TW202237537A - Hydrothermal treatment system - Google Patents

Abstract

A hydrothermal treatment system (1) includes a hydrothermal treatment apparatus (10) that lets a waste containing an organic matter hydrothermally react; an adjusting tank (11) that humidifies a hydrothermal treatment product underwent the hydrothermal reaction; a first transfer device (21) that transfers the humidified hydrothermal treatment product; a depression separating device (12) that depresses the transferred hydrothermal treatment product and thereby separates a hydrothermal treatment solution from a residue; a solubilization tank (13) that stores and heats the separated hydrothermal treatment solution; a second transfer device (22) that returns the heated and solubilized hydrothermal treatment solution to the adjusting tank (11); a methane fermenting device (14) that generates methane gas and a digestive fluid, using the hydrothermal treatment solution stored in the solubilization tank (13); a dehydrating device (15) that separates the digestive fluid into dehydrated sludge and a dehydrated separated solution; and a waste solution treatment device (16) that nitrifies and denitrifies the dehydrated separated solution and thereby generates reusable water. When the concentration of the organic matter contained in the hydrothermal treatment solution stored in the solubilization tank (13) is a predetermined concentration, the second transfer device (22) transfers the hydrothermal treatment solution to the methane fermenting device (14).

Description

Hydrothermal Treatment System

The present invention relates to a hydrothermal treatment system for generating methane gas from waste containing organic matter.

In the past, a system has been developed that uses high-temperature and high-pressure water vapor to remove waste (kitchen waste), woody waste such as paper, plants, etc., livestock excrement, sludge, etc. Organic waste is dissolved by hydrothermal reaction (hydrothermal treatment), and liquid (hydrothermal treatment liquid) such as solution or slurry is separated from waste containing organic matter (hydrothermal treatment product) after hydrothermal treatment, and the liquid is reused A system that performs gas generation such as methane fermentation by microorganisms, fungi, etc. (for example, Patent Documents 1 and 2). In order to separate the hydrothermally treated liquid from the hydrothermally treated product, in this system, for example, a screen, a screw press described in Patent Document 3, or the like can be used. [Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2009-119378 [Patent Document 2] Japanese Patent Laid-Open No. 2019-181397 [Patent Document 3] Japanese Patent Laid-Open No. 2011-200836

[Problem to be solved by the invention]

Generally, waste containing organic matter recovered by garbage trucks and waste containing organic matter stored in garbage pits of garbage cleaning plants does not contribute to gas generation or does not contribute to gas generation except for organic matter that contributes to gas generation. The generated organic matter (such as plastic), inorganic matter such as metal or glass may not be completely removed and remain. Also, depending on the area, season, and time, the ratio of organic matter to inorganic matter in recycled or stored waste containing organic matter, the ratio of leftovers to paper in organic matter, organic matter that contributes to gas generation and almost non-contributing The ratio etc. of gas-generated organic matter (that is, the ratio of each of the plurality of contents in a predetermined amount of waste containing organic matter) varies.

In addition, in general, regardless of the ratio of each content of the waste containing organic matter, in the hydrothermal treatment device, a predetermined amount of waste containing organic matter is hydrothermally processed within a predetermined period of time (predetermined time). For heat treatment, after the predetermined time is over, the hydrothermal treatment is ended immediately, and then the hydrothermally treated object is taken out from the hydrothermal treatment device. Therefore, the properties of the taken out hydrothermally treated product differ depending on the ratio of each content to the waste containing organic matter. For example, sandy or powdery hydrothermally treated products with little water content may be obtained, and muddy or liquid hydrothermally treated products with high water content may be obtained.

In addition, when methane fermentation is performed by using a hydrothermal treatment liquid to generate methane gas, it is desirable that fine organic substances contained in the hydrothermal treatment product be contained in the hydrothermal treatment liquid as much as possible. Therefore, as described in Patent Document 3, when separating the hydrothermal treatment liquid from the hydrothermal treatment product, it is preferable to use a pressurized screw press. However, using a screw press to pressurize a low-moisture (for example, sand-like) hydrothermally-treated product greatly increases power consumption and may cause failure, so it is not preferable.

Furthermore, when using a hydrothermal treatment liquid to generate methane gas, the concentration of fine organic substances contained in the hydrothermal treatment liquid is an important factor in improving the gas generation efficiency. However, since the concentration of the organic matter differs greatly between the hydrothermally treated product with high moisture content and the hydrothermally treated product with low moisture content, it is difficult to stably generate gas in the methane fermentation apparatus.

Therefore, an object of the present invention is to provide a hydrothermal treatment system capable of stably generating methane gas regardless of the ratio of contents contained in organic matter-containing waste. [Technical means to solve the problem]

The hydrothermal treatment system of the present invention is provided with: a hydrothermal treatment device, which makes the waste containing organic matter undergo a hydrothermal reaction; an adjustment tank, which humidifies the hydrothermally treated product that has undergone the aforementioned hydrothermal reaction; the first transfer device, which is used to transfer the hydrothermally treated object that has been humidified in the aforementioned adjusting tank; the pressurized separation device, which is used to pressurize the hydrothermally treated object transferred by the aforementioned first transfer device, and separate it into hydrothermally treated liquid and Residue; dissolving tank, which stores and heats the hydrothermal treatment liquid separated by the aforementioned pressure separation device; second transfer device, which is the hydrothermal treatment liquid heated and dissolved by the aforementioned dissolving tank Return to the aforementioned adjustment tank; methane fermentation device, which uses the hydrothermal treatment liquid stored in the aforementioned dissolving tank to generate methane gas and digested liquid; dehydrator, which separates the aforementioned digested liquid into dewatered sludge and dehydrated separation liquid; and a waste liquid treatment device, which at least performs nitrification and denitrification on the dehydration separated liquid to generate reused water. When the concentration of organic matter suitable for methane gas generation by microorganisms or bacteria is met, that is, the predetermined concentration, the aforementioned hydrothermal treatment solution is returned to the aforementioned adjustment tank, and when the concentration of the aforementioned organic matter is above the aforementioned predetermined concentration, the aforementioned water The heat-treated liquid is transferred to the aforementioned methane fermentation device. [Invention effect]

According to the present invention, methane gas can be stably generated regardless of the ratio of the respective contents contained in waste containing organic matter.

Hereinafter, the hydrothermal treatment system of the present invention will be described with reference to the drawings and the like. The configurations shown below are for illustration purposes only, and are not intended to exclude various modifications, application of techniques, etc. that are not clearly described. Various modifications can be made to the configurations and the like shown below without departing from the essential components and technical concepts of the present invention.

FIG. 1 is a schematic diagram showing a hydrothermal treatment system 1 of this embodiment. The hydrothermal treatment system 1 is to dissolve the waste containing organic matter through a hydrothermal reaction with high-temperature and high-pressure water vapor (hereinafter referred to as "hydrothermal treatment"). A system in which a liquid such as a solution, a mixed liquid, or a slurry (hereinafter referred to as a "hydrothermal treatment liquid") separated from a "hydrothermally treated product" is subjected to gas generation by microorganisms, bacteria, etc. The structure of the hydrothermal treatment system 1 includes at least: a hydrothermal treatment device 10, an adjustment tank 11, a first transfer device 21, a pressure separation device 12, a dissolution tank 13, a second transfer device 22, a methane fermentation device 14, and a dehydrator 15 And waste liquid treatment device 16. Therefore, all the structures of the hydrothermal treatment system 1 shown in FIG. 1 will be described in detail as follows.

The hydrothermal treatment device 10 is a device for hydrothermally treating waste containing organic matter. Examples of waste containing organic matter to be charged into the hydrothermal treatment apparatus 10 include leftovers (kitchen waste) discharged from households, woody waste, livestock excrement, sludge, and the like. The waste containing organic matter recovered by garbage trucks and the waste containing organic matter stored in the garbage pit of the garbage cleaning site can be directly put into the hydrothermal treatment device 10, and the inorganic matter can also be removed from the waste containing organic matter. Then, it is put into the hydrothermal treatment device 10 . It is also possible to selectively take out leftovers, paper, and plants containing organic matter suitable for gas generation from the waste containing organic matter, and then throw the taken out leftovers, paper, or plants into the water. Heat treatment device 10. In recent years, the hydrothermal treatment device 10 is also capable of hydrothermally treating disposable diapers that have disposal problems in facilities for the elderly. As will be described in detail later, in the hydrothermal treatment system 1, the proportion of each content in the predetermined amount of waste containing organic matter processed by the hydrothermal treatment device 10 in one hydrothermal treatment, even in each of the multiple times of implementation. The wastes containing organic matter treated by hydrothermal treatment are very different, and methane gas (biogas) can also be stably generated by the methane fermentation device 14 described later. The hydrothermally treated product discharged from the hydrothermal treatment device 10 after undergoing hydrothermal treatment for a predetermined period of time is stored in the adjustment tank 11 .

The adjustment tank 11 is a device for humidifying the hydrothermally treated product discharged from the hydrothermal treatment device 10 to adjust the properties of the hydrothermally treated product. In addition, here, "humidifying" the hydrothermally-treated object includes immersing the hydrothermally-treated object in water, liquid, etc. in addition to wetting the hydrothermally-treated object with water, liquid, or the like. Since the hydrothermal treatment liquid stored in the dissolution tank 13 described later is poured into the adjustment tank 11, the hydrothermally treated product stored in the adjustment tank 11 is humidified. In addition to the hydrothermal treatment liquid, tap water (not shown), recycled water to be described later, and the like may be suitably injected into the adjustment tank 11 . Also, a stirring device may be provided in the adjustment tank 11 to stir and mix the hydrothermally treated product stored in the adjustment tank 11 with the liquid or water to be injected or water injected. When a stirring device is provided, the adjustment tank 11 can adjust the properties of the hydrothermally treated product in a short time. For example, when the hydrothermally treated material stored in the adjustment tank 11 is in the form of sand, the hydrothermally treated material can be changed into a slurry form in a short time by performing the aforementioned liquid injection or the aforementioned water injection and activating the stirring device. Stirring device, such as air stirring, mechanical stirring, etc., can stir and mix the hydrothermally treated product stored in the adjustment tank 11 and the liquid or water to be injected or water injected, and any device may be used.

Furthermore, the hydrothermal treatment device 10 and the adjustment tank 11 are equipment for hydrothermally treating waste containing organic matter, and for humidifying and storing the hydrothermally treated product obtained by the hydrothermal treatment, and are part of the hydrothermal treatment system 1. Components of the first device 2 that performs the first-stage processing. Also, as will be described in detail later, the hydrothermally treated product stored in the first facility 2 is pressurized to separate the hydrothermally treated liquid (hereinafter referred to as "pressure separation"), and the water obtained by the pressurized separation is The equipment for dissolving the heat treatment liquid is the second equipment 3 of the hydrothermal treatment system 1 for the second stage of treatment. Furthermore, the facility for generating gas using the hydrothermal treatment liquid dissolved in the second facility 3 is the third facility 4 for performing the third-stage treatment in the hydrothermal treatment system 1 .

The first transfer device 21 is a device that transfers the hydrothermally treated product humidified in the adjustment tank 11 of the first facility 2 to the second facility 3 . When the first facility 2 and the second facility 3 are installed close to each other, for example, in the same or adjacent area where the distance between the first facility 2 and the second facility 3 is less than about 500 m, it is desirable that the first transfer The device 21 is connected to the adjustment tank 11 of the first equipment 2 and the pressure separation device 12 of the second equipment 3, and is equipped with a pulverization mechanism for sending the hydrothermally treated product whose properties have been adjusted by the adjustment tank 11 to the pressure separation device 12. Pump lines. Generally, a pipeline is configured by connecting a plurality of pipes so as to form one path. In this case, the hydrothermally treated product stored in the adjustment tank 11 of the first facility 2 is pulverized by the crushing pump through the pipeline, and then transferred to the pressurized separation device 12 of the second facility 3 . When transferring the hydrothermally-treated substance, the hydrothermally-treated substance can be miniaturized by the pulverization pump, so the load on the pressurized separation device 12 (for example, a screw press) described later can be reduced.

Furthermore, in the following, when two of the first facility 2, the second facility 3, and the third facility 4 are installed [nearly], it means that the distance between the two facilities is less than about 500m. or a different region.

In addition, when the first equipment 2 and the second equipment 3 are installed at remote places, it is desirable that the first transfer device 21 is a vehicle (for example, a vacuum vehicle, etc.) equipped with a storage tank. For example, if the first device 2 and the second device 3 are installed at a distance of about 500 m or more from each other, regardless of whether they are in the same area or different areas, they are all considered to be installed in the "remote place". In this case, the hydrothermally treated product stored in the adjustment tank 11 of the first equipment 2 is loaded on the vehicle, and then transported to the pressurized separation device 12 of the second equipment 3, and then the transported hydrothermally treated material is put into the pressurized Separation device 12.

Here, the vehicle may be a human-operated vehicle, or may be an automatic driving vehicle that operates under computer control such as artificial intelligence (AI). In addition, a central control room may be installed in the hydrothermal treatment system 1, and the operator may control the operation of the vehicle while performing remote monitoring by using a monitoring camera. In this case, if monitoring cameras are installed in the equipment, devices, and facilities included in the hydrothermal treatment system 1, such remote monitoring can be performed in the central control room, and the operation safety of the hydrothermal treatment system 1 can be improved. Moreover, the hydrothermal treatment system 1 can also control the operation of the equipment, devices and facilities included in the hydrothermal treatment system 1 in the central control room, or use AI to fully automate the operation of the hydrothermal treatment system 1 .

Furthermore, in the following, when two devices [remote] among the first device 2, the second device 3, and the third device 4 are installed, it means that the distance between the two devices is about 500 m or more. different regions. Also, hereinafter, when referred to as a "vehicle", the vehicle may be a human-operated vehicle or an automatic driving vehicle. The car can also be controlled by manual remote monitoring.

The pressurized separation device 12 of the second equipment 3 pressurizes the hydrothermally treated product transferred from the adjustment tank 11 of the first equipment 2 by the first transfer device 21, and separates it into a hydrothermally treated liquid and a residue (from the hydrothermally treated product). A device that separates the hydrothermal treatment liquid and leaves the rest). Furthermore, the hydrothermal treatment liquid is also called a suitable fermented product, and the residue is called an unsuitable fermented product. The structure of the pressure separation device 12 may be, for example, as shown in FIG. 2 , in which a rotary screen roll 12A is arranged at the front stage, and a screw press 12B is arranged at the rear stage. The rotary screen drum 12A may be, for example, a perforated metal drum screen device described in Japanese Patent No. 6384015 Quasi-Specific Publication of Mitsubishi Heavy Industries Environmental-Chemical Engineering Co., Ltd. In addition, the screw press 12B may be, for example, the dehydration system described in FIG. 13 of Japanese Patent No. 6734496 of Mitsubishi Heavy Industries Environmental-Chemical Engineering Co., Ltd. The pressurized separation device 12 is based on the water content, viscosity, etc. of the hydrothermally treated product, which will affect the recovery rate of the hydrothermally treated liquid and the removal rate of unsuitable fermentation products. Therefore, the mesh, opening ratio, screw pitch (screw The distance from the outlet), etc. need to be carefully set. The dehydration system described in FIG. 13 of the aforementioned Japanese Patent No. 6734496 Quasi-Patent Publication can change the mesh according to the change of the properties of the hydrothermally treated product, so it can be ideally applied to the pressure separation device 12 . The pressurized separation device 12 can also change the pressure inside the device by increasing or decreasing the size of the discharge port in response to changes in the properties of the hydrothermally treated product. In addition, the pressure separation device 12 may also be different from that shown in Fig. 2, and may be constituted only by a single screw press.

In the pressure separation device 12 of FIG. 2 , the hydrothermally treated product transferred from the adjustment tank 11 of the first facility 2 by the first transfer device 21 is first put into the rotary drum screen 12A. Then, a part of the hydrothermally treated liquid is separated from the hydrothermally treated product by the rotary drum 12A. Then, the hydrothermally treated product discharged from the rotary drum 12A is charged into the screw press 12B. Therefore, the screw press 12B at the rear stage will be transferred by the first transfer device 21 more than the case where the rotary drum screen 12A is not arranged in the front stage (the pressure separation device 12 is only a single case of the screw press machine). The hydrothermally treated substance after the total amount of the hydrothermally treated substance has been reduced is pressurized and separated into a hydrothermally treated liquid and a residue. Therefore, the pressure separation device 12 of FIG. 2 can achieve power reduction (power saving) of the screw press 12B. Furthermore, part of the hydrothermal treatment liquid separated by the rotary drum screen 12A and the hydrothermal treatment liquid separated by the screw press 12B are both stored in the dissolving tank 13 of the second equipment 3 .

The dissolving tank 13 of the second equipment 3 is a device for storing the hydrothermal treatment liquid separated by the pressure separation device 12 and heating it to dissolve the hydrothermal treatment liquid. The heating temperature can be set at about 40°C to 60°C, for example. By dissolving the hydrothermal treatment liquid in the dissolving tank 13, the insoluble solids (Suspended Solids, hereinafter referred to as "SS") floating in the hydrothermal treatment liquid are changed into solids (Dissolved Solids) dissolved in the hydrothermal treatment liquid. , hereinafter referred to as "DS"). Therefore, the SS occupied by the total solids (Total Solids, hereinafter referred to as "TS"; TS=SS+DS) contained in the hydrothermal treatment liquid stored in the dissolving tank 13 decreases. Therefore, the dissolving tank 13 can also be called a device for reducing the SS of the stored hydrothermal treatment liquid and increasing the DS to promote acid fermentation. Generally, TS organic matter has a large amount of DS, which contributes to gas generation by microorganisms, fungi, and the like. TS, SS, or DS of the hydrothermal treatment liquid stored in the dissolution tank 13 can be measured by a dedicated measuring device (not shown). Also, in the dissolving tank 13, similarly to the adjustment tank 11, a stirring device may be provided to stir the hydrothermal treatment liquid stored in the dissolving tank 13 to promote the dissolution of the hydrothermal treatment liquid.

The second transfer device 22 is to transfer the organic matter contained in the hydrothermal treatment liquid stored in the dissolving tank 13 of the second equipment 3 to a predetermined concentration (for example, about 10% for TS and about 6% for DS). The hydrothermal treatment liquid is returned from the dissolving tank 13 to the adjustment tank 11 of the first equipment 2, and when it reaches the predetermined concentration (including the situation that can be substantially above the predetermined concentration. In addition, the predetermined concentration can also be, for example, about TS 10%~12%, DS about 6%~8%, etc.), the hydrothermal treatment liquid is transferred from the dissolving tank 13 to the device of the methane fermentation device 14 of the third equipment 4. The structure of the second transfer device 22 can also be based on the measurement results of the aforementioned measurement device, one of the adjustment tank 11 and the methane fermentation device 14 is automatically selected as the transfer object, and the water stored in the dissolution tank 13 is automatically selected. The heat treatment liquid is transferred to the selected transfer destination. Furthermore, the predetermined concentration is set to the concentration of organic matter suitable for methane fermentation in the methane fermentation device 14 described later, that is, the concentration of organic matter suitable for methane gas generation by microorganisms or bacteria. At this predetermined concentration, the pH value (pH value) of the hydrothermal treatment solution stored in the dissolution tank 13 is acidic less than 7, and is preferably pH 5 or lower.

The second transfer device 22 is the same as the first transfer device 21. When the first device 2 and the second device 3 are installed close to each other, it is desired to dissolve the adjustment tank 11 connected to the first device 2 and the second device 3. The melting tank 13 is provided with a pipeline for pumping the hydrothermal treatment hydraulic pressure in the dissolving tank 13 to the adjusting tank 11 . In addition, in the case where the first facility 2 and the second facility 3 are located at a distance from each other, it is desirable that the second transfer device 22 is a vehicle (for example, a vacuum vehicle, etc.) equipped with a storage tank. In this case, the hydrothermal treatment liquid is conveyed from the dissolution tank 13 to the adjustment tank 11 by a vehicle. In either case, the hydrothermal treatment liquid is circulated between the first device 2 and the second device 3 by the second transfer device 22 .

In addition, the second transfer device 22 is preferably connected to the dissolving tank 13 of the second facility 3 and the methane fermentation device 14 of the third facility 4 when the second facility 3 and the third facility 4 are arranged close to each other, and, It is equipped with a pump line for hydraulically sending the hydrothermal treatment in the dissolving tank 13 to the input port of the methane fermentation device 14 .

Furthermore, when the first equipment 2, the second equipment 3, and the third equipment 4 are arranged close to each other, the second transfer device 22 is, for example, between the dissolving tank 13 of the second equipment 3 and the adjustment tank of the first equipment 2. A switching device is provided in the middle of the pipeline connected with 11, and other pipelines diverging from this pipeline are connected to the switching device and the inlet of the methane fermentation device 14 of the third equipment 4. As mentioned above, in response to the concentration of organic matter contained in the hydrothermal treatment liquid stored in the dissolving tank 13 of the second device 3, the pipeline connecting the dissolving tank 13 of the second device 3 and the adjustment tank 11 of the first device 2 , and any one of the above-mentioned other pipelines, the way of transferring the hydrothermal treatment liquid stored in the dissolving tank 13, the second transfer device 22 can be selected alternatively by switching the device.

In addition, in the case where the second equipment 3 and the third equipment 4 are located at a distance from each other, it is desirable that the second transfer device 22 is a vehicle (for example, a vacuum vehicle, etc.) equipped with a storage tank. In this case, the hydrothermal treatment liquid is conveyed from the dissolution tank 13 to the methane fermentation device 14 by a vehicle, and the hydrothermal treatment liquid is injected into the inlet of the methane fermentation device 14 . Furthermore, in the case where the first equipment 2 and the second equipment 3 are set close to each other, and the second equipment 3 and the third equipment 4 are located at a distance from each other, as the second transfer device 22, it can also be the first equipment 2 and the second equipment 2. The transfer of the hydrothermal treatment liquid between the two devices 3 is through pipelines, and the transfer of the hydrothermal treatment liquid between the second device 3 and the third device 4 is through a vehicle. That is, the second transfer device 22 can also serve as two types of transfer devices for the pipeline and the vehicle. Similarly, in the case where the first device 2 and the second device 3 are located far away from each other and the second device 3 and the third device 4 are arranged close to each other, as the second transfer device 22, the first device 2 and the second device 3 The transfer of the hydrothermal treatment liquid between the second equipment 3 and the third equipment 4 may be via a pipeline.

The second transfer device 22 returns the hydrothermal treatment solution to the adjustment tank 11 of the first facility 2 until the concentration of organic matter contained in the hydrothermal treatment solution stored in the dissolving tank 13 of the second facility 3 reaches the predetermined concentration. Therefore, the hydrothermally treated product stored in the adjustment tank 11 of the first equipment 2 can be humidified, so the transfer of the hydrothermally treated material by the first transfer device 21 is easy, and the pressure separation device 12 of the second equipment 3 can be reduced. power.

Moreover, the hydrothermal treatment liquid returned from the dissolving tank 13 of the second equipment 3 to the adjustment tank 11 of the first equipment 2 is heated by the dissolving tank 13, so even in the state of the heated temperature or due to natural heat dissipation, etc. The liquid can be poured into the adjustment tank 11 while cooling for a while while maintaining a temperature higher than normal temperature. In this case, the returned hydrothermal treatment liquid can promote the dissolution of at least a part of the hydrothermally treated product stored in the adjustment tank 11, and contribute to the adjustment of the properties of the hydrothermally treated product.

In addition, in the hydrothermal treatment system 1, hydrothermal treatment is performed several times sequentially in time, but even if the hydrothermal treatment device 10 of the first equipment 2 performs the hydrothermal treatment, the proportion of each content in the waste containing organic matter will be in the range of Each hydrothermal treatment is greatly different, and the concentration of organic matter contained in the hydrothermal treatment liquid obtained by each hydrothermal treatment is very uneven, and the aforementioned return can also be used to make the hydrothermal treatment liquid between the first equipment 2 and the second equipment. Circulation between the two devices 3 can average the concentration of organic matter contained in the hydrothermal treatment liquid stored in the dissolving tank 13 . Also, when the concentration of the organic matter contained in the hydrothermally treated liquid stored in the dissolving tank 13 becomes a predetermined concentration, the hydrothermally treated liquid with the predetermined concentration is transferred to the methane fermentation device 14 by the second transfer device 22 . Therefore, the concentration of the organic matter contained in the hydrothermally treated liquid injected into the methane fermentation device 14 is substantially constant and changes little, and the hydrothermally treated liquid contains many organic matters that contribute to the generation of methane gas. Therefore, the methane fermentation device 14 can stably generate methane gas.

In a methane fermentation device that uses organic matter as a raw material and generates methane gas by microorganisms, fungi, etc., usually, inside the device, two processes of solubilization of organic matter and acid fermentation are firstly required. However, in the hydrothermal treatment system 1 , when the concentration of the organic matter contained in the hydrothermal treatment liquid stored in the dissolving tank 13 is the predetermined concentration, the above two processes have already been executed and completed in the dissolving tank 13 . Therefore, the methane fermentation device 14 can omit the dissolving process and the acid fermentation process, so methane gas can be generated at high speed.

The methane fermentation device 14 of the third facility 4 is a device that generates methane gas and digestate using the hydrothermal treatment liquid stored in the dissolving tank 13 of the second facility 3 . The methane fermentation device 14 heats the hydrothermal treatment solution (about 37° C. or about 55° C.) to generate methane gas by methane fermentation. The remaining liquid fertilizer (also known as fermentation residue, digested sludge) after methane gas generation is digestive juice. In the case where the hydrothermal treatment solution stored in the dissolving tank 13 of the second equipment 3 contains a large amount of fiber components such as paper, the fiber components cannot be completely decomposed by the methane fermentation device 14, and a part remains and is contained in the digestive juice. And discharge. Therefore, when the digestive juice contains a large amount of fiber components, there is no need to install the defibrating solution supply device 17 described later, the excrement receiving tank 18 described later, etc. for the purpose of improving the dehydration efficiency of the dehydrator 15 described later.

The dehydrator 15 is a device (for example, a screw press) that separates the digested liquid discharged from the methane fermentation device 14 into dehydrated sludge and dehydrated separated liquid. The separated dewatered sludge is transferred to a waste incineration facility 20 described later, and is incinerated at the waste incineration facility 20 . In addition, the separated dehydration separation liquid is transferred to the waste liquid treatment device 16 .

The waste liquid treatment device 16 is a device that performs at least nitrification and denitrification treatment on the dehydration separation liquid separated by the dehydrator 15, that is, performs biological treatment to purify the dehydration separation liquid to generate reuse water. Examples of the waste liquid treatment device 16 include a biological treatment device that performs nitrification and denitrification, a waste treatment facility, and the like. The recycled water generated by the waste liquid treatment device 16 can be supplied to the adjustment tank 11 of the first facility 2 through the supply path 25 (for example, a pipeline). After the hydrothermal treatment system 1 just starts running, because the hydrothermal treatment liquid is not stored in the dissolving tank 13 of the second equipment 3, the hydrothermal treatment system 1 cannot return the hydrothermal treatment liquid to the adjustment tank 11, and cannot The hydrothermal treatment liquid humidifies the hydrothermally treated product stored in the adjustment tank 11 . Therefore, in this case, the hydrothermal treatment system 1 can humidify the hydrothermally treated product stored in the adjustment tank 11 by supplying recycled water from the waste liquid treatment device 16 to the adjustment tank 11, and the hydrothermal treatment system 1 can immediately After starting the operation, the transfer of the hydrothermally treated product by the first transfer device 21, the operation of the pressure separation device 12 of the second facility 3, and the like can be smoothly performed. In the case where the aforementioned return cannot be performed, the hydrothermal treatment system 1 can also inject tap water into the adjustment tank 11 to humidify the hydrothermally treated product. However, in order to improve the cost efficiency of the hydrothermal treatment system 1 , it is desirable to use recycled water instead of tap water.

In the above, at least the configuration included in the hydrothermal treatment system 1 has been described. However, as shown in FIG. 1 , the hydrothermal treatment system 1 may further include the following devices, facilities, and the like.

The defibrating liquid supply device 17 is a device that defibrates paper (for example, waste paper such as old newspapers) and supplies the liquid defibrating liquid to the digested liquid discharged from the methane fermentation device 14 . Since the fiberizing solution supply device 17 mixes the fiberizing solution into the digestive juice, the dehydrator 15 dehydrates the mixture of the digestive fluid and the fiberizing solution. Since the fibrous solution contains a large amount of fiber components, the fiber components contained in the mixed solution function as a substitute for the dehydration aid and absorb the water in the mixed solution. Therefore, the dehydration efficiency of the mixed liquid in the dehydrator 15 can be improved. In addition, since the fiber component is discharged from the dehydrator 15 as a part of the dewatered sludge, the volume of the dewatered sludge can be increased compared to the case where the fiberizing solution is not mixed into the digestive solution. Moreover, the fiber component contained in the defibrating liquid does not contain a nitrogen component, and when absorbing the moisture of the aforementioned mixed solution, the nitrogen component contained in the mixed solution is also absorbed. The nitrogen concentration becomes thinner. Therefore, the load of the biological treatment in the waste liquid treatment apparatus 16 can be reduced. The defibrating liquid supply device 17 can be, for example, a paper supply device, a defibrating device, a defibrating waste paper storage tank, and a defibrating waste paper described in Japanese Patent No. 5905364 of Mitsubishi Heavy Industries Environmental and Chemical Engineering Co., Ltd. Consists of paper supply pumps.

Excrement receiving tank 18 is a water tank for storing excrement. In the hydrothermal treatment system 1, the [C/N ratio] of feces (the ratio of the amount of nitrogen contained in the liquid to the amount of carbon used as a nutrient source by microorganisms during biological treatment of denitrification) can be used to be about 3 to 5, and The characteristics of fiber content in feces. Specifically, in the hydrothermal treatment system 1 , the excrement stored in the excrement receiving tank 18 is supplied to the methane fermentation device 14 , or the digested liquid discharged from the methane fermentation device 14 , or the waste liquid treatment device 16 . Furthermore, not only one of these three places can be supplied, but also excrement can be supplied to two or three places.

In order to efficiently carry out methane fermentation in the methane fermentation apparatus 14, the amount of nitrogen contained in the hydrothermal treatment liquid needs to be about 1000 mg/L or more and about 3000 mg/L or less. However, the amount of nitrogen contained in the hydrothermal treatment liquid transferred from the dissolution tank 13 to the methane fermentation device 14 may be less than this range. In this case, by supplying excrement from the excrement receiving tank 18 to the methane fermenter 14 and mixing it with the hydrothermally treated liquid, deficiencies in the amount of nitrogen contained in the hydrothermally treated liquid transferred to the methane fermenter 14 can be supplemented with excrement. That is, in order to adjust the balance of the amount of nitrogen at the time of methane fermentation, excrement is supplied. Furthermore, by supplying feces and urine to the methane fermentation device 14, the amount of carbon contained in the hydrothermal treatment liquid stored in the methane fermentation device 14 will increase, but in the methane fermentation device 14, most of the carbon will be changed into methane gas , therefore, it will not have a bad influence on the hydrothermal treatment system 1 . Also, the excrement and urine in the excrement and urine receiving tank 18 may not be directly supplied to the methane fermentation device 14, but to the upstream of the methane fermentation device 14 such as the adjustment tank 11 of the first equipment 2, the dissolving tank 13 of the second equipment 3, etc. In this case, excrement is indirectly supplied to the methane fermentation device 14 .

In addition, when the excrement and urine in the excrement and urine receiving tank 18 are supplied to the digestive liquid discharged from the methane fermentation device 14 to make a mixed solution, the fiber component contained in the excrement and urine is used as the same as the fiber component contained in the above-mentioned defibrating liquid. The substitute of the dehydration auxiliary agent functions to improve the dehydration efficiency of the mixed liquid in the dehydrator 15 . If it is a hydrothermal treatment system 1 equipped with both the fibrinolysis liquid supply device 17 and the excrement receiving tank 18, the fiber component contained in the digestive juice is small, and in order to improve the aforementioned dehydration efficiency, it is necessary to supplement the fiber component. Fiber components such as fibrinolytic solution and excrement make up the deficiency. Furthermore, the hydrothermal treatment system 1 may include one or both of the defibrating liquid supply device 17 and the excrement receiving tank 18 .

In addition, in general, when performing biological treatment of denitrification of a liquid, if the C/N ratio of the liquid is about 2 to 3, the treatment can be efficiently performed. Therefore, in the case of biological treatment of the dehydration separation liquid with the waste liquid treatment device 16, when the C/N ratio of the dehydration separation liquid is less than 2, by supplying the excrement and urine receiving tank 18 to the dehydration separation liquid and mixing, It is preferable to increase the value of the C/N ratio. When the dehydration separation liquid is mixed with feces and urine to make a mixed liquid, adding feces and urine to the dehydration separation liquid will increase the amount of carbon and nitrogen. However, as mentioned above, because the C/N ratio of excrement and urine is about 3~5 , so the increase in carbon is greater than the increase in nitrogen. Therefore, even if the C/N ratio of the dehydration separated liquid is less than 2, the C/N ratio of the mixed liquid can be easily made approximately 2 to 3 by mixing with feces. That is, here, excrement is supplied in order to adjust the balance of the C/N ratio of the dehydrated separation liquid subjected to the biological treatment.

The third transfer device 23 is a device for transferring the methane gas generated in the methane fermentation device 14 of the third facility 4 to the gas utilization facility 19 described later. When the methane fermentation device 14 and the gas utilization facility 19 are arranged close to each other, it is desirable that the third transfer device 23 is connected to the methane fermentation device 14 and the gas utilization facility 19, and the methane gas generated in the methane fermentation device 14 is transferred to Pipelines of gas utilization facilities 19. In addition, in the case where the methane fermentation device 14 and the gas utilization facility 19 are located at a distance from each other, it is desirable that the third transfer device 23 is a vehicle (truck) equipped with a stage on which a gas cylinder can be placed, a vehicle equipped with a gas tank, etc. . In this case, the methane gas generated in the methane fermentation device 14 can be filled in a gas cylinder, a gas tank, etc., placed or mounted on a vehicle, and then transferred to the gas utilization facility 19 .

The gas utilization facility 19 is a facility for utilizing the methane gas generated in the methane fermentation device 14 of the third facility 4 . The gas utilization facility 19 is, for example, generating steam by burning the methane gas or a mixed gas of the methane gas mixed with other gases in a boiler to generate steam, and then using the steam to drive a steam turbine to generate electricity The power plant. In recent years, in thermal power plants, in order to reduce the emission of carbon dioxide during combustion, liquefied natural gas (LNG) (Liquefied Natural Gas) with methane as the main component has become the mainstream of thermal power plants, and gas utilization facilities 19 can also be used as a basis for this thermal power plant A power plant for a power plant. The gas utilization facility 19 may also be a power plant equipped with a gas turbine, a gas engine, or a fuel cell, which reforms the methane gas to generate city gas or the like. When the gas utilization facility 19 is a power plant equipped with a gas engine, it usually includes a heat recovery device for exhaust gas generated by the gas engine. The heat recovery unit generates warm water from the exhaust gas.

When the gas utilization facility 19 is a power plant that generates electricity through a steam turbine, and at least one of the first facility 2, the second facility 3, and the third facility 4 is installed close to the gas utilization facility 19, the The steam turbine of the gas utilization facility 19 utilizes the high-temperature water vapor, that is, the waste water vapor, which is used for power generation in the adjacent first facility 2 , second facility 3 or third facility 4 . For example, when the gas utilization facility 19 equipped with a steam turbine is installed close to the first facility 2, the gas utilization facility 19 is connected to the first facility 2 through a pipeline, and the waste water vapor is transferred to the first facility through the pipeline. The hydrothermal treatment device 10 of 2 is used as high-temperature and high-pressure water vapor or a part thereof for use in the hydrothermal treatment device 10 . Also, when the gas utilization facility 19 equipped with a steam turbine is installed close to the second facility 3, the gas utilization facility 19 is connected to the second facility 3 through a pipeline, and the waste water vapor is transferred to the second facility through the pipeline. The dissolving tank 13 of 3 is used for heating the hydrothermal treatment liquid stored in the dissolving tank 13 . Furthermore, when the gas utilization facility 19 equipped with a steam turbine is installed close to the third facility 4, the gas utilization facility 19 is connected to the third facility 4 through a pipeline, and the waste water vapor is transferred to the third facility through the pipeline. The methane fermentation device 14 of 4 is used for heating the hydrothermal treatment liquid stored in the methane fermentation device 14 .

And, in the case that the gas utilization facility 19 equipped with a gas engine is installed close to the second equipment 3, the gas utilization facility 19 is connected to the second equipment 3 through a pipeline, and then through the pipeline, the heat recovery device described above will The generated warm water is transferred to the dissolving tank 13 of the second facility 3 and used for heating the hydrothermal treatment liquid stored in the dissolving tank 13 . Similarly, in the case where the gas utilization facility 19 equipped with a gas engine is installed close to the third facility 4, the gas utilization facility 19 is connected to the third facility 4 through a pipeline, and the warm water is passed through the pipeline. The methane fermentation device 14 transferred to the third facility 4 is used for heating the hydrothermal treatment liquid stored in the methane fermentation device 14 . As mentioned above, the heating temperature of the dissolving tank 13 is about 40°C to 60°C, and the heating temperature of the methane fermentation device 14 is about 37°C or about 55°C. Therefore, to ferment the dissolving tank 13 and methane The device 14 and the like are heated, and warm water is easier to handle than waste water vapor.

In this way, when the gas utilization facility 19 is equipped with a steam turbine, the waste water vapor discharged from the steam turbine can be used as a heat source in the hydrothermal treatment system 1, and when the gas utilization facility 19 is equipped with a gas engine, it can be used as a heat source. The warm water generated by the aforementioned heat recovery device is used as a heat source in the hydrothermal treatment system 1 , so the cost efficiency of the hydrothermal treatment system 1 can be further improved.

The fourth transfer device 24 is a device that transfers the residue separated by the pressure separation device 12 of the second facility 3 to the waste incineration facility 20 described later. In the case where the second equipment 3 and the waste incineration facility 20 are arranged close to each other, it is desirable that the fourth transfer device 24 be connected to the residue discharge port of the pressurized separation device 12 and the garbage pit of the waste incineration facility 20, and the The conveyor that conveys the residue discharged from the pressure separation device 12 to the garbage pit. In addition, when the second facility 3 and the waste incineration facility 20 are located at a distance from each other, it is desirable that the fourth transfer device 24 is a vehicle such as a truck or a garbage truck. In this case, the residue discharged from the pressurized separation device 12 can be loaded or stored in the cabin of a truck or in a garbage truck, and then transferred to the waste incineration facility 20 .

The waste incineration facility 20 is a facility for incinerating waste with an incinerator, and can also incinerate the residue discharged from the pressurized separation device 12 of the second equipment 3 and the dewatered sludge separated by the dehydrator 15 . The waste incineration facility 20 uses the heat generated in the incinerator to generate high-temperature and high-pressure steam in the boiler, and then uses the high-temperature and high-pressure steam to drive the steam turbine to generate electricity. In the case where at least one of the first equipment 2, the second equipment 3, and the third equipment 4 and the waste incineration facility 20 are arranged close to each other, the steam turbine at the waste incineration facility 20 can be used for generating high-temperature steam That is, waste water vapor is utilized in the adjacent first facility 2 , second facility 3 or third facility 4 . For example, when the waste incineration facility 20 is installed close to the first facility 2, the waste incineration facility 20 is connected to the first facility 2 through a pipeline, and then the waste water vapor is transferred to the first facility 2 through the pipeline. The hydrothermal treatment device 10 is used as high-temperature and high-pressure steam or a part thereof for use in the hydrothermal treatment device 10 . Also, when the waste incineration facility 20 is installed close to the second facility 3, the waste incineration facility 20 is connected to the second facility 3 through a pipeline, and the waste water vapor is transferred to the second facility 3 through the pipeline. The dissolving tank 13 is used for heating the hydrothermal treatment liquid stored in the dissolving tank 13 . In addition, when the waste incineration facility 20 and the third facility 4 are installed close to each other, the waste incineration facility 20 and the third facility 4 are connected by a pipeline, and the waste water vapor is transferred to the methane fermentation device of the third facility 4 through the pipeline. 14. It can be used to heat the hydrothermal treatment liquid stored in the methane fermentation device 14. In this way, the waste water vapor from the waste incineration facility 20 can be used effectively as a heat source in the hydrothermal treatment system 1 , so the cost efficiency of the hydrothermal treatment system 1 can be further improved.

Furthermore, the hydrothermal treatment system 1 may also be without (1) the defibrating liquid supply device 17, (2) the excrement receiving tank 18, (3) the third transfer device 23 and the gas utilization facility 19, (4) the fourth The system of any one of the four of the transfer device 24 and the waste incineration facility 20 may be a system provided with only one, two or three of them, or a system provided with all four.

1: Hydrothermal treatment system 2: First device 3: Second device 4: Third device 10: Hydrothermal treatment device 11: Adjustment slot 12: Pressurized separation device 12A:Rotary drum screen 12B: Screw press 13: Dissolving tank 14: Methane fermentation device 15: Dehydrator 16: Waste liquid treatment device (excrement and urine treatment facility) 17: Fiberolysis liquid supply device 18: Feces and urine receiving tank 19: Gas Utilization Facilities 20:Waste incineration facilities 21: The first transfer device 22: The second transfer device 23: The third transfer device 24: The fourth transfer device 25: Supply Road

[ Fig. 1 ] is a schematic diagram showing a hydrothermal treatment system of an embodiment. [ Fig. 2 ] is a schematic diagram showing an example of the second facility of the hydrothermal treatment system of the embodiment.

1: Hydrothermal treatment system

2: First device

3: Second device

4: Third device

10: Hydrothermal treatment device

11: Adjustment slot

12: Pressurized separation device

13: Dissolving tank

14: Methane fermentation device

15: Dehydrator

16: Waste liquid treatment device (excrement and urine treatment facility)

17: Fiberolysis liquid supply device

18: Feces and urine receiving tank

19: Gas Utilization Facilities

20:Waste incineration facilities

21: The first transfer device

22: The second transfer device

23: The third transfer device

24: The fourth transfer device

25: Supply Road

Claims (5)

A hydrothermal treatment system comprising: a hydrothermal treatment device, which makes waste containing organic matter undergo a hydrothermal reaction; Adjusting tank, which is to humidify the hydrothermally treated product that has undergone the aforementioned hydrothermal reaction; The first transfer device is used to transfer the hydrothermally treated object humidified in the adjustment tank; A pressurized separation device, which pressurizes the hydrothermally treated product transferred by the first transfer device, and separates it into a hydrothermally treated liquid and a residue; Dissolving tank, which stores and heats the hydrothermal treatment liquid separated by the aforementioned pressure separation device; The second transfer device is used to return the hydrothermal treatment liquid heated and dissolved by the aforementioned dissolving tank to the aforementioned adjusting tank; A methane fermentation device, which uses the hydrothermal treatment liquid stored in the aforementioned dissolving tank to generate methane gas and digestion liquid; A dehydrator, which separates the aforementioned digestive liquid into dewatered sludge and dehydrated separation liquid; and A waste liquid treatment device that at least performs nitrification and denitrification on the aforementioned dehydration separated liquid to generate reused water, The aforementioned second transfer device transfers the aforementioned concentration of organic matter contained in the hydrothermal treatment solution stored in the aforementioned dissolving tank to a concentration suitable for methane gas generation by microorganisms or bacteria, that is, a predetermined concentration. The hydrothermal treatment liquid is returned to the adjustment tank, and when the concentration of the organic matter is above the predetermined concentration, the hydrothermal treatment liquid is transferred to the methane fermentation device. The hydrothermal treatment system according to claim 1, further comprising a defibrating liquid supply device for supplying the defibrating liquid after the paper has been deflated to the aforementioned digestive liquid. The hydrothermal treatment system according to claim 1 or 2, wherein it also has a waste receiving tank for storing waste, supplying the excrement and urine in the aforementioned excrement and urine receiving tank to the aforementioned methane fermentation device, and mixing with the aforementioned hydrothermal treatment liquid, Or, mixing the excrement and urine in the aforementioned excrement and urine receiving tank with the aforementioned digestive juice, Or, mix the excrement and urine in the aforementioned excrement and urine receiving tank with the aforementioned dehydration separation liquid. The hydrothermal treatment system as claimed in claim 3, wherein the aforementioned pressurized separation device is Equipped with a rotary drum wire mesh in the front section and a screw press in the rear section, The hydrothermal treatment liquid separated by the rotary drum screen and the hydrothermal treatment liquid separated by the screw press were stored in the dissolution tank. The hydrothermal treatment system according to claim 4, further comprising: a third transfer device for transferring the methane gas generated in the methane fermentation device, and a gas utilization facility for utilizing the methane gas transferred by the third transfer device, or, A fourth transfer device that transfers the residue separated by the aforementioned pressure separation device and a waste incineration facility that incinerates the residue transferred by the aforementioned fourth transfer device, In the case where the hydrothermal treatment device and the adjustment tank are installed close to the pressurized separation device and the dissolution tank, the first transfer device is a pipeline equipped with a crushing pump, and the second transfer device is a pipeline equipped with a pump. the pipeline, In the case where the aforementioned hydrothermal treatment device and the aforementioned adjusting tank, the aforementioned pressurized separation device and the aforementioned dissolving tank are located at remote places from each other, both the aforementioned first transfer device and the aforementioned second transfer device are vehicles, In the case where the aforementioned methane fermentation unit and the aforementioned gas utilization facility are installed close to each other, the aforementioned third transfer unit is a pipeline, In the case where the aforementioned methane fermentation device and the aforementioned gas utilization facility are located in remote places, the aforementioned third transfer device is a vehicle, In the case where the waste incineration facility is installed close to the pressurized separation device and the dissolution tank, the fourth transfer device is a conveyor, In the case where the aforementioned waste incineration facility, the aforementioned pressurized separation device, and the aforementioned dissolving tank are located far away from each other, the aforementioned fourth transfer device is a vehicle, The aforementioned gas utilization facility is provided with a steam turbine or a gas engine, and the steam used for power generation in the aforementioned steam turbine is supplied to at least one of the aforementioned hydrothermal treatment device, the aforementioned dissolution tank, and the aforementioned methane fermentation device, or, Warm water generated from exhaust gas generated by the gas engine is supplied to at least one of the dissolution tank and the methane fermentation device, The waste incineration facility is equipped with a steam turbine, and the water vapor used for power generation in the steam turbine is supplied to at least one of the hydrothermal treatment device, the dissolution tank, and the methane fermentation device, The waste liquid treatment device is an excrement treatment facility, and the recycled water is supplied to the adjustment tank.

Images