, a screw press 10, a methane fermentation tank 12, a sludge dryer 14, and a deodorization facility 16.

[0011] The hydrothermal treatment device 4 is a sealed pressure vessel for hydrothermally treating biomass contained in waste. The hydrothermal treatment device 4 is connected to a waste input line 18, a steam supply line 20, a hydrothermal treatment product discharge line 22, and a release steam line 24. Biomass-containing waste is input to the hydrothermal treatment device 4 through the waste input line 18, and high-temperature, high-pressure steam (e.g., steam at approximately 120°C to 180°C) is supplied through the steam supply line 20, heating and pressurizing the interior of the hydrothermal treatment device 4. The waste input through the waste input line 18 may be paper-rich waste such as municipal solid waste, and includes materials suitable for methane fermentation (organic waste suitable for methane fermentation), such as paper and kitchen waste, and materials unsuitable for methane fermentation (waste unsuitable for methane fermentation), such as plastics, cloth, and metals.

[0012] The hydrothermal treatment device 4 hydrothermally treats biomass (e.g., materials suitable for methane fermentation, such as paper and kitchen waste) contained in waste input from a waste input line 18 using high-temperature, high-pressure steam supplied from a steam supply line 20, and discharges a hydrothermally treated biomass product (hydrothermally treated biomass). Note that the hydrothermally treated biomass product is a group of substances obtained by hydrothermal treatment of biomass (biomass modified by hydrothermal treatment), and includes biomass with lower molecular weight than the biomass input from the waste input line 18. Hereinafter, the hydrothermally treated biomass product may be simply referred to as the "hydrothermally treated product."

[0013] In the illustrated exemplary embodiment, the hydrothermal treatment device 4 is configured to perform the hydrothermal treatment of biomass in a batch process, in which a predetermined amount of waste is input into the hydrothermal treatment device 4 at once from a waste input line 18, the hydrothermal treatment reaction of the biomass proceeds for a predetermined time, and the hydrothermal treatment product of the biomass is discharged from the hydrothermal treatment device 4 at once into a hydrothermal treatment product discharge line 22. When the hydrothermal treatment of the biomass for the predetermined time in the hydrothermal treatment device 4 is completed, the steam inside the hydrothermal treatment device 4 is discharged from the hydrothermal treatment device 4 into a release steam line 24 before the hydrothermal treatment product of the biomass is discharged from the hydrothermal treatment device 4. In the illustrated exemplary embodiment, one end of the release steam line 24 is connected to the hydrothermal treatment device 4, and the other end of the release steam line 24 branches into release steam branch lines 24a to 24c, which will be described later.

[0014] By using the hydrothermal treatment device 4 as described above, biomass such as paper and kitchen waste is pulverized by hydrothermal treatment, and when it is introduced into the mixing and adjustment tank 8, it becomes easy to disperse and form a slurry in the mixing and adjustment tank 8. On the other hand, in the hydrothermal treatment device 4, materials unsuitable for fermentation such as plastics retain their original shape and stick together, becoming larger.

[0015] An electric valve 23 is provided on the hydrothermally treated product discharge line 22, and when discharging the hydrothermally treated biomass product from the hydrothermally treated treatment device 4, the discharge rate of the hydrothermally treated biomass product can be controlled by the electric valve 23 while monitoring the residual pressure in the hydrothermally treated treatment device 4 (i.e., the internal pressure of the pressure vessel).

[0016] In the illustrated exemplary embodiment, the coarse sorting device 6 is provided at a position between the motor-operated valve 23 and the mixing adjustment tank 8 in the hydrothermal treatment product discharge line 22. The coarse sorting device 6 removes relatively large materials unsuitable for methane fermentation, such as plastics and cloth, that are mixed in the hydrothermal treatment product of biomass discharged from the hydrothermal treatment device 4 to the hydrothermal treatment product discharge line 22.

[0017] The mixing and adjustment tank 8 is configured to mix the hydrothermally treated biomass product discharged from the hydrothermal treatment device 4 with dilution water (dilution liquid) to reduce the solids concentration of the hydrothermally treated product, thereby adjusting the properties of the hydrothermally treated product. In the illustrated exemplary embodiment, the mixing and adjustment tank 8 is connected to a hydrothermally treated product discharge line 22 and a dilution water supply line 26. The mixing and adjustment tank 8 receives the hydrothermally treated biomass product supplied from the hydrothermally treated product discharge line 22 (the hydrothermally treated product discharged from the hydrothermal treatment device 4 and from which materials unsuitable for methane fermentation have been removed in the coarse sorting device 6), and mixes the hydrothermally treated product with dilution water supplied from the dilution water supply line 26 to form a slurry of the hydrothermally treated product. Because pre-separated food waste does not need to be subjected to hydrothermal treatment, the food waste may be directly introduced into the mixing and adjustment tank 8 and mixed with the hydrothermally treated product and dilution water.

[0018] A release steam branch line 24a is connected to the mixing adjustment tank 8, and after the hydrothermal treatment reaction of biomass in the hydrothermal treatment device 4 is completed, steam (release steam) discharged from the hydrothermal treatment device 4 is supplied from the release steam branch line 24a to the inside of the mixing adjustment tank 8. An odor line 60a is connected to the mixing adjustment tank 8, and odors discharged from the mixing adjustment tank 8 into the odor line 60a are supplied to the deodorization equipment 16 and deodorized in the deodorization equipment 16. The odors discharged from the mixing adjustment tank 8 into the odor line 60a include, for example, volatile organic compounds, hydrogen sulfide, and ammonia.

[0019] In the mixing and adjustment tank 8, heat exchange occurs between the steam supplied from the release steam branch line 24a and the slurry of the hydrothermal treatment product in the mixing and adjustment tank 8, and a portion of the steam condenses. Therefore, compared to when the steam discharged from the hydrothermal treatment device 4 is directly supplied to the deodorization equipment 16 (when the release steam line 24 is directly connected to the deodorization equipment 16 without being connected to the mixing and adjustment tank 8), the amount of steam to be treated in the deodorization equipment 16 can be reduced, and the amount of odor emitted into the atmosphere can be reduced with a simple configuration. Furthermore, the steam supplied from the release steam branch line 24a can be used to increase the temperature and pressure inside the mixing and adjustment tank 8, so the thermal energy of the steam can be effectively utilized to promote the solubilization of the hydrothermal treatment product.

[0020] The mixing and adjustment tank 8 and the methane fermentation tank 12 are connected by a slurry supply line 30, and the slurry discharged from the mixing and adjustment tank 8 (the hydrothermal treatment product slurried by adding dilution water in the mixing and adjustment tank 8) is supplied to the methane fermentation tank 12 after substances unsuitable for methane fermentation are removed as it passes through the slurry supply line 30, as described below.

[0021] A metering tank 32 is provided on the slurry supply line 30, and a slurry return line 34 is connected to the metering tank 32, which is configured to return a portion of the slurry (slurried hydrothermal treatment product) discharged from the mixing adjustment tank 8 to the slurry supply line 30 to the mixing adjustment tank 8. The metering tank 32 distributes the slurry discharged from the mixing adjustment tank 8 to the slurry supply line 30 between the mixing adjustment tank 8 and the drum screen 9. A crushing pump 38 is provided on the slurry supply line 30 upstream of the metering tank 32. The crushing pump 38 includes a cutter (not shown) and is configured to crush and finely mill solids contained in the slurry with the cutter.

[0022] On the downstream side of the metering tank 32 in the slurry supply line 30, a drum screen 9 and a screw press 10 are provided as separation devices for removing impurities from the slurry discharged from the mixing adjustment tank 8.

[0023] The drum screen 9 is configured to remove impurities from the slurry distributed from the metering tank 32. The liquid portion of the slurry distributed from the metering tank 32 passes through the drum screen 9 and is supplied to the methane fermentation tank 12. Of the slurry distributed from the metering tank 32 to the drum screen 9, the solid portion with a relatively large particle size that does not pass through the drum screen 9 is supplied to the screw press 10 and concentrated by a screw (not shown), and the liquid in the solid portion is separated from the solid portion, and the liquid is supplied to the methane fermentation tank 12.

[0024] A release steam branch line 24b is connected to the drum screen 9, and steam discharged from the hydrothermal treatment device 4 is supplied from the release steam branch line 24b to the drum screen 9. An odor line 60b is connected to the drum screen 9, and odors discharged from the drum screen 9 to the odor line 60b are supplied to the deodorization equipment 16 and deodorized in the deodorization equipment 16. The odors discharged from the drum screen 9 to the odor line 60b include, for example, volatile organic compounds, hydrogen sulfide, ammonia, and the like.

[0025] According to this configuration, the steam supplied from the release steam branch line 24b to the drum screen 9 cleans the filtering surface (not shown) of the drum screen 9, thereby preventing clogging of the drum screen 9. Furthermore, heat exchange between the steam supplied from the release steam branch line 24b and the slurry (slurried hydrothermal treatment product) in the drum screen 9 can raise the temperature of the slurry in the drum screen 9. This reduces the amount of energy consumption required to maintain the internal temperature of the methane fermentation tank 12 at a temperature suitable for methane fermentation. Furthermore, heat exchange between the steam supplied from the release steam branch line 24b and the slurry in the drum screen 9 can condense the steam in the drum screen 9. This reduces the amount of steam to be treated in the deodorization equipment 16, thereby reducing the amount of odor emitted into the atmosphere with a simple configuration.

[0026] In addition, an odor line 60c is connected to the screw press 10, and odors discharged from the screw press 10 into the odor line 60c are supplied to the deodorization equipment 16 and deodorized in the deodorization equipment 16. The odors discharged from the screw press 10 into the odor line 60c include, for example, volatile organic compounds, hydrogen sulfide, ammonia, and the like.

[0027] In the illustrated exemplary embodiment, of the hydrothermal treatment product discharged from the mixing and adjustment tank 8, the liquid fraction separated from the solid fraction by the drum screen 9 and the liquid fraction separated from the solid fraction by the screw press 10 are supplied to an input pit 46, and from the input pit 46 are supplied to the methane fermentation tank 12 by a pressure pump 48. An odor line 60d is connected to the input pit 46, and the odor discharged from the input pit 46 to the odor line 60d is supplied to the deodorization equipment 16 and deodorized therein.

[0028] The methane fermentation tank 12 produces methane gas using the liquid portion of the slurry supplied from the slurry supply line 30 (the liquid portion of the hydrothermal treatment slurry discharged from the mixing and adjustment tank 8 that has been separated from the solid portion by the drum screen 9 and screw press 10). More specifically, in the methane fermentation tank 12, methane fermentation substrates (e.g., organic matter such as sugars, volatile fatty acids, and amino acids) contained in the liquid portion of the slurry supplied from the slurry supply line 30 are decomposed by microorganisms such as methanogens under anaerobic conditions, producing methane gas and carbon dioxide. The sludge discharged from the methane fermentation tank 12 (the fermentation residue remaining after methane fermentation in the methane fermentation tank 12) passes through a sludge supply line 50 and is dewatered in a sludge dewatering system 13. The dewatered sludge is supplied to a sludge dryer 14 and dried therein.

[0029] A release steam branch line 24c is connected to the sludge dryer 14, and steam discharged from the hydrothermal treatment device 4 is supplied to the sludge dryer 14 from the release steam branch line 24c. In addition, an odor line 60e is connected to the sludge dryer 14, and odors discharged from the sludge dryer 14 into the odor line 60e are supplied to the deodorization equipment 16 and deodorized in the deodorization equipment 16. The odors discharged from the sludge dryer 14 into the odor line 60d include, for example, volatile organic compounds, hydrogen sulfide, ammonia, etc.

[0030] In the illustrated exemplary embodiment, the odor lines 60a to 60e join together to form a joined odor line 60m, which is connected to the deodorizing equipment 16. In addition, the joined odor line 60m is provided with a suction fan 62, so that by operating one suction fan 62, odors can be sucked from each of the mixing adjustment tank 8, the drum screen 9, the screw press 10, the input pit 46, and the sludge dryer 14 and supplied to the deodorizing equipment 16.

[0031] In the sludge dryer 14, heat exchange is performed between the sludge discharged from the methane fermentation tank 12 and the steam supplied from the release steam branch line 24c, thereby making it possible to dry the sludge by utilizing the thermal energy of the steam discharged from the hydrothermal treatment device 4. Furthermore, since the steam supplied from the release steam branch line 24c can be condensed by this heat exchange, the amount of steam to be treated in the deodorization equipment 16 can be reduced, and the amount of odor emitted into the atmosphere can be reduced with a simple configuration.

[0032] FIG. 2 is a schematic cross-sectional view illustrating an example of the general configuration of the mixing adjustment tank 8. As shown in FIG. 2 , the release steam branch line 24a includes a release pipe 25 configured to supply steam discharged from the hydrothermal treatment device 4 to the inside of the mixing and adjustment tank 8. The release pipe 25 protrudes from the inner surface 8i of the mixing and adjustment tank 8 into the inside of the mixing and adjustment tank 8. In the illustrated example, the release pipe 25 protrudes downward from the ceiling 8a of the mixing and adjustment tank 8.

[0033] In this way, by supplying steam into the mixing adjustment tank 8 from the release pipe 25 protruding from the inner surface 8i of the mixing adjustment tank 8, the steam can be supplied to a position close to the hydrothermally treated product accumulated inside the mixing adjustment tank 8, and heat exchange between the steam and the hydrothermally treated product can be efficiently carried out. This allows the hydrothermally treated product to be efficiently heated and the steam to be efficiently condensed. This can enhance the effect of promoting the solubilization of solids contained in the hydrothermally treated product, and can reduce the amount of steam to be treated in the deodorization equipment 16.

[0034] Also, in the exemplary form shown in FIG. 2, the release pipe 25 includes a steam outlet 25a inside the mixing and adjusting tank 8, and the outlet 25a is located in the region S occupied by the gas inside the mixing and adjusting tank 8. If the steam outlet 25a of the release pipe 25 is inside the slurry of the hydrothermally treated product in the mixing and adjusting tank 8, a rapid pressure change occurs when the steam from the release pipe 25 condenses, generating a strange noise called hammering. In this regard, as shown in FIG. 2, since the steam outlet 25a of the release pipe 25 is located in the region S occupied by the gas inside the mixing and adjusting tank 8, the occurrence of the above hammering can be suppressed.

[0035] Also, in the exemplary form shown in FIG. 2, the mixing and adjusting tank 8 includes a hydrothermally treated product inlet 52 for receiving the hydrothermally treated product discharged from the hydrothermal treatment device 4, a dilution water inlet 28 for receiving dilution water from the dilution water supply line 26, and a slurry inlet 29 for receiving the slurry from the slurry return line 34 on the upper surface 8u of the mixing and adjusting tank 8. Also, if the longitudinal dimension of the mixing and adjusting tank 8 is L and the horizontal distance between the hydrothermally treated product inlet 52 and the outlet 25a of the release pipe 25 in the mixing and adjusting tank 8 is d1, it may satisfy d1 < L / 2, or it may satisfy d1 < L / 4. That is, d1 may be smaller than half of L, or may be smaller than one-fourth of L. Also, if the horizontal distance between the outlet 25a of the release pipe 25 and the dilution water inlet 28 is d2, it may satisfy d2 < L / 2, or it may satisfy d2 < L / 4. That is, d2 may be smaller than half of L, or may be smaller than one-fourth of L. Also, if the horizontal distance between the outlet 25a of the release pipe 25 and the slurry inlet 29 is d3, it may satisfy d3 < L / 2, or it may satisfy d3 < L / 4. That is, d3 may be smaller than half of L, or may be smaller than one-fourth of L.

[0000] Also, in the exemplary form shown in FIG. 2, the mixing and adjusting tank 8 includes on the upper surface 8u of the mixing and adjusting tank 8.

[0036] As shown in FIG. 2, when receiving the hydrothermal treatment section from the hydrothermal treatment product inlet 52 received on the upper surface 8u of the mixing and adjustment tank 8, a mound 53 on which solids contained in the hydrothermal treatment product accumulate is likely to be formed below the hydrothermal treatment product inlet 52 in the mixing and adjustment tank 8. In this regard, by satisfying d1 < L / 2 as described above, steam can be injected into the mound 53 of the hydrothermal treatment product from a position relatively closer to the mound 53 of the hydrothermal treatment product than when d1 < L / 2 is not satisfied, and the mound 53 of the hydrothermal treatment product can be broken down. Thereby, the effect of promoting the solubilization of the hydrothermal treatment product can be enhanced. Further, by satisfying d2 < L / 2, the dilution water supplied from the dilution water inlet 28 and the steam supplied from the release pipe 25 are more likely to come into contact with each other and the steam is more likely to condense than when d2 < L / 2 is not satisfied. Thereby, the condensed liquid can be circulated in the mixing and adjustment tank 8 to effectively break down the mound 53 of the hydrothermal treatment product, and the effect of promoting the solubilization of the hydrothermal treatment product can be enhanced. Further, by satisfying d3 < L / 2, the slurry supplied from the slurry inlet 29 and the steam supplied from the release pipe 25 are more likely to come into contact with each other and the steam is more likely to condense than when d3 < L / 2 is not satisfied. Thereby, the condensed liquid can be circulated in the mixing and adjustment tank 8 to effectively break down the mound 53 of the hydrothermal treatment product, and the effect of promoting the solubilization of the hydrothermal treatment product can be enhanced.

[0037] FIG. 3 is a diagram for explaining an example of a method of cleaning the drum screen 9 using the steam supplied from the release steam line 24. As shown in FIG. 3, the drum screen 9 includes a screen 43 (screen body), which is a cylindrical filter, and a casing 45 that houses the screen 43. The screen 43 is configured to remove impurities in the slurry (slurried hydrothermal treatment product) supplied from the slurry supply line 30, and separate the slurry into a solid component and a liquid component according to the particle size.

[0038] In the illustrated exemplary embodiment, the release steam branch line 24b includes an upstream line 24b1 for supplying steam discharged from the hydrothermal treatment device 4 to the screen 43 from the upstream side of the screen 43 (in the illustrated example, the inner side of the screen 43), and a downstream line 24b2 for supplying steam discharged from the hydrothermal treatment device 4 to the screen 43 from the downstream side of the screen 43 (in the illustrated example, the outer side of the screen 43).

[0039] The release steam line 24 also includes a switching device 49 that can switch the line through which the steam discharged from the hydrothermal treatment device 4 flows between the upstream line 24b1 and the downstream line 24b2. The switching device 49 includes a valve 49a provided in the upstream line 24b1 and a valve 49b provided in the downstream line 24b2. Each of the upstream line 24b1 and the downstream line 24b2 may be provided with nozzles 51 for spraying the steam discharged from the hydrothermal treatment device 4 at multiple positions in the axial direction of the drum screen 9. This allows the steam to be dispersed onto the surface of the screen 43 at multiple positions in the axial direction of the drum screen 9, thereby efficiently cleaning the screen 43. In the illustrated exemplary embodiment, the nozzle 51 of the upstream line 24b1 is disposed on the inner periphery of the screen 43, and the nozzle 51 of the downstream line 24b2 is disposed on the outer periphery of the screen 43.

[0040] According to this configuration, by switching the line through which the steam discharged from the hydrothermal treatment device 4 flows between the upstream line 24b1 and the downstream line 24b2, it is possible to effectively clean both sides (the upstream side and the downstream side) of the screen 43. This can enhance the effect of suppressing clogging of the screen.

[0041] The present disclosure is not limited to the above-described embodiments, but also includes modifications to the above-described embodiments and appropriate combinations of these modifications.

[0042] For example, in the above-described embodiment, an example was given of the case where steam discharged from the hydrothermal treatment device 4 is supplied to the mixing and adjustment tank 8, the drum screen 9, and the sludge dryer 14 via the release steam line 24, but the steam discharged from the hydrothermal treatment device 4 may also be supplied to only one of the mixing and adjustment tank 8, the drum screen 9, and the sludge dryer 14 via the release steam line 24, or to any two of the mixing and adjustment tank 8, the drum screen 9, and the sludge dryer 14.

[0043] Furthermore, for example, the steam discharged from the hydrothermal treatment device 4 to the release steam line 24 in one batch treatment in the hydrothermal treatment device 4 may be distributed to the mixing and adjustment tank 8, the drum screen 9, and the sludge dryer 14. Alternatively, of the steam discharged from the hydrothermal treatment device 4 to the release steam line 24 in N batch treatments, the steam discharged from the hydrothermal treatment device 4 to the release steam line 24 in m batch treatments may be supplied to the drum screen 9, the steam discharged from the hydrothermal treatment device 4 to the release steam line 24 in n batch treatments may be supplied to the mixing and adjustment tank 8, and the steam discharged from the hydrothermal treatment device 4 to the release steam line 24 in p batch treatments may be supplied to the sludge dryer 14. Here, N is an integer of 3 or more, and m, n, and p are natural numbers that satisfy the equation N=m+n+p.

[0044] The contents described in each of the above embodiments can be understood, for example, as follows.

[0045] [1] At least one embodiment of the waste treatment system according to the present disclosure (e.g., the waste treatment system 2 described above) includes: a hydrothermal treatment device (for example, the above-mentioned hydrothermal treatment device 4) configured to hydrothermally treat biomass contained in waste using steam and discharge a hydrothermal treatment product of the biomass; a release steam line (e.g., release steam line 24 described above) connected to the hydrothermal treatment device and configured to discharge steam from the hydrothermal treatment device; a methane fermenter (for example, the methane fermenter 12 described above) configured to produce methane gas using the liquid portion of the hydrothermal treatment product discharged from the hydrothermal treatment device; a biomass-derived substance treatment device (for example, the above-mentioned mixing and adjusting tank 8, drum screen 9, or sludge dryer 14) configured to treat a substance derived from the biomass (for example, a hydrothermal treatment product of biomass, or sludge, which is a fermentation residue after methane fermentation using the liquid fraction of the hydrothermal treatment product); an odor line (for example, the odor line 60a, odor line 60b, odor line 60c, odor line 60d, or odor line 60e, and the combined odor line 60m) connected to the biomass-derived material treatment device and through which odor is discharged from the biomass-derived material treatment device; a deodorization facility (for example, the above-described deodorization facility 16) connected to the odor line and configured to deodorize the odor discharged from the biomass-derived material treatment device; Equipped with the release steam line is connected to the biomass-derived material treatment device and is configured to supply the steam discharged from the hydrothermal treatment device to the biomass-derived material treatment device; The biomass-derived material treatment device is configured to perform heat exchange between the steam supplied from the release steam line and the material derived from the biomass.

[0046] According to the waste treatment system described in [1] above, steam discharged from the hydrothermal treatment device can be supplied to the biomass-derived material treatment device via the release steam line. In the biomass-derived material treatment device, heat exchange occurs between the steam supplied via the release steam line and biomass-derived materials, condensing at least a portion of the steam. This reduces the amount of steam to be treated in the deodorization device compared to when steam discharged from the hydrothermal treatment device is directly supplied to the deodorization device (when the release steam line is connected to the deodorization device), thereby reducing the amount of odor released into the atmosphere with a simple configuration. Furthermore, because the biomass-derived materials in the biomass-derived material treatment device can receive the thermal energy of the steam supplied via the release steam line (steam discharged from the hydrothermal treatment device), the heat content of the steam can be effectively utilized.

[0047] [2] In some embodiments, in the waste treatment system described in [1] above, the biomass-derived material treatment device is a mixing and adjustment tank (for example, the above-mentioned mixing and adjustment tank 8) configured to receive the hydrothermal treatment product discharged from the hydrothermal treatment device, the mixing and adjusting tank is configured to mix the hydrothermally treated product with a dilution liquid to adjust the properties of the hydrothermally treated product, The release steam line is connected to the mixing and adjusting tank and is configured to supply the steam discharged from the hydrothermal treatment device to the mixing and adjusting tank.

[0048] According to the waste treatment system described in [2] above, by bringing the steam discharged from the hydrothermal treatment device into contact with the hydrothermal treatment product (a substance derived from biomass) in the mixing and adjustment tank, the hydrothermal treatment product is heated with the steam, which promotes the solubilization of solids contained in the hydrothermal treatment product, thereby making effective use of the heat contained in the steam. Furthermore, since at least a portion of the steam can be condensed by heat exchange with the hydrothermal treatment product in the mixing and adjustment tank, the amount of steam to be treated in the deodorization equipment can be reduced, and the amount of odor emitted into the atmosphere can be reduced with a simple configuration.

[0049] [3] In some embodiments, in the waste treatment system described in [2] above, the release steam line includes a release pipe (e.g., the above-described release pipe 25) configured to supply the steam discharged from the hydrothermal treatment device to the inside of the mixing and adjustment tank, The release pipe protrudes from the inner surface of the mixing adjustment tank (for example, the inner surface 8i described above) into the inside of the mixing adjustment tank.

[0050] According to the waste treatment system described in [3] above, by supplying steam from the release pipe protruding from the inner surface of the mixing and adjustment tank into the inside of the mixing and adjustment tank, steam can be supplied to a position close to the hydrothermal treatment product accumulated inside the mixing and adjustment tank, and efficient heat exchange between the steam and the hydrothermal treatment product can be performed. Thereby, the hydrothermal treatment product can be efficiently heated and the steam can be efficiently condensed. For this reason, the effect of promoting the solubilization of the solid matter contained in the hydrothermal treatment product can be enhanced, and the amount of steam to be treated by the deodorization equipment can be reduced.

[0051] [4] In some embodiments, in the waste treatment system described in [3] above, the release pipe includes an outlet of the steam (for example, the above-described outlet 25a) inside the mixing and adjustment tank, and the outlet is located in a region occupied by gas inside the mixing and adjustment tank (for example, the above-described region S).

[0052] If the outlet of the steam of the release pipe is inside the slurry of the hydrothermal treatment product in the mixing and adjustment tank, a sudden pressure change occurs when the steam condenses, generating a strange noise called hammering. In this regard, according to the waste treatment system described in [4] above, since the outlet of the steam of the release pipe is located in the region occupied by gas inside the mixing and adjustment tank, the occurrence of hammering can be suppressed.

[0053] [5] In some embodiments, in the waste treatment system described in [4] above, the mixing and adjustment tank includes a hydrothermal treatment product inlet (for example, the above-described hydrothermal treatment product inlet 52) for receiving the hydrothermal treatment product discharged from the hydrothermal treatment device on the upper surface (for example, the above-described upper surface 8u) of the mixing and adjustment tank, when the longitudinal dimension of the mixing and adjustment tank is L and the horizontal distance between the hydrothermal treatment product inlet and the outlet in the mixing and adjustment tank is d1, d1 < L / 2 is satisfied.

[0054] When receiving the hydrothermally treated material from the hydrothermally treated material inlet received on the upper surface of the mixing and adjusting tank, a mound where solids contained in the hydrothermally treated material accumulate is likely to be formed below the hydrothermally treated material inlet in the mixing and adjusting tank. In this regard, according to the waste treatment system described in the above [5], by satisfying d1 < L / 2, steam can be injected into the mound of the hydrothermally treated material from a position relatively closer to the mound of the hydrothermally treated material than when d1 < L / 2 is not satisfied, and the mound of the hydrothermally treated material can be collapsed. Thereby, the effect of promoting the solubilization of the hydrothermally treated material can be enhanced.

[0055] [6] In some embodiments, in the waste treatment system described in the above [4], the mixing and adjusting tank includes a dilution water inlet for receiving dilution water on the upper surface of the mixing and adjusting tank (for example, the above-mentioned upper surface 8u), when the longitudinal dimension of the mixing and adjusting tank is L and the horizontal distance between the dilution water inlet and the outlet in the mixing and adjusting tank is d2, d2 < L / 2 is satisfied.

[0056] According to the waste treatment system described in the above [6], by satisfying d2 < L / 2, the dilution water supplied from the dilution water inlet and the steam supplied from the release pipe are more likely to come into contact and the steam is more likely to condense than when d2 < L / 2 is not satisfied. Thereby, the condensed liquid can be circulated in the mixing and adjusting tank to effectively collapse the mound of the hydrothermally treated material, and the effect of promoting the solubilization of the hydrothermally treated material can be enhanced.

[0057] [7] In some embodiments, in the waste treatment system described in the above [4], the mixing and adjusting tank includes a slurry inlet for receiving slurry discharged from the mixing and adjusting tank and returned to the mixing and adjusting tank, when the longitudinal dimension of the mixing and adjusting tank is L and the horizontal distance between the slurry inlet and the outlet in the mixing and adjusting tank is d3, d3 < L / 2 is satisfied.

[0058] According to the waste treatment system described in [7] above, by satisfying d3 < L / 2, the slurry supplied from the slurry inlet and the steam supplied from the release pipe are more likely to come into contact with each other and the steam is more likely to condense than when d3 < L / 2 is not satisfied. As a result, the condensed liquid can be circulated in the mixing adjustment tank to effectively break up the hydrothermally treated product mass, and the effect of promoting the solubilization of the hydrothermally treated product can be enhanced.

[0059] [8] In some embodiments, in the waste treatment system described in [1] above, the biomass-derived substance treatment device is a separation device (for example, the drum screen 9 described above) for removing impurities in the hydrothermally treated product, the release steam line is connected to the separation device and is configured to supply the steam discharged from the hydrothermal treatment device to the separation device.

[0060] According to the waste treatment system described in [8] above, by performing heat exchange between the steam supplied from the release steam line and the hydrothermally treated product (substance derived from biomass) in the separation device, the temperature of the hydrothermally treated product in the separation device can be increased. Therefore, in the methane fermentation tank to which the liquid component of the hydrothermally treated product discharged from the separation device is supplied, the energy consumption required to maintain the internal temperature of the methane fermentation tank at a temperature suitable for methane fermentation can be reduced. In addition, by performing heat exchange between the steam supplied from the release steam line and the hydrothermally treated product in the separation device, the steam can be condensed in the separation device. As a result, the amount of steam to be treated in the deodorization facility can be reduced, and the amount of odor released into the atmosphere can be reduced with a simple configuration.

[0061] [9] In some embodiments, in the waste treatment system described in [8] above, the separation device includes a screen (for example, the screen 43 described above) for removing impurities in the hydrothermally treated product, the release steam line is configured to supply the steam discharged from the hydrothermal treatment device to the screen.

[0062] According to the waste treatment system described in [9] above, the screen can be cleaned using steam supplied from the release steam line, which can prevent clogging of the screen.

[0063]

[10] In some embodiments, in the waste treatment system described in [9] above, The release vapor line An upstream line (for example, the above-mentioned upstream line 24b1) for supplying the steam discharged from the hydrothermal treatment device to the screen from the upstream side of the screen in the separation device; A downstream line (for example, the above-mentioned downstream line 24b2) for supplying the steam discharged from the hydrothermal treatment device to the screen from the downstream side of the screen in the separation device; A switching device (for example, the above-mentioned switching device 49) capable of switching the line through which the steam discharged from the hydrothermal treatment device flows between the upstream line and the downstream line; Equipped with.

[0064] According to the waste treatment system described in

[10] above, by switching the line through which the steam discharged from the hydrothermal treatment device flows between the upstream line and the downstream line, both sides of the screen (the upstream side and the downstream side) can be effectively cleaned, thereby enhancing the effect of suppressing clogging of the screen.

[0065]

[11] In some embodiments, in the waste treatment system described in [1] above, the biomass-derived material treatment device is a sludge dryer (for example, the above-mentioned sludge dryer 14) for drying sludge discharged from the methane fermentation tank, The release steam line is connected to the sludge dryer and is configured to supply the steam discharged from the hydrothermal treatment device to the sludge dryer.

[0066] According to the waste treatment system described in

[11] above, by performing heat exchange in the sludge dryer between the sludge (biomass-derived material) discharged from the methane fermentation tank and the steam supplied from the release steam line, the thermal energy of the steam discharged from the hydrothermal treatment device can be used to dry the sludge. In addition, since the steam supplied from the release steam line can be condensed by this heat exchange, the amount of steam to be treated in the deodorization equipment can be reduced, and the amount of odor emitted into the atmosphere can be reduced with a simple configuration. [Explanation of symbols]

[0067] 2: Waste treatment system 4: Hydrothermal treatment equipment 6: Rough sorting device 8:Mixing adjustment tank 8a: Ceiling 8i: Inner surface 8u:Top surface 9: Drum screen 10:Screw press 12: Methane fermentation tank 13: Sludge dewatering equipment 14: Sludge dryer 16: Deodorizing equipment 18: Waste input line 20: Steam supply line 22: Hydrothermal treatment product discharge line 23: Motor-operated valve 24: Release steam line 24a, 24b, 24c: Release steam branch lines 24b1: Upstream line 24b2: Downstream line 25: Release piping 25a:Exit 26: Dilution water supply line 28: Dilution water inlet 29: Slurry receiving port 30: Slurry supply line 32:Measuring tank 34: Slurry return line 38: Fracturing pump 43: Screen 45: Casing 46: Input pit 48: Pressure pump 49: Switching device 49a, 49b: Valve 50: Sludge supply line 51: Nozzle 52: Hydrothermal treatment product receiving port 60a, 60b, 60c, 60d, 60e: Odor line 60m: Confluence odor line 62: Suction fan

Claims

1. a hydrothermal treatment device configured to hydrothermally treat biomass contained in waste using steam and discharge a hydrothermally treated product of the biomass; a release steam line connected to the hydrothermal treatment device and configured to discharge steam from the hydrothermal treatment device; a methane fermenter configured to produce methane gas using the liquid portion of the hydrothermal treatment product discharged from the hydrothermal treatment device; a biomass-derived material processing device configured to process the biomass-derived material; an odor line connected to the biomass-derived material treatment device, through which odors are discharged from the biomass-derived material treatment device; a deodorization facility connected to the odor line and configured to deodorize the odor discharged from the biomass-derived material treatment device; Equipped with the release steam line is connected to the biomass-derived material treatment device and is configured to supply the steam discharged from the hydrothermal treatment device to the biomass-derived material treatment device; A waste treatment system, wherein the biomass-derived material treatment device is configured to perform heat exchange between the steam supplied from the release steam line and the material derived from the biomass.

2. the biomass-derived material treatment device is a mixing and adjustment tank configured to receive the hydrothermal treatment product discharged from the hydrothermal treatment device, the mixing and adjusting tank is configured to mix the hydrothermally treated product with a dilution liquid to adjust the properties of the hydrothermally treated product, 2. The waste treatment system according to claim 1, wherein the release steam line is connected to the mixing and adjustment tank and is configured to supply the steam discharged from the hydrothermal treatment device to the mixing and adjustment tank.

3. the release steam line includes a release pipe configured to supply the steam discharged from the hydrothermal treatment device to the inside of the mixing and adjustment tank, 3. The waste treatment system according to claim 2, wherein the release pipe protrudes from an inner surface of the mixing and adjusting tank toward the inside of the mixing and adjusting tank.

4. the release pipe includes an outlet for the steam inside the mixing and adjusting tank, The waste treatment system according to claim 3 , wherein the outlet is located in a region occupied by gas inside the mixing and adjusting tank.

5. the mixing and adjustment tank includes a hydrothermal treatment product receiving port that receives the hydrothermal treatment product discharged from the hydrothermal treatment device, 5. The waste treatment system according to claim 4, wherein the longitudinal dimension of the mixing adjustment tank is L and the horizontal distance between the hydrothermal treatment product receiving inlet and the outlet in the mixing adjustment tank is d, and d<L / 2 is satisfied.

6. The mixing and adjusting tank includes a dilution water receiving port for receiving dilution water, 5. The waste treatment system according to claim 4, wherein the longitudinal dimension of the mixing and adjustment tank is L and the horizontal distance between the dilution water receiving inlet and the outlet in the mixing and adjustment tank is d2, and the relationship d2<L / 2 is satisfied.

7. the mixing and adjusting tank includes a slurry receiving port that receives the slurry discharged from the mixing and adjusting tank and returned to the mixing and adjusting tank, 5. The waste treatment system according to claim 4, wherein, when the longitudinal dimension of the mixing adjustment tank is L and the horizontal distance between the slurry receiving inlet and the outlet of the mixing adjustment tank is d3, d3<L / 2 is satisfied.

8. the biomass-derived material treatment device is a separation device for removing impurities from the hydrothermal treatment product, The waste treatment system of claim 1 , wherein the release steam line is connected to the separation device and configured to supply the steam discharged from the hydrothermal treatment device to the separation device.

9. the separation device includes a screen for removing impurities from the hydrothermal treatment product; The waste treatment system of claim 8 , wherein the release steam line is configured to supply the steam discharged from the hydrothermal treatment device to the screen.

10. The release vapor line an upstream line for supplying the steam discharged from the hydrothermal treatment device to the screen from the upstream side of the screen in the separation device; a downstream line for supplying the steam discharged from the hydrothermal treatment device to the screen from the downstream side of the screen in the separation device; a switching device that can switch the line through which the steam discharged from the hydrothermal treatment device flows between the upstream line and the downstream line; The waste treatment system of claim 9, comprising:

11. the biomass-derived material treatment device is a sludge dryer for drying sludge discharged from the methane fermentation tank, The waste treatment system according to claim 1 , wherein the release steam line is connected to the sludge dryer and is configured to supply the steam discharged from the hydrothermal treatment device to the sludge dryer.

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