waste treatment system

Abstract

A waste treatment system is provided that can efficiently transfer a hydrothermally treated product from a hydrothermal treatment device to a mixing and adjusting tank and can effectively utilize the thermal energy contained in the hydrothermally treated product. [Solution] A hydrothermal treatment device for hydrothermal treatment of biomass contained in waste, comprising: a hydrothermal treatment device having an outlet for discharging a hydrothermal-treated biomass product; a mixing and adjustment tank including a hydrothermal-treated product receiving port for receiving the hydrothermal-treated product discharged from the outlet and configured to mix the hydrothermal-treated product received from the hydrothermal-treated product receiving port with a diluent to adjust the properties of the hydrothermal-treated product; and a methane fermentation tank configured to produce methane gas using the liquid portion of the hydrothermal-treated product discharged from the mixing and adjustment tank, wherein the outlet of the hydrothermal treatment device is located at a higher position than the hydrothermal-treated product receiving port of the mixing and adjustment tank.

Description

[Technical Field]

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

[0002] Patent Document 1 discloses a waste treatment system that includes a reforming device that hydrothermally treats waste with a low moisture content, such as municipal waste, a separation device that separates the hydrothermally treated product that leaves the reforming device into solid and liquid, and a methane fermentation tank that produces methane gas using the liquid obtained from the separation device.

[0003] Patent Document 2 discloses a hydrothermal treatment system that includes a hydrothermal treatment facility (hydrolysis device) that hydrothermally treats organic matter-containing waste, an adjustment tank (mixing adjustment tank) that adjusts and stores the moisture content of the hydrothermally treated product obtained by the hydrothermal treatment, and a methane fermentation tank that produces methane gas using a hydrothermal treatment liquid, which is a slurry contained in the hydrothermally treated product. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2022-12974 A [Patent Document 2] Japanese Patent Application Publication No. 2022-97822 Summary of the Invention [Problem to be solved by the invention]

[0005] Regarding the waste treatment system described in Patent Document 1, since the hydrothermally treated product of miscellaneous garbage, such as combustible waste generated by ordinary households, has a low moisture content, it is generally assumed that conveyors will be used to transport the hydrothermally treated product. However, when transporting the hydrothermally treated product using conveyors, power is required to drive the conveyor, and the temperature of the hydrothermally treated product drops during transport, which is likely to result in energy loss. Furthermore, Patent Document 2 does not disclose any specific configuration for transporting the hydrothermally treated product from the hydrothermal treatment device to the mixing and adjustment tank.

[0006] In view of the above circumstances, at least one embodiment of the present disclosure aims to provide a waste treatment system that can efficiently transfer hydrothermally treated material from a hydrothermal treatment device to a mixing adjustment tank and can effectively utilize the thermal energy contained in the hydrothermally treated material. [Means for solving the problem]

[0007] 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 apparatus for hydrothermal treatment of biomass contained in waste, the hydrothermal treatment apparatus having an outlet for discharging the hydrothermal treatment product of the biomass; a mixing and adjusting tank including a hydrothermally treated product receiving port for receiving the hydrothermally treated product discharged from the discharge port, the mixing and adjusting tank being configured to mix the hydrothermally treated product received from the hydrothermally treated product receiving port with a diluent to adjust the properties of the hydrothermally treated product; a methane fermentation tank configured to produce methane gas using the liquid portion of the hydrothermal treatment product discharged from the mixing and adjustment tank; Equipped with The discharge port of the hydrothermal treatment device is provided at a position higher than the hydrothermal treatment product receiving port of the mixing and adjusting tank. [Effects of the Invention]

[0008] According to at least one embodiment of the present disclosure, a waste treatment system is provided that can efficiently transfer hydrothermally treated material from a hydrothermal treatment device to a mixing adjustment tank and effectively utilize the thermal energy contained in the hydrothermally treated material. [Brief explanation of the drawings]

[0009] [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 showing the positional relationship between a hydrothermal treatment device 4 and a mixing adjustment tank 8, etc. FIG. [Figure 3]FIG. 2 is a plan view showing a schematic internal structure of a mixing adjustment tank 8. [Figure 4] 4 is a view of the partition wall 73 in FIG. 3 as viewed from the direction A. FIG. [Figure 5] FIG. 10 is a diagram for explaining a modified example of the waste treatment system. [Figure 6] FIG. 10 is a diagram showing another modified example of the waste treatment system 2. [Figure 7] FIG. 2 is a schematic cross-sectional view showing an example of the configuration of a mixing adjustment tank 8. DETAILED DESCRIPTION OF THE INVENTION

[0010] 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.

[0011] (Overall configuration of waste treatment system 2) 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 mixing and adjusting tank 8, a drum screen 9, a screw press 10, a methane fermentation tank 12, and a deodorization facility 16, etc.

[0012] The hydrothermal treatment device 4 is a sealed pressure vessel for hydrothermally treating biomass contained in waste. Connected to the hydrothermal treatment device 4 are a waste input line 18, a steam supply line 20, and a hydrothermal treatment product discharge line 22. Waste containing biomass is input into the hydrothermal treatment device 4 through the waste input line 18, and high-temperature, high-pressure steam (for example, 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, for example, 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.

[0013] 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."

[0014] In the illustrated exemplary embodiment, the hydrothermal treatment device 4 is configured to perform hydrothermal treatment of biomass in a batch processing manner, where a predetermined amount of waste is input into the hydrothermal treatment device 4 at once from the waste input line 18, the hydrothermal treatment reaction of the biomass is allowed to proceed for a predetermined period of time, and the hydrothermal treatment product of the biomass is discharged from the hydrothermal treatment device 4 at once into the hydrothermal treatment product discharge line 22.

[0015] 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.

[0016] 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).

[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 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. Since pre-separated food waste does not require 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. The internal temperature of the mixing and adjustment tank 8 may be adjusted to, for example, 35°C to 55°C to promote solubilization of materials suitable for methane fermentation, such as kitchen waste and paper.

[0018] In addition, an odor line 60a is connected to the mixing adjustment tank 8, and the odor discharged from the mixing adjustment tank 8 to the odor line 60a is supplied to the deodorization equipment 16 and deodorized therein. The odor discharged from the mixing adjustment tank 8 to the odor line 60a contains gases of components derived from biomass (for example, volatile organic compounds, hydrogen sulfide, ammonia, etc.).

[0019] 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.

[0020] The slurry supply line 30 is provided with a metering tank 32, 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 from the metering tank 32 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. The metering tank 32 may distribute half or more (e.g., three-quarters or more) of the slurry supplied from the slurry supply line 30 to the mixing adjustment tank 8. In other words, the metering tank 32 may distribute half or more (e.g., three-quarters or more) of the slurry supplied from the slurry supply line 30 to the slurry return line 34.

[0021] Furthermore, a crushing pump 38 is provided upstream of the metering tank 32 in the slurry supply line 30. The crushing pump 38 includes a cutter (not shown) and is configured to crush and finely fragment solid matter (fermentation substrate for methane fermentation) 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 in 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 using a mesh, punched metal, or the like. Fine particles suitable for fermentation out of the slurry distributed from the metering tank 32 pass through the drum screen 9 and are supplied to the methane fermentation tank 12. Of the slurry distributed from the metering tank 32 to the drum screen 9, solids with relatively large particle sizes that do not pass through the drum screen 9 are supplied to the screw press 10 and concentrated by applying pressure with a screw (not shown) to filter through fine hexagonal holes, and the liquid in the solids is separated from the solids, and the liquid is supplied to the methane fermentation tank 12.

[0024] An odor line 60b is connected to the drum screen 9, and the odor discharged from the drum screen 9 to the odor line 60b is supplied to the deodorization equipment 16 and deodorized therein. The odor discharged from the drum screen 9 to the odor line 60b contains gases of components derived from biomass (for example, volatile organic compounds, hydrogen sulfide, ammonia, etc.).

[0025] In addition, an odor line 60c is connected to the screw press 10, and the odor discharged from the screw press 10 to the odor line 60c is supplied to the deodorization equipment 16 and deodorized in the deodorization equipment 16. The odor discharged from the screw press 10 to the odor line 60c contains gases of components derived from biomass (for example, volatile organic compounds, hydrogen sulfide, ammonia, etc.).

[0026] In the illustrated exemplary embodiment, of the slurry of the hydrothermal treatment product discharged from the mixing and adjustment tank 8, the mixed slurry from which materials unsuitable for fermentation have been removed by the drum screen 9 and the liquid fraction separated from the solids of the unsuitable materials by the screw press 10 are supplied to a charging pit 46, and from the charging pit 46 is supplied to the methane fermentation tank 12 by a pressure pump 48. An odor line 60d is connected to the charging pit 46, and the odor discharged from the charging pit 46 to the odor line 60d is supplied to the deodorization equipment 16 and deodorized therein.

[0027] The methane fermentation tank 12 produces methane gas using the slurry supplied from the slurry supply line 30 (a fermentation-suitable slurry obtained by removing impurities from the hydrothermal treatment slurry discharged from the mixing and adjustment tank 8 using the drum screen 9 and screw press 10). More specifically, in the methane fermentation tank 12, methane fermentation substrates (e.g., organic substances 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.

[0028] In the illustrated exemplary embodiment, the odor lines 60a to 60d join together to form a joined odor line 60m, which is connected to the deodorizing equipment 16. In addition, since the joined odor line 60m is provided with a suction fan 62, 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, and the input pit 46 and supplied to the deodorizing equipment 16.

[0029] (Positional relationship between the hydrothermal treatment device 4 and the mixing adjustment tank 8) 2 is a cross-sectional view schematically showing the positional relationship between the hydrothermal treatment device 4 and the mixing adjustment tank 8. In FIG. 2, a schematic vertical cross section of the mixing adjustment tank 8 is shown.

[0030] 2, the hydrothermal treatment device 4 is provided above the mixing adjustment tank 8. The hydrothermal treatment device 4 is provided with an outlet 40 for discharging the hydrothermally treated biomass product at the bottom 40a of the hydrothermal treatment device 4 (the bottom surface of the pressure vessel), and in the exemplary embodiment shown in the figure, the rate at which the hydrothermally treated biomass product is discharged from the outlet 40 can be adjusted by adjusting the aperture of the motor-operated valve 23 connected to the outlet 40.

[0031] 2, the hydrothermally treated product discharge line 22 is configured by a discharge chute 41 into which the hydrothermally treated product discharged from the discharge port 40 flows. In the illustrated exemplary embodiment, an upper end 41a of the discharge chute 41 is connected to the discharge port 40 via the motor-operated valve 23.

[0032] The mixing and adjustment tank 8 is also provided with a hydrothermal treatment product receiving port 52 for receiving the hydrothermal treatment product of the biomass from the discharge chute 41, a dilution water receiving port 54 for receiving the dilution water from the dilution water supply line 26, and a slurry receiving port 55 for receiving the slurry from the slurry return line 34, on the upper surface 8u of the mixing and adjustment tank 8. The discharge outlet 40 of the hydrothermal treatment device 4 is provided at a position higher than the hydrothermal treatment product receiving port 52 of the mixing and adjustment tank 8. The discharge outlet 40 of the hydrothermal treatment device 4 is located above the hydrothermal treatment product receiving port 52 of the mixing and adjustment tank 8, and more specifically, is located directly above the hydrothermal treatment product receiving port 52 of the mixing and adjustment tank 8 (on the vertical line V passing through the hydrothermal treatment product receiving port 52 of the mixing and adjustment tank 8). The discharge chute 41 extends along the vertical line V passing through the hydrothermal treatment product receiving port 52 of the mixing and adjustment tank 8. The hydrothermally treated product discharged from the discharge port 40 of the hydrothermally treated device 4 falls through the inside of the discharge chute 41 and then flows into the interior of the mixing and adjusting tank 8 through the hydrothermally treated product receiving port 52 .

[0033] As described above, the discharge port 40 of the hydrothermal treatment device 4 is located higher than the hydrothermally treated product receiving port 52 of the mixing adjustment tank 8. This allows the hydrothermally treated product of the hydrothermal treatment device 4 to be rapidly transferred by gravity to the mixing adjustment tank 8, utilizing the potential energy of the hydrothermally treated product within the hydrothermal treatment device 4. Therefore, compared to transferring the hydrothermally treated product using a transport device such as a conveyor, the transport device and the power to drive it are not required. Furthermore, since the temperature drop of the hydrothermally treated product during transfer can be suppressed, the heat contained in the hydrothermally treated product can be used to heat the interior of the mixing adjustment tank 8, thereby promoting solubilization of the hydrothermally treated product within the mixing adjustment tank 8. Therefore, the hydrothermally treated product of the hydrothermal treatment device 4 can be efficiently transferred to the mixing adjustment tank 8 with a simple configuration, and the thermal energy contained in the hydrothermally treated product can be effectively utilized.

[0034] In the mixing and adjustment tank 8, solids contained in the hydrothermally treated product that has dropped from the discharge port 40 of the hydrothermal treatment device 4 may accumulate below the hydrothermally treated product receiving port 52, forming a pile of solids below the hydrothermally treated product receiving port 52. For this reason, the pile of solids may be broken up at the appropriate time by linking the control valve 27 provided on the dilution water supply line 26 with the motor-operated valve 23. For example, by increasing the valve opening of the control valve 27 to increase the flow rate of dilution water at the timing when the motor-operated valve 23 is opened to feed the hydrothermally treated product of the hydrothermal treatment device 4 into the mixing and adjustment tank 8, the pile of solids below the hydrothermally treated product receiving port 52 can be quickly broken up and the solubilization of the hydrothermally treated product can be promoted.

[0035] (Configuration example of mixing adjustment tank 8) Fig. 3 is a plan view showing a schematic internal structure of the mixing adjustment tank 8. Fig. 4 is a view of the partition wall 73 in Fig. 3 as seen from the direction A.

[0036] 2 and 3, the mixing adjustment tank 8 includes a mixing adjustment chamber 70 (pre-stage water tank), a bar screen 71 (first screen), and a slurry chamber 72 (post-stage water tank). In the illustrated exemplary embodiment, the mixing adjustment tank 8 has a hollow, approximately rectangular parallelepiped shape, and the mixing adjustment chamber 70 and the slurry chamber 72 are separated by a partition wall 73.

[0037] As shown in FIG. 2, the mixing adjustment chamber 70 is configured to mix the hydrothermally treated product received through the hydrothermally treated product receiving inlet 52 with the dilution water received through the dilution water receiving inlet 54 within the mixing adjustment chamber 70 to form a slurry of the hydrothermally treated product.

[0038] The bar screen 71 is provided on the partition wall 73 side of the mixing adjustment chamber 70, and is configured to be able to separate the hydrothermal treatment product mixed with dilution water in the mixing adjustment chamber 70 into solids (substances unsuitable for methane fermentation) and slurry. The mesh width of the bar screen 71 is larger than that of the drum screen 9. The mesh width of the bar screen 71 may be, for example, approximately 15 to 25 mm, and the mesh width of the drum screen 9 may be, for example, approximately 3 to 9 mm. The bar screen 71 is installed at an angle with respect to the horizontal plane, and the installation angle θ of the bar screen 71 with respect to the horizontal plane may be, for example, approximately 30 to 60 degrees.

[0039] The mixing and adjusting tank 8 also includes a scraping device 75 and an unsuitable material pit 76. The scraping device 75 is disposed, for example, between slits (not shown) of the bar screen 71, and is configured to be driven by a motor (not shown). The scraping device 75 is configured to scrape up solids (materials unsuitable for methane fermentation) captured by the bar screen 71 from the hydrothermal treatment product mixed with dilution water in the mixing and adjusting chamber 70, along the bar screen 71. The unsuitable material pit 76 stores materials unsuitable for methane fermentation (for example, plastics and vinyl that are not supplied with water) scraped up by the scraping device 75 from the hydrothermal treatment product in the mixing and adjusting chamber 70.

[0040] Of the hydrothermally treated product mixed with dilution water in the mixing adjustment chamber 70, slurry that has passed through the bar screen 71 flows into the slurry chamber 72. A slurry discharge port 74 is formed in the slurry chamber 72 for discharging the slurry of the hydrothermally treated product (slurry that has passed through the bar screen 71) from the mixing adjustment tank 8. The capacity of the mixing and adjusting chamber 70 may be sufficient for the retention time of the hydrothermal treatment material to be about one day, and the slurry chamber 72 may have a storage capacity for about two hours or more. By retaining the material unsuitable for methane fermentation in the mixing and adjusting chamber 70 for about one day under conditions of, for example, 35 to 55°C and a pH of 6.5 or less, solubilization progresses and the material passes through the bar screen 71 and flows into the slurry chamber 72 with almost no adhesion to the material unsuitable for fermentation.

[0041] The mixing and adjustment tank 8 shown in Figure 2 can separate (wet separation) the solids and slurry of the hydrothermal treatment product supplied from the hydrothermal treatment device 4. Therefore, compared to a configuration in which the hydrothermal treatment product is transported from the hydrothermal treatment device 4 to a dry separation device using, for example, a conveyor, the amount of open space to the outside can be reduced, making it easier to deal with odors.

[0042] The above-mentioned slurry supply line 30 is connected to the slurry discharge port 74 of the slurry chamber 72, and the slurry in the slurry chamber 72 is discharged from the slurry discharge port 74 to the slurry supply line 30 and supplied to the metering tank 32 (see FIG. 1) through the slurry supply line 30 as described above. Note that the materials unsuitable for methane fermentation include long vinyls and plastics with small particle sizes, and some of these pass through the slit-shaped bar screen 71 together with the slurry, are discharged from the slurry discharge port 74 to the slurry supply line 30, and are removed by the above-mentioned drum screen 9.

[0043] The above-mentioned slurry return line 34 connects the metering tank 32 and the mixing adjustment chamber 70, and a portion of the slurry discharged from the slurry chamber 72 to the slurry supply line 30 is returned from the metering tank 32 through the slurry return line 34 to the mixing adjustment chamber 70. With this configuration, the slurry that has passed through the bar screen 71 is returned to the mixing adjustment tank 8 and circulated, thereby preventing problems such as clogging of the fracturing pump 38 provided on the slurry supply line 30 by substances unsuitable for methane fermentation and promoting stable solubilization. This makes it possible to efficiently remove substances unsuitable for methane fermentation at the bar screen 71 and recover substances suitable for methane fermentation.

[0044] In addition, the slurry supplied from the slurry return line 34 to the mixing adjustment chamber 70 via the slurry receiving port 55 can break up the pile of solids that has accumulated below the hydrothermal treatment product receiving port 52, thereby promoting the solubilization of the hydrothermal treatment product without adding water other than a fixed amount of dilution water.

[0045] 2, the bottom surface 77 of the mixing adjustment chamber 70 includes an inclined surface 77a inclined with respect to the horizontal plane, and the inclined surface 77a is inclined with respect to the horizontal plane so as to slope downward along the inclined surface 77a toward the bar screen 71. The inclined surface 77a is connected to a wall surface 78 of the mixing adjustment chamber 70 on the opposite side to the bar screen 71 (a wall surface of the mixing adjustment chamber 70 facing the partition wall 73). In other words, the inclined surface 77a is formed at a corner 84 where the wall surface 78 of the mixing adjustment chamber 70 on the opposite side to the bar screen 71 and the bottom surface 77 are connected.

[0046] In this way, by providing an inclined surface 77a on the bottom surface 77 of the mixing adjustment chamber 70 that is inclined relative to the horizontal plane so as to slope downward as it approaches the bar screen 71, it is possible to prevent solids of the hydrothermal treatment product from accumulating at the bottom of the mixing adjustment chamber 70 (especially the corners 84).

[0047] 2, the mixing adjustment tank 8 includes a stirring member 79 provided inside the mixing adjustment chamber 70 so as to stir the hydrothermally treated product and dilution water in the mixing adjustment chamber 70. In the illustrated exemplary embodiment, the stirring member 79 is located below the dilution water receiving port 54 and above the inclined surface 77a, and is driven by a motor 79m to stir the hydrothermally treated product and dilution water.

[0048] In this way, by stirring the hydrothermally treated product and the diluent inside the mixing adjustment chamber 70 with the stirring member 79, it is possible to suppress settling of solids in the hydrothermally treated product, promote homogenization of the slurry of the hydrothermally treated product, and promote solubilization of the hydrothermally treated product. Furthermore, because the stirring member 79 is located above the inclined surface 77a, the hydrothermally treated product (slurry) that has been well mixed with the diluent can be supplied along the inclined surface 77a to the bar screen 71 side.

[0049] 3 and 4, the partition wall 73 includes a pair of end walls 73a, 73b and a central wall 73c located horizontally between the pair of end walls 73a, 73b. The height hc of the central wall 73c is lower than the height ha of the end wall 73a and lower than the height hb of the end wall 73b. As shown in FIG. 2, the bar screen 71 is provided to cover an upper portion 73c1 of the central wall 73c.

[0050] According to this configuration, the height hc of the central wall portion 73c is lower than the height of each of the pair of end wall portions 73a, 73b, and therefore, the slurry of the hydrothermally treated product in the mixing adjustment chamber 70 that has passed through the bar screen 71 can overflow the central wall portion 73c and flow into the slurry chamber 72. This makes it possible to separate the slurry that has passed through the bar screen 71 from the hydrothermally treated product in the mixing adjustment chamber 70 with a simple configuration.

[0051] In some embodiments, as shown in FIG. 3 , the wall surface 73a1 of the end wall portion 73a facing away from the slurry chamber 72 includes an inclined surface 80 inclined with respect to the width direction dw of the bar screen 71. The end wall portion 73a also includes an opposing surface 81 connecting the inclined surface 80 to the central wall portion 73c. ​​The wall surface 73b1 of the end wall portion 73b facing away from the slurry chamber 72 includes an inclined surface 82 inclined with respect to the width direction dw of the bar screen 71. The end wall portion 73b also includes an opposing surface 83 connecting the inclined surface 82 to the central wall portion 73c. ​​The opposing surfaces 81 and 83 face each other, and in the illustrated exemplary embodiment, each of the opposing surfaces 81 and 83 is perpendicular to the width direction dw of the bar screen 71. In the illustrated example, the width direction dw of the bar screen 71 is the width direction of the central wall portion 73c, the width direction of the partition wall 73, and the width direction of the mixing adjustment tank 8.

[0052] Here, if the horizontal direction perpendicular to the width direction dw of the bar screen 71 is defined as the first direction d1, the distance W between the inclined surface 80 of the end wall portion 73a and the inclined surface 82 of the end wall portion 73b becomes smaller as it moves toward the bar screen 71 along the first direction d1.

[0053] According to this configuration, the inclined surface 80 of the end wall portion 73a and the inclined surface 82 of the end wall portion 73b can guide the hydrothermally treated product in the mixing adjustment chamber 70 to the bar screen 71, thereby preventing the hydrothermally treated product from stagnating in the mixing adjustment chamber 70.

[0054] 3, for example, the thickness ta of the end wall portion 73a is greater than the thickness tc of the central wall portion 73c, and the thickness ta increases in the direction away from the central wall portion 73c along the width direction dw of the bar screen 71. The thickness tb of the end wall portion 73b is greater than the thickness tc of the central wall portion 73c, and the thickness tb increases in the direction away from the central wall portion 73c along the width direction dw of the bar screen 71. The lower portion 71a of the bar screen 71 is disposed between the pair of end wall portions 73a, 73b (more specifically, between the opposing surfaces 81 and 83). According to this configuration, compared to the case where the bar screen 71 is installed across the entire width of the partition wall 73, the hydrothermally treated product can be separated into solid matter and slurry with a simpler configuration.

[0055] (Cleaning of fracturing pumps) 5, the waste treatment system 2 may further include a tank 35 for storing dilution water (diluent), and a dilution water supply line 36 (diluent supply line) connecting the tank 35 to a position on the slurry supply line 30 upstream of the fracturing pump 38. The dilution water supply line 36 is configured to be able to supply the dilution water stored in the tank 35 to a position on the slurry supply line 30 upstream of the fracturing pump 38. In this case, the dilution water supply line 26 may be configured to branch off from the dilution water supply line 36 and connect to the mixing adjustment tank 8.

[0056] In the illustrated exemplary embodiment, a valve 43 is provided in the dilution water supply line 36, and a valve 44 is provided in the slurry supply line 30 upstream of the position where the dilution water supply line 36 is connected. In this case, for example, during normal operation of the waste treatment system 2, the valve 43 is closed and the valve 44 is opened to supply slurry from the mixing adjustment tank 8 to the metering tank 32, and when the fracturing pump 38 and the piping downstream thereof are to be cleaned, the valve 44 is closed and the valve 43 is opened to supply dilution water from the tank 35 to the fracturing pump 38 and the piping downstream thereof.

[0057] According to this configuration, by supplying diluted water from the tank 35 storing diluted water to the upstream side of the fracturing pump 38, the inside of the fracturing pump 38 and the piping downstream of the fracturing pump 38 can be cleaned with diluted water, thereby preventing clogging of the fracturing pump 38 and the piping downstream of it.

[0058] (Utilization of released steam) FIG. 6 is a diagram showing a modified example of the waste treatment system 2. In FIG. In the waste treatment system 2 shown in Figure 6, symbols that are common to each component of the waste treatment system 2 shown in Figure 1 indicate the same components as those of the waste treatment system 2 shown in Figure 1 unless otherwise specified, and explanations thereof will be omitted.

[0059] The waste treatment system 2 shown in FIG. 6 differs from the waste treatment system 2 shown in FIG. 1 in that it includes a sludge dewatering facility 13, a sludge dryer 14, a release steam line 24, and an odor line 60e.

[0060] The sludge dehydration equipment 13 is connected to the methane fermentation tank 12 via a sludge supply line 50, and dehydrates the sludge (fermentation residue remaining after methane fermentation in the methane fermentation tank 12) discharged from the methane fermentation tank 12. The dehydrated sludge is supplied to the sludge dryer 14 through a sludge supply line 51, and is dried in the sludge dryer 14.

[0061] The release steam line 24 is connected to the hydrothermal treatment device 4. When the hydrothermal treatment of the biomass for a predetermined time is completed in the hydrothermal treatment device 4, before the hydrothermal treatment product of the biomass is discharged from the hydrothermal treatment device 4, the steam inside the hydrothermal treatment device 4 is discharged from the hydrothermal treatment device 4 to the release steam line 24. 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.

[0062] In addition, a release steam branch line 24a is connected to the mixing adjustment tank 8, and after the hydrothermal treatment reaction of the biomass is completed in the hydrothermal treatment device 4, the steam (release steam) discharged from the hydrothermal treatment device 4 is supplied into the inside of the mixing adjustment tank 8 from the release steam branch line 24a.

[0063] 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.

[0064] A release steam branch line 24b is connected to the drum screen 9, and steam discharged from the hydrothermal treatment device 4 is supplied to the drum screen 9 from the release steam branch line 24b.

[0065] 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.

[0066] 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 deodorization equipment 16 and deodorized in the deodorization equipment 16. The odors discharged from the sludge dryer 14 into the odor line 60d contain gases of components derived from biomass (for example, volatile organic compounds, hydrogen sulfide, ammonia, etc.).

[0067] 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.

[0068] 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.

[0069] FIG. 7 is a schematic cross-sectional view illustrating an example of the general configuration of the mixing adjustment tank 8. As shown in FIG. 7 , 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.

[0070] 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.

[0071] Also, in the exemplary form shown in FIG. 7, the release pipe 25 includes a steam outlet 25a inside the mixing adjustment tank 8, and the outlet 25a is located in the region S occupied by the gas inside the mixing adjustment tank 8. If the steam outlet 25a of the release pipe 25 is inside the slurry of the hydrothermally treated product in the mixing adjustment tank 8, when the steam from the release pipe 25 condenses, a rapid pressure change occurs, generating an abnormal noise called hammering. In this regard, as shown in FIG. 2, by positioning the steam outlet 25a of the release pipe 25 in the region S occupied by the gas inside the mixing adjustment tank 8, the occurrence of the above-mentioned hammering can be suppressed.

[0072] Also, in the exemplary form shown in FIG. 7, the mixing adjustment 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 54 for receiving dilution water from the dilution water supply line 26, and a slurry inlet 55 for receiving the slurry from the slurry return line 34 on the upper surface 8u of the mixing adjustment tank 8. Also, if the longitudinal dimension of the mixing adjustment 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 adjustment tank 8 is e1, it may satisfy e1 < L / 2, or it may satisfy e1 < L / 4. That is, e1 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 54 is e2, it may satisfy e2 < L / 2, or it may satisfy e2 < L / 4. That is, e2 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 55 is e3, it may satisfy e3 < L / 2, or it may satisfy e3 < L / 4. That is, e3 may be smaller than half of L, or may be smaller than one-fourth of L.

[0073] As shown in FIG. 7, 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 where 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 e1 < 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 e1 < 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. Also, by satisfying e2 < L / 2, the dilution water supplied from the dilution water inlet 54 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 e2 < 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. Also, by satisfying e3 < L / 2, the slurry supplied from the slurry inlet 55 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 e3 < 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.

[0074] The present disclosure is not limited to the above-described embodiments, and also includes forms obtained by modifying the above-described embodiments and forms obtained by appropriately combining these forms. For example, in the configuration shown in FIG. 2, the case where the discharge port 40 is directly above the hydrothermal treatment product inlet 52 is illustrated, but the discharge port 40 may be provided at a position deviated from the vertical line V passing through the hydrothermal treatment product inlet 52. In this case, the discharge chute 41 may extend in a direction inclined with respect to the vertical line, or may include a curved portion.

[0075] Furthermore, for example, in the embodiment shown in Figure 6 etc., an example is given in which 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 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 may be supplied to any two of the mixing and adjustment tank 8, the drum screen 9 and the sludge dryer 14.

[0076] 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.

[0077] The contents described in each of the above embodiments can be understood, for example, as follows.

[0078] [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) for hydrothermally treating biomass contained in waste, the hydrothermal treatment device having an outlet (for example, the above-mentioned outlet 40) for discharging the hydrothermally treated biomass; a mixing and adjusting tank (for example, the above-mentioned mixing and adjusting tank 8) including a hydrothermally treated product receiving port (for example, the above-mentioned hydrothermally treated product receiving port 52) ​​for receiving the hydrothermally treated product discharged from the discharge port, and configured to mix the hydrothermally treated product received from the hydrothermally treated product receiving port with a diluent to adjust the properties of the hydrothermally treated product; a methane fermentation tank (for example, the above-mentioned methane fermentation tank 12) configured to produce methane gas using the liquid portion of the hydrothermal treatment product discharged from the mixing and adjustment tank; Equipped with The discharge port of the hydrothermal treatment device is provided at a position higher than the hydrothermal treatment product receiving port of the mixing and adjusting tank.

[0079] According to the waste treatment system described in [1] above, the discharge port of the hydrothermal treatment device is located higher than the inlet of the hydrothermal treatment product in the mixing and adjustment tank. Therefore, the potential energy of the hydrothermal treatment product in the hydrothermal treatment device can be utilized to rapidly transfer the hydrothermal treatment product to the mixing and adjustment tank by gravity. Therefore, compared to transporting the hydrothermal treatment product using a transport device such as a conveyor, the transport device and the power to drive it are not required. Furthermore, because the temperature drop of the hydrothermal treatment product during transport can be suppressed, the heat contained in the hydrothermal treatment product can be utilized to heat the interior of the mixing and adjustment tank, promoting the solubilization of the hydrothermal treatment product in the mixing and adjustment tank. Therefore, with a simple configuration, the hydrothermal treatment product of the hydrothermal treatment device can be efficiently transported to the mixing and adjustment tank, and the thermal energy contained in the hydrothermal treatment product can be effectively utilized.

[0080] [2] In some embodiments, in the waste treatment system described in [1] above, The discharge port of the hydrothermal treatment device is located on a vertical line (for example, the above-mentioned vertical line V) that passes through the hydrothermal treatment product receiving port of the mixing and adjustment tank.

[0081] According to the waste treatment system described in [2] above, the hydrothermally treated product can be smoothly dropped from the discharge outlet of the hydrothermal treatment device to the hydrothermally treated product receiving port of the mixing adjustment tank, thereby enhancing the effect of quickly transferring the hydrothermally treated product from the hydrothermal treatment device to the mixing adjustment tank.

[0082] [3] In some embodiments, in the waste treatment system described in [1] or [2] above, The mixing adjustment tank is a mixing and adjusting chamber (for example, the above-mentioned mixing and adjusting chamber 70) including the hydrothermally treated product receiving port and configured to mix the hydrothermally treated product received from the hydrothermally treated product receiving port with the diluent to form a slurry of the hydrothermally treated product; a first screen (for example, the bar screen 71 described above) for separating the hydrothermally treated product mixed with the diluent into a solid and a slurry; a slurry chamber (for example, the above-mentioned slurry chamber 72) into which the slurry that has passed through the first screen flows out of the hydrothermal treatment product mixed with the diluent in the mixing adjustment chamber; Includes:

[0083] According to the waste treatment system described in [3] above, the solid matter and slurry of the hydrothermally treated product can be separated (wet separation) in the mixing and adjustment tank. Therefore, compared to a configuration in which the hydrothermally treated product is transported from the hydrothermally treated treatment device to a dry separation device using, for example, a conveyor, the amount of open space can be reduced, making it easier to deal with odors.

[0084] [4] In some embodiments, in the waste treatment system described in [3] above, a scraping device (for example, the scraping device 75 described above) configured to scrape up the solid matter captured on the first screen among the hydrothermally treated product mixed with the dilution liquid in the mixing adjustment chamber along the first screen; a reject pit (for example, the above-mentioned reject pit 76) for storing the solid material scraped up by the scraping device; Further provided with:

[0085] According to the waste treatment system described in [4] above, the solid matter in the hydrothermally treated product can be separated and stored in an unsuitable matter pit using a scraping device.

[0086] [5] In some embodiments, in the waste treatment system described in [3] or [4] above, The bottom surface of the mixing adjustment chamber includes an inclined surface (for example, the inclined surface 77a) inclined with respect to a horizontal plane, The inclined surface extends downward toward the first screen.

[0087] According to the waste treatment system described in [5] above, it is possible to prevent solids from the hydrothermal treatment product from remaining at the bottom of the mixing and adjustment chamber.

[0088] [6] In some embodiments, in the waste treatment system described in [5] above, The inclined surface is connected to a corner (for example, the above-mentioned corner 84) where the wall surface of the mixing adjustment chamber opposite to the first screen and the bottom surface are connected.

[0089] According to the waste treatment system described in [6] above, it is possible to prevent solids from the hydrothermal treatment product from accumulating at the corner between the wall surface and the bottom surface on the opposite side of the first screen in the mixing and adjustment room.

[0090] [7] In some embodiments, in the waste treatment system according to any one of [3] to [6] above, The apparatus further includes a stirring member (for example, the stirring member 79 described above) provided inside the mixing adjustment chamber so as to stir the hydrothermal treatment product and the dilution liquid.

[0091] According to the waste treatment system described in [7] above, by stirring the hydrothermally treated product and the diluted liquid inside the mixing adjustment chamber using a stirring member, it is possible to suppress the settling of solids in the hydrothermally treated product, promote the homogenization of the slurry of the hydrothermally treated product, and promote the solubilization of the hydrothermally treated product.

[0092] [8] In some embodiments, in the waste treatment system described in [5] or [6] above, The apparatus further includes a stirring member (for example, the stirring member 79) provided inside the mixing adjustment chamber so as to stir the hydrothermal treatment product and the dilution liquid, The stirring member is located above the inclined surface.

[0093] According to the waste treatment system described in [8] above, the hydrothermally treated product (slurry) that has been well mixed with the diluent can be supplied to the first screen side along the inclined surface.

[0094] [9] In some embodiments, in the waste treatment system according to any one of [3] to [8] above, The mixing adjustment tank includes a partition wall (for example, the above-mentioned partition wall 73) that separates the mixing adjustment chamber from the slurry chamber, the partition wall includes a pair of end wall portions (for example, the pair of end wall portions 73a, 73b described above) and a central wall portion (for example, the central wall portion 73c described above) located between the pair of end wall portions in the horizontal direction, a height of the central wall portion (for example, the height hc) is lower than each height of the pair of end wall portions (for example, the heights ha and hb); The first screen is provided so as to cover the upper part of the central wall part (for example, the above-mentioned upper part 73c1).

[0095] According to the waste treatment system described in [9] above, since the height of the central wall portion is lower than the height of each of the pair of end walls, the slurry of the hydrothermally treated product in the mixing and adjusting chamber that has passed through the first screen can overflow the central wall portion and flow into the slurry chamber. This makes it possible to separate the slurry that has passed through the first screen from the hydrothermally treated product in the mixing and adjusting chamber with a simple configuration.

[0096]

[10] In some embodiments, in the waste treatment system described in [9] above, a wall surface (e.g., the wall surfaces 73a1 and 73b1) of each of the pair of end wall portions facing away from the slurry chamber includes an inclined surface (e.g., the inclined surfaces 80 and 82) inclined with respect to the width direction of the first screen, If the horizontal direction perpendicular to the width direction of the first screen is defined as a first direction (for example, the above-mentioned first direction d1), then: The distance (e.g., the distance W mentioned above) between the inclined surface of one of the pair of end wall portions and the inclined surface of the other of the pair of end wall portions becomes smaller along the first direction toward the first screen.

[0097] According to the waste treatment system described in

[10] above, the inclined surfaces of each of the pair of end wall portions can guide the hydrothermally treated material in the mixing and adjustment chamber to the first screen, thereby preventing the hydrothermally treated material from stagnating in the mixing and adjustment chamber.

[0098]

[11] In some embodiments, in the waste treatment system described in [9] or

[10] above, the thickness of each of the pair of end wall portions (e.g., the thicknesses ta and tb) is greater than the thickness of the central wall portion (e.g., the thickness tc); The lower part of the first screen (for example, the lower part 71a described above) is disposed between the pair of end wall parts.

[0099] According to the waste treatment system described in

[11] above, the hydrothermally treated material can be separated into solid matter and slurry with a simpler configuration than when a first screen is installed across the entire width of the partition wall.

[0100]

[12] In some embodiments, in the waste treatment system according to any one of [3] to

[11] above, a slurry supply line (e.g., the slurry supply line 30 described above) configured to supply the slurry discharged from the slurry chamber; a metering tank (for example, the above-mentioned metering tank 32) provided in the slurry supply line; a slurry return line (for example, the above-mentioned slurry return line 34) that connects the metering tank and the mixing adjustment chamber and is configured to return a portion of the slurry discharged from the slurry chamber from the metering tank to the mixing adjustment chamber; Equipped with.

[0101] According to the waste treatment system described in

[12] above, the slurry that has passed through the first screen is returned to the mixing and adjustment tank for circulation, thereby preventing problems such as clogging of the pump in the slurry supply line due to materials unsuitable for methane fermentation and promoting stable solubilization. This makes it possible to efficiently remove materials unsuitable for methane fermentation on the first screen and recover materials suitable for methane fermentation. Furthermore, the slurry supplied from the slurry return line to the mixing and adjustment chamber can break up the pile of solids that has accumulated below the hydrothermal treatment product receiving port, promoting solubilization of the hydrothermal treatment product without adding water other than a fixed amount of dilution water.

[0102]

[13] In some embodiments, in the waste treatment system described in

[12] above, The system further includes a crushing pump (for example, the above-mentioned crushing pump 38) located upstream of the metering tank in the slurry supply line and configured to crush solids contained in the slurry discharged from the slurry chamber.

[0103] According to the waste treatment system described in

[13] above, the solid matter (fermentation substrate for methane fermentation) contained in the slurry discharged from the slurry chamber is crushed by a crushing pump, thereby enhancing the effect of promoting the solubilization of the solid matter.

[0104]

[14] In some embodiments, in the waste treatment system described in

[12] or

[13] above, The metering tank is configured to distribute at least half of the slurry supplied from the slurry supply line to the slurry return line.

[0105] According to the waste treatment system described in

[14] above, the effect of promoting the solubilization of solids contained in the slurry can be enhanced.

[0106]

[15] In some embodiments, in the waste treatment system according to any one of [3] to

[14] above, a slurry supply line (e.g., the slurry supply line 30 described above) configured to supply the slurry discharged from the slurry chamber; A second screen (for example, the above-mentioned drum screen 9) provided in the slurry supply line; Further provided with The mesh width of the second screen is smaller than the mesh width of the first screen.

[0107] According to the waste treatment system described in

[15] above, solids in the hydrothermal treatment slurry that are not captured by the first screen (solids smaller than the mesh size of the first screen) can be captured by the second screen, thereby increasing the removal rate of materials unsuitable for methane fermentation. This stabilizes the agitation and methane gas generation rate in the methane fermentation tank, and makes it possible to effectively utilize the digested sludge discharged from the methane fermentation tank by, for example, making it into fertilizer.

[0108]

[16] In some embodiments, in the waste treatment system according to any one of

[13] or

[14] above, a tank for storing a diluent (for example, the tank 35 described above); A diluent supply line (for example, the above-mentioned diluent supply line 36) that connects the tank to a position upstream of the fracturing pump in the slurry supply line and is configured to supply the diluent stored in the tank to the position upstream of the fracturing pump in the slurry supply line; Further provided with:

[0109] According to the waste treatment system described in

[16] above, by supplying diluted liquid from a tank storing diluted liquid to the upstream side of the crushing pump, the inside of the crushing pump and the piping downstream of the crushing pump can be cleaned, and clogging of the crushing pump and the piping downstream of it can be prevented.

[0110]

[17] In some embodiments, in the waste treatment system according to any one of [1] to

[16] above, The waste treatment system includes: 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 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.

[0111] According to the waste treatment system described in

[17] 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 emitted 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.

[0112]

[18] In some embodiments, in the waste treatment system described in

[17] above, The biomass-derived material treatment device is the mixing and adjusting tank.

[0113] According to the waste treatment system described in

[18] 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.

[0114]

[19] In some embodiments, in the waste treatment system according to any one of [1] to

[18] above, The biomass-derived material treatment device is a separation device (e.g., the above-mentioned drum screen 9) for removing impurities from the slurry of the hydrothermal treatment product discharged from the mixing and adjustment tank, The release steam line is connected to the separator and configured to supply the steam discharged from the hydrothermal treatment device to the separator.

[0115] According to the waste treatment system described in

[19] above, the temperature of the hydrothermally treated product (biomass-derived material) in the separator can be increased by heat exchange between steam supplied from the release steam line and the hydrothermally treated product in the separator. This reduces the amount of energy consumed in the methane fermenter, which receives the liquid portion of the hydrothermally treated product discharged from the separator, to maintain the internal temperature of the methane fermenter at a temperature suitable for methane fermentation. Furthermore, heat exchange between steam supplied from the release steam line and the hydrothermally treated product in the separator can condense the steam within the separator. This reduces the amount of steam to be treated in the deodorizing equipment, thereby reducing the amount of odor released into the atmosphere with a simple configuration. Furthermore, if the separator is equipped with a screen, the screen can be cleaned using steam supplied from the release steam line. This reduces clogging of the screen.

[0116]

[20] In some embodiments, in the waste treatment system described in

[17] 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.

[0117] According to the waste treatment system described in

[20] 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 sludge can be dried using the thermal energy of the steam discharged from the hydrothermal treatment device. 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]

[0118] 2: Waste treatment system 4: Hydrothermal treatment equipment 8:Mixing adjustment tank 8a: Ceiling 8i: Inner surface 8u:Top surface 9: Drum screen 10:Screw press 12: Methane fermentation tank 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: Release steam branch line 24b: Release steam branch line 24c: Release steam branch line 25: Release piping 25a:Exit 26: Dilution water supply line 27: Control valve 30: Slurry supply line 32:Measuring tank 34: Slurry return line 35: Tank 36: Dilution water supply line 38: Fracturing pump 40: Outlet 40a: bottom 41: Discharge chute 41a: Upper end 43: Valve 44: Valve 46: Input pit 48: Pressure pump 50: Sludge supply line 52: Hydrothermal treatment product receiving port 53:Mountain 54: Dilution water inlet 55: Slurry receiving port 60a: Odor line 60b: Odor line 60c: Odor line 60d: Odor line 60e: Odor line 60m: Confluence odor line 62: Suction fan 70:Mixing adjustment room 71: Bar Screen 71a: Lower part 72: Slurry chamber 73: Partition wall 73a: End wall 73a1: Wall 73b: End wall 73b1: Wall 73c: Central wall 73c1 :Top 74: Slurry outlet 75: Raising device 76: Unsuitable material pit 77: Bottom 77a: Inclined surface 78: Wall 79: Stirring member 79m: Motor 80: Inclined surface 81: Opposite surface 82: Inclined surface 83: Opposite surface 84: Corner

Claims

1. a hydrothermal treatment apparatus for hydrothermal treatment of biomass contained in waste, the hydrothermal treatment apparatus having an outlet for discharging the hydrothermal treatment product of the biomass; a mixing and adjusting tank including a hydrothermally treated product receiving port for receiving the hydrothermally treated product discharged from the discharge port, the mixing and adjusting tank being configured to mix the hydrothermally treated product received from the hydrothermally treated product receiving port with a diluent to adjust the properties of the hydrothermally treated product; a methane fermentation tank configured to produce methane gas using the liquid portion of the hydrothermal treatment product discharged from the mixing and adjustment tank; Equipped with A waste treatment system, wherein the discharge outlet of the hydrothermal treatment device is provided at a higher position than the hydrothermal treatment product receiving inlet of the mixing and adjustment tank.

2. 2. The waste treatment system according to claim 1, wherein the discharge outlet of the hydrothermal treatment device is located on a vertical line passing through the hydrothermal treatment product receiving inlet of the mixing and adjustment tank.

3. The mixing adjustment tank is a mixing and adjusting chamber including the hydrothermally treated product receiving port and configured to mix the hydrothermally treated product received through the hydrothermally treated product receiving port with the diluent to form a slurry of the hydrothermally treated product; a first screen for separating the hydrothermally treated product mixed with the diluent into a solid and a slurry; a slurry chamber into which the slurry that has passed through the first screen flows out of the hydrothermal treatment product mixed with the diluent in the mixing adjustment chamber; 10. The waste treatment system of claim 1, comprising:

4. a scraping device configured to scrape up the solid matter captured on the first screen from the hydrothermal treatment product mixed with the dilution liquid in the mixing adjustment chamber along the first screen; an unsuitable material pit for storing the solid material scraped up by the scraping device; The waste treatment system of claim 3 further comprising:

5. a bottom surface of the mixing adjustment chamber including an inclined surface inclined with respect to a horizontal plane; The waste treatment system according to claim 3 , wherein the inclined surface extends downward toward the first screen.

6. 6. The waste treatment system according to claim 5, wherein the inclined surface is formed at a corner where the bottom surface and a wall surface of the mixing adjustment chamber opposite to the first screen are joined.

7. 4. The waste treatment system according to claim 3, further comprising an agitator provided inside the mixing adjustment chamber to agitate the hydrothermally treated product and the dilution liquid.

8. The apparatus further includes a stirring member provided inside the mixing adjustment chamber so as to stir the hydrothermal treatment product and the dilution liquid, The waste treatment system according to claim 5 , wherein the agitating member is located above the inclined surface.

9. The mixing adjustment tank includes a partition wall that separates the mixing adjustment chamber from the slurry chamber, the partition wall includes a pair of end wall portions and a central wall portion located between the pair of end wall portions in the horizontal direction, the height of the central wall portion is lower than the height of each of the pair of end wall portions; The waste treatment system according to claim 3 , wherein the first screen is provided so as to cover an upper portion of the central wall portion.

10. a wall surface of each of the pair of end wall portions facing away from the slurry chamber includes an inclined surface inclined with respect to the width direction of the first screen, If the horizontal direction perpendicular to the width direction of the first screen is defined as a first direction, 10. The waste treatment system of claim 9, wherein a distance between the inclined surface of one of the pair of end wall portions and the inclined surface of the other of the pair of end wall portions decreases toward the first screen along the first direction.

11. the thickness of each of the pair of end walls is greater than the thickness of the central wall; 10. The waste treatment system of claim 9, wherein a lower portion of the first screen is disposed between the pair of end walls.

12. a slurry supply line configured to supply the slurry discharged from the slurry chamber; a measuring tank provided in the slurry supply line; a slurry return line connecting the metering tank and the mixing adjustment chamber and configured to return a portion of the slurry discharged from the slurry chamber from the metering tank to the mixing adjustment chamber; The waste treatment system of claim 3 , comprising:

13. 13. The waste treatment system according to claim 12, further comprising a crushing pump located upstream of the metering tank in the slurry supply line and configured to crush solids contained in the slurry discharged from the slurry chamber.

14. 13. The waste treatment system of claim 12, wherein the metering vessel is configured to distribute at least half of the slurry supplied from the slurry supply line to the slurry return line.

15. a slurry supply line configured to supply the slurry discharged from the slurry chamber; a second screen provided in the slurry supply line; Further provided with 4. The waste treatment system according to claim 3, wherein the mesh width of the second screen is smaller than the mesh width of the first screen.

16. a tank for storing a dilution liquid; A diluent supply line that connects the tank to a position upstream of the crushing pump in the slurry supply line and is configured to be able to supply the diluent stored in the tank to the position upstream of the crushing pump in the slurry supply line; 14. The waste treatment system of claim 13, further comprising:

17. The waste treatment system includes: a release steam line connected to the hydrothermal treatment device and configured to discharge steam 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 waste treatment system according to claim 1 , 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.

18. 18. The waste treatment system according to claim 17, wherein the biomass-derived material treatment device is the mixing and adjusting tank.

19. the biomass-derived material treatment device is a separation device for removing impurities from the slurry of the hydrothermal treatment product discharged from the mixing and adjustment tank, 18. The waste treatment system of claim 17, 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.

20. the biomass-derived material treatment device is a sludge dryer for drying sludge discharged from the methane fermentation tank, 18. The waste treatment system of claim 17, wherein the release steam line is connected to the sludge dryer and configured to supply the steam discharged from the hydrothermal treatment device to the sludge dryer.

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