KR20230092009A - hydrothermal treatment system - Google Patents

Abstract

The hydrothermal treatment system 1 includes a hydrothermal treatment device 10 for hydrothermal reaction of wastes containing organic matter, an adjustment tank 11 for humidifying the hydrothermally reacted hydrothermal treated product, and a first transfer device for transporting the humidified hydrothermal treated product. (21), a pressure separation device 12 for pressurizing the transferred hydrothermal treatment liquid and separating it into a hydrothermal treatment liquid and a residue, a solubilization tank 13 for storing and warming the separated hydrothermal treatment liquid, and warming, and A second transfer device 22 for conveying the solubilized hydrothermal treatment liquid to the conditioning tank 11, and a methane fermentation device 14 for generating methane gas and digestion liquid using the hydrothermal treatment liquid stored in the solubilization tank 13 , It has a dehydrator 15 that separates the digested liquid into dewatered sludge and separated dewatered liquid, and a waste liquid treatment device 16 that generates reused water by digesting and denitrifying the separated dehydrated liquid. The second transfer device 22 transfers the hydrothermal treatment liquid to the methane fermentation device 14 when the concentration of the organic matter contained in the hydrothermal treatment liquid stored in the solubilization tank 13 is a predetermined concentration.

Description

hydrothermal treatment system

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

Kitchen waste (food waste) discharged from households such as urban waste, woody waste such as paper and vegetation, livestock manure, and organic matter-containing waste such as sludge are hydrothermally reacted with high-temperature and high-pressure steam to solubilize (hydrothermal treatment), A system has been developed in which a liquid (hydrothermal treatment liquid) such as a solution or slurry is separated from heat-treated organic matter-containing waste (hydrothermal treatment product), and gas generation by microorganisms or bacteria, for example, methane fermentation, is performed using the liquid. There is (for example, Patent Documents 1 and 2). In order to separate the pancreatic juice treatment liquid from the hydrothermally treated material, in this system, for example, a screen or a screw press as described in Patent Document 3 can be used.

Patent Document 1: Japanese Unexamined Patent Publication No. 2009-119378 Patent Document 2: Japanese Unexamined Patent Publication No. 2019-181397 Patent Document 3: Japanese Unexamined Patent Publication No. 2011-200836

In general, in organic matter-containing waste recovered by a garbage truck or organic matter-containing waste stored in a garbage pit of a garbage cleaning plant, in addition to organic matter that contributes to gas generation, organic matter that does not contribute to or is difficult to contribute to gas generation (e.g. For example, plastics), metals, and inorganic substances such as glass remain without being completely removed. In addition, depending on the region, season, and time, the ratio of organic matter and inorganic matter contained in the collected or stored organic matter-containing waste, the ratio of kitchen waste and paper even if organic matter is present, and the organic matter contributing to gas generation and the organic matter hardly contributing to gas generation The ratio of the waste and the like (i.e., the ratio of each of the plurality of contents to a predetermined amount of organic matter-containing waste) is different.

In general, regardless of the ratio of each content to the organic matter-containing waste, in the hydrothermal treatment device, a predetermined amount of organic matter-containing waste is subjected to hydrothermal treatment only for a predetermined period of time (predetermined time), and the predetermined time period ends. As such, the hydrothermal treatment ends, and the hydrothermal treatment product is taken out from the hydrothermal treatment device. For this reason, the property of the hydrothermally treated material taken out differs depending on the ratio of each content to the organic matter-containing waste. For example, in some cases, a sandy or powdery hydrothermally treated product having little moisture is obtained, and in other cases, a sludge or liquid hydrothermally treated product having a lot of moisture is obtained.

On the other hand, when methane gas is produced by methane fermentation using the hydrothermal treatment liquid, it is preferable that the hydrothermal treatment liquid contain as many fine organic matters as possible in the hydrothermal treatment liquid. For this reason, as described in Patent Literature 3, when separating the hydrothermal treatment liquid from the hydrothermal treatment product, it is suitable to use a pressurized screw press. However, pressurizing a hydrothermally treated material having a low moisture content (for example, sand) with a screw press is not preferable because it increases power consumption and may cause a failure.

In addition, when methane gas is generated using the hydrothermal treatment liquid, the concentration of fine organic matter contained in the hydrothermal treatment liquid is an important factor for increasing gas generation efficiency. However, since the concentration of the organic matter differs greatly between a hydrothermal product having a high moisture content and a hydrothermally treated product having a low moisture content, it has been difficult to stably generate gas in a methane fermentation device.

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

The hydrothermal treatment system of the present invention includes a hydrothermal treatment device for hydrothermally reacting organic matter-containing waste, an adjustment tank for humidifying the hydrothermally reacted hydrothermal treatment material, and a first conveying the humidified hydrothermal treatment material in the adjustment tank. A conveying device, a pressurized separation device for pressurizing the hydrothermal treatment material transferred to the first conveying device to separate the hydrothermal treatment liquid and a residue, and a solubilization tank for storing and warming the hydrothermal treatment liquid separated by the pressure separation device ( solubilization tank), a second transfer device for conveying the hydrothermal treatment liquid heated and solubilized in the solubilization tank to the conditioning tank, and generating methane gas and digestion liquid using the hydrothermal treatment liquid stored in the solubilization tank A methane fermentation device, a dehydrator that separates the digested liquid into dewatered sludge and a separated dewatered liquid, and a waste liquid treatment device that generates reusable water by at least digesting and denitrifying the dehydrated separated liquid. When the concentration of the organic matter contained in the hydrothermal treatment liquid stored in the solubilization tank is less than a predetermined concentration, which is the concentration of the organic matter suitable for the generation of methane gas by microorganisms or bacteria, the hydrothermal treatment liquid is returned to the adjustment tank, and the concentration of the organic matter When is greater than or equal to the predetermined concentration, the hydrothermal treatment liquid is transferred to the methane fermentation device.

According to the present invention, methane gas can be stably generated regardless of the ratio of each content included in the waste containing organic matter.

1 is a schematic diagram showing a hydrothermal treatment system according to an embodiment.
2 is a schematic diagram showing an example of a second facility of the hydrothermal treatment system according to the embodiment.

Hereinafter, the hydrothermal treatment system of the present invention will be described with reference to the drawings. The configurations and the like shown below are merely examples, and there is no intention to exclude the application of various modifications or techniques that are not specified. The configurations and the like shown below can be variously modified and implemented without departing from the essential configuration requirements and the meaning of the present invention.

1 is a schematic diagram showing a hydrothermal treatment system 1 of this embodiment. The hydrothermal treatment system 1 hydrothermally reacts organic matter-containing waste with high-temperature, high-pressure steam to solubilize it (hereinafter referred to as "hydrothermal treatment"), and separates it from the hydrothermally treated organic matter-containing waste (hereinafter referred to as "hydrothermal treatment product") It is a system for generating gas by microorganisms or bacteria using a liquid such as a solution, mixed liquid, or slurry (hereinafter referred to as "hydrothermal treatment liquid").

The hydrothermal treatment system 1 includes a hydrothermal treatment device 10, a conditioning tank 11, a first transfer device 21, a pressure separation device 12, a solubilization tank 13, and a second transfer device. (22), the methane fermentation device 14, the dewatering device 15, and the waste liquid treatment device 16 are included at least.

Then, all configurations of the hydrothermal treatment system 1 shown in FIG. 1 will be described in detail below.

The hydrothermal treatment device 10 is a device for hydrothermal treatment of organic matter-containing waste. Examples of wastes containing organic matter introduced into the hydrothermal treatment device 10 include kitchen waste (food waste), woody waste, livestock manure, and sludge discharged from households. The organic matter-containing waste collected by the garbage collection truck or the organic matter-containing waste stored in the garbage pit of the garbage cleaning plant may be directly introduced into the hydrothermal treatment device 10, and after inorganic substances are removed from the organic matter-containing waste, the hydrothermal treatment device 10 ) can be put into From these organic matter-containing wastes, kitchen wastes, papers, and plants containing organic matter suitable for gas generation may be selectively taken out, and the extracted kitchen wastes, papers, or plants may be introduced into the hydrothermal treatment device 10. there is.

The hydrothermal treatment device 10 can also hydrothermally treat disposable diapers, which have recently been problematic in disposal in facilities for the elderly and the like.

As will become clear later, in the hydrothermal treatment system 1, the ratio of each content to a predetermined amount of organic matter-containing waste handled by the hydrothermal treatment apparatus 10 in one hydrothermal treatment is Methane gas (biogas) can be stably generated by the methane fermentation device 14 described later, even if it varies greatly for each organic matter-containing waste treated by hydrothermal treatment.

Hydrothermal treatment is performed for a predetermined time in the hydrothermal treatment apparatus 10, and the hydrothermal treated material discharged from the hydrothermal treatment apparatus 10 is stored in the conditioning tank 11.

The conditioning tank 11 is a device for humidifying the hydrothermal treatment material discharged from the hydrothermal treatment device 10 and adjusting the properties of the hydrothermal treatment product. In addition, here, "humidification" of a hydrothermally treated material includes the meaning of soaking a hydrothermally treated material in water or a liquid as well as the meaning of soaking the hydrothermally treated material in water or liquid.

Since the hydrothermal treatment liquid stored in the solubilization tank 13 described later is injected into the conditioning tank 11, the hydrothermal treatment material stored in the conditioning tank 11 is humidified. In the adjustment tank 11, together with the hydrothermal treatment liquid, tap water (not shown) or reusable water to be described later may be suitably injected.

Moreover, a stirrer may be installed in the conditioning tank 11, and the water heat-treated material stored in the conditioning tank 11 may be stirred and mixed with the liquid or the liquid or water to be poured.

When a stirring device is provided, the adjustment tank 11 can adjust the properties of the hydrothermally treated material in a short time. For example, when the hydrothermally treated material stored in the conditioning tank 11 is sandy, the hydrothermally treated material can be changed into a slurry in a short time by operating the stirring device while performing the pouring or the pouring.

The stirring device may be any device such as air agitation or mechanical agitation, as long as it stirs and mixes the water heat-treated material stored in the conditioning tank 11 and the liquid or water to be injected or poured.

In addition, the hydrothermal treatment device 10 and the conditioning tank 11 are facilities for hydrothermal treatment of organic matter-containing waste and then humidifying and storing the hydrothermal treatment product obtained by the hydrothermal treatment, and the first in the hydrothermal treatment system 1 It is a component of the first facility 2 that performs the processing of the step.

In addition, as will be described later, the facility for pressurizing the hydrothermal treatment product stored in the first facility 2 to separate the hydrothermal treatment liquid (hereinafter referred to as "pressure separation") and solubilizing the hydrothermal treatment liquid obtained by the pressurized separation is , It is the second facility 3 that performs the second step process in the hydrothermal treatment system 1. In addition, the facility for generating gas using the hydrothermal treatment liquid solubilized by the second facility 3 is the third facility 4 that performs the third step process in the hydrothermal treatment system 1 .

The first transfer device 21 is a device that transfers the hydrothermal treated material humidified in the conditioning 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, on the same or adjacent site where the distance between the first facility (2) and the second facility (3) is less than about 500 m When installed, the 1st transfer device 21 is connected to the adjustment tank 11 of the 1st installation 2 and the pressure separation device 12 of the 2nd installation 3, and is connected to the adjustment tank 11 A pipeline equipped with a crushing pump for pressure-feeding the adjusted hydrothermal treated material to the pressure separator 12 is preferred. A pipeline is generally configured by connecting a plurality of pipes to form one path.

In this case, the hydrothermal treated material stored in the conditioning tank 11 of the first facility 2 is transferred to the pressurized separator 12 of the second facility 3 while being crushed by a crushing pump through a pipeline. When transporting the hydrothermally treated product, since the hydrothermally treated product can be made fine with a crushing pump, the load on the pressure separator 12 (for example, a screw press) described later can be reduced.

In addition, hereinafter, when two facilities among the first facility 2, the second facility 3, and the third facility 4 are installed "close to each other", the distance between the two facilities is about 500 means to be installed on the same or different site of less than m.

On the other hand, when the first facility 2 and the second facility 3 are installed far from each other, the first transfer device 21 is preferably an automobile (eg, a vacuum car) equipped with a storage tank or the like. do. For example, if the first facility 2 and the second facility 3 are installed at a distance of about 500 m or more from each other, it can be said that they are installed at a "distant place" whether on the same site or on a different site. In this case, the hydrothermal treated material stored in the adjustment tank 11 of the first facility 2 is loaded onto the automobile, transported to the pressurization separation device 12 of the second facility 3, and the transported hydrothermal treated material is It is injected into the pressure separation device 12.

Here, the car may be a car driven by a human, and may be an automatically driving car in which a computer such as artificial intelligence (AI), not a human, controls driving.

In addition, a central control room may be installed in the hydrothermal treatment system 1, and a person may remotely monitor and control the driving of a vehicle using a monitoring camera. In this case, if surveillance cameras are installed in facilities, devices, and facilities included in the hydrothermal treatment system 1, they can be remotely monitored from the central control room, and thus the operational safety of the hydrothermal treatment system 1 can be improved. there is.

In addition, the hydrothermal treatment system 1 may be configured to control each operation of facilities, devices, and facilities included in the hydrothermal treatment system 1 in the central control room, and by using AI, the hydrothermal treatment system 1 ) is also possible to fully automate the operation.

In addition, in the following, when two facilities of the first facility 2, the second facility 3, and the third facility 4 are installed "far away", the distance between the two facilities is about means installation on the same or different sites over 500 m.

In addition, in the case of "car" hereinafter, the vehicle may be a vehicle driven by a person or an autonomous vehicle. The vehicle may be a vehicle that is remotely monitored and controlled by a person.

The pressurized separation device 12 of the second facility 3 pressurizes the hydrothermal treatment product transferred from the conditioning tank 11 of the first facility 2 to the first transfer device 21, so as to obtain the hydrothermal treatment solution and the residue. It is a device that separates the hydrothermal treatment liquid from the hydrothermal treatment product into remaining products. In addition, the hydrothermal treatment liquid is also called a material suitable for fermentation, and the residue is also called a material unsuitable for fermentation.

As shown in FIG. 2, for example, the pressure separation device 12 can have a configuration in which a rotary drum screen 12A is disposed at the front stage and a screw press 12B is disposed at the rear stage. The rotary drum screen 12A may be, for example, a punching metal drum screen device described in Registration Publication of Patent No. 6384015 of Mitsubishi Heavy Industries Environment/Chemical Engineering Co., Ltd. In addition, the screw press 12B may be, for example, the dewatering system described in FIG. 13 of Patent No. 6734496 of Mitsubishi Heavy Industries & Construction Chemical Engineering Co., Ltd.

In the pressurized separator 12, since the recovery rate of the hydrothermal treatment liquid and the removal rate of unsuitable fermentation substances are affected by the water content and viscosity of the hydrothermal treatment product, the mesh size, aperture ratio, screw pitch (distance between the screw and the discharge port), etc. This is carefully set up. The dewatering system described in FIG. 13 of Patent No. 6734496 is suitable for the pressure separation device 12 because the mesh size is changed in response to changes in properties of the hydrothermal treated material. The pressure separation device 12 may change the pressure within the device by, for example, increasing or decreasing the size of the discharge port in response to a change in properties of the hydrothermal treated material.

In addition, unlike FIG. 2, the pressure separation device 12 can also be configured as a single unit of only a screw press.

In the pressure separation device 12 of FIG. 2 , the hydrothermal treated material transferred from the adjustment tank 11 of the first facility 2 to the first transfer device 21 is first put into the rotary drum screen 12A. Then, with the rotary drum screen 12A, a part of the hydrothermal treatment liquid is separated from the hydrothermal treatment material. Thereafter, the hydrothermal treated material discharged from the rotary drum screen 12A is put into the screw press 12B.

Therefore, compared to the case where the rotary drum screen 12A is not disposed at the front stage (when the pressure separator 12 is a single screw press only), the screw press 12B at the rear stage is transferred to the first conveying device 21. The hydrothermal treated material reduced in weight from the total amount of the transferred hydrothermal treated material is pressurized and separated into a hydrothermal treated liquid and a residue. For this reason, the pressure separation device 12 of FIG. 2 can reduce the power (power saving) of the screw press 12B.

In addition, a 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 all stored in the solubilization tank 13 of the second facility 3.

The solubilization tank 13 of the second facility 3 is a device that stores and warms the hydrothermal treatment liquid separated by the pressurized separator 12 to solubilize the hydrothermal treatment liquid. The heating temperature can be, for example, about 40°C to 60°C.

By solubilizing the hydrothermal treatment liquid in the solubilization tank 13, insoluble solids (Suspended Solids, hereinafter referred to as "SS") floating in the hydrothermal treatment liquid are dissolved in the hydrothermal treatment liquid (Dissolved Solids, hereinafter "SS"). DS”). For this reason, SS occupied in the total amount of solids (Total Solids, hereinafter referred to as “TS”. TS=SS+DS) contained in the hydrothermal treatment liquid stored in the solubilization tank 13 decreases. Therefore, the solubilization tank 13 can be said to be a device for promoting acid fermentation by reducing the SS of the stored hydrothermal treatment liquid and increasing the amount of DS.

In general, a larger amount of organic DS in TS is preferable for gas generation by microorganisms or bacteria. TS, SS, or DS of the hydrothermal treatment liquid stored in the solubilization tank 13 can be measured by a dedicated measuring device (not shown).

In addition, in the solubilization tank 13, similarly to the adjustment tank 11, a stirring device may be installed to stir the hydrothermal treatment liquid stored in the solubilization tank 13 to promote solubilization of the hydrothermal treatment liquid.

The second transfer device 22 controls the concentration of organic matter contained in the hydrothermal treatment liquid stored in the solubilization tank 13 of the second facility 3 to a predetermined concentration (eg, about 10% for TS and about 10% for DS). 6%), the hydrothermal treatment liquid is returned from the solubilization tank 13 to the adjustment tank 11 of the first facility 2, and when the predetermined concentration is reached (substantially the predetermined concentration or more, including the case where In addition, the predetermined concentration may be within a range, for example, about 10% to 12% of TS, about 6% to 8% of DS, etc.), the hydrothermal treatment liquid is added to the solubilization tank (13 ) to the methane fermentation device 14 of the third facility 4.

The second transfer device 22 automatically selects either of the adjustment tank 11 or the methane fermentation device 14 as a transfer destination based on the measurement result of the above-described measuring device, and stores it in the solubilization tank 13 The hydrothermal treatment liquid may be configured to be transferred to the selected transfer destination.

In addition, the predetermined concentration is set to a concentration of organic matter suitable for methane fermentation in the methane fermentation device 14 described later, that is, a concentration of organic matter suitable for production of methane gas by microorganisms or bacteria. At the predetermined concentration, the pH value (lower pH value) of the hydrothermal treatment liquid stored in the solubilization tank 13 is less than 7 acidic, and the pH value is preferably 5 or less.

Like the first transfer device 21, the second transfer device 22 is an adjustment tank of the first facility 2 when the first facility 2 and the second facility 3 are installed close to each other ( A pipeline connected to 11) and the solubilization tank 13 of the second facility 3 and equipped with a pump for pumping the hydrothermal treatment liquid in the solubilization tank 13 to the conditioning tank 11 is preferable.

On the other hand, when the first facility 2 and the second facility 3 are installed far from each other, the second transport device 22 is preferably an automobile (eg, a vacuum car) equipped with a storage tank or the like. do. In this case, the hydrothermal treatment liquid is transported from the solubilization tank 13 to the conditioning tank 11 by means of an automobile.

In either case, the hydrothermal treatment liquid is circulated between the first facility 2 and the second facility 3 by the second transfer device 22 .

In addition, the second transfer device 22, when the second facility 3 and the third facility 4 are installed close to each other, the solubilization tank 13 of the second facility 3 and the third facility ( A pipeline connected to the methane fermentation device 14 of 4) and equipped with a pump for pumping the hydrothermal treatment liquid in the solubilization tank 13 to the inlet of the methane fermentation device 14 is preferable.

In addition, when the 1st facility 2, the 2nd facility 3, and the 3rd facility 4 are installed close to each other, the 2nd transfer device 22 is, for example, of the 2nd facility 3 A switching device is provided in the middle of the pipeline connecting the solubilization tank 13 and the conditioning tank 11 of the first facility 2, and a separate pipeline branched from the pipeline is connected to the switching device and the third facility ( It can also be set as the structure connected to the inlet of the methane fermentation apparatus 14 of 4).

As described above, the solubilization tank 13 of the second facility 3 and the first facility 2 The second transfer device 22 is a switching device so that the hydrothermal treatment liquid stored in the solubilization tank 13 is transferred in either one of the pipeline connecting the adjustment tank 11 of the ) and the other pipeline. can be selected alternatively.

On the other hand, when the second facility 3 and the third facility 4 are installed far from each other, the second transfer device 22 is preferably an automobile (for example, a vacuum car) equipped with a storage tank or the like. do. In this case, the hydrothermal treatment liquid is transported from the solubilization tank 13 to the methane fermentation device 14 by car, and the hydrothermal treatment liquid is introduced into the inlet of the methane fermentation device 14.

In addition, when the first facility 2 and the second facility 3 are installed close to each other, and the second facility 3 and the third facility 4 are installed far from each other, the second transfer device ( 22), the transfer of the hydrothermal treatment liquid between the first facility 2 and the second facility 3 is a pipeline, and the transport of the hydrothermal treatment solution between the second facility 3 and the third facility 4 is It could be a car. That is, the second transport device 22 may have two types of transport devices, a pipeline and an automobile.

Similarly, when the first facility 2 and the second facility 3 are installed far away from each other, and the second facility 3 and the third facility 4 are installed close to each other, the second transfer device ( As 22), transport of the hydrothermal treatment liquid between the first equipment 2 and the second equipment 3 is carried by an automobile, and transport of the hydrothermal treatment fluid between the second equipment 3 and the third equipment 4 is carried out by a pipe. may be a line.

The second transfer device 22 feeds the hydrothermal treatment liquid stored in the solubilization tank 13 of the second facility 3 until the concentration of the organic matter contained in the hydrothermal treatment liquid reaches the predetermined concentration described above. It is conveyed to the adjustment tank 11 of the facility 2.

Therefore, since the hydrothermal treated material stored in the conditioning tank 11 of the first installation 2 can be humidified, the transfer of the hydrothermal treated material by the first transfer device 21 is facilitated, and the second facility 3 The power of the pressure separation device 12 can be reduced.

In addition, since the hydrothermal treatment liquid conveyed from the solubilization tank 13 of the second facility 3 to the conditioning tank 11 of the first facility 2 is heated in the solubilization tank 13, the heated temperature is maintained as it is. Alternatively, even if the liquid is slightly cooled by natural radiation or the like, it is possible to inject the liquid into the conditioning tank 11 while maintaining a temperature higher than room temperature.

In this case, the transported hydrothermal treatment liquid can contribute to the adjustment of properties of the hydrothermal treatment product stored in the conditioning tank 11 by promoting solubilization of at least a part of the hydrothermal treatment product.

Furthermore, in the hydrothermal treatment system 1, the hydrothermal treatment is sequentially performed a plurality of times in time, but the ratio of each content to the organic matter-containing waste hydrothermally treated by the hydrothermal treatment apparatus 10 of the first facility 2 is a number. Even if the concentration of the organic matter contained in the hydrothermal treatment liquid obtained by each heat treatment is greatly different for each heat treatment, the hydrothermal treatment liquid is circulated between the first facility 2 and the second facility 3 by the conveyance. , the concentration of organic matter contained in the hydrothermal treatment liquid stored in the solubilization tank 13 can be averaged.

Then, when the concentration of the organic matter contained in the hydrothermal treatment liquid stored in the solubilization tank 13 reaches a predetermined concentration, the hydrothermal treatment liquid at the predetermined concentration is transferred to the methane fermentation device 14 by the second transfer device 22 do. For this reason, the concentration of the organic matter contained in the hydrothermal treatment liquid introduced into the methane fermentation device 14 is substantially constant at all times and there is little variation, and the hydrothermal treatment liquid contains a large amount of organic matter that contributes 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 produces methane gas by microorganisms or bacteria, it is generally necessary to first perform two steps of solubilization of organic matter and acid fermentation inside the apparatus.

However, in the hydrothermal treatment system 1, when the concentration of the organic matter contained in the hydrothermal treatment liquid stored in the solubilization tank 13 reaches the predetermined concentration, the above two steps are already executed in the solubilization tank 13, and It is done. Therefore, since the process of solubilization and the process of acid fermentation can be omitted for the methane fermentation apparatus 14, methane gas can be produced|generated at high speed.

The methane fermentation device 14 of the third facility 4 is a device that generates methane gas and digestion liquid using the hydrothermal treatment liquid stored in the solubilization tank 13 of the second facility 3. The methane fermentation device 14 heats the hydrothermal treatment liquid (about 37°C or about 55°C), and generates methane gas by methane fermentation. The liquid fertilizer (also called fermentation dregs or digestion sludge) that remains after the production of methane gas is digestion fluid.

When the hydrothermal treatment liquid stored in the solubilization tank 13 of the second facility 3 contains a large amount of fiber, for example, of paper, the fiber is not completely decomposed by the methane fermentation device 14 and partially remains and is contained in the digestive juices and excreted. Therefore, when the digestive fluid contains enough fiber, a fibrillate supplying device 17 described later or an excreta storage tank 18 described later are used for the purpose of improving the dehydration efficiency of the dehydrator 15 described later. no need to install

The dehydrator 15 is a device (for example, a screw press) that separates the digestion liquid discharged from the methane fermentation device 14 into dewatered sludge and separated dewatering liquid. The separated dewatered sludge can be transferred to a waste incineration facility 20 to be described later and incinerated in the waste incineration facility 20. Meanwhile, the separated dewatering liquid is transferred to the waste liquid treatment device 16 .

The waste liquid treatment device 16 is a device that purifies the dewatered liquid separated by the dehydrator 15 by at least digestion and denitrification, that is, biological treatment, to generate reused water. As the waste liquid treatment device 16, a biological treatment device or excreta treatment facility that performs digestion and denitrification treatment is exemplified.

Reusable water generated by the waste liquid treatment device 16 can be supplied to the conditioning tank 11 of the first facility 2 through a supply path 25 (eg, a pipeline).

Since the hydrothermal treatment liquid is not stored in the solubilization tank 13 of the second facility 3 immediately after the operation of the hydrothermal treatment system 1 is started, the hydrothermal treatment system 1 transfers the hydrothermal treatment liquid to the conditioning tank 11 ), and the hydrothermal treatment material stored in the conditioning tank 11 cannot be humidified with the hydrothermal treatment liquid. Therefore, in this case, the hydrothermal treatment system 1 supplies reused water from the waste liquid treatment device 16 to the conditioning tank 11, so that the hydrothermal treatment material stored in the conditioning tank 11 can be humidified, and the hydrothermal treatment system ( Immediately after the start of operation in 1), the transfer of the hydrothermal treated material by the first transfer device 21 and the operation of the pressure separation device 12 of the second facility 3 can be performed smoothly.

In the case where the above-described conveyance cannot be performed, the hydrothermal treatment system 1 may pour tap water into the conditioning tank 11 to humidify the hydrothermal treatment product. However, in order to improve the cost performance of the hydrothermal treatment system 1, it is preferable to use reused water instead of tap water.

In the above, the configuration provided at least 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 and facilities.

The fibrillation solution supply device 17 is a device for fibrillating paper (for example, used paper such as old newspapers) and supplying the fibrillation solution in the form of a liquid to the digestion liquid discharged from the methane fermentation device 14.

Since the fibrillar fluid supply device 17 mixes the fibrillar fluid with the digestive fluid, the dehydrator 15 dehydrates the mixed solution of the digestive fluid and the fibrillar fluid. Since the fibrillation liquid contains a large amount of fiber, the fiber contained in the mixed liquid functions as a substitute for the dehydration aid and absorbs moisture in the mixed liquid. Therefore, the dehydration efficiency of the mixed liquid in the dehydrator 15 can be improved. In addition, since the fibrous content is discharged from the dewatering machine 15 as a part of the dewatering sludge, the volume of the dewatering sludge increases compared to the case where the fibrillation solution is not mixed with the digestion liquid.

In addition, since the fibers contained in the fibrillation solution do not contain nitrogen components and absorb the nitrogen components contained in the mixed solution when absorbing moisture in the mixed solution, nitrogen in the dewatering separated liquid separated by the dehydrator 15 concentration is reduced. Therefore, the load of biological treatment in the waste liquid treatment device 16 can be reduced. The fibrillation solution supply device 17 is, for example, a paper supply device, a fibrillation device, a fibrillation storage tank, and a fibrillation waste paper supply described in Patent No. 5905364 of Mitsubishi Heavy Industries, Ltd. Environment and Chemical Engineering Co., Ltd. It may also consist of a pump.

The manure storage tank 18 is a water tank for storing manure. In the hydrothermal treatment system 1, the "C/N ratio" of excreta (the ratio of the amount of nitrogen contained in the liquid to the amount of carbon used as a nutrient source by microorganisms during denitrification in biological treatment) is about 3 to 5. , and the characteristics that manure contains fibers can be used.

Specifically, in the hydrothermal treatment system 1, the manure stored in the manure storage tank 18 is removed from the methane fermentation device 14, or the digestion liquid discharged from the methane fermentation device 14, or the waste liquid treatment device 16 ) to supply In addition, manure may be supplied to not only one of these three places, but also to two or all of them.

For efficient methane fermentation in the methane fermentation device 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, there may be cases where the amount of nitrogen contained in the hydrothermal treatment liquid transferred from the solubilization tank 13 to the methane fermentation device 14 is not satisfied therewith.

In this case, by supplying the manure in the manure storage tank 18 to the methane fermentation device 14 and mixing it with the hydrothermal treatment liquid, the lack of nitrogen contained in the hydrothermal treatment liquid transferred to the methane fermentation device 14 is supplemented with manure. can do. That is, manure is supplied to balance the amount of nitrogen during methane fermentation.

In addition, since the manure is supplied to the methane fermentation device 14, the amount of carbon contained in the hydrothermal treatment liquid stored in the methane fermentation device 14 increases, but in the methane fermentation device 14, most of the carbon is converted to methane gas. Since it changes, the hydrothermal treatment system 1 is not adversely affected.

In addition, the manure in the manure storage tank 18 is not directly supplied to the methane fermentation device 14, but upstream of the methane fermentation device 14, for example, the control tank 11 of the first facility 2 or the first 2 It may be supplied to the solubilization tank 13 of the facility 3. In this case, the manure is indirectly supplied to the methane fermentation device 14 .

In addition, when the manure in the manure storage tank 18 is supplied to the digestive fluid discharged from the methane fermentation device 14 to make a mixed solution, the fiber contained in the manure similarly to the fiber contained in the above-mentioned fibrillation solution is used as a substitute for dehydration aid. function, and the dehydration efficiency of the liquid mixture in the dehydrator 15 can be improved.

In the case of the hydrothermal treatment system 1 having both the fibrillate supply device 17 and the excrement storage tank 18, the amount of fiber contained in the digestive fluid is small, and it is necessary to supplement the fiber content to improve the dehydration efficiency In this case, the deficiency can be supplemented by isolating fluid or manure fiber. In addition, the hydrothermal treatment system 1 may include only one of the fibrillate supply device 17 and the manure storage tank 18, or may include both.

By the way, in general, when carrying out the biological treatment of denitrification of a liquid, if the C/N ratio of the said liquid is about 2-3, it can process efficiently. Therefore, when the biological treatment of the dewatering separation liquid is performed by the waste liquid treatment device 16, when the C / N ratio of the dehydration separation liquid is less than 2, the manure in the excrement storage tank 18 is supplied to the dehydration separation liquid and mixed, It is good to raise the value of C/N ratio.

When mixing the dewatering separation liquid and manure to form a mixed liquid, the amount of carbon and nitrogen increases as manure is added to the separation liquid, but as described above, since the C/N ratio of manure is about 3 to 5, the amount of carbon The increment of is greater than the increment of the nitrogen content. Therefore, even if the C/N ratio of the separated dewatering liquid is less than 2, the C/N ratio of the mixed liquid can be easily set to about 2 to 3 by mixing with manure. That is, here, manure is supplied in order to balance the C/N ratio of the dewatering separated liquid subjected to biological treatment.

The third transfer device 23 is a device that transfers the methane gas generated by the methane fermentation device 14 of the third facility 4 to a gas utilization facility 19 described later.

When the methane fermentation device 14 and the gas utilization facility 19 are installed close to each other, the third transfer device 23 is connected to the methane fermentation device 14 and the gas utilization facility 19, and the methane fermentation A pipeline for transporting the methane gas generated by the device 14 to the gas utilization facility 19 is preferred.

On the other hand, when the methane fermentation device 14 and the gas utilization facility 19 are installed far from each other, the third transfer device 23 is a vehicle equipped with a carrier for loading a gas bombe (gas container) (truck) or a car equipped with a gas tank is preferred. In this case, the methane gas generated by the methane fermentation device 14 can be filled in a gas cylinder or gas tank, loaded or mounted on a vehicle, and transported to the gas utilization facility 19 .

The gas utilization facility 19 is a facility utilizing methane gas generated by the methane fermentation device 14 of the third facility 4 . The gas utilization facility 19, for example, burns the methane gas or a mixed gas obtained by mixing the methane gas with other gases in a boiler to generate steam by heat generated, and uses the steam to turn a steam turbine to generate electricity. It is a power plant. In recent years, in thermal power plants, in order to reduce carbon dioxide emissions during combustion, thermal power plants using liquefied natural gas (LNG) as a main component of methane have become mainstream, and gas utilization facilities 19 are also It can be set as a power plant conforming to the said thermal power plant.

The gas utilization facility 19 may be a power plant equipped with a gas turbine, gas engine, fuel cell, or the like, or a facility that reforms the methane gas to produce city gas or the like.

When the gas utilization facility 19 is a power plant equipped with a gas engine, it is generally equipped with a heat recovery device for exhaust gas generated by the gas engine.

The heat recovery device can generate hot water from the exhaust gas.

The gas utilization facility 19 is a power plant that generates power with a steam turbine, and at least one of the first facility 2, the second facility 3, and the third facility 4 and the gas utilization facility 19 are mutually connected. When it is installed in close proximity, wastewater steam, which is high-temperature steam after being used for power generation in the steam turbine of the gas utilization facility 19, is transferred to the first facility 2, the second facility 3, or the third facility in the vicinity. (4) is available.

For example, when a gas utilization facility 19 equipped with a steam turbine is installed close to the first facility 2, the gas utilization facility 19 and the first facility 2 are connected by a pipeline, The waste steam is transported to the hydrothermal treatment device 10 of the first facility 2 through the pipeline and used as high-temperature and high-pressure steam used by the hydrothermal treatment device 10 or as a part thereof.

In addition, when the gas utilization facility 19 equipped with a steam turbine is installed close to the 2nd facility 3, the gas utilization facility 19 and the 2nd facility 3 are connected by a pipeline, and the said pipe The waste water vapor is transferred to the solubilization tank 13 of the second facility 3 through the line, and can be used for heating the hydrothermal treatment liquid stored in the solubilization tank 13.

In addition, when the gas utilization facility 19 equipped with a steam turbine is installed close to the 3rd facility 4, the gas utilization facility 19 and the 3rd facility 4 are connected by a pipeline, and the said pipe The wastewater steam can be transferred to the methane fermentation device 14 of the third facility 4 through the line and used for heating the hydrothermal treatment liquid stored in the methane fermentation device 14.

Further, when the gas utilization facility 19 equipped with a gas engine is installed close to the second facility 3, the gas utilization facility 19 and the second facility 3 are connected by a pipeline, and the pipe The hot water generated by the heat recovery device is transferred to the solubilization tank 13 of the second facility 3 through the line, and can be used to heat the hydrothermal treatment liquid stored in the solubilization tank 13.

Similarly, when a gas utilization facility 19 equipped with a gas engine is installed close to the third facility 4, the gas utilization facility 19 and the third facility 4 are further connected by a pipeline, and the The hot water can be transferred to the methane fermentation device 14 of the third facility 4 through the pipeline and used for heating the hydrothermal treatment liquid stored in the methane fermentation device 14.

As described above, since the heating temperature of the solubilization 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., the solubilization tank 13 or In order to heat the methane fermentation device 14, hot water is easier to handle than waste steam.

In this way, when the gas utilization facility 19 is provided with a steam turbine, wastewater steam discharged from the steam turbine can be used as a heat source in the hydrothermal treatment system 1, and the gas utilization facility 19 can generate gas When an engine is provided, since hot water generated by the heat recovery device can be used as a heat source in the hydrothermal treatment system 1, the cost/performance ratio 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 a waste incineration facility 20 described later.

When the second facility 3 and the waste incineration facility 20 are installed close to each other, the fourth transfer device 24 is the outlet of the residue of the pressurized separation device 12 and the waste pit of the waste incineration facility 20. A conveyor that connects to and transfers the residue discharged from the pressurized separation device 12 to a waste pit is preferred.

On the other hand, when the second facility 3 and the waste incineration facility 20 are installed far from each other, the fourth transfer device 24 is preferably an automobile 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 a truck carrier or a garbage truck, and transferred to the waste incineration facility 20.

The waste incineration facility 20 is a facility that incinerates waste in an incinerator, and can also incinerate the residue discharged from the pressure separator 12 of the second facility 3 and the dewatered sludge separated by the dehydrator 15. The waste incineration facility 20 can generate electricity by generating high-temperature and high-pressure steam in a boiler by heat generated in the incinerator and turning a steam turbine with the high-temperature and high-pressure steam.

In the case where at least one of the first facility 2, the second facility 3, and the third facility 4 and the waste incineration facility 20 are installed close to each other, in the steam turbine of the waste incineration facility 20 The waste steam, which is high-temperature steam after being used for power generation, can be used in the first facility 2, the second facility 3, or the third facility 4 in the vicinity.

For example, when the waste incineration facility 20 is installed close to the first facility 2, the waste incineration facility 20 and the first facility 2 are connected by a pipeline, and through the pipeline. The waste steam is transported to the hydrothermal treatment device 10 of the first facility 2 and used as high-temperature and high-pressure steam used by the hydrothermal treatment device 10 or as a part thereof.

In addition, when the waste incineration facility 20 is installed close to the second facility 3, the waste incineration facility 20 and the second facility 3 are connected by a pipeline, and the waste steam is discharged through the pipeline. can be transferred to the solubilization tank 13 of the second facility 3 and used for heating the hydrothermal treatment liquid stored in the solubilization tank 13.

Moreover, when the waste incineration facility 20 is installed adjacent to the 3rd facility 4, the waste incineration facility 20 and the 3rd facility 4 are connected by a pipeline, and the wastewater is discharged through the said pipeline. The steam can be transferred to the methane fermentation device 14 of the third facility 4 and used for heating the hydrothermal treatment liquid stored in the methane fermentation device 14.

In this way, since the waste steam of the waste incineration facility 20 can be efficiently used in the hydrothermal treatment system 1 as a heat source, the cost/performance ratio of the hydrothermal treatment system 1 can be further improved.

In addition, the hydrothermal treatment system 1 includes (1) a fibrillate supply device 17, (2) a manure storage tank 18, (3) a third transfer device 23 and a gas utilization facility 19, ( 4) Of the four of the fourth transfer device 24 and the waste incineration facility 20, a system that does not have all of them may be a system, and a system that includes only one, two or three of them may be provided, and all four are provided Any system that does is free.

1: hydrothermal treatment system
2: Facility 1
3: Second Facility
4: Third Facility
10: hydrothermal treatment device
11: adjustment tank
12: pressure separation device
12A: rotary drum screen
12B: screw press
13: solubilization tank
14: methane fermentation device
15: dehydrator
16: waste liquid treatment device (sewage treatment facility)
17: fibrillar fluid supply device
18: manure storage tank
19: Gas Utilization Facility
20: waste incineration facility
21: first transfer device
22: second transfer device
23: third transfer device
24 fourth transport device
25: supply path

Claims (5)

A hydrothermal treatment device for hydrothermal reaction of organic matter-containing waste;
An adjustment tank for humidifying the hydrothermally reacted hydrothermally treated material;
a first conveying device for conveying the hydrothermal treated material humidified in the conditioning tank;
a pressurized separation device for pressurizing the hydrothermal treatment material transferred to the first transfer device to separate the hydrothermal treatment liquid and the residue;
A solubilization tank for storing and warming the hydrothermal treatment liquid separated by the pressure separation device;
A second transfer device for conveying the hydrothermal treatment liquid heated and solubilized in the solubilization tank to the conditioning tank;
A methane fermentation device for generating methane gas and digestion liquid using the hydrothermal treatment liquid stored in the solubilization tank;
A dehydrator for separating the digestion liquid into dehydration sludge and dehydration separation liquid;
A waste liquid treatment device for generating reuse water by at least digesting and denitrifying the dewatering separated liquid
have,
When the concentration of the organic matter contained in the hydrothermal treatment liquid stored in the solubilization tank is less than a predetermined concentration, which is the concentration of the organic matter suitable for the generation of methane gas by microorganisms or bacteria, the second transfer device transfers the hydrothermal treatment liquid to the conditioning tank and transporting the hydrothermal treatment liquid to the methane fermentation device when the concentration of the organic matter is equal to or greater than the predetermined concentration. According to claim 1,
The hydrothermal treatment system further having a fibrillation solution supplying device for supplying fibrillation fluid obtained by fibrillation of paper to the digestive fluid. According to claim 1 or 2,
It further has a manure storage tank for storing manure,
The manure in the manure storage tank is supplied to the methane fermentation device and mixed with the hydrothermal treatment liquid;
Alternatively, the manure in the manure storage tank is mixed with the digestive fluid,
Alternatively, the hydrothermal treatment system for mixing the manure in the manure storage tank with the dewatering separation liquid. According to claim 3,
The pressure separation device,
Equipped with a rotary drum screen at the front end and a screw press at the rear end,
The hydrothermal treatment system in which the hydrothermal treatment liquid separated by the rotary drum screen and the hydrothermal treatment liquid separated by the screw press are stored in the solubilization tank. According to claim 4,
A third transfer device for transferring methane gas generated by the methane fermentation device and a gas utilization facility using the methane gas transferred to the third transfer device;
or,
It further has a fourth transfer device for transporting the residue separated by the pressure separation device and a waste incineration facility for incinerating the residue transferred to the fourth transfer device,
When the hydrothermal treatment device and the conditioning tank, the pressure separation device and the solubilization tank are installed close to each other, the first transfer device is a pipeline with a crushing pump, and the second transfer device is a pipe with a pump is a line,
When the hydrothermal treatment device and the conditioning tank, the pressure separation device and the solubilization tank are installed far from each other, the first transport device and the second transport device are both automobiles,
When the methane fermentation device and the gas utilization facility are installed close to each other, the third transfer device is a pipeline,
When the methane fermentation device and the gas utilization facility are installed far from each other, the third transport device is a vehicle,
When the waste incineration facility, the pressure separation device, and the solubilization tank are installed in close proximity, the fourth conveying device is a conveyor,
When the waste incineration facility, the pressure separation device, and the solubilization tank are installed far from each other, the fourth transport device is a vehicle,
The gas utilization facility includes a steam turbine or a gas engine, and supplies steam used for power generation in the steam turbine to at least one of the hydrothermal treatment device, the solubilization tank, and the methane fermentation device, or the gas engine Supplying hot water generated from the exhaust gas generated in at least one of the solubilization tank and the methane fermentation device;
The waste incineration facility has a steam turbine, and supplies steam used for power generation in the steam turbine to at least one of the hydrothermal treatment device, the solubilization tank, and the methane fermentation device,
The waste liquid treatment device is a manure treatment facility, and the reused water is supplied to the control tank.

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