JP6887556B1 - Hydrothermal treatment system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably generate gas. SOLUTION: A hydrothermal treatment system 1 transfers a hydrothermal treatment apparatus 10 for hydrothermally reacting organic matter-containing waste, an adjusting tank 11 for humidifying the hydrothermally reacted hydrothermally treated product, and a humidified hydrothermally treated product. The first transfer device 21, the pressure separation device 12 that pressurizes the transferred hydrothermally treated product to separate it into the hydrothermally treated liquid and the residue, and the solubilization tank that stores and heats the separated hydrothermally treated product. 13 and a second transfer device 22 that returns the heated and solubilized hydrothermal treatment liquid to the adjusting tank 11, and methane that produces methane gas and digestive juice using the hydrothermal treatment liquid stored in the solubilization tank 13. It has a fermentation apparatus 14, a dehydrator 15 that separates digestive juice into dehydrated sludge and a dehydration separation liquid, and a waste liquid treatment apparatus 16 that nitrifies and denitrifies the dehydration separation liquid to generate recycled water. The second transfer device 22 transfers the hydrothermal treatment solution to the methane fermentation apparatus 14 when the concentration of the organic matter contained in the hydrothermal treatment solution stored in the solubilization tank 13 is a predetermined concentration. [Selection diagram] Fig. 1

Description

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

Solubilization (hydrothermal treatment) of kitchen waste (garbage) discharged from households such as municipal waste, woody waste such as paper and vegetation, and organic waste such as livestock manure and sludge is hydrothermally reacted with high temperature and high pressure steam. ), A liquid (hydrothermal heat treatment liquid) such as a solution or slurry is separated from the hydrothermally treated organic substance-containing waste (hydro heat treatment product), and the liquid is used to generate gas by microorganisms or bacteria, for example, methane fermentation. Systems have been developed (eg, Patent Documents 1 and 2). In order to separate the pancreatic juice treatment from the hydrothermally treated product, for example, a screen or a screw press as described in Patent Document 3 can be used in this system.

JP-A-2009-119378 Japanese Unexamined Patent Publication No. 2019-181397 Japanese Unexamined Patent Publication No. 2011-200836

In general, organic matter-containing waste collected by garbage trucks and organic matter-containing waste stored in the garbage pits of garbage trucks do not contribute to or contribute to gas generation in addition to organic matter that contributes to gas generation. Hard-to-difficult organic substances (for example, plastic) and inorganic substances such as metal and glass are not completely removed and remain. Also, depending on the region, season, and date and time, the ratio of organic matter to inorganic matter contained in the collected or stored organic matter-containing waste, the ratio of organic matter to paper even if it is organic matter, and most of the organic matter that contributes to gas generation. The ratio to non-contributory organic matter and the like (that is, the ratio of each of the plurality of contents to the predetermined amount of organic matter-containing waste) are different.

Further, in general, regardless of the ratio of each content to the organic matter-containing waste, a predetermined amount of the organic matter-containing waste is discharged in a predetermined amount for a predetermined time (predetermined time) in the hydrothermal treatment apparatus. ) Is hydrothermally treated, and as soon as the predetermined time is completed, the hydrothermal treatment is completed and the hydrothermally treated product is taken out from the hydrothermal treatment apparatus. Therefore, the properties of the hydrothermally treated product to be taken out differ depending on the ratio of each content to the organic matter-containing waste. For example, a sandy or powdery hydrothermally treated product having a low water content may be obtained, or a muddy or liquid hydrothermally treated product having a high water content may be obtained.

On the other hand, when methane gas is produced by methane fermentation using a hydrothermal treatment solution, it is desirable that the hydrothermal treatment solution contains as much fine organic matter as possible. Therefore, as described in Patent Document 3, it is preferable to use a pressure type screw press when separating the hydrothermal treatment liquid from the hydrothermal treatment product. However, pressurizing a hydrothermally treated product having a low water content (for example, sandy) with a screw press is not preferable because it increases power consumption and may induce a failure.

Further, when methane gas is produced using the hydrothermal treatment solution, the concentration of fine organic substances contained in the hydrothermal treatment solution is an important factor for increasing the gas generation efficiency. However, since the concentration of the organic matter is significantly different between the hydrothermally treated product having a high water content and the hydrothermally treated product having a low water content, it has been 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 the contents contained in the organic matter-containing waste.

In the hydrothermal treatment system of the present invention, a hydrothermal treatment apparatus for hydrothermally reacting organic matter-containing waste, an adjusting tank for humidifying the hydrothermally reacted hydrothermally-reacted product, and a hydrothermally treated product humidified in the adjusting tank are transferred. The first transfer device, the pressure separation device that pressurizes the hydrothermally treated product transferred by the first transfer device and separates it into the hydrothermal treatment liquid and the residue, and the hydrothermal treatment separated by the pressure separation device. A solubilization tank for storing and heating the liquid, a second transfer device for returning the hydrothermal treatment liquid heated and solubilized in the solubilization tank to the adjustment tank, and storage in the solubilization tank. A methane fermentation device that produces methane gas and digestive juice using a hydrothermal treatment liquid, a dehydrator that separates the digestive juice into dehydrated sludge and dehydration separation liquid, and at least nitrification and denitrification of the dehydration separation liquid to reuse water. In the second transfer device, the concentration of the organic substance contained in the hydrothermal solution stored in the solubilization tank is the concentration of the organic substance suitable for the production of methane gas by microorganisms or bacteria. When the concentration is less than a certain predetermined concentration, the hydrothermal solution is returned to the adjusting tank, and when the concentration of the organic substance is equal to or more than the predetermined concentration , the hydrothermal solution is transferred to the methane fermentation apparatus.

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

It is a schematic diagram which shows the hydrothermal treatment system which concerns on embodiment. It is a schematic diagram which shows an example of the 2nd equipment of the hydrothermal treatment system which concerns on embodiment.

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

FIG. 1 is a schematic view showing the hydrothermal treatment system 1 of the present embodiment. The hydrothermal treatment system 1 solubilizes the organic matter-containing waste by hydrothermally reacting it with high-temperature and high-pressure steam (hereinafter referred to as "hydrothermal treatment"), and hydrothermally heat-treats the organic matter-containing waste (hereinafter referred to as "hydrothermal treatment product"). It is a system that generates gas by microorganisms and bacteria using a liquid (hereinafter referred to as "hydrothermal heat treatment liquid") such as a solution, a mixed liquid, or a slurry separated from the water vapor.
The water heat treatment system 1 includes a water heat treatment device 10, a adjusting tank 11, a first transfer device 21, a pressure separation device 12, a solubilization tank 13, a second transfer device 22, a methane fermentation device 14, and the like. The dehydrator 15 and the waste liquid treatment device 16 are included at least.
Then, all the configurations of the hydrothermal treatment system 1 shown in FIG. 1 will be described in detail below.

The hydrothermal treatment apparatus 10 is an apparatus for hydrothermally treating organic matter-containing waste. Examples of the organic matter-containing waste charged into the hydrothermal treatment apparatus 10 include kitchen waste (food waste) discharged from home, wood-based waste, livestock manure, sludge and the like. The organic matter-containing waste collected by the garbage truck or the organic matter-containing waste stored in the garbage pit of the garbage truck may be directly put into the hydrothermal treatment apparatus 10, or the inorganic matter is removed from these organic matter-containing wastes. After that, it may be put into the hydrothermal treatment apparatus 10. From these organic matter-containing wastes, kitchens, papers, and plants containing organic matter suitable for gas generation are selectively taken out, and the taken out kitchens, papers, and plants are put into the hydrothermal treatment apparatus 10. You may. The hydroheat treatment apparatus 10 can hydroheat treat disposable diapers, which have recently had a problem of disposal in facilities for the elderly and the like.
As will be clarified later, in the hydrothermal treatment system 1, the ratio of each content to the predetermined amount of organic matter-containing waste handled by the hydrothermal treatment apparatus 10 in one hydrothermal treatment is determined a plurality of times for each water. Methane gas (biogas) can be stably produced by the methane fermentation apparatus 14 described later, even if the wastes containing organic substances handled by the heat treatment differ greatly.
The hydrothermal treatment apparatus 10 performs hydrothermal treatment for a predetermined time, and the hydrothermally treated product discharged from the hydrothermal treatment apparatus 10 is stored in the adjusting tank 11.

The adjusting tank 11 is an apparatus for adjusting the properties of the hydrothermally treated product by humidifying the hydrothermally treated product discharged from the hydrothermally treated product 10. Here, "humidifying" the hydroheat-treated product includes not only the meaning of moistening the hydro-heat-treated product with water or liquid, but also the meaning of immersing the hydro-heat-treated product in water or liquid.
Since the hydrothermal treatment solution stored in the solubilization tank 13 described later is injected into the adjustment tank 11, the hydrothermal treatment product stored in the adjustment tank 11 is humidified. In addition to the hydrothermal treatment liquid, tap water (not shown) or recycled water described later may be appropriately injected into the adjusting tank 11.
Further, a stirring device may be installed in the adjusting tank 11 to stir and mix the hydrothermally treated product stored in the adjusting tank 11 with the liquid or water to be injected. When the stirring device is installed, the adjusting tank 11 can adjust the properties of the hydrothermally treated product in a short time. For example, when the hydrothermally treated product stored in the adjusting tank 11 is sandy, the hydrothermally treated product is changed into a slurry in a short time by operating the stirring device while performing the above-mentioned liquid injection or the above-mentioned water injection. be able to.
The stirring device can be any device as long as it is a device such as air stirring or mechanical stirring that stirs and mixes the hydrothermally treated product stored in the adjusting tank 11 and these liquids or water to be injected or injected. It may be.

The hydrothermal treatment apparatus 10 and the adjusting tank 11 are equipment for hydrothermally treating organic matter-containing waste and humidifying and storing the hydrothermally treated product obtained by hydrothermal treatment, and are the first in the hydrothermal treatment system 1. It is a component of the first equipment 2 that performs step processing.
Further, as will be described later, the hydrothermal treatment liquid stored in the first facility 2 is pressurized to separate the hydrothermal treatment liquid (hereinafter referred to as “pressurization separation”), and the hydrothermal treatment liquid obtained by the pressure separation can be used. The equipment to be melted is the second equipment 3 that performs the second stage treatment in the hydrothermal treatment system 1. Further, the equipment that generates gas using the hydrothermal treatment liquid solubilized in the second equipment 3 is the third equipment 4 that performs 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 adjusting tank 11 of the first equipment 2 to the second equipment 3. When the first equipment 2 and the second equipment 3 are installed close to each other, for example, they are installed on the same or neighboring sites where the distance between the first equipment 2 and the second equipment 3 is less than about 500 m. If so, the first transfer device 21 is connected to the adjusting tank 11 of the first equipment 2 and the pressure separating device 12 of the second equipment 3, and a hydrothermally treated product whose properties have been adjusted in the adjusting tank 11 is added. A pipeline equipped with a crushing pump that pumps to the pressure separator 12 is desirable. A pipeline is generally constructed by connecting a plurality of pipes so as to form one path.
In this case, the hydrothermally treated product stored in the adjusting tank 11 of the first equipment 2 is transferred to the pressure separating device 12 of the second equipment 3 while being crushed by the crushing pump through the pipeline. Since the hydroheat-treated product can be finely divided by a crushing pump when the hydro-heat-treated product is transferred, the load on the pressure separation device 12 (for example, a screw press) described later can be reduced.

In the following, when two of the first equipment 2, the second equipment 3, and the third equipment 4 are installed in "close proximity", the distance between the two equipment is less than about 500 m. It means that it will be installed on the same or different site.

On the other hand, when the first equipment 2 and the second equipment 3 are installed far from each other, the first transfer device 21 is preferably an automobile equipped with a storage tank or the like (for example, a vacuum car or the like). For example, if the first equipment 2 and the second equipment 3 are installed at a distance of about 500 m or more from each other, they are installed "far away" regardless of whether they are on the same site or on different sites. I can say. In this case, the hydrothermally treated product stored in the adjusting tank 11 of the first equipment 2 is loaded on the automobile and transported to the pressure separating device 12 of the second equipment 3, and the transported hydrothermally treated product is transported by the pressure separating device. It is thrown into 12.

Here, the automobile may be a vehicle driven by a person, or may be an automatically driven vehicle in which a computer such as artificial intelligence (so-called AI) controls driving instead of a person.
Further, the hydrothermal treatment system 1 may be provided with a central control room, and the driving of the automobile may be controlled while a person remotely monitors using a surveillance camera. In this case, if a surveillance camera is installed in the equipment and devices included in the hydrothermal treatment system 1 and the facility, these can be remotely monitored in the central control room, and the operational safety of the hydrothermal treatment system 1 is improved. be able to.
Further, the hydrothermal treatment system 1 can be configured to control the operation of each of the equipment, devices, and facilities included in the hydrothermal treatment system 1 in the central control room, and the hydrothermal treatment system 1 can be configured by using AI. It is also possible to fully automate the operation of.

Hereinafter, when two of the first equipment 2, the second equipment 3, and the third equipment 4 are installed in a "distant place", the distance between the two equipments is the same of about 500 m or more. Or it means that it will be installed on a different site.
Further, hereinafter, when the term "automobile" is used, the automobile may be a human-driven vehicle or an automatically driven vehicle. The vehicle may be a vehicle that is remotely monitored by a person to control driving.

The pressure separating device 12 of the second equipment 3 pressurizes the hydroheat-treated product transferred from the adjusting tank 11 of the first equipment 2 by the first transfer device 21, and the hydrothermal treatment liquid and the residue (water from the hydro-heat-treated product to water). It is a device that separates the heat treatment liquid into the one that remains after being separated. The hydrothermal treatment liquid is also called a fermentation-suitable product, and the residue is also called a fermentation-unsuitable product.
As shown in FIG. 2, the pressure separating device 12 may have a configuration in which the rotary drum screen 12A is arranged in the front stage and the screw press 12B is arranged in the rear stage, for example. The rotary drum screen 12A may be, for example, the punching metal drum screen device described in the registration publication of Japanese Patent No. 6384015 of Mitsubishi Heavy Industries Environmental & Chemical Engineering Co., Ltd. Further, the screw press 12B may be, for example, the dehydration system described in FIG. 13 of the registration publication of Japanese Patent No. 6734496 of Mitsubishi Heavy Industries Environmental & Chemical Engineering Co., Ltd.
Since the pressure separation device 12 affects the recovery rate of the hydroheat treatment liquid and the removal rate of unsuitable fermentation substances depending on the water content and viscosity of the hydrothermally treated product, the opening ratio, the opening ratio, and the screw pitch (screw and discharge port). Distance with) etc. are set carefully. The dehydration system described in FIG. 13 of the registration publication of Japanese Patent No. 6734496 is suitable for the pressure separation device 12 because the opening is changed in response to a change in the properties of the hydrothermally treated product. The pressure separating device 12 may change the pressure in the device by increasing or decreasing the size of the discharge port in response to the change in the properties of the hydrothermally treated product.
Further, unlike FIG. 2, the pressure separating device 12 may be configured by a single screw press only.

In the pressure separating device 12 of FIG. 2, the hydrothermally treated product transferred from the adjusting tank 11 of the first equipment 2 by the first transfer device 21 is first charged into the rotary drum screen 12A. Then, on the rotary drum screen 12A, a part of the hydrothermal treatment liquid is separated from the hydrothermal treatment product. After that, the hydrothermally treated product discharged from the rotary drum screen 12A is charged into the screw press 12B.
Therefore, compared to the case where the rotary drum screen 12A is not arranged in the front stage (when the pressure separation device 12 is a single unit with only a screw press), the screw press 12B in the rear stage is a hydrothermally treated product transferred by the first transfer device 21. The hydrothermally treated product, which is less than the total amount of the above, is pressurized and separated into the hydrothermally treated liquid and the residue. Therefore, the pressure separating device 12 of FIG. 2 can reduce the power of the screw press 12B (power saving).
A part of the hydrothermal treatment liquid separated by the rotary drum screen 12A and the hydroheat treatment liquid separated by the screw press 12B are both stored in the solubilization tank 13 of the second facility 3.

The solubilization tank 13 of the second equipment 3 is an apparatus that stores and heats the hydrothermal treatment liquid separated by the pressure separation device 12 to solubilize the hydrothermal treatment liquid. The heating temperature can be, for example, about 40 ° C to 60 ° C.
By solubilizing the hydrothermal solution in the solubilization tank 13, insoluble solids (Suspended Solids, hereinafter referred to as “SS”) suspended in the hydrothermal solution are dissolved in the hydrothermal solution (the solids (hereinafter referred to as “SS”)). It changes to Dissolved Solids (hereinafter referred to as "DS"). Therefore, SS 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 is reduced. Therefore, the solubilization tank 13 can be said to be an apparatus for reducing the amount of SS in the stored hydrothermal treatment solution, increasing the amount of DS, and promoting acid fermentation.
In general, it is desirable that the amount of organic DS in TS is large for gas production by microorganisms and fungi. The TS, SS, or DS of the hydrothermal treatment solution stored in the solubilization tank 13 can be measured with a dedicated measuring device (not shown).
Further, in the solubilization tank 13, similarly to the adjustment tank 11, a stirring device may be installed to stir the hydrothermal treatment solution stored in the solubilization tank 13 to promote the solubilization of the hydrothermal treatment solution. ..

In the second transfer device 22, when the concentration of the organic substance contained in the hydrothermal treatment solution stored in the solubilization tank 13 of the second facility 3 is less than a predetermined concentration (for example, TS is about 10% and DS is about 6%). When the hydrothermal treatment solution is returned from the solubilization tank 13 to the adjustment tank 11 of the first equipment 2 and reaches the predetermined concentration (including the case where the concentration is substantially equal to or higher than the predetermined concentration), the predetermined concentration is , For example, TS may have a concentration of about 10% to 12%, DS may have a concentration of about 6% to 8%, etc.), and the hydrothermal treatment solution is mixed with the solubilization tank 13 to the methane of the third facility 4. It is an apparatus to be transferred to the fermentation apparatus 14.
The second transfer device 22 automatically selects either one of the adjusting tank 11 and the methane fermentation device 14 as the transfer destination based on the measurement results of the above-mentioned measuring device, and the hydrothermal treatment liquid stored in the solubilization tank 13. May be configured to be transferred to the selected transfer destination.
The predetermined concentration is set by the methane fermentation apparatus 14 described later to a concentration of an organic substance suitable for methane fermentation, that is, a concentration of an organic substance suitable for the production of methane gas by a microorganism or a fungus. At the predetermined concentration, the pH value (pH value) of the hydrothermal treatment solution stored in the solubilization tank 13 is less than 7, and it is desirable that the pH value is 5 or less.

Similar to the first transfer device 21, the second transfer device 22 has the adjusting tank 11 and the second facility 3 of the first facility 2 when the first facility 2 and the second facility 3 are installed close to each other. A pipeline provided with a pump connected to the solubilization tank 13 and pumping the hydrothermal solution of the solubilization tank 13 to the adjustment tank 11 is desirable.
On the other hand, when the first equipment 2 and the second equipment 3 are installed far from each other, the second transfer device 22 is preferably an automobile equipped with a storage tank or the like (for example, a vacuum car or the like). In this case, the hydrothermal treatment liquid is transported from the solubilization tank 13 to the adjustment tank 11 by an automobile.
In either case, the hydrothermal treatment liquid is circulated between the first equipment 2 and the second equipment 3 by the second transfer device 22.

Further, in 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 methane fermentation device 14 of the third facility 4 are installed. A pipeline having a pump that is connected to the solubilization tank 13 and pumps the hydrothermal treatment liquid of the solubilization tank 13 to the inlet of the methane fermentation apparatus 14 is desirable.

When the first equipment 2, the second equipment 3, and the third equipment 4 are installed close to each other, the second transfer device 22 may be, for example, the solubilization tank 13 and the first equipment of the second equipment 3. A switching device is provided in the middle of the pipeline connecting the adjusting tank 11 of No. 2, and another pipeline branched from the pipeline is connected to the switching device and the inlet of the methane fermentation apparatus 14 of the third facility 4. It may be configured to be used.
As described above, the solubilization tank 13 of the second equipment 3 and the adjustment tank 11 of the first equipment 2 are used according to the concentration of the organic matter contained in the hydrothermal treatment solution stored in the solubilization tank 13 of the second equipment 3. The second transfer device 22 is selectively selected by the switching device so as to transfer the hydrothermal treatment solution stored in the solubilization tank 13 to one of the pipeline connecting the above and the other pipeline described above. can do.

On the other hand, when the second equipment 3 and the third equipment 4 are installed far from each other, the second transfer device 22 is preferably an automobile equipped with a storage tank or the like (for example, a vacuum car or the like). In this case, the hydrothermal treatment liquid is transported from the solubilization tank 13 to the methane fermentation apparatus 14 by an automobile, and the hydrothermal treatment liquid is charged into the inlet of the methane fermentation apparatus 14.
When the first equipment 2 and the second equipment 3 are installed close to each other and the second equipment 3 and the third equipment 4 are installed far from each other, the second transfer device 22 may be used. The transfer of the hydrothermal solution between the first facility 2 and the second facility 3 may be performed by a pipeline, and the transfer of the hydrothermal solution between the second facility 3 and the third facility 4 may be performed by an automobile. That is, the second transfer device 22 may include two types of transfer devices, a pipeline and an automobile.
Similarly, when the first equipment 2 and the second equipment 3 are installed far from each other and the second equipment 3 and the third equipment 4 are installed close to each other, the second transfer device 22 may be used. The transfer of the hydrothermal solution between the first facility 2 and the second facility 3 may be performed by an automobile, and the transfer of the hydrothermal solution between the second facility 3 and the third facility 4 may be performed by a pipeline. ..

The second transfer device 22 adjusts the hydrothermal treatment solution of the first facility 2 until the concentration of the organic substance contained in the hydrothermal treatment solution stored in the solubilization tank 13 of the second facility 3 reaches the above-mentioned predetermined concentration. It will be returned to the tank 11.
Therefore, since the hydroheat-treated product stored in the adjusting tank 11 of the first equipment 2 can be humidified, the hydro-heat-treated product can be easily transferred by the first transfer device 21, and the pressure separation device 12 of the second equipment 3 can be easily transferred. Power can be reduced.

Further, since the hydrothermal treatment solution returned from the solubilization tank 13 of the second equipment 3 to the adjustment tank 11 of the first equipment 2 is heated in the solubilization tank 13, the heated temperature remains unchanged or Even if it is cooled a little by natural heat dissipation or the like, it is possible to inject liquid into the adjusting tank 11 while maintaining a temperature higher than room temperature.
In this case, the returned hydrothermal treatment liquid can contribute to the adjustment of the properties of the hydrothermal treatment product by promoting solubilization of at least a part of the hydrothermal treatment product stored in the adjusting tank 11.

In addition, in the hydrothermal treatment system 1, a plurality of hydrothermal treatments are sequentially performed in time, and the ratio of each content to the organic matter-containing waste to be hydrothermally treated by the hydrothermal treatment apparatus 10 of the first facility 2 is Even if the concentration of organic substances contained in the hydrothermal solution obtained by each hydrothermal treatment varies greatly depending on the hydrothermal treatment, the hydrothermal treatment between the first equipment 2 and the second equipment 3 is performed by the above return. By circulating the liquid, the concentration of the organic substance contained in the hydrothermal treatment liquid stored in the solubilization tank 13 can be averaged.
Then, when the concentration of the organic substance contained in the hydrothermal treatment solution stored in the solubilization tank 13 reaches a predetermined concentration, the hydrothermal treatment solution having the predetermined concentration is transferred to the methane fermentation apparatus 14 by the second transfer device 22. Therefore, the concentration of the organic matter contained in the hydrothermal treatment liquid charged into the methane fermentation apparatus 14 is substantially always constant and has little variation, and the hydrothermal treatment liquid contains a large amount of organic matter that contributes to the generation of methane gas. There is. Therefore, the methane fermentation apparatus 14 can stably generate methane gas.

In a methane fermentation apparatus that produces methane gas by microorganisms or bacteria using organic matter as a raw material, it is generally necessary to first perform two steps of solubilization of the organic matter and acid fermentation inside the apparatus.
However, in the hydrothermal treatment system 1, when the concentration of the organic substance contained in the hydrothermal treatment solution stored in the solubilization tank 13 reaches the predetermined concentration, the above two steps are already executed and completed in the solubilization tank 13. doing. Therefore, since the methane fermentation apparatus 14 can omit the solubilization step and the acid fermentation step, methane gas can be generated at high speed.

The methane fermentation apparatus 14 of the third facility 4 is an apparatus that produces methane gas and digestive juice using the hydrothermal treatment liquid stored in the solubilization tank 13 of the second facility 3. The methane fermentation apparatus 14 heats the hydrothermal treatment liquid (about 37 ° C. or about 55 ° C.) and produces methane gas by methane fermentation. The liquid fertilizer (fermentation residue, also called digestive sludge) that remains after the production of methane gas is the digestive juice.
When, for example, a large amount of paper fibers is contained in the hydrothermal treatment solution stored in the solubilization tank 13 of the second facility 3, the fibers are not completely decomposed by the methane fermentation apparatus 14 and partially remain. , Contained in digestive juices and excreted. Therefore, when the digestive juice contains a sufficient amount of fiber, it is necessary to provide the defibrating liquid supply device 17 described later and the human waste receiving tank 18 described later for the purpose of improving the dehydration efficiency of the dehydrator 15 described later. Absent.

The dehydrator 15 is an apparatus (for example, a screw press) that separates the digested liquid discharged from the methane fermentation apparatus 14 into dehydrated sludge and dehydrated separated liquid. The separated dehydrated sludge is transferred to the waste incinerator 20 described later, and can be incinerated at the waste incinerator 20. On the other hand, the separated dehydration separation liquid is transferred to the waste liquid treatment device 16.

The waste liquid treatment device 16 is a device that purifies the dehydration separation liquid by at least nitrification and denitrification treatment, that is, biological treatment, on the dehydration separation liquid separated by the dehydrator 15, and generates recycled water. Examples of the waste liquid treatment device 16 include a biological treatment device and a urine treatment facility that perform nitrification and denitrification treatment.
The recycled water generated by the waste liquid treatment device 16 can be supplied to the adjusting tank 11 of the first facility 2 through the supply path 25 (for example, a pipeline).
Immediately after the start of operation of the hydrothermal treatment system 1, since the hydrothermal treatment liquid is not stored in the solubilization tank 13 of the second facility 3, the hydrothermal treatment system 1 cannot return the hydrothermal treatment liquid to the adjusting tank 11. , The hydrothermally treated product stored in the adjusting tank 11 cannot be humidified with the hydrothermally treated liquid. Therefore, in this case, the hydrothermal treatment system 1 can humidify the hydrothermally treated product stored in the adjusting tank 11 by supplying the recycled water from the waste liquid treatment device 16 to the adjusting tank 11. Immediately after the start of the operation of No. 1, the hydrothermally treated material can be smoothly transferred by the first transfer device 21 and the pressure separation device 12 of the second facility 3 can be smoothly operated.
When the above-mentioned return is not possible, the hydrothermal treatment system 1 can also inject tap water into the adjusting tank 11 to humidify the hydrothermally treated product. However, in order to improve the cost performance of the hydrothermal treatment system 1, it is desirable to use recycled water instead of tap water.

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

The defibrating liquid supply device 17 is a device that defibrate papers (for example, used paper such as old newspapers) and supply the liquefied defibrating liquid to the digestive liquid discharged from the methane fermentation device 14.
Since the defibrating liquid supply device 17 mixes the defibrating liquid with the digested liquid, the dehydrator 15 dehydrates the mixed liquid of the digested liquid and the defibrated liquid. Since the defibrating solution contains a large amount of fiber, the fiber contained in the mixed solution functions as a substitute for the dehydration aid and absorbs the water content of the mixed solution. Therefore, the dehydration efficiency of the mixed solution in the dehydrator 15 can be improved. Since the fiber content is discharged from the dehydrator 15 as a part of the dehydrated sludge, the volume of the dehydrated sludge increases as compared with the case where the defibrating liquid is not mixed with the digestive juice.
Further, the fiber content contained in the defibrating solution does not contain a nitrogen component, and when the water content of the mixed solution is absorbed, the nitrogen component contained in the mixed solution is also absorbed, so that the fiber content is separated by the dehydrator 15. The nitrogen concentration in the dehydration separation solution diminishes. Therefore, the load of biological treatment in the waste liquid treatment device 16 can be reduced. The defibration liquid supply device 17 is, for example, a paper supply device, a defibration device, a defibration waste paper storage tank, and a defibration waste paper supply pump described in the registration publication of Japanese Patent No. 5905364 of Mitsubishi Heavy Industries Environmental & Chemical Engineering Co., Ltd. It may be composed of.

The human waste receiving tank 18 is a water tank for storing human waste. In the hydrothermal treatment system 1, the "C / N ratio" of urine (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 said to be about 3 to 5. The property and the property that the urine contains fiber can be utilized.
Specifically, in the hydrothermal treatment system 1, the human waste stored in the human waste receiving tank 18 is supplied to the methane fermentation apparatus 14, the digestive juice discharged from the methane fermentation apparatus 14, or the waste liquid treatment apparatus 16. .. In addition, urine may be supplied not only to one of these three locations but also to two or all of them.

In order to efficiently ferment methane in the methane fermentation apparatus 14, the amount of nitrogen contained in the hydrothermal treatment solution 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 solution transferred from the solubilization tank 13 to the methane fermentation apparatus 14 may be less than this.
In this case, by supplying the human waste from the human waste receiving tank 18 to the methane fermentation apparatus 14 and mixing it with the hydrothermal treatment solution, the amount of nitrogen contained in the hydrothermal treatment solution transferred to the methane fermentation apparatus 14 is supplemented with urine. Can be done. That is, human waste is supplied to balance the amount of nitrogen during methane fermentation.
By supplying urine to the methane fermentation apparatus 14, the amount of carbon contained in the hydrothermal treatment liquid stored in the methane fermentation apparatus 14 increases, but most of the carbon in the methane fermentation apparatus 14 becomes methane gas. Since it changes, it does not adversely affect the hydrothermal treatment system 1.
Further, the human waste in the human waste receiving tank 18 is not directly supplied to the methane fermentation apparatus 14, but is upstream of the methane fermentation apparatus 14, for example, the adjusting tank 11 of the first equipment 2 and the solubilization tank 13 of the second equipment 3. May be supplied to. In this case, human waste is indirectly supplied to the methane fermentation apparatus 14.

Further, when the urine from the urine receiving tank 18 is supplied to the digestive juice discharged from the methane fermentation apparatus 14 to form a mixed solution, the fibers contained in the urine are dehydrated in the same manner as the fibers contained in the defibrating solution described above. It functions as a substitute for an auxiliary agent, and can improve the dehydration efficiency of the mixed solution in the dehydrator 15.
In the case of the hydrothermal treatment system 1 provided with both the defibration liquid supply device 17 and the urine receiving tank 18, the fiber content in the digestive juice is small and it is necessary to supplement the fiber content in order to improve the dehydration efficiency. The deficiency can be supplemented by the fiber content of the defibrating solution and palm urine. The hydrothermal treatment system 1 may be provided with only one of the defibration liquid supply device 17 and the urine receiving tank 18, or may be provided with both.

By the way, in general, when the biological treatment of denitrification of a liquid is performed, the treatment can be efficiently performed when the C / N ratio of the liquid is about 2 to 3. Therefore, when the biological treatment of the dehydrated separation liquid is performed by the waste liquid treatment device 16, when the C / N ratio of the dehydrated separation liquid is less than 2, the human waste from the human waste receiving tank 18 is supplied to the dehydrated separation liquid and mixed. Therefore, it is advisable to increase the value of the C / N ratio.
When urine is mixed as a dehydration-separated solution to make a mixed solution, the amount of carbon and nitrogen increases due to the addition of urine to the dehydration-separated solution, but as described above, the C / N ratio of urine is about 3 to. Since it is 5, the increase in the amount of carbon is larger than the increase in the amount of nitrogen. Therefore, even if the C / N ratio of the dehydrated separation solution is less than 2, the C / N ratio of the mixed solution can be easily set to about 2 to 3 by mixing with human waste. That is, here, human waste is supplied in order to balance the C / N ratio of the dehydrated separation liquid to which the biological treatment is performed.

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 the gas utilization facility 19 described later.
When the methane fermentation apparatus 14 and the gas utilization facility 19 are installed close to each other, the third transfer apparatus 23 is connected to the methane fermentation apparatus 14 and the gas utilization facility 19 and is generated by the methane fermentation apparatus 14. A pipeline that transfers the generated methane gas to the gas utilization facility 19 is desirable.
On the other hand, when the methane fermentation apparatus 14 and the gas utilization facility 19 are installed far from each other, the third transfer apparatus 23 is preferably an automobile (truck) equipped with a loading platform for loading a gas cylinder or an automobile equipped with a gas tank. In this case, the methane gas generated by the methane fermentation apparatus 14 can be filled in a gas cylinder or a gas tank, loaded or mounted on an automobile, and transferred to the gas utilization facility 19.

The gas utilization facility 19 is a facility that utilizes methane gas generated by the methane fermentation apparatus 14 of the third facility 4. The gas utilization facility 19 is, for example, a power plant that generates steam by burning the methane gas or a mixed gas obtained by mixing the methane gas with another gas in a boiler to generate steam and turning a steam turbine with the steam. Is. In recent years, in order to reduce carbon dioxide emissions during combustion, thermal power plants that use methane-based liquefied natural gas LNG (Liquefied Natural Gas) as fuel have become the mainstream of thermal power plants. The facility 19 can also be a power plant similar to the thermal power plant.
The gas utilization facility 19 may be a power plant equipped with a gas turbine, a gas engine, a fuel cell, or the like, or a facility that 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 generally includes 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 electricity 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 installed close to each other. If so, use the waste steam, which is the high-temperature steam after being used for power generation by the steam turbine of the gas utilization facility 19, in the adjacent first facility 2, second facility 3, or third facility 4. Can be done.
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 and the first facility 2 are connected by a pipeline and via the pipeline. The waste steam can be transferred to the hydrothermal treatment apparatus 10 of the first equipment 2 and used as high-temperature and high-pressure steam used by the hydrothermal treatment apparatus 10 or as a part thereof.
When the gas utilization facility 19 equipped with the steam turbine is installed close to the second facility 3, the gas utilization facility 19 and the second facility 3 are connected by a pipeline and via the pipeline. The waste steam 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.
Further, when the gas utilization facility 19 equipped with the steam turbine is installed close to the third facility 4, the gas utilization facility 19 and the third facility 4 are connected by a pipeline and via the pipeline. The waste steam can be transferred to the methane fermentation apparatus 14 of the third facility 4 and used for heating the hydrothermal treatment liquid stored in the methane fermentation apparatus 14.

Further, when the gas utilization facility 19 equipped with the 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 via the pipeline. The hot water generated by the heat recovery device 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.
Similarly, when the gas utilization facility 19 equipped with the gas engine is installed close to the third facility 4, the gas utilization facility 19 and the third facility 4 are connected by a pipeline to the pipe. The hot water can be transferred to the methane fermentation apparatus 14 of the third facility 4 via the line and used for heating the hydrothermal treatment liquid stored in the methane fermentation apparatus 14.
As described above, the heating temperature of the solubilization tank 13 is about 40 ° C. to 60 ° C., and the heating temperature of the methane fermentation apparatus 14 is about 37 ° C. or about 55 ° C. To heat the methane fermentation apparatus 14, warm water is easier to handle than waste steam.

As described above, when the gas utilization facility 19 is equipped with a steam turbine, the waste 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 is equipped with a gas engine. In this case, since the hot water generated by the heat recovery device can be used in the hydrothermal treatment system 1 as a heat source, the cost performance 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 incinerator 20 described later.
When the second facility 3 and the waste incinerator 20 are installed close to each other, the fourth transfer device 24 is a waste discharge port of the pressure separation device 12 and a waste pit of the waste incinerator 20. It is desirable that the conveyor is connected to the waste pit and transfers the residue discharged from the pressure separating device 12 to the waste pit.
On the other hand, when the second facility 3 and the waste incinerator 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 pressure separation device 12 can be loaded or stored in the truck bed or the garbage collection vehicle and transferred to the waste incinerator 20.

The waste incinerator 20 is a facility that incinerates waste in an incinerator, and can also incinerate the residue discharged from the pressure separating device 12 of the second facility 3 and the dehydrated sludge separated by the dehydrator 15. it can. The waste incinerator 20 can generate electricity by generating high-temperature and high-pressure steam in a boiler by the heat generated in the incinerator and turning a steam turbine with the high-temperature and high-pressure steam.
When at least one of the first facility 2, the second facility 3, and the third facility 4 and the waste incinerator 20 are installed close to each other, the steam turbine of the waste incinerator 20 is used for power generation. The waste steam, which is the high-temperature steam after that, can be used in the adjacent first equipment 2, second equipment 3, and third equipment 4.
For example, when the waste incinerator 20 is installed close to the first facility 2, the waste incinerator 20 and the first facility 2 are connected by a pipeline, and the waste steam is connected through the pipeline. Can be transferred to the hydrothermal treatment apparatus 10 of the first equipment 2 and used as high-temperature and high-pressure steam used by the hydrothermal treatment apparatus 10 or as a part thereof.
When the waste incinerator 20 is installed close to the second facility 3, the waste incinerator 20 and the second facility 3 are connected by a pipeline, and 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.
Further, when the waste incinerator 20 is installed close to the third facility 4, the waste incinerator 20 and the third facility 4 are connected by a pipeline, and the waste steam is connected through the pipeline. Can be transferred to the methane incinerator 14 of the third facility 4 and used for heating the hydrothermal treatment liquid stored in the methane incinerator 14.
As described above, since the waste steam of the waste incinerator 20 can be effectively used in the hydrothermal treatment system 1 as a heat source, the cost performance of the hydrothermal treatment system 1 can be further improved.

The hydrothermal treatment system 1 includes (1) a defibrating liquid supply device 17, (2) a urine receiving tank 18, (3) a third transfer device 23 and a gas utilization facility 19, (4) a fourth transfer device 24, and disposal. A system that does not have any of the four incinerators 20, a system that has only one, two, or three, or a system that has all four. There may be.

1 Hydrothermal treatment system 2 1st equipment 3 2nd equipment 4 3rd equipment 10 Hydrothermal treatment equipment 11 Adjustment tank 12 Pressurized separation equipment 12A Rotary drum screen 12B Screw press 13 Solubilization tank 14 Methan fermentation equipment 15 Dehydrator 16 Waste liquid treatment Equipment (sewage treatment facility)
17 Defibering liquid supply device 18 Human waste receiving tank 19 Gas utilization facility 20 Waste incinerator 21 1st transfer device 22 2nd transfer device 23 3rd transfer device 24 4th transfer device 25 Supply channel

Claims (5)

A hydrothermal treatment device that reacts organic matter-containing waste with water heat,
An adjustment tank that humidifies the hydrothermally reacted hydrothermally treated product, and
The first transfer device that transfers the hydrothermally treated product humidified in the adjustment tank, and
A pressure separation device that pressurizes the hydrothermally treated product transferred by the first transfer device and separates it into a hydrothermal treatment liquid and a residue.
A solubilization tank that stores and heats the hydrothermal treatment solution separated by the pressure separation device, and
A second transfer device that returns the hydrothermal treatment solution that has been heated and solubilized in the solubilization tank to the adjustment tank.
A methane fermentation apparatus that produces methane gas and digestive juice using the hydrothermal treatment liquid stored in the solubilization tank, a dehydrator that separates the digestive juice into dehydrated sludge and dehydrated separate liquid,
It has a waste liquid treatment device that at least nitrifies and denitrifies the dehydrated separation liquid to generate recycled water.
The second transfer device, when less than the predetermined concentration levels of organic matter contained in the hydrothermal treatment liquid stored in the solubilization tank is at a concentration of organic substances which are suitable for the generation of methane by microorganisms or fungi, said adjusting tank A hydrothermal treatment system that returns the hydrothermal solution to the methane fermentation apparatus and transfers the hydrothermal solution to the methane fermentation apparatus when the concentration of the organic substance is equal to or higher than the predetermined concentration. The hydrothermal treatment system according to claim 1, further comprising a defibration liquid supply device that supplies a defibration liquid obtained by defibrating paper to the digestive liquid. It also has a human waste receiving tank to store human waste,
The human waste from the human waste receiving tank is supplied to the methane fermentation apparatus and mixed with the hydrothermal treatment liquid.
Alternatively, the human waste from the human waste receiving tank is mixed with the digestive juice to mix it with the digestive juice.
Alternatively, the hydrothermal treatment system according to claim 1 or 2, wherein the human waste from the human waste receiving tank is mixed with the dehydration separation liquid. The pressure separation device is
Equipped with a rotary drum screen in the front stage and a screw press in the rear stage
The hydrothermal treatment system according to claim 3, wherein 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. A third transfer device that transfers the methane gas produced by the methane fermentation apparatus, a gas utilization facility that uses the methane gas transferred by the third transfer apparatus, and a gas utilization facility.
Or
It also has a fourth transfer device that transfers the residue separated by the pressure separation device and a waste incinerator that incinerates the residue transferred by the fourth transfer device.
When the hydrothermal treatment device and the adjustment tank and the pressure separation device and the solubilization tank are installed close to each other, the first transfer device is a pipeline provided with a crushing pump, and the first transfer device is a pipeline. (Ii) The transfer device is a pipeline equipped with a pump,
When the hydrothermal treatment device and the adjustment tank and the pressure separation device and the solubilization tank are installed far from each other, the first transfer device and the second transfer device are both automobiles. ,
When the methane fermentation apparatus and the gas utilization facility are installed in close proximity to each other, the third transfer apparatus is a pipeline.
When the methane fermentation device and the gas utilization facility are installed far from each other, the third transfer device is an automobile.
When the waste incinerator, the pressure separation device, and the solubilization tank are installed close to each other, the fourth transfer device is a conveyor.
When the waste incinerator, the pressure separation device, and the solubilization tank are installed far from each other, the fourth transfer device is an automobile.
The gas utilization facility is equipped with a steam turbine or a gas engine, and supplies steam used for power generation by the steam turbine to at least one of the hydrothermal treatment apparatus, the solubilization tank, and the methane fermentation apparatus, or , Hot water generated from the exhaust gas generated by the gas engine is supplied to at least one of the solubilization tank and the methane fermentation apparatus.
The waste incinerator is equipped with a steam turbine, and the steam used for power generation by the steam turbine is supplied to at least one of the hydrothermal treatment apparatus, the solubilization tank, and the methane fermentation apparatus.
The water heat treatment system according to claim 4, wherein the waste liquid treatment device is a urine treatment facility, and the reused water is supplied to the adjustment tank.

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